ML20024G977

LER 91-005-00:on 910410,determined That Tech Spec Required Surveillance of Suppression Chamber Oxygen Sampling Missed. Caused by Inadequate Review of Tech Spec Change.Drywell & Suppression Chamber Checked for oxygen.W/910510 Ltr

ML20024G977
Person / Time
Site:	LaSalle
Issue date:	05/10/1991
From:	Diederich G, Sanders L COMMONWEALTH EDISON CO.
To:	Office of Nuclear Reactor Regulation
References
LER-91-005-03, LER-91-5-3, NUDOCS 9105160068
Download: ML20024G977 (5)

Text

.- _ . _ . . _ _ _ _ - - _ . - __ - . _ . .- . . _ _ _ - - - _ _ _ _ _ .

t

• Cc nm:nw:alth Edis:n LaSane County Nuclear Station I i f. Rural Route #1, Box 220

\ v Marseines, Illinois 61341

\ Telephone 815/357-6761 l

i May 10, 1991

\

l Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission i Mail Station PI-137 Washington, D.C. 20555 Dear Sir Licensee Event Report #91-005-00, Docket #050-373 is being submitted to your office in accordance with 10CFR50.73(a)(2)(1).

r yll l.

p d G. J. Diederich

[StationManager LaSalle County Station GJD/LRS/mk1 Enclosure xc Nuclear Licensing Administrator NRC Resident Inspector NRC Region III Administrator INPO - Records Center IDNS Resident Inspector l

i l

l l

l l

9105160068 910510 PDR ADOCK 05000373 S PM /

1. .

r

• LICENSEE EVENT REPORT (LER) F rm Rev 2.0 Facility Name (1) Docket Number (2) Pace (3) taf alle Mntv Station Unit 1 01 51 01 01 O! 31 71 31 1lofl0l4 Title (4)

MLued Technical Soeetfication surveillante On Containment Monitorina Due To Inadeauste Pre-License Revitw Event Date (5) t[R Numter (6) Report Date (7) Other Facilities involved (3)

Month Day Year Year // Sequential // Revision Month Day Year Facilltv Names Doelet Number (s) j//jj// Number

/j/j f

// Number taSalle Unit 2 015101010131714

~~~ ~~~

01 4 11 0 91 1 91 1 01015 010 015 10 1 9_f 1 01 $1 01 01.01 1 l THIS REPORT !$ SUBMITTED PUR$UANT TO THE REQUIREMENTS OF 10CFR OPWTM # "' ' *"'

mDE (9) 5 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b)

POWER __ 20.40$(a)(1)(1) , , , , 50.36(c)(1) ._. $0.73(a)(2)(v) _ 73.71(c)

LEVEL 20.40$(a)(1)(li) $0.36(c)(2) 50.73(a)(2)(vii) Other (Specify 0 l0 l0 (10) , 20.40$(a)(1)(lit) 1. 50.73(a)(2)(1) _ 50.73(a)(2)(viii)(A) in Abstract

///,/,/ / / /,/ / / /,/,//// /// /,//,///, ,,.__ 20.405(a)(1)(iv) _ 50.73(a)(2)(ii) ,_ 50.73(a)(2)(viii)(B) below and in

//'/,}///'////}/'/////////'

/

j , j//' //'/

j ,_ 20.40$( a)(1)(v) 50.73(a)(2)(iii) _ 50.73(a)(2)(a) Tent)

LICENSEE CONTACT FOR THIS LER (12)

Name 1ElEPHO*lE NUMDER AREA CODE

. teen Sanders. . Technical Staff Enaineer. Estention 2772 8 l 1 l$ 31$l71-l6171611 COMPLETE ONE LINE FOR EAJH COMPO EMI FAltVRE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC- REPORTABLE CAUSE $YSTEM COMPONENT MANUFAC- REPORTABLE TUAER 10 NPRDs TURER TO NPPDS

,, A 1. ! K l i i l ! I N l i l l I l l l l l l t i I f I i l l l l

$UPPLEMENTAL REPORT EXPECTED (14) Espected Month.I Dav i Year Submission lyes (If ves, complete EXPECTED SUBM!$$10N DATE) X l NO I !l !l ABSTRACT (Limit to 1400 spaces, i.e. approximately fif teen single-space typewritten lines) (16)

On April 10, 1991 at 1230 hours0.0142 days <br />0.342 hours <br />0.00203 weeks <br />4.68015e-4 months <br /> with Unit 1 in Mode 5 (Refuel) and Unit 2 in Mode 1 (Run) at 0%/100% power respectively, it was determined that LaSalle Station had not performed a Technical Specification surveillance requirement on suppression chamber osygen sampling. Technical Specification 3.6.6.2. was changed f rom taking an oxygen sample f rom Primary Containment to taking the osygen sample f rom the Drywell and Suppression Chamber during pre-licensing (1981). LaSalle Operating Surveillance LOS-AA-W1 " Technical Specification Weekly Surveillances" performs sampling of the drywell en a weekly basis but did not get revised to include sampling of the suppression chamber.

The apparent cause of the event was due to an inadequate review of the Technical Specification change to determine procedures that required revisions.

The consequences of this event are minimal since the drywell and suppression chamber are inerted in parallel and the drywell free air space is_ larger than the suppression chambers free air space, therefore making it highly likely that a non-combustible mixture has been maintained in the suppression chamber.

LaSalle Operation Surveillance LOS-AA-W1, was revised and performed satisf actorily on April 10, 1991 and found the drywell and suppression chamber at 2.4% and 3.2% onygen concentration respectively.

This event is reportable to the NRC pursuant to the requirements of 10CFR50.73(a)(2)(1) due to a condition prohibited by the plant Technical Specifications.

e

• LIQgEE E\ fNT REPORT (LER) TEXT CONTINUATJJ)N fnm P.tv 2.0.

FACILIT,Y NAME ,(1) DOCKET NUMBER (2) _LER NUMBER (6) Paae (3) ,,

Year j/jj// Sequential /jj/j/ Revision

/// Number /// Number LaSalle County Station Unit 1 01510l0l0131?!3 911 - 010l5 - 0 i0 Of 2 0F OL4 TEXT Energy Industry Identification System (E115) codes are identified in the test as (XX) l PLANT AND SYSTEM IDENTIFICATION General Electric - Boiling Water Reactor Energy Industry Identification $ystem (Ells) codes are identified in the text as (XX).

i l

A. CON 01110N PRIOR TO EVENT Unit (s): J/2. Event Date: 04/10/91 Event Time: 1230 Hours j Reactor Mode (s): $4L Mode (s) Name: Refuel /Run Power Level (s): 0.0/100%

0. DESCRIPTION OF EVENT On April 10,1991 at 1230 hours0.0142 days <br />0.342 hours <br />0.00203 weeks <br />4.68015e-4 months <br /> with Unit 1 in Mode 5 (Refuel) and Unit 2 in Mode 1 (Run) at 01/100%

power respectively it was detemined that LaSalle Station had not perfortned a Technical Specification surveillance requirement since initial reactor startup for each unit. This missed surveillance requirement was discovered during the investigation of another event when the Unit 2 Suppression Chamber inadvertently had Unit 1 Reactor Building air introduced into it (Deviation Report 1-2-91-011),

i During pre-licensing (1981) of Unit I and Unit 2, when the Technical Specifications initially rere being reviewed and approved by the station and the NRC, a Technical Specification change submittal was requested for specification 3.6.6.2, " Primary Containment Oxygen Concentration". This requested specification change had the requirement to verify the oxygen concentration in the primary containment at least once per seven days while in Operational Condition 1 (Run). The approved specification change also included a change to the specification title, which changed to "Drywell and Suppression Chambe, Onygen Concentration" and changes to the Limiting Condition for Operation (LCO) and Surveillance Requirement sections, which changed " primary containment" to "drywell and suppression chamber". After approval from the NRC, the station proofed and reviewed the changes. It is believed that the reviewer determined that these changes were strictly editorial, since the drywell and suppression chamber make up .

the primary containment, and thus required no procedure or surveillances revisions. In fact, the change  !

required oxygen concentration to be verified in two locations (drywell and suppression chamber) instead of just the primary containment, as per the original Technical Specification change request.

This event is reportable to the NRC pursuant to the requirements of 10CFR50.73(a)(2)(1) due to a condition prohibited by the plant Technical Specifications.

e l __

LICENSEE EVENT REPORT QLR) TEXT CONTINUATION Fem Rev 2 !L FACit!1,Y NAME ,(1) DOCKET NUMBER (2) LER NUMBER (6) Past_L3)

Year / Sequential /j/,

/ Revision

/j/j/j

// Number f

/// Number Walle County Stalion Unit 1 0 1 5 1 0 1 0 1 0 l 31 71 3 911 - 01015 -

0 IO 01 3 Of 01 4 1 EXT Energy Industry Identification System (Ells) codes are identified in the text as (XX)

C. APPAR[Ni CAUSE OF EVENT The requested change submitted to the NRC was changed at the NRC to reflect that primary containment samples were to be taken f rom the drywell and the suppression chamber. During the pre-licensing of the station it was not unconinon f or the NRC to include editorial changes back with approved submittals. It is believed that the station reviewer of the approved change thought that this change was editorial only, due to the primary containment being the same as the drywell and suppression chamber, and did not further pursue a change to the sampling procedure. The apparent cause of the event was due to an inadequate review to determine the ef fects of the Technical Specification change on applicable station procedures.

D. SAFETY ANALYSIS OF EVENT Prior to this event, the drywell oxygen concentration has been monitored (weekly) in accordance with LOS-AA-W1 which did not explicity state to monitor the suppression chamber f ree air space. The consequences of this event are minimal since the drywell and suppression chamber are inerted in parallel and the drywell f ree air space is larger than the suppression chambers f ree air space, theref ore making it highly likely that a non-combustible mixture has been maintained in the suppression chamber.

LOS-AA-W1 was perfonned satisf actorily on April 10, 1991 and found the drywell and suppression chamber at 2.4% and 3.2% oxygen concentration respectively. These readings provide assurance that the suppression pool was inerted at the same time the drywell was inerted. Had an accident occurred and suppression chamber pressure increased, the f ree air space in the drywell and suppression chamber would mix together so that a oxygen sample f rom the drywell would be a representative sample of the oxygen concentration in the drywell and suppression chamber. Safe operation of the plant was not af fected.

E. CORRECTIVE ACTIONS Once the discovery of the missed surveillance requirement was made, corrective actions were immediately taken to check the Unit 2 drywell and suppression chamber for oxygen concentration and to revise LOS-AA-W1. A procedure revision to LOS-AA-W1 was initiated and, when approved on April 10, 1991 the procedure was performed satisf actorily and found the drywell and suppression chamber at 2.4% and 3.2%

ouygen concentration respectively.

LaSalle Administrative Procedure LAP-1200-12 " Operating License Technical Specification Changes" has been developed to provide guidance for properly preparing and processing Technical Specification CSanges. This procedure contains checklists for review of procedures that may be af fected by the change an involves a tracking mechanism to ensure their completion.

This type of missed surveillance has been detennined to be an isolated case and no further review is warranted.

e *

, e

)

ll(t$ftEVINTRIPORT(LfR) IfXT CONTINUATION Form Rev 2.0 ,

FACIL11Y.NAME,(1) LOCKET NUMBER (2) LfR NUMBfR (6) _

Pace (3) __

Year fj/j/ Sequential ///

/

fff Revision

/// Number /// Number AA3alle Countv Station Unit 1 015101010131713 9l1 - 01015 - 0 10 01 4 0F 01_4 ftXT Energy Industry Identification System (t!!$) codes are identified in the test as (XX)

F. PREVIOU$ [VENi$

LtR Number Title  ;

374/88-004-00 Missed Technical Specification $vrveillance Due To Personnel Error, 374/68-006-00 Missed Loose Partt Surveillance Due To Personnel trror.

374/89-015-00 Missed Technical $pecification $urvel11ance On Standby Liquid Control System Due to Administrative trror, t

G. COMPONENT FAILURE DATA There were no component f ailure, i

t l

i

' ,-;. .#.,. _, _ 2 , _ .._2._  :..._.. _;_. . . _ _ _ .