Containment Shell or Liner Moisture Barrier Inspection

The U.S. Nuclear Regulatory Commission (NRC) is seeking public comment on a draft regulatory issue summary (RIS) to reiterate the NRC staff's position in regard to American Society of Mechanical Engineers (ASME) code-required inservice inspection requirements for moisture barriers. The NRC's regulations require, in part, that licensees implement the inservice inspection program for pressure retaining components and their integral attachments of metal containments and metallic liners of concrete containments in accordance with the ASME Code. If a material prevents moisture from contacting inaccessible areas of the containment shell or liner, especially if the material is being relied upon in lieu of augmented examinations of a susceptible location, the material must be inspected as a moisture barrier. The applicable ASME Code sections require licensees to inspect 100 percent of accessible moisture barriers during each inspection period.