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.
Explore membership for yourself or for your organization.
Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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
Sep 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
Fusion Science and Technology
October 2025
Latest News
Shifting the paradigm of supply chain
Chad Wolf
When I began my nuclear career, I was coached up in the nuclear energy culture of the day to “run silent, run deep,” a mindset rooted in the U.S. Navy’s submarine philosophy. That was the norm—until Fukushima.
The nuclear renaissance that many had envisioned hit a wall. The focus shifted from expansion to survival. Many utility communications efforts pivoted from silence to broadcast, showcasing nuclear energy’s elegance and reliability. Nevertheless, despite being clean baseload 24/7 power that delivered a 90 percent capacity factor or higher, nuclear energy was painted as risky and expensive (alongside energy policies and incentives that favored renewables).
Economics became a driving force threatening to shutter nuclear power. The Delivering the Nuclear Promise initiative launched in 2015 challenged the industry to sustain high performance yet cut costs by up to 30 percent.
Robert I. Brasier, L. D. P. King, Carroll B. Mills
Nuclear Technology | Volume 6 | Number 4 | April 1969 | Pages 266-273
Technical Papers and Note | doi.org/10.13182/NT69-A28333
Articles are hosted by Taylor and Francis Online.
Recent theoretical and experimental work has established minimum critical masses for uranium and plutonium reactor fuels. Studies at Los Alamos show a minimum of 300 to 600 g in the critical mass of 235U for H2O or D2O moderator and D2O or Be reflectors. An H2O-moderated, Be-reflected core containing 0.070 g 235U/mliter has a very low critical mass, which is of interest in the design of small power reactors and has attractive features for a new high neutron flux reactor concept. This report relates nuclear parameter studies to specific design objectives and shows how special effects of geometry and materials are important to such studies.
