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
2025 ANS Winter Conference & Expo
November 8–12, 2025
Washington, DC|Washington Hilton
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Oct 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
November 2025
Nuclear Technology
Fusion Science and Technology
Latest News
Japan gets new U for enrichment as global power and fuel plans grow
President Trump is in Japan today, with a visit with new Prime Minister Sanae Takaichi on the agenda. Takaichi, who took office just last week as Japan’s first female prime minister, has already spoken in favor of nuclear energy and of accelerating the restart of Japan’s long-shuttered power reactors, as Reuters and others have reported. Much of the uranium to power those reactors will be enriched at Japan’s lone enrichment facility—part of Japan Nuclear Fuel Ltd.’s Rokkasho fuel complex—which accepted its first delivery of fresh uranium hexafluoride (UF₆) in 11 years earlier this month.
L. R. Bunney, D. Sam
Nuclear Science and Engineering | Volume 39 | Number 1 | January 1970 | Pages 81-91
Technical Paper | doi.org/10.13182/NSE70-A21173
Articles are hosted by Taylor and Francis Online.
Experimental measurements of the gamma-ray spectra emitted by the products of thermal-neutron fission of 235U have been made at nine selected times (¼, ½, 1, 2, 5, 10, 24, 48, and 72 h) after fission. A calibrated and highly collimated 5- × 5-in. NaI(T1) detector was used. The 100-energy-bin γ-ray spectra were unfolded from the pulse-height distributions by means of an iterative method. Extensive use was made of machine computation. The number of fissions in each sample was determined radiochemically. Significant differences between this work and calculated spectra were found. At the earlier times the experimental photon emission rate is higher than the calculated rate by as much as 40%. At later times the experimental rate is 20% lower than the calculated rate. Surprisingly large differences (as much as 33%) were found between the photon emission rates of products of fission by slow neutrons and by fast neutrons.
