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
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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
Aug 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
October 2024
Nuclear Technology
Fusion Science and Technology
August 2024
Latest News
New laws offer nuclear industry incentives for existing power plant uprates
This year, the U.S. nuclear industry received a much-needed economic boost that could help preserve operating nuclear power plants and incentivize upgrades that extend their lifespan and power output.
Signed into law in 2022, the Inflation Reduction Act offers production tax credits (PTCs) for existing nuclear power plants and either PTCs or investment tax credits (ITCs) for new carbon-free generation. These credits could make power uprates—increasing the maximum power level at which a commercial plant may operate—a much more appealing option for utilities.
O. Köberl, R. Seiler, R. Chawla
Nuclear Science and Engineering | Volume 146 | Number 1 | January 2004 | Pages 1-12
Technical Paper | doi.org/10.13182/NSE04-A2391
Articles are hosted by Taylor and Francis Online.
The shift toward low-enrichment uranium (LEU) fuel for gas-cooled high-temperature reactors (HTRs) has revealed a lack of experimental data for validating neutronics codes that are used for the design and licensing of such systems. In the framework of the LEU-HTR experimental program at the PROTEUS critical facility, the safety-related effects of accidental moderation increase (ingress of water or other hydrogeneous compounds) in pebble-bed HTR core configurations employing low-enriched (16.7%) fuel were investigated. An important neutron balance component in this context is the integral reaction rate ratio of 238U capture (C8) relative to 235U fission (F5).It was necessary to develop new experimental techniques for the accurate measurement of C8/F5 in the doubly heterogeneous fuel pebbles. These have involved the utilization of specially prepared particle foils on the one hand and the counting of whole fuel pebbles on the other. Core-center measurements employing both experimental methods have been carried out in two different HTR-PROTEUS configurations (with and without accidental moderation increase simulation, respectively). In each case, satisfactory agreement was obtained between the experimental results based on the two techniques. By carrying out a comparison of particle-foil C8/F5 measurements in the PROTEUS reactor's thermal column with the results of standard foil-activation measurement techniques, the systematic uncertainty (1) of the core-center measurements could be reduced by ~0.6%, yielding a net experimental error of ±1% with either of the new methods. A comparison of the experimental results with calculations based on the MICROX-2/TWODANT codes in conjunction with JEF-1 cross sections has indicated that this calculational route overpredicts the core-center C8/F5 value by ~2.5% in both the investigated configurations.