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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.
Albert E. Evans, M. S. Krick
Nuclear Science and Engineering | Volume 62 | Number 4 | April 1977 | Pages 652-659
Technical Paper | doi.org/10.13182/NSE77-A15208
Articles are hosted by Taylor and Francis Online.
A 3He neutron spectrometer has been used to measure the energy spectra of delayed neutrons in equilibrium with fission induced by sub-MeV neutrons incident upon 235U, 238U, and 239Pu. Full contribution of shorter lived delayed neutron groups not previously measured was ensured by bombarding samples for 35 out of every 100 ms and measuring delayed neutrons for 40 ms between each bombarding pulse. Results show delayed neutron spectra of somewhat higher average energy than have previously been reported. Examination of the energy end points of delayed neutron emitters as a function of precursor half-life shows that the higher average delayed neutron energies are probably due to the inclusion of neutrons from the shorter lived precursors.