Monte Carlo Calculations for Recriticality During the Reflood Phase of a Severe Accident in a BWR

Conference · Sun Jun 02 00:00:00 EDT 1991 · Transactions of the American Nuclear Society

OSTI ID:5854580

Monte Carlo calculations were performed to assess the possibility of recriticality during the core relocation phase of a severe accident in boiling water reactors (BWRs). The MCNP Monte Carlo code was chosen both because of its inherent accuracy for such calculations and because many continuous-energy isotopic cross-section libraries based on ENDF/B-V were already available for it. These results suggest that a BWR core may be able to remain subcritical during reflood even when a large fraction of the control rod has been lost. In fact, it appears as if the core might remain subcritical even if 60 or 70% of the boron content of the affected control rods were lost. However, additional calculations at those conditions would be required to determine a realistic estimate of the amount of boron that could be lost without producing criticality.

• Research Organization: Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• OSTI ID: 5854580
• Report Number(s): CONF-910603-; CODEN: TANSA
• Journal Information: Transactions of the American Nuclear Society, Vol. 63; Conference: Annual Meeting of the American Nuclear Society (ANS), Orlando, FL (United States), 2-6 Jun 1991; ISSN 0003-018X
• Publisher: American Nuclear Society
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
97 MATHEMATICS AND COMPUTING
BWR TYPE REACTORS
REACTOR CORE DISRUPTION
CORIUM
CRITICALITY
REACTOR KINETICS
ACCURACY
CONTROL ELEMENTS
CROSS SECTIONS
DAMAGE
FISSION PRODUCTS
HEAT TRANSFER
HYDRAULICS
MELTING
MONTE CARLO METHOD
NUCLEAR DATA COLLECTIONS
REACTOR ACCIDENTS
REACTOR SAFETY
ACCIDENTS
ENERGY TRANSFER
ENRICHED URANIUM REACTORS
FLUID MECHANICS
ISOTOPES
KINETICS
MATERIALS
MECHANICS
PHASE TRANSFORMATIONS
POWER REACTORS
RADIOACTIVE MATERIALS
REACTOR COMPONENTS
REACTORS
SAFETY
THERMAL REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS
Nuclear Criticality Safety Program (NCSP)
Monte Carlo Calculations
Recriticality
Boiling Water Reactors (BWRs)
ENDF/B-V
220900* - Nuclear Reactor Technology- Reactor Safety
210100 - Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled