NuClear Decontamination
RADIOLOGICALLY PROVEN and efficient dry process
With the PhotonClean Laser cleaning equipment, nuclear contamination with rates of 99.6 % and more for α and particularly high factors for β and γ radiation can be removed.
The homogenized blasting technology makes it possible to gently clean all common geometries and metal materials below the degradation threshold for reuse or recycling.
The process can thus be used economically and in an environmentally friendly manner for both decommissioning and maintenance work on running nuclear power plants.
Cleaning using laser light as a dry process replaces the chemical wet and mechanical blasting process.
ADVANTAGES of nuclear decontamination by laser cleaning
Decontamination rates of 99.6 % and more
High decontamination area rates with > 15 m²/h for slightly adhering contaminations (rust, oxides) and > 8 m²/h for solid contamination (hot area, paint)
Enormous reduction of hazardous and expensive secondary waste (further development of extraction systems)
Flexible technology configurations in mobile or stationary control cabinets, hand-held and/or automated optics, up to 50 m fiber tube package
Negligible influence on base material allows reuse of decontaminated devices/products (hardness, tensile and macro tests successful)
Prevention of the spread of impurities (corrosion infiltration tests successful)
Tests at the different Nuclear Power Plants confirmed that laser technology can successfully release up to 94% of reinforced concrete and 78% of dismantled equipment from strict radiation control.
Removal of uranium compound particles such as uranyl nitrate (UO2(NO3)2 6H2O) and uranium dioxide (UO2) on surfaces in the nuclear industry is of utmost importance. Metal canisters in hot cell complexes and instrumentation in nuclear fuel production need to be cleaned of these particles. Potential applications exist in Pebble Bed Modular Reactors (PBMR). Uranyl nitrate is the basic feed material for PBMR fuel production, and uranium dioxide is the fissionable material of the fuel element kernels.
The issue of cleaning uranium particles from metal canisters remains a common issue for all types of nuclear reactors.
Loose uranium compounds are much easier to remove as a form of contamination as compared to the contamination that has penetrated into the oxide layers of metal surfaces in a nuclear reactor. However, loose contamination is dangerous because, firstly, it can be inhaled by a person and, secondly, it can be carried by footwear or clothing to another location outside of the restricted areas. Once these particles are inside the body, they pose a radiation hazard, and as well as they are also considered toxic.
There are many different methods of cleaning these loose particles, such as chemical cleaning or water jetting. However, the addition of chemicals or water implies dealing with the secondary waste that is generated. The secondary waste is radioactive and needs to be properly disposed of. This adds to the cost of using these cleaning methods and improper disposal of secondary waste could create health hazards or contaminate water supplies.
An alternative method is laser cleaning, where a pulsed laser ablates the surface and removes the particles. This method is a dry process and removes all the contamination without the use of a secondary medium (such as water or chemicals). The particles are removed using an extraction system that contains a disposable dry filter such as a HEPA filter
As far as the choice of the laser is concerned, both the surface layer removal and Dry Laser Cleaning (DLC) are more efficient at shorter wavelengths, such as in the visible region, which could reduce the substrate damage. However, the choice of the laser is dictated by the overall efficiency of cleaning large areas, which dictates the use of either a Q-switched Nd: YAG laser at the fundamental wavelength of 1064 nm, or an industry-grade pulsed fiber laser.
Radioactive Decontamination: Decontamination costs as low as only a few cents per kilogram
Precision laser ablation for nuclear environments: Non-contact, waste-minimizing surface decontamination engineered for the nuclear industry. Reduce waste by up to 95%, lower worker dose exposure, and cut project costs by up to 60%.
PhotonClean laser cleaning technology achieves the release of metal for recycling while reducing decontamination costs to a few cents per kilogram.
The process is media-free and thus free of recontamination, causes no mechanical stress to workers, is fast to implement, and requires no pre-treatment.
It is a sustainable and efficient alternative to previous processes.
Decontamination results by several testings!
TESTING PROCESSES
Testing was performed on various surfaces, which consisted of carbon steel and lead. Both small-area (10cm²) and large-area (12m²) tests were done for efficiency, with even passes. In cases when the surface did not show a 100% removal of contaminants, further passes were made until contaminants were undetectable or the decrease in detectable activity had reached its negative threshold. The laser cleaning solutions were tested on a variety of materials with fixed contamination to better understand the effectiveness and safety of laser ablation for radiologically contaminated surfaces. The surface radiation on these materials included Alpha and Beta contaminants.
CARBON-STEEL
Source: Contaminated dump truck beds used in the decommissioning of a nuclear site
- Contaminant Details
- Varying isotopic consistencies, primarily Uranium 238
- Largely Beta emitters, with very low Alpha contamination
- Results
- Lighter, Beta particles were found more deeply into the materials than heavier Alpha particles
- Varied results based on Alpha/Beta concentrations, but, overall, highly effective in time efficiency
LEAD
Source: Contaminated lead bricks, lead containers used for transporting radiological materials.
- Contaminant Details
- Mostly Alpha contamination, especially Radium contaminants
- Results
- 100% efficiency of contamination elimination
- Up to 60% time-efficiency improvement
GENERAL TEST RESULTS
- For the small areas (10 cm²), the laser treatment took around 25 seconds to remove all foreign materials from the base layer of the carbon steel. For lead, the ablation time was even less.
- Decontamination for the large area (12 m²) required only four hours of work from one individual, as compared to the 200 man-hours needed to complete the task using the standard method of power tool grinding.
- For Alpha-contaminated materials, the lasers were able to achieve 100% removal effectiveness of the radiological contaminants.
Data also showed a great improvement in operator safety and a significant reduction in radwaste produced. These Testings prove that the use of laser ablation is an effective, environmentally-friendly solution for nuclear decontamination.
LIMITATIONS
Although laser ablation was able to achieve excellent results removing Alpha contaminant layers, the process had more limited success with the more penetrating Beta contaminants in carbon steel. Test data showed the laser treatment was most effective when radiological contamination did not exceed a depth of 2.5cm. Even in the most challenging areas, laser ablation was able to significantly reduce the overall time required to decontaminate the treated steel to a releasable limit, compared to other options.
Nuclear laser cleaning, or laser ablation, is a dry, contactless decontamination process used to vaporize hazardous and radioactive surface layers from metals and concrete.
It reduces secondary radioactive waste by 80–95% compared to liquid blasting and cuts worker radiation exposure by up to 70%
Why the Nuclear Industry Uses Laser Decontamination
Zero Liquid/Chemical Waste: By eliminating high-pressure water jets or chemical solvents, the process produces only dry particulate matter, severely reducing the volume of waste requiring geological disposal.
Recycling and Clearance: Because laser cleaning removes contaminants down to the base material without micro-fracturing (unlike grit blasting), heavily contaminated components can often be decontaminated to below regulatory thresholds and subsequently recycled.
Reduced Human Exposure: The ability to mount laser heads onto remote robotic arms allows for safe operation inside highly radioactive, high-dose containment environments without risking human health.
Operational Efficiency: Facilities bypass the need for prolonged drying, liquid wastewater treatment, and chemical disposal steps.
Recent Industry Milestones
Tests at the Ignalina Nuclear Power Plant confirmed that laser technology can successfully release up to 94% of reinforced concrete and 78% of dismantled equipment from strict radiation control.
Recent United Kingdom Research and Innovation (UKRI) projects demonstrated that utilizing multiple passes at lower laser powers provides the best overall cleaning results, safely preventing radioactive materials from melting into the metal substrate during ablation.
Operational Challenges & Safety
Aerosol Containment: Ablating radioactive material releases airborne aerosols. The laser beam must be enclosed within a specialized "soft seal" shroud (sometimes utilizing a water vapour mist) to instantly capture and sequester particulates.
Laser Safety: Operators are required to wear specialized protective eyewear tuned to the specific wavelength of the laser, alongside personal respirators to guard against inhaling potentially harmful fumes.