05000400/LER-1999-006, :on 981124,noted Failure to Comply with TS 4.0.4 & TS 3/4.6.3, Civs. Caused by post-maint Testing That Did Not Adequately Test Control Circuitry & Verify Isolation Time Following Maint.Procedure Was Revised
| ML18016B048 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 08/04/1999 |
| From: | Ellington M CAROLINA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML18016B047 | List:
|
| References | |
| LER-99-006, NUDOCS 9908100060 | |
| Download: ML18016B048 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(viii) 10 CFR 50.73(a)(2)(x) |
| 4001999006R00 - NRC Website | |
text
NRC FORiV 366 U.S. NUCLEAR REGULATORY COMMISSION (6-1996)
LICENSEE EVENT REPORT (LER)
F (See reverse for required number of digits/characters for each block)
APPROVED BY OMB NO. 3150.0104 EXPIRES 06/30/2001
, the NRC may not conduct or
- sponsor, and e person is not required to respond to. the information collection.
FACILITYNAMEI1)
Harris Nuclear Plant, Unit 1 DOCKET NUMBER I2) 05000400 PAGE (3) 1 OF 3
TITLE I4I Containment Isolation Valve Technical Specification Noncompliance EN DA MONTH DAY YEAR E
ERG YEAR SEQUENTIAL REVISION NUMBER NUMBER MONTH DAY YEAR FACILITYNAME I
I V D
DOCKET NUMBER 11 24 1998 1999
- - 006
01 08 04 1 9 9 9 FACILITYNAME DOCKET NUMBER 05000 OPERATING MODE (9)
POWER LEVEL (10) 000 20.2201(b) 20.2203(al(1) 20.2203(al(2) (i) 20.2203(e)(2)(ii) 20.2203(e) (2)(iij) 20.2203(a) (2) (iv) 20.2203(a)(2) (v) 20.2203(a) (3)(il 20.2203(a) (3) (ii) 20.2203(a)(4) 50.36(c) (1) 50.36(c)(2) x 50.73(a)(2)(i) 50.73(a) (2) (ii) 50.73(a)(2) (iii) 50.73(a)(2)(iv) 50.73(al(2)(v) 50.73(a) (2)(vii) 50.73(a) (2) (viii) 50.73(a)(2)(x) 73.71 OTHER Specify in Abstract below or in NRC Form 366A NAME Mark Ellington, Senior Analyst - Licensing TELEPHONE NUMBER IInctude Ares Code)
(919) 362-2057 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 13
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTABLE TO EPIX
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTABLE TO EPIX D
CC ISV LIMITORQUE YES (If yes, complete EXPECTED SUBMISSION DATE).
NO EXPECTED MONTH DAY YEAR ABSTRACT (Limitto 1400 speCes, i.e., apprOximately 15 single. spaced typewritten lines)
(16)
At 16:39 on November 24, 1998, with the Harris Nuclear Plant (HNP) shutdown in Mode 4, HNP failed to comply with Technical SpeciTications (TS) 4.0.4 and TS 3/4.6.3 "Containment Isolation Valves."
On May 6, 1999, HNP determined that Containment Isolation Valve, 1CC-176 was inoperable followingpreventive maintenance performed during the previous refueling outage. Post-maintenance Testing performed on 1CC-176 was inadequate in that safety-related portions ofthe valve circuitry were not adequately tested followingmaintenance.
Subsequent investigation determined that TS Surveillance 4.6.3.1 was not performed as required on 1CC-202 and 1CC-176 in that HNP failed to verify isolation time following maintenance on the valves control circuitry. Therefore, when HNP changed from Mode 5 to Mode 4 on November 24, 1998, HNP was in noncompliance with TS 4.0.4. In addition, with 1CC-176 inoperable, HNP violated TS 3.6.3 due to not performing the required a'ctions within the specified action time. On December 6, 1998, 1CC-176 failed to automatically shut during an applicable slave relay test. The associated penetration was isolated within four hours as required by TS 3.6.3.b. ICC-176 was subsequently repaired and satisfactorily retested.
ICC-202 was not restored to compliance until the isolation time was veriTied on December 22, 1998 during normal quarterly inservice testing.
Cause of this TS violation: (1.) Post-maintenance testing did not adequately test control circuitry and verify isolation time following maintenance. (2.) The procedure which specifies the required post maintenance testing was based on a non-conservative interpretation ofTS 4.6.3.1. Corrective actions include: (1.) Revise the plant post-maintenance testing procedure to identify appropriate testing requirements for the preventive maintenance associated with this event. (2.) Perform training with applicable site personnel on Irtr ntirvina nrnner nnst-maintenance testing requirements for motor operated valves.
9908l00060 990804 PDR ADOCK 05r)00400I6.96)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION U.S. NUCLEAR REGULATORY COMMISSION FACILITYNAME I1I Harris Nuclear Plant, Unit 1 DOCKET 05000400 LER NUMBER I6)
YEAR SEQUENTIAL REVISION NUMBER NUMBER 1999
006
01 PAGE )3) 2 OF 3
TEXT flfmore space fs sequJied, use addiuonal copies ofNRC Form 366A) )17)
DESCRIPTION OF EVENT
At 16:39 on November 24, 1998, with the Harris Nuclear Plant (HNP) shutdown in Mode 4, HNP failed to comply with Technical Specifications (TS) 4.0.4 and TS 3/4.6.3 "Containment Isolation Valves."
On October 29, 1998, preventive maintenance was performed on the valve actuator for containment isolation valve ICC-202.
On November 11, 1998, similar preventive maintenance was performed on containment isolation valve 1CC-176 (EIIS CC-ISV). The preventive maintenance performed on 1CC-176 inadvertently misaligned contacts associated with the automatic isolation signal used to close the valve. The preventive maintenance for both 1CC-176 and 1CC-202 was performed in mode 5 when the valves were not required to be operable per TS 3/4.6.3. The post-maintenance test for the applicable valves consisted ofa cycling test using the associated control switch on the main control board. Contrary to TS 4.6.3.1, a verification of isolation time was not performed. Additionally, adequate post-maintenance testing was not performed on the automatic portion ofcircuitry affected by the maintenance.
On November 21,1998, HNP performed plant procedure OST-1825 "ESF Response Time Train A"which normally includes cycling of 1CC-202 and 1CC-176. During the performance ofthis test, 1'CC-176 failed to isolate as expected on an automatic signal. However, verification of 1CC-176 was not part ofthe acceptance criteria for OST-1825 and therefore inoperability of 1CC-176 was not identified at that time. 1CC-202 automatically isolated during performance ofOST-1825. Therefore, the automatic isolation circuitry for ICC-202 was verified by testing prior to entering a mode when it was required to be operable.
On November 24, 1998, HNP entered Mode 4. TS 3/4.6.3, Containment Isolation Valves, is applicable in Modes 1 - 4. Failure to perform TS 4.6.3.1 for ICC-176 and 1CC-202 and subsequent entry into Mode 4 resulted in non-compliance with TS 4.6.3.1 and TS 4.0.4. In addition, with 1CC-176 inoperable, HNP violated TS 3.6.3 due to not performing the required actions within the specified action time On December 6, 1998, HNP performed plant procedure OST-1045 which partially implements the TS requirement to perform.
a quarterly slave relay test per TS 3/4.3.2 "Engineered Safety Features Actuation System Instrumentation". During performance ofthis test, plant personnel determined that 1CC-176 would not isolate on an automatic signal. Plant personnel isolated the affected penetration within four hours ofidentifying ICC-176 inoperability as required by TS 3.6.3.b. On December 7, 1998, HNP repaired 1CC-176 and restored operability by performance ofa cycling test, a verification of automatic isolation upon receipt ofan isolation test signal, and satisfactory verification ofisolation time.
On December 22, 1998, plant personnel performed a scheduled quarterly inservice test. During performance ofthis test, containment isolation valve, ICC-202, successfully passed an isolation time test restoring ICC-202 to compliance with TS 4.6.3.1.
On May 6, 1999 during evaluation ofthe performance ofOST-1825, it was determined conclusively that ICC-176 had been inoperable from November 24, 1998 until December 7, 1998. Subsequent evaluation determined that isolation time testing had not been performed in accordance with TS 4.6.3.1 followingmaintenance on the control circuits for 1CC-176 and ICC-202.
1CC-176 is the Component Cooling Water (CCW) containment isolation valve to the Reactor Coolant Drain Tank Heat Exchanger and Excess Letdown Heat Exchanger. 1CC-202 is the Component Cooling Water containment isolation valve from the Reactor Coolant Drain Tank Heat Exchanger and Excess Letdown Heat Exchanger. These valves are used to isolate separate penetrations and are therefore not redundant. CCW to and from the Reactor Coolant Drain Tank Heat Exchanger and the Excess Letdown Heat Exchanger are considered General Design Criteria 57 type penetrations which rely on the closed system inside ofcontainment to provide redundancy to the containment isolation valves located outside containment.
ICC-176 and 1CC-202 are designed to shut upon the receipt ofa Containment Isolation Phase "A"signal to isolate CCW to non-essential heat exchangers located in containment.
NRC FORM 366 I6 96)(6 98)
'0 LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION U.S. NUCLEAR REGULATORY COMMISSION FACILITYNAME (1)
Harris Nuclear Plant, Unit 1 DOCKET 05000400 LER NUMBER (6)
YEAR SEQUENTIAL REVISION NUMBER 1999
006
01 PAGE (3I 3
OF,3 TEXT (lfmore space Is reguIred. use addrVonal copIes ofNRC Form 366AJ (17)
The preventive maintenance (PM) activity associated with this event was a Motor Operated Valve (MOV)Limitorque Lubrication and Inspection procedure. A Limitorque base plate was inadvertently misaligned during this PM for 1CC-176 resulting in contacts associated with the automatic closure signal being misaligned. Previous to this event, plant personnel considered that the Limitorque valve automatic closure circuitry was common to the Limitorque main control board (MCB) switch manual closure circuitry. Investigation has determined followingthis event that certain Limitorque MOVs have a separate circuitry associated with automatic valve closure. A test using the MCB switch for these certain Limitorque MOVs would not verify automatic valve closure operability. Plant personnel performed a visual check ofLimitorque base plate alignment followingmaintenance. This visual check did not identify the misalignment ofthe base plate for 1CC-176. The base plate for 1CC-202 was not misaligned as a result ofthe specified PM activity. However, HNP failed to perform TS 4.6.3.1 for isolation time verification. Subsequent testing ofautomatic closure capability and isolation time verification determined that the specified PM did not affect the abilityof 1CC-202 to perform its safety function. The investigation ofthe failure to recognize the applicability of TS 4.6.3.1 for the maintenance performed on 1CC-176 and 1CC-202 determined that the procedure which specifies the required post maintenance testing was based on a non-conservative interpretation on TS 4.6.3.1.
11.
CAUSE OF EVENT
1.
Post-maintenance testing did not adequately test control circuitry and verify isolation time followingmaintenance.
2.
The procedure which specifies the required post maintenance testing was based on a non-conservative interpretation of TS 4.6.3.1.
III. SAFETY SIGNIFICANCE
There were no actual safety consequences as a result ofthis event. 1CC-202 remained capable ofperforming its required safety function as demonstrated through subsequent testin'g followingmaintenance. Redundant containment isolation capability was provided for 1CC-176 and 1CC-202 by the intact closed CCW system inside containment. Additionally, manual isolation capability was available to close ICC-176.
This is being reported per 10 CFR 50.73(a)(2)(i) as a operation or condition prohibited by Technical Specifications.
IV.
CORRECTIVE ACTIONS
1.
Revise the plant post-maintenance testing procedure to identify appropriate testing requirements for the preventive maintenance associated with this event.
2.
Perform training with applicable site personnel on identifying proper post-maintenance testing requirements for motor operated valves.
V.
SIMILAREVENTS There were no HNP events identified where maintenance on Limitorque valves and subskquent inadequate testing caused a TS required valve to be inoperable.
i'