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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.
S. Prasad, S. D. Clarke, S. A. Pozzi, E. W. Larsen
Nuclear Science and Engineering | Volume 172 | Number 1 | September 2012 | Pages 78-86
Technical Paper | doi.org/10.13182/NSE11-60
Articles are hosted by Taylor and Francis Online.
A response matrix method (RMM) is applied to Monte Carlo simulations to efficiently compute neutron pulse height distributions (PHDs) in organic scintillation detectors. The PHD calculations and their associated uncertainty are compared for a polyethylene-shielded and lead-shielded 252Cf source for three different techniques: fully analog MCNPX-PoliMi, the RMM, and the RMM with source biasing. The RMM with source biasing reduces computation time or improves the figure of merit on average by a factor of 600 for polyethylene shielding and a factor of 300 for lead shielding (when compared to the fully analog calculation). The simulated neutron PHDs show good agreement with the laboratory measurements, thereby validating the RMM.