Resource Type

Benchmark Critical Experiments on Low-Enriched Uranium Oxide Systems With H/U = 0. 77 (open access)

Benchmark Critical Experiments on Low-Enriched Uranium Oxide Systems With H/U = 0. 77

Ten benchmark experiments were performed at the Critical Mass Laboratory at Rockwell International'1s Rocky Flats Plant, Golden, Colorado, for the US Nuclear Regulatory Commission. They provide accurate criticality data for low-enriched damp uranium oxide (U/sub 3/O/sub 8/) systems. The core studied consisted of 152 mm cubical aluminum cans containing an average of 15,129 g of low-enriched (4.46% /sup 235/U) uranium oxide compacted to a density of 4.68 g/cm/sup 3/ and with an H/U atomic ratio of 0.77. One hundred twenty five (125) of these cans were arranged in an approx. 770 mm cubical array. Since the oxide alone cannot be made critical in an array of this size, an enriched (approx. 93% /sup 235/U) metal or solution driver was used to achieve criticality. Measurements are reported for systems having the least practical reflection and for systems reflected by approx. 254-mm-thick concrete or plastic. Under the three reflection conditions, the mass of the uranium metal driver ranged from 29.87 kg to 33.54 kg for an oxide core of 1864.6 kg. For an oxide core of 1824.9 kg, the weight of the high concentration (351.2 kg U/m/sup 3/) solution driver varied from 14.07 kg to 16.14 kg, and the weight of the …
Date: August 1, 1979
Creator: Tuck, G & Oh, I
System: The UNT Digital Library
Beta Particle Measurement and Dosimetry Requirements at NRC-Licensed Facilities (open access)

Beta Particle Measurement and Dosimetry Requirements at NRC-Licensed Facilities

Researchers from Pacific Northwest Laboratroy (PNL) have conducted beta radiation measurements under laboratory and field conditions to assess the degree of the measurement problem and offer suggestions for possible remedies. The primary measurement systems selected for use in this study were the silicon (Si) surface barrier spectrometer system and the multielement beta dosimeter. Three boiling water reactors (BWRs), two pressurized water reactors (PWRs), and one fuel fabrication facility were visited during the course of the study. Although beta fields from cobalt-60 were the most common type found at commercial reactor facilities, higher energy beta fields were found at locations associated with spent fuel handling, liquid radioactive waste, and BWR turbine components. Commercially-available dosimeters and survey instruments were used to measure the same laboratory and licensee facility beta fields characterized with PNL's active and passive spectrometers. A prototype spectrometer was also used in the laboratory measurements. The commercial instruments and dosimeters used in this study typically responded low to the beta fields measured, especially where maximum beta energies were less than approximately 500 keV.
Date: August 1, 1984
Creator: Rathbun, L. A.; Endres, G. W. R.; Fox, R. A.; Roberson, P. L. & Scherpelz, R. I.
System: The UNT Digital Library
Multiple time scale perturbation for two frequency nonlinear Taylor instability (open access)

Multiple time scale perturbation for two frequency nonlinear Taylor instability

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Date: August 1, 1974
Creator: White, G. N.
System: The UNT Digital Library