Japan's experimental fast reactor JOYO MK-I core; Sodium-cooled uranium-plutonium mixed oxide fueled fast core surrounded by UO blanket

Yokoyama, Kenji   ; Shono, Akira*

Under the framework of the International Reactor Physic Experimental Evaluation Project (IRPhEP) organized by OECD/NEA, eight types of nuclear characteristics parameters, criticality, control rod worth, sodium void reactivity, fuel replacement reactivity, isothermal temperature coefficient and burnup reactivity coefficients, measured in the experimental fast reactor JOYO MK-I core were evaluated. In the present evaluation, not only nominal values but also uncertainties of experiments and analytical models were fully re-investigated according to the evaluation policy of the IRPhEP. In addition, each evaluation provides a reactor physics benchmark problem, which are expected to utilize for validating analytical models and nuclear data.