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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.
Hiroki Takezawa, Toru Obara
Nuclear Science and Engineering | Volume 171 | Number 1 | May 2012 | Pages 1-12
Technical Paper | doi.org/10.13182/NSE09-59
Articles are hosted by Taylor and Francis Online.
This work aims to show the possibility of using the integral kinetic model, which is applicable to any geometry, for general space-dependent kinetic analysis. A space-dependent kinetic analysis methodology and code were developed based on the integral kinetic model. The developed kinetic analysis code was verified by comparing results from the developed code with the one-point model in the Godiva reactor geometry. It is possible to explain discrepancies between the two kinetic models using error introduced into Cij() in the fitting process of original Monte Carlo data Cij(kΔ). This is because the fitting error changes the mean generation time of a system. The verification concluded that it is important to always monitor the fitting error introduced to Cij() in order to understand the calculation results of the developed code. The space-dependent kinetic analysis code was also demonstrated in a fast-thermal coupled reactor geometry including feedback effects. The demonstration results showed a time difference in kinetic behaviors between a fast region and a thermal region that was theoretically expected to appear. In conclusion, this work shows a new approach to solving general space-dependent kinetic problems by using the integral kinetic model including feedback effects.
