There are currently 99 nuclear reactors in the United States operating at a total of 61 sites across the country. (See Figure 1 - although 1 reactor at Fortt Calhoun, Nebraska has since retired.) Most reactors were originally licensed to operate for 40 years with the ability to renew the license for an additional 20 years. Since most nuclear plants were built in the 1970's and 80's, these plants are nearing the end of their licenses, and, in fact, 71 of the reactors have already been granted license extensions. There are a total of 38 possible units on a retirement list because they exhibit a number of risk factors, including competition from lower-cost energy sources, declining demand, upgrade and repair expenses, and rising operating costs.
Nuclear plant retirements have recently become very big news and are indicative of a very new dynamic in the nuclear power industry with the glee of the anti-nuclear crowd subdued by the concern over loss of significant quantities of green power. Some of the most news-worthy retirements are:
- San Onofre Nuclear Generating Station (California - Figure 2) - In 2010 and 2011 Southern California Edison (SCE) replaced the steam generators for San Onofre Units 2 and 3 in a $680 million contract with Mitsubishi Heavy Industries (MHI). The project was planned as a "replace in kind" effort, which required relatively minimal review by the Nuclear Regulatory Commission (NRC). In January 2012, a little more than a year after start-up of Unit 2, a leak developed in the new heat exchange tubing system that resulted in shut-down of the unit. Inspection of Unit 3 showed similar damage. This triggered a series of lawsuits with SCE claiming that there were design flaws attributed to MHI, MHI claiming there were design changes by SCE to increase power output and that recommendations from MHI were rejected, and the NRC ultimately concluding that there wasn't sufficient oversite or quality control by both parties. The plant was permanently shut down, eliminating approximatley 9% of California's total electrical power generation capabilty and over 20% of its green energy. Decommissioning is expected to start as early as 2018 and will take approximately 20 years to complete at an expected cost of $4.4 bn.
- Crystal River Nuclear Power Plant (Florida) - In 2009, the plant's owner, Progress Energy, made the decision to handle construction management of a steam generator replacement project internally in order to save money. They contracted out engineering support to a company that had never worked on a nuclear plant, and made management decisions to short-cut standard practices for cutting into the containment structure. As a result, the containment structure began to fall apart and was ultimately deemed unrepairable. Replacement of the containment structure was estimated at over $2.5 billion. In 2013 Duke (after merging with Progress Energy) made the decision to decommission the plant rather than repair it, a process that is expected to cost about $1.2 billion and take about sixty years.
- Diablo Canyon Power Plant (California - Figure 3) - In September 2016, PG&E announced that they were going to shut down the two nuclear reactors at the Diablo Canyon Power Plant when its license from the NRC expires in 2025. This decision was made not after facing expensive problems like the two previous example plants, but apparently because PG&E was tired of fighting the anti-nuclear lobby and didn't want to go through the effort to recertify the plant for the standard 20-year license renewal. As a result, another approximately 9% of California's power generation capacity and another 20% of its green energy resources will be eliminated (on top of the impact from the San Onofre closure).
These and other potential nuclear plant closures have led to creation of some pro-nuclear advocacy groups whose primary issue is to address climate change and the need for nuclear power to help transition to a 100% renewable energy future, such as Environmental Progress
and Mothers for Nuclear
Partially offseting these retirements is the first nuclear reactor in 2 decades to achieve commercial operations in October 2016 - Tennessee Valley Authority's Watts Bar 2. Watts Bar 2 began construction in 1974, suspended construction in 1985 and was mothballed, then restarted in 2007. Ironically, prior to this, the last nuclear plant to come on-line in the US was Watts Bar 1, which started construction in 1973 and didn't achieve commercial operations until 1996.
Until July 2017, there were 4 new nuclear reactors under construction in the US - two new reactors at Plant Vogtle in Georgia (Figure 4) and two new reactors at Virgil C Summer in South Carolina. These projects were the first to be licensed by the NRC under new rules established under the 2005 Energy Policy Act and were expected to achieve commercial operations in 2020-2021. They were the first in what was envisioned as a second wave of nuclear plant construction, referred to as the "Nuclear Renaissance"
. However, plans for all other projects were either cancelled or shelved. The plants under construction, Vogtle and Summer, soon became significantly over budget and behind schedule, and the company behind the nuclear technology being used at both, Westinghouse, filed for bankruptcy. Summer was subsequently canceled, but the decision was made in January 2017 to complete construction on Plant Vogtle, with completion of the 2 units now estimated in 2023.
Although a significant source of non-polluting power that doesn't contribute to greenhouse gasses in the atmosphere, nuclear power in the US is on a downward trajectory.