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.
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
2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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
Jun 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
July 2025
Nuclear Technology
Fusion Science and Technology
Latest News
Smarter waste strategies: Helping deliver on the promise of advanced nuclear
At COP28, held in Dubai in 2023, a clear consensus emerged: Nuclear energy must be a cornerstone of the global clean energy transition. With electricity demand projected to soar as we decarbonize not just power but also industry, transport, and heat, the case for new nuclear is compelling. More than 20 countries committed to tripling global nuclear capacity by 2050. In the United States alone, the Department of Energy forecasts that the country’s current nuclear capacity could more than triple, adding 200 GW of new nuclear to the existing 95 GW by mid-century.
Kiyoshi Takeuchi, Nobuo Sasamoto
Nuclear Technology | Volume 62 | Number 2 | August 1983 | Pages 207-221
Technical Paper | Analyse | doi.org/10.13182/NT83-A33218
Articles are hosted by Taylor and Francis Online.
To examine the effect of modeling of a pres-surized water reactor (PWR) on predicting neutron field at the beltline of its pressure vessel (PV), neutron transport calculations were performed for various models of a 1000-MW( electric) class PWR in three different geometries-(R,θ), (R,Z), and a combination of (X,Y,Z) and (R,θ). A three-dimen-sional calculation with PALLAS-XYZ is used as a standard for the other two-dimensional (R,θ) and (R,Z) calculations made with PALLAS-2DRT and -2DCY. The source normalization essential for the (R,θ) calculation is reasonably made by dividing the total source neutrons by an effective core length, which provides calculated results in fair agreement with those calculated with a standard model for both radial attenuation and azimuthal variation of the integral fluxes above 1.0 and 0.1 MeV and also of displacements per atom (dpa). The (R,Z) calculations made in two different models were reviewed to find which model is more reasonable in evaluating neutron integral fluxes and dpa in a pressure vessel without underestimation. The effect of neglect of the axial leakage in (R,θ) transport calculations on neutron fluxes in a PV at the beltline region indicates little effect up to the distance before the vessel outer surface in contrast with an appreciable effect outside it. The azimuthal peaking is conspicuous and a factor of ∼2.7 at 40 deg compared with the results at 0 deg in both integral fluxes above 1.0 and 0.1 MeV and dpa for the PWR. The peaking values at the PV inner surface are 3.8 X 1010 and 7.4 X 1010 n/cm2.S for integral fluxes above 1.0 and 0.1 MeV, respectively, and 5.4 X 10−11 dpa/s. The analysis of a PC A 8/7 configuration indicates accuracy of within 30% and the analysis of Arkansas Nuclear One PWR plant indicates accuracy of the order of 20% for integral fluxes above 1.0 and 0.5 MeV at one measuring position in the cavity behind its PV, although marked discrepancies within a factor of 2 are observed at several energies in a neutron energy spectrum at the same position. The integral flux above 1 MeV is 1.01 X 1010 n/cm2. s at 12.5 deg, a peak azimuthal position of the inner surface of the PV; however, the azimuthal peaking is rather small (within 10%) compared with 9.29 X 109 n/cm2 .s at 0 deg.
