United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 94-03: Deficiencies Identified During Service Water System Operational Performance Inspections

                                 UNITED STATES
                         NUCLEAR REGULATORY COMMISSION
                            WASHINGTON, D.C. 20555

                               January 11, 1994



All holders of operating licenses or construction permits for nuclear power


The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to alert the addressees to deficiencies identified by the NRC during
service water system operational performance inspections that were recently
performed.  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 are not NRC requirements; therefore, no specific action or written
response is required.

Description of Circumstances

Design and operational concerns associated with service water systems have
been identified in licensee event reports and during NRC inspection
activities.  To address these concerns, the NRC issued Generic Letter 89-13,
"Service Water System Problems Affecting Safety-Related Equipment," on
July 18, 1989.  This generic letter requested that licensees and applicants
perform actions to ensure that their service water systems are in compliance
with 10 CFR Part 50 (Appendix A, General Design Criteria 44, 45, and 46 and
Appendix B, Section XI).  The NRC conducted four workshops on Generic
Letter 89-13 and issued information developed from the transcripts of these
workshops as Supplement 1 to the generic letter on April 4, 1990.

Because problems continued to be experienced with service water systems, the
NRC developed the service water system operational performance inspection to
assess licensee actions in response to Generic Letter 89-13 and to evaluate
such aspects of the service water system as design, operations, maintenance,
surveillance/testing, and quality assurance/corrective actions.  These
inspections are performed in accordance with Temporary Instruction 2515/118,
Revision 1, "Service Water System Operational Performance Inspection
(SWSOPI)," contained in the NRC Inspection Manual.  As indicated in the
temporary instruction, these inspections will generally be conducted at plants
licensed before 1979, as well as at newer plants that are perceived to have
service water system problems or more general maintenance, engineering, and
technical support problems.


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During the initial seven service water system operational performance
inspections, deficiencies and weaknesses were found in the evaluation of heat
transfer requirements and in the development of testing programs and
procedures.  In addition, the results of these inspections indicated that, in
general, licensees have not taken all actions requested by Generic
Letter 89-13 in a completely effective manner.

Some examples of the deficiencies and weaknesses that were identified during
the initial inspections are summarized in this section.

(1)  Evaluation of Heat Transfer Requirements

     The findings in this area pertain to inadequacies in analyses of the heat
     loads to be removed by the service water systems, evaluations of the
     performance of the heat exchangers and room coolers, and verification of
     hydraulic analyses.  For example, the following deficiencies were

     o  The calculated heat load in a compartment containing safety-related
        pumps exceeded the rated room cooler capacity.  Also, initial
        calculations failed to include heat loads from auxiliary motors
        located in the compartment.  During the inspection, the licensee
        performed a new calculation and determined that equilibrium room
        temperature would be higher than the existing analyzed temperature in
        the compartment.  Additional evaluations were performed to verify that
        the electrical equipment in these areas could operate at the higher
        room temperature.  (Quad Cities)

     o  A calculation to demonstrate the heat removal capacity of a safety-
        related room cooler failed to consider that the actual flow through
        the room cooler was less than design flow.  (Monticello)

(2)  Testing Programs and Procedures

     The findings in this area are related to failure to include safety-
     related service water system valves in the inservice testing (IST)
     program, failure to perform required tests in accordance with the IST
     program, failure to test the service water system components to verify
     their functional capabilities, and failure to use appropriate test
     acceptance criteria.  For example, the following deficiencies were

     o  Various safety-related valves were omitted from the IST programs at
        several plants.  In one case, many manual valves in the service water
        system that perform specific functions in shutting down the reactor
        were not included in the IST program.  In another case,.

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        manual valves and check valves that perform safety functions in
        aligning the emergency backwash lines to the essential service water
        strainers were not included in the IST program.  Also, power-operated
        flow-control valves that are normally closed, but perform a safety
        function in opening to admit service water flow, were not included in
        the IST program.  (Monticello, South Texas, Quad Cities)

     o  Periodic testing of valves as required by the IST program was not
        performed.  The service water system valves in the control room
        heating, ventilation, and air conditioning system were not tested
        quarterly, as required by the plant's IST program.  (Quad Cities)

     o  Deficiencies were noted in IST programs for the service water system
        pumps.  The service water pump curves were used in testing the pumps
        instead of specific reference values as required by Section XI of the
        ASME Boiler and Pressure Vessel Code (ASME Code) without obtaining NRC
        staff approval for relief from the provisions of the Code.  Flow
        instruments that were not in compliance with the instrument accuracy
        requirements specified by Section XI of the ASME Code were used in the
        testing of essential cooling water pumps without obtaining relief from
        the Code requirements. (Monticello, South Texas)

     o  The preoperational test results of the service water system had not
        been reconciled with the current system configuration and operation.
        For example:  (a) the system was tested with the nonsafety-related
        portions isolated, although the existing operation of the system did
        not isolate these portions on a safety injection signal alone, (b) the
        system was not tested with two pumps operating to verify system
        performance under post-accident recirculation conditions, and (c) the
        system flow balance was established on the basis of three-pump
        operation instead of the limiting case of one-pump operation supplying
        all the loads.  (Ginna)

(3)  Weaknesses in the Implementation of Generic Letter 89-13

     In addition to the specific deficiencies discussed above, weaknesses were
     noted in the implementation of Generic Letter 89-13 actions.  Significant
     weaknesses in the implementation of Actions II and III of Generic Letter
     89-13 are discussed below.

     Action II of Generic Letter 89-13 requested that licensees establish a
     test program to periodically verify the heat transfer capability of all
     safety-related heat exchangers cooled by service water.  The total test
     program was to consist of an initial test program and a periodic retest
     program.  The following examples illustrate some of the implementation
     weaknesses found at one or more plants for this action item:

     o  Several safety-related room coolers were not tested in accordance with
        commitments in the licensee response to the generic letter.

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     o  No baseline testing was done to verify that minimum flow to each
        component was achieved.

     o  Where the periodic maintenance method was chosen in lieu of heat
        transfer performance testing of heat exchangers and room coolers, no
        sound technical basis for inspection and preventive maintenance
        frequencies was established.

     o  The design temperature difference across a heat exchanger was used as
        an acceptance criterion without correcting for the actual test
        conditions where the test heat load was substantially less than the
        design value.

     Action III of Generic Letter 89-13 requested that licensees establish a
     routine inspection and maintenance program for open-cycle service water
     system piping and components to ensure that corrosion, erosion,
     protective coating failure, silting, and biofouling would not degrade the
     performance of the safety-related systems supplied by service water.  The
     following examples illustrate some of the implementation weaknesses found
     at one or more plants for this action item:

     o  Adequate training or guidance was not provided for personnel to
        evaluate potentially degraded conditions of service water system

     o  Maintenance and inspection programs did not provide assurance that
        critical instrument lines and small-bore piping would not become
        clogged or degraded.

     o  Actions were not taken within a reasonable time period to inspect and
        clean room coolers in the second unit when similar coolers in the
        first unit were found to be significantly degraded.

     o  Nonsafety-related service water system piping in the discharge path
        from safety-related components was not included in an inspection and
        maintenance program.

The findings of these inspections illustrate the importance of systematic
engineering analyses, testing, inspection, and maintenance of service water

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This information notice requires no specific action or written response.  If
you have any questions about the information in this notice, please contact
the technical contacts listed below or the appropriate NRR project manager.

                                    /S/'D BY BGRIMES

                                    Brian K. Grimes, Director
                                    Division of Operating Reactor Support
                                    Office of Nuclear Reactor Regulation

Technical contacts:   S. K. Malur, NRR
                      (301) 504-2963

                      S. R. Jones, NRR
                      (301) 504-2833

1.  List of SWSOPI Reports
2.  List of Recently Issued NRC Information Notices.
Attachment 1                                                             IN
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                          List of SWSOPI Inspections

The following seven SWSOPI reports were reviewed to identify the types of
deficiencies and weaknesses that are discussed in this information notice:

1. 50-237/93008(DRS); 50-249/93008(DRS) (Dresden Nuclear Power Station)
2. 50-244/91-201 (Ginna Nuclear Power Station)
3. 50-335/91-201; 50-389/91-201 (St. Lucie Plant)
4. 50-263/92010 (Monticello Nuclear Generating Plant)
5. 50-254/92-201; 50-265/92-201 (Quad Cities Nuclear Power Station)
6. 50-498/92-201; 50-499/92-201 (South Texas Project)
7. 50-397/93-201 (Washington Nuclear Plant, Unit
Page Last Reviewed/Updated Friday, November 15, 2013