While politicians may mock or belittle the importance of '34 millimeters'---that miniscule difference is a vital safety concern. 34 millimeters can mean the difference between an intact reactor or-- a chain reaction bomb. Nuclear regulations mandated that the vessel be scrapped. Had the warped reactor walls been discovered; the replacement cost of the vessel would have bankrupted the company. Tanaka claimed that his boss ..."asked him to reshape the vessel so that no one would know it had ever been damaged." Tanaka further claimed that workers at the plant covered the damaged vessel with a sheet. It is noted that the same "protective covering' of a white sheet is still employed at Fukushima in 2012. (Source: http://tepco.co/jp/en/nu/fukushima-np/images/handouts_120423_06-e.pdf )
Tanaka's fix involved using pumpjacks to "pop out' the warped areas on the walls. The company was happy because the end result looked like nothing had ever been damaged or compromised. There is no record of stress tests to determine ongoing viability of these compromised vessel walls on its own structural integrity, yet this same reactor pressure vessel is the sole defense protecting Fukushima's No. 4 reactor.
"Luckily' reactor #4 was shut for maintenance on March 11th, 2011--the day the earthquake and subsequent tsunami hit. Tanaka claims, ..."I could be the father of a Japanese Chernobyl."
The GE Connection to Fukushima...
Tanaka has not been the only engineer involved in the building and operation of "boiling-water' reactors who became a whistle-blower against corporate practices deemed scientifically negligent in the nuclear industry. Dale G. Bridenbaugh, Gregory C. Minor and Richard B. Hubbard, all former engineers with GE resigned in protest over major design flaws in the Mark 1 nuclear reactor designs they were reviewing. Dubbed the "GE Three"--these engineers switched sides and joined the anti-nuclear movement in 1975.
The GE Three were reviewing the Mark 1 system which is among the oldest reactors in use. Arguing that the Mark 1 system was a disaster in the making to deaf corporate ears--the three engineers quit in disgust. It should be noted that 5 of the 6 reactors at Fukushima-Daiichi are GE manufactured Mark 1 systems. To add further insult to injury--the GE Mark 1 reactors at Fukushima--have "23 sisters in the US." According to Nuclear Regulatory Commission (NRC) data, 23 of the 104 existing nuclear plants in the US are GE boiling-water reactors with GE's Mark 1 radiation containment systems. (Source: http://openchannel.msnbc.msn.com/_news/2011/03/13/6256121-general-electric-designed-reactors-in-fukushima-have-23-sisters-in-us )
Bridenbaugh was interviewed March 15, 2011 by ABC News and explained the concerns;
..."The problems we identified in 1975 were that, in doing the design of the containment, they (GE) did not take into account the dynamic loads that could be experienced with a loss of coolant."
In other words, the integrity of the nuclear reactor's coolant system to withstand what engineers call a "station blackout"--(where a power loss compromises or totally destroys the coolant system)-- must be reexamined in older and newer nuclear plants. Without a coolant system in play for these "boiling water' reactors--there is no way to prevent spent radioactive fuel from going "critical' and exploding into the atmosphere. As Bridenbaugh explains in more genteel tech-speak:
"The impact loads the containment would receive by this very rapid release of energy could tear the containment apart and create an uncontrolled release." (Source : http://abcnews.com/Blotter/fukushima-mark-nuclear-reactor-design-caused-ge-scientist/story?id=13141287 )
Subsequently, secondary or back-up power generators are critical to public safety. Without such precautions, nuclear reactors such as those at Fukushima are little more than a radioactive time-bomb ..."looking for a place to happen.'
Fukushima--revolving door ...
The problems of Fukushima are endemic to the nuclear industry at large, where executives are frequently selected from government or business ranks rather than the scientific community. Fukushima was no exception. In a WikiLeaks revelation--cables sent from the US Embassy in Vienna to Washington DC cited Tomihiro Tanguchi's weak leadership as head of Safety and Security for the International Atomic Energy Agency ( IAEA). Complaints mounted concerning Taniguchi's incompetence and negligence especially with regards to the Japanese nuclear industry--eighteen months before the Fukushima disaster.
"For the past 10 years, the Department has suffered tremendously because of (deputy director general) Taniguchi's weak management and leadership skills," said one despatch on Dec 1, 2009.