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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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ANS joins others in seeking to discuss SNF/HLW impasse
The American Nuclear Society joined seven other organizations to send a letter to Energy Secretary Christopher Wright on July 8, asking to meet with him to discuss “the restoration of a highly functioning program to meet DOE’s legal responsibility to manage and dispose of the nation’s commercial and legacy defense spent nuclear fuel (SNF) and high-level radioactive waste (HLW).”
F. V. Orestano, F. Pistella
Nuclear Science and Engineering | Volume 46 | Number 3 | December 1971 | Pages 376-384
Technical Paper | doi.org/10.13182/NSE71-A22374
Articles are hosted by Taylor and Francis Online.
The investigation of the neutron spectral effects in actual cell geometry in a plutonium-fueled lattice is the final step of a program undertaken at LFCR of CNEN on the investigation of the physics problems for the plutonium recycle in light water reactors. Spectral indices have been measured by foil activation techniques, in the fuel pins and in the moderator, both in a uniform lattice and in the presence of a cross-shaped water gap; the presence of the water gap reduces the value of the index 239Pu-fission/235U fission by about 8%. The measured values have been compared with the results of the design calculational methods as well as those of a more detailed method and agreement is good. In particular, it has been found that the use of two thermal-energy groups (in a five-group scheme) is necessary to describe properly the effect of water gaps on the plutonium effective cross sections. The 239Pu absorption rate has been evaluated from the measured spectral indices by applying a previously tested correlation method; the presence of the water gap also reduces the 239Pu absorption/235 U-fission-ratio by about 10%.