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NRC looks to leverage previous approvals for large LWRs
During this time of resurging interest in nuclear power, many conversations have centered on one fundamental problem: Electricity is needed now, but nuclear projects (in recent decades) have taken many years to get permitted and built.
In the past few years, a bevy of new strategies have been pursued to fix this problem. Workforce programs that seek to laterally transition skilled people from other industries, plans to reuse the transmission infrastructure at shuttered coal sites, efforts to restart plants like Palisades or Duane Arnold, new reactor designs that build on the legacy of research done in the early days of atomic power—all of these plans share a common throughline: leveraging work already done instead of starting over from square one to get new plants designed and built.
Byoung Kyu Jeon, Cheol Ho Pyeon, Hyung Jin Shim
Nuclear Technology | Volume 191 | Number 2 | August 2015 | Pages 174-184
Technical Paper | Fission Reactors | doi.org/10.13182/NT14-83
Articles are hosted by Taylor and Francis Online.
Experiments on the isothermal temperature reactivity coefficient (ITRC) have been carried out at the light water–moderated core with or without a D2O tank in the Kyoto University Critical Assembly. The ITRC experiments are analyzed by a continuous-energy Monte Carlo (MC) neutron transport analysis code, McCARD. Through the temperature changes of H2O and D2O, effects of the coolant density changes in moderator and reflector regions and the microscopic cross-section variations on the ITRC are investigated by sensitivity analyses with the use of the MC adjoint-weighted perturbation method. An adjoint-weighted correlated sampling method for the stochastic mixing technique of cross-section libraries is devised to estimate the reactivity change from a perturbation of the thermal scattering cross sections due to the temperature change. From results of the MC perturbation analyses, it is clearly seen that the ITRCs of the two core configurations are dominated by a negative contribution of the number density change of hydrogen in the moderator region and a positive contribution of the thermal scattering cross-section change of hydrogen in the reflector region.
