After a string of good luck, it seems Entergy Vermont Yankee has landed right back into its old bad habits of introducing Vermonters to a leak of the week.
This past Friday marked two straight weeks in which ENVY released bad news (and radioactive isotopes) to the Vermont media after regular business hours.
Late Friday Saturday, ENVY's top communications director Larry Smith issued a press statement (see below) claiming that a "new leak" had been found Friday at Vermont Yankee. And, as luck would have it, the leak is right near that pesky Advanced Off Gas (AOG) system that was the subject of a months-long investigation into a massive leak of tritiated water that dumped tritium, cesium and strontium-90 into the nearby soils, groundwater and likely the Connecticut River.
The statement was issued to the media around 9:30 p.m.
The leak will not affect the plant's return to full power, which was stalled last week when a massive storm wiped out a connection to the main grid, and a substation on site failed. In the meantime, VY will examine how to fix the leak while the plant operates.
"Repair options under evaluation include removing the line from service, replacing the line, or performing an on-line leak repair," Smith said in a statement. "The identified leak should not reoccur during normal plant operation, with the AOG system in service."
On May 21, Entergy released news that it found evidence of strontium-90 in the soils it had excavated from the AOG soils contaminated with tritium. That release came around 5:30 p.m., which is certainly plenty of time to get it on the 6 p.m. news, right?
At the same time, as I noted in last week's "Fair Game," state health and environmental officials, along with a consultant hired by the state, believe the Vermont Yankee tritium leak began more than two years ago — a leak that left up to five sink holes in the area around the AOG buildings.
So, VY inspectors who somehow were not curious about five observable sink holes from July 2008 to April 2010 now missed an eighth-inch-diameter hole in a two-inch drain pipe? A pipe, mind you, that was the focus of one of the most intense inspection regimens in recent years at the aging reactor.
In the release, Smith said VY plans to remediate the soil affected by the new leak, and further "evaluate the condition of the two-inch pipe."
Legislative consultant Arnie Gundersen, who's been proven prescient when it comes to ENVY errors, has plenty of questions about the source of the leak, and hopes to hear more from ENVY about what caused it.
"It is new water flowing through an old hole," said Gundersen, noting that the list of short-lived isotopes VY identified in the soil means it's new water that is leaking. But, he adds, "The hole could have been there for years."
The list of radioactive isotopes can be found below in the full text of ENVY's statement to the media.
"The big question is what caused this leak," Gundersen said. "the other two had the same root cause — not enough money spent on steam trap replacement. But, this leak is different. The other big question is why, given all the attention to this piece of AOG real estate, they did not find it until it leaked. This is the most well-studied real estate in the plant."
A special legislative oversight panel, on which Gundersen sits as a member, is expected to issue a complete report on the tritium leak and Entergy's response by mid-June, according to panel chairman Peter Bradford.
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Here is the full press statement from Entergy Vermont Yankee's communications director Larry Smith:
During plant start-up activities Friday night, plant operators identified a condition described as vapor and water dripping in the Advanced Off Gas excavated area. The volume was estimated to be extremely small and occurred over a period of approximately four hours.
This was a new leak. The leak has been stopped and there is no leak at this time.
There is no threat to public health or safety.
The vapor and water dripping was identified at approximately 7:30 pm during warm up of the AOG system.
No leakage was visible after warm up and shortly after the AOG system was placed in service.
The leak has been located on a two inch drain line and is approximately one eighth of an inch in diameter.
The vapor and water dripping was observed coming from the end of a concrete enclosure surrounding a two inch drain line in the AOG excavation just before the pipe enters the wall of the drain tank room.
Soil testing of the area has been performed and tested positive for several radioisotopes in a one foot radius from the leak source.
The surface areas where water had previously been observed were sampled for surface contamination. Samples were positive for tritium. A sample of wood that had been exposed to the leak and soil below the leak site showed measurable levels of radio-isotopes. Isotopes detected were chromium-51, manganese-54, cobalt-58, cobalt-60, zinc-65, zinc-69, niobium-95, rhodium-105, xenon-131, cesium-137, barium-140 and lanthanum-140. Some of these isotopes (rhodium-105, xenon-131, barium-140 and lanthanum-140) are short lived and are evidence that the contamination was recent.
Current plans are to remediate the soil at the area of the leak and evaluate the condition of the two inch drain line.
Repair options under evaluation include removing the line from service, replacing the line, or performing an on-line leak repair.
The identified leak should not reoccur during normal plant operation, with the AOG system in service.
The NRC and State of Vermont have been notified.
Vermont Yankee reconnected to the New England electrical grid shortly after midnight Saturday. The plant is currently in power ascension and should reach 100% steady state power in the next several days.