Paragraph 2 Screening for certain radionuclides or for an individual radionuclideF1
Where screening of the water is carried out for certain radionuclides or for an individual radionuclide, Scottish Water must carry out an analysis of additional radionuclides if, in relation to any supply referred to in paragraph 1—
one of the activity concentrations of a radionuclide referred to in the second column of the table below exceeds 20% of the corresponding derived concentration in the third column; or
the tritium concentration exceeds the prescribed concentration or value for tritium.
Scottish Water must, in deciding which radionuclides require to be measured for each supply, take into account all relevant information about likely sources of radioactivity.
| Origin | Radionuclide (Note 1) | Derived concentration (Bq/1) | Notes |
|---|---|---|---|
| Natural | U-238 | 3.0 | Note 2 |
| U-234 | 2.8 | Note 2 | |
| Ra-226 | 0.5 | ||
| Ra-228 | 0.2 | ||
| Pb-210 | 0.2 | ||
| Po-210 | 0.1 | ||
| Artificial | C-14 | 240 | |
| Sr-90 | 4.9 | ||
| Pu-239 / Pu-240 | 0.6 | ||
| Am-241 | 0.7 | ||
| Co-60 | 40 | ||
| Cs-134 | 7.2 | ||
| Cs-137 | 11 | ||
| I-131 | 6.2 | ||
| Note 1: This table includes values for the most common natural and artificial radionuclides. These are precise values, calculated for a dose of 0.1 mSv, an annual intake of 730 litres and using the dose coefficients laid down in Table (A) of Annex III to Council Directive 96/29/Euratom laying down basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionizing radiation. Derived concentrations for other radionuclides may be calculated on the same basis. | |||
| Note 2: This allows only for the radiological properties of uranium, not for its chemical toxicity. | |||
Annotations
Textual amendments
- F1
Sch. 1A inserted (27.10.2017) by The Public Water Supplies (Scotland) Amendment Regulations 2017 (S.S.I. 2017/281), reg. 1(1), sch. 1 (as amended by The Public and Private Water Supplies (Miscellaneous Amendments) (Scotland) Regulations 2017 (S.S.I. 2017/321), regs. 1, 3(2))