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
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.
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.
R. Lo Frano
Nuclear Technology | Volume 189 | Number 1 | January 2015 | Pages 1-10
Technical Paper | Fission Reactors | doi.org/10.13182/NT14-23
Articles are hosted by Taylor and Francis Online.
The aim of the study is to investigate the structural effects induced by a beyond design basis earthquake on the main safety relevant structures and components of an isolated liquid metal reactor, such as the European Lead-cooled SYstem (ELSY) or ALFRED projects. An extensive R&D program related to heavy-metal cooled systems was recently carried out as Euratom projects of the 6th and 7th Framework Programmes, addressing many of the most important issues related to the viability of a lead-cooled fast reactor. The importance of seismic effects is mainly related to the high inertial forces of the primary coolant (liquid metal) and associated with the impact of the liquid waves on the reactor structures. The isolation devices considered for the design were represented by means of an iso-elastic approach. Moreover, the influence of isolator failure was also evaluated. The fluid-structure interaction and the sloshing phenomenon, characterized by hydrodynamic and impact forces, were numerically investigated, since an explicit analytical solution for structures of such complex geometry is not possible. Numerical calculations (i.e., dynamic nonlinear analyses) were carried out with appropriate finite element method codes and external coupling. A validation analysis was further performed to check the consistency and adequacy of the method used with respect to the American Society of Civil Engineers (ASCE) 4-98 rules. The accelerations propagated in the reactor building confirmed the favorable effect of the seismic isolation, even with 2% faulted isolators. The results indicated that the stress state, in the reactor internals, is not sufficient to impair their structural integrity, although there is localized plastic deformation.