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
Decommissioning & Environmental Sciences
The mission of the Decommissioning and Environmental Sciences (DES) Division is to promote the development and use of those skills and technologies associated with the use of nuclear energy and the optimal management and stewardship of the environment, sustainable development, decommissioning, remediation, reutilization, and long-term surveillance and maintenance of nuclear-related installations, and sites. The target audience for this effort is the membership of the Division, the Society, and the public at large.
Meeting Spotlight
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
May 2024
Nuclear Technology
Fusion Science and Technology
Latest News
College students help develop waste-measuring device at Hanford
A partnership between Washington River Protection Solutions (WRPS) and Washington State University has resulted in the development of a device to measure radioactive and chemical tank waste at the Hanford Site. WRPS is the contractor at Hanford for the Department of Energy’s Office of Environmental Management.
Swaminathan Vaidyanathan
Nuclear Technology | Volume 207 | Number 12 | December 2021 | Pages 1793-1809
Technical Paper | doi.org/10.1080/00295450.2020.1846987
Articles are hosted by Taylor and Francis Online.
Although η, the number of neutrons released per neutron absorbed in a 232Th-233U (thorium) fuel cycle, is greater than 2 in the thermal spectrum and therefore the possibility of breeding in a water-moderated reactor exists, it has been found difficult to achieve in practice. It is useful to relax the constraint for breeding and examine a thorium cycle for pressurized water reactors PWRs, denoted as PWR-Th, with the provision that the shortfall be made up by 233U bred in a PWR operating on a uranium fuel cycle, denoted as PWR-U, both of which utilize bimetallic thorium-zirconium alloy cladding as part of the fuel rod design. The number of complementary PWRs that could be sustainably operated on a thorium cycle was seen to critically depend on the moderator-to-fuel ratio (MF). Detailed cycle-by-cycle analysis shows that at the end of the first cycle, the sustainability ratio, namely, the ratio of sustainable PWR-Th reactors to PWR-U reactors, is 1.07 at an MF of 1.91, 1.4 at an MF of 1.43, and 4.45 at an MF of 0.954. The shortfall in 233U was found to decrease continually in subsequent cycles with the sustainability ratio increasing to 1.45, 2.01, and 28.3 at the respective MF values of 1.91, 1.43, and 0.954 by the 25th cycle. Although the sustainability ratio increases with lower MF, the achievable discharge exposure decreases necessitating larger material throughput in reprocessing. Detailed evaluations for fuel thermal, mechanical performance and nuclear reactivity feedback parameters require a further narrowing of potential design parameters based on holistic considerations arising from reprocessing. The PWR-Th reactors generate only trace amounts of transuranic (TRU) waste, and combined with a PWR-U design with bimetallic thorium cladding that generates only a fourth of the TRU waste compared to the standard all-UO2 fuel cycle, a significant reduction in TRU waste is possible.