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Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
Meeting Spotlight
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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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Reboot: Nuclear needs a success . . . anywhere
The media have gleefully resurrected the language of a past nuclear renaissance. Beyond the hype and PR, many people in the nuclear community are taking a more measured view of conditions that could lead to new construction: data center demand, the proliferation of new reactor designs and start-ups, and the sudden ascendance of nuclear energy as the power source everyone wants—or wants to talk about.
Once built, large nuclear reactors can provide clean power for at least 80 years—outlasting 10 to 20 presidential administrations. Smaller reactors can provide heat and power outputs tailored to an end user’s needs. With all the new attention, are we any closer to getting past persistent supply chain and workforce issues and building these new plants? And what will the election of Donald Trump to a second term as president mean for nuclear?
As usual, there are more questions than answers, and most come down to money. Several developers are engaging with the Nuclear Regulatory Commission or have already applied for a license, certification, or permit. But designs without paying customers won’t get built. So where are the customers, and what will it take for them to commit?
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.
