Even In Shutdown Mode Fort Calhoun Nuclear Plant Requires Electricity To Avoid Melting Of The Core


An aerial view of the Fort Calhoun Nuclear Power Plant in eastern Nebraska, surrounded by Missouri River flood waters on June 24.

Waters Encircle Nuclear Plant (Wall Street Journal, June 27, 2011):

A protective berm holding back floodwaters from a Nebraska nuclear power plant collapsed early Sunday after it was accidentally torn, surrounding containment buildings and key electrical equipment with Missouri River overflow.

The berm’s collapse allowed floodwaters to wash around the main electrical transformers. As a result, emergency diesel power generators were started. Later in the day, power was restored.

The NRC’s Mr. Dricks said temperature monitors were working properly and temperatures of key parts of the nuclear power plant were normal. Water has not seeped into any of the containment structures, he said.

Even when in shutdown mode, a nuclear plant requires electricity to keep key components cool in order to avoid any degradation or melting of the core that could result in the release of radiation.

Flood Berm Collapses At Fort Calhoun Nuclear Plant After Being Punctured By Some Sort Of Machinery

Flood berm bursts at Nebraska nuclear plant (CNN, June 27, 2011):

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.

Read moreFlood Berm Collapses At Fort Calhoun Nuclear Plant After Being Punctured By Some Sort Of Machinery

Fort Calhoun Nuclear Plant: Floodwater Seeps Into Turbine Building At Nebraska Nuke Station

Fort Calhoun Nuclear Plant: Flood Seeps Into Turbine Building At Nebraska Nuke Station (Huffington Post, June 27, 2011):

OMAHA — 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.

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.

Read moreFort Calhoun Nuclear Plant: Floodwater Seeps Into Turbine Building At Nebraska Nuke Station

NRC In 2010: Floods Above 1010 Feet Had A 100 Percent Chance Of Core Meltdown At Fort Calhoun Nuclear Plant – Now: Missouri River Reaches Height Of Nearly 1,007 Feet

A Nuclear Plant’s Flood Defenses Trigger a Yearlong Regulatory Confrontation (New York Times, June 24, 2011):

Pictures of the Fort Calhoun nuclear power plant north of Omaha, Neb., show it encircled by the swollen waters of the Missouri River, which reached a height of nearly 1,007 feet above sea level at the plant yesterday.

The plant’s defenses include new steel gates and other hard barriers protecting an auxiliary building with vital reactor controls, and a water-filled berm 8 feet tall that encircles other parts of the plant. Both systems are designed to hold back floodwaters reaching 1,014 feet above sea level. Additional concrete barriers and permanent berms, more sandbags and another power line into the plant have been added. The plant was shut down in April for refueling and will remain so until the flood threat is passed.

“Today the plant is well positioned to ride out the current extreme Missouri River flooding while keeping the public safe,” Nuclear Regulatory Commission spokesman Victor Dricks said on an agency blog this week.

But a year ago, those new defenses were not in place, and the plant’s hard barriers could have failed against a 1,010-foot flood, the Nuclear Regulatory Commission contends in a yearlong inspection and enforcement action against the plant’s operator, the Omaha Public Power District (OPPD).

The NRC in Action at Fort Calhoun (Monthly Review, June 27, 2011):

The Union of Concerned Scientists often complains about Nuclear Regulatory Commission inaction — the agency’s failure to enforce its regulations prohibiting unmonitored and uncontrolled releases of radioactively contaminated water, the agency’s tolerance of four dozen reactors operating in violation of fire protection regulations, and so on.

Today, we commend the NRC in action.

Read moreNRC In 2010: Floods Above 1010 Feet Had A 100 Percent Chance Of Core Meltdown At Fort Calhoun Nuclear Plant – Now: Missouri River Reaches Height Of Nearly 1,007 Feet

Two Feet Of Water Already Made Its Way To Several Areas Of The Fort Calhoun Nuclear Plant

Although the Fort Calhoun plant is surrounded by an eight foot tall and 16 foot wide protective berm, two feet of water have already made its way to several areas of the Fort Calhoun plant, but authorities say there is no immediate danger at either plant.


Sirens Blare as Flooding Hits North Dakota (ABC News, June 22, 2011):

Sirens are blaring at this moment in Minot, N.D., as the overflowing Souris River floods over the top of local levees five hours before the evacuation deadline for 11,000 residents. Farther south, the overflowing Missouri River has put two nuclear power plants at risk, necessitated evacuations and produced a travel nightmare as interstate highways shut down.

“What I see right now is probably the most devastating in terms of the number of people directly impacted and what will likely be the damage to homes as the water begins to overtop the levees and fill in behind,” National Guard Cmdr. Dave Sprynczynatyk said today.

Nearly 500 North Dakota National Guard soldiers are in the town of 41,000 people to help the last stragglers in the affected area get out of harm’s way. They are accompanying the roaring sirens with shouts of “All residents must evacuate!”

“We’ve never seen anything like what we’re expecting,” Minot Mayor Curt Zimbleman told ABC News. The mayor had warned residents previously today that the river could top the levees earlier than expected, and has been urging residents to leave potentially affected areas.

Read moreTwo Feet Of Water Already Made Its Way To Several Areas Of The Fort Calhoun Nuclear Plant

Nebraska: Record Missouri River Surge – Inches Toward Nuclear Plant Shutdown Level

River inches toward nuke plant shutdown level (Journal Star, June 20, 2011):

The Missouri River rose to record height Sunday at Brownville, prompting Cooper Nuclear Station three miles south of the community to declare a low-level emergency at 2:06 a.m.

NPPD said it would take the plant offline if the water level reached 902 feet above sea level. At 6 p.m., the level was 901.73 feet.

Water levels at the Brownville gauge increased approximately two feet in a 24-hour period from 5:30 a.m. Saturday to 5:30 a.m. Sunday.

Record River Surge Recorded In Southeast Nebraska (WOWT, Jun 20, 2011):

The Missouri River surged to a new record at Brownville in southeast Nebraska Sunday afternoon as workers have been adding sandbags to the levee.

The National Weather Service said the river measured at 44.75 feet surpassing a record of 44.3 feet set in 1993. Flood stage is 33 feet.

The U.S. Army Corps of Engineers said the river level at Brownville surged two feet from Saturday morning to Sunday morning. Col. Bob Ruch attributed that to heavy rain on the Nishnabotna River, which flows into the Missouri,
and to some erosion along a levee upstream at Hamburg, Iowa, that created a water pulse.

The Nebraska Emergency Management Agency says water was flowing over a levee there and into farmland, but the levee is being built up.

Read moreNebraska: Record Missouri River Surge – Inches Toward Nuclear Plant Shutdown Level

Nebraska: Second Nuclear Plant Declares ‘Notification of Unusual Event’

Declaration at Cooper Nuclear Station (June 19, 2011):

As the Missouri River rises, the Nebraska Public Power District has declared a “Notification of Unusual Event” for the Cooper Nuclear Station. The notification was made at 4:02am Sunday. It is part of the safety and emergency preparedness plan that the station follows when certain flooding conditions are present.

NPPD says there is no threat to plant employees or the general public. The plant continues to operate safely. The Omaha Public Power District made the same declaration nearly two weeks ago when the Missouri River continued to rise near the Fort Calhoun Nuclear Station.

Read moreNebraska: Second Nuclear Plant Declares ‘Notification of Unusual Event’

Dear Nebraska: Sorry About Water, But More On The Way. Love, Montana


FILE – In this June 14, 2011 file photo, the Fort Calhoun nuclear power station, in Fort Calhoun, Neb., is surrounded by flood waters from the Missouri River. The pictures of a Nebraska nuclear power plant were startling: Floodwaters from the swollen Missouri River had risen nearly to the reactor building, with the potential to climb even higher.

See also:

Floodwaters Might Hit Kansas City By Midweek – Army Corps Running Out Of Options – ‘At This Point, We Have Very Little Flexibility Remaining’


Dear Nebraska: Sorry about water, but more on the way. Love, Montana (JournalStar, June 17, 2011):

From his tackle shop near Three Forks, Mont., Rich Gay is watching three rivers.

They’re running high out of the mountains, skirting his town, fraying his nerves and converging, more than a mile away.

This is the headwaters of the Missouri River — and the source this summer of so much Nebraska pain.

But this isn’t where the flood begins.

Read moreDear Nebraska: Sorry About Water, But More On The Way. Love, Montana

Nebraska Emergency Management Officials: Most Missouri River Levees Built To Withstand For 3 To 4 Days – Levees Will Likely Face Punishing Amounts Of Water For Several Months – Nuclear Plant Surrounded By Floodwaters

Governor: Punishing amounts of water threaten levees (JournalStar, June 14, 2011):

…..

The river at Sioux City, Iowa, reached 33.12 feet by midafternoon Tuesday, down from 33.55 feet in the morning, as the release from Gavins Point Dam in Yankton, S.D., reached a historic high of 150,000 cubic feet per second.

Most levees around the Missouri River are built to withstand surge waters for three to four days, according to Nebraska Emergency Management officials.

This year, they likely will face punishing amounts of water for several months as the Army Corps of Engineers releases record amounts of water from Gavins Point.

……

Farther south, near Fort Calhoun, farmland and the nuclear power plant are surrounded by floodwaters, Heineman said. The power plant is offline for routine maintenance.