PNNL workers helping secure Chernobyl

Apr 25 - McClatchy-Tribune Regional News - Annette Cary Tri-City Herald, Kennewick, Wash.

Twenty-five years after one of four nuclear power plants at Chernobyl exploded, employees of Pacific Northwest National Laboratory are working to reduce the dangers remaining from the accident.

Battelle, which operates the Department of Energy national lab in Richland, helped develop the 1997 Shelter Implementation Plan, a step-by-step approach to solve the technical problems left by the meltdown of the reactor core on April 26, 1986, and convert Chernobyl into a safe and secure site.

Now it has employees assigned to the responsible execution of the plan, which includes building a massive new structure to cover the open reactor for the next 100 years. Six PNNL employees are living in the Ukraine, bringing expertise as engineers, safety professionals and contract specialists to the project.

"We stand on the shoulders of giants," said Eric Schmieman, a PNNL senior technical adviser at Chernobyl. The people who came before them on the Chernobyl project include many who gave their lives, including during the emergency response to the disaster.

Within months of the reactor core meltdown, workers had risked their lives to cover the open reactor with a sarcophagus, or shelter. But that was a short-term fix.

The sarcophagus is leaky and with its walls in danger of collapse, a major project already has been completed to transfer the weight of its roof to a new external support structure.

Now construction is close to starting on the New Safe Confinement, a structure that will cover the destroyed reactor and sarcophagus. It is intended to prevent the further release of radioactive contamination, better protect the damaged reactor from the elements that add to its deterioration and help with its cleanup.

It's a civil engineering challenge that Schmieman compares to the Egyptians building the pyramids.

"Working conditions are very difficult," he said in a telephone interview. He is the signature authority for all design and technical decisions for the construction phase.

The damaged reactor remains too radioactive to safely be covered directly.

Instead, construction will start soon 650 yards away to build a 32,000-ton arched structure that will be slid into position to cover the damaged reactor in summer 2015 or sooner. The arch will stand about 360 feet tall -- taller than the Statue of Liberty -- and will be about 840 feet wide and 530 feet long. Inside will be robotic cranes to help dismantle the destroyed reactor, limiting worker exposure.

Radioactive contamination remains a worry and workers try to avoid digging. The foundation for the confinement structure is being built by injecting grout into the ground, Schmieman said.

Battelle has provided safety leadership, working with Ukrainian colleagues to bring the best international safety practices to the project, including respiratory protection, occupational medical screening and radiation detection and measurement programs. Ukrainian workers had been relying on masks similar to those surgeons tied over their faces in the United States half a century ago.

Western practices for fall protection also have been instituted, replacing safety belts that were required in the Ukraine but not allowed in the U.S. at tall heights with safer full-body harnesses.

Developing a safety culture has been no simple feat, but the project now has achieved almost 4 million work hours without a lost-time accident, Schmieman said.

As challenging as the project is, it's been not just professionally but also personally rewarding, Schmieman said.

"Work here is very important from a global perspective," he said. "It's rare you get an opportunity to act globally."