INL News Release
April 24, 2017

Jennifer Eisenbeis, 208.524.2500,
Sarah Neumann, 208.520.1651,

100th Licensing Agreement signed for INL Software RELAP5-3D

Idaho National Laboratory’s Reactor Excursion and Leak Analysis Program5-3D (RELAP5-3D) reached a milestone this week when it signed its 100th active license agreement. The RELAP5-3D code is used primarily for analysis of potential accidents and transients in water-cooled nuclear power plants, and for analysis of advanced reactor systems.

Since it was first introduced in 1996, RELAP5-3D has become one of the most widely licensed software products within DOE. Use of the code has grown steadily, nearly doubling in the last five years, and continued growth is expected. Licensees, both international and domestic, include universities, government agencies, nuclear steam supply system providers and utilities with operating power plants.

RELAP5-3D sustains itself primarily with membership fees from the International RELAP Users Group (IRUG), which provides funding to continually upgrade and maintain this safety analysis code.

INL is one of the U.S. Department of Energy’s national laboratories. The laboratory performs work in each of DOE’s strategic goal areas: energy, national security, science and environment. INL is the nation’s leading center for nuclear energy research and development. Day-to-day management and operation of the laboratory is the responsibility of Battelle Energy Alliance.

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