Experimental studies on the upward fuel discharge for elimination of severe recriticality during core-disruptive accidents in sodium-cooled fast reactors

ナトリウム冷却型高速炉の炉心崩壊事故時における厳しい再臨界の排除のための溶融燃料上方向流出に関する実験研究

神山 健司  ; 小西 賢介 ; 佐藤 一憲 ; 豊岡 淳一  ; 松場 賢一  ; Zuyev, V. A.*; Pakhnits, A. V.*; Vityuk, V. A.*; Vurim, A. D.*; Gaidaichuk, V. A.*; Kolodeshnikov, A. A.*; Vassiliev, Y. S.*

Kamiyama, Kenji; Konishi, Kensuke; Sato, Ikken; Toyooka, Junichi; Matsuba, Kenichi; Zuyev, V. A.*; Pakhnits, A. V.*; Vityuk, V. A.*; Vurim, A. D.*; Gaidaichuk, V. A.*; Kolodeshnikov, A. A.*; Vassiliev, Y. S.*

Recently, a design option which leads molten fuel to upward discharge has been considered to minimize technical difficulties for practical application to JSFR. In the present study, a series of experiments which consisted of three out-of-pile tests and one in-pile test were conducted to investigate effectiveness of the upward discharge option on eliminating energetics potential. Experimental data which showed a sequence of upward fuel-discharge and effects of initial pressure conditions on upward-discharge were obtained through the out-of-pile and in-pile test. Preliminary extrapolation of the present results to the supposed condition in early phase of the CDA in the JSFR design, suggested that sufficient upward flow rate of molten-fuel was expected to prevent the core-melting from progressing beyond the fuel subassembly scale and that the upward discharge option would be effective in eliminating the energetic potential.