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Division Spotlight
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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New laws offer nuclear industry incentives for existing power plant uprates
This year, the U.S. nuclear industry received a much-needed economic boost that could help preserve operating nuclear power plants and incentivize upgrades that extend their lifespan and power output.
Signed into law in 2022, the Inflation Reduction Act offers production tax credits (PTCs) for existing nuclear power plants and either PTCs or investment tax credits (ITCs) for new carbon-free generation. These credits could make power uprates—increasing the maximum power level at which a commercial plant may operate—a much more appealing option for utilities.
Felix C. Difilippo
Nuclear Science and Engineering | Volume 133 | Number 2 | October 1999 | Pages 163-177
Technical Paper | doi.org/10.13182/NSE99-2
Articles are hosted by Taylor and Francis Online.
This work originated because of the need to measure (in situ and nondestructively) the degree of purity of the graphite of the Swiss critical facility Proteus. The comparison between measured and calculated values of the decay constant of a pulse of neutrons was the chosen technique. The decay constant (in the absence of fissile materials) depends, mainly, on the purity of the graphite (via the absorption process) and leakage. The leakage factor depends on the thermalization process and the geometry of the system. Because it is very difficult to calculate in complex geometries like the Proteus cavity, Monte Carlo simulations of the behavior of a pulse of neutrons were made with the MCNP code. Despite all the sophistication of MCNP, the ultimate accuracy of the calculations is dependent upon the quality of the nuclear data that describe the thermalization process in the graphite. A recent review of these data shows that very little has changed in the last 30 yr in the ENDF/B evaluation of the double-differential scattering cross section. We decided then to benchmark the current state of the art to compute kinetics experiments in graphite (the MCNP code and the ENDF/B-VI cross-section set) against experimental data and other theoretical results for the analysis of the thermalization problem. Two classes of experiments were analyzed: (a) neutron wave propagation, where the observable is the complex relaxation length, and (b) pulsed neutron decay, where is measured as a function of the dimensions of the graphite. Once the bias of the calculational technique was known, it was used to calculate the neutron decay constant of the Proteus cavity as a function of the 10B equivalent impurity concentration. A comparison with pulsed neutron decay experiments made at Proteus allowed the determination of the degree of purity of the graphite. In this last part, we took full advantage of the sophistication of the MCNP code to model many details of the facility quite accurately including room return effects.