A new research program headed by the US Department of Energy will begin to investigate the case for reactor lifespans of greater than 60 years.
There are 104 operating nuclear power reactors in the USA, all of which are either boiling water reactors or pressurized water reactors. Both these designs are types of light water reactor - refering to the fact they use water as a moderator.
The US system sees reactors originally licensed for a period of 40 years, with the possibility of a one-off 20 year licence renewal. The majority of operating US reactors have already received this and the remainder are expected to eventually apply. As part of this process, operators have to submit information on the technical considerations of plant-aging and how they intend to manage them. The safety and economic case has not yet been made for going beyond 60 years, although operators and regualtors are aware of some risks and benefits.
The Light Water Reactor Sustainability (LWRS) program will look to clarify these risks by investigating technical foundations for ensuring the safe and economic operation of reactors in any second life extension period. In an 'integrated program plan' released on 1 February, four distinct research and development pathways were outlined, including materials aging and degradation, advanced light water reactor nuclear fuels, advanced instrumentation, and information and control systems technologies.
Answers will soon need to be known. The oldest operating power reactors in the USA passed the 40 year mark in 2009 and have renewed licences due to expire in 2029. The program report notes that without further extending reactor lifespans and adding new reactors, nuclear generation in the USA will begin to fall off rapidly after 2030 and possibly much sooner resulting in the loss of one of the country's main low carbon generating sources.
The research is considered a priority for helping America meet its long-term objectives of energy and environmental security. While for now cheap gas prices make a new nuclear plant a risky investment in the USA, existing nuclear remains more than competitive and a very important contributor to the energy mix.
According to the authors, "Extending the operating lifetimes of current plants beyond 60 years and, where practical, making further improvements in their productivity is essential to realizing the administration's goals of reducing greenhouse gas emissions to 80% below 1990 levels by the year 2050."
Researched and written
by World Nuclear News