Survey of MELCOR assessment

MELCOR is a fully integrated, engineering-level computer code that models the progression of severe accidents in light water reactor nuclear power plants and is being developed at Sandia National Laboratories for the USNRC and the USDOE. The entire spectrum of severe accident phenomena, including reactor coolant system and containment thermal/hydraulic response, core heatup, degradation and relocation, and fission product release and transport, is treated in MELCOR in a unified framework for both BWRs and PWRS. MELCOR was the first of the severe accident analysis codes to undergo a formal review process, and one of the major conclusions of the MELCOR Peer Review was the need for a more comprehensive and more systematic program of MELCOR assessment. Since then, a number of assessment analyses have been completed and more assessment calculations axe under way. This paper presents a review of MELCOR verification, validation and assessment to date.