Nuclear Disasters

The electrical failure caused the operator to not know that the valve was still open, which led to cooling water pouring out of the valve and caused the reactor core to overheat. As a result of all of these things, the instruments that the operators read to know what was happening provided confusing information. The operators could not tell how much coolant was in the reactor core because they didn't

his led to the melting of the fuel and a drastic increase in radioactivity within the reactor coolant.This also resulted in leaks in the coolant system, which led to small amounts of radiation escaping into the environment.[7]

The basic causes of the meltdown were the damages to backup generators on reactors 1 through 3 by the sea water. This forced the emergency lights and cooling system to shutdown (which resulted in an overheating of the reactors). What made the situation worse is that Japanese officials were in a state of panic after the disaster. This is because they did not realize that the cooling systems were shut off and that the problem was compounded from the lack of response. ("Fukushima Utility")

This did not mean that the valve had actually performed that action, but rather that the message was received by the valve (History Channel…). The light shut off, which indicated to the operators that the valve had been opened and reclosed, however the valve did not reclose (Wikipedia). The PORV remained open and was releasing a combination of coolant and radioactive material. As coolant water was released, no instrument indicated this to the operators; the operators had only been trained to estimate the amount of water in the reactor by doing calculations based upon pressure readings. These pressure readings were now skewed and thus the calculations were wrong and based upon these wrong calculations, the operators stopped the flow of cooling water to the reactor. The lack of water caused overheating within the reactor and according to the US Nuclear Regulatory Commission’s findings, about half of the reactor’s core melted. Operators had no way of knowing this and also were not trained to handle such an event. Unlike the event at Chernobyl, the reactor stayed intact and massive amounts of radiation were not leaked into the surrounding area. This containment, led nuclear engineer, Jack Herbein to announce publically that the citizens of Harrisburg were in no danger. Herbein’s comments on the plant were near fraudulent because no one was certain as to the actual danger that they were in

At 1:00 A.M. on 25 April, the command was given to start reducing power to the station. “This could not be done quickly because the xenon gas that came from the radioactive decay of uranium 135 absorbed neutrons. If not allowed to decay, which it did in a few hours, it could accelerate the decline in the reactor’s activity and close it down altogether.” (Read p.59) Twelve hours after the start of the power reduction, the reactor had reached half-power, and generator number 7 was switched off. The number 8 generator would be next, but there was a slight risk that the decrease in water supply to the reactor or the start up of the auxiliary generator would signal an emergency to the system sensors that would automatically start the emergency core cooling system. If this happened, the reactor would be flooded and it would be closed down. Dyatlov had the emergency system disconnected so that the test could continue uninterrupted. After the this system was disconnected, the test was ready to proceed, which was to reduce power in the number 8 generator and take it off line, all the while keeping the reactor on low power. As the order was given, a call came in from the power grid dispatcher in Kiev saying that the power that the number 8 generator produced was needed until 11 P.M., which meant that the test had to be postponed. (Read, 1993)

You may not know much about nuclear power, you may not know anything at all but most importantly you may not know how dangerous it is. I am going to take a look back at Chernobyl and show you just how dangerous it can be.

Mistakes happen every day, and you have the privilege to learn from them or not. Some faults can result to injures or even death. In the power world, incidents occur daily, whether they are big or small. And it is very important for any power plant to correct their mistakes and prevent them from happening in the future. As the industrial disasters occur in our world, the world starts to develop regulations and policies that must be followed before performing a power production plant. This essay is going to present two major accidents that happened in the world, Three Mile Island Unit 2 and Chernobyl, and how we can learn from their mistakes.

The operator opened the relief valve to release the pressure in which is in the reactor, while the pressure inside the reactor was decreasing up to the required level due to the improper respond and malfunctioning lead to failure of the valve to close. Not only wrong readings by the engineers, but also an inputting excess amount of computer data lead to the technical failure, the slag in the ongoing analyzing process and immediately human alert was alarmed in the power plant. But this issue as not stopped yet, the core of the reactor was beginning to cook. The incident China syndrome was named since there was the increasing of temperature from 4300 degrees Celsius to 5300degree at which meltdown. Hazardous radioactive gas was exposed all over the plant because of the leaked water from the open valve in an adjacent building. No emergency precaution was taken when the second accident of radioactive gas took place. In the video, there was also a communication error to note down and transfer the report were the problems facing the operators to take the decision quickly. Also, one of the employers found the fault in the explosion theory of co-worker prediction the hydrogen bubble was never a threat, it was a human error. Finally, it was the most devastating incident that was spread in the news all over the world and local people

For some reason, the center control rod, possibly for maintenance purposes, was manually lifted approximately 50 cm (Stacy, 2000, 141). This caused there to be an instant, or prompt, criticality which caused the reactor to blow up (Stacy, 2000, 141). The reason for this appears to be that the reactor activated due to the reaction caused by the influx of water, a moderator, into the system. The reaction rapidly heated the moderator and the cooling water to steam which expanded in the small containment vessel and caused the reactor pressure lid to blow off of the vessel (Stacy, 2000, 141). Two of the three men, who were working inside the reactor compartment, apparently died instantly from the explosion. The other

The occurrence of the explosion was a direct effect of Cold War isolation and the subsequent lack of safety regulations. From its beginning the Soviet nuclear effort, primarily focused on making an atomic bomb, was done with complete disregard for human life. Run by skilled, determined and callous managers, the nuclear industry did not take human life into account if such concerns did not serve the task at hand. And, like many of the Soviet’s projects, the emerging nuclear industry was covered in secrecy, with little to no information of what was going on made public. This was mainly due to the fact they wanted to conceal any plans from their enemies, such as the United States. The Soviet government also wanted to control the scientists and

* The engineers also continued to turn off addition safety precautions including the emergency reactor cooling system.

There have been lots of nuclear accident around the world. One of the accident that had a major impact on the world was the Chernobyl disaster. The disaster took place on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine. The disaster was caused by a reaction explosion induced by design faults and staff application errors. The accident took place in the course of scheduled tests to check the power supply mode in the event of external sources loss. Even after 10 days, explosions and ejections of radioactive substances continued. The release of radiation and radioactive substance polluted the places within 30 km of Chernobyl, and those areas have been closed for a long period of

Early in the morning of April 27, 1986, the world experienced its largest nuclear disaster ever (Gould 40). While violating safety protocol during a test, Reactor 4 at the Chernobyl power plant was placed in a severely unstable state, and in a matter of seconds the reactor output shot up to 120 times the rated output (Flavin 8). The resulting steam explosion tossed aside the reactor’s 1,000 ton concrete covering and released radioactive particles up to one and a half miles into the sky (Gould 38). The explosion and resulting fires caused 31 immediate deaths and over a thousand injuries, including radiation poisoning (Flavin 5). After the

The disaster took place on April 1986, and was caused by inexperienced staff. When the power plant had to undergo a special test, to make sure that sufficient amount of cooling water would be supplied to the reactor in case of a power outage. However, the test had been delayed, because the national grid required the power output more than the expected time. Hence, the test was postponed after midnight where the night shift had to come. The night shift had little experience about such a test as most of them were electrical engineers rather than nuclear. On the other hand, the night shift had to perform the test before the grid needed the power again, otherwise they would have all been fined or fired. Consequently, lead to an unnecessary pressure on the personnel, which in turn increased the probability of making incorrect

The causes of the accident was quite complex. In brief, it began with a closed bypass valve, which stopped the water flowing to the secondary main feed water pumps, once the steam generators could not receive water, they stopped and the reactor emergently shutdown. Control rods were inserted into the