Chernobyl Today

“The third angel blew his trumpet, and a great star fell from heaven, blazing like a torch, and it fell on a third of the rivers and on the springs of water.The name of the star is Wormwood. A third of the waters turned bitter, and many people died from the waters that had become bitter…”
(In Ukrainian wormwood is - "chernobyl")
Revelation of St John the Divine 8:10-11

25 years ago, on April 26, 1986, the Chernobyl Nuclear Station disaster marked the biggest accident on Earth. As a result of an explosion the Reactor # 4 was completely destroyed. The explosion was mechanical, not nuclear. There was 180-200 tons of nuclear fuel inside the reactor # 4 at the moment of an explosion: 400 kg of uranium, 400 kg of plutonium-239, and 170 kg of plutonium-240. Approximately 8 tons (4% from the total amount) were dispersed into the atmosphere.

The total amount of the emitted material was 6.2 billion curie. A fire broke out following the explosion. The burning of graphite resulted in the increased temperature inside the destroyed reactor. That is why part of the radionuclide dispersed into the atmosphere during the fire was rare-earth metals’ oxides and carbides.

Radionuclide did not join the atomic structure of the air and were bound into the aerosol particles, which were chemically active and insoluble in water. The radionuclide still remain intact in the 5 cm upper layers of the unplowed soil and are easily carried away with wind, dust storms and rain droplets.

450 different radionuclide types were dispersed into the atmosphere and had affected Chernobyl that we know today. As a result of nuclear chain reaction they also caused the radiation of the environment. In 1986 50-70% of the total radiation pollution level was due to iodine -131, which has 8.04 days half-life.

During three days people in Kiev were breathing in the radioactive air, each cubic meter of which contained up to 10 heated particles (nuclear fuel residual particles). Today Chernobyl has lowered this per unit volume but it remains high nevertheless.

Due to beta and gamma-radiation only, people in Kiev received 5 rem per person in 1986.
8 days after the accident, the amount of the iodine in atmosphere reduced to half of the initial amount, in 8 more days, a quarter of the initial amount was present, then 1/8, 1/16 and so on. In 2 months the iodine level was practically reduced to zero. The biological impact became apparent in 3 years.

It has been estimated that as a result of Chernobyl nuclear fallout 3.5 million hectares of farm fields, 2.5 million hectares of crop fields, 1.5 million hectares of forests and orchards in 12 regions of Ukraine are contaminated. In ten years after the accident due to high level of radioactive contamination (more than 15 curies/square km) 180 000 square meters of crop fields and 157 square meters of forests were deemed unusable.

186 towns have been relocated, along with 116 000 citizens. Today Chernobyl area is 2044 square meters, and its large part, approximately 1856 square meters, is contaminated with cesium, strontium and plutonium. The full life of plutonium is 23 thousand years, and the half-life of other trans-uranium elements is 300 years. Radiation level higher than normal has been recorded on one third of Ukraine’s territory. 4.8 million people have sustained an impact on their health from Chernobyl fallout. In areas of strict measurements approximately 170 000 people have received 1 to 5 rem per person radiation: and up to 90 000 people sustained 5 to 10 rem per person. Large doses of internal organs radiation were mostly due to radioactive iodine. Approximately 1.2 million out of 1.5 million of the adult population living on the radioactively contaminated territories, have received up to 300 rem radiation to thyroids, about 150 000 people – 30 to 100 rem radiation to thyroid, and around 30 000 people – ore than 100 rem per person. The radiation to thyroid in children was even higher. The received doses increase the risk of developing thyroid cancer up to 1 out 50 000 adult population and 1 out of 12 000 children. 

The evaluations of the impact that Chernobyl accident has had on people differ. Greenpeace and Physicians Against Nuclear Weapons Organization insist that tens of thousands of Chernobyl Liquidators died as a result of Chernobyl fallout, 10 000 birth abnormalities have been recorded in Europe, along with 10 000 cases of thyroid cancer, and 50 000 more cases are expected to be revealed in near future. Although according to Union Chernobyl estimate, 50% of the Chernobyl Liquidators died and 165 000 received permanent disabilities.

Considering the high density of population who were victims to the radioactive contamination in the affected areas, even slight variations in estimates might cause great variance in expected rates of diseases due to radiation. Green peace and some other organizations insist that it is paramount to take into consideration the impact that Chernobyl fallout has made in other countries. Relatively low impact rates make it more difficult to receive reliable data and lead to inaccurate evaluations.

Chernobyl – the Future

The # 4 reactor that is called “Shelter” still contains 185 tons of radioactive material inside its lead and reinforced concrete tomb. 

This fuel has partially melted with graphite and concrete. Nobody knows what is happening inside the reactor today.

The sarcophagus had been hastily assembled: the structure is unique, and perhaps the engineers from Saint Petersburg should be given a credit for this achievement. The expected usage life of this containment was 20 years. However, it had been built using the remote control and the blocks had been brought together using the robots and helicopters, hence the cracks in the structure. Today it has been estimated that the total area of cracks and gaps is 100 square meters, and the radioactive aerosols still have been emitted into the atmosphere. If the wind is southbound, the uranium, plutonium and cesium can be traced in the South. On a sunny day, light columns are visible inside the reactor building in daylight. What are these columns? Rain finds its way inside as well, and moisture raises the probability of chain reaction inside the fuel containment. 

Sarcophagus is a dead structure that is breathing. It is exhaling death. For how long could it be sustained? Nobody could answer because it is still not possible to reach many of the blocks and parts of the building to learn just how reliable is the containing structure. Yet everybody knows that the destruction of the “Shelter” would bring far more terrible results than those of 1986.
The potential danger of “Shelter” for the environment and humans is been estimated based on the following factors:
Presence of 185 tons of radioactive material with no apparent re-criticality control tool, and lack of reliable physical barriers to prevent the radioactive spreading into the atmosphere.

It is clear today that inside the “Shelter” there is 95% of the total fuel that had been present at the moment of the 1986 fallout. Its full activity level is 16 million curies. There are following modifications of nuclear fuel inside the “Shelter”: fuel-carrying materials, fragments of the active zone, atomized fuel (dust), heated fuel particles, hardened, lava-like fuel-carrying materials, secondary uranium minerals that had been developed through crystallizing of the fuel-carrying materials, melted uranium, plutonium and americium materials.

The measurements of exposure characteristics of gamma-radiation in areas of fuel-carrying materials accumulation (compared with 1994) show a slight tendency of decreasing and comprise 3300 roentgen/hour today.

The destructive processes inside the fuel-carrying materials make it more dangerous every passing year. Lava-like fuel0carrying materials are self-destructed and radionuclide that they contain change the binding condition to unbound particles (dust), which are capable of leaving the containment, carried away with the air. Today the amount of radioactive dust, even by the conservative estimation standards, is around 4 tons. There is a potential danger of radioactive dust emission into the atmosphere during the feasible decay of the principle structures and due to water migration. 

The main danger that the radioactive fuel carries is in its dust-generating capacity, which is estimated as 40 Bq/ (cm2.day) in regards with alpha-emission, and 2400 Bq/ (сm2.day) in regards with beta-emission. The dust is being developed on the surface of radioactive fuel and carried away from the “Shelter” through the air ventilation system. Today we have a large amount of radioactive material underneath the layer of soil, sand and concrete, which is not isolated from the hydrogeological environment.

Ukraine’s everyday spending on solving the consequences of Chernobyl fallout is 1 billion dollars.
Therefore, during the years of peaceful use of the nuclear energy the implication of a “peaceful atom” has lost its meaning. The 60s scientists’ forecasts implied that the probability of nuclear stations fallout was small: just one accident per 500 000 years of exploitation of a nuclear station. The Chernobyl example indicates something entirely different. There is no economic justification to compensate the impact that Chernobyl has made on human health.
Based on internet-materials