Workers are repairing a leak in a water main connected to the boiling water reactor at Vermont Yankee Nuclear Power Plant. Officials say they plan to repower the plant on Tuesday night.
The Vernon facility was manually shut down on Sunday to make the repair to the 24-inch diameter pipe, according to Larry Smith, spokesman for Vermont Yankee. The facility had operated continuously for 163 days up to that point. In the spring, Vermont Yankee officials shut down the plant for refueling.
This is the first time the plant has been deactivated for such a repair in the last year. Vermont Yankee continued to operate, as crews fixed three previous isolated leaks.
Another nuclear power plant owned by Entergy Corp., Indian Point Nuclear Power Plant, located on the Hudson River, also shut down last weekend. A transformer outside the facility exploded. (Vermont Yankee also had a transformer blow, in 2004.)
Smith said the Vermont Yankee shutdown on Sunday was necessary because, “unfortunately, it’s the only one (pipe) feeding water into the system.”
He emphasized that the leak isn’t a “safety issue.”
Technicians are replacing the seal weld around a 2-inch “port” or “access plug” in the high- pressure pipe that was used to assess the integrity of welds in the piping system when the plant was under construction in 1970.
The Nuclear Regulatory Commission considers the main water feed pipe to be a non-safety-related system, according to Neil Sheehan, spokesman for the federal agency that oversees plant safety.
The agency has sent to the site metallurgical experts who are evaluating the integrity of the piping and other “ports” on the line.
“We want to better understand the faulty weld or other aging and degradation issues,” Sheehan said. “It’s better to know this is a port, rather than the pipe wall itself.”
Vermont Yankee has had three other leaks of radioactive liquid in other locations over the course of the last 12 months. In those instances, tritium and small traces of cobalt, cesium and strontium were found in soils on the plant compound.
The newest leak, located in the ceiling of the “feed pump room,” was discovered at 9:30 p.m. Saturday. The radioactive water was contained inside the building and captured in a floor drain and vacuumed by a sump pump, Smith said. Crews removed insulation from the ceiling to locate the source of the leak – a 3-inch welded plug in the pipe that was used when the plant was built to evaluate the integrity of the system, according to Sheehan.
Sheehan said the flow from the “flaw” in the pipe was 120 drops of liquid per minute on Saturday.
There was “no way to easily isolate the leak” without shutting the plant down, Sheehan said.
Gundersen: Will the ports go like dominoes or popcorn?
Arnie Gundersen, a nuclear expert and a member of Vermont’s legislative Public Oversight Panel, said there was a similar leak from a port discovered last year. It took three days to repair, he said.
“There are dozens more (plugs) throughout the big pipe in the plant,” Gundersen said. “I think you will see more (leaks) in the future. The question is whether they’ll go like dominos, or if they’ll go like
popcorn.”
Gundersen said the problem with degraded welding around the plugs speaks “to the 40-year life issue.” The boiling water reactor wasn’t designed to continue operation for more than four decades, he said.
In and of itself, Gundersen said, the main feed is not a “safety-related piece of pipe.” However, he described the pipe as “high energy” – water in the pipe is at 400 degrees and under 400 pounds of pressure.
“If the seal had gone (disappeared) all the way around (the port), it would have been a big deal,” Gundersen said.
Gundersen pointed to two recent accidents that involved similar “non-safety” systems that resulted in the deaths of plant employees. In 1986, scalding hot water from a pipe killed four workers at a nuclear power plant in Virginia. Superheated steam killed five employees of a plant in Kyoto, Japan, in 2004.
Sheehan said the agency, as part of its safety oversight mandate, is concerned with the maintenance of the reactor itself and the cooling system in the event of an accident.
Vermont’s Public Oversight Panel warned the NRC and the Department of Public Service that Entergy has neglected non-safety systems.
Previous problems with “non-safety” systems at the plant under Entergy’s ownership – including a transformer fire, the collapse of a cooling tower and the recent discovery of tritium and other radioactive isotopes leaking from the facility into soils – have intensified public and legislative
scrutiny of the 38-year-old nuclear power facility. The NRC and Entergy say none of these issues have had an impact on public safety.
Gundersen said any one of these problems could happen, and it wouldn’t be all that worrying for the agency, “but you start building this pile, and the NRC has got to be saying, what are these guys doing wrong?”
“It’s not anything they (the plant operators) do on a given day,” Gundersen said. “It’s the corporate plant managers fighting for money.” He said Entergy’s 11 plants have less money for the repair of non-safety components. “There is a long list of things they know need to be done, and they aren’t getting done because there isn’t enough money in the pot,” Gundersen said. “That’s a cultural thing.”
Last week, Entergy Corporation, based in Louisiana, announced it has put Vermont Yankee on the market. It purchased the plant in 2002 for $180 million.
Gundersen said the backlog of eight to nine years worth of deferred maintenance at the plant could inhibit the sale. “I don’t see how they’re going to get a penny for it,” he said.
A new owner, in a best-case scenario, would have a matter of months to clean up the plant before the license expires in March 2012, according to Gundersen.
“Mother Teresa couldn’t turn this plant around in 11 months,” Gundersen said. “We would wind up taking it on faith, and we’ve taken a lot of stuff on faith already. I don’t know how someone can say that by March 2012 it’ll be brand spanking new … you can’t clean it up that fast.”
