ML20214E337
| ML20214E337 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/13/1987 |
| From: | Sieber J DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20214E338 | List: |
| References | |
| 2NRC-7-119, NUDOCS 8705220044 | |
| Download: ML20214E337 (4) | |
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May 13, 1987 Shippmgport PA 15077-0004 2NRC-7-119 U. S. Nuclear Regulatory Commission Attn:
Document Control Desk Washington, DC 20555
Reference:
Beaver Valley Power Station, Unit No. 1 and No. 2 BV-1 Docket No. 50-334, License No. DPR-66 BV-2 Docket No. 50-412 Control Room Habitability Gentlemen:
On April 30 and May 1, 1987, your staff members, Messrs. Knight, Burrows and Pedersen met with us to discuss several specific concerns related to our proposed design and Technical Specifications associated with our combined control room and emergency ventilation systems.
During that meeting we provided electrical design drawings reflecting the current status of the various electrical inter-connections associated with the control room habitability systems.
These include the control room radiation monitors and chlorine detectors and the method by which redundancy is provided.between the two Units.
As discussed at the meeting, these drawings should permit completion of the design review process for the habitability systems.
Other items discussed during this meeting included minor, mutually agreed upon changes to our proposed Technical Specification Change No.
126, Revision 2.
Included as Attachment A to this letter is a marked up version of the recommended changes and a complete typed version of the proposed change for NRC processing.
These have been found acceptable for incorporation into the Control Room Emergency Habitability Systems Technical Specifications.
We also determined that our previous submittal of this proposed change had two bases section pages numbered the same but containing different information (B
3/4 9-4).
Included in Attachment A is the correct page for the referenced proposed change.
We have also included in Attachment A
a new action statement on T.S. 3.7.7.1.
Item d.1 has been added as a result of our telephone conversation with members of i
the staff on May 13, 1987.
During the review of the control room radiation monitors, the need for incorporating these instruments into the Unit 1 Technical Specifications was discussed.
These monitors were added to Unit 1 as a
result of a Unit 2 analysis demonstrating a need to provide control room isolation capability for several accidents defined in the Standard Review Plan.
We intend to submit changes to the Unit 1 Technical Specifications incorporating these radiation monitors by July 1, 1987.
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0 8705220044 B70513
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Bbavar Valley Powar Station, Unit No. l' Dockat:No._50-334.and 50-412, Licensa No. DPR-66 Control' Room Habitability Page 2
-In addition to the above
- concerns, there were three specific questions to which we agreed to provide a written response.
Included as Attachment B are the specific concerns and our response to each.
The-above information addresses all the concerns the NRC-i identified to us -prior to the site visit with the exception of the l
footnote in the proposed Technical Specification stating " emergency i
power. for one train of dampers of the unit in Modes _5 or 6 need not be available".
The intent of this footnote is to permit. declaring i
the. affected isolation dampers operable if the backup emergency power supply is the only. reason for considering the dampers inoperable.
- Thus, if the shutdown. unit is performing a diesel overhaul it_will-not be necessary to isolate that units side of the normal air intake and exhaust _ portion of the ventilation system.-
By isolating the dampers on the shutdown unit the_ fresh air make-up may be reduced by greater than 50 percent.
Therefore, it is our intent to. declare both trains of dampers operable on the shutdown. unit.
The operating unit-will still have all redundant ESF equipment operable Jper its respective Technical Specifications and be capable of meeting single failure criteria.
rIt was our understanding the-NRC was going to continue their review and-no further action on our behalf was needed at this time.
j We believe this rationale is consistent with industry practices in that make-up air to_ the control rooms for single or dual-units would not be isolated _ to perform diesel generator-maintenance.
WeL are concerned that there would -be a potential to create an oxygen i
deficient environment'
.in lower levels of the control room
)
pressurization envelope during welding or burning. operations-if this requirement was imposed.
Upon review of our s'ubmittals and discussions with the NRC staff, it was determined that. more information regarding-the Unit 4 1-emergency ventilation system desigr.
and operation was_needed with respect to eliminating bypass flow around the emergency ventilation system.
This issue was identified by-Duquesne Light-during a i
previous on-site meeting ' with NRC personnel.-
The emergency i
ventilation system was originally designed -to have parallel-air-supplies from the outside atmosphere.
The primary sourcefwas through i
the series normal air intake dampers which receive signals for auto i
positioning and the backup source was a manually initiated system.
i The primary _ source is also the normal air intake for the normal control room ventilation system.
During our _ system review we determined the potential existed forJbypass flow through the maximum o
air flow damper.
This system is. illustrated on UFSAR Figure.9.13-2.
This damper is designed to permit a flow of approximately 33,200 cfm and the minimum flow damper permits a flow of 300 cfm.
The maximum flow damper is maintained closed in. order to_ eliminate the potential for high flow rates of potentially contaminated' air to the control room.
However,'when closed, this type of damper-will'still permit a l
3-4 percent leakage flow.
Upon determining. this, we-elected 133 remove the connecting duct work.between:the primary intake source and the emergency _ ventilation: system and tas install a removable seal near-.
the maximum flow damper to eliminate damper leakage.:
This E
effectively eliminates.all possibility of bypass-flow around the
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LB avar Valley Power Station, Unit-No. Docket:No. 50-334 and 50-412,' License No. OPR-66
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Page 3 emergency-ventilation system.
As a result of this modification, the 2 '
Lcontrol wiring for the series intake and exhaust dampers was modified
.ta) - - remove the auto open signal following a 60 minute' time delay.
We also ~ removed the auto start. capability of the Unit 1 emergency ventilation -system fans by placing their control switches-in the stop position which. will now require manual operator action to initiate operation-of.this. system.
~The testability of this system in this configuration _ was defined in Lour -Technical Specification Change Request No.
- 126, Revision 2.
The above description is provided as additional. information
.in support of. the referenced Technical Specification Change.-
If you have any questions ~ regarding this' submittal,- please contact me cr members of my staff.
Very truly yours, Ak e _.
. D. Sieber Vice President, Nuclear t
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(Beaver. Valley Power Station,' Unit No. 1 Docket No. 50-334-and'50-412, License No. DPR-66 Control Room Habitability Page 4 i
cc:
Mr. S. M. Pindale, Resident Inspector U. S. Nuclear. Regulatory Commission Beaver Valley' Power Station Shippingport, PA 15077-U. SE Nuclear Regulatory Commission Regional Administrator Region 1 631 Park Avenue King of Prussia,-PA 19406
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Mr. Peter S. Tam U. S. Nuclear Regulatory Commission Project Directorate No. 22
. Division of PWR' Licensing - A 4
Washington, DC 20555
-. Mail Stop 316 Addressee only Director, Safety Evaluation & Control i
Virginia Electric & Power Company P.O. Box 26666 One James River Plaza Richmond, VA 23261 Mr. Thomas M. Gerusky, Director Bureau of Radiation Protection-i:
Pennsylvania Dept. of Environmental Resources P.O. Box 2063
- Harrisburg, PA 17120 i
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