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.
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
Utility Working Conference Virtual Summit (UWC)
August 11, 2020
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
Latest Journal Issues
Nuclear Science and Engineering
Fusion Science and Technology
Penfield and Enos: Outage planning in the COVID-19 era
Energy Harbor’s Beaver Valley plant, located about 34 miles northwest of Pittsburgh, Pa., was one of many nuclear sites preparing for a scheduled outage as the coronavirus pandemic intensified in March. The baseline objective of any planned outage—to complete refueling on time and get back to producing power—was complicated by the need to prevent the transmission of COVID-19.
While over 200 of the plant’s 850 staff members worked from home to support the outage, about 800 contractors were brought in for jobs that could only be done on-site. Nuclear News Staff Writer Susan Gallier talked with Beaver Valley Site Vice President Rod Penfield and General Plant Manager Matt Enos about the planning and communication required.
Beaver Valley can look forward to several more outages in the future, now that plans to shut down the two Westinghouse pressurized water reactors, each rated at about 960 MWe, were reversed in March. “The deactivation announcement happened in the middle of all our planning,” Enos said. “It’s a shame we haven’t had a chance to get together as a large group and celebrate that yet.”
While the focus remains on safe pandemic operations, the site now has two causes for celebration: an outage success and a long future ahead.
Timothée Kooyman, Laurent Buiron, Gérald Rimpault
Nuclear Science and Engineering | Volume 185 | Number 2 | February 2017 | Pages 335-350
Technical Paper | dx.doi.org/10.1080/00295639.2016.1272381
Articles are hosted by Taylor and Francis Online.
A methodology dedicated to the optimization of the transmutation of minor actinides (MAs) in dedicated blankets is discussed here. This methodology relies on recently developed optimization tools. In the so-called heterogeneous transmutation approach, MAs are loaded into specific assemblies located at the periphery of a fast reactor core. Thus, the resulting perturbation of the core behavior is limited and the management of MAs is entirely decoupled from standard fuel management. This also allows greater flexibility in the blanket design, in terms of material, volume fraction, and neutron spectrum to be used. On the other hand, the low neutron flux level experienced at the periphery of the core slows down the transmutation process. If this effect can be compensated for by an increase of the MA fraction loaded in the blankets, this also strongly increases their decay heat and neutron source level, which complicates spent fuel reprocessing and handling. An optimization is carried out with regard to the neutron spectrum and americium concentration in the blankets, with the dual objective of maximizing the transmuted MA mass while minimizing the total MA inventory in the fuel cycle by limiting the cooling time of such blankets. Artificial neural networks are coupled with a genetic algorithm to reduce the total calculation time. It is shown here that regardless of the MA mass to be loaded, a slightly moderated neutron spectrum is the most promising option for heterogeneous transmutation. This result is confirmed by full-core calculations. An analysis of the irradiation time is also performed, and it is shown that maximization of the irradiation time should be sought in the specific case studied here. It is concluded that from a purely physical point of view, no breakthrough can be obtained for heterogeneous transmutation.