Low Level Radioactivity Laboratories
The laboratory performs analysis of anthropogenic and natural radionuclides in a variety of sample materials in connection with discharge control, environmental monitoring, research projects, and on assignment from external customers:
- environmental samples (e.g. water, soil, sediment, bedrock, vegetation...)
- non-nuclear waste (LSA scale, produced water...)
- non-nuclear industrial products
- foodstuffs, feedingstuffs, drinking water, urine, faeces
The laboratory has equipment for measuring alpha, beta and gamma radiation. In many cases a chemical separation of the element of concern must be performed before measuring the activity. The measurements may often be performed directly on the sample, or following a simple pre-treatment. When measuring pure alpha or beta emitters or nuclides with very week gamma lines, the nuclide of concern must be separated chemically before it can be measured by alpha spectrometry or gross beta counting. The analyses make great demands on the competence and accuracy of the analyst, and on quality assurance.
Typical radionuclides being analysed are 3H, 60Co, 90Sr, 137Cs, 210Pb, 210Po, 226Ra, 228Ra, 234,235,238U, 228,232Th, 238,239,240Pu and 241Am.
Working with samples. HPGe spectrometry
- spectrometry with Si-detectors in vacuum-chambers, all computer controlled
- liquid scintillation spectroscopy with Quantulus low level liquid spectrometer
- liquid scintillation spectroscopy with Quantulus low level liquid spectrometer. Typical detection limits for tritium ( 3H) are 0.5 Bq/ L and for 14C 0.05 Bq/ L.
- a set of low level gas flow anti-coincidence proportional counters with background lower than 0.003 cps and counting effeiciency of about 60 % for 90Sr/90Y.
- a set of HPGe-detectors in lead shields connected to appropriate electronics and controlled by computer for gamma spectrometry. Various calibrated sources for counting efficiency are available. Detection limits will vary depending on pre-concentration of the sample, detector background and efficiency and counting time. 0.1-1.0 Bq/ l are obtainable dependent on the energy
- large volume NaI( T1)-scintillation detectors with high counting efficiency