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Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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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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Glass strategy: Hanford’s enhanced waste glass program
The mission of the Department of Energy’s Office of River Protection (ORP) is to complete the safe cleanup of waste resulting from decades of nuclear weapons development. One of the most technologically challenging responsibilities is the safe disposition of approximately 56 million gallons of radioactive waste historically stored in 177 tanks at the Hanford Site in Washington state.
ORP has a clear incentive to reduce the overall mission duration and cost. One pathway is to develop and deploy innovative technical solutions that can advance baseline flow sheets toward higher efficiency operations while reducing identified risks without compromising safety. Vitrification is the baseline process that will convert both high-level and low-level radioactive waste at Hanford into a stable glass waste form for long-term storage and disposal.
Although vitrification is a mature technology, there are key areas where technology can further reduce operational risks, advance baseline processes to maximize waste throughput, and provide the underpinning to enhance operational flexibility; all steps in reducing mission duration and cost.
M. P. Sharma, A. K. Nayak
Nuclear Science and Engineering | Volume 180 | Number 2 | June 2015 | Pages 172-181
Technical Paper | doi.org/10.13182/NSE14-102
Articles are hosted by Taylor and Francis Online.
The Advanced Heavy Water Reactor (AHWR) is a vertical pressure tube–type, heavy water–moderated, boiling light water–cooled, natural-circulation–based reactor. The fuel bundle of AHWR contains 54 fuel rods arranged in three concentric rings of 12, 18, and 24 fuel rods. This fuel bundle is divided into a number of imaginary interacting flow passages called subchannels. A single-phase-flow condition exists in the reactor rod bundle during the start-up condition and up to a certain length of rod bundle when it is operating at full power. Predicting the thermal margin of the reactor during the start-up condition has necessitated the determination of the turbulent mixing rate of the coolant among these subchannels. Thus, it is vital to evaluate the turbulent mixing between the subchannels of the AHWR rod bundle.
In this paper, experiments were carried out to determine the turbulent mixing rate in the simulated subchannels of the reactor. The size of the rod and the pitch in the test were the same as those of the actual rod bundle in the prototype. Three subchannels are considered in 1/12th of the cross section of the rod bundle. Water was used as the working fluid, and the turbulent mixing tests were carried out at the atmospheric condition without heat addition. The mean velocity in the subchannel was varied from 0 to 1.2 m/s. The flow conditions were closer to the actual reactor condition. The turbulent mixing rate was experimentally determined by adding tracer fluid in one subchannel and measuring the concentration of that in other subchannels at the end of the flow path. The test data were compared with existing models in literature. It was found that none of the models could predict the measured turbulent mixing rate in the rod bundle of the reactor. This is because the turbulent mixing rate is highly dependent on geometry. An empirical model is derived based on these experimental data, and it is found that this correlation can predict the turbulent mixing rate quite accurately.