The SIPPING16 system developed by Framatome ANP in Germany for detecting leaking fuel in BWR cores has now been deployed with great success at three German nuclear power plant units. Measurements of reactor coolant activity levels following the sipping tests at these plants verified that all fuel assemblies containing fuel leakers had been identified by SIPPING16, thus confirming the system’s excellent reliability. Customers have made a point of stressing how satisfied they are with the features of this innovative system.

At the twin-unit BWR plant Gundremmingen B and C, the SIPPING16 system supplied by Framatome ANP enabled all 784 fuel assemblies in each of the reactors to be inspected in just 16 hours – a world record for inspections of this kind. This short inspection time was made possible by the system’s sipping hood that allows up to 16 fuel assemblies to be tested simultaneously for leak-tightness in just one operation. The system also has been successfully deployed on two occasions at the Krümmel BWR plant with a core of 840 fuel assemblies.

Special Requirements for Different Core Configurations

Plants with core configurations similar to that of the German BWR unit Isar 1 can likewise use the SIPPING16 hood for sipping all of their fuel, with the exception of the 12 fuel assemblies located on the core periphery. These 12 are inspected using Framatome ANP’s MAST SIPPING technique, deployed until recently only in PWRs, that utilizes the same control and measuring equipment as the SIPPING16 system. A MAST SIPPING has now been qualified for use in BWR plants, too. BWR plant operators can leak-test all of their fuel assemblies, even in cores with different peripheral configurations using just one system: the SIPPING16 system with an integral MAST SIPPING module.

Market Prospects

SIPPING16, now a yardstick throughout the world in terms of minimized BWR fuel inspection times combined with maximum reliability, has attracted more new customers. Isar 1, for example, also wishes to benefit from these time savings during its 2003 refueling outage and has awarded Framatome ANP a corresponding contract.

The Japanese utility Tokyo Electric Power Company (TEPCO) has commissioned Framatome ANP to study the feasibility of deploying SIPPING16 in its ABWR plants. With its fleet of 17 units, TEPCO is the world’s largest operator of BWR nuclear power plants.

Sipping hood being disconnected from refueling platform mast after completion of sipping tests.

Benefits of SIPPING16:

• Significant savings in time and personnel due to reduction in inspection time from around 50 to 16 hours
• Inspection results are calculated on-line after degassing water samples removed from each fuel assembly inserted in a core. The results are available after each sipping hood placement
• Sipping tests can be carried out routinely from the refueling platform using a sipping hood for up to 16 fuel assemblies at a time
• Fully automatic system control, as well as on-line data acquisition and processing, reduce workload for inspection personnel
• By measuring water-soluble fission products contained in grap water samples, independent results from gas measurements are achievable. These samples are considered as a reference