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NRC proposes changes to its rules on nuclear materials
In response to Executive Order 14300, “Ordering the Reform of the Nuclear Regulatory Commission,” the NRC is proposing sweeping changes to its rules governing the use of nuclear materials that are widely used in industry, medicine, and research. The changes would amend NRC regulations for the licensing of nuclear byproduct material, some source material, and some special nuclear material.
As published in the May 18 Federal Register, the NRC is seeking public comment on this proposed rule and draft interim guidance until July 2.
G. T. Chapman, W. R. Burrus
Nuclear Science and Engineering | Volume 34 | Number 2 | November 1968 | Pages 169-180
Technical Paper | doi.org/10.13182/NSE68-A19542
Articles are hosted by Taylor and Francis Online.
Measurements of the pulse-height distribution of gamma rays observed as a function of position and angle in the water shield of the Bulk Shielding Reactor II, a water-moderated and water-cooled pool-type reactor with stainless steel clad fuel plates, have been transformed to gamma-ray energy flux spectra by a computer program which removed the effects of the spectrometer's nonunique pulse-height response and accounted for the energy variation of the spectrometer's efficiency. The results show that the photons above 5 MeV originate primarily from thermal-neutron capture in the components of the stainless steel. Gamma rays due to the 57Fe component were identified as those known to be at 5.91, 6.02, and 7.6 MeV. Others were due to 58Fe at 10.16 MeV, to 54Cr at 8.88 and 9.72 MeV, and to 59Ni at 8.53 and 8.99 MeV. Below 5 MeV the spectra consist of a strong contribution at 2.2 MeV from thermal-neutron capture in the hydrogen of the pool water, combined with a continuum presumably composed of prompt and delayed gamma rays following fission, lower energy components in the capture spectra from the stainless steel, scattering in the reactor or shield, and other lesser sources.