Assessment of accident energetics in LMFBR core-disruptive accidents

Abstract

Dlimil kr «M IMM (MM Ctm-inl Mi Mill jfc» IMM 1MW« mr am MM »W iMqy Wijhuil, MC M« *T IMi wwitcwi.

Numerical Analysis on the Reactor Core Expansion and Energy Behaviors During Cda Using Underwater Explosion Theory

“…본 해석에서는 노심폭주사고로 발생 시 원자로 출력의 급 격한 증가로 인해 정상상태 시 고체 상태였던 노심은 순식간 에 기체상태로 변하고, 충격파 방출과 동시에 급격히 팽창하 는 폭발이 발생한다고 가정하였다 [1,5,6,7,8]. 팽창 과정 중 노 심의 온도, 압력, 내부에너지는 감소하고, 감소한 에너지는 냉 각재의 운동에너지로 변환되어 원자로 용기에 응력을 가한다.…”

Assessment of the thermal-hydraulic technology of the transition phase of a core-disruptive accident in a LMFBR

“…In the absence of detailed mechanistic models, it has been assumed (Fauske, 1977b;Ostensen, 1976) that the oxide fuel-steel system will act as a saturated, homogeneous mixture of heat source (molten fuel) and vapor source (boiling steel), subject to volumetrically distributed heating. Predictions of the extent of fuel dispersal have been based upon flow regime transition criteria and associated vapor-liquid void dynamics models.…”

“…The independent phenomenological models, however, were pieced together to provide plausibility arguments pertaining to the sequence of transition phase events leading to accident termination. Subsequent analyses, related to the CRBR, relied heavily on fundamental "behavior principles" (Fauske, 1977b) which were to be verified experimentally. Basic heat transfer and multiphase flow principles were applied to transition phase safety issues, generally with little detailed mechanistic analysis and, again, supported by only limited experimental evidence.…”

SACO-1: a fast-running LMFBR accident-analysis code

“…, ~'t ) , (16) an approximation of which is derived later in this section, and the function y'(z, t)(pcpA)F+ (pcpA) y(z,t) '=AFc+cI, (17) (P cpA)i whe re (p cpA)pi (P cpA)c+cl + (p cpA) 1 F (18) we can rewrite Eq. 15 as y(z, t)(pcpA).Tc(z, t) = P(z, t) -cpW(t)c( t)…”