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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
Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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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Nuclear Science and Engineering
August 2024
Nuclear Technology
Fusion Science and Technology
Latest News
ARPA-E announces $40 million to develop transmutation technologies for UNF
The Department of Energy’s Advanced Research Projects Agency–Energy (ARPA-E) announced $40 million in funding to develop cutting-edge technologies to enable the transmutation of used nuclear fuel into less-radioactive substances. According to ARPA-E, the new initiative addresses one of the agency’s core goals as outlined by Congress: to provide transformative solutions to improve the management, cleanup, and disposal of radioactive waste and spent nuclear fuel.
Liujun Pan, Ruihong Wang, Song Jiang
Nuclear Science and Engineering | Volume 180 | Number 2 | June 2015 | Pages 199-208
Technical Paper | doi.org/10.13182/NSE14-73
Articles are hosted by Taylor and Francis Online.
We propose a modified method to improve the stability of the Monte Carlo fission matrix acceleration (FM) method. In the existing FM method, the weights of fission neutrons are adjusted by the fundamental-mode eigenvector of the fission matrix, which can be calculated by power iteration (PI). In this paper, the PI procedure to calculate the fundamental-mode eigenvector of the fission matrix in each cycle is called the inner iteration to distinguish it from the Monte Carlo iteration cycles. In our proposed method, the fission source distribution tallied during the Monte Carlo simulation is taken as the initial vector for the inner iteration. The weights of the fission neutrons are not adjusted by the fundamental-mode eigenvector of the fission matrix but by the vector obtained with only a few inner iteration steps. We call the proposed method the Monte Carlo fission matrix acceleration method with limited inner iteration (FM_lii). The FM_lii method possesses the following properties: It is more stable than the existing fission matrix acceleration method, and it preserves considerable acceleration efficiency. Moreover, we analyze the stability property of the proposed method for the case of two weakly coupled fissile arrays. A number of numerical tests for practical large-scale, loosely coupled systems are presented that demonstrate the theoretical analysis and efficiency of our scheme.