Big Rock Point nuclear plant demolition
Three individual and precisely controlled blasts were completed on Dec. 8, 9 and 11 at Consumer’s Energy’s Big Rock Point Restoration Project. The work assists in the demolition of the large concrete monolith located inside the plant’s former containment sphere.
The blasts were used to “soften the concrete and steel rebar monolith that once housed Big Rock Point’s reactor vessel, steam drum, spent fuel pool and other equipment. The explosives were designed, placed and detonated in order to fracture– but not drop–the structure which stands 75-feet tall at its apex.
The “softening” allows workers to more efficiently demolish the structure using standard demolition equipment–a 16,000 pound wrecking ball and ramming equipment.
The explosives were employed in response to the difficulty encountered in earlier demolition projects of similar structures at Big Rock Point and other nuclear sites across the country.
“Demolition of the turbine building earlier this year using the wrecking ball proved just how solidly the plant was constructed,” said Ray Flowers, Big Rock Point site general manager. “In addition to successfully performing similar work at other nuclear sites, they have also brought down such recognizable structures as the containment building at the Maine Yankee nuclear site, Seattle’s Kingdome, Pittsburgh’s Three Rivers Stadium and the J.L.HudsonBuilding in Detroit. For a job like this, it was important that we identify and hire the industry leader.”
Controlled Demolition Inc. (CDI) was contracted by Consumers Energy to plan, engineer and execute the blasts.
“CDI was hired because it is the recognized worldwide leader in using explosives to assist in the demolition of unwanted buildings,” said Kurt Haas, Big Rock Point site general manager. “In addition to successfully performing similar work at other nuclear sites, they have also brought down such recognizable structures as the containment building at the Maine Yankee nuclear site, Seattle’s Kingdome, Pittsburgh’s Three Rivers Stadium and the J.L.HudsonBuilding in Detroit. For a job like this, it was important that we identify and hire the industry leader.”
Preparation for the blasts began several months ago as the plant’s trademark containment sphere was being dismantled. CDI personnel developed the blast plan, which details the amount and placement of explosives in the concrete, along with safety procedures and contingency blast.
Blast 1 occurred Dec. 8 and was located in the area where the reactor vessel was once located; blast 2 occurred Dec. 9 and was located in the former spent fuel pool area; blast 3 occurred Dec. 11 and occurred in the former steam drum area. Approximately 500 pounds of explosives were used in the three blasts.
An extensive number of safety precautions were implemented for the work, including:
-Establishment of an 800-foot blast zone in which all personnel were required to vacate;
-A blast mate constructed of chain link fencing and fabric was laid over the individual blast zones to keep debris in place;
-A detailed countdown procedure and contingency plans were established and followed;
-Site security was increased and all nonessential personnel left the site during the blasts; and
-Advance notification of appropriate authorities were made.
“The months of planning paid off–the structure remains standing as planned after the blasts and the concrete and rebar has been softened,” said Haas.
The structure is now being brought down using the wrecking ball and other equipment. The approximately 23 million pound of debris will be loaded into containers and shipped out of state for disposal.
The concrete monolith is the last large remaining structure at Big Rock Point. The majority of the site is scheduled to be returned to a green field status, free for unrestricted use, by fall 2007.
Big Rock Point was the world’s first high powerdensity boiling water reactor and an important research site for the nuclear power industry. The plant was shut down on August 29, 1997, after 35 years of service; making it the nation’s longest running nuclear plant. Due to its many contributions to the nuclear and medical communities, Big Rock Point was named a Nuclear Historic Landmark by the American Nuclear Society.
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