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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.
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2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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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Nuclear new build procurement considerations
It may seem counterintuitive, but the best time to enhance the ability to support operations and maintenance for a new plant is before construction starts. This is one of many lessons learned by the currently operating nuclear fleet. As construction and startup of many nuclear facilities was completed, it quickly became evident that the ability to efficiently support operations and maintenance was limited. Most of the information necessary to establish and manage procurement of spare and replacement items, maintenance, and configuration of the facilities was unavailable and had to be gathered on a case-by-case, “on-demand” basis. Absence of necessary information and the associated challenges resulted in the need for staff augmentation and multiyear-long projects to develop equipment bills of material and maintenance programs and to perform technical evaluations for the huge quantities of spare and replacement items being requested.
M. Freitag, S. Gupta, S. Beck, M. Sonnenkalb
Nuclear Science and Engineering | Volume 193 | Number 1 | January-February 2019 | Pages 198-210
Technical Paper – Selected papers from NURETH 2017 | doi.org/10.1080/00295639.2018.1479091
Articles are hosted by Taylor and Francis Online.
Timely evolution of radioactive airborne aerosols, the mass of particles deposited on structures or transported with condensing water into the sump, and any influence of safety systems on the aerosol distribution will have a crucial influence on the potential aerosol source term into the environment. Different phenomena affect the main aerosol processes, and important ones besides gravimetrical and diffusive settling require experimental investigations to improve and validate modeling assumptions. Experimental investigations in the THAI (Thermal-hydraulics, Hydrogen, Aerosol, Iodine) test facility have been performed to investigate (a) insoluble silver aerosol wash-down behavior from vertical steel and horizontal decontamination paint-coated surfaces by condensing steam (test AW-3, supported by a laboratory-scale wash-down test series), and (b) the depletion of the airborne aerosol concentration by wash-out due to the use of a nuclear power plant typical water spray system (test AW-4). The paper discusses experimental findings of both tests supported by analytical analyses using the containment code system COCOSYS developed by Gesellschaft für Anlagen- und Reaktorsicherheit (GRS). To validate and further improve the new model Abwaschmodell für unlösliche Aerosole (AULA) in COCOSYS, used for the wash-down of insoluble aerosols from containment typical structures, the AW-3 laboratory tests related to the AW-3 test were used. Building upon these results, the AW-3 wash-down test is simulated. The results of the calculation for the AW-3 test show that the wash-down of insoluble silver particles at least qualitatively resembles the experimental results, though generally the washed-down aerosol mass is lower compared to the experiment. In test AW-4, it was in question if the modeling of aerosol wash-out with spray systems is adequately treated by assuming monodisperse spray droplets or if a droplet distribution has to be applied. Posttest calculation of AW-4 indicates that the wash-out of CsI aerosols by spray systems can be captured qualitatively. However, it is also shown that the calculated wash-out rate is too large and the depletion of the CsI aerosols during the dry phase is underestimated.