Enhanced Ex-Vessel Analysis for Fukushima Daiichi Unit 1: Melt Spreading and Core-Concrete Interaction Analyses with MELTSPREAD & CORQUENCH

Technical Report · Fri Feb 01 04:00:00 EST 2013

DOI:https://doi.org/10.2172/1063828· OSTI ID:1063828

Robb, Kevin R. ^[1]; Farmer, Mitchell ^[2]; Francis, Matthew W. ^[1]

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1. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
2. Argonne National Laboratory (ANL), Argonne, IL (United States)

System-level code analyses by both United States and international researchers predict major core melting, bottom head failure, and corium-concrete interaction for Fukushima Daiichi Unit 1. Although system codes such as MELCOR and MAAP are capable of capturing a wide range of accident phenomena, they do not contain detailed models for evaluating ex-vessel core melt behavior. However, specialized codes containing more detailed modeling are available for melt spreading—such as MELTSPREAD—as well as long-term molten corium-concrete interaction (MCCI) and debris coolability—such as CORQUENCH. On this basis, the Office of Nuclear Energy within the U.S. Department of Energy (DOE-NE) funded an analysis to further evaluate the ex-vessel core debris location and extent of interaction for Unit 1 using modern modeling and simulation tools. The high-level objective was to utilize MELTSPREAD and CORQUENCH to provide rigorous “best estimate” predictions and analysis of ex-vessel core melt accident progression and final debris configuration. Argonne National Laboratory (ANL) performed the MELTSPREAD calculations, while Oak Ridge National Laboratory (ORNL) performed the CORQUENCH calculations.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1063828
• Report Number(s): ORNL/TM--2012/455
• Country of Publication: United States
• Language: English

Related Subjects

CORQUENCH
Corium
Fukushima
MELTSPREAD
Molten Core-Concrete Interaction
Severe Accident