PIPING CONDITION HOLDS A KEY TO POWER PLANT LIFE EXPECTANCY.

Standards, inspections, maintenance and retrofits dominate today's world of piping. The high level of pipe system awareness may have been stimulated initially by some recent scattered failures of reheat piping. This, combined with the urge to extend power plant operating life, has stimulated considerable activity in several quarters. Service organizations and suppliers plan to spend more time in analysis of systems. This will include nondestructive evaluation (NDE) to study welds and the pipe thinning phenomenon that has caused some problems at older plants. In restoration, intergranular stress corrosion cracking (IGSCC) has been a problem in some of the older boiling water reactors (BWR), such as the Mark I design. In that case, there are recirculation piping replacement programs at various plants using 316 stainless steel piping that mitigates IGSCC. Also, new piping materials are being developed and tested, such as 6% molybdenum stainless steel alloys for containment cooling piping and the Sea-Cure alloy (27. 5% chromium, 3. 4% molybdenum, 1. 7 nickel, 0. 5% titanium) for use in power plant condenser tubing. Refs.