Chornobyl sarcophagus is 20 years old

The Chornobyl Nuclear Power Station doesn’t just mark the April anniversary. November 29 was the 20

th anniversary of the launch of the containment structure popularly known as the sarcophagus, which protects the world from the radioactive waste at the wrecked power unit. Construction of the concrete containment structure began immediately after the disaster and lasted slightly more than six months. Every day over 10,000 people worked at the construction site, pouring several thousand cubic meters of concrete every day. The 20 th anniversary of the sarcophagus is marked not only in Ukraine. Two weeks ago a one-day commemorative event was held in Moscow to honor those who perished during the rescue operations and the people that survived the Chornobyl tragedy of Chornobyl. For Ukrainians this anniversary is important because it is not just another reminder of the thousands of people who worked to build the sarcophagus. The structure needs to be renovated and replaced. Reconstruction will cost at least half a billion dollars, a sum that is being provided by the international community.

The urgent need to start working on the sarcophagus is linked to a great many objective factors. A number of bearing structures are supported by fragments of the damaged power unit. Most of the structural units were installed by remote control, which means they lack the required abutment precision. In the aftermath of the disaster and owing to load stress, separate components of the structure have shifted from the design parameters.

The other Chornobyl power units also require careful maintenance and considerable spending; they cannot be completely shut down until all the fuel is removed and disposed. Experts estimate that power unit no. 1 alone contains over 270 tons of fuel. Unloading and burying this waste should be completed by 2008.

Today most of the focus is on the sarcophagus. Because it is on the verge of collapsing, special reactor emergency drills are regularly held in the Exclusion Zone. The Day’s reporters attended a drill held in collaboration with the Ministry of Emergency Management.

TWO-MINUTE ALERT

The siren’s piercing scream lasted exactly two minutes from the time the emergency signal from power unit no. 4 sounded. Then the public address system came alive to announce that the light roofing on the sarcophagus had caved in as a result of a nocturnal earthquake in the Carpathian Mountains and that there was a cloud of radioactive dust over the reactor, being carried by the wind in the direction of Chornobyl. It was only a drill, but the personnel had to be evacuated and every unit in the Exclusion Zone had to act as though the emergency were real.

A tense silence fell in the Chornobyl administration-residential building. The silence was illusory, however, because at that very moment the station’s personnel was on its way to the shelter, and heads of departments were gathering for an emergency meeting in the safe room. We journalists were led through the checkpoint to the basement shelter. We walked down a winding corridor with blue walls and then stepped through a thick steel door with a disk lock. Behind the door were two rows of worn steel beds where people were supposed to sit. At the entrance everyone had to pass through a tall turnstile the size of a man, if not taller. There was no buzzing sound, so everyone was cleared to proceed. Everyone had a bag with a gas mask, but no more than a third of the people were wearing masks.

Some people’s masks were missing lenses, others had disconnected filters. Every station worker had a seat in the shelter, but a crowd formed in the passage between the beds, with people looking for their seats and trading jokes.

Behind the wall were two rows of desks. This was the operations headquarters with charts, telephones, and a loudspeaker. Within ten minutes the shelter was full of people. Departmental heads and workshop foremen were issuing instructions on the phone to those who remain at their stations even during an emergency. In a minute calls started coming in with reports from the contaminated surface. The loudspeaker reported operational data on the disposition of manpower, readiness status, rescue, decontamination, and protection teams, sanitary procedures; the voice also reported that an operations team was still on the surface and acting as instructed.

Fifteen minutes later we left the shelter with the rest of the station workers. In the meantime, the radioactive cloud was supposed to have long passed over the administrative building and reached the town of Chornobyl. There were five buses on the square in front of the building. These would evacuate the people to a safe location. Station workers wearing gas masks emerged from the building in organized groups and boarded the buses. Although there were five buses, two were empty while people wearing gas masks had to stand in the other three buses.

The evacuation procedures took slightly longer than 30 mihnutes. However, time is not the main factor, as the journalists were assured by the people in charge of the drill. “The main thing in an emergency and during evacuation is to avoid panic,” said Ihor Krol, the emergency management ministry’s press secretary. “Everyone must know his role, place, and sequence of procedures. There were some delays but they did not impede evacuation.”

NEW SARCOPHAGUS IN TEN YEARS

The sarcophagus will be partially reinforced by the end of 2006. Supporting girders in the upper section will be replaced in a matter of days and the light roof reinforced. The wall supporting the roof is the one that was left in the power unit after the disaster, but over the past two decades it has rusted and significantly shifted from the vertical position. According to Volodymyr Kashtanov, deputy director for technical matters at the Chornobyl Nuclear Power Station, this wall may collapse given the scale of underground quakes assumed during such drills. If there were a real emergency, a considerable part of the wall would collapse precisely onto that part of the reactor where the greatest amount of radioactive dust has accumulated. No one knows whether it will fall, but the Chornobyl personnel insist that replacing the girders will prevent a catastrophe.

“Special metal constructions will be made to take over the load of the old girders,” says Kashtanov. He and his colleagues are convinced that this replacement will not cause additional radioactive discharges and thus does not represent any danger to life and health. “This work is being done in line with the overall program to stabilize the Chornobyl sarcophagus,” says director Ihor Hramotkin. “The whole thing will be perfectly safe because the work plans take into account, and prevent, any negative consequences.” According to the management, such stabilizing measures are designed to last for 10-15 years and cost over 40 million euros. In fact, there is a chance that a new and more reliable sarcophagus will have been built by the time the new girders become obsolete.

The viewing platform where the journalists were shown structural replacement by means of a model is about 200 meters from the damaged power unit. Here the radiation level reaches over 300 roentgens an hour.

While the journalists were examining the reactor model, the second part of the drill took place on the territory of the power unit and in the adjacent area. A carrier with a special team to locate radiation sources and place special markers slowly moved toward the reactor. People wearing respirators were taking manual measurements of background radiation, using special new devices that allowed them to determine the radioactive chemical elements on the spot, instead of sending samples to distant laboratories.

“How can you work like this with just one respirator?” we asked one of the specialists. “It’s even more convenient this way,” replied a member of the radiation detection team. “These respirators aren’t like the ones we used to have before. Those could melt in high temperatures.” In addition to special clothing, respirators, and other protective devices, the special team’s gear includes radiation storage devices - small rectangles affixed to the suits. They are designed to absorb the largest and most harmful dose of radiation.

The Chornobyl personnel did not succeed in placing markers as scheduled. Another operations team recorded higher radiation levels and marked them with small flags. Its members wore fatigues covering the entire body. “What do you think you are doing? Don’t forget to place the markers!” the team leader scolded them. “Just don’t forget the markers!” Every flag imprinted with the word “contaminated” has a small pocket into which a card is inserted, specifying the contaminant.

“The units coped with their tasks effectively and boosted their practical experience,” notes Vasyl Kvashuk, head of the emergency management ministry’s civil defense department. “There are problems, but this way we enhance our capacities in terms of protecting the population and special treatment of equipment. It is too bad that our radiation surveillance equipment is mostly obsolete, but there is already a program for re-equipping these units.”

EVERYTHING HAS BEEN FORESEEN

In addition to controlling the reactor and preserving people’s health, the administration of the compulsory resettlement zone faces a number of environmental problems. Radiation is not everywhere, but in the event of a fire, the contaminated area would expand significantly and exceed the conventional limits of the 30 km zone. According to the drill that day, besides increased seismic activity, the weather worsened considerably in Kyiv oblast, with the temperature dropping dramatically during the night, with strong gusts of wind, higher precipitation level, collapsed power lines, motor transport stoppages, and of course, fires, floods, and other events facilitating the spread of radiation. According to the drill scenario, exercises are envisaged for special state enterprises, like Ekotsentr, Chornobyllis, Chornobylservis, and Chornobylvodekspluatatsiia.

There are 29 contamination monitoring stations in the Exclusion Zone. Every hour they transmit reports on ground, water, and air composition to Chornobyl and elsewhere. In an emergency these reports are sent every 15 minutes. People wearing brightly colored uniforms comb the contaminated territories. Their devices flash and squeak. “These drills are nothing new to us,” says Valentyna Hanzha, head of the medical unit. “We do this regularly, and we are on special alert during heavy precipitations or when solar activity is especially high.”

Fortunately, the personnel observe safety regulations, and no emergencies with loss of life have been recorded. It is much harder to cope with unscheduled events, like fires. The peak fire period in the Exclusion Zone lasts 240 days and every fire must be extinguished quickly, so water alone is not enough. There is a special fire brigade in the 30 km zone, and it is specially equipped with two converted tanks in addition to conventional fire trucks.

Two workers in shapeless gray coveralls douse a heap of boxes with gasoline and set it on fire. At a signal, a converted tank (known as the Slavutych Impulse 2M) rumbles out of the park and is in position within 60 to 90 seconds. The turret turns, training the barrel on the fire. The journalists freeze in a state of shock. The sound is like a gunshot, but the projectile is not a shell but a special powder. Another shot is fired, the tank creeps back to the park, and the firemen kill the rest of the fire with water and foam.

After such an exercise the personnel (and the equipment) need to get cleaned up and rest. The carrier that was working inside the radioactive cloud moves into a special hangar. Jets of water and foam shoot out at one end of the vehicle and then the other side. After three to five minutes of washing it is checked for radiation and, if need be, rewashed. The water is drained into a special sedimentation tank and then pumped into a storage pit.

“This water is mixed with special powders that help decontaminate the equipment,” says Mykola Orlov, head of a department at the emergency management ministry. “In summer the vehicles are washed manually, the standard being one square meter a minute.” There are special washing procedures for people arriving from contaminated areas. The standard for personnel cleanup is eight minutes.”

Leaving the Exclusion Zone is no simple matter either. The road is lined with radiation danger warnings and endless rows of metal high-voltage power line pylons, and finally, ghost towns where no windows are lit at night, villages are overgrown with weeds. The houses have curtains in the windows and locked and bolted doors — against thieves? The bus stops at the Dytiatka checkpoint and all travelers are rechecked for radiation. Is this the third time or the fifth? No one has bothered to count. You stand facing the device, legs spread apart even with your shoulders, and your arms are pressed to the side panels. You’re cleared.