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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.
John P. Church
Nuclear Science and Engineering | Volume 21 | Number 1 | January 1965 | Pages 49-61
Technical Paper | doi.org/10.13182/NSE65-A21015
Articles are hosted by Taylor and Francis Online.
The integral neutron-transport equation is solved for the space-dependent mono-energetic neutron density in a unit cell. By using step functions to represent the spatial dependence of the collision probabilities, one may rearrange the integro-differential transport equation in a special way such that the left-hand side contains only the leakage term and the term describing the total collision probability for the homogeneous medium of one region, k′, of the original problem. The Green's-function technique is then used to convert the integro-differential equation to an integral equation. Thus, although the resulting equation may be applied to a heterogeneous cell, the kernel of the equation depends only on the total collision probability in the particular region k′. Numerical results are presented for a two-region unit cell in slab geometry and compared with published results of DSN, PN double-PN and variational calculations. For unit cells that are of the order of two mean free paths or less in thickness, the zeroth-order spherical harmonic approximation for this method yields results comparable to very high order DSN, PN and double-PN calculations. Further, once the Green's function has been computed, additional cell calculations can be performed with relatively little additional computational effort.