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Division Spotlight
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
Meeting Spotlight
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
Standards Program
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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Latest News
Proving DRACO will deliver
The United States is now closer than it has been in over five decades to launching the first nuclear thermal rocket into space, thanks to DRACO—the Demonstration Rocket for Agile Cislunar Orbit.
Hyung Jin Shim, Chang Hyo Kim
Nuclear Science and Engineering | Volume 157 | Number 2 | October 2007 | Pages 132-141
Technical Paper | doi.org/10.13182/NSE06-33
Articles are hosted by Taylor and Francis Online.
Two new stopping criteria designed to terminate automatically inactive cycle runs in Monte Carlo (MC) neutronics eigenvalue calculations are derived in terms of the covariance matrix of stochastic error components inherent in the stationary fission source distribution (FSD) from each stationary MC cycle run. A practical way to determine the covariance matrix using nonstationary FSD in the course of inactive cycle MC runs is presented. The effectiveness of the new stopping criteria including the way to calculate the covariance matrix is examined through continuous energy MC neutronics calculations for ten pressurized water reactor test problems with varying dominance ratios. It is shown that the empiricism-free new stopping criteria stop inactive cycle MC runs effectively and that FSDs from the termination of inactive MC runs are stationary consistent with the available posterior source convergence diagnosis.