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Swiss nuclear power and the case for long-term operation
Designed for 40 years but built to last far longer, Switzerland’s nuclear power plants have all entered long-term operation. Yet age alone says little about safety or performance. Through continuous upgrades, strict regulatory oversight, and extensive aging management, the country’s reactors are being prepared for decades of continued operation, in line with international practice.
Nam Zin Cho, Jaejun Lee
Nuclear Science and Engineering | Volume 159 | Number 3 | July 2008 | Pages 229-241
Technical Paper | doi.org/10.13182/NSE159-229
Articles are hosted by Taylor and Francis Online.
A coarse-mesh nodal method in cylindrical (r, ,z) geometry, e.g., of pebble bed reactors, based on the analytic function expansion nodal (AFEN) methodology, is described in this paper. Two unique features are (a) no use of transverse integration - allowing a nodal scheme in (r, ,z) geometry - and (b) nodal solution expressed in terms of analytic basis functions - leading to high accuracy and readily available reconstruction of homogeneous flux distributions. Additional features of multigroup formulation, two methods of void region treatment, and coarse-group-rebalance acceleration are implemented in the TOPS code and tested on several benchmark problems, including the Organisation for Economic Co-operation and Development/Nuclear Energy Agency PBMR-400 Benchmark Problem. The TOPS results are in excellent agreement with those of the VENTURE code, using significantly less computer time.