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
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
May 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
June 2026
Nuclear Technology
Fusion Science and Technology
Latest News
WIPP: Lessons in transportation safety
As part of a future consent-based approach by the federal government to site new deep geologic repositories for nuclear waste, local communities and states that are considering hosting such facilities are sure to have many questions. Currently, the Waste Isolation Pilot Plant in New Mexico is the only example of such a repository in operation, and it offers the opportunity for state and local officials to visit and judge for themselves the risks and benefits of hosting a similar facility. But its history can also provide lessons for these officials, particularly the political process leading up to the opening of WIPP, the safety of WIPP operations and transportation of waste from generator facilities to the site, and the economic impacts the project has had on the local area of Carlsbad, as well as the rest of the state of New Mexico.
Ang Zhu, Yunlin Xu, Thomas Downar
Nuclear Science and Engineering | Volume 182 | Number 4 | April 2016 | Pages 435-451
Technical Paper | doi.org/10.13182/NSE15-39
Articles are hosted by Taylor and Francis Online.
Three-dimensional (3D), full-core transport modeling with pin-resolved detail for reactor dynamic simulation is important for some multiphysics reactor applications. However, it can be computationally intensive due to the difficulty in maintaining accuracy while minimizing the number of time steps. An innovative Predictor-Corrector Quasi-static Method (PCQM) is introduced that is based on a Transient MultiLevel (TML) methodology. Two levels of couplings are used between 3D-transport/3D-CMFD (coarse-mesh finite difference) and 3D-CMFD/EPKE (exact point-kinetics equation). In each level, the original flux equation is solved in the coarse predictor step and then is factorized as an amplitude and a shape function in the corrector step, where the predicted solution is adjusted using multiple fine steps. In the first-level 3D-transport/3D-CMFD coupling, the angular and subpin flux shape functions in the Boltzmann transport equation are assumed to vary slowly over time, and the CMFD cellwise amplitude function is solved using multiple steps by the 3D-CMFD transient equation. In the second level, the CMFD scalar flux calculated in the last step is further corrected by a whole-core-wise amplitude function generated by the EPKE solver. The utilization of hierarchical multilevel neutronics transient solvers achieves the goal to balance the numerical accuracy and computational efficiency. In addition, a new iteration scheme with pin-resolve thermal-hydraulic feedback and theoretical proof for the accuracy of PCQM are also presented. Finally, a stripe assembly case adopted from the SPERT (Special Power Excursion Reactor Test) transient tests is used to demonstrate the accuracy and efficiency of the TML method.