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
Mathematics & Computation
Division members promote the advancement of mathematical and computational methods for solving problems arising in all disciplines encompassed by the Society. They place particular emphasis on numerical techniques for efficient computer applications to aid in the dissemination, integration, and proper use of computer codes, including preparation of computational benchmark and development of standards for computing practices, and to encourage the development on new computer codes and broaden their use.
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
Sep 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
November 2024
Nuclear Technology
October 2024
Fusion Science and Technology
Latest News
NRC restores expiration dates for renewed Turkey Point licenses
The Nuclear Regulatory Commission announced this week that it has restored the expiration dates of the Turkey Point nuclear power plant's units 3 and 4 subsequent license renewals (SLR) to July 19, 2052, and April 10, 2053, respectively.
P. Yarsky, Y. Xu, A. Ward, N. Hudson, T. Downar
Nuclear Technology | Volume 197 | Number 3 | March 2017 | Pages 265-283
Technical Paper | doi.org/10.1080/00295450.2016.1273707
Articles are hosted by Taylor and Francis Online.
On November 3, 2008, an unexpected drift of the last three of 177 control rods occurred at the Dresden Unit 3 boiling water reactor. The root cause of the control rod drift was the manner in which the hydraulic control units (HCUs) were isolated during the outage. The U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research (RES) performed a demonstration study of inadvertent control blade drift using RES-sponsored nuclear analysis tools. The smallest margin to recriticality was determined by calculating the control rod worths at each core state using the core simulator PARCS/PATHS and an innovative algorithm to identify the highest worth combination of rods. This study did not try to evaluate any correlation between drifting rods that may occur in a real plant due to the actual physical configuration of the system. The purpose of the analysis was to demonstrate the tools that could be used to analyze the situation if that information is known.
For the current purpose of this demonstration, Edwin Hatch Unit 1 Cycle 3 (H1C3) was selected as the reference core and cycle. Based on the results of these calculations, it was possible to determine the fraction of rod groups that would produce criticality consequences in each of these scenarios. The results confirmed several aspects of conventional thinking, such as the most reactive point being the beginning of the cycle at the coldest conditions. Further, with a single blade drifting out of the core, the analysis results confirm that shutdown margin is maintained. It was found that a small population (about 1%) of drift scenarios with two rods produced criticality consequences according to our best-estimate-plus-uncertainty method, while this fraction increases to about 3.5% for three rods and about 14% for four rods. The results of the study have confirmed the adequacy of the NRC control rod drift analysis methodology; however, the results are not generically applicable and apply only to H1C3.