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What happened at Fukushima?

More information has begun to emerge as to actually what happened at Fukushima, with it now being clear that full fuel melt-down did occur, perhaps even starting before the tsunami hit, although we are still some way off knowing what the longer term impacts will be, and what should done to avoid a recurrence. Indeed a global agency that covers nuclear safety, based on the 72-nation Convention on Nuclear Safety (which was set up after the 1986 Chernobyl meltdown), has decided to delay reporting on its assessment of the accident until August next year, saying that ‘the lessons-learned process cannot be completed until sufficient additional information is known and fully analyzed.’ This makes the UK safety review, to be completed by this coming September, seem a little hasty, but then the government evidently want to get on with processing the nuclear consents programme - the Generic Design Assessment has been delayed until the NII safety review is complete.

However we do have some information. Japan’s Nuclear Safety Agency has claimed that the release of radioactive materials from Fukushima was equal to 10% of those from Chernobyl. That was why they re-set the accident classification at level 7 on the UN’s International Nuclear Events Scale- i.e. involving “major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures”. Safety agency official Hidehiko Nishiyama said, however, that the two events were markedly different. “In Chernobyl, there was acute exposure to a high level of radiation, and 29 people died from it. This is not the case in Fukushima. In Chernobyl, reactors themselves exploded. In Fukushima… the reactors themselves have stayed intact, although we are seeing some leakage.” There are likely to be disagreements about this assessment. For example there were crucial releases into the sea, which may have very significant long-term effects.

There are also likely to be disagreements about who was to blame. UK Nuclear consultant John Large has produced a report for Greenpeace looking at the accident and says that much of blame must fall on the operating company, TEPCO. He say they ‘would be well aware of the ways and times over which an unattended and un-cooled reactor core would run its inevitable course to a fuel melt and, thus, pose a threat to security of the primary and secondary containments. It follows that TEPCO would also have been aware and would have had, surely, plans and procedures, including spare equipment, with which the fuel melt could have been managed within the known timeframes to stability and a safe resolution”

However ‘whatever plans TEPCO had in place, if it had any at all, have failed. In fact, certain of TEPCO’s actions in the aftermath of the explosions have been confused and, some might opine, lacking discipline of purpose to the extent that expedient decisions have been made without proper forethought and judiciousness to avoid knock-on consequences: for example, the injection of seawater may have resulted in salt deposits sufficient to foul cooling flows in the lower regions of the RPV [reactor pressure vessel] ; the liberation of hydrogen from seawater is more rampant than from freshwater and radiolysis of oxygen from the cooling water could provide stoichiometric conditions and ignition with hydrogen in the absence of air in the containments; and the latest and most recent announcement to deploy a nitrogen purge to the Unit 1 reactor seems yet another ill-explained and unjustified desperate measure’.

He went on ‘The situation relating to the violent destruction of the Unit 4 spent fuel pond is even more surprising. This is because it is a relatively straightforward calculation to predict the boil-down time to when the fuel is uncovered (several days) at which the risk of hydrogen generation and deflagration occurs, so just why the simple and obvious expedient of providing cooling water via a temporary pump (i.e. a fire tender) was not implemented by TEPCO in a timely manner is baffling. In other words, the station blackout that occurred at Fukushima Dai-ichi was a prescribed event for which TEPCO should have had in place procedures and countermeasures - obviously, adequate plans and countermeasures were not in place so, in this respect, the nuclear safety culture at Fukushima Dai-ichi was fundamentally flawed’.

He concluded ‘If it is the case that, at Fukushima Dai-ichi, TEPCO failed then, it follows that the Japanese nuclear safety regulator NISA also failed because it permitted TEPCO to operate a hazardous nuclear complex in an unsafe way and without adequate emergency plans with which to counter the inevitable. If this is correct, then the Japanese nuclear safety culture is fundamentally flawed which means, because the same nuclear safety rules, limits and conditions are almost universally adopted internationally, that the demonstration and regulation of nuclear safety worldwide is equally and, perhaps, irrevocably flawed’. www.largeassociates.com/3195%20Fukushima/R3196-A1%2010%20April%202011.pdf

Dr Large’s May 2011 update is even more forthright-TEPCO must have known about the meltdowns early on, a claim backed by Greenpeace: www.greenpeace.de/themen/atomkraft/presseerklaerungen/artikel/tepcosbetrugdielehrenaus_fukushima (scroll down to Large’s PDFs)

While debates on who or what was at fault will no doubt continue, the nuclear industry has clearly suffered a major blow, with nuclear looking to be unreliable and costly. In terms of reliability, the recent accident isn’t the first time the Fukushima plants have been in the news. As US energy expert Paul Gipe has pointed out, several of the reactors were shut down from 2002 to 2005 for safety inspections as a result, evidently, of TEPCO’s falsification of inspection and repair reports.

He notes that the Fukushima plants generated, on average, 30 TWh per year. He says: ‘The key word here is “on average”. Despite nuclear power’s reputation as reliable base load generation, the Fukushima plants were anything but reliable over the four decades that the plants were in operation. Annual generation was surprisingly erratic’.

He went on ‘Take Unit 6, the most modern unit, for example. In 2004 generation dropped from 4.6 TWh in 2003 to 1.1 TWh, and both were a far cry from the reported generation in 1997 of more than 9 TWh. Similarly, Unit 5’s generation fell from 6.2 TWh in 1999 to 1.6 TWh in 2000.’

And on cost, with the 150,00 or so evacuees not likely to be able to return home finally until perhaps December, or even January, there is talk of $130bn in compensation/damages, but that’s just the start. The clean up could cost $300bn or more. Who will insure nuclear plants now? Who will invest in them?

It’s perhaps not surprising then, that following on from Germany’s decision to speed up is nuclear phase out, Italy has now frozen its plan for new nuclear plants, as has Switzerland. Meanwhile Thailand is contemplating calling off five planned plants, while Malaysia, which was to have its first plant operating by 2020, is set to abandon the plan. A US project in Texas lost financial backing, maybe the first of several as investors look at the liability risks. It does seem that the nuclear renaissance is unravelling.

Last year the IEA forecast that global demand for nuclear energy would rise from 6% of primary energy in 2008 to 8% in 2035. But, as the FT reported, Nobuo Tanaka, the chief executive of the International Energy Agency, has warned that the role of nuclear power in global energy supply may be less than previously forecast, following the events in Japan. “Building nuclear power or expanding nuclear power may mean more costs or more delay. That means the nuclear option may not play as big a role as we predicted.”

Posted by Dave Elliott on May 28, 2011 11:49 AM | Permalink