Nuclear Medicine Type A Pig Shielding Manual
Technical specification for medical isotope packaging: tungsten versus virgin lead syringe pigs, 511 keV annihilation radiation attenuation, DOT 7A drop test validation, and transport index (TI) classification.
01 Isotope Activity & Shielding Configuration
Surface Dose Rate & Transport Index (TI) Telemetry
RADIATION PHYSICSRadiopharmaceutical Shielding Dynamics & DOT Type A Packaging Physics
High-density tungsten alloys (18.5 g/cm³) provide identical attenuation to lead at roughly half the physical thickness. Tungsten pigs offer superior structural rigidity, resisting deformation during drop accidents.
For 511 keV positron annihilation photons (F-18), the HVL in lead is 4.1 mm (3.1 mm in tungsten). Every HVL of shielding cuts transmitted gamma flux by 50%. A 12 mm tungsten pig represents nearly 4 HVLs (93.75% attenuation).
Packages must endure a 4-foot free fall onto an unyielding concrete pad, a 1-hour heavy water spray test, and compressive stacking without loss of shielding or breach of internal containment.
| DOT RAM Label | Maximum Surface Dose Rate | Maximum 1-Meter Dose Rate (TI) | Vehicle Placarding Trigger |
|---|---|---|---|
| White-I | < 0.5 mrem/hr (0.005 mSv/hr) | 0 (Background Level) | No Placards Required |
| Yellow-II | 0.5 to 50.0 mrem/hr | ≤ 1.0 mrem/hr (TI ≤ 1.0) | No Placards Required |
| Yellow-III | 50.0 to 200.0 mrem/hr | > 1.0 to 10.0 mrem/hr (TI ≤ 10.0) | Mandatory Radioactive Placard |
| Yellow-III (Exclusive Use) | > 200.0 to 1,000 mrem/hr | > 10.0 mrem/hr (TI > 10.0) | Dedicated Transport Vehicle Only |
Request Type A Packaging Certification & Shielding Protocol
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