3AParent nuclides and progeny nuclides included in secular equilibrium

#### 3A Parent nuclides and progeny nuclides included in secular equilibrium (1) For these regulations, in determining the activity of a parent nuclide mentioned in an item in the table in clause 3 of Schedule 2, include the activity of any progeny nuclide mentioned in that item that is included in secular equilibrium with the parent nuclide. > Note: Parent nuclides are also marked a in the table in clause 2 of Schedule 2. (2) Except for subregulation (1), the activity of a progeny nuclide mentioned in an item in the table in clause 3 of Schedule 2 is taken to be nil when included in secular equilibrium with a parent nuclide mentioned in that item.