Development of the inventory database

The inventory database is the core of all decommissioning planning and costing activities. Thus, its development plays a key role in preparation of well-structured, understandable and defendable decommissioning plan and schedule.

In the nuclear decommissioning, the inventory database is also known as "Systems, Structures and Components" database, a.k.a SSC.

Database structure

For the purpose of planning and costing, the all three main groups of inventory items (systems, structures and components) can be put together into a single complex inventory database. Then, information about item of such database (an "inventory item") can be further split into following main areas:

• Uniqueness: Each inventory item must get its unique number for exact identification when used in planning or costing. The pattern for numbering is not set in the stone and can be different for various nuclear power plants.
• Physical parameters: Thy physical form of each inventory item must be described. This should include (at least) dimensions, material composition, mass, volume and quantity.
• Radiological parameters: For better accuracy of decommissioning plans and cost estimations, the radiological inventory of the item should be described. This may include the induced activity, inner or outer contamination or dose rate at a specified distance from the item (e.g., equipment or wall). Also the nuclide composition of the previously mentioned parameters should be available.

Storage

Most commonly used storage is a simple spreadsheet file. For its simplicity and variability, this storage type is very often unbeatable. However, the isolated files does not provide some extra functionality which can be achieved by another storage technologies, especially SQL database engines.

The costing module of the Aquila 3decom platform uses the SQL database (formerly known as AquilaCosting) engine and therefore provides full-featured access to the inventory database and ability to perform large-scale statistical and mathematical operations, enabling it to be used for comprehensive cost estimations even for large nuclear power plants.

3D models

Linking of the inventory database to the 3D model of the plant provides additional layer for storing, visualizing and processing the inventory database. Especially, visual browsing feature has very strong potential to replace traditional "spreadsheet based" browsing.

And, if the 3D model is integrated with a complex IT platform based on the SQL database, the full-featured planning and costing platform can be developed. Such solution simplifies many decommissioning planning activities, such as browsing through the complex inventory database, training of the personnel or estimating costs. The 3d-planner module provides exactly this set of features.