Energy and Environment

Services related to LSA scale. Results within 24 hours

IFE has through the years gained competence in fields related to measurements of LSA scale, both field measurements and laboratory measurements. The institute has, in co-operation with the Norwegian Radiation Protection Authority (NRPA), carried out projects on the instructions of OLF (Norwegian Oil Industry Association) concerning measurement and classification of LSA scale. IFE was highly complimented for work performed in connection with classification of sludge from the Brent Spar and LSA scale from Maureen.

Ramsøy, Tore

Technical Group Manager

Strålberg, Elisabeth

Department Head


The exemption levels for LSA scale, set by the NRPA, are 10 Bq/g for 226Ra, 228Ra or 210Pb. If the specific activity exceeds this level for one or more of the three radionuclides, the material is classified as radioactive and must be treated as such. The exemption levels are in accordance with those given by the EU.

Field measurements
Identification of equipment contaminated with LSA scale can be done offshore. The measurements are performed with a hand held monitor sensitive for beta or gamma radiation. When measuring LSA scale that might contain 210Pb, a beta sensitive probe must be used. Each probe must be calibrated against a set of standards with known specific activity (Bq/g). Such standards can be produced at IFE.

Measurements can either be made directly at the component, or by collecting a sample of scale from the component and measure this. The sample container should have the same geometry as the standards.

Laboratory measurements – Results within 24 hours
Hand held monitors used for field measurements can only measure the total activity and do not distinguish between the two radiumisotopes. In some cases, these measurements can only be used to decide whether it is necessary to measure the sample with more accurate methods. High-resolution gamma spectrometry (picture) is such a method, and is used to identify and measure the amount of each nuclide in question.

226Ra is measured directly or through its daughters 214Pb and 214Bi. 228Ra is measured through its daughter 228Ac. At radioactive equilibrium the activity of 226Ra equals the activities of 214Pb and 214Bi. Similarly the activity of 228Ra is equal to the activity of 228Ac.

When it is urgent to have accurate results for classification of samples of LSA scale, IFE offers rapid measurements with delivery of results within 24 hours (working days). In that case, please notify us in advance.

We can also offer courses for radiation protection supervisors on- and offshore. Please contact us if you need more information about our services!