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
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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.
Joonhong Ahn
Nuclear Technology | Volume 121 | Number 1 | January 1998 | Pages 24-39
Technical Paper | Kiyose Birthday Anniversary | doi.org/10.13182/NT121-24
Articles are hosted by Taylor and Francis Online.
Presented are results of a mathematical analysis on radionuclide transport in parallel planar fractures in water-saturated geologic formations integrated with the source term model, where precipitation of hardly soluble species at the waste-form alteration location and subsequent radionuclide transport in the engineered barriers are considered. Radioactive decay chains of an arbitrary length are considered. A computer code has been developed based on the analytical solutions.The major hazard contributors are 241Am and 243Am in the waste form; 239Pu, 229Th, and 243Am at the surface of the engineered barriers; 223Ra, 231Pa, and 227Ac at a 10-m location from the engineered barriers; and 99Tc, 223Ra, and 225Ra at a 100-m location. With a transport distance of 100 m through the natural barrier, a four-orders-of-magnitude reduction in the total hazard is observed.Thus, the importance of the region in the vicinity of the engineered barriers in the context of the safety assessment can be pointed out. Because the region is disturbed by repository construction, further analysis must be performed by taking into account differing geochemical, hydrological, and mechanical properties from those in the undisturbed host rock.Because the major contributors in the host rock are the decay daughters of minor actinides, recovery of minor actinides reduces the total hazard evaluated at the exit of the geosphere. However, the radiological hazard would be reduced much more effectively by the 100-m-thick geologic formation around the repository than by even a 99% recovery of the actinides.