FAID/SPAR field tests at KAHL. Final report

LWR fuel assemblies are convenient units for item accounting. Application of a fuel assembly seal which gives both integrity and a unique identity to the fuel assembly offers the potential of increased safeguards over present methods. This is particularly the case if the seal can be read at frequent intervals. The BWR Kahl reactor has been used to field evaluate FAID type ultrasonic seals. Twenty-four seals were applied to fresh fuel assemblies before their being placed in the reactor core. At convenient times when the reactor was shut down and the fuel moved to the spent fuel storage pool, the seal's identity and integrity were checked with a seal pattern reader (SPAR). After the reactor was decommissioned all seals were reidentified and their integrity checked. Five seals were removed from their fuel assemblies and embrittlement of the fracture link observed. Several seals were in the reactor core for three years.