Flood wall fails at Nebraska nuke plant

[The Stig]

Original story from Omaha.com
(http://www.omaha.com/article/20110626/NEWS01/110629782#flood-wall-fails-at-fort-calhoun)


Published Sunday June 26, 2011
Flood wall fails at Fort Calhoun

By Sam Womack
WORLD-HERALD STAFF WRITER

Floodwaters surrounded several buildings at the Fort Calhoun Nuclear Station early Sunday morning after a water-filled wall collapsed.

The plant, about 19 miles north of Omaha, remains safe, Omaha Public Power District officials said Sunday afternoon.

The U.S. Nuclear Regulatory Commission is monitoring the Missouri River at the plant, which has been shut down since early April for refueling.

The 2,000-foot berm collapsed about 1:25 a.m. Sunday due to “onsite activities,” OPPD officials said. The Aqua Dam provided supplemental flood protection and was not required under NRC regulations.

“We put up the aqua-berm as additional protection,” said OPD spokesman Mike Jones. “(The plant) is in the same situation it would have been in if the berm had not been added. We're still within NRC regulations.”

According to the NRC, the berm was eight-feet tall and 16-feet wide at the base. It was designed to provide protection for the plant's "powerblock" for up to six feet of water. Crews will look at whether it can be patched, OPPD officials said.

On Sunday, floodwater surrounded the nuclear plant's main electrical transformers, and power was transferred to emergency diesel generators.

OPPD officials said the transfer was precautionary because of water leaking around the concrete berm surrounding the main transformers.

Efforts were underway to reconnect to offsite power once all safety checks have been completed.

The floodwaters also surrounded auxiliary and containment buildings, which are designed to handle water up to 1,014 feet above sea level. The Missouri River is at 1,006.3 feet and isn't expected to exceed 1008 feet.

The NRC says its inspectors were at the plant when the berm failed and have confirmed that the flooding has had no impact on the reactor shutdown cooling or the spent fuel pool cooling.

In a statement released Wednesday, the NRC said there is a separate, earthen berm to protect the electrical switchyard and a concrete barrier surrounding electrical transformers.

Last week, the NRC augmented its inspection staff at Fort Calhoun. In addition to the two resident inspectors, three more inspectors and a branch chief were added to provide around the clock coverage of plant activities.

Both Fort Calhoun and Cooper Nuclear Plant, in Brownville, Neb., remain under “unusual event” declarations, the lowest of four levels of emergency notification.

[The Stig]

Original story from cnn
(http://www.cnn.com/2011/US/06/26/nebraska.flooding/index.html?hpt=hp_t2)


Flood berm bursts at Nebraska nuclear plant
By the CNN Wire Staff
June 26, 2011 5:17 p.m. EDT

(CNN) -- A water-filled berm protecting a nuclear power plant in Nebraska from rising floodwaters collapsed Sunday, according to a spokesman, who said the plant remains secure.

Some sort of machinery came in contact with the berm, puncturing it and causing the berm to deflate, said Mike Jones, a spokesman for the Omaha Public Power District (OPPD), which owns the Fort Calhoun plant.

The plant, located about 20 miles north of Omaha, has been shut since April for refueling.

"The plant is still protected. This was an additional, a secondary, level of protection that we had put up," Jones said. "The plant remains protected to the level it would have been if the aqua beam had not been added."

Parts of the grounds are already under water as the swollen Missouri River overflows its banks, including areas around some auxiliary buildings, Jones said.

In addition to the berm, authorities have put in place flood gates and other barriers to help protect the facility.

The plant is designed to withstand waters up to 1,014 feet above mean sea level, according to the OPPD. The river currently stands at 1,006.3 feet and is not expected to exceed 1,008 feet, the Power District said.

Heavy rainfall in Montana and North Dakota, combined with melting snow from the Rocky Mountains, have sent the Missouri surging downstream this summer. The river washed over and punched through levees in nearby northwestern Missouri, spurring authorities to urge about 250 nearby residents to leave their homes.

The 6 to 12 inches of rainfall in the upper Missouri basin in the past few weeks is nearly a normal year's worth, and runoff from the mountain snowpack is 140% of normal, according to forecasters.

[RedJohn]

That could be bad news. It happened in France not too long ago, and we were near catastrophy.

[piranha2]

Hopefully, their Emergency Preparedness procedures will prevail. If they follow the book.

[RedJohn]

Hopefully, their Emergency Preparedness procedures will prevail. If they follow the book.

Well, here, we've learnt recently that safety was second to profit on nuclear powerplants.

[The Stig]

That could be bad news. It happened in France not too long ago, and we were near catastrophy.

Out of curiosity, how did the French emergency organizations respond? They do anything interesting trying to contain/prevent disaster?

[RedJohn]

Out of curiosity, how did the French emergency organizations respond? They do anything interesting trying to contain/prevent disaster?

They just could not do anything on this one. Flash flood went over the berm but stopped meters away from that bad point. Just lucky I guess. After that they just raised the berm and everybody is on the same level saying that it is not enough, but nobody cares but the people leaving around.

[The Stig]

Original story from AP (http://hosted.ap.org/dynamic/stories/U/US_MISSOURI_RIVER_FLOODING_NUCLEAR_SAFETY?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2011-06-27-09-36-51)


NRC chairman says Neb. nuke plants remain safe

By JOSH FUNK and NELSON LAMPE
Associated Press

OMAHA, Neb. (AP) -- The nation's top nuclear power regulator said Monday that both of Nebraska's nuclear power plants have remained safe as they battle floodwaters from the bloated Missouri River.

Nuclear Regulatory Commission Chairman Gregory Jaczko visited both Fort Calhoun and Cooper nuclear power plants in eastern Nebraska this week to see how the utilities that run them are coping with the flooding. Both plants sit on the river.

The Omaha Public Power District's Fort Calhoun is the subject of more public concern because the floodwaters are closer to that plant. Nebraska Public Power District's Cooper plant is more elevated.

Jaczko's visit to Fort Calhoun Monday came one day after an 8-foot-tall, water-filled temporary berm protecting the plant collapsed early Sunday. Vendor workers were at the plant Monday to determine whether the 2,000 foot berm can be repaired.

"We don't believe the plant is posing an immediate threat to the health and safety of the public," Jaczko said.

Omaha Public Power District spokesman Jeff Hanson said pumps at Fort Calhoun were handling the problem and that "everything is secure and safe." The plant, about 20 miles north of Omaha, has been closed for refueling since April. Hanson said the berm's collapse didn't affect the shutdown or the spent fuel pool cooling.

Missouri River floodwater seeped into the turbine building at a nuclear power plant near Omaha on Monday, but plant officials said the seepage was expected and posed no safety risk because the building contains no nuclear material.

Jaczko said the Army Corps of Engineers doesn't expect the river to rise enough to cause additional significant problems at either of the nuclear plants in Nebraska.

"Bottom line, it looks like the levels are going to be at a place where the plant should be able to deal with it," Jaczko said.

Flooding remains a concern all along the Missouri because of massive amounts of water the U.S. Army Corps of Engineers has released from upstream reservoirs. The river is expected to rise as much as 5 to 7 feet above flood stage in much of Nebraska and Iowa and as much as 10 feet over flood stage in parts of Missouri.

The corps expects the river to remain high at least into August because of heavy spring rains in the upper Plains and substantial Rocky Mountain snowpack melting into the river basin.

Both nuclear plants issued flooding alerts earlier this month, although they were routine as the river's rise has been expected.

The main building at Fort Calhoun is at 1,004 feet above sea level, which is about 2 feet below the level of the Missouri River. That's why floodwaters have been able to get so close to the plant.

OPPD officials say Fort Calhoun is designed to be protected from floodwaters up to 1,014 feet above sea level - that's about 8 feet higher than the river's current level. And the latest prediction from the Corps of Engineers is that the river won't rise more than 2 feet above its current level near Fort Calhoun.

Jackzo inspected the Cooper Nuclear Station, which sits on the Missouri River about 75 miles south of Omaha, on Sunday. He asked plant officials and the NRC's local inspectors questions about the plant and this year's flooding.

The plant, which is owned by Nebraska Public Power District, remains dry because it sits at an elevation above the river and continues to operate at full capacity. The base of Cooper and its storage area for used nuclear fuel is 903 feet above sea level. The river was 900.2 feet above sea level early Monday.

One of the biggest threats to the safety of any nuclear power plant would be a prolonged loss of electrical power because the plants need to be able to continue pumping water over the radioactive fuel to keep it cool.

A key factor in the disaster at Japan's Fukushima Dai-ichi facility earlier this year was the loss of all off-site power and emergency generators after the earthquake and tsunami struck.

Fort Calhoun has at least nine backup power sources in place, including six different power lines and two diesel generators, which were just tested Sunday after the failure of the water-filled berm.

Cooper also has two main lines of outside power, at least three generators on site and a battery system that can power the plant in an emergency.

Officials with the NRC and the Nebraska utilities have said that one of the key differences between the Fukushima disaster and the Missouri River flooding is that the river flooding has progressed slowly and the utilities had several weeks to prepare.

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