DETECTION EFFICIENCY OF A TOTAL-ENERGY AB SORPTION PEAK FOR A GE DETECTOR IN WATER USING WATER TANK EXPERIMENT

Applicability of a Ge detector was studied for in situ measurements of gamma-ray emitting radionuclides in water. A Ge detector was lowered into a large tank filled with the air, tap water, seawater, and seawat er spiked with Cs-137 and Co-60 isotopes by turns to measure the gamma rays. The detection efficiency of the Ge detector in seawater was 0.0 30, 0.024 and 0.012cps/ (photon/s . l) for the 662keV(Cs-137), 1,332ke V(Co-60) and 1,462keV(K-40) gamma rays, respectively. The detection li mits were 0.28 and 0.22Bq/l for Cs-137, (CO)-C-60 in seawater, and 11B q/l for K-40 in tap water, respectively. It could be concluded that th e Ge detector could be used not only for monitoring systems around nuc lear facilities but also as an accidental release of radionucides from nuclear power plant such as the Chernobyl one.