BWR RECIRCULATION INLET SAFE ENDS-A THREAT TO PLANT LIFE ANDSAFETY

AN ON-GOING THREAT TO THE RESIDUAL LIFETIME AND SAFETY OF BOILING WATER REACTORS (BWRS) IS INTERGRANULAR STRESS CORROSION CRACKING (IGSCC). A COMPONENT OF SPECIAL CONCERN IN THE RECIRCULATION INLET NOZZLE SAFE END (RINSE). FOR EXAMPLE, WITHIN THE LAST 2 YEARS 30 OUT OF 30 RINSES ARE KNOWN TO BE CRACKED AT A 3-UNIT BWR SITE AND IT IS BELIEVED THAT 20 OUT OF 20 RINSES ARE CRACKED AT A 2-UNIT BWR SITE. RESEARCH BY THE PROPOSER HAS LED TO THE CONCLUSION THAT THE RINSE IS DESIGNED AND BUILT IN SUCH A WAY THAT ITS LIFETIME IS LIMITED TO 10 YEARS. THIS INCLUDESTHE CURRENT STATE-OF-THE-ART DESIGN, REFERRED TO AS THE "TUNING FORK" DESIGN. REPAIRS AND/OR REPLACEMENTS OF RINSES USING CONVENTIONAL TECHNOLOGY (MSIP, IHSI, OR TUNING FORK) CAN GIVE A FALSE PERCEPTION OF SAFETY THAT CAN ACTUALLY INCREASE THE OVERALL RISK, NOT TO MENTION THE RESOURCES WASTED (MASSIVE OUTAGES AND ASSOCIATED COSTS). ASDISCUSSED IN THE PROPOSAL, MSIP, IHSI, OR ALTERNATIVE MATERIALS WILL NOT WORK ON RINSES. PHASE I OF THE PROPOSEDWORK WILL FURTHER DEFINE THE NATURE AND MAGNITUDE OF THE PROBLEM AND WILL CONCEPTUALIZE A REMEDY. PHASE II WILL VERIFY THE REMEDY AND THE MEANS TO IMPLEMENT IT. PHASE III WILL IMPLEMENT THE REMEDY.