Studies of the radionuclide content of fuel particles sampled from the chernobyl nuclear power plant’s No. 4 reactor unit

Spectroscopic studies are performed of the Lx, Kx, and Γ emanations from fuel particles sampled in 2011 inside the Chernobyl Nuclear Power Plant’s (ChNPP’s) No. 4 reactor unit. The isotope ratios for 134,135Cs, 154,155Eu, Pu isotopes, 241,243Am, and 243Cm are measured. The data on α emitters for all radionuclides above 241Am exhibit considerable inconsistency with the theoretically calculated values. A systematic deviation of the 90Sr and 137Cs ratios for the fuel component from the 1986 data is observed. Zirconium is shown to be the main radionuclide in the fuel particles.