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Division Spotlight
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
Meeting Spotlight
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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!
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Latest News
New laws offer nuclear industry incentives for existing power plant uprates
This year, the U.S. nuclear industry received a much-needed economic boost that could help preserve operating nuclear power plants and incentivize upgrades that extend their lifespan and power output.
Signed into law in 2022, the Inflation Reduction Act offers production tax credits (PTCs) for existing nuclear power plants and either PTCs or investment tax credits (ITCs) for new carbon-free generation. These credits could make power uprates—increasing the maximum power level at which a commercial plant may operate—a much more appealing option for utilities.
Gad Shani
Nuclear Science and Engineering | Volume 65 | Number 1 | January 1978 | Pages 183-187
Technical Note | doi.org/10.13182/NSE78-A27142
Articles are hosted by Taylor and Francis Online.
The hybrid fusion reactor is becoming an interesting and promising model. In the present Note, a method for controlling the breeding-fission ratio is investigated. Since 238U fission occurs mainly with fast neutrons and breeding occurs with intermediate and slow neutrons, an optimal ratio can be obtained by partial slowing down of the original 14.9-MeV neutrons. This is done using iron as the moderator. Uranium samples were irradiated with 14.9-MeV neutrons from a deuterium-tritium reaction with iron layers of various thicknesses between the samples and the neutron source. It was found that with a relatively thin layer of iron (12 cm), any breeding-fission ratio can be obtained within a range of two decades. The breeding rate changes by only 50% when the iron-slab thickness changes from 0 to 12 cm, while the fission rate follows (more or less) the 14-MeV neutron flux and drops by more than two decades. Good agreement was obtained between the measurement and the calculated results.