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Nuclear Nonproliferation Policy
The mission of the Nuclear Nonproliferation Policy Division (NNPD) is to promote the peaceful use of nuclear technology while simultaneously preventing the diversion and misuse of nuclear material and technology through appropriate safeguards and security, and promotion of nuclear nonproliferation policies. To achieve this mission, the objectives of the NNPD are to: Promote policy that discourages the proliferation of nuclear technology and material to inappropriate entities. Provide information to ANS members, the technical community at large, opinion leaders, and decision makers to improve their understanding of nuclear nonproliferation issues. Become a recognized technical resource on nuclear nonproliferation, safeguards, and security issues. Serve as the integration and coordination body for nuclear nonproliferation activities for the ANS. Work cooperatively with other ANS divisions to achieve these objective nonproliferation policies.
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Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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NRC engineers share their expertise at the University of Puerto Rico
Robert Roche-Rivera and Marcos Rolón-Acevedo are licensed professional engineers who work at the U.S. Nuclear Regulatory Commission. They are also alumni of the University of Puerto Rico–Mayagüez (UPRM) and have been sharing their knowledge and experience with students at their alma mater since last year, serving as adjunct professors in the university’s Department of Mechanical Engineering. During the 2023–2024 school year, they each taught two courses: Fundamentals of Nuclear Science and Engineering, and Nuclear Power Plant Engineering.
Charles W. Forsberg, Per F. Peterson
Nuclear Technology | Volume 205 | Number 5 | May 2019 | Pages 748-754
Rapid Communication | doi.org/10.1080/00295450.2019.1573619
Articles are hosted by Taylor and Francis Online.
Three reactor types can be designed with pebbles (carbon spheres) as the reactor core: the pebble-bed high-temperature gas-cooled reactor (PB-HTGR), the pebble-bed fluoride-salt-cooled high-temperature reactor (PB-FHR), and the thermal-spectrum molten salt reactor (MSR) with fuel dissolved in coolant. In the HTGR and FHR, the pebbles are fuel (coated-particle fuel) and moderator (graphite). In a MSR the pebbles would be the moderator (no fuel). Recent advances enable prediction and modeling of pebble beds with two or more sizes of pebbles.
This may enable the use of pebble beds with multiple size pebbles that create new options. A second smaller size of HTGR/FHR fuel pebble that fills some of the space between the regular pebbles can increase the power output for the same size reactor. For the FHR the second pebble size would reduce inventory of expensive coolant and may widen choices of salt coolants. In an HTGR or FHR, smaller pebbles with high actinide loadings and high heat transfer rates could be used to burn actinides while the larger pebbles are the driver fuel. Multiple pebble sizes in MSRs may enable varying the carbon-to-fuel ratio to optimize the neutron spectrum over time to more efficiently utilize the fuel and allow easy replacement of moderator. The smaller pebbles with no fuel and a high surface-to-volume ratio could be designed to remove (1) HTGR/FHR/MSR tritium from the coolant and (2) noble metal fission products and potentially other impurities in MSRs. We examine the potential incentives for pebble beds with multiple size pebbles. With the tools now available to quantify pebble-bed behavior with multiple size pebbles, the next step is to begin to quantify benefits and limitations for different applications of pebble-bed reactors with multiple sizes of pebbles.