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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
A. Y. Ying, A. R. Raffray, M. A. Abdou
Fusion Science and Technology | Volume 19 | Number 3 | May 1991 | Pages 1481-1486
ITER | Proceedings of the Ninth Topical Meeting on the Technology of Fusion Energy (Oak Brook, Illinois, October 7-11, 1990) | doi.org/10.13182/FST91-A29550
Articles are hosted by Taylor and Francis Online.
This paper addresses the thermal transport issues associated with a loss of flow accident (LOFA) for US ITER solid breeder blanket. Two LOFA scenarios were considered. For a LOFA due to a simultaneous catastrophic pump failure, the coolant temperature reaches its boiling point within only about 15 – 20 seconds. This scenario appears extremely unlikely and should be better characterized through a probability risk assessment study in order to determine to what extent corrective actions such as the use of backup pump should be taken. For a LOFA due to loss of power to the coolant pumps, the resulting flow transient is characterized by considering the effect of fluid inertia and pump inertia. Once a determination of the flow coastdown has been made, the temperature histories of blanket elements and coolant are analyzed using lumped parameter techniques. The results of the analyses indicate that the rate of coolant temperature rise due to the heat (generated and/or stored) transferred from the solid breeder area is strongly dependent on the transient flow behavior. If the coolant pump can be designed with a sufficiently large pump inertia (with an inertia time constants of about 1.5 s or more), the coolant temperature can stay under its boiling point for several minutes to allow for corrective action to be implemented. As an added safety measure, it seems prudent to include in the design a system of expansion volumes and/or safety valves for accommodating coolant pressure transients.
