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#REDIRECT [[05000528/LER-1994-002, :on 940422,determined That TS 3.1.1.1,3.3.1 & 3.9.1 LCO May Not Ensure That Plant Operation Is Maintained within Safety Analysis.Caused by Groundrules Adjunct to Ts. TS Change Request Is Being Prepared]]
| number = ML17311A202
| issue date = 08/08/1994
| title = LER 94-002-01:on 940422,determined That TS 3.1.1.1,3.3.1 & 3.9.1 LCO May Not Ensure That Plant Operation Is Maintained within Safety Analysis.Caused by Groundrules Adjunct to Ts. TS Change Request Is Being prepared.W/940808 Ltr
| author name = Grabo B, Levine J
| author affiliation = ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
| addressee name =
| addressee affiliation = NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
| docket = 05000528
| license number =
| contact person =
| document report number = 192-00901-JML-B, 192-901-JML-B, LER-94-002, LER-94-2, NUDOCS 9408230102
| document type = LICENSEE EVENT REPORT (SEE ALSO AO,RO), TEXT-SAFETY REPORT
| page count = 23
| project =
| stage = Other
}}
 
=Text=
{{#Wiki_filter:REGULATORY XNFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:9408230102                DOC.DATE:    94/08/08      NOTARIZED: NO          DOCKET FACIL:STN-50-528 Palo Verde Nuclear Station,                  Unit 1, Arizona Publi 05000528 AUTH. NAME            AUTHOR AFFILIATION GRABO,B.              Arizona Public, Service          Co..  (formerly Arizona Nuclear Power      p LEVINE,J.M.          Arizona Public Service            Co.  (formerly Arizona, Nuclear Power RECXP.NAME            RECIPIENT AFFILIATION                                                      R
 
==SUBJECT:==
LER  94-002-01:on 940422,determined that TS 3.1.1.1,3.3.1 &
3.9.1  LCO may not ensure that plant operation is maintained within safety analysis. Caused by groundrules adjunct to TS.
TS change request is being prepa'red.W/940808 ltr.
DXSTRXBDTION CODE:        XE22T      COPIES RECEIVED:LTR        I  ENCL  Q SIZE:    //
TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.
NOTES:STANDARDIZED PLANT                                                                  05000528 I RECIPIENT                COPIES              RECIPIENT          COPIES ID  CODE/NAME              LTTR ENCL          ID CODE/NAME        LTTR ENCL PD4-2 PD                        1      1      HOLIAN,    B          1 . 1 TRAN,L                          1      1 INTERNAL: ACRS                            1      1      AEOD/DS P/TPAB          1    1 AEOD/ROAB/DS P                  2      2      NRR/DE/EELB            1    1 NRR/DE/EMEB                    1      1      NRR/DORS/OEAB          1    1 NRR/DRCH/HHFB                  1      1      NRR/DRCH/HICB          1    1 NRR/DRCH/HOLB                  1      1      NRR/DRSS/PRPB          2    2 NRR/DSSA/SPLB                  1      1      NRR/J>SSA/SRXB          1    1            D NRR/PMAS/IRCB-E                1      1    - REG ~FLE          02    1    1 RES/DSIR/EXB                    1      1      GN4    FILE 01        1    1 EXTERNAL    EG&G BRYCE J ~ H F
2      2      L ST LOBBY    WARD    1    1 NOAC MURPHY,G.A                1      1      NOAC POORE,W.          1    1 NRC PDR                        1      1      NUDOCS FULL TXT        1    1 U
NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE iVASTE! CONTACT THE DOCUMENT          CONTROL DESK, ROOM Pl-37 (EXT. 504-2083 ) TO ELIMIiNATEYOUR  NAME FROM DISTRIBUTIONLISTS I'OR DOCUMENTS YOU DON'T NEED!
FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR                    28  ENCL      28
 
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Arizona Public Service Company
                                        'PALO VERDE NUCLEAR GENERATING STATION P.O, BOX 52034 ~ PHOENIX, ARIZONA85072-2034 JAMES M; LEVINE 192-00901-JML/BAG/R JR VICE PAE8 I CENT                                                  August 8, 1994 NUCI.EAA PRODUCTION U. S. Nuclear Regulatory Commission ATT: Document Control Desk Mail Station P1-37 Washington, DC 20555
 
==Dear Sirs:==
 
==Subject:==
Palo Verde Nuclear Generating'Station (PVNGS)
Units 1, 2 and 3 Docket No. STN 50-528/ 529/ 530 (License No. NPF-41/51/74)
Licensee Event Report 94-002-01 File: 94-020-404 Attached please find supplement 01 to Licensee Event Report (LER) 94-002 prepared and submitted pursuant to 10CFR50.73. This supplement. reports the identification of an additional Technical Specifications'imiting Condition for Operation that would not ensure Plant operation was maintained within the assumptions of the safety analysis as required by 10CFR50.36. In accordance with 10CFR50.73(d), a copy of this LER is being forwarded to the Regional Administrator, NRC Region IV.
If you have any questions, please contact Burton. A. Grabo, Supervisor, Nuclear Regulatory Affairs, at (602) 393-6492.
Sincerely, JML/BAG/RR/rv Attachment cc:        W. L. Stewart        (all with attachment)
L. J. Callan K. E. Perkins K. E. Johnston INPO Records Center 9408230102 9'40808 PDR    ADOCK 05000528 8                    PDR
 
0 4I 5
 
LlCENSEE EVENT REPORT (LER)
FACII.ITYIthME (IJ                                                                                                                    DOCKET NUMBER (2)                        PACE 3 Palo Verde Unit                      1                                                                                                o  s    o  o    o5 28 {QF10
'IITLE (c)
Technical Specification Limiting Condition for Operation Not Supported by 'Safety Analysis EVEtIT DATE IOI                        LER IIVMBER(6)                    REPORT DhTE(7)                                    OTHER FACIUTIES INVOLVED(6)
MONTH      DAY                                                                                                        FACIUTY NAMES                    DOCKET NUMBER(S)
NUMBER MONTH AT  NUMBER                                  OAY Palo Verde Unit                  2              0  5    0    0    0    5 0 4 2 2              94 94                  0    02          0    1    0 8 0 8 9 4                  Palo Verde Unit 3                                o60            0    053        0 OPERATINQ                THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR $ 1(Check one or more of the kslbvrlng) (11)
MODE {0)
                            ]           20A02(b)                            20AOS(c)                          50.73(a)(2) {Iv)                                73.71{b) 20A05(aN I )(i)                      50.36(c){ I)                      50.73(a)(2)(v)                                  73.71(c)
LEYEL (IOJ            8                20AO5(a)(I)P)                        5026(c)(2)                        50.73{a)(2){vs)                                OTHER (Speci(pin Abstract briers rnctin Trxh HRC Form 20A05(a)(1)(ii)                      50.73(a)(2){i)                    50.73{a)(2)(vll){A)                            366A) 20A05(a)(1)(iv)                      50.73(a)(2)(il)                    50.73(a)(2)(vli)(B) 20A05(a)(1){v)                      50.73(a)(2~w                      50.73(a){2)(x)
UC EN SEE    CONTACT FOR THIS LER (12) tthME                                                                                                                                                  TELEPHONE NUMBER AR Burton Grabo, Supervisor, Nuclear Regulatory Affairs                                                                                      602          3  93-            64 92 COMPLETE ONE UNE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT {13)
MANUFAC                                                                                      MANUFAC        EPORTABLE CAUSE SYSTEM          COMPONENT              TURER                                                        SYSTEM      COMPONENT          TURER        TO NPRDS v sax Aprxxc <<c'e<<ccxxci SUPPLEMENTAL REPORT EXPECTED {14)                                                                              MONTH      DAY EXPECTED SUBMSSION YES (III rr. ccvriptrtr 8TPEC TED S VShttSSIOH DATE)                                    NO DATE {15)
I    004 hBSTRhCT (Unit to      IGLOO rpecrs; I r r rppoxlmrtrtplihrrn ringtr.space tpprvrrftrrn Iirrs) (16)
At approximately                      1300 MST on                April 22,            1994, Palo Verde Units                    1  and 2 were              in Mode 1 (POWER OPERATIONS) and Unit 3 was in a refueling outage with the core off      loaded eo the spent fuel pool when APS Nuclear Fuel Management personnel determined that Technical Specifications (TS) 3.1.1.1, 3.3.1, and 3.9.1 Limiting Conditions for Operation (LCO) may not ensure that plant operation is maintained within ehe assumpeions used in the associated. safety analysis as required by 10CFR50.36. On June 7, 1994, while continuing to investigaee the original condition, TS Table 4.3-1 was identified as having a similar
            -condieion. An investigaeion into the consequences and implications of these conditions is continuing to be conducted. A supplement to this LER will be submitted providing this determination based on aceual plant operations.
There have been no previous                                    similar events.
 
LICENSEE EVENT REPORT (LER) TEXT CONTINuATION FAClllTTNAME                                  OOCKET NUMBER                LER NUMBER                PAGE SEQUENTlht. REVISION NUMBER    NUMBER Palo Verde Unit 1 o  5  o o  o  5  2894        0  02      0    1  0 2 OF    1 0 TEXT I. DESCRIPTION OF WHAT OCCURRED:
A. Initial Conditions:
At approximately    1300 MST on    April 22,    1994, Palo Uerde Units 1 and 2  were  in Mode 1  (POWER OPERATIONS)      and Unit 3 was in its 4th refueling outage    (3R4)  with    the core (AC) off loaded to the spent fuel pool (ND).
B. Reportable Event
 
== Description:==
 
Event  Classification:        A  condition that resulted in the plant being in an unanalyzed condition.
A  condition that resulted in the plant being in    a condition not covered by the plant's operating procedures.
APS  has recently completed a Technology Transfer Program with the fuel vendor to allow increased involvement in the reload analysis process. As a result, on March 18, 1994, while performing the reload analysis for Unit 3, Cycle 5 and reviewing associated Operating Procedures, APS Engineering personnel (utility, nonlicensed) identified that Technical Specification (TS) Limiting Conditions for Operation (LCO) 3.1.1.1, 3.3.1, and 3.9.1 may not ensure that plant operation is maintained within the assumptions used in the'current safety analysis as required by 10CFR50.36.
On  April 22,  1994, APS Engineering personnel        completed an      initial investigation of TSs 3,.1.1.1, 3.3.1, and 3.9.1 Basis, associated safety analysis, and in-place administrative controls. This investigation determined that these TSs did not correctly reflect the current reload analysis and that administrative controls may not have been effective in maintaining Plant operations within safety analysis assumptions. At approximately 1354 MST, PVNGS informed the USNRC Operations Center of the potential condition.
TSs  3.1.1.1, 3.3.1,  and  Subcritical      CEA  Withdrawal Analysis TS  3.1.1.1 requires a 1 percent shutdown margin in Modes 3, 4,                  and 5  with all Control Element Assemblies (CEA)(RCT) inserted.
However, the operating procedures and current safety analysis
 
4b Ik LICENSEE EVENT REPORT (LER) TEXT CON INUATION FACILITYNAME                                DOCKETNUMBER              LER NUMBER                    PACE NUMBER I)
YEAR ~Rc,'EQUENTIAL <?.". REVISION NUMBER Palo Verde Unit  1 0 5  0 0 0 528  94 002 0                      1  03 OF 1 0 require that the boron concentration be maintained > Hot Full Power (HFP) All Rods Out (ARO) Equilibrium Xenon Boron Concentration (EXBC) while subcritical (Modes 3, 4, and 5) with the trip breakers (BRK)  closed.
TS  3.3.1 requires the Core Protection Calculators (CPC) to be operable in Modes  1 and 2. However, the operating procedures and current safety analysis require that the CPC Bypass be functional during any subcritical operation (Modes 3, 4, and 5) with the trip breakers closed.
                "When the discrepancy between TS and the Safety Analysis was identified, the Subcritical CEA Bank Withdrawal Safety Analysis assumed protection was provided by the High Log Power Trip (HLPT) at 1.0 E-2 percent power (except in cases where less than four Reactor Coolant Pumps (RCP)(RCT)(P) are running). When less than four RCPs are running, the analysis assumed protection was provided by the automatic removal of the CPC Bypass at 1.0 E-4 percent power prior to reaching the  HLPT  setpoint.
In June 1991, ABB-Combustion Engineering (ABB-CE) informed APS of an  error in the source term used in the Subcritical CEA Bank Withdrawal Safety Analysis. Based on plant procedures, ABB-CE determined that there was no immediate safety concern since the RCS boron concentration would be maintained at or above HFP ARO EXBC.
This boron concentration would prevent criticality on any CEA bank withdrawal with all other CEAs completely inserted. ABB-CE'lso stated that either the boron restriction or operation of the CPCs was sufficient to correct for the source term error.            Based on this statement, APS changed the Operating Procedures to require the boron restriction or operable CPCs. However, the need for the CPCs to be operable during Modes 3, 4, and 5 with < 4 RCPs running was not addressed in the TS.
In 1992, the reload groundrule concerning subcritical CEA withdrawal was changed such that the required RCS boron concentration was assumed to prevent criticality on a CEA Shutdown Bank withdrawal. The HLPT was assumed to protect against a CEA Regulating Bank withdrawal condition. The CPCs continued to generate a trip in any condition above 1.0 E-4 percent power where
                  < 4 RCPs are running (see Section V, Additional Information for a definition/explanation of groundrule). At this point, the
 
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LICENSEE EVENT REPORT (LER) TEXT CONTINUATION LER NUMBER                PACE FACILITYNAME                                  OO CKET NUMBER W SEOUENTIAL ii" REVISION kC  NUMBER  .:.'i NUMBER Palo Verde Unit  1 o  s  o  o  o 5 28  9 4      002            0  1  0 40F previously described Administrative Controls (which required one or the other of the above requirements) no longer assured operation within the safety analysis since both the boron restriction and CPCs would be required.      The need to change the Operating Procedures was not identified during review of the groundrules.
In February 1994, Nuclear Fuel Management (NFM) identified that the subject groundrule required both the boron restriction and operable CPCs  to cover the analysis assumptions.        Corrected Operating Procedures became  effective    on March 4, 1994.
TS  3.9.1 and Mode 6 Boron    Dilution Analysis TS  3.9.1 requires either a K-effective of </ 0.95 or a boron concentration of >/- 2150 ppm, whichever is more restrictive, when in Mode 6. The Mode 6 boron dilution analysis (prior to Unit 3 Cycle 5) assumed an initial boron concentration of 4000 ppm.
ABB-CE performed previous boron dilution analysis using the Refueling Water Tank (RWT) limits of > 4000 ppm and ( 4400 ppm as specified in TS 3.1.2.5. This analysis assumed that when the refueling cavity was flooded, the RWT would be the source of make-up. APS Engineering personnel performing the reload analysis for Unit 3 determined that procedures do not limit the source of make-up to the RWT.
The  Unit 3 Boron Dilution Analysis for Mode 6 was analyzed prior to entry into Mode 6 using an initial boron concentration set at the calculated refueling boron concentration. This boron concentration is more restrictive than a 0.95 K-effective and complies with TS 3.9.1. The analysis verified that the Source Range Monitoring (SRM) Setpoint Ratio of 2.2 remained val'id. The COLR Table 5 "Required Monitoring Frequencies for Backup Boron Dilution Detection as a Function of Operating Charging Pumps" for Mode                  6 required revision.
Reanalysis for the current Unit 1 Core 5 and Unit 2 Core 5 were performed. This verified that the Mode 6 SRM Setpoint ratio of 2.2 remained valid, but COLR Table 5 required changes.            The required monitoring frequencies for backup boron dilution detection in Table 5 of the COLR, for Units 1, 2, and 3 were revised.
 
!! Cl LIC  SEE EVENT REPORT(LER) TEXT CON          UATlON FACII.ITYNAME                                  DOCKET NUMBER                LER NUMBER                  PACE
                                                                          @ SEOUENTIAL >'"': REVISION NUMBEA  4    NUMSEA Palo Verde Unit  1 5    0 0 0  5 28 94        00    2        0    1  0 5or-10 TEXT' On  June 7, 1994,  APS NFM  personnel    (utility, nonlicsensed) identified an additional condition        where the  safety analysis used more restrictive requirements than          the requirement described in 'the TS. TS Table 4.3-1 requires adjustments to linear power level, CPC Delta T Power and CPC nuclear power signals          if  they differ from the calorimetric by an absolute difference of > 2 percent. The ABB-CE letter that transmitted the final CPC/CEAC addressable constants for Unit 3 Cycle 5 requires the calibration tolerance to -be administratively restricted below 30 percent power.
This restriction is based on implementation of the interim approach to the CPC power calibration that was first identified by ABB-CE in 1988. Currently the difference between CPC neutron power, CPC Delta T Power, and COLSS primary calorimetric power is between the range of -0.5 percent to +2.0 percent.          These requirements are currently administratively controlled.
C. Status of structures, systems, or components that were inoperable at the start of the event that contributed to the event:
Not applicable - no structures, systems, or components were inoperable at the start of the event which contributed to this event.
D. Cause    of each component  or system failure,      if known:
Not applicable    - no component    or system failures were involved.
E. Failure known:
mode, mechanism,  and  effect of  each  failed    component,          if Not applicable    - no component    failures  were involved.
F. For    failures of  components  with multiple functions,        list      of systems or secondary functions that were also affected:
Not applicable - no    failures of    components  with multiple functions were involved.
 
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LICENSEE EVENT REPORT (LER) TEXT CON        UATION DOCVET NUMBER                LER NUMBER                PAOE FACILITYNAME REVISION V EAR g$ SEQUENTIAL  NUMBER NUMBER Palo Verde Unit  1 o 5    o o  o  5 28          002          0  1  0 6      1 0 TEXT G. For a    failure that rendered a train of a safety system inoperable, estimated time elapsed from the discovery of the f'ailure until the train was returned to service:
Not applicable - no failures that rendered a          train of      a safety system inoperable were involved.
H. Method    of discovery of each component or system failure or procedural error:
As  discussed in Section I.B, the discrepancies between TS and the current safety analysis were identified as part of the Unit 3 Core 5 Reload Analysis and during a review of an Operating Procedures.
I. Cause    of event:
In previous reload analysis, the nuclear fuel reload groundrules have been treated as an adjunct to the TS.          When groundrules were more  restrictive  than the current TS, Administrative Controls were used to implement the groundrule restrictions and allow operation of the Plant. The limits defined in the TS were not always revised to reflect the reload analysis        if  the Administrative Controls were more restrictive. Because of this, analysis assumptions in the groundrules were not completely consistent with the TS.
Secondly, NFM depends upon the cross discipline review of the groundrules to target Operating Procedure changes. These cross discipline reviews did not always identify the impacts that the groundrule changes had on Operating Procedures.            This is likely related to the complexity of the analyses (SALP Cause Code A:
Personnel Error).
An  investigation of this event is continuing to be conducted in accordance with the APS Incident Investigation Program. As part of the investigation, a determination of the cause(s) will continue.
If  the evaluation results differ from the determinations already identified in this LER, a supplement to this report will be submitted.
 
0 0 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITYNAME                                    DOCKET NUMBER              LER NUMBER                  PACE SEOUENZIAL  REVISION NUMBER    NULIBER Palo Verde Unit o so      ooS28      9 40 02            0  1  0 7 OF    1 0 TEXT J. Safety System Response:
Not applicable - there were no safety system responses              and none were necessary.
K. Failed  Component    Information:
Not applicable - no component        failures  were involved.
II. ASSESSMENT OF THE SAFETY CONSEQUENCES AND IMPLICATIONS OF THIS EVENT:
              ~ TS  3.1.1.1  and  3.3.1    Control Element Assembly    (CEA)  Withdrawal from Subcritical Conditions The RCS boron    concentration  was  to be  administratively controlled at such  a  level that the  shutdown margin requirement would be met and a subcritical CEA withdrawal would not result in criticality.
Even though the administrative control was incorrect, allowing use of the  CPCs  rather than maintaining the boron restriction, the CPC Bypass removal    at 1.0 E-4 percent power would provide a trip for subcritical CEA withdrawal with < 4 RCPs operating. There have been no rod withdrawal events during the time the Administrative Controls were incomplete.
            ~ TS  3.9.1    -    Mode 6 Boron  Dilution The Boron Dilution analysis for Mode 6 was recalculated using the minimum boron concentration required by TS 3.9.1 for each Unit.
When this was done,      it was determined that the Mode 6 Source Range Monitoring    (SRM)  setpoint ratio of 2.2 remained valid for            all    three Units.
            ~ TS  Table 4.3-1    - CPC Power  Calculations The more    restrictive requirements for adjustments to linear power level, CPC Delta T power, and CPC neutron power have been administratively controlled since they were first identified by ABB-CE in 1988 and at no time have the safety analysis results been compromised.
 
0 0 LICENSEE EVENT REPORT (LER) TEXT CONTI UATION FACILITYtIAME                                      DOCKET tiVMBER                LERNVMBER                PAGE Pg SEQUENTIAL @ REVIBION NUMBER    NVMBER Palo Verde Unit    1 p 6    p  p  p 528    94 002              0  1  08oF10 Based on the above, the conditions identified in this LER did not result in any challenges to the fission product barriers or result in any releases    of radioactive materials. An. investigation into the consequences    and implications of these conditions is continuing to be conducted. A supplement to th'is LER will be submitted providing this determination based on actual plant operations.
III. CORRECTIVE ACTION:
A. Immediate:
TS  3.1.1.1  and 3.3.1 Operating Procedures became effective on March 4, 1994, which required HFP ARO EXBC and operable CPCs during subcritical operations when the CEAs are capable of being withdrawn.
A TS change    request is being prepared which will define shutdown margin requirements based on CEA Trip Breaker position rather than CEA position.      To eliminate the need for the CPC Bypass in Modes 3, 4, and 5, the TS change will lower the HLPT setpoint to match the removal of the CPC Bypass setpoint. A reference to the minimum boron requirement will also be incorporated into the COLR. These changes are expected to be submitted to the NRC by August 31, 1994.
TS  3.9.1 The assumption    of  4000 ppm for the initial boron concentration in the Mode    6  Boron  Dilution analysis has been changed to the boron concentration required to comply with TS 3.9.1 and the Boron Dilution Analysis for Mode 6 was reanalyzed.
Table  5  of the  COLRs,  Frequencies      for Backup Boron    Dilution Detection    as a Function of Operating Charging Pumps for Mode 6, has been changed to explicitly include conditions when boron concentrations are < 4000 ppm.
 
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LlCE SEE EVENT REPORT (LER) TEXT CON            UATION FACILITYNAME                                  DOCKET NUMBER                      LER NUMBER                  PAGE YEAR P~.I SEOUENTIAL g  REVISION NUMBER ".oI NUMBER Palo Verde Unit  1 0  5  0  0  0  5      9  400          2      0    1 0 9 oF  1 0 TEXT B. Action to Prevent Recurrence:
The process for reviewing groundrule changes for impact on Operating Procedures will be reviewed to determine                  if  changes are required to enhance the process. This review is expected to be completed by August 12, 1994.
APS NFM  personnel are continuing to review the issues identified and the reload    analysis process to determine          if    additional corrective actions that may be required. This review is expected to be completed by August 31, 1994.            If information is developed which would affect the safety consequences, root cause, or the reader's understanding or perception of this event, a supplement will be submitted.
An  investigation into the    consequences      and implications of these conditions is continuing to      be  conducted.. A supplement to this LER will be submitted providing, this determination based on actual plant operations. This investigation is expected to be completed by August 31, 1994.
IV. PREVIOUS SIMILAR EVENTS:
There have been no previous    similar events.
V. ADDITIONAL INFORMATION:
Groundrule Definition:
The  groundrule document provides        a  singular reference        and method for communicating detailed assumptions used in the reload analysis that are not captured in other analysis inputs, such as:
Performance Objectives, Technical Specifications, Updated Final Safety Analysis Report, Code of Federal Regulations, etc.
Groundrule    prior to March 4, 1994 "Subcritical CEA Withdrawal - The Reload Analysis Report (RAR) analysis for subcritical CEA Bank Withdrawal shall assume that Reactor Coolant System (RCS) boron concentration shall be maintained such that K-effective will be less than 1.0 upon withdrawal of shutdown Full Length (FL) CEAs when the trip breakers
 
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LICENSEE EVENT REPOFIT (LER) TEXT CON NUATION FACILITYNAME                                DOCKET NUMBER                  LEA NUMBER                PACE YEAR,'.~ SEQUENTIAL g> REVISION W NUMBER 4 NUMBEA Palo Verde Unit  1 TEXT osooo 528              94      002            0  1  10OF1  0 are closed with  all other FL  CEAs    fully inserted."
Groundrule  after Harch 4, 1994 "Subcritical CEA Withdrawal - The CPCs will be operable when the RTSG  is closed. The RCS boron concentration will be maintained at or above the boron concentration required for HFP ARO EX conditions until  the shutdown groups are    fully withdrawn."
 
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