With the specter of the devastating March 11 earthquake, tsunami and subsequent meltdown at Japan's Fukushima Daiichi nuclear power plant still fresh in the public mind, a spreading wildfire and rising floodwaters near three U.S. nuclear facilities further heightened concerns on Monday -- though officials asserted that all three facilities remained essentially safe.
Two nuclear power plants on the swollen Missouri River -- the Fort Calhoun Station, 19 miles north of Omaha, Neb., and the Cooper Nuclear Station, located 85 miles downriver near Hamburg, Iowa -- were dealing with rising floodwaters.
Meanwhile, a wildland fire near the Los Alamos National Laboratory in New Mexico -- a massive research facility that is home to several metric tons of plutonium and numerous other hazardous and volatile materials -- had inched to within just over a mile of the southern edge of that facility's boundary.
Officals at Los Alamos, which was closed as a precaution on Monday, announced that the lab would remain closed on Tuesday due to "risks presented by the Las Conchas wildfire and the staged, mandatory evacuation of the Los Alamos town site." A statement posted to the laboratory's Web site also noted that a one-acre spot fire was reported on the Lab’s southwestern boundary.
Yet officials at all three facilities said their nuclear material was safe, though some nuclear watchdog groups remained skeptical.
The Nuclear Regulatory Commission on Sunday established an incident response center for tracking the situation at Fort Calhoun, which was surrounded by floodwaters hovering at around 1,006 feet above mean sea level on Monday, according to agency spokesman Victor Dricks.
The facility is designed to withstand floodwaters up to 1,014 feet, and water levels were not expected to rise beyond 1,008 feet, according to officials. The rupture of a flood protection berm on Sunday, however, allowed water to threaten the facility's main power transformers, and the plant was temporarily cut off from power supplied by the electric grid as a precaution. Backup diesel generators provided power for about 12 hours on Sunday, Dricks said, but grid power has since been restored.
The plant has also been shut down since early April for scheduled refueling, officials noted. This would afford operators much more time to deal with any potential loss of power situation, since heat levels from the reactor are already vastly reduced.
Though the historic earthquake off the coast of Japan set the disaster there in motion, the Fukushima plant ultimately failed when power to the electric grid was lost and a subsequent tsunami flooded and disabled the backup diesel generators. Batteries designed as a third layer of defense in the event of lost power were expended in less than a day, leaving that facility with no ready means to keep nuclear material cool.
But David Lochbaum, a frequent critic of nuclear safety oversight and the head of the Nuclear Safety Project with the Union of Concerned Scientists, noted that Fort Calhoun's preparedness for rising floodwaters was actually enhanced due to actions taken last year by nuclear regulators. The regulator sanctioned the plant's operator, Omaha Public Power District, for having what it deemed to be inadequate flood protections, and forced improvements.
The NRC had estimated that without such improvements, reactor core damage was a veritable certainty if flood waters rose above 1,010 feet.
"However high the waters ultimately get," Lochbaum said, "we can definitely say that facility is better prepared for a flood now than it was before the NRC got involved."
"The biggest concern now would be an upstream dam," he added. "If one of those were to fail, that would change the situation, but then you just start doing a lot of 'what ifs' -- like what if a meteor hits the plant."
The Cooper Station to the south, operated by Nebraska Public Power District, is also facing rising waters. Workers have spent the last month preparing the facility with sandbags, barricades and obtaining additional supplies. The plant sits at 903 feet above mean sea level, though waters are not expected to exceed that level, according to Dricks, who added that there was no threat to the reactor's vital equipment.
But Paul Gunter, director of the Reactor Oversight Project with the group Beyond Nuclear, suggested that similar assurances were made at the Cooper Station during a serious flood in 1993. A subsequent investigation by the Nuclear Regulatory Commission, published in March the following year, suggested that water had penetrated some parts of the facility -- including some areas where key electrical equipment could have been compromised.
"While NRC was telling me back then that there were no safety implications and everything was under control, in fact, floor drains inside the plant had backup and the water level was rising on safety related electrical circuitry for reactor cooling systems," Gunter said in an email.
Nuclear Regulatory Commission chairman Gregory Jaczko visited the Cooper facility on Sunday and was scheduled to fly over Fort Calhoun on Monday. He insisted that the nation's nuclear plants were designed to withstand rising waters.
"Mother nature takes care of the floods, so we have to do the best we can to make sure we're prepared," Jaczko was quoted as saying by ABC News, "and all the plants in the U.S. have been designed to deal with historically the largest possible floods."
Gunter, however, pointed to an NRC event notification from June 17 at Fort Calhoun, which suggested that the facility was still struggling to plug leaks even with water levels below the designed flood limit of 1,014 feet. The notification, Gunter said, showed that the facility's operator "was still discovering and plugging additional holes at 1,007 feet that, if flooded, could disable accident mitigation systems in the reactor."
The fire near Los Alamos National Laboratory, meanwhile, prompted that facility to be shut down on Monday. Natural gas service to some parts of the facility along its southern border was cut off as a precaution, according to Kevin Roark, a spokesman for the laboratory. Roark added that nuclear material housed at the facility was in no danger, and that combustible material -- trees, brush and grass -- were not close enough to sensitive buildings to serve as fuel for an approaching fire.
Of greatest concern at Los Alamos is a part of that facility called Technical Area 55 (TA-55), which includes Plutonium Facility 4 (PF-4). Peter Stockton, a senior investigator with the Project on Government Oversight, said a fire at PF-44 would be "a fucking disaster" that could result in large and lethal releases of radiation. He noted, too, that the Los Alamos facility has had problems with its internal fire suppression systems in the past.
But Roark said that those problems, which have been addressed, involved fire threats inside the building, and that they were unrelated to an approaching wildland fire. He also pointed to the Cerro Grande fire of 2000 -- a massive New Mexico wildfire that ultimately breached the facility's boundary, burning some 7,000 acres of laboratory property and damaging several buildings.
Even in that instance, Roark said, critical buildings containing nuclear material remained safe.