Tag Archive for: BWR

News & View, Volume 45 | Interval Relief from RPV Threads in Flange Examination Requirements

News & Views, Volume 45 | Interval Relief from RPV Threads in Flange Examination Requirements

By:  Scott Chesworth

News & View, Volume 45 | Interval Relief from RPV Threads in Flange Examination RequirementsASME Code Section XI requires that the RPV Threads in Flange component (Category B-G-1, Item Number B6.40, see Figure 1) be inspected each inspection Interval using volumetric examination.  However, there is general agreement that the inspection does not contribute to the overall safety of the RPV.  Industry experience indicates that these examinations have not been identifying service-induced degradation and that they have negative impacts on worker exposure, personnel safety, and outage critical path time.  Savings from the elimination of this inspection can be applied to other more meaningful inspections of other more risk-significant plant components.

EPRI Report 3002007626 (March 2016) provides the basis for eliminating the RPV Threads in Flange examination requirement.  This report includes the results of an industry survey in which 168 units provided the status of their RPV Threads in Flange examination, as well as insight into the impacts of conducting these examinations.

READ MORE