ML20245D228

Proposed Tech Specs Re Cycle 15 Operation Coastdown Analysis & Operation

ML20245D228
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	06/15/1989
From:	CONNECTICUT YANKEE ATOMIC POWER CO.
To:
Shared Package
ML20245D215	List: ML20245D212 ML20245D228
References
NUDOCS 8906270022
Download: ML20245D228 (2)

Text

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Docket No. 50-213 f 813276 Attachment Haddam Neck Plant Revised Page 7-2 for the Technical Report Supporting Cycle 15 Operation Coastdown Addendum l

i June 1989 8906270022 890616 PDR ADOCK 05000213 PDC p

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reduced power peaking factors used in the reactor physics state point evaluation during the accident. The net effect of these changes is that the mimuum DNBR and maximum centerline fuel temperature results from the original Cycle 15 analysis remain bounding for coastdown operation.

The Small Break LOCA design basis re-analysis was approved by the NRC '

(Reference 3) subsequent to the Reference 1 submittal. The impact of reduced reactor .

power and RCS temperature during coastdown operation has been evaluated and there -

is no negative impact on the peak cladding temperature.

The Large Break LOCA design basis was re-analyzed to assess the impact of the-reduced RCS temperature during coastdown' operation. Previous coastdown -

sensitivity studies of the Westinghouse Interim Acceptance Criteria (IAC) evaluation model have shown that at 100% power, a reduction in the core inlet temperature yields a higher Peak Cladding Temperature (PCT). The sensitivity to the core inlet .

temperature, however, changes between 90% and 100% power , such that below 90%

power, the effect of core inlet temperature on PCT is insignificant.

The current limiting case, which establishes the Linear Heat Generation Rate Technical Specification limits, was re-analyzed for bounding coastdown conditions. Reac.or -

power was conservatively maintained at 102%, but the core inlet temperature was reduced from 536F to 510F. The 510F core inlet temperature corresponds to a coastdown power level of 90%. The analysis also assumed a conservative reduction in the normal end of cycle LHGR from 14.6 to 13.5 kw/ft. The resulting PCT at 13.5 kw/ft is 2269F, which yields over 30F margin to the IAC limit of 2300F.

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