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Division Spotlight
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
Meeting Spotlight
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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
The short life of the Hallam plant
The Hallam nuclear power plant in Nebraska, about 25 miles southwest of Lincoln, was a 75-MWe sodium-cooled, graphite-moderated reactor operated by Consumers Public Power District of Nebraska (CPPD). It was co-located with the Sheldon Power Station, a conventional coal-fired plant. The facility had a shared control room and featured a shared turbo generator that could accept steam from either heat source.
Ethwart Pollmann, Joachim Schulze, Dieter Kreuter
Nuclear Technology | Volume 108 | Number 3 | December 1994 | Pages 350-360
Technical Paper | Nuclear Reactor Safety | doi.org/10.13182/NT94-A35017
Articles are hosted by Taylor and Francis Online.
In a boiling water reactor, nuclear-thermal-hydraulic instabilities can occur if extreme operating conditions prevail. In various nuclear reactors, stability measurements have been carried out during which the location and the shape of the stability threshold was measured at a certain exposure point during the cycle. Earlier sensitivity studies have already shown that fuel assembly parameters have only a small influence on stability compared with plant parameters. The influence of plant parameters has been verified by measurements that were carried out in the German boiling water reactor Würgassen every 4 to 6 weeks during cycle 14. The results of the measurements showed for the single-loop operation point (least stable point in the core map) a strong variation of the stability threshold power during the cycle. From the beginning of cycle to the middle of cycle, the stability threshold power decreases by ∼16% (relative). After the minimum was reached, the stability threshold power increased again. Smaller variations of the stability threshold power in the core map at natural circulation indicate that not only the stability threshold varies during the cycle, but also the shape of the stability threshold is changed. Analyses with the code system STAIF have shown that the stability behavior during the cycle can clearly be correlated with the variation of the axial and radial power density profile due to control rod maneuvering and fuel burnup. Furthermore, it could be shown that for the estimation of the neutronic feedback not only the density coefficient must be taken into account but also the void variation caused by a power perturbation.