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
Young Members Group
The Young Members Group works to encourage and enable all young professional members to be actively involved in the efforts and endeavors of the Society at all levels (Professional Divisions, ANS Governance, Local Sections, etc.) as they transition from the role of a student to the role of a professional. It sponsors non-technical workshops and meetings that provide professional development and networking opportunities for young professionals, collaborates with other Divisions and Groups in developing technical and non-technical content for topical and national meetings, encourages its members to participate in the activities of the Groups and Divisions that are closely related to their professional interests as well as in their local sections, introduces young members to the rules and governance structure of the Society, and nominates young professionals for awards and leadership opportunities available to members.
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
College students help develop waste measuring device at Hanford
A partnership between Washington River Protection Solutions (WRPS) and Washington State University has resulted in the development of a device to measure radioactive and chemical tank waste at the Hanford Site. WRPS is the contractor at Hanford for the Department of Energy’s Office of Environmental Management.
Justin K. Watson, Kostadin N. Ivanov
Nuclear Technology | Volume 180 | Number 2 | November 2012 | Pages 174-190
Technical Paper | Reactor Safety | doi.org/10.13182/NT12-A14632
Articles are hosted by Taylor and Francis Online.
Historically, large physics problems have been divided into smaller problems based on the individual physics, typically referred to as operator splitting. The analysis of a nuclear reactor for design-basis accidents is performed by a handful of computer codes each solving a portion of the problem, based on the physics involved. The reactor thermal-hydraulic response to an event is determined using a system code like TRAC RELAP Advanced Computational Engine (TRACE). The core power response to the same accident scenario is determined using a spatial neutron kinetics code like Purdue Advanced Reactor Core Simulator (PARCS). The drive of industry to uprate power for reactors has motivated analysts to move from a conservative approach to design-basis accidents toward a best-estimate method. To achieve a best-estimate calculation, efforts have been aimed at coupling the individual physics models to improve the accuracy of the analysis and reduce margins. The current coupling techniques are sequential in nature (i.e., they treat shared data explicitly in time). During a calculation time-step data are passed between the two codes. The individual codes solve their portions of the calculation and converge to a solution before the calculation is allowed to proceed to the next time step. This paper presents a fully implicit method of simultaneously solving the neutron balance equations, heat conduction equations, and constitutive fluid dynamics equations. The paper also outlines the basic concepts behind the nodal balance equations, heat transfer equations, and thermal-hydraulic equations, which will be coupled to form a fully implicit nonlinear system of equations. It presents a monolithic method for the solution of the implicit equation set. The coupling technique described in this paper was implemented into the TRACE/PARCS coupled code system and is applicable to other similar coupled thermal-hydraulic and core physics reactor safety codes. This technique is demonstrated using coupled input decks to show that the system is solved correctly and then verified by using simple one-dimensional coupled problems. These simplified problems demonstrate the ability of this method to solve nonlinear coupled systems and maintain accuracy while removing time-step dependency of the coupled calculation.