ML20247E736
| ML20247E736 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 05/06/1998 |
| From: | Thomas S HOUSTON LIGHTING & POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9805180446 | |
| Download: ML20247E736 (8) | |
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Nuclear Operating Company South Tcaasnrptih1rkGmerstogSutkm m &w289 YMmwth Taas77483 m.
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May 6, 1998 l
NOC-AE-000139
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File No.: G03.16 l
10CFR50.59 STI: 30601877 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 South Texas Project Units I and 2 Docket Nos. STN 50-498, STN 50-499 Response to Request for Additional Information on Elimination of Environmental Qualification of Mechanical Components
Reference:
Letter to Mr. William T. Cottle, STP Nuclear Operating Company, from Mr. T.
I Alexion, Nuclear Regulatory Commission, dated April 8,1998 (AE-NOC-0126)
Pursuant to the request for additional information referenced above, the South Texas Project submits the attached responses to the Nuclear Regulatory Commission's questions regarding Unreviewed Safety Question Evaluation 95-0044," Elimination of the Environmental Qualification of the Mechanical Components at STP."
This letter provides the information requested by the Nuclear Regulatory Commission and is not considered to contain any further commitments.
l If there are any questions, please contact Mr. G. C. Sandlin at (512) 972-7543 or me at (512) 972-7162.
S. E. Thomas
- Manager, Design Engineering kaw l
Attachment:
Response to Request for Additional Information on Elimination of Environmental Qualification of Mechanical Components
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k' 9805180446 900506 l
PDR ADOCK 05000498 P
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NOC-AE-000139 File No.: G03.16 Page 2 Ellis W. Merschoff Jon C. Wood Regional Administrator, Region IV Matthews & Branscomb U. S. Nuclear Regulatory Commission One Alamo Center 611 Ryan Plaza Drive, Suite 400 106 S. St. Mary's Street, Suite 700 Arlington, TX 76011-8064 San Antonio,TX 78205-3692 Thomas W. Alexion Institute of Nuclear Power Project Manager, Mail Code 13H3 Operations - Records Center U. S. Nuclear Regulatory Commission 700 Galleria Parkway Washington, DC 20555-0001 Atlanta, GA 30339-5957 David P. Loveless Richard A. Ratliff Sr. Resident Inspector Bureau of Radiation Control c/o U. S. Nuclear Regulatory Commission Texas Department of Health P. O. Box 910 1100 West 49th Street Bay City, TX 77404-0910 Austin, TX 78756-3189 J. R. Newman, Esquire D. G. Tees /R. L. Balcom Morgan, Lewis & Bockius Houston Lighting & Power Co.
1800 M. Street, N.W, P. O. Box 1700 Washington, DC 20036-5869 Houston,TX 77251 M. T. Hardt/W. C. Gunst Central Power and Light Company City Public Service A'ITN: G. E. Vaughn/C. A. Johnson P. O. Box 1771 P. O. Box 289, Mail Code: N5012 San Antonio,TX 78296 Wadsworth,TX 77483 A. Ramirez/C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin,TX 78704
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l Response to Request for Additional Information on Elimination of Environmental Qualification of Mechanical Components I) a) Question: What are the differences between the Mechanical EQ Program that was previously in the Updated Final Safety Analysis Report (UFSAR) and what is currently in the UFSAR to replace the program?
Answer: Under the old South Texas Project (STP) Mechanical Environmental Qualification (MEQ) program a database was maintained tojustify General Design Criteria-4 (GDC-4) compliance. The MEQ database included evaluations of safety related mechanical equipment in accordance with Paragraph 3.11.2 of the previous UFSAR.
In order to comply with GDC-4 of Appendix A to 10 CFR Part 50 for mechanical equipment, reviews and evaluations were performed to include the following: (Refer to UFSAR 3.11.2, Rev.0)
Identification of safety-related mechanical equipment located in harsh environmental areas Identification of the non-metallic sub-components in mechanical equipment e
Identification of the environmental conditions for which these components must be qualified Identification of non-metallic materials capabilities Under the new program, with the elimination of the MEQ Program, evaluations documented in the above MEQ database are no longer utilized to justify GDC-4 compliance for safety related mechanical components. Instead GDC-4 compliance is being maintained through the STP Procurement, Maintenance and Surveillance programs. Under the STP Maintenance Program, routine monitoring of mechanical i
equipment is performed to prevent failure of critical parts due to aging. In addition, the program verifies mechanical equipment safety function is maintained in normal, abnormal and accident environments. The Procurement, Maintenance and Surveillance programs at STP provide reasonable assurance and take necessary corrective actions to maintain the equipment in the best operating condition based on the following documentation:
Vendor Certification (Certificate of Compliance) e Design and Purchase Specification for Replacement Parts e
Material Evaluation for Replacement Parts e
The South Texas Project Procurement Program, in conjunction with Maintenance and l
Surveillance programs, is adequate to provide reasonable assurance that the safety I
related mechanical equipment and components will remain operable in applicable harsh and normal environmental conditions. Documentation generated through the Procurement, Maintenance and Surveillance programs demonstrates compliance with GDC-4 and meets requirements of Standard Review Plan Section 3.11.
NOC-AE-0139 Page 2 of 6
Answer: No. A complete list of safety related equipment was provided in the 10 CFR 50.49 submittal. (Refer to Section 3.11.1 of UFSAR, Rev.0)
- 1) c) Question: Are there any components that were in the Mechanical EQ program that do not have any maintenance, surveillance orperiodic testing associa:ed with them in the current UFSAR?
Answer: All safety-related mechanical equipment / components are subject to maintenance, surveillance and periodic testing.
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Question: Section A.I.III of the USQE #95-0044 states "...out of 2578 safety related mechanical components, 2527 components do not require replacement or refurbishment during 40-year hfe of the plant and therefore do not require any EQ related maintenance activities. " However, ifone of the 2527 components had to be replaced within the 40-year hfe of the plant, what controls would be in place to ensure that the replacement component would be processed through the appropriate design andprocurementprocess ?
Answer: All replacement parts procured for safety related mechanical equipment are controlled by purchase specifications. In the event the exact part is no longer available, an item Equivalency Evaluation is initiated to demonstrate and confirm that the design and performance of the equipment have not been compromised by the change in the material or construction of the replacement part, and that the environmental capabilities of the replacement part is either equal to or better than the existing part. If the replacement part is determined to be not equivalent to the existing part based on the Item Equivalency Evaluation, a Design Chan,e is processed.
- 3) a) Question: What types ofcomponents are included in the remaining 51 components that do require replacement or refurbishment during the 40-year hfe of the plant?
Answer: The types of components included in the remaining 51 components include valves, equipment (i.e. dampers, door, cabinets), pumps, and instruments such as actuators.
At the time the Mechanical Environmental Qualification program was eliminated from the South Texas Project Equipment Qualification program, there were 51 components with non-metallic parts which were critical for GDC-4 compliance.
These components included non-metallic parts with a qualified life of 40 years or less.
Since MEQ is no longer applicable at STP, the replacement of these non-metallic components during 40 year life of the plant is controlled by the following STP Procurement, Maintenance, Surveillance Testing and Periodic Testing Programs:
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NOC-AE-0139 Page 3 of 6 STP Procurement Program provides detailed and sophisticated control of parts and effectively evaluates any changes in the material. These activities are necessary to support the equipment safety function and GDC-4 compliance. STP performs l
analyses and initiates Technical Evaluations prior to de-classification of parts in l
safety related equipment.
The Preventive Maintenance Program at STP contributes to plant safety by analyzing I
equipment vendor recommendations, including equipment /part replacement based on environmental aging of non-metallic parts, as necessary, to maintain equipment reliability per the Preventive Maintenance Identification Guide and Preventive Maintenance Program.
At STP, the requirements for performing preventive maintenance and monitoring conditions in order to maintain equipment in satisfactory operating condition are invoked in the STP Preventive Maintenance Procedure.
In order to verify the effectiveness of the Procurement and Maintenance / Surveillance l
programs in maintaining compliance with GDC-4, the maintenance / surveillance program data and records are reviewed periodically in accordance with the ASME Section XI testing to ensure that the equipment has not suffered any degradation which may include the effects of thermal, radiation and/or cyclic aging.
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- 3) b) Question: Are these components safety-related?
l Answer: Yes. All components that were included in the South Texas Project MEQ program are safety-related Active or Passive components.
- 3) c) Question: What controls are in place to ensure that the replacement components would be processed through the appropriate design and procurement process?
Answer: As stated in an earlier answer, all replacement parts procured for safety related mechanical equipment are controlled by purchase specifications. In the event the exact part is no longer available, an Item Equivalency Evaluation is initiated to demonstrate and confirm that the design and performance of the equipment have not been compromised by the change in the material or construction of the replacement part, and that the environmental capabilities of the replacement part is either equal to or better than the existing part. If the replacement part is determined to be not equivalent to the existing part based on the Item Equivalency Evaluation, a Design Change is processed.
- 4) a) Question: Does the FIT, FORM, and FUNCTION methodology used in the item Equivalency Evaluation identify the non-metallic material capabilities of components and their replacements?
Answer: Yes.
Attachment I
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NOC-AE-0139 Page 4 of 6
- 4) b) Question: How does the FIT, FORM and FUNCTION methodology evaluate the environmental effects of non-metallic material in components and their replacements?
Answer: An item Equivalency Evaluation is performed to determine part equivalency. An item Equivalency Evaluation includes consideration of environmental effects of non-metallic materials.
- 4) c) Question: Does this methodology inc:ade a 10.R screen to identify when a design change exists?
Answer: An Item Equivalency Evaluation is performed to determine part equivalency. An Item Equivalency Evaluation does not involve a change to the facility as described in I
the SAR or involve a test or experiment not described in the SAR because the part is demonstrated as equivalent to the existing part by the Item Equivalency Evaluation.
If the part is not equivalent a design change is processed with a proposed change to the facility.
The South Texas Project does not use a 50.59 evaluation to determine if a design change exists. A 50.59 evaluation is used for changes to the facility or procedures as described in the SAR to determine ifit involves an unreviewed safety question. Also, a 50.59 evaluation is used to evaluate tests or experiments not described in the SAR to determine if an unreviewed safety question exists.
- 4) d) Question: Does the methodology provide a mechanism to send the change through the design change process, if necessary ?
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Answer: A design change is processed if an Item Equivalent Evaluation determines a replacement part to be not equivalent to the existing part.
5)
Question: How do the maintenance, surveillance, and periodic testing currently at STP detect aging mechanisms?
Answer: The South Texas Project continually monitors system and component performance through preventive maintenance, surveillance testing, and periodic testing.
Degradation or reduction in performance beyond established limits results in corrective actions to identify the cause of the degradation and institute corrective and preventive measures.
- 6) a) Question: Section A.3.1 of Unreviewed Safety Question Evaluation #95-0044 states that the STP Surveillance Program is in place to venfy the operability ofsafety-related mechanical equipment with non-metallic parts. Does the surveillance program include testing non-metallic partsfor harsh environments?
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NOC-AE-0139 Page 5 of 6 Answer: The old Mechanical Equipment Qualification (MEQ) Program included a well established program of preventive maintenance and surveillance testing, and a review of non-metallic parts which may be degraded by thermal, radiation, or wear aging. An evaluation was perfomled for each non-metallic part in safety related mechanical equipment based on degradation caused by thermal, radiation or wear aging. The results of this evaluation were included in a data base as part of the MEQ program.
For parts identified in this database with a life of 40 years or less, a preventive maintenance instruction was generated for maintenance of these parts to ensure that GDC 4 requirements were implemented.
The Surveillance Testing Program implements surveillance tests as required by the Technical Specifications. Technical Specifications do not specifically require testing of non-metallic parts for harsh environments. However, the program is written to ensure that equipment and components are maintained in the best operating condition.
This includes assessment of the condition of non-metallic parts to ensure that degradation is identified.
After this program was determined to be well established, the information included in the MEQ data base was evaluated by USQE 95-0044 to be redundant. Preventive Maintenance (PM) instructions that were generated as a result of the MEQ program were left in place, and if a change to a PM is required, engineering evaluation of this change is performed. The program now consists of the identified pans, PMs to replace certain parts, Engineering Evaluation of changes, and surveillance's to verify operability. Placing parts in a harsh environment for testing purpose is not a part of I
the program.
- 6) b) Question: Explain how the testing is perfonned.
Answer: Testing is performed as delineated in the STP approved surveillance test procedures, including Local Leak Rate Tests, Valve Stroke Tests, and Inservice Tests.
Results of above surveillance tests provide reasonable assurance and help to take necessary corrective actions in order to maintain the equipment in the best operating condition.
The periodic testing program verifies safety related equiprnent is within performance specification requirements.
The equipment surveillance program includes periodic inspections, analysis of equipment and components failures, and a review of the results of periodic testing program.
The well supported maintenance and surveillance programs, in conjunction with the procurement program at STP, assure that the equipment is in compliance with GDC-4 requirements, ineets the equipment Design and Purchase specifications, and is i
l qualified for the design life.
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NOC-AE-0139 Page 6 of 6 t
Furthermore, the Preventive Maintenance and Surveillance Programs data and records are periodically reviewed to ensure that the design qualified life has not suffered thermal and/or radiation degradation resulting from environmental stresses due to its service condition. The engineering department is used to modify the replacement program and/or replace the equipment as deemed necessary.
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