The Ionising Radiations Regulations 2017 No. 1075

SCHEDULE 7 Quantities and concentrations of radionuclides

Regulations 2(1) and 2(4)

PART 4 Table of quantities of radioactive material defining high-activity sealed sources

For radionuclides not listed in the table below, the relevant quantity value is the same as the D-value defined in section 2 Table 1 of the IAEA publication: Dangerous quantities of radioactive material (D-values), (EPR-D-VALUES 2006)

Radionuclide	Quantity (Bq)
(*) The activity given is that of the alpha-emitting radionuclide.
Co-60	3 × 1010
Se-75	2 × 1011
Sr-90 (Y-90)	1 × 1012
Cs-137	1 × 1011
Pm-147	4 × 1013
Gd-153	1 × 1012
Tm-170	2 × 1013
Yb-169	3 × 1011
Ir-192	8 × 1010
Ra-226	4 × 1010
Pu-238	6 × 1010
Pu-239/Be-9(*)	6 × 1010
Am-241	6 × 1010
Am-241/Be-9(*)	6 × 1010
Cm-244	5 × 1010
Cf-252	2 × 1010