NPO worked closely with AVANTech in designing a set of three shielded casks that reduced dose from 26,000-30,000 mRem/hr (260,000-300,000 μSv/hr) to less than 60 mRem/hr (600 μSv/hr) on contact. Two casks were utilized with one as a spare. Each shielded cask housed one of their Solids Collection Filter canisters for torus water/sludge filtration at Fermi. To achieve their goals, it needed to provide quite a bit of shielding during this process and also required a specialized lid that would allow for an inlet and outlet manifold piping assembly to the canister lid as well as the ability to insert a radiation detection probe. Because of the plant safe lift requirements, the cask lifting lugs were designed and verified by a professional engineer to have a 11.5:1 factor of safety and loaded tested per ASME B30.20. Three total casks were delivered to AVANTech for Fermi’s outage and they were able to successfully meet their dose reduction goals.
- Stainless steel cask filled on all sides with 3.5” (89 mm) of solid lead to provide a better than 99.8% dose reduction for Co-60
- Stores an AVANTech SCFT-005 radwaste solids collection filter canister
- Split lid allows for shielding on one half while nozzles are being connected/disconnected to/from the filter canister
- Plugs for the holes on top of the lid keep workers shielded as the nozzles are detached
- 11.5:1 factor of safety when lifted, Loaded tested per ASME B30.20
- 7,500 lb (3402 kg) total weight
- Reduced dose from 26,000-30,000 mRem/hr (260,000-300,000 μSv/hr) to less than 60 mRem/hr (600 μSv/hr) on contact
- The design allows to the lid to be locked to the body of the shield to prevent access
