Nuclear official warns of explosions at Fukushima plant — Gases accumulating in sediment underneath highly contaminated water — Spark caused by static electricity could ignite hydrogen blast
Published: May 23rd, 2015 at 8:42 pm ET
Asahi Shimbun, May 23, 2015 (emphasis added): Risk of hydrogen explosion from leaking containers at Fukushima plant… at least 10 percent have leaks, which could trigger a hydrogen explosion. [TEPCO] reported its findings at a meeting with a study group from the Nuclear Regulation Authority on May 22… there were about 1,300 such containers at the plant… The first leak was discovered in a lid on April 2… Of the 278 it had examined by May 20, it found 26 had some sort of leak or were bleeding from their lids… likely caused by hydrogen and other types of gases that resulted from the water’s exposure to high levels of radiation. Such gases appear to have accumulated in sediment at the bottom of the containers, expanding the volume of the liquid. An NRA official said the accumulating hydrogen poses a potential danger…
Unnamed Gov’t Official: “If the concentration level is high, a spark caused by static electricity could cause a container to explode.”
Mainichi, May 23, 2015: Container for Fukushima waste found without gas venting holes… [NRA officials] had asked TEPCO to create the holes. In early April, containers were found to be leaking radioactive waste liquids through the venting holes. Later in the month… it discovered the container without the venting holes. Out of the approximately 1,400 containers, 334… have not yet been checked for venting holes. TEPCO has speculated that the work to create the holes was skipped over at a factory in the United States.
NHK, May 22, 2015: Radioactive wastewater leak linked to hydrogen – The operator of the Fukushima Daiichi nuclear plant says recent leaks of highly radioactive wastewater from their containers were likely due to accumulated hydrogen gas in the tanks… TEPCO has found since April that the wastewater, produced during the process of treating radioactive water, had seeped out through the lids of a number of containers. The utility says that 26 of the 278 inspected containers had leaked, and in 15 of them, bubbles formed when workers stirred the liquid inside, and water levels went down. The utility believes the bubbles mainly consist of hydrogen, generated by strong radiation inside the containers. TEPCO officials suspect the gas increased the volume of the wastewater, forcing some to overflow.
See also: Gundersen: Fukushima tanks releasing x-rays in very high quantities offsite — Exposure to people outside plant is very, very high from ‘Bremsstrahlung’ phenomenon