Experience from the extension and licensing of the Swedish central interim storage facility for spent fuel

Since the operation start of CLAB in 1985, 3 880 tonnes of spent fuel has been stored at CLAB. Spent fuel together with radioactive components, stored at CLAB, occupies 92% of the storage pools. The plan for sending spent fuel to CLAB during the next years indicates that CLAB will be full at the end of 2003. In order to meet the coming supply from the NPPs, the CLAB capacity will be extended from 5 000 to 8 000 tonnes of spent fuel. The project to build storage pools in connection with already existing storage pools began in 1999. The first step was to excavate the rock in parallel with the existing storage pool area at a distance of approximately 40 m. During this time, the existing CLAB was measured to detect vibration that could harm. The excavation was done with help of explosives. After the excavation was finished in the beginning of 2001, the building of the storage pools and other concrete structures began. At the beginning of the building period, a group of skilled people from both the project and the operation of CLAB were formed in order to detect and analyse potential risks that could jeopardise the integrity of CLAB. The building of the concrete structure is planned to be accomplished in the beginning of 2004. In parallel with the building of the concrete structure, the upgrading of the systems in operation, which also should serve the new storage pools, began and continues until the new storage pools are connected. This upgrading of the existing system demands a thorough planning to not violate the operation condition set by the regulatory body. Approximately 6 month before operation of the extended CLAB, no spent fuel or radioactive material will be received, though this time will be used to test all systems and to show the regulatory body that the extended CLAB meets all regulatory demands. From the start, the regulatory body through inspections and meetings has followed the project very close. Some experience from the interaction with the regulatory body is: (1) the regulator should be active very early; (2) an open and regular dialogue with the regulator to discuss regulatory requirements and review findings; (3) regular meetings between the regulator, operator and the operator's contractors; and (4) on site inspections.