Practical Application of Technology Exhibition


“Live demonstration of UCC’s Underwater Coatings System.”

Underwater Construction Corporation is a company name that only begins to describe the service we provide. Since 1969, UCC has been a diversified force, supporting needs in submersed environments from bridges to nuclear reactor vessels.

UCC is a company of firsts. It’s considered a world leader in specialized underwater techniques for inspection, leak detection, repair, renovation, and new construction. Often we are the only ones able to do the job.

UCC was the first to dive in a nuclear reactor vessel, the first to qualify an underwater safety-related weld repair in a reactor vessel, and the first to develop safe and efficient, hand-held underwater plasma cutting.

Underwater Construction Corporation has completed more nuclear dives than any other company. And our resolve to be the first in industry safety, quality, and customer satisfaction is paramount.

Our success as the largest, US inland commercial diving company is attributed to many innovative creations from UCC’s R&D team and the most comprehensive diver training program in the industry. UCC Research & Development efforts have pioneered and perfected many safety, welding, and operational techniques. These innovations have greatly expanded efficiency and capability for dive services in nuclear and non-nuclear industry and general marine construction. R&D also entails the custom evolution of remote operative tooling and procedures for underwater cutting, welding, and coating of various materials. In the R&D department we have an 18-foot hyperbaric chamber that we also use for training.  Due to atmospheric changes and variation at depths of as little as 10 feet there are significant changes in underwater welding and cutting characteristics. The chamber enables simulation of actual depth pressures to 95 feet providing us the unique opportunity to study, document and teach with great accuracy.

A Company Of Firsts

“UCC: The first to dive in a nuclear reactor vessel, the first to qualify an underwater safety-related weld repair in a reactor vessel, and the first to develop safe and efficient, hand-held underwater plasma cutting.”

UCC’s extensive marine construction experience includes dive support services for water dependent facilities, bridge structures, dams, bulk heads, and numerous other tasks below the surface. Debris and marine growth can profoundly impede industrial plant operation. A comprehensive maintenance program from UCC is the first line of defense to prevent obstructions to intake and discharge water systems.

UCC is a full-serve OEM vendor for traveling water screen installation and repair. Our divers can often renovate screens in the water to eliminate receding and resealing costs. UCC is also equipped to remove and overhaul traveling water screens at three of our facilities in the United States.

Since 1969, UCC has continually developed preventative maintenance programs which amplify the longevity and performance of traveling water screen operation. The normal defense against debris may be traveling water screens and trash racks. But unique situations require unique applications.

At a paper plant in Michigan, UCC repaired and modified a dam to prevent heavy storm damage. This contract included the reconstruction of a fish lap. Also in Michigan, UCC divers annually install and maintain a 3-mile long net that prevents salmon and other large species from entering the intakes of a hydroelectric plant. By removing growth build-up, the free flow of water through the net is maintained and substantial damage from strong currents is averted. All submerged plant equipment such as nets, pipes, intake bays, and storage tanks are susceptible to obstruction. Often the largest accumulate from the smallest of sources: mollusks.

In 1986, the European-born Zebra Mussel, invaded inland waterways of North America fouling industry water systems from Canada to Louisiana and now as far east as Connecticut. Since 1970, UCC has been at the forefront of environmentally sound techniques for mollusk remediation. Be it Zebra Mussels, Asian Clams, and other species, UCC is the expert in applying the most appropriate mollusk-removal technique and can design and install a control system to reduce future infestation.

The expansive range of our underwater tasks require that UCC has on-hand numerous resources. From the latest technology in dive hats to ROVs and a fleet of support vessels, UCC is equipped to perform the work. This decompression chamber is mobilized for use on deep water dives and a support vessel, ‘Jasper,’ is unique to all the Great Lakes. Its jack-up capability provides a stable work platform supporting many UCC assignments both below and above the surface. From below the surface of this man-made reservoir deterioration caused by leaks in the basin floor is averted by UCC divers specially trained in the application of silica sand fillers. UCC divers are also utilized extensively with bridge support inspection. Employing state of the art audio and video equipment as well as still photography, the divers report and demonstrate accurately the condition and position of any degradation of piers, bulk heads, or other structure. Seeing is believing and UCC is meticulous about documentation in our inspection process. Underwater Construction Corporation reaches the world from its home office located in Essex, Connecticut. Additional permanent support facilities are located in Michigan, Florida, and Tennessee.

To facilitate any requirement, temporary facilities are established as needed at any international location.

No matter what the job our first task is to always excel at what we do.

To be at the top of our business, we start at the bottom.


“We set high standards from the bottom up.”

Every nuclear power plant in the world utilizes water in massive amounts for cooling, shielding, and power generation. UCC’s extensive and unique dive experience, including the first dives in reactor vessels and spent fuel storage pools, can reduce plant downtime significantly.

Piping, pump rooms, submerged equipment, and structures are all targets for UCC’s fast, efficient, and cost-effective servicing. Comprehensive inspection programs, desludging, plasma cutting, welding, and the application of protective coatings are just some of the services UCC can perform in a nuclear underwater environment.

In a reactor vessel with a fully loaded core, highly trained UCC divers are able to work safely as far down as the core spray tee box. We regularly inspect, clean and renovate condensate tanks, spent fuel pools, and tourist tubes. Typical tourist tube dive applications include desludging, service inspection, coating, and the installation ECCS suction strainers. We desludge with a UCC-developed, high-efficiency vacuum system.  Reactor vessel dives often involve thermal shield replacement and the installation and repair of core spray tee boxes, steam separators, and dryers, feed water sparkers, and transfer cart systems. A specialty of UCC is the innovative work we perform on fuel storage pools, racks, and transfer systems.

With our exclusive underwater capacity to plasma cut, we can remove obstructions quickly and cleanly. Our divers can work as close as 7 feet away from spent fuel, executing vacuum box leak detection in the liner, hot tap liner weld repairs, oil seam grinding, new support welding, and the installation of new FSR configurations. When conditions dictate, we utilize remote operated tooling to get the job accomplished.

Finally, when the life of a nuclear power plant comes to an end, decommissioning services are a forte of Underwater Construction Corporation. In a Midwestern US plant, twenty-two UCC divers performed one thousand-six hundred-fifty dives in adverse conditions. The work resulted in thirty-seven major task completions, and the safe removal of more than a thousand tons of medium-high dose radioactive waste. We take innovation to new depths.

Nuclear Programs

The first dive in a spent fuel storage pool.


Developed & used hand-held underwater plasma arc cutting

– First in the industry

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From rapid response, emergent work, to large-scale, multi-year service contracts.

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