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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.
Bradley J. Knutson, Richard A. Harris
Nuclear Technology | Volume 89 | Number 1 | January 1990 | Pages 9-17
Technical Paper | Fission Reactor | doi.org/10.13182/NT90-A34355
Articles are hosted by Taylor and Francis Online.
Experience using an automated core reactivity monitoring technique at the Fast Flux Test Facility (FFTF) through eight operating cycles is described. This technique relies on comparing predicted-to-measured rod positions to detect any anomalous (or unpredicted) core reactivity changes. Reactivity worth predictions of core state changes (e.g., temperature and irradiation changes) and compensating control rod movements are required for the rod position comparison. A substantial data base now exists to evaluate changes in temperature feedback reactivity effects operational in the FFTF, rod worth changes due to core loading, temperature and irradiation effects, and burnup effects associated with transmutation of fuel materials. This preliminary work focuses on resolving observed reactivity anomalies by evaluating the prediction models using additional zero-power rod worth measurement data along with calculations of rod worths and burnup rates for each cycle using cross-section data processed from the latest ENDF/B-V data set.