The terms used in these Regulations are defined as follows:1. Naturally Occurring Radioactive Materials (NORM): naturally occurring radioactive materials (NORM) generally contain radionuclides such as uranium, thorium & kalium found in nature or after disintegrations. The nuclear source material or nuclear fuels are excluded. 2. Activity: refers to the number of spontaneous disintegrations occurring in a certain amount of radionuclides at a given time.3. Specific activity: activity per unit mass.4. Specific activity index: referred to the summation of the ratio of specific activity to its standard level for each radionuclide contained in the Waste containing Naturally Occurring Radioactive Materials (hereinafter referred as “ NORM Waste”). The mathematical formula shall be in accord with the appendix table. 5. Clean-up: the clearance, bury and release of NORM Waste. 6. Site: referred to the building or land used for the treatment, storage and clean-up of NORM Waste.