ML20059D172

Intervenor Exhibit I-MFP-168,consisting of Mgt Summary, Ncr DCO-91-EM-N009, FCV 495/496 Corrosion,

ML20059D172
Person / Time
Site:	Diablo Canyon
Issue date:	08/23/1993
From:	AFFILIATION NOT ASSIGNED
To:
References
OLA-2-I-MFP-168, NUDOCS 9401070046
Download: ML20059D172 (22)

Text

, @ 3 '/bj'O 28 - 06r) -J ~ MW ~ /b 5 ff&&Wg l I NUCLEAR REGULATORY COMMISSION g M 85Le ls -YOf?' l4'8 we, nbONl6-OLAL_. on>cial E@U ## M in es mner s PM/FIC Gr6 W I 0blEM-N009 snn _

w a _- November 22, 1991 r.- - t n au / nu cita 93 OCT 28 .P6 :24 Cv , Tr r

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C y m. .- Stt{$ MTE [,

0:ner . Witness , j ;g, Reporter D i t' ! --

J MANAGEMENT

SUMMARY

f On June 29, 1990 the manual handwheel for Auxiliary l Saltwater (ASW) pump crosstie valve SW-1-FCV-496 was identified as not manually operable due to extensive rust i build up. Design Criteria Memorandum (DCM) S-17B, l " Auxiliary Saltwater System", states that manual operation of this valve may be required to support the long term recirculation phase of post-accident operation. NECS evaluation justified operability of the system with the valve in-the as found condition stating that the inability to manually operate the handwheel of SW-1-FCV-496 does not impact the ability of the system to be aligned to support long term recirculation. Operability is justified as long-as the unit crosstie valve, FCV-601, remains in'the closed.

position since the other train crosstie valve, FCV-495, can be closed to provide train separation.

The root cause was determined to be inadequate preventative maintenance and monitoring of the condition of the handwheel to prevent corrosion from rendering the handwheel inoperable.

Corrective actions to prevent recurrence include revising appropriate STPs to require manual testing of Class I valves that have Class II actuators that require manual actuation of the valve to satisfy a safety function and to increase the frequency of preventive maintenance on the ASW crosstie valves. j 1

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1 91NCRWP\91EMN009.HTH Page 1 of 22  !

9401070046 930823 PDR ADOCK 05000275 ,

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DCO-91-EM-N009 November 22, 1991

.i NCR DCO-91-EM-N009 [

FCV 495/496' CORROSION '

I. Plant Conditions-i i

Unit 1 was in Mode 1 (Power Operation) at 100% power  !

l (Reference 1).

1 II. Description of Event A. Event: ,

i On June 29, 1990 during corrective maintenance, l the manual handwheel for Au: ciliary Salt Water i j

(ASW) pump crosstie valve SW-1-FCV-496.was.

identified "y maintenance personnel as not:  ;

manually operable due to extensive rust > build up-(Reference 2 & 3). This problem'was documented in.

accordance with Administrative Procedure (AP) C.

12, " Identification And Resolution Of Problems And- ,

Nonconformances," on Action Request (AR)' A0196648 on July 2, 1990.

The AR was. assigned a priority of 4F in accordance with AP C-81, " Standard Plant Priority Assignment- l Scheme." Since the actuator:is Class II.and was i still electrically and remotely operable, the i priority was low and'the "F" code meant that repairs should be accomplished within.90 days.

9 On September 6, 1990 a work order was written to

~

free the handwheel for SF-1-FCV-496..

On September 14, 1990, utility' personnel. attempted to free the handwheel without disassembly of the valve. All attempts fail. (Reference 5).

Further efforts were not attempted because sufficient parts were not-available.for an overhaul at the time.

! On January 16, 1991, the NRC resident noticed a i

relatively old AR tag on-FCV-495 during a walkdown. The resident was aware'of the j importance of manual operation-of-FCV-495 and ,

I brought the item to the Plant Manager's attention. l l

91NCRWP\91EMN009.MTH Page 2 of 22 l

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DCO-91-EM-tC C November 22, 1991 The ASW lines, normally cross-connected, are fitted with crosstie valves which function to-provide ASW train separation. Design Criteria Memorandum (DCM) S-17B, " Auxiliary Saltwater i System," states that manual operation of these j valves may be required to support the long term recirculation phase of post-accident-operation l (reference 4). The crosstie. valves are verified ,

as electrically operaale every 92 days in accordance with Surveillance Test Procedure (STP)

V-3F2 (reference 10).

The Electrical Maintenance Manager directed l

Electrical Maintenance to again attempt to free

! the handwheel utilizing all available techniques..

! Copious quantities of penetrating oil,-picks, emery paper and hacksaw blades 1:ere.all used in a cautious and methodical effort to free the handwheel. This effort began on swing shift of January 16* and continued through the shif t. The job was turned over to day shift'who were finally successful around mid-day on January 17, 1991.

This job was done cautiously and methodically to avoid damage to the operator because spare parts were still not available.

On January 16, 1991, in parallel with the aforementioned effort, an AR action evaluation was assigned to engineering to determine _the

. operability of SW-1-FCV-496 in the as found condition. NECS evaluation justified operability of the system with the valve in the as-found condition. NECS evaluation stated that the inability to manually operate the handwheel of SW-1-FCV-496 does not impact the ability of the system to be aligned to support the long term recirculation phase of post-accident operation (Reference 6 & 2) as long as the unit crosstie, FCV-601, remains closed, the other train crosstie valve, FCV-495, can be_ closed to provide train separation.

On January 18, 1991, the remaining Unit 1 and Unit 2 crosstie valves, SW-1-FCV-495, SW-2-FCV-495, SW-2-FCV-496, and the Unit Crosstie valve, SW-0-FCV-601, were examined to determine if corrosion of the handwheel to the actuator body is 91NCRWP\91EMN009.MTH Page 3 of 22

's DCO-91-EM-N009 November 22, 1991 a recurring problem. Valve SW-1-FCV-495 was found to be inhibited from manual operation due to '

excess paint between the handwheel and actuator frame. The handwheel was engaged manually and was ,

easily rotated once the paint broke loose. Manual operation of valve SW-2-FCV-495 was found to have some resistance due to corrosion. Inspection of valve SW-2-FCV-496, and SW-0-FCV-601 identified no corrosion of the handwheel shafts and all handwheels were determined to be manually operable (Reference 8).

Nonconformance: SW-1-FCV-496 failed to operate manually.

B. Inoperable Structures, Components, or Systems that Contributed to the Event:

None.

C. Dates and Approximate Times for Major Occurrences:

1. June 11, 1982: Valve mechanically closed using handwheel. This is the last documentation of the operability of SW FCV-496 hand wheel (Reference 9).

- 2. June 29, 1990: Discovery date. SW-1-FCV-496 identified as not manually operable' l (Reference 2). l

3. September 6, 1990: Work Order to free handwheel on SW-1-FCV-496  !

written (Reference 5).  ;

4. September 14, 1990: Initial attempts to free handwheel on SW-1-FCV-496 fail (Reference 5).

5. January 17, 1991: Handwheel on SW-1-FCV-496 freed successfully (Reference 7).

D. Other Systems or Secondary Functions Affected:

91NCRWP\91EMN009.MTH Page 4 of 22

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• DCO-91-EM-N009 November 22,.1991 1 i

None.

E. Method of Discovery:

i Utility personnel, during the performance of scheduled maintenance to verify local position- ,

switch adjustments, identified the problem- t (Reference.2).

F. Operators Actions: l None.

G. Safety System Responses:

None.

III. Cause of the Event A. Immediate Cause:

SW-1-FCV-496 was not manually operable due to corrosion between the handwheel and the operator.

B. Determination of.Cause: ,

1. Human Factors:

a. Communications: No' surveillance-is-performed on.the manual operator? portion  :

of this MOV. Because no surveillanceLis i' performed, the corrosion of the handwheel was identified during routine maintenance not during a STP. Had the corrosion been identified during the routine surveillance of the valve a different. priority'would

, have been assigned to the restoration of.

l manual operation of this valve.even though.

I the MOV is class II. Therefore,  ;

communications was not a factor-in this ,

event.

( .b. Procedures: The routine surveillance test for this valve did not include the-requirement to; engage and manipulate the manual hand wheel portion of the valve.

Had this been the case the corrosion condition would have been identified and a 91NCRWP\91EMN009.MTH Page 5 of 22 ,

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! 's l DCO-91-EM-N009 l November 22, 1991 different priority placed on the maintenance,

c. Training: Not Applicable

d. Human Factors: Not Applicable l

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e. Management System: Not applicable.

2. Equipment / Material:

a. Material Degradation: FCV-495 and FCV-496 are subject to extreme environmental conditions which are conducive to corrosion. Past incidents of material denradation have been documented for SW FCV-495 on August 28, 1981 (Reference 9),-

for SW-1-FCV-496 on May 23', 1989 and again on June 29, 1990 (Reference 9), and for SW-2-FCV-495 on July 11, 1988-(Reference

! 9).

l b. Design: The system is designed such that the valve is a Class I component to maintain pressure boundary. The operator is a Class II component that supports system alignment for the hot-leg recirculation phase or post-accident operation.

c. Installation: Not Applicable

d. Manufacturing: Not Applicable

e. Preventive Maintenance: These valves are located at the intake structure and are subject to harsh environmental conditions.

The frequency of preventative maintenance is too low to prevent corrosion of the handwheel in these environmental conditions,

f. Testing: The STPs do not require manual cycling of the valve to verify manual operability of the handwheel. STPs require verification of remote operability.

only.

91NCRWP\91EMN009.HTH Page 6 of 22

DCO-91-EM-!lMS November 22, 1991

g. End-of-life failure: Not. Applicable C. Root Cause:

Preventative maintenance and monitoring of the condition of the-handwheel were inadequate to prevent corrosion from rendering the handwheel' inoperable.

D. Contributory Cause:

None.

IV. Analysis of the Event A. Safety Analysis:

The Auxiliary Saltwater System functions to '

transfer the combined heat load from structures, systems, and components important to safety to the ultimate-heat sink under normal-and accident conditions. Assuming a single? failure, redundancy is provided to assure that this safety function will be accomplished. FCV-495 and FCV-496, which remain open during normal ~ operation'and during the injection and cold leg recirculation phases of an event, function to provide train separation'in support of.the long term recirculation phase of post-accident operation. Closure of either FCV-

• 495 or FCV-496-is required to achieve ASW train separation. In the event of 1000 of power or control signal such that the motor operators were unable to function, these valvcs will fail open and manual operation would be required to' provide train separation. -Either train is capable of supplying the minimum long term cooling requirement, thus providing protection against a passive failure.

The ASW system is not aligned to support long term recirculation until approximately 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> after an accident, as required by Emergency Procedure E-1.4, " Transfer to Hot Leg Recirculation". This phase establishes two separate, redundant trains of recirculation outside of containment. As no set time is stated in the procedure for separation of the trains, and since a passive failure is not postulated until 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after a LOCA, a large-91NCRWP\91EMN009.MTH Page 7 of 22

DCO-91-EM-N009 November 22, 1991 ,

time window is allowed for closure of the valves.

If valve alignment can be accomplished within a reasonable time frame, the system would be '

considered operable for this phase of recirculation.

Based on the results of the motor operator quarterly surveillance verifying remote operability of FCV-495 and 496, and the time available for closure of the crosstie valve (s),

! the Unit 1 ASW system is considered ~ operable.

The system was operable since both valves could have been closed using their motor actuators as demonstrated by the STP. In addition, maintenance j personnel demonstrated that the. valves could be manually operated within the time window allowad for closure of the valves. Therefore, with the crosstie valves able to be remotely or manually closed, .the ASW system would have functioned as l designed to support post-accident operation, and -i

the health and safety of the public.were not ,

adversely affected by this condition.

B. Reportability:

1

1. Reviewed under QAP-15.B'and determined to be i non-conforming in accordance with:Section 2.1.8.

- 2. Reviewed under 10 CFR 50.72 and 10 CFR 50.73 per NUREG 1022 and determined not to.be reportable.

Emergency Procedure (EP) E-1.4 step 8 provides for ASW train separation when Hot Leg Recirculation:is initiated (Reference-10).

l Train separation during the initiation of Hot.

l Leg Recirculation is done to protect against a passive failure, rather than in the event of a passive failure, and a maximum' time window of 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> exists for manually repositioning the-valves. Because of this time window'the ASW system was determined to be operable inethe as l found condition.

3. This problem does not require a 10LCFR 21 l report.

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.. i i DCO-91-EM-N009' November 22, 1991 1

4. This problem does not' require reporting via an INPO Nuclear Network entry.. l

5. Reviewed'10 CFR 50.9 and determined event was not reportable under 10 CFR 50.9.-

V. Corrective Actions A. Immediate Corrective' Actions:

Electrical' Maintenance repaired the-valve.

B. Corrective Actions.toLPrevent Recurrence: ,

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1. STP V3F2 will be revised to require testing of- -

the manual operation of FCV-495 and 496. t In addition'to-the above action,.a' review will. i be performed to' identify all-power. operated-Class I valves.that have Class II' actuators l

valves that. require manual' operation of.the-valve to fulfill a safety function. Once all of the valves are. identified, each associated STP will be revised to require manual testing of the. valve actuator.

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RESPONSIBILITY: C. Pendleton ECD: 12/31/91  !

DEPARTMENT: System Engineering Tracking AR: A0214840 , ; AE.# 06 e Outage Related? No JCO Related?- No >

! NRC Commitment? No I CMD Commitment? Yes

2. Increase the frequency of the preventative maintenance'on the ASW' crosstie valves RESPONSIBILITY: H. Phillips COMPLETE DEPARTMENT: Electrical. Maintenance:

l Tracking AR: A0214840 , AE #05 l

Outage Related? No.

JCO Related? No NRC Commitment?LNo i CMD Commitment? Yes VI. Additional Information _;

1 i

91NCRWP\91EMN009.MTH Page 9 of 22  ;

I DCO EM-N009 November 22, 1991 i

A. Failed Components:

None.

B. Previous Similar Events:

None.

C. Operating Experience Review:

1. NPRDS:

No specific failures relating to corrosion were identified. (Reference 14)

2. NRC Information Notices, Bulletins, Generic Letters:

NRC IE Information Notice 83-46, " Common Mode Valve Failure Degrades Surry's Recirculation Spray subsystem" discusses the common mode failure to open of'the Surry Power Stations ,

motor-operated. valves which admit service water to the containment recirculation spray cooler. The cause of the failure was attributed partly to corrosion of motor and torque switch due to accidental flooding of equipment or due to high moisture content in the air, and infrequent testing. Diablo Canyon's ASW system is analogous to the Surry service water system cooling of the containment recirculation spray coolers. No action was recommended as PG&E's response to the information notice states that design of the ASW Fystem precludes its susceptibility to l common-mode failure due to valve failure. The response also states that valve operability will be verified by the ISI and Valve Test Program on a quarterly basis, and references STP V-2F. Additional research indicated that 3 STP V-2 and subprocedure STP V-2F are i performed on 18 month or 24 month intervals,  ;

not quarterly as indicated. (Reference 12) 1

3. INPO SOERs and SERs:

None. I l

i 91NCRWP\91EMN009.HTH Page 10 of 22 l

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o i DCO-91-EM '509 November 22, 1991 D. Trend Code:

TN-B1, System Engineering,- Procedural Deficiency.:

a EM-B1,JElectrical Maintenance - Procedural- 1 Deficiency.  ;

F Corrective Action Tracking:  ;

.. 'The tracking' action request is AO'214840.. l

.2. Are the corrective actions' outage.-related? .

No

i F. Footno+ ' and Special' Comments:-

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1. NL G.

References:

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1. Control Room Logs; ,

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2. Initiating AR A0196648.

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3. T C0069890. I

4. Design Criteria Memorandum DCM-17B, " Auxiliary L Saltwater System.  !

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- 5. W/O C0076259.

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6. QE Q0008313.

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7. W/O C0090996. ,

8. W/O C0081089. ,

9. Component. History. Work Order Closure Remarksk '

, 10. EP E-1.4, " Transfer to-Hot': Leg l Recirculation". [

i

• i i

11. STP V-3F2, " Exercising Valve:FCV-496:ASW: Pump _ j 1 Crosstie Valve". j

12. Safety Event Review Follower, " Common Mode.

Valve Failures Degrade-Surry's1 Recirculation' l Spray Subsystem".

p.-

91NCRWP\91EMN009.MTH Page 11 of 22 i

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. _ . _ . . ca. . .. _ . _ _ _1

l DCO-91-EM-N009 November 22, 1991 I

13. QE 00006496.

14. Nuclear Plant Reliability Data System General l Report. l l

15. Memo on NECS evaluation of operability, design '

J criteria and seismic analysis. R

16. Root Cause Analysis for DCO-91-EM-N009: FCV-496 Failed to Operated Manually.

17. AR.A0179542.

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H. TRG Meeting Minutes: ,.

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1. On January 25,.1991, the-TRG convened and considered the following:

1 l The TRG Chairman, Electrical Maintenance,  !

initially addressed the issues facing the TRG. l The first-issue is torunderstand the design _ l basis for the Class II. manual operator on'the l Class I-ASW' crosstie valves and to address the j question of whether this operatorsshould be l Class I. The second issue is to~ evaluate the reportability of the event based on the _ ]

operability of the valves in the as-found condition considering the results of the design basis research discussed above.

In order to address these. issues,.the-following action. items were assigned-to members of the TRG to be completed before.the reconvene.

a. NECS (see AR A0214840, AE.#'01):

i. Clarification of the design basis for-the manual operator. 1 l 11. Determination:of'the operability.of  !

l the operator,in:the as found 1 l

condition. {

iii. Assessment of operabilityfof separate trains of ASW system with handwheel for'both SW-1-FCV-496, and SW-1-FCV- 3 495 manually inoperable. '

91NCRWP\91EMN009.MTH Page 12 of-22 i 1 I

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l DCO-91-EM-N009 November 22, 1991 iv. Resolution of placement of crosstie valves on the Q-List.

b. System Engineering - Compilation of a maintenance history for the five ASW crosstie valves, SW-1-FCV-495, SW-1-FCV-496, SW-2-FCV-495, SW-2-FCV-496, and SW FCV-601.

c. Electrical Maintenance - Investigate why the valve is corroding,-and determine if the preventive maintenance is sufficient l

in frequency and actions.

2. On January 29, 1991, the TRG reconvened to address the actions assigned at the initial TRG.

NECS stated that the valves are required to be functional in order to support long term recirculation which is initiated 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> after the LOCA. The function of the valves is to provide train separation during a passive failure.

Electrical Maintenance asked that if, as Class II operators, the equipment cannot be credited for operability in the case of an accident, how credit could be taken for the equipment'in

- an accident mitigation role. NECS replied that the Class II operators are required to support the Class I equipment, but is not required to function to actually mitigate an accident. Long-term recirculation functions to support Class I equipment. The system is designed with redundant: valves such that the probability of both crosstie valves not being .

able to function to support long-term l recirculation is small. j 1

Electrical Maintenance asked at what time _ . 4 after an accident the valves are required to be repositioned to support the recirculation.

NECS answered that the valves were required to be repositioned at approximately 13 to 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> after a LOCA, but that the time window I allowed for repositioning the valve was not known. The Chairman requested that NECS 1

91NCRWP\91EMN009.HTH Page 13 of 22 i

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= . - .

DCO-91-EM-N009 November 22, 1991 research and document the window allowed for repositioning the valves and evaluate the.

operability of the valves, based on the time required to. free the valves, with respect to. i this time.

Electrical Maintenance addressed the definition of valve operability as presented in the STP V-3F1, "Exarcising Valve FCV-495 ASW Pump 2 Crosstie Valve", in which. .

1 operabilityf is indicated if the valve can txa operated remotelyLfrom the control room.

Electrical Maintenance asked if this i i

definition was adequate, and questioned the.

adequacy of STP V-3F1. Electrical Maintenance questioned the ability'of.DCPP to. credit the j function of the Class II.operato.s,;both"of which are powered;from' vital bus H, and questioned what is'_ required by the design l basis to justify operability.

Action Item assigned to'NECS: )

a. Clarify the definition of operabilitp_of the valves with respect to the design basis.

4

b. Justify the operability of the ASW system with valves SM-1-FCV-495.and SW-1-FCV-496  ;

+ in the as:found condition.

NECS commented that it'is more important-that -

I the valves operate, whether operat.on is-manual or remote is irrelevant. The design-basis is to separate.the_ trains using at least'

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one valve. The operability of the valves, for the as found case, is dependent'on the amount' of time allowed to reposition the:valvesLand whether or not-that allotment is flexible.

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-System engineering. addressed the component-  ;

history, stating that the handwheels for-FCV- )

495 and-496 for-Units 1 & 2 have been i documented'in a similar: condition five' times.  !

Electrical: Maintenance stated'that after the handwheels were last found corroded, changes-were made to MP E-53.11AltoLadd'a step to inspect and oil the handwheeliand interface 91NCRWP\91EMN009.HTH Page 14 of 22 l

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f ea DCO-91-EP "009 November 22, 1991 areas every 18 months.

The suggestion was made that the valve be manually operated at the time that STP V-3F2 is performed, but noted that if the valve.is manually operated, remote operation must also be verified. It was suggested that the procedure be revised to include stationing an operator at the valve to partially cycle the valve closed manually, and then verify remote operability by opening the valve from the control room.

Regulatory Compliance asked why maintenance on the handwheel was not done at the time that the corrosion was identified. Electrical Maintenance replied that naintenance was not scheduled because the parts required-were not available at the time. In addition, Electrical Maintenance stated that the judgement was made, though not documented, that because the handwheel was Class II, repair was not required immediately.

The TRG will reconvene February 7, 1991-to consider root cause.

3. On February 7, 1991, the TRG reconvened to discuss operability of.the ASW system in the

- as found condition, the design basis of the Class II operator on a Clann I valve and a preliminary root cause.

NECS returned an answer on the operability of the ASW system with the valves in the as found condition. The function of the valves is to provide train' separation to protect against the possibility of a passive failure, and the valves are not required to function to prevent or mitigate an accident. These valves are repositioned when the unit enters hot leg recirculation at 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> after the: accident.

The FSAR does not postulate a passive failure until 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the LOCA. This allows a maximum time window for re-aligning the valve of 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br />. Based on this time frame, and the fact that maintenance crews required approximately 15 seconds with a two man crew 91NCRWP\91EMN009.MTH Page 15 of 22

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DCO-91-EM-N009 November 22, 1991 l l

to remove paint from SW-1-FCV-495 to return the valve to manual operability, it was determined that the trains of the ASW system could be separated within the required time window, and the ASW system was determined operable with the valves in the as found condition. In addition, NECS stated that if a passive failure, defined not to exceed 50 gpm flow, were to occur with the crosstie valves.

open, the amount of flow lost with ASW pumps j

capable of discharging approximately 11,000 gpm would have no significant effect on the ability of the ASW system to cool the unit.

Discussion of the design basis led to the consideration of the design class previously determined for the ASW' crosstie operatore,_and its acceptance by the-NRC. Information on the past design classification for the operators, l and NRC acceptance or acknowledgement of the l past design classification, will be_ researched j in the SSER. NUREG 0138 will be used to research the case-by-case acceptance and credibility of non-Category I equipment in a seismic situation. DCM M-58 will be used in conjunction with ANSI Standards to document l seismic analysis for the crosstie valves.

NECS, in formalizing a response to the question of the design basis for a Class II l

1 operator on a class I valve, will document any past acceptance of component classifications by the NRC.

The preliminary root cause was determined to i be that no method exists to identify Class II  !

! equipment which requires higher priority maintenance or to convey the importance of the i equipment to craftsmen. Discussion of the root cause of the event noted that corrosion 1

of the handwheel was to be expected in the i i

harsh environment which it is located, but l that the untimelinesa of corrective maintenance needed to be examined. Based on the unavailability of replacement parts, the decision had been made to wait on corrective l

maintenance until replacement parts were available rather than attempt to disassemble the valve to correct the handwheel and risk ,

91NCRWP\91EMN009.MTH Page 16 of 22 I 1

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DC0-91-EM-N009 November 22, 1991 damaging the valve. A portion of this decision had been made on the assumption that the equipment in question an electrically operable, Class II. valve, and therefore could be allowed.to" wait. FCV-495 and FCV-496, however, are important equipment used to protect against passive failure following an accident and need to be maintained. Equipment control _ Guidelines'(ECG) were' identified as.

the mechanism which classifies equipment as

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requiring'a certain level of maintenance.

System Engineering will complete a review-ofL the ECG generation process:to determine how-design engineering fitsEinto to the process,-

and what type of cross-disciplinary review is completed for the ECGS. In-addition, the review will identify the methods.used to ensure that maintenance-is given the proper priority.

Proposed corrective actions include the following:

a. Include a field in PIMS Component Data Base which will identify the equipment as Class II, but requiring prompt maintenance, or:

. b. Add the. operators ~to the equipment' listed

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AP C-55 as Quality Class "B"fand code the operators as Quality class "B"-in the DIMS Component Data' Base.

The TRG will reconvene February 14, 1991'to finalize root cause and incorporate information f. rom AP C-55 and System Engineering review of.the ECG generation process into corrective actions.

4. The TRG reconvened February 14, 1991 to discuss the following.

In consideration of the manual operation of' the valve, the question was-asked as to how not properly.ma'intaining the manual ~ operator would affect the' seismic qualification of the operator. NECS replied that the seismic 91NCRWP\91EMN009.MTH Page 17 of 22

DCO-91-EM-N009 November 22, 1991 qualification of the operator would not have been affected by maintenance as long as the configuration was maintained. Any changes to the configuration, however, would have been documented because they affect a safety system. Replacing any parts on the assembly with other than identical parts would have required a DCN.

After having established the operability of the ASW system with the handwheel in the as found condition, the scope of the nonconformance was revised. The issue.being addressed in the TRG is the failure of SW FCV-496 to operate manually, which encompasses the maintenance priority of the handwheels.

OSRG asked why the FSAR review by System Engineering did not identify the need to 3 maintain this operator. In its. review, System i Engineering would have seen what appeared to be an adequate PM. It was noted that, had System Engineering identified the need for ,

maintenance on a higher level than that I

specified, this need would have been lost because there is no method to identify this '

need in PIMS. If the handwheel.had broken, nothing in the component data base would have identified it as needing prompt attention.

Discussion concluded that a system is needed j to incorporate this information into PIMS. '

Action: System Engineering will identify a method to procedurally identify equipment that is not Class I as having an important function and requiring prompt maintenance.

Action: Chairman will address this issue in the Plant Managers meeting, identifying to i

whom the responsibility for identifying maintenance level on equipment and developing a system to do so belongs.

Discussion of the root cause determined that the corrosion of the handwheel to the actuator body was due to the following:

i

a. The frequency of the handwheel maintenance 91NCRWP\91EMN009.MTH Page 18 of 22 1

DCO-91-EM-N009 November 22, 1991 is too low to prevent corrosion of the handwheel. The lack of timeliness of.

inspection of the valve was the result of a failure to incorporate DCM requirements for manual operation of the valve into plant procedures.

Proposed corrective actions include the.

following:

To correct for the low priority of maintenance assigned to this equipment:

Develop a method to identify equipment identified in Action Requests as important to plant operations and requiring prompt maintenance.

To compensate for harsh environmental conditions:

b. Increase frequency of preventative maintenance on valves affected by the corrosive environment (SW-1-FCV-495, SW FCV-496, SW-2-FCV-495, SW-2-FCV-496, and SW-0-FCV-601)

The TRG will reconvene Thursday February 28, 1991, to finalize corrective actions.

5. The TRG reconvened Thursdav, February 28, 1991 and finalized corrective actions'to prevent recurrence of this event. l

a. To ensure that DCM requirements are I incorporated into working level dvcuments  ;

to indicate the importance of' prompt l maintenance on certain Class II. equipment, l System Engineering will:

1

~i. Revise AP A-350 to incorporate a requirement that system engineers review DCMs to identify equipment which requires a higher level of maintenance. i ii. Revise AP C-55 to create new category which will identify certain equipment 91NCRWP\91EMN009.HTH Page 19 of 22

DCO-91-EM-N009 November 22, 1991 in working level documents as ,

requiring prompt maintenance. j iii. Initiate a change in the PIMS database to allow for inclusion of ,

the category created as a result of revision to AP C-55 in working level 3 documents.

b. To prevent the recurrence of corrosion on the handwheel, electrical maintenance will increase the frequency of preventative maintenance or revise the appropriate STPs to include cycling the valves manually as well as electrically to verify manual operability or place the manual operators on a list to have the valves cycled quarterly.

QA noted that, based upon the corrective actions assigned to System Engineering,.the responsibility to ensure that equipment that

is other than Class I and requires a higher l level of maintenance will fall with System Engineering. If the need for the maintenance of such equipment is not identified or not performed, System Engineering would be held responsible. System Engineering indicated that this responsibility was understood. i The implications of the handwheel on FCV-495 being painted over were discussed in the TRG

. as to whether this situation could potentially l affect operability on other systems. The TRG  !

l chairman has committed to investigate what l type and the adequacy of guidance given to maintenance personnel when a valve is to be

! painted.

l QA disagreed with the root cause as oefined in i

the last TRG, that the frequency of handwheel l

! maintenance was too low to prevent corrosion' l of the handwheel. QA stated that the fact that the handwheel corroded indicates inadequate preventative maintenance, not an insufficient maintenance frequency. The root cause was re-phrased to state that l preventative maintenance or condition 91NCRWP\91EMN009.MTH Page 20 of 22 l

I

i l.-

DCO-91-EM-N009 November 22, 1991 monitoring was inadequate to prevent corrosion of the handwheel, f In addition, the root cause relating to l incorporation of design basis information into I working level documents was reworded to state l that neither the responsibility nor.the.

methodology had been proceduralized for identifying equipment which11s required for important plant system realignment.

l

! This TRG will not reconvene.

1

6. On October 17, 1991, the TRG reconvened at i 1:00 pm PDT in Room 527 of the Administration

! Building to evaluate the corrective actions

assigned by previous TRG meetings. System l Engineering was not represented in the meeting, therefore the TRG rescheduled the meeting for October 18, 1991 at 1

00 pm PDT in Room 425 of the Administration Building.

7. On October 29, 1991, the TRG reconvened to evaluate the corrective actions proposed by-previous TRGs. It was' agreed that a mechanism for identifying Non-Class I components,- d' important to safety', which require prompt maintenance was not needed. What was aeeded, was to perform the proper surveillance of this equipment. Proper surveillance should identify degraded conditions. Onca these conditions are identified, the equipment would be treated the same as any other TS equipment identified as degraded during a surveillance.

Based on this discussion in the TRG, the Root Cause section of the NCR was revised, Corrective Action 1 was added and the following original corrective actions were deleted:

o Revise AP A-350 to incorporate a requirement that system engineers review DCMs to identify equipment which requires a higher priority for maintenance. j o Revise AP C-55 to create a new category j which sill identify equipment in working  ;

91NCRWP\91EMN009.MTH Page 21 of 22 l

T DCO-91-EM-N009 November 22, 1991 level documents as requiring prompt maintenance.

o Initiate a change in the PIMS database to allow for inclusion of the category created as a result of revision to AP C-55 in working level documents.

The TRG determined that this NCR was ready fa-PSRC review.

The TRG established a new overall ECD of 2/14/92.

I. Remarks:

None.

J. Attachments:

Root Cause Analysis for DCO-91-EM-N009.

91NCRWP\91EMN009.MTH Page 22 of 22 i