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
Materials Science & Technology
The objectives of MSTD are: promote the advancement of materials science in Nuclear Science Technology; support the multidisciplines which constitute it; encourage research by providing a forum for the presentation, exchange, and documentation of relevant information; promote the interaction and communication among its members; and recognize and reward its members for significant contributions to the field of materials science in nuclear technology.
Meeting Spotlight
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
May 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Glass strategy: Hanford’s enhanced waste glass program
The mission of the Department of Energy’s Office of River Protection (ORP) is to complete the safe cleanup of waste resulting from decades of nuclear weapons development. One of the most technologically challenging responsibilities is the safe disposition of approximately 56 million gallons of radioactive waste historically stored in 177 tanks at the Hanford Site in Washington state.
ORP has a clear incentive to reduce the overall mission duration and cost. One pathway is to develop and deploy innovative technical solutions that can advance baseline flow sheets toward higher efficiency operations while reducing identified risks without compromising safety. Vitrification is the baseline process that will convert both high-level and low-level radioactive waste at Hanford into a stable glass waste form for long-term storage and disposal.
Although vitrification is a mature technology, there are key areas where technology can further reduce operational risks, advance baseline processes to maximize waste throughput, and provide the underpinning to enhance operational flexibility; all steps in reducing mission duration and cost.
Song Hyun Kim, Hong-Chul Kim, Jong Kyung Kim, Jea Man Noh
Nuclear Technology | Volume 177 | Number 2 | February 2012 | Pages 147-156
Technical Paper | Fission Reactors | doi.org/10.13182/NT12-A13362
Articles are hosted by Taylor and Francis Online.
The Dancoff factor is used in deterministic codes for the calculation of resonance absorption. In using the Monte Carlo simulation, some techniques, such as repeated structure, are commonly used for geometry modeling of pebbles and kernels. However, these methods, with some assumptions, can cause an error in the calculation of the Dancoff factor. In this study, a Monte Carlo simulation method for the evaluation of the Dancoff factor was developed to solve these problems. Random sampling and rejection techniques are used for geometry modeling of pebbles and kernels. Also, the random selection method of the pebble type is used for modeling of the fuel and moderator pebbles that are randomly mixed in the core. By using this method, the Dancoff factor was calculated, and the results were compared with the results calculated by the INTRAPEB code and the MCNP5 code. The results of the average intrapebble Dancoff factor agree well within 1% difference compared with the result of the other study that was calculated by the INTRAPEB code. The result of the average interpebble Dancoff factor was underestimated by [approximately]8%, compared with the result by using the MCNP5 code. Analysis shows that the difference is caused by modeling assumptions in using the MCNP5 code. In addition, the Dancoff factor of the HTR-PRTEUS reactor and its spatial dependency were evaluated. The results show that the method can be used in the calculation of the Dancoff factor with the consideration of the spatial dependency with good accuracy. It is expected that the method can simply calculate the average Dancoff factor calculation without the direct modeling of the complex pebble bed reactor geometries. Also, the Monte Carlo simulations with various fuel-to-moderator ratios can be evaluated. Therefore, it will be a powerful method to evaluate the Dancoff factor with consideration of a real geometrical distribution for the pebble bed reactors.