ML20238D649
| ML20238D649 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 08/31/1987 |
| From: | Sieber J DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 2NRC-7-199, TAC-62943, NUDOCS 8709110305 | |
| Download: ML20238D649 (3) | |
Text
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'Af Telephone (412) 393-6000 -
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j senppinopon. PA 1MU4M4 August 31, 1987 2NRC-7-199 i
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, License No. NPF-73 10 CFR 50.62, ATWS Rule Implementation Gentlemen:
l On' February 27, 1987 and April 24, 1987, we provided design
'information on the ATWS Mitigation System Actuation Circuitry (AMSAC)
L to_ be ' installed in Beaver Valley Power Station Units 1 and 2 as required by 10 CFR 50.62.
In these submittals, we indicated that we are implementing' an AMSAC' design consistent with the Westinghouse Owner's Group'(WOG) generic design' described in WCAP-10858.
On _ August 3, 1987, the WOG submitted Revision 1 of WCAP-10858 for NRC review.
Accordingly, we are revising our AMSAC design to be consistent with this revision.
In summary, the changes to the AMSAC design are as follows:
(1) The' time -delay for the actuation timer has been changed from 25 seconds to a
variable delay that is a function of power level._
To determine the power level for timer setting, the two existing turbine impulse chamber pressure signal in AMSAC will be
- delayed, via a
log function, and then auctioneered high.
The -bases for this change is to allow the reactor proteciton system to respond first at power levels less than 100%.
'(2) The. time delay for the C-20 permissive has been changed from 120 seconds to longer than the variable timer.
This is to ensure that AMSAC will remain armed long enough to actuate.
]
A more detailed description of these
- changes, including the variable. time delay function was provided in WCAP-10858, Revision 1, submitted on August 3, 1987 by the WOG (OG-87-35).
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Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Docket No. 50-412, License No. NPF-73 10 CFR 50.62, ATWS Rule Implementation Page 2 i
If you have any question on this subject, please contact my office.
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Very truly yours,
.s,
. D.
r Vice President, Nuclear i
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F.
I. Young, NRC Resident Inspector J. Beall, NRC Sr. Resident Inspector NRC Regional Administrator P. S. Tam, NRC Project Manager Director Safety Evaluation and Control, VEPCO H. R. Denton, Director, NRR INPO d
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