The operator of Japan's wrecked Fukushima nuclear plant will double the pay of contract workers as part of a revamp of operations at the station, after coming under criticism for its handling of clean-up efforts. Reuters reports, hazard pay for the thousands of workers on short-term contracts will be increased from 10,000 yen ($100) to 20,000 yen a day, Tokyo Electric Power Co said in a statement on Friday. The plan released on Friday also lays out improvements to the management of hundreds of thousands of tonnes of contaminated water building up, which comes from groundwater mixing with coolant poured over melted uranium rods. All of this as the riskiest phase of the decommissioning of Fukushima begins soon...

Via Pater Tenebrarum of Acting-Man blog,

Fuel Rod Removal 'No Problem'?

TEPCO spokesmen express confidence that the soon to begin removal of spent (and a number of not yet spent) fuel rods from the storage pool 30 meters above ground in reactor building number 4 of the Fukushima Daiichi nuclear plant will proceed without a hitch. Indeed, as the photograph below shows, a fairly sturdy looking gantry crane has been installed to accomplish the task, but it is no longer the fully computer-controlled machinery that was previously used to move the rods to and fro with great precision in what is a fairly cramped environment. The problem is two-fold: for one thing, the damaged building is listing and the crane will have to be operated manually. The second problem is that the number 4 reactor was undergoing a maintenance shutdown when the tsunami hit. This saved it from suffering a meltdown, but it means that the unspent fuel from the reactor is whiling away its time in the pool as well. Removing this 'hot fuel' is the most dangerous part of the operation, as it is far more likely to go critical than the spent rods ('spent' doesn't mean 'can no longer go critical').

Hitachi gantry crane hovering above the fuel rod pool in reactor building 4.

(Photo via fukuleaks.org / Author unknown)

Here is what TEPCO says according to a report at Bloomberg:

“An uncontrolled nuclear reaction due to structural failures or mishandled fuel is highly unlikely because of safeguards and workers’ experience with the procedure, Akira Ono, the Dai-Ichi plant’s chief supervisor, said at a news conference at the power station yesterday. Ono’s remarks coincide with preparations to remove fuel rods from the No. 4 reactor’s cooling pool at the plant operated by Tepco, as the utility is known. The task is an early milestone in decommissioning that experts say could threaten another crisis if mishandled. Were the rods to break or overheat, it could prompt a self-sustained nuclear chain reaction similar to the meltdowns at three Fukushima reactors following the March 2011 earthquake and tsunami. “I personally believe this kind of thing is very close to being impossible,” Ono said. “It’s not the first time for us to do this operation. At any ordinary nuclear power plant, workers remove spent fuel.” Still, working amid high radiation emitted by other reactors with melted cores and dealing with possible debris remaining in the pool could present problems, Ono said.

(emphasis added)

It is of course true that there are workers who are familiar with removing spent fuel from the pool. However, the conditions for doing so have changed all around. The things that Ono admits could become a problem actually pose a fairly big problem: due to the radiation, no crew can work beyond a strict and presumably fairly small time limit. Any debris in the pool will make a mishap inherently more likely.

A glimpse of what's in the fuel rod pool. The rods are tightly packed, so this is going to require a sure touch.

(Photo via fukuleaks.org / Author unknown)

Critics are adamant that TEPCO is downplaying the risks, and they are probably right to be a bit worried:

“The 1,533 fuel assemblies earmarked for removal are stored in a building heavily damaged by the March 2011 explosion. Removal is expected to begin this month, with practice drills scheduled for as early as next week, Ono said. Some experts, such as former nuclear engineer Michael Friedlander, say Tepco could be playing down the dangers of the process. “The thing that keeps me up late at night is that they’re getting ready to unload the spent fuel in unit 4,” said Friedlander, who spent 13 years operating U.S. nuclear plants. Tepco’s record of accidents at the plant, including power failures and contaminated water leaks, tests faith in its competence to perform such a delicate task, Friedlander said this week from Hong Kong during a phone interview. “It has the potential if it doesn’t go well to create a very, very serious accident,” he said.”

(emphasis added)

It is one thing when laymen are worried, it is another when former nuclear engineers are 'kept up late at night' when contemplating the fuel rod removal operation. It is probably true that the chances for an accident are fairly low, just as TEPCO says. Even with its tarnished reputation, its managers are surely aware of the delicacy of the task, so one can presumably expect them to take every precaution. The problem is that if an accident does happen, the effects will be phenomenally catastrophic in this case.

Beset by Murphy's Law

If one thinks about the Fukushima nuclear plant, it has been an uncanny attractor of the 'Murphy's law' effect from the beginning. Murphy's law states that “anything that can go wrong, will go wrong”.

Consider the accident's progression so far. Fukushima was protected by extra-high barriers against tsunami waves. It turned out though that some tsunami waves are so high and powerful that these barriers, against all previous experience and expectation, failed anyway (a 2008 study that warned of tsunami waves higher than 10 meters was ignored because it was held to be too unlikely an event). Because no-one thought the barriers would ever fail, the back-up power generators were housed on the ground level – where the seawater could get at them and destroy them. The long list of mishaps that have occurred since then, from tanks leaking radioactive water, to contaminated groundwater flowing into the ocean, to sudden steam eruptions spewing highly radioactive steam from cracks opening up around the plant, are all testament to Murphy practically squatting atop the plant.

What one has to wear near the spent fuel pool – full radiation riot gear.

(Photo via fukuleaks.org / Author unknown)

Looking at the photograph above, the first thought that struck us was how uncomfortable and difficult it must be to work clad in these protective radiation outfits, especially considering the work is delicate and stressful. Let us assume though that everything goes as planned, and no-one actually makes a mistake.

Could Murphy's law still strike anyway? The answer is definitely yes. Again, there are a number of risks that simply have to be taken, as it is not possible to leave the fuel rods where they are. Consider for instance the following scenario: just as an assembly of rods is being lifted out of the pool, another strong earthquake strikes and the fuel rod assembly falls where it isn't supposed to fall. Game over. The evacuation of Tokyo would presumably be on the menu next.

It is impossible to predict such events, and it is probably also impossible to guard against them. Here is an interesting documentary on the Chernobyl accident that looks at what happened in the minutes leading up to the disaster. In essence it was a combination of design problems and human error that caused the accident. A failure of various operators that were assigned different tasks to communicate with each other during the critical moments was all it ultimately took (they may have realized the implications of the design problem in time had they been in contact with each other).

The cylinder is one of the transport containers that will be used to remove the fuel rods from the site.

(Photo via fukuleaks.org / Author unknown)

Conclusion:

Nothing can be done about the remaining 'Murphy' risk that is going to attend the fuel rod removal. One can only hope that it all goes as planned.

And it gets worse... As Reuters reports,