Is working in a nuclear power plant risky?

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January 1, 2014

Updated: January 2, 2014 04:02 IST 

Is working in a nuclear power plant risky?

K.S. PARTHASARATHY

 

APNuclear power plant workers receive low doses of radiation.

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energy and resource

nuclear power

Several studies of nuclear power plant workers have shown that work in a nuclear power plant is not a risky occupation

A 24-year-old man who was about to join the Nuclear Power Corporation of India Limited (NPCIL) and his parents were troubled by what they saw on a TV channel about the alleged damage to DNA by radiation. TV channels often go overboard and make unsubstantiated claims.

A 63-year-old person asked this writer whether the throat malignancy, which, his 33-year-old daughter was suffering from, was likely due to the possible radiation exposure he might have received while working in a nuclear power plant when he was 28 years old. The explanations offered appeared to have dispelled their doubts.

Is work in a nuclear power plant risky?

Several extensive epidemiological studies of nuclear power plant workers have shown that work in a nuclear power plant is not a risky occupation.

Radiation workers in nuclear industry like other radiation workers form a unique group. They are adult workers whose radiation doses received at work are regularly measured; these records are maintained.

Radiation protection specialists accept that ionising radiation at high dose levels can cause cancer. Nuclear power plant workers receive low doses of radiation.

Cancer induced by radiation is indistinguishable from those caused spontaneously or by other cancer-causing agents. Since there are no unique biomarkers for radiation-induced cancer, specialists depend on statistical methods to predict cancer incidence in a group of exposed workers.

Specialists have carried out long-term studies of these workers in many countries. Most of these studies have low statistical power.

To get statistically respectable population groups, specialists carried out a pooled study of radiation worker populations from 15 nations. The participants in this international collaborative study included 407,391 workers whose external radiation doses were individually monitored; the total follow up was about 5.2 million person-years.

The study published in Radiation Research in 2007 quite unexpectedly showed statistically significant increased risks per unit of occupational ionising radiation dose for mortality from solid cancer and from all cancers excluding leukaemia, compared to those of A-bomb survivors.

The observation that the radiation risk at low doses is more than that at high doses attracted wide attention. In the pooled analysis, Canadian workers had the highest cancer radiation risk estimates among the 15 countries. None of the other 14 country cohorts individually had significantly raised cancer mortality risk estimates. Exclusion of Canadian workers (4 per cent of the sample) from the pooled analysis changed the findings to statistically non-significant.

Critics questioned the data and the analytical validity of the study because of the apparent difference in the results between the Canadian and the 15-country studies.

A recent paper dispelled the disproportionate alarm caused by the pooled study.

A paper published on November 13, 2013 inthe British Journal of Cancer, indicated that the significantly increased risks for early AECL workers are most likely due to incomplete transfer of AECL dose records to the National Dose Registry.

Researchers reported that the analysis of the remainder of the Canadian nuclear workers (93.2 per cent) provided no evidence of increased risk; also the risk estimate was compatible with estimates that form the basis of radiation protection standards.

“Study findings suggest that the revised Canadian cohort, with the exclusion of early AECL workers, would likely have an important effect on the 15-country pooled risk estimate of radiation-related risks of all cancer excluding leukaemia by substantially reducing the size of the point estimate and its significance,” the researchers clarified.

Workers in nuclear power plants will receive some radiation dose. Nuclear Power Corporation of India Limited (NPCIL) has strict procedures in place to keep the doses to workers within the limits prescribed by the Atomic Energy Regulatory Board (AERB).

The AERB Annual Report of 2012-2013 published at (www.aerb.gov.in) indicates that in 2012 no radiation worker in any nuclear power plant exceeded the dose limits prescribed by AERB.

The average radiation dose varied from 0.35 mSv to 2.84 mSv, a fraction of the AERB annual dose limit of 30 mSV. Conclusions were similar in earlier years. At these doses, radiation risks, if any, are insignificant.

Since the dose limits are based on conservative assumptions, it is inconsequential if anyone receives, occasionally, a dose above the limit.

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 — similar to those received by nuclear power plant workers — radiation risks, if there are any, are negligibly small. Such risks are no risks at all. Work in a nuclear power plant is not a risky occupation.

K.S. PARTHASARATHY

Former Secretary, Atomic Energy Regulatory Board

(ksparth@yahoo.co.uk )

Keywords: Nuclear power plant, NPCIL, ionising radiation, radiation risks

 

News of the death of nuclear energy is highly exaggerated

 

News of the death of nuclear energy is highly exaggerated

K S Parthasarathy

August 8, 2013

Some scientists have serious disagreements with nuclear power enthusiasts. A part of the disconnect is due to disinformation. Nuclear proponents must dispel it through  healthy dialogue. Anti nuclear activists claim that the USA decided to halt the all-out nuclear programme after many Nobel laureates debated the issue. According to them,   everyone started rethinking after the Three Mile Island (TMI - 1979) and Chernobyl (1986) accidents and that, post Fukushima (2011), most nations concluded ‘that nuclear energy is a risk not worthy of  taking.’

These conclusions are wrong. In 1973, when the debate took place, US-companies operated 50 nuclear power reactors (NPPs). Now they operate 104. Notwithstanding the TMI accident, US companies installed 50 out of these  after the accident; nineteen more after the Chernobyl accident. Canada  installed 14 NPPs and France 53 of its 59 NPPs post TMI accident.

Post Fukushima accident, Pakistan, China, Iran and Russia have installed new reactors. US Nuclear Regulatory Commission granted combined construction and operation licences to four reactors. Construction of two have started. USA may not build more reactors as it has discovered plenty of shale gas which is cheaper now. In spite of setbacks in Germany, Switzerland and temporarily in Japan, nuclear programme progresses well in Russia, France, Finland, China and India. It is poised to start  in 45 more countries. Beating US and French companies, South Korea won a contract to construct four nuclear reactors in UAE. It may be a game changer as South Korea has the technology, and UAE the funds. Saudi Arabia plans to install 16 reactors.  Activists  ignore these developments.

Contrary to what the anti nuclear activists want us to believe, there is universal consensus on disposal of high level nuclear waste in deep geological repositories; waste  issues are political and not technological. Activists ignore the shining examples of Finland, Sweden and France which are ahead in solving the high level nuclear waste management problem. Some anti nuclear activists state that the USA has plans to vitrify (incorporating radioactive waste into glass) spent fuel. The USA has no such plan.

There are allegations that uranium mines are contaminated with radioactive argon; the actual contaminant is radon, a decay product of radium in the uranium series. Anti nuclear activists want Kudankulam reactors to be run on gas. “Convert all new reactors into steam turbines and coal fired boilers. Change to reactor-boilers when reactors are proved to be safe,” activists argue. But can these system  be interchanged that easily?

Expensive source

Our railways may collapse if it has to handle an additional 86 million tonnes (MT) of coal needed by coal stations that replace new nuclear reactors. In 2011-2012, our ports barely managed to handle 135 MT of coal. Can it handle 86 MT  more? “A 50 km x 50 km area in Rajasthan desert can produce 75,000 mw of solar power which can be fed into the national grid,” some activists say. Solar power generators cannot provide power night and day. Technology to store large quantities of power does not exist now. Solar power is expensive. It may become cheap only if  solar panels and the auxiliary equipment  to maintain the stability of  large scale power networks remain cheap.  

To those opposed to nuclear power, ‘fast breeder is a nasty piece of equipment’ and almost ‘all countries have lost hope in fast breeders.’ Nuclear opponents paint a dismal picture of  fast breeder technology. Facts are otherwise. About 20 Fast Neutron Reactors (FNR) have already been operating, a few since the ’50s, accumulating over 400 reactor-years of experience. Some supplies electricity commercially. All advanced countries carry out  research  to overcome the challenges in technology. At present, fast reactors are not cheap; they cannot compete with current thermal reactors. As uranium is available, there is no incentive to invest in fast reactors.

Anti-nuclear activists habitually  quote  from ‘Poisoned Power’ (1971) and ‘Population Control Through Nuclear Pollution’ (1970), two anti nuclear books by John W Gofman and Arthur R Tamplin. Those who know the credentials of Dr Gofman will not touch these  books! He  was an expert witness in Johnston Vs United States (1984), a case in which four aircraft employees of Aircraft Instruments and Development Inc claimed  personally or through representatives that  their cancers were due to exposures to radium-containing luminous dials. 

In his judgment, Judge Patrick F Kelly commented thus on Gofman: “Indeed, he is an alarmist, truly obsessed with the righteousness of his long espoused concerns regarding exposure to radiation in any setting...it is clear from the outset that this man enjoys the ‘limelight’ and is no stranger to courtroom,” Judge Kelley rejected  Gofman’s testimony  on 15 grounds. He called him unreliable as an expert witness. The activists’ allegation that prime minister Manmohan Singh gave natural uranium reactors a holiday is incorrect. Four pressurised heavy water reactors (Kakrapar 3&4 and Rajasthan 7&8) of 700 MWe are now under construction. Government has planned or firmly proposed 14 similar reactors at Kaiga, Kumharia, Chutka, Bheempur, Banswada,  Rajouli and Nawada.

Regrettably, without verifying facts, even organisations such as the Kerala Sastra Sahitya Parishath,  which promotes science and technology  get carried away by disinformation campaigns. 

(The writer is a former secretary of the Atomic Energy Regulatory Board)

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