Comparison of Discrete and Continuous Thermal Neutron Scattering Treatments in MCNP5

Conference · Fri Apr 15 04:00:00 EDT 2011

OSTI ID:1114444

Pavlou, Andrew T. ^[1]; Brown, Forrest B. ^[2]; Martin, William R. ^[1]; Kiedrowski, Brian C. ^[2]

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1. University of Michigan, Ann Arbor, MI (United States)
2. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

The advanced nuclear system will significantly advance the science and technology of nuclear energy systems and to enhance the spent fuel proliferation resistance. Minor actinides (MA) are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. MAs can play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. In this work, an Advanced CANDU Reactor (ACR) fuel unit lattice cell model with 43 UO₂ fuel rods will be used to investigate the effectiveness of a Minor Actinide Reduction Approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance. The main MARA objective is to increase the ²³⁸Pu / Pu isotope ratio by using the transuranic nuclides (²³⁷Np and ²⁴¹Am) in the high burnup fuel and thereby increase the proliferation resistance even for a very low fuel burnup. As a result, MARA is a very effective approach to enhance the proliferation resistance for the on power refueling ACR system nuclear fuel. The MA transmutation characteristics at different MA loadings were compared and their impact on neutronics criticality assessed. The concept of MARA significantly increases the ²³⁸Pu/Pu ratio for proliferation resistance, as well as serves as a burnable absorber to hold-down the initial excess reactivity. It is believed that MARA can play an important role in atoms for peace and the intermediate term of nuclear energy reconnaissance.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); University of Michigan, Ann Arbor, MI (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1114444
• Report Number(s): LA-UR--11-06160; LA-UR--11-6160
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
97 MATHEMATICS AND COMPUTING
ACR
CANDU
Fuel Cycle
Minor Actinide
Nuclear Criticality Safety Program (NCSP)
Plutonium
Proliferation Resistance