Fukushima Update: TEPCO Prepares Risky Fuel Rod Removal on Monday

November 17th, 2013 - by admin

William Boardman / Reader Supported News & Kazuaki Nagata / The Japan Times – 2013-11-17 02:12:31


Fukushima Update: TEPCO Tests Technique, Predictions, Nerves
William Boardman / Reader Supported News

If the end of the world hasn’t started yet, maybe it will start soon

(November 16, 2013) — Soon enough, if it hasn’t started already, the Tokyo Electric Power Company (TEPCO) will begin removing the first of more than 1,500 fuel assemblies from the Fukushima Unit 4 fuel pool that sits about 100 feet above the ground. Each assembly contains 50-70 radioactive fuel rods. If this removal procedure goes seriously awry or the plant is hit by another major earthquake, some scientists say, “It’s bye-bye Japan and everyone on the west coast of North America should evacuate.”

Fukushima is a continuing disaster, and the Japanese haven’t done that great a job keeping it from getting worse, but that’s not the bad news. The bad news is that nobody else in the world has a much better idea about what to do, and even less of an idea of how to do it, and that’s why the stampede of global rescue workers rushing to Japan isn’t happening now and isn’t likely to happen soon.

Fulminating over Fukushima is fun for the whole family, and lord knows there’s plenty to fulminate about, but when all the fulminating and fear-mongering and freak-out fomenting is done, the deteriorating disaster that is Fukushima continues to deteriorate unaffected. The only likely effect of the fussing is further deterioration of the ability to think clearly about a situation in which the future is even more unknowable and uncontrollable than the future usually is.

And now it’s turning out that nuclear power will also contribute to climate change, indirectly, at least in the short run, because Japan has announced that it can’t afford to reduce greenhouse gas emissions as much as promised, because taking care of Fukushima is too expensive and has led to a shutdown of all the rest of Japan’s nuclear power plants. In the short term at least, Japan will rely more on electricity produced by coal, oil, and gas-burning power plants.

As a metaphor, Fukushima now has familiar apocalyptic and terrifying implications, but the reality of the place itself is more complicated. After all, if the sky really is falling, what are you going to do about it anyway?

Fukushima will definitely get worse before it gets better, or worse still.

When it was hit by an earthquake followed by a tsunami on March 11, 2011, Fukushima was a six-reactor nuclear power station. Units 1, 2, and 3 all melted down; at least 1 and 3 exploded, and an explosion tore off the roof of Unit 4, leaving its fuel pool precariously exposed. Units 5 and 6, although undamaged, have been shut down and pose no immediate threat.

Continuously since 2011, Fukushima has been releasing radioactivity into the air, although that seems now to be minimized. The release of radioactive water into the Pacific Ocean continues at varying intensities that appear to be still increasing, with little possible control in the near future. Groundwater flows into the plant and leaves contaminated. Water used as coolant is contaminated and flows out. And contaminated water that TEPCO collects in huge holding tanks leaks out.

There is broad agreement that the Unit 4 fuel pool is the highest priority for making Fukushima safer, not that it will be actually safe for a long, long time. Even if the fuel removal goes smoothly, it is expected to take more than a year to complete.

In 1982, TEPCO damaged one of the fuel assemblies now in the Unit 4 fuel pool, and a reference to that damage — the assembly is bent almost at a right angle — was included in an August 2013 report. On November 12, Japan Times and Reuters reported this news, along with news from an April 2010 TEPCO report that: “it found two other spent fuel racks in the reactor’s cooling pool had what appeared to be wire trapped in them. Rods in those assemblies have pin-hole cracks and are leaking low-level radioactive gases….”

TEPCO has the only plan in town.

TEPCO knows what it wants to do with the 1500 assemblies in Unit 4. The procedure, as described by Reuters, is straightforward in concept: “The assemblies must first be lifted from their storage frames in the pool and individually placed in a steel cask — kept all the while under water to prevent overheating. The cask, weighing around 90 tonnes when filled, will then be hoisted by crane from the pool, lowered to ground level and transported by trailer to a common storage pool about 100 metres away.”

No one’s criticizing the TEPCO plan, and no one has come forward claiming to have a better plan. What TEPCO doesn’t know, and no one else knows, is whether they will be able to execute the plan according to plan. And what else TEPCO and everyone else doesn’t know is what will happen if and when the plan hits a glitch. And that’s where the panic-laden extreme scenarios come in: “If something goes wrong this could be a global catastrophe that dwarfs what has happened in Fukushima Daiichi thus far,” says nuclear waste specialist Kevin Kamps with Beyond Nuclear, without suggesting a different approach.

Nuclear engineer Arnie Gundersen of Fairewinds Energy Education told radio station KZYX in September: “Tokyo Electric has admitted that the boron between these fuel cells — there’s a boron wafer in between the fuel to prevent something called an inadvertent criticality, you can have a nuclear chain reaction in the fuel pool, and that’s not a good thing — but they’ve admitted that all the boron has disintegrated. So the only thing preventing a chain reaction from occurring … in the fuel racks themselves, is the fact they put all sorts of boron in the water. But if the rods get too close to each other, they can still fire up again and create a chain reaction in the nuclear fuel pool.”

TEPCO has confidence, is that reassuring?

TEPCO has produced a reassuring short video describing how the fuel removal process is supposed to go, mixing animation and documentary footage to soothe away any viewer’s worries. Arnie Gunderson calls it a “fantasy cartoon” and provides a 17-minute podcast [see below] showing excerpts from the TEPCO production followed by his own explanations of how TEPCO is misleading.

Not surprisingly, TEPCO is counter-alarmist, as Japan Times reported: “Asked if it’s possible for the spent fuel to achieve recriticality, Zengo Aizawa, vice president of Tepco overseeing the Fukushima crisis, said this is highly improbable since the removal process basically deals with one assembly at a time, and the utility has confirmed that one assembly alone cannot cause a nuclear chain reaction.”

The company’s confidence was shared by one of their consultants, Lake Barrett, an American whose four decades of experience in nuclear energy included overseeing much of the clean-up after the accident at Three Mile Island. Barrett visited the Fukushima site on November 13, and told Japan Times he was impressed with TEPCO’s preparations, including the reinforcement and cover at Unit 4 protecting the fuel pool: “Now I feel confident that they can complete this job properly,”

Meanwhile, at nearby Units 1, 2, and 3 — all of which melted down — the status of the molten cores has remained uncertain since 2011. Talking about this on Art Bell’s Dark Matter program in October, Beyond Nuclear’s Paul Gunter said:
“We’ve got 3 reactors, the cores have left the vessel. They’ve burned through the bottom of the vessel. We don’t really know where they are, because the radioactive environment even fries robots that TEPCO’s been trying to send in there. They have been sending very innovative robotic machinery and sensors in there to get a picture, to get a reading, and these things don’t return.

“We have opened a door to hell that cannot be easily closed — if ever. We’ve got those 3 cores that are melting, they could be somewhere in the concrete base mat burning their way through, they could have already burned through and entered into the ground. They hopefully have formed a huge solid ‘elephant’s foot’ of highly radioactive material.”

Think it’s bad on the outside?
Inside it’s instant death.

On November 14, Japanese media reported that, for the first time, a remote-controlled robot had found the locations in Unit 1 where radioactive water was leaking out of the reactor. TEPCO acknowledged that it was unable to do anything about these leaks any time soon, and they suspected there were similar leaks in Units 2 and 3. As long as TEPCO can keep the molten cores cooled, they will remain stable — and the flow of contaminated water into the environment will continue.

According to RT.com: “The radiation levels in the inspected area were reported at 0.9 to 1.8 sieverts an hour, while a typical release of radiation is generally accepted to be 1 millisievert a year.” In less technical language, a sievert is a unit of measurement for a radiation dose to humans — a dose of more than one sievert in a brief period will likely cause radiation sickness and possibly death. A millisievert is one one-thousandth of a sievert. In other words, roughly calculated, the radiation level the robot found is about 9 million times greater than the so-called “safe” annual human exposure.

Beyond the confines of the Fukushima plant, in the partly evacuated Fukushima Prefecture, local officials are confirming an increase in thyroid cancer in children. The rate is more than 7 times higher than for the general population and reflects a similar pattern experienced around Chernobyl after the accident there.

The Indian government is meanwhile pressing ahead to complete a nuclear cooperation agreement with Japan that would clear the way for Japanese nuclear energy companies to do business building nuclear power plants in India.

William M. Boardman has over 40 years experience in theatre, radio, TV, print journalism, and non-fiction, including 20 years in the Vermont judiciary. He has received honors from Writers Guild of America, Corporation for Public Broadcasting, Vermont Life magazine, and an Emmy Award nomination from the Academy of Television Arts and Sciences.

Risky Fuel Removal about to Start
Kazuaki Nagata / The Japan Times

(November 14, 2013) — The decades-long decommissioning process at the crippled Fukushima No. 1 plant is about to take what Tokyo Electric Power Co. says is “an important step,” as the utility starts removing fuel rod assemblies from the spent fuel pool high up in reactor building 4 sometime this month.

Moving the massive amount of radioactive fuel assemblies out of the shattered building is significant because it will allow Tepco to monitor the fuel much more easily at another pool in an undamaged facility, experts say.

Meanwhile, they stress the task must be handled very carefully to avoid dropping and damaging the assemblies.

“Usually, spent fuel rods are safely stored in sturdy reactor buildings, but reactor building 4 experienced a hydrogen explosion, so it has lost its full containment capability,” said Kiyoshi Takasaka, an adviser on nuclear issues to Fukushima Prefecture.

The hydrogen blast occurred March 15, 2011, four days after the earthquake and tsunami, blowing the roof off the building and showering debris into the pool.

The pool has 1,533 fuel rod assemblies, 202 of which are unused. Once removed from the pool, the assemblies will be stored in a common pool in a different building.

Each assembly, a zirconium alloy box, is about 4.5 meters long and contains 60 to 80 fuel rods.

A fuel handling machine, which is like a hoist, set up over the pool will lift the assemblies one by one and place them into special transport casks. The casks will be put into the pool ahead of time, so that this work is done underwater to prevent gamma radiation from spilling to the outside environment.

Each cask can store 22 assemblies. A crane installed above the fuel-handling machine will load them onto a trailer for transport to the common pool.

If all goes well, removing all of the assemblies will take about a year. Tepco said it is using nearly the same removal equipment used for regular nuclear operations.

Lake Barrett, a special adviser to Tepco who was in charge of the cleanup work after the Three Mile Island nuclear accident in the U.S., said he visited the plant Wednesday and was impressed with Tepco’s preparations.

Building 4 has been reinforced with steel frames and a cover, the equipment is in place and the workers have been trained well for the operation, Barrett said.

“Now I feel confident that they can complete this job properly,” he said, adding that the level of Tepco’s preparations will make the operation almost like a normal fuel removal.

Still, it will be different than performing this operation in an undamaged building, and extra caution is a must.

For instance, engineers normally program coordinates into the fuel handling hoist and let it run automatically, but they will manually control it for this operation.

Takasaka said it is essential that the people in charge of the task have enough training in handling the manual operations.

He added that although Tepco has been picking debris out of the pool, there are still small pieces that could fall between the assemblies and racks that contain the assemblies, possibly making it harder to lift them or even breaking them.

Barrett, who saw the pool for himself, said the water clarity is good but it is true that the assemblies could get jammed by small debris.

Tepco said it is ready for such eventualities. For instance, it plans to use underwater vacuum cleaners as much as possible.

Also, if the hoist detects extra weight when removing the assemblies, it will stop moving to avoid forcing the assemblies.

Another risk is dropping the assemblies and damaging them.

“It is imperative not to drop the assemblies when removing and after removing them from the racks,” said Hisashi Ninokata, a nuclear expert and professor at Polytechnic University of Milan in Italy.

“In the worst-case scenario, dropping a cask is conceivable. To avoid that, it is important to come up with multiple layers of measures,” said Masayuki Ono, a Tepco spokesman.

For instance, the crane’s control wires have been doubled, and it is designed not to drop the assemblies if the power is cut off, Tepco says.

And if an assembly is dropped and gets damaged enough to release radioactive materials, the radiation level outside Fukushima No. 1 will still not exceed the legal limit, the utility claims. This estimation is based on a scenario in which one assembly falls and strikes others, resulting in damage to all of the fuel rods contained in two assemblies.

Earlier this week, Tepco found three damaged assemblies that will be difficult to remove, but officials said the damage appeared to have occurred before the March 11 disasters.

Ninokata feels that as long as Tepco is sufficiently prepared and proceeds carefully, it is hard to imagine that any assemblies will get damaged, but if this does happen, he agrees with the utility that harmful amounts of radioactive materials won’t escape into the environment.

Asked if it’s possible for the spent fuel to achieve recriticality, Zengo Aizawa, vice president of Tepco overseeing the Fukushima crisis, said this is highly improbable since the removal process basically deals with one assembly at a time, and the utility has confirmed that one assembly alone cannot cause a nuclear chain reaction.

Posted in accordance with Title 17, Section 107, US Code, for noncommercial, educational purposes.