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
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
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
June 2024
Nuclear Technology
May 2024
Fusion Science and Technology
Latest News
Commercial nuclear innovation "new space" age
In early 2006, a start-up company launched a small rocket from a tiny island in the Pacific. It exploded, showering the island with debris. A year later, a second launch attempt sent a rocket to space but failed to make orbit, burning up in the atmosphere. Another year brought a third attempt—and a third failure. The following month, in September 2008, the company used the last of its funds to launch a fourth rocket. It reached orbit, making history as the first privately funded liquid-fueled rocket to do so.
Jean-Christophe Lecoy, Jean-Yves Sauvage, Camille Charignon
Nuclear Technology | Volume 205 | Number 12 | December 2019 | Pages 1567-1577
Technical Paper | doi.org/10.1080/00295450.2019.1580528
Articles are hosted by Taylor and Francis Online.
Combined approaches are now applied in safety analyses of design-basis accidents. They consist of using best-estimate models in the computer codes together with their estimated uncertainties, and require the most unfavorable initial and boundary conditions (IBCs) to be found with respect to the plant operating conditions. This implies determining first the worst-case scenarios, then predicting the figures of merit (FOMs) that must fulfill safety criteria. Such scenarios can be identified by sensitivity studies on IBCs resulting in an input vector of fixed values to realize a deterministic bounding calculation. However, it is a difficult and time-consuming iterative task especially for complex transients with interactions between parameters. Alternatively, the RIPS (Reduction of the Interval of variation of the Parameters of the Scenario) method has been developed in a best-estimate plus uncertainty approach to find the worst IBCs as a set of reduced ranges of variation of the related inputs, rather than by a vector of discrete values. It defines a critical zone for which the FOM is maximized (or minimized). To this end the RIPS method provides quantitative and graphical outcomes enabling identification of the detrimental (or favorable) ranges of variation of the preponderant IBC parameters. This is done through a statistical analysis of a large set of calculations in which all the input parameters and code model uncertainties are randomly sampled. The RIPS method analyzes the higher (or lower) quantiles of the FOM cumulative density function and determines for each input parameter the critical zone within its variation interval, i.e., where it is the most influential. Correlations between parameters are also detected. This paper describes the RIPS method and demonstrates with several examples its ability to adequately identify the critical zone of the IBC configuration space.