Can pulsed lasers help to achieve ALARA guidelines in nuclear plants?

In nuclear facilities, one of the primary challenges is managing radioactive contamination that accumulates on equipment, tools, and materials in contact with cooling liquids. To address this, the facility employs two main strategies:

1. Reducing Radiation at the Source

This strategy focuses on lowering radiation levels by addressing the contaminated surfaces, tools, and equipment. Radioactive contaminants typically concentrate on the surface of materials, such as metals, because these contaminants tend to remain at the surface rather than penetrating deeply. By removing or reducing surface contamination, the overall radiation exposure can be significantly lowered, minimizing risks to workers and the environment.

2. Chemical Stripping and Solidification

Chemical stripping is a commonly used method to remove surface contaminants. However, this approach has a significant drawback: the contaminants are dissolved into a liquid form, which must then be carefully managed and disposed of. One method to handle this liquid waste is mixing it with concrete, which solidifies the liquid, making it easier to dispose of. However, this process still involves challenges, such as the safe handling of the contaminated liquid and its eventual disposal.

Laser Cleaning as an Alternative

Laser cleaning presents an innovative alternative to chemical stripping, offering several important advantages for decontaminating surfaces:

• Contactless Removal: Unlike chemical methods, laser cleaning is a non-contact process. This is crucial because it eliminates the need for direct interaction with the contaminated surface, thereby reducing the risk of generating secondary waste or exposing workers to radiation during the cleaning process.

• Minimized Airborne Contaminants: When using lasers to remove surface oxides and contaminants, the amount of waste that becomes airborne is minimized. This is important because it further reduces the potential for radiation spread in the air, making the process safer for workers and more environmentally friendly.

• Surface-Only Impact: Since radioactive contaminants are typically concentrated at the surface of materials, laser cleaning can effectively target and remove them without affecting the underlying material. This not only reduces radiation exposure but may also render the material safe for reuse or recycling, provided the radiation level is reduced to acceptable thresholds.

  P-laser has developed specialized pulsed laser beam profiles designed to optimize the removal rate of surface oxides, particularly for applications in nuclear facilities where contamination is concentrated on the surfaces of materials, such as pump components. In these cases, the contamination typically resides within the first few micrometers of the base material.

  To effectively reduce radioactive contamination in these situations, it may be necessary to remove not just the surface oxide layer but also a small amount of the base material beneath it. This ensures that the radioactive contaminants are fully removed or sufficiently reduced to safe levels. To achieve this, P-laser's laser systems utilize a more aggressive beam profile designed for deeper penetration into the material. These laser beams are optimized to remove a thin layer of the base material while maintaining precision and control, thus addressing the contamination effectively.

  Key Points About P-Laser’s Aggressive Beam Profiles:

  • Tailored Pulse Profiles: P-laser's pulsed laser technology uses tailored beam profiles that allow for high energy density delivery in a controlled manner. This is especially useful when dealing with thin, contaminated surface layers that need to be removed without causing unnecessary damage to the underlying material.

  • Targeting Surface Contamination: In nuclear facilities, contaminants like radioactive isotopes are often concentrated on the surface layer. By using more aggressive laser pulses, the system can precisely target and remove the contaminated surface layer without disturbing the integrity of the deeper material, such as pump components.

  • Material Removal: For components like pumps, where the contamination resides in the first micrometers, laser cleaning needs to remove a small amount of the base material, often just a few micrometers. This ensures the radioactive contaminants are completely eliminated or reduced to acceptable levels. The aggressive beam profile helps in removing this material efficiently.

  • Maintaining Precision: Despite the higher aggressiveness of the beam, the laser system still allows for precision, ensuring that only the contaminated surface layer is removed. This minimizes the loss of material, preserving the structural integrity of the component.

  • Inline sensor technology (patent): by measuring the reflected light at the surface where the infrared laser beams hits we can control the cleaning inline in an automated modus. This allows you to control the cleaning efficiency over spectral analysis. 

  By incorporating these specialized pulsed laser beam profiles, P-laser’s technology provides a highly effective method for decontaminating surfaces, particularly when deeper material removal is required. This approach optimizes the balance between effectively removing radioactive contamination and preserving the underlying material, making it a powerful tool for nuclear facilities operating under the ALARA (As Low As Reasonably Achievable) principle.