Analysis of long-term station blackout at Peach Bottom using MELCOR

Conference · Mon Jan 01 04:00:00 EST 1990 · Transactions of the American Nuclear Society; (United States)

OSTI ID:7089057

Madni, I K ^[1]

---

1. Brookhaven National Lab., Upton, NY (United States)

MELCOR is a fully integrated computer code that models all phases of the progression of severe accidents in nuclear power plants. It is being developed for the US Nuclear Regulatory Commission (NRC) by Sandia National Laboratories and is designed to provide an improved severe-accident/source term analysis capability relative to the older source term code package (STCP). Brookhaven National Laboratory has a program with the NRC to verify and apply the MELCOR code to severe-accident analysis for several plants. This paper presents the results from a MELCOR calculation of a long-term station blackout accident sequence with failure to depressurize the reactor vessel. Peach Bottom, a boiling water reactor with Mark I containment, was used in the analysis. The paper also compared MELCOR predictions with STCP calculations for the same sequence. This sequence assumes that batteries are available for 6 h following loss of all power to the plant. Station blackout sequences have often been determined to be important contributors to the risk from severe accidents. Following battery failure, the reactor coolant system (RCS) inventory is boiled off through the relief valves by continued decay heat generation. This leads to core uncovery, heat-up, clad oxidation, core degradation, relocation, and, eventually, vessel failure at high pressure. The STCP has calculated the transient up to 13.5 h after core uncovery. MELCOR calculations have been carried out to 16.7 after core uncovery. The results include the release of source terms to the environment.

• OSTI ID: 7089057
• Report Number(s): CONF-901101--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 62
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210100 -- Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled
22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
ACCIDENTS
AFTER-HEAT REMOVAL
ALKALI METALS
ALKALINE EARTH METALS
ALLOYS
BARIUM
BLACKOUTS
BNL
BWR TYPE REACTORS
CERIUM
CESIUM
CHEMICAL REACTIONS
COMPUTER CODES
COMPUTERIZED SIMULATION
CONTAINERS
CONTAINMENT
CONTAINMENT SYSTEMS
CONTROL EQUIPMENT
CORIUM
DEPOSITION
DEPRESSURIZATION
ELECTRIC BATTERIES
ELECTROCHEMICAL CELLS
ELEMENTS
ENGINEERED SAFETY SYSTEMS
ENRICHED URANIUM REACTORS
EQUIPMENT
ERRORS
FISSION PRODUCT RELEASE
FLOW REGULATORS
FUEL CANS
HALOGENS
IODINE
LANTHANUM
LOSS OF COOLANT
M CODES
MELTDOWN
METALS
NATIONAL ORGANIZATIONS
NONMETALS
OXIDATION
PEACH BOTTOM-2 REACTOR
PEACH BOTTOM-3 REACTOR
POWER REACTORS
PRESSURE VESSELS
RADIOACTIVITY TRANSPORT
RARE EARTHS
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR CORE DISRUPTION
REACTOR CORES
REACTOR SAFETY
REACTORS
RELIEF VALVES
REMOVAL
RUBIDIUM
S CODES
SAFETY
SANDIA LABORATORIES
SEMIMETALS
SIMULATION
SOURCE TERMS
STRONTIUM
TELLURIUM
THERMAL REACTORS
TIME DEPENDENCE
US AEC
US DOE
US ERDA
US NRC
US ORGANIZATIONS
VALVES
VERIFICATION
WATER COOLED REACTORS
WATER MODERATED REACTORS
ZIRCALOY
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS