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Accelerator Applications
The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
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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.”
James E. Tarpinian
Nuclear Technology | Volume 87 | Number 2 | October 1989 | Pages 429-432
Technical Paper | TMI-2: Health Physics and Environmental Release / Nuclear Safety | doi.org/10.13182/NT89-A27733
Articles are hosted by Taylor and Francis Online.
The dose reduction objectives for the Three Mile Island Unit 2 reactor building (RB) were designed to lower the dose rates in working areas so that the total collective dose to workers would be as low as reasonably achievable. As part of these objectives, a large-scale effort was devoted to the decontamination of RB surfaces. The presence of very high removable surface contamination levels, sometimes in excess of 1.7 × 103 Bq/cm2 (4.6 µCi/100cm2), contributed to high airborne radioactivity conditions, which necessitated the extensive use of respiratory protection. It became an objective of the decontamination program, therefore, to reduce the removable contamination levels to such an extent that the use of respirators could be reduced or even eliminated. The progress of the decontamination program was hampered when it was discovered that large areas of the RB were becoming recontaminated. Recontamination rates were measured to be ∼1.5 Bq/cm2·day−1 (4.1 × 10−3 µCi/100cm2·day−1). After a series of tests, it was determined that the air handling systems in the RB were distributing radioactivity from highly contaminated surfaces. Cascade impactor studies of the aerosols indicated a bimodal distribution of particle sizes. Particles >20-µm activity median aerodynamic diameter (AMAD) accounted for 30% of the collected activity and particles <5-µm AMAD were associated with 60% of the activity. Examinations by optical and electron microscopy and Raman spectroscopy helped determine that the larger particles were organic dusts associated with the air handling systems and the smaller particles were associated with the boric acid dissolved in decontamination water. Reducing the airflow through the air cooler fans and restricting the airflow to the highly contaminated D-rings helped to reduce the recontamination to 4 × 10−2 Bq/cm2·day−1 (1.1 × 10−4 µCi/100cm2·day−1). Subsequently, the recontamination of surfaces due to airborne vectors ceased to be an operational concern. Further decontamination of the floors enabled a significant reduction in the use of respiratory protection equipment.
