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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.
David D. Lanning
Nuclear Technology | Volume 88 | Number 2 | November 1989 | Pages 139-156
Technical Paper | NSF Workshop on the Research Needs of the Next Generation Nuclear Power Technology / Fission Reactor | doi.org/10.13182/NT89-A34321
Articles are hosted by Taylor and Francis Online.
The modular high-temperature gas-cooled reactor (MHTGR) is modularized primarily to provide the passive safety that will prevent fuel damage over a wide spectrum of accidents. Specifically, this range of safety includes the simultaneous accidental loss of primary coolant flow, depressurization of the coolant system, and failure to trip control mechanisms. The high-temperature capability of the fuel to retain fission products provides a safe margin over this broad spectrum. The passive safety feature of the MHTGR allows elimination of active safety-related cooling components (e.g., pump and valves). The result is a savings in capital cost and an important simplification of management and operator requirements for surveillance of the reactor system. Safety is also less affected by human error. Other advantages of modularization include cost reduction and quality control by factory fabrication and possibilities for stepwise additions to a power plant to follow load growth. A new approach to licensing has been initiated as part of the MHTGR development. This concept includes a system to bridge between the integrated approach to the MHTGR design requirements and the regulatory licensing process. The projected busbar costs (mills per kilowatthour) are estimated to be competitive with coal-fired plants of the same size when two or more MHTGR modules are utilized. Designs with the passive safety features are discussed. Some incentives and impediments for deployment of the MHTGR are examined. In addition, suggestions for university research related to MHTGR are presented.