The explosions 20 years ago at Chernobyl were so powerful they blew the nuclear reactor’s 1,000-ton concrete lid (the upper biological shield) out of place and spread radiation over 40 percent of Europe.
The lid fell back into the reactor at an unstable angle, where it still leans uneasily above heaps of radioactive debris. If the lid loses its war with gravity, it will land on the mess below with such force it could dislodge a highly contaminated dust cloud. One of many unsettled questions about Chernobyl is if the dust could escape the reactor. Thus, the unstable lid symbolizes why Chernobyl remains an international concern – and why fixing the mess is one of the most formidable engineering challenges ever.
Experts say the mangled reactor could harbor 30 tons of radioactive fuel dust and 2,000 tons of combustible materials. Understandably, Ukraine wants to remove and securely store the radioactive wastes, but the firsttask is to keep the situation from worsening.
A Colorado firm wants to ride to the rescue.
Shortly after the lethal 1986 accident, the then-Soviet government hastily built a concrete structure around the blasted-out reactor. That structure, nicknamed “the sarcophagus,” aged so badly it’s now cracking and listing. While there’s little risk of another nuclear explosion at Chernobyl, the deteriorating sarcophagus could lead to a second disaster if it collapses or just doesn’t keep dust from escaping.
Ukrainian President Viktor Yushchenko wants to build a new containment structure by 2010. Unquestionably, the Ukrainians need international assistance: The economically struggling country spends about 5 percent of its gross domestic product just coping with consequences of the 1986 disaster. The European Bank for Reconstruction and Development would fund the $1.1 billion project but needs another $200 million in donations from European countries. In any case, the bank and Ukrainians haven’t announced which of two bidders will get the job.
One is a French group. The other is CH2MHill, an international engineering firm based in metro Denver. Locally, it’s best known as part of the partnership that cleaned up Rocky Flats, the former nuclear bomb factory near Boulder. In Washington state, the company is cleansing one of the worst messes at the Hanford nuclear site: draining hundreds of tanks filled with a mixture of toxic chemicals and nuclear wastes. These folks really must like a challenge.
But that’s one reason the firm wants the Chernobyl job, explained company spokesman John Corsi. CH2MHill’s mission focuses on projects that improve the environment and protect public health. In this regard, making the Chernobyl site safer would be the achievement of a lifetime. Corsi, quoting company president Ralph Peterson, said, “It would be something we’d be proud to tell our grandchildren about.”
How to build a 370-foot structure on a site so radioactive it’s unsafe to stand outside there for any length of time? By assembling the building’s walls elsewhere and trucking them to the site, where they can quickly be installed by crews wearing protective garb, Corsi explained.
CH2MHill has lots of experience dealing with nuclear cleanups and earning the trust of nearby communities. At Chernobyl, the public trust issue looms especially large. Appallingly, in April 1986 the Soviet government waited three days to tell the Ukrainians of the accident, thus unnecessarily exposing them to radioactive dust. Moscow admitted the problem only because other European governments detected elevated radiation levels.
About 30 workers died in the first few hours after the 1986 explosions and more than 20 firefighters died soon thereafter from radiation exposure. Two United Nations agencies last week estimated that 4,000 people eventually will die of cancers related to the accident. Environmental group Greenpeace claims, though, that 90,000 people worldwide could eventually die from Chernobyl-related diseases. Independent experts say the lower U.N. numbers are more credible.
But hyperbole is uncalled for when describing Chernobyl, as the agreed-upon facts are sobering enough: It was the worst nuclear accident in history. It let loose more than twice as much radiation as the bombs that fell on Hiroshima and Nagasaki.
And it’s still not safe. Whether the job goes to CH2MHill or its competitor, it’s imperative that the containment structure be built, and soon. The international community simply must help the Ukrainians prevent a second Chernobyl disaster.
