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
Materials Science & Technology
The objectives of MSTD are: promote the advancement of materials science in Nuclear Science Technology; support the multidisciplines which constitute it; encourage research by providing a forum for the presentation, exchange, and documentation of relevant information; promote the interaction and communication among its members; and recognize and reward its members for significant contributions to the field of materials science in nuclear technology.
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
May 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
June 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Securing the advanced reactor fleet
Physical protection accounts for a significant portion of a nuclear power plant’s operational costs. As the U.S. moves toward smaller and safer advanced reactors, similar protection strategies could prove cost prohibitive. For tomorrow’s small modular reactors and microreactors, security costs must remain appropriate to the size of the reactor for economical operation.
Ashlea V. Colton, Blair P. Bromley
Nuclear Technology | Volume 196 | Number 1 | October 2016 | Pages 1-12
Technical Paper | doi.org/10.13182/NT16-70
Articles are hosted by Taylor and Francis Online.
Thorium, a fertile nuclear fuel that is nearly three times as abundant as uranium, represents a long-term energy source that could complement uranium and eventually replace it. With the expected refurbishment and new construction of pressure tube heavy water reactors (PT-HWRs) within the international community, there is an opportunity to gain experience with thorium-based fuels and to start the transition toward the use of thorium as part of the nuclear fuel cycle.
This paper presents an evaluation of fuel types that could be implemented in the near-term to transition into thorium-based fuels in current PT-HWRs. The near-term fuel consists of small amounts of thorium (in a traditional 37-element fuel bundle that is mostly filled with natural uranium or slightly enriched uranium). In addition, a modified 37-element fuel bundle type comprised of slightly enriched uranium fuel (1.2 wt% 235U/U or less), a thorium central element, and the mass equivalent of 1-cm thorium end pellets was studied. Both lattice physics depletion simulations and full-core time-averaged neutron diffusion simulations were carried out to evaluate the performance and safety characteristics of the different studied full-core configurations.
The results demonstrate that adding small amounts of thorium into the fuel of a 37-element bundle is feasible, through enrichment, without reducing power in the reactor or incurring a severe burnup penalty. The most viable core configuration is a core filled with modified 37-element fuel containing slightly enriched uranium dioxide with 1.2 wt% 235U/U. Even with the addition of 1.2 kg of thorium metal to the bundle, significant gains are achieved, including an increased margin to maximum bundle power limit of 40 kW and a 50% increase in fissile utilization.