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Meeting Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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July 2025
Latest News
The U.S. Million Person Study of Low-Dose-Rate Health Effects
There is a critical knowledge gap regarding the health consequences of exposure to radiation received gradually over time. While there is a plethora of studies on the risks of adverse outcomes from both acute and high-dose exposures, including the landmark study of atomic bomb survivors, these are not characteristic of the chronic exposure to low-dose radiation encountered in occupational and public settings. In addition, smaller cohorts have limited numbers leading to reduced statistical power.
C. W. Forsberg, J. D. Stempien, M. J. Minck, R. G. Ballinger
Nuclear Technology | Volume 194 | Number 3 | June 2016 | Pages 295-313
Technical Paper | doi.org/10.13182/NT15-87
Articles are hosted by Taylor and Francis Online.
Fluoride salt–cooled High-temperature Reactors (FHRs) are a new type of power reactor that delivers heat to the power cycle between 600°C and 700°C. The FHR uses High-Temperature Gas-cooled Reactor (HTGR) graphite-matrix coated-particle fuel with failure temperatures of 1650°C. The FHR coolants are clean fluoride salts that have melting points above 350°C and boiling points above 1400°C. This combination may enable the design of a large FHR that will not have significant fuel failure and thus radionuclide releases to the environment even in a beyond-design-basis accident (BDBA) that include failure of all cooling systems, the vessel, and containment systems. A first effort has been undertaken to understand FHR BDBAs and develop an FHR BDBA system to prevent major fuel failure if an accident occurs in a large FHR.
Four design features limit BDBA fuel temperatures to lower than fuel failure temperatures. First, there is a large temperature drop to transfer decay heat from the fuel to the environment in a BDBA. Second, the large temperature difference between normal operating temperatures and fuel failure temperatures allows the use of increasing temperatures in an accident to degrade the insulation system and other barriers that prevent efficient transfer of decay heat from the reactor core to the environment in an accident. Third, the silo around the reactor vessel contains a BDBA salt that in an accident heats up, melts, and partly floods the silo to improve heat transfer from fuel to the environment. Fourth, the fuel and coolant retain fission products and actinides at high temperatures.