ML17324B136
| ML17324B136 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 11/13/1986 |
| From: | INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | |
| Shared Package | |
| ML17324B135 | List: |
| References | |
| NUDOCS 8611180253 | |
| Download: ML17324B136 (10) | |
Text
REACTOR COOLANT SYSTEM STEAM GENERATOR TUBE INTEGRITY LIMITING CONDITION FOR OPERATION 3.4.5 The tube integrity of each steam generator shall be maintained.
APPLICABILITY:
MODES 1, 2,
3 and 4.
ACTION:
With the tube integrity of one or more steam generators not maintained, restore the tube integritg of the affected steam generator(s) prior to increasing T
above 200 F.
avg SURVEILLANCE RE UIREMENTS 4.4.5.0 The tube integrity of each steam generator shall be demonstrated by performance of the following augmented inservice inpsection program and the requirement of Specification 4.0.5.
4.4.5.1 Steam Generator Sam le Selection and Ins ection
- The tube integrity of each steam generator shall be determined during shutdown by selecting and inspecting at least the minimum number of steam generators specified in Table 4.4-1.
4.4.5.2 Steam Generator Tube Sam le Selection and Ins ectio
- The steam generator tube minimum sample size, inspection result classification, and the corresponding action required shall be as specified in Table 4.4-2.
The inservice inspection of steam generator tubes shall be performed at the frequencies specified in Specification 4.4.5.3 and the inspected tubes shall be verified acceptable per the acceptance criteria of Specification 4.4.5.4.
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 (subsequent to the preservice inspection) of each steam generator shall include:
D.
C.
COOK - UNIT 1 3/4 4-7 Amendment No.
8611180253 861113'DR" ADOCK 05000315 P
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REACTOR COOLANT SYSTEM SURVEILLANCE RE UIREMENTS Continued The tube integrity of the steam generator shall be determined after completing the corresponding actions (plug all tubes exceeding the plugging limit and all tubes containing through-wall cracks) required by Table 4.4-2.
4.4.5.5 R~e etts Following each inservice inspection of steam generator
- tubes, the number of tubes plugged in each steam generator shall be reported to the Commission within 15 days.
The complete results of the steam generator tube inservice inspection shall be included in the Annual Operating Report for the period in which this inspection was completed.
This report shall include:
1.
Number and extent of tubes inspected.
2.
Location and percent of wall-thickness penetration for each indication of an imperfection.
3.
Identification of tubes plugged.
Results of steam generator tube inspections which fall into Category C-3 and require prompt notification of the Commission shall be reported pursuant to Specification 6.9.1 prior to resumption of plant operation.
The written followup of this report shall provide a description of investigations conducted to determine cause of the tube degradation and corrective measures taken to prevent recurrence.
D.
C.
COOK - UNIT 1 3/4 4-11 Amendment No.
n n00 I
TABIZ 4.4-1 MMIMJMNUMKR OF STEAM GENEKQQRS 10 BE INSPlKTlU) DURING INSEFilICE INSPECTION Preservice Inspection No. of Steam Generators per Unit Four First Inservice Inspection Two Second
& Subsequent Inservice Inspections Table Notation:
1.
ale i@service inspection may be limited to one steam generator on a rotating schedule encompassing 3 N 4 of the tubes (where N is the number of steam generators in the plant) if the results of the first or previous inspections indicate that all stmn generators are 1'
g one or more steam generators may be found to be more severe than those in other steam 1
most severe conditions.
40 2.
'Ihe third and fourth steam generators not inspected during the first inservice inspection shall be inspected during the second and third inspections, respectively.
The fourth and, subsequent inspections shall follcar the instructions described in 1 above.
REACTOR COOLANT SYSTEM BASES 3 4.4 5
STEAM GENERATOR TUBE INTEGRITY The Surveillance Requirements for inspection of the steam generator tubes ensure that the structural integrity of this portion of the RCS will be maintained.
The program for inservice inspection of steam generator tubes is based on a modification of Regulatory Guide 1.83, Revision 1.
Inservice 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 desi,gn, manufacturing errors, or inservice conditions that lead 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.
The plant is expected to be operated in a manner such that the secondary coolant will be maintained within those chemistry limits found to result in negligible corrosion of the steam generator tubes.
If the secondary coolant chemistry is not maintained within'hese parameter limits, localized corrosion may likely result in stress corrosion cracking.
The extent of cracking during plant operation would be limited by the limitation of steam generator tube leakage between the primary coolant system and the secondary coolant system (primary-to-secondary leakage 500 gallons per day per steam generator).
Cracks having a primary-to-secondary leakage less than this limit during operation will have an adequate margin of safety to withstand the loads imposed during normal operation and by postulated accidents.
Operating plants have demonstrated that primary-to-secondary leakage of 500 gallons per day per steam generator can readily be detected by radiation monitors of steam generator blowdown.
Leakage in excess of this limit will require plant shutdown and an unscheduled inspection, during which the leaking tubes will be located and plugged.
In MODES 1, 2,
3 and 4 the tube integrity of the steam generators shall be considered maintained if the primary-to-secondary leakage rate is within the limits of Specification 3.4.6.2.
Wastage-type defects are unlikely with the all volatile treatment (AVT) of secondary coolant.
- However, even if a defect of similar type should develop in service, it will be found during scheduled inservice steam generator tube examinations.
Plugging will be required for all tubes with imperfections exceeding the plugging limit which, by the definition of Specification 4.4.5.4.a is 40% of the tube nominal wall thickness.
Steam generator tube inspections of operating plants have demonstrated the capability to reliably detect degradation that has penetrated 20% of the original tube wall thickness.
Whenever the results of any steam generator tubing inservice inspection fall into Category C-3, these results will be promptly reported to the Commission pursuant to Specification 6.9.1 prior to resumption of
'lant operation.
Such cases will be considered by the Commission on a case-by-case basis and may result in a requirement for analysis, laboratory examinations,
- tests, additional eddy-current inspection, and revision of the Technical Specifications, if necessary.
D.
C.
COOK - UNIT 1 B 3/4 4-2a Amendment No.
REACTOR COOLANT SYST STEAM GENERATOR TUBE INTEGRITY LIMITING CONDITION FOR OPERATION 3.4.5 The tube integrity of each steam generator shall be maintained.
APPLICABILITY:
MODES 1, 2,
3 and 4.
ACTION:
With the tube integrity of one or more steam generators not maintained, restore the tube integritg of the affected steam generator(s) prior to increasing T
above 200 F.
avg SURVEILLANCE RE UIREMENTS 4.4.5,.0 The tube integrity of each steam generator shall be demonstrated by performance of the following augmented inservice inpsection program and the, requirement of Specification 4.0.5.
4.4.5.1 Steam Generator Sam le Selection and Ins ection
- The tube integrity of each steam generator shall be determined during shutdown by selecting and inspecting at least the minimum number of steam generators specified in Table 4.4-1.
4.4.5.2 Steam Generator Tube Sam le Selection and Ins ection
- The steam generator tube minimum sample size, inspection result classification, and the corresponding action required shall be as specified in Table 4.4-2.
The inservice inspection of steam generator tubes shall be performed at the frequencies specified in Specification 4.4.5.3 and the inspected tubes shall be verified acceptable per the acceptance criteria of Specification 4.4.5.4.
The tubes selected for each inservice inspection shall include at least 3S 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 (subsequent to the preservice inspection) of each steam generator shall include:
D.
C.
COOK - UNIT 2 3/4 4-7 Amendment No.
I
REACTOR COOLANT SYSTEM SURVEILLANCE RE UIREMENTS Continued 9.
Preservice Ins ection means an inspection of the full length of each tube in each steam generator performed by eddy current techniques prior to service to establish a baseline condition of the tubing.
This inspection shall be performed after the field hydrostatic test and prior to initial POWER OPERATION, using the equipment and techniques expected to be used during subsequent inservice inspections.
The tube integrity of the steam generator shall be determined after completing the corresponding actions (plug all tubes exceeding the plugging limit and all tubes containing through-wall cracks) required by Table 4.4-2.
4.4.5.5
~Re ores Following each inservice inspection of steam generator
- tubes, the number of tubes plugged in each steam generator shall be reported to the Commission within 15 days.
The complete results of the steam generator tube inservice inspection shall be included in the Annual Operating Report for the period in which this inspection was completed.
This report shall include:
1.
Number and extent of tubes inspected.
2.
Location and percent of wall-thickness penetration for each indication of an imperfection.
3.
Identification of tubes plugged.
Results of steam generator tube inspections which fall into Category C-3 and require prompt notification of the Commission shall be reported pursuant to Specification 6.9.1 prior to resumption of plant operation.
The written followup of this report shall provide a description of investigations conducted to determine cause of the tube degradation and corrective measures taken to prevent recurrence.
D.
C.
COOK - UNIT 2 3/4 4-11 Amendment No.
TABIZ 4.4-1
~
~
O00
~ K I
C Preservice Inspection MINIIMUMNUMBER OF STEAN GENEEGQHS TO BE INSPECZED IXJRING INSERVICE INSPECTION No. of Steam Generators per Unit First Inservice Inspection Second
& Subsequent Inservice Inspections One Table Notation:
0 1.
The inservice inspection may be limited to one steam generator on a rotating schedule
~passing 3 N 4 of the tubes (where N is the number of steam generators in the plant) if the remQts of the first or previous lions indicate that all steam generators are W
one or more steam generators may be found to be more severe than those in other steam P
g most severe conditions.
2.
The~ and fourth steam generators not inspected during the first inservice inspection shall be inspected during the second and third inspections, respectively.
'Jhe fourth and subsecpent inspections shall follcar the instructions described m 1 above.
REACTOR COOLANT SYSTEM BASES 3
4 4.5 STEAM GENERATOR TUBE INTEGRITY The Surveillance Requirements for inspection of the steam generator tubes ensure that the structural integrity of this portion of the RCS will be maintained.
The program for inservice inspection of steam generator tubes is based on a modification of Regulatory Guide 1.83, Revision 1.
Inservice 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 lead 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.
The plant is expected to be operated in a manner such that the secondary coolant will be maintained within those chemistry limits found to result in negligible corrosion of the steam generator tubes.
If the secondary coolant chemistry is not maintained within these limits, localized corrosion may likely result in stress corrosion cracking.
The extent of cracking during plant operation would be limited by the limitation of steam generator tube leakage between the primary coolant system and the secondary coolant system (primary-to-secondary leakage - 500 gallons per day per steam generator).
Cracks having a primary-to-secondary leakage less than this limit during operation will have an adequate margin of safety to withstand the loads imposed during normal operation and by postulated accidents.
Operating plants have demonstrated that primary-to-secondary leakage of 500 gallons per day per steam generator can readily be detected by radiation monitors of steam generator blowdown.
Leakage in excess of this limit will require plant shutdown and an unscheduled inspection, during which the leaking tubes will be located and plugged.
In MODES 1, 2,
3 and 4 the tube integrity of the steam generators shall be considered maintained if the primary-to-secondary leakage rate is within the limits of Specification 3.4.6.2.
Wastage-type defects are unlikely with secondary coolant.
- However, even if a defect should develop in service, it will be found during scheduled inservice steam generator tube examinations.
Plugging will be required for all tubes with imperfections exceeding the plugging limit of 40% of the tube nominal wall thickness.
Steam generator tube inspections of operating plants have demonstrated the capability to'eliably detect degradation that has penetrated 20% of the original tube wall thickness.
Whenever the results of any steam generator tubing inservice inspection fall into Category C-3, these results will be promptly reported to the Commission pursuant to Specification 6.9.1 prior to resumption of plant operation.
Such cases will be considered by the Commission on a case-by-case basis and may result in a requirement for analysis, laboratory examinations,
- tests, additional eddy-current inspection, and revision of the Technical Specifications, if necessary.
D.
C.
COOK - UNIT 2 B 3/4 4-2a Amendment No.