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2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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OECD NEA meeting focuses on irradiation experiments
Members of the OECD Nuclear Energy Agency’s Second Framework for Irradiation Experiments (FIDES-II) joint undertaking gathered from September 29 to October 3 in Ketchum, Idaho, for the technical advisory group and governing board meetings hosted by Idaho National Laboratory. The FIDES-II Framework aims to ensure and foster competences in experimental nuclear fuel and structural materials in-reactor experiments through a diverse set of Joint Experimental Programs (JEEPs).
J. G. Carver, W. R. Morgan, C. R. Porter, M. A. Robkin
Nuclear Science and Engineering | Volume 41 | Number 2 | August 1970 | Pages 209-225
Technical Paper | doi.org/10.13182/NSE70-A20708
Articles are hosted by Taylor and Francis Online.
Measurements have been made of relative nuclear-reaction rates within sub-critical water-moderated plutonia-urania fuel lattices, under conditions considered typical for plutonium recycle in central-station power reactors. Measurement conditions included water:fuel ratios of 3:1 and 2:1; temperatures of 70, 235, 330, 430, and 540°F; and three positions within the unit cell. Nuclear reaction rates measured included relative fission rates in 235U, 239Pu, and 241Pu, as well as relative capture rates in 176Lu (principal resonance at 0.143 eV), 168Yb (0.597 eV), 191Ir (0.654 eV), 193Ir (1.303 eV), 197Au (4.906 eV), 139La (73.5 eV), and 63Cu (1/v detector). To facilitate comparison with predicted values, the experimental resonance absorption-rate ratios were normalized to ratios measured within a pure water spectrum. Experimental reaction-rate ratios were compared with values predicted using the THERMØS code in conjunction with a modified version of EPITHERMØS; and agreement varying from fair to good was observed. The internal consistency of the measurements suggests their future utility for evaluating methods of calculating neutron spectra and relative reaction rates within lattices of the type considered.
