ML19211C746
| ML19211C746 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/02/1980 |
| From: | Counsil W NORTHEAST UTILITIES |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8001140393 | |
| Download: ML19211C746 (1) | |
Text
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January 2, 1980 Docket No. 50-336 Director of Nuclear Reactor Regulation Attn:
Mr. R. Reid, Chief Operating Reactors Branch #4 U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Reference:
(1)
G. Lear letter to D. C. Switzer dated November 23, 1976.
Gentlemen:
Millstone Nuclear Power Station. Unit No. 2 Axial Shane Index In response to the Reference (1) request for information regarding the degree to which Millstone Unit No. 2 can maintain the Axial Shape Index (ASI) within the required limit utilizing excore detectors, Northeast Nuclear Energy Company (NNECO) provides the following information.
The ASI limits are determined from certain physics and thermal-hydraulic charac-teristics of the core. An uncertainty is applied to these limits to account for ASl measurement uncertainty. The magnitude of this uncertainty is such that allowances for excore calibration, shape annealing, signal processing, and rod shadowing are adequately accounted for.
The Millstone Unit No. 2 Technical Specification limiting condition for operation (LCO) on ASI is derived by applying this uncertainty which reduces the allowable ASI operating space such that safety limits are not violated when the indicated ASI is at the limit permitted by the ICO.
We trust that this information is responsive to the Reference (1) request.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY
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