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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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Latest News
First astatine-labeled compound shipped in the U.S.
The Department of Energy’s National Isotope Development Center (NIDC) on March 31 announced the successful long-distance shipment in the United States of a biologically active compound labeled with the medical radioisotope astatine-211 (At-211). Because previous shipments have included only the “bare” isotope, the NIDC has described the development as “unleashing medical innovation.”
Tawfik A. Al-Kusayer
Nuclear Technology | Volume 69 | Number 3 | June 1985 | Pages 293-307
Technical Paper | Nuclear Safety | doi.org/10.13182/NT85-A33612
Articles are hosted by Taylor and Francis Online.
The availability of the emergency core cooling system (ECCS) as a long-term safety backup system following a small loss-of-coolant accident (LOCA) has been analyzed for the Pickering NGS Unit A, a Canada deuterium uranium (CANDU) type of pressurized heavy-water reactor (PHWR). Fault tree analysis methodology was used to assess the unavailability of the ECCS. The PREP and KITT computer codes were used to estimate the failure probabilities. From these computations, the unavailability of the ECCS to supply sufficient coolant to the core is estimated as 3.63 × 10−3. This figure is higher than the failure probability target 3 × 10−3 that is specified by the Canadian Atomic Energy Control Board for the safety systems of CANDU PHWRs. It has been found that human error might make a very important contribution to ECCS unavailability, especially if the human error rates have been assigned the upper bound values in the fault tree calculations. That should be the case, therefore, for any fault analysis and reliability assessment of nuclear generating stations. Unlike the case for light water reactors, the ECCS in a CANDU PHWR is not the last defense against the LOCA, because of the availability of quite a large amount of D2O moderator in the calandria around the pressure tubes.
