Sunday, July 23, 2017

Nuclear waste is dangerous

We are concerned about the amount of waste and how nuclear waste is treated when operating a power plant. But we seem to be ignorant with the fact that they are radioactive and it's waste is hazardous. 

After burning 4-5% of the U-235 isotope, a small fraction of U-238 is metabolized, the fuel rod after use has more than 90% U-238, the rest are fission products. 

All of them remain in the fuel rod, which is brought out and put into the reservoir for 2-3 years before it is transported to storage. Once removed from the reactor, two radioactive layers, including the "circulation loop" and the "storage house" have been lost, so that the fuel is still counted as an anti-radiation layer. What is a fission product? In the thousands of fuel rods disposed, are there no bars leaking? 

The answers to these questions are only probability-related. The radiation level of the spent fuel rod is several times higher than that of the new fuel rod, which proves that fission products are radioactive (also partially stable). Especially produced fission products in the gas, accumulating and compressing inside the closed fuel rod. The spent fuel rods still emit 5-7% more residual heat compared to those in the reactor and are decreased over time, requiring refrigeration. There is the probability that some of the radioactive materials that emit the neutron primer for the remaining fission in the fuel rods of U-238 / Pu-239 are horrible. 

Then the spent fuel was separated from the fuel rod, boxed and put into a silo for about 50 years. Another idea is to throw these emissions into space, or the sun, which in itself is the source of gamma rays. But it's a wasteful idea knowing that the U-238's neutron generation can still be used, and uranium mining is not easy. The process of nuclear waste recycling requires a high level of education and costs, depending on the countries and their safety standards. 

Currently, only Russia has a full line of closed systems from fuel extraction> fuel production> power generation> treatment> recycling> and nuclear material reuse. 

So how many nuclear power plants each year? 

Each unit with a VVER 1000/1200 reactor with a capacity of 1000MW / 1200MW has 163 fuel bundles, each bundle has 312 fuel rods (corresponding to 505 kg / 530 kg uranium). Every year (after 7,000 operating hours) the unit replaces one third of the fuel bundle. 

So each year a unit generates 54 to 55 fuel bundles, corresponding to 27.3 to 29.2 tons of waste (of which more than 90% is U-238 can be re-used if there is enough technology). The volume of waste taken out of the fuel rod is only about 45-50% of this volume. 

Affected nature factors and expensive lessons from Fukushima 
Looking back 6 years ago (03/2011 - 03/2017) on the earthquake and the tsunami disaster in Sendai coastal city, Fukushima prefecture. This magnitude 9 earthquake led to the 39-meter-high tsunami disaster off Japan's Tohoku coast left more than 16,000 dead, over 6,000 injured in Iwate, Miyagi and Fukushima provinces, about 2,600 people missing, and nearly 200,000 people homeless. Although the Japanese strongly re-established the country, progress was not as fast as the government's initial plan. 

According to the latest statistics of the Government of Japan, more than 3,400 survivors of the 2011 disaster have died of health-related disasters. Fukushima Prefecture accounts for 58%. 

The consequences of radioactive leakage 
The March 11 earthquake also caused a double disaster when tsunamis destroyed three of the six nuclear reactors at the Fukushima plant, causing radiation to spread out, forcing more than 160,000 people who live within an 18 mile radius around the factory evacuate. Nearly 250,000 people still live in temporary houses, while hundreds of square kilometers of agricultural, forestry and village land are left vacant due to the effects of radiation. The surrounding countryside is filled with radiation-filled radioactive plastic bags packed into mountains. 

The level of radiation around the Fukushima nuclear power plant is 10 times higher than normal. A number of villages and towns are closed, despite large-scale clean-up efforts. Japanese officials said that the recovery process in the worst affected area was very slow. Especially in Iitate Village, Fukushima Prefecture. Initially, the village chief said that people did not have to fear radiation because they were 19 miles from Fukushima nuclear power plant, however, several days later, the entire evacuation order was issued when the radiation index increased. Now, villagers are only allowed to go home during the day, but do not stay overnight or permanently move back. Previously the village has more than 6,000 people, but now only a few hundred people returned to the village during the day. 

Mr. Muneo Kanno, who owns a farm in Iitate Village, now head of the volunteer radioactive monitoring group, said: "The scene in the village is now gloomy. At night, the village is without lights, during the day, monkeys and wild pigs wander in the village."

The latest assessment by the Ministry of the Environment of Japan says that the pollution treatment (including cleanup of radioactive substances) following the 11 March 2011 nuclear disaster, is still taking place in many cities. The NHK television report shows that, out of the 43 cities in Fukushima Prefecture, only 14 cities are completely clean. 

Currently, the remediation of the No. 1 Fukushima nuclear power plant is still at its earliest stages. They estimated it would take more than thirty or forty years to complete the workload. Three former executives of the Tokyo Electric Power Company (TEPCO), along with the factory owner, have been charged with irresponsibility in ensuring safeguards to prevent the nuclear disaster in 2011. 

Flooded radioactive contaminated water 
The earthquake and tsunami disaster that occurred in March 2011 damaged the reactor cooling system at the Fukushima 1 nuclear power plant. Tokyo Electric Power Company pumped seawater into it's cooling system, this resulted to the reactors,storing contaminated water into the plant. Nearly 800,000 tons of contaminated water is stored in more than 1,000 basins at the Fukushima plant, which has no treatment plans.

According to Kyodo news agency, in one hour, a puddle of radiation capable of radiating up to 100 millisieverts. "100 millisieverts per hour is equivalent to a high level of radiation in which direct exposure to the workers in the nuclear industry, would make them suffer for five years," said Masayuki Ono, chief executive of TEPCO. 

There is a group of workers surrounded by a leaky basin trying to block and suck the water out of the sandbags. BBC correspondent Rupert Wingfield-Hayes said: "It is hard work and dangerous." 

Effects of radiation on animals and plants 
The impact of atomic radiation is not only harmful to humans, but also affects plants and animals. In one study, zoologists examined 61 monkeys living about 70 km away from the site of the radioactive leak and 31 monkeys living on the Shimokita Peninsula about 400 km away. The results showed that the monkeys in the first location were found to be positive for Caesium (a chemical element in the periodic table with the symbol Cs), concentration in the soil and at their lips. 

Japanese monkeys have a habit of bathing in hot springs, eating tree tops and bark where Caesium can accumulate at high concentrations during winter. Blood abnormalities can make them susceptible to infectious diseases. The monkeys living in areas affected by radiation from the Fukushima nuclear power plant have a high number of red blood cells and white blood cells with marked hemoglobin (hemoglobin) levels. This study was conducted for monkeys, however its results will put a strong pressure on Tokyo Electric Power Company.

Earlier this year, a fish was caught carrying 2.58 times as much radioactive Caesium as possible for any seafood in the bay near the main Fukukshima plant. Another report also found that, until now, the amount of radiation absorbed by fish caught off the coast of Fukushima has not decreased.

A Korean website also posted a series of pictures of dehydrated fruits and vegetables with the comment that they were the product of the Fukushima disaster. 

It can be said that the catastrophic radiation leakage at the Fukushima nuclear power plant in 2011 has caused long-lasting consequences. In addition, people, animals, and plants in the affected area by radioactivity also varied abnormally

Green Trees ( Fb Cao Vinh Thinh )
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