Benchmark Evaluation of HTR-PROTEUS Pebble Bed Experimental Program

• Published in: Nuclear science and engineering 2014-11, Vol.178 (3), p.387-400
• Main Authors: Bess, John D., Montierth, Leland M., Köberl, Oliver, Snoj, Luka
• Format: Article
• Language: English
• Subjects: Absorption cross sections; Benchmark; Benchmarking; Density; Impurities; IRPhEP; Mathematical models; MATHEMATICS AND COMPUTING; NUCLEAR FUEL CYCLE AND FUEL MATERIALS; NUCLEAR PHYSICS AND RADIATION PHYSICS; Pebble; Pebble bed; PROTEUS; Reactor physics; SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; TRISO; Uncertainty
• ISSN: 0029-5639; 1943-748X
• DOI: 10.13182/NSE14-13

Benchmark models were developed to evaluate 11 critical core configurations of the HTR-PROTEUS pebble bed experimental program. Various additional reactor physics measurements were carried out as part of this program; currently, only a total of 37 absorber rod worth measurements have been evaluated as acceptable benchmark experiments for cores 4, 9, and 10. Dominant uncertainties in the experimental K eff for all core configurations come from uncertainties in the 235 U enrichment of the fuel, impurities in the moderator pebbles, and the density and impurity content of the radial reflector. Calculations of K eff with MCNP5 and ENDF/B-VII.0 neutron nuclear data are greater than the benchmark values but are within 1% and also within the 3σ uncertainty, except for core 4, which is the only randomly packed pebble configuration. Repeated calculations of k eff with MCNP6.1 and ENDF/B-VII.1 are lower than the benchmark values but are within 1% (∽3σ), except for cores 5 and 9, which calculate lower than the benchmark eigenvalues by