Dose Rates and Lead Shielding for Different Radionuclides

The following table provides the dose rates (in mSv/h) at 1 meter per TBq for different radionuclides, and the corresponding thickness of lead shielding (in cm) required to reduce the dose rate to 1 μSv/h.

Gamma Radiation Abundance and Energy

Radionuclide 99mTc 111In 18F 124I
Dose Rate (mSv/h) at 1m per TBq 18 81 135 117
Thickness of Lead Shield (cm) for 1 μSv/h at TBq 0.28 1.0 5.8 20
1.0 TBq 0.36 1.3 7.1 22
10.0 TBq 0.43 1.6 8.5 27