ML20235W998
| ML20235W998 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 10/14/1987 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 5211-87-2190, IEB-85-003, IEB-85-3, NUDOCS 8710190159 | |
| Download: ML20235W998 (6) | |
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9 USNRC-DS GPU Nuclear Corporation
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Nuclear mU 20 A 9 59 Ee "ES$'*
Middletown, Pennsylvania 17057 0191 717 944 7621 I
TELEX 84 2386 Writer's Direct Dlal Number:
l October 14, 1987 I
5211-87-2190 U.S. Nuclear Regulatory Commission Attn:
Document Control Desk Washington, DC 20555
Dear Sir:
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Three Mile Island Nuclear Station, Unit 1 (TM1-1)
Operating License No. DPR-50 Docket No. 50-289 Response to Request for Additional Information - IED 85-03 This letter responds to NRC letter dated September 9,1987 from W. F. Kane to H. D. Hukill requesting additional information on the GPUN TMI-l response to IEB 85-03.
NRC Question 1 Unlisted MOVs CF-V1 A and CF-V1B in discharge lines of the core flooding tank safety injection system are shown normally open on FSAR Figures 6.0-2 (Update 2, 7/83) and 6.1-1 (Update 5, 7/86).
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 bulletin, revise the attachments of the response of May 27 and September 15, 1986 to include these valves.
GPUN THI-l Response Valves CF-V1 A snd CF-VlB are not in the scope of IEB 85-03. These valves are not part of the High Pressure Injection System or the Emergency Feedwater System.
For this reason these two valves will not be added to our previous responses.
GPUN does not believe these valves fall into the category that they can be inadvertently left closed.
These valves are normally open during operation with the electrical breakers locked open.
An alarm activates in the Control Room when the valves are in the closed position. Also these valves are included in the GPUN Independent Verification Program, which independently would verify proper alignment after a maintenance or surveillance activity.
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GPU Nuclear Corporation is a subsidiary of the General Pubile Utilities Corporation
5211-87-2190 October 14, 1987 NRC Ouestion 2 The following MOVs are not included in the list of valves of the emergency feedwater system to be examined for maximum differential pressure. That is, they are not identified in the attachments of the response of May 27 and September 15, 1986.
As a general question, what controls are placed on these valves to ensure that they will. be in the proper position when needed?
In accordance with the request of Action Item a of the bulletin to assume inadvertent equipment operations, revise the response attachments to include these valves.
l (a) EF-V1 A and EF-V1B are shown normally open in series in suction lines, on Drawing 5130-302-082, Revision 8.
(b) EF-V2A and EF-V2B are shown normally open in series in crossover discharge lines, on the drawing mentioned above in Item 2(a).
GPUN THI-1 Response EF-V1 A, EF-V1B, EF-V2A and EF-V2B are in the emergency feedwater system but are not required to be tested for 10CFR50.55a(g). The valves are normally open during operation and have no automatic safety function.
Because the valves are not required to be tested for 10CFR50.55a(g), they are outside of the scope of the bulletin and will not be added to our previous response.
However, these valves have been evaluated to determine required thrust (torque) and M0 VATS testing was done to verify the operator performance. The testing was accomplished as part of a program (larger in scope than valves covered by IEB 85-03) to test motor operated valves on a prioritized basis and the data is available at TMI.
The controls to ensure proper position are in the GPUN Independent Verification Program.
NRC Question 3 Has water hammer due to valve closure been considered in the determination of pressure differentials? If not, please explain.
CPUN TMI-1 Response Water hammer has been considered based on the discussion of fluid hammer by J. Lyons in the Valve Designers Handbook.
It was determined not to be of concern for the TMI-1 IEB 85-03 valves.
Water hammer depends on the time it takes to close the valve, fluid velocity and length of pipe. These conditions do not exist to a degree that would i
create the significant delta pressure " surges" known as water hammer.
5211-87-2190 October 14, 1987 NRC Question 4 The following statement appears on page 3 of the response of May 27, 1986:
"GPUN believes that the calculation and quantitative verification of the torque switch setpoint provides sufficient assurance that the valves will perform their safety function.
No special differential pressure testing is planned."
This statement does not comply with the requirement of Action Item c to demonstrate operability by testing at maximum dif ferential pressure, or by stroke testing if testing with differential pressure cannot be performed.
Furthermore, justification should be provided for any case where testing with the maximum differential pressure cannot be performed because of practical considerations. Please provide details.of the calculation method planned to establish the correct switch settings.
GPUN TMI-1 Response The Torrey Pines Technologies calculations (GPUN accepted) of thrust for MOVs consider " worst-case," high differential pressure AP conditions which include
. consideration of all accident scenarios.
" Worse-case" is defined as the valve opening under full (accident) AP, after closing with zero AP at the highest recommended torque switch setting.
We believe these calculations, which account for all plausible operating conditions, conservatively predict the thrust requirements for a normally operating MOV under the predicted pressure conditions. This conclusion is supported by the results of extensive full pressure testing conducted recently by Toledo Edison (TECO) in their Summary Report for the Davis-Besse MOVRIP.
GPUN has reviewed these results, discussed them with TECO personnel, and believe the results also are applicable to TMI-1.
NRC Question 5 Flease state the planned date of completion of Action Item f of the bulletin.
Note that the due date specified by the bulletin is January 15, 1988.
GPUN TMI-1 Response Item f of the bulletin was a written report on the completion of the program.
GPUN letter 5211-87-2105 dated June 25, 1987 from H. D. Hukill to the Document Control Desk was the " Final Response to IE Bulletin 85-03."
This item is complete by this letter.
NRC Question 6a Please include the following details as a minimum in a program for Action Items b, e and d of the bulletin:
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l (a) Commitment to a training program for setting switches, maintaining valve operators, using signature testing equipment and interpreting signatures.
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5211-87-2190 October 14, 1987
't GPUN TMIll' Response'
- TMI-1. has.in place. and is committed to continuing, and upgrading when needed, a' training programithat includes the setting of switches and maintaining valve operators. This' is in accordance with INPO accredited OJT modules E-16A and E-16B.
Signature testing is presently done by a vendor using their equipment.
Training will be provided and incorporated into the TMI-1 INPO accredited training process _ at such time as the signature testing equipment is purchased 4
1 and the signature testing activity is performed' by.GPUN' employees without the direction or assistance of a vendor.
- A training program for interpreting valve operator signatures has been compl eted. -
. The training was provided by a vendor and has provided the necessary knowledge and skills to' perform the signature analysis. Additional training will be provided at such time as there.are additional people involved in the signature interpretation process or when the process would change such that retraining would be required.
. NRC Question 6b Please include the following details as a minimum in a program for Action Items-b, c and d of the bulletin:
(b) Commitment to justify continued operation of a valve determined to be inoperable.
GPUN TMI-1 Response As previously stated in GPUN letter 5211-86-2084 dated May 27, 1986 from H. D. Hukill to T. E. Murley.
"The results of the above were reviewed and it was concluded that the as-found conditions did not produce results which were determined to be reportable or made the valves inoperable."
Our position on this statement has not changed. Justification for continued operation of a valve determined to be inoperable will be in accordance with TMI-l Technical-Specification requirements.
NRC Question 6c Please include the following details as a minimum in a program for Action Items b, c and d of the bulletin:
(c) Description of a method possibly needed to extrapolate valve stem thrust determined by testing at less than maximum differential pressure.
o 5211-87-2190 October 14, 1987 GPUN TMI-1 Response r
As described in, response to Item 4, we believe our method of calculating thrusts conservatively predicts normal valve loading conditions, as shown by full AP testing at Davis-Besse.
NRC Question 6d i
Please include the following details as a minimum in a program for Action Items b, c and d of the bulletin:
(d) ' Justification of a possible alternative to testing at maximum differential pressure at the plant.
GPUN TMI-1 Response As mentioned above, our calculations of required stem thrust allow us to verify valve (accident pressure) operability at zero line pressure.
NRC Question 6e i
Please include the following details as a minimum in a program for Action
' Items b, c and d of the bulletin:
(e) Consideration of pipe break conditions as required by the bulletin.
I GPUN TMI-1 Response Pipe break was not considered for low energy lines (<200*F or 275 psi);
however, where pipe break was considered a credible sceaario or where valve function was required subsequent to such an event, pipe break was considered.
This included the following valves:
MU-V-16 A/B/C/D MU-V-36 MU-V-37 MS-V-2A/B EF-V-2A/B Pipe break was not considered for MS-V10A/B because the valves are required to open to supply sufficient steam to the turbine driver of EF-P-1 when MS-V13A/B cannot pass sufficient flow to support EF-P-1 operation.
In this case, the maximum delta pressure is the 800 psi stated in our final response letter.
i NRC Question 6f Please include the following details as a minimum in a program for Action Items b, c and d of the bulletih:
(f) Stroke testing when necessary to meet bulletin requirements.
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5211-87-2190 October 14, 1987 1
GPUN TMI-1 Response Each of the IEB 85-03 valves were stroke tested as part of the M0 VATS testing
' that was done for the bulletin.
NRC Question 6g Please include the following details as a minimum in a program for Action Items b, c and d of the bulletin:
(g) Consideration of applicable industry recommendations in the preparation of procedures to ensure maintenance of correct switch settings.
GPUN TMI-1 Response Action Item b of the bulletin was to establish the correct switch settings.
To be included was a program to review and revise as necessary the methods for selecting and setting all switches (i.e., torque, torque bypass, position limit, overload) for each valve operation (opening and closing).
Procedure 1420-LTQ-2 has been revised in response to Bulletin 85-03 and includes the methods for setting and maintaining torque, torque bypass and position limit switches.. Applicable industry recommendations were considered in the preparation of this procedure.
Overload switches were previously selected so that they would not trip for less than 300 percent of normal current for the operating time of the valve.
This criteria is in accordance with Regulatory Guide 1.106 " Thermal Overload i
Protection for Electric Motors on Motor Operated Valves" and correspondence with the NRC.
However future overload selections on bulletin motor operators will be accomplished in accordance with GPUN Technical Functions Engineering Standard ES-024.
ES-024 takes into consideration Reg. Guide 1.106 and applicable industry recommendations.
I Sincerely, H. D. Huki 1 Vice President & Director, TMI-l HDH/DVH/spb:1008A cc:
W. Russell Sworn and subscribed to G. Edison before me this /6/A day R. Conte of 4.defit;
, 1987.
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