Power profile evaluation of the JCO precipitation vessel based on the record of the -ray monitor

Tonoike, Kotaro; Nakamura, Takemi*; Yamane, Yuichi; Miyoshi, Yoshinori

Nuclear Technology, 143(3), p.364 - 372, 2003/09

https://doi.org/10.13182/NT03-A3424

no abstracts in English

Evaluation of dose equivalent rate distribution in JCO critical accident by radiation transport calculation

Sakamoto, Yukio

JAERI-Research 2002-025, 34 Pages, 2002/11

JAERI-Research-2002-025.pdf:1.91MB

no abstracts in English

Summary of the JCO criticality accident in Tokai-mura and a dose assessment

Tanaka, Shunichi

Journal of Radiation Research, 42(Suppl.), p.S1 - S9, 2002/00

A criticality accident occured on September 30,1999, in a conversion facity at the JCO tokai site. The accident continued for about 19 hours before the criticality could be stopped, during which time neutrons and gamma-rays were emitted continuously due to fission reactions. The total number of fission reactions was 2.5x10. The accident gave radiation dose to 3 employees and fatal dose to 2 of them. The individual dose was estimated for 234 resident, 169 JCO employees and 260 emergency personnel, of which the maximum dose was 48 mSv.

Experience of the JCO criticality accident

Tonoike, Kotaro

no journal, , 

The JCO criticality accident occurred in the morning of September 30, 1999, where the critical condition continues for 19.5 hours and the total fission number reached 2.510. This was the first criticality accident in Japan that resulted in two fatalities due to their severe exposures to radiation. During the accident, the assessment and prognosis on the criticality of nuclear material was relatively easy. The planning and implementation of the public evacuation was, however, difficult. This presentation summarizes judgements and their processes in the day on those issues.