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Division Spotlight
Accelerator Applications
The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
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2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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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Latest News
Contractor selected for Belgian LLW/ILW facility
Brussels-based construction group Besix announced that is has been chosen by the Belgian agency for radioactive waste management ONDRAF/NIRAS for construction of the country’s surface disposal facility for low- and intermediate-level short-lived nuclear waste in Dessel.
Eleodor Nichita
Nuclear Science and Engineering | Volume 175 | Number 2 | October 2013 | Pages 157-171
Technical Paper | doi.org/10.13182/NSE12-59
Articles are hosted by Taylor and Francis Online.
Modern analysis of nuclear reactor transients uses space-time reactor kinetics methods. In the Canadian nuclear industry, safety analysis calculations use almost exclusively the improved quasi-static (IQS) flux factorization method. The IQS method, like all methods based on flux factorization, relies on calculating effective point-kinetics parameters, which dominate the time behavior of the flux, using adjoint-weighted integrals. The accuracy of the adjoint representation influences the accuracy of the effective kinetics parameters.Routine full-core calculations are not performed using detailed models and transport theory, but rather using a cell-homogenized model and two-group diffusion theory. This work evaluates the effect of homogenization and group condensation on the calculated effective kinetics parameters of an equilibrium CANDU core.Results show that homogenization combined with group condensation introduces a positive bias of ~5% in the effective delayed neutron fraction over a wide range of discharge burnups. Homogenization alone induces a positive bias of only ~2%.The bias in the effective generation time is <1% for all studied discharge burnups, and its effect on the results of a positive-reactivity transient is found to be negligible, with differences being caused solely by the effective delayed neutron fraction bias. The fractional delayed neutron fraction bias for the equilibrium core is found to be very close to that for a fresh-fuel core. However, because of the lower effective delayed neutron fraction of the equilibrium core, the effects of the bias are larger for the equilibrium core than for the fresh-fuel core. For a sample positive-reactivity transient, the maximum power is found to be underestimated by 9% for the fresh core and by 14% for the equilibrium core as a consequence of homogenization and group condensation.