The PULSTAR Reactor and Experience in Education and Research

Ayman I. Hawari

Nuclear Reactor Program, Department of Nuclear Engineering, North Carolina State University, Raleigh, North Carolina, USA

The history of nuclear research reactors on the campus of North Carolina State University (NCSU) is extensive.  On September 5, 1953, the Raleigh Research Reactor went critical with the R-1 license.  In 1969, NCSU initiated construction of the current PULSTAR reactor with a maximum power of 1-MWth, which achieved criticality on September 9, 1972.  In 1978, the Nuclear Reactor Program (NRP), where the PULSTAR reactor is housed, was formally established as a university center.  The mission of the NRP derives directly from the institutional mission and focuses on the three pillars of education, research and discovery, and outreach and extension.  Consequently, on annual basis the PULSTAR serves the educational and research essentials of hundreds of students (undergraduate and graduate) and faculty, supports the technological needs of various industrial and governmental organizations, and provides many public outreach opportunities for K-12 students and teachers, technical 2-year colleges, and the community at large.  Since 2010/2011, the NRP carries the designation of “Board of Governors’ Center” within the University of North Carolina (UNC) system’s 17 campuses.  Over the past 20 years, the PULSTAR initiated major upgrades of its operational capabilities and facilities.  This includes enhancing core reflection, licensing of new fuel, and major digital upgrades of its control console and instrumentation. In addition, several facilities for nondestructive materials examination and fundamental science were established on its beamports, which includes an intense positron beam facility, a neutron imaging facility, a neutron powder diffractometer, and an ultracold neutron source.  Recently, a hot cell facility was installed, and a fuel testing loop is expected to be operational in the near future.  Among the applications that are currently ongoing at the PULSTAR is a study of the characteristics of neutron moderators and reflectors (e.g, nuclear graphite and FLiBe molten salt) for advanced fission reactors to quantify accurately the thermalization process, which depends directly on the material’s dynamic structure factor, i.e., S(Q,w).  The PULSTAR irradiation facilities, and positron annihilation and neutron diffraction instruments are utilized to explore a material’s atomistic microstructure and to relate it to its identity, in momentum-frequency space, to support establishing a predictive approach for generating the required data for the design and licensing of advanced thermal fission reactor systems.