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Nuclear Science & Technology Department

Nuclear Analysis Group

The staff in the Nuclear Analysis Group are experts in neutronics and/or thermal-hydraulics and knowledgeable about nuclear reactor and fuel cycle design. The reactor expertise includes power reactors that are currently in operation (light and heavy water cooled reactors) as well as those being proposed for the future (water, liquid metal, and gas cooled reactors) and core design including current designs and those proposed with new fuels and clad material. They are also knowledgeable about research, test, and isotope production reactors, spent fuel pools, critical facilities and hybrid accelerator-critical facilities. This expertise is combined with the use of state-of-the-art, complex computer tools to analyze issues of interest to our client base; primarily the Nuclear Regulatory Commission (NRC), Department of Energy (DOE), and National Institutes for Science and Technology (NIST). 

Examples of model development with reactor analysis codes and their application include:

Modeling of a boiling water reactor with the TRACE/ PARCS coupled thermal-hydraulic/ neutronic codes to determine reactor response to hypothetical anticipated transients without reactor trip;

Modeling of the NIST research reactor with the stochastic MCNPX code (planar view of the reactor at the core midplane shown at right) in order to determine the composition of fuel during an equilbrium cycle; and

Modeling of a pressurized water reactor fuel assembly with the lattice physics code TRITON to understand reactor behavior with fuel consisting of grains of uranium within SiC in a graphite compact.

reactor core midplane

Planar view of NIST research reactor at core midplane

In addition to computer analysis, the work involves the review of this type of analysis as requested by the NRC or DOE and this activity also involves knowledge of the regulatory framework in which these reviews are carried out. An example of the latter was a review of a proposed aqueous homogeneous reactor for production of the widely used medical isotope, Mo-99. The review was carried out to understand what guidance the NRC should provide for the licensing of that design. Another example was participation in an expert panel that reviewed the response of integrated pressurized water reactors (aka small modular reactors) to various upsets. The idea was to understand the important phenomena during these events in order to determine if current computer codes will encounter dif!culty in analyzing these events. The group maintains ties with universities and research and regulatory technical support organizations in other countries. Student interns are frequently working with staff in the group. Staff give lectures at universities and are encouraged to go to technical conferences and be committee members in professional societies.

NA Group