EPRI Technical Support for Nuclear Plant Operation to 60 Years, 80 Years, or More

EPRI Technical Support for Nuclear Plant Operation to 60 Years, 80 Years, or More

05 September 2023

EPRI’s efforts to study the option of long-term operation (LTO) or operation beyond the original license period have been underway for decades. EPRI worked with the U.S. nuclear industry in the 1980’s and 1990’s to research the options and challenges for operation beyond 40 years, which was the original license period for U.S. nuclear power plants. After extensive studies, both technical and economic, EPRI was able to provide needed technical support for the first license renewal applicants in the late 1990’s.  Due in large part to the success of those first license renewal projects, more than 90% of the 93 nuclear plants currently operating in the U.S. have received regulatory approval to operate for up to 60 years [1] and most of the remaining plants have applications under review or have announced plans to submit applications. 


In 2010, EPRI embarked on additional research to evaluate the potential to operate even longer. By 2020, EPRI’s research results concluded that there were no generic technical issues to preclude operation to 80 years or longer. This research and the technical reports produced have been used by utilities to successfully obtain regulatory approval for up to 80 years of operation. Based on recent U.S. industry reports, greater than 90% of the 80 units surveyed anticipate seeking approval to operate to at least 80 years. [2]


EPRI’s international members have also taken advantage of LTO research results to extend operation of their nuclear power plants. Globally, of over 400 operating reactors, more than 300 reactors have been operating for 20 or more years and more than 100 of these have been operating for 40-plus years. [3]  About 100 of these plants have received life extension licenses, and others are pursuing extension.  EPRI-led efforts currently underway in this area include global collaborative research, technology transfer, customized solutions, and application services.


The EPRI approach, regardless of plant location, focuses on forming a sound technical basis on key aging parameters including assessing and estimating the remaining useful life of components, which may well extend beyond 80 years of operation. To address aging components, EPRI has developed options to monitor degradation, assess and estimate remaining life, mitigate aging effects during operations, and specific repairs or replacements. These options have been developed based on decades of well documented research, operating experience, and inspection results. [4]


EPRI is committed to providing vital research and technical support for LTO of nuclear power plants worldwide for the long-term to benefit the public and while addressing potential safety and reliability concerns.



  1. https://www.nrc.gov/reactors/operating/licensing/renewal/applications.html
  2. https://www.ans.org/meetings/am2023/session/view-1661/
  3. https://pris.iaea.org/PRIS/
  4. Life-Limiting Issues for Long-Term Operation of Nuclear Power Plants. EPRI, Palo Alto, CA: 2010. 1021115.


For more information please contact


Robert Krivanek
Long Term Operation Liaison