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
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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:
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(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.
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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
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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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