Reaction rates in a uranium pile surrounding a 14-MeV neutron source: calculations of the Weale experiment

Journal Article · Wed Sep 01 04:00:00 EDT 1976 · Nucl. Sci. Eng.; (United States)

OSTI ID:7247701

Haight, R C; Lee, J D; Maniscalco, J A

To validate the neutronics analysis of hybrid fusion-fission reactor blankets, calculations were made of an experiment by Weale et al., where a 14-MeV neutron source was surrounded by a natural uranium metal pile. The evaluated nuclear data libraries, ENDL and ENDF/B, were used. The calculated parameters were found to be in closer agreement for present versions of these libraries than for preceding versions; however, there were still 15 percent differences in the /sup 235/U(n,f) and /sup 238/U(n,f) reaction rates. The present version of ENDL gives the results that are the closest to the experimental values for these reactions. For the /sup 238/U(n,..gamma..) reaction, the calculations with the ENDF/B libraries are closer to the measured values. Both the ENDL and ENDF/B evaluations, however, fail to calculate correctly the neutron leakage or derived values for the /sup 238/U(n,2n) and /sup 238/U(n,3n) reaction rates. The spatial variations of the /sup 235/U(n,f), /sup 238/U(n,..gamma..), /sup 238/U(n,f), and /sup 239/Pu(n,f) reaction rates show that the penetration of high-energy neutrons in the pile is better described by the calculation with ENDL, which gives a greater penetration. The effects of resonance self-shielding were investigated and found to require a much smaller correction than the differences between calculations with different data libraries.

• Research Organization: Univ. of California, Livermore
• OSTI ID: 7247701
• Journal Information: Nucl. Sci. Eng.; (United States), Journal Name: Nucl. Sci. Eng.; (United States) Vol. 61:1; ISSN NSENA
• Country of Publication: United States
• Language: English

Related Subjects

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
BARYON REACTIONS
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CAPTURE
DAYS LIVING RADIOISOTOPES
DIRECT REACTIONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FERMIONS
FISSION
GAMMA RADIATION
HADRON REACTIONS
HADRONS
HEAVY NUCLEI
IONIZING RADIATIONS
ISOTOPES
KNOCK-OUT REACTIONS
MINUTES LIVING RADIOISOTOPES
NEUTRON REACTIONS
NEUTRONS
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
NUCLEONS
RADIATIONS
RADIOISOTOPES
TARGETS
URANIUM 235 TARGET
URANIUM 236
URANIUM 237
URANIUM 238 TARGET
URANIUM 239
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES