Legalectric

While looking up photos of nuclear plants, I found this Catfish

OK, back to nuclear. Notice a trend here? Last time there was a radioactive incident at Prairie Island, it took a week for news of it to be reported, and then, we were told that there were 12 affected workers, not the 100 reported by the NRC. Oh, great. Well, now here’s another one, a 35,000 pound control box fell from the ceiling. Oh, great. 35,000 pounds is nearly a truck load, it’s 20x6x6. Big enough to flatten even moi! And it takes a week to see it in the paper. Oh, I feel really safe. Here’s the poop from the STrib:

Nuclear plant at Monticello shut down

A large metal box broke loose inside the plant, triggering an automatic shutdown.

By Tom Meersman, Star Tribune
Last update: January 16, 2007 â?? 8:25 PM

The Monticello nuclear power plant remains shut down indefinitely, as an investigation continues into why a large metal component broke loose inside the plant, federal officials said Tuesday.

A 35,000-pound control box fell off a steel beam inside the plant last Wednesday, they said, triggering safety systems that shut down the nuclear reactor automatically.

The incident was outside the reactor, and no radiation was released, federal and company officials said.

“We’re working as quickly and safely as possible to get the plant back online,” said Arline Datu, spokeswoman for the Nuclear Management Co., which operates the plant for Xcel Energy, its owner. “I can’t speculate one way or another how long or how short that will take.”

The Monticello plant, about 45 miles northwest of the Twin Cities, began operating in 1970.

Last November federal officials renewed Xcel’s license to operate it for 20 years beyond 2010, when its original 40-year license will expire.

According to Jan Strasma, spokesman for the Nuclear Regulatory Commission, a rectangular control box came loose from the steel I-beams to which it was welded.

He said the control box is about 20 feet long, 6 feet wide and 6 feet high.

Vibrations loosened welds?

“The initial assessment is that the welds broke due to vibration over the years,” he said, and one side of the box dropped about a foot onto a large steam pipe. The mechanisms inside the box apparently malfunctioned and opened valves in four other steam pipes, he said, which in turn activated sensors that shut the plant down immediately, shortly before 3:30 p.m. last Wednesday.

The control box probably damaged the steam pipe and perhaps insulation on other steam lines, he said.

“There was no release of radioactivity, no threat to public health and safety, and all of the reactor’s safety systems functioned normally,” Strasma said.

David Lochbaum, director of the nuclear safety project at the Union of Concerned Scientists, said that the aging of nuclear plants is a continuing concern, but that utilities have strong economic incentives to replace components before they wear out, to avoid unexpected and costly shutdowns.

The union is a nonprofit organization based in Cambridge, Mass., that often advocates for more government scrutiny of the nuclear industry.

Lochbaum said that even though the sensors at Monticello worked successfully last week, it can be risky to rely too much on a nuclear plant’s automatic shutdown system. “If that were to happen too often, then someday, because it’s not 100 percent reliable, you’re increasing the odds of it not working the way it’s supposed to,” he said.

Lochbaum said aging nuclear plants could face additional stress if utilities try to run them too long between maintenance shutdowns, or try to boost their power output beyond what they were designed to produce.

Datu, of Nuclear Management, said that utilities have invested billions in new and upgraded equipment for nuclear plants, and that all aspects of nuclear power are closely watched, regulated and graded by federal regulators and industry groups.

“These nuclear plants go through rigorous inspection, and the upkeep is continual,” she said.

Strasma said that federal officials are investigating the Monticello incident, but that he did not know whether Nuclear Management will be required to inspect all welds at the plant. “They not only have to fix the problem, they have to assess why it happened and make sufficient repairs so it won’t happen again,” he said.

“It obviously is a very unusual set of circumstances,” Strasma said, and one that will probably be shared with other nuclear utilities so that they can check for similar problems.

Xcel Energy spokeswoman Mary Sandok said the temporary loss of Monticello’s power will not significantly affect the supply or price of electricity. “Because it’s just one of many plants, we do not expect that it will raise the average cost of electricity dramatically for our customers,” she said.

Datu said Nuclear Management has brought in experts from several other nuclear plants who are working around the clock to determine what went wrong and to make repairs.

Fish killed by thermal shock

She also said that when Monticello shut down last week, about 3,000 small fish died in the Mississippi River near the plant. Nonradioactive water used in the plant’s cooling system is normally discharged into the river, she said, creating warm spots. When the discharge stopped, she said, the water quickly cooled, and the fish died of thermal shock. Officials of the Minnesota Department of Natural Resources were notified, she said.

The last time that Monticello shut down unexpectedly was in 2002, Strasma said, when it stopped producing power between Jan. 21 and 27 because of a malfunction in the turbine control system.

Tom Meersman â?¢ 612 673-7388 â?¢ meersman@startribune.com

©2007 Star Tribune. All rights reserved.