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DOE nuclear cleanup costs, schedule delays continue to rise, GAO says
The Department of Energy’s Office of Environmental Management faces significant cost increases, schedule delays, and data management issues in completing nuclear waste cleanup projects, according to a new report from the U.S. Government Accountability Office.
S. Bian
Nuclear Technology | Volume 41 | Number 3 | December 1978 | Pages 401-407
Technical Note | Reactor | doi.org/10.13182/NT78-A32124
Articles are hosted by Taylor and Francis Online.
A rod ejection accident introduces a large positive reactivity insertion in a core, causing a large power excursion. The point kinetics method is usually used to analyze this type of accident. The reactivity changes due to Doppler effect are usually obtained by static neutronics calculations with nominal (pre-ejection) core flux shapes for different fuel temperatures. The effect of locally peaked shapes due to the rod ejection is not included in the Doppler reactivity calculation. The resultant Doppler reactivity feedback is considerably underestimated, while the magnitude of the power excursion is overestimated. A simplified method that incorporates the local flux peaking effect on the Doppler feedback in a point kinetics code has been developed. The results based on this weighted Doppler feedback compare favorably with a three-dimensional kinetics analysis.