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Title: Comparison of thermal neutron activation measurements and Monte Carlo calculations in light-water moderated uranium cells (LWBR Development Program)

Technical Report ·
OSTI ID:6720447

Thermal disadvantage factors and spectral indices have been measured in a variety of lattices. One series contained slightly enriched uranium rods in hexagonal geometry; another used natural uranium fuel in slab geometry. Both types employed water as the moderator. The detectors used were /sup 164/Dy, /sup 176/Lu, and /sup 239/Pu. Full energy range (0 to 10 MeV) Monte Carlo calculations with explicit cell geometry representations were performed using the RECAP program. In addition, thermal energy range (0 to 0.625 eV) calculations were obtained with the Monte Carlo program MARC as well as with the integral transport theory code THERMOS. The purpose of these investigations was to test the adequacy of the various water scattering kernel models--Nelkin, Koppel, and Haywood--for a broad range of thermal flux characteristics: from a soft moderator spectrum with a steep spatial gradient to a very hard spectrum which was relatively flat as a function of position. Conclusions are presented. (21 references). (NSA 24: 24886)

Research Organization:
Bettis Atomic Power Lab., Pittsburgh, PA (USA)
DOE Contract Number:
AT(11-1)-GEN-14
OSTI ID:
6720447
Report Number(s):
WAPD-TM-932
Country of Publication:
United States
Language:
English