Japan has a discrete problem. In the aftermath of the Fukushima meltdown, many operations and actions were taken to limit the damage, without proper and in depth assessment of the danger those actions entailed, and the consequences of less than perfect diligence in disposal.
The news this week from Japan's Fukushima operators is bleak : the water, temporarily stored after the nuclear disaster, is highly irradiated, much more than previously assessed, constituting a hazard by its very containment and presence.
And yet, there is no better or further solution to the disposal of the irradiated water in the storage tanks built next to the reactors.
The problem began with the incredible rush to store the water after the nuclear meltdown, which was placed in cheap, readily available steel tanks. The tanks are huge, some of them as large as a three storey building. The water was being pumped from the reactors that were in danger of a meltdown, following the frantic efforts to stave off catastrophe after a 9.0 earthquake that triggered a terrifying tsunami.
The tanks were sealed with resin, and were supposed to be useful until 2016 when Tepco would have had the time to study the situation and come up with a final solution for the disposal.
The problem is that the tanks are failing. One already has, and has leaked highly radioactive water onto the surrounding ground.
This is the fifth reported leak from the tanks since their adoption. The discovery of the leaks, and the possible dispersal of highly radioactive water into the Pacific Ocean renews calls for better planning and solution to problems to nuclear meltdowns and the storage or disposal of irradiated substance or fluids.
The problem is also compounded by the sheer volume of the irradiated water. In order to properly dispose of the more contaminated fluids, the operators will have to actually release the less irradiated water into the sea.
An investigation is under way to determine why the tanks failed so much in advance of their perishable date. There are also suspicions that Tepco could have commissioned a company that was more competitive in pricing the tanks, leading to speculation that the materials might not have been the best in their class.
There are more than 1,060 tanks at Fukushima. A third are bolted, the rest are welded together. Bolting is much faster, but also, as is evidenced by the leaks, much less durable.
The environmental risk of the water release is being studied, but it is a moot point. The water that has escaped can no longer be measured nor contained. The one that must be released is equally beyond the ability to be mitigated.
There is a radiation filtering machine capable of removing the gross particles of cesium and strontium in the water. However, such system cannot remove all radiation. The machine was supplied by Toshiba Corporation to the Fukushima plant. The element Tritium, a much less radioactive element is being used in the coolant water, since it is one of the least radioactive elements. But this machine can only diminish the water that is being now used to cool the still melting cores. The water already contaminated might not be mitigated, and the one released, is already out of reach.
No matter how complicated the dynamics of the disposal of the irradiated waters, the World Nuclear Association has said that Japan should release the least irradiated water into the ocean, as a measure to diminish the larger problem of the storage of the immense quantities of water used to cool the reactors and the water that is much more radioactive.
Tepco however, will never regain the confidence of the Japanese citizenry or the international community. The placement of a quadruple nuclear reactor on the coast at Fukushima without a protective barrier in the tsunami prone area, and the failure to even plan for such an event, have forever marred the reputation of the energy company.
Another solution that has been devised, is to possibly freeze the ground around Fukushima to prevent further seepage of the irradiated water. The frozen perimeter would have a circumference of 1.4 km around the reactor.
Many experts in the field of nuclear energy however, have expressed their opinion that Tepco is absolutely incompetent in the management of the Fukushima meltdown aftermath. For that reason, Tepco has been asked to bring in experts to manage the already difficult situation.
Interestingly, the seawater in the neighboring areas to the reactors has not yet shown a rise in the level of radioactive elements, which could imply that the seepage is limited or does not have a way to continue until it reaches the sea. In that sense it might be temporarily contained.
Source: NatGeo/ 8.23.13
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