ML20155A516

Forwards Response to IE Bulletin 85-003,Suppl 1,including Design Basis for Operation of Added Valve & 180-day Schedule for Completion of Items b-d of Bulletin & NRC 880511 Request for Addl Info on Original IE Bulletin 85-003

ML20155A516
Person / Time
Site:	Big Rock Point File:Consumers Energy icon.png
Issue date:	06/02/1988
From:	Berry K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20155A519	List: ML20155A516 ML20155A522
References
IEB-85-003, IEB-85-3, NUDOCS 8806100104
Download: ML20155A516 (13)

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lee ikeming MKJNEAN5 MISEftE55 General off.ces: 1945 West Parnali Road, Jackson, MI 49201 * (517) 788 1636 June 2, 1988 Nuclear Regulatory Commission Document Contro: Desk Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT -

RESPONSE TO NRC BULLETIN 85-03, SUPPLEMENT 1 AND BULLETIN 85-03 REQUEST FOR ADDITIONAL INFORMATION Nuclear Regulatory Commission Bulletin 85-03 Supplement 1 dated April 27, 1988 requires a written response ~ithin 30 days of receipt of the bulletin.

Attachment 2 provides Consumers Power Company's response. In accordance with the Bulletin, the attachment contains (1) the design basis for the operation of the added valve and (2) a 180 day schedule for completion of items b.

through d of the bulletin. The final report as specified by the bulletin will be submitted within 60 days of completion.

In addition, NRC letter dated May 11, 1988 requires a response to a request for additional information on the original bulletin. Attachment 1 provides the requested additional information. The additional information has been discussed with the cognizant Regional Inspectors. As required by the bulletin and request for additional information, our responses are submitted under oath and affirmation under the provisions of the Atomic Energy Act of 1954.

f Y Kenneth W Berry l Director, Nuclear Licensing l CC Administrator, Region III, NRC NRC Resident Inspector - Big Rock Point Attachments OC0588-0028-NLO4 8806100104 880602 4lIl e

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PDR ADOCK 05000155 Q DCD _ _,

CONSUMERS POWER COMPAhi Big Rock Point Plant Docket 50-155 License DPR-6 NRC Bulletin 85-03, Supplement 1 and NRC Bulletin 85-03 Request for Additonal Information At the request of the Commission and pursuant to the Atomic Energy Act of 1954 and the Energy Reorganization Act of 1974, as amended, and the Commission's Rules and Regulations thereunder, Consumers Power Company submits our responses to NRC Bulletin 85-03, Supplement I dated April 27, 1988, entitled, "Motor-Operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Settings" and NRC Bulletin 85-03 Request for Additional Information dated May 11, 1988. Consumers Power Company's response is dated June 2, 1988.

CONSUMERS WER COMPANY By M

• Originato

• u bordon L Heins, Senior Vice President

-- T C B'ordine, Administrator Energy Supply Nuclear Licensing Dept.

Sworn and subscribed to before me this 2nd day of June 1988.

tt w/

Elaine E Buehrp , Notary Public Jackson Couhty, Michigan My commission expires October 31, 1989 OC0588-0028-NLO4

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1 ATTACHMENT 1 l Consumers Power Company Big Rock Point Plant Docket 50-155 1

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RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION DATED MAY 11, 1988 June 2, 1988 l 4

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2 Pages OC0586-0028-NLO4 l

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ATTACHMENT 1 RESP 0NSE TO REQUEST FOR ADDITIONAL INFORMATION DATED MAY 11, 1988

1. Describe the additional actions needed to revise Test Procedure T30-22 (see the response of 02/01/88.

As discussed in the 02/01/88 submittal, the change to T30-22 did not provide positivo assurance that pressure was relieved in the spool piece between MO-7071 and VPI-303. The potential for creating a high differential pressure across MO-7071 exists if reactor pressure is trapped in the spool piece. To insure that MO-7071 is capable of stroking under this higher dP, a change was made to the shutdown procedure; 0-TCS-1, Part A. Step 26 (Attachment 3 - 5 pages) to require stroking MO-7071 when reactor pressure is less than 50 psig. Under system conditions where the spool piece is holding pressure capable of establishing a high dP, this change insures the valve is stroked under these conditions to demonstrate operability. With this change, a minimum of two valve strokes per cycle (each start-up and shutdown) are performed at: an elevated dP of approximately 1200 - 1300 psi.

The initial change to T30.22 which was unsuccessful was subsequently deleted.

2. In addition to MO-7070 and MO-7071, which are identified in the response of 02/01/88 to the inspection report, include at least the following motor-operated valves in your response to IEB 85-03, or jus *.ify their exclusion:

M0-7051 MO-7066 MO-7071 M0-7061 MO-7068 MO-7072 MO-7064 MO-7070 MO-7080

Response

MO-7051, MO-7061 - These MOVs are used in the Primary Core Spray System at Big Rock Point (BRP). As discussed in the Msy 6, 1986 response, this is not a high pressure injection system covered by the scope of the bulletin.

During a design basis event the differential pressure across these valves i is approximately 110 psi, the dif ference in core spray pressure and primary pressure. The concern raised in Inspection Report 87-022, with regard to creating a high differential pressure, is mitigated by procedursi actions. ,

Following monthly stroke testing of MO-7061, reactor pressure could be i trapped in the spool piece between MO-7061 and the upstream check valve VPI-304, assuming the check valve has zero leakage. To insure this trapped pressure is relieved following testing, steps 5.18 through 5.22 of procedure T30-22 (Attachment 4 - 15 pages) vent the spool piece through the instrument line to pressure transmitter PT-186. These steps also insure ]

1 that MOV-7061 has reseated tightly following testing. These actions insure ,

that high differential pressures do not exist across MO-7051 or MO-7061 and  !

thus the valves do not fall within the scope of IEB 85-03.

MIO588-0273A-BX01

As added information, since the spool piece is vented following testing and M0-7061 is verified as reseated, each subsequent exercise test is performed at a differential pressure of approximately 1200 - 1300 psi.

MO-7070, MO-7071 - These MOVs are used in Back-up Core Spray System at Big Rock Point. As discussed in the May 6, 1986 response, this is not a high pressure injection system covered by the scope of the bulletin. During a design basis event the differential pressure across these valves is approxi-mately 110 psi. However, under the assumptions documented in Inspection Report 87-022, the potential exists for creating a high differential pressure across MO-7071. This could occur if reactor pressure is trapped in the spool piece between M0-7071 and the upstream check valve VPI-303 following monthly testing. Unlike the Primary Core Spray valve M0-7061, no positive means exist for venting this spool piace following stroke testing.

Under these assumptions the dif ferential pressure across MO-7071 could be approximately 1150 psi (difference between trapped pressure; 1350 psia and actuation pressure; 200 psia). Although testing as described in the response to question 1 does demonstrate that M0-7071 is capable of opening under these conditions. Consumers Power does agree to include this valve in its response to IEB 85-03, Supplement 1 (see Attachment 2).

MO-7064, M0-7068 - These MOVs are used in the Primary and Back-up Containment Spray Systems at BRP. These are not high pressure injection systems and do not fall within the scope of IEB 85-03. The maximum differential pressure on either of these valves is required to open at approximately 90 psid (difference between fire system pressure and containment pressure).

MO-7066, MO-7080 - These MOVs are used in the Post Incident System and supply cooling water to the Core Spray Heat Exchanger used for long term cooling of Core Spray. This is not a high pressure injection system and doks not fall within the scope of IEB 85-03. The maximum differential pressure either of these valves is required to open against is approximately 90 psid (difference between fire system pressure and atmospheric). As added information, both of these valves are stroked monthly at this differential pressure as part of test procedure T30-22.

MO-7072 - This MOV is used as an alternate core spray path assuming a  ;

failure of the normal supply paths to the Primary and Back-up Core Spray l Systems. This valve also is not used in a high prersure application and does not fall within the scope of IEB 85-03. Like the other valves interfacing the fire system, the maximum differential pressure this valve is required to open against is approximately 90 psid. This valve is stroked against this differential pressure each Refueling Outage, j

3. Provide a scheduled date for submittal of a final report, in response to Action Item F of IEB 85-03. ]

This informatior and submittal date is included in our response to l IEB 85-03 Supplement 1. Attachment (2) to this letter, j 1

MIO588-0273A-BX01

ATTACHMENT 2 Consumera Power Company Big Rock Point Plant Docket 50-155 RESPONSE TO NRC BULLETIN 85-03 SUTfLEMENT 1 June 2, 1988 1

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OC0588-0028-NLO4 l

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ATTACKKENT 2 RESPONSE TO NRC BULLETIN 85-03. SUPPLEMENT 1 MO 7071

a. Big Rock Point has two redundant piping systems to provide core spray from the fire water system in the event of a primary system break. Each core spray system has redundant valves in series to control fire water system flow. M0-7071 is the primary valve (ie, closest to the reactor) in the back-up system. Automatic actuation is provided by a 480 volt AC powered Rotork valve actuator. The actuator causes MO-7071 to open when both reactor pressure is below 200 psig and reactor water level is less than 2 feet 9 inches above the top of the core.

Once core spray actuation has occurred, the core spray valves remain open until containment water level (sump level) is adequate to allow recirculation.

This level is approximately 587' to 590' cr a total depth of 17' to 20' from the bottom of the sump and occurs from 4 to 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br /> af ter the break.

Normal system pressure will result in a differential pressure across MO-7071 of approximately 110 psi. Circumstances particular to this piping configuration may, however, result in a differential pressure when opening MO-7071 of approximately 1150 psi. More detail of these circumstances are provided in Attachment 1 to this letter. Maximum differential pressure when closing MO-7071 is approximately 110 psi.

b. The valve actuator for M0-7071 is a Rotork model 14NA1. This operator was installed in 1983 and switch settings were made under the direction of an authorized Rotork representative. In the open direction, the valve actuator is controlled by a limit switch; the torque switch is bypassed for the complete stroke. In the closed direction, the valve actuator is controlled by the torque switch. CPCo considers the valve and its actuator to be completely operable in accordance with the Plant Technical Specifications.

This fact was verified during the most recent plant shutdown in April, 1988 in accordance with our revised procedure 0-TGS-1 discussed in Attachnent I to this letter.

To reassure that MO-7071 valve actuator is properly set, CPCo will contact Rotork within 180 days.

c. CPCo tests this valve a minimum of twice each operating cycle with a differential pressure of approximately 1200 pai. These tests are described in more detail in Attachment 1 and are considered to fully demonstrate MO-7071 operability,

d. Procedures are currently in use at Big Rock Point to ensure that correct switch settings are maintained throughout the life of the plant. Should follow-up discussions with Rotork require a revision to these procedures, this information will be included in our final response.

A final response to NRC Bulletin 85-03 will be provided within 60 days following completion.

MIO588-0279A-BX01

ATTACHMENT 3 Consumers Power Company Big Rock Point Plant Docket 50-155 PROCEDURE 0-TGS-1 Part A. Section 1 June 2, 1988 5 Pages OC0588-0028-NLO4

Rsvision 59 0-TGS-1 Page 1 of 25 Part A, Section 1 Init Date Time

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PART A SECTION 1 - TAXING UNIT DOWN AND OFF-LINE NOTE: This sheet to be initiated and completed whenever the unit is, or is to be, taken out of service. Adherence to step-by-step sequence is recommended for Section 1.

1. Notify I&C Deparment to turn up HV to source range channels. If the reactor is above 10%

power the source range channels should show a significant increase in counts with the chambers in the "out" position. Perform "Cal Check" and "Period Check" also.

(OP)

2. Reduce power by decreasing reactivity. Follow control rod insertion sequence or the reverse of the withdrawal sequence as issued and authorized by the Reactor Engineer for the current fuel cycle. (Use start time).

(OP)

3. Allow IPR to reduce turbine load.

(OP) 3

4. Close Breaker 13 on Control Panel 1Y to open CV-4106, Turbine Bypass Warm-up Valve.

(OP)

5. CAUTION: When power is reduced to minimum load to perform turbine or other associated maintenance, either place turbine bypass valve controller in "manual mode" or reduce reactor power to q auberitical and cool the system with l

the main condenser. If the time ,

, duration is such the' steam pressure l i falls to below 150 pais, interrupt I

steam to the SJAE and maintain the system in a hot standby, suberitical I condition.

When load reaches ~ 10 MWeG, transfer to governor control.

(OP)

6. At 5 MWeG square up amplidyne and place in of f

{ position, j (OP)

O-TGS-1-BA05

Ravision 59 0-TGS-1 Page 2 of 25 Part A, Section 1 Init _Date Time,

7. Feedwater to manual control. (Optional)

(OP)

8. Reduce turbine generator load to zero.

(OP)

9. Start Auxiliary oil pump.

(0P)

10. Trip Turbine. ( )

X Phase ()

Y Phase ()

2 Phase '( )

Push Button ()

Read watthour meters and enter in Control Room Log.

NOTE: Rotate methods of tripping turbine so that all phases and push button are tested periodically.

(OP)

11. Check bleeder trip velves closed.

, (0P)

12. Open 112 disconn ets.

(0P)

13. Check the following:

Stop valve after seat drain open.

Jumper pipe drain open.

(OP) l

14. When machine stops rolling place on turning gear immediately.

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0-TGS-1-BA05

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Rsvision 59 0-TGS Page 3 of 25 Part A Section 1 Init Date_ Time i  !

15. Maintain cooling curve on reactor vessel with SJAE, insert all control rod drives. (Bypass >

valve may be used for cooldown.) A high drum

, level may be required to minimize temperature

spread.

(0P)

If complete cooldown is required, valve in #1 i shutdown HX (valve out #2) and cut in #1 shutdown system when steam pressure reaches ~ 280 psig.

_ N/A (SS)

(OP) ,

De-energize the Yarway Reference Les Temperature Control System when steam pressures reaches 100 psig by opening and caution tagging the supply breaker on 2B bus.

(OP)

16. Determine if condenser tube leaks exist; if it does, refer to SOP-21, Section 3.3.

(OP) i

17. CAUTION: Turbine auxiliary oil pump must be on '

for lo-vac alarm to function.

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I Open condenser vacuum breaker valve and check  :

setpoint of "LO-VAC" alarm and record.  !

1 (OP) )

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18. When vacuum reaches zero, close vacuum breaker.

(OP) i

19. Close steam supply valve to turbine seals and

SJAE.

(OP) i l 20. Remove pumps and other auxiliary equipment from i service as required.

l (OP)

21. Set hydrogen control panel for shutdown mode.

9 (OP) i 0-TcS-1-BA05 i

Rovision 59 0-TGS-1 Page 4 of 25 Part A, Section 1 _Init Date_ Time

22. Open turbine stop valve before seat drain.

(0P)

23. If they are not high-radiation areas, open slide links to high-radiation door alarm (s).

Turbine Access Gate (CO2-2 KH15) N/A Verified By:

(OP)

Condense.- Area (CO2-2 HH13) N/A Verified By:

(0P)

NOTE: Caution Tags are not required to icentify these bypasses in place.

24. If outage is to be for prolonged duration, (ie, refueling outage etc), 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after steam supply to turbine seals and SJAE has been closed, take turbine off of turning gear.

(OP)

NOTE: During prolonged outages place turbine on turning gear once every 30 days, for

~ 30 minutes.

25. If shutdown is for a refueling outage - terminate Procedure TV-30 in use during the cycle, and issue a new copy marked "refueling" for use during the outage.

N/A (SS) 0-TGS-1-BA05

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Revision 59 0-TGS-1 Page 5 of 25 .

Part A, Section 1 Init Date Time s'

26. When the reactor pressure is less than 50 psig stroke M0-7071.

(0P)

27. If NSSS is to be cooled to less than 212*F }

inhibit RDS si ren when NSSS reaches < 212'F. .l.

(d)

____ RDS Siren Inhibited .

N/A (OP)

NOTE: Proceed to Step 6.0 for reviews. ,

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