The HEVA Experimental Program

Lessons learnt from VERCORS tests.

“…In order to attain these objectives, specific technical facilities, set up in shielded hot cells at the CEA-Grenoble, have been developed around the so-called ÔHEVA-VERCORSÕ program [3,4]. Financed by IRSN in association with EdF, it is more specifically devoted to the source term of FPs released from PWR fuel samples during conditions representative of severe accidents, up to loss of fuel integrity.…”

“…The first step of this program [3] (HEVA-01 to HEVA-08 experiments) was carried out between 1983 and 1989 on standard PWR samples at temperature up to 2300 K in a steam and hydrogen environment. The first two tests were performed to demonstrate the feasibility of the experiments, and the six subsequent ones were carried out following the definition of the operating parameters based on the results of calculations of the most likely accident sequence.…”

Background and Derivation of ANS-5.4 Standard Fission Product Release Model

“…Lewis et al 14 estimated the tellurium diffusion coefficient to be a factor of 4 greater than the noble gases based on trace irradiations 15 and release from a failed fuel experiment in a hydrogen/steam atmosphere. 16 The diffusion coefficient form was one proposed by Turnbull et al 10 as the sum of three components: …”

Overview of experimental programs on core melt progression and fission product release behaviour

“…Numerous in-pile and out-of-pile experiments [28][29][30][31][32][33][34][35][36][37][38][39] have been conducted to better understand light water reactor (LWR) severe accident progression following the accident at the Three Mile Island Unit 2 (TMI-2) nuclear power plant. These experiments have principally focused on high temperature core melt progression and fission product release behaviour.…”