ML20235N334
| ML20235N334 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 10/02/1987 |
| From: | Whittier G Maine Yankee |
| To: | Thomas C NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM), Office of Nuclear Reactor Regulation |
| References | |
| 9180L-LMO, GDW-87-232, IEB-85-003, IEB-85-3, MN-87-109, NUDOCS 8710060481 | |
| Download: ML20235N334 (5) | |
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MaineYankee REUABLE ELECTRICITY FOR MAINE SINCE 1972 w[
i' ED: SON DRIVE. AUGUSTA, MAINE 04330 907) 622 4808 October 2, 1987 MN-87-109 GDH-87-232 u
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Director of Nuclear Reactor Regulation l-United States Nuclear Regulatory Comission Washington, D. C.
20555 Attention:
Mr. Cecil 0. Thomas, Director PHR Project Directorate I-3 Division of Licensing
References:
(a) License No. DPR-36 (Docket No. 50-309)
(b) USNPC Letter to MYAPCo dated July 29, 1987 (c) MYAPCo Letter to USNRC dated August 27, 1987 (MN-87-94)
(d) MYAPCo Letter to USNRC dated June 4, 1986 (MN-86-66)
Subject:
IE Bulletin 85 Request for Additional Information
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Gentlemen:
This letter is in response to your request for additional information concerning our response to Action Item e of IE Bulletin 85-03, Reference (b).
For clarity, the questions are restated below with our responses following.
NRC Ouestion 1:
Unlisted MOVs SIA-N-11, --21, and -31 in discharge lines of the Safety Injecti.on Tank System are shown normally open on Drawing 11550-FM-918, Revision 17.
The possible problem that the system would be inoperable if the MOVs were left closed inadvertently should be addressed.
Based on the assumption of inadvertent equipment operations as required by Action Item a of the'bullbtin, revise Table 1 of the response of June 4, 1986 to 1
include these valves.
Maine Yankee Resoonse:
MOVs SIA-M-11, -21, and -31 were not included in our response of June 4, 1986, Reference (d),
since they are outside the scope for IE8 85-03.
During plant start-up, these valves are opened and verified open in accordance with plant operating procedures. After the valves are verified open, the procedure requires that power be removed from the valve to prevent spurious closure.
These valves are not required to function during a LOCA nor does the position of the valve have any effect on the performance of the High Pressure Safety Injection System.
Therefors, these valves are not in the scope of valves subject to the requirements of IEB 85-03. Maine Yankee believes that the precautions already in effect preclude mispositioning these valves.
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United States Nuclear Regulatory Commission Page Two' s
Attention: Mr. Cecil 0. Thomas i
MN-87-109
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i NRC Ouestion 2:
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i Has water hammer due to valve closure been considered in the determination 9 iJ
'I of pressure differentials? If not, please explain.
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y Maine Yankee Response:
Haterhammerduetovalveop'eningorclosingwasnotconsidergbinthe 2
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determination of the pressbro differentials. The valves Lovoved by this f(,
bulletin stroke in approximately,four seconds or greater.e The stroke time f
of the valves was measured and recorded during MOVAT testrhg Nnder no-flow conditions.
For stroke times of this magnitude, we do not.febl it,fe,
necessary to address water hammer.
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0-NRC Ouestion 3:
'f Unlisted MOV CH-M-86 is shown ' locked open in a miniflow line leadir)g from
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the charging pumps to tui teal water heat exchanger:in Zone I-l oi" Drawing 11550-FM-91F3 Revision 17.
If power is removed from the motor in addition to the. locked-open position of this MOV, please state this in your re';ponse. Otherwise, address the effect of assuming inadvertent equipment opork; ions as requested by Action Item a of the buif etir:, and revise Table E of the response of June 4,1986 to inc?ade OL% valve. He r note that simila'3y located MOVs in some other CE plants are listed for e
j inspection per buitetin requirements.
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Maine Yankee Respont,ti,
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Power is not removed from CH-M-86 when it is in tra locked-open +
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position. " Maine Yankee will remove power from thMalve,when it is.
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required to be in the locked open position.
Admini trative Controls 4 S
will be established to remove power from this valv by November 30, 1987.
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'g tlRC Ouestion 4:
Unlisted MOVs HSI-M-40 and 43 are shown normally closed (fail as is) in s
crossover lines in discharge of the charging pumps in zones H-7 and H-8 of Drawing Il550-FM-918, Revision 17. Address the effect of assuming inadvertent equipment operations.
Maine Yankee Resoonsel Inadvertent opening of either HSI-H-40 or 43 simultaneously with a safety injection actuation signal is acceptable.
Inadvertent actuation of either 3
valve would be considered a single failure.
Since we are only required to assume one unrelated single active failure simultaneous with a L& A, all other valves and systems would he assumed to operate. 'Therefece,.both trains of HPSI would be operating and cros; tying them at thb 'locatica would not be a problem.
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United States Nuclear Regulatory Commission-Page Three
- Attention: Mr. Cecil 0. Thomas MN-87-109
.c j NRC Ouestion 5:
-l Listed MOVs HSI-M-11, -12, -21, -22, -31 and -32 of the HPSI System are three-inch globe valves.
Listed MOVs HSI-M-41 and -42 of this system are four-inch globe valves. He were advised recently that the MOVATS data
-base does not include globe valves with orifice sizes less than 1.75 or greater than 2.0 inches. Hill representative samples of these-three-inch and four-inch g!che valves be tested at full differential pressure?
-Maine Yankee Response:
The orifice size of MOVs HSI-M-11, -12, -21, -22, -31 and -32 of the HPSI System is 2.0 inches.
Therefore, the MOVATS data base will cover these
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valves. The;four inch globe valves, HSI-M-41 and -42 have 2.50 inch orifices and are presently not covered by the MOVATS database.
If the database is not expanded to. include these valves, full differential pressure testing of HSI-M-41 and -4? can be conducted during the next scheduled refueling outage.
" NRC Ouestion 6:
Please expand the proposed program for action items b, c and d of the bulletin to include the following details as a minimum:
(a) commitment to a training program for setting switches, maintaining valve operators, using signature testing equipment and interpreting signatures, (b) commitment to justify continued operation of a valve determined to be inoperable, and (c) description of a method possibly needed to extrapolate valve stem thrust measured at less than maximum differential pressure.
Maine Yankee Response:
(a) Currently Maine Yankee has a training program for setting switches and maintaining valve operators. Maine Yankee will require personnel conducting signature testing and interpreting signatures to be trained for those activities.
(b) Whenever a component in a system covered by Technical Specifications 3-is declared inoperable, Maine Yankee's standard practice is to 1(
assess its impact on the system and determine the remedial actions which should be taken.
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MaineYankee United States Nuclear Regulatory Commission Page Four
' Attention: Mr. Cecil 0. Thomas MN-87-109 (c) The method for extrapolation of thrust values for valves at differential pressure higher than actually tested is based on the following:
A standard industry method for calculating target thrust from differential pressure can be expressed as a straight line of the form y - mx + b, where y - thrust and x = differential pressure.
Test data could be used to confirm the calculated thrust _or.
Test data alone could be used to generate the line using linear regression, correlation factor, confidence, etc.
The line which results can be used to give values of target thrust for selected differential pressures.
NRC Ouestion 7:
Please explain why no differential pressure for closing MOVs HSI-M-11, -12,
-21, -22. -31,--32. -41, and -42 is given in Table 1 of the response of June 4, 1986.
These valves are in discharge lines of the charging pumps. He note that maximum differential pressure for opening and closing is equal for the typical CE plant.
Resoonse The primary function of the valves in the near term of a LOCA/HPSI is to open.
Later in the accident, the operator may need to throttle HPSI using Valves HSI-M-41 and 42 or terminate HPSI by closing MOVs HSI-M-11. -12. -21,
-22, -31. -32, -41, and -42.
When we originally responded to the IEB 85-03, we viewed these valves in the near term of the accident when HPSI is most crucial. However, taking the long-term actions into consideration, as noted above, similar differential pressures could be applied to the valves for closing. Therefore, a maximum differential pressure of 2,700 psid will be assumed under the seat when closing the above-noted valves, this includes an additional 100 psid of differential pressure from the spray pump head during RAS.
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MaineYankee United States Nuclear Regulatory Commission Page Five Attention: Mr. Cecil 0. Thomas MN-87-109 NRC Ouestion 8:
Please submit a date for planned completion of Action Item f of the bulletin. The specified due date is January 15, 1988.
Maine Yankee Resoonse:
Due to delays in obtaining certain engineering calculations and recent changes in the database which may require testing of additional valves, we will be unable to complete the program until after the next scheduled refueling outage.
Therefore, a final report on completion of the program cannot be made by January 15, 1988.
- Instead, 2.
Maine Yankee will submit a status report by November 15, 1987 which outlines the. portions of the program that have been completed, the items remaining to be done, and a 1,chedule for completion of those items.
3.
The final program report will be submitted within 60 days following completion of the items as scheduled in the status report.
He'believe this response should adequately address your concerns.
However, if you should have any further questions, please feel free to contact me.
Very truly yours, MAINE YANKEE
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.ff 2O O'V A G. D. Whittier, Manager Nuclear Engineering and Licensing GDH/bjp
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cc: Mr. William T. Russell Mr. Pat Sears Mr. Cornelius F. Holden 9180L-LM0
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