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Conference 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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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.
Jennifer S. Butler, Darvin Kapitz, Robert P. Martin, Farrokh Seifaee, Ramu K. Sundaram
Nuclear Technology | Volume 170 | Number 1 | April 2010 | Pages 244-260
Technical Paper | Special Issue on the 2008 International Congress on Advances in Nuclear Power Plants / Reactor Safety | doi.org/10.13182/NT10-A9462
Articles are hosted by Taylor and Francis Online.
AREVA NP's U.S. EPR is a 4590-MW(thermal) evolutionary pressurized water reactor that incorporates proven technology with an innovative system architecture to provide an unprecedented level of safety. One of the measures of safety is provided by probability risk assessment (PRA). PRA Level 1 concerns the evaluation of core damage frequency based on various initiating events and the success or failure of various plant event mitigation features. Determination of this measure requires mission success criteria, which are used to build the logic that makes up the fault trees and event trees of the Level 1 PRA. Developing mission success criteria for the wide variety of accident sequences modeled in the PRA Level 1 model requires a large number of thermal-hydraulic calculations. AREVA selected the MAAP4 code to perform these calculations because of its fast computation times relative to more sophisticated thermal-hydraulic codes. This is a unique application of the MAAP4 code, which was developed specifically for severe accident and PRA Level 2 analysis. As such, a study was performed to assess MAAP4's thermal-hydraulic response capabilities against AREVA's S-RELAP5 best-estimate integral systems thermal-hydraulic analysis code.
