Deep underground measurements of 60Co in steel exposed to the Hiroshima atomic bomb explosion.
When using gamma-ray spectrometry performed deep underground, it is possible to measure 60Co activities down to 0.1 mBq in steel samples of some 100 g without any pre-concentration. It is thus still possible to measure 60Co induced by neutrons from the atomic bomb explosion in Hiroshima in pieces of steel collected at distances up to about 1200 m slant range. The results of non-destructive measurements of eight steel samples are compared with the 1986 Dose Re-Evaluation (DS86) model calculations.
Hult
Mikael
M
Institute for Reference Materials and Measurements, EC-JRC-IRMM, Retieseweg, Geel B-2440, Belgium.
Gasparro
Joël
J
Vasselli
Roberto
R
Shizuma
Kiyoshi
K
Hoshi
Masaharu
M
Arnold
Dirk
D
Neumaier
Stefan
S