Japan's lesson for U.S. reactors: Disaster is possible

A new turbine at the Dresden Nuclear Statioin in Illinois.

When the giant winter storm Nemo hit New England two weeks ago, the Pilgrim Nuclear Power Generating Station in Plymouth, Mass., lost outside power for several days. Diesel backups took over operating the reactors' cooling system. Pilgrim has the same kind of reactors that failed less than two years ago at Fukushima, Japan, after an earthquake and tsunami crippled offsite power and emergency back-ups. The Pilgrim incident comes as the U.S. nuclear industry is fighting proposed new safety measures meant for a crisis that might begin exactly this way.

Of the 104 reactors in the U.S., 31 are very like those in Fukushima, that lost power, melted down and exploded. I'm entering one of them, the Dresden Nuclear Station, about an hour southwest of Chicago.

View GE Mk I & Mk II Reactors in the U.S. in a larger map

After Fukushima, the Nuclear Regulatory Commission studied what happened. Should it require new safety measures here, even though a crisis is very unlikely?

It's not zero," says Charles Casto, director of NRC Region III, the Midwest. "Hah. The probability's not zero; it's something."

Region III has about two dozen reactors. We spoke at Casto's office. Nuclear regulation, he said, is about possibility more than probability.

"You take your best -- based on history...you know, what has history shown you that the probability would be?" Casto said. "But that doesn't mean zero."

The Fukushima reactors, and their 31 U.S. cousins, including Dresden and the Pilgrim Station, are old Mk I and II boiling water reactors, built by General Electric. The safety enclosures for the reactors are too small. If their cores start to melt down, the containments could fail in several ways, including radioactive hydrogen gas building up and exploding ...as at Fukushima. There's an increasingly politicized dispute between the industry and the NRC over how to make preventing meltdowns safer.

Dresden, the first commercial nuclear plant in the country, is operated by the largest nuclear energy company in the U.S. -- Exelon Generation. It looks dated but extremely well maintained. It hums.

Gregory Roach, the senior NRC inspector here, showed me back-ups on backups on backups, flood protection, fire protection. An hour into the tour, we came to the part I most wanted to see -- the venting system.

"We showed you where the hardened vents were for the dry well, so now this is downstream," Roach said.

He was pointing to a pipe overhead that exits the container wall. The vent system...if power fails, and the back-ups fail, and radioactive hydrogen builds up, you can probably save the reactors by venting the hydrogen.

"And this pipe goes up to the main stack, 300 feet, and then releases into the environment," Roach said.

The Japanese vents mostly didn't work; that's what caused the explosions.

"So you learn a lesson of Fukushima Daiichi," Casto said. "And then you put in standards and say your vent must be able to operate under those conditions."

A year ago, the NRC issued a new order: vents must be reliable.

"Does that mean during an accident you have to be able to get access to it?" Casto asked. "Does that mean you have to do it remotely?

The industry and the NRC are working on it; the industry has until the end of 2016.

Now, here's what the fight is about: do the vents at these 31 plants also need filters? Because, in the best of conditions, some radioactive gas and particles may escape in venting -- and in the very, very unlikely worst of conditions, a lot could escape.

"You have to establish the 'what if'," Casto said. "What if it does happen? What if the improable happens?"

Reactor cores hold dozens of tons of radioactive material. At Pennsylvania's Three Mile Island in 1979, about half the core melted, but the containment held, and the venting was relatively minor. We don't yet know how much escaped from Fukushima; it's too dangerous to go look. But there are scenarios in which it's possible to lose a good part of those dozens of tons through the vents. With filters, virtually all of it is captured.

To a layperson, nuclear regulation can be almost as daunting as nuclear physics. The Dresden plant is a wonder of machine technology -- in it I got reacquainted with the idea of awe.

The NRC process for new rules...that's messier.

The chances of a reactor ever needing a filter are so small that you can't justify the cost. But the NRC staff concluded that the consequences of no-filter could be so bad, they should be required anyway. By NRC procedures, if the staff wants to override normal cost-benefit standards, the five commissioners have to vote to approve, and the fight is on.

A week after the NRC staff testified for filters in January, 21 House Re-publicans on the Energy and Commerce Committee sent the NRC a letter admonishing the staff. There is plenty of money at stake.

"External filter vents would be an additional approximately $15-20 million per unit," said David Czufin, an engineer who runs the Dresden plant for Exelon.

Exelon has 10 more of these reactors, so filters could cost the company more than $200 million -- on top of many other precautions, he said.

"Additional connections, additional equipment, stored equipment for readiness..."

Exelon does plan to spend $400 million in the next three years for post-Fukushima modifications, some of that for vents -- but not filters.

"The one thing I would tell you is that the Fukushima event, we have learned a lot from it," Czufin said. "We continue to look at how the plant in Japan was operated differently from my plant."

He's right; they are different. The independent Japanese commission on Fukushima says so: U.S. plants are much better regulated, run and prepared. And nuclear is already at a competitive disadvantage, according to Bloomberg New Energy Finance, natural gas plants can produce electricity for about 40 percent less. If the industry loses this one, it's going to hurt.

A last question for the director of NRC Region III, Charles Casto. Is he satisfied now that under circumstances like Fukushima Daiichi, he has the technology to operate vents at the stations that are under his authority?

"Yes, we believe that we have reliable vents and that the operators can do a controlled vent in a reliable way during an accident," Casto said.

But unusual things do happen, as at the Pilgrim Station. Without the filters, there is a very small chance that those vents might become a kind of radioactive fire hose. That's what the fight is about.

The NRC Commissioners are voting on this now -- a process that can take weeks, or longer.

About the author

Alex Chadwick is an independent journalist, renowned public radio correspondent and contributor to Marketplace. He is host of BURN: An Energy Journal.
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Free market, right? I demand free energy devices. But I guess there is no money in that.

Without feed water, a vent is still on the path to meltdown. I don’t understand why the main turbines would be valved out when offsite power is lost. I can understand scraming the reactor because there is no place to dump the electrical power, but why not run the turbines and generate local power as long as there is sufficient steam pressure on the high side and coolant on the low side? This would hold the diesel powered generators in reserve. As long as integrity of the pressurized system is maintained, over pressure, over temperature, failure of the diesel generators, and exhaustion of diesel fuel would not occur.

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Golly people, I sense a lot of fanatical anger here. Disasters are always a possibility no mater what we are talking about, and sure we should make continuous improvements (and I favor the filters), but personally I have to ask why this was even referred to as an "incident", since apparently everything worked as it was supposed to.

Several General Electric engineers quit their jobs with GE over how unsafe this plant design is. Japan was not one in a million; it was predicted by the men who helped create these horribly flawed power plants.
These plants were marketed as cheap to build. They were cheap because they have no containment structure to speak of. Profit before safety an old story.
The Dresden plant has been sighted by the NRC numerous times for safety violations.
The U.S. government recommended that all U.S. citizens evacuate from a 50 mile circle drawn around Fukushima, draw that same circle around the Dresden plant. Yes, that is Chicago.
Fukushima sits on the ocean, tons of radioactive water was and is being released into the sea. Dresden sits on the Illinois River. The water shed for that is down the Mississippi river and the heart of America.
It’s great that the reporter was awed by the big machines but where is the reporting?
This is not about being against nuclear power or for nuclear power, this is about a bad unsafe aging design.
These plants were predicted to fail and one did, if they keep running more will fail. This is simple.

Hi, I'm Marketplace's sustainability editor. Here are some responses from Alex Chadwick to questions raised in the comments.

"Thanks for your comments.

"Speaking for BURN, yes, we mean hydrogen gas carrying radioactive debris.

"On the influence of political money, of the 21 members of the House Energy and Commerce Committee who signed the letter to the NRC critical of the staff recommendations for filters, 12 received contributions from Exelon in this last election cycle, ranging from $10,000 to $1,000, for a total of $71,000. In the process of politics today, that doesn't seem determinative.

"On the question of vents and filters maintaining functionality in a crisis where a reactor might lose power, there are vent and filter designs that are designed to work passively, with no outside power."

Alex Chadwick

Interesting (or not) how the Republicans seem to care only about company profits, and not our well-being.

Just a technical comment. Hydrogen is not a radioactive element. So when you mention radioactive hydrogen do you mean its isotope tritium or do you mean hydrogen gas carrying a lot of radioactive debris, which is what the rest of your report suggests.

It took me 3 minutes upon reaching home after listening to this story to discover that Exelon earned $2.5 billion in net profit last year. Demanding that they spend $200million to add filters to their plants would barely put a dent in their profits. How could you have left this out of the story? And why did you not mention how much money in contributions from the nuclear power industry was received by the 21 Republican Senators who admonished the NRC for testifying for the need for filters? These two important facts should have been part of this report and I am ashamed of Alex Chadwick and the producers of MarketPlace for not including them. You seem to be so enamored of the industry and its technology that you forgot the importance of informing the public of these important details. If those 21 US Senators care more about saving the Nuclear industry money than they do about the potential effects of an unfiltered nuclear disaster, the public must depend on NPR to care enough to inform us. Shame on you for not doing a better job.


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