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{{Adams
#REDIRECT [[IR 05000361/1998018]]
| number = ML20199H452
| issue date = 01/15/1999
| title = Insp Repts 50-361/98-18 & 50-362/98-18 on 981109-1218. Violations Noted.Major Areas Inspected:Operations, Maintenance & Engineering
| author name =
| author affiliation = NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
| addressee name =
| addressee affiliation =
| docket = 05000361, 05000362
| license number =
| contact person =
| document report number = 50-361-98-18, 50-362-98-18, NUDOCS 9901250212
| package number = ML20199H447
| document type = INSPECTION REPORT, NRC-GENERATED, TEXT-INSPECTION & AUDIT & I&E CIRCULARS
| page count = 19
}}
See also: [[see also::IR 05000361/1998018]]
 
=Text=
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I'                                                ENCLOSURE 2
                                  U.S. NUCLEAR REGULATORY COMMISSION
l                                                  REGION IV
!
l          Docket Nos.:        50-361                                                  l
                                                                                        i
                                50-362                                                  l
            License Nos.:      NPF-10                                                  l
                                NPF-15                                                  !
            Report No.:        50-361/98-18
I
I
                                50-362/98-18                                            i
                                                                                        f
            Licensee:          Southern California Edison Co.
            Facility:          San Onofre Nuclear Generating Station, Units 2 and 3
                                                                                        '
            Location:          5000 S. Pacific Coast Hwy.                              )
                              ' San Clemente, California                                ;
                                                                                        i
            Dates:              November 9 through December 18,1998                    )
            Inspectors:        J. J. Russell, Resident inspector
i                              J. G. Kramer, Resident inspector                        >
:
                                                                                        '
.
            Approved By:        L. J. Smith, Acting Chief, Branch E
'
                                Division of Reactor Projects
    *                                                                                  e
                                                                                        .
;                        .
                                                                                        ,
            ATTACHMENT:      Supplemental Information                                  ;
l
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I                                                                                        l
                                                                                        l
i                                                                                      ,
                                                                                        1
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1
*
  .
      9901250215 990115
      gDR    ADOCK 05000361                                                            '
'
                            PDR      .
                                                                                        i
                                                                                        l
                                                                                        l
                                                                                        1
        - .
 
    . ._ . _ _ _.._ _ . _ _ _ _ _ _                                          - . _ _ _ _ _ _ . _              _ _ . _ _ . _ _ . . _
  *
  .                                                                                                                                      >
l                                                              EXECUTIVE SUMMARY
f                                              San Onofre Nuclear Generating Station, Units 2 and 3
                                                  NRC Inspection Report 50-361/98-18; 50-362/98-18
l                                                                                                                                        '
                  Operations
                                                                                                                                          !
                  *            A faulty temperature control unit, an incorrectly set electrical demand switch, and                        i
                              noncondensable gases rendered Chiller E335 inadvertently inoperable for 20                                !
                              consecutive days in August 1998. Similarly, a miswired low chilled water temperature
                              cutout switch or a combination of noncondensable gases, oil in the refrigerant, and an                    !
                              electrical demand setting of 80 percent rendered Chiller E335 inoperable for 22
                              consecutive days in September 1998. The time periods for these inoperabilities
                              exceeded the Technical Specifications Limiting Condition for Operation 3.7.10 allowed                      .
                              outage time and was identified as an apparent violation (Section 08.1.b.3).                                l
                  *            The emergency chilled water system operating procedure specified that the electrical                      !
                              demand be limited to 80 percent, which reduced chiller capacity below that assumed in                      i
                              design bases document. The failure to translate the design basis requirement for
                              emergency chiller capacity in the operations procedures for setting electrical demand
                              contributed to emergency Chiller E 335 in operability during August and September
                              1998. This failure was identified as a noncited violation of 10 CFR Part 50, Appendix B,                  i
l                              Criterion Ill, " Design Control." However, this deficiency alone did not render the                        !
                              emergency chiller inoperable. Tims nonrepetitive, licensee-identified and corrected                        l
                              violation is being treated as a noncited violation consistent with Section Vll.B.1 of the
                              NRC Enforcement Policy (Section 08.1.b.5).
                  *            Operators demonstrated poor awareness of the effects of compressor oil pump
                              operation on a standby emergency chiller. Operators operated the oil pump with the
                              compressor in standby for greater than the time allowed by procedure in attempts to                        !
                              lower a high oil level. The inspectors identified this as a failure to follow a procedure
                              required by Technical Specification 5.5.1.1.a. Since the licensee implemented                              i
                              appropriate corrective actions, no response was required (Section O8.2).
                  Maintenance                                                                                                              ;
                  *            Postmaintenance testing, as prescribed by operations work control, for scheduled
                              emergency chiller maintenance was not adequate because work that affected the start
                              circuit for the chiller was not tested. This deficiency was identified as a noncited
                              violation of 10 CFR Part 50, Appendix B, Criterion V, consistent with Section Vll.B.1 of
                              the Enforcement Policy. This deficiency contributed to inoperability of Chiller E335 for
                              22 days in September 1998 (Section 08.1.b.2).
                  *            Maintenance personnel demonstrated poor control of lifted leads and of emergency
:
                              chiller switch settings. An instrumentation and control (l&C) technician failed to
l                              properly reconnect wires to an emergency chiller low temperature cutout switch,
j                              rendering the chiller inoperable. The failure to follow procedure was identified as a
'
                              noncited violation of Technical Specification 5.5.1.1.a consistent with Section Vll.B.1 of
l                              the Enforcement Policy. During the same maintenance activity, the chiller was left with
!
                              an improper thermostat setting and the sequence for the low chilled water and low
i
l
(                          .            -      ._      -    .                        .          .
                                                                                                          --                        . . >
 
  . -__ ..          _ . _ - . . . _ -    .    _ . _ . _ _ _ . _ _ . _ _ . _ _ _ _ . _ _ . . _ _ . _ _
  .
4
                                                                                                                  l
                                                                        -2-
                                                                                                                  ,
;                  refrigerant temperature chiller trips was not in accordance with procedural
                  recommendations. These deficiencies reflected inattention to detail by an l&C                  ;
                  technician (Section M8.1).
            Enoineerina                                                                                          i
          *
                  Engineering personnel demonstrated poor assessment of equipment operability and                i
                  understanding of information contained in a vendor manual. A flawed operability                !
                  assessment when an emergency chiller could not achieve design cooling resulted in an            !
                  inadvertent inoperability of the chiller for approximately 20 days during August 1998.
                  The failure of engineers to take appropriate actions to demonstrate operability of the          !
                  Train B emergency chiller, as specified by the corrective action program, was identified
                  as a noncited violation of 10 CFR Part 50, Appendix B, Criterion XVI, " Corrective
                  Action," consistent with Section Vll.B.1 of the Enforcement Policy. Had the licensee            ,
                  implemented the vendor manual recommended performance monitoring of the chillers,              l
                  the buildup of noncondensable gases in the refrigerant during August and
                  September 1998 could have been detected (Section E8.1).
          *      An engineering evaluation of Chiller E335 operability from September 3 to 25 was
                  generally thorough. However, some of the reasons for the chiller inoperability, including
                  introduction of oil and noncondensable gases into the refrigerant, were not completely
                  understood by the licensee until questioned by the inspectors (Section E8.2).
          =      Licensee use of equipment specific configurations and human reliability analysis in the
                  risk assessment associated with the inadvertent Train B chiller inoperability was a
                  strength. The overall increase in risk because of the inoperable chiller was potentially
                  risk significant (Section E8.3).
                                                                                                                  i
                                                                                                                  !
                                                                                                                  i
                                                                                                                  i
,
                                                                                                      ,    ,,v--
 
-      . - . - - . _ .              . -    ..  . - - - .-.            - . - _ . - - -                _ ~ . - - - . ~ - .
  *
                                                                                                                              I
                                                                                                                              !
                                                                                                                              l
  -
                                                                                                                              l
                                                                Report Details
                Summary of Plant Status                                                                                      l
                Units 2 and 3 operated at essentially 100 percent power during this inspection period.                      J
                                                                                                                              l
                                                                l. Operations
                                                              -                                                              j
                08          Miscellaneous Operations lasues (92700)                                    ,
                08.1        f, Closed) Licensee Event Reoorts 50-361: 362/98-020-00 and 98-021-00: emergency                )
                            chilled water (ECW) inoperable because of faulty temperature control unit and ECW                !
                            inoperable because of an incorrectly wired switch.
                                                                                                                              l
                    a.      Inspection Scope                                                                                '
                            The inspectors reviewed the circumstances conceming two periods of inadvertent
                            inoperability of Units 2 and 3 Train B ECW, as pertains to operations. The inspectors
                            reviewed Procedure SO23-1-3.1," Emergency Chilled Water System Operation,"
                            Temporary Change Notice 10-2, and Design Bases Document SO23-800, " Auxiliary
                            Building Chilled Water System," Revisions 0 and 2. The inspectors reviewed portions of
                            Work Action Request (WAR) C-9802021 and a work schedule for implementing this
                            WAR prepared on August 13,1998. The inspectors reviewed portions of the chiller
                          - vendor manual Technical Manual SO23-410-7-164-2, " Operating Instructions for Carrier
                            Centrifugal Refrigeration Machines," Revision 2. The inspectors also interviewed
                            operators and operations management personnel,
                    b.      Observations and Findinos
                    b.1      Seouence of Events
                            As described in the licensee event reports, Chiller E335, Train B emergency chiller
                          ' (common to both units), was inadvertently inoperable for 20 continuous days in
                            August 1998 and for 22 continuous days in September 1998.
                            *      On August 6, Chiller E335 was operated to support a monthly control room
                                    essential air cleanup system surveillance. Operators observed that the chilled
                                    water temperature leaving the chiller decreased to approximately 51 *F; however,
                                    the normal chilled water outlet temperature was 43'F. Operators considered
                                    Chiller E335 operable; however, they generated an action request (AR) to have            j
                                                                                                                              '
                                    engineering assess operability.
                            *      On August 26, operators removed Chiller E335 from service for scheduled
                                    maintenance and declared the emergency chiller inoperable.
                            *      On August 28, I&C technicians replaced the temperature control unit. Operators
                                    performed a postmaintenance test that demonstrated satisfactory performance              3
                                    and declared Chiller E335 operable.                                                      ;
                                                                                                                              l
                                                                                                                              I
                                                                                                                              !
    ,-            - , _ _                              -
                                                                _                                                            >
 
                                                                                                      i
  .
I
                                                    -2-
                                                                                                      l
        *      On August 31, operators removed Chiller E335 from service for scheduled
                maintenance.                                                                          )
                                                                                                      ,
        *      On September 3, an l&C technician disconnected the leads from a low
                temperature chilled water cutout switch, in order to perform a dynamic calibration    j
                of the switch setpoint. During the dynamic calibration, the l&C technician            '
                stopped the calibration after hearing the emergency chiller make a rumbling
                noise.
        *      On September 4, operators declared Chiller E335 operable after verifying that
                the chiller continued to operate satisfactorily; however, the operators did not start
                Chiller E335.                                                                        1
        *      On September 25, Chiller E335 failed to start when operators attempted to
                perform a monthly control room essential air cleanup system surveillance.
                Subsequently, the licensee determined that the l&C technician had incorrectly
                wired the low chilled water temperature cutout switch for Chiller E335, and the
                postmaintenance test failed to detect the error. This error rendered Chiller E335
                inoperable from September 4 to 25.
        *      During troubleshooting on and after September 25, the licensee determined that
                noncondensable gases present in Chiller E335 from August 6 to September 25
                degraded the capability of the chiller condenser. In October 1998, as part of the
                operability review, the licensee determined that Chiller E335 had been degraded
                from August 6-26, because of several factors: (1) a faulty temperature control
                unit, (2) an incorrectly set electrical demand switch in the control circuit, and (3)
                the presence of noncondensable gases in the refrigerant. The licensee
                determined that these factors combined with a 51"F chilled water outlet
                temperature rendered Chiller E335 inoperable under design bases load
                conditions.
    b.2 Postmaintenance Testina
        Chiller E335 was removed from service for scheduled maintenance on August 31.
        WAP, C-9802021 and a work schedule prepared on August 13 directed that Chiller E335
        be operated in accordance with Procedure SO23-1-3.1 to verify operability following the
        maintenance. Concurrent with the operability test, a dynamic calibration of low chilled
        water and low refrigerant temperature cutout switches was scheduled to be performed.
        The design chilled water outlet temperature for Chiller E335 is 43'F. The low chilled
        water temperature cutout switch has a nominal setpoint of 38'F. The switch contacts
        are normally closed above 38*F and normally open below 38'F. When the switch
        contacts open, the chiller compressor trips and the chiller shuts down. The switch
        contacts were installed in the start circuit for the chiller, such that the chiller would not
        start manually or automatically with the contacts open. During the dynamic calibration,
        an I&C technician disconnected the wires from the low chilled water temperature cutout
        switch and installed a jumper to disable the switch cutout from tripping the chiller.
        Because of personnel error, an l&C technician had reterminated the switch wires
 
_  . _ _ _ _ _ . _ _ . _ _ _ _ _ _ _ _ . _                                _ _ _ _ . _ _ . _ _ _ . _ _ _ _ . _ _ _ _
  .
                                                                            -3-
                              incorrectly. In addition, although the dynamic calibration affected contacts in the chiller
                              start circuit, the postmaintenance test did not test the capability of the start circuit to
                              start the emergency chiller. Failing to provide instructions for postmaintenance testing
                              appropriate to the circumstances was a violation of 10 CFR Part 50, Appendix B,              ,
                        *
                              Criterion V, " Instructions, Procedures, and Drawings."                                      i
                              The licensee initiated the following corrective actions to prevent recurrence: (1) add a
                              postmaintenance test requirement to start the chiller after a dynamic calibration and      l
                              (2) assess the adequacy of the retest program and evaluate the committee that met to        :
                              approve retest requirements. This nonrepetitive, licensee-identified and corrected          i
                              violation is being treated as a noncited violation, consistent with Section Vll.B.1 of the  l
                              NRC Enforcement Policy (50 361; 362/98018-01).                                              )
                  b.3        Technical Specifications
                              The licensee determined that Chiller E335 was inadvertently inoperable from August 6        l
                              to 26, and from September 3 to 25 (periods of 20 days and 22 days, respectively).          !
                              Unit 3 was in Mode 1 operation for this entire period. Unit 2 was in Mode 1 for 22
                              consecutive days in August and the first 15 of the 22 consecutive days in September.
                              Technical Specification Limiting Condition for Operation 3.7.10 directs that, with one      r
                              train of ECW inoperable, each unit shall restore the train to operability in 7 days. If the !
                              train is not restored by the end of the 7 days, then the limiting condition for operation
                              requires operators to place the unit in Mode 3 in 6 hours and be in Mode 5 in 36 hours.
                              Because operators were not aware that Train B ECW was inoperable, these completion          i
                              times were not complied with, which resulted in an apparent violation of Technical          ;
                              Specification Limiting Condition for Operation 3.7.10 (50-361; 362/98018-02).              i
                              The inspectors verified that Train A ECW remained operable throughout the 2-month          ,
                              period. Operations had declared Train A ECW inoperable from September 15 to 16,            i
                              because of an air leak on the expansion tank, which caused the tank to fill with water      ,
                              and pressure to decrease. Also, the operators had declared the Train A Emergency            l
                              Diesel Generator (EDG) 2G002 (the power source Chiller E336, Train A emergency
                              chiller) inoperable on September 15 because the fuel transfer pump was returned to          :
                              service without the required inservice test. As discussed below, the Train A chiller and    l
                              the Train A EDG were shown operable throughout the period the Train B emergency            ;
                              chiller was inoperable,
                  b.4        Train A Operability Assessments
                                                                                                                          l
                              For the occurrence with the Train A expansion tank full of water, the expansion tank        ;
                              pressure increased to approximately 15 psig, which was the hydrostatic pressure that        l
                              resulted from 70 feet of water in the chilled water piping above the expansion tank. The    >
                              chilled water pump required approximately 4 psig suction pressure to avoid cavitation      ,
                              from a loss of net positive suction head. This 15 psig hydrostatic pressum exceeded the
                              4 psig required suction pressure. The chilled water pump would have provided 54 psig        ;
                              discharge pressure, given an expansion tank at 15 psig. The 54 psig discharge              ;
                              pressure would have been sufficient to pump chilled water throughout the chilled water      i
                                                                                                                          !
                              piping. The licensee demonstrated, via analysis in AR 980900850, that some gas
                                                                                                                          !
                                                                                                                          i
                                                                                                                          i
                                                                      _. - . -              _ _
                                                                                                                    .
 
                                              -4-
    pockets and separation of water from gas may have occurred on the chilled water pump
    suction side high points; however, the licensee determined that the chilled water flow
    would have been sufficient to collapse or mix these gas pockets, such that flow through
    all sections of piping would be maintained. Consequently, the inspectors found that the
    Train A emergency chilled water system could perform its intended function under these
    conditions.
    A second occurrence resulted with Train A chilled water powered by EDG 2G002, which
    was declared inoperable because both fuel transfer pumps were inoperable. Each EDG
    has two fuel transfer pumps that transfer fuel from the EDG fuel storage tank to the day
    tank. On September 15, one EDG fuel transfer pump (Pump 2P096) was removed from
    service for maintenance. Subsequently, this fuel transfer pump was declared operable,
    and the second EDG fuel transfer pump (Pump 2P093) was removed from service for
    maintenance. While the second fuel transfer pump was removed from service,
    engineers decided that the retest for the first fuel transfer pump should have included an
    inservice test because the pump had been decoupled from its motor during the
    maintenance. Consequently, for a period of time, operators declared both fuel transfer
    pumps inoperable. The first fuel transfer pump passed an inservice test that was
    subsequently administered. Since one fuel transfer pump had remained available, the
    inspectors found that the fuel transfer system for EDG 2G002 could perform its intended
    function.
b.5 Electrical Demand
                                                                                                *
    Train B Chiller E335 had an electrical demand setting on the control module that could
    limit the amount of current that the chiller compressor motor would draw. Prior to
    September 25, Procedure SO23-1-3.1 directed operators, during prestart checks of the
    chiller, to set electrical demand to 80 percent. This electrical demand setting of
    80 percent limited the Chiller E335 to 85 percent of nameplate capacity and contributed
    to Chiller E335 inoperability during August and September 1998 because this limited the
    capacity of the chiller.
                                                                                                  I
    Setting the electrical demand to 80 percent was not referenced in any design
    documents, and the licensee could not present a bases for this setting. The vendor
    manual stated that the variable electrical demand limited chiller capacity during colder
    periods, so that the chiller would not unnecessarily consume electrical power. The
    design bases for Chiller E335, as stated in Design Bases Document SO23-800,
    indicated that the chiller would provide 4.8 x 106BTU / hour cooling. However,
    Procedure SO23-1-3.1 limited the chiller capacity to approximately 4.1 x 10 6BTU / hour
    when the electrical demand was set at 80 percent. While less than the design basis
    specification, the licensee stated that the limited chiller capacity was still sufficient to
    cool design basis heat loads, if the chiller was functioning properly.10 CFR Part 50,
    Appendix B, Criterion 111, " Design Control," states, in part, that the design bases for
    components shall be correctly translated into procedures. The failure to translate design
    basis requirements for chiller capacity into operations procedures for setting electrical
    demand is a violation of NRC requirements. Upon discovery of this condition, the
    licensee revised Procedure 8023-1-3.1 to require setting electrical demand at
    100 percent. The inspectors found this corrective action satisfactory. This
                                                    .
 
      . ___      __          _ _ . _ _ _ . _ _ _ _ _ - _                  _ _ _ _ ___._..____.__-
    .
                                                                                                                '
                                                                      -5-
i
l                                                                                                                i
                                                                                                                '
,                  nonrepetitive, licensee-identified and corrected violation is being treated as a noncited
l                  violason, consistent with Section Vll.B.1 of the NRC Enforcement Policy
                  (50-3611362/98018-03).
,                  Also, on September 30, operators had started the Train A Chiller E336 with the electrical
l                  demand set at 80 percent; however, the motor current slightly exceeded the nameplate          l
l                  value, indicating that electrical demand switch was not properly limiting current. The        !
                  licensee calibrated the electrical demand for Train A Chiller E336 and verified that the
                  electrical demand for Train B Chiller E335 met specifications. Although the vendor            i
                  manual did not have a recommended calibration interval for operational settings, such
                  as electrical demand, the licensee had calibrated electrical demand on 6-year intervals.
                  From August 28 to 31, the inspectors determined that I&C technicians had set electrical
                  demand at 100 percent for Chiller E335 after replacing the temperature control unit.
                  Although this setting met the design bases and maintenance procedure requirements,
                  the inspectors noted that the setting conflicted with the requirements specified in            l
                                                                                                                  i
                  Procedure SO23-1-3.1. Consequently, the inspectors found that control of chiller                '
,                  electrical demand was poor and contributed to the noncited violation of design control
(                  since the maintenance and operations procedures conflicted.
l
              c.  Conclusions
                  Postmaintenance testing, as prescribed by operations work control, for scheduled
                  emergency chiller maintenance was not adequate because work that affected the start
                  circuit for the chiller was not tested. This deficiency was identified as a noncited
                  violation of 10 CFR Part 50, Appendix B, Criterion V, consistent with Section Vll.B.1 of
                  the Enforcement Policy. This deficiency contributed to inoperability of Chiller E335 for
                  22 days in September 1998.                                                                      ;
                                                                                                                  1
                  A faulty temperature control unit, an incorrectly set electrical demand switch, and
                  noncondensable gases rendered Chiller E335 inoperable for 20 consecutive days in                l
                  August 1998. Similarly, a miswired low chilled water temperature cutout switch or a
                  combination of noncondensable gases, oilin the refrigerant, and an electrical demand            ,
                    setting of 80 percent rendered Chiller E335 inoperable for 22 consecutive days in              i
                    September 1998. The time periods for these inoperabilities exceeded the Technical              l
                    Specifications Limiting Condition for Operation 3.7.10 allowed outage time and was
                    identified as an apparent violation.
                    The emergency chilled water system operating procedure specified that the electrical
                    demand be limited to 80 percent, which reduced chiller capacity below that assumed in
                    design bases document. The failure to translate the design basis requirement for
                    emergency chiller capacity in the operations procedures for setting electrical demand
;                  contributed to emergency Chiller E 335 in operability during August and
:                  September 1998 was identified as a noncited violation of 10 CFR Part 50, Appendix B,      '
:                  Criterion ill, " Design Control." However, this deficiency alone did not render the
'
                    emergency chiller inoperable. This nonrepetitive, licensee-identified and corrected
                    violation is being treated as a noncited violation consistent with Section Vll.B.1 of the  o
                    NRC Enforcement Policy.
i
!
  ,        -
                    -    -                              -- - - - _ ,
 
  .                                                                                                      l
!
                                                                                                          i
{
                                                        -6-
                                                                                                          ,
      08.2 Chiller Oil Pumo Ooeration                                                                    )
        a.    Inspection Scoce (92700)                                                                    :
              The inspectors reviewed the circumstances surrounding operators lowering Chiller E335
              oillevel. The inspectors reviewed AR 980900388 and portions of
              Procedure SO23-1-3.1 and interviewed station technical personnel.                          ;
        b. - Observations and Findinos
              On September 7,1998, operators noted that, with Chiller E335 in standby, compressor
              oil level was out-of-sight high in the upper sight glass. Chiller E335 has both upper and  :
              lower bulls-eye sight glasses vertically aligned to indicate compressor oil level.          l
              Procedure SO23-1-3.1, step 6.1.10.3, directed for compressor oil level out-of-sight high    !
              that operators run the lube oil pump for approximately 15 seconds to separate
              refrigerant from oil and then recheck the oillevel. Operators followed this procedure
              step and confirmed that the oil level lowered within the top sight glass and met the
                                                                                                          ;
              specification of Procedure SO23-1-3.1, which required the oil level to be less than the
              top sight glass and above one-half of the lower sight glass. Subsequently, operators
              ran the oil pump a second time for approximately 3-4 minutes, which decreased the oil
              level to approximately seven-eighths of the lower sight glass,                              j
              Operators generated AR 980900388, which documented the oil pump starts and
                                                                                                          '
              recommended procedure changes to incorporate operating the oil pump for
              3-3% minutes in order to more completely lower the oil level. Engineers rejected the
              procedure change during the AR disposition because the additional oil pump operation
              introduced oilinto the cooler and degraded Chiller E335 performance (refer to
              Section E8.2).' The inspectors found that the operators involved failed to recognize that
              excessive oil pump operation, with Chiller E335 in standby, could degrade chiller
              performance when the chiller was started.
              The licensee initiated the following corrective actions to correct this deficiency:
              (1) changed Procedure SO23-1-3.1 to emphasize the limits on oil pump operating time
              and frequency with the chiller in standby, (2) scheduled additional operator training in
              chiller dynamics, and (3) initiated a Level 3 event report to assess corrective actions for
              operators failing to correctly interpret what "approximately" meant. Failure to follow
              Procedure SO23-1-3.1 violated Technical Specification 5.5.1.1.a; however, the
              inspectors found the corrective actions for this deficiency to be adequate, consequently
              no response to the violation is required (50-361; 362/98018-04).
        c.    Conclusions
              Operators demonstrated poor awareness of the effects of compressor oil pump
              operation on a standby emergency chiller. Operators operated the oil pump with the
              compressor in standby for greater than the time allowed by procedure in attempts to
              lower a high oil level. The inspectors identified this as a failure to follow a procedure
              required by Technical Specification 5.5.1.1.a. Since the licensee implemented
              appropriate corrective actions, no response was required.
    ..                                            _    ._.                .              .    -
 
                                                                                                      1
!,
t
  .
  -
                                                      -7-                                              ]
,
                                              11. Maintenance                                          y
t-
                                                                                                          l
    M8    Miscellaneous Maintenance issues (92700)
    M8.1 Maintenance of Emeroency Chiller E335
                                                                                                          i
      a.  Inspection Scope
l
          The inspectors reviewed the circumstances concerning two periods of inadvertent
          inoperability of Units 2 and 3 Train B ECW, as pertains to maintenance. The inspectors      l
                                                                                                        '
          reviewed Licensee Event Reports 50-361; 362/98-020-00 and 98-021-00. The
,
          inspectors reviewed Procedure S023-11-8.25 and interviewed l&C technicians, as well as      l
                                                                                                        '
I          maintenance supervisors. The inspectors reviewed portions of
          Procedure SO123-ll-15.3," Temporary System Alteration and Restoration Form,''                  j
          Revision 7, and portions of Technical Manual SO23-410-7-164-2, Revision 2.                  i
                                                                                                          l
      b.  Observations and Findinas                                                                      ;
                                                                                                          i
;    b.1  Lif ted Lead Control                                                                        ,
          On September 3,1998, an l&C technician disconnected the leads from the Chiller E335
          low chilled water temperature cutout switch, as instructed by Procedure SO23-ll-8.25, in      i
          order to perform a dynamic calibration of the switch setpoint (nominally 38"F) and reset      l
          point (nominally 48'F). As directed by Procedure SO23-il-6.25, a day shift l&C                ]
          technician jumpered out the low refrigerant temperature and low chilled water                  i
                                                                                                        I
          temperature cutouts and disconnected the wires from both of these switches. A swing
          shift l&C technician continued with the calibration by lowering thermostat temperature,
          until the refrigerant switch actuated. When the thermostat was lowered further, to
          provide approximately 38"F chilled water temperature (nominal switch setpoint), the
          chiller began to make loud, rumbling noises. In addition, cooler pressure lowered to
          about 30 psi, the minimum cooler pressure allowed by Procedure SO23-ll-8.25. The
          I&C technician decided to back out of the calibration and restore the chiller.
I
            Procedure SO23-ll-8.25, step 6.3.3, directed that the wires removed from the low chilled
          water temperature cutout switch be reconnected. The low chilled water temperature
          switch contact is normally closed above switch setpoint (chilled water temperature above
            38"F) to allow operation. The low chilled water temperature switch contact opens to
I
            either trip the chiller and prevent chiller automatic and manual start, when the switch is
            below setpoint (chilled water temperature below 38"F). The switch has four connection
            points for the two wires. The technician reconnected the wires to the connection point
            screws that corresponded to a closed contact by using a voltmeter to establish these
            points. The technician then reported to operations work control that he was unable to
l          complete the dynamic calibration.
I
!          The licensee determined that, on September 25, when Chiller E335 failed to start, the
I          l&C *echnician had connected the wires to the wrong screws. The low temperature
            cutout switch had changed state, such that the I&C technician had unknowingly
                                                                                                          I
 
      - - - - . - - - - - - - - - -                                                                  -          -
                                                                                                                      .=
                                                                                                                                      l
                                                                                                                                      l
                      .
                                                                                                                                    i
                                                                                                                                    :
                                                                                                                                      '
,
  ~,
)-                                                                              -8-
                                                                                                                                    1
                                                                                                                                    !
                                    connected the wires to the normally open contacts. The emergency chiller had not
i                                    tripped because the reset point of the switch had not been reached. The failure to
l                                    reconnect the low temperature cutout switch wires did not meet the requirements of              i
l                                    Procedure SO23-Il-8.25, step 6.6.3; consequently, the failure to properly implement a          {
!                                    procedure recommended in Regulatory Guide 1.33 was a violation of Technical
!                                    Specification 5.5.1.1.a.                                                                        i
                                                                                                                                    l
                                    As described in Procedure S0123-11-15.3, the inspectors noted that the licensee
                                    controlled jumpers and lifted leads connected or disconnected during maintenance
                                    activities in three primary ways: (1) used an alteration form, (2) controlled in a
l                                    procedure, or (3) verified by a test or other indication that would demonstrate adequate        i
!                                    restoration. The I&C technician's activities described above were controlled by                i
                                    procedure, as allowed by the lifted lead and jumper program. The inspectors found that,        !
                                    to an extent, the technician demonstrated poor skill-of-the-craft by not recognizing that
l                                    the low temperature switch may have changed state. The inspectors also found that, to
l                                    an extent, the program for controlling lifted leads and jumpers was weak. The exact            i
                                    location of jumpers and positions that leads were lifted from was not required to be            l
                                    recorded as work progressed when these activities were controlled by procedure and
;                                    when a functional test would be performed. Both the procedure weakness and                      i
i                                    personnel error contributed to the violation described above.                                    i
                                    Following identification of this deficiency, the licensee implemented the following              !
                                    corrective actions: (1) conducting a site-wide standdown on November 20 to discuss              j
                                    this occurrence with all site personnel, (2) requiring the use of an alteration form for all    I
                                    jumpers and lif ted leads as an interim measure, while conducting a review of their
                                    program for controlling lifted leads (3) assessing the adequacy of the alteration form,
                                    and (4) reviewing the occurrence for disciplinary action. The inspectors found these
                                    corrective actions adequate. This nonrepetitive, licensee-identified and corrected
                                    violation is being treated as a noncited violation, consistent with Section Vll.B.1 of the
                                      NRC Enforcement Policy (50-361; 362/98018-05),
                        b.2          Thermostat and Temperature Switch Settinos
                                      Procedure SO23-il 8.25 directed that personnel: (1) lower the chiller thermostat setting
l
                                      until the low refrigerant and low chilled water temperature switches actuated, (2) raise
                                      the chiller thermostat setting to check the reset points of the switches, and (3) return the
                                      chiller thermostat to the position corresponding to 43'F. The chiller thermostat was
                                      controlled by a dial on the temperature control module. However, no markings existed
                                      on the dial face or the panel on which the dial was mounted to identify the correct
                                      setting. When the l&C technician attempted the dynamic calibration on September 3,
                                      the procedure step that returned the chiller thermostat to 43*F had been marked *NA,"
                                      and the chiller thermostat was lef t at a lower setting. Based on review of data for the
                                      operation of the chiller on September 4, the inspectors found that operations had
i
                                      corrected the chiller thermostat setting after noting a low chilled water temperature          ;
;                                    during operation.                                                                              l
l
;                                    The inspectors also noted that the vendor manual and Procedure SO23-ll-8.25
{                                      recommended that the low refrigerant temperature switch be set such that, as
,
                                                                                                                                      l
l
                                  -                  - -            -                - _ .    -        ,    _-          .,_      _l
 
                                  __ _    _ . -    __.
.
                                                  9
        refrigerant and chilled water temperature lowered, the low chilled water temperature
        switch would actuate before the low refrigerant temperature switch. This was because
      the low refrigerant temperature switch had to be locally reset, while the low chilled water
      switch would reset when chilled water temperature was 48'F and a 15-minute time
      delay had been met. The inspectors found that on September 3 the I&C technician
      achieved the low refrigerant temperature switch setpoint before he had achieved the low
      chilled water temperature switch setpoint, as he was lowering the thermostat. This
      indicated that the switch setpoints were not left in accordance with the recommendations
      noted above. The inspectors found that, on September 3, when the l&C technicians
      informed operators that Chiller E335 was restored from maintenance, two settings were
      left in nonrecommended positions, indicating poor attention to detail.
  c.  Conclusions
      Maintenance demonstrated poor control of lifted leads and of emergency chiller switch
      settings. An l&C technician failed to properly reconnect wires to an emergency chiller
      low temperature cutout switch, rendering the chiller inoperable. The failure to follow
      procedure was identified as a noncited violation of Technical Specification 5.5.1.1.a.      l
      consistent with Section Vll.B.1 of the Enforcement Policy. During the same
      maintenance activity, the chiller was left with an improper thermostat setting and the
      sequence for the low chilled water and low refrigerant temperature chiller trips was not
      in accordance with procedural recommendations. These deficiencies reflected
      inattention to detail by an I&C technician.
                                        lil. Enaineerina
  E8  Miscellaneous Engineering issues (92700)
  E8.1 Enaineerina Assessment and Support of Emeraency Chiller E335
  a.  Insoection Scope
      The inspectors reviewed the circumstances concerning two periods of inadvertent
      inoperability of Units 2 and 3 Train B ECW, as pertains to engineering. The inspectors      I
      reviewed Licensee Event Reports 50-361; 362/98-020 00 and 98-021-00. The
      inspectors reviewed portions of Procedure SO123-XX-1," Action Request / Maintenance
      Order initiation and Processing," Revision 9, Issue 2. The inspectors reviewed portions
      of Technical Manual SO23-410-7-164-2 and Procedure SO23-1-3.1. The inspectors              !
      reviewed data for Chiller E335 operation at various times from February 1997 until
      September 1998 and interviewed station technical and design engineers and
                                                                                                  l
                                                                                                  '
      supervisors.
 
      .                          _                    __    __.    ._ _ __            _.
    .
t
    .
                                                    -10-
        b.  O.bgervations and Findinas
        b.1 Ooerability Assessme_n_t
                                                                                                      "
            On August 6,1998, operators started Chiller E335 to support a control room essential
            air cleanup system surveillance. Operators generated AR 980800326 because
            Chiller E335 was maintaining 51 *F outlet chilled water temperature, instead of the
            design 43*F. The cognizant engineer performed an operability assessment, approved
            by an acting supervisor, which concluded the chiller remained operable. The engineer
            concluded in the operability assessment that 51 *F chilled water outlet temperature was
            acceptable to cool the actualloads on the chiller. However, the operability assessment
            did not address increased loading on the chiller that would result from a design basis
            accident condition (one unit in a loss of coolant accident and the other shutting down).
            The licensee subsequently determined that noncondensable gases in the refrigerant
            and problems with the temperature control unit had rendered the chiller inoperable on
            August 6. The inadvertent inoperability remained until August 26, when Chiller E335
            was declared inoperable for scheduled maintenance, which included replacing the faulty
            temperature control unit.
            Procedure SO123-XX-1, step 6.6.2.2.5, states, in part, that to accept a condition as-is
            and justify that the configuration continues to satisfy design requirements, a
            nonconformance report is required. The operability assessment was not accomplished
            in accordance with Procedure SO123-XX-1. Utilization of a nonconformance report, in
            principle, would have caused increased engineering attention to the design of the chiller
            and the effect of the degradation on the chiller. The failure to promptly identify and
            correct a condition adverse to quality is a violation of 10 CFR Part 50, Appendix B,      ,
            Criterion XVI," Corrective Action." The licensee had implemented corrective actions that
            included: (1) developing a station technical reading assignment, (2) counseling
            personnelinvolved, and (3) considering enhancing standard questions used during
            operability assessments. This nonrepetitive, licensee-identified and corrected violation
            is being treated as a noncited violation, consistent with Section Vll.B.1 of the NRC
            Enforcement Policy (50-361; 362/98018-06).
        b.2 Vendor Information
            The inspectors noted that the chiller vendor manual recommended that a set of
            operating logs be taken when operating the chiller in order to be able to detect
            degradation in chiller performance. The recommended logs included chilled water            ,
            temperature entering and leaving the chiller, refrigerant temperatures and pressures,      '
            and component coolirig water temperatures entering and leaving the chiller. The
            inspectors determined that Procedure SO23-1-3.1 did not require operators to monitor    J
            any of these parameters in order to analyze for performance degradation,                  i
            In addition, the chiller vendor manual provided saturation tables for refrigerant
,            temperature and pressure to be used in order to detect noncondensable gases in the
f            refrigerant. A refrigerant temper 0ture 2'F below the saturation temperature for any
  '
            9 i ven pressure was indicative of noncondensable gases. Licensee personnel had not
j            utilized this information on September 3. nor during other past attempts at dynamic
 
                  -                    _ .    - .      __            - _      .-  -.          . . _ . -
.
                                                  -11-
                                                                                                        i
                                                                                                        I
      calibration, when refrigerant pressure (limited to 30 psi) prevented completing the
      dynamic calibration. This information was not used until September 25 when a vendor
      representative suggested that noncondensable gases were present in the refrigerant.
      Noncondensable gases had degraded chiller performance for at least 2 months prior to
      September 25. The inspectors concluded that station technical engineers demonstrated
      weak performance monitoring of the chillers, in that personnel failed to make full use of
      the information available in the chiller vendor manual.
  c.  Conclusions
      Engineering demonstrated poor assessment of equipment operability and understanding
      of information contained in a vendor manual. , A flawed operability assessment when an
      emergency chiller could not achieve design cooling resulted in an inadvertent
      inoperability of the chiller for approximately 20 days during August 1998. The failure of
      engineers to take appropriate actions to demonstrate operability of the Train B
      emergency chiller, as specified by the corrective action program, was identified as a
      noncited violation of 10 CFR Part 50, Appendix B, Criterion XVI, * Corrective Action,"
      consistent with Section Vll.B.1 of the Enforcement Policy. Had the licensee
      implemented the vendor manual recommended performance monitoring of the chillers,
      the buildup of noncondensable gases in the refrigerant during August and September
      1998 would have been detected.
  E8.2 Effect of Noncondensable Gases on Chiller Performance
  a.  Inspection Scope
      The inspectors reviewed data of Chiller E335 performance to assess operability,
  b.  Observations and Findinas
      Licensee Event Reports 50-361; 362/98-020-00 and 98-021-00 described that the
      chillers have a 35 percent capacity margin and that the noncondensable gases
      degraded the chiller performance by 11 percent. The capacity margin was based on
      calculations of design load (one unit in a loss of coolant accident and one shutting
      down). The loads on the chiller were divided by the chiller capacity to determine the
      excess capacity the chillers possessed. The licensee based the 11 percent degradation
      on comparisons of chiller performance when equipment status as well as the presence
      of noncondensable gases was known.
      The inspectors identified that chilled water exit temperature (as a function of time) data
      recorded for September 25,1998, and chiller operation with control room essential air
      cleanup system loading contradicted either or both the 35 percent capacity margin or
      the 11 percent degradation resulting from the noncondensable gases. The inspectors
      noted that, in principle, for the chiller operation on September 25, the chiller should have
      had a 9 percent excess capacity for design loading. Specifically, operators had set the
        current limiter to 80 percent, which provided 85 percent available capacity. Since
        noncondensable gases were present, this 85 percent capacity should have been
        reduced to no lower than 74 percent chiller output (based upon the 11 percent
 
  .    - - - . - - - - . - -                          - . - - -                  - - - - . - - -.- - --
    -
                                                                                                                          :
    .
                                                                      -12-
.                            degradation). The 74 percent chiller output exceeded the 65 percent chiller output by
                            9 percent, which the licensee stated would maintain the chiller capability within design.
                            On September 25, Chiller E335 only achieved 49"F chilled water outlet temperature with
                            significantly less than the design loading; however, the chiller should have easily          i
                            achieved 43*F chill water outlet temperature. Normally, chiller operation provided for a      :
                                                                                                                          i
                            relatively sharp drop in chilled water temperature in the first 10 to 20 minutes of chiller
                            operation, as the chiller " worked" hard to lov.er the outlet temperature to the setpoint.
                            After the setpoint was reached, the chiller would draw less amperage since it would be
                            easier to mcintain the chill water outlet temperature at the 43*F setpoint. In this          ,
                            instance, for the first hour (the extent of the chiller operation with current demand at      >
'
                            80 percent), the chiller operated at the maximum amperage for 80 percent electrical          i
                            demand. Even though the temperature difference between setpoint and actual chilled            i
"
                            water outlet temperature (43 versus 49*F) was not that great, the capability of the chiller
                            unit was exceeded, as demonstrated by the controller continuing to generate a full open        l
                            signal for the refrigerant guide vanes. Consequently, Chiller E335 had operated at            l
                            maximum capacity for the conditions reported (74 percent) instead of functioning              1
                            normally even though, in principle, the chiller capacity exceeded the design capacity          !
                            (65 percent) by 9 percent.
                            In response to the above information, a reanalysis determined that the 11 percent
                            degradation resulting from noncondensable gases was dependent on current available
                            to the compressor motor and component cooling water temperature. The degradation
                            would increase above 11 percent if the chiller was current-limited or component cooling
                            water temperature was elevated. Consequently, for a current-limited setting of
                            80 percent, degradation resulting from noncondensable gases would exceed
                            11 percent. The licensee also stated that, for the inoperability from September 3 to
                            25, Chiller E335 would have been inoperable because of the noncondensable gases
                            and the 80 percent current limited setting, independent of the miswired low temperature
                            cutout switch.
                            On December 1 station technical engineers informed the inspectors that Chiller E335 oil
                            pump operation on September 6 (as described in Section 08.2) had introduced
                            approximately 1 gallon of oilinto the Chiller E335 cooler. This oil had been absorbed by
                            the refrigerant and, during Chiller E335 startup on September 25, had degraded
                            Chiller E335 performance. The chiller was designed to remove oilin the refrigerant
                            through a weep hole that directed oil separated from refrigerant by the action of the
                              compressor to be returned to the oil reservoir. This would occur during the first 2
                              to 3 hours of Chiller E335 operation such that the performance degradation would              j
                              correct itself.
                                                                                                                            i
                              Based on licensee statements, the inspectors found that Chiller E335 was operable from
                              August 28 to 31. Any additional Chiller E335 pedormance degradation, resulting from
                              oilin the Refrigerant, had occurred after August 31. The inspectors also noted that
                              operating the Chiller E335 compressor tube oil pump, in order to lower oil level with the
                              chiller in standby, was not an action that was mentioned in the chiller vendor manual.
                              However,15 seconds of operation, as specified in Procedure SO23-1-3.1, should not
                              adversely affect chiller performance,
                                                                                                                            l
                                                                                                            e y ~        g
 
.
                                                                                                          k
.
                                                  -13-
                                                                                                          1
                                                                                                          !
        Based on the above, the inspectors found that the retrospective evaluation of operability
        of Chiller E335, as stated in Licensee Event Report 50-361; 362/98-021-00, was                  ,
        accurate and generally thorough. However, the reasons for Chiller E335 inoperability            i
        from September 3 to 25 included more than the miswirirg of the low chilled water                ,
        temperature cutout switch, independent of the switch miswiring, Chiller E335 was also            l
        inoperable because of the combination of noncondensable gases and oilin the                      l
        refrigerant. The chiller performance degradstion caused by the oil and noncondensable            :
        gases was compounded by the chiller electrical demand being set at 80 percent from              i
        September 3 to 25, but a setting of 100 percent would have still rendered Chiller E335          ;
        inoperable based on the effects of the oil and noncondensable gases in the refrigerant.          !
  c.    Conclusions                                                                                      j
        An engineering evaluation of Chiller E335 operability from September 3 to 25 was
        generally thorough. However, some of the reasons for the chiller inoperability, including        ,
        introduction of oil and noncondensable gases into the refrigerant, were not completely          !
                                                                                                          ;
        understood by the licensee until questioned by the inspectors.
                                                                                                          l
  E8.3 Licensee Assessment of Risk
  a.    Inspection Scope
        The inspectors reviewed the licensee assessment of the increase in risk that resulted
        from the inadvertent chiller inoperability. The inspectors reviewed NSG/PRA                      i
                                                                                                          '
        Report NSG-98-021,"The unavailability of Emergency Chiller SA1513ME335," dated
        October 23,1998, and had discussions with licensee representatives.
                                                                                                    .
  b.    Observations and Findinas
        The risk assessment determined that the Train B chiller inoperability during August and
        September 1998 increased the risk in Unit 2 by 8.9E-06 and Unit 3 by 9.6E-06. The
        licensee concluded that the increr.ses in risk were small when using the criteria of
        Regulatory Guide 1.174, "An Approach for Using Probabilistic Risk Assessment in
        Risk informed Decisions on Plant-Specific Changes to the Licensing Basis." The
        inspectors noted that the risk analysis was comprehensive in that specific plant
        configurations had been used to assess the impact of the chiller outage. Additionally, a
        human reliability analysis had been performed to evaluate the operator performance
        issues associated with the chiller inoperability.
        The inspectors noted that Regulatory Guide 1.174 was intended to evaluate plant-
          specific changes to the licensing bases and not necessarily to evaluate the risk
          significance of plant configurations or events. In addition, the inspectors noted that,
          even when using Regulatory Guide 1.174, the overall risk bordered on the region of
          potential risk significance.
      --    -      -      -          ._.            -  -. .              ---    ,            -  - _
 
                                                                                  _.          .. .  _ _ _ _ _ _ _ _
                                                                                                                            . .
                                                                              .
                                  .
                                        ..                .
      .
    .
    &
                                                          -14-
              c.    Conclusions
                    Licensee use of equipment specific configurations and human reliability analysis in the
                    risk assessment associated with the inadvertent Train B chiller inoperability was a
                  strength. The overall increase in risk because of the inoperable chiller was potentially
                    risk significant.
                                              V. Manseement Meetinas
            X1    Exit Meeting Summary
                  The inspectors conducted a status meeting with members of licensee management on
                  November 13,1998.
                  The inspectors presented the inspection results to members of licensee management at
                  the exit meeting on December 18,1998. The licensee acknowledged the findings
                  presented.
                  The inspectors asked the licensee whether any materials examined during the
                  inspection should be considered proprietary. No proprietary information was identified.
                                            .
                                                                                                                                1
i.,,    - .    .
                        . . . . .
                                    . ..
                                                                                .
                                                                                            _ . _ , _                __ _.
 
. . . -        .-        -        . - . ~ .._            - -  - .    . - . _        . - . -    _ . - - . . - . - . . _
                                                                                                                        i
'
                                                                                                                        !
                                                                                                                        f
'
                                                      ATTACHMENT                                                        l
                                                                                                                        ;
                                            SUPPLEMENTAL INFORMATION                                                    i
                                                                                                                        !
                                  EARTIAL LIST OF PERSONS CONTACTED
        Licensee                                                                                                        j
        D. Brieg, Manager, Station Technical
        J. Fee, Manager, Maintenance                                                                                    i
        D. Herbst, Manager, Site Quality Assurance                                                                      i
        R. Krieger, Vice President Nuclear Generation                                                                    ;
        A. Scherer, Manager, Nuclear Regulatory Affairs                                                                  !
        D. Nunn, Vice President, Engineering and Technical Services                                                      !
        T. Vogt. Plant Superintendent, Units 2 and 3                                                                    !
        R. Waldo, Manager, Operations                                                                                    ;
                                                                                                                        !
                                          INSPECTION PROCEDURE USEiQ                                                    l<
        IP 92700:      On Site LER Review
                                                                                                                        i
                                                                                                                        !
                                              IIEMS OPENED AND CLOSED                                                  !
        Ooened                                                                                                          l
                                                                                                                        !
        361; 362/98018-02      eel Technical Specification LCO completion times not complied with                      J
                                          (Section 08.1.b.3)
        Closed
                                                                                                                          i
        361;362/98-020-00      LER ECW inoperable due to faulty temperature control unit switch                          I
                                          (Section 08.1)                                                                )
                                                                                                                          i
        361; 362/98-021-00      LER ECW inoperable due to incorrectly wired switch (Section 08.1)
        Opened and Closed
        361; 362/98018-01      NCV inadequate postmaintenance test (Section 08.1.b.2)
        361;362/98018-03        NCV emergency chiller capacity reduction not in accordance with
                                          design basis (Section 08.1.b.5)
                                                                                                                          1
        361;362/98018-04        VIO failure to follow procedures (Section 08.2.b)
                                                      . _ -  .    --      -  --
 
                              .  .  _
.
.
                                              2
  361;362/98018-05    NCV failure to reconnect low temperature cutout switches
                            (Section M8.1.b.1)
  361;362/98018-06    NCV failure to perform adequate operability assessment
                            (Section E8.1.b.1)
                                LIST OF ACRONYMS USED
  AR          action request
  CFR        Code of Federal Regulations
                                                                                -
  ECW        emergency chill water
  EDG        emergency diesel generator
  I&C        instrumentation and control
  NRC        Nuclear Regulatory Commission
  PDR        Public Document Room
  WAR        work action request
                                                                                  l
                                                                                  I
                                                                                  l
                                                                                  l
                                                                                  !
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