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 Winter Conference & Expo
November 15–18, 2026
Phoenix, AZ|Arizona Grand Resort & Spa
Latest Magazine Issues
Sep 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
October 2026
Nuclear Technology
Fusion Science and Technology
Latest News
Westinghouse, Nordion, and PSEG team up to produce Co‑60 in the United States
This past January, Westinghouse Electric Company, Nordion, and PSEG Nuclear formalized agreements to implement newly developed cobalt-60 production technology at Units 1 and 2 of PSEG’s Salem nuclear power plant in New Jersey, with the Co-60 to be supplied to Nordion. Through an ongoing joint initiative, the companies aim to harness U.S. pressurized water reactors to produce a key medical isotope and build the first commercial-scale Co-60 production platform in the United States.
Wendell C. Demarcus
Nuclear Science and Engineering | Volume 5 | Number 5 | May 1959 | Pages 336-337
Technical Paper | doi.org/10.13182/NSE59-A25606
Articles are hosted by Taylor and Francis Online.
An integral equation is derived for the function giving the average number of collisions required to thermalize neutrons by elastic collisions with nuclei of relative mass M. An asymptotic solution is obtained which corrects the customary result by between and 1 collision (depending on M). Numerical results for small lethargy increments are presented for the cases M = 2 and M = 235.