Gundersen Letter to NRC ACRS Re: Vermont Yankee Uprate 11-05

Rather than being granted an uprate to produce 20% more power than Yankee was designed to produce, Arnie Gundersen recommends that it continue to operate at its current power level until its 40-year license expires in 2012.  An uprate would reduce safety margins, add stresses on the plant’s aging components, and changes the most critical safety design feature of Vermont Yankee, reducing the plant’s ability to protect Vermonters in the event of a “single failure.”  

Open Letter to: The Citizens of Vermont, The Vermont State Legislature, Vermont's Congressional Delegation, and the Nuclear Regulatory Commission's (NRC's) Advisory Committee on Reactor Safeguards (ACRS)

I write to you as the only private citizen who has been accepted as an Expert Witness before both the Vermont Public Service Board (PSB) and the NRC's Atomic Safety and Licensing Board in the case regarding the proposed power increase at Entergy's 33- year-old Vermont Yankee Nuclear Power Plant to 120 percent of design capacity. Although New England Coalition retained me as a technical expert witness throughout the entire evaluation process, I am not a member of New England Coalition. My technological recommendation is to continue Vermont Yankeeʼs operation at its existing power level until its 40-year license expires in 2012.

I believe that increasing the power output of this 33-year-old nuclear reactor by 20% more than it was designed to produce should be reexamined for three broad reasons: reduction of safety margins, additional increased power production stresses of the Extended Power Uprate (EPU) on the plant's aging components, and the inability of the EPU design to protect Vermonters in the event of a "single failure."

Briefly, my personal technical safety concerns are as follows:

  1. After a power increase of this magnitude, if Vermont Yankee should ever have an accident, 40% more radiation would be released, and according to Entergy's own expert witness testimony, the likelihood of such an accident will be 25% higher than if the EPU power increase were not approved.
  2. Vermont Yankee is already an old plant, a 33-year-old plant, which will be subjected to new increased stresses.
  3. Finally, Entergy's proposed EPU power increase changes the most critical safety design feature of Vermont Yankee. This so-called “NPSH issue” leaves Vermont Yankee open to a China Syndrome type accident, a situation that does not exist with Vermont Yankee's current operational design – only with the proposed EPU power increase changes that would be made to the operational and safety design.

Let me elaborate on each power related safety concern with technical details:

My first concern: In the event of an accident after a 20% EPU power increase, there is an international consensus that the radiation available to be immediately released will increase by more than 40%. To avoid exceeding State and Federal allowable exposure limits to the citizens of Brattleboro after the EPU power increase, Entergy requested and the NRC has allowed Vermont Yankee to lower the theoretical radiation releases at its present power level by about 40%. This 40% theoretical reduction offsets the real 40% net increase. Thus it appears on paper as if there is no difference. This radiation assessment shell game is called the "Alternate Source Term." The real net effect after the EPU is that the actual radiation released from a potential accident will be 40% more than what would be released at the power level Vermont Yankee operates at today.

Furthermore, during the actual hearings before the Vermont Public Service Board in 2003, Entergy's expert witness acknowledged that the likelihood of an accident after the EPU power increase would be 25 percent higher than if operations at this nuclear power plant remained unchanged. If the likelihood of an accident increases by 25% and the consequences of an accident increase by more than 40%, it is clear that Vermont Yankee's safety margins will be significantly reduced after the EPU.

My second concern: Vermont Yankee has already been operating for 33 years, and the age related problems the plant already has will be compounded by the additional stresses of the proposed EPU power increase. During the hearings before the Vermont Public Service Board, an expert hired by Entergy and Vermont Yankee acknowledged that this nuclear power plant would be less reliable after the EPU power increase. The industry record of EPU power increase related failures is replete with five steam dryer failures, two cracked turbine generator shaft failures, and numerous other failures of aging equipment after much smaller uprate power increases than that which is currently proposed for Vermont Yankee.

However, we need not look to other reactors to identify that age related equipment failures are already impacting Vermont Yankee's performance.

  • Vermont Yankee's steam dryer has 40 new cracks since only 18 months ago,
  • the Main Steam Isolation Valves are no longer able to meet their original leak criterion, and
  • the condenser is so old that Entergy itself has stated that Vermont Yankeeʼs condenser is "lucky to withstand gravity"!

Remember last year's fire that shut down Vermont Yankee for almost three weeks? In a direct quote to the NRC about what really caused the fire, Vermont Yankee employees stated, "The root causes of the event were determined to be inadequate preventative maintenance…and failure to monitor age related degradation." The evidence shows that the preventative maintenance issues to which Vermont Yankee refers in its statement were known as critical preventive maintenance issues throughout the nuclear industry since 1990, and yet, still ignored by Entergy as late as 2004 in its rush to put Vermont Yankee back on line.

That fire confirmed what I stated back in October 2003 in formal testimony before Vermont's Public Service Board, that there is "growing evidence that aging management programs aren't working." My question remains the same in 2005. "What will break next in a very old plant under very new EPU increased power stresses?"

If the Vermont Yankee nuclear power plant is indeed as robust as Entergy claims, there is a reliable scientific and technical method to test the plant under the additional stress of the proposed EPU power increase, called Full Power Transient Testing. The NRC originally required this test in order to allow Vermont Yankee to complete its proposed EPU power increase and I also endorsed Full Power Transient Testing. Entergy has consistently and adamantly opposed these tests, and with one minor exception, after several years of pressure from Entergy, the NRC now appears to be willing to allow Entergy to avoid any rigorous testing of Vermont Yankee.

Finally, my third concern: With the proposed EPU power increase, but not as Vermont Yankee now operates, any one of several common, routine single failures within the containment system must inevitably also cause the failure of the entire emergency cooling system. This is the so-called "NPSH problem" or Net Positive Suction Head. Containment failure simultaneous with emergency core cooling failure is catastrophic, yet it becomes a profound possibility at Vermont Yankee for the first time with this proposed EPU power increase.

In lay terminology, the proposed EPU power increase generates extra heat so that the emergency pumps will not be able to draw a suction unless the containment is absolutely leak-tight to push the water into the pumps. This is not a problem as Vermont Yankee operates today, but it becomes a serious problem if the proposed EPU power increase is approved. The ACRS and the NRC have published two written directives prohibiting the use of containment pressure to push water toward the emergency pumps. These regulations make a lot of sense, for if there were to be a "single failure" of the containment system, Vermonter's need the emergency core cooling system at Vermont Yankee to still operate in order to reduce the amount of radiation released to the environment and to prevent a China Syndrome. After this proposed EPU power increase, the Vermont Yankee Nuclear Power Plant will not be able to withstand a "single failure". Yet with Entergy's push for increased power and increased revenue, the NRC is now choosing to ignore both of the published NPSH safety directives in order to grant Entergy its proposed EPU power increase for Vermont Yankee.

What benefits do Vermonters gain to offset these increased risks? Entergy will pay Vermonters about one million dollars a year, or a buck and a quarter per Vermonter. The extra power will not be used in Vermont, and the $20,000,000 in yearly profits will go directly to the Louisiana-based Entergy Corporation.

If there is an accident, even a "small accident", all that we hold dear about the purity of our natural lifestyle will be lost forever, all for a buck and a quarter per person per year. Vermonters are risking the reputation of the integrity of our dairy, produce, recreational, and tourist industries to gain that buck and a quarter. To me, a Vermont citizen with nothing to gain financially or professionally on either side of this argument, the benefits simply do not warrant the extensive risks.