Nuclear Diving Services: Elite Dive Teams, Worldwide Support

Support for the Nuclear Power Industry

UCC is the premier global provider of underwater services to the commercial nuclear power industry. We understand that licensees expect service providers to aid in achieving higher plant reliability, maintaining and improving plant safety, minimizing cost, and facilitating regulatory interaction. As the first commercial diving company to specialize in services to nuclear power plants, UCC has set a standard for safety, reliability and cost-effectiveness which the industry has come to expect.

UCC Nuclear Divers are an elite team of commercial divers that support nuclear power plants performing inspections, ongoing maintenance and emergent support.

UCC maintains a quality assurance program that meets the requirements of 10 CFR 50 Appendix B, N-QA1, ANSI N45.2. UCC is a participating member of the Nuclear Industry Assessment Committee (NIAC) audit program, which is similar to the joint audit program operated by utilities through the Nuclear Procurement Issues Committee (NUPIC). We’re also audited periodically by NUPIC. Safety-related programs for inspection and maintenance meet applicable industry codes and standards as set forth by ASME, ASTM, ANSI and other industry organizations.

Primary Nuclear Diving Services

As a premier nuclear diving company, UCC provides a comprehensive selection of services including underwater inspection, maintenance and remedial work for:

  • Reactor vessel
  • Fuel pool
  • Fuel transfer system
  • Suppression pool
  • Intake and discharge systems
  • Pumps
  • Traveling water screens
  • Cooling towers
  • Storage tanks

UCC offers state-of-the-art underwater stainless steel welding on reactor internals, underwater plasma arc cutting, fuel storage rack installation and removal, coating inspection and repair, and concrete repair.

secondary-side Nuclear diving services

  • Pier and pile restoration
  • Maintenance, repair and replacement of traveling water screens
  • Maintenance dredging of intakes and discharge systems
  • Inspection services
  • Mollusk remediation
  • Contaminated water diving
  • Underwater nuclear welding
  • Concrete repair

UCC has the resources to manage turnkey maintenance projects, and the management depth that allows us to perform construction management when required.

Nuclear Diving Support

Inspection Services

UCC performs inspections on safety-related and non-safety-related structures, systems, and components to provide the licensee with the information needed to make informed maintenance decisions. These include:

  • Intake cribs, tunnels, and canals;
  • Traveling water screens;
  • Intake structures and circulating water pumps;
  • Condenser water boxes;
  • Condensate storage tanks, reactor vessels and vessel internals, tori and suppression pools; and
  • Fuel pool liners, transfer systems and gates.

Industry Qualified Inspectors

All of UCC’s Level I, II, and III VT-1 and VT-3 inspectors are qualified commercial divers. This ensures that inspections and assessments will receive the necessary hands-on attention. Our inspector training program meets the requirements of ANSI N45.2.6 and ASME Section XI, CP 189. Training is updated regularly to ensure that that all codes and standards are properly addressed. Inspection information is documented using the latest video and electronic data management techniques.

specialized inspection programs

UCC has developed a number of specialized inspection programs to support the nuclear industry. For example, UCC provides a complete underwater coatings inspection, assessment and repair program. The UCC coatings program is supported by experienced coatings professionals and registered professional engineers who specialize in safety-related protective coatings applied to service Level I areas. In accordance with UCC’s 10 CFR 50 Appendix B QA program, we have developed the inspection procedures and specialized quality control practices required by the industry to address safety-related qualified nuclear coatings under IWE inspection criteria.

UCC also has inspection programs that address weld inspection, traveling water screens, fuel pool liners and condensate storage tanks. Our inspection programs are typically integrated in a comprehensive maintenance program. In the case of traveling water screens, for instance, we begin with a comprehensive 33-point inspection to determine the current screen condition and the optimum frequency and level of scheduled maintenance required. Following the initial inspection, an assessment is performed to determine precisely what repairs, replacement, or refurbishment is required. Based on this analysis, UCC develops recommendations that include any deficiencies requiring immediate action as well as a detailed annual maintenance program specific to the needs of each screen.

  • Mechanical and structural inspection
  • Coating and corrosion inspection
  • Weld Inspection
  • Leak detection

Maintenance Services

UCC provides maintenance and repair services to support emergent work or as part of a structured preventative maintenance program. When an unexpected need arises, our dive teams are available on a callout basis. In supporting an ongoing maintenance program, UCC works with site personnel to implement procedures and programs that are consistent with site technical specifications and operating requirements.

Underwater Nuclear Welding

With the top nuclear industry welders, UCC’s specialized maintenance support includes underwater nuclear welding procedures qualified in accordance with ASME Section IX, ASME Section XI, IWA 4660 (formerly Code Case N-516) and AWS D3.6. The ASME procedures are qualified for all position groove welds on stainless steel plate and pipe. UCC has qualified carbon steel welding procedures to ASME Section XI IWA 4660, P1 to P1 base metal using an E309L-16 filler. The procedures were qualified for metals with a carbon equivalent of up to 0.525.

Underwater Nuclear Coatings

UCC’s underwater coating applicators undergo extensive training. Candidates receive instruction in the use of application tools as well as in application techniques. In-water, hands-on training is conducted in our test tank at UCCs wet testing facility. Repair procedures are continually updated to reflect the latest in industry practice and to ensure that underwater coatings can be applied efficiently and effectively. This includes surface preparation and application procedures and equipment. In addition, UCC is conducting its own R&D to develop new methods for rapidly coating large areas.

Typical underwater maintenance services:

  • Debris, sludge and sediment removal from intake structures, vessels and storage tanks
  • Concrete repair and leak sealing
  • Epoxy and chemical grout injection
  • Traveling water screen adjustment and repair
  • Weld repair of carbon and stainless steel structures, systems and components
  • ASTM/ANSI certified underwater Applied coatings services
  • Underwater leak detection and weld repair
  • Fuel transfer system upenders, transfer carts, limit switches and drive mechanism repair

Construction Services

Whether in support of new construction, extensive infrastructure rehabilitation, or decommissioning, UCC can perform turnkey work or provide diving support as a subcontractor on large marine construction projects. When it is not practical or cost-effective to dewater, the work must be performed underwater. Comparisons of work performed underwater versus similar projects done dry have shown that the cost to dewater can exceed 50% of the total cost of the job. In one example, the estimate just to dewater was placed at $500,000 to $750,000. The actual cost of underwater concrete placement was $128,000.

There are other benefits as well. Underwater repair minimizes the impact on power generation and eliminates the adverse structural and environmental impacts often associated with dewatering.

UCC has experience in the following:

  • Spent fuel pool reracking – installation, removal and volume reduction
  • ECCS and HPCI suction strainer installation and removal services
  • Decommissioning services
  • CP installation
  • Concrete restoration
  • Pump, pipe and cable installation
  • Erosion control and mitigation
  • Bulkhead, pier and pile rehabilitation
  • Traveling water screen installation and underwater rehabilitation

Technical Services

UCC can assist with complex technical issues. We routinely work with our customers to develop safe, efficient solutions to address to project-specific requirements. We provide safe innovative solutions that support demanding projects and tight schedules.

UCC’s technical support services include the following:

Project Management

UCC project managers and supervisors are trained and have the experience to ensure work is performed in a safe and efficient manner. They are closely involved in procedure development, work planning, scheduling, cost tracking, quality control and project co-ordination. All personnel maintain current commercial diver certifications and project-specific qualifications as well as safety-related certifications such as first aid, CPR, hazmat training and confined space entry.

Staff Augmentation

Working with the customer or prime contractor, UCC has a variety of experienced personnel who can provide project management and administrative support, supplement technical services and maintenance crews, or provide stand-alone services.

Procedure Development and Qualification

UCC has extensive experience in procedure development and qualification to meet plant-specific needs. These services include procedure writing, qualification of techniques and personnel, as well as materials testing. UCC has the capability to support or perform the mock-up and testing required to validate one-of-a-kind processes and procedures.

Facility Assessment and Maintenance Programs

Many of our procedures supplement or define ongoing assessments or maintenance programs. These include coatings and corrosion assessments and specialized maintenance programs for traveling water screens, pressure vessels, and other operating equipment.

Specialized Tooling

Specialized diver-operated or remote tooling is often crucial to completing a successful project. UCC can assist with the design and fabrication of pneumatic, hydraulic, or electric tool systems. We have experience developing purpose-built tools or modifying existing equipment, such as plasma arc cutting equipment, for use underwater.


Quality Assurance Program

UCC maintains a quality assurance program that meets the requirements of 10 CFR 50 Appendix B, N-QA1, ANSI N45.2. UCC is a participating member of the Nuclear Industry Assessment Committee (NIAC) audit program, which is similar to the joint audit program operated by utilities through the Nuclear Procurement Issues Committee (NUPIC). We are also audited periodically by NUPIC.

nuclear power plant inspection

UCC inspectors are trained in accordance with industry-specific codes and standards. UCC provides a complete underwater inspection and assessment programs, supported by experienced inspection professionals and registered professional engineers. Under UCC’s 10 CFR 50 Appendix B QA program, we have developed the inspection procedures and specialized quality control practices required by the industry to address safety-related structures, systems and components.

Certifications, Qualifications and Procedures

  • ASME Section XI, CP 189 VT-1 Level I, II, III ISI, IWE inspector certification
  • ASME Section XI, CP 189 VT-3 Level I, II, III ISI, IWE inspector certification
  • ANSI N45.2.6 coating inspector certification
  • EPRI certified nuclear coating specials
  • QP.09.03: qualification and certification of ASME Section XI visual examination personnel (VT-1 and VT-3)
  • QP.09.04: training, qualification and certification of underwater and topside coatings applicator personnel
  • QP.10.09A: procedure for containment inspections – visual examinations (VT-1 and VT-3)
  • QP.12.01: control of measuring and test equipment
  • QP.12.02: calibration and use of underwater coatings measuring and test equipment
  • QP.15.01: reporting and evaluating defects and non-compliance
  • IOP.02.11: vacuum box testing procedure
  • QP.09.02: qualification and certification of non-destructive examination personnel

Inspection Capabilities

  • VT-1 and VT-3 inspection of Class MC and CC safety-related components
  • IWE/ISI coating inspection
  • Corrosion inspection
  • ASME pressure vessel inspection
  • UT straight beam thickness measurements
  • Weld inspection
  • Class MC and CC pressure retaining structures
  • Torus, suppression pool, CST, SSW inspections
  • Potable water and fire suppression tanks
  • Intake structures and tunnels
  • Traveling water screens
  • Welding to Nuclear Codes

UCC is the most experienced and qualified underwater welding company in the nuclear industry. We have completed numerous nuclear underwater welding projects on various components of the reactor, and in the reactor vessel itself. In addition, we have qualified procedures and have performed welding on carbon and stainless steel components in suppression pools, condensate storage tanks, and other safety-related water storage basins.

UCC qualifies nuclear underwater welders and welding procedures in our pressurized wet pot chamber in order to simulate exact production welding depths. UCC’s underwater hyperbaric welding facility in Essex, Connecticut, is the largest of its kind. The hyperbaric tank was designed exclusively for the nuclear underwater welding industry and can achieve a simulated depth of 95 feet. The tank is 12 feet in diameter and 18 feet high, and is equipped with an access hatch large enough for mock-up sections to pass through for assembly inside the tank. It is also equipped with a 24-inch view port to allow customer and quality control personnel to monitor diver’s activities.

Certifications, Qualifications and Procedures

  • ASME Section IX, ASME Section XI, IWA 4660 (formerly Code Case N-516)
  • AWS D3.6. The ASME procedures are qualified for all position groove welds on stainless steel plate and pipe
  • Carbon steel welding procedures to ASME Section XI IWA 4660, P1 to P1 base metal using an E309L-16 filler. The procedures were qualified for metals with a carbon equivalent of up to 0.525.
  • Welding procedures for mild carbon steel using an E7014 filler for carbon equivalents up to 0.495 have also been qualified in accordance with AWS D 3.6.
  • Quality assurance manual – This governs the overall application of our quality assurance program in accordance with 10CFR50, Appendix B, NQA-1 and ANSI N45.2.
  • GWP-SMAW-1A (general welding procedure) – This procedure governs shielded metal arc welding qualification requirements (dry and wet).
  • GWPQ-SMAW-1A (general welding performance qualification) – This procedure governs the qualification process of all welders’ qualifications (dry and wet).
  • WPS (welding procedure specification) – The WPS is written in accordance with ASME Section XI, IX and/or AWS D3.6.M.
  • PQR (procedure qualification record) – In accordance with applicable welding codes, a welder produces a test coupon and the coupon is tested in accordance with ASME or AWS acceptance criteria. If the test is successful, then the PQR document serves to prove that the WPS is valid.
  • WPQ (welder performance qualification) – Once the WPS has been certified, welders may test and become certified to weld within the parameters indicated on the WPS. They weld a test coupon, which is then tested in accordance with ASME or AWS criteria. If the test passes, the WPQ document serves as the documentation and that welder’s successful completion and certification.

Welding Capabilities

  • In-vessel welding cladding repair
  • Core spray tee Box modifications and repairs
  • Feedwater sparger replacement
  • Feedwater sparger modification and repairs
  • Steam dryer modification and repairs
  • Steam separator modification and repairs
  • Spent fuel pool leak detection and weld repairs
  • Seismic support modifications
  • Fuel pool liner installation
  • Transfer cart modification and repairs
  • Safety-related pipe hangers and supports
  • Traveling water screen repair
  • Trash rack and gate repair
  • Pipe hangers and supports
  • Support for Industry and Professional Organizations
  • GE BWR Owners Group Vendor member
  • ASTM D33 Nuclear Coatings Standards Committee member
  • Society for Protective Coatings (SSPC) member
  • National Association of Corrosion Engineers (NACE) member
  • EPRI Coatings Aging Task Group member

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