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
2026 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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
Dec 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
December 2025
Nuclear Technology
Fusion Science and Technology
November 2025
Latest News
Perpetual Atomics, QSA Global produce Am fuel for nuclear space power
U.K.-based Perpetual Atomics and U.S.-based QSA Global claim to have achieved a major step forward in processing americium dioxide to fuel radioisotope power systems used in space missions. Using an industrially scalable process, the companies said they have turned americium into stable, large-scale ceramic pellets that can be directly integrated into sealed sources for radioisotope power systems, including radioisotope heater units (RHUs) and radioisotope thermoelectric generators (RTGs).
R. C. Kern, M. T. Hsu
Nuclear Science and Engineering | Volume 68 | Number 1 | October 1978 | Pages 141-143
Technical Note | doi.org/10.13182/NSE78-A27282
Articles are hosted by Taylor and Francis Online.
One difficulty in using the RELAP4 code is that, owing to the overspecification of the volume and junction input data for the initial conditions, a residual friction term must be defined to establish steady-state conditions. If the corresponding residual friction coefficient is out of allowable range, the calculation is terminated at the initial data checking phase. An allowable residual friction coefficient is added to the form loss coefficient and is used throughout the transient calculation. This might affect the results if the residual friction coefficient is large. However, to model a system represented by a large number of volumes and junctions, manual adjustment of the input data, such as the pressure distribution, to reduce the effect of residual terms can take a significant amount of engineering time. A procedure that allows the code to do the adjustment internally is described in this Note.