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Alternative Reflectors for The NIST Neutron Source



Yaniv Shaposhnik, Osman Celikten, Jeremy Cook, Abdullah Weiss, Dagistan Sahin


A conceptual design of a replacement reactor at the NIST Center for Neutron Research (NCNR), referred to as the NIST Neutron Source (NNS), is underway in collaboration with the Brookhaven National Laboratory. The NNS reactor design favors the production of cold and thermal neutrons and in-core irradiation facilities are of secondary importance. Therefore, the focus of the neutronic core design is to maximize neutron leakage from the core to maximize the neutron flux in the beams. As a result, the NNS reactor core differs from typical modern multipurpose reactors which prioritize "in-core" (in-pool) irradiation over neutron beams. In the preliminary NNS design, a heavy water reflector tank was adopted based on "similar" core designs such as OPAL, HANARO, and RA-10. Such a heavy water tank becomes one of the most complicated and sophisticated systems of the reactor. Since the NNS reactor pre-conceptual design does not have any "in-core" (in-pool) radiation facilities, this work is focused on the investigation of an alternative reflector design, which explores the possibility of alternatives to the heavy-water tank and why the latter might be necessary for achieving our goals. The investigation involves using beryllium, graphite, and aluminum "blocks" arranged around the core, similar to what is utilized in the ETRR-2 and TRIGA reactors.
Conference Dates
June 18-22, 2023
Conference Location
College Park, MD, US
Conference Title
2023 TRTR-IGORR Joint Research Reactor Conference


NNS, Reflector, MCNP, Cold Source


Shaposhnik, Y. , Celikten, O. , Cook, J. , Weiss, A. and Sahin, D. (2023), Alternative Reflectors for The NIST Neutron Source, 2023 TRTR-IGORR Joint Research Reactor Conference, College Park, MD, US (Accessed May 23, 2024)


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Created June 18, 2023, Updated September 7, 2023