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
Human Factors, Instrumentation & Controls
Improving task performance, system reliability, system and personnel safety, efficiency, and effectiveness are the division's main objectives. Its major areas of interest include task design, procedures, training, instrument and control layout and placement, stress control, anthropometrics, psychological input, and motivation.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
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.