Fort Calhoun NPP Surrounded by Floodwaters, as Berm Collapses

Fort Calhoun NPP containment buildings and electrical transformers surrounded by 70cm of water, as temporary flood berm collapses

The breach in the  inflatable berm protecting the Fort Calhoun nuclear power plant occurred at about 1:30 am (1:25am) local time Sunday, the Nuclear Regulatory Commission (NRC) said.

An aerial view of Fort Calhoun Nuclear Power Plant taken on June 16, 2011 showing the extent of flooding at the station. Photo: U.S. Army Corps of Engineer

Reactor shutdown cooling and spent-fuel pool cooling were unaffected, the NRC said.

The plant, operated by the Omaha Public Power District, has been off line since April for refueling.

Emergency diesel generators were activated after the breach, but normal electrical power supply was restored by Sunday afternoon, the agency said.

Containment buildings at the Fort Calhoun plant are watertight, and the reactor cooling system and spent-fuel pool cooling ponds were unaffected, NRC added.

The 2.7m (8 foot) high, 600m long inflatable flood berm surrounding the plant collapsed after being punctured by heavy equipment.

Fort Calhoun, which is about 30 km (19 miles) north of Omaha, was shut down for refueling on April 7 and has not since been restarted. It remains under the Unusual Event declared on June 6.

The 480-megawatt plant which is located north of Omaha shut down about 10 weeks ago to refuel, but has remained shut since due to flooding, according to Omaha Public Power District (OPPD).

The Fort Calhoun NPP has a single CE pressurized water reactor generating about 480 megawatts of electricity, the smallest commercial power reactor in North America.

OPPD is “a customer-owned utility,” which provides electricity to about 346,000 customers in all or parts of 13 counties in east and southeast Nebraska.

Flooding along the Missouri River to continue until mid-August

Water release from the reservoirs and dams along the Missouri River is expected to continue until at least mid-August, resulting “in near-record flooding along portions of the Missouri River.”

Probability of a Nuclear Disaster by Country

The following probability figures are calculated by FIRE-EARTH on April 8, 2011

• Japan (880)³
• United States (865)
• France (855)
• Taiwan (850)
• Belgium, China, Finland, India,  South Korea, United Kingdom, Ukraine, Russia, Slovakia, Czech Republic, Armenia, Slovenia, Croatia, Romania,  Hungary, Bulgaria, Spain,  Pakistan, Argentina, Brazil, Mexico,  South Africa, Canada (810)
• Germany, Sweden, Netherlands (800)
• Switzerland  (750)

Notes:

1. The list represents a snapshot of events at the time of calculating the probabilities. Any forecast posted  here is subject to numerous variable factors.
2. Figures in the bracket represent the probability of an incident occurring out of 1,000; the forecast duration is valid for the next 50  months.
3. Probability includes a significant worsening of Fukushima nuclear disaster, and future quakes forecast for Japan.
4. A nuclear incident is defined as a level 5 (Accident With Wider Consequences), or worse, on the International Nuclear and Radiological Event Scale (INES). See below.
5. Safety issues considered in compiling these lists include the age, number of units and capacity of nuclear reactors in each country/state, previous incidents, probability of damage from human-enhanced natural disasters, e.g., earthquakes, tsunamis, volcanic activity, hurricanes, tornadoes, storms, wildfires, flooding… ]
6. The  Blog’s knowledge concerning the extent to which the factors described in (3) might worsen during the forecast period greatly influences the forecast.

(UPDATED: June 26, 2011)

External Links

• Berm Collapses at Nuclear Plant: NRC Claims No Danger
• Japanese parents fume over Fukushima radiation impact

Related Links

• FLOODING AT TWO NEBRASKA NUCLEAR POWER PLANTS
• Nebraska Nuke Plant Remains Shut After Missouri River Flooding

FLOODING AT TWO NEBRASKA NUCLEAR POWER PLANTS

Floodwaters rising at Cooper and Fort Calhoun nuclear power plants, Nebraska

The U.S. Nuclear Regulatory Commission (NRC) said in a statement that is was closely watching conditions along the Missouri River where floodwaters are rising at two Nebraska nuclear power plants, the Cooper Nuclear Station and the Fort Calhoun NPP.

The lowest of four levels of emergency notification remain in effects at both plants, NRC said.

“We are closely following events at both plants,” NRC Region IV Administrator Elmo Collins said. “Both plants have activated their flood response plans and taken appropriate steps to protect vital structures, systems and components from rising floodwaters and maintain their plants in a safe condition.”

Cooper NPP, located in Brownville, Nebraska, is currently about 70 cm (two and a half feet) above current river levels, and is operating at full power. However, it remains under the ‘Unusual Event’ declared on June 19, NRC said.

Fort Calhoun, which is about 30 km (19 miles) north of Omaha, was shut down for refueling on April 7 and has not since been restarted. It remains under the Unusual Event declared on June 6.

“The NRC has augmented its inspection staff at Fort Calhoun where there is now two feet of water in many areas onsite,” the report said.

Cooper Nuclear Power Plant on the edge of the Missouri River surrounded by floodwaters on June 15, 2011. Photo: Corps of Engineers

An aerial view of Fort Calhoun Nuclear Power Plant taken on June 16, 2011 showing the extent of flooding at the station. Photo: U.S. Army Corps of Engineer

Flooding along the Missouri River to continue until mid-August

Water release from the reservoirs and dams along the Missouri River is expected to continue until at least mid-August, resulting “in near-record flooding along portions of the Missouri River.”

Earlier the NWS released the following statement:

“The upper Missouri River Basin (Montana, Wyoming, North and South Dakota and Nebraska) has received 100 to 800 percent of normal precipitation during the past several weeks. Snow pack runoff entering the upper portion of the river system is more than twice the normal amount.

“These conditions have resulted in Missouri basin reservoirs across eastern Montana and the Dakotas nearing their maximum levels. Reservoir water release rates are expected to stay at high release levels (150,000 cfs) into August. These extremely high flows, combined with normal rainfall, will result in near-record flooding along portions of the Missouri River.”

The graphic above shows where recent river gauge forecasts are available, and are colored according to their values.  They are the most recent guidance forecasts we have issued as of the date/time stamp on the bottom of the graphic.  Orange, magenta, and red dots represent river points that are forecast to be in flood.  Yellow dots represent those which are under flood stage, but are high enough to merit some internal action (e.g., perhaps a crest forecast is issued, or a forecast is issued more frequently).  Green dots represent stages that are below the action stage and are not high enough to merit much hydrologic concern.  Gray dots mean that the status couldn’t be determined (perhaps because no forecasts for these points have been recently issued). Source: NWS Missouri Basin/ pleasant Hill

• UPPER MISSOURI RIVER – Range of peak flows …
• LOWER MISSOURI RIVER – Range of peak flows …
• Missouri Basin River Forecast Center http://www.crh.noaa.gov/mbrfc/

France

Meantime, France’s EDF has denied reports/rumors of radioactive leaks at at least two French nuclear plants since early April this year.

Probability of a Nuclear Disaster by Country

The following probability figures are calculated by FIRE-EARTH on April 8, 2011

• Japan (880)³
• United States (865)
• Taiwan (850)
• Belgium, China, France, Finland, India,  South Korea, United Kingdom, Ukraine, Russia, Slovakia, Czech Republic, Armenia, Slovenia, Croatia, Romania,  Hungary, Bulgaria, Spain,  Pakistan, Argentina, Brazil, Mexico,  South Africa, Canada (810)
• Germany, Sweden, Netherlands (800)
• Switzerland  (750)

Notes:

1. The list represents a snapshot of events at the time of calculating the probabilities. Any forecast posted  here is subject to numerous variable factors.
2. Figures in the bracket represent the probability of an incident occurring out of 1,000; the forecast duration is valid for the next 50  months.
3. Probability includes a significant worsening of Fukushima nuclear disaster, and future quakes forecast for Japan.
4. A nuclear incident is defined as a level 5 (Accident With Wider Consequences), or worse, on the International Nuclear and Radiological Event Scale (INES). See below.
5. Safety issues considered in compiling these lists include the age, number of units and capacity of nuclear reactors in each country/state, previous incidents, probability of damage from human-enhanced natural disasters, e.g., earthquakes, tsunamis, volcanic activity, hurricanes, tornadoes, storms, wildfires, flooding… ]
6. The  Blog’s knowledge concerning the extent to which the factors described in (3) might worsen during the forecast period greatly influences the forecast.

Related News headlines

• NRC: “Two Feet of Water” at Fort Calhoun But Nuke PLant Still “Safe”
• “About 12,000 people are told to leave their homes, most of them in the city of Minot, as the Souris River swells to record levels. It is expected to rise 8 feet more before cresting.”
• 600 Iowans told to evacuate
• Evacuations widespread in northwest Missouri
• Residents of Craig in northwest Missouri are under orders to evacuate

Related Links

• Japan’s Nuclear Industry: Mega Disaster in the Making
• Japan Earthquakes, Disasters: Recent History and FIRE-EARTH Forecasts
• Major floods forcing evacuations from North Dakota to Missouri
• Nebraska Nuke Plant Remains Shut After Missouri River Flooding

Nebraska Nuke Plant Remains Shut After Missouri River Flooding

The Fort Calhoun NPP in Nebraska still in shutdown following Missouri River flooding  

The federal government insists the plant has not flooded and is NOT expected to pose any danger.

Original caption: The Fort Calhoun nuclear power station in Fort Calhoun, Neb., currently shut down for refueling, is surrounded by flood waters from the Missouri River, Tuesday, June 14, 2011. On Tuesday, the releases at Gavins Point Dam in South Dakota hit the maximum planned amount of 150,000 cubic feet of water per second, which are expected to raise the Missouri River 5 to 7 feet above flood stage in most of Nebraska and Iowa. (AP Photo/Nati Harnik). Image may be subject to copyright.

The 480-megawatt plant which is located north of Omaha shut down about 10 weeks ago to refuel, but has remained shut since due to flooding, according to Omaha Public Power District (OPPD).

The Fort Calhoun NPP has a single CE pressurized water reactor generating about 480 megawatts of electricity, the smallest commercial power reactor in North America.

OPPD is “a customer-owned utility,” which provides electricity to about 346,000 customers in all or parts of 13 counties in east and southeast Nebraska.

“Floodwaters are already surrounding the Fort Calhoun plant. The river has risen 1.5 feet higher than Fort Calhoun’s 1,004-foot elevation above sea level, but the water is being held back by an 8-foot-tall flood barrier,” a report said on Friday.

“When the river reaches 1,004 feet above mean sea level, we shut down,” said OPPD spokesman Jeff Hanson. “We don’t have any idea when we’ll be able to start again.”

OPPD has not issued any updates since June 16, 2011.

Map of the flight restricted areas. Click image to enlarge.

News Links:

• Nebraska Nuclear Plant Lost Cooling System After Fire
• NRC Notification of Unusual Event 
• Temporary flight restrictions

Related Links

• Japan’s Nuclear Industry: Mega Disaster in the Making
• Fukushima NPP: “There must be a large leak”

• Unreported News: Motion to Dump Japan’s Nuclear Power Plants
• Shut Nuclear Plants: Electric Power Co Stockholders
• Storm Shuts Down 3  TVA Nuclear Reactors at Browns Ferry in Alabama

• Chernobyl nuclear disaster: 25th anniversary
• Tornado Damage Forces Virginia Nuclear Plant Shutdown
• Probability of a Nuclear Disaster – by Country