NRC: ‘70s to blame for tritium
BRATTLEBORO -- The Nuclear Regulatory Commission states the leak of tritium at the Vermont Yankee nuclear power plant is a nearly four-decade problem.
According to the Nuclear Regulatory Commission’s inspection report, released Wednesday, "The failure to satisfy early construction and housekeeping standards during the 1970s, as well as the lack of corporate emphasis and commitment to the timely implementation of a buried piping inspection and remediation program, are what ultimately resulted in the tritium contamination in 2009/10."
Ray Shadis, technical advisor for the New England Coalition, said the NRC’s inspection report reads more like an extracurricular testimonial than an actual inspection report.
The Root Cause Evaluation Report "is something of a dark joke because it does not identify a root cause, that is, it does not point out the design or physical defect or human error that actually caused the chain of events resulting in the pipe leak," Shadis said.
NRC inspectors determined that the root causes identified by Entergy, which owns and operates the Vermont Yankee plant, in response to the groundwater contamination issues were "well supported," Neil Sheehan, spokesman for the NRC, said.
"Our inspectors’ objective was to determine whether Entergy used sufficient rigor when carrying out these evaluations and whether the company was appropriately self-critical when it came to the problems that resulted in the leakage," Sheehan said.
On Jan. 7, Entergy informed the NRC that tritium, a radioactive byproduct of nuclear power as well as a naturally occuring isotope, was detected in a ground water monitoring well at the plant.
During plant startup from its refueling outage on May 28, another leak was observed from a two-inch drain line associated with the Advanced Off-Gas system.
The report states that the "normally buried pipe was in the excavated Advanced Off-Gas (system) area in the vicinity of the pipes associated with the earlier leak."
Entergy concluded that, "the pipe likely also leaked on or around May 26 during an earlier startup from the refueling outage."
Although no violations of NRC requirements were identified, there was a performance deficiency associated with the apparent cause evaluation and the circumstances associated with the secondary leak, Sheehan said.
"Entergy failed to conduct an adequate extent-of-condition review after the first leak, which led to its failure to identify the degraded two-inch Advanced Off-Gas (system) drain pipe prior to it causing additional tritium contamination in May 2010," the report states.
Larry Smith, spokesman for Vermont Yankee, said the NRC concluded that Entergy’s root cause and apparent cause evaluations were appropriate.
He added, "There was no impact on public health and safety and no violations of NRC requirements or findings were identified."
However, Arnie Gundersen, chief engineer for Fairewinds Associates, a paralegal and nuclear consulting firm, said the real root causes are not enough money being spent to ensure safety measure are maintained.
"Blaming 1970 implies that there may be other design residuals that may crop up in the future," Gundersen said.
Last week a sample taken from a former drinking water well at the plant was found to be contaminated with tritium.
While no tritium was detected at the deepest range of the well, 360 feet, a single sample, collected on Oct. 2 from the 200 and 220-foot range indicated a tritium concentration of 1,380 picocuries per liter.
"While this single data point indicates a detectable amount of tritium in the Construction Office Building well, it’s insufficient information on which to draw any conclusion as to the impact of the tritiated groundwater plume on the bedrock aquifer," Sheehan said. "Clearly more work is necessary to determine the significance of the sample."
The Construction Office Building well was removed from service as a drinking water well on Feb. 22 as a result of a leak of tritiated water found in January.
"Flow of water in this well behaves according to the established site hydrogeologic model and flows in the direction of the Connecticut River," Smith said. "The flow characteristics within this well column itself are upward, meaning that contamination of the deep aquifer remains highly unlikely."
Samples collected on a daily basis during January and February were continually free of tritium, he said.
Entergy has applied to the NRC to extend the plant’s operating license from 2012 to 2032. In addition to NRC approval, Entergy must also receive an OK from the Vermont State Legislature and the Vermont Public Service Board to continue operation past 2012.
In February, the state Senate voted 26-4 against the continued operation of the plant beyond its current operating license.
Josh Stilts can be reached at firstname.lastname@example.org, or 802-254-2311 ext. 273.
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