News

Panel’s interim report condemns response to disaster at Fukushima Daiichi

TEPCO

Publish date: December 27, 2011

Written by: Charles Digges

As the reactors at Japan's Fukushima Daiichi nuclear power plant overheated and three of its reactors melted down, poorly trained operators misread a key backup system and waited too long to start pumping water into the units, a panel of Japanese government investigators reported Monday.

The report, which is the beginning of what many hope is a public reckoning by the Japanese government that will finally reveal the truth, comes quickly on the heels of an announcement last week that the plant’s melted down reactors have achieved “cold shutdown.”

The report – which is strongly critical of Tokyo Electric Power Co (TEPCO), the Fukushima Daiichi plant’s owner – also bears striking similarities to an uncommonly introspective report the utility itself released in June, in which the company spared little in the way of criticisms managerial oversights and praise for workers dealing with unprecedented conditions.

In fact, one of the new government report’s central arguments is that the Japanese nuclear industry is grossly underprepared for tsunamis, which are not an uncommon phenomenon in the seismically active eastern Pacific rim. He

The release of the government report and the cold shutdown announcement come at a time when new Japanese Prime Minister Yoshihiko Noda is particularly anxious to ratchet his country down from crisis footing.

Cold shutdown cold comfort

Noda said last week that the cold shutdown mode announced last week may pave the way for the resettlement of some 90,000 to 110,000 people who were displaced by the nuclear disaster – a notion environmentalists strongly oppose.

“It will take decades before the evacuees can move back to their homes,” Bellona’s executive director and nuclear physicist Nils Bøhmer said.

Bøhmer also noted that the cold shutdown, while positive as it indicated the reactors are at least under control, is a largely symbolic milestone, as it will take some 30 to 40 years to fully decommission the plant, and there is little room given Japan’s geological conditions to store the overflow of radioactive waste.

Aside from that, many experts including Bøhmer cite the risk of uncontrolled chain reactions – or fission incidents – occurring within the molten fuel of the melted down reactors, a danger that could lead to more radiation spreads. TEPCO itself confirmed one such incident last month.

New report shows workers thought back-up coolant was working

The two key errors cited in the report delivered by the panel appointed by the Japanese government to investigate the catastrophe on Monday were that an emergency cooling system was assumed to be working when the disaster struck, and that there were severe delays in reporting how much radiation was being released.

Norway’s Institute for Air Research has reported that figure at 40 percent of what was released by Chernobyl, the worst nuclear disaster to precede Fukushima.

Tsunamis underestimated

The interim report by the government panel said TEPCO didn’t train its operators well enough to deal with severe accidents, according to the interim report from the government committee probing the worst nuclear accident since Chernobyl. And neither TEPCO nor government regulators were prepared for the chance that a tsunami could trigger a nuclear disaster.

When a roughly 15-meter tsunami hit the plant after the historic 9.0 magnitude earthquake that struck Northeastern Japan on March 11, operators misjudged the status of reactor No 1’s isolation condenser, which had shut down when the tsunami knocked out the plant’s electrical system, said the report, as quoted my media.

This device is designed to remove heat from the reactor in the event of a crisis. When it shut down, “appropriate corrective action was not taken nor instruction was given,” the report said according to various media sources.

And when operators began to suspect the isolation condenser wasn’t working, they didn’t report that move to the officials managing the emergency response, who believed the system was still operating normally.

Those steps suggest that officials both at the scene and at Tokyo Electric’s headquarters “did not fully understand” the backup system, said the report.

“Such a situation is quite inappropriate for nuclear operators,” the report states, in an excerpt published by CNN. As a result, “an earlier opportunity for core cooling was missed,” it found.

Hydrogen explosions and cooling difficulties

A hydrogen explosion – which Bellona’s Bøhmer pointed out early in the crisis is a symptom of melting fuel rods – blew the upper walls off the reactor No 1 building on March 12, the day after the earthquake. A similar explosion two days later ripped apart the housing around reactor No 3, where operators had failed to recognize how badly the reactor needed outside water injections to keep cool, the report states.

Operators and managers at the plant didn’t start pumping water into reactor No 3 until the morning before the explosion. However, the report adds, “It is still too early to judge” whether those steps could have prevented the explosions.

TEPCO in June already pointed out many errors

This and many of the conclusions stated in the panel’s report are not dissimilar to those already reached in a 41-page report on the disaster released by TEPCO in June – though it may be argued that TEPCO’s report was somewhat more self-searching.

Aside from citing the delays in pumping water, that report was also explicit in saying the government had dragged its feet in allowing hydrogen venting in reactor No 1, which may have prevented the explosion.

TEPCO’s report laid less blame on the workers themselves and turned it toward management itself and the reigning chaos of lacking safety manuals and equipment. It also indicated that workers in reactor No 1 – who had failed to get the venting system to work remotely because of the power black out – had to search for manuals elsewhere which showed them how to trigger the venting system manually.

But even when the lever to begin the manual venting was discovered, workers had to wait for government clearance that the surrounding area had been evacuated, given the high radiation released expected with the venting.

Keiji Miyazaki, professor emeritus at Osaka University and an expert on reactor accident management, said the delay in venting was unconscionable and was shocked there were no directions that showed how to do a manual hydrogen vent.

“TEPCO should have prepared a manual on (manual) venting in advance, but it seems that wasn’t the case,” he said in earlier interviews when the TEPCO report was released.

Miyazaki also said it was foolhardy for TEPCO to wait for government orders to perform the venting procedures.

“TEPCO also should have started the venting procedure right after the station blackout occurred,” he said.

The time line in the report showed that Japan’s nuclear industry minister Banri Kaieda ordered venting to begin at 6:50 am on March 12, nearly a day after the initial disaster.

The TEPCO report also showed that workers also had to borrow equipment that was critical to cooling reactors to arresting the rising temperatures from a contractor, whose arrival at the site was delayed by the damage wreaked by the earthquake.

When it became apparent that a last ditch effort to cool the reactors with sea water was necessary, even those efforts, reported TEPCO in it’s June assessment, were thwarted when fire trucks were blocked from entering the site by a huge tank that had been washed into the roadway by the tsunami. A gate had to be knocked down for the fire brigade to gain access.

And even when fire vehicles were in place, they ran out of water, occasioning the desperate measure of dumping sea water from helicopters and water cannons.

In the end, reactor Nos 1, 2 and 3 at Fukushima suffered meltdowns, TEPCO acknowledged in June. And reactor No 4, which had been shut down at the time, suffered extensive damage from used but still-highly radioactive fuel rods that were stored in a cooling pond on top of the building. The plant’s two other reactor – Nos 5 and 6 – were not operating at the time the quake hit.

The 10-member panel, led by Tokyo University engineering professor Yotaro Hatamura, plans to issue a final report in summer of 2012. In the meantime, it noted, about 110,000 people “are still obliged to spend restricted life in evacuation for a long period of time.”

Monday’s 500-page report also criticized the government for failing to follow its own manuals for handling a nuclear accident and for not being able to make decisions involving people’s safety in the aftermath of the nuclear accident. It also criticized the speed of the government’s response and the vague statements given by company and government officials as the disaster unfolded.

“Transmission and public announcement of information on urgent matters was delayed, press releases were withheld and explanations were kept ambiguous,” the report states.

“Whatever the reasons, such tendency was hardly

appropriate, in view of communication in an emergency.”

In addition, the plant’s emergency command center — located about 5 kilometers (3 miles) away – “was not designed to withstand elevated radiation levels, although it was intended for use in nuclear emergencies,” the report states. A 2009 government report recommended improvements to the command center, but they weren’t made, the report states.

And plans for managing nuclear accidents were not only voluntary, they ignored the possibility of an earthquake or tsunami, it said. In the future, “Measures against severe accident should not be left with the operator’s voluntary activities,” the report states.

There was no immediate response to the report from TEPCO.