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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.
Ahmet Bozkurt, Nicholas Tsoulfanidis
Nuclear Technology | Volume 119 | Number 1 | July 1997 | Pages 38-47
Technical Paper | Radiation Protection | doi.org/10.13182/NT77-A35393
Articles are hosted by Taylor and Francis Online.
Gamma-ray dose rate distribution around a pressurized water reactor spent-fuel assembly is studied using the Monte Carlo N-particle transport code (MCNP) version 4a. A detailed rod-by-rod modeling of the assembly is utilized, showing explicitly the fuel, cladding, control rod channels, and the instrumentation tube. A cylindrically distributed source of gamma rays, within every fuel rod, is considered with a seven-group energy spectrum. Dose rates are obtained by tallying the gamma rays at several axial and radial positions outside the assembly. The results indicate that the radial distribution of the dose rate can be represented by a power relationship of the form r−n, where r is the radial distance from the assembly center. Another important conclusion from this study is that the dose rate close to the assembly surface is overestimated if a homogeneous assembly model is used.