India : Nuclear Technology Scenario

India: Nuclear Technology Scenario
by K S Parthasarathy
RECENT developments in nuclear technology and allied fields have given nuclear advocacy groups and their well-wishers in India, an inspiration for calm contemplation; an occasion to assess the weaknesses of the programme and to appreciate its inherent strengths.
India has made laudable progress in operating the entire nuclear fuel cycle consisting of mining, milling, fuel fabrication, nuclear reactor operation and spent fuel management. The latest annual report of the Department of Atomic Energy (DAE, 2006-07) amply demonstrates “a paradigm shift in terms of far greater mobilisation of resources and technologies” for uranium exploration activities.
The Atomic Minerals Directorate for Exploration and Research (AMD) established over 6600 tonnes of additional uranium resources at Lostoin, Wahkyn, West Khasi Hills in Meghalaya, Chitrial, Nalgonda district, Andhra Pradesh and Rahul, Sikar district in Rajasthan. The agency is leaving no stones unturned to locate uranium resources across different regions in the country.
Prospecting and drilling for the precious resource continued with renewed vigour in several areas in Andhra Pradesh, Karnataka and Madhya Pradesh. AMD estimated over 120 million tonnes of total heavy mineral resources as an inferred category along the 30 km coastline in Puri district, Orissa. The operating units of the Uranium Corporation of India Limited (UCIL) showed improved capacity utilisation during the year. Narwapahar mine and Jaduguda plant maintained their excellent performance; the quantity of uranium ore they produced and processed, respectively exceeded their production capacities.
The Nuclear Fuel Complex (NFC) met the fuel requirements of all the operating pressurised heavy water reactors and boiling water reactors. NFC supplied the entire initial full core fuel requirement of unit 3 of the Tarapur Atomic Power Project (TAPP-3), the reactor internals of unit 6 of Rajasthan Atomic Power Project (RAPP-6), the coolant tubes and Garter springs for replacement in Units 1 and 2 of the Narora Atomic Power Station and the first supply of titanium half alloy hydraulic tubes (a critical component in the Light Combat Aircraft) for the Aeronautical Development Authority. The scientists and engineers at the India Gandhi Centre for Atomic Research operated the Fast Breeder Test Reactor (FBTR) at Kalpakkam without any failure of the mixed carbide fuel used, for a record length of time. Four sodium pumps operated trouble free for 5,50,000 hours. The experience gained in operating FBTR will be invaluable in our fast breeder reactor programme.
The construction of the Prototype Fast Breeder Reactor (PFBR) and related facilities at Kalpakkam is on course. The manufacture of a few important systems and components of the 300 MWe Advanced Heavy Water Reactor (AHWR) being developed by Bhabha Atomic Research Centre have been completed.
During 2006-07, the Nuclear Power Corporation of India Limited (NPCIL) achieved the target capacity addition of 1300 MWe in the Xth plan with the commissioning of two nuclear power reactors of 540 MWe capacity at Tarapur (TAPP-3 and 4) and two units of 220 MWe at Kaiga (Kaiga-3 and 4). Unit 4 of the Rajasthan Atomic Power Station operated continuously for 373 days, breaking an earlier record. Unit 1 of the Kaiga Atomic Power Station operated non-stop for 356 days. Units 1 and 2 of the Tarapur Atomic Power Station, the first nuclear power station in the country, recorded the highest power generation since the station began its commercial operation.
The total generation including wind power generation at Kudankulam was 398 million units more than the last year. But the overall capacity factor for the nuclear power plants was low at 63 per cent. The annual report of NPCIL for 2006-07 noted that the capacity factor will improve proportionately when the mismatch between fuel supply and generation is resolved, shortly. NPCIL successfully completed the life extension and safety up-gradation of unit 1 of the Narora Atomic Power Station (NAPS-1) within the estimated cost and time. The Raja Ramanna Centre for Advanced Technology (RRCAT) and NPCIL developed various laser-based tools indigenously to reduce radiation exposure to workers involved in en masse replacement of coolant tubes at NAPS-1; this was possible as the duration in which the coolant tubes were removed and replaced became shorter, when these advanced tools were used.
NPCIL concentrates its research and development (R&D) activities in 21 areas in nuclear and electronic systems. These include new and improvised technologies to enhance safety, safety experiments to validate design parameters, methods to reduce operation and maintenance costs of operating units, management of radioactive waste, ageing and degradation studies, remote inspection, maintenance, emergency handling and refurbishment/repair technologies, indigenisation of processes, equipment and components, development of electronics and computer-based systems for new projects and up-gradation of systems for existing nuclear power plants among others.
The sophisticated tools used by NPCIL included a “remote operated vehicle” to carry out in situ inspection to identify locations where suspected leakages on the steel liners in the calandria vault of KAPS-1 occur and an indigenously developed automatic cutting/beveling machine for feeder pipe replacement during the en masse coolant channel replacement campaign. This helped to reduce plant outage time and to save substantial foreign exchange.
The NPCIL’s annual report for 2006-07 indicates that its R&D expenditure was Rs 120.43 million or 0.33 per cent of the turnover. It registered a considerable increase over the amount for 2005-06 of Rs 61.9 million or 0.17 per cent of the turnover.
The enchanting mustard fields with Narora Atomic Power Station in its background, the colourful and beautiful birds like the Red Avadavat at the Rajasthan Atomic Power Station, the mixed group of painted storks, grey pelicans and cormorants near the Kudankulam project site and a variety of butterflies at the Madras Atomic Power Station; NPCIL’s annual report contains the images of “a microcosm of the ideal eco-friendly biosphere.” I wonder how the NPCIL staff missed the shoal of colourful fish swimming against the water currents at the outfall of Rajasthan Atomic Power Station. Nuclear stations in India show that they can exist harmoniously with flora and fauna at each location.

Radiation workers and infertility,impotence

Radiation workers and infertility, impotence

There is no scientific evidence that radiation exposure will cause impotence

Temporary sterility may occur at a lower dose of 0.15Gy (150mGy) in a few months post exposure

All available resources need to be used while counselling persons exposed to radiation

Ill-informed radiation workers have very exaggerated notions about the health effects of ionizing radiation. Fortunately, they are a minority. They rarely get opportunities to clear their doubts. Often, they are reluctant to ask. More so, if their doubts are on intensely private topics such as the impact, if any, of radiation exposure on fertility and sexual performance!

Sterility due to radiation exposure is a deterministic effect.

These effects do not occur until the radiation dose reaches a minimum threshold. For instance, the threshold dose for permanent sterility in the male for a single absorbed dose in the testes is about 3.5Gy (3,500mGy) to 6Gy (6,000mGy).
Speedy recovery

Temporary sterility may occur at a lower dose of 0.15Gy (150mGy) after a few months post exposure. It may continue for some months.

The exposed person will recover after a few months. (Gy is a unit of radiation dose; since Gy is large, milligray (mGy) — a dose equal to one thousandth of a Gy — is commonly used; the annual dose limit for radiation workers recommended by the Atomic Energy Regulatory Board (AERB) is 30 mGy for x-rays, gamma rays and electrons; average dose to radiation workers is a fraction of a mGY to a few mGy).

The annual reports of AERB contain relevant details about the radiation doses to workers in India (please see www.aerb.gov.in ).

As the doses received by different groups of radiation workers are several hundred to several thousand times lower than the threshold dose, no worker will suffer sterility due to radiation exposure.

Workers in India have been handling radiation sources for the past several decades. Over the years, there were a few serious incidents involving high radiation doses to individuals who carried sources inadvertently.

There has not been even a single instance of any worker becoming permanently sterile due to occupational radiation exposure. There is no scientific evidence that radiation exposure will cause impotence.
Scientific facts

Publication 60 of the ICRP contains scientific facts about radiation exposure and health effects including sterility. Patients trust their physicians. But few physicians have adequate knowledge in the subject. This became evident during the radiation protection appreciation programmes arranged by AERB a few years ago.
Wrong advice

According to WHO, 10 to 15 per cent of Indian couples are sterile. An exposed person may not get the right advice if he approaches homeopaths and doctors practicing alternative medicine; they are not equipped to offer counsel.

I came across an instance in which in spite of the ‘advice,’ he received, an exposed worker was worried over his erectile dysfunction, which he wrongly attributed to radiation exposure.

Apparently, he had less faith in the really competent physician who offered correct advice!

Scholarly discussion with facts and figures on radiation and its effects has a role to play during medical counselling; but that alone may not reassure an exposed worker.

While researching to write this paper, I asked Dr Robert Brent, Distinguished Professor of paediatrics, radiology and pathology, Thomas Jefferson University, whether he has an information package to counsel exposed workers. Dr. Brent has counselled many thousands of patients, particularly pregnant women, on effect of radiation on the unborn, during his distinguished career over several decades. He contributed significantly to address the topic at the Health Physics Society Ask the Expert (HPS ATE) web site.

“We have many answers on the HPS ATE website that pertain to these questions, however, the anxiety level of the questioner is usually high and they want a personal answer to their questions and concerns.

Each exposure is different as are the circumstances; generic answers do not help these contacts.

They want the personal touch and that is what we give them. The risk of cancer from low exposures of radiation is very anxiety provoking and an erudite generic paragraph just does not solve the contact’s concern,” Dr Brent responded to an e-mail message. Counselling persons who were exposed to radiation is a challenging job. A specialist can do it competently if he uses all the resources available to him.

K.S.PARTHASARATHY

Former Secretary, AERB

( ksparth@yahoo.co.uk)

© Copyright 2000 - 2008 The Hindu

CT scanning: safety issues

The Committee on Medical Aspects of Radiation in the Environment (COMARE), UK, has just now published its report on the impact of personally initiated X-ray computed tomography (CT) scanning for the health assessment of asymptomatic individuals. Every one must be read this, as it is a scholarly assessment of a powerful medical imaging tool.




Science and technology Janaury 4, 2008, Chandigarh, India


CT scanning: safety issues
K.S. Parthasarathy

ON December 19, the Committee on Medical Aspects of Radiation in the Environment (COMARE), UK, published a report on the impact of personally initiated X-ray computed tomography (CT) scanning for the health assessment of asymptomatic individuals. Everyone must read this 83-page report (www.comare.org.uk/documents/COMARE12thReport.pdf) which comprehensively deals with the safety issues of CT scanning.

The report noted that in UK, some commercial CT services market CT scanning of the asymptomatic individual directly to the public as a form of preventative medicine to give individuals some peace of mind!

We are not far behind. Advertisements extolling the virtues of CT scanning have started appearing in India also.

CT scans promise greater diagnostic accuracy and an increased range of clinical applications; there is also the potential for greater radiation doses to individuals, from interventional techniques and from changes of practice within X-ray computed tomography (COMARE, 2007).

According to COMARE, a typical CT scan with an effective dose of 10 mSv is associated with a predicted average risk of fatal cancer induction of 1 in 2000 over a lifetime. (mSv is a unit of biologically effective radiation dose. A chest x-ray test exposes the patient to a dose of 0.02mSV)

The harm associated with a medically necessary CT scan is below that considered to be unacceptable, compared to the spontaneous fatal cancer risk of approximately 1 in 4.

“If 100,000 people undergo a CT scan every five years from age 40 to 70 years, receiving an effective dose of 10 mSv from each scan, then the estimated impact is approximately 240 excess fatalities…….. For scanning at higher frequencies (every two years or annually) this increases to 600 and 1200 fatalities, respectively.” COMARE cautioned.

The risk from repeated scans is unacceptable. Physicians must consider the use of alternative techniques using lower doses of ionising radiation or non-ionising radiation.

In any country, medical radiation exposure constitutes the major part of the radiation exposure from artificial sources of radiation. COMARE considered the detriment caused by radiation from the CT scan and also the subsequent psychological effects and potential physical detriment from further investigations.

Commercial CT services should provide comprehensive information regarding dose and risk of the CT scan, as well as rates of false negative and false positive findings. False negatives will lead to wrong feeling of good health, while tests that provide false positives may cause psychological trauma followed by more diagnostic tests.

The committee clarified that “it may not be possible to give an asymptomatic person a complete ‘all clear’ after a scan….It is also not clear whether CT imaging detects some cancers (eg lung) that are not as clinically as aggressive as those identified following presentation with symptoms”. Some cancers may be present at the individual’s death and would not have been life-threatening.

COMARE recommended that any individual displaying symptoms and requesting a CT scan from a commercial service should not be scanned and should be referred back to their physician.

The report considered in detail scanning of whole-body and three specific anatomical regions.

COMARE asserted that it is not possible to optimise exposure parameters for CT scans of the whole of the body. Services offering whole body CT scanning of asymptomatic individuals should discontinue to do so. CT should not be used to assess spinal conditions, body fat and osteoporosis in asymptomatic individuals (COMARE Press release, December 19)

COMARE concluded that there is no evidence that CT scanning for lung conditions is of benefit. However, cardiac CT scanning has been shown to have value for predicting cardiovascular risk and similarly CT colonography has the potential to detect small lesions. Both cardiac CT scanning and CT colonography should only be carried out in certain asymptomatic individuals.

The report recommended that CT scanning should only be undertaken on individuals with intermediate risk identified by a comprehensive cardiovascular risk assessment, unless the referral is by a cardiac specialist.

In view of the safety significance of CT scan units, they are subjected to licensing by the Atomic Energy Regulatory Board (AERB). It is illegal to operate a CT scan unit in India without obtaining a licence issued by AERB

Dr K.S. Parthasarathy is former Secretary, AERB