ML20045H917

LER 93-008-01:on 930505,discovered That RHR Pump Suction MOV Had Not Been Environ Qualified Since 901129 Because Replacement of Drain T Not Completed.Drain T Missing from RH-0060B Replaced & Bulletin Issued to Maint Dept

ML20045H917
Person / Time
Site:	South Texas
Issue date:	07/14/1993
From:	Pinzon J HOUSTON LIGHTING & POWER CO.
To:
Shared Package
ML20045H907	List: ML20045H906 ML20045H917
References
LER-93-008, LER-93-8, NUDOCS 9307220110
Download: ML20045H917 (5)

Text

_ _ _ _ _ _ .

l NRC f o'tM 366 U.S. [11 CLEAR REGULATORY COMMISSl(EJ APPROVED BY OMB No. 3150-0104 (5-92) EXPIRES 5/31/95

. ESilMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

LICENSEE EVENT REPORT (LER) FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH l (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, (See reverse for required ruber of digits / characters for each block) WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJE CT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON. DC 20503.

DOCKET NtMBER (2) PAGE (3) lFACILITYNAME(1) South Texas Unit 2 05000 499 1 OF 5 TITLE (4) Failure to Maintain Environmental Qualification of a Residual Heat Removal Motor operated Valve j EUENT DATE '5) lER NUMBE R (6) REPORT DATE (7) OTHER T AClllTIES INVOLVED (8)

MONTH DAY YEAR MONTH DAY YEAR YEAR NUMBER NUM6ER 05000

'# "^" "' " "

05 05 93 93 -- 008 -- 01 07 14 93 O 00 l

l OPEkATING THIS RE RT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR f: (Check one or more) (11) l CDDE (9) N!A 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b)

POWER " ' " '

0 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) OTHER

! LEVEL (10) 20.405(a)(1)(iii) X 50.73(a)(2)(1) 50.73(a)(2)(viii)(A) (Specify in AD C Od 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)(lii) 50.73(a)(2)(x) NRC Form 366A) i LICENSEE CONTACT FOR THIS lER (12)

( NAME TELEPHONE NUMBER (include Area Code) l Jairo Pinzon - Senior Engineer (512) 972-8027 l

l COMPLETE ONE LINE FOR EACH COM'ONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEM COMPONENT MANUFACTURER 0 NP D SUPPL EMENT At REPOU EXPfCTED (14) EXPECTED MONTH DAY YEAR YES SUBMISSION '

(If yes, complete EXPECTED SUBMISSION DATE). NO X DATE (15)

ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)  ;

On May 5, 1993, at 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br />, Unit 2 was defueled at 0% power. It was discovered that a Residual Heat Removal Pump suction Motor Operated Valve (MOV) had not been environmentally qualified since November 29, 1990 because replacement of a "T" drain was not completed. This discovery was

! made during a review of work documents prompted by the NRC Diagnostic Evaluation Team. The apparent cause of the event is lack of knowledge regarding the requirements to maintain the environmental qualification of I

! harsh environment MOVs. Corrective actions for this event include I

replacing the "T" drain, walking down other MOV's, reviewing open work documents for similar issues, screening new Service Requests for similar conditions and training on equipment qualification requirements.

t l

l l

9307220110 930714 NRC FORM 366 (5-92)

PDR ADOCK 05000499 S PDR LER 93\t93008R1.U2 I

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 (5-92) EXPIRES 5/31/95

+ ESTIMA1ED BURDEN PEQ RESPCNSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE LICENSEE EVENT REPORT (LER) INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB TEXT CONTINUATION 7714), U.S. NUCLEAR REGULATORY COMM]SSION, WASHINGTON, DC 20555 0001 AND TO THE PAPERWORK REDUCTION PROJECT (31'!O-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LER NtMBER (69 PAGE (3)

SEQUENTIAL REVISION YEAR South Texas, Unit 2 05000 499 2 OF 5 93 -- 008 -- 01 TEXT (If more space is reautred, use additional copies of NRC Form 366A) (17)

EVENT DESCRIPTION:

On May 5, 1993, at 1400 nours, Unit 2 was defueled at 0% power. It was l discovered that a Residual Heat Removal (RHR) Pump suction MOV (RH-0060B) had not been environmentally qualified since November 29, 1990 because replacement of a "T" drain had not been accoinplished. The requirement to install the "T" drain had been transferred to a second work document which was not completed. This discovery was made during a review of work documents prompted by the NRC Diagnostic Evaluation Team.

On November 29, 1990, work activities were completed on RH-0060B with the exception of replacing a "T" drain. The motor was being replaced because the associated supply breaker was repeatedly tripping on overcurrent. The workers attempted to obtain the correct size "T" drain for installation, but apparently the correct size was not readily available. On November 27, 1990, a new Service Request (SR) , which was issued for the installation of the "T"

, drain, was reviewed by the Shift Supervisor. The Shift Supervisor did not recognize that the SR affected the environmental qualification of the MOV.

The original SR was reviewed by control room personnel for closure and l RH-0060B was declared operable.

On May 5, 1993, the NRC Diagnostic Evaluation Team notified HL&P that a potential deficiency existed concerning the "T" drain. HL&P determined that the absence of the "T" drain rendered RH-0060B technically inoperable in a

" harsh environment" following a postulated design basis accident. Technical Specification 3.5.6 requires three RHR loops be operable in Modes 1, 2, and

3. Because STP Unit 2 operated in Modes 1, 2, and 3, since November, 1990, with RH-0060B inoperable, Technical Specification 3.5.6 was violated.

CAUSE OF EVENT:

The apparent cause of this event is lack of knowledge regarding the requirements to maintain the environmental qualification of harsh environment MOVs.

l 1 ANALYSIS OF EVENT: l The failure to install the "T" drain in RH-0060B constitutes a failure to maintain the environmental qualification requirements of this " harsh I environment" MOV. "T" drains are required to ensure proper moisture removal l from the motor casing during and following postulated high energy line breaks inside containment. Failure of RH-0060B in its normal (closed) position would render the suction of the B Train Unit 2 RHR pump inoperable I for long term cooling processes. The RHR system provides long term decay l

! LER-93\t93008R1.02

NRC FORM 3664 U.S. NUCLEAR REGULATORY COMMISSIC APPROVED BY OMB NO. 3150-0104 (5 92) ,

EMPIRES 5/31/05

• ESitMATED BUPDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

• FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE LICENSEE EVENT REPORT (LER) INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB TEXT CONTINUATION 7714), u.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

, FAClllTY NAME (1) DOCKET NUMBER (2) LFR NUMHfR (6S PAGE (3)

YEAR SEQUENTIAL REVISION

"#8" "*""

South Texas, Unit 2 05000 499 3 OF 5 93 -- 008 -- 01 l TEXT (if more space is reouired, use additional copies of NRC Form 366A) (17) t 1

l ANALYSIS OF EVENT: (Cont'd) l heat removal under normal and accident conditions such as small break LOCA, l secondary side break (main steam and feedwater line) and steam generator l tube rupture. Only one train of RHR is required to perform this function.

With RH-0060B failed closed, sufficient long-term cooling is provided by either RHR Trains A or C. The only design basis scenario that would j preclude RHR Trains A or C from functioning is a design basis accident (such

! as a steam line break, feedline break, or LOCA), in conjunction with a loss of offsite power and loss of safety Train A power. With the RHR system not available, reactor heat removal would be maintained using the AFW system and safety-grade steam generator power operated relief valves. In light of the low probability of a design basis accident in conjunction with a loss of offsite power and loss of safety Train A power, the failure to install the "T" drain in RH-0060B does not have significant impact on the health and l safety of the public.

The NRC Operations Center was notified on May 5, 1993, at 1404 hours0.0163 days <br />0.39 hours <br />0.00232 weeks <br />5.34222e-4 months <br />. This l event was reported as a violation of Plant Operating License NPF-80 (Unit 2), section 2.6.

l CORRECTIVE ACTIONS: l Corrective actions to address this event include:  !

l

1. The "T" drain missing from RH-0060B has been replaced.

2. A 100% walkdown of harsh environment MOV's in Units 1 and 2 was performed l to determine if other potential operability issues existed due to "T"  ;

drain configuration. Although four MOV's had "T" drain discrepancies, no other reportable conditions were identified.

3. Open SRs have been reviewed to determine if non-conformances that i potentially affect operability have been identified and resolved. No j additional issues affecting operability were identified.

l 4. The Operations Work Control Group has been established to screen new SRs.

l The personnel in this group have been trained on equipment qualification l requirements to enable them to properly identify conditions similar to l

those which occurred in this event.

LER 93\L93008R1.U2 l

t

! NRC FORM 366A U.S. C2) CLEAR REGULATCY COMMIS$10 APPROvCD BY GMB NO. 3150-0104 (5-92) EXPIRES 5/31/05

. ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

• FORWARD COMMENTS REGARDING BURDEN EST! MATE TO THE LICENSEE EVENT REPORT (LER) INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB TEXT CONTINUATION 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150 0104), OFflCE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

k FACILITY NAME (1) DOCKET NUMBER (2) (ER NtMBER (61 PAE (3)

SEQUENTIAL REVISION YEAR South Texas Unit 2 05000 499 4 OF 5 93 -- 008 -- 01 TEXT (If more mace is reauired. use additional copies of NRC Form 366A) (17)

CORRECTIVE ACTIONS: (Cont'd)

5. The Maintenance Department has issued a training bulletin to address equipment qualification requirements. To reinforce the importance of equipment qualification, the training bulletin will be discussed in the Maintenance Department Manager's quarterly meeting by August 1, 1993.

6. Training on equipment qualification requirements has been provided to ,

System Engineers.

7. A briefing paper, which discusses the lessons learned from this event, will be provided to supervisors in the Operations, Plant Engineering, Design Engineering and Quality Control Departments to share with their work groups by August 15, 1993.

l

8. The training provided to System Engineers, Senior Reactor Operators, Quality Control Inspectors, Maintenance Planners and craft will be revised by December 15, 1993, to ensure that the requirements of equipment qualification and configuration management are being clearly communicated.

ADDITIONAL INFORMATION:

! Three other events involving equipment qualification, Unit 1 LER 93-016

" Technical Specification Violation Due to Steam Generator Power Operated Relief Valves and Post Accident Monitoring Instruments Being Inoperable",

Unit 1 LER 93-017 " Extension of Feedwater Isolation Bypass Positioner and Solenoid Beyond Equipment Qualification Life", and Unit 2 LER 93-010,

" Failure of an Essential Cooling Water Traveling Screen Drive Coupling",

have been reported to the NRC. The causes of LERs 1-93-017 and 2-93-010 are

not similar to the cause of this event. However, a contributing cause of l

LER 1-93-016 was a lack of knowledge of equipment qualification requirements, which is similar to the cause of this event.

Unit 2 LER 93-008 (this LER), Unit 1 LER 93-016, and eight other conditions l

related to configuration management prompted HL&P to perform additional actions to evaluate the adequacy of plant configuration management. These i additional actions included:

i

1. Walkdowns of Class 1E 480V and 4.16 KV switchgear for missing brackets, fasteners and loose terminations.

2. Walkdowns of a sampling of cabinets for compliance with the requirements of Regulatory Guide 1.75, " Physical Independence of Electric Systems" and 10CFR50 Appendix R, " Fire Protection Program".

LER-93\L9300BR1.U2

! NRC FORM 366A U.S. NUCLEAR REGULATCY CCMMISSION APPROVED BY OMB No. 3150-0104 L

(5-92) ,

EXPICES 5/31/95

• ESilMATED BURDEN PEC CESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

l

' - FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE LICENSEE EVENT REPORT (LER) INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB TEXT CONTINUATION 7714), U.S. NUCLEAR REGULATORY COMMIS$10N, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (31500104), OFFICE OF MANAGEMENT AND BUDGE 1 WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NLMBER (2) LER NtMBER (65 PAGF (3)

SEQUENTIAL REVISION YEAR NUMBER NUMBER South Texas, Unit 2 05000 499 5 OF 5 93 -

008 -- 01 TEXT (If more space is reavired. use additional copies of NRC Form 366A) (17)

ADDITIONAL INFORMATION: (Cont'd) l 3. Programmatic review of the proper application of seismic II/I requirements and torquing requirements.

l

4. Review of work history associated with MOV motor replacements.

Based on the additional walkdowns and reviews, HL&P has concluded that the l impact of the identified conditions are confined to switchgear and process cabinet maintenance activities which could have affected the seismic configuration and MOV replacement activities which could have affected the environmental qualification. The corrective actions for Unit 2 LER 93-008 and Unit 1 LER 93-016 address these generic implications.

l I

l l

l l

LER-93\L93008R1.U2