nuclear-news

Japanese (Toshiba) owned Westinghouse announced (26-May-2016) completion of a cold hydrostatic pressure test for Sanmen Nuclear Power Unit 1 (AP 1000) in China. The reactor unit is more than three years behind schedule, and has been under construction for over 8 years.

The test showed that welds held at a pressure of 3,107 psig (21.4 MPa) for a whole 10 minutes didn’t appear to leak. This was apparently not at operating temperatures, so is not reflective of the real system stresses. The entire test was completed within 4 hours.

Compare to the California Code which says 30 minutes “without leakage, undue distortion, excessive permanent expansion or evidence of impending failure“. The Westinghouse press release merely says that “Inspection of the more than 1800 welds found no leaks“.

This 10 minutes of maximum pressure was around 1.48 times the operating pressure for the AP 1000 reactor. 1.5…