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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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Risk-informed, performance-based design in INL’s MARVEL reactor
The American Nuclear Society’s Risk-informed, Performance-based Principles and Policy Committee (RP3C) has held another presentation in its monthly Community of Practice (CoP) series. Former RP3C chair N. Prasad Kadambi opened the meeting with brief introductory remarks about the RP3C and the need for new approaches to nuclear design that go beyond conventional and deterministic methods. He then welcomed this month’s speaker: Doug Gerstner, a nuclear safety engineer at Idaho National Laboratory, who presented “Application of a Qualitative RIPB Approach for the MARVEL Microreactor at INL.”
Watch the full webinar here.
Rafael Macian, Paul Coddington
Nuclear Technology | Volume 139 | Number 3 | September 2002 | Pages 185-204
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT02-A3313
Articles are hosted by Taylor and Francis Online.
RETRAN-3D, a system analysis code currently employed by the nuclear industry in studies covering a wide variety of operational and accident scenarios, has not been extensively validated for application to loss-of-coolant accident (LOCA) scenarios.The results of the in-depth analysis of two experimental loss-of-coolant transients, namely, Test No. 9 in the French OMEGA facility, and the International Standard Problem 26 (ISP-26) in the Japanese ROSA-IV Facility are discussed. The OMEGA test simulated the blowdown phase of a double-ended cold-leg break, whereas the ISP-26 test simulated a small break (5%) in a full height, volume (1/48), and power (~1/342) scaled facility representing a typical two (or four)-loop pressurized water reactor (PWR) system.The RETRAN-3D results for the OMEGA test show good estimates of the important system parameters, with the best agreement corresponding to the use of the dynamic-slip flow model. A sensitivity analysis on the break flow showed that the Henry/Fauske-Isoenthalpic Expansion critical flow model yields the best results, which are significantly improved with a refined nodalization upstream of the break.The ISP-26 was also simulated using the dynamic-slip flow model. The results indicate that the code is able to calculate a small-break LOCA with a model including the main PWR system components and to reproduce the principal physical processes in a reasonable manner.In summary, this assessment shows the ability of RETRAN-3D to model LOCA scenarios in a reasonable way and also points to areas where further model improvement could result in more accurate simulations.
