NRC has rubber-stamped license extensions and "power uprates" at 22 of 23 GE BWR Mark I reactors operating in the U.S.
Pat Birnie of the GE Shareholders Alliance has compiled U.S. Nuclear Regulatory Commission (NRC) data on "power uprates" which the agency has approved at 22 of the 23 General Electric boiling water reactors of the Mark I design still operating across the U.S. (Nine Mile Point Unit 1 in NY is the only exception). Her chart is accessible here. The Fukushima Daiichi Units 1 to 4 which exploded and melted down beginning in March 2011 are also GE BWR Mark Is.
The single biggest power uprate, as a percentage of heat output (measured as Megawatts-thermal, or MWt), was a 20% "extended" type power uprate, granted in 2006 to Entergy Nuclear at its 34 year old (at the time) Vermont Yankee atomic reactor. This amounted to a 319 MWt power uprate (MWt must be divided by three to determine the Megawatts-electric, MWe, generated, due to the fact that 2/3rds of the heat generated by splitting atoms is lost as waste). The vibrational stresses caused by Vermont Yankee's power uprate led to the collapse of its cooling tower (see photo at left), and even contributed to a separate fiery explosion, when the increased pressure of flowing steam picked up loose metallic slag that had lain dormant for decades and slammed it into an operational transformer.
However, even bigger power uprates have been rubberstamped by NRC. The single biggest, at an individual Mark I reactor, was the 547 MWt of power uprates, granted in two installments (one a "Measurement Uncertainty Recapture" type uprate), at the Hope Creek, New Jersey Mark I. However, both Brunswick Mark Is, Units #1 and #2 in North Carolina, have each enjoyed a total of 487 MWt of power uprates, including a "stretch" type uprate, for a whopping 974 MWt of power uprates at the Brunswick nuclear power plant.
NRC gave the newly formed Exelon Nuclear Corporation (formed by the merger of Commonwealth Edison of Chicago and Philadelphia Electric Company, the first and second largest nuclear utilities in the U.S.) an early Christmas gift in 2001: a 17.8% power uprate at both of its Quad Cities 1 & 2 Mark Is, worth 446 MWt each; and a 17% power uprate, worth 430 MWt, at each of its Dresden 2 & 3 Mark Is. All four approvals took place on a single day, December 21, 2001. The combined power uprates at the four Mark I reactors netted Exelon 1,752 MWt of additional output.
While the nuclear utilities enjoy increased profits from the additional electricity sales associated with power uprates, the public downwind and downstream bears the risks of running these Mark Is harder and hotter than they were originally licensed or designed for. To make safety risks even worse, 22 of the 23 operating Mark Is have already received NRC rubberstamps for 20 year license extensions; Fermi 2 is the only exception, and it plans to apply for one in 2014. Pat Birnie has also compiled a listing of the 23 operating Mark Is in the U.S., including the reactor units' names, locations, expiration dates for their original 40 year licenses, and expiration dates for their NRC-authorized 20 year license extensions.
Pat Birnie has succeeded in getting an anti-nuclear shareholder resolution, written in the aftermath of the Fukushima Nuclear Catastrophe, onto the agenda of the General Electric annual shareholders meeting, to be held in downtown Detroit on April 25th.