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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.
Man Gyun Na, Dong Won Jung, Sun Mi Lee
Nuclear Science and Engineering | Volume 148 | Number 1 | September 2004 | Pages 153-161
Technical Paper | doi.org/10.13182/NSE04-A2447
Articles are hosted by Taylor and Francis Online.
A receding horizon control method is used to solve on-line, at each time step, an optimization problem for a finite future interval and to implement the first optimal control input as the current control input. The receding horizon control method is combined with a parameter estimator to overcome the problems of the linear modeling and time-varying characteristics of a process. It is a suitable control strategy for time-varying systems, in particular, because the parameter estimator identifies a controller design model recursively at each time step, and also the receding horizon controller recalculates an optimal input at each time step by using newly measured signals. The proposed controller is applied to the axial power distribution control in a pressurized water reactor. The reactor dynamics model used for computer simulations is a two-point xenon oscillation model in which the reactor core is axially divided into two regions (upper and lower halves) and each region is assumed to have a single input and a single output and to be coupled with the other region. It is shown from numerical simulations that the proposed controller exhibits very fast tracking responses due to the step and ramp changes of axial target shape and also works well in a time-varying parameter condition.