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
Fusion Energy
This division promotes the development and timely introduction of fusion energy as a sustainable energy source with favorable economic, environmental, and safety attributes. The division cooperates with other organizations on common issues of multidisciplinary fusion science and technology, conducts professional meetings, and disseminates technical information in support of these goals. Members focus on the assessment and resolution of critical developmental issues for practical fusion energy applications.
Meeting Spotlight
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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
Jan 2025
Jul 2024
Latest Journal Issues
Nuclear Science and Engineering
February 2025
Nuclear Technology
January 2025
Fusion Science and Technology
Latest News
Marzano sworn in as NRC commissioner
Marzano
Matthew Marzano became the newest member of the Nuclear Regulatory Commission when he was officially sworn into office by chair Christopher Hanson this week.
The nuclear engineer and former reactor operator was confirmed last month in a 50–45 vote in the U.S. Senate. Last July, President Biden nominated Marzano to serve on the commission, which is tasked with formulating policies, developing regulations, issuing orders, and resolving legal matters.
Marzano’s term expires June 30, 2028.
Joseph O. Erb, James G. Miller
Nuclear Technology | Volume 83 | Number 3 | December 1988 | Pages 367-373
Technical Paper | Fifth International Retran Meeting / Heat Transfer and Fluid Flow | doi.org/10.13182/NT88-A34149
Articles are hosted by Taylor and Francis Online.
The rod ejection transient is a postulated Condition IV event initiated by the mechanical failure of a control rod mechanism pressure housing. Such a failure results in the rapid ejection of a rod cluster control assembly from the core, followed by a fast reactivity insertion. A severe asymmetric core power distribution may result, possibly leading to fuel rod damage. Reactor protection for the transient is provided by negative reactivity feedback effects and by reactor trips on high neutron flux levels. This transient has been modeled for Virginia Electric and Power Company’s Surry and North Anna nuclear power stations using RETRAN-02. The analysis is performed in two parts. First, the core average power history is calculated using a single-loop model with point kinetics and three axially stacked core control volumes. The ejected rod’s reactivity is inserted linearly over 0.1 s. The negative reactivity feedback effects due to Doppler and moderator temperature changes and the reactor trip are also modeled. The effect of the locally peaked core flux shape, omitted by the nominal point kinetics model, is approximated by applying a conservative power weighting factor to the Doppler reactivity feedback. The core average power history is adjusted to represent peak core power conditions and input to the hot spot thermal-hydraulic analysis model. The hot spot model, which represents a single fuel rod at the core’s peak power, predicts maximum fuel enthalpy and temperature transients. This model has two control volumes, one for the hot spot location and the second for a sink for flow from the hot channel. From these results, the amount of fuel damage and the radiological consequences can be assessed.
