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The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
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November 12–15, 2023
Washington, D.C.|Washington Hilton
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Fusion Science and Technology
Standard on fixed neutron absorbers in nuclear facilities outside reactors just issued (ANS-8.21)
ANSI/ANS-8.21-2023, Use of Fixed Neutron Absorbers in Nuclear Facilities Outside Reactors, has just been issued by the American Nuclear Society Standards Committee. The standard was approved by the American National Standards Institute (ANSI) on June 20, 2023, as a revision and consolidation of ANS-8.21-1995 (R2019) (withdrawn) (same title) and ANS-8.5-1996 (R2022) (withdrawn), Use of Borosilicate-Glass Raschig Rings as a Neutron Absorber in Solutions of Fissile Material. ANSI/ANS-8.21-2023 provides guidance for the use of neutron absorbers, including Raschig rings, as an integral part of nuclear facilities equipment, fissile material, or fuel components outside reactors, where such absorbers are credited to provide criticality safety control.
Katherine Royston, Stephen Wilson, Joel Risner, Ahmad Ibrahim, Michael Loughlin
Fusion Science and Technology | Volume 72 | Number 3 | October 2017 | Pages 368-373
Technical Paper | doi.org/10.1080/15361055.2017.1333867
Articles are hosted by Taylor and Francis Online.
Detailed spatial distributions of the biological dose rate due to a variety of sources are required for the design of the ITER tokamak facility to ensure that all radiological zoning limits are met. During operation, water in the Integrated loop of Blanket, Edge-localized mode and vertical stabilization coils, and Divertor (IBED) cooling system will be activated by plasma neutrons and will flow out of the bioshield through a complex system of pipes and heat exchangers. This paper discusses the methods used to characterize the biological dose rate outside the tokamak complex due to 16N gamma radiation emitted by the activated coolant in the Neutral Beam Injection (NBI) cell of the tokamak building.
Activated coolant will enter the NBI cell through the IBED Primary Heat Transfer System (PHTS), and the NBI PHTS will also become activated due to radiation streaming through the NBI system. To properly characterize these gamma sources, the production of 16N, the decay of 16N, and the flow of activated water through the coolant loops were modeled. The impact of conservative approximations on the solution was also examined. Once the source due to activated coolant was calculated, the resulting biological dose rate outside the north wall of the NBI cell was determined through the use of sophisticated variance reduction techniques. The AutomateD VAriaNce reducTion Generator (ADVANTG) software implements methods developed specifically to provide highly effective variance reduction for complex radiation transport simulations such as those encountered with ITER. Using ADVANTG with the Monte Carlo N-particle (MCNP) radiation transport code, radiation responses were calculated on a fine spatial mesh with a high degree of statistical accuracy. Advanced visualization tools were also developed and used to determine pipe cell connectivity, to facilitate model checking, and to post-process the transport simulation results.