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Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
C. D. Andriesse, R. H. J. Tanke
Nuclear Technology | Volume 65 | Number 3 | June 1984 | Pages 415-421
Technical Paper | Nuclear Safety | doi.org/10.13182/NT84-A33397
Articles are hosted by Taylor and Francis Online.
Existing data on the release of fission products (FPs) from UO2 above 1000°C show that the dominant transport process consists of elementary diffusion within grains. For many FPs, the noble gases among them forming an exception, this diffusion is characterized by an activation energy of ∼2.6 eV, which is close to the one for oxygen and very different from the one for uranium. Assuming that oxygen diffusion represents the diffusion of FPs, it can be predicted that diffusion is enhanced when there is excess oxygen in the lattice. An empirical relation between the pertinent activation energy and the overstoichiometry induced by uranium fission (burnup) is given. The transport by diffusion has to be driven by some gradient, and it is argued that the temperature gradient dominates over the concentration gradient. This argument leads to a complete description of the release rate in terms of the grain size, the central and surface temperatures, and the heat of transport. The heat of transport plays a crucial role as it varies greatly for the various FPs. Existing data allow estimation of values ranging from 0.1 eV for refractory products to more than 100 eV for volatile products. These variations appear to be correlated with variations in the bond strengths between FPs and oxygen, being the more reactive element in UO2. An empirical model of the dependence of the heat of transport on this bond strength is given, so that release rates for all the FPs can be derived from chemical tables. Finally, consistency of the measured release data with other independently obtained fuel parameters is proven.
