How long do nuclear power plants last?

Although nuclear plants are theoretically engineered to operate safely for 40 years, almost two dozen reactors were shut down long before their initial license/design life expired. Among plants built before 1973, fully HALF did not make it to 40 years, or much beyond that, before closing down.

Some nuclear plants were shut down for economic reasons, but most plants simply wore out, broke down, or never functioned properly in the first place. This record of failure can be viewed in the closure report below. You can also view this chart in its original printable PDF form

Ages of US Nuclear Power Plants* at Closure

PLANT

SHUTDOWN DATE

AGE

REASON / NOTES

Connecticut Yankee

December 1996

29 yrs

Steam tube damage, ECCS undersized

Millstone I (CT)

July 1998

28 yrs

Improper operation, Cost of safety improvements

Maine Yankee

August 1997

25 yrs

Steam generator tube damage, Electrical power cable separation

Yankee Rowe (MA)

October 1991

28 yrs

Reactor vessel embrittlement, Steam generator tube damage

Three Mile Island II (PA)

March 1979

4 months

Partial meltdown!

Indian Point I (NY)

October 1974

12 yrs

Lack of an Emergency Cooling System

Shippingport (PA)

October 1982

35 yrs

1st commercial plant in US

Peach Bottom I (PA)

November 1974

7 yrs

Helium cooled graphite core

Dresden I (IL)

October 1978

18 yrs.

1st full scale private funded plant

Zion I (IL)

February 1997

22 yrs.

Steam generator tube cracking, poor operation

Zion II (IL)

November 1996

22 yrs.

Steam generator tube cracking

Big Rock Point (MI)

August 1997

35 yrs.

Economics

Fermi I

September 1972

2 yrs.

Partial meltdown, 1966! Restarted (?) 1970-72

La Crosse (WI)

April 1987

17 yrs.

Economics

Fort St. Vrain (CO)

August 1989

10 yrs.

Helium cooled graphite core, Control rod failure, never dependable

Trojan I (OR)

November 1992

16 yrs.

Steam generator cracking, economics

San Onofre I (CA)

November 1992

25 yrs.

Cost of seismic retrofit, Steam generator tube cracking

San Onofre II/III (CA)

January 2012

30/29 yrs.

Steam generator tube cracking

Humbold Bay (CA)

July 1976

17 yrs.

2nd oldest commercial plant

Rancho Seco (CA)

June 1989

15 yrs.

Poor operating history (39% capacity)
Only nuclear plant closed by referendum

Kewaunee (WI)

May 2013

39 yrs.

Economics

Crystal River 3 (FL)

September 2009

33 yrs.

Steam generator, containment cracking

* US commercial plants of significant size that shut down prior to their initial license expiration (40 years)

Oldest Operating U.S. Nuclear Plants

PLANT

START DATE

AGE

ISSUES

Oyster Creek

December 1969

47 yrs.

Oldest running in US (closure in 2019)
Thermal pollution to bay
GE mark I (Fukushima type)

Nine Mile Pt. I

December 1969

47 yrs.

Internal cracking (worst nationally)
Cooling system malfunctions

R.E. Ginna (NY)

June 1970

46 yrs.

Radiation release in 1982
Steam generators replaced

Dresden II (IL)

June 1970

46 yrs.

Cooling system failure, 1989

Point Beach I (WI)

1970

46 yrs.

2nd oldest in total hours run

Monticello (MN)

1971

45 yrs.

GE mark I (Fukushima type)
“Safety culture” issues

U.S. Commercial Plants Operating by/before 1973 = 38. Number of these still operating today (at 43+ yrs) = 19 (50%)

Oldest Reactors Around the World

PLANT

START DATE

AGE

ISSUES

Obninsk (Russia)

1954

48 at shutdown

5MW

Calder Hall (UK)

1953

47 at shutdown

military/commercial

Chapelcross (UK)

1959

45 at shutdown

military/commercial

Oldbury (UK)

1967

45 at shutdown

Shut down on 2/29/12

Beznau 1 (Swiss)

1969

47

Slated for shutdown

Tsuruga – 1 (Japan)

1970

41 at shutdown

Radiation leaks, Shut down on 3/2011
Permanent shutdown 3/2015