ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
Meeting Spotlight
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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!
Latest Magazine Issues
May 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
June 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Strontium: Supply-and-demand success for the DOE’s Isotope Program
The Department of Energy’s Isotope Program (DOE IP) announced last week that it would end its “active standby” capability for strontium-82 production about two decades after beginning production of the isotope for cardiac diagnostic imaging. The DOE IP is celebrating commercialization of the Sr-82 supply chain as “a success story for both industry and the DOE IP.” Now that the Sr-82 market is commercially viable, the DOE IP and its National Isotope Development Center can “reassign those dedicated radioisotope production capacities to other mission needs”—including Sr-89.
Pierre Benoist, Jacques Mondot, Ivan Petrovic
Nuclear Science and Engineering | Volume 118 | Number 4 | December 1994 | Pages 197-216
Technical Paper | doi.org/10.13182/NSE94-A21491
Articles are hosted by Taylor and Francis Online.
This method, which takes into account the influence of assembly heterogeneity on neutron leakage, is based on the heterogeneous B1 formalism, which assumes the existence of a fundamental mode in an infinite and regular lattice of heterogeneous assemblies. A simplified formalism, TIBERE, is presented that allows one to define directional space-dependent leakage coefficients. This method, introduced for two-dimensional x-y geometry in the APOLLO-2 multigroup transport code, uses classical and directional first-flight collision probabilities. One can now define leakage cross sections as additional absorption cross sections that have space and energy dependence, as well as all other cross sections. Hence, one obtains perfectly consistent reaction and leakage rates used in an equivalence procedure, determining cell-homogenized parameters for a whole core calculation. The study of this refined heterogeneous leakage treatment was undertaken because of the insufficiency of the homogeneous leakage model, especially in cases when an assembly contains voided zones or almost voided zones, i.e., zones with a long mean free path, so that the streaming effect may become important. The fission rate comparisons between the EPICURE reactor experimental results and the results of the corresponding whole reactor calculations were accomplished, with leakages calculated by the homogeneous and the TIBERE procedures of the APOLLO-2 code.