LOFC fission product release and circulating activity calculations for gas-cooled reactors

Conference · Sat Jan 01 04:00:00 EST 1977

OSTI ID:7096067

Apperson, Jr, C E; Carruthers, L M; Lee, C E

The inventories of fission products in a gas-cooled reactor under accident and normal steady state conditions are time and temperature dependent. To obtain a reasonable estimate of these inventories it is necessary to consider fuel failure, a temperature dependent variable, and radioactive decay, a time dependent variable. Using arbitrary radioactive decay chains and published fuel failure models for the High Temperature Gas-Cooled Reactor (HTGR), methods have been developed to evaluate the release of fission products during the Loss of Forced Circulation (LOFC) accident and the circulating and plateout fission product inventories during steady state non-accident operation. The LARC-2 model presented here neglects the time delays in the release from the HTGR due to diffusion of fission products from particles in the fuel rod through the graphite matrix. It also neglects the adsorption and evaporation process of metallics at the fuel rod-graphite and graphite-coolant hole interfaces. Any time delay due to the finite time of transport of fission products by convection through the coolant to the outside of the prestressed concrete reactor vessel (PCRV) is also neglected. This model assumes that all fission products released from fuel particles are immediately deposited outside the PCRV with no time delay.

• Research Organization: Los Alamos Scientific Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 7096067
• Report Number(s): LA-UR-77-1569; CONF-770708-10
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210300* -- Power Reactors
Nonbreeding
Graphite Moderated
ACCIDENTS
FISSION PRODUCT RELEASE
GAS COOLED REACTORS
GRAPHITE MODERATED REACTORS
HTGR TYPE REACTORS
LOSS OF FLOW
MATHEMATICAL MODELS
REACTOR ACCIDENTS
REACTORS