RA22-051, Submittal of the Snubber Program Plan for the Fourth 10-Year Interval
| ML22320A046 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 11/16/2022 |
| From: | Hansett P Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| RA22-051 ER-LS-330-1008 Revision 0 | |
| Download: ML22320A046 (1) | |
Text
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LaSalle County Station 2601 North 21 51 Road Marseilles. IL 61341 815-415-2000 Telephone RA22-051 November 16, 2022 10 CFR 50.55a U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001
Subject:
LaSalle County Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374 LaSalle Station Submittal of the Snubber Program Plan for the Fourth 10-Year Interval In accordance with the American Society of Mechanical Engineers (ASME) Operations and Maintenance of Nuclear Power Plants (OM Code), Subsection ISTA-3200, "Administrative Requirements," paragraph (a), attached for your information is a copy of the Lasalle Station Snubber Program Plan for the fourth ten-year interval. The Lasalle Station fourth ten-year interval Snubber Program Plan complies with the requirements of the ASME OM Code 2004 Edition through the 2006 Addenda. The fourth ten-year interval for both Unit 1 and 2 began on October 12, 2017 and ends on October 11, 2027.
There are no regulatory commitments contained in this letter.
Should you have any questions concerning this letter, please contact Mr. Dan Mearhoff, Regulatory Assurance Manager, at (815) 415-2800.
Respectfully,
!%/;4r-Phil W. Hansett Site Vice President LaSalle County Station
Attachment:
ER-LS-330-1008, Revision 0, LaSalle County Generation station Units 1 & 2 Snubber Program Plan, Fourth Ten-Year Inspection Interval.
cc:
NRC Senior Resident Inspector - LaSalle County Station NRC Project Manager, NRR - LaSalle County Station NRC Regional Administrator, Region Ill Illinois Emergency Management Agency - Division of Nuclear Safety
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ER-LS-330-1008 Revision 0 Page 1 of 11 LASALLE COUNTY GENERATING STATION UNITS 1 &2 SNUBBER PROGRAM PLAN FOURTH TEN-YEAR INSPECTION INTERVAL Commercial Service Dates:
Unit 1-01/01/84 Unit 2-10/17/84 LaSalle County Generating Station 2601 N 21st Rd Marseilles, Illinois 61341 Constellation Energy Generation, LLC 4300 Winfield Road Warrenville, Illinois 60555
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SECTION TABLE OF CONTENTS DESCRIPTION ER-LS-330-1008 Revision 0 Page 2 of 11 PAGE 1.0 SNUBBER GENERAL REQUIREMENTS........................................................................ 3 2.0 VISUAL EXAMINATION, FUNCTIONAL TESTING, AND SERVICE LIFE MONITORING PROGRAM............................................................................................... 5 3.0 ASME OM CODE CASE OMN-13 IMPLEMENTATION............................................. 10 4.0 VISUAL EXAMINATION, FUNCTIONAL TESTING, AND SERVICE LIFE MONITORING RESULTS............................................................................................... 10 5.0 REPORTS/RECORDS...................................................................................................... 11 6.0 SNUBBER DATABASE................................................................................................... 11
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1.0 SNUBBER GENERAL REQUIREMENTS ER-LS-330-1008 Revision 0 Page 3 of 11 The LCGS Snubber Plan includes snubbers as defined in ASME OM Code 2004 Edition through the 2006 Addenda, Paragraph ISTA-2000. Procedures ER-AA-330-004, "Visual Examination of Snubbers," ER-AA-330-010, "Snubber Functional Testing," and ER-AA-330-011, "Snubber Service Life Monitoring," implement the ASME OM Code Snubber Plan.
(Note: The LCGS Support ISi Plan in the ISi Program Plan, Section 4.0, includes the supports (including snubbers) of ASME Section XI nonexempt ISi Class 1, 2, 3, and MC piping and components. Procedure ER-AA-330-003, "Inservice Inspection of Section XI Component Supports," implements the ASME Section XI Support ISi Plan.)
1.1 Nonexempt Code Class Snubbers The Class 1, 2, 3, and MC nonexempt snubbers are those which do not meet the exemption criteria of Paragraph IWF-1230 of ASME Section XI. These Class 1, 2, 3, and MC nonexempt snubbers are included in the scope of the ASME OM Code Snubber Program. A summary of the ASME OM Code snubbers is included in Section 4.0 of this document.
1.2 Identification of Class 1, 2, 3, and MC Nonexempt Snubbers Class 1, 2, 3, and MC nonexempt snubbers are identified on the ISi Isometric and Component Drawings listed in Section 2.4, Tables 2.4.1 and 2.4-2 of the LCGS ISi Program Plan. Class 1, 2, 3, and MC nonexempt snubbers are identified by controlled LCGS individual support detail drawings.
1.3 As required by 1 0CFR50.55a(b )(3)(v)(B), LCGS will use Subsection ISTD, "Inservice Testing of Dynamic Restraints (Snubbers) In Light Water Reactor Power Plants," ASME OM Code, 2004 Edition through the 2006 Addenda, to meet the visual examination (ISTD-4000), functional testing (ISTD-5000), and service life monitoring (ISTD-6000) requirements for safety related snubbers.
This approach is consistent with ASME Section XI, Paragraph IWF-1220, which excludes inservice inspection of snubbers and defers to the ASME OM Code for visual examination, functional testing, and service life monitoring requirements.
Per a NRC TS requirement, dated 10/20/1980, "All snubbers are required to be operable... " except for non-safety related snubbers whose failure would not have an adverse effect on a safety related system. At that time, non-safety related snubbers that were evaluated and added to the TS snubber population at LCGS.
These non-safety related snubbers were then removed from the Snubber Program during the conversion to the TRM. Thus, these non-safety related snubbers shall be treated and considered for snubber visual examination only as 'good engineering practice'. LCGS has chosen to consider the safety related TRM snubber population in accordance with TRM Section 3.7.i. (See details below).
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ER-LS-330-1008 Revision 0 Page 4 of I I Snubbers installed on non-safety related systems whose failure or failure of the system on which they are installed would have no adverse effect on any safety related system are excluded from the visual examination and functional testing requirements of the ASME OM Code. At LCGS Units I and 2, the non-safety related snubbers were procured and installed to the quality standards of safety related snubbers. As such, it is LCGS's plan to continue to maintain all non-safety related snubbers to quality standards. Therefore, this Snubber Program also provides examination requirements necessary for continued assurance of the quality of the subject non-safety related snubbers.
Example: the mechanical and hydraulic snubber functional testing sample shall consist of I 0% of each Defined Test Plan Group (DTPG) taken from the combined safety related TRM snubber population. Any failure within these test sample plan groups require an expansion sample per the applicable Subsection ISTD requirements.
The program snubber population may be categorized as Accessible or Inaccessible for small, medium or large bore snubbers and classified as Safety Related. Accessibility was determined based on snubber location and accessibility during reactor operations, consideration of manufacturers design characteristics, and plant operating conditions (radiation levels during plant operation, temperature and atmosphere). Accessible snubbers are those snubbers that can be inspected/examined during normal plant operating conditions; and Inaccessible snubbers are those snubbers that are in high radiation areas or other environments/conditions that would render it impractical for the snubbers to be examined during normal plant operation without exposing plant personnel to undue hazards. (Note: Typically, inaccessible snubbers are those snubbers located in containment during plant operation.) Although snubbers can be separated into Accessible or Inaccessible categories, the current LCGS categories are combined and considered as one population for the purpose of examinations.
This may be changed, as required, by the Snubber Program Owner and so documented prior to any scheduled interval examinations and shall not be changed during the examinations.
Procedure ER-AA-330-004, "Visual Examination of Snubbers," implements the visual examination program for safety related snubbers. Procedures ER-AA-330-010, "Snubber Functional Testing," ER-AA-330-011, "Snubber Service Life Monitoring Program," and site procedures L TS-600-11 and L TS-500-14 are used to implement the visual examination, functional testing, and service life monitoring requirements for safety related snubbers.
The ASME OM Code specifies the visual examination, functional testing, and service life monitoring requirements for snubbers in the ASME OM Code, Subsection ISTD. ASME Section XI also has inspection requirements for supports that apply to snubbers, as well as to other supports. This Snubber Plan is in place to provide a link between the visual examination and functional testing of
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ER-LS-330-1008 Revision 0 Page 5 of 11 the snubbers performed at LCGS per the ASME OM Code and the ASME Section XI visual examination requirements.
The general requirements of ASME Section XI, Subsection IW A, such as examination methods, personnel qualifications, etc., will still apply. Additionally, examination of integral and non-integral attachments, all repairs, replacements, records and reports will be performed in accordance with ASME Section XI.
2.0 Visual Examination, Functional Testing, and Service Life Monitoring Program 2.1 The visual examination of all snubbers included in this program shall be performed in accordance with procedures L TS-600-11, ER-AA-330-004, and ER-AA-335-016. The required examination schedule is determined by Paragraph ISTD-4252 and Table ISTD-4252-1 of the ASME OM Code.
This visual examination for snubbers is to verify: a) no indications of damage or impaired operability; b) attachments to foundations or supporting structure are functional, and c) fasteners for the snubber attachment to the component and to the anchorage are functional. The visual examination is to be performed in the as-found condition before the snubber is disconnected or removed for maintenance or functional testing and extends, as a minimum, from pin-to-pin connection, inclusive, also referred to as "pin-in".
The typical interval for visual examination for all snubbers is a normal fuel cycle, up to 24 months(+/- 25% to coincide with the actual plant outage). The examination scope for visual examinations performed during refueling outages is based on the results of the previous inspections as detailed in Table ISTD-4252-1.
(Per Note 2 in Table ISTD-4252-1, the examination interval may be as great as twice, the same, or as small as fractions of the previous interval as required by the associated notes in the table. The examination intervals may vary by +/- 25% of the current interval to coincide with the actual outage.)
A visual examination of all snubbers is to be performed according to the schedule in the Snubber Program. This examination schedule is based upon maintaining a constant level of snubber protection to each safety-related system. Therefore, the required examination interval is determined by the number of inoperable snubbers found during an examination of the total population of each category or group, and the previous examination interval.
As part of ASME Section XI, Subsection IWF, various snubbers require an additional visual examination outside of the ASME OM Code visual examination (pin-to-pin) requirement. These snubbers will be identified in the ISi Program and the Snubber Program prior to the outage scope and scheduling, so that the applicable snubbers can be examined for any additional requirements.
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ER-LS-330-1008 Revision 0 Page 6 of 11 The ASME Section XI visual examination boundary of a support containing a snubber is defined in Figure IWF-1300-l(f). This boundary does not include the snubber pin-to-pin and does not include the connections to the snubber assembly (pins) per Paragraph IWF-l300(h).
This results in the remaining ASME Section XI requirements for visual examinations of the snubber attachment hardware including bolting and clamps, also referred to as "pin-out". The ASME Section XI ISi Program uses Subsection IWF to define the inspection requirements for all Class 1, 2, 3, and MC supports, regardless of type. The ISi Program maintains the Code Class snubbers in the support populations subject to inspection per Article IWF-2000. This is done to facilitate scheduling, preparation including insulation removal, and inspection requirements of the snubber attachment hardware (e.g., bolting and clamps).
(Note: The visual examination and functional testing of the snubber body and extension will be performed in accordance with the ASME OM Code Snubber Program.)
The visual examination criterion for ASME Section XI snubbers is to determine that there are no visible indications of damage or impaired operability, and that fasteners for the attachment of the snubber to the piping system and to the associated building structure are functional.
When the ASME Section XI, visual examination is to be performed during a refueling outage, it will be performed before the snubber is disconnected or removed for maintenance or functional testing. The visual examination requirements for the ASME OM Code and ASME Section XI may be performed as separate scopes or performed as one at the same time, as long as the more stringent, applicable procedural requirements are met.
It should be noted that the examination of snubber welded attachments will be performed in accordance with the ASME Section XI Subsections IWB, IWC, and IWD welded attachment examination requirements (e.g., Examination Categories B-K, C-C, and D-A).
ASME OM Code and ASME Section XI visual examinations will be performed by individuals qualified in accordance with site procedures.
2.2 The functional testing of snubbers included in this program shall be performed in accordance with procedures LTS-500-14 and ER-AA-330-010. Functional testing shall be scheduled every fuel cycle in accordance with the ASME OM Code, Paragraph ISTD-5240.
During each refueling outage a representative sample of snubbers will be functionally tested according to the schedule determined by the Snubber Program, to verify inservice operability performance. (This testing cycle is based on 24-
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ER-LS-330-1008 Revision 0 Page 7 of 11 month plant refueling but may vary by +/- 25% to coincide with the actual shutdown).
Snubbers will be tested in their as-found condition, to the fullest extent practicable, with regard to the required test parameters and test methods and removal procedures, which will not alter the condition of a snubber to the extent that the results do not represent the as-found snubber condition.
Snubbers may be removed or tested in their installed location by using LCGS approved test methods and equipment. Snubbers may be tested using an "in-situ" test machine (in place testing) or a bench-type machine. Bench-type testing of the snubber is performed by securing the snubber at both ends and as such, requires the complete removal of the snubber from a plant location. "In-situ" testing of a hydraulic snubber follows the principle of pressuring fluid inside the snubber cylinder to perform various functional tests to determine lock-up velocities, bleed rates, and seal integrity. Using this technique, a snubber can be tested in-place without completely removing the snubber except, if required, the removal of one rod side pin for piston movement verification.
When the visual examination for operability or visual inspection as part of the ASME Section XI, Subsection IWF is to be performed during a refueling outage, it should be performed before the functional tests. When this inspection is not required, a visual check of the snubber for indications of service-related degradation and installation settings should be made before the snubber is disconnected or removed for functional testing.
A representative sample from each group/population is selected randomly, which as far as practical defines the various configurations, operating environments, ranges of sizes, and capacity of each group/type snubber. Selection may also be from snubbers concurrently scheduled for seal replacement or other similar activity related to maintenance or service life monitoring. The snubbers will be tested, as practical, dependent upon the plan groups selected, on a generally rotational basis that may coincide with the service life monitoring activity.
The sample plan will be selected prior to the test period. Changes can be made to this initial sample plan before testing begins as long as the sample does not decrease below the minimum required number, submitted for review, and then not changed during the test period. If the sample plan is not reviewed/approved prior to the test period, then the sample plan used in the prior test period will be implemented.
When selecting a snubber that is part of a tandem installation (parallel or multiple) even though they are identified and counted individually, the mate of that snubber may also be selected and credited toward the total number of snubbers required by any sampling plan. If a tandem snubber is deleted from the list, its mate may also be manually deleted.
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ER-LS-330-1008 Revision 0 Page 8 of ll ASME OM Code functional testing will be performed by individuals qualified in accordance with site procedures.
Snubbers are grouped into DTPG's by design type, in accordance with Paragraph ISTD-5252 for testing purposes. Snubbers at LCGS will be tested using the I 0%
testing sample plan. (See Section 3.3.2.2 below for Testing Sample Plan options.)
Functional testing of snubbers can be performed as a sampling of the entire snubber population per Article ISTD-5000.
2.2. I Defined Test Plan Group The DTPGs shall include all snubbers except replacement snubbers and snubbers repaired or adjusted as a result of not meeting the examination acceptance requirements of Subarticle ISTD-4200. These snubbers shall be exempt for the concurrent test interval. Spare snubbers shall be rebuilt using safety related parts and functionally tested in accordance with approved procedures and tagged with the date and results of the functional test.
Except as required by Paragraph ISTD-5253, the total snubber population may be considered one DTPG, or alternatively, differences in design, application, size, or group/type may be considered in establishing DTPG's.
The representative sample selected for the functional test will be randomly selected from the snubbers of each group/type and reviewed before beginning the testing. This review will ensure as far as practical, that they are representative of the DTPGs.
The snubbers at LCGS will be split into six (6) DTPG's -
DTPG-1 Mechanical Snubbers (PSA-1/4 and PSA-1/2)
(Accessible/Inaccessible)
DTPG-2 Mechanical Snubbers (PSA-1, PSA-3, and PSA-10)
(Accessible/Inaccessible)
DTPG-3 Mechanical Snubbers (PSA-35) (Accessible/Inaccessible)
DTPG-4 Hydraulic Snubbers (Lisega 30 Series)
(Accessible/Inaccessible)
DTPG-5 Hydraulic Snubbers (Lisega 30 Series - AK-350 Valves/AP-280 Fluid) (Temporary DTPG per ER-LS-330-1007)
DTPG-D+ Hydraulic Snubbers (Lisega 30 Series) (Safety Significant) (Accessible/Inaccessible) 2.2.2 Testing Sample Plans
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ER-LS-330-1008 Revision 0 Page 9 of 11 The snubbers of each DTPG shall be tested using either of the following:
(a) the 10% testing sample plan (LCGS's sample plan)
(b) the 37 testing sample plan Testing at LCGS will be conducted for each DTPG using the 10% testing sampling plan above, as applicable, where at least l 0% of the total of each group/type of snubber population will be functionally tested (fractional numbers will be rounded up).
Nonmandatory Appendix D includes a comparison of sample plans.
Snubber testing plans are presented in flow chart form in Nonmandatory Appendix E. A test plan shall be selected for each DTPG before the scheduled testing begins.
2.3 Service life monitoring of snubbers shall be performed in accordance with Article ISTD-6000 with the use of Nonmandatory Appendix F providing supplemental guida11ce. Nonmandatory Appendix F discusses methods and considerations that can be used to predict and reevaluate snubber service life to optimize snubber availability during plant operation. The service life monitoring program should be based on knowledge of the operating environment, snubber design limits, and service records. Additional implementation requirements for Service Life Monitoring are described in procedure ER-AA-330-011.
The object of service life monitoring is to identify service environment conditions and maintenance functions (rebuilds, handling, replacements) that can adversely affect snubber performance. Service life varies with manufacturer recommendations, design limits, actual conditions and materials, and should be adjusted based on plant experience and trending to ensure that the snubbers periodically undergo a performance evaluation.
The service life of all snubbers included in this program shall be monitored to ensure that the service life is not exceeded between examination/testing intervals.
The maximum expected service life for various seals, springs, and other critical parts shall be determined and established based on engineering information and shall be extended or reduced based on monitored test results and failure history.
Critical parts shall be replaced so that the maximum service life will not be exceeded during a period when the snubber is required to be operable.
The performance of snubbers is indicated by the results of functional tests.
Tracking and trending snubber performance may be required relating to snubbers installed in the same location and for snubbers that failed previous outage tests, due to location variables or unknown causes. When the same snubber has been tested several times, its test results may be reviewed to determine whether a trend is developing or if the snubber test values are degrading.
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ER-LS-330-1008 Revision 0 Page 10 of 11 Snubbers shall be replaced or reconditioned as required to ensure that the service life is not exceeded between examination/testing intervals, during a period when the snubber is required to be operable. The replacement or reconditioning shall be documented and records retained in accordance with ASME Section XI and site procedures.
If the indicated service life will be exceeded prior to the next scheduled snubber service life review, the snubber service life shall be re-evaluated or the snubber shall be replaced or reconditioned so as to extend its service life beyond the date of the next scheduled service life review.
3.0 ASME OM Code Case OMN-13, Revision 1 Implementation 3.1 ASME OM Code Case OMN-13, Revision 1 (OMN-13, Revision l) was implemented by meeting the applicable General and Specific requirements as addressed in corporate and site procedures and TAP 14 T-0 l S. During the Second ISi Interval, visual examinations were performed utilizing the VT-3 visual examination method on an every other outage frequency governed by TRM 3.7.i.
The last l 00% visual examination was performed successfully during the second period/ first outage for Unit l and the second period / second outage for Unit 2 of the Second ISi Interval. A maximum l 0-year visual examination frequency started from the date that the last visual examination was performed on each snubber.
Specific requirements of this ASME OM Code Case are addressed in TAP l4T-OlS.
4.0 Visual Examination, Functional Testing, and Service Life Monitoring Results 4.1 The results of the visual examinations and the functional tests will be evaluated using the criteria of the ASME OM Code and site procedures. ASME Section XI provisions may be used for supplemental guidance.
Snubbers that do not appear to conform to the Visual Examination requirements of procedure ER-AA-330-004, shall be reported for evaluation and appropriate corrective action.
Snubbers that do not appear to conform to the visual examination acceptance requirements and are later confirmed as operable as a result of functional testing may be declared operable for the purpose of establishing the next visual inspection interval, providing that the unacceptable condition did not affect operational readiness.
Snubbers that do not meet the operability testing acceptance criteria shall be evaluated to determine the cause of the failure and appropriate corrective action taken.
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ER-LS-330-1008 Revision 0 Page 11 of 11 The service life of all snubbers is evaluated using manufacturing input and engineering information gained through consideration of the snubber service conditions and in-service functional test results.
5.0 Reports/Records 5.1 The visual examination and functional testing results will be recorded and kept in accordance with the ASME OM Code and site procedures. Repair and replacement records and reports will be kept in accordance with ASME Section XI and site procedures.
Records of the service life of all hydraulic and mechanical snubbers listed in this program, including the date at which the service life commences or expires, and associated installation and maintenance records will be maintained. When snubbers are rebuilt or overhauled, the service life shall be updated which will provide future statistical bases for consideration of snubber service life.
Details of examinations and tests conducted under this program need not be included in the ASME Section XI Summary Report and Form NIS-1. An abstract of examinations completed may be provided in the Summary Report. Form NIS-2 shall be included in the Summary Report for any ASME Section XI repairs or replacements performed on the snubbers within the scope of this program.
6.0 Snubber Database 6.1 LCGS utilizes the "Snubb Works" database as a tool to manage and maintain the ASME OM Code related snubber components, examination, testing, and service life data. The database contains information on all applicable installed and spare snubbers and the associated plant safety related locations for the Snubber Program.
In order to build and maintain the Snubber Program database, information from the applicable Snubber Program examination and testing data sheets should be transferred into the database to build historical files for each location and individual snubber. When a snubber is replaced, added, or removed from the plant location or is moved from one location to another and a spare snubber put in its place, the database should be updated to maintain program integrity.
(Note: LCGS utilizes the "Schedule Works" database as a tool to manage and maintain the ASME Section XI related snubber components and examination data.)