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May 31–June 3, 2026
Denver, CO|Sheraton Denver
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Blades-in turbine inspections at Quad Cities set new benchmark for Constellation
When Constellation decided to install replacement Alstom low-pressure turbines at three of its boiling water reactor plants more than 15 years ago, one benefit was knowing the new turbines should operate reliably—and without major inspections—for several years.
W. F. Miller, Jr., Wm. H. Reed
Nuclear Science and Engineering | Volume 62 | Number 3 | March 1977 | Pages 391-411
Technical Paper | doi.org/10.13182/NSE62-391
Articles are hosted by Taylor and Francis Online.
Using projection operators, we rederive x-y geometry discrete ordinates-to-spherical harmonics (SN → PN-1.) fictitious sources defined in the literature as ray-effect mitigating devices. We define a new x-y geometry fictitious source with certain properties that are superior to earlier sources. A detailed description of the S2 → P1 source, including a discussion of vacuum and reflective boundary conditions, is provided. We then derive fictitious sources in r-z geometry that give spherical harmonics and spherical-harmonics-like solutions. Finally, a simple algorithm is presented that allows a significant reduction in the iteration time needed to obtain ray-effect-free solutions. This algorithm effectively reduces the size of the fictitious source in energy groups where ray-effect distortions are not expected. The new sources and the algorithm for reduction of computation time make this approach viable for solving the ray-effect problem.