ML20080K062
| ML20080K062 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 02/07/1984 |
| From: | Heider L VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20080K064 | List: |
| References | |
| FVY-84-7, NUDOCS 8402150283 | |
| Download: ML20080K062 (4) | |
Text
o VERMONT YANKEE NUCLEAR POwnR CORPORATION Proposed Change Fo.109 RD 5. Box 169. Ferry Road, Brattleboro, VT 05301
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y ENGINEERING OFFICE 1671 WORCESTER ROAD FR AMINGHAM, MASSACHUSETTS 01701 TELE PHONE 617-872-8100 February 7,1984 FVY 84-7 United States Nuclear Regulatory Commission Washington, D. C. 20555 Attention:
Office of Nuclear Reactor Regulation Mr. D. G. Eisenhut, Director Division of Licensing Ref erences :
(a) License No. DPR-28 (Docket No. 50-271)
(b) NUREG/CR-2182, Vol. I - Station Blackout at Brown's Ferry Unit One - Accident Sequence Analysis (c) GEK 9613 - HPCI System for Vermont Yankee
Subject:
Request for License Amendment - HPCI Automatic Suction Transfer
Dear Sir:
Pursuant to Section 50.59 of the Commission's Rules and Regulations, Vermont Yankee Nuclear Power Corporation hereby proposes the following modification to Appendix A of the Operating License:
Proposed Change This change involves a revision of Pages 38 and 52 of the Vermont Yankee Technical Specifications.
Tables 3.2.1 and 4.2.1 have been revised to reflect the deletion of the HPCI Automatic Suction Transfer on high torus water le vel.
The proposed changes to the Technical Specifications are being supplied as an attachment to this letter.
Reason and Basis for Change This Technical Specification change is being requested so that the HPCI Automatic Suction Transfer on high torus water level can be eliminated. The elimination of this transfer function is being prompted by an evaluation performed as a result of the questions raised in Reference (b).
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United States Nuclear Regulatory Commission February 7,1984 Attention:
Mr. Darrell G. Eisenhut Pag e 2 Safety Consideration The " Station Blackout at Brown's Ferry Unit One - Accident Sequence Analysis" [ Reference (b)] has raised a question concerning the desirability of an automatic shif t in HPCI pump suction on high suppression pool water level.
The basis for this concern is the possibility that following a station blac kout, the combination of remote manual operation of the primary relief valves to control primary pressure and the loss of suppression pool cooling will result in suppression pool temperature of about 1600F af ter about three (3) hours.
By this time, the suppression pool level would have increased enough to cause the HPCI pump suction to automatically transfer f rom the Condensate Storage Tank (CST) to the torus. The temperature limit for the fluid being pumped by the HPCI System is 1400F since the lubricating oil f or the HPCI turbine is cooled by the water being pumped.
This situation could threaten the viability of the HPCI System at a time when its use is vital to plant safety.
Further evaluations have disclosed that this problem is also a concern for other accidents which would cause a high torus water temperature.
Technical Specifications for suppression pool level are based upon design considerations associated with worst case LOCA blowdown.
The basis for the maximum suppression pool level is to limit the stress to the torus due to the blovdown of the vessel to the torus and the f act that there must be sufficient f ree air space available in the case of a blowdown. Control of suppression pool level is not a function of the HPCI System.
The HPCI System is designed for a small diameter line break, and as such, it would not be depressurizing rapidly into the torus.
Therefore, this high limit for suppression pocl level does not apply for the accident where the HPCI System is required to function.
It should be noted that although the HPCI System is safety class, the automatic transfer of HPCI suction to the torus for high suppression pool level is non-nuclear safety related.
In addition, the design basis of the plant does not require protection against a Design Basis Accident (DBA) followir4: a small or intermediete break LOCA.
Finally, all alarms of f of the HPCI System are being maintcined to alert the operator that a high suppression pool level condition is being approached and to allow him to evaluate whether manual transfer of the HPCI suction to the torus is appropriate.
l Based on the above and the fact that there is a separate provision made I
for HPCI Automatic Suction Transfer on CST low water level, the removal ( f the HPCI Automatic Suction Transfer on high torus water level will have no adverse affect on any plant safety system.
The ref o re, this change does not involve an unreviewed safety question as defined in 10CFR50.59(a)(2).
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_s United State's. Nuclear Regulatory Commission! % '
February 7,1984 ittention:
Mr. 4 Darreib G. Eisenhut Page 3 N*
This chanie has been reviewed by the Vermont Y nkee Nuclear Safety and a
Audit Review Committ$e.
Significant Hazard 2 Consideralion The Commission has provided guidance concerning the application of standards for determining whether a significant hazards consideration exists by providing certain examples [487R14370]; 'One of these examples (vi) of actions which involve no signfficant hazards consideration is a change which either may result in 'some increase to the pro $ ability or consequences of a previously analyzed accident, or 'may in some way reduce a margin of safety, but where the results of the change are clearly within all acceptable criteria.
As discussed.above, contrNk of suppression pool level is not a function of the HPCI System and automatic-transfer af the HPCI suction to the suppression pool is non-nuclear safety-related.
In addition, we have concluded as a result of our ccasideration of the Station Blackout at Brown's Ferry (Reference (b)], that the HPCI Automatic Transfer feature may actually threaten HPCI System operebility at a time when the system is vital to plant safety.
Theref ore, we have concluded that this change is within all acceptable criteria for HPCI System operabilit} add does not constitute a significant hazards consideration as defined Jo 10CFR50.92(c).'s Fee Determination h
This proposed change requires an approvalithat-does not involve a safety issue and is deemed not to involve a significant hazards consideration.
For these reasons, Vermont' Yankee Nuc lear Power Corporation proposes this change as a Class III amendment.
A payment of. 84,'000.00 is enclosed.
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Schedule of Change i
This proposed change is scheduled to be implemented during our 1984 refueling outage, scheduled to commence in Juite 1984.
Your approval of this i
proposed change is requested by the end of May 1984'.
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United States Nuclear Regulatory Commission February 7,1984 Attention:
Mr. Darrell G. Eisenhut Page 4 l-This change will be incorporated -
our Technical Specifications as soon as practicable following receipt of your approval.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION Jh'/kW d L. H. Heider Vice President JBS/ gad Enclosure cc: Vermont Department of Public Services 120 State Street Montpelier, VT 05602 Attn:
Mr. Richard Saudek, Chairman COMMONWEALTH OF MASSACHUSETTS)
)ss MIDDLESEX COUNTY
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Then personally appeared bef ore me, L. H. Heider, who, being duly sworn, did state that he is a Vice President of Vermont Yankee Nuclear Power Corporation, that he is duly authorized to execute and file the foregoing document in the name and on the behalf of Vermont Yankee Nuclear Power Corporation and that the etatements therein are true to the best of his knowledge and belief.
GA 4
B. Sinclair Notary Public My Commission Expires June 1, 1984
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