What went wrong in Japan BY gupta1006 On March 1 1, a 9. 0 magnitude earthquake hit Japan and caused tremendous damage to Japan. The earthquake sparked off a 30-foot tsunami within an hour, which only compounded the, already extensive, damage to the country. One of the greatest fears was the potential of a nuclear fall out. Specifically, the Fukushima Daiichi power plant was in question. The nuclear plant in Fukushima had six nuclear reactors, and three out of six of them were in critical state – possibly melting down.
The potential of adiation damage spread panic and fear, not only within Japan, but also around the world. Although nuclear power plants have an enormous risk factor, their benefits are greater – or almost as great. Nuclear plants are a means to produce large amounts of energy, in an environmentally friendly manner. However, the potential for disaster is also present. We have seen this throughout history, with the Chernobyl and Three Mile Island disaster. Nonetheless, we continue to use nuclear energy.
This is due to the fact that there is a global safety standard and there are several precautionary easures in place to minimize the damage and potential for fail. If there are so many precautions and safety nets, this gives rise to the question: “What went wrong in Japan then? ” There are several aspects to why the disaster happened in Japan. One of the most prominent one is the fact that the reactors that failed in Japan were Mark 1 boiling water reactors designed by General Electric in the 1960’s.
This is one of the earlier and primitive reactor designs, in which the uranium fuel boils water that directly turns the steam turbine. Although effective, this design was later replaced by ressurized water reactors. Safety concerns surrounding the Mark 1 design, in particular, regarding the cooling system were the reason why these designs were quickly replaced. As we have seen, those safety concerns turned into safety failures in Japan. The main flaw with nuclear reactor systems is their complete reliance on electricity for their cooling system.
Without a fresh supply of water in the boiler, the water continues boiling off, and the water level starts falling. Having a stable supply of water is extremely important, because the water is what keeps the nuclear rods at a table temperature. However, if enough water boils off, the fuel rods are exposed and they overheat. This is extremely dangerous, due to the fact that even at the lowest heat, there is enough heat in the rods to melt the nuclear fuel. Having said this, safety measures were put in place.
There is a large redundancy around the pumps and their supply of electricity. There are several sets of fail-safe pumps and supplies of power. Power can come from the power grid. If that fails, there are several layers of backup diesel generators. If they fail, there is a backup battery system. All of this was put into place in order to prevent the rods being exposed and overheating. Unfortunately, shortly after the earthquake, the worst-case scenario unfolded. At tne epicenter 0T tne eartnquaKe, tne power plants snut down I . nls reactlon was expected and was a part of procedure.
However, the power grid supporting the cooling systems became unstable due to the earthquake and it shut down as well. The second source of electricity for the cooling pumps was gone. That brought the backup diesel generators into the picture, diesel-run generators are a stout and eliable method to produce power; there was not much worry at this moment in time. When preparing for such situations, the planners should have anticipated the fact that after a large earthquake, and given Japan’s geographical situation, a tsunami would be something to take into account.
It seemed that the 30-foot tsunami took everyone by surprise. The tsunami was several times bigger than anyone anticipated. As a result of lack of anticipation, the diesel-run generators were not high off the ground and were subject to water damage from the tsunami. There was still space for relief, as there was yet another layer to keep the cooling pumps powered – the batteries. The batteries executed their task as per norm. However, the batteries only had enough power to keep the cooling pumps active for a few hours.
The batteries were designed under the premise that the other two power supplies would be fixed within the time span ofa few hours. The Japanese tried to contain the situation by bringing in new generators via truck, however their efforts took too long. This was expected, as the whole country was iscombobulated and the country was physically shaken. Even though there were so many measures to prepare for a power shortage, the weakness in the cooling system was no longer protected by their layers of redundancy.
The main issue with the cooling system was the lack of water, as pumps driven by electricity were bringing in the water. With the complete power shortage, the Japanese had very limited options to contain the damage to a minimum. Even though the situation appeared to be dire, they handled it extremely well. The tsunami had brought in an abundance of water. The operators, as a last chance exertion, flooded the nuclear reactors with the seawater. Boron was added to the seawater, so that the combination would effectively cool the rods.
It would also lead to the complete deterioration of the plant. Even though this was not a desirable situation, it was more preferable than a nuclear meltdown. Boron absorbs neutrons and is one of the main constituents in the control rods. This was necessary, because the water started to interact with the boiling hot rods and broke into hydrogen. The high pressure during the situation caused the uild of hydrogen to turn into a series of hydrogen based explosions. This was not a serious matter; there was no radioactive explosion.
However, with the cracks in the power plants, nuclear explosions were inevitable unless drastic measures were taken. Therefore their last-ditch effort was Justified. According to radiation expert Andrew Karam, “The amount of radiation that thus far has traveled beyond the immediate area of Fukushima is infinitesimal; it doesnt pose a danger to residents outside the 18-mile radius of the shelter-in-place zone??”and certainly not to anyone lsewhere in the world. Even inside the zone, the radiation dose is not immediately damaging”.
This is a testament to the quick and effective decision making processes of the Japanese, given the extremity of their situation. Although the Japanese dealt wltn tne artermatn 0T tne sltuatlon In a relatively erective manner, tne Tact tnat a disaster happened is a very concerning matter. Apart from a primitive reactor system, a large reason why the disaster occurred is the Japanese power company ‘TEPCO’ (Tokyo Electric Power Company). In a report from the TEPCO task force, it was tated: “When looking back on the accident, the problem was that preparations were not made in advance”.
The company did not fully ensure the safety of the power plant, as it neglected the implementation of multiple cooling systems and power sources – in an attempt to cut costs and speed up the building of the plant. Apart from this, TEPCO has also made errors in handling the situation. They have conceded the point that 300 tons of toxic water is being leaked into the Pacific every day. Even a year ago, researchers found trace amounts of cesium from the Daiichi in West Coast Fish.