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.
Explore membership for yourself or for your organization.
Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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
Jul 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
August 2025
Nuclear Technology
Fusion Science and Technology
Latest News
ANS joins others in seeking to discuss SNF/HLW impasse
The American Nuclear Society joined seven other organizations to send a letter to Energy Secretary Christopher Wright on July 8, asking to meet with him to discuss “the restoration of a highly functioning program to meet DOE’s legal responsibility to manage and dispose of the nation’s commercial and legacy defense spent nuclear fuel (SNF) and high-level radioactive waste (HLW).”
A. Bousbia Salah, J. Vlassenbroeck, H. Austregesilo
Nuclear Technology | Volume 192 | Number 1 | October 2015 | Pages 1-10
Technical Paper | Fission Reactors | doi.org/10.13182/NT14-51
Articles are hosted by Taylor and Francis Online.
Following an accidental event in a nuclear pressurized water reactor, involving the loss of primary-side forced coolant flow, the core decay heat is generally removed through a natural circulation convection process. The cooldown of the reactor coolant system is carried out through the secondary-side heat sink following prescribed guidelines. However, under asymmetric primary-side cooling conditions, natural circulation interruption (NCI) in the loops with an inactive steam generator may take place. Under such conditions, the cooldown of the primary side may be hindered and the transient may evolve toward a degraded state. The NCI issue was recently addressed within the thermal-hydraulic experimental projects ROSA-2 and PKL-2 of the Nuclear Energy Agency of the Organisation for Economic Co-operation and Development. The objective was to identify the conditions that may lead to the occurrence of NCI, to develop cooldown procedures that prevent the occurrence of NCI, and to assess the thermal-hydraulic code capabilities in predicting this phenomenon. In the current study, NCI experimental tests carried out in the LSTF (Large Scale Test Facility) and PKL (Primaer-KreisLauf) facilities are assessed using the best-estimate thermal-hydraulic system codes CATHARE and ATHLET. The simulation results are presented and conclusions are derived accordingly.