Division 3 Performance characteristics and methods of analysis
United Kingdom
For the following parameters and radionuclides, the method of analysis used must, as a minimum, be capable of measuring activity concentrations with a limit of detection specified below:
| Note 1: The limit of detection shall be calculated according to the ISO standard 11929: Determination of the characteristic limits (decision threshold, detection limit and limits of the confidence interval) for measurements of ionising radiation — Fundamentals and application, with probabilities of errors of 1st and 2nd kind of 0,05 each. | ||
| Note 2: Measurement uncertainties shall be calculated and reported as complete standard uncertainties, or as expanded standard uncertainties with an expansion factor of 1,96, according to the ISO Guide for the Expression of Uncertainty in Measurement. | ||
| Note 3: The limit of detection for tritium and for radon is 10 % of its parametric value of 100 Bq/l. | ||
| Note 4: The limit of detection for gross alpha activity and gross beta activities are 40 % of the screening values of 0,1 and 1,0 Bq/l respectively. | ||
| Note 5: This limit of detection applies only to initial screening for ID for a new water source; if initial checking indicates that it is not plausible that Ra-228 exceeds 20 % of the derived concentration, the limit of detection may be increased to 0,08 Bq/l for routine Ra-228 nuclide specific measurements, until a subsequent re-check is required. | ||
| Parameters and radionuclides | Limit of detection (Notes 1, 2) | Notes |
|---|---|---|
| Tritium | 10 Bq/l | Note 3 |
| Radon | 10 Bq/l | Note 3 |
| gross alpha activity | 0,04 Bq/l | Note 4 |
| gross beta activity | 0,4 Bq/l | Note 4 |
| U-238 | 0,02 Bq/l | |
| U-234 | 0,02 Bq/l | |
| Ra-226 | 0,04 Bq/l | |
| Ra-228 | 0,02 Bq/l | Note 5 |
| Pb-210 | 0,02 Bq/l | |
| Po-210 | 0,01 Bq/l | |
| C-14 | 20 Bq/l | |
| Sr-90 | 0,4 Bq/l | |
| Pu-239/Pu-240 | 0,04 Bq/l | |
| Am-241 | 0,06 Bq/l | |
| Co-60 | 0,5 Bq/l | |
| Cs-134 | 0,5 Bq/l | |
| Cs-137 | 0,5 Bq/l | |
| I-131 | 0,5 Bq/l | |