Overview of the Hanford Lead Canister - 22340

The Hanford site is preparing to place cesium and strontium material in a dry storage canister system that is similar in design to spent nuclear fuel dry storage systems. The system includes a welded stainless steel canister inside a vertical concrete overpack. As part of the site's aging management plan, a spare canister system will be deployed with heaters inside to accurately simulate the environmental conditions experienced by units containing radioactive material. The heated unit is intended to act as a leading indicator of canister degradation as the nuclear material sits in dry storage for potentially many decades. The Hanford Lead Canister is intended to offer the site an early warning of canister degradation. Regular inspection of the Hanford Lead Canister and data collection is expected to benefit the site by reducing the need for inspections of the canisters containing radioactive material. A second use of the Hanford Lead Canister is as an accessible facility for research and development efforts related to canisters. The similarity in design and function between the Hanford canisters and spent nuclear fuel canisters makes it an opportunity to collect data that is relevant to spent nuclear fuel storage (such as temperatures, particle deposition rates, etc.) and to demonstrate technologies (such as nondestructive evaluation tools, repair or mitigation processes, etc.) that could assist the long-term storage of spent nuclear fuel. This paper provides a technical overview of the Hanford Lead Canister, describes the current state of its development, and discusses the plans for long-term operation and data collection. Thermal analysis of the Hanford cesium and strontium canister systems is presented that compares the system to SNF canister dry storage systems. Heater units were designed to simulate the decay heat from the cesium and strontium capsules. Thermal modeling was conducted to ensure the electrical heater units can produce a similar temperature distribution to what is expected within a cesium and strontium capsule storage system. A detailed computational fluid dynamics model of the Hanford Lead Canister was constructed using the commercial software STAR-CCM+. The detailed computational fluid dynamics model included the stainless steel canister within the concrete overpack, and explicitly modeled the parts that make up the heater assembly, including the carrier tube, heater rod tape, and sleeve tube. Temperature results for the Hanford Lead Canister thermal model compares well with the baseline cesium and strontium canister thermal model, with very similar canister temperature profiles between the two models. Thermal modeling indicates that the heater units provide prototypic canister temperatures. (authors)