The G7 nations agreed to fund a complete rehab of the Shelter in 1997. They chartered SIP to oversee dozens of projects: plugging holes in its walls, replacing its roof, stabilizing its west wall and ventilation stack, installing monitoring equipment, and so on. In essence, the Shelter had to be fixed up in order for it to be safely torn down. The costliest project to date, and the last in SIP's mandate, is the New Safe Confinement, a $1.3-billion arch that will, if all goes well, completely seal off the Shelter from the environment. Schmieman, the principal member of the arch's conceptual design team, has tackled complex engineering problems all over the world. But the arch, he said, is by far the most challenging project he's ever worked on. Everything about the arch—its size, its purpose and the hazardous conditions under which it's being built—is unprecedented. Now he grinned. "This is kind of like what working on the pyramids must have been for engineers back in Egyptian times."