ML20043A772

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LER 90-007-00:on 900421,reactor Protection Sys Bus a Transfer & Reactor Recirculation Hydraulic Power Unit a Inboard Isolation Valves Closed,Causing Partial Group II isolation.Out-of-svc Procedure revised.W/900518 Ltr
ML20043A772
Person / Time
Site: LaSalle Constellation icon.png
Issue date: 05/18/1990
From: Diederich G, Wiemholt T
COMMONWEALTH EDISON CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-007-02, NUDOCS 9005230101
Download: ML20043A772 (5)
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                ..                   ! Commonwealth Edison LaS; tis County Nucl ar Station i :.
                      .                Rural Route #1, Box 220
            .                          Marseilles, Illinois 61341
                                     ; Telephone 815/357.-6761
                                                                                                                         'l 1,;
                                                                                   'May 18,11990-
                                                                                                                          -4 Director-of Nuclear Reactor Regulation                                                                i U.S-. Nuclear Regulatory Commission Mall Station'PI-137 Washingtons D.C. 20555-                                                                              -1
                    . Dear Sirs i

Licensee Event Report 590-007-00, Docket- 5050-374 is being 'l submitted to your office in accordance with '; 10CFR50.73(c)(2)(.lv). f / >  ! i G.s J. Diederich l I i ' Station Manager LaSalle County Station- i o 

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r 'j Enclosure l j ! xc Nuclear Licensing Administrator NRC Resident Inspector l NRC Region III Administrator  ! 4 INPO - Records Center 1: l \

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        ,:       -'                                                 LICENSEE EVENT REPORT-(LER)                                             Form Rev 2.0
   . Facility Name (1)                                                                                     Docket Number (2)               Paoe (3)

LaS3 Jg County Stgijon -Unit 2 01 51 01 01 01 31 71 4 1lof!0l4 11tle (4) Partial-Group 11 Isolation during Reactor Protection System DuiJinifer._d.ve to Inadande Procedure and omi-of-service - _CRnJJ) Alt.J5) LER Numb.gr (6) . Rep 9rt .Dete (7) Other Facilities Involved (8) Honth Day Year Year /// Sequential /// Revision Month Day Year Facility Names Docket Number (s) 

                                      /j/jfl _thmber       ,/j/
                                                           /

f Humber I 015101'0101 I l 

                                      ~                    ~~~

_0] 4 '21 1 91 0 91 0 _j)_l O' l 7 01 0' 015 11 8 91 0 01510101OL I-1 OPERATING g (Check one or more of the followino) (11) 20.402(b) . __ 20.405(c) .l._ 50.73(a)(2)(iv) ___ 73.71(b) f POWLR _ 20.405(a)(1)(i) _._ 50.36(c!(1) .__. 50.73(a)(2)(v) . _ 73.71(c) -{ LEVEL _ 20,405(a)(1)(ii) __ 50.36(c)(2) _ 50.73(a)(2)(vii)- _ Other (Specify i (101 0!0!O __. 20.405(a)(1)(iii) __._ 50.73(a)(2)(1) __ 50.73(a)(2)(viii)(A)' 'in Abstract' 

     //////////////////////////       _      20.405(a)(1)(iv)        _        50.73(a)(2)(li)    _ _ . 50.73(a)(2)(viii)(B)-            below and in         i
     //////////////////////////       _      20.405(a)(1)(v)              __  50.73(a)(2)(iii)   _     50.73(a)(2)(x)                 -

Text) LICENSEE CONTACT FOR THIS LER (12) i Name TELEPHONE NUtER ] AREA CODE . 

                                                                                                                                                   .   . 1 Jerry W. Wiemholt. Technical Staff E D aineer. extension 2319                                              81115          31 51 71 l 6] 7l bj._1_        f COMPLETE ONE L?NE FOR EACH COM ON N FAILURE DESCRIBED IN THIS REPORT i13)                                                   j CAUSE        SYSTEH   COMPONENT      MANUFAC-      REPORTABLE                   CAUSE     SYSTEM     COMPONENT    HANUFAC-         REPORTABLE           j TURER         TO NPRDS                 .                                    TURER            TO NPRDS           1

___D_ ___j l _[_l- _ 1 I I H l l l l l l 'l f* E' l l l l I l I N l l l l 'l ' l I 

     -                          SUPPLEMENTAL REPORT EXPECTED (14)                                                      Expected Month I Day l Year Submission

_ lyss (Ifves.completeEXPECTEDSUBMISSIONDATE) X l NO l l l ADSTRACT (Limit to 1400 spaces, i.e, approximately fif teen single-space typewritten lines) (16)  ! On April 21, 1990 at approximately 0525 hours with Unit 2 defueled at 0 percent power, while transferring l "2A" Reactor Protection System (RPS) Bus from its ALTERNATE feed to its NORMAL feed per LaSalle 0perating 

                                                                                                                                                           -l l:          Procedure LOP-RP-03, "RPS Bus A Transfer", the "A" Reactor Recirculation (RR)-(AD) Hydraulic Power Unit (HPU)-

{ l inboard isolation valves 2833-F338A, 2033-F340A, 2B33-F342A, and 2033-F344A closed. Other system isolations q l were defeated or out-of-service. 1 l The apparent.causes of this event were an inadequate procedure and a deficiency in the preparation of an Out-of-Service (005). i RPS Bus Transfer procedures were revised to require that all Primary Containment isolation-test switches be vertfled in the " NORMAL" position prior to RPS bus transfer. l The appropriate operating department shift personnel will be informed that when writing 00$ special' j instructions guidance must be provided to ensure all equipment is returned to normal. -LAP-900-4, " Equipment j nut-of-Service Procedure" will be revised to incorporate this practice. This event Is reportable to the NRC pursuant to the requirements of 10CFR50.73(a)(2)(lv) due to the actuation ! of an Engineered Safety Feature (ESF) System. J

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                                           ' LICENSEE EVENT REPORT (LER) TEXT CONTINUATION                                    ' Form Rev 2.0_         ;

j FACIllTY HAME (1).. DOCKET NUMBER (2) LER NUHDER (6)c Paoe (3) 

  '                                                                           , Year    /// . Sequential         / Revision fjj
                                                                                        ///     Number-      //j/j f
                                                                                                             //     Number                             *

(dtlt_l CRY.01LS1LtiOR. Unit '2 0 1 5 1 0'l 0 1 0 l'31 71 4 9 l' 0 J 01017 - 0 lJ O .01 2 OF' Ob TEXTJ Energy Industry Identification System (EIIS) codes are identified in the, text as (XX]) i i PLANT AND. SYSTEM IDENTIFICATI0H 

              ~ General. Electric - Boiling Water Reactor                                                                                            f 1
                                                   ~
                                                                       .            . .        .           .                                        1 Energy Industry Identification System (EIIS) codes are identified in the text.as (XX).                                                 ;

s i A. CO.NDITION PRIOR TO EVENT. Unit (s): .2_ ' Event Date: 4/21/9L. -Event Time: 0525 Hours i Reactor Hode(s): _Dely11gd_- Mode (s) Name: Defueldd -- ' Power Level (s): ' 0% B. DESCRIPTION.0F EVENT 4 On April.21, 1990 at approximately 0525 hours with Unit 2.defueled at 0 percent power while transferring "2A" Reactor Protection System (RPS) -(EF) Bus f rom e s ALTERNATE feed to its NORMAL feed . q per LaSalle.0perating Procedure LOP-RP-03, "RPS Bus A Transfer" _the "A" Reactor Recirculation (RR)-(AD)- Hydraulic Power Unit (HPU) Inboard ' isolation -valves 2833-F330A, .2B33-F340A, ,2033-F342A, and 2B33-F344A . closed. This occurred because a half trip was ef fectively inserted for. Primary Containment Isolation, System (PC) d (JHJ logic "D" Channel due to the Group II Bypass switch, 2021H-S800, being in the':" TEST",(bypass)- position. When the."2A"'RPS Bus was transferred it caused the "A" and "C" PC: Channels to' trip due to loss of RPS Bus "A" power to the reactor low level (level 2) . trip relays and ithe Primary Containment l' High Drywell Pressure relays. This resulted in a Primary Containment Isolation l System Division.II l- isolation signal to perform .the following: l Close the inboard isolation valvss for-Groups II, IV,'and X. 

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               -. Initiate the Division II Post-LOCA_H2-02 monitor and both' Standby. Gas Treatment Systems.
Only the "A" Reactor Recirculation (RR) (AD) Hydraulic Power Unit-(HPU). inboard; isolation valves a i

2B33-F338A, 2B33-F340A, 2B33-F342A, and 2B33-F344A closed, because all of'.the other Group II and Group X i valves were.already closed or out of service. A Group ~IV isolation was not received due to. Temporary l System Change (TSC) 2-251-90 which overrode all Group.IV Isolations not required for ~this plant ' condition. The isolation logic was reset. The "A" RR HPV inboard isolation valves 2B33-F338A, 2B33-F340A, I 

              '2033-F342A, and 2B33-F344A were reopened.                                                                                             4 i

This event is reportable to the NRC pursuant to the requirements of 10CFR50.73(a)(2)(lv) due to the actuation of an Engineered Safety Feature (ESF) System. _o i n 

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l . LIC[t(1ELEVENT REPORT (LER) TEXT CONTINUATION Form Rev 2.D_ l' . FACILITY NAME (1) DOCKET NUMBER (2)- LER NUMBER (6) Pace (31 Year /// fjj Sequential // Revision e /// Number j/j 

                                                                                                  /     Number LaSallel0unty Station Unit 2           0 l 5 1 0 1 0 l 0 1 31 71 4 9l0       -   Ol0l7       -

0l _0 - O l_1 0F OLs 

     -TEXT        Energy Industry Identification System (EIIS) codes are identified in the text as (XX)

C. APPARENT CAUSE OF EVENT The apparent causes of this event were an inadequat3 procedure and a deficiency in the preparation of an Out-of-Service (005). Procedure LOP-RP-03,~"RPS Bus A Transfer" was inadequate in that it did not ensure that the PC test switches are.in the " NORMAL" position prior to transferring the RPS tms. 005 2-479-90 was written in accordance with LAP-900-4, " Equipment Out-of-Service Procedure". - This 005 was written to' isolate the 2021H-S00D switch so that:1t could be worked on per work request L92086. . No f, 005 card could be placed on the 2B21-S80D switch because doing so would prohibit the work from being. done. The individual .who wrote the 005 Checklist wanted the circuit opened before lif ting the leads to.- Isolate the switch. To accomplish this-he provided special instructions on the 00S to " PLACE KEYLOCK SWITCH 2021-S800 in ' TEST' before hanging (the 005)." These instructions failed to specify that the. switch must be returned to "NORHAL". The switch was placed in " TEST" prior to hanging the-00$ cards-on April 16, 1990 as required by the 00S special instructions. The work was completed and the 005 cleared , the next day by a different crew who did not reposition the switch. On April 19,'1990, the return to service test required by the work request was performed by Operating Department. Thisl test cycled the- ' switch, but the operator returned the switch to the as found position,1" TEST", upon completion. The switch was returned to " NORMAL" only af ter the ESF actuation on April 21. 1990. D. SAFETY ANALYSIS OF EVENT The power supplies for the PC system are arranged so that loss of one power supply cannot prevent autumatic isolation when required. The PC system actuated as designed. fhe consequences of this event were minimal since the -system which isolated =(RR) 'is not a safety related system and was not required to be operating with Unit 2'defueled. This type of work (taking PC logic OOS) is not normally done with the' Unit In Operational Condition 1 (RUN), 2 (STARTUP), or 3 (HOT SHUTDOWN). Had this event occurred in one of_these conditions all of the. Inboard isolation valves for Group II, IV and X would have closed and Division 11 Post-LOCA H2-02 monitor and both Standby Gas Treatment Systems would have initiated. These actuations, by themselves,  ; would not have caused a scran or placed the Unit in an unsafe condition. However, loss'of these and. other systems would have required immediate response by the operators to prevent a subsequent unit scram. i 

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y LICEN$EE EVENT REPORT (LER) TEXT CONTINUAIION Form Rev 2.0 rACILITY,NAME-(1) DOCKET NUMBER (2)- LER HUMBER (6) Page (3)' l f.__

  • K Year / Sequential / Revision
                                                                                         /j/j/j
                                                                                         //      Humber    /j/j/j
                                                                                                           //      Bumber La.51]le_foun t y Station Unit 2         0 l 51010 l 0131714 910                 -    0 I 0 l'7    -     01 0       01 4    0F       01 4 Energy Industry Identification System (EIIS) codes'are identified in the text as (XX).
iEXT .
              'E. CORRECTIVE ACTIONS
                   ' Procedures LOP-RP-03.. "RPS Bus A Transfer" and LOP-RP-04, "RPS Bus B' Transfer" were revised 'to require -

that all PC isolation test switches be verified in the " NORMAL" position prior to a RPS bus transfer. Training is being provided to licensed shif t operators on the importance of recognizin' g off-normal panel: conditions, and taking appropriate corrective action when abnormal conditions are . identified. . Action- 

                    . Item Record (AIR) 374-200-90-03101 will track completion of this training.
                    -AIR 374-200-90-02702 will-be developed and issued to inform the appropriate operating' department shift personnel that when writing OOS.special instructions which place a~ component in an abnormal position, specific guidance must.be provided to ensure its return to the normal position.

LaSalle Administrative Procedure LAP-900-4, " Equipment Out-of-Service Procedure" will be revised to incorporate this practice. AIR 314-200-90-02701 will track completion of this. revision. F. PREVIOUS EVENTS LER Humber Title 373/06-037-00 Spurious Group II and Group.IV Isolation.

  • 374/90-005-00 Inadvertent Division I Isolation Due to Loss of DC Power to.' Isolation Logic due to Procedural Error 374/90-006-00 Inadvertent Actuation of Group 11 due 'to Procedural Deficiency and Inadequate Out of Service.

G. COMPONENT FAILURE DATA There was no component failure. l ___}}

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