The Vermont Public Service Board held four days of technical hearings last week on petitions from environmental groups seeking to shut down the Vermont Yankee nuclear power plant and revoke its state operating permit in the wake of revelations that the facility was leaking radioactive water into the environment.
A year ago, Entergy Corp., the owner of Vermont Yankee, announced that tritium from the plant had been released into soils on the compound.
In the hearings, lawyers for the New England Coalition, the Conservation Law Foundation, Vermont's Agency of Natural Resources, and Vermont's Department of Public Service cross-examined Entergy experts about written testimony they had submitted regarding the leaks, their causes, what was released, and what is being done to prevent future leaks.
The “root cause” of the leaks was the most contentious issue.
Timothy Trask, an Entergy engineer, opened the hearings by answering questions from Jared Margolis, representing the New England Coalition on Nuclear Pollution, about Entergy's root cause analysis report.
Margolis referred to Entergy guidance for root cause analysis, which says that when Entergy has identified a condition as “consequential,” they investigate whether it occurs elsewhere in the plant. Margolis wanted to know how plant officials had investigated whether similar pipes had holes, or were in danger of developing holes.
After some back and forth, in which Margolis grew visibly frustrated and repeatedly said Trask wasn't answering the question, Trask said the holes in the pipes were not the “root cause” of the leaks into the environment, but a “contributing cause.” The root cause, he said, was the pipe tunnel. Until the tunnel was breached, there was no leak outside the plant, according to Trask.
Margolis asked Trask if identifying holes in the pipes as a “contributing cause” meant that Entergy's root cause analysis did not need to evaluate whether similar plant pipes were developing holes. Trask replied that Entergy is “already constantly looking for where that is occurring in the plant.”
Margolis occasionally consulted with Ray Shadis, a consultant to the New England Coalition, who sat by his side during the questioning.
Shadis commented during a break in the testimony, “Entergy is straining the definition of 'root cause.' If you accept the definition that the leaks in the pipe were only a contributing factor, that means that they need not look at the remainder of the pipes to see if any of them are corroding, being eroded, or about to fail. That's ideal for them, because it's a big, expensive operation.”
Trask said the holes in the pipes were not the “root cause” of the leaks into the environment, but a “contributing cause.” The root cause, he said, was the pipe tunnel. Until the tunnel was breached, there was no leak outside the plant, according to Trask.
Larry Smith, communications manager for Vermont Yankee, insists the plant has “defense in depth” against future leaks, including moving inaccessible pipes above ground, to where they can be inspected, and 20 monitoring wells that can indicate a leak has occurred.
Smith accepted that this analogy explains Yankee's concept of “root cause” - in a car crash where the brakes fail and then the airbag fails and the driver is injured, the root cause of the driver's injury is the airbag failure, and the brake failure is a contributing cause.
Two informed Yankee observers, neither of whom attended the hearings, had differing views on the root cause analysis.
Neil Sheehan of the Nuclear Regulatory Commission said there was no one root cause, but a combination of problems - the holes in the pipes and the flaws in the pipe tunnel. He expressed confidence in Entergy's root cause analysis.
Arnie Gundersen, a member of the Vermont legislature's Public Oversight Panel, said the panel had concluded that Entergy's analysis was “flat-out inadequate,” and that the root cause of the leaks was the lack of a questioning attitude by Entergy's management.
He cited five sink holes that appeared in the soil around the nuclear power plant in 2008 and 2009, which indicated there was water in the soil. Yet Entergy officials, he said, never asked why they were there. Entergy “never points the finger at management,” Gundersen said, “It's always some component.”
Later in his testimony, Trask would not commit to inspecting all the buried and difficult-to-access pipes at Yankee, but he said their program would use the nuclear industry's best practices to sample them.
He did not know how extensive the samples would be or when the inspections will be completed.
“Inspections” may not be visual at all; Trask described monitoring wells - which indicate a leak has occurred when it is detected outside the plant - as a type of inspection.
In response to a Public Service Board member's question, however, Trask agreed that finding radionuclides - atomic matter with unstable nuclei, like tritium - in a monitoring well means “the horse has left the barn by the time you realize you've got a problem,” and that there can be a “substantial release into the environment” before they figure out there's a problem.
Other witnesses at the hearings discussed sampling procedures and results for heavier radionuclides like zinc and cesium and indicated that no soil had been tested for other, non-radioactive substances.