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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.
R. L. French, L. G. Mooney
Nuclear Technology | Volume 10 | Number 3 | March 1971 | Pages 348-365
Technical Paper | Radiation | doi.org/10.13182/NT71-A30969
Articles are hosted by Taylor and Francis Online.
Techniques were developed for applying the results of Straker’s recent discrete ordinates calculations of neutron transport in an air-over-ground geometry to predict the neutron -radiation environment produced by the detonation of nuclear weapons. Straker’s results include the spatial, energy, and angle distributions of neutrons at the air-ground interface from source neutrons in each of nine source-energy bands emitted from a point isotropic source 50 ft above the ground. The source-energy bands cover the range from 0.0033 to 15.0 MeV. The energy spectrum of the leakage neutrons from a particular weapon may be integrated over corresponding energy bands toob-tain source intensities which are then multiplied by the transport data for corresponding bands and summed over source energy. The results thus obtained are for Straker’s original air density of 1.1 x 10-3 g/cm3, but they may be sealed to other air densities by use of mass equivalent ranges. A satisfactory adjustment to source heights other than the 50-ft height used in the original calculations may be made with the “first-last collision method” if the source-detector separation is as much as 2 or 3 mean-free-paths (∼1000 ft). When folded with leakage spectra for numerous test devices and adjusted to the proper air density and burst height, Straker’s data give neutron-dose spatial distributions generally within 25% of those measured infield tests.