Sampling a painted surface for alpha contamination

A client asked whether ViridiScope could sample through paint and into the contaminated concrete underneath.

  • Posted On: 25 March 2024
Sampling a painted surface for alpha contamination

It is sometimes the case in legacy buildings, where radioactive contamination has occurred, that walls or other surfaces have been painted over to reduce exposure from alpha emitters such as plutonium. This means that the usual monitoring tools will not reflect the true nature of the hidden activity. If the area is to be characterised, samples must be removed from below the paint layer for analysis.

We showed that our laser sampler can penetrate through paint and into the surface below, allowing the operator to collect material for subsequent analysis. The sample is collected on a supported filter and can be counted in situ for alpha/beta and gamma activity without further treatment. The surface is characterised in a matter of minutes, with detection limits for alpha activity down to 0.1 Bq/g.

If you would like more information on detection limits for beta and gamma activity, or have any questions about ViridiScope, please contact us at

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