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Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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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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Proof of concept: The Molten Salt Reactor Experiment in Nuclear News
By late 1960, when the U.S. Atomic Energy Commission authorized plans to build a Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory, the lab already had about 13 years of experimentation with molten salt reactors under its longest-serving lab director, Alvin Weinberg. The MSRE operated from 1965 to 1969, proving that molten salt reactors could operate reliably, and with alternatives to uranium-235 too.
Leonhard Meyer, Mireia G. Gargallo
Nuclear Technology | Volume 141 | Number 3 | March 2003 | Pages 257-274
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT03-A3366
Articles are hosted by Taylor and Francis Online.
Experiments were performed in a scaled annular cavity design, to investigate melt dispersal from the reactor pit when the reactor pressure vessel (RPV) lower head fails at low system pressure of less than 2 MPa. The fluid dynamics of the dispersion process was studied using model fluids, water, or bismuth alloy instead of corium, and nitrogen or helium instead of steam. The effects of different breach sizes and locations and different failure pressures on the dispersion were studied, specifically by testing central holes, lateral holes, horizontal rips, and complete unzipping of the bottom head.With holes at the base of the bottom head, the most important parameters governing the dispersion of melt are the hole size and the burst pressure. The fraction dispersed into the reactor compartments increases with larger holes and higher pressures. Values up to 76% have been found for both melt simulant liquids, water, and metal. With lateral breaches the liquid height in the lower head relative to the upper and lower edge of the breach is an additional parameter for the dispersion process, and usually not all the liquid is discharged out of the RPV. The liquid fraction entrained out of the RPV can be higher with a small breach than with a large one because of the longer blowdown time. With lateral failures, maximum dispersed fractions of 50% were found with water as melt simulant and less than 1% with liquid metal. It follows from similarity considerations that the results from the liquid metal tests represent the lower bound for the dispersed melt fractions; however, they are probably closer to the expected values than the results from the water tests, which represent the upper bound. So, significantly less dispersion of melt can be expected for lateral breaches at pressures below 2 MPa, probably less than 10%. If higher dispersion occurs, due to higher pressure at failure or with failures near the bottom center, simple devices to reduce the dispersion out of the cavity may be feasible.