Decontamination Services

Manual Scrubbing

This process has been used on both pressurized water reactors (PWR) and boiling water reactors (BWR). Typically, the gross activity is flushed to a low point or lower cavity using hoses (fire and garden varieties), water brooms, and squeegees. The area is then cleaned using scrub brushes on a handle, mops and commercial floor buffers. Walls are decontaminated using scrub brushes or pads to a predetermined height that varies for 6 to 8 feet from the floor to the entire wall and fixtures. Person-baskets suspended from overhead cranes are the most frequently used device for high vertical surfaces.

Advantages

  • Inexpensive equipment and supplies relative to other options.
  • Project cost is low, but is dependent on required labor.
  • Minimal training requirements.
  • Extensive industry experience.
  • Less prone to equipment failures, (hydrolyser, water supply, others).

Strippable Coatings

Strippable coatings are a simple, effective means of removing or preventing contamination. The material is applied easily to most dry or wet (depending on the product) surfaces. Once dry, the material serves as a barrier that prevents contamination from reaching the protected surfaces. If the barrier becomes contaminated, it can be stripped away or the contamination can be sealed in place with a second layer and subsequently stripped away. If the surface is contaminated, strippable coatings can be applied and then stripped, carrying the contamination with it. Any method normally used for applying coating (airless sprayers, paint rollers, or brushes) can be used to apply strippable coatings.

Advantages

  • Significant decontamination factors (DF)
  • Reactor Vessel Head may be reassembled in single layer protective clothing (PC). This results in improved work efficiency and quality as well as significant reductions in personnel exposure.
  • Leaves cavity in better condition for next Refueling & Inspection Outage.
  • Reduced instances of PCEs.

High Pressure Washing

High pressure washing employs the use of a positive displacement pump to deliver a relatively high pressure water stream, typically up to 3,000 psi. The pressurized jet of water is typically applied via a hand held gun/wand with the wand tip in close proximity to the Rx Cavity surface. This method has been used successfully in the nuclear industry for decontamination and other cleaning applications.

Advantages

  • Historically provided consistently good results.
  • Use of rotating tips reduces the potential for creating airborne activity in highly contaminated areas.
  • Equipment is simple to operated and fairly easy to maintain.
  • Supply water can be heated to improve boric acid removal efficiency.

Hydrolasing

Hydrolasing employs the use of a positive displacement pump to deliver a very high pressure water stream. The pressurized jet of water is typically applied via a hand held gun/wand with the wand tip in close proximity to the Rx Cavity surface. This method has been used for decades in the nuclear industry for decontamination and other cleaning applications.

Advantages

  • Historically provided consistently good results.
  • The required volume of water is low. This minimizes the generation of a secondary liquid waste stream that requires processing via Radwaste.
  • The latest generation of Hydrolasing equipment has tips and shields that reduce the potential for creating airborne activity.