Decay Heat Measurement of Actinides at YAYOI

Actinides decay heat was measured for fast neutron fissions in the fast neutron source reactor “YAYOI” of the University of Tokyo. Measured nuclides were U-235 and Np-237, using beta and gamma spectroscopic method. The latest results on beta-ray and gamma-ray decay heat are reviewed in this paper. Measurement results were compared with those measured for U-235 in 1983 by Akiyama using the same method, as well as with the summation calculation results using JNDC-V2, ENDF-B/VI and JEF-2.2.