Use of the Crystal Diffraction Method to Study the Transmutation of Long-Lived Nuclides

It is shown that the 4-meter Cauchois crystal diffraction γ-spectrometer with a very high energy resolution have been used for in-pile control of fission nuclides in nuclear waste products transmutation. It is known that more than 90% of the waste activity after 10 years storage provides with two longlived 90 Sr and 137 Cs nuclides. Their transmutation (burning up in a high neutron flux) produces the 91 Sr and 138 Cs nuclides. Strong γ-transitions of 91 Sr and 138 Cs have been measured with our crystal diffraction