UKHSA has one of the most comprehensive radiation testing facilities in the world. In addition our radiation facilities are one of few in the UK able to accurately provide photon, beta and neutron doses and dose-rates at a variety of doses, energies and angles.
Our gamma facilities include three radiation laboratories: one in Leeds and two at Chilton
Dose-rates are controlled by a remotely operated exposure assembly. The various sources are housed within a heavily shielded enclosure. The selection of a particular source, the source to instrument distance and the operation of the beam exposure shutter, are all controlled remotely from outside the exposure cell. The instrument under test is viewed by a CCTV system. The facilities provide highly collimated radiation beams to minimise any effects due to environmentally scattered radiation.
Gamma sources: 137Cs, 60Co, 241Am and 226Ra.
Our X-ray facility at Chilton can generate the full range of ISO filtered X-ray qualities. Dose rates available, dependent on ISO quality, range from a few uSv h-1 up to a few tens of Sv h-1.
Filtered (transmission) x-rays are produced by a high frequency 300 kV constant potential X-ray generator. A total of 31 ISO qualities are available. These are from the ISO LOW, NARROW and WIDE series, with nominal energy resolutions of 20%, 30% and 50% respectively, and also the ISO HIGH series.
ISO LOW Series: 8 energies, 30 keV - 211 keV
ISO NARROW Series: 12 energies, 16.3 keV - 248 keV
ISO WIDE Series: 7 energies, 45 keV - 202 keV
ISO HIGH Series: 4 energies, 102 keV - 147 keV
We operate the only secondary standard Beta dose-rate jig in the UK.
Beta dose-rates are delivered using a PTW-Freiburg manufactured secondary standard Beta dose rate jig calibrated by the PTB (Physikalisch-Technische Bundesanstalt) - the German primary standards laboratory.
Beta sources; 90Sr/90Y, 85Kr and 147Pm
Our automated neutron exposure facility greatly enhances efficiency and a same day test and calibration service is possible by prior arrangement.
The instrument or dosemeter under test is positioned on a remotely operated trolley mounted on a tracking system; the source to monitor distance is changed to increase or decrease the dose rate. All tests undertaken satisfy regulatory requirements and are performed in accordance with the relevant good practice guides, such as GPG 14.
The calibration of the 241Am(Be) neutron source is directly traceable to the UK primary standard at the National Physical Laboratory. In addition to neutron monitor testing, special equipment has been designed for the large volume irradiation of both passive and active personal dose meters, e.g.: PADC and EPD.
Neutron sources: 241Am(Be) and 252Cf
In addition to the above facilities, we also hold a wide range of extended area and point sources contamination standards, for Alpha, Beta and Electron-capture radionuclides, specifically for the testing of contamination monitoring instruments.
Our sources are used in conjunction with precision engineered jigs to ensure consistent geometry and include:
90Sr/90Y Extended area and point sources
36Cl Extended area and point source
60Co Extended area source
147Pm Extended area sources
14C Extended area and point sources
125I Extended area sources (129I with filter)
55Fe Extended area source
241Am Extended area and point sources
238Pu Extended area sources
Since 1981 the Radon Group of Public Health England (UKHSA) has operated a radon exposure facility for calibration and research purposes. Radon gas concentrations are measured using instruments with calibrations traceable to the UK National Physical Laboratory and PTB, Germany.
The primary facility is a 43 m3 walk-in chamber accessed by an airlock. Radon gas is maintained at a level in this chamber that is high enough to allow exposures to be completed in a relatively short period of a few days whilst allowing staff reasonable access to carry out work.
The chamber is suitable for a wide variety of radon detectors and instruments. UKHSA staff have experience with most types in current use. The chamber has also been used to test other types of equipment, such as determining the radon response of actinide in air contamination monitors and etched-track neutron dosemeters.
Whilst most calibrations will be carried out by UKHSA staff, it is also possible for customers to hire the chamber by the day in order to carry out work or calibrate instruments. UKHSA staff monitor, control and report the conditions in the radon chamber.
UKHSA also carries out an annual intercomparison of passive radon detectors using the radon chamber, which is open to anyone wishing to participate.
A secondary facility, the Fast Radon Exposure Device (FRED) is also available. This facility has a very high radon concentration suitable for carrying out radon exposures in a short time interval or for giving high exposures to detectors for such purposes as determining linearity of response. This facility is much smaller than the radon chamber and can only be used for small numbers of detectors. It is not suitable for most active instruments.
Typical radon concentration: 2,000-8,000 Bq m-3
Volume: 43 m3
Monitored continuously: radon gas, temperature, humidity, barometric pressure
Additional variables available for monitoring: decay products, working level, equilibrium factor, ambient aerosol
Controllable parameters: radon gas concentration, equilibrium factor (F), aerosol concentration
Uncertainties (95% CL):radon gas 10%, decay products, working level, equilibrium factor 20%
Fast Radon Exposure Device (FRED) details
Typical radon concentration:40-70 kBq m-3Standard services offered by the Radon Dosimetry Team
Passive CalibrationsUKHSA operate two environmental chambers. These can simulate various environmental conditions by accurately controlling the temperature and humidity within the chamber. Our largest chamber is traceable via a UKAS calibration.
Temperature range: -40˚C to +180˚C, ±0.5˚C
Humidity range: 10% RH to 98% RH, ±3% RH
Internal volume: 335 litres
Internal size: 540mm x 750mm x 765mm (W x H x D)
Cable ports: 1x 50mm diameter and 1x 125mm diameter