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
Aug 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
August 2025
Fusion Science and Technology
Latest News
Chris Wagner: The role of Eden Radioisotopes in the future of nuclear medicine
Chris Wagner has more than 40 years of experience in nuclear medicine, beginning as a clinical practitioner before moving into leadership roles at companies like Mallinckrodt (now Curium) and Nordion. His knowledge of both the clinical and the manufacturing sides of nuclear medicine laid the groundwork for helping to found Eden Radioisotopes, a start-up venture that intends to make diagnostic and therapeutic raw material medical isotopes like molybdenum-99 and lutetium-177.
Gerardo Martinez-Guridi, Pranab Samanta, Tsong-Lun Chu, Ji-Wu Yang
Nuclear Technology | Volume 131 | Number 3 | September 2000 | Pages 297-318
Technical Paper | Reactor Safety | doi.org/10.13182/NT00-A3118
Articles are hosted by Taylor and Francis Online.
Following a loss-of-coolant accident (LOCA) in a nuclear power plant (NPP), the loss of electric-power generation, as might be precipitated by the unit tripping, may cause switchyard- and grid-instability with a subsequent loss-of-off-site power (LOOP). The LOOP usually is delayed by a few seconds or longer. This accident is called a LOCA with consequential LOOP, or a LOCA with delayed LOOP (abbreviated as LOCA/LOOP). NPPs are designed to cope with simultaneous LOCA and LOOP. The U.S. Nuclear Regulatory Commission (NRC) identified this issue as generic safety issue (GSI) 171, "Engineered Safety Feature Failure from a Loss-Of-Off-Site Power Subsequent to a Loss-of-Coolant Accident." NRC subsequently dropped GSI-171 and considers it resolved. We present the probabilistic risk analysis of the LOCA/LOOP scenario that was conducted as part of NRC's resolution of GSI-171. We analyze and quantify the core damage frequency (CDF) associated with this accident. Event/fault trees are developed covering the progression of the accident to core damage. We used engineering evaluations and judgments to estimate probabilities for the conditions identified in a LOCA/LOOP scenario and to obtain a bounding evaluation of the CDF. We show that the contribution of such an accident to CDF depends on electrical-load sequencing and shedding capabilities; plants with adequate capabilities incur a minimal additional contribution to risk. No single plant design is known to be vulnerable to all the conditions; only some of the conditions may apply to some plants.