ML20214W616
| ML20214W616 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 09/24/1986 |
| From: | SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | |
| Shared Package | |
| ML20214W550 | List: |
| References | |
| NUDOCS 8610030149 | |
| Download: ML20214W616 (10) | |
Text
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RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards 4.17 STEAM GENERATORS Applicability Applies to inservice inspection of the steam generator tubes.
Objective 76> To verify the operability and structural integrity of the tubing as part of
< the reactor coolant boundary.
I Specification
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Each steam generator shall be demonstrated OPERABLE by performance of the following auguented inservice inspection program and the requirements of !
Specification 1.3.
4.17.1 Steam Generator Sample Selection and Inspection 76> Steam generator tubing shall be demonstrated OPERABLE by selecting
< and inspecting steam generators as specified in Table 4.17-1.
4.17.2 Steam Generator Tube Sample Selection and Inspection The steam generator tube minimum sample size, inspection result classification, and the corresponding action required shall be as 76> specified in Table 4.17-2A. The inspection result classification and
, the corresponding action required for inspection of " specific limited l areas" (see paragraph 4.17.2e) shall be as specified in Table
< 4.17-2B. The inservice inspection of steam generator tube.1 shall be performed at the frequencies specified in Specification 4.17-3 and the inspected tubes shall be verified acceptable per the acceptance criteria of Specification 4.17.4. The tubes selected for these inspections shall include at least 3% of the total number of tubes in both steam generators and be selected on a random basis except:
- a. If 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.
Amendment No. 76 4-51 0610030149 860924 PDR ADOCK 05000312 P PDR
RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards 4.17.2 (continued)
- b. The first sample inspection during inservice inspection (subsequent to the first inservice inspection) of each steam generator shall include:
134> 1. All tubes that previously had detectable wall penetrations
(>20%), that have not been plugged or sleeve repaired in the
< affected area, and
- 2. Tubes in those areas where experience has indicated potgntial problems.
- c. The second and third sample inspections during each inservice inspection may be less than a full tube inspection by concentrating (selecting at least 50% of the tubes.to be inspected) the inspection on those areas of the tube sheet array and on those portions of the tubes where tubes with imperfections were previously found.
- d. A tube inspection (pursuant to Specification 4.17.4.5) shall be performed on each selected tube. If any selected tube does not permit the passage of the eddy current probe for a tube inspection, this shall be recorded and an adjacent tube shall be selected ana :djected to a tube inspection. (" Adjacent" is interpreted to mean tic nearest tube capable of being inspected.) Tubes which do not permit passage of the eddy current probe will be considered as degraded tubes when classifying inspection results.
- e. Tubes in specific limited areas which are distinguished by unique operating conditions and/or physical construction (for example, tubes adjacent to the open inspection lane or tubes whose 15th tube support plate hole is not broached but drilled) may be excluded from random samples if all such tubes in the specific area of a steam generator are inspected. No credit will be taken for these tubes in meeting minimum sample size requirements.
The results of each sample inspection shall be classified into one of the following three categories:
l Category Inspection Results l C-1 Less than 5% of the total tubes inspected are degraded l
tubes and none of the inspected tubes are defective.
C-2 One or more tubes, but not more than 1% of the total l tubes inspected are defective, or between 5% and 10% of i 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 i defective.
l l Note: In all inspections, previously degraded tubes must exhibit significant (>10%) further wall penetrations to be included in the above percentage calculations.
Proposed Amendment No. 134 4-52 l
RANCHO SECO UNIT 1 TECHNICAL SPEClFICATIONS Surveillance Standards 4.17.3 Inspection Frequencies The above required inservice inspections of steam generator tubes shall be performed at the following frequencies:
- a. The first inservice inspection shall be performed during the first refueling outage. Subsequent 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 following service 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 significant additional degradation has 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 76>< conducted in accordance with Table 4.17-2A and/or Table 4.17-2B at 40-month intervals falls 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 a subsequent inspection meets the conditions specified in 4.17.3a 76>< and the interval can be extended to a 40-month period.
- c. Additional, unscheduled inservice inspections shall be performed on each steam generator in accordance with the first sample 76>< inspection specified in Table 4.17-2A during the shutdown subsequent to any of the following conditions:
- 1. Primary-to-secondary tube leaks (not including leaks originating from tube-to-tube sheet welds) in excess of the limits of Specification 3.10,
- 2. A seismic occurrence greater than the Operating Basis l Earthquake, t 3. A loss-of-coolant accident requirin; automatic actuation of the engineered safeguards, or l 4. A main steam line or feedwater line break as defined in the 76>< USAR.
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4.17.4 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 of less than 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 l of a tube.
Amendment No. 76 4-53
RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards 4.17.4 Acceptance Criteria 134>< 3. Degraded Tube means a tube in the pressure boundary containing imperfections >20% of the nominal wall thickness
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caused by degradation.
134> 4. Defect means an imperfection >40% of the nominal tube or sleeve wall thickness unless 'riigher limits are shown acceptable by analysis. A tube or sleeve containing a defect in its pressure boundary is defective, and shall be
< either plugged or repaired by sleeving.
- 5. Tube Inspection means an inspection of the steam generator tube from the point of entry completely to the point of exit (except as noted in 4.17.2c).
- b. The steam generator shall be determined OPERABLE after completing the corresponding actions required by Table 4.17-2A (and Table 4.17-2B if provisions of paragraph 4.17.2e are utilized).
4.17.5 Reports
- a. Following each inservice inspection of steam generator tubes, 134>< the number of tubes plugged or repaired in each steam generator shall be reported to the Commission within 15 days.
- b. The results of the steam generator tube inservice inspection shall be included in a Monthly 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.
- c. Results of steam generator tube inspections which fall into Category C-3 and require notification of the Commission shall be reported pursuant to Specification 6.9.5P 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.
4.17.6 O_TSG Auxiliary Feedwater Header Surveillance On the first refueling outage following the 1983 refueling outage, and at the 10-year ISI, the following inspections will take place:
Proposed Amendment No.134 4-54
RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards Bases (Continued)
Wastage-type defects are unlikely with AVT chemistry treatment of the secondary coolant. However, even if a defect should develop in service, it will be found during scheduled inservice steam generator tube examinations.
134>< Repair or plugging will be required for defective tubes. 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.
134> Degraded steam generator tubes can be repaired by the installation of sleeves which span the area of degradation and serve as a replacement pressure boundary for the degraded portion of the tube, thus permitting the tube to remain in service. Total tube sleeving is limited due to cumulative increased
< pressure drop through the steam generator tubes as more and more are sleeved.
Whenever the results of any steam generator tubing inservice inspection fall into Category C-3, these results will be reported to the Commission pursuant-to Specification 6.9 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.
The visual and eddy current inspections provide the capability of determining the success of the internal aux feedwater header stabilization by monitoring the long term effects to tube integrity and crack propagation. The inspections will focus on known crack growth, new crack identification (if any), and tube effects in localized areas near the internal header brackets.
! Additionally, visual inspection of the external header thermal sleeves will l
provide assurance that the new design header will not introduce additional problems by demonstrating sleeve integrity.
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Proposed Amendment No.134 4-55a l l
RANCHO SEC0 UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards 13>
TABLE 4.17-1 MINIMUM NUMBER OF STEAM GENERATORS TO BE INSPECTED DURING INSERVICE INSPECTION Preservice l1spection No No. of Steam Generators per Unit Two First Inservice Inspection All Second Subsequent Inservice Inspection Onel Table Notation:
- 1. The inservice inspection may be limited to one steam generator. on a rotating schedule encompassing 6 of the tubes in the steam generator if the results of the first or previous inspections indicate that both steam generators are performing in a like manner. Note that under some circumstances, the operating conditions in one steam generator may be found to be more severe than those in the other steam generator. Under such .
circumstances the sample sequence shall be modified to inspect the most
< severe conditions.
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l Change No. 13 j 4-56
RANCHO SECJ UNIT 1 TECHNICAL SPECIFICATIONS Surva111ance Standards TABLE 4.17-2A STEAM GENERATOR TUBE INSPECTION IST SAMPLE INSPECTION 2ND SAMPLE INSPECTION 3RD SAMPLE INSPECTION Sample Size Result Action Required Result Action Required Result Action Required A minimum of C-1 None N/A N/A N/A N/A S of the 134>< Tubes per C-2 Plug or repair defective C-1 None N/A N/A S.G. tubes and inspect 134,4 - additional 2S of C-2 Plug or repair defective C-1 None the tubes in this tubes and inspect 134>< S.G. additional 45 of the C-2 Plug or repair defective tubes i this S.G. tubes C-3 Perform action for C-3 result of first sample C-3 Perform action for C-3 N/A N/A result of first sample C-3 Inspect all tubes The other hone N/A N/A 134> in this S.G., plug or S.G. is
< repair defective tubes C-1 and inspect 25 of the tubes in the The other Perform action for C-2 N/A N/A other S.G. S.G. is result of second sample C-2 Notification to NRC pursuant to specification 6.9 The other Inspect all tubes in N/A N/A 134, S.G. is each S.G. and plug or
< C-3 repair defective tubes.
. Notification to NRC pursuant to specifica-tion 6.9 6
S = ii Where n is the number of steam generators inspected during an inspection Proposed Amendment No.134 4-57 J
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RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards TABLE 4.17-2B STEAM GENERATDR TUBE INSPECTION IST SAMPLE INSPECTION OF A " SPECIFIC LIMITED AREA" 2ND SAMPLE INSPECTION OF A " SPECIFIC LIMITED AREA
- Sample Size Result Action Required Result Action Required 100% of Area C-1 None N/A N/A in both OTSGs 134>< C-2 Plug or repair defective tubes N/A N/A 134>< C-3 Plug or repair defective tubes. N/A N/A Notification to NRC pursuant to specification 6.9.
100%'of Area C-1 None N/A N/A in one OTSG 134>< C-2 Plug or .vpair defective tubes and C-1 None inspect 100% of corresponding area in other OTSG.
134>< C-2 Plug or repair defective tubes 134 4 C-3 Plug or repair defective tubes 134>< C-3 Plug or repair defective tubes and C-1 None inspect 100% of corresponding area in 134,4 other OTSG. Notification to NRC pursuant to specification C-2 Plug or repair defective tubes 6.9.
134>< C-3 Plug or repair defective tubes Proposad Amendment No.134 4-57a M
RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards i TABLE 4.17-3 OTSG Auxiliary Feedwater Header Surveillance OTSG A Special Interest Tubes Row Tube No 5 1, 46 6 2, 3, 49, 50, 51 7 1, 2, 53, 54 8 1, 2, 56, 57 44 1, 119 45 1, 120 46 1, 121 47 1, 122 48 1, 123 49 1, 124 103 1, 124 105 1 106 1, 119 107 1, 120 108 1, 119 144 1, 2, 56, 57 145 1, 2, 53, 54 146 2, 3, 49, 50, 51 147 1, 46 l
Amendment No. 76 i 76>< 4-57b l I
. - - , - , , , ,-n-. .- - , - - --- - -,
RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Surveillance Standards TABLE 4.17-3 (Continued)
OTSG Auxiliary Feedwater Header Surveillance OTSG B Special Interest Tubes Row Tube No 5 1, 46 6 2, 3, 49, 50 7 1, 2, 53, 54 8 1, 2, 56, 57 44 1, 119 45 1, 120 46 1, 121 47 122 48 1, 123 49 1, 124 103 1, 124 104 123 105 122 106 1, 119 107 1, 120 108 1, 119 144 1, 2, 56, 57 145 1, 2, 53, 54 l
146 2, 3, 49, 50, 51 147 1, 46 l
l Amendment No. 76 76>< 4-57c t
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