ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
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.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
Standards Program
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!
Latest Magazine Issues
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Lester M. Waganer
Fusion Science and Technology | Volume 39 | Number 2 | March 2001 | Pages 458-461
Advanced Designs | doi.org/10.13182/FST01-A11963278
Articles are hosted by Taylor and Francis Online.
Two generic approaches for maintaining commercial fusion power plants are compared to determine the most desirable maintenance scheme and reactor design approach to consider for the next generation, advanced tokamak power plant, the ARIES-AT1. The scheduled and unscheduled maintenance times for the power core of fusion plants are extremely important as they directly determine the plant availability and, ultimately, the cost of electricity. The plant down time is determined by the time to access the failed or worn out part(s), the time to accomplish the replacement, and the time to verify the replacement.
The ARIES-AT power core2 is the design basis for this comparison. One possible maintenance approach is the in-situ removal of moderate-sized modules of individual first wall, blanket, and divertor elements from inside the tokamak power core. This approach potentially allows smaller and lower cost toroidal and poloidal field coils that tightly fit around the outer surface of the power core shield or vacuum vessel. A second approach uses larger toroidal and poloidal field coils that will allow much larger ports to extract a complete, intact sector module of the first wall, blanket, shield, and divertor elements.
The time to access and egress the power core components is largely determined by operations independent of the maintenance approach, such as reactor cool down, draining/filling fluids, unfastening/fastening doors, vacuum leak checks, etc. Replacement time of the core elements was found to significantly favor the modular sector approach because there are fewer and more accessible coolant and structural joints to unfasten and fasten. For the in-situ maintenance approach for ARIES-AT, there are more, but smaller, modules to handle than with the modular sector approach. Verification of the successful refurbishment is a distinct advantage for the modular sector approach because it can be operationally tested in a remote assembly area before being installed. Only a few main coolant connections will be verified within the power core region. For these reasons, the modular sector maintenance approach was adopted for the ARIES-AT conceptual design.
