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Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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Remembering Joseph M. Hendrie
Joseph M. Hendrie
To those of us who knew Joe, even prior to his appointment as chair of the Nuclear Regulatory Commission, it is an understatement to say that he was a larger-than-life member of the nuclear science and technology enterprise. He was best known to the broader community for two major accomplishments: the design and construction of the High Flux Beam Reactor (HFBR) at Brookhaven National Laboratory and the creation of the standard review plan (SRP) for the U.S. Atomic Energy Commission.
In addition to the products of these endeavors becoming major fundaments to their respective communities, they were uniquely Joe. The safety analysis report for the HFBR was written essentially single-handedly by him. This was true of the SRP as well, which became the key safety review document for the NRC as it performed safety reviews for the growing number of power reactor applications in the United States. His deep technical knowledge of nuclear engineering and his extraordinary management skills made this possible.
Ansar Calloo, Jean-François Vidal, Romain Le Tellier, Gérald Rimpault
Nuclear Science and Engineering | Volume 180 | Number 2 | June 2015 | Pages 182-198
Technical Paper | doi.org/10.13182/NSE14-57
Articles are hosted by Taylor and Francis Online.
In reactor physics, calculation schemes with deterministic codes are validated with respect to a reference Monte Carlo code. The remaining biases are attributed to the approximations and models induced by the multigroup theory (self-shielding models and expansion of the scattering law on Legendre polynomials) to represent physical phenomena (resonant absorption and scattering anisotropy). This work focuses on the relevance of a polynomial expansion to model the scattering law. Since the outset of reactor physics, the latter has been expanded on a truncated Legendre polynomial basis. However, the transfer cross sections are highly anisotropic, with nonzero values for a small range of the scattering angle. The finer the energy mesh and the lighter the scattering nucleus, the more exacerbated is the peaked shape of these cross sections. As such, the Legendre expansion is less well suited to represent the scattering law. Furthermore, this model induces negative values, which are nonphysical. Piecewise-constant functions have been used to represent the multigroup scattering cross section. This representation requires a different model for the diffusion source. Thus, the finite-volume method for angular discretization has been developed and implemented in the PARIS environment. This method is adapted for both the Legendre moments and the piecewise-constant functions representations. It provides reference deterministic results that validate the standard Legendre polynomial representation with a P3 expansion.