30 Years After Chernobyl Disaster, Shelter Nears Completion
On the night of April 26, 1986, engineers at the Chernobyl nuclear plant in what was then Soviet Ukraine performed a safety test at the plant’s No. 4 reactor. It did not go well.
In a matter of seconds, power inside the uranium-and-graphite core of the reactor surged out of control, setting off a steam explosion that was followed by a fire that spewed radioactive particles into the atmosphere.
By official Soviet accounts several dozen plant workers and firefighters died in the immediate aftermath. Thousands more were sickened by radiation, over the short and long term. The surrounding countryside, contaminated by radioactive fallout, was declared off limits to anyone without a pass to get through security checkpoints.
On the 30th anniversary of the accident, access within the 18-mile exclusion zone, which includes the abandoned city of Pripyat, is still restricted. But at the plant itself, things are looking up. An arched shelter designed to enclose the radioactive remains of the destroyed reactor is nearing completion.
The arch, called the New Safe Confinement, is being built — at a cost of at least $1.7 billion — to last 100 years. Inside, the radioactivity levels will be so high that normal maintenance, like painting, will not be possible. So inside and out, the arch is covered in stainless steel, and dehumidified air will be circulated around the structure’s steel trusses to prevent rust.
正在修建的拱顶称为“新安全壳”(New Safe Confinement)，成本达17亿美元，设计寿命100年。那里面的放射性水平极高，像刷涂料这类正常的维护工作是不可能进行的。因此，拱顶从内到外都用不锈钢包裹着，除湿空气将被灌入钢桁架，以防生锈。
It was built several hundred yards from the destroyed No. 4 reactor, and later this year will be slid in place over the reactor building. That will eliminate one of the greatest risks that still exists at Chernobyl: a structural collapse that could raise a cloud of radioactive dust and spread more contamination across Ukraine and into Western Europe.
But it will also mark the start of a new phase in coping with what is generally considered the world’s worst nuclear power disaster. Inside the arch will be a heavy duty crane and other remote-operated equipment to be used to start removing the crumbling radioactive fuel that remains in Unit 4.
It will not be an easy task. There is a lot of fuel — 195 tons, by one estimate — along with tons of lead, sand and other materials that were dropped on the reactor by helicopter in a desperate effort to extinguish the fire. It all melted together into a lethal lava-like substance that poured through pipes and holes in the structure and solidified.
The government of Ukraine will be responsible for the work, and it is unclear where the money will come from to pay for it, or for a repository that will be needed for the fuel and other highly radioactive waste. It may take much more than another century before the mess started in a few seconds 30 years ago is fully cleaned up.