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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.
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2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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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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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.
M. J. Ohanian, R. S. Booth, R. B. Perez
Nuclear Science and Engineering | Volume 30 | Number 1 | October 1967 | Pages 95-103
Technical Paper | doi.org/10.13182/NSE67-A17246
Articles are hosted by Taylor and Francis Online.
Neutron-wave propagation in moderating media is investigated within the framework of the diffusion approximation to the Boltzmann equation, using a realistic scattering model and the eigenfunction expansion method. The eigenfunctions are obtained from the thermalization theory solution to the exponential experiment with their corresponding eigenvalues being the fundamental and higher diffusion lengths of the medium. Expanding the energy dependence of the neutron-wave problem in these eigenfunctions leads to a simpler and more accurate secular determinant than that obtained from a Laguerre polynomial expansion. Solving the secular determinant yields the squared complex inverse relaxation lengths for the asymptotic energy mode and for the continuum energy modes. A discrete energy formulation, Simpson's rule integration scheme, and the Jacobi method of matrix diagonalization are used in the numerical solution to the eigen-value problem. The dispersion law for graphite, obtained by direct solution of the complex secular determinant, is compared with experimental results. This investigation indicates that high-energy-mode contamination will not seriously affect neutron-wave experiments in graphite in the frequency range where diffusion and thermalization parameters can be obtained.