Title:

Challenges in source term generation for pebble-bed reactors

Speaker:

Dr. Dr. Friederike (Rike) Bostelmann

Affiliation:

Oak Ridge National Laboratory

When:

Thursday, September 11, 2025 at 11:00:00 AM   Add to Calendar

Where:

Boggs Building, Room 3-47

Host:

Shaheen Dewji
shaheen.dewji@gatech.edu

Abstract

Pebble-bed reactors pose significant computational challenges for source term generation due to their continuous refueling scheme and heterogeneous fuel distribution. Unlike conventional reactors, fuel pebbles circulate through the core multiple times before discharge, resulting in a core that contains a mixture of pebbles with varying irradiation histories and burnup states. The heterogeneity of such a core complicates accurate radionuclide inventory calculations. However, the prediction of accurate inventory is, essential for predicting reactor behavior during both normal and off-normal events and for fuel cycle and safeguards assessments. This presentation describes a novel computational approach utilizing the SCALE code system to enable rapid and accurate fuel inventory generation for both equilibrium pebble-bed reactor cores and discharged fuel pebbles. The method employs iterative depletion calculations of representative surrogate models. Modeling considerations and challenges, and key capabilities within SCALE that support these analyses will also be discussed.

Biography

Dr. Friederike (Rike) Bostelmann is a research and development staff member in the Nuclear Energy and Fuel Cycle Division at Oak Ridge National Laboratory (ORNL). Her primary research interests include non-LWR reactor analysis, depletion modeling, validation, and uncertainty methods and assessments. In her recent research, she has investigated the impact of uncertainties and gaps of nuclear data on reactor physics analysis and the development of source terms and decay heat in support of severe accident analysis for non-LWRs. One of the goals of her work is to effectively support the preparedness of the US Nuclear Regulatory Commission staff with state-of-the-art computational tools and know-how for addressing incoming license applications of non-LWRs. Prior to joining ORNL, Dr. Bostelmann worked at GRS, an independent technical support organization in Germany. She earned a Ph.D. in nuclear engineering from the EPFL (Switzerland).

Notes

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