The possibility of a sudden and complete rupture of large diameter piping in nuclear power plants represents a serious concern because of its impact upon the public and the severe and costly damage which could result in the reactor buildings and equipment. Ontario Hydro employs the leak-before-break (LBB) approach to demonstrate that sudden, catastrophic failure of critical nuclear heat transport piping will not occur. The concept relies on the application of elastic-plastic fracture mechanics and the concept that pipe deterioration would be progressive, not a sudden occurrence. This report describes an extensive experimental leak rate testing program which supports analytical efforts regarding use of the LBB concept. It presents details of the test fixture and measurement techniques, some experimental leak rate results, and a comparison between experimental results and a leak rate predictive computer model.

This is a state-of-the-art report on Exhaust Air Heat RecoveryHeat Pump (EAHRHP) devices primarily for residential andcommercial use. These devices provide mechanical ventilation tocontrol humidity and improve indoor air quality, while recoveringa large part of the exhaust air energy and returning it to theliving space.

This report documents a comprehensive laboratory program which involved the development of a measurement system for the on-line investigation of stress/vibration degradation mechanisms in steam generator tubes. Past Bruce Nuclear Generating Station A steam generator tube failures, prompted this development so that future problems could be measured. The report presents the results of 3 interrelated investigations.