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Materials Science & Technology
The objectives of MSTD are: promote the advancement of materials science in Nuclear Science Technology; support the multidisciplines which constitute it; encourage research by providing a forum for the presentation, exchange, and documentation of relevant information; promote the interaction and communication among its members; and recognize and reward its members for significant contributions to the field of materials science in nuclear technology.
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2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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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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Smarter waste strategies: Helping deliver on the promise of advanced nuclear
At COP28, held in Dubai in 2023, a clear consensus emerged: Nuclear energy must be a cornerstone of the global clean energy transition. With electricity demand projected to soar as we decarbonize not just power but also industry, transport, and heat, the case for new nuclear is compelling. More than 20 countries committed to tripling global nuclear capacity by 2050. In the United States alone, the Department of Energy forecasts that the country’s current nuclear capacity could more than triple, adding 200 GW of new nuclear to the existing 95 GW by mid-century.
Hiroshi Okuno, Tomohiro Sakai
Nuclear Technology | Volume 122 | Number 3 | June 1998 | Pages 265-275
Technical Paper | Reactor Safety | doi.org/10.13182/NT98-A2868
Articles are hosted by Taylor and Francis Online.
It is well known that the maximum reactivity is realized for the flat fuel distribution with the fuel importance function being constant. The Lagrange method of an undetermined multiplier was used to incorporate the constraint that the mean uranium concentration or the total uranium mass shall be conserved. The OPT-SN computer program is developed, which includes an SN code ANISN-JR to solve the multigroup neutron transport equations. This program has given more reliable results than the previous scheme using the diffusion approximation, especially for bare and partially reflected fuel systems. OPT-SN was applied to criticality calculations for mixtures of 5 wt% 235U-enriched uranium dioxide and water (slurries) covered with a water reflector in all directions, in half directions, and uncovered. The calculations made for the UO2-H2O slurries in a sphere, an infinitely long cylinder, and an infinite slab with a water reflector in all directions revealed that a degree of nonuniformity effect tends to increase as the mean uranium concentration increases. It amounts to ~6% k/k for these systems at the mean uranium concentration of 4000 gU/l. The degree of nonuniformity effect is found more than 6% k/k even for as low a mean uranium concentration as 700 gU/l of the slab fuel system with a reflector only on one side. This fact confirmed from the viewpoint of nuclear criticality safety the importance of evaluating the optimum distribution of fuel in slurry contained in a tank placed on the concrete floor. Precipitation is regarded as a realistic example.
