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.
Explore membership for yourself or for your organization.
Conference Spotlight
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
Mar 2026
Jan 2026
Latest Journal Issues
Nuclear Science and Engineering
April 2026
Nuclear Technology
February 2026
Fusion Science and Technology
Latest News
Swiss nuclear power and the case for long-term operation
Designed for 40 years but built to last far longer, Switzerland’s nuclear power plants have all entered long-term operation. Yet age alone says little about safety or performance. Through continuous upgrades, strict regulatory oversight, and extensive aging management, the country’s reactors are being prepared for decades of continued operation, in line with international practice.
F. E. LeVert, M. A. Schultz
Nuclear Science and Engineering | Volume 49 | Number 2 | October 1972 | Pages 188-201
Technical Paper | doi.org/10.13182/NSE72-A35506
Articles are hosted by Taylor and Francis Online.
Local measurements of the inherent fluctuations in the gamma-ray density at specific locations in the core of the Pennsylvania State Triga Reactor have been conducted using two externally located detectors. Local power was determined for positions up to the center of the core from a distance of approximately 200 cm by measuring the zero-time cross correlation function in small intervals. Voids introduced by the removal of single fuel elements were readily located and mapped. Single collimator dc scans along diagonal rows in the core were successful in resolving the individual rows of fuel in the core. A comparison between the neutron distribution predicted by two dimensional multi-group diffusion theory and a single collimator measurement showed very good agreement in their respective shapes. Cospectral densities were obtained for the two cases where the collimators focused on and off a volume of fuel in the core. The frequency response data indicated, when interpreted in terms of an analytical model, that the observed output fluctuations were caused by temperature and coolant flow input fluctuations.