ML20099C852

Forwards Response to NRC Questions Re Spent Fuel Cooling Pump Grounding as Part of Independent Assessment Program Phases 1 & 2

ML20099C852
Person / Time
Site:	Comanche Peak
Issue date:	03/06/1985
From:	Williams N CYGNA ENERGY SERVICES
To:	Noonan V NRC
References
83090.024, NUDOCS 8503110447
Download: ML20099C852 (6)

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$deVfCfl 101 California Street, Suite 1000 San Francisco. CA 94111-5894 415 397-5600 March 6, 1985 d '

83090.024 Mr. V. Noonan U.S. Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, Maryland 20814

Subject:

Response to NRC Questions - Spent Fuel Cooling Pump Grounding Comanche Peak Steam Electric Station Independent Assessment Program - Phases 1 and 2 Texas Utilities Generating Company Job No. 83090

Reference:

Cygna Final Report, Phases 1 and 2 TR-83090-01, Revision 0 Observation WD-07-01

Dear Mr. Noonan:

Attachrent 1 documents a discussion with Mr. Om Chopra of your staff in which Cygna was requested to determine whether TUGC0 had performed any corrective action as a result of Phase 1 Observation WD-07-01. This observation concerns the walkdown in which it was noted that the spent fuel pool cooling pump was single grounded where design drawings call for two ground connections. Cygna originally closed this issue based on the fact that double grounding is required for personnel safety only and not for the purpose of satisfying any safety re-lated system function or design requirement.

A subsequent discussion with Mr. Ivan Vogelsang of TUGC0 (see Attachment 2) has revealed that the pump is double grounded by an acceptable alternate means dif-ferent than the configuration shown on the design drawing. This was not docu-mented by TUGC0 since the double grounding of the pump is not a safety related requirement and as such is not subject to the Class 1E quality assurance re-quirements applicable to the pump.

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Mr. V. Noonan March 6, 1985 Page 2 If you have any further questions or wish to discuss this response, please call at your convenience.

Very truly yours, s /

Q N.H. Williams Project Manager NHW/ajb Enclosures cc: Mr. G. Bagchi Mr. J. George Mr. D. Wade Mr. D. Pigott Mr. S. Treby Ms. J. Ellis Mr. S. Burwell 0

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Communications kk k & ATTACHMENT 1 Report N111111111111811111111lll11

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Protect Job No.

Comnche Peak Stean Electric Station 83090 Independent Assessment Program - Phase 1 2/4/85 Sutgect Teme:

Observation WD-07-01 11:20 a.m.

Single Grounded Pump SFR0

Participants:

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0. Choora USNRC N. Williams Cyana 4

item Regwred Comments Action By i

Mr. Chopra called to find out if TUGC0 had brought the single grounded pump into compliance with the drawing. He understood that the double grounding requirement was for personnel safety but he was concerned that a design requirement was not implemen-ted. N. Williams explained that Cygna did not pursue the matter further since it was not a safety related requirement and as suc h the same quality assurance measures do not apply. Cygna will, however, check with TUGC0 to establish whether they installed th a second ground and call G. Bagchi (301/492-8251) back with the

response.

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'""6"a INM /ajb 1 1 l N. Williams, D. Wade, J. van Amerongen, R. Hess, L. Weingart, S. Treby, J. Ellis, wo oi. 3. uurweil, s . re r u n , n. tee , n vJ e u rise l.-.- . . - _

i ATTACHMENT 2 Communications 4L ii Report munmumilmmmel

• ""* coner.nce n.pon Texas Utilities R T. won Protect Job No.

Comanche Peak Steam Electric Station 83090 D*

Independent Assessment Program - Phase 1 2/26/85 Sube.ct Time Observation WD-07-01 1:00 p.m.

Single Grounded Pump g

1. Vogelsang, J. van Amerongen TUGC0 K. Zee, L. Weingart Cygna 4

ltem Comments AC On y I. I. Vogelsang described the "as-built" grounding of the Spent Fuel Cooling Pump Motor:

A. A 1" rigid steel conduit is installed between the motor space heater terminal box and the cable tray - no " flex" used.

B. Another rigid steel conduit is installed for the motor power

, circuit. Approximately 3' of liquidtight " flex" is used at the connection to the motor terminal box. Approximate total

> raceway length is 22'.

C. One #4/0 ground cable is installed between the " ground loop" and the motor's ground pad - cable is routed in parallel to the 1" conduit.

D. One #4/0 bonding jumper is connected in parallel to the liquidtight " flex" using approved fittings.

II. Regarding conformance of the as-built configuration to the grounding details shown on EH drawing El-1703-01, Revision 6; I. Vogelsang indicated that the "as-built" condition provided the required two connections as per Table 1 of the referenced details.

K. Zee agreed that although the installation did not match the grounding details, it did " effectively" provide the two-point connection required by the grounding details.

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} Y] L{ )./L4t./3 /a3b 1 2 N. Williams, D. Wade, J. van Amerongen, R. Hess, T. Martin, K. Zee, L. Weingart, uswa 5. Treby, J. Ellis, 5. Burwell, Project 1 ile

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ATTACHMENT 2 (Cont'd.)

Communications 4L Report L a i N1111ll11lll1111111lll1611lll Item Comments Ac y

1. The first connection is provided by Item 3 of the "as-built" condition.

2. The second condition is " effectively" provided by a combination of Items 2 and 4 of the "as-built" con-dition and Details 3 and 4 of G&H drawing El-1703, Revision 6.

Discussion The bonding jumper and the physical connection of the power terminal box to the motor frame " effectively" bonds the rigid steel power conduit to the motor frame. The rigid steel con 6 it is acceptable as a ground conductor thus grounding the motor frame to the tray system. Detail 3 of G&H drawing El-1703, Revision 6, shows the tray system grounded via #4/0 cable. This ,

in combination with Item 3 of the "as-built" condition provides '

the required two connections of the " ground loop" to the motor.

III. According to I. Vogelsang, this discrepancy with the drawing was not docuirented due to the fact that double grounding the pump in question is a non-safety related (i.e., non-1E) requirement.

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