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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.
Jun Yang, Michael Scott Greenwood, Matthew De Angelis, Michael Avery, Mark Anderson, Michael Corradini, James Matos, Floyd Dunn, Earl Feldman
Nuclear Science and Engineering | Volume 180 | Number 2 | June 2015 | Pages 141-153
Technical Paper | doi.org/10.13182/NSE14-45
Articles are hosted by Taylor and Francis Online.
A critical heat flux (CHF) experimental study at low pressure and natural convection condition has been conducted. The test apparatus is a natural circulation loop with an upward flow channel, simulating TRIGA (Training, Research, Isotopes, General Atomics) reactors. CHF is studied in three types of geometries: a single-rod annulus, a three-rod bundle in a trefoil tube, and a four-rod bundle in a square tube. The full-scale fuel pin heater rod is electrically heated with a prototypic axial power profile, equipped with thermocouples for CHF detection. Experiments are carried out at the following conditions: inlet subcooling from 10 to 70 K, pressure from 110 to 290 kPa, and mass flux from 0 to 400 kg/m2·s. It is observed that CHF increases as the pressure or mass flux increases but does not significantly depend on the inlet subcooling within the testing range. The current CHF data are compared with a few selected CHF correlations whose application ranges are close to the testing conditions. The relevance of the CHF to the testing parameters is investigated. A modified CHF correlation compatible with TRIGA reactor conditions is proposed based on a previous correlation and current experimental data.