ML20213A443

Proposed Tech Specs,Providing Flexibility in Areas Governing Integrity Testing of Steam Generator Tubes

ML20213A443
Person / Time
Site:	Yankee Rowe
Issue date:	01/22/1987
From:	YANKEE ATOMIC ELECTRIC CO.
To:
Shared Package
ML20213A430	List: ML20213A428 ML20213A443
References
NUDOCS 8702030280
Download: ML20213A443 (4)

Text

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MAIN COOLANT SYSTEM STEAM GENERATORS LIMITING CONDITION FOR OPERATION 3.4.10 Each steam generator in a non-isolated main coolant loop shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3 and 4 ACTION:

With one or more steam generators in non-isolated main coolant loops inoperable, restore the inoperable generator (s) to OPERABLE status prior to increasing TAVG above 200 F. ,

l SURVEILLANCE REQUIREMENTS 4.4.10.0 Each steam generator shall be demonstrated OPERABLE by performance of the following augmented inservice inspection program and the requirements of Specification 4.0.5.

4.4.10.1 Steam Generator Sample Selection and Inspection - Each steam generator shall be determined OPERABLE during shutdown by selecting and inspecting at least the minimum number of steam generators specified in Table 4.4-4.

4.4.10.2 Steam Generator _ Sample Selection and Inspection - The steam generator tube minimum sample size, inspection result classification and the corresponding action required shall be as specified in Table 4.4-5.

The inservice inspection of steam generator tubes shall be performed at the frequencies specified in Specification 4.4.10.3 and the inspected tubes shall be verified acceptable per the acceptance criteria of Specification 4.4.10.4. The tubes selected for each inservice inspection shall include at least 3". of the total number of tubes in all steam generators; the tubes selected for these inspections shall be selected on a random basis except:

a. Where experience in similar plants with similar water chemistry indicates critical areas to be inspected, then at least 50?/, of the tubes inspected shall be from these critical areas.

b. The first sample of tubes selected for each inservice inspection of each steam generator shall include:

o-JEn. 1. All nonplugged tubes that previously had detectable wall penetrations (greater than 20*4). l O

@8 2. Tubes in those areas where experience has indicated O s:

Potential problems.

80 8e 8

OW E$n. YANKEE-ROWE 3/4 4-32 AmendmentNo.J((

i 4

MAIN COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued)

3. A tube inspection (pursuant to Specification 4.4.10.4.a.8) shall be performed on each selected tube. If any selected

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tube does not permit the passage of the eddy current probe j for a tube inspection, this shall be recorded and an

- adjacent tube shall be selected and subjected to a tube

inspection.

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c. The tubes selected as the second and third samples (if required by Table 4.4-5) during each inservice inspection may be subjected to a partial tube inspection provided:

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1. The tubes selected for these samples include the tubes from those areas of the tube sheet array where tubes with imperfections were previously found.

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{ 2. The inspections include those portions of the tubes where imperfections were previously found.

1 1 d. Samples sets for each steam generator may be combined, provided l that:

l i 1. The size of the combined sample set meets or exceeds the sum of the C-2 minimum tube requirement of Table 4.4-5.

! 2. The response to the test results is prescribed according to

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the Action Required by the higher of the combined Sample Inspection criteria.

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j 3. The partial tube inspection described in Surveillance 1 4.4.10.2.c is not used if the combined sample includes the 1st Sample Inspection.

The results of each sample inspection shall be classified into one of the

, following three categories:

! Category ,

Inspection Results C-1 Less than 5*4 of the total tubes inspected are degraded

tubes and none of the inspected tubes are defective.

J C-Z One or more tubes, but not more than 1?? of the total 1

! tubes inspected are defective, or between 5?; and 10?; of the total tubes inspected'are degraded tubes.

1 C-3 More than 10?4 of the total tubes inspected are degraded tubes or more than 1*4 of the inspected tubes are j defective. l 1

! NOTE: In all inspections, previously degraded tubes must exhibit i significant ('10*4) further wall penetrations to be included

! in the above percentage calculations, i

YANKEE-ROWE 3/4 4-33 Amendment No.,54' i

r MAIN COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued) 4.4.10.4 Acceptance Criteria

a. As used in this Specification:

1. Imperfection means an exception to the dimensions, finish or contour of a tube from that required by fabrication drawings or specifications. Eddy-current testing indications below 20% of the nominal tube wall thickness, if detectable, may be considered as imperfections.

2. Degradation means a service-induced cracking, wastage, wear or general corrosion occurring on either inside or outside of a tube.

3. Degraded Tube means a tube containing impe"fections 220% of the nominal wall thickness caused by degrr.dation.

4.  % Degradation means the percentage of the tube wall thickness affected or removed by degradation.

5. Defect means an imperfection of such severity that it exceeds the plugging limit. A tube containing a defect is defective.

6. Plugging Limit means the imperfection depth at or beyond which the tube shall be removed from service because it may become unserviceable prior to the next inspection and is equal to (40%) of the nominal tube wall thickness.

7. Unserviceable describes the condition of a tube if it leaks or contains a defect large enough to affect its structural integrity in the event of a loss-of-coolant accident or a steam line or feedwater line break as specified in 4.4.10.3.c, above.

8. Tube Inspection means an inspection of the steam generator tube from the point of entry past the top (fifth) support and, where practical, include the full length of the tube.

b. The steam generator shall be determined OPERABLE after completing the corresponding actions (plug all tubes exceeding the plugging limit and all tubes containing through-wall cracks) required by Table 4.4-5.

YANKEE-ROWE 3/4 4-35 Amendment No. ,54'

6 MAIN COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued) 4.4.10.3 Inspection Frequencies - The above required inservice inspections l of steam generator tube shall be performed at the following frequencies:

a. Inservice inspections shall be performed at intervals of not less than 12 nor more than 24 calendar months after the previous inspection. If two consecutive inspections result in all inspection results falling into the C-1 category or if two consecutive inspections demonstrate that previously observed degradation has not continued and no additional degradation has l occurred, the inspection interval may be extended to a maximum of once per 40 months,

b. If the results of the inservice inspection of a steam generator conducted in accordance with Table 4.4-5 at 40 month intervals fall in Category C-3, the inspection frequency shall be increased to at least once per 20 months. The increase in inspection frequency shall apply until the subsequent inspections satisfy the criteria of Specification 4.4.10.3.a; the interval may then be extended to a maximum of once per 40 months.

c. Additional, unscheduled inservice inspections shall be performed on each steam generator in accordance with the first sample inspection specified in Table 4.4-5 during the shutdown subsequent to any of the following conditions:

1. Primary-to-secondary tubes leaks (not including leaks originating from tube-to-tube sheet welds) in excess of the limits of Specification 3.4.5.2.

2. A loss-of-coolant accident requiring actuation of the engineered safeguards.

3. A main steam line or feedwater line break.

i l YANKEE-ROWE 3/4 4-34 Amendment No. J4', ,68' I