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Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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Securing the advanced reactor fleet
Physical protection accounts for a significant portion of a nuclear power plant’s operational costs. As the U.S. moves toward smaller and safer advanced reactors, similar protection strategies could prove cost prohibitive. For tomorrow’s small modular reactors and microreactors, security costs must remain appropriate to the size of the reactor for economical operation.
L. F. Hansen, H. M. Blann, R. J. Howerton, T. T. Komoto, B. Pohl
Nuclear Science and Engineering | Volume 92 | Number 3 | March 1986 | Pages 382-396
Technical Paper | doi.org/10.13182/NSE86-A17527
Articles are hosted by Taylor and Francis Online.
The emission spectra from holmium (0.8 mfp), tantalum (1 and 3 mfp), gold (1.9 mfp), and lead (1.0 mfp) have been measured using the sphere transmission and time-of-flight techniques. The 14-MeV incident neutrons are from the Lawrence Livermore National Laboratory insulated-core-transformer accelerator using the 3H(d, n)4He reaction. These materials were chosen to span a wide range of heavy nuclei, including deformed (holmium and tantalum), spherical (gold), and closed-shell (lead) nuclei. The neutron emission spectra have been measured in the 1- to 15-MeV energy interval and the results compared with Monte Carlo calculations performed using the neutron-photon transport code TART and evaluated neutron cross-section files. An alternative representation of the secondary neutron spectra has been carried out by using model calculations for precompound processes and collective effects in the calculations of the pulsed sphere emission spectra. Their importance in the quality of the agreement between measurements and calculations is discussed. The measurements are compared with the predictions of two evaluated neutron libraries, the ENDF/B-V and evaluated nuclear data library (ENDL). In addition, calculations have been carried out using neutron cross sections calculated directly from well-accepted nuclear models by the ALICE/LIVERMORE 82 and ECIS 79 codes. The quality of the agreements between the measurements and calculations obtained with the latter cross sections and those from the ENDL library is reasonably good for all the targets, and these are systematically better than the results obtained with the ENDF/B-V files. Discrepancies between measurements and calculations as great as 80% are found using the ENDF/B-V files for the emission of neutrons from gold in the 5- to 10-MeV energy range.