05000338/LER-1998-001, :on 980108,determined That Potential to Miss Interlock Logic Surveillance Testing During Previous mid- Cycle Shutdowns Existed.Caused by Inadequate Test Design Supplied by Vendor.Info from Last Startup Reviewed

:on 980108,determined That Potential to Miss Interlock Logic Surveillance Testing During Previous mid- Cycle Shutdowns Existed.Caused by Inadequate Test Design Supplied by Vendor.Info from Last Startup Reviewed

ML20202C830
Person / Time
Site:	North Anna
Issue date:	02/03/1998
From:	Matthews W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML20202C802	List: 05000338/LER-1998-001, :on 980108,determined That Potential to Miss Interlock Logic Surveillance Testing During Previous mid- Cycle Shutdowns Existed.Caused by Inadequate Test Design Supplied by Vendor.Info from Last Startup Reviewed
References
LER-98-001, LER-98-1, NUDOCS 9802130038
Download: ML20202C830 (3)

LER-1998-001, on 980108,determined That Potential to Miss Interlock Logic Surveillance Testing During Previous mid- Cycle Shutdowns Existed.Caused by Inadequate Test Design Supplied by Vendor.Info from Last Startup Reviewed

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
3381998001R00 - NRC Website

text

NRC FORM 366 u S. NUCLEAR REGULATORY CoMMISSloN APPROVED BY oMB No. 3160-0104 (4 95)

EXPIRES 4/30/98 00??J.'lJ'L"'cM20.',"M' LICENSEE EVENT REPORT (LER)

ELL"ll'#'."Mt OTW1s

% %E,T l 0"l3f C.ji',"'14 (s'ee reverd for required number of digitt/ characters for each block)

'l,

lr I, North Anna Power Station, Units 1 and 2 m i,..,,,

m,,.-

05000338 1 OF 3 l TITLE (4) l INCOMPLETE SURVEILLANCE ON REACTOR PROTECTION P8 LOGIC CIRCUlTRY l EVENT DATE (5) l LER NUMBER (6)

REPORT DATE (7)

OTHER F ACILITIEs INVOLVED (B) l MONTH l YEAR l YEAR North Anna, Unit 2 05000339 DAY II DN MONTH DAY YtAR NMR

,wnR l1 8 l 98 l 98 I

I

'^C "Y N.

D M NT NMR 001 00 02 03 98 05000 I OPERATING l THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS oF 10 CFR $: (Check one or more) (11)

MODE (9) ]1 20 2201(b) 20 2203(a)(2)(v)

X 50 73(a)(2)(i) 50 73(a)(2)(vtit)

POWER l

20 2203(a)(1) 20 2203(a)(3)(l) 60 73(a)(2)(it) 60 73(a)(2)(x)

LEVEL (10) 100 %

20 2203(a)(2)(l) 20 2203(a)(3)(le) 60 73(a)(2)(lit) 73 71 20 2203(a)(2)(,1) 20 2203(a)(4) 50 73(a)(2)(ev) oTHER 20 2203(a)(2)(iii) 50 36(c)(1) 50 73(a)(2)(v) arece m Ateed t.in.

r 20 2203(a)(2)(iv) 50 36(c)(2) 50 73(a)(2)(Vh) w m NRC Form Et.A LICENSEE CONTACT FOR THIS LER (12) sw mtenow Nouer R m...c W. R. MatthewS, Station Manager (540) 894-2101 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT ji3)

CAust SylitM COMPONENT MANUF ACTURE R RE PORT ABLE CAU$E SYSil M COMPONE NT MANU$ACTURER RE POR1 ABLE TO NPRDs 10 NPRDS NA SUPPLEMENTAL REPORT EXPECTED (14)

EXPECTED MONTH DAY YEAR YES X

No SUBMISSloN (if yet comp 6ete EXPECTFD SUBMISSION DATF)

ABSTRACT (Limit to 1400 spaces. I e, approximately 16 single-spaced typewritten lines) (16)

On January 8,1998, with Units 1 and 2 at 100 percent power, Mode 1, it was determined that a potential to miss interlock logic surveillance testing during previous mid cycle shutdowns existed.

Notification was received from Westinghouse concerning a Solid State Protection System interlock circuit that is not fully tested during semi-automatic testing of the system. The reactor trip system interlock, P8, blocks the reactor trip function for low flow in a single reactor coolant loop below 28 percent power. It is likely that the surveillance was not performed during mid-cycle shutdowns since no reactor coolant pumps would have been shutdown. This is reportable pursuant to 10 CFR 50.73 (a)(2)(i)(B), for a condition prohibited by the Technical Specifications.

The cause of the incomplete surveillance is attributed to inadequate test design supplied by the vendor and the assumption that all functions, above and below P8 setpoint, were fully tested during the semi-automatic test performed on each train of SSPS every other 31 days.

This condition posed no significant safety implications since it was determined the logic circuits could perform their design function, and did not affect the operability of the system. Therefore, the health and safety of the public were not atfected at any time during this condition.

9002130038 900203 PDR ADOCK 05000338 8

PDR J

logs, plant computer (Ells System ID, Component CPU) points, and control room alarm printers determined that this portion of the PS circuitry was verified operable within 92 days prior to the last Unit 1 & 2 reactor startups.

The problem arises with mid-cycle shutdowns, especially shutdowns which do not require cooldown and entry into Mode 5. For these outages, it is likely that the surveillance was not performed since no RCPs would have been shutdown. If these outages occurred more than 92 days from the end of the previous refueling, then this surveillance would have been missed.

On August 27,1996 Unit i experienced an automatic reactor trip from 100 percent power.

The unit was stabilized and remained in Mode 3 before being returned to power on August 29, 1996. During this time the RCPs were not shutdown and the trip was greater than 92 days from the last refueling outage. As such, the surveillance for the P8 interlock logic that prevents a reactor trip following low flow in a single reactor coolant loop with 3 of 4 power range levels below 28 percent was not tested. Since the test procedures did not contain steps to ensure adequate testing, we believe the surveillance was missed during other mid cycle shutdowns which did not require cooldown and entry into Mode 5.

2.0 Significant Safety Consequences and implications

This coridition posed no significant safety implications since it was determined the logic circuits could perform their design function, and did not affect the operability of the system. Therefore, the health and safety of the public were not affected at any time during this condition.

This incomplete surveillance is reportable pursuant to 10 CFR 50.73 (a)(2)(i)(B) for a condition prohibited by the TS.

NRC f ORM Sfi6A (4 95) l

{u s. NUCLEAR REGULATORY CoMMISSloN

( 4 5)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1)

DOCKET LER NUMBE R (6)

PAGE (3)

North Anna Power Station Units 1 and 2 05000338

" ^

• l ",ff,jy l ajg,*,

98 001

'00 30F3 TEXT Of more space is rewred, use amonal copes of NRC form 366A) (17)

3.0 Cause of the Event

The cause of the incomplete surveillance is attributed to inadequate test design supplied by the vendor. As a result, the test procedures did not ensure that functions below P8 setpoint were fully tested during the semi automatic test performed on each train of SSPS.

4.0 immediate Corrective Actions

- Reviewed information from the last startup following refueling for each unit and noted that the surveillance was met and the reactor trip system interlocks were operable.

5.0 AdditionalCorrective Actions A review of the SSPS and associated procedures and drawings determined the other interlocks are being fully tested in accordance with TS. Procedure changes were written to the channel functional tests and are ready to be implemented prior to the next reactor startup to ensure the required P8 surveillance is met. In addition, P8 was placed in action to alert the Operators to the requirement for demonstrating the P8 function in question operable prior to the next reactor startup.

6.0 Actions to Prevent Recurrence The vendor recommendation to ensure adequate testing is being evaluated along with other possible solutions. Corrective actions will be implemented as necessary.

7.0 Similar Events

LER N197-009 00 identified an incomplete surveillarice on Solid State Protection System circuits for feedwater isolation from P14, S/G Hi Hi Level, and P 10 block of the Source Range Trip due to inadequate test design supplied by the vendor.

8.0 AdditionalInformation None

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gr-NRC ronid 36cA t4 s5)