ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
Meeting Spotlight
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
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!
Latest Magazine Issues
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
Fusion Science and Technology
Latest News
TerraPower begins U.K. regulatory approval process
Seattle-based TerraPower signaled its interest this week in building its Natrium small modular reactor in the United Kingdom, the company announced.
TerraPower sent a letter to the U.K.’s Department for Energy Security and Net Zero, formally establishing its intention to enter the U.K. generic design assessment (GDA) process. This is TerraPower’s first step in deployment of its Natrium technology—a 345-MW sodium fast reactor coupled with a molten salt energy storage unit—on the international stage.
George Tessler, Ben R. Beaudoin, William J. Beggs, Louis B. Freeman, Albert C. Kahler, William C. Schick, Jr.
Nuclear Technology | Volume 82 | Number 3 | September 1988 | Pages 275-289
Technical Paper | Nuclear Fuel | doi.org/10.13182/NT88-A34129
Articles are hosted by Taylor and Francis Online.
The light water breeder reactor (LWBR) was developed by the Bettis Atomic Power Laboratory under the technical direction of the Office of Naval Reactors, U.S. Department of Energy. The LWBR operated successfully in the Shippingport Atomic Power Station from 1977 to 1982, producing more than 29 000 equivalent full-power hours. Because of the small breeding gain (1.35%) predicted for this selfsustaining breeder, proof of breeding required accurate nondestructive assay of expended fuel from the LWBR. The fact that breeding has been proven in the LWBR means that this reactor provides a vast alternative energy resource using plentiful thorium fuel. A gauge, called the production irradiated fuel assay gauge (PIFAG), was developed to nondestructively assay whole irradiated fuel rods from the LWBR. The gauge uses the method of active interrogation with 252Cf source neutrons and delayed neutron counting. It is remotely operated inside a hot cell and has the capability to interrogate fuel rods with two different neutron energy spectra, one with primarily low-energy (<0.625-eV) neutrons and the second with the lowenergy neutrons removed. In addition to delayed neutron counting, the PIFAG has provision for counting 252Cf source neutrons close to the surface of a fuel rod during interrogation, and for gamma scanning the fuel rod. These data are used to calculate a selfshielding correction to the delayed neutron data. A description is given of the PIFAG, its calibration, and its application to the assay of irradiated LWBR fuel rods. A comparison of the PIFAG results with destructive assay results for 17 irradiated LWBR fuel rods shows that the two methods are in excellent agreement, differing by 0.069 and 0.162% for the lowand high-energy PIFAG interrogation spectra, respectively.
