UCL Environmental Radiometric Facility

The UCL Environmental Radiometric Facility uses low-background hyper-pure germanium gamma spectrometers capable of measuring low-level environmental radioactivity.

The facility currently employs four ORTEC^® HPGe GWL series coaxial well-type gamma detectors, each housed in a 100mm thick lead shield. Resulting spectra may be analysed for different environmental radioisotopes including ²¹⁰Pb, ²²⁶Ra, ¹³⁷Cs, ¹³⁴Cs, ²⁴¹Am, ⁷Be and ⁴⁰K.

The facility was established in 2003 since when the main application has been for the radiometric dating of lake sediments and peats via the measurement of ²¹⁰Pb, ¹³⁷Cs and ²⁴¹Am. This enables chronologies of 100 - 150 years to be accurately determined. This approach can also be used in a number of other ways to investigate the distribution of radioisotopes in the environment through measurements of a wide range of environmental and ecological samples. The facility has undertaken analyses for research projects based in many areas of the world.

Applications

• Radiometric dating of lake, marine and coastal sediments and peat accumulations by establishing chronologies and accumulation rates through the measurement of atmospheric fallout of naturally produced ²¹⁰Pb and artificially produced ¹³⁷Cs and ²⁴¹Am radionuclides.
• Determining the extent of sediment focusing within a lake basin by measuring ²¹⁰Pb distribution in sediment cores from across the accumulation zone
• Modelling the transfer of radionuclides through catchment-lake systems and assessing soil erosion in catchments by investigating inventories of environmental radioisotopes such as ²¹⁰Pb, ¹³⁷Cs, ¹³⁴Cs and ²⁴¹Am in soils as well as in sediments and peats
• Tracing atmospherically deposited pollutants through terrestrial and lake ecosystems by comparing distributions of ²¹⁰Pb and other pollutants, in particular trace metals.
• Monitoring radioactive discharges and emissions from nuclear and non-nuclear sites; assessing state and changes of gamma radiation does rates in the environment.

Research Projects

The facility has been involved in a large number of research projects including the following. Click on the project below for more information:

• Hydroscape
• Lake sediment evidence for long-range air pollution on the Tibetan Plateau
• European lakes under environmental stressors (EULakes)
• Palaeolimnology of lakes in the Wood Buffalo Region, Canada
• Open Air Laboratories (OPAL)
• Eurolimpacs
• Palaeoclimatology studies in Russia

Sending samples

Before sending samples for analysis it is important to contact either the Facility Manager Handong Yang, the Financial Coordinator Jamahl Holland, or the Academic Coordinator Lucy Roberts (see Contacts) regarding up-to-date costs and the time from receipt of samples to reporting as this can vary depending on demand. When submitting samples, please consider the following requirements:

Basic information

• Site name
• Location (Latitude; longitude)
• Sampling date

Samples

• For sediment analyses, we require 0.5g dry mass of each sample as a minimum. Please send more sample mass if at all possible as this can reduce counting time for samples with low-level radionuclide activity and also reduces counting errors derived from the background.
• For core dating work, it is also a good idea to send as many samples as possible at the start. If during the analysis we find we need to request additional samples from you, this can considerably increase the time it takes to complete the work and send you a report.
• Samples should be submitted dry. Freeze-drying or air-drying are both fine.

Data

For sediment and soil core samples dry density data are required for the core as these are used for calculating radionuclide inventories. If you do not have these data, sediment dry density may be calculated from the sample’s dry weight (or water content) and the wet density. Please do send us an e-mail if you have any questions about this.

Quality Control

A document covering the Standard Operating Procedures for our laboratory is available upon request.

Sending and returning samples

• Please send your samples to The Department of Geography, North-West Wing, University College London, Gower Street, London WC1E 6BT, UK. Please mark for the attention of either Dr Handong Yang, Jamahl Holland or Dr Lucy Roberts.
• The analysis is non-destructive and we are happy to return your samples, so do let us know if you want them sent back to you after the analysis is complete.