ML18052B123

Proposed Tech Specs,Revising 840928 Change to Allow Steam Generator Insp Interval to 24 Months But Can Be Extended to 30 Months Provided Mean Degradation Increase of Steam Generator Tubes from Previous Insp Interval Less than 1%

ML18052B123
Person / Time
Site:	Palisades
Issue date:	06/05/1987
From:	CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Shared Package
ML18052B121	List: ML18052B120 ML18052B123
References
NUDOCS 8706090431
Download: ML18052B123 (5)

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ATTACHMENT Consumers Power Company Palisades Plant Docket 50-255 REVISED PROPOSED TECHNICAL SPECIFICATION PAGE CHANGES June 5, 1987 I i

( 8706090431 870605 * .1r* * *l '

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ADOCK 05000255 PDR I \. JI

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4 Pages TSP0687-0085-NL04

4.14 Augmented Inservice Inspection Program for Steam Generators Applicability Applies to the tubes within both steam generators ..

Objective To provide assurance of continued integrity of the steam generator tubes over their service lifetime.

Specification 4.14.1 Inspection Interval Inspections will be performed at an interval of up to 24 calendar months after the previous inspection.* Additional tube inspections shall be performed when primary to secondary leakage (not including leaks originating from tube to tube sheet welds) exceeds the leakage limits delineated in Section 3.1.Sd.

4.14.2 Inspection Requirements 4.14.2.1 For the purposes of this specification, "tube" refers to that portion of the steam generator tubing from the point of entry on the cold leg side to the top support of the cold leg, or from the point of entry on the hot leg side to the top support of the cold leg.

4.14.2.2 Tubes requiring inspection will include all unplugged tubes with eddy current indications of tube wall degradation greater than or equal to 30% in either of the previous two inspections. Limited access tubes subject to this requirement, which result in significant added radiation exposure to inspect, shall be inspected during an interval not to exceed two consecu~ive inspections.

4.14.2.3 Tubes requiring inspection will also include a random sample of 2%

of the hot leg tubes and 1% of the cold leg tubes in each steam generator. Random samples shall be drawn from those unplugged tubes that ,do not have tube wall degradation identified as greater than or equal to 30% during the previous two inspections.

4.14.2.4 A b~~eline inspection of all newly installed sleeves shall be performed prior to plant operation. Inspection of each installed sleeve shall be performed at a minimum frequency of once .per three steam generator tube inspections whose interval is defined in Section 4.14.1.

• The interval'may be extended to 30 months if the mean degradation increase for the previous steam generator inspection interval was less than +1%.

4-68 Proposed TSP0687-0085-NL04

4.14.2.5

• In the case where a tube is sufficiently restricted to prevent passage of an 0.540-inch diameter probe (blocked), all unplugged tubes surrounding the blocked tube will be gauged to ensure acceptable denting levels.

4.14.2.6 *In the event that tube inspections are required due to primary to secondary leakage, a 3% sample of unplugged tubes in the affected leg(s) in each steam generator with leakage in violation of the limits of Section 3.l.5d shall be inspected.

4.14.3 Inspection Techniques 4.14.3.1 Inspection techniques used shall separately or in combination be capable of providing results that serve to fulfill the inspection requirements and to which the repair criteria can be applied.

4.14.3.2 In determining that a defect exists at a given tube location, indications from several eddy current tests may be averaged during a given inspection. However, such averaging shall be based on not less than three eddy current tests.

4.14.4 Supplementary Sampling Requirements 4.14.4.1 If the inspection pursuant to 4.i4.2.2 and 4.14.2.3 or 4.14.2.6 yields results that exceed one or more of the following criteria, then additional samples of unplugged tubes shall be inspected .

according to Figure 4.14.1.

p a) More than 10% of the inspected tubes in a leg have detectable wall degradation (greater than or equal to 30% through wall) where no previous degradation was detected.

b) More than 10% of the inspected tubes in a leg exhibit further wall degradation (greater than a 10% increase in through wall degradation).

c) More than 1% of the inspected tubes in a leg have indications of tube wall degradation in excess of the repair criteria of Section 4.14.5 where no wall degradation greater than 30% was detected in the previous two inspections.

4.14.4.2 In the event that any of the above limits are exceeded, prompt notification to the Nuclear Regulatory Commission pursuant to 10 CFR 50.72 shall occur.

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4.14.4.3

• When applying the criteria of Paragraph 4.14.4.1 to the inspection sample of Paragraph 4.14.2.6, the leaking tubes that initiated the inspection are not to be reflected in the sample inspection results.

4.14.4.4 When applying the criteria in Paragraph 4.14_.4.l to the tube sample inspection results, the samples are not to be treated cumulatively.

The criteria shall be applied only to the inspection results from the immediate additional sample when deciding whether or not to inspect-the next additional sample in the progression of Figure 4 .14 .1.

4.14.5 Repair Criteria 4.14.5.1. A tube shall be declared defective and shall be repaired using metho~s consistent with Paragraph 4.14.5.5 under the following conditions:

a) Inspection of the tube produces an eddy current indication of volumetric degradation exceeding the limits as listed in Paragr~phs 4.14.5.2 and 4.14.5.3.

b) Inspection of the tube identifies the presence of a crack indication.

c) Inspection of the tube produces an eddy current indication of tube wall degradation that is uninterpretable and was greater than or equal to 45% during the previous inspection.

d) Tube restrictions prevent passage of an 0.540-inch diameter probe.

4.14.5.2 The-following volumetric degradation limits shall be used to identify defective tubes:

a) Indications greater than 51% through wall identified by the 4C4F eddy current technique or equivalent.-

b) Indications greater than 58% through wall identified by a bobbin probe eddy current technique or equivalent.

c) - - Multiple indications greater than 29% through wall identified by a bobbin probe eddy current technique or equivalent.

4-68b Proposed TSP0687-0085-NL04

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4.14.5.3

• The volumetric degradation limits for regions in the tube/sleeve assemblies are as follows:

Region Degradation Limit

1. The undeformed region of the Sleeve degradation = 34% and tube/sleeve assembly containing tube degradation exceeds the the original imperfection degradation limit for an requiring sleeving. unsleeved tube.

2. The region containing the expansion Either sleeve degradation = 25%

joint~ Specifically, the region when tube degradation in region 1 of the tube/sleeve assembly bounded exceeds the degradation limit for by lines approximately 1/4 inch .and an unsleeved section; or tube 2 inches in board from the sleeve degradation in region Z-is ends. greater than the degradation limit for an unsleeved tube.

3. The region of the tube/sleeve Tube degradation exceeds the assembly-containing approxiriiately degradation limits for an 1/4 inch of each end of the assembly. unsleeved tube.

4.14.5.4 If the mean degradation increase over the interval since the previous steam generator inspection is greater than or equal to 1%,

then the Nuclear Regulatory Commission shall approve new degradation limits.

4.14.5.5 Plugging each end of a defective tube is considered *as acceptable .

repair for all cases in Paragraph 4.14.5.1. However, sleeving may be selected as an alternative repair method.

4.14.6 Reporting Requirements A steam generator inspection report shall be submitted to the Nuclear Regulatory Commission within 30 days of completion of the inspection and required repairs.

Basis Guidance for establishing the requirements of this specification is taken from Regulatory Gui4es 1.83 and 1.121, Combustion Engineering Standard Technical Specifications.,, and past experience with the Palisades steam generator problems.

In October 1974, the secondary side water chemistry treatment was changed from coordinated phosphate treatment to all volatile treatment in order to arrest the degradation that had been observed in the steam generators. Both intergranular attack and wastage were present at the time and appeared to be growing. The steam generators suffered from excess leakage in January 1973, in August 1973, and in May 1974.

4-68c Proposed TSP0687-0085-NL04