Weapons-Grade Plutonium-Thorium PWR Assembly Design and Core Safety Analysis

Journal Article · Thu Jul 15 04:00:00 EDT 2004 · Nuclear Technology

DOI:https://doi.org/10.13182/NT147-69· OSTI ID:20837867

Dziadosz, David; Ake, Timothy N; Saglam, Mehmet; Sapyta, Joe J ^[1]

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1. Framatome ANP, Inc. (France)

A light water reactor (LWR) fuel assembly design consisting of a blend of weapons-grade plutonium and natural thorium oxides was examined. The design meets current thermal-hydraulic and safety criteria. Such an assembly would have enough reactivity to achieve three cycles of operation. The pin power distribution indicates a fairly level distribution across the assembly, avoiding hot spots near guide tubes, corners, and other sections where excessive power would create significant loss to thermal-hydraulic margins.This work examined a number of physics and core safety analysis parameters that impact the operation and safety of power reactors. Such parameters as moderator coefficients of reactivity, Doppler coefficients, soluble boron worth, control rod worth, prompt neutron lifetime, and delayed-neutron fractions were considered. These in turn were used to examine reactor behavior during a number of operational conditions, transients, and accidents. Such conditions as shutdown from power with one rod stuck out, steam-line break accident, feedwater line break, loss of coolant flow, locked rotor accidents, control rod ejection accidents, and anticipated transients without scram (ATWSs) were examined.The analysis of selected reactor transients demonstrated that it is feasible to license and safely operate a reactor fueled with plutonium-thorium blended fuel. In most cases analyzed, the thorium mixture had less-severe consequences than those for a core comprising low-enriched uranium fuel. In the analyzed cases where the consequences were more severe, they were still within acceptable limits. The ATWS accident condition requires more analysis.

• OSTI ID: 20837867
• Journal Information: Nuclear Technology, Journal Name: Nuclear Technology Journal Issue: 1 Vol. 147; ISSN 0029-5450; ISSN NUTYBB
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
ATWS
CONTROL ELEMENTS
CONTROL ROD WORTHS
DELAYED NEUTRON FRACTION
DESIGN
DOPPLER COEFFICIENT
FEEDWATER
FUEL ASSEMBLIES
PLUTONIUM
POWER DISTRIBUTION
PROMPT NEUTRONS
PWR TYPE REACTORS
REACTIVITY
SAFETY ANALYSIS
SLIGHTLY ENRICHED URANIUM
STEAM LINES
THERMAL HYDRAULICS
THORIUM
THORIUM OXIDES
WEAPONS