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United States
Abandoned Constructions
42
Under Construction
0
Operating
94
Closed
41
Number of Reactors
(as of August 2026)
44.8
Mean Age of Reactor Fleet
(as of August 2026)
17.3%
Stable
Nuclear Share in Electricity Production
(2025)
1
2
3
4
5
WNISR
Essential News –
8 June 2016
Watts Bar-2 (
US
): Grid Connection 43 Years After Construction Start—Shutdown 2 Days Later
Watts Bar-2 (
US
): Grid Connection 43 Years After Construction Start—Shutdown 2 Days Later 8 June 2016 More than four decades after construction began, the Watts Bar-2 reactor was finally connected to the grid on 3 June 2016. However, two days later, while operating at 12.5 percent power, the reactor automatically shut down. According to the
U.S.
Nuclear Regulatory Commission (
NRC
), the reactor tripped when a high pressure turbine valve failed to open. As of 8 June 2016, the reactor has (…)
WNISR
Essential News –
29 November 2013
Forty Years Later—
NRC
Extends Construction Permit for Watts Bar Unit 2
On 21 November 2013, the
U.S.
Nuclear Regulatory Commission (
NRC
) extended the construction permit for the Tennessee Valley Authority (
TVA
) Watts Bar 2 Pressurized Water Reactor (
PWR
). Following an earlier request from
TVA
, the
NRC
has granted an extension to the planned completion date from March 2013 until 30 September 2016. The original Construction Permit for the reactor was issued by the Atomic Energy Commission on 23 January, 1973, with a completion date no later than May 1977. Ten (…)
WNISR
Essential News –
26 April 2012
US
Reactor Watts Bar 2 Start-up Delayed Again
In April 2012 the Tennessee Valley Authority (
TVA
) in the United States announced that its plans to complete the second unit at the Watts Bar nuclear power plant would be delayed again. Construction originally started in 1972 (nineteen-seventy-two) and makes it the longest building project in nuclear history. The revised start-up date is now 2015, a delay of three years and the estimated construction cost has risen by between 60-80% from $2.49 billion to between $4-4.5 billion. The cost of (…)
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