Mission Complete

Every job a demolition contractor encounters has its own set of safety and structural challenges. But when those challenges include potentially radioactive material, a 25-foot hole and 5-foot-thick concrete walls, the potential risks become greater than on a more routine job.

In January 2012, crews from two Cleveland-area companies joined forces to enter that exact scenario. Chemtron Corp. and B&B Wrecking and Excavating were hired to dismantle the Plum Brook Reactor Facility in Sandusky, Ohio—a former test reactor used by NASA in the 1960s and 1970s to explore a national nuclear rocket program.

According to NASA, more than 70 experiments were conducted in the reactor while it was active. Many of the experiments studied the effects of radioactivity on various materials. The facility closed in 1973 when budget restraints forced NASA to cut back on its research programs. The facility stood idle for about 15 years before it was decommissioned. The decommissioning process began in 1998 and took 12 years to complete.

Filling in the Gaps
In 2012, the property owners decided to return the property back into open land. From its heydays during the Kennedy Administration to sitting empty for nearly 40 years, the facility that made history was about to become history. Chemtron was hired to handle the demolition in an environmentally safe manner.

Chemtron Vice President Karl Guenther oversaw the project which was completed by B&B. “I brought in B&B as a team, and I basically orchestrated the demo with their equipment and our equipment,” Guenther says.

The scope of the project included demolishing the entire Research and Test Reactor Facility to 3 feet below grade, removing the steel reactor dome, including the steel shell below grade. Backfilling the reactor pit and site grading were the final steps.

Before demolition work began, crews gutted the inside of the building. Steel and wood were cut out and the roof of the reactor was removed.

The dome-shaped roof that covered the reactor needed to be pulled off in a manner that prevented any debris from entering the reactor hole. “I couldn’t let anything go in the hole other than clean concrete,” explains Guenther. “We had to go in and really gut it and be very careful that no insulation went into the hole and we only put in clean, hard fill.”

Before crews could obtain access to the reactor crater, they had to collapse basements and backfill the 20-foot-deep tunnels and canals surrounding it. “You couldn’t crawl a machine over it. You had to work from the outside in,” describes Guenther.

Extra Precautions
Everyone who worked on the site received 16 hours of radioactive material handling training. This included 20 B&B employees.

“Working with NASA is always a challenge,” says Brian Baumann, president of B&B. “It is very high security. Every worker had to be [radiation] trained.” He adds, “Those are things you have got to do for jobs these days, especially at a former nuclear reactor.”

Equipment operators kept dosimeters inside their equipment to make sure they were not exposed to radiation. “They [NASA] did a great job protecting us, that is for sure,” says Guenther. “We had four [radiation] techs with Geiger counters by our side at all times.”

With the danger of coming into contact with radioactive materials a constant threat, safety was at the forefront of the project. A meeting was held each day to go over the safety plan, and more in-depth safety talks were held once a week. The safety precautions paid off, as no injuries or incidents were recorded.

Baumann knows there are plenty of risks at any demolition job but says, “At the end of the day, we all want to go home to our wives and our kids.”

Demolition was performed using a “piece-by-piece” method. Having to inspect each piece of material was time consuming, according to Baumann. He says the biggest challenge was dealing with the size and scale of the facility. “Everything was bigger, it was stronger, it was thicker,” he says.

Five excavators equipped with shears and grapples tore away at 5-foot-thick concrete walls that contained what Guenther describes as densely populated reinforcement bars.

“You can’t just bring in a normal 70,000-pound excavator. You needed a 140,000-pound excavator,” Baumann says. “All the ‘toys’ were bigger. You needed bigger equipment and more of it,” he adds.

Recycling and Reuse
It took approximately 25,000 cubic yards of dirt and concrete to backfill the void of the reactor. Baumann estimates 95 percent of all the demolished material by weight and volume were reused and/or recycled, including 100 percent of the concrete and metals.

“Basically all the concrete that was on site stayed on site and went into the holes. All the scrap steel was scanned [for radiation] before it could go to the scrap yard,” Guenther says.

Conduit was found in only a few pieces of debris tested at the demolition site. The contaminated material was placed into boxes for disposal at a radioactive landfill in Utah.

Additionally, 22,000 tons of soil were brought in from Cleveland to meet grading requirements of three feet below the reactor to about four feet above the site. B&B has been recycling at jobsites for the last 20 years. “As demolition contractors we are really in tune with [recycling]. It just makes sense,” Baumann says. While NASA kept the profits made from recycling scrap on this job, Baumann says 30 to 40 percent of B&B’s gross sales come from recycling revenues.

The project was completed in June 2012—right on schedule. Guenther reports it was competed at about 10 percent under budget.

The extra attention to detail and increased safety measures were well worth it to Baumann. “I was glad I did it,” he says. “I was glad it turned out well.”
 

The author is managing editor of Construction & Demolition Recycling and can be reached at ksmith@gie.net.

Time Lapse Video
To watch a time-lapse video of the NASA Plumb Brook demolition, below: