Electrochemical monitoring of vessel penetrations
US5323429A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 1993 |
| Grant date | Jun 21, 1994 |
| Priority date | — |
| Expiry date | Jan 15, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E30/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Stress-corrosion damage is monitored in penetrations traversing the wall of a vessel containing an electrolyte, such as a nuclear reactor pressure vessel containing a coolant. The vessel wall has tubular penetrations for coupling external devices to internal structures of the vessel while maintaining a pressure barrier, such as control rod guides and sensor signal cables. The penetrations are subject to stress-corrosion damage, especially adjacent welds affixing the tubes to the vessel head. One or more of the penetrations is provided with a probe forming with the tube an electrochemical sensor cell, including an electrode exposed to the electrolyte together with the surface of the penetration. The electrode and the surface are otherwise insulated, and a plurality of electrodes can be arrayed for monitoring distinct localized areas. The electrodes are wired to a detector circuit developing signals as a function of electrochemical activity due to stress and corrosion, indicative of corrosion of all the penetrations. Electrochemical potential, impedance, current, and particularly noise levels in these signals are detected and read out for assessing deterioration of the penetration su…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.