TN®MW: a family of triple purpose casks for HLA waste
Compact shielded casks for a dual and triple purpose (transport-storage-disposal) solution dedicated to Medium and High Level activated waste with possible fissile material.
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During the operational phase of a nuclear facility or when preparing for its decommissioning, one has to consider a large diversity of nuclear waste in term of types, volumes and activities. These range from High-Level Waste to Low Level Waste with different nature, such as fissile waste, activated fuel structures, metallic structures, in-core instrumentation, contaminated equipment, sludge, resins, liquids…
Operators frequently face the obligation to undertake multiple handling, reconditioning or re-transfer operations from one package to another, for example when moving from on-site storage to transportation or from transportation to final disposal. Moreover, they have too often to select a different packaging solution for each different waste type, or even more to develop the packaging solution. This is also induced by the variety of administrative requirements (transport regulations, site safety requirements) that can be very different from one waste type to another.
Operators are increasingly expressing their concerns about the complexity, cost and sub-optimization of their waste management strategies.
Orano NPS has developed a new cask family, the TN®MW (MW for Multi Waste), answering to transport regulations with a total weight of 10 MT.The TN®MW is a new cask system developed as a “Triple Purpose Solution” dedicated not only to waste packaging and transportation (on-site transfer or public transportation) but also to long-term interim storage and final disposal.This flexible solution is applicable for both wet and dry loading/unloading and accommodates to various waste types, with or without conditioning:• metallic activated waste,• legacy waste,• sludge, resins, and ‘radiolysable’ materials,• fissile materials (uranium residues, research-reactor spent fuel...),• waste from reprocessing.TN®MW short version: Transport - Long term interim storage - Up to Final disposal- IP2 / A / B(U) / B(U)F and multimodal transportations Volume of cavity up to 1 m3
- Maximum activity 300 TBq Co-60
- Maximum payload 2 MT (4 409 lbs)
- Bulk loading or waste conditioned in drum Wet or dry operations
- Transportable in a ISO 20’ container
The concept of the TN®MW family takes into account Orano NPS’s know-how acquired through the licensing and manufacturing of more than 150 heavy casks.The manufacturing, licensing and delivery of the first TN®MW took place in 2017 for a fissile content (uranium residues conditioned in cans).
The total duration of the project (including design, licensing and manufacturing of 2 casks) was only 2 years. The transport certificate was delivered by both French and Belgium Competent Authorities. Main challenge was the reduced time Schedule for licensing: Orano NPS succeeded in it by designing a robust cask (with high safety margin) without the need to perform drop test with scale model, as the design is based on proven high resistance material and benchmarked products and technologies.
Two additional casks were delivered in 2018, one year after the order. The first transport successfully took place in 2019.TN®MW: the best combination between waste form and waste container:
- simplification,
- rationalization,
- standardization.
- High benefit: minimize costs for future package development & manufacturing, as well as avoid extra handling because of transferring the waste package in the future.
- Moreover this approach pushes for a forward-looking vision and package standardization as much as possible: another source of cost savings.
We guaranty the leaktightness of the cask thanks to its forged steel material and metallic gaskets. Forged Stainless steel provides more safety for long term storage (Corrosion resistance) against cast iron. It also offers a better shielding compared with cast iron at equivalent thickness. Metallic gaskets, which guaranty and control the leaktightness of the cask, are qualified for at least 40 years.
We have already licensed the cask in France and in Belgium for fissile content as B(U) package: Specifically developed for transport and storage of irradiated uranium residue equipped with special boron basket (fissile material).
The triple purpose means that the cask answers to three functions: transport, store and dispose waste.
