Interview with Dr Jack Valentin, Scientific Secretary, ICRP - AERB NEWSLETTER 2000 Vol 13, No 1

Interview with Dr Jack Valentin, Scientific Secretary, ICRP - AERB NEWSLETTER 2000 Vol 13, No 1
www.aerb.gov.in/T/NewsLetters/2000/vol-1/newsltr6.html

Dr. K.S.Parthasarathy in conversation with Dr. Jack Valentin, Scientific Secretary, ICRP: Dr. Jack Valentin, Scientific Secretary, International Commission of Radiological Protection (ICRP), is a Ph.D in genetics. After various positions in research, teaching and forensic laboratory work, he was recruited to the Swedish Radiation Protection Institute (a licensing authority) in 1983 as one of its Deputy Directors. There, he was first responsible for non-nuclear activities, turning then in 1989 to nuclear energy supervision. In February 1997, he took up his current post as Scientific Secretary of ICRP He has authored about 100 publications and has held various commissions of trust within the area of radiation protection, including a current assignment as a member of the Executive Council of IRPA (the International Radiation Protection Association).
Secretary, AERB interviewed Dr. Valentin at Mumbai.

Dr. Valentin, Swedish scientists have contributed enormously to medical physics and radiological protection. I remember Prof.- William Spiers, the pioneering medical physicist from UK, used to proudly remember his association with Rolf Sievert. Whenever we discussed the early developments in the field of medical physics, Professor Spiers described the efforts in various countries. The Stockholm technique in the treatment of uterus cancer was always referred to as a major contribution. Professor Spiers used to pay glowing tributes to Prof. Sievert.

Dr. Valentin: Prof. Sievert was a disciplined scientist.

KSP: It is appropriate that the unit of some of the important radiation quantities is named after him. I was told that the pressurized ion chamber he designed and fabricated in early fifties responded to Chernobyl fall out in 1986. Originally this equipment was used to measure radioactivity in the human body.
Dr.Valentin: There was a network of instruments available all over the country to measure radiation levels. But at the time of Chernobyl, one had to call it to get the results. They were not continuously reporting. But now the situation is different. If measurements exceed certain trigger levels, staff on call are automatically alarmed.

KSP: I remember the pioneering contribution by Prof. Hultquist who measured radon levels in Swedish dwellings during late fifties. Measurement of radon levels to study its impact on the dose to man become fashionable and important in the late seventies in several countries. What was the inspiration for Prof. Huitquist to carry out those measurements?
Dr Valentin: Maybe for the fun of it. Some of the earlier papers were written very well. I recollect that there were newspaper clippings stating that the radon levels in some house is dangerous.
KSP: When the instruments were crude, those who handled them had special expertise. All the care is taken so that measurements made are reliable. Nowadays in view of the availability of computer guided instrumentation, the persons who handle them do not get the insight and understanding of the problems. Prof. Hultquist used very primitive instruments to make very reliable measurement of radon levels. Do you think that sophisticated instruments may come in the way of gaining insight about the true nature of physical phenomena?
Dr. Valentin: I can see your point, and it applies to other areas of science as well, but after all better equipment does permit better science. The important thing is to remember that the demand on brains remains at least as tough as, before, even f modern equipment simplifies some of the manual work.
KSP: I understand you are a geneticist by profession. How did you become a radiation protection specialist? How did you choose this area of specialty?
Dr.Valentin: After graduating in genetics at a department in the University of Stockholm which had interest in the effect of radiation on genes, I began teaching at the University of Gothenborg. Then I wanted to get back to Stockholm as my wife was there. At that point of time, a vacant post was advertised in Stockholm. They wanted a person with radiation protection experience. I applied and got the job. Actually, that, is the way I chose radiation protection for a career.
KSP: How long were you associated with the International Commission on Radiological Protection?
Dr. Valentin: I was elected to the International Commission on Radio- logical Protection in 1989. Before that also I was in contact with ICRP.
KSP: Historically, In 1 934, an exposure rate limit for ionizing radiation was recommended to ensure protection of persons. This corresponded to about 500 mSv/year. In 1950, the ICRP recommendations lowered the permissible exposure rate to 150 mSv/ year. Currently, ICRP recommends a dose limit of 100 mSv averaged over 5 years, in effect, 20 mSv/year. Yesterday's safe dose limit becomes unsafe today. How will you explain this to public?
Dr.Valentin: That is an interesting question. It is a major problem. In 1934 and 1950, the objective of radiation protection was still limited to protecting radiation workers from deterministic harm. It was not dealing with public safety. Protection of public was not envisaged.
KSP: The information available then was skin damage suffered by those who handled x-ray units carelessly.
Dr.Valentin: That is right. The atmospheric weapon testing during the fifties lead to increased awareness. In 1 956, a dose limit of 50mSv per year for workers was introduced. For the first time, a dose limit to public of 5mSv/year was recommended. These recommendations were aimed at protection against stochastic harm. These recommendations recognized the possibility of a linear, non-threshold dose-response relationship. They did not conclude that the doses should be reduced even below the dose limit.- In 1965, ICRP retained the 1956 dose limits, but stated that the doses ought to be reduced if this was readily achievable. In 1977, ICRP observed that the dose limits are not a means to keep doses low but these are values that should not be exceeded. The concept of optimization to keep doses as low as reasonably achievable was put forward.
KSP: The evolution of the philosophy of radiation protection is very interesting indeed. The specialist may fully appreciate the consistency and cogency of the concepts. But public may not follow these nuances. As a matter of fact, public is sensitized about the lowering of dose limits. They may be disturbed by the fact that yesterday's safe limit becomes unsafe today. How are we sure that today's safe limit will not be unsafe tomorrow? I used to draw the example of aircraft. Modern jet aircraft is safer than propeller driven aircraft. Notwithstanding this, propeller driven aircraft is still in use. As technology improved, better and safer airplanes were manufactured. Propeller- driven airplanes have their own limitations. Since they are still used, -they are accepted to be safe.
Dr.Valentin: I think that it is a good example. We have increased safety in every field Radiological protection is no exception. It is a fact that society demands more safety in every field of activity.
KSP: But public perception of radiation risk is admittedly disproportionate with any measurable harm. How can we help to improve public perception? Does ICRP add to the confusion?
Dr.Valentin: I agree, at times we add to the confusion! But it is not certainly intentional. I feel that it is better not to trivialise the risk but to evaluate the risk from the practice. There are so many practices. We have to judge them on merit. We accept large risk because of large benefit.
KSP: Recently, I saw a report that the Federal Legislation regarding radiation workers in a European country recommends a cytogenetic examination as a part of the routine medical check up. I also noticed a comment that this sounds like the ultimate job-creation scheme for unemployed cytogeneticists!! Do you have any views on the practices
Dr.Valentin: It is a waste of effort. It is better to spend resources differently.
KSP: The field of radiation protection is unique. Probably in no other field such exacting and very often expensive epidemiological studies of millions of people in dozens of investigations were carried out to establish harmful effect, if any, of an agent. For instance, the study of the survivors of the atomic bombings at Hiroshima and Nagasaki started in during late forties and continues to- date. The Radiation Effects Research Foundation (RERF) continues to publish their important findings.
Dr. Valentin: These are very important studies and must be continued.
KSP: Some of the newer lines of study in radiobiology emerged from. unexpected observations. For instance, let us take the example of what is currently called genomic instability.
Dr. Valentin: There are experimental results which appeared to be strange in some ways. They could not be explained according to conventional hypotheses.
KSP: The hypothesis that cells which were exposed to ionising radiation may transmit some chromosomal instability to daughter cells was exciting enough. I vividly remember the early studies of the irradiation of stem cells by alpha particles. The National Radiological Protection Board has asserted that the estimates of radiation- induced cancer risk in humans have been derived directly from epidemiological observations and are, therefore, independent of the otential contribution from any novel cellular mechanism. Do you think that genomic instability will have any impact on ICRP recommendations?
Dr. Valentin: At present, I find that unlikely, but it would seem wise to avoid being categorical. Genomic instability is an interesting phenomenon. We must investigate it thoroughly. ICRP is interested in all radiation related phenomena.
KSP: Currently the Commission believes that the standards of environmental control needed to protect man to the degree currently thought desirable will ensure that other species are not put at risk. How is it that ICRP made such an assumption? Is there any evidence?'
Dr.Valentin: This is a very timely question. ICRP plans to set up a Task Group to make sure that our next set of basic recommendations provides a rather more convincing section on protection of the natural environment. The present statement is not necessarily wrong, but at the very least it needs to be corroborated by proper references to pertinent research. The rare exceptions that we know of today should be mentioned and evaluated. Perhaps we should even change the vantage point - it may be more in line with regulation of other dangers to say, if possible, that proper protection of the environment will be sufficient to also protect man. We do not currently envisage any significant change to authorised release limits, but we need to argue and express this much more cogently.
KSP: DNA molecule may have some molecules of radioactive carbon or H3 associated with it. What will be the impact of radioactive decay and transmutation of the element to another element? ICRP is ignoring such events.

Dr.Valentin: I would not say that we are ignoring such events. As a matter of fact, we do not know what the effects are. There has been, similarly, the effects of Auger electrons. For want of adequate information, we are unable to comment on them.
KSP: Any comment on the on-going linear non-threshold controversy on dose response.
Dr.Valentin: LNT concept is simple and practical. Recent studies have shown that there is a statistically significant response at dose levels as low as 5OmSv. There is reasonably acceptable evidence that children x- rayed while they are in their mothers womb have increased incidence of leukemia. Certainly there are wide uncertainties in the response of any organism to low doses.
KSP: Professor Roger Clarke, the current Chairman of ICRP, has circulated a position paper proposing certain changes in the concept and philosophy of radiation protection. The new concepts may make the philosophy of radiation protection more acceptable and cogent. What is the current status of the paper? Any comments?
Dr.Valentin: Professor Clarke's proposal, and some other suggestions, will be discussed at the IRPA 10 Congress in Hiroshima in May 2000. Health physicists and other interested parties all over the world have been invited to comment, primarily through the IRPA meeting. In October 2000, ICRP will discuss the proposal and the comments received. Based on that, I assume that we will be able to devise terms of reference for a Task Group which will draft new recommendations. The Clarke proposal will have served marvelously to initiate discussions. Judging from the many comments already received, positive and negative, my personal guess would be that the end result includes many parts from the Clarke proposal and many other parts which are quite different.
KSP: What will be the direction in which the ICRP will proceed in the next ten years?
Dr.Valentin: You have certainly touched on two of the major things: New fundamental recommendations are to be expected around 2005, and protection of the natural environment will be addressed more ambitiously. The new recommendations will, as usual, require detailed guidance which will occupy us later in the ten-year period. Another aspect, which we haven't talked about, is that ICRP is keen to increase its transparency and make processes and persons involved known. Our ideal is to be well known, well understood and well respected not only among health physics experts but also by environmentalists, users of radiation, and any other persons interested in radiation and in protection against radiation harm.

India's innovative nuclear power reactor

Date:10/06/2010 URL: http://www.thehindu.com/thehindu/seta/2010/06/10/stories/2010061050631600.htm
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India's innovative nuclear power reactor
The reactor's development is an effort to realise futuristic objectives through innovative configuration of present-day technologies
— Photo: K. Ramesh Babu



Advantages:The new reactor produces much less plutonium and helps in thorium utilisation.
People waiting for a nuclear renaissance expect that the new reactors on the drawing board should assure a very high level of safety and security; they must have the ability to perform with a lower level of technological infrastructure prevailing in several developing countries; they must have high fuel use efficiency and superior waste disposal options.
“The development of the Advanced Heavy Water Reactor, AHWR300-LEU, is an effort to realize these futuristic objectives through innovative configuration of present day technologies,” Anil Kakodkar and Ratan Sinha, the designers of India's innovative nuclear reactor wrote in the May 2010 issue of Nuclear Engineering International.
They called the reactor India's passive breeder.
“As a result of its fuel mix and fuel breeding properties, the 300 MWe plant requires 42 per cent less mined uranium per unit of energy produced than a modern high burn up PWR”, they added.
AHWR300-LEU with an estimated design life of 100 years is a vertical, pressure tube type, boiling light water-cooled, heavy water- moderated reactor with reduced environmental impact. It has many features which are likely to reduce both its capital and operating costs.
The designers have eliminated primary coolant pumps and drive motors and related control and power supply equipment, thereby saving the electric power to run them. This helps to reduce cost and to enhance reliability.
The use of heavy water at low pressure reduces the potential for leakages. The heat generated in the moderator will be recovered and used for heating the feed-water.
Quick replacement
The shop assembled-coolant channels have features which enable quick replacement of pressure tubes alone without affecting other components.
The design objective of the reactor is to require no exclusion zone beyond the plant boundary. The reactor will use natural circulation to remove heat from its core under operating and shut down conditions. In case the primary and the secondary shut down systems are not available due to the failure of all active systems or malicious employee action, passive injection of a “poison” — a high neutron absorbing liquid, in to the moderator will shut down the reactor.
When the reactor operates, its core will be very hot. Coolant removes the heat. If coolant is not available due to a Loss of Coolant Accident (LOCA), the emergency core cooling system (ECCS) will remove heat by passive means.
If the primary coolant tube ruptures, a large flow of water from accumulators will cool the reactor initially. Later, the core will be cooled by the injection of cold water from a 7000 cubic metre Gravity Driven Water Pool (GDWP) located at the top of the reactor building. After that, the passive containment cooling system (PCCS) provides long term containment cooling. GDWP serves as passive water sink giving a grace period of three days.
The reactor has a double containment with an elegant design which assists the formation of a passive water seal in the event of a loss of coolant accident. The seal isolates the reactor containment and the external environment, preventing the spread of radioactivity.
Fission of Uranium-233
The reactor fuel on an average contains 19.75 per cent of enriched uranium and the balance thorium oxide. A significant fraction of the reactor power, about 39 per cent, comes from the fission of Uranium-233 derived from in-situ conversion of thorium-232.
The reactor physics design has inherent safety characteristics during all conditions likely to be encountered during startup, shutdown and LOCA.
During an interview, Dr Sinha has stated that the scientists and engineers at BARC have designed a novel advanced heavy water reactor to burn thorium ( IEEE Spectrum, 2008)
“They say that because no reactor in the world today uses thorium on a large scale, they will be breaking new ground”, he added
Currently BARC has the facility for large scale validation work.
Partly as a result of this, the reactor can achieve commercial operation by 2020.Indian scientists have been exploring various fuel cycle options for improved versions of AHWR.
AHWR300-LEU has all the safety features of AHWR. It also helps in thorium utilization.
It produces much less plutonium and minor actinides compared to Pressurized Water Reactors(PWR) which is the mainstay internationally. In view of that, this reactor is more proliferation resistant.
Since minor actinides (which have relatively long half life) are less than those in PWR, it is a better choice from considerations of waste management.
AHWR300-LEU has better reactor physics characteristics.
K.S.PARTHASARATHY
Raja Ramanna Fellow, Department of Atomic Energy
( ksparth@yahoo.co.uk )
© Copyright 2000 - 2009 The Hindu

Radiation Incidents in Delhi: The Way Forward

Radiation Incidents in Delhi: The Way Forward May 2, 2010 - 00:51

By Dr K S Parthasarthy
The unfortunate radiation incident in which several persons got exposed to radiation in Delhi highlights the need to enforce strictly the multilayer radiation monitoring system recommended by the Atomic Energy Regulatory Board (AERB).
This must be implemented at different stages of value addition of metal scrap.
In the Delhi incident, seven persons were admitted to hospitals for treatment. Scientists handling the emergency located and safely removed 11 radiation sources of various types. None of these are indigenously fabricated sources.
Over the past few years, AERB has been publicising measures to prevent such incidents. It arranged meetings, workshops and discussions in different regions in the country. As it happened in the USA, only those firms who faced adverse economic outcomes due to contaminated steel products cared to follow AERB’s suggestions. If everyone bought and used the relatively inexpensive radiation monitoring equipment, which AERB recommended, the incident would have been prevented.
AERB was concerned about the incidents in which steel got contaminated with Co-60. It took such events as wake up calls. The Board interacted with the Engineering Export Promotion Council (EEPC), Chambers of Commerce and Industry (CII) and All India Induction Furnaces Association and licenses of industrial gamma radiography institutions and unfolded its plan of action.
The multilayer radiation check system recommended by AERB includes various elements introduction of procedure that every importer of metal scrap should obtain a certificate from the exporting country that the scrap is free from radioactivity; Inclusion of a clause in the purchase specification that the material shall be free from radioactivity; establishment of independent check/test system for radioactivity in the incoming and outgoing material, if any radioactivity detected, segregation of material at least 10 m away from the occupied areas and information to AERB immediately; selling /supplying the material with a self certificate that the material is free from radioactivity.
Other measures included radiation monitoring of the metal scrap after the import and prior to melting the scrap; radiation monitoring by steel mills prior to rolling of steel ingots into the desired shape; radiation monitoring by manufacturers and exporters of SS products prior to manufacture/export of products and inclusion of radioactive contamination check in the check list of QA program prior to export or supply of the material.
AERB wanted all concerned agencies in steel metal recycling industry such as metal scrap dealers, steel foundry owners, steel rolling mills and manufacturers of steel products, small or big to scan the metal for the presence of radioactivity with the help of radiation sensing devices prior to using the metal for value addition. If radiation is detected in any material, AERB shall be notified so that appropriate control can be instituted over the contaminated material.
AERB informed various stakeholders that radiation sensing devices, which can detect and measure just above the natural background radiation level (5-10 microR/h), can be procured indigenously imported.
The associations of scrap dealers must arrange radiation safety awareness programs related to the detection of radiation in the steel melting industry. AERB proposed that they may develop a facility with trained man power and equipment to provide service of radiation monitoring for the needed industry; and coordinate with AERB for disposal of the identified contaminated material and related matters. In spite of the vigorous measures, it is obvious that AERB’s suggestions have not percolated down to every stake holder in this lucrative business.
Scientists from the Bhabha Atomic Research Centre have developed inestimable expertise in tracing lost sources. They have been training various dedicated groups for several years in handling radiation emergencies. This priceless contribution became very useful in the hour of need. The Department of Atomic Energy is making available a few radiation monitors to the association of scrap dealers, so that they can monitor the presence, if any, of radiation sources in the scrap material they gather. If they find any, they can notify the concerned authorities for further follow up.
An important element in the defence in depth arrangement to prevent radiation incidents due to imported sources is the installation of portal monitors at ports and airports through which scrap material in bulk may enter the country. Scientists from BARC have surveyed various locations and identified places for installing them.
The unfortunate event at Delhi may accelerate the process. Admittedly, the project involves the coordination of various agencies. Installing the monitors with the assistance of specialists and making foolproof arrangements to maintain them 24X7, is a complex activity. It can be and has to be carried out with the support and coordination of every one.
Prompt medical assistance is an important element in handling patients exposed to radiation. The patient may approach general practitioners. They may think that the injury is due to reasons such as insect bite. Radiation injury has no special signs or symptoms (IAEA/WHO, 2000). Few physicians have adequate knowledge to identify them.
Recognising this fact, AERB published “A Handbook for the Medical Management of Persons Exposed in Radiation Accidents” in 1989 and a detailed guide in 1990. The guide received critical reviews from H Jammet, Jeane Claude Nenot and other internationally acclaimed specialists.
AERB published a poster highlighting the course to be followed while treating the patients. In 2000, WHO/IAEA realised that in most cases, physicians will not be able to identify the reasons for symptoms suffered by radiation exposed persons. They published a leaflet titled “How to recognise and initially respond to an accidental injury” at http://w.w.w.who.int/ionizing_radiation/a_c/IAEA WHO Leaflet-Eng%20blue.pdf.
The leaflet recommends the following books by IAEA/WHO for further reading: Diagnosis and Treatment of Radiation Injuries. Safety Report Series, No 2, IAEA, Vienna, 1998: Planning the Medical Response to Radiological Accidents. Safety Report Series, No 4, IAEA, Vienna, 1998; Health Surveillance of Persons Occupationally Exposed to Ionizing Radiation. Safety Report Series, No 5, IAEA, Vienna, 1998. These documents are available for free download.
The unfortunate incident at Delhi may act as the final wakeup call for establishing the way forward to handle such potential emergencies. (PTI Feature)

Lessons to be learnt from Delhi radiation incident

Date:15/04/2010 URL: http://www.thehindu.com/thehindu/seta/2010/04/15/stories/2010041551311400.htm
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Lessons to be learnt from Delhi radiation incident
Photo: K. PIchumani

The source: Virtually all instances of steel contamination seem to have been caused by radioactive sources which came with imported scrap. —
At 12:45 hrs on April 7, 2010 the Atomic Energy Regulatory Board (AERB) received a fax message from Indraprastha Apollo Hospital, Delhi stating that a scrap metal dealer admitted to the hospital showed symptoms suspected to be caused by radiation exposure.
Six more workers who also exhibited similar symptoms were admitted elsewhere. On receiving the information, two AERB officers who were already in Delhi inspected the shop and its surroundings, identified high radiation levels and promptly shielded some suspected high radiation locations with metal sheets to reduce the radiation levels.
As per the procedure in place, a team of scientists from Bhabha Atomic Research Centre (BARC)and the Narora Atomic Power Station , mobilized by the Crisis Management Group of the Department of Atomic Energy (DAE) and scientists from AERB visited the site again and restored normalcy by safely removing the sources into appropriately shielded containers. By April 9, 2010, the radiation levels at the site became normal background radiation levels.
“It was indeed a difficult operation; we collected cobalt-60 sources of high strengths in the form of wires under trying circumstances and secured them in special containers. We instituted strict dose control procedures which ensured that the radiation doses to us were within limits,” said Dr. K.S.Pradeep Kumar, Senior Scientist and Head, Emergency Response System and Methods Section.
“We learnt a few lessons. The team from Narora brought many tools and accessories; their support proved to be very crucial,” he clarified. He paid compliments to the excellent cooperation extended by the Delhi police.
A handful of radiation incidents in which persons got exposed to very high radiation doses occurred in India. Most of the cases were because of gross violation of safety procedures in handling industrial gamma radiography sources.
In the most serious case, a railway gang man received high dose as he kept gamma source in his pocket for a few hours. The source was lost in transit because of negligence of radiation workers in a company. Follow up action led to the winding up of the company.
The victim pocketed the shining object assuming that it is valuable. He was admitted into BARC Hospital initially for three months and was followed up for one and a half years. He survived after several skin drafts and other procedures.
The Delhi incident was a serious one. That such incidents were rare would be poor consolation for those seven persons who were exposed to radiation. There must be zero tolerance to such events.
AERB had suggested several preventive measures ( The Hindu, Nov 13, 2008). In the light of a few steel contamination incidents, AERB proposed to put in place a multi layered radiation check system ( The Hindu, February 26, 2009). These need closer review, strengthening and more effective enforcement.
Many scrap dealers have bought radiation monitors. The proposal to erect radiation monitors at major ports is yet to be implemented. Since virtually all instances of steel contamination seem to have been caused by radioactive sources which came along with imported scrap, radiation monitors must be installed urgently at all ports. The radiation incident at Delhi must be considered as the final wake up call. There are plans to equip selected police stations in major cities with radiation monitors. The task is humongous but achievable through dedicated efforts.
Radiation exposure from “orphan sources” was a topic of discussion in many meetings held by the International Atomic Energy Agency (IAEA) since 1998.An initial review indicated that, more than 110 countries may not have minimum infrastructure to properly control radiation sources (IAEA, 1999).
Since 1990, 300 radioactive sources were recovered from Georgia. There were instances in which intense radiation sources used in agricultural research such as mutation studies were found abandoned in trucks
In the United States alone, the Nuclear Regulatory Commission (NRC) annually receives about 200 reports of lost, stolen or abandoned radioactive sources. This is disconcerting as U.S. has a stringent regulatory system. AERB receives less number of reports annually, presumably because we have far less number of sources in use. Also as in U.S., AERB has a very effective system to track high intensity sources.
K.S. PARTHASARATHY
FORMER SECRETARY, AERB
ksparth@yahoo.co.uk
© Copyright 2000 - 2009 The Hindu

Radiation dose reduction in medical imaging needed

Of late there has been renewed interest in reducing radiation doses from medical imaging procedures.This has been partly due to extensive media coverage of a few over exposure incidents

K.S.Parthasarathy

Date:18/02/2010 URL: http://www.thehindu.com/thehindu/seta/2010/02/18/stories/2010021850111500.htm Back Sci Tech



Radiation dose reduction in medical imaging needed

CT scans involve extended exposure to radiation, and hence higher radiation dose



















— Photo: K. R. Deepak

Overdose: The adult effective dose from a CT exam of the head is equivalent to the adult effective dose from roughly 100 chest X-rays.

On February 9, 2010, the US Food and Drug Administration (FDA) published a white paper titled “Initiative to reduce unnecessary radiation exposure in medical imaging.” FDA found out several instances of radiation over exposures; some of them were as appalling as the ones reported within a few months of the discovery of X rays!

The new FDA initiative promotes safe use of medical imaging devices, supports informed clinical decision making and offers measures to increase patient awareness.

On October 8, 2009, FDA issued a radiation alert when it discovered that 206 patients who underwent CT perfusion studies in a hospital may have received 6 to 8 times more dose than what is necessary.
Media coverage

Some patients suffered hair loss and reddening of the skin indicating high radiation doses. The Agency found out that the overexposures were more wide-spread. Media covered these excesses extensively.

In January 2008, 23 month old Jacoby Roth fell out of bed; his doctor ordered a CT scan to find out damage, if any, to his spine.

A technologist carried out 151 scans in 68 minutes. Within a few hours, the child developed a bright red ring around his head from the massive overdose of radiation (AuntMinnie.com, 2009).

The dose to the child may have been about 2800 mSv to 11,000mSv. (mSv is a unit of radiation dose, the dose in a normal paediatric study of the entire spine may be about 1.5 to 4 mSv). The California Department of Public Health (CDPH) imposed a fine of $25,000 on the hospital. The technologist is fighting to retain her licence. Parents are suing the hospital.

Clinically indicated computed tomography (CT), nuclear medicine procedures and fluoroscopy carry immense benefits for patients when they are executed by trained professionals using optimally adjusted equipment. Misadministrations are rare.
The assertion

FDA asserted that there must be appropriate justification for ordering and performing each procedure, and careful optimization of the radiation dose used. International Commission on Radiological Protection (ICRP) upholds these basic principles.

“Because CT, fluoroscopy, and nuclear medicine procedures involve repeated or extended exposure to radiation, these types of exams are associated with a higher radiation dose than projection radiography.

For example, the adult effective dose from a CT exam of the head is equivalent to the adult effective dose from roughly 100 chest X-rays. The adult effective dose from a CT exam of the abdomen is roughly equivalent to the adult effective dose from roughly 400 chest X-rays”, the FDA paper cautioned.

FDA may require that CT and fluoroscopic devices display, record, and report radiation dose and alert users when the dose exceeds a diagnostic reference level, a peak skin-dose threshold for injury, or some other established value.

The Atomic Energy (Radiation Protection) Rules, 2004 (RPR2004) require that the licensee “shall for optimising the medical exposure ensure that performance of the equipment is verified periodically by appropriate quality assurance tests.”

The licensee shall also “ensure that any accidental medical exposure is investigated and a written report submitted to the competent authority.” The Atomic Energy Regulatory Board (AERB) has not so far received any report of accidental exposures in medical imaging, though there is anecdotal evidence of their occurrence.

RPR 2004 requires that the licensee shall maintain the records of radiation doses received by therapy patients and activities administered to patients in diagnostic and therapeutic nuclear medicine procedures. The rules need amendment to make recording of diagnostic X-ray dose mandatory in line with recent trends.

Inputs from an AERB funded safety research project indicate that at least 1.5 lakhs of children are found to be receiving excess radiation exposure because some of the CT Centres do not follow paediatric protocols. Parents should insist that the physicians should refer their children to only centres which follow appropriate protocols.

AERB’s effort to enforce strict compliance of rules in an area which grew unbridled for the past several decades is a daunting task.

ksparth@yahoo.co.uk

(The author is Raja Ramanna Fellow, Department of Atomic Energy)

K.S. PARTHASARATHY

© Copyright 2000 - 2009 The Hindu

Is work in a nuclear power plant risky?

The Tribune

SCIENCE & TECHNOLOGY Friday, February 12, 2010, Chandigarh, India

Is work in a nuclear power plant risky?
K S Parthasarathy
A 24 year old who is about to join the Department of Atomic Energy (DAE) as a scientific officer, is troubled by what he saw on a TV channel. He is unmarried; his parents are worried about the alleged damage to DNA by radiation. I assured him that there is no such harm. TV channels often go overboard and make unsubstantiated claims.
A 63 year old person asked me whether the throat malignancy, which, his 33 year old daughter is suffering from, is likely due to the possible radiation exposure he might have received while working in a nuclear power plant when he was 28 year old.
Thyroid diseases are not infrequent. No one knows for sure the reason for getting it. But there is no evidence that radiation exposure to father may lead to cancer in their children.
Workers in nuclear power plants will receive some radiation dose. Nuclear Power Corporation of India Limited (NPCIL) has instituted strict procedures to keep the doses to workers within the limits prescribed by the Atomic Energy Regulatory Board (AERB) and to values As Low As Reasonably Achievable (ALARA). Their radiation risk is insignificant.
ALARA committees with Chief Superintendents as chairmen, section heads as members and health physicists as member secretary review radiation work at each station periodically. Sectional ALARA committees plan work involving radiation exposures.
Each Station prepares a work plan, identifies various activities involving radiation exposure and gets AERB's approval for an annual “Radiation Budget”. If any Station exceeds the budget, AERB will not be amused!
The interior areas of the plant buildings are categorised into four zones for radiation and contamination control. Healthphysicists record radiation levels and airborne activity with prescribed frequency. Movement of every worker within the zones is controlled. Before entering Zone 2, 3 &4, they must wear lab coat, gloves and shoe covers and personnel dosimeters. They come out through sensitive portal monitors which will detect contamination, if any, present. They check hands and shoes using special monitors.
Annual reports published at (www.aerb.gov.in) indicate that the compliance with its stipulations is near total. For instance, during 2001 to 2008, among the annual average workforce of about 14,000 workers, one worker each in Rajasthan Atomic Power Station (RAPS) and Narora Atomic Power Station (NAPS) exceeded the limit in 2001; in 2002, one worker each in Madras Atomic PowerStation (MAPS) and NAPS; in 2007, two workers in NAPS exceeded the limits. This is indeed a creditable record.
Dose limits are based on conservative assumptions. It is inconsequential if any one receives, occasionally, a dose above the limit.
The Station managements made improvements in ventilation, reduced heavy water leakages, shielded hotspots, filtered crud from heat transport system, promptly detected and removed failed fuel bundles and used cobalt-free materials (Radiation from Cobalt-60, formed by actrivation of cobalt present in certain reactor components increases the radiation field). Many elegant engineering solutions helped to reduce radiation doses to workers.
Radiation protection standards assume that any dose of radiation, no matter how small, involves a possible risk to human health (World Nuclear Association, November 2009). After reviewing 200 peer-reviewed publications, Electric Power Research Institute (EPRI) concluded that this methodology may have been over-estimating the risks. (World Nuclear News, December 2).
Radiation protection standards are based on studies by scholarly bodies such as the US National Academy of Sciences (NAS)’ Biological Effects of Ionizing Radiation Committee, the International Agency for Research on Cancer (IARC) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). They indicate that at low doses, radiation risks, if there are any, are very small. Negligibly small risks are no risks at all. Work in a nuclear power plant is not a risky occupation.
The writer is Raja Ramanna Fellow, Department of Atomic Energy

Many glaciers, ice caps worldwide in retreat

Date:04/02/2010 URL: http://www.thehindu.com/thehindu/seta/2010/02/04/stories/2010020450051400.htm Back Sci Tech



Many glaciers, ice caps worldwide in retreat

90 per cent of the 612 glaciers across the High Asian region were retreating; this increased to 95 per cent from 1990 to 2005

— Photo: AFP





Core evidence: Ice cores collected in 2006 from the 6050 metre high Naimona’nyi Glacier lack the distinctive nuclear fallout footprints suggesting no net accumulation of ice since at least 1950s. This file picture shows the Khumbu Glacier in the Everest-Khumbu region.

Ice cores drilled from glaciers around the world generally contain elevated levels of beta radioactivity including chlorine-36 and tritium associated with thermonuclear bomb testing in the 1950s and 1960s (Kehrwald, Thompson and others, Geophysical Research Letters, Nov 22, 2008). These researchers found that the ice cores collected in 2006 from the 6050 metre high Naimona’nyi Glacier, in the Himalayas (Tibet), lack the distinctive nuclear fallout footprints suggesting no net accumulation of ice since at least 1950s .

Surprisingly, no one referred to these studies in the recent controversy over the Statement of the Intergovernmental Panel on Climate Change (IPCC) on the Himalayan Glaciers.

Professor Lonnie Thompson a leading glaciologist and a co-author of the paper made similar observations many months earlier (“Missing footprints of A-bomb fallout in Himalayan ice fields,” The Hindu, January 31, 2008).

Responding to my e-mail query, Prof. Thompson wrote that he conducted his research on glaciers across the Tibetan Plateau and on the Tibetan side of the Himalayas.

“From the Qilian Mountains on the northeast side of the Plateau, to the Kunlun Mountains in the west, to the northern slopes of the central and western Himalayas, all the glaciers and ice caps that I have studied are retreating,” he asserted.

He pointed out that all the glaciers he has studied in the Peruvian Andes are also shrinking. The glaciologists at the Institute of Tibetan Plateau Research in Beijing have found that from 1980 to 1990, 90 per cent of the 612 glaciers across the High Asian region were retreating, and from 1990 to 2005, this increased to 95 per cent.

Thompson admitted that meteorological records from the Tibetan Plateau and the Himalayas are scarce and of relatively short duration, most beginning in the mid-1950s to early 1960s; however those that do exist show that surface temperatures are rising, and rising faster at higher elevations than at lower elevations.

According to him, the Tibetan Plateau has been warming at a rate of 0.16 degrees centigrade per decade, with winter temperatures rising 0.32 degrees centigrade per decade.
GRACE data

“A recent paper by Matsuo and Heki in Earth and Planetary Science Letters (time-variable ice loss in Asian high mountains from satellite gravimetry) shows that from 2003 to 2009 the average ice loss from the Asian high ice fields, as measured by GRACE satellite observations, had accelerated twice as fast as the rate over four decades before, but the loss was not consistent over space and time”, he cautioned

He observed that ice retreat in the Himalayas slowed slightly, while loss in the mountains to the northwest increased markedly.

“So, between the surface temperature measurements, the satellite studies, the ground studies on glaciers, and ice core results, a case can be made that glacier retreat at high elevations is indeed occurring concomitantly with increasing temperatures, which is consistent with the IPCC model results which show not only low-latitude warming but an amplification of that warming at higher elevations where these glaciers are located,” he argued

Thompson stated that the rate at which glaciers respond to climate change depends on their size; larger a glacier, the longer it takes to retreat in response to a warmer/drier climate, or grow in response to a cooler/wetter climate.

“Thus, among the 15,000 glaciers in the Himalayas, the largest are currently reacting to changes that happened 100 years ago. However, some of the growing glaciers are in fact surging; that is, they are advancing because of dynamics of ice flow and not because of climate.
Temporal differences

On the short term, glaciers show rapid changes in response to changes in snowfall amounts as well as temperature, but over the long term temperature will dominate,” he clarified.

Prof. Thompson referred to their latest paper titled ‘Glacier loss on Kilimanjaro continues Unabated’ in the Proceedings of the National Academy of Sciences (November 2, 2009) which demonstrates that ice loss on Kilimanjaro is unfortunately right on track as predicted in their 2002 Science paper. New measurements completed on GEOEYE satellite images from July 17, 2009 shows that the loss of ice continues right along the project from their Science paper.

According to Anna Barnet, assistant editor and copy editor of Nature Reports Climate Change (July 9, 2009), Thompson has spent more time above 20,000 ft than any other human being. She noted that by collecting a vast library of ice samples from mountain peaks, he has developed a unique view of past and present-day climate change. Thompson had 7,000 metres of glacial ice in his collection (PNAS, 2006). He is eminently qualified to comment on the topic.

Prof. Thompson noted that the recent document by V.K. Raina, formerly Deputy Director General of the Geological Survey of India, has been catapulted into the fray over the Himalayan glacier retreat.

According to Prof. Thompson Mr. Raina states quite correctly in his report (before going on to present case studies of only 3 glaciers) that “a few glaciers cannot be taken as the representative of around 10,000 glaciers of various sizes that exist in the Indian part of the Himalayas.”

Prof. Thompson clarified that very few solid peer-reviewed papers exist on glacier retreat in this region of the world, and as Mr. Raina would evidently agree, nothing conclusive can be claimed based on studies of a handful of glaciers out of over 15,000 throughout the Himalayas, both on the Indian and the Tibet sides.

Poster child glaciers

Prof. Thompson stated that participants on both sides of the issue are drawing conclusions about what is happening in a very large and climatologically and topographically complex region based on the “behaviour” of a few glaciers that have been adopted collectively as the “poster child” for all the world’s bodies of ice.

He conceded that most glaciologists and climatologists, he included, do not believe that most of the Himalayas will be ice-free by as early as 2035.

‘The provenance of this statistic may not be scientific or peer-reviewed, and the authors and reviewers … may have erred by allowing it to slip past the fact-checking process while the report was being prepared, but it doesn’t invalidate the entire IPCC report.

If any of the report’s authors felt compelled for whatever reason to include such material, as apparently admitted by Murari Lal, one of the lead coordinating authors of the 2007 IPCC report’s chapter on Asia (US News and World Report, Jan 25), then that should be investigated and the current guidelines should be strengthened and more rigorously enforced to prevent future occurrences of non-peer reviewed material slipping through,” he suggested.

“Scientists hold the peer-review process as the “gold-standard” for publication, but as in all human endeavors mistakes are occasionally made.

“In the end, it is the total body of substantiated evidence on global climate change that is important, not occasional errors or miscommunications that provoke unbalanced and hyperbolic reactions,” Prof. Thompson clarified.

K.S. PARTHASARATHY

Raja Ramanna Fellow, Department of Atomic Energy

( ksparth@yahoo.co.uk )

© Copyright 2000 - 2009 The Hindu

My articles: Radiation: cancer risk estimates remain same

My articles: Radiation: cancer risk estimates remain same

Radiation: cancer risk estimates remain same

The complete report (UNSCEAR 2006) with all Annexes from the United Nations Scientific Committee on the Effects of Atomic Radiation has now been published the first set of Annexes in 2008 and the next set in 2009. Because of resource crunch, UNSCEAR could not publish the report which was ready in 2006. That the Committee did not have funds to publish its report promptly is regrettable. UNSCEAR reports underpin international standards for radiation protection.


Dr K.S.Parthasarathy







Date:17/12/2009 URL: http://www.thehindu.com/thehindu/seta/2009/12/17/stories/2009121750111300.htm
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Back Sci Tech



Radiation: cancer risk estimates remain same
Radiation protection specialists can breathe easy due to the overall view of the U.N. Committee on current risk estimates
The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) in its latest report has reiterated that the current risk estimates for cancer and hereditary effects in humans from irradiation need not be changed, in spite of new findings about non-targeted and delayed cellular effects.
Latest annexures
The October 2009 issue of the Health Physics Journal has summarised the latest annexures which covered “Non targeted and delayed effects of exposure to ionizing radiation,” “Effects of ionizing radiation on the immune system”, and “Source to effects assessment for radon in homes and work places”. UNSCEAR published two other earlier annexures in August 2008.
“Non-targeted and delayed effects occur in cells that were themselves not irradiated. They include genomic changes in the daughters of irradiated cells, changes in non-irradiated cells as a result of signals from irradiated cells (so-called bystander effects), and potential health effects in offspring due to irradiation of the parents,” the Committee clarified in a press release.
Scientists have observed “genomic instability” (effect appearing later in cells formed after several multiplications) and “bystander effects” (effects that manifest in cells not directly affected).
These could not be explained by conventional hypotheses. The International Commission on Radiological Protection (ICRP) did not consider them while estimating radiation risk estimates.
In 2000, I sought the views of Dr Jack Valentin, the Scientific Secretary, ICRP, on the impact of genomic instability on ICRP recommendations.
The argument
The then National Radiological Protection Board (NRPB), U.K., has argued that the estimates of radiation induced cancer risk in humans have been derived directly from epidemiological observations, and are, therefore, independent of the potential contribution from any novel cellular mechanism (Interview in AERB Newsletter 13: 1, 2000)
“At present, I find that unlikely, but it would seem wise to avoid being categorical,” he cautioned. “We must investigate it thoroughly,” he asserted.
UNSCEAR 2006 seems to have settled the issue.
Norman Gentner, Chairman of UNSCEAR conceded that these non-targeted effects may potentially amplify the biological effectiveness of a given radiation dose by increasing the number of cells that experience effects over those directly exposed to the radiation (UNSCEAR Release, 2009)
UNSCEAR noted that any clear relationship between non-targeted effects and observed health effects attributable to radiation remains contentious.
“Risk estimates are based on population health studies, which implicitly incorporate all elements including direct targeted effects of irradiation as well as non-targeted and delayed effects,” the latest UNSCEAR statement, is almost similar to NRPB’s, made nine years ago.
Radiation protection specialists and regulators can breathe easy; the overall view of the Committee is that the currently available risk estimates do not require changes.
UNSCEAR 2006 noted that some recent studies have shown that low levels of radiation can stimulate the immune system, at least for short periods.
Experimental studies
These findings emerge from experimental studies and large scale epidemiological assessments of A-bomb survivors, residents of areas in Russia and the U.S. contaminated by weapons production, Chernobyl emergency workers and residents and patients undergoing radiotherapy. Data from these groups showed common patterns (UNSCEAR release, 2009).
The impact of ionizing radiation may be stronger during foetal development and in some diseases such as HIV AIDS; autoimmune diseases and genetic disorders also compromise the immune system making it more sensitive to irradiation.
The disclosure
UNSCEAR disclosed that there is direct evidence to confirm a small but detectable risk of lung cancer from living with radon in home.
The Committee evaluated recent direct studies of the public in Europe, North America and China exposed to relatively low levels of radon in their dwellings.
Thus far, researchers estimated the risk from radon from health studies of underground miners who were exposed to high levels of radon and its decay products.
United Nations set up UNSCEAR in 1955; its mandate is to report on levels and effects of radiation to the UN General Assembly. Resource crunch delayed the publication of UNSCEAR 2006. It has hopefully been corrected. The work of the Committee is crucial as it underpins international standards for radiation protection.
Raja Ramanna Fellow, Department of Atomic Energy
( ksparth@yahoo.co.uk )
K.S. PARTHASARATHY
© Copyright 2000 - 2009 The Hindu

Kaiga incident serves as a wake-up call

Date:03/12/2009 URL: http://www.thehindu.com/thehindu/seta/2009/12/03/stories/2009120350081300.htm
________________________________________




Kaiga incident serves as a wake-up call
Tritium is the least toxic of all radioactive materials, not posing any external hazard but internal hazard if ingested















Treating ingestion: Tritium can be removed faster by drinking more fluids and water. Administering diuretics to the workers is another effective method.


Recently, a bizarre incident at the Kaiga Generating Station received wide media attention. Someone deliberately added some tritiated heavy water into a water cooler at the Kaiga Generating Station causing radiation exposure to 55 workers who drank water from it.
Authorities have characterised it as “sabotage,” “act of mischief,” “malevolent act” etc. Specialists in the appropriate discipline will identify the right term to be used!
Very serious incident
It is a very serious incident. It adds a new dimension to the already existing security and access control procedures. Some procedures need tightening. It is a wake up call.
Media reports reflected heightened perception, concerns and some misunderstanding about the way the Station handled the incident.
Extracts of the reports and the related facts are listed thus:
“Tritium is very difficult to remove from the body.” It is not true. Tritium is another form of hydrogen; like ordinary hydrogen it reacts with oxygen and forms tritiated water. Ninety seven per cent of tritium entering the body remains in soft tissue, will reach equilibrium in 2 hours and will get removed with a typical half period of 6 days, through urine and perspiration.
Three per cent remains for a longer period (about 40 days). The two components are considered in calculating the radiation dose. Tritium’s physical half life of 12.3 years is not relevant.
We can remove tritium faster by drinking more fluids and water. Administering diuretics to the workers is another effective method (diuretics are drugs that help to remove water from body). This has to be done under medical supervision.
Effective dose control
That is why the workers whose intakes exceeded certain limits were sent to the hospital (Such interventions are done for effective dose control over the monitoring period). They were not admitted. They did not fall sick as reported by some newspapers.
Is tritium, a highly radioactive substance? Tritium emits beta particles of very low energy. It does not pose any external radiation hazard; it poses internal hazard if ingested. Tritium is the least toxic of all radioactive materials. But we must control all tritium intakes.
“How is it likely to impact the employees who drank the water?” “Doctors say that even the smallest exposure to radiation will have a long term health impact.”
The impact depends on the dose received by the workers. In the present case, only two workers marginally exceeded the radiation dose limit of 30 mSv prescribed by the Atomic Energy Regulatory Board.
No worker had received contamination from any radionuclide other than tritium.
Even the currently estimated doses will be reduced further as these workers take diurectics under medical guidance. When radiation doses are within, close to or below the limit, the health impact is insignificant. However, the doses to workers must be as low as reasonably achievable. Getting doses close to the limit repeatedly is not acceptable. In such instances the work practices must be evaluated to reduce the dose further.
What happens to people living along the Kali River? Especially downstream, who spend a substantial amount of time standing in water to catch fish and eat it?
The contamination was confined to a single water cooler. Specialists located and isolated it from use. The contamination incident has no environmental impact.
The Annual report of AERB (available at www.aerb.gov.in) gives the data on radioactive releases from all power stations.
The resultant radiation doses are small fractions of the AERB limit and are within the variations in the natural background radiation present everywhere. The Kaiga Generating Station is no exception.
Are there legal provisions against such malevolent acts? Rule 23 of the Atomic Energy (Radiation Protection) Rules, 2004, issued under Section 17 of the Atomic Energy Act 1962 states that “Every worker shall observe the safety requirements and follow safety procedures and instructions and shall refrain from any wilful act that could be detrimental to self, co-workers, the radiation installation and public.”
The penalties
Violation of rules made under Section 17 of the Act shall be punishable with imprisonment for a term which may extend to five years, or with fine, or with both.
Depending on the circumstances, if proved guilty, the accused may be convicted for violating the provisions under Section 10 of The Weapons of Mass Destruction and their Delivery Systems (Prohibition of Unlawful Activities) Act, 2005.
K.S. PARTHASARATHY
Former Secretary, AERB
( ksparth@yahoo.co.uk )

Dr K.S.Parthasarathy in conversation with Mr.Yuri Vishnevskiy

Dr. K S Parthasarathy, Secretary, Atomic Energy Regulatory Board Interviewed Yuri Vishnevskiy, the then Chairman of Federal Nuclear and Radiation Safety authority of Russia (RF Gosatomnadzor) at Vienna during May 3-7, 1999. Extracts were published in AERB Newsletter
[Reproduced from AERB Newsletter Vol 12, No2, 1999]
[ Mr. Yuri Vishnevskiy is currently the Chairman of Federal Nuclear and Radiation Safety authority of Russia (RF Gosatomnadzor). He graduated from the Tomsk Polytechnic Institute in 1966 and worked in different official capacities (Engineer, Senior Engineer, Deputy Shift Head, Shift Head and Senior Shift Head) of the Syberia Chemical Plant from 1966 to 1988. He was Head of RF Gosatomnadzor Inspection at Balakovo Nuclear Power Plant from 1985-1991. In 1990 he was elected a People's Deputy of the Russian Federation. Mr. Vishnevskiy was appointed Chairman of Federal Nuclear and Radiation Safety Authority of Russia in 1991.
Dr. K.S. Parthasarathy, Secretary, AERB interviewed Mr.Yuri G. Vishnevskiy, Chairman, Gosatomnazdor of Russia. (Gosatomnadzor is the State Safety Regulatory Authority of Russia) at Vienna].
Excerpts:
KSP: Mr Vishnevskiy, I consider it a proud privilege and honour to talk to you on behalf of the readers of AERB Newsletter on the functions and the activities of the State Safety Regulatory Authority in Russia. Your enthusiastic participation at the Peer Review Discussion on 'Assessment of Regulatory Effectiveness' at the International Atomic Energy Agency gave me ample opportunity to observe you closely. Your interventions on several occasions assisted us to focus on key issues in nuclear regulation. Which are the areas of responsibility of Gosatomnadzor?

Mr.Vishnevskiy: Gosatomnadzor was set up in 1991 by a Decree of the President of the Russian Federation. It is the legal successor to Gosatomnadzor of the USSR. It is a federal executive body with responsibility for the state regulation of safety in relation to the use of atomic energy (except for regulation of activities connected with the development, production, testing, maintenance, storage, and decommissioning of nuclear weapons and also with the development, production and maintenance of military nuclear power installations. The aim of the agency is to establish a situation where the staff of the nuclear facilities, the population at large and the environment are protected from undue radiation risks and where uncontrolled distribution of nuclear material is excluded.

KSP: So the Gosatomnadzor has a wide spectrum of responsibilities.

We issue licenses to various users of atomic energy after ensuring that safety requirements are met. My agency organises and implements the superiision of the production and use of atomic energy, of handling of nuclear materials, radioactive substances and radioactive waste. We carry out the supervision for non-proliferation of nuclear technology and nuclear materials, physical protection of nuclear materials, nuclear installations, radioactive sources, storage facilities for nuclear materials, radioactive substances and radioactive waste as well as the control of the observance by the Russian Federation of international and other agreements in force. We organise scientific research to substantiate the principles and criteria, the standards and rules for safe usage of atomic energy. We have responsibility

to inform the public and the state authorities about the safety status of nuclear installations, radiation sources and storage facilities. The Regulatory Agency operates from its Headquarters, Interregional Offices, Interregional Department for Information Gathering and Information Security as well as the Scientific & Engineering Centre for Nuclear and Radiation Safety. The interregional offices are located in seven regions and the Headquarters is in Moscow.

KSP : Administratively to whom do you report?

Mr.Vishnevskiy : We report to the President of Russian Federation. My reports and observations are sent to the Government. I shall send my remarks and points of view to the ministry if my directives are not complied with. Parliament helps me to speed up the Bills.

KSP : In the Peer Discussions, one of the issues which was discussed at length was the independence of the regulatory agency. The need to develop core competence in house was highlighted. While a great degree of independence can be achieved by incorporating appropriate legislation, there is no easy way to develop independent core competence in a short period of time. Since financial resources are limited, it is essential to avoid unnecessary duplication of research efforts. Fortunately in India we have the support of Bhabha Atomic Research Centre - a centre of excellence. ln fact many of us in AERB, spent several decades in BARC before joining AERB. What is your experience in Russia? Where do you get the technical and scienfific support from?

Mr.Vishnevskiy : Probably our situation is a bit easier. Though our first nuclear power reactor was commissioned in 1954, the regulatory organisation was set up only in 1984. We have several research institutes such as the Kurchatov Institute, the Academy of Sciences and Institute of Minnatom. Besides these, we have our own Scienfific and Engineering Centre for Nuclear and Radiation Safety (SEC NRS). As a matter of fact, at any time, there is some sort of competition between these institutions. We use this carefuly and effectively. We assign a task to one institution and request another institution to review their results. The SEC NRS co-ordinates all research efforts. Occasionally we send some projects to the Academy of Sciences.

KSP : Do you pay these institutions?

Mr.Vishnevskiy: (Smiles) Oh! Payments! all payments are made by the applicant. The Scienfific and Engineering Centre (SEC NRS) can hire any specialist. For adequate accomplishing the varriety of the problems the experts from other organizations are invited on the contract basis. SEC NRS renders the engineering and scientific support to the RF Gosatomnadzor; the research conducted by SEC NRS is the scientific ground for all other activities to support the Gosatomnadzor of Russia. The R&D works are directed to verify or validate the criteria and principles of nuclear and radiation safety used in the regulatory documents and for expertise. The SEC NRS carries out safety assessments of nuclear installations, radiation sources and storage facilities; participates in establishing the legislative basis in the field of the use of nuclear energy, nuclear materials, radioactive substances and radioactive waste management, as well as in the works aimed .at providing the legislative basis for nuclear and radiation safety regulation (except for sanitary and hygienic standards and rules).

KSP: In India, the Regulatory Board assisted the Government in drafting the Factory Rules as applicable to nuclear facilities and installations and administers them in those installations and facilities. During the discussions with other participants who attended the Peer discussions at the International Atomic Energy Agency I found that this practice is unique to India. What are the other responsibilities of SEC?

Mr.Vishnevskiy : 'Child as it was', SEC NRS was involved in nuclear safety issues only. Now, the terms of activity include all peaceful nuclear power facilities. SEC NRS conducts scienfific research to substantiate the principles and criteria for nuclear and radiation safety. The Centre verifies and validates computer codes, generates the concepts of and makes necessary entries into the data bases for safety assessment of nuclear installations, for radioactive substances and radioactive waste. The Concept of the State Control and Accounting for Nuclear Materials, approved by the Government of the Russian Federation, has been worked out with participation of SEC NRS.
Besides, SEC NRS conducts training of the staff, organizes workshops, seminars and
conferences, prepares for publication of various kinds of information materials and documentation authorized by the Gosatomnadzor of Russia.

KSP : Is the Regulatory Authority responsible for the safe application of radiation in the medical field?

Mr.Vishnevskiy : We do not consider how radiation is used by doctors. This is done by the Ministry of Health. But we issue licenses to use radiation equipment. We control the storage and transport of radioactive substances.

KSP : The Atomic Energy Act in India was adopted in the Indian Parliament in 1948. It was primarily meant to preserve natural resources or atomic minerals. In fact, radiation safety or nuclear safety requirements are not even referred to in the Act. This Act was repealed and replaced by the Atomic Energy Act 1962. A few Sections in the Act refer to safety requirements. Several rules under the Act have been promulgated over the years. How was the evolution of Atomic Energy Law in Russia?

Mr.Vishnevskiy : The Regulatory Board in the erstwhile USSR was set up in 1984. Then there was no Law as such. In the early years, there were some Decrees and Ordinances from the Party and Government. Gosatomnadzor was set up by a decree of the President of the Russian Federation in 1991. The competence, rights, duties and responsibilities of Gosatomnadzor and its officials are determined by the Provisions on Gosatomnozdor, approved by the President of the Russian Federation in 1992 and amended in 1993 and 1995.

KSP : What were the reasons for setting up the regulatory agency? Was it in the light of international developments?

Mr.Vishnevskiy : As far as I can recollect, there was no such reason. I am not able to indicate any specific reason for the development. After the accident at Chernobyl nuclear power station, we obtained more powers! Power to use sanctions, for instance. Chernobyl accident turned out to be a blessing in disguise!

KSP : But that was too expensive a way to secure regulatory power! I thought that everyone knew that nuclear technology at its current level of technology is an unforgiving technology.

Mr.Vishnevskiy : Not really. Probably more important than the regulatory agency getting more powers is that the accident brought about important changes in the minds of those who operate the reactors. Greater awareness in the operator.

KSP : What was the strength of the regulatory agency prior to the accident?

Mr.Vishnevskiy : Much less than now. Currently, the strength of Gosatomnadzer is 1000 plus; four to five fold increase since Chernobyl accident. Prior to the accident, there was no realisation that regulatory principles should be implemented fully in all nuclear power plants.

KSP: You mean that prior to the accident, regulatory principles were not formaly implemented in the nuclear power plants in Russia.
Mr.Vishnevskiy : I think, you can say so. Now our regulatory responsibility covers all stages of the nuclear fuel cycle, including mining, fuel fabrication, reactor operation, reprocessing and waste management.

KSP : For the regulator to be effective, he should be as competent and knowledgeable, preferably more competent and knowledgeable than those who operate the reactor. How do you achieve this? Do you offer any training to your staff?

Mr.Vishnevskiy : Yes, we have our training centre for training regulatory personnel.

KSP : Do you recruit young people to the regulatory agency?

Mr.Vishnevskiy : As a matter of fact, no new comer joins the regulatory agency. We recruit people of average age with experience in industry

KSP : What is the incentive for experienced people to join the regulatory board?

Mr.Vishnevskiy : There are different reasons. Stable job, stable government job. They have some advantages after retirement. A lot of people joined because of their interest. For instance, I myself came; my deputy joined. In principle we could have setfled down in reactor operation. But we concluded that we can improve safety. Nuclear power has future only if we reach a certain level of safety.

KSP: Mr Vishnevskiy, you have rich and varied expertise and experience and you are currently occupying the chair of the top regulator in the Russian Federation. Can you tell us about any unique and memorable era in your career?

Mr.Vishnevskiy : Unique and memorable era! I was a Member of Parliament for some rime. I made speeches to my electorate! Then the situation was different. That was way back in 1990. 1 was elected from the region in which I was staying then. I was then serving the government.
KSP : Can government officials contest elections?

Mr.Vishnevskiy: Government staff could contest elections then. Now there is a law against it. In 1993, 1 resigned as an M.P.

KSP : You must have enjoyed a high level ,of popularity?

Mr.Vishnevskiy : It was unique. I also learnt that life is not a bed of roses.

KSP : One of the important functions of any regulatory authority is to inspect the installations to ensure compliance with safety requirements. How is inspection of nuclear installation carried out in the Russian Federation?

Mr.Vishnevskiy : We have the system of resident inspectors at the NPP sites. We post the group of five inspectors per site, one Chief Inspector and four inspectors. They belong to different disciplines: radiological safety, lnstrumentation and Control, etc.
In the regulatory authority, the licensing and inspection sections are kept separately. We assign inspection work to specialists, they visit the utility and make recommendations.

KSP : How did you enter the regulatory field?

Mr.Vishnevskiy : I attended a special technical course in technical institute which has special faculty working in the nuclear and engineering physics. I have graduated with specialisafion in management of Nuclear Power Plants. In 1966, 1 graduated in engineering and physics and joined a nuclear power plant. In 1985, 1 entered the regulatory field.

KSP : Whenever the issue of public awareness come up for discussion in the Peer Review meeting, you argued passionately in favour of various public information programmes. What is the role of Gosatomnadzor in the area?

Mr.Vishnevskiy : We keep contact with mass media, hold meetings in which representatives of the regulatory authority meet public organisarion, information agencies and private persons. In order to coordinate these activities we established the Interregional Territorial Department of Information gathering and Information Protection as a Public Relations Division. Summarised information on the nuclear and radiation safety status in the country is sent monthly to the main information agencies in Russia. The information is transmitted to the electronic mass media regularly. In case of an emergency they will receive updated 'fresh' information.

KSP : AERB publishes its annual report. We publicise the regulatory restrictions placed on nuclear installations. The fact that AERB - a government agency - can place restrictions on government nuclear installations appears to improve the credibility of the Organisation. The restrictions include reducing power levels of nuclear power plants, delicensing of crew and occasionally shutting down installations. What do you do to improve the credibility of your organisaflon? Have you taken any special steps?

Mr.Vishnevskiy : In Russia nuclear power plants are in the government sector. Nuclear industries (industries producing nuclear components and system) might also be the private enterprises. The credibility question can be easily solved. My prescription is: don't tell a lie, be honest, open and transparent. I invite Green Peace. I discuss safety issues with them. I get a lot of material from their placards and transparencies. Many such information, I receive, I may not get from normal government channels.

KSP : Where were you when the accident occurred at the Chernobyl Nuclear Power Station?

Mr.Vishnevskiy : I was the then Chief Inspector at the Balakovo Nuclear Power Station. We were just finishing the tests to start up the reactor.


KSP : How did the people react?

Mr.Vishnevskiy : Nobody could understand that such an accident can happen. We spend time investigating the possibility of such accidents in VVER, the Russian version of the Pressurised Water Reactor

KSP : Chernobyl power reactors had known deficiencies.

Mr.Vishnevskiy: Frankly speaking, there were some observations on the weaknesses of Chernobyl reactors. But nobody could foresee that
the deficiencies could lead to such a reactor accident. To create such accidents, many events were to be postulated or imagined.

KSP : How was the attitude of the staff?

Mr.Vishnevskiy : Before the accident, the attitude of the management towards the nuclear power reactor was the some as towards a conventional power station. The only difference was that they know that one is 'a nuclear boiler' and the other 'a conventional boiler'. But after the accident of Chernobyl Nuclear Power Station, there was clear change in the attitude. They started respecting the process of nuclear reactions.

KSP : What were the criteria followed to evacuate the population from the contaminated zone around the reactor?
Mr.Vishnevskiy : After the accident specific measures were taken. We measured the radioactivity levels at different areas and divided them into different zones depending on the radioactivity levels. On this basis, we decided from which zone people will have to be removed. We decided that people should be evacuated from all the zones in which they are likely to be exposed to more than 35 Bert in 70 years. (Bert was mentioned as the Unit it appears to be equal to rem).

KSP : Did the staff of nuclear power stations leave in large numbers?

Mr.Vishnevskiy : Some people left. Others did not.

KSP : Has the accident affected the morale of the staff?

Mr.Vishnevskiy : No, it did not. Certainly it did influence some people coming to the faculty of nuclear science. Now we have fully recovered. Now there is competition among people!

KSP : If you have the option, would you advise your son to join the nuclear field?

Mr.Vishnevskiy : My son is in the nuclear field! Earlier he worked in a nuclear power station. Now he is member of staff of Scientific and Engineering Centre for Nuclear and Radiation Safety.

KSP : What is the future of nuclear power in the world? There is a move against nuclear power in several European countries.

Mr.Vishnevskiy . It is a challenging question! Nuclear power contributes substantially to the total power generated. I don't think we can eliminate nuclear power completely.

KSP : What is the future of fusion power?

Mr.Vishnevskiy : It is difficult to say. Even if fusion power becomes reliable, the cost is likely to be high. I think it may take 10 - 20 years of further technological development.

KSP : India has consciously planned to set up a three stage nuclear power programme. Our ultimate goal is to make use of the vast resources of thorium available in the country as our uranium resources are modest. How is the programme envisaged in the Russian Federation?

Mr.Vishnevskiy: We have established the thermal reactor technology. We have reactors of advanced design under planning stage. We have considerable interest in breeder reactors. There are economic issues, fast reactor fuel is costlier. Currently, our breeder programme is at stand still. We have to continue R&D in this area to develop newer concepts. We are carrying out work in the liquid metal cooling system.

KSP : It is known that Pressurized Water Reactors become popular because lot of development work has gone into them while nuclear submarines were constructed. What was the background in the development of RBMK reactors?

Mr.Vishnevskiy : Such reactors were primarily used to produce plutonium.

KSP : It is reported that Chernobyl nuclear power station had performed extremely well and had achieved record levels of power production. Was it one of the reasons for complacency? Was it one of the factors which led to the nuclear disaster?

Mr.Vishnevskiy : Chernobyl power station performed well. Today we may say that complacency was one of the reasons for the disaster. The operators were known to be skilled specialists. Production of power was their main goal.

KSP : You have spent the earlier part of your career as a nuclear operator. Now you are Chief of the Regulatory Organisation. There was on going debate on the various factors that led to the accident at Chernobyl Nuclear Power Station. The designers blamed the operators and the operators blamed the designers. Recently a physicist from Russia's Kurchatov Institute disputed the official version. An interview with him appeared in the January issue of Nuclear Engineering International. What is currently the official position?

Mr.Vishnevskiy : Right in April, the Russian Academy of Earth Sciences published another reason. According to them, there was a localized earthquake close to Unit 4, the bottom structure of the unit developed a crack. There are different versions. Therefore, I cannot comment finally. Now we are closely reviewing all opinions.

KSP : How did the Laws relate to Atomic Energy develop in Russia?

Mr.Vishnevskiy : The Federal Law on the Use of Atomic Energy was issued in 1995.
This was followed by the Federal Law on Radiation Protection of Population in 1996. Earlier the practice used to be to issue Decrees or Ordinances. When I was a member of Russian Supreme Soviet, I took part in the drafting of the Low.

KSP: The regulatory mechanism in India evolved gradually. Till 1983, the regulatory work was carried out in house. The regulatory procedures and the mechanisms established have been the subject of review of high level committees of specialists. These have evolved and were strengthened as per national requirements. How was it done in Russian Federation. Is there any peer review of the regulatory agency?

Mr.Vishnevskiy : No, we do not have formal peer review of the activities of the regulatory agency. We function very carefully. We are able to show that we act as per the international requirements.

KSP : One of the most important areas of activities in the nuclear field is the management of radioactive wastes. What is the role of the Russian regulatory agency in the area?

Mr.Vishnevskiy : Our main role is in the development of scientifically well supported and justified criteria. Our role is that of an initiator. For example, before the establishment of the regulatory board, radioactive wastes were put underground. Today we do not provide a licence for it. We prohibit such a procedure. We require additional justification for the safety of such a method.
Actually, waste management is a common job. Regulatory agency work with the utility and the government will support the programme. Today we have started a programme to manage radioactive wastes.

KSP : Decommissioning of nuclear submarines is reported to be another important area. How big is the issue? What is the responsibility of regulatory agency in the area?

Mr.Vishnevskiy : Speaking precisely, we just started supervising the programme. This activity is with the Defence Department right now. Department of Defence is transferring the responsibility to Department of Atomic Energy. Then the programme will come under the supervision of the regulatory body. Currently we are developing the conceptual approaches ourselves. Decommissioning unused nuclear submarines is an important safety issue.

KSP : Exhaustive and dedicated review of certain areas is one of the ongoing activities of the Atomic Energy Regulatory Board. Thirteen such reviews have been completed So for. Some of these are identical to the IAEA Operational Safety Review Team Mission. Do you organise such programmes.

Mr.Vishnevskiy : We do conduct reviews of certain topics such as strength of containment matters connected with the new design of breeder reactors, Design of VVER for India among others.

KSP : Thank you very much Mr. Vishnevskiy. I am very grateful to you for sparing your time to convey your views on very wide ranging subjects.

Technologies to harvest uranium from sea

India has made modest progress in extracting uranium from sea water. The quantity still remains in milligrammes. There are plans to "scale up" the facilities

K.S.Parthasarathy





Date:12/11/2009 URL: http://www.thehindu.com/thehindu/seta/2009/11/12/stories/2009111250321300.htm
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Back Sci Tech



Technologies to harvest uranium from sea
There are 4.5 billion tonnes of uranium in sea water, a thousand times more than what is known to exist in uranium mines


The way ahead: BARC and the Commissariat a’ Energie Atomique (CEA), France, are collaborating to develop three innovative and efficient methods of uranium extraction.
Uranium in trace quantities is present in soil, rock and water. Bounteous nature leaves about 4.5 billion tonnes of uranium in sea water, a thousand times more than what is known to exist in uranium mines. Since its concentration is extremely low (only one particle of uranium for 34 million particles of other elements), harvesting uranium from sea is a formidable task.
Japanese technology
Japan developed a technology by using plastic sheets to which amidoxime, which is capable of selectively absorbing uranium from seawater, is grafted by high energy electron beam irradiation.
Scientists from the Desalination Division, Bhabha Atomic Research Centre recovered uranium at milligram levels from sea water using electron beam grafted amidoxime.
They developed a semi pilot scale facility to produce radiation grafted sheets of 1 metre X 1 metre size.
They collected about 800 microgrammes of uranium in five campaigns from CIRUS Jettyhead; about 1.8 milligrammes from the seawater intake and outfall canals at the Tarapur Atomic Power Station and around 200 microgrammes from Andaman and Nicobar Islands. Though these amounts are trivial, it gives confidence in the technology
Field trials carried out at the three locations gave concentration factors of 300, 600 and 700 for the submergence of the absorbent material for 12, 14 and 23 days respectively.
“What are the reasons for obtaining different concentration factors at different locations?” “The concentration factor depends on corrosion, bio-fouling and their combined effect on the adsorption kinetics. These may be different at different locations”, Dr P.K. Tewari, Head, Desalination Division, BARC responded to my query.
BARC scientists studied these factors and the mechanical properties of the materials used in the suspension assembly and the substrate. They established their compatibilities with seawater and process chemicals and the optimum submergence periods for various locations.
They also evaluated the potential of Polyhydroxamic Acid (PHOA) sorbent, for uptake of uranium from seawater. They obtained a concentration factor of over 190, when the resin, filled in a porous bag was dipped in seawater for a period ranging from 10-30 days.
BARC and the Commissariat a’ Energie Atomique (CEA), France, are collaborating to develop three innovative and efficient methods of uranium extraction from the concentrated brine rejected by integrated nuclear desalination systems, which both partners are currently developing.
The first method uses resin-grafted with calixarene (a synthetic material, indecently expensive!); magnetic separation is the second method and the third uses a canal system using absorbents.
These methods are highly selective but need further research and development.
Using three absorption cages, each of cross sectional area of 16 square metres and height of 16 cm and consisting of stacks of 52,000 uranium specific, non-woven sheets with a total mass of 350 kg, a Japanese group recovered more than one kg of uranium in terms of yellow cake during a submersion period of 240 days in the ocean.
Underwater farm
Dr Masao Tanada of the Japanese Atomic Energy Agency hopes to get funding to construct an under-water uranium farm covering nearly 400 square miles that would meet one-sixth of Japan’s annual uranium requirements.
Tanada asserts that Japan’s nuclear power industry can harvest the 8,000 tons it needs annually from the Kuroshio Current that flows along Japan’s eastern seaboard.
Japanese researchers found out that they can harvest uranium from sea by cultivating genetically engineered gulfweed which will grow in sea at an unbelievable rate of two metres an year. The weed selectively soaks up heavy metals including uranium.
A spin-off
What will you do with possibly the millions of tons of grass left over after recovering uranium? Convert it to bioethanol! Gulfweed is an ideal non-food source of bio-ethanol. Gulfweed traps carbondioxide from sea.
Conventional uranium mining requires environmental restoration including long term tailings management. Uranium recovery from the sea does not leave any tailings. With superb green credentials, it is an environmental friendly process.
India has miles to go to reach kilogramme capacities of uranium. BARC has plans to upgrade the capacity.
K.S. PARTHASARATHY
Raja Ramanna Fellow, Department of Atomic Energy
( ksparth@yahoo.co.uk )
© Copyright 2000 - 2009 The Hindu

High fissile fuel in nuclear submarine lasts long

High fissile fuel in nuclear submarine lasts long

The prototype is serving as a training centre for the nuclear submarine crew

Reactor internals must be rugged and resilient

Reactor internals remain inaccessible for inspection

Every year, on October 30, scientists, engineers and other officials from the Department of Atomic Energy gather near the Central Complex Building, Trombay to celebrate the Founder’s Day. Being the Birth Centenary year of Dr. Homi Bhabha, this year’s celebration was unique. The stock taking of the research and development activities at the Bhabha Atomic Research Centre (BARC) covered compact reactor for Arihant (the nuclear submarine), improved gas centrifuges for uranium enrichment, fuel fabrication for fast reactors and work on innovative reactors among other areas in the cutting edge of technologies.

BARC designed, developed and built the steam generating unit of Arihant by facing many technical challenges

“The compact Pressurized Water Reactor was designed for this purpose with several features; such as very quick response for power ramping, extremely stable undership motions and resistance against exposure to very high acceleration resulting from eventual depth charges”, Dr Sukumar Banerjee, Director, BARC said in his Founder’s Day Address

“Since the nuclear reactor is fuelled with high fissile containing fuel, it can supply energy in the submerged condition for an extended period without refuelling”, he clarified. Details about the reactor are classified.

Generally, Pressurized Water Reactors (PWR) power nuclear submarines. A PWR has a core of highly enriched uranium. When uranium nuclei undergo fission, the fission fragments carry enormous energy. They dissipate the energy in the core which gets heated up. The high pressure primary system with water as coolant removes the heat from the core continuously.

Water at high temperature enters the steam generators. In the steam generators, the heat from the water in the primary system is transferred to the secondary system to create steam. In the secondary system, the steam flows from the steam generators to drive the turbine generators, which supply the ship with electricity, and to the main propulsion turbines, which drive the propeller. After passing through the turbines, the steam condenses into water which is fed back to the steam generators by the feed pumps.

Naval reactors pitch and roll. Demands of power change rapidly. The manufacturing and quality assurance of reactor components must be of exceptionally high standard.

The reactor internals remain inaccessible for inspection or replacement throughout the long life of their core. They must be rugged and resilient. Reactor components and systems must withstand, harsh and hostile environment, long term effects of radiation, corrosion, high temperature and pressure.

As the reactor operates radiation level increases. Appropriate shields are built around the reactors to ensure radiation safety. A reactor may use over 100 tons of lead as shielding.

“Many systems and equipment designed and built were first of its kind in the country. The entire steam generating plant has been designed to give highly reliable offshore operation in a completely isolated environment”, Dr Banerjee noted.

“Control and instrumentation design is fault tolerant and requires minimum operator interventions. An elaborate diagnostic system enables a very high availability factor. Many new materials and technologies have been developed and new infrastructure has been created for this project”, he revealed.
Prototype system

The development of the steam generating plant of Arihant was preceded by setting up of the land based prototype system at Kalpakkam. The reactor which has been working for the past three years has served as a technology demonstrator.

“The entire plant with primary, secondary, electrical and propulsion system along with its integrated control was packed in the aft end of a land based submarine hull designed and built specifically for the purpose.

This protoype is serving as a training centre for the crew for the nuclear submarine”, Dr Banerjee said. The crew gets training with the help of an indigenously designed and built full scope simulator.

K.S. PARTHASARATHY

Raja Ramanna fellow, Department of Atomic Energy

( ksparth@yahoo.co.uk)

© Copyright 2000 - 2009 The Hindu