Late last week, Constellation Energy (NASDAQ:CEG) and Microsoft (NASDAQ:MSFT) signed a power deal to help resurrect the Three Mile Island nuclear plant in Pennsylvania. Should the pair manage to pull it off, it would be the first-ever restart of its kind — and a major confidence boost for a world desperate for new sources of clean and reliable energy.
“Nuclear plants are the only energy sources that can consistently deliver on that promise,” Constellation CEO Joe Dominguez said in a statement.
However, regulators say the necessary permits for the plant’s second wind have not yet been filed, while federal, state, and local approvals have also not been received.
The accident at Three Mile Island
Located near Harrisburg, Pennsylvania, the Three Mile Island plant was the site of a partial meltdown in 1979. At around 4:00 am on Wednesday, 28 March, the plant experienced a failure in the secondary, non-nuclear section of the site — one of two reactors at Three Mile Island.
According to the US Nuclear Regulatory Commission (NRC), either a mechanical or electrical issue prevented the main feedwater pumps from sending water to the steam generators, which remove heat from the core reactor. This caused the turbine-generator, and then the reactor itself, to automatically shut down.
Immediately, pressure began to build. In order to control that pressure, the pilot-operated relief valve on top of the pressuriser opened as intended. However, rather than closing when the pressure dropped to normal levels, it remained stuck open.
In the plant’s control room, however, instruments indicated that the valve was in fact closed. Plant staff were therefore unaware that cooling water, in the form of steam, was pouring out of the stuck valve.
Part of the problem — as alarms wailed and warning lights flashed — was that other instruments available to staff in the control room showed inadequate or misleading information. Under normal circumstances, the large pressure valve that holds the reactor is always filled to the top with water. As a result, there was no need for an instrument to show whether the reactor was actually covered with water.
Staff therefore assumed that as long as the water level in the pressuriser was shown as high enough, the reactor core would be properly covered as well. They had, of course, assumed incorrectly.
Before long, the stuck valve had reduced the pressure of the primary system to such an extent that the reactor coolant pumps started to vibrate and were turned off. The emergency cooling water being pumped into the system then threatened to fill up the pressuriser completely — which the NRC said was not a desirable situation — and the flow of water was cut back.
Without the coolant pumps circulating water and with the system dry of emergency cooling reserves, the water level in the pressuriser dropped, the core overheated, and the US suffered its worst nuclear disaster ever.
The fallout
Per the NRC’s estimation, a combination of personal error, design flaws, and component failures lead to the accident at Three Mile Island, which culminated in permanent changes to America’s nuclear industry. As public fear and distrust rose, the NRC’s regulations and oversights became more stringent, and management of the plants was put under a greater degree of scrutiny.
One of the most immediate concerns in the aftermath of the accident was about the possibility of radiation-related health effects, particularly cancer. As a result, the Pennsylvania Department of Health maintained a database of more than 30,000 people who lived within roughly 8km of the plant for 18 years. The registry was discontinued in mid-1997 with no evidence of unusual health trends in the area.
In fact, the World Nuclear Association has noted that more than a dozen independent health investigations found no signs of abnormal instances of cancer in the years after the accident. The radiation released at the time was found to be minimal — well below any levels that had previously been associated with adverse effects of radiation exposure.
The only noticeable impact was the mental stress experienced by locals during and after the accident.
Ultimately, the reactor core unit at the centre of the incident — TMI 2 — was permanently shut down and 99% of its fuel was removed. The coolant system was fully drained, while the radioactive water was decontaminated and then evaporated.
A second life
Now, with the Constellation-Microsoft deal in place, the Three Mile Island nuclear plant appears set to enjoy that rarest of treasures: a second chance.
Whispers of such an arrangement had first been reported by Reuters back in July. The news agency said at the time that Constellation was in talks with the Pennsylvania governor’s office and state lawmakers in an effort to secure funding for a restart of the plant.
According to an announcement from Constellation on Friday, the deal pertains to the plant’s Unit 1 core reactor, the Unit 2 reactor having been more or less destroyed in the accident.
Microsoft will purchase energy from the renewed plant for a period of 20 years, which will be used to help power its massive data centre.
“Powering industries critical to our nation’s global economic and technological competitiveness, including data centres, requires an abundance of energy that is carbon-free and reliable every hour of every day,” Constellation’s Dominguez said on Friday.
“Before it was prematurely shuttered due to poor economics, this plant was among the safest and most reliable nuclear plants on the grid, and we look forward to bringing it back with a new name and a renewed mission to serve as an economic engine for Pennsylvania.”
Perhaps in a bid to distance the plant from the 1979 incident, it will be reopened as the Crane Clean Energy Centre (CCEC) — a nod to the company’s former chief Chris Crane, who passed away in April.
According to a recent report by the Pennsylvania Building and Construction Trades Council, the proposed revival of the plant would create 3,400 jobs, add more than 800 megawatts of carbon-free power to the state’s energy grid, boost Pennsylvania’s economy by US$16 billion (AU$23.3 billion), and generate more than US$3 billion in state and federal taxes.
Constellation plans to spend about US$1.6 billion to revive the plant, which it expects to come online by 2028.
“The CCEC will support thousands of family-sustaining jobs for decades to come,” Rob Bair, President of the Pennsylvania State Building and Construction Trades Council, said.
“It will help make Pennsylvania a leader in attracting and retaining the types of reliable, clean energy jobs that will define the future.”
Likewise, Pennsylvania’s Governor Josh Shapiro said the CCEC will operate under the careful watch of state and federal authorities.
“My administration will continue to work to cut energy costs and ensure the reliability of our energy grid so that Pennsylvanians can have access to affordable power made right here in Pennsylvania for years to come — and the Crane Clean Energy Center will help us achieve those goals,” he said.
Data-driven energy demand
Big tech has led to a sudden surge in US electricity demand for data centres that are key to expanding new technologies like artificial intelligence and cloud computing. Nuclear energy has therefore become a popular option for tech companies that have made climate pledges and require clean, reliable, uninterrupted power.
Prominent US tech executives, including OpenAI CEO Sam Altman and Microsoft co-founder Bill Gates, have been strong proponents of nuclear power. Altman has backed and is the Chairman of nuclear start-up Oklo (NYSE:OKLO), which listed by way of a blank-check merger in May this year. Gates, on the other hand, has co-founded TerraPower, which broke ground on a nuclear facility in June.
According to data from the Energy Information Administration, nuclear plants generated roughly 18.6% of the total electricity in the US last year.
“We started to get some clarity about data centre opportunities and the numbers are staggering,” Timothy Winter, a portfolio manager at Gabelli Funds, told Reuters in August.
Since the start of this year, US utilities have raised their 2030 guidance of cumulative data centre energy demand by around 50%, according to Ben Levitt, associate director of power and renewable at S&P Global Commodity Insights.
Analysts have therefore suggested utilities firms could enjoy meaningful sales growth, and are well-positioned to meet or exceed their long-term growth targets after two years of underperformance.
Write to Oliver Gray at Mining.com.au
Images: US Department of Energy, US Nuclear Regulatory Commission, Microsoft
