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Division Spotlight
Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
Meeting Spotlight
Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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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Latest News
Oklo completes end-to-end demonstration of advanced fuel recycling
Oklo Inc. has announced that it has completed the first end-to-end demonstration of its advanced fuel recycling process as part of an ongoing $5 million project in collaboration with Argonne and Idaho National Laboratories. Oklo’s goal: scaling up its fuel recycling capabilities to deploy a commercial-scale recycling facility that would increase advanced reactor fuel supplies and enhance fuel cost effectiveness for its planned sodium fast reactors.
Tim H. J. J. Van Der Hagen, Imre Pázsit, Ola Thomson, Bengt Melkerson
Nuclear Technology | Volume 107 | Number 2 | August 1994 | Pages 193-214
Technical Paper | Nuclear Reactor Safety | doi.org/10.13182/NT94-A34987
Articles are hosted by Taylor and Francis Online.
Measurements, taken in the Ringhals-1 boiling water reactor after revision in 1990, showed that instability occurred at high power and low core flow. Measurements in several points of the power-flow map showed that the decay ratio (DR), obtained by conventional methods, jumps from a moderate value directly to unity. This was valid for DR values calculated from both average power range monitor (APRM) and local power range monitor (LPRM) signals. Thus, the conventional DR cannot be used as a measure of the margin to instability. It was found that both global (in-phase) and regional (out-of-phase) oscillations occur, the global with low DR but large signal amplitude, and the regional with high DR but low signal amplitude. The former dominates the DR calculated from both APRMs and LPRMs, except when the instability is fully developed and impedes detection of the actual margin to instability. Methods for obtaining the stability characteristics of both modes separately from neutron noise signals were developed. The DR of the out-of-phase mode appears to be a good indicator of the margin to instability.