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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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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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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.
J. Ramon Ramirez, Gustavo Alonso, Robert T. Perry, Javier Ortiz-Villafuerte
Nuclear Technology | Volume 156 | Number 3 | December 2006 | Pages 247-255
Technical Paper | Fuel Cycle and Management | doi.org/10.13182/NT06-A3788
Articles are hosted by Taylor and Francis Online.
Reprocessing benefits are still being debated from the standpoint of economy. However, it is a clear option to reduce the amount of depleted fuel assemblies and a reduction of the reactor plutonium inventories. Several mixed-oxide (MOX) fuel concepts have been considered as an option for mixed-fuel reload assemblies in boiling water reactors in the past. In this work, a new MOX fuel assembly design is proposed. The design is based on the use of a proportional fissile ratio between equivalent fissile plutonium (239Pu + 241Pu) and fissile uranium (235U). This is referred to as the PUF ratio. Furthermore, the moderation ratio will be increased in the assembly as a way to reduce the possible impact of using MOX fuel on the reactivity control systems. The design and performance of the MOX fuel assembly and the mixed core are presented and discussed. The new design, for the cases considered, can increase the MOX batch reload up to 52 MOX assemblies, in comparison with the 24 assemblies from a design that does not increase the moderation ratio. The use of the combined PUF ratio and increased moderation ratio for the MOX assembly allows for a reduction in the average enrichment of fissile plutonium to 4.68 wt%, instead of the 6.75 wt% necessary without increasing the moderation ratio. Both MOX designs produce the same amount of energy during the proposed cycle length and satisfy the same thermal limits. Some comparisons are performed between the core with this MOX fuel assembly and the core that uses only standard uranium assemblies.
