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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 Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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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September 2024
Nuclear Technology
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August 2024
Latest News
Nuclear new build procurement considerations
It may seem counterintuitive, but the best time to enhance the ability to support operations and maintenance for a new plant is before construction starts. This is one of many lessons learned by the currently operating nuclear fleet. As construction and startup of many nuclear facilities was completed, it quickly became evident that the ability to efficiently support operations and maintenance was limited. Most of the information necessary to establish and manage procurement of spare and replacement items, maintenance, and configuration of the facilities was unavailable and had to be gathered on a case-by-case, “on-demand” basis. Absence of necessary information and the associated challenges resulted in the need for staff augmentation and multiyear-long projects to develop equipment bills of material and maintenance programs and to perform technical evaluations for the huge quantities of spare and replacement items being requested.
Minoru Yamada, Ikuo Kinoshita, Toshihide Torige, Michio Murase, Yoshitaka Yoshida, Hideo Nakamura
Nuclear Technology | Volume 200 | Number 2 | November 2017 | Pages 125-143
Technical Paper | doi.org/10.1080/00295450.2017.1362940
Articles are hosted by Taylor and Francis Online.
Application of the statistical safety evaluation method to the analysis for reflux cooling in the loss of residual heat removal system (RHR) event during mid-loop operation was conducted with RELAP5/MOD3.2 as the best-estimate code. The evaluation parameters for this event are the reactor coolant system (RCS) pressure and reactor vessel (RV) water level. A phenomena identification and ranking table was developed previously to identify important phenomena that have a large influence on the evaluation parameters. The uncertainties of the analytical models which are related to the important phenomena were quantified to use as input for the statistical analysis. Actual plant sensitivity analyses were carried out to confirm the influence of the uncertainty which was quantified. Validation analysis of the RELAP5/MOD3.2 code was carried out for the reflux cooling test conducted with the ROSA-IV Large-Scale Test Facility to confirm that the experimental RCS pressure results were within the range of the uncertainty of the analytical models. A statistical analysis for 93 cases was carried out for a four-loop plant to evaluate the RV water level in the steady state and the maximum RCS pressure with 95% cumulative probability and 95% confidence. As a result, it was confirmed that reflux cooling using two cooling steam generators was successful.