While the criticality was continuing at the uranium conversion building of
the JCO Company Limited, Tokai, Japan on September 30, 1999, the gamma dose
rate was measured by carborne GM survey meters. The maximum dose rate alon
g Route 6, 20.8 mu Sv/h, was observed at a distance of 280 m from the sourc
e at 16:45 on September 30, 1999. Along Prefectural road 62, the maximum do
se rate, 510 mu Sv/h, was recorded at a distance of 70 m from the source at
about 30:00 on September 30, 1999. (C) 2000 Published by Elsevier Science
Ltd. All rights reserved.