The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 21, 1994
Filed:
Jan. 15, 1993
David H Roarty, Murrysville, PA (US);
David A Eden, Manchester, GB;
Westinghouse Electric Corporation, Pittsburgh, PA (US);
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 surface as a function of the electrochemical activity.