The HSST V-7B intermediate test vessel was fabricated from 152-mm thick A533B, Class 1 steel. It was pressurized at 93°C (200°F) to 151 MPa (21 800 psig) where it failed at a flaw machined into the outer surface.

Acoustic emission (AE) generated during testing of the vessel was measured for two purposes: (1) to provide indications of distress in the vessel at locations other than the machined defect, and (2) to acquire AE data for analysis relevant to development of AE/flaw relationships for inservice reactor monitoring.

Two AE monitor systems, a Dunegan/Endevco (DE) 1032 and a Battelle Northwest (BNW) multiparameter, digital memory AE system, were used to more effectively meet the two requirements. Results and conclusions include:

∎ AE source location indications clearly followed flaw development.

∎ Growth of a flaw in 152-mm thick A533 B, Class 1 material at 93°C (200°F) produced readily detectable AE.

∎ Two separate AE monitor systems using substantially different approaches to isolating AE from the defect exhibited consistent results.

∎ AE data correlates well with stress intensity factor (K) and crack opening displacement (COD) showing a basis for relating AE to flaw severity in the pressure vessel configuration.