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
2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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
Jun 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
July 2025
Nuclear Technology
June 2025
Fusion Science and Technology
Latest News
Former NRC commissioners lend support to efforts to eliminate mandatory hearings
A group of nine former nuclear regulatory commissioners sent a letter Wednesday to the current Nuclear Regulatory Commission members lending support to efforts to get rid of mandatory hearings in the licensing process, which should speed up the process by three to six months and save millions of dollars.
Neil E. Todreas
Nuclear Technology | Volume 167 | Number 1 | July 2009 | Pages 127-144
Technical Paper | NURETH-12 / Fission Reactors | doi.org/10.13182/NT09-A8857
Articles are hosted by Taylor and Francis Online.
Thermal-hydraulic challenges in the design of the following four Generation IV fast reactor concepts are presented: sodium \[sodium-cooled fast reactor (SFR)\], lead \[lead-cooled fast reactor (LFR)\], gas \[gas-cooled fast reactor (GFR)\], and liquid salt \[liquid salt-cooled fast reactor (LSFR)\]. The supercritical carbon dioxide Brayton cycle in indirect mode is the candidate power cycle for all coolants except gas, which is direct cycle. Thermal-hydraulic considerations must be closely integrated with neutronic analysis to properly control reactivity feedbacks, particularly that of the coolant density coefficient. The thermal-hydraulic performance of all reactors is compared to the sodium concept, which has superior performance because of the inherent properties of sodium. The chemical incompatibility of sodium with water and air remains a concern, should a steam generator tube or other sodium line leak. Challenges in steady-state operation, transient performance, shutdown heat removal, and loss-of-coolant-accident design accommodation in gas reactors are reviewed.
