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Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Can hydrogen be the transportation fuel in an otherwise nuclear economy?
Let’s face it: The global economy should be powered primarily by nuclear power. And it probably will by the end of this century, with a still-significant assist from renewables and hydro. Once nuclear systems are dominant, the costs come down to where gas is now; and when carbon emissions are reduced to a small portion of their present state, it will become obvious that most other sources are only good in niche settings. I mean, why use small modular reactors to load-follow when they can just produce that power instead of buffering it?
A. C. Morreale, D. R. Novog
Nuclear Science and Engineering | Volume 164 | Number 2 | February 2010 | Pages 151-161
Technical Paper | doi.org/10.13182/NSE08-16
Articles are hosted by Taylor and Francis Online.
The pursuit of more realistic models for nuclear power plant systems is becoming increasingly important and has led to an expansion in statistical uncertainty analysis coupled with the use of best-estimate predictions. Within these methodologies, derived acceptance criteria have been developed to ensure that the ultimate safety criteria are met with acceptably high levels of probability and confidence. The meeting of these derived criteria with a probability of 95% for a confidence interval of 95%, the 95/95 criteria, ensures consistency between analysis and instrumentation accuracy requirements set forth in ISA 67.04 standards. However, the application of these statistical methods to accidents requiring operator intervention, such as complete loss-of-feedwater events, has not previously been the topic of investigation. This paper applies the extreme value statistics (EVS) methodology to the steam generator-level transients predicted to result from a total loss-of-feedwater accident and compares the result to other uncertainty propagation methods and deterministic calculations. The transient was modeled using a full-circuit one-dimensional thermal-hydraulic code, and the epistemic and aleatory uncertainties inherent in the reactor are assessed. Based upon these results the available steam generator inventories at the time of trip were statistically determined, and subsequently, the available times for operator action were determined. Comparisons were made between the EVS methods and limiting deterministic analysis results for a standard CANDU 9 design as well as to other best-estimate and uncertainty-analysis techniques. Key uncertainties were identified based on phenomena identification and ranking tables and were confirmed through sensitivity studies. The requirement for operator-initiated actions for the EVS case was ˜46 min with 95% probability and 95% confidence from the time of annunciation, and this was 30 min longer than the limiting deterministic case.