 As recently as December 2006, a spate of rumors had many in Ukraine, particularly Kyiv, convinced that something major might be amiss at the Chornobyl Nuclear Power Plant. As usual with these frequent eruptions, the reality turned out to be that the emissions were not nuclear but hot air from those who love to start rumors that always find an easy audience here. In response to this non-event, we decided to, as well as possible, put Chornobyl facts and fictions into perspective in this issue of the Observer. We believe the following article by Jim Hydzik meets that goal.
The Editor
Work on the damaged block is known world-wide, but it is not the only headline news concerning Chornobyl NPP. The long-awaited construction of a spent nuclear fuel repository is also controversial, and the rumors and misunderstandings associated with the project are manifold. As recently as January 2007, President Yushchenko was forced to clarify his statements regarding the need to build the facility. As he accurately pointed out, Ukraine has serious problems with storing its nuclear waste. No material from foreign countries is slated to be stored at Chornobyl, and there is plenty of spent material from Ukraine's reactors to go into the site, if it ever gets built.
Fuel from the three intact blocks at Chornobyl NPP has been in temporary wet storage, called ICF-1, at Chornobyl. Attempts by the French company Areva ANP to dry the fuel and prepare it for long-term storage began in 1999 but ran afoul into technical difficulties, and the project has been in limbo since 2003. The delay is unwelcome, and the ICC pointed out in 2005 that building the permanent storage facility, ICF-2, is one of the most urgent tasks related to the Chornobyl site as a whole, as the useable life of ICF-1 expires in 2016.
The ICC points out that the decommissioning of the plants is complicated by the fact that nobody has ever decommissioned this type of plant before. Even without the additional pressure from having to work in a location contaminated by a nuclear accident, the technical issues themselves require a unique solution. Stringent safety measures required by the Ukrainian government further add to the complexity of the matter. The facility must have a 100-year life span. The fuel is to reside in two independent containers and be observed with specific monitoring capabilities.
In 2006, the American company Holtec International, headquartered in New Jersey, announced the design of a dry-storage facility that would meet the Ukrainian government's conditions. The European Bank for Reconstruction and Development, which oversees the disbursement of Chornobyl-related funds from foreign donors, has already conducted a safety review of the plan, and a 900-page technical proposal was given to EBRD and Chornobyl NPP for an in-depth examination in November 2006.
At the earliest, Holtec can expect the go-ahead in March 2007. However, given the technical enormity of the project as well as the political sensitivity of building a nuclear spent fuel repository at the Chornobyl site, the possibility of a delay is a real one. In the mean time, spent nuclear fuel from other sites goes to Russia for storage at considerable expense. Ukraine's experience in storing some of the most difficult nuclear material might give it the experience to begin handling waste from its currently operating plants that are nearing the end of their operational lives. But the experience needs to be gained now in order to be prepared for future decommissionings as well as to clean up Chornobyl NPP.
Former US Secretary of Defence Donald Rumsfeld's dictum, "There are known knowns, known unknowns and unknown unknowns," sums up most sorts of catastrophes, including the current state of the Chornobyl Nuclear Power Plant (CNPP). On top of this, sorting out the known knowns from the rumors and unreliable or deliberately misstated statistics regarding Chornobyl is tough work. What can be stated for certain at the moment is that the Chornobyl project is between two milestones desperately needed to keep the site safe. The first is the physical stabilization of the sarcophagus. This was largely completed in December 2006, though as we will show, stabilization will continue to be a work in progress. The second milestone, one that is expected to cost over 1 billion euros, is the awarding of a contract to build the New Safe Containment (NSC) housing, known here as the shelter, or NSC.
To get an idea about just what is being covered up and what might happen if something goes horribly wrong, we sought the help of Dr. George Laszkiewicz, who has the unusual perspective of being one of the few Moscow-trained nuclear engineers to have worked for the American government in the early days of the international projects regarding Chornobyl. The Ukraine-born Laszkiewicz left his home in Lviv with his family on foot to escape the horrors of the Great Patriotic War. Although a long-time resident of the United States, Laszkiewicz has remained extremely active in Ukraine and makes frequent visits that allow him to be extremely well-informed about current Chornobyl realities.
Further information comes from the International Chornobyl Center (ICC), which has released documentation on a yearly basis regarding, among other things, the conditions inside the sarcophagus. From what we understand, the summary below is the clearest, most accurate brief description you can find on the general state of the Chornobyl plant as well as what the shelter project is supposed to and is not intended to do.
Laszkiewicz says that an event on the same level as the explosion and fire at Chornobyl in the 1986 catastrophe is not possible, as it was a "man-made explosion as the result of an experiment conducted on the order of Moscow's 'best scientists'." The three other reactors at CNPP were closed down at the end of 2000, and though significant amounts of radioactive fuel are still present in those reactors, none of the reactors are 'live' enough to cause an explosion of the same magnitude.
It should also be remembered that none of Ukraine's functioning nuclear power plants are of the same type as CNPP. "The other plants are of a Pressurized Water Reactor design PWR (Russian and Ukrainian acronym VVER). PWR/VVER reactors have a different "physics" design concept and are safer. The majority of US reactors are of this type, too.
"Also, existing Ukrainian VVER plants are undergoing constant safety upgrades. The US has contributed greatly to safety issues at Ukrainian NPPs, and one of the best projects financed by the US government is Ukraine's first modern reactor simulator and training center for the Ukrainian operational personnel. The operation and safety of Ukrainian NPPs are subject to International Atomic Energy Agency (IAEA) reviews and evaluation. It works well."
Most of the known knowns are not very encouraging, and they serve to highlight the importance of the creation of the shelter. Understanding the enormity of the construction of the sarcophagus as well as its weaknesses helps put this in perspective.
Of the 18 proposals fielded in 1986 to enclose the damaged reactor, the Soviet Union's All-Union Scientific, Research and Design Institute of Power Engineering (AUSRDIPE) chose the most expedient and riskiest variant. Cement was mixed on site, and a covering was created that utilized the remaining walls of the reactor as stressed members of the enclosure. On top of these walls was a roof and supports including the 50 meter-long concrete 'Mammoth.' The walls supporting the Mammoth have had to receive attention due to buckling and the cracks that have appeared, and the cement itself is crumbling, but the structure was put up as well as could be expected under intense physical conditions. Could the initial covering have been built better? "Probably not," says Laszkiewicz, "but some loss of life and health damage could have been prevented."
From May through November 1986, teams of hundreds of thousands of workers implemented the plan set by AUSRDIPE, with an estimated 90,000 workers being involved in the actual construction itself. Much of the work had to be improvised based on low-level aerial photographs taken on a daily basis during the construction, and the resulting structure had weak or missing joints between beams and walls. However, by the end of November 1986, the construction of the sarcophagus was largely complete, and radiation, especially in the direction facing the third reactor, which had been shut down, was being constantly monitored. Operational guidelines were then set up.
The international community became involved in handling the Chornobyl enclosure issue with the break up of the Soviet Union. By the mid-1990s it was obvious that emergency work was needed. A 2-year study was conducted to better understand the nature of the situation, and alarming problems were discovered. The ventilator stack was in danger of falling onto reactor unit 3, which was again operational at the time. The ICC reports that work on the stack as well as the Mammoth's supports were among the five priority spots that received urgent attention.
The roof of the structure had been compromised as well. "The existing shelter was like a planetarium at one time - you could see the sky," Laszkiewicz notes. "Substantial patching work was done in this respect and finished last year. But this is rather a continuous process because the shelter's concrete is crumbling constantly." The ICC reported that cracks from 20mm to 50cm have been found, and that some of the walls, before they were buttressed, were leaning up to a meter off the vertical.
One common myth concerning CNPP is that the area inside the sarcophagus is an unknown unknown - that nobody really knows what is going on in there. Not so. People do work inside. The work is hazardous and frightening. Laszkiewicz said that "no one in the United States would accept such work (and compensation) in this very dangerous and unhealthy condition." Just how dangerous is it?
Consider the air that they breathe. The ICC points out that the radioactive dust in the sarcophagus contains transuranium elements. This includes plutonium-238, plutonium-239, plutonium-240, plutonium-241, americium-241, strontium-90 as well as caesium-137. The last two isotopes figure in the creation of dirty bombs, and the collapse of the sarcophagus, which Laszkiewicz claims would be the worst-case scenerio at the site, would release significant amounts of all these into the air.
The psychological pressure that workers inside the site face as they breathe air that has had these isotopes filtered out is intense. It may or may not be helped by the knowledge that activity inside the site was suspended over May-June 2005 due to increased radiation levels found among workers. A review found that all workers were still within strict criteria set by the Ukrainian government, but air filtering was improved nonetheless.
The work done to the sarcophagus and upcoming shelter should reduce the chances of an airborne catastrophe. The 'planetarium' that Laszkiewicz referred to brings up a far greater problem, though. Rain water seeping into the enclosure has definitely added to the damage present, and localized ground water pollution has been noted.
"Rain water as well as surface water found its way to the shelter," says Laszkiewicz. "This is a big problem because it constitutes a big environmental hazard for the groundwater system in the vicinity of damaged reactor. Some radioactivity has already found its way to the groundwater, contaminated the water in the reservoir and elevated the radioactivity level measured along the Prypiat River. Some experts believe that the radioactivity is accumulating in the river bottom mud. It could be a problem in the future if the river bed is disrupted."
Hats off, but not Inside
Just what do workers inside the plant do? First and foremost is the work of the dosimetrists. These people gather data about radiation levels within the confines of the sarcophagus as well as in the surrounding area. Several agencies are involved, including ICC and IAEA.
Even without the functioning reactor, some systems at Block 4 are working. A total shut down would be inadvisable, as Laszkiewicz notes that "at the damaged unit some systems should be kept operational. This includes radiation safety systems, ventilation systems and auxiliary heating and cooling systems. The United States financed a new boiler house as well as some support structures and ventilation. This plant is 'living', in a way."
Construction work goes on inside the structure as well. Though much of the buttressing needed to stabilize the site can be done from the outside, Laszkiewicz emphasizes that "serious repair works are conducted inside the shelter. Some beams have been replaced; some strengthened. Support structures have been erected and built inside the shelter. A lot of constant and very dangerous work is performed and those designers and very dedicated workers deserve a huge amount of recognition. They work in very dangerous and unhealthy conditions, as the radioactive dust has to be suppressed and there is a high radiation level."
The environment that the workers and dosimetrists work in is further complicated by known and unknown unknowns, such as the state of what the ICC notes is roughly 50-100kg of nuclear material still within the confines of the explosion site. Nobody knows for sure exactly how much is left. Parts of the reactor site are accessible, but the 1986 explosion, which the ICC points out shoved a 2,000 metric ton containment roof on-end, mangled much of the structure that was left. This was further encased in the tons of concrete dumped in by helicopter as the containment process went under way. The debris, and worse yet, lava containing nuclear fuel, are mostly unreachable, and everything inside is highly contaminated.
The damaged reactor is not the only site of nuclear material at Chornobyl, and not even the site of the only accident there. Known knowns also include accidents at the Unit 1 and Unit 2 blocks. The ICC claims that the first, in 1982, damaged a reactor fuel channel, and fuel fragments migrated into undesired locations within the plant. The second, a 1991 fire in Unit 2, damaged turbine equipment and the roof overhead, though radiation levels never reached dangerous levels and the reactor remained intact. These reactors constitute a source of dangerous nuclear material that must be taken care of as well, and controversy over the handling of spent fuel continues.
Gimme Shelter
With the sarcophagus stabilized and maintenance work continuing, the next milestone will be the awarding of the contract to build the New Safe Confinement shelter that will cover the sarcophagus and allow further work to go on. What the NSC is and is not supposed to do is important, as these parameters helped determine both the method and the type of construction.
First, the NSC is not a substitute for the sarcophagus. The ICC puts it succinctly: the NSC will be a giant workshop. Keeping this 'workshop' idea in mind will help in understanding what it is supposed to do. The sarcophagus will be protected from the elements, and the most important contaminant - rainwater - will no longer enter the site.
One requirement may surprise less-informed readers. The NSC is supposed to protect the sarcophagus from a strong tornado. While tornadoes are relatively uncommon occurrences in Europe compared to the US, they do happen. British sources indicate that several European countries have been repeatedly hit by tornadoes more than a kilometer wide. In Ukraine, small tornados appear occasionally in oblasts bordering the Black Sea, but the possibility - along with the greater likelihood of damaging straight-line winds - is being taken into account. While the idea of a 20,000 ton, 100m tall arch withstanding an F4 tornado may sound farfetched, other requirements also call for a unique structure.
The NSC is to be designed with a 100-year life span, handling heavy snow and wind loads as well as earthquakes, while still providing a safe place for workers and four gantry cranes capable of lifting 50 tons each. Since one of the long-range goals of the project is the dismantling of the current sarcophagus, the ability to raise local radiation shields and protect workers in case of accidental high-radiation exposure must be taken into account as well.
To complicate matters further, the NSC will be built next to the site and then slid on rails over the existing structure. The foundation itself will be supported by concrete walls and will be completed as the construction on the arc begins. The sections of the arc will be made off-site and transported by land or river. Remember, though, that the river cannot be dredged in order to allow deep draft boats in, so transporting the sections, which ICC notes can be up to 65 meters long and weigh 200 tons, is going to be a Herculean task in itself.
Out of 30 companies that showed interest in creating the NSC in 2003, only two remain. The announcement has been delayed, so the French team led by Vinci and Bouygues and a US-Ukraine consortium headed by the American company CH2M Hill are still waiting to uncover the next known unknown.
The generation of electricity using nuclear material will always be subject to some level of controversy and the Chornobyl Nuclear Power Plant will always be remembered as the classic and tragic example of what may happen if safety precautions are not followed. The lessons learned since 1986 are perhaps the best guarantee that there will be no repetition of such an event in the future.
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