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Information Notice No. 88-70: Check Valve Inservice Testing Program Deficiencies
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION WASHINGTON, D.C. 20555 August 29, 1988 Information Notice No. 88-70: CHECK VALVE INSERVICE TESTING PROGRAM DEFICIENCIES Addressees: All holders of operating licenses or construction permits for nuclear power reactors. Purpose: This information notice is being provided to alert addressees to potential problems uncovered by recent inspections of the check valve inservice testing (IST) programs at Wm. B. McGuire Nuclear Station, Units 1 and 2 (McGuire), Zion Nuclear Plant, Units 1 and 2 (Zion), and R. E. Ginna Nuclear Power Plant (Ginna). It is expected that recipients will review the information for applicability to their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice do not constitute NRC requirements; therefore, no specific action or written response is required. Background: During November 30 to December 11, 1987, and January 4 to 8, 1988, a diagnostic inspection was performed at McGuire by a team led by personnel from the Office for Analysis and Evaluation of Operational Data. The major inspection findings pertaining to check valves were as follows: (1) Check valves located in the steam supply line to the turbine-driven auxiliary feedwater (AFW) pump were not included in the McGuire IST program. (2) AFW system valves, which include both isolation and check valves used to isolate the three sources of non-safety-related water to the AFW system, were not included in the McGuire IST program. The non-safety-related water sources include the hot well, the AFW condensate storage tank, and the upper surge tanks. (3) No reverse-flow operability tests were being performed on check valves other than those valves used for containment isolation and reactor coolant system pressure boundary isolation. This omission 8808230112 . IN 88-70 August 29, 1988 Page 2 of 4 disregards Section XI of the ASME Boiler and Pressure Vessel Code (ASME code), which requires testing in the open or closed position (or both), as necessary, to verify the valve's safety function. Consequently, undetected check valve failures could have existed because of the lack of testing. From September 14 to 18, 1987, an inspection team performed a special check valve inspection at Zion. Many check valves in the AFW system, the component cooling water system, the chemical and volume control system, the diesel cooling water system, and the feedwater system were found to be not included in the IST program. Other major inspection findings were as follows: (1) Pressure isolation valves (PIVs) were not being adequately tested individually as required by an NRC confirmatory order issued February 29, 1980. (2) Valve testing did not ensure that all safety functions could be accomplished. (3) Test procedures did not result in valid tests of all valves listed as having been tested in accordance with the ASME code. (4) Valves failing leak-rate testing were not being repaired before re- start, contrary to commitments made in a June 11, 1987, response to Generic Letter 87-06, "Periodic Verification of Leak-Tight Integrity of Pressure Isolation Valves (PIVs)." This inspection was followed by a special safety inspection on PIVs at Zion, which was performed between September 21 and October 26, 1987. Major in- spection findings were as follows: (1) Zion procedures did not provide adequate leak tests for certain check valves in the safety injection system. (2) Test procedures failed, in some cases, to provide a viable means to determine the actual leak rate. In other cases, a viable means existed, but the licensee failed to calibrate the measuring in- struments. (3) Leaking valves had been left unrepaired since mid-1986. As a result of this inspection, the NRC issued a Level III violation to the Commonwealth Edison Company on January 4, 1988. From May 16 to 20, 1988, an inspection team performed a special announced inspection on the IST activities at Ginna. The major inspection findings pertaining to check valves were as follows: . IN 88-70 August 29, 1988 Page 3 of 4 (1) Certain check valves in the main feedwater (MFW) system and in the turbine-driven AFW pump steam supply lines were not included in the Ginna IST program. (2) A check valve in the steam supply line to the turbine-driven AFW pump was found by the inspection team to have serious binding and to be in need of repair. If this valve had been undergoing full-stroke exercising and reverse-flow closure testing, this failure would not have gone undetected. (3) Numerous check valves in the service water system, the containment spray line, the residual heat removal system, the safety injection (SI) system, and the SI accumulator discharge line were not being full-stroke exercised. (4) Certain check valves in these systems were not being tested for reverse-flow closure capability in accordance with the ASME code requirements. As a result of this inspection, the NRC issued a Level III violation to the Rochester Gas and Electric Company on July 27, 1988. Similar problems were also discovered at the San Onofre Nuclear Generating Station Unit 1 (SONGS 1) when a serious water hammer occurred on November 21, 1985 in the MFW system. This water hammer event occurred after a reactor trip because of injection of auxiliary feedwater into a main feedwater line that had partially drained through multiple inoperable check valves. Information Notice 86-01, "Failure of Main Feedwater Check Valves Causes Loss of Feedwater System Integrity and Water-Hammer Damage," was issued to call attention to this incident. Discussion: The common findings from these inspections are as follows: (1) Not all safety-related check valves have been identified and included in the IST programs. (2) When check valves are included in the program, the valves are not always tested in a way that verifies their ability to perform their safety-related functions. These findings point out the importance of verifying the completeness of the list of components included in IST programs and of ensuring the adequacy of the actual testing being performed when developing an IST program. Not taking these two factors into account could result in undetected serious degradation of components, as happened at SONGS 1 and Ginna. The incident at SONGS 1 is an example of the possible consequences of such degradation. . IN 88-70 August 29, 1988 Page 4 of 4 No specific action or written response is required by this information notice. If you have any questions about this matter, please contact the technical contact listed below or the Regional Administrator of the appropriate regional office. Charles E. Rossi, Director Division of Operational Events Assessment Office of Nuclear Reactor Regulation Technical Contact: Horace K. Shaw, NRR (301) 492-0906 Attachment: List of Recently Issued NRC Information Notices . Attachment IN 88-70 August 29, 1988 Page 1 of 1 LIST OF RECENTLY ISSUED NRC INFORMATION NOTICES _____________________________________________________________________________ Information Date of Notice No._____Subject_______________________Issuance_______Issued to________ 88-69 Movable Contact Finger 8/19/88 All holders of OLs Binding in HFA Relays or CPs for nuclear Manufactured by General power reactors. Electric (GE) 88-48, Licensee Report of Defective 8/24/88 All holders of OLs Supplement 1 Refurbished Valves or CPs for nuclear power reactors. 88-68 Setpoint Testing of Pres- 8/22/88 All holders of OLs surizer Safety Valves with or CPs for nuclear Filled Loop Seals Using power reactors. Hydraulic Assist Devices 88-67 PWR Auxiliary Feedwater Pump 8/22/88 All holders of OLs Turbine Overspeed Trip or CPs for nuclear Failure power reactors. 88-66 Industrial Radiography 8/22/88 All NRC industrial Inspection and Enforcement radiography licensees. 88-65 Inadvertent Drainages of 8/18/88 All holders of OLs Spent Fuel Pools or CPs for nuclear power reactors and fuel storage facilities. 88-64 Reporting Fires in Nuclear 8/18/88 All holders of OLs Process Systems at Nuclear or CPs for nuclear Power Plants power reactors. 88-63 High Radiation Hazards 8/15/88 All holders of OLs from Irradiated Incore or CPs for nuclear Detectors and Cables power reactors, research reactors and test reactors. 88-62 Recent Findings Concerning 8/12/88 All holders of NRC Implementation of Quality quality assurance Assurance Programs by program approval Suppliers of Transport for radioactive Packages material packages. _____________________________________________________________________________ OL = Operating License CP = Construction Permit .
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