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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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Proving DRACO will deliver
The United States is now closer than it has been in over five decades to launching the first nuclear thermal rocket into space, thanks to DRACO—the Demonstration Rocket for Agile Cislunar Orbit.
Jan Leen Kloosterman, Evert E. Bende
Nuclear Technology | Volume 130 | Number 3 | June 2000 | Pages 227-241
Technical Paper | Fission Reactors | doi.org/10.13182/NT00-A3090
Articles are hosted by Taylor and Francis Online.
The reactor physics trends that can be observed when the moderator-to-fuel (MF) ratio of a mixed-oxide (MOX) fuel lattice increases from two (the standard value) to four are investigated. The influence of the MF ratio on the moderator void coefficient, the fuel temperature coefficient, the moderator temperature coefficient, the boron reactivity worth, the critical boron concentration, the mean neutron generation time, and the effective delayed neutron fraction has been investigated. Increasing the MF ratio to values larger than three gives a moderator void coefficient sufficiently large to recycle the plutonium at least four times. Also, the values of other parameters like the boron reactivity worth, the fuel temperature coefficient, the moderator temperature coefficient, and the mean neutron generation time improve with increasing MF ratio. The effective delayed neutron fraction is almost independent of the MF ratio. According to a point-kinetics model, the response of a MOX-fueled reactor with an MF ratio of four to a moderator temperature decrease is similar to that of a UO2-fueled reactor with an MF ratio of two.Scenario studies show that recycling plutonium four times in pressurized water reactors reduces the plutonium production by a factor of three compared with a reference once-through scenario, but the americium and curium production triples. If the plutonium remaining after recycling four times is disposed of, the radiotoxicity reduces by only a factor of two. This factor increases to a maximum of five if the plutonium can be eliminated in special burner reactors. Recycling of americium and curium is needed to reduce the radiotoxicity of the spent fuel to lower values. In general, the plutonium mass reduction increases and the minor actinide production decreases with increasing MF ratio of the MOX fuel.Enlarging the MF ratio can be achieved by increasing the rod pitch or by reducing the fuel pin diameter. In both cases, the economic penalty is about the same and is quite large.