Integral experiments of technetium-99 using fast-neutron source reactor 'YAYOI'

The present study performed integral experiments of ⁹⁹Tc by an activation method using a fast-neutron source reactor 'YAYOI' of the University of Tokyo to validate evaluated nuclear data libraries: JENDL-4.0, ENDF/B-VII and VIII. Technetium-99 samples were irradiated with reactor neutrons using a pneumatic system, and repeated 74 times to accumulate statistics. Reaction rates of ⁹⁹Tc were obtained by measuring decay gamma rays emitted from ¹⁰⁰Tc. The fast-neutron flux spectrum at the YAYOI was checked with flux monitors and MCNP calculations. The experimental reaction rate of ⁹⁹Tc was compared with the reaction rates given using both the fast-neutron flux spectrum and evaluated nuclear data libraries. The present integral experiments supported the evaluated nuclear data library JENDL-4.0. (author)