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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.
August W. Cronenberg, Daniel J. Osetek
Nuclear Technology | Volume 81 | Number 3 | June 1988 | Pages 347-359
Technical Paper | Nuclear Safety | doi.org/10.13182/NT88-A16056
Articles are hosted by Taylor and Francis Online.
The chemical reaction kinetics of fission product iodine and cesium released from fuel to a steam/hydrogen atmosphere are investigated at conditions associated with severe core damage accidents. The results are used to assess the time to establish equilibrium and the ultimate chemical form of iodine and cesium as a function of gas mixture concentration and temperature conditions. Illustrative calculations are presented for interpretation of the chemical form of iodine and cesium during the Three Mile Island Unit 2 accident, as well as for recent severe fuel damage experiments. At low fission product concentrations (fission product/steam mole ratio < 10−8), the time to establish equilibrium may be on the order of tens of seconds, with the principal species being CsOH and HI. However, at fission product/steam mole ratios exceeding 10−5, the principal species are CsOH and Csl, with an equilibrium time of ∼10−4 s. Concentration conditions thus influence the ultimate chemical form of fission products in a steam/hydrogen gas mixture and the time to establish thermochemical equilibrium. Fission product concentration conditions should therefore be considered in the specification of the chemical form of iodine and cesium gas-phase transport for nuclear plant accident consequence analysis.
