ML030870880

Operations Notebook-4 Documents. Includes Contingency Strategy for Failure of One B Train EDG in Regards to Issue Raised by CAP030227

ML030870880
Person / Time
Site:	Point Beach
Issue date:	11/23/2002
From:	Harper R Nuclear Management Co
To:	Office of Nuclear Reactor Regulation
References
FOIA/PA-2003-0094
Download: ML030870880 (11)

Text

Page I

of Point Beach Nuclear Plant OPERATIONS NOTEBOOK FILE:

SUBJECT:

Contingency Strategy The PSA Group has provided us with a Contingency Strategy for the Failure of one "B" Train EDG in regards to the issue raised by CAP030227, Service Water (SW) to Auxiliary Feedwater (AFW) Pump Suction Power Supply. The Contingency Strategy is attached.

In summary, there are three key elements of the strategy should we have a failure of a "B" train EDG"

1. Align the operable "B" train EDG to both "B" train buses per OI-35A which is our normal practice.

2. Protect the operable "B" train EDG IAW NP 10.3.7 (post the protected signs and list as protected equipment on the Plan Of The Day)

3. Expedite repair and return to service of the failed "B" train EDG. This means a Priority 2 WO, call in the required support groups, and work around-the-clock.

See the detailed risk discussion in the attached PSA Group writeup.

Approved By:

e--ýRon Hiarperý Place in Section:

Placed in Notebook:

11/2310O Date Schedule for Removal:

Night Orders: 4 days or less Operational Information: 31 days or less Significant Events: 31 days or less Industrial Safety: 31 days or less Administrative: 31 days or less Operational Experience: 31 days or less Modifications: 31 days or less Miscellaneous: 31 days or less juest for Data: Until data is gathered Remove By:

DSS Acknow*gd ement Crew A:

/

Crew B:

Crew C:

Crew2.

Crew E:

Crew F:

12/23/02 Date PBF-2015 Revision 9 04/09/01 OPS Info Reference OM 3.13 I

2 Pýl -ýyý

Contingency Strategy for the Failure of One B Train EDG Recommended Contingency Actions to Mvitigate Risk Impact

"* Align the operable B Train EDG to both B Train 4KV safeguards buses per OI-35A

"* Designate the remaining operable B Train EDG as protected equipment per NP-10.3.7

"* Expedite repair and return to service of the failed EDG Discussion If either G03 or G04 becomes inoperable, the normal action would be for Operations to align the remaining operable B Train EDG to both of the B Train 4KV emergency buses, 1-A-06 and 2-A-06, per OI-35A. This is still the correct action to take.

Given the current plant design with service water supply valves for three AFW Pumps (P38B, 1P29, and 2P29) fed from B Train, this alignment will make the operability of these service water supply valves vulnerable to the single failure of the remaining operable B Train EDG. However, making this alignment is still the best action to take in response to a B Train EDG failure because:

The random failure probability of the second EDG is relatively low - approximately 5 chances out of 100 (5E-02 probability) over a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> mission time. The alternative action of not aligning the operable EDG to both of the B Train 4KV buses will, in the event of a LOOP, guarantee failure of at least one AFW service water valve (for 1P29) if IA06 is left unaligned or two AFW service water valves (for P38B and 2P29) if 2A06 is left unaligned.

" Even with a failure of the second B Train EDG, three AFW pumps will still be available as long as the CST inventory lasts. After that, P38A can be aligned to service water from the Control Room.

For every accident except a seismic event or an ATWS, the CSTs will provide an initial supply of water to the AFW pumps that will last several hours. This will allow plenty of time for a local operator to open the service water supply valves manually if AC power is lost. The failure probability for this manual action is also low - less than 8 chances out of 1000 (8E-03 probability).

A seismic event or an ATWS could require a quick transition to service water as the supply for AFW. This can still be accomplished from the Control Room unless there is also a loss of offsite power. A seismic event with a consequential loss of offsite -

c

.or.

power occurs with a frequency on the order of 2E-05/year, and an ATWS followed by

, 7-a random loss of offsite power has a frequency on the order of 3E-09/year.

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Prepared By:ý

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Approved By:/,

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ý Paul Knoespel Rick Wood

Page 1

of I

Point Beach Nuclear Plant OPERATIONS NOTEBOOK FILE:

SUBJECT:

AF SW MOV power supplies The attached CAP030227 brings up a scenario allowed by our technical specifications where the availability of required AFW flow is questioned.

The scenario is that one "B" train EDG is aligned to both "B" train buses. A seismic event occurs which results in a loss of off site power, the CST's are lost, and then a single failure results in the loss of the operable "B" train EDG.

This would result in losing power to the AFW pumps SW suction MOV's for P-38B and both TDAFP's. The question now is: "Are 3 of the 4 AFW pumps inoperable due to a single failure?"

As described in the attached CAP, P-38A MDAFP and it's SW suction MOV remain fully operable for one unit. For the other unit, there is ample time to locally open the SW suction MOV for that unit's P-29 TDAFW pump which will provide more than the required AFW flow prior to SG dryout, and the SG's can be recovered to normal levels.

For the postulated scenario, the AFW system remains capable of meeting it's required safety function.

it Approved By:

Rn Harper Place in Section:

Placed in Notebook:

11/22/02 Date Schedule for Removal:

Night -Orders: 4 days or less Operational Information: 31 days or less Significant Events: 31 days or less Industrial Safety: 31 days or less Administrative: 31 days or less Operational Experience: 31 days or less Modifications: 31 days or less Miscellaneous: 31 days or less quest for Data: Until data is gathered Remove By:

DSS Acknowledgement Crew A:

Crew B:

Crew C:

Crew D Crew E: _

Crew F:

14A PBF-2015 Revision 9 04/09/01 Reference OM 3.13 OPS Info 12122102 Date

ILZdI +/-kd1aageriIerJL oizipany Page 1 of3 STATE CHANGE HISTORY Initiate A

A Submit to Screening Team A A

SAR Pre-Screen AR Screening Que 11/22/2002 6:25 53 PM E*

11/22/2002 7.55"30 PM Owner (None)

I Owner PBNP CAP Admin by CLINT DRESCHER 'q V

by RON HARPER 1

V SECTION 1 Activity Request Id:

Activity Type:

• One Line

Description:

0 Detailed

Description:

CAP030227 CAP Submit Date:

11/22/2002 6:25:53 PM Service Water (SW) to Auxiliary Feedwater (AFW) Pump Suction Power Supply Issues 11/22/2002 6:25:53 PM - CLINT DRESCHER:

During further research into electrical power supply issues associated with the AFW system, an anomojy was noticed in the power supplies to the motor operated valves (MOVs) between the SW system and each pump suction. For the most part, the power supplies to the components associated with turbine driven AFW pump 1 P-29 and motor driven AFW pump P-38A are fed from Unit 1 A-train supplies, and the power supplies to the components associated with motor driven AFW pump P-38B and turbine driven AFW pump 2P-29 are fed from Unit 2 B-train. The anomoly is that the SW supply MOV to 1 P-29 (1AF-4006) is powered from Unit 1 B-train.

This may pose an issue with aligning the SW system to the AFW pumps following a loss of the Condensate Storage Tank (CST) supply due to depletion or loss from a seismic evenL This may become an issue during the following credible design basis event: a loss of offsite power (LOOP) from a seismic event combined with a single active failure of a piece of equipment important to safety. The worst case single failure could occur if one of the B-train emergency diesel generators (EDGs G-03 or G-04) is aligned to the Unit 1 and Unit 2 B-train buses. This condition is allowed by Technical Specifications without entry into a TSAC. This configuration combined with the event mentioned above, would disable the remote opening capability of three of the valves (1AF-4006, AF-4016 and 2AF-4006). AF-4016 is associated with P-38B and 2AF-4006 is associated with 2P-29. This would not challenge the operability of the pumps, except P-38B which is powered from B-train, but would challenge operations to locally align SW to AFW suction in the five minutes as credited in the FSAR.

The Loss Of AC power transient (LOAC) is described in FSAR section 14.1.11. That analysis assumes that only a single motor driven AFW pump is available to a unit, and that flow is restored within 5 minutes of the loss of feedwater (due to the loss of AC).

The 5 minute / 200 gpm criterion would be met for whichever unit is to be fed from motor driven AFW pump P-38A. Power would be available to manually open AF-4009 from the control room, and promptly (re)start pump P-38A. These actions are procedurally directed.

The other unit would not have any feed water available until an Operator could be dispatched to the AFW pump room, manually de-clutch the MOV operator, and manually open the valve locally. These valves are periodically stroked to ensure free motion, and the operation is expected to be completed within 5-15 minutes of the loss of power. Loss of power to the MOVs cause the control board position indication lights to de-energize, giving prompt Indication that local manual action is required to reposition the valve.

Westinghouse WCAP 15154 Table 2-22 conservatively provides the decay heat fraction of rated thermal power as a function of time post-trip. At 1 minute, the decay heat fraction is 0.039 of the full 102% rated power of 1518.5 MWt, or 3.46E+6 BTU/min. Assuming 120 deg F AFW and an 1100 psia steam generator, a boil-off of -381 gpm is required to remove decay J.

(heat. This is less than the 400 gpm capacity of the turbine driven pump. Therefore, if the 4" -

turbine driven AFW pump is aligned to SW and started at any time prior to steam generator dry

o.

out, steam generator level recovery will be achieved and a pressurizer solid condition avoided.

From SAMG SAG-i, it Is noted that the time to steam generator dry-out from a normal trip is conservatively 30 minutes for an LOAC event. Therefore, ample time and margin is available to take procedurally directed manual action to open the SW supply to AFW MOV and restore the associated 400 gpm turbine driven pump.

-2015 DRESCHER, CUNT A Initiator Department:

EDEP Engineering Design https:llnmc.ttrackonline.conitmtrackltmtrack.dll?IssuePage&TabeId= 1 000&RecordId=284 11/22/2002 N

4 Initiator:

'iu*lval ldCl~l t-olnpany Page I of 3

ividiudgetiient t.ornpany Date/Time of Discovery:

Identified By:

Equipment # (1st):

Equipment # (2nd):

Equipment # (3rd):

Site/Unit:

Why did this occur?:

Immediate Action Taken:

Recommendations:

0 Notify Me During Eval?:

Date/Time of Occurrence:

System:

Page 2 of 3 Electncal PB 11/22/2002 5-36.06 PM AF PB (None)

Equipment Type (1st):

(None)

(None)

Equipment Type (2nd):

(None)

(None)

Equipment Type (3rd):

(None)

Point Beach - Common 11/22/2002 6:25:53 PM - CLINT DRESCHER:

Unknown. This appears to be part of the original plant design (as-bult configuration).

11/22/2002 6:25:53 PM - CLINT DRESCHER:

Researched potential consequences of power supply failure. Initiated CAP to track final resolution.

11/22/2002 6:25:53 PM - CLINT DRESCHER:

Evaluate feasability of powering 1 AF-4006 from Unit 1 A train power to be consistent with similar diversity/redundancy powering schemes found within the plant.

N 0 SRO Review Required?:

N SECTION 2 Operability Status:

Basis for Operability:

0 Unplanned TSAC Entry:

Operable 0 Compensatory Actions:

11/22/2002 7:55:30 PM - RON HARPER:

All AFW pumps and their SW suction MOV's are operable.

N In the scenario described above, P-38A MDAFW pump and it's associated SW suction MOV will remain operable to provide the AFW requirements to one unit. For the other unit, the CAP describes that we have ample time to align a P-29 TDAFW pump to the other unit. The P-29 TDAFW pump SW suction MOV can be locally opened prior to SG dry out to provide more than the required AFW flow for that unit. For these reasons, the AFW system will be able to provide the required AFW flow to each unit within the required times and therefore meets it's required safety function.

N 0 External Notification:

N SECTION 3 Screened?:

N 6 Significance Level:

(None)

INPO OE Reqd?:

N Potential MRFF?:

N 0 QA/Nuclear Oversight?:

N 0 Licensing Review?:

N Good Catch/Well Doc'd?: NA SECTION 4 Inappropriate Action:

Process:

Human Error Type:

Equip Failure Mode:

Org/Mgt Failure Mode:

Hot Buttons:

(None)

(None)

(None)

(None)

(None)

Activity:

Human Perf Fail Mode:

Process Fail Mode:

0 Group Causing Prob:

https:llnmc.ttrackonline.com/tmtrackltmtrack.dll?IssuePage&Tableld=1000&RecordId=21...

11/22/2002 11/22/2002 5:36:06 PM Site-identified (None)

(None)

(None)

(None)

Point Beach NuLIlcal PI,1t OPERATIONS NOTEBOOK P.age of FILE:

SUBJECT:

AFw FZo-, Indication To ensure we are able to maintain the Operability of our AFW pumps it is essential that we are able to accurately detenrnine the individual AFW pumps flowrates in order to maintain the required minimum flows for each pump.

The attached figure shows the arrangement of individual pump flow indicators and the total flow indicators to each S/G. Should a single AFW pump flow indicator fail, it is still possible to readily determine that pumps flow by looking at the total AFW flow to the applicable S/G and subtracting the known flow of any other AFW pump that may be providing flow. It may also be possible to readily determine individual AFW pump flows for multiple AFW pump failures and/or individual AFW pump flow indicators, depending on the combination of failures, utilizing the same methodology.

If at anytime an individual AFW pump flow cannot be determined to be greater than the minimum required (50 gpm for P-38A/B and 75 gpm for 1(2)P-29) then the affected AFW pump shall be immediately secured to prevent pump damage until adequate flow can be established.

Approved By:

Place in Section:

Placed in Notebook:

11/22/02 Date Schedule for Removal:

Night Orders: 4 days or less Operational Information: 31 days or less Significant Events: 31 days or less Industrial Safety: 31 days or less Administrative: 31 days or less Operational Experience: 31 days or less Modifications: 31 days or less

"'scellaneous: 31 days or less rNequest for Data: Until data is gathered PDBF-2015 Revision t 04/09/01 Remove By:

DSS Acknowledgement Crew A:

Crew B:

12/22/02 Date Crew C:

4-Crew D

Crew E:

\\

Crew F:

-i Refernce OM 3 13 D"

FLOW INDICATORS FOR BOTH UNITS

1

Page I

of 4

Point Beach Nuclear Plant OPERATIONS NOTEBOOK FILE:

SUBJECT:

AFW Recirc. with Loss of D-01 See attached CAP regarding issue associated with Loss of Bus D-01 and its effect on AFW Recirc flow.

Approved By:

Placed in Notebook:

R.Harrsch 11/21/02 Date Schedule for Removal:

Night Orders: 4 days or less Operational Information: 31 days or less Significant Events: 31 days or less Industrial Safety: 31 days or less Administrative: 31 days or less Operational Experience: 31 days or less Modifications: 31 days or less Miscellaneous: 31 days or less Request for Data: Until data is gathered Place in Section:

Remove By:

12/21/02 Date DSS Ackno gement Crew A:

Crew B:

Crew C:

Crew D:

Crew E:

Crew F:

/

PBF-2015 Revisicn q 04/09/01 Reference OM 3.13

Initiate A

rage I ot 3 STATE CHANGE HISTORY AR Pre-Screen

[*

AR Pre-Screen 11V21/2002 2.28 33 PM by CLINT DRESCHER -M Owner (None)

SECTION 1 Activity Request Id:

Activity Type:

0 One Line

Description:

• Detailed

Description:

CAP030209 CAP Submit Date:

11/21/2002 2:28:33 PM Loss of 125VDC Bus D-01 Could Make Three AFW Pumps Inoperable.

11/21/2002 2:28.33 PM - CLINT DRESCHER:

As part of researching a solution for the issues associated with the auxiliary feedwater (AFW) pump recirculation valves, I discovered that the recirculation valves for both turbine-driven AFW pumps (1AF-4002 and 2AF-4002) and the control power for motor-driven AFW pump P.

38A are supplied from 125VDC bus DOI. (Valve 1AF-4002 and the P-38A control circuit are powered from D11 and valve 2AF-4002 is powered from D12) This was evaluated to check if the AFW system would continue to meet its design basis requirement to supply 200 gpm per unit following a low-low level signal associated with a design basis accident or event A single failure of equipment important to safety must also be considered when evaluating if a system will continue to meet its design basis requirements following a design basis accident or event Since the loss of D01 makes the fail closed recirculation valves on 1 P-29 and 2P-29 go closed, it has been concluded that the loss of D01 could make 1 P-29, 2P-29 and P-38A inoperable, not allowing the 200 gpm per unit value to be met.

11/21/2002 3:08:39 PM - RON HARPER:

The loss of Bus D-01 would cause the recirculation valved for 1 P-29, 2P-29 and P-38A to fail shut, thus challenging their ability to provide a reliable source of AFW to the steam generators.

Initiator:

DRESCHER, CLINT Initiator Department:

Date/Time of Discovery:

11/21/2002 1:16:34 PM Date/Time of Occurrence:

Identified By:

Equipment # (1st):

Equipment # (2nd):

Equipment # (3rd):

Site/Unit:

Site-identified P-029 PB P-038A PB (None)

Point Beach - Common System:

Equipment Type (1st):

Equipment Type (2nd):

Equipment Type (3rd):

EDEP Engineering Design Electrical PB Z 11/21/2002 1:16:34 PM AFPB 9 STG CENT CENTRIFUGAL (None)

Why did this occur?:

11/21/2002 2:28:33 PM - CLINT DRESCHER:

Unknown.

Immediate Action Taken: 11/21/2002 2:28:33 PM - CLINT DRESCHER:

Initiated this action request. Notification of engineering supervisor and operations.

11/21/2002 3:08:39 PM - RON HARPER:

Submitted (Operations Notebook entry to ensure information is provided to the operating crews Recommendations:

11/2112002 2:28:33 PM - CLINT DRESCHER:

(1) It appears that changing recirculation valves 1 AF-4002 and 2AF-4002 from fail closed to fail open will resolve this issue without having to change the power supplies of the valves. The turbine driven AFW pumps could supply the necessary 200 gpm with the recirculation valves open from a single failure.

(2) Revise the current operability determination (OD) associated with the recirculation valves to encompass this issue and not allow closure of the OD until this issue has been resolved.

11/21/2002 3:08:39 PM - RON HARPER:

Revise OPR 000031 rev 3 to address this issue, due in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Clint Drescher has lead https://nmc.ttrackonline.com/tmtrack/tmtr-ack.dll?IssuePage&TableId=1000&Recordld=284 11/2 1/2002

responsibility for completing OPR revision Q Notify Me During Eval?:

N 0 SRO Review Required?:

Y SECTION 2 A 0 /-.,J L

/ -/r,,

{ o Operability Status

(None) 0 Compensat Actions:

Y, Basis for Operability:

11/21/2002 3.08:39 PM - RON H PER:

Based on current compensato actions being taken under OPR 000031 rev 3, AFW system remains operable but non-conforming in regards to the pumps recirculation flowpath.

0 Unplanned TSAC Entry:

N 0 External Notification:

N SECTION 3 Screened?:

N G Significance Level:

(None)

INPO OE Reqd?:

N Potential MRFF?:

N V QA/Nuclear Oversight?:

N 0 Licensing Review?:

N Good Catch/Well Doc'd?: NA SECTION 4 Inappropriate Action:

Process:

(None)

Activity:

(None)

Human Error Type:

(None)

Human Perf Fall Mode:

(None)

Equip Failure Mode:

(None)

Process Fail Mode:

(None)

Org/Mgt Failure Mode:

(None) 0 Group Causing Prob:

(None)

Hot Buttons:

(None)

SECTION 5 CAP Admin:

0 Project:

• State:

• Submitter:

AR Type:

0 Last Modifier:

• Last State Changer:

NUTRK ID:

1. of Children:

References:

Update:

Prescreen Comments:

Import Memo Field:

OPR Completed?:

PBNP CAP Admin Corrective Action Program (CAP)

AR Pre-Screen CUNT DRESCHER Parent RON HARPER fg CLINT DRESCHER Prescreener

• Active/Inactive:

0 Owner:

0 Last Modified Date:

0 Last State Change Date:

0 Close Date:

(None)

Active (None) 11/21/2002 3:08:39 PM 11/21/2002 2:28"33 PM 0

N https://nmc.ttrackonline.com/tmtrack/trtrack.dlI?lssuePage&TableId= 100O&RecordId=2... I 1/-21/-002 C)

L..i8C 3) 01 _

OLDACTIONNUM:

sub-tsid:

0 original-project-id:

0 originalissueid:

Site:

Point Beach Cartridge and Frame:

CHANGE HISTORY 11V21/2002 3:08:39 PM by RON HARPER Detailed Description Changed From '[Onginal Text]' To 'Appended.] The loss of Bus D-01 would cause the recirculation valved for 1 P-29, 2P-29 and P-38A to fail shut, thus challenging their ability to provide a reliable source of AFW to the steam generators.'

System Changed From (None) To AF PB Equipment N (1st) Changed From (None) To P-029 PB Equipment # (2nd) Changed From (None) To P-038A PB Immediate Action Taken Changed From '[Onginal Text]' To '[Appended:] Submitted Operations Notebook entry to ensure Information Is provided to the operating crews' Recommendations Changed From '[Original Textr To '[Appended:] Revise OPR 000031 rev 3 to address this Issue, due in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Clint Drescher has lead responsibility for completing OPR revision' Compensatory Actions Changed From N To Y Basis for Operability Changed From "To '[Appended:] Based on current compensatory actions being taken under OPR 000031 rev 3, AFW system remains operable but non-conforming In regards to the pumps recircutation flowpath.'

Last Modified Date Changed From 11/21/2002 2:28:33 PM To 11/21/2002 3:08:39 PM Last Modifier Changed From CUNT DRESCHER To RON HARPER https://nmc.ttrackonline.com/tmtrack/tmtrack.dlI?IssuePage&Tableld= I OOO&Recordld=2L.. 1 I/21/2002 Zý -

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