Measured and calculated neutron albedo for concrete and iron

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

OSTI ID:7143250

Meyer, W; Leighty, J W; Thiesing, J W

Albedos were experimentally determined for a spectrum of fast fission neutrons incident on a 24- x 24- x 9-in. concrete slab and a 24- x 24- x 6-in. cold-rolled steel slab. The experimental dose albedos were compared with those from Oak Ridge National Laboratory (ORNL) 05R Monte Carlo calculations and with orders-of-scattering calculations performed using readily available multigroup cross sections. The source of fast neutrons for the experimental studies was the Kansas State University Triga Mark II reactor; the direct and reflected neutron spectra were detected using a 2- x 2-in. liquid-scintillation spectrometer system. A computer code has been developed to normalize the experimental reflected spectra to a reference direct neutron beam measurement, to calculate the experimental dose albedos, and to evaluate the Monte Carlo dose albedos in terms of the experimental conditions. A comparison of the Monte Carlo and experimental results showed similar trends and structure, but the experimental dose albedos were smaller than the calculated ones by an average of 70 to 80%. The large energy bin widths and inaccuracies in the cross sections (errors up to 65%) used in the Monte Carlo calculations have contributed to the differences between the calculated and experimental results. Orders-of-scattering calculations for steel were performed using the ORNL DLC-2B 99-group cross-sectionset and similar calculations were performed for concrete using the DLC-9/FARS group cross-section set. In general, the orders-of-scattering calculated reflected spectra compare well with the experimental fast-neutron reflection spectra. Discrepancies arise in the orders-of-scattering calculated results at particular energies and scattering angles due to deficiencies identified in the multigroup compilations.

• Research Organization: Kansas State Univ., Manhattan
• OSTI ID: 7143250
• Journal Information: Nucl. Sci. Eng.; (United States), Journal Name: Nucl. Sci. Eng.; (United States) Vol. 60:4; ISSN NSENA
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200* -- Nuclear Reactor Technology-- Components & Accessories
654002 -- Radiation & Shielding Physics-- Shielding Calculations & Experiments-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALBEDO
BARYONS
BUILDING MATERIALS
COMPARATIVE EVALUATIONS
CONCRETES
DATA
ELEMENTARY PARTICLES
ELEMENTS
FAST NEUTRONS
FERMIONS
HADRONS
INFORMATION
IRON
MATERIALS
METALS
NEUTRAL-PARTICLE TRANSPORT
NEUTRON TRANSPORT
NEUTRONS
NUCLEONS
POWER REACTORS
RADIATION TRANSPORT
REACTORS
REFLECTION
SHIELDING
SHIELDS
SLABS
TRANSITION ELEMENTS