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Nuclear Nonproliferation Policy
The mission of the Nuclear Nonproliferation Policy Division (NNPD) is to promote the peaceful use of nuclear technology while simultaneously preventing the diversion and misuse of nuclear material and technology through appropriate safeguards and security, and promotion of nuclear nonproliferation policies. To achieve this mission, the objectives of the NNPD are to: Promote policy that discourages the proliferation of nuclear technology and material to inappropriate entities. Provide information to ANS members, the technical community at large, opinion leaders, and decision makers to improve their understanding of nuclear nonproliferation issues. Become a recognized technical resource on nuclear nonproliferation, safeguards, and security issues. Serve as the integration and coordination body for nuclear nonproliferation activities for the ANS. Work cooperatively with other ANS divisions to achieve these objective nonproliferation policies.
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2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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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.
R. van Geemert, F. Tani
Nuclear Science and Engineering | Volume 149 | Number 1 | January 2005 | Pages 74-87
Technical Paper | doi.org/10.13182/NSE05-A2478
Articles are hosted by Taylor and Francis Online.
A methodology is presented that allows a higher-order accurate treatment of system perturbations that are assumed to have a substantial magnitude and therefore also a substantial effect on flux distributions in nuclear systems. Examples are localized material choice variations, burnable poison density variations at lattice level, complete fuel assembly permutations at core level, or specific uncertainties defined in the system composition. For these cases, it is necessary to raise the accuracy of the estimated responses above what can be achieved using first-order perturbation methods only, of course preferably without having to simply pursue computationally expensive exact recalculations for each case if the effects of many variations or uncertainties are to be assessed. Focusing on the neutronics of multiplying systems (without thermal-hydraulic feedback mechanisms incorporated), the setup of a polynomial form for quantification of the flux shape change due to imposed system perturbations is pursued. In a mathematical sense, this method allows one to set up a polynomial expansion of the change in the lowest-mode solution of the neutronics eigensystem due to an imposed perturbation in the operators determining the lowest-mode solution and eigenvalue. This form features the property that the flux shape change, caused by variations in certain parameters localized in space and energy, can be expanded polynomially up to higher-order accuracy, with the imposed system composition variations themselves as functional arguments. Numerical results, showing the validity of the method, are reported, and possible application areas are discussed.