TNAG-1503-FCO40-2061-Guangdong-nuclear-power-station-project-at-Daya-Bay-safety-c-1986 — Page 88

TAH

The importance was emphasised of rapidly setting up an emergency headquarters which had power to produce the main resources required quickly. Near the plant there were about a thousand people in protective clothing with all sorts of equipment, including concrete mixers (they found a lot of concrete was necessary to cover up surfaces).

The availability of medical resources had been vital. They had mobilised many doctors, some of whom travelled with the evacuees.

Finally, it was agreed that international initiatives were necessary to look at reference levels in safeguarding

livestock. The IAEA would be asked to organise discussions on this subject.

Session 3B, Working Group 4

Chairman D Beninson

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Discussion of the Radiological Consequences of the Accident.

Formation of plume, dispersion of aerosols and gases,

environmental effects, dose assessment (internal and external) for operational personnel and the public, acute health effects, late health effects.

1.

2.

3.

4.

5.

The discussion covered:

Estimating the magnitude, chronology and composition of the radioactive releases.

Modelling the subsequent behaviour of the activity firstly in the physical environment and then in the biological environment.

Comparing the theoretical estimates with actual measure-

ment.

Deriving and using the action levels of activity required for protecting the population.

Estimates of individual and collective doses.

The Russians have no local micro-meteorological data for the reactor site itself at the time of the accident. All their meteorological data came from the Met station in Kiev some 100 km distant. Neither was any data given on particle sizes of activity or deposition velocities.

The Soviet atmospheric modelling capability does not seem to be as developed as the West. The figure of 3% given by the Russians may refer to the fraction of the actual fuel itself released. It underestimates the release of the volatiles, especially iodine and caesium where the release may have been up to a factor 5 greater.

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