- Picture courtesy of Progress Energy
Following up on my story in the Indy this week about whether Duke Energy, soon (?) to be merged with Progress Energy, should be spending hundreds of millions of $$$ of customers’ money on maybe building another nuclear plant (estimated pricetag, pre-Japan disaster, $11 billion) …
… as The New York Times is reporting, the danger posed by the loss of cooling water in the pools containing spent fuel rods is almost as bad as from a reactor core meltdown. Indeed, a better term than “spent” for these retired fuel rods would be “partially used but still highly radioactive for a long, long time.”
Like the Japanese, most U.S. nuclear plants also store their spent fuel in pools — like the one shown above, one of four (three operational) located at the Shearon Harris plant in Wake County.
From the Times story today about the problems with the cooling pools in Japan (a longer excerpt is below the fold) —
If the American analysis is accurate and emergency crews at the plant have been unable to keep the spent fuel at that inoperative reactor properly cooled — it needs to remain covered with water at all times — radiation levels could make it difficult not only to fix the problem at No. 4, but also to keep servicing any of the other problem reactors at the plant. In the worst case, experts say, workers could be forced to vacate the plant altogether, and the fuel rods in reactors and spent fuel pools would be left to melt down, leading to much larger releases of radioactive materials.
Another NYT story, headlined “Danger of spent fuel outweighs reactor threat.”, begins —
Years of procrastination in deciding on long-term disposal of highly radioactive fuel rods from nuclear reactors is now coming back to haunt Japanese authorities as they try to control fires and explosions at the stricken Fukushima Daiichi Nuclear Power Station.
Some countries have tried to limit the number of spent fuel rods that accumulate at nuclear power plants — Germany stores them in costly casks, for example, while Chinese nuclear reactors send them to a desert storage compound in western China’s Gansu province. But Japan, like the United States, has kept ever larger numbers of spent fuel rods in temporary storage pools at the power plants, where they can be guarded with the same security provided for the power plant.
This is the problem that critics pointed to at the Shearon Harris nuclear plant in Wake County prior to and again following the 9/11 terrorist attacks. The reactor core at Shearon Harris is protected by a concrete-and-steel containment vessel, designed to keep any radiation that leaks from the core from escaping into the atmosphere. But the partially used fuel rods at Shearon Harris, as at many U.S. reactors, are stored in pools located in a different building, one which is highly fortified but not to the same degree that the containment for the core is.
Moreover, while there’s only one reactor at Shearon Harris, at least so far, there are four containment pools — built in anticipation of three additional reactors that were cancelled following the crisis at the Three-Mile Island plant in Pennsylvania in 1979. And for years, Progress Energy shipped spent fuel rods from its other nuclear facilities to Shearon Harris because of the surplus storage pools there.
(I’ve got a call in to Progress Energy to ask whether all four pools are in use — last I knew it was two out of four, but the two were filling up — and whether the company did in fact stop shipping spent fuel rods to Shearon Harris for storage from its Robinson and Brunswick nuclear plants. The answer, from Progress Energy spokesman Julie Milstead, is that three of the pools are now in use; no fuel rods have been shipped to Harris since 2008.)
The upshot is that Shearon Harris is one of the biggest, if not the biggest, nuclear-waste storage facilities in the country.
Like Japan, the U.S. has never figured out how — or where — to create a permanent storage facility for these wastes. Yucca Mountain, in Nevada, was supposed to be the U.S. answer. But unless something changes, it’s not going to be — and there is no alternative in sight. (Japan, while it has no permanent waste facility either, does reprocess its used fuel, so less is stored in a cooling pool there than here, according to NC WARN’s Jim Warren.)
Progress Energy took some reporters through Shearon Harris in 2000. I wrote about it then and recalled it in a post-9/11 story, “What If,” about the possibility that a terrorist attack could result in water escaping the cooling pools, — exactly what’s happened in Japan because of the earthquake, apparently.
This is from my own “What If” piece eight years ago:
Re-racked for dense packing, Harris has storage space for 20 more years even if the Robinson-Brunswick shipments continued, Kimble says. But Harris expects to stay in use longer than that, so rather than run out of pool space for its own spent fuel, Progress is thinking it could put dry casks in at the other two plants and buy itself more time for Harris’ wastes.
Since Sept. 11, the NRC has ordered nuclear plants to stop conducting media tours, but the Independent was allowed to visit the pool-storage building in 2000. It’s not constructed to the same, 12-foot thickness as the containment dome around the reactor core, but it is reinforced concrete, 4-6 feet thick, according to Kimble, and the walls that surround each of the four pools are also reinforced concrete, up to 8 feet thick, and sit on top of a 12-foot-thick concrete block. [Update, 3/17/11: Milstead just gave me different numbers — see below.]
The effect, Kimble says, is containment-like: An airplane, or missile, would have to break through the exterior walls and keep going with enough strength to penetrate the pool walls before the stored fuel rods would be in any jeopardy. Even at that, the pools are 40 feet deep, and the fuel-rod assemblies only 13 feet tall, so there’s a cushion of time for plant operators to start pumping back-up water before the tubes would be uncovered, the hottest fuel rods would start heating up, and the zirconium cladding would ignite, releasing radioactivity into the building.
The exact specifications of the building are kept secret, for security purposes, and Kimble declined to say how thick the roof is.
It’s the roof, however, that the Princeton authors think could be compromised in an air attack. The blast from an airliner explosion might not be sufficient to destroy a pool by itself, they say, but it could collapse the building into it. Or the turbine engine from a diving fighter jet might be able to punch through and puncture a pool wall.
Progress Energy is “watching and monitoring, along with the rest of the industry,” Milstead said today, everything that’s happening in Japan. That said, the company continues to have “extreme confidence” in the structural integrity of the waste pools at Shearon Harris, she said.
On the dimensions of the containment dome and the waste-storage building, Milstead said the dome is 3-4 feet thick and is reinforced with steel rebar; the storage building is 3 feet thick and its roof 2 feet thick, she said. The pool walls are 6 feet thick and its bed—the bottom—is 12 feet thick, she added. The pools have extensive equipment to monitor for leaks.
Milstead said the Shearon Harris reactor is licensed through 2046, and the storage capacity of the four pools is sufficient to last at least that long.
This is from the main NYT story today:
Some of the maneuvers seemed at odds with the most startling assertion by Mr. Jaczko (pronounced YAZZ-koe) that there was little or no water in the pool storing spent nuclear fuel at the No. 4 reactor, leaving fuel rods stored there exposed and bleeding radiation into the atmosphere. His testimony before Congress was the first time the Obama administration had given its own assessment of the condition of the plant, apparently mixing information it had received from Japan with data it had collected independently. “We believe that radiation levels are extremely high, which could possibly impact the ability to take corrective measures,” Mr. Jaczko said.
His statement was quickly but not definitively rebutted by officials of Tokyo Electric, the plant’s operator.
“We can’t get inside to check, but we’ve been carefully watching the building’s environs, and there has not been any particular problem,” Hajime Motojuku, a spokesman for Tokyo Electric, said Thursday morning in Japan.
Later, a spokesman for Japan’s Nuclear and Industrial Safety Agency, Yoshitaka Nagayama, was more equivocal, saying, “Because we have been unable to go to the scene, we cannot confirm whether there is water left or not in the spent fuel pool at Reactor No. 4.”
At the same time, officials raised concerns about two other reactors where spent fuel rods were stored, Nos. 5 and 6, saying they had experienced a slight rise in temperature.
On Wednesday night, Mr. Jaczko reiterated his earlier statement and added that commission representatives in Tokyo had confirmed that the pool at No. 4 was empty. He said Tokyo Electric and other officials in Japan had confirmed that, and also emphasized that high radiation fields were going to make it very difficult to continue having people work at the plant.
If the American analysis is accurate and emergency crews at the plant have been unable to keep the spent fuel at that inoperative reactor properly cooled — it needs to remain covered with water at all times — radiation levels could make it difficult not only to fix the problem at No. 4, but also to keep servicing any of the other problem reactors at the plant. In the worst case, experts say, workers could be forced to vacate the plant altogether, and the fuel rods in reactors and spent fuel pools would be left to melt down, leading to much larger releases of radioactive materials.
