February 25, 2014
On Monday, February 24th, Bloomberg posted a brief article about a minor power loss at Fukushima Daiichi; Fukushima Nuclear Fuel Removal Suspended After Cooling Failure. (1) Today, Tepco reported that the cause was excavation in the ground outside unit #4, resulting in equipment damaging an underground power cable. The cooling system electricity was cut off for the unit #4 spent fuel pool for a period of four hours. By procedure, the transfer of spent fuel bundles was stopped until the cooling system was restored. During the power loss, pool temperature raised all of 0.1oC. As soon as power was restored, the spent fuel transfer resumed. (2)
The Monday’s Bloomberg article was essentially correct, based on today’s Tepco report, until the final sentence/paragraph, which read, “Were the [spent fuel] rods to break or overheat, it could prompt a self-sustained nuclear chain reaction similar to the meltdowns at three Fukushima reactors that followed the March 2011 earthquake and tsunami, experts have warned.” There are so many things wrong with this statement, it is difficult to know where to start…. But I’ll try.
Who are these alleged “experts”? They are certainly not anyone with actual nuclear engineering or commercial reactor operations experience. Anyone with actual spent fuel expertise would know that spent fuel bundles transfers are about as low risk as it gets. Movement of fuel bundles is completely routine…it happens every time a reactor gets refueled. It’s about as risky as clipping fingernails! Those who have followed the situation at F. Daiichi every day for three years (like yours truly) would know that Tepco took extreme care in inspecting the pool and storage racks, including the removal and in-depth inspection of two unused bundles, to insure that there would be no problems. Further, there have been some 374 fuel bundles already moved to their new home in the common facility storage pool next door, and no fuel bundle incidents have occurred.
The probability of a unit #4 fuel bundle breaking is vanishingly small, given all the study done before the fuel transfer process began last year. Even if one did break, it would probably not cause a criticality situation because the water in the pool is treated with neutron-absorbing boron. No neutrons equals no criticality. Plus, a self-sustained chain reaction (criticality) occurs at such a miniscule level that there isn’t enough heat generated to increase water temperature. It’s not enough energy to activate a single LED pixel on a modern high-definition TV. Unlikely does not mean absolutely impossible, but in this case it is for all intents and purposes impossible!
Finally, and perhaps most importantly, the meltdowns at F. Daiichi units #1, 2 & 3 happened when the reactors were completely shut down. There were no chain reactions occurring. The shutdowns from full power were entirely automatic as soon as the pre-tsunami earthquake was detected by the nuke station’s sensitive ground movement sensors. The fuel damage was due to the inability to remove the heat of radioactive decay after the reactors had been shut down for nearly an hour. It wasn’t the chain reactions at F. Daiichi that led to the meltdowns. It was decay heat…pure and simple. No doubt about it. Thus, the “sustained nuclear chain reaction similar to the meltdowns at three Fukushima reactors” portion of the Bloomburg posting is essentially a materially-false statement.
Once again I must ask…who are the “experts” Bloomberg alludes to? Who are the “expert” sources for their preposterous assumption? It seems they are experts in scaring people who haven’t the foggiest notion that they are being rhetorically manipulated… experts skilled in twisting a kernel of truth so severely that it no longer resembles the truth it was taken from… experts in exploitation of the ignorant. But, experts in what is real with respect to spent fuel bundles? Absolutely not!
Bloomberg ought to be ashamed of what they have posted. Have they been bamboozled by the prophets of nuclear energy doom? Or, are they merely resorting to scare-mongering to boost revenue? Regardless, Bloomburg has been a reputable source of information for decades, thus this instance is disappointing to the point of being deplorable.
2. http://www.tepco.co.jp/en/press/corp-com/release/2014/1234483_5892.html
