ActivityNuclear services

The business area specialises in maintenance services for the main components of the nuclear steam supply system, such as reactor, fuel (in all phases of the cycle), steam generators, and reactor coolant pumps. It has experience in the decommissioning of nuclear facilities.


Maintenance service

  • Disassembly and assembly of auxiliary elements
  • Reactor vessel opening and closing
  • Reactor internals removal

Repair service

  • Replacement of guide tube pins in the lower internals
  • Repair of studs and threaded holes
  • Inspection, cleaning and repair of reactor vessel and reactor vessel head flanges
  • Cutting and Welding

Other activities

  • Extraction of irradiated samples
  • Replacement of guide tubes
  • Visual inspection of the vessel and internals
  • Foreign object search and retrieval
  • Tooling and equipment maintenance (bolt tensioning and threading, flange cleaning, etc.)


Maintenance service

  • Opening and closing of manholes
  • Inspection, opening and closing of the pressurizer
  • Gaskets replacement
  • Bolts tensioning

Repair service

  • Removal of seized bolts and installation of helicoils
  • Flange machining and repair
  • Tube plugging (expanded and welded)
  • Assembly of Nozzle Dams

Other activities

  • Pressurizer heaters replacement
  • Primary and secondary side inspection
  • Steam generator sludge lancing
  • Measurement of bolt elongation by UT


  • Assembly and disassembly of reactor coolant pumps and motors.
  • Inspection and cleaning of components (seals, bearings, thermal barrier).
  • Overhaul of associated equipment (oil lift pump, exchangers, instrumentation, etc.)
  • Overhaul and change of seals.
  • Overhaul of pump and motor bearings (radial and thrust).
  • On-site component repair and machining.
  • Inspection, cleaning and repair of bolts and housings.


New and spent fuel handling.

Drive shaft assembly coupling and decoupling.

Fuel inserts handling (rod control cluster assemblies, thimble plugs, burnable poisons).

Refuelling equipment check-up:

  • Handling and fuel crane.
  • Fuel transfer system.
  • Associated tools (drive shaft assembly coupling, inserts handling.)

Fuel inspection:

  • Leak detection by sipping and UT
  • Visual inspection of fuel assemblies.

Fuel repair:

  • Repair (MFRS and RTN).
  • Fuel reconstruction.
  • Ultrasonic fuel cleaning.


Container loading (ENSA-ENWESA Group):

  • Handling of the casks before loading.
  • Loading of spent fuel into casks.
  • Closing of the cask, draining and drying process.
  • Leak test.
  • Cask handling and transport to temporary storage.


System modifications:

  • Cutting, machining and welding of equipment and systems.
  • Replacement of piping.
  • Design modifications.

Collaboration with ENSA:

  • Laboratories (metallurgical, mechanical testing, welding, metrology, instrumentation and robotics).
  • Calculation, design and development engineering.

Decommissioning activities:

Radiation protection supervision.


  • TIG, MIG and SMAW welding processes.
  • Approved welding procedures.
  • Qualified welders.
  • Heat treatment equipment.
  • Non-destructive testing and visual inspection levels 2 and 3.

Special interventions:

  • Repairs and welding in Nuclear Power Plants.