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
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
Hanlin Shu, Liangzhi Cao, Qingming He, Qi Zheng, Tao Dai
Nuclear Science and Engineering | Volume 198 | Number 11 | November 2024 | Pages 2209-2229
Research Article | doi.org/10.1080/00295639.2023.2295065
Articles are hosted by Taylor and Francis Online.
The unstructured mesh (UM)–based Monte Carlo (MC) method can utilize modern computer-aided-design/computer-aided-engineering platforms to obtain geometric models with reduced human effort and is capable of generating high-resolution tally data. This approach presents a significant advantage over the traditional Constructive Solid Geometry (CSG)–based MC method in handling complex geometries and conducting multiphysics calculations. In this study, the UM-based MC calculation capability was developed in the MC code NECP-MCX. On this basis, an automatic UM-based Consistent Adjoint-Driven Importance Sampling (CADIS) method was further studied and implemented in which the adjoint deterministic calculation, forward MC calculation, and variance reduction (VR) parameter generation were performed on the unified UM model. To achieve this, the discrete ordinates (SN)–Discontinuous Finite Element Method (DFEM) code NECP-SUN was embedded into NECP-MCX as the adjoint transport solver. Validations of the developed code and evaluations of the VR performance of the UM-based CADIS method were conducted on the Pool Critical Assembly (PCA) Replica benchmark and H. B. Robinson Unit 2 (HBR-2) benchmark. The numerical results indicated that the developed UM-based particle tracking capability achieved comparable accuracy to the CSG-based approach. Furthermore, compared to the traditional CADIS method, the UM-based CADIS method demonstrated higher figure-of-merit (FOM) values (3.5 to 44 times higher for the PCA Replica benchmark and 2.22 to 2.92 times higher for the HBR-2 benchmark), highlighting the superior VR performance of the UM-based CADIS method over the traditional CADIS method.
