Slavutych is a small, pretty town 50km from Chernobyl in Ukraine. Its tidy apartment blocks, restaurants and bars were built after 1986 to accommodate those forced to leave homes that were within the 30km exclusion zone created after Chernobyl nuclear-power plant's Reactor Four exploded.
This is where Laurin Dodd, 65, is picked up from his cottage every morning and driven to the site of the disaster. His journey takes him through the exclusion zone and a barrier at a checkpoint 10km from the former power plant. Dodd, a US citizen, sits in the back reading the Wall Street Journal and checking email on his iPad.
After the explosion 26 years ago, helicopter pilots dumped thousands of tonnes of sand to smother the fire, which burned for two weeks. Soldiers gathered radioactive rubble using wheelbarrows and shovels and tipped it on to the smouldering heap. Then the construction crews arrived: from May to November they built a containment structure called the sarcophagus (now named the Chernobyl nuclear power plant object shelter) over the reactor's remains. But, in their haste to finish, the contractors didn't seal it properly. The sarcophagus is failing. A 2006 report by the Chernobyl Forum – a group of UN agencies – described it as having been hastily built in horrendous conditions leading to "imperfections". It is supported by the remains of Reactor Four, the structural stability of which is unknown. And its own structure has corroded over time. The same report summarised that "the main potential hazard of the shelter is a possible collapse". That would mean another release of radioactive material into the environment.
Dodd is in Ukraine to prevent this. As the managing director of the 220-person project management unit (PMU), he's responsible for building a new shelter over the top of the sarcophagus called the new safe confinement (NSC). The building, which will rise from one of the most treacherous construction sites on Earth, will be 108m tall and 150m wide, have an arch span of 257 metres and will weigh 29,000 tonnes. Unlike the hastily constructed sarcophagus, it is designed to last 100 years. The construction site is a concrete pad 180m west of the reactor; once finished, the NSC will be slid into place and properly sealed. Remote-controlled cranes suspended from its roof will then dismantle the sarcophagus and robots will remove all remaining radioactive material. The project is due to be finished by 2015. But every day the chances of the sarcophagus's collapse increase. "That's the schedule," Dodd says. "There are always hurdles, there are always surprises. Whenever we dig here we run into stuff – old cranes, Caterpillars or pieces of [nuclear] fuel. And many of the things we have done have never been done before, and when you do something for the first time..."
Steel erection began in April this year; the central section of the arch has already been completed and now sits on the concrete pad, which is slightly wider and longer than the NSC.
The remaining pieces are laid on the floor like unpacked LEGO, with huge cranes looming over it. To the east is the sarcophagus. Behind it are a long turbine hall and three other reactors – all defunct.
Dodd, who is on site by 8am every day, is employed by US construction giant Bechtel, which won the project-management contract with its partner, Battelle, from the Ukranian government.
The client is the Chernobyl nuclear-power plant, which is owned by the Ukrainian government. Dodd attends a conference every morning, along with around 20 other managers and Igor Gramotkin, the plant's general director.
After the meeting, his driver takes him to the PMU office, a three-storey grey block a few hundred yards from the sarcophagus.
Dodd gets out of the white SUV, walks inside the building and stands on a machine that scans his hands and feet for radioac tive particles. All employees must follow the same procedure when entering any building here. He gets the green light, a gate opens and Dodd walks up to his office.
He was born in Portland, Oregon. After school he enlisted in the US Army. He then studied engineering physics at Oregon State University. After completing a master's in nuclear engineering at the University of Washington he worked at the Hanford nuclear site, which had made the plutonium for the atom bomb dropped on Nagasaki.
In 1980 he took a job at Battelle that involved analysing Soviet nuclear reactors for the US government. After the Chernobyl explosion in 1986 he compiled the official US report. In 1991 the USSR broke up, and nuclear engineers in the former bloc sought his help in improving safety at their neglected reactors. Three years later a Ukrainian MP invited him to see the site.
The following year he returned, along with emergency funding and equipment from the US government. "The situation was horrendous," he says. "We took a tour of one of the operating units and didn't go through any radiation monitors. One of the people with us was walking down this hallway and we had whites [protective clothing] on. One of our booties came off and he said, 'Don't worry about it.' The attention to safety was completely different from what we were used to." The sarcophagus was the most urgent problem: Dodd saw birds flying through holes in the structure.
"They had workers going in there every day without respirators, and the lighting was almost non-existent," Dodd says. "Conditions were horrible. Between 1995 and 1997 I went there a dozen times, and there were places where the roof was being held up by a beam that went across the top of a vertical element that had partially collapsed during the accident. Just one jolt and it would have collapsed. If it falls down it's going to release a lot of radioactive dust and this will, depending upon wind speed and direction, cause a problem. "The real physical problem would primarily be on site. By the time the dust reached the perimeter of the exclusion zone, calculations have shown that it would exceed regulatory limits. But the psychological impact would probably be the greatest impact.
Everybody in the country and surrounding countries would have a lot of concern."
Dodd and his firm lobbied for a solution. In 1997 the G7 nations agreed that a new shelter was needed and the European Bank of Reconstruction and Development was asked to raise and manage €1.2 billion (£960 million). Eventually 30 countries contributed. That same year the bank awarded Bechtel and Battelle the project management contract (French firm EDF was also part of the team, but pulled out in 2010). Fifteen years later, construction has started, but the sarcophagus remains.
The first challenge for the NSC's designers was how to build the structure without workers suffering the radiation exposure and cancers now synonymous with Chernobyl. The 600,000 official "liquidators" who originally cleared up Chernobyl received an average radiation dose of 100 millisieverts; at that level there is evidence of an increase in cancer, although doctors are still monitoring those involved. The answer was to build the NSC away from the sarcophagus and slide it into place once erected. No one knows the identity of the person who came up with this solution. "I wish I could attribute it to a single individual or even a company, but I can't," says Eric Schmieman, senior technical adviser at the NSC.
Schmieman, another American 65-year-old, began working on the NSC's design in 2001 and helped choose the sliding arch from ten competing proposals. But problems remain. For instance, the NSC will contain two million cubic metres of free volume, meaning open space without partitions. According to him, all four structures with a similar volume (the Goodyear Airdock in Ohio, the US Navy Hangar One, Tustin Marine Corps air station and Nasa's vehicle assembly building) have suffered from the same problem – what he calls "rain". "When these four structures were enclosed they developed their own environments inside," he says. "The atmosphere at the top of the building would become close to saturated and the inside surface only had to be a couple of degrees cooler than the atmosphere for water to condense on it. We're especially concerned about that happening here, because if we have water inside it generates radioactive liquid waste."
The easiest solution would be to install air conditioning to remove moisture from the air. But, according to Schmieman, to air-condition a building the size of the NSC would require its own dedicated power station. Instead, they installed a 12m annular space between the inner and outer layers of the roof. If the space is heated so that the inner surface of the roof is a few degrees warmer than the main volume, it will prevent water from condensing on it – the roof would act as a giant radiator. The sealed annular space, which contains all of the steel for the arch, also solves a second problem: corrosion. "There are steel structures that have lasted 100 years, such as the Eiffel Tower," Schmieman says. "But they last because they're continually repainted. We're not able to do that once we slide this into place – the radiation levels are so high we can't send people in. So what are we going to do? We are going to condition the air that goes into that space. We're going to keep the relative humidity in there at less than 40 per cent. Steel does not corrode at that level."
The design work was agreed and in 2007 the PMU (also responsible for procurement) hired Novarka, a French consortium of Bouygues and Vinci, to build the NSC. But Dodd was worried. The site would not be ready for several years and the western wall of the sarcophagus was cracking. It might fall down before the NSC was built. The PMU decided to install a steel reinforcement, but to do that they needed to jack up the roof. The Ukrainian government publicised the progress. Then Dodd got the jitters. "The concern was that the weight of the roof could be keeping the wall up," Dodd says, "so if you take it off it could have fallen down. We stopped work at one point because we had concerns about the whole process." The Ukrainians shared Dodd's uncertainty.
They undertook more analysis and calculations and it was decided that the roof should be raised in two stages, with a period of several months between each stage. A few weeks later everyone returned to the site and the roof was slowly jacked up over the course of a few days. The process remained on track and was finished in June 2008. The steel reinforcement now supports 80 per cent of the weight of the roof and will last 15 years.
In the same year a Ukrainian firm, UTEM, was hired to decontaminate the site (during the initial clean-up, radioactive material had simply been buried). In a layer of clean earth that had been laid down by liquidators there was new shrubbery and grass which had bioaccumulated radiation. The firm cleared and levelled the ground. To the north and south of the sarcophagus it also dug trenches several metres deep for the foundations of the NSC. In the south trench they found a contaminated crane; in the north a contaminated truck. The grim work was completed in 2010. That summer the concrete pad was also laid to provide a stable surface for steel erection and to protect workers from ground radiation. Running along the eastern edge of the pad is a fence that separates the work area from the sarcophagus. Here, in a place called the "local zone", workers face conditions unlike any construction site on Earth. The radioactive hazard is tremendous, and even the simplest tasks require procedures and safety standards necessary to protect workers from potentially fatal consequences.
Don Kelly is a safety inspector for the PMU. In 2007 he was working for Battelle in the US when he saw the Chernobyl opportunity advertised ("I think I was the only one interested," he says). He moved to Slavutych and has been working on the site's safety ever since. Kelly, 56, is proud of its record of 6.3 million safe working hours. The run was broken by a steel rail crushing a worker's foot.
To carry out inspections in the local zone he faces the same process as everyone else. He enters the changing block, passes through security and receives a briefing on radiological conditions. He then passes through a turnstile and enters the local zone. The sarcophagus is just yards away. Kelly's respirator must not leave his face. If his nose itches, he can't scratch it.
If he wants to drink water, he must wait until he is back in the changing block (and he has to wash his mouth out first). Permanent radiation monitors – which are monitored by a Frenchman in a hut – are positioned along the perimeter fence. If they detect high levels of radiation, an alarm goes off and the site is evacuated.
The last drill took seven minutes.
Everyone in the local zone wears two dosimeters. One gives a display of real-time exposure, the other keeps a record for the worker's dose log (dose is the term for measuring radiation exposure). Everyone has a designated dose limit; Kelly's is 300 microsieverts per day and 5,000 per year. If the daily limit is reached, the dosimeter beeps and the worker leaves for the day. If the annual limit is reached, workers lose their jobs. On the roof of the sarcophagus a worker might last just ten minutes before his daily limit is reached. To reduce their dose some workers practise tasks on mock-ups. According to Kelly, a fall from height is now a bigger worry than radiation. But if anyone's count is higher at the end of the shift, their site access is immediately cancelled and they are sent to Kiev for three days of testing at a programme for special biophysical control. Between 20 and 30 people are sent there each month. Most likely, they swallowed or inhaled a speck of radioactive dust.
Dust doesn't generally stay in the lungs. "Sometimes it works its way out from coughing and could be swallowed and end up in the stomach," says Michael Smith, head of the PMU's biomed programme.
If it's soluble it can be digested and enter the bloodstream. Then it can be incorporated into the body. Where it goes in the body depends on what type of radionuclide it is and what chemical it's mimicking."
Smith, a 45-year-old American, is responsible for radiation safety at the NSC. Another part of his job is to protect the PMU, donor nations and Ukrainian government from litigation – Ukraine is still paying compensation to many of those who cleaned up Chernobyl the first time, an amount estimated to be five per cent of the country's GDP. Smith studied nuclear engineering at Kansas State University and at Ohio State, moving to Slavutych in 2010.
Dodd says the target of completing the NSC by October 2015 is "ambitious". And with every day of delay, the risk of the sarcophagus disintegrating increases. It also jeopardises the next two steps towards decommissioning Chernobyl within the NSC's 100-year lifespan. The first step after completing the NSC is dismantling the sarcophagus. If it isn't dismantled and it collapses, step two, the removal of fuel-containing material becomes more difficult. According to Dodd, dismantling the sarcophagus will take five years. It has to be finished by 2023, which is when the western wall's reinforcement expires. After that it's at a greater risk of collapse.
Some believe the NSC will not be the last shelter at Chernobyl, but will instead become another tomb that will be replaced one day.
Robert Alvarez is a senior scholar at the Institute for Policy Studies, a Washington DC think tank. He's sceptical that the material could be removed from Chernobyl in the near future. He believes the Ukrainians will have to revisit Chernobyl long after the NSC has been built and "come to terms with building another containment".
Alvarez's prediction of a much slower decommissioning process is supported by the nuclear industry's track record of clearing up disasters. The International Atomic Energy Agency has a seven-point scale for rating disasters. Chernobyl and Fukushima are the only two so far to be rated seven ("major accident") – Chernobyl is now 26 years old; nobody knows how long Fukushima will take. Three Mile Island in Pennsylvania suffered a partial meltdown in 1979 and was rated five ("accident with wider consequences"): fuel has been removed but it has not been
completely decommissioned. And the 1957 fire at Windscale, England is also rated five, but progress is even slower there – decommissioning work is scheduled to be finished by 2041, 84 years after the disaster.
To match that pace Chernobyl will have to be made safe by 2070, but the real deadline is to decommission Chernobyl within the 100-year life-span of the NSC by removing the fuel-containing material. Dodd declines to speculate on whether or not the Ukrainians will manage it. "They have a lot to do before that can happen," he says. Instead, he wants to concentrate on the present and getting the NSC built as quickly and safely as possible before the sarcophagus collapses. As wired went to press, it was still standing.
Andrew Hankinson is a freelance writer
This article was originally published by WIRED UK
