Davis-Besse weatherproofing Shield Building after cracks found - 13abc.com Toledo (OH) News, Weather and Sports

The Davis-Besse Nuclear Power Plant in Oak Harbor closed last year, then re-opened several months later after workers found cracks in the Shield Building.  Those cracks are blamed on the Blizzard of 1978.

Now crews are putting a weatherproof coating on that concrete building which protects the steel vessel containing the nuclear reactor.

Plant engineers say the weatherproofing will add another layer of safety.

You may not see it from the road but a massive 8-week long project is underway at Davis-Besse.

Painters are working on spider swing stages using rollers to cover more than 100,000 square feet of the 250-foot tall Shield Building.

"They go up to the top of the building and they apply the weather coating from the top to the bottom," says Bob Karr, project manager for First Energy.

Crews are applying more than 25-hundred gallons of paint to the concrete walls of the shield building. They're applying one coat of primer and two top-coats.

"What these coatings will do is they'll ensure that no additional moisture enters the concrete to the building," says Karr.

The painters are using Sherwin Williams commercial paint to protect the building from severe weather.

"It's the wind-driven rain, it's been qualified to 98 miles an hour, so it'll protect the concrete from absorbing that rain," says Tim Ridlon, site coating specialist for First Energy.

The Nuclear Regulatory Commission says that a lack of that coating, the structural design, and the Blizzard of 1978 all played a role in creating cracks that were discovered last fall.  Those cracks are mostly on the south side and were there for more than three decades.

"The crack width are very, very tight," says Jon Hook, design engineering manager at Davis Besse.  "We measured them. They are approximately 'point-zero-one' inches."

Hook says the cracks have not grown and no new ones have been found.
So this added layer of coating is an added layer of protection to the concrete Shield Building which protects the steel vessel containing the nuclear reactor.

"We have evaluated it for all of our design conditions: tornado, earthquake, wind load, all of those parameter and it meets all of our design conditions," says Hook. "So the Shield Building is fully operable."

The painting project should be complete by the end of September. The coating should last for 15 years. The project manager says the cost of this project is classified.