ML20207N882
| ML20207N882 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/13/1988 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| TAC-R00486, TAC-R00487, TAC-R486, TAC-R487, NUDOCS 8810190438 | |
| Download: ML20207N882 (14) | |
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s TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 374ot SN 157B Lookout Place 08T is 1988 U.S. Nuclear Regulatory Commission ATTN: Document control Desk Washingt.on, D.C.
20555 centlemen:
In the Matter of
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Docket Nos. 50-327 Tennessee Valley Authority
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50-328 SEQUOYAH NUCLEAR PLANT (SQN) UNITS 1 AND 2 - TEMPORARY DEVIATION REQUEST FROM REQUIREMENTS OF 10 CFR 50, APPENDIX R, SECTION III.C.2 A noncompliance with section III.C.2 of 10 CFR 50, Appendix R requirements was discovered by SQN personnel on October 5, 1988, involving the 125-volt vital battery board rooms located in the auxiliary building.
1 This matter was discussed with Rex Woscott, of your staff, during his visit to SQN on October 6, 1988.
Mr. Wescott inspected each of the rooms involved.
Following inspection of the battery board rooms, he informed plant personnel in an afternoon meeting that, based on the existing fire protection features, the low combustible loading in the area, the 1-hour fire-rated barrior on redundant train equipment in the rooms, and the compensatory measuro in place to hourly monitor these areas, SQN was providing adequato interim protection until permanent action could be taken to resolvo the deficiency.
Mr. Wescott concluded that no further actions wero necessary for unit I restart, llowever, during discussions between Jack Donohew, of your staf f, and M. A. Cooper, of SQN Site Licensing, on October 7, 1988, Mr. Donohew conveyed that an approved deviation request would be necessary before unit i restart. is a temporary deviation request, including justification, for both units 1 and 2 from the requirements of Appendix R, section III.C.2, for the 125-volt vital battery board rooms. The temporary deviation will remain in place until actions are selected and implemented to resolvo the deficiency.
i TVA will provido NRC the long-term actions to be taken to resolvo this deficiency by November 30, 1988. contains a summary of commitments contained in this submittal.
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l G810190438 881013 PDR ADOCK 05000327 l
P PDC An Equal Oppo tunity Employer L
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U.S. Nuclear Regulatory Comission h hhh If you have any questions, please telephone M. A. Cooper at (615) 870-6549 Very truly yours, TENNESSEE VALL AUTHORITY
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. Gr diey, Mana er Nuclear Licensing and Regulatory Affairs Enclosures cc (Enclosures):
Ms. S. C. Black, Assistant Director for Projects TVA Projects Division U.S. Nuclear Regulatory Commission One Whlte Filnt, North t
11555 Rockville Piko RockvLlio, Maryland 20852 Mr. F. R. McCoy, Assistant Director for Inspection Programs TVA Projects Divlsion U.S. Nucicar Regulatory Commisclon Region 11 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Sequoyah Resident Inspector Sequoyah Nuclear Plant i
2600 Igou Ferry Road Soddy Daisy, Tennensco 37379 l
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Temporary Deviation from 10 CFR 50, Appendix R Section III.G.2 Requirements Deviation Section III.G.2 requires redundant safe shutdown components to be separated from each other by one of the following methods:
"a.
Separetion of cables and equipment and associated non-safety circuits of redundant trains by a fire barrier having a 3-hour rating.
b.
Separation of cables and equipment and associated non-safety circults of redundant trains by a horizontal distance of more than 20 feet with no intervening combustible or fire hazards. In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area; or c.
Enclosure of cable and equipment and associated non-safety circuits'of one redundant train in a fire barrier having a 1-hour rating. In addition, fire detectorr and an automatic fire suppression system shall be installed in the fire area.
Discussion The following conditions identified by TVA's corrective action program have been documented in condition Adverse to Quality Report (CAQR) SQP880513, revision O.
Contrary to section III.G.2.a. which requires separation by a 3-hour barrier, the, cables discussed below are protected by a 1-hour fire-rated barrier (wrap). A manually activated fire suppression system is available in these areas.
An automatic detection system is also available for the vital battery board rooms. The specific interactions are as follows:
1.
Cables IPP750A (6.9-kilovo1L [kV) feed to 480-volt [V) shutdown board transformer 1A-A) and IPP759A (6.9-kV feed to 480-V shutdown board transforme. 1A2-A) were routed and protected through the fifth vital battery board room.
A fire in the flfth vital battery board room with the fifth vital battery system in service to vital battery systems 11 or IV could cause loss of olther of these train "B" associated direct current (de) power systems and loss of above specified unit 1 train "A" shutdown board transformer feeds.
2.
Cablo B1641 is routed through vital battery board room 11 and provides power supply from the fifth vital battery to battery board I.
Cable
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B1681V is routed through vital battery board room III and provides power supply from the fifth vital battery to battery board IV.
With the fifth vital battery in service, a fire in either of these two rooms could cause loss of two redundant channels of de vital power systems, i
3.
Cables 182511 and 183011 were lnstalled in battery board rova I, and l
cables 2B11111 and 2B16111 woro installed in battery board room IV.
These cables are the normal de power supply cables to 480-V shutdown boards 181-B, 182-B, 2Al-A, and 2A2-A.
A fire in olther of those rooms could cause loss of de power control bus of the boards plus loss of the applicable channel of vital de supply.
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JustifierJion The auxiliary building is a designated fire area and is separated from adjacent fire areas by reinforced concrete construction that is equivalent to 3-hour fire-rr.ted barriers. The 125-V vital battery board rooms (I-IV) are located on rievation 734 of the auxillary building, and the fifth vital battery boced room is located on elevation 749 of the auxillery building.
All rooms are separated from adjacent rooms in the auxiliary building by reinforced concrete construction that is equivalent to 1.5-hour fire-rated barriers. This is an adequate level of separation considering the combustible s
loading of the rooms and has previously been accepted by WRC in the Safety Evaluation Report dated February 1980.
These rooms have very low in situ combustibio loading.
An exposuro fire at the floor from transient combustibles represents the only significant fi.re hazard. The type and quantity of transient combustibles allowed through thono rooms are minimized by SQN physical Security Instruction 13. "Fire."
A smoke detection system is otso provided in these rooms, and firefighters dispatched to the room in the event of a fire would be able to activate the existing installed manual suppression system that protects each room.
In addition to the 1-hour fire-rated wrap and the other existing fire protection features in these rooms, employees inspect these rooms fta translent combustibles and other fire hazards during hourly roving fire 9
watches.
i it is TVA's position that, based on the 1-hour fire-rated wrap, other fire protection features in the rooms, and the compenr.atory measures in placo, adequate protection for redundant safo shutdown equipment la provided until additional actions can bo taken to resolve the deficiency.
Thereforo, wo 4
request approval of this temporary deviation from section III.G.2.a requirements for the 125-V vital battery board rooms.
o Enclosura.!
List of Commitments 1.
TVA will submit to NRC the lor.g-term actions to be taken to resolve this deficiency by Novt.: abor 30, 1988, t
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