Recirculating pump seal investigation. Volume 2. Technical planning study TPS-76-626. Final report

A review of the BWR recirculation pump seals was conducted as the first step in the possible development of a new pump seal with improved sealing capability and service life. The first task of this study was the identification of the major seal failure mechanisms. A new seal specification was written. Existing seal designs were then investigated. The fourth task was the conception of a combination seal based on results of the three previous tasks. Unknown causes were the leading reasons for seal replacement, followed by crud in the seal, incorrect manufacturing, and design errors. The seal specification established design goals for a low leakage, long life dynamic recirculation pump seal. Existing seal designs including the present face seal configurations, ferrofluidic, visco, hydrostatic face, hydrodynamic face, and bushing seals, were investigated in the third task. The hydrodynamic spiral groove face seal was judged to be the best replacement for the present face seal design