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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
Mathieu Hursin, Thomas J. Downar, Brendan Kochunas
Nuclear Science and Engineering | Volume 170 | Number 2 | February 2012 | Pages 151-167
Technical Paper | doi.org/10.13182/NSE10-75
Articles are hosted by Taylor and Francis Online.
The current state of the art in the analysis of a control rod ejection event in a pressurized water reactor (PWR) relies on homogenization methods in which the assembly-averaged power from a whole-core nodal neutronics simulator is used with some type of flux reconstruction to estimate the individual fuel rod power. Recently, there has been interest in taking advantage of methods that do not require homogenization, such as the DeCART code, to perform time-dependent neutron transport calculations. These calculations could provide not only more accurate pin power results but also intrapin power information during the transient. The work described in this paper is the analysis of a PWR control rod ejection transient using the nodal core simulator PARCS, which employs homogenization methods, and the method of characteristics (MOC) code DeCART, which treats the explicit geometry. Higher-fidelity methods such as those used by DeCART have the potential to quantify the homogenization and modeling errors inherent in the lower-order methods. The methods used in PARCS and DeCART are briefly described as well as the approach to generate the temperature feedback for the rod ejection event. The results are compared and discussed. For the considered transient scenario, PARCS and DeCART are in generally good agreement for the predicted global and local powers as well as for the temperature.
