Simulation of cold leg manifold break and station blackout revised sequences for reduced ECCS (emergency core cooling system) in the N Reactor

Technical Report · Mon Feb 01 04:00:00 EST 1988

OSTI ID:6961153

Bolander, M A; Chapman, J C; Fletcher, C D

This report presents analyses of two loss-of-coolant-accident sequences of the N Reactor using the RELAPS/MOD2 computer code. RELAP5/MOD2 is a best estimate, two phase, nonhomogeneous, nonequilibrium, thermal-hydraulic, computer code designed for light water pressurized reactor transient. The N Reactor is a graphite- moderated, pressurized water reactor. The primary coolant is channeled through 1003 horizontal pressure tubes which contain two concentric tubular metallic fuel elements. The two accident sequences simulated were a double-ended guillotine break in the cold leg manifold and a station blackout. Both simulations cover the period beginning with the initiating event, either the break or the loss of ac power, to the stabilization of the core fuel element temperatures. (The station blackout calculation was carried out until the core was quenched.) The discussion presented in this report includes brief descriptions of the N Reactor, of the computer code and specific code modifications for horizontal reflood, and the computer code model used for the simulation. This discussion also presents the results and the analyses of the two calculations.

• Research Organization: EG and G Idaho, Inc., Idaho Falls (USA)
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 6961153
• Report Number(s): EGG-TFM-7962; ON: DE88015092
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
22 GENERAL STUDIES OF NUCLEAR REACTORS
220700 -- Nuclear Reactor Technology-- Plutonium & Isotope Production Reactors
220900* -- Nuclear Reactor Technology-- Reactor Safety
99 GENERAL AND MISCELLANEOUS
990220 -- Computers
Computerized Models
& Computer Programs-- (1987-1989)
ACCIDENTS
BLACKOUTS
COMPUTER CODES
COMPUTERIZED SIMULATION
ECCS
ENERGY TRANSFER
ENGINEERED SAFETY SYSTEMS
ENRICHED URANIUM REACTORS
FLUID MECHANICS
FUEL ELEMENTS
GRAPHITE MODERATED REACTORS
HEAT TRANSFER
HYDRAULICS
LOSS OF COOLANT
LWGR TYPE REACTORS
MECHANICS
N-REACTOR
PLUTONIUM PRODUCTION REACTORS
POWER REACTORS
PRODUCTION REACTORS
R CODES
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR PROTECTION SYSTEMS
REACTORS
SIMULATION
WATER COOLED REACTORS