TNAG-1503-FCO40-2061-Guangdong-nuclear-power-station-project-at-Daya-Bay-safety-c-1986 — Page 73

In 1969 the Soviet population protection criteria for use in a nuclear accident were published by the IAEA. Soviets are not in favour of developing preliminary standards for water, food etc within very narrow limits. They feel that these must be based on certain principles but details should depend on actual circumstances. Ilyin thought their criteria corresponded more or less with those used in other countries though with some specific differences.

From their previous consideration of maximum design accidents and maximum imaginable accidents the situation resulting from the Chernobyl accident was "not totally unexpected". However, the accident has emphasised the importance of skin dose in determining the prognosis of accident victims. Twenty percent of the victims had lost 80-90% of their skin area from beta and other radiation. However, there was no neutron irradiation involved. Professor Ilyin concluded by referring to the warmth of the enormous emotional response in the rest of the population engendered by the unfortunate victims.

Enviromental Monitoring

Professor Petrov gave a detailed account of the results of environmental monitoring in areas both close to and further away from the plant, from the time of the accident to the end of May.

The detailed information is in one of the Annexes to the report and will be available in the UK at the end of the Conference.

Two aeroplanes plus helicopters and vehicles were quickly deployed for monitoring activities over 20,000 sq kilometers. An enormous number of samples was taken of soil, waterways and air.

After the accident radiation levels of the accident plume reached dose rates of 1000 millirem per hour on 27 April and 500 mr per hour on 28 April at a distance of 5-10 km from the reactor site at a height of 200 metres. Aircraft measured a plume height of 1200 metres in north westerly directions at 30 km from the site of the reactor, though at that height the dose rate was only 1 millirem per hour.

Later calculations put the total activity release in European Russia at 50 megacuries.

Medical Aspects

Professor Kuskova gave a presentation on medical aspects. At the time of the accident there were 176 operational staff on site plus 268 workers on the construction sites and auxiliary work areas. 300 people were checked for radiation sickness in the first few days. 203 were found to be suffering from it.

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