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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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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Rui Hu, Mujid S. Kazimi
Nuclear Technology | Volume 176 | Number 1 | October 2011 | Pages 57-71
Technical Paper | Second Seminar on Accelerated Testing of Materials in Spent Nuclear Fuel and High-Level Waste Storage Systems / Fission Reactors | doi.org/10.13182/NT11-A12542
Articles are hosted by Taylor and Francis Online.
To help achieve the necessary natural circulation flow, a fairly long chimney is installed in a natural circulation boiling water reactor (BWR) like the ESBWR. In such systems, hot water near the chimney exit could flash, thus leading to thermal-hydraulic instability during low-pressure start-up. A BWR stability analysis code in the frequency domain, named the Flashing-Induced STability Analysis for BWR (FISTAB), was developed in this work to address the issue of flashing-induced instability. The FISTAB code was benchmarked against the experimental results from the SIRIUS-N facility at the Central Research Institute of Electric Power Industry in Japan. Both stationary and perturbation results agreed well with the experimental observations.The proposed ESBWR start-up procedure under natural convection conditions was examined by the FISTAB code. It was confirmed that the examined operating points along the ESBWR start-up trajectory from TRACG simulation would be stable. Furthermore, to avoid the instability resulting from the transition from single-phase natural circulation to two-phase circulation, a simple criterion was proposed for the natural convection BWR start-up when the steam dome pressure is still low.