ML20236B354

Rev 0 to TVA Employee Concerns Special Program Seqouyah Element Rept 235.2(B), Electrical Safety:Exposed 480 Volt Bus at Panel Top

ML20236B354
Person / Time
Site:	Sequoyah
Issue date:	10/14/1987
From:	Joyce J, Worthy J TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20236B339	List: ML20236B336 ML20236B344 ML20236B348 ML20236B351 ML20236B354 ML20236B358
References
235.2(B)-01, 235.2(B)-1, 235.2(B)-R, 235.2(B)-R00, NUDOCS 8710260112
Download: ML20236B354 (7)

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TVA EMPLOYEE CONCERNS REPORT NUMBER: 235.2(B)

SPECIAL PROGRAM REPORT TYPE: SEQU0YAH ELEMENT REVISION NUMBER: 0 TITLE: ELECTRICAL SAFETY Exposed 480 V Bus at Panel Top PAGE 1 0F 7 REASON FOR REVISION:

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TVA EMPLOYEE CONCERNS REPORT NUMBER: 235.2(B)

SPECIAL PROGRAM REVISION NUMBER: 0 PAGE 2 0F 7

1. CHARACTERIZATION OF ISSUES: i

_ l Concern: Issue: i IN-85-064-002 a. Top of 480 V shutdown boards are "480V shutdown boards (E1. 757 open at conduit (cable) entry.

AZR and A14T) feeders to bus bar compartments. The cabinets are )

open on top where the conduits '

enter the MCC."

2. HAVE ISSUES BEEN IDENTIFIED IN ANOTHER SYSTEMATIC ANALYSIS? YES X NO Documentation Identifiers: {

l Identified by TVA WBN Electrical Engineering Branch (EEB)

Date 06/24/85

.m TVA WBN - Quality Information Request (QIR) No. WBNEEB85025, Watts W Bar Nuclear Plant Units 1 and 2 480 V shutdown boards (switchgear) contract 84647 Identified by TVA WBN Nuclear Safety Review Staff (NSRS)

Date 06/28/85 TVA WBN - Nuclear Safety Review Staff Investigation Report I-85-115-WBN, 480 V Shutdown Board

3. DOCUMENT NOS., TAG NOS., LOCATIONS OR OTHER SPECIFIC DESCRIPTIVE IDENTIFICATIONS STATED IN ELEMENT:

No further information available. The employee concern for WBN cited a specific location, but the implied generic concern for SQN is general in nature.

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TVA EMPLOYEE CONCERNS REPORT NUMBER: 235.2(B)

SPECIAL PROGRAM REVISION NUMBER: 0 PAGE 3 0F 7 4 INTERVIEW FILES REVIEWED:

The interview file for IN-85-064 was reviewed and no additional unreviewed information for Sequoyah was identified for the concern l

in this report.

S. DOCUMENTS REVIEWED RELATED TO THE ELEMENT:

See Appendix A.

6. WHAT REGULATIONS, LICENSING COMMITMENTS, DESIGN REQUIREMENTS OR OTHER APPLY OR CONTROL IN THIS AREA?

See Appendix A.

7. LIST REQUESTS FOR INFORMATION, MEETINGS, TELEPHONE CALLS, AND OTHER DISCUSSIONS RELATED TO ELEMENT.

m Ed See Appendix A.

8. EVALUATION PROCESS:

a. Reviewed available transcripts of NRC investigative ,

interviews for additional information on the concern,

b. Reviewed TVA Specification 1775, "480 Volt Switchgear and Transformers for Watts Bar Nuclear Plant Units 1 and 2,"

regarding detailed requirements of shutdown board cabinet cable entries and ventilating openings. j

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c. Reviewed Electrical Design Standard, General Construction Specification, and applicable drawings to evaluate existing top entry conduit installation procedures for switchgear.

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d. Reviewed existing reports to determine if this issue has been l previously addressed and if any corrective actions were identified.

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e. Performed field walkdown to check and verify conduit penetrations to the shutdown boards. ,

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'TVA EMPLOYEE. CONCERNS REPORT NUMBER: 235.2(B)'

SPECIAL PROGRAM REVISION NUMBEP,: 0 PAGE 4 0F 7

9. DISCUSSION, FINDINGS, AND CONCLUSIONS: j 1

Chronolooy:

l 06/03/85: Concern submitted to TVA for WBN 06/24/85: Problem identified by TVA for WBN 06/28/85: Investigation / evaluation report issued for WBN 3 1

08/23/86: SQN walkdown performed by evaluation team l l

Discussion: ,

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The Nuclear Safety Review Staff Report NSRS No. I-85-115-WBN (06/28/85, App. A, 5.b) indicated that the 480 voit shutdown boards e on elevation 757 feet at the Watts Bar Nuclear Plant (WBN) were d either open or covered with duct tape where the main and auxiliary feeders enter the bus bar compartments. Per TVA Specification 1775

( App. A, 5.c) and Electrical Design Standard DS-El.3.1 (04/17/86, App. A, 5.d) duct tape is not an approved permanent cover. In response, Office of Engineering initiated corrective action by issuing Engineering Change Notices (ECN) No. 5821 and 5822 for WBN (07/30/85, App. A, 5.q). This change modified the area on top of the 480 V shutdown boards by enclosing the cable entran?.e openings per the design detail added on Electrical Equipment drawing (08/15/85, App. A, 5.1).

Because similar equipment is used at SQN and WBN, on 08/23/86 the evaluation team conducted a walkdown of the Sequoyah plant ( App. A, 1 7.a) to determine whether the 480 V shutdown boards have unsealed I openings as at Watts Bar. This walkdown determined that all of the l 480 V shutdown boards at SQN have a conduit entry area on top l provided by the vendor. The conduit was installed by cutting the proper size hole in the specified area of the board, and there were no instances of exposed 480 V buses or cables running from the conduit to the panel top. The conduit penetrations to the shutdown boards were fcund correctly sealed as specified in Electrical Design Standard DS-El.3.1 and General Construction Specification G-40 (App. A, 5.k).

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'TVA EMPLOYEE CONCERNS REPORT NUMBER: 235.2(B)

SPECIAL PROGRAM REVISION NUMBER: 0 PAGE 5 0F 7

. 1 Findina:

l 5 Based on the evaluation conducted, it was determined that construction specifications reflecting design requirements were =--

observed to be correctly implemented at SQN for the concern identified.

Conclusion:

Procedures for top entry into the 480 V shutdown boards were properly followed at Sequoyah. Since there is no exposed cable .

entry into the top of the 480 V shutdown boards at Sequoyah, and none of the shutdown boards have unsealed openings exposing 480 V -

buses, the concern is not valid for SQN.

10. CORRECTIVE ACTION:

No corrective action is required.

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TVA EMPLOYEE CONCERNS REPORT NUMBER: 235.2(B)

SPECIAL PROGRAM REVISION NUMBER: 0 l PAGE 6 0F 7 APPENDIX A l i

5. DOCUMENTS REVIEWED RELATED TO THE ELEMENT:

a. QIR WBNEEB 85025 (B26 850625 006), " Watts Bar N.P. Units 1 and 2 480V Shutdown Boards (Switchgear) Contract 84697,"

(06/25/85)

b. TVA memo from Whitt to Pierce, " Nuclear Safety Review Staff Investigation Report Transmittal," (07/01/85); Attachment -

NSRS Report No. I-85-115-WBN, (06/28/85) ,

c. TVA Specification 1775 for 480 Volt Switchgear and Transformers for Watts Bar Nuclear Plant Units 1 and 2.

d. TVA Electrical Design Standard DS-E1.3.1, " Protection of Electric Equipment Susceptible to Failure from Fluid Spray ,

and Condensation," (04/17/86) l

e. TVA memo from Utley to Civil Engineering Branch (B41850710 q 258), " Watts Bar Nuclear Plant, Contract No. 84647, CAS U Identification No. WBN-84, Qualification of 480V Shutdown Boards (Switchgear)," (07/10/85)

f. TVA memo from Pierce to Whitt, " Watts Bar Nuclear Plant -

Request for Investigation / Evaluation," 07/17/86) 9 Engineering Change Notice (ECN) Nos. 5821 and 5822 (B26 850730 500 and 502), " Modify Tops of 480V Shutdown Boards to Enclose Cable Openings Made for Cable Entrances," (07/30/85) j

h. TVA memo from Whitt to Ennis, " Employee Concern l IN-85-064-022,"(11/29/85) (

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i. TVA WBN Drawing No. E45N282-2 R31, " Electrical Equipment 480V  !

Shutdown Board 1A2B and 182B Board Arrangement," (08/15/85) l

j. Letter from Youngblood, NRC, to White, TVA, (06/23/86), with the attached transcript of the investigative interview conducted by the NRC on 02/21/86 at the First Tennessee Bank Building in Knoxville, Tennessee.

k. TVA General Construction Specification G-40, R9, " Installing Electrical Conduit Systems and Conduit Boxes," (01/15/86) 05770 - 17./18/86

, 'TVA EMPLOYEE CONCERNS REPORT NUMBER: 235.2(B)

SPECIAL PROGRAM l REVISION NUMBER: 0 1 PAGE 7 0F 7 APPENDIX A (cont'd)

6. WHAT REGULATIONS, LICENSING COMMITMENTS, DESIGN REQUIREMENTS OR OTHER APPLY OR CONTROL IN THIS AREA?

a. TVA Specification 1775 for 480 Volt Switchgear and Transformers for Watts Bar Nuclear Plant Units 1 and 2.

b. TVA Electrical Design Standard DS-E1.3.1, " Protection of Electric Equipment Susceptible to Failure from Fluid Spray )

and Condensation," (04/17/86)

c. TVA General Construction Specification G-40, R9, " Installing Electrical Conduit Systems and Conduit Boxes," (01/15/86)

7. LIST RE00ESTS FOR INFORMATION, MEETINGS, TELEPHONE CALLS, AND OTHER DISCUSSIONS RELATED TO ELEMENT.

a. Field walkdown at Sequoyah site conducted by Jack Wheeler, Bechtel, and Norm Black, TVA, (08/23/86) 1 1

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