ML19256B162
| ML19256B162 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 01/19/1979 |
| From: | Cavanaugh W ARKANSAS POWER & LIGHT CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| 1-019-8, 1-19-8, NUDOCS 7901240186 | |
| Download: ML19256B162 (7) | |
Text
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ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 LITTLE ROCK, ARKANSAS 72203 (501) 371-4422 January 19, 1979 WILLIAM CAVANAUGH lli Executive Director Generation & Construction 1-019-8 Director of Nuclear Reactor Regulation ATTN; Mr. R. W. Reid, Chief Operating Reactor Branch #4 U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Subject:
Arkansas Nuclear One - Unit 1 Docket No. 50-313
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License No. DPR-51 Proposed Technical Specification Change (File:
1511.1)
Gentlemen:
Enclosed is a proposed change to the Arkansas Nuclear One-Unit 1 (AN0-1)
Technical Specification for Steam Generator Tube Surveillance. This change will implement more effective inspections of tubes by increasing to 100%
the sample size from a problem area, and by conducting inspections of a group of tubes at intervals which are based on the results of previous inspections of that particular group of tubes.
Pursuant to 10 CFR 170.12, we have determined that this croposed change
- involves a single, acceptable issue and is, therefore, a Class III amend-ment requiring a remittance of $4,000.00.
A check for that. amount is enclosed.
Very truly yours, -
1 9e '
William Ca g augh, III WC: ERG:ce
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L-Enclosures gof s
1lI 790124o/f[o p
o ao MCMGEA MOOLE SOUTH UTIUTIES SYSTEM
STATE OF ARKK;SAS
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SS COUUTY OF PULASKI
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William Cavanaugh III, being duly sworn, states that he is Executive Director, Generation & Construction, for Arkansas Power & Light Company; thct he is authorized on the part of said Company to sign and file with the Nuclear Regulatory Commission this Supplementary Information; that he has reviewed or caused to have reviewed all'of the statements contained in such inf:mation, and that all such statements made and matters set forth therein are true and correct to the best of his knowledge, informa-tion and belief.
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William Cavb augh III SUBSCRIBED A';D SWORN TO before me, a Notary Public in and foi +he Counti and State above named, this p enday of
- hnum, 1979 b
Notary Public My Com.nission Expires:
February 17, 1982 4
4.18 STrAM GENERATOR TUBING SURVEILLANCE Applicability Applies to the surveillance of tubing of each steam generator.
Objective To define the inservice surveillance program for steam generator tubing.
Specification 4.18.1 Baseline Inspection The first steam generator tubing inspection performed according to Specifications 4.18.2 and 4.18.3.a shall be considered as constituting the baseline condition for subsequent inspecticas.
4.18.2 Examination Methods Inservice inspection of steam generator tubing shall include non-destructive examination by eddy-current testing or other equivalent techniques.
The inspection equipment shall provide a sensitivity that will detect defects with a penetration of 20 percent or more of the minimum allowable as-manu-factured tube wall thickness.
4.18.3 Selection and Testing The steam generator sample size is.specified in Table.4.18.1.
The steam generator tube minimum sample size, inspection result classification, and the corresponding action required shall be as specified i'n Table 4.18'.2.
The. inservice inspection of steam generator tubes shall. be performed at the frequencies specified in Specification 4.18.4 and the inspected tubes shall be verified acceptable per the acceptance criteria of Specification 4.18.5.
The tubes selected for each inservice inspection shall include at least 3% of the total number of tubes in both steam generators; the tubes selected for these inspections shall be selected on a random basis except:
a.
The first sample inspection during'cach inservice inspection (subsequent to the~ baseline inspection) of each steam generator
.shall include:
1.
All nonplugged tubes that previously had detectable wall penetrations (>20%)., and 2.
At least 50% of the tubes inspected shall be in those areas where experience has indicated po~tential problems.
3.
A tube inspec' tion (pursuant to Specification 4.18.5.a.8) shall.be performed on each selected tube.
12 any selected tube does not permit the passage of the eddy current probe for a tube in'spection, this shall be recorded and an adjacent tube shall be selected and subjected to a tube inspection.
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4.
Tubes in the following groups may be excluded from the first random sample if all tubes in a group in both steam generators are inspected. No credit will be taken for these tubes in meeting minimum sample size requirements.
(1)
Group A-1.
Tubes within ene, two or three rows of the open inspection lane.
(2) Group A-2: Tubes having a drilled opening in the 15th support plate.
b.
The secon'd and third sample inspections during each inservice inspection as required by Table 4.18.2 nay be less than'a full tube inspection by concentrating the inspection ~on those areas of the tube sheet array and on those portions of the tubes where tubes with imperfections were previously found.
The results of each sample inspection shall be classified into one of the following three categories:
Category Inspection Results C-1 ~
Less than 5% of the total tubes inspected are degraded tubes and none of the inspected tubes are defective.
C-2 One or more tubes, but not more than 1% of the total tubes inspected are defective, or between 5% and 10% of the total tubes inspected are degraded tubes.
C-3 More than 10% of the total tubes inspected are degraded tubes or more than 1% of the inspected tubes are defective.
NOTES:
(1)
In all inspections, previously degraded tubes must exhibi-significant (>10%) further wall penetrations to be included in the above percen age calculations.
(2)
Where special inspections are performed pursuant to 4.18.3.a.4, defective or degraded tubes found as a result of the. inspection shall be included in deternining the Inspection Results Category for that special inspection but need not be included in determining the Inspection Results Category for the general steam generator inspection.
'4.18.4 Inspection Intervals The above required inservice inspections of steam generator tubes shall be performed at the following frequencies:
The baseline inspection shall be performed during the first a.
refueling shutdown. Subsequent. inservice inspections shall be performed at intervals of not less than 10 nor more than 24 calendar months after the previous inspection.
If two consecutive
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inspections for a given group *of tubes following service under all volatile treatment (AVT) conditians fall into the C-1 category or if two consecutive inspections demonstrate that previously observed 110k
degradation has not continued and no.. additional degradation has occurred, the inspection interval for that group may be extended to a maximum of 40 months.
b.
If the results of the inservice inspection of a steam generator performed in accordance with Table 4.18.2 at 40 month intervals for r
a given group
- of tubes fall in Category C-3, subsequent inservice inspections shall be performed at intervals of not less than 1, nor more than 20 calendar months after the previous inspection.
The increase in inspection frequency shall apply until a subsequent inspection meets the conditions specified in 4.18.4.a and the in-terval can be extended to 40 months.
c.
Additional, unscheduled inservice inspections shall_be performed on each steam generator in accordance with the first sample
' inspection specified in Table 4.18.2 during the shutdown sub-sequent to any of the following conditions:
1.
Primary-to-secondary leakage in excess of the limits of Spec-ification 3.10 (inservice inspection not required if leaks' originate from tube-to-tube sheet welds),
2.
A' seismic occurrence greater than the Operating Basis Earthquake,
'3.
A loss-of-coolant accident requiring actuation of the engineered safeguards, or 4.
A main steam line or feedwater line. break-4.18.5 Acceptance Criteria As used in this specification:
a.
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 indicationt below 20% of the nominal tube wall thickness, if detectable, may be consicered as imperfections.
2.
Degradation means a service-induced cracking, wastage, wear or general corrosion occurring on either the inside or out-side of a tube.
3.
Degraded Tube means a tube containing imperfections > 20% of the nominal wall thickness caused by degradation.
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.
- A group of tubes means:
(a) All tubes inspected pursuant to 4.18.3.a.4, or (b) All tubes in a steam generator less those inspected pursuant to 4.18 3.a.4.
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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 insp,ection; it is equal to 40%
of the nominal tube wall thickness.
7.
Unserviceable describes the condition of a tube if it Icaks or contains a defect large enough to affect its structural integrity in the event -of an Operating Basis Earthquake, a loss-of-coolant accident, or a steam line or feedwater line break as specified in Specification 4.18.4.c.
8.
Tube Inspection means an inspection of the steam generator tube from the point of entry completely to the point of exit.
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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 4.18.2.
4.18.6 Reports Following each inservice inspection of steam generator tubes, the complete results of the inspection shall be reported to the NRC. This report, to be submitted within 4S days of inspection completion ~, shall include:
a.
Number and extent of tubes inspected;
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b, Location and percent of wall-thickness penetration for each indication of an imperfection; and c.
Identification of tubes plugged.
This report shall be in addition to the report of results of steam generator tube inspections which fall into Category C-3 and which require prompt noti-fication of the NRC per Specification 6.12.3.
Bases.
The surveillance requirements for inspection of the steam generator tubes ensure that the structural integrity of this portion of the RCS will be The program for inservice ins ~ection of steam generator tubes p
maintained.
is bascd on a modification of Regulatory Guide 1.83, Revision 1.
Inservice
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inspection of steam generator tubing is essential in order to maintain surveillance of'the conditions of the tubes in the event that there is evidence of mechanical damage or progressive degradation due to design, manufacturing errors, or inservice conditions that Icad to corrosion.
Inservice inspection of steam generator tubing also provides a means of characterizing the nature and cause of any tube degradation so that corrective measures can be taken.
110m
TABLE 4.18-2 STEAM GENEftATOR TUCE INSPECTION g,
8 f,
1ST SAMPLE INSPECTION 7ND SAMPLE INSPECTION 3RD SAMPLE INSPECTION Act on Required Result Action RcQuir-d i
Sample Size Resu:t Action Required Result A minimum of C-1 None N/A N/A-N/A N/A S Tubes per S. G. (1)
N/A N/A C-2 Plug defective tubes C-1 Nor e and Inspect additionat Plug defective tubcs C-1 None 25 tubes in this S. G.
C-2 and inspect additional C-2 Plug defective tur es 4S tubes in this S. G.
Perfo!m action for C-3 C-3 re:vit of first sample Perform actiors for C-3 C-3 result of first N/A N/A simple C-3 Inspect all tubes in Other 3
this S. G.. plug de.
S.G. in None
~N/A N/A O
tective tubes and C-1 in:r,ect 25 tubes in ODicr Perform action for N/A N/A Other S.C.
s,c-
'.,-2 result of second i
C-2.
sample Crompt notification to NRC Pursuant
- to specification Other Inspect all tubes in 6.12.3.
s.g, ig each S. G. and plug di:lective tubes.
C ~)
Prompt notificetion N/A N/A to NRC pursuant to sprcification 6.1_2. 3.
(1) 's 3 h Where N is the number of steam gencrptors In the unit, and n is the numbc/cf steam generators Intpected notes:
during an inspection n
(2) For tubco inspected pursuant to 4.18.3.a A: No action is. required for C-1 results. For C-2 results in one or both st. cam geacrators plug defective tu'.cs.
For C-3 results in one or both steam generators, plug defective tubco and provide prompt notification of NRC pursuant to specification 6.12.3.
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