NRC 10 CFR § 71.43 & 49 CFR § 173.441 COMPLIANCE MODEL

Type B Cask Shielding & Thermal Calculator

Simulate gamma shielding attenuation, surface dose rates, decay heat thermal equilibrium, and maximum accessible skin temperatures (185°F exclusive use) for certified Type B transport casks.

01 Cask Architecture & Source Characteristics

02 Dose Attenuation & Thermal Equilibrium Profile

Cask Outer Surface Radiation Dose
14.2 mrem/hr (0.14 mSv/h)
< 200 mrem/hr
Dose Rate at 2 Meters (6.6 ft)
2.8 mrem/hr
Meets 10 mrem/hr Limit
Cask Accessible Skin Surface Temperature
148°F (64.4°C)
Below NRC 10 CFR § 71.43(g) exclusive use limit of 185°F (85°C) in shade.
Hypothetical Accident Condition (HAC) Margin
STRUCTURAL INTEGRITY RETAINED (30-FT DROP & 1,475°F FIRE)
Depleted uranium / lead containment geometry modeled within certified safety envelopes.
Governed by NRC 10 CFR Part 71 (Packaging and Transportation of Radioactive Material) and IAEA Safety Standards SSR-6.
01

Gamma Half-Value Layer (HVL)

Radiation transmission decreases exponentially: I = I₀ · (0.5)^(x / HVL). Depleted uranium provides superior attenuation (HVL ≈ 0.28 in for 1.25 MeV gammas), reducing cask weight while maintaining regulatory dose thresholds.

02

Decay Heat & Thermal Equilibrium

Radioactive payload emits continuous decay thermal energy. Under 10 CFR § 71.43, a package in exclusive use transport cannot exceed 185°F (85°C) on any accessible surface when operating in 100°F still air without solar insolation.

03

In-Cab Exposure Limits (2 mrem/hr)

In addition to outer cask dose rates, 49 CFR § 173.441 mandates that radiation levels in any normally occupied space of the truck tractor cab cannot exceed 2.0 mrem/hr (0.02 mSv/h). Exspeedite validates tractor sleeper berth geometry before dispatch.

Equip Specialized Nuclear Cask Fleets with Exspeedite Heavy Haul TMS

Manage heavy dual-axle transporter tare weights, NRC Certificate of Compliance (CoC) renewal dates, and pre-trip radiation survey documentation directly in your operations center.