05000271/LER-1993-009

LER 93-009-00:on 930716,B Train of RHR Sys Declared Inoperable.Caused by Personnel Error Re Failure to Initiate Rev to Calibration Procedure OP 4347.Instrument re-calibrated & OP 4347 revised.W/930813 Ltr

ML20056D928
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	08/13/1993
From:	Wanczyk R VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-93-009, LER-93-9, NUDOCS 9308190021
Download: ML20056D928 (4)

LER-2093-009,

Event date:
Report date:
2712093009R00 - NRC Website

text

s VERMONT YANKEE ,

NUCLEAR POWER CORPORATION ,

e

'~T  ;- - P.O. Box 157, Governor Hunt Road

'g y T Vemon, Vermont 05354-015'7 x V (A02) 257-7711 h9 (L.'k:'~'l,'V \

,]

v August 13, 1993 i

U.S. Nuclear Regulatory Commission '

Document Control Desk washington, D.C. 20555

REFERENCE:

Operating License DPR-28 Docket No. 50-271 Reportable Occurrence No. LER 93-09

Dear Sirs:

As defined by 10 CFR 50.73, we are reporting the attached Reportable Occurrence as LER 93-09. t Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION Robert J. Wa czyk Plant Manager cc: Regional Administrator USNRC Region I  ;

475 Allendale Road '

King of Prussia, PA 19406 ,

170005

[SE**%88!A!!88537, m

F y

fM8I i

b WltC Form 366 U.S. NUCLEAR REcVLATORY C0m!SSIDW APPROVED OMS NO. 3150-0104

, (6-E9) EXPIRES 4/30/92

, ESTIMATED BURDEN PER CIESPONEE TO COMPLY WITH THIS

' INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD

. COMMENTS RECARDING BURDEN ESTIMATE TO THE RECORDS AND l

! REPORTS MANAGEMENT BRANCH (P-350), U.S. NUCLEAR REGULATORY l COMMISSION, WASHlWGTON DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3160-0104), OFFICE OF MANAGEMENT AND ,

BUDGET, WASH!NGTON, DC 20603.

FACILITY NAME (1) DOCKET No. (2) PACE (3)

VERMONT YANKEE NUCLEAR POWER STATION Ol5l0l0l0l2l7l1 0 1 0F 0 3 TITLE (4) "B" CORE SPRAY SYSTEM DECLARED INOPERABLE DUE TO INSTRUMENT DUT OF TOLERANCE AS A RESULT OF PERSONNEL ERROR l

l 1

i EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR SEQ # REV # MONTH DAY YEAR FACILITY WAMES DOCKET NO. (S) 0 5 0 0 0 i

0 7 1 6 9 3 9 3 -

0 0 9 -

0 0 0 8 1 3 9 3 0 5 0 0 0 l

OPERATING THis REPORT IS SUBMITTED PURSUANT TO REQ'MTS OF 10 CFR i: CHECK ONE OR MORE (11)

MODE (9)

N 20.402(b) ?0.405(c) 50.73(a)(2)(iv) 73.71(b) -

POWER 20.405(a)(1)(1) 50.36(c)(1) x 50.73(a)(2)(v)+(vi) 73.71(c)

LEVEL (10) 1l0l0 20.405(a)(1)(li) 50.36(c)(2) 50.73(a)(2)(vii) OTHER:

.................. 20.405(a)(1)(iii) 50.73(a)(2)(i) 50.73(a)(2)(viii)(A)  !

.......... ... ... 20.405(a)(1)(iv) 50.73(a)(2)(li) 50.73(a)(2)(viii)(B)

.................. 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LER (12)

EAME TELEPHONE NO.

J AREA CabE ROBERT J. WANCZYK, PLANT MANAGER 8l0l2 2l5l7l-l7l7l1l1 ,

COMPLETE ONE LINE FOR EACH COMPONENT FA!LUPE DESCRIBED IN THIS REPORT (13)

CAUSE SYST COMPONENT MFR REPORTABLE CAUSE SYST COMPONENT MTR REPORTABLE TO WPRDs .... TO NPRDS ....

A BlG P DlI l5 Bl0l8l0' Y .... kA l l l l l l l l 1 SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MO DAY YR SUBMISSION DATE (15)

YES (If yes, cocplete EXPECTED SUBMISSION E. ATE) X WO l l l ABSTRACT (Limit to 1400 spaces, i.e., approx. fif teen single space typewritten lines) (16)

On 7/16/93 at 0840, with the plant operating at 100% power and the *B* Train of the Residual Heat Removal System (RHR) removed from service, the *B* Train of the Core Spray System (CS) was declared inoperable. In accordance with l Technical Specifications, with one RHR System and one Core Spray System inoperable, a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> shutdown LCO was entered. l The basis for declaring the *B* Train of the CS System inoperable was the identification that the respective Sparger Break i Detection System differential pressure indicating switch (DPIS) setpoint was out of specification. DPIS-14-43B was cahbrated to within the required limits and at 0930 on 7/16/93 the *B" Core Spray System was returned to service.

As discussed in LER 93-006, an interim administrative setpoint for the Sparger Break Detection Sensors was imposed by Plant fAanagement on 5/27/93 due to questions relative to the appropriateness of the TS setpoint. On 7/12/93, DPIS 43B was cal:brated and left outside the administrative limit due to the f act that the calabration procedure had not been revised to the new interim setpoint values. The root cause of this event is personnel error irs that timely revision to the instrument calibration procedure was not performed by the responsible manager. The instrument was immediately re calibrated to within the interim administrative setpoint, the calibration procedure was revised to reflect the new setpoint, and a corrective action report is being prepared.

I NRC Foira 366 (6-29)

i

.NRC Form 366A U.S. NUCLEAR REGULATC3i coMMiss10N APP 30VED oms No. 3150-0104 l' (6-G9) EXPIRES 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY VITH THIS INFORMATION COLLECTION REoVEST: 50.0 hrs. FORWARD COMMENTS RECARDING BURDEN ESTIMATE TO THE RECORDS AND I

' LICENSEE EVENT REPORT (LER)  !

TEXT CONTINUATION REPORTS MANAGEMENT BRANCH (P-350), U.S. NUCLEAR REGULATORT COMMISSION, WASHINGTON DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3160-0104), OFFICE OF MANAGEMENT AND BUDCET, WASHINGTON, DC 20603.

FACILITY NAME (t) DOCKET NO (2) LER NUMBER (6) PAGE (3)  !

YEAR SEQ # REV # f VERMONT YANKEE NUCLEAR POWER CORPORATION 9 3 -

0 0 9 -

0 0 0 0F 0 0l5l0l0l0l2l7l1 l2 l3 TEXT (If more space is required, use additional NRC Form 366A) (17)  !

DESCRIPTION OF EVRE On 7/16/93 " 0840, with the plant operating at 100% power and the *B* Train of the Residual Heat Removal System (RHR)(*BO) removed from service for Limiting Condition for Operation (LCO) Maintenance, the *B' Train of the Core Spray ,

System (CS)(*BG) was declared inoperable. In accordance with Technical Specifications (TS) section 3.5.A.6, with one train of the RHH System removed from service and one train of the Core Spray System declared inoperable, a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> shutdown LCO was entered. The reason for declaring the *B' Train of the CS System inoperable was the identification that the respective '[

Sparger Break Detection System differential pressure indicating switch (DPIS) setpoint was out of specification. The condition L was identified during the review of the calibration procedure data sheet by the system engineer. DPIS-14-43B was calibrated  ;

to within the required limits and at 0930 on 7/16/93 the "B" Core Spray System was retumed to service. l i

in LER 93-006 (event date 5/27/93) Vermont Yankee reported to the Commission that sufficient information existed to suspect that the Technical Specification Table 3.2.1 setpoint for CS Sparger Break Detection Sensors DPIS-14-43A/P d 5 5 psid was non-conservative based upon information contained in Generr' Electric (GE) Services information Letter (SIL, MO and  ;

recent discussions with GE. Information in SIL 300 indicates that the A 5 psid TS setpoint for the sparger break detection sensors may be inappropriate and that a setpoint of i 4 psid would be consistent with the Sll data.

l On 5/27/93 Plant Management had determined that the setpoint of the CS Break Detection System would be n.aintained at S 4 psid until a more thorough review could be conducted of the data contained in the SIL 300, this review is currently ongoing and scheduled to be commted by 8/31/93. Since the previous setpoint for the DPISs was 4 psid + /-0.3 psid, the immediate response to the potentially inappropriate TS setpoint was to set both DPIS-14-43A and B to the low side of the existing setpoint tolerance band (eg: 3.7 psid). A ionnal change to the setpoint was to follow on the next day that would remove the upper tolerance band from the cabbratu procedure (eg: + 0.3). Contrary to the above, the setpoint change was not initiated on the following day and the calibration procedure was not revised. On 7/12/93, DPIS-14-43B was calibrated and the trip point was left at 4.2 psid, this is above the 14 psid setpoint determined necessary on 5/27/93. Although this is not technically a violation of a Technical Specification setpoint, based upon the information presented above and the intent to administratively maintain the setpoint of 14 psid until further review of the setpoint could be performed, this event is conservatively being reported to the Commission.

CAUSE OF EVENT The root cause of this event is personnel error. The ccgnizant manager was informod on 5/27/93 of the need to initiate a revision to the calibration procedure OP 4347

• Core Spray Header Differential Pressure Functional / Calibration

• to include the revised setpoint tolerance. It was identified on 7/16/93 that the procedure revision was not done and that the DPIS-14-43B was out of the administrative tolerance.

ANALYSIS OF EVENT ,

The purpose of the Core Spray Sparger Break Detection System is to alert Control Room Operators of a pipe break in  !

the Core Spray Sparger piping within the reactor vessel. l There were negligible safety implications resulting from declaring the *B' Train of the Core Spray System inoperable.

The instrument was calibrated to within specification approximately 50 minutes after identification of the error. It is estimated that the DPIS setpoint was above the 4.0 psid setpoint since mid-June 1993. It should be noted that both Trains of the Core Spray System were intact during this avent and would have functioned if required. *

• Energy industry identification System (Ells) Identifier L

NRC form 366 l (6-89) ,

i

1. NRC Forn 366A U.S. NUCLEAR REGULATORY COMMISS10N APPROVED OMS NO. 3150-0104 (6 09)

EXPleES 4/30/92

+

ESTIMATED BURDEN PER RESPONSE TO COMPLY LIITH THIS t

~

INFORMATION COLLECTION REQUEST: 50.0 HRS. FoRWARG LICENSEE EVENT REPORT (LER) COMMENTS RECARDING BURDEN ESTIMATE TO THE RECORDS AND i TEXT CONTINUATION REPORTS MANAGEMENT BRANCH (P-350), U.S. NUCLEAR REGULATORY I COMMISSION, WASHINGTON DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3160-0104), OFFICE OF MANAGEMEkT AND 1 BUDGET, WASHINGTON, DC 20603.  ;

FACILITY NAME (1) DOCKET No (2) LER NUMBER (6) PAGE (3) i YEAR SEQ # REV #

VERMONT YANKEE NUCLEAR POWER CORPORATION 9 3 -

0 0 9 -

0 0 0 0 0l5l0l0l0l2l7l1 l3 DF l3 TEXT (if more space is required, use additional NRC Form 366A) (17) j l  ?

ANALYSIS OF EVENT (continued)

The safety implication associated with the personnel error is that the potential existed for both Core Spray System Sparger Break Detection System DPISs to be set high. Therefore had a break in the Core Spray Sparger Piping occurred, the instruments would not have provided the alarm function. The safety significance of this is considered to be minor since the Core Spray Sparger Piping is inspected each outage to verify physical integrity and only one train of the Break Detection System I was found to be out-of specification.  ;

CORRECTIVE ACTIONS [

Immediate:

1. Upon discovery of the personnel error, the instrument was immediately re-calibrated to the f. 4 psid setpoint.

i

2. OP 4347 was revised to reflect the removal of the upper tolerance band (eg: + 0.3 psid). The current setpoint in the procedure is 4 psid + 0, -0.3. i Long-Term:

i

1. Preparation of a corrective action report has been assigned to the instrument and Control Department to document the cause and recommend further corrective actions if required.

ADDITIONAL INFORM ATION As described previously in this report, a similar condition was reported to the Commission in LER 93-006 in that a concern with the Core Spray Break Detection System Setpoint resulted in the determination that a Core Spray System Train (s) l was inoperable.

l l

j l 4 ,

j

• Energy Industry identification System (Ells) Identifier i

I 1

4 J

NRC Form 366 (6-89) l

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