ML20212H753
| ML20212H753 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 01/05/1987 |
| From: | Murphy W VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Ebneter S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| FVY-87-03, FVY-87-3, IEB-80-11, NUDOCS 8701280006 | |
| Download: ML20212H753 (3) | |
Text
wJ VERMONT YANKEE NUCLEAR POWER CORPORATION 87-03 RD 5, Box 169. Ferry Road, Brattleboro, VT 05M1 g
. g ENGINEERING OFFICE g
N 1671 WORCESTER ROAD FRAMINGHAM, MASSACHUSETTS 01701
+
TELEPHONE 617-672 8100 January 5, 1987 United States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 Attention:
Mr. Stewart D. Ebneter, Director Division of Reactor Safety
References:
(a) License No. DPR-28 (Docket No. 50-271)
(b) Letter, VYNPC to USNRC, FVY 86-85, dated September 19, 1986 (c) Letter, USNRC to VYNPC, NVY 86-219, dated October 23, 1986, NRC Inspection Report No. 86-17 (d) Letter, VYNPC to USNRC, FVY 86-103, dated November 21, 1986
Subject:
IE Bulletin 80-11, Masonry Wall Design
Dear Sir:
As discussed in letters, dated September 19, 1986 and November 21, 1986
[ References (b) and (d)], Vermont Yankee's recent IE Bulletin 80-11 re-evaluation program reconsidered the validity of excluding masonry walls in nonseismic areas. Accordingly, to ensure that no significant masonry walls had been excluded from consideration, our re-evaluation scope addressed block walls adjacent to safety-related equipment within the Turbine Building, including systems upgraded to safety class status subsequent to NRC approval of the original plant design basis.
As a result of this expanded review, four specific instances where
" safety-related" equipment was determined to be potentially impacted by Turbine Building masonry wall failure were identified. Although our evaluation of potential operational impacts associated with each of these four walls concluded that there existed no immediate safety concern, we also concluded that these areas should be upgraded.
In accordance with our commitment of September 19, 1986 (Reference (b)),
we herein provide the results of our assessment program which evaluated the corrective actions that could be taken associated with the four Turbine Building walls. The four block walls identified as potentially affecting safety class equipment if they fail in a seismic event are located on Column Lines 10, 9, 7, and 6 in the Turbine Building HVAC Room. Failure of the walls was postulated to potentially affect equipment in the following systems:
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~ ~. e United St tec Nuc10cr R:gulatory Commie 31cn January 5, 1987 Attrntion:
Mr. Stew;rt D. Ebnitse PIgt 2 Control Room HVAC Syster)
Diesel Generator Ventilation System ECCS Equipment Ventilation System RPS and PCIS System Vermont Yankee's evaluation included a review of both structural modifications to the walls and electrical modifications, i.e.,
relocating equipment away from the affected area. The following, presented on a wall-by-wall basis, provides the modifications proposed for each wall.
Turbine Building Block Wall Column Line 10 Block Wall 10 is located in the vicinity of Control Room HVAC equipment which includes:
o Control Room Air Conditioner Supply Fans (SAC-1A and 1B) o Control Building Chilled-Water Pump (SP-1) o Water Chiller Unit (SCH-1) o Condenser Fans (SACC-1A and SACC-1B) o Associated Ductwork, Dampers, and Controls o
HVAC Local Control Panel No. 2 Vermont Yankee's corrective action plan involves supporting the wall using structural steel.
Turbine Building Block Wall Column Line 9 Conduits containing cables for Control Room HVAC equipment and RPS and PCIS signals pass through this wall near one side of the wall.
The wall modification proposed for this wall is to remove blocks above and around the affected equipment and replace the blocks with a sheet metal barrier.
Turbine Building Block Wall Column Line 7 Block Wall 7 is located in the vicinity of a control panel and cable tray which contain circuits for the Diesel Cenerator Ventilation System and the ECCS Equipment Ventilation System. In addition, conduits containing cables for Control Room HVAC equipment pass through the wall near one side.
Vermont Yankee's corrective action plan includes a combination of electrical and structural fixes to relocate and protect the equipment identified above.
Turbine Building Block Wall Colunn Line 6 Conduit which contains power and control cable for the Control Room HVAC equipment runs vertically and horizontally along this wall.
In order to prevent the loss of this equipment, the corrective action for Block Wall 6 involves the combination of a partial wall modification and
=m ia Unitid Stttic Nucliar R2gulttory Commission Jrnurry 5, 1987 Attcnticn:
Mr. Stewart D. Ebnitcr Pegs 3 conduit relocation..This mddification would consist of running the affected conduits along the base of Wall 6 and protecting it by a steel barrier. It would then run vertically up to the existing pull box (See Sketch 1).
The wall would be modified in the vicinity of the vertical run, to protect the conduit.
Vermont Yankee proposes to complete these corrective actions associated with each of the Turbine Building masonry walls prior to startup from our 1987 refueling outage.
We trust that our proposed corrective actions and schedule for completion are acceptable; however, should you have any questions or require additional information regarding this matter, please contact us.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION W
Warren P Murphy I
Vice President and ager of Operations WPM /RWC/bam
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