The Accident evaluation of JRR-3

Iguchi, Shintaro; Horiguchi, Hironori; Araki, Masaaki

The intervention level on the practical use by which the principle measurement which are the spatial radiation dose rate and the density of the radioactive materials in the environment sample, etc. as the standard by which implementation of protective measure is judged is expressed in the possible price (OIL) is established by the atomic disaster countermeasures guideline an atomic regulatory committee set. The dose evaluation when changing the fuel damaged percentage conservatively about over the design basic accident of JRR-3 and the reactor core way way blockade accident, was put into effect and OIL1 and OIL2 were compared with the implementation standard of the protective measure by this publication. Just after flow pass of a fuel element was blocked up, radioactive materials are damaged, and are released from fuel to a cooling system, and an evaluation phenomenon and a done reactor core way way blockade accident are the accident released from exhaust equipment for emergency use to ambient surroundings via a shift to a nuclear reactor pool and a building. It didn't operate with the case when exhaust equipment for emergency use normally operated by evaluation, and the occasion which did the ground release was assumed. The dose rate by the nuclide released in the atmosphere from a nuclear reactor building and the dose rate by the nuclide floating in the nuclear reactor building were estimated about dose evaluation. The evaluation point was made a distance 329m spot from JRR-3 to the atomic scientific research place site boundary. It was confirmed that there are also no dose rates beyond the initialization value of OIL1 in the result and just after accident. It was confirmed that the dose rate falls and falls below the initialization value of OIL2 after 6 time course rapidly after an accident.