Use of Thorium for Transmutation of Plutonium and Minor Actinides in PWRs

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

OSTI ID:20837866

Shwageraus, Eugene; Hejzlar, Pavel; Kazimi, Mujid S ^[1]

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1. Massachusetts Institute of Technology (United States)

An assessment is made of the potential for Th-based fuel to minimize Pu and minor actinide (MA) production in pressurized water reactors (PWRs). Destruction rates and residual amounts of Pu and MA in the fuel used for transmutation are examined. In particular, sensitivity of these two parameters to the fuel lattice hydrogen to heavy metal (H/HM) ratio and to the fuel composition was systematically investigated. All burnup calculations were performed using CASMO4, the fuel assembly burnup code. The results indicate that up to 1000 kg of reactor-grade Pu can be burned in Th-based fuel assemblies per gigawatt (electric) year. Up to 75% of initial Pu can be destroyed per passage through reactor core. Addition of MA to the fuel mixture degrades the burning efficiency. The theoretically achievable limit for total transuranium (TRU) destruction per passage through the core is 50%. Efficient MA and Pu destruction in Th-based fuel generally requires a higher degree of neutron moderation and, therefore, higher fuel lattice H/HM ratio than typically used in the current generation of PWRs. Reactivity coefficients evaluation demonstrated the feasibility of designing a Th-Pu-MA fueled core with negative Doppler and moderator temperature coefficients. Introduction of TRU-containing fuels to a PWR core inevitably leads to lower control material worths and smaller delayed-neutron yields than with conventional UO{sub 2} cores. Therefore, a major challenge associated with the introduction of Th-TRU fuels to PWRs will be the design of the whole core and reactor control features to ensure safe reactor operation.

• OSTI ID: 20837866
• 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
BURNUP
CONTROL
DELAYED NEUTRONS
DESIGN
FUEL ASSEMBLIES
HEAVY METALS
MIXTURES
NUCLEAR FUELS
PLUTONIUM
PWR TYPE REACTORS
REACTOR CORES
REACTOR OPERATION
TEMPERATURE COEFFICIENT
THORIUM
TRANSMUTATION
URANIUM DIOXIDE