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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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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.
Andrew Denig, Michael Eades
Nuclear Technology | Volume 206 | Number 8 | August 2020 | Pages 1171-1181
Technical Paper | doi.org/10.1080/00295450.2020.1719798
Articles are hosted by Taylor and Francis Online.
Two methodologies for performing decay heat analysis with Monte Carlo simulations were developed and implemented on a representative nuclear thermal propulsion (NTP) system. This paper presents the underlying theory, discusses the methodology, and states the key results. This work investigated the importance of utilizing a time-dependent Q-value for fission in NTP systems due to their short burn time. Two approaches for deriving the Q-value were taken: one based on deconvolving the fission rate from the reactor power to yield the rate of fission energy deposition, and the other based on the convergence of the fission product decay power during a long burn. The fission product decay power method is hypothesized to be the more accurate representation of an NTP system as it captures more of the underlying physics occurring during burnup, such as fission product transmutation. The calculated Q-values were employed to derive decay power profiles that were compared to the current state-of-the-art NTP decay power model. According to these new models, it is shown that the cooling requirements for decay heat removal calculated with the state-of-the-art model differ from the developed methods by as much as 23.3%. There exists a need to experimentally validate, and by extension improve, the proposed methods to better understand the nature of decay heat production in NTP systems.