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
May 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Argonne researching “climate-ready” nuclear plant design
Scientists at Argonne National Laboratory have partnered with Washington state–based Energy Northwest to look at alternative ways to cool nuclear reactors as climate change impacts relied-upon water sources.
Dimitar Altiparmakov, Robert Wiersma
Nuclear Science and Engineering | Volume 182 | Number 4 | April 2016 | Pages 395-416
Technical Paper | doi.org/10.13182/NSE15-28
Articles are hosted by Taylor and Francis Online.
The size and the density of the collision probability matrix have been recognized as major deficiencies since the early era of development of the collision probability method. The computing time of the matrix inversion is proportional to the third degree of the number of unknowns per group and increases rapidly with the increase of the problem size. This is a severe limitation that restricts the capabilities of the method and makes it inapplicable to large-size neutron transport problems. This paper presents a new solution method that overcomes these deficiencies and extends the capabilities of the collision probability approximation. To reduce the matrix inversion time, a block partition is applied, and the solution is obtained by block iteration. Owing to the partition, the method is suitable for parallel calculations on contemporary computers. To illustrate the potential advantages, the following three groups of calculations are presented. In the first group, results of sequential calculations reveal the advantage over traditional methods of direct solution and point iteration. In the second group, memory shared parallelism results present the speedup that can be achieved in solving medium-size problems on a standard multicore desktop computer. In the third group, distributed memory calculations show an example of the solution of a large-size two-dimensional model problem of a heavy water power reactor invoking 100 thousand unknowns per group.