ML20128H646

Forwards Position Papers on Information Notice 92-18, Arkansas Nuclear One,Units 1 & 2

ML20128H646
Person / Time
Site:	Arkansas Nuclear
Issue date:	10/02/1996
From:	Alexion T NRC
To:	NRC
References
IEIN-92-018, IEIN-92-18, NUDOCS 9610100020
Download: ML20128H646 (23)

Text

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l October 2, 1996 l l 1

l l 1

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MEMORANDUM T0: PDIV-1 FILE g '

FROM: TOM ALEXION I

SUBJECT:

POSITION PAPERS ON INFORMATION NOTICE 92-18, .

ARKANSAS HUCLEAR ONE, UNITS 1 AND 2  !

I received the subject position papers from the licensee.

l Docket Nos. 50-313 and 50-368

Attachment:

Fax from Licensee i

l DISTRIBUTION:

cDocket File PUBLIC (PDR)

TAlexion

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l C9\ i NRC FILE CENTER C8PY W 1

( 0iCC:10 \

9610100020 961002 PDR O ADOCK 05000313 PDR

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- 14485.R,333 l

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IELECOPY REOUEST TO: 6r I Mc/I85L '

COMPANY:  !

TELEPHONE NUMBER:

FACSIMILE (FAX) NUMBER: l VERIFICATION l NUMBER:

FROM: 5 M'

TELEPHONE NUMBER: (50!) 858 _ [6 I l ARKANSAS NUCLEAR ONE LOCATION: - GENERATION SUPPORT BUILDING-IC OUR FAX NUMBER: _

501-858-4685 OUR VERIFICATION NUMBER: 501-858 5000 OUR MACHINE WPE: RICOH FAX 3100L NUMBER OF PAGES INCLUDING l COVER: _

COMMENTS:

ATTACHMERT l

\

7 P.2/8

( Position Paper l Concerning the Effects of Information Notice 92-18 on the Ability to Perform J Alternate Shutdown at l Arkansas Nuclear One Unit 1 for a fire in the control room, a common method for achieving rafe shutdown is to transfer control of critical components to an alternate shutdown panel. Typically, the alternate shutdown system relies on a single train of components to achieve safe shutdown. ANO has a unique position in regards to Alternate Shutdown capability in two respects.

First, the Alternate Shutdown procedure currently aligns two independent, fully redundant systems. This includes .but .' is not limited to) two electrical buses, two Emergency Teedweter trains, two Make-up trains (i.e. RCS inventory) and two Service water trains. Either system is capable of achieving Hot Shutdown and no single failure on one train will prevent the redundant train from performing it's function.

Secondly, instead of transferring control to an alternate panel, ANO relies upon manual alignment of the required control valves.

This is facilitated by de-energizing the safety related buses i prior to exiting the control room. De-energization will However, during l

" freeze" the valves in their pre-fire position.

ANo's analysis of a control room fire, the only action that was allowed to be credited prior to control room evacuation, was manual reactor trip (reference Generic Letter (GL) 86-10, Enclosure 2, section 3.8.4). Consequently, in the initial stages of the Alternate Shutdown (ASD) Procedure follow-up actions, operations personnel open the feeder breakers of the safety related buses at the switchgear, thus insuring control circuit de-energization as well as isolating power to each valve. .

In developing ANO's Appendix R analysis, the assumption was made that any valve with control cables located in the control room could be subject to spurious operation due to conductors in the control cable shorting together (i.e. hot short). Since credit could not be taken for removing control power from the MOVs prior to control room evacuation, the ASD procedure was written under the assumption that any safe Shutdown valve could have transferred to an incorrect position. Therefore, the operators are tasked with manually aligning all Safe Shutdown valves to their correct position.

Page1

,s EP 23 '% 02:29PM ANO GSB LOBBY P. 34 This strategy is consistent with the guidance provided in Generic Letter 86-10, Enclosure 2, section 5.3.10, which states in part, l

a. The safe shutdown capability should not be adversely l affected by any one spurious actuation or signal resulting from a fire in any plant area; and l b. The safe shutdown capability should not be adversely l affected by a fire in any plant area which results in l

the loss of all automatic function (signals, logic) from l the circuits located in the area in conjunction with one I worst case spurious actuation er signal resulting from i

the fires and ...

Further guidance is provided in Inspection Procedure 64100, section 03.01.e.2.f which states in part, l

... These assumptions are therefore consistent with the established NRR review practice of requiring licensees to I analyze for any and all spurious actuations or failures where no such spurious actuations or failures occur simultaneously.

ANO foresees that in a control room fire, HOVs could fail l (electrically) in one of three ways (1) Shorts to ground or open circuits would cause the motor to fail, leaving the valve in its current position, (2) Shorts between conductors could cause the valve to spuriously operate (i.e. change position) or l

(3) A "92-18" short which bypasses valve protection features possibly causing mechanical damage to the valve.

l The latter two failures can both be classified as a hot short.

l However, the "92-18" short could possibly prevent the valve from l being positioned manually as explained in the following.

Information Notice 92-18 presented a scenario in which a hot short could cause physical damage to a MOV. Effectively, the short bypasses the protective features of the limit and/or torque switch thereby allowing the motor to continue running until the motor stalls or the valve is unable to handle the l mechanical stresses (i.e. bent stem, yolk bolt breakage,"etc.)

l A valve failure of this nature could prevent operations l

personnel from performing the required manual alignment for the subject valve. Consequently, ANO performed a detailed review of all valves credited in the Appendix R analysis to' determine if a single 92-18 type hot short could prevent Safe Shutdown. The specifies of this review are presented in the attached evaluation.

A brief overview of the evaluation is as follows:

Pap 2

~ ~

g SEP '30' '96 ' 02:29PM ftQ GSB LOBBY P 4/8 l

EVALUATIQW MET 50DOLOGY The 92-18 short is of particular concern to those valves which need to change state in order to reach their desired Safe Shutdown position (ex. a normally closed valve that needs to be opened). The 92-10 short could signal these valves to attempt to move further into their current position (i.e. a closed valve would get a close signal, an open valve would get an open signal). Refer to figure 1 for an explanation of the circuitry.

Consequently, the Safe Shutdown valves were examined to determine their required safe Shutdown position versus their l l

normal operating position. Valves could be removed from further consideration if the correct Safe Shutdown position coincides .

l with the failed valve position and the valve was capable of maintaining the pressure boundary. 1 Next, the valves that were identified as possibly failing in the incorrect position were examined to determine if an additional previously credited and approved Alternate Shutdown path was available to perform the desired function.

The results did not identify any single valve failure which could prevent Safe Shutdown.

SUMMARY

In summary, ANO acknowledges that a 92-18 type hot short is theoretically possible. However, the existing Alternate Shutdown measures, which include

1) aligning redundant Safe Shutdown systems and

2) eliminating the possibility of additional hot shorts by promptly de-energizing Hov circuits, are sufficient to preclude a single hot short from preventing Safe Shutdown. .

l t

pnp 3

. SEP 30 '96 02:30Pt1 ANO GSB LOB 3Y P.5/8 l

Position Paper t

l Concerning the Effects of Information Notice 92-18 on the Ability to Perform t

Alternate Shutdown at

- Arkansas Huclear one Unit 2 1 For a fire in the control room, a coninon method for achieving safe shutdown is to transfer control of critical components to an alternate shutdown panel. Typically, the alternate shutdown system relies on a single train of components to achieve safe shutdown. ANO has a unique position in regards to Alternate Shutdown Capability in two respects.

First, the Alternate Shutdown procedure currently aligns two independent, fully redundant systems. This includes (but is not limited to) two electrical buses, two Emergency Feedwater trains, two Make-up trains (i.e. RCS inventory) and two Service Water trains. Either system is capable of achieving Hot Shutdown and no single failure on one train will prevent the redundant train from performing it's function.

Secondly, instead of transferring control to an alternate panel, ANO relies upon manual alignment of the required control valves.

During ANo's analysis of a control room fire, the only action '

that was allowed to be credited prior to control room evacuation, was manual reactor trip (reference Generic Letter (GL) 86-10, Enclosure 2, section 3.8.4). Unit 2 differs slightly' from the approach of Unit 1 in that an attempt to de-energize all safety related buses is not performed prior to control room evacuation. Instead, Operations personnel open select breakers throughout the performance of the Alternate Shutdown procedure.

The af fected breakers isolate power to the required Safe Shutdown valves and allow manual operation.

In developing ANO's Appendix R analysis, the assumption was made that any valve with control cables located in the control room could be subject to spurious operation due to conductors in the control cable shorting together (i.e. hot short) . Since credit could not be taken for removing control power from the MOVs prior to control room evacuation, the ASD procedure was written under the assumption that any Safe Shutdown valve could have transferred to an incorrect position. Therefore, the operators are tasked with manually aligning all Safe Shutdown valves to their correct position.

Page1

LOL@Y P.6/8 This. strategy is consistent with the guidance provided in Generic Letter 86-10, Enclosure 2, section 5.3.10, which states in part,

s. The safe shutdown capability should not be adversely affected by any one spurious actuation or signal resulting from a fire in any plant area; and

b. The safe shutdown capability should not be adversely affected by a fire in any plant area which results in l

the loss of all automatic function (signals, logic) from the circuits located in the area in conjunction with one i

worst case spurious actuation or signal resulting from the fire; and ...

Further guidance is provided in Inspection Procedure 64100, section 03.01.e.2.f which states in part,

... These assumptions are therefore consistent with the established NRR review practice of requiring licensees to analyze for any and all spurious actuations or failures where no such' spurious actuations or failures occur i simultaneously.

ANo foresees that in a control room fire, MOVs could fail (electrically) in one of three ways:

(1) Shorts to ground or open circuits would cause the motor I

to fail, leaving the valve in its current position, (2) Shorts between conductors could cause the or valve to spuriously operate (i.e. change position)

(3) A "92-18" short which bypasses valve protective features possibly causing mechanical damage to the valve.

The latter two failures can both be classified as a hot short.

However, the "92-18" short could possibly prevent the valve from being positioned manually as explained in the following.

Information Notice 92-18 presented a scenarioEffectively, in which a hot the i

l short could cause physical damagc to a MOV.

short bypasses the protective featuces of the ILmit and/or torque switch thereby allowing the motor to continus running until the motor stalls(i.e. or the bentvalve stem,isyolk unatie bolttobreakage, handle the etc.)

mechanical stresses A valve failure of this nature could prevent Operations personnel from performing the required manual alignment for the subject valve, consequently, AHo performed a detailed review of r

all valves credited in the Appendix R analysis to determine Theif a single 92-18 type hot short could prevent Safe Shutdown.

l specifics of this review are presented in the attached

evaluation.

A brief overview of the evaluation is as follows:

Fus2

l ;

SEP 30 '96 02:31FM ft40 GSB LOBBY P.7/e f I

l EvhLonTIott isTsopotAst 1 i

The 92-18 short is of particular concern to those valves which need to change state in order to reach their desired Safe Shutdown position (ex. a normally closed valve that needs to be opened). The 92-18 short could signal these valves to attempt to move further into their current position (i.e. a closed valve would signal).

get a close signal, an open valve would get an openRefer to fig.

l Consequently, the safe Shutdown valves were examined tod normal operating position. Valves could be removed from further consideration if the correct Safe Shutdown position coincides with the failed valve position and the valve was capable of naintaining the pressure boundary. .

Next, the valves that were identified as possibly failing in the incorrect position were examined to determine if an additional previously credited and approved Alternate Shutdown path was available to perform the desired function.

The results did not identify any single valve failure which could prevent safe Shutdown.

SUMMARY

ANO acknowledges that a 92-18 type het short is theoretically possible. However, the existing Alternate Shutdown measures which include

1) aligning redundant Safe Shutdown systems and

2) eliminating the possibility of additional het shorts by promptly de-energizing HOV circuits are sufficient to preclude a single hot short from preventing safe Shutdown, i

I Page 3 l

,, Nm KND @SL4 LOBBY P.8/8 Valve in Closed Position l

l

( MOV Limit Switches

(+) l .

-/  :: -/

I _ . _ _

/ / l M ' -- - -- "

C .. . ..<>

c C "

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GND Close open Note : Torque switches are not shown but would be in parallel with "Open" and "Close" limit switches.

l The postulated 92-18 short would occur between the conductor leading to the green lamp and the conductor downstream of the "Close" contact. This would cause the i MOV to continue to drive close until motor stall. A short to the downstream side of the "Open" contact would cause the valve to spuriously open. However, upon reaching the 100% open position, the limit switch contact providng power to the green indicator light would open (prior to valve damage). A similar scenario would occur with a "Normally" open valve receiving a spurious "Open" signal.

s

' SEP 30 '96 02:31Pt1 ANO GSB LOBBY P.2/14 i

i NRC Information Notice 92-18

Evaluation I

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Performed ate P d Reviewed y s24,V ate,, 9/A//g y .

i

• F~W~"EE E'mAMnM#V3fR@#Y P.3/14 NRC Information Notice 92-18 Evaluation Purnose 1

Information Notice 92-18 concerns MOVs that could become inadvertently energized by control cable shorting to other energized conductors during a control room fire. The speci6c type of" hot short" described would bypass the nonnal motor protection such as limit and torque switches and possibly damage the operator such that further operation either remotely or manually would not be possible. The purpose of this evaluation was to determine if ANO is subject to " hot shorts" and then to document our position concerning this unlikely scenario.

ESSEf MOVs within ANO Unit I and Unit 2 that are contained on the Components ofInterest list (Attachment 1) were evaluated. This evaluation utilized the assumptions and conditions as stated in the original Fire Hazards Analysis and Appendix R Safe Shutdown Analysis.

Evaluation Methodology An evaluation process was established to review the MOVs on the components ofinterest list for Unit 1 and Unit 2. The first step was to determine if the valves were subject to hot shorts. This was done by reviewing the schematic drawings for each valve and comparing it to the drawings presented in the Infonnation Notice. If the valve was subject to a possibility of hot shorts, then ibrther evaluation was performed to determine if the valve fails in the desired safety position. If the component does not fail in the safe position, then further research was performed to determine if an alternate path was available to accomplish the speel6c safbty fbnction to which it was credited. If the failure position of the valve is also the safety fbnction position, and no alternate means existed to isolate the valve, then an evaluation was performed to determine if the force the valve operator could generate could damage the valve and breach the pressure boundary.

Those components that remained from the analysis described above, were subject to further evaluation and will be described later in this report.

Hot Short Evaluation Pg.2 Rev 9/16/96 1:51 FM

E.SEllh

.ueu i

The fifty.nine MOVs on the components ofinterest list were evaluated and the results are

! as follows: -

All MOVs on the components ofinterest !!st have a control circuit with the potential fer hot shorts during a control room file.'

"' ' '~ ~~~ ~

When subjected to hot shorts, fifteen of the valves will fkil in their safe shutdown position

{ =

Nine of the MOVs do not have an alternate means ofisolatlon. These valves we evaluated from a structural analysis standpoint and determined to remain intact when operated with no overload protection.(See attechment 2) 1

, e i

Fifty-five valves were found to have attemate means to accomplish the necessary safety fbactions when subjected to a hot short situation.

J Only four valves did not fhil in the safe position er have alternate means to accomplish j the necessary safety fbnetions. They will be evaluated individually as follows:

) CV-1410 Decay Heat Suction Isolation Valve CV-1050 Decay Heat SuctionIsolation Valve l .

j These valves are required to open in order to establish decay heat removal for achieving cold shutdown conditions. The circuit breakers for these valves are opened during normal I

' operation so the valves are not subject to a hot short situation unless they are re-energized after a fire in the control room. However, actions are called out in the alternate shutdown

- procedure (OP1203.02) to disconnect all control wiring from the MCC to th.e control room before these valves are operated. Therefore, these valves will not be affected by a j control room fire.

1 l CV-1404 k)ecayHeat SuctionIsolation Valve I

This valve is required to open in order to establish decay heat removal for achieving cold shutdown conditions. In the altamate shutdown procedure, power to this valve operator is removed early in the control room fire scenario in order to prevent spurious operation of this component.

Hot Shon Evaluation Pg. 3 Rev 9/16/96 1:51 FM 4

P.5/14 1

This valve has aho been evaluated from a structural analysis standpoint. The results show that when this valve is subjected to closing force from the motor when in the closed position, the yoke bohs may yield and/or'the stem may band. However, the bolts are not <

expected to break which would leave the manual operator still in place and possibly functional, if the valve stem were to buckle, it would most likely bend on the threaded portion which is.above the valve body. In any case, however, the valve could stiU be manually opened by removing the operator completely and pulling the stem and disc out  ;

by extemal mechanical means. Unit I does not have a time limit on achieving cold  ;

shutdown conditions which would allow enough time to accomplish the necessary actions I to this valve to establish decay heat cooling.

The necessary operations procedures are being revised to open the circuit breaker for CV- '

1404 during power operations. This will eliminate any possibility ofhot shorts occurring In addition, the procedure currently directs plant staff to disconnect all control wiring from the MCC to the control room before this valve is operated.

CV-3643 Service Water Discharge to Aux Cooling Water This valve serves to isolate the non vital Auxiliary Cooling Water (ACW) system fFom the rest of the Service Water System during emergency conditions. Even though this component currently appears on the Components ofInterest list, it is not required to function in order to achieve the safety fbnetion of the Service Water System during a control room fire scenario. Adequate flow exists firom the Service Water Pumps to meet flow demands without this valve closed since no other accident is assumed during a control room fire. This position is supported by an analysis performed by Mechanical Engineering and is documented in IRF 8156. This component will be evaluated for removal from the Appendix R Components ofInterest List. Therefore, in the unlikely event of a hot short in this valve circuit, failure of this valve in the open direction would not have an impact on our ability to cope with a control room fire scenario.

Other Issues CV-1274, RCP Seal Bleedoff Block valve, fbnctions to isolate the normal RCP seal bleedoff during an Appendix R shutdown due to seal damage concerns This valve is the alternate isolation path for CV-1270, CV-1271, CV-1272, and CV-1273. CV-1274 is normally open and fails in the open direction. A mechanical weaklink evaluation has determined that this valve, if failed in the open direction, would not be damaged to the point where it could not be closed manually. The Altemate Shutdown procedure provides guidance to operate this valve manually if electrical operation is not possibid.

Hot Short Evaluation Pg.4 Rev 9/16/96 1:51 PM

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,  :- eg 3e ,g 02: 3.#ti rnGSB LOBBF ~ ~~ ~ ~~ ~ ~' ~ ~ ^ ~ ~~ '~~ K U((~

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! Unit 2 i

l The sixty-three MOVs on the components ofinterest list were evaluated and the results are as follows:

All MOVs on the components ofinterest list have a control circuit with the potential fbr hot shorts during a control room file.

i e When subjected to hot shorts, twenty-three of the valves will fall in their safe - -

shutdown position i . Twenty-one of the MOVs do not have a'n alternate means ofisolation. These valves

) were evaluated from a structural analysis standpoint and detennined to remain intact when operated with no overload protection.(See attachment 2) e Fifty-nine valves were found to have alternate,means to accomplish the necessary

] safety functions when subjected to a hot short situation.

! Only four valves did not failin the safe position or have alternate means to accomplish the necessary safety functions. They will be evaluated individually as follows:

i -

2CV-4873-1 VCT Discharge Valve T

I This valve serves to isolate the Volume Control Tank (VCT) so that an inventory source

! can be provided to the Charging Pumps from the Refbeling Water Tank (RWT), Bonc

, Acid Makeup Tanks, or Boric Acid Pumps. In the attemate shutdown procedure (OP

2203.14), this valve is closed as one of the immediate actions taken'before evacuation of

! the control room. ,

) An evaluation has been performed to determine if failure of 2CV-4873-1 in the open i direction could prevent the accomplishment of the reactor coolant inventory safety fbnction. It has been determined that even if 2CV-4873-1 failed to close, enough head

)

t would likely be available from the alternate sources of water (Boric Acid Makeup Tanks, RWT or Boric Acid Pumps) to seat the VCT outivt check valve (2CVC-20) and prevent su carryover from the VCT to the charging pumps (Ref. IRF 8158).

Additionally, a weak link evaluation of this valve has revealed that the worst case actuator j

stall thrust is below the maximum allowed thmst in the open direction. Even though the backseat may experience some cracking in this overload condition, it will not affect the f ability of the valve to be closed mar.ually using the handwheel.

y .

i Hot Short Evaluation

• j Pg. 5 Rev 9/16/961:51 PM i

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srp 3a >% ez:33pr1h5Gsitossy Md

' Therefore, even in the unlikely event of a hot short in this valve circuit, fhilure of this valve in the open direction would not have a significant impact on our ability to cope with a control room fire scenario.

j 2CV-5086 RCS to Shutdown' Cooling i

1. This valve is required to open along with the other valves in series, 2CV 5038-1 and 2CV-5084-1, in order to establish shutdown oooling for achieving cold shutdown conditions.

This valve breaker is open during normal operation so it is not subject to a hot short

situation during a control room fire.

! The only possible scenario in which this valve could fall would be in the event that the breaker for this component were to be closed after a control room fire which had caused a i

" hot short" in the control wiring. For this reason, this valve has also been evaluated from a structural analysis standpoint. The results show that when this valve is subjected to i

closing force from the motor when in the closed position, the yoke bolts may yield and/or the yoke clamp band. Neither the bolts nor the clamp are expected to break, which would leave the manual operator still in place and possibly fbactional. In any case, however, the valve could still be manually opened by removing the operator completely and pulling the i stem and disc out by external mechanical means.

1

{ The alternate shutdown procedure is being revised to include instructions to disconnect the control wiring before attempting to operate this valve after a fire in the control room.

2CV-5038-1 RCS to Shutdown Cooling This valve is required to open alorns with the other valves in sedes, 2CV-5084-1 and 2CV-

! 5086-2, in order to establish shutdown cooling for achieving cold shutdown conditions.

f .

1 This valve has been evaluated &om a structural analysis standpoint. The results show that when this valve is subjected to closing force from the motor when in the closed position, i

the yoke bolts may yield and/or the stem may bend. However, the bolts are not expected

to break which would leave the manual operator still in place and possibly fhnetional If the valve stem were to buckle, it would most likely bend on the threaded portion which is above the valve body. In any case, however, the valve could still be manually opened by removing the operator completely and pulling the stem and disc out by extemal

} mechanical means.

1 i

The necessary operations procedures have been revised to open the circuit breaker for 2CV-5038 during power operations. This will eliminate any possibility of hot shorts occurring. In addition, the alternate shutdown procedure is being revised to include q Instructions to disconnect the control wiring before attempting to operate this valve after a l fire in the control room.

l Hot ShortEvaluation j Pg. 6 ,

Rev 9/16/961:51 PM

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. #2FY3 175 GE:3fPM CGD G5Le Lo@W P.8/14

'2CV-5084 1 RCS to Shutdown Cooling This valve is required to open along with the other valves in series, 2CV-5038-1 and 2CV-5086-2, in order to establish shutdown cooling for achieving cold shutdown conditions.

This valve has also been evs usted fiom i structural analysis standpoint. The results show that when this valve is subjeaed to the closing force from the motor when in the closed position, the yoke bolts may yield and/or the yoke clamp band. Neither the bolts nor the clamp are expected to break which would leave the manual operator still in place and probably functional. In any case, however, the valve could still be manually opened by removing the operator completely and pulling the stem and disc out by external mechanical means. - ~ " - - --

The necessary operations procedures have been revised to open the circuit breaker for 2CV-5084-1 during power operations. This will eliminate any possibility ofhot shorts occurring. In addition, the alternate shutdown procedure is being revised to include instructions to disconnect the control wiring before attempting to operate this valve after a fire in the control room.

Alternate Shutdown Procedure Review As part of this effort, the alternate shutdown procedures for each unit were reviewed against the results of the " hot short" review. . The alternate shutdown procedures for Unit 1 and Unit 2 are OP-1203.02 and OP-2203.014 respectively. These procedures were reviewed to detennine if the nece'ssary guidance was contained in the procedure to accomplish an orderly shutdown while coping with the results of a possible hot short condition. While only one train or component may be necessary to accomplish a particular safety function, the procedures contained guidance for establishing the fbnetion through a variety ofmeans, (with the exception of the components previously discussed). The .

procedures were thorough, clear and except for the previously noted exceptions, do not need revision to include additional guidance for coping with a " hot short" situation.

Other Actions The MOV Program Plan has been revised to include a section providing g" Wee to inspect or evaluate any MOVs on the Components ofInterest list after a control room fire.

This would insure that structuralintegrity had not been compromised and appropriate repair actions were taken before restart 'of the unit.

In addition, a memo has been issued to control room personnelm* forming them of the potential for " hot shorts." Specific attention is given to the components whose ,

procedures are being changed as a result of this analysis.

Hot Short Evaluation Pg.7 Rev 9/16/96 1:$1 PM A

1. 1. -'fS "5% l@3MW1 ANO GSB LOBBY P.9/14 l

Summary

• IN 92-18 has been reviewed against current plant configuration, design bases and operating procedures and the results have been documented in this report. ANO Unit 1 an'd Unit 2 have procedures in place to cope with a control room fire even in the unkkely event of a " hot short" occurring for the vast majority ofMOVs. For the remaining valves, analysis shows that failure of these valves can be dealt with through manual operation of the components. Also, the DH/SDC components are not needed until near the end of the scenario which would allow sufficient time to develop the necessary g*m for their repair.

... .~.

The necessary procedure changes are being made for these MOVs to eliminate any i possibility of " hot shorts" occurring. In summary, " hot shons" occurring during a control room fire at ANO will not affect our ability to safely shut down the reactors and maintain them in a safe shutdown condition.

References

l. CR C-96-0046, Evaluation of NRC Information Notice 92-18

2. ER-95-0011-04, ANO MOV Program Plan

3. Memo to U-1 and U-2 Control Rooms from Larry Kilby and David McKinney dated September 12,1996 on MOV hot shorts

4. IRF 8157, Additionalinformation on weak link evaluations for MOVs

5. IRF 8158, Review of system response for 2CV-4873-1 failing open

6. IRF 8156, Review of system response for CV-3643 failing open

7. ANO Prefire Plan for Unit 1 and Unit 2 (4 volumes)

8. ANO Fire Hnzards Analysis (1 volume)

I I

Hot Short Evaluation I pg,g Rev 9/16/96 1:51 PM

I i i NRC M S2-15 Attactament 1 Evaksation f

~

c_-- --. f ofIntwest (MOVs) o- Cosnponent r--nJJ:--a, System _ Hot _Short SSP Fall Mode Nenn Pos Alt Path ISO NOTES CV-1295 RCP Seal BO ,

Mt1 Y C O O Y_ Y CV-1050 DH SuctIse DH N .

BKR Open, PB OK ,

CV-1410 DH SuchIso DH Y O C C N N_ BKR Open, PB OK ,

CV-1270 RCP Seal BO MU Y C O O Y Y -

CV-1271 RCP Seal BO MU Y C O O Y Y CV-1272 RCP Seal BO MU. Y C O O- Y Y CV-1273 RCP Seel BO MU Y C O O Y Y _

CV-1274 RCP Seel Blod MU Y C O O Y Y ManuelOpereBan OK CV-1000 ERVEBed RCS Y C O O Y N PB OK CV-1221 Letdown iso RCS Y C O O .Y Y CV-1214 Letdown Iso RCS Y C O O Y N PB OK 4 CV-1216 Letdown les RCS Y C O O Y N PB OK Y Y CV-1220 HPlIri HPI Y O C C  ;

CV-1219 HPl inj tFl Y O C C Y Y  !

CV-1227 FPIInj 6Pl. Y O C -

C Y Y CV-1228 SPIInj FPI Y O C C- Y Y -

CV-1407 BWST Out Ifl Y O C C Y N PB OK CV-1408 BWST Out lff Y O C C Y N PB OK .

CV-1406 RB Sump to DH LPl Y C C C Y Y ,

CV-1405 RB Sumpto DH LPl. Y- C C C Y Y

>- CV-2878 ADV Block MS~ Y C C C. Y Y ,

Y Y

+

m CV-2619 ADV EBock MS: Y C C C

$' O C Y WA SG-7 Sluice Gate SW Y C

@ SG-6 Sluice Gate SW: Y O C C Y WA

" SG-5 Squice Gate SW, Y O C C Y WA SG-4 Sluice Gate SW. Y :O l0 O Y WA .

h O iO O Y WA r ISG-3 Sluice Gate SW Y -

% SG-2 Sluice Gate SW Y O O O Y WA 0 SG-1 Shoce Gate SW Y O O O Y WA i o CV-3646 SW Crosoever SW Y O O O Y Y

, CV-3641 SW Dischosge SW Y O O O Y Y P CV-3645 SW Duchesge SW: Y O 'O O Y Y - ,

a CV-3644 SW Cressever SW- Y C O O Y Y

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SW X-Over SW- Y C O O Y Y CV-3642 Page1 Revision eft 6/98134 PM

Attachement 1 NRC IN 92-18 Evaluation T CV-3640 SWX-Over SW Y ,C OE OC- Y Y d CV-3543 SWto ACW SW Y C O O ,N fi~ Flour analysis, OKw8hout rin==d i CV-2883 EFW Steam EFW Y O C C Y Y CV-2613 EFW saammi EFW Y O C C Y Y CV-2867 EFW Sem BEL EFW Y O O O Y N PB_OK CV-2817 EFW SEm B8t EFW Y O O O Y N PB OK CV-2889 EFW Rodr EFW Y C C C Y Y ,

CV-2870 EFW Rodr EFW Y C C C Y Y CV-2828 P7B Block EFW Y O C C Y Y- '

CV-2627 P7A Bock EFW Y O C C Y Y ~

CV-2820 P7A Modt EFW -

Y O C C Y Y >

CV-2670 P7BENodt EFW Y O C C Y Y CV-2808 SWto PTA SW Y O '

C C Y Y CV-2803 SWto P7B SW Y O C C .

Y Y CV-2800 Cond to P7B CS Y O O O <

Y CV4802 Cond to P7A CS Y O O O Y Y CV-3851 SW to P7A SW Y O C C Y Y CV-3850 SW to P7B SW Y O C C Y Y CV-3821 SW to DH SW Y O C C_ Y -

Y CV-3822 SW to LH SW Y O C C Y Y CV-1400 DH Iso DH Y O C C Y Y '

CV-1401 DH Iso OH Y O C C Y Y CV-1404 D H h r*Eart DH Y- O C C N N PB OK, Revise proc to tag open g CV-3807 SWto EDG SW Y O C C Y Y g CV-3808 SW to EDG SW Y O C C Y Y

_a 0 ,

9 Unit 2 h 2CV-0340-2 Steam to EFW EFW Y O O C Y Y

. 2CV-0716-1 SW to2P78 EFW Y O C C Y .Y El 2CV-1038-2 EFW to SG EFW Y O O .O Y Y 2CV-1925-1 EFW to SG EFW Y O C C Y Y

[ 2CV-0789-1 Cgnd to EFW EFW Y O O O Y Y i a 2CV-0795-2 Cond to EFW EFW Y O O O Y Y  !

• 2CV-1028-2 EFW to SG EFW , Y O C C Y l Y  :

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l Page 2 ,

Revealen 9f987981:34 PM ,

Attachment 1 NRC IN 92-18 Evaluation 2CV-1076-2 EFW to SG lEFW Y O C C Y Y U 2CV-1837-1 EFW to SG EFW .

Y O O ,

O Y Y n' 2CV-1939-1 EFWto SG EFW Y O O O Y Y 2CV-1036-2 EFWtoSG EFW Y O O O Y Y 2CV-1075 EFW to SG EFW Y O C C Y Y 2CV-1000-1 Steam to EFW EFW Y ,O O O Y N PB OK 2CV-1050-2 Steam to EFW iEFW Y O O O Y N PB OK E~

2CV-0711-2 SWto EFW EFW Y O OfC C Y 2CV-0707 CST to EFW 'EFW Y O O O Y Y 2CV-1474-2 Sluice Gate SW Y O O O Y NA 2CV-1472-5 Seuice Gate SW ,Y O O O Y NA 2CV-1400-1 SW to ESF .SW Y O O ~

O Y Y 2CV-1543-1 SW to Cing Tw SW Y 'O O D Y N PB OK 2CV-1560-2 SW to Pond SW Y .

O OPC C Y N PBOK 2CV-1542-2 SWto Cing Tur SW Y O O ,O ;Y N PB OK 2CV *S40 SW to Cing Tw SW Y O C C Y N PB OK 2CV-1473-5 Sluice Gate SW Y O C C Y NA ,

2CV-14752 Sluice Gate SW Y O C C Y NA 2CV-1470-1 Sluice Gate SW, Y O O O. Y -

NA 2CV-1422-2 SW X Over- SW. Y .O OfC OfC  : Y Y 2CV-1471-1 51ulce Gate SW: Y O C C :Y NA 2CV-1480-2 SWto Late SW Y O O O Y N PB OK 2CV-1481-1 SWto Lake SWi Y O .O O Y N ..PB OK

y. 2CV-1541-1 SW to ECP SW. Y O ,

O C Y N PB OK E 2CV-1406-2 SW to ESF SW: Y O O O Y Y 3 2CV-1418-1 SWXOver SW Y O OPC OfC Y Y  !

$ 2CV-1419-1 SW X Over SW lY O OfC OfC Y Y '

C 2CV-1421-2 SWX Over .SW . Y O OPC OfC- Y Y -

y 2CV-4840-2 Chg Pump DischCVCS Y O O O Y N PB OK 2CV-4873-1 VCTto Chg P CVCS Y C O O N N PB OK, analysis-ek, manuel op r

o- 2CV-4820-2 LD to Regut Hx CVCS Y C O O .Y N PB OK h 2CV-4740-2 LTOP iso RCS Y C C C Y N 'PBOK El 2CV-47301 LTOP iso RCS Y C C C Y N PB OK 2CV-4950-2 RWTto Chg CVCS Y O C C Y Y I

$ 2CV-40961 ECCS Vent RCS Y C C C Y Y~~

$ 2CV-4741-1 LTOP iso RCS Y C C C Y M 2CV-4731-2 LTOP iso RCS ;Y C C C Y Y 0

m ,

. Paes3 Revision 9ff0f961:34 PM

Attachrnent i NRC BI S2-13 Evalum8on v

T 2CV-4821-1 RCS LD iso CVCS Y C lO O Y Y 2CV-4920-1 .BA to Chg CVCS Y O C C Y Y h CVCS Y O C C Y Y

a. 2CV-4921-1 BA to Chg 2CV-6015-1 tPSI to RCS HPSI Y O OC C Y Y 2CV-5075-1 HPSI to RCS HPSI Y O OC O Y Y

2CV-5055-1 FPSI to RCS tPSI Y O OC C Y Y 2

' CV-6035-1 FPSIto RCS tPSI Y O OPC C- Y Y ,

'2CV-5008-2 RCS to SD CI SDC N .O NFA C Bresheris open, PB OK 2CV-5038-1 RCS to 80 CI SDC Y O C C N N PB OK, Brooker open 2CV-5084-1 RCSto SD CI SDC Y O C C N N PB OK,Breeter spen 2CV-5077-2 SDC to LPSI LPSI Y O OC C Y N PBOK 2C%5057-2 SDCto LPSt LPSI Y O OC .C Y N PB OK 2CV-5017-1 SDC to LPSI LPSI Y O OC C Y N PBOK 2CW5037-1 SDCto LPSI LPSI Y O OC C Y N PBOK 2CV-1453-1 SW to SDC SW Y O OC C Y Y 2CV-1458-2 SWto SDC SW Y O OC C Y Y 2CV-1503-1 SW to EDG SW Y O C C Y Y Y

2CV-1504-2 SW to EDG SW Y O C C Y i2CV-4918-2 BA to Chg BA Y  ; O C C. Y -Y M .

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