ML20062G387

Sleeved Guide Tube Inspec Prog, CEN-104(N)-NP.Describes Inspec Prog to Show Performance Re Wear.Edited to Delete Info W/Held from Pub Disclosure IAW 10CFR2.790

ML20062G387
Person / Time
Site:	Millstone
Issue date:	12/14/1978
From:	NORTHEAST UTILITIES
To:
Shared Package
ML19289A038	List: ML20062G381 ML20062G387
References
CEN-1-4(N)-NP, CEN-104(N)-NP, TAC-46174, NUDOCS 7812280142
Download: ML20062G387 (9)

Text

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l DOCKET NO. 50-336 j

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t i i ATTACHMENT 1 I '

' MILLSTONE NUCLEAR POWER STATION, UNIT NO. 2 i

4 SLEEVED GUIDE TUBE INSPECTION PROGRAM l

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781228oI'4 7 i DECEMBER, 1978 i

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CEN-104(N)-NP, -

MILLSTONE UNIT 2 SLEEVED GUIDE TUBE INSPECTION PROGRAM

DECEMBER 14, 1978 9

Combustion Engineering, Inc.

Nuclear Power Systems Windsor, Connecticut

" LEGAL NOTICE" "This report was prepared as an account of work Neither sponsored by Cembustion Engineering, Inc. -

- Corbustion Engineering nor any person acting on its ,

behalf:

"a. Makes any warranty or representation, express or implied including the warranties of fitness for a particular purpose or cerchantability, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of any infctmation, apparatus, rethod, or process dis-closed in this report may not infringe privately owned rights; or "b. Assumes any liabilities with respect to the use of, or for damages resulting from the use of, any information, apparatus, method or process disclosed in this report."

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SLEEVED GUIDE TURE INSPECTION PROGRAM INTR 000CTI0tl The purpose of this transmittal is to define the requirements of C-E inspection programs aimed at confirming the satisfactory performance of fuel assembly guide tube wear sleeves in support of continued reactor operation.

This document defines inspection program objectives, criteria for selection ,

of fuel assemblies for inspection and details of the proposed inspection e'f forts.

PROGRAM OBJECTIVES The general objective of the proposed inspection program is to verify that the fuel assembly guide tube wear sleeves have fulfilled their intended function of limiting the magnitude of guide tube wear to an acceptably low value that supports further use of the sleeved assemblies for reactor operation.

The presence of the chrome plated wear sleeves has been shown out-of-pile to pieclude wear of the guide tube with minimum wear of the chrome plated sleeve surface. An objective of the inspection program is to evaluate the extent of sleeve wear which may occur during a reactor operating cycle. From the standpoint of overall fuel assembly integrity, sleeve wear is acceptable provided that the( ,

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SELECTIO 10F FUEL ASSEMBLIES FOR IflSPECTI0fl fuel assemblies will be selected for examination to verify that the use of sleeves to prevent guide tube wear did not result in any unanticipated adverse behavior.

The criteria used to select assemblies for poolside examinations during the refueling period include:

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EXAMINATION PROGRAM The examinations will employ both eddy current and visual inspection techniques. Eddy current techniques similar to those employed in previous inspections will be used to examine guide tubes containing sleeves to assess wear condition. Direct visual observations by either borescope or periscope may then be used to supplement the results obtained by eddy current testing.

Additional tests may also be performed on a limited number of discharged assembliestodetermine( .

.' This test will provide additional confirmation of the mechanical integr'ity of the sleeve / guide tube joint after one irradiation cycle. '

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J EXAMINATION PROGRAM DETAILS The scope of the proposed inspection program includes; (a) Eddy current testing of sleeved fuel assemblies under CEA's to

. ascertain the level of wear that may be present.

(b) Visual examination of sleeved assemblies that were examined during the last refueling outage to confirm guide tube integrity after one operating cycle, 1

(c)e . s in discharged assemblies to verify mechanical e

integrity of the sleeve / guide tube joint, ,

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This inspection program is to confirm the performance of tha sleeved guide tube fuel assemblies during the previous operating cycles of CE Nuclear Steam Supply Systems. The details of individual plant inspections will be issued in plant specific amendments. The precise scope of plant specific inspections will depend on the results of the inspection of sleeved fuel assemblies frory the first operating CE reactor to shutdown in the March / April 1979 refueling period.

At the present time, it is expected that Millstone Unit #2 of Northeast Utilities will be the first plant shutdown and fuel made available for inspection. Predicated on that assumption Table 1 lists the[ [ fuel assemblies that represent high priority candidates for inspection with thecontrollingcriterionbeingaverage{ ],asrecorded after Cycle 1 operation at the location during operation in Cycle 2.

Figure 1 shows assembly locations in Cycle 2 and indicates that in addition to covering high wear locations a fairly core-wide geometric representation is available.

Additionally, Table 2 lists [] assemblies that were visually examined following Cycle 1 sleeving operations and which are candidates for re-examination following Cycle 2 operation.

The inspection programs at BG&E Unit #1 and FPLL St. Lucie Unit #1 are expected to be similar with either an abbreviation or expansion predicated on results from Millstone Unit #2.

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TABLE I

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MILLSTONE-II FUEL ASSEMBLIES SELECTED FOR GUIDE TUBE SLEEVE EDDY CURRENT EXAMINATION Cycle 2 Cycle 2 Average .

Bundle Core CEA for Core 70sition ID Position Bank After Cycle I s

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TABLE 2 MILLSTONE-II

. SLEEVED FUEL ASSEMBLIES VISUALLY EXAMINED FOLLOWING CYCLE.I WHICH ARE CANDIDATES FOR RE-EXAMINATION FOLLOUING CYCLE 2 Assembly Identity 9

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, FIGURE I MILLSTONE-II .

. ASSEMBLIES SELECTED FOR EXAMINATION i

AFTER CYCLE 2 BY ECT

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