Evaluation of fuel reactivity worth measurement in the prototype fast reactor Monju

高速増殖原型炉「もんじゅ」における燃料等価反応度の評価

大釜 和也   ; 竹越 淳*; 片桐 寛樹; 羽様 平 

Ohgama, Kazuya; Takegoshi, Atsushi*; Katagiri, Hiroki; Hazama, Taira

In the prototype fast breeder reactor Monju, fuel reactivity worth was measured at six positions as the reactivity corresponding to the differences of critical control rod positions between cores with and without a dummy fuel subassembly. In this paper, the measurements are evaluated in detail, and their reliability and usefulness as the validation data for fast reactor neutronics design methodologies are investigated through a comparison with calculations by using the latest methodology developed in Japan Atomic Energy Agency. Calculated-to-experiment values (C/Es) and their uncertainties of fuel reactivity worth were 0.97 to 1.02 and 4% to 6%. Through this study, the measurements and calculations were found consistent and reliable.