Design for Safeguards of System for Transfer of Spent Nuclear Fuel Assembly from Containment to Storage Building

摘要

The spent nuclear fuel assembly transfer process from the containment building to the fuel storage building is complicated and has several important constraints. Continuity of Knowledge (COK) must be maintained throughout the process while also keeping the fuel assembly underwater and away from workers to assure safety (radiation shielding) and security (accountability in the transport system). A reference system was developed by an amalgamation of several key design features from currently deployed systems. The reference system involves a process of transitioning the fuel assembly from a vertical orientation to a horizontal orientation and then transporting the individual fuel assembly with an underwater tunnel between the two buildings. Once the fuel assembly has arrived in the fuel storage pool, it must then be upended back into a vertical orientation and then transferred to its storage slot in the spent fuel storage pool. Many mechanical systems are involved in the entire process which is mostly manual.Because, the conveyance is mechanical in nature, it must provide for worker safety and easy access for repair/maintenance. Reliability, safety, and safeguards requirements and regulations must be met for the entire expected life span of the nuclear facility.In this work, we have analyzed the reference fuel transfer system and have developed a new engineering design system for safeguards and enhanced safety and reliability for transfer of spent fuel assemblies from the reactor building to the fuel storage building. A physical scaled prototype of the transport system has been manufactured has been tested for functional non-nuclear testing for mechanical performance.The goal of this project was not to design a new transfer system per se, we were using this as a vehicle to teach nuclear safeguards in a way that could be applicable to a nuclear engineering design topic. While there are aspects of this design that could be incorporated into future fuel transfer systems, it was never our intention to rectify "deficiencies". Including a way to have detectors onboard during travel or just leaving space for future equipment is normally a positive for nuclear safeguards.