Gamma emitters in environment at radiation accident in NPP (experience from 1986)

Gamma-spectroscopic analysis has been made of environmental samples from post-Chernobyl contaminated regions of Bulgaria. The following technogenic radionuclides have been found: 54Mn, 55Fe, 59Fe, 58Co, 65Zn. 110mAg, 124Sb, 137Cs, 239Np, 241Am, and fission products 95Zr, 95Nb, 99Mo, 99mFe, 103Ru, 106Ru + 106Rh, 125Sb, 127Sb, 129mTe, 131mTe, 132Te, 131I, 132I, 136Cs, 137Cs + 137mBa, 140Ba, 140La, 141Ce, 144Ce. The registration of a given radionuclide depends on the count rate in its main gamma peak. The values of the parameter Seni(t) of the main gamma fission products are calculated by Ge(Li) detector (energy range 50-1800 KeV) for the period 1-60 days. In view of the accident conditions and physical nature of the samples it was possible to identify radionuclides with Seni(t) > 2.104 cps/W. Additionally it could be possible to detect also radionuclides with Seni(5) > 2.104 cps/W. In case of an accident of nearly situated reactor, comparable in size with Chernobyl's, radionuclides with Seni(1) > 2.10 3 cps/W could be detected. 1 tabs., 4 refs