ML18152A279
| ML18152A279 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 08/28/1998 |
| From: | Hartz L VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 98-288, NUDOCS 9809040227 | |
| Download: ML18152A279 (26) | |
Text
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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 August 28, 1998 United Stated Nuclear Regulatory Commission Attention: Document Control Desk Washington D.C. 20555 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 ASME SECTION XI RELIEF REQUESTS SUBSECTIONS IWE AND IWL Serial No.:
98-288 NL&OS/GDM R3 Docket Nos.: 50-280, 281 License Nos.: DPR-32, 37 Surry Power Station Units 1 and 2 are presently in the third ten-year lnservice Inspection Interval, and examinations are conducted in accordance with the requirements of the 1989 Edition of ASME Section XI. In Federal Register Notice 154 (Volume 61 ), dated August 8, 1996, the Nuclear Regulatory Commission amended 10 CFR 50.55a to incorporate by reference the 1992 Edition with the 1992 Addenda of Subsections IWE and IWL. The effective date of the amended rule was September 9, 1996.
The rule requires expedited implementation of the first period examination requirements within five years from the effective date of the rule, which is September 9, 2001.
Pursuant to 10 CFR 50.55a(a)(3), relief is requested from certain requirements of the Subsections IWE and IWL of the 1992 Edition with the 1992 Addenda of ASME Section XI.
The relief requests and the bases for the reliefs are included in Attachments 1 and 2 for Surry Units 1 and 2, respectively. Relief is requested from Subsections IWE and IWL of Code requirements based on proposed alternatives that would provide an acceptable level of quality and safety. These Relief Requests have been reviewed and approved by the Station Nuclear Safety and Operating Committee:
If you have any questions or require additional information, please contact us.
Very truly yours,
~~ViJ:iC'i8 L. N. Hartz Vice President - Nuclear Engineering and Services Commitments made in this letter: None Attachments 980C:,O'f0~27~98082B PDR ADOCK 05000280 G
('
cc:
U.S. Nuclear Regulatory Commission Region II Atlanta federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303 R. A. Musser NRC Senior Resident Inspector Surry Power Station
r ASME Code Subsections IWE and IWL Relief Requests IWE-2, 4 through 6 and IWL-2 Virginia Electric and Power Company Surry Power Station Unit 1
t Virginia Electric & Power Company Surry Power Station Unit 1 First Containment Inspection Interval Relief Request RR-IWE2 SYSTEM/COMPONENT(S) FOR WHICH RELIEF IS REQUESTED Seals and gaskets of Class MC pressure retaining components, Examination Category E-D, Item Numbers E5.10 and E5.20 of IWE-2500, Table IWE-2500-1, ASME Section XI, 1992 Edition, and 1992 Addenda.
CODE REQUIREMENT(S):
IWE-2500, Table IWE-2500-1 requires seals and gaskets on airlocks, hatches, and other devices to be visually examined, VT-3, once each interval to assure containment leak-tight integrity.
CODE REQUIREMENT FROM WHICH RELIEF 15 REQUESTED:
Relief is requested from performing the Code-required visual examination, VT-3, on the above identified metal containment seals and gaskets.
BASIS FOR RELIEF:
The components discussed below contain seals and gaskets.
Electrical Penetrations Electrical penetrations use a header plate attached to a containment penetration nozzle flange with redundant 0-rings between the header plate and flange face.
Modules through which electrical conductors pass are installed in the header plate.
One type, manufactured by Amphenol, uses seals and gaskets to assure leak tight integrity.
A second type, manufactured by Conax, uses a set of compression fittings. Replacement modules for the Amphenol penetrations use a combination of 0-rings and compression fittings. These seals and gaskets cannot be inspected without aisassembly of the penetration to gain access to the seals and gaskets.
Containment Personnel, Equipment, and Emergency Escape Hatches The personnel, equipment, and emergency escape hatches utilize an inner and outer door with gasketed surfaces to ensure a leak tight integrity. These hatches also contain other gaskets and seals such as electrical penetrations and equalizing
pressure connections that require disassembly to gain access to the gaskets and seals.
Fuel Transfer Tube The fuel transfer tube utilizes a blank flange inside containment with redundant 0-rings between the header plate and flange face.
Per 1 OCFRSO Appendix J, seals and gaskets receive a Type B test. As noted in the CFR, the purpose of Type B tests is to measure leakage of containment or penetrations whose design incorporates resilient seals, gaskets, sealant compounds, and electrical penetrations fitted with flexible metal seal assemblies. For those penetrations that are routinely disassembled, a Type B test is required upon final assembly and prior to start-up.
For those penetrations that are not routinely disassembled, Table IWE-2500-1, Category E-D, Note 1 (1993 Addenda and later) states "Sealed or gasketed connections need not be disassembled solely for the purpose of examination." Therefore, these seals and gaskets would not be visually examined.
Table IWE-2500-1, Category E-P, Item E9.40, requires performance of an Appendix J Type B test for seals and gaskets. Since the Type B test will assure the leak tight integrity of primary containment at the same frequency as that of the Code visual exams, the performance of the visual examination is redundant and will not increase the level of safety or quality.
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii).
Compliance with the visual examination of seals and gaskets in accordance with IWE-2500, Table IWE-2500-1, Category E-D is a burden without any compensating increase in the level of safety or quality. Visual examination of seals and gaskets will not ensure leak tight integrity.
Implementing an ASME Section XI Code program to perform these examinations is the unnecessary administrative burden. Testing the seals and gaskets in accordance with 1 OCFRSO Appendix J is superior to performing a visual examination and provides assurance of the leak-tight integrity of the seals and gaskets.
The Appendix J testing frequency is greater than that of ASME Section XI and, therefore, is more conservative and provides a greater level of safety.
Appendix J testing is a superior alternative method of establishing seal integrity.
ALTERNATIVE EXAMINATION(S):
The leak-tightness of seals and gaskets will be tested in accordance with 1 OCFRSO Appendix J. The 1 OCFRSO Appendix J Type B testing is performed at least once each inspection interval.
e e
Virginia Electric & Power Company Surry Power Station Unit 1 First Containment Inspection Interval Relief Request RR-IWE4 SYSTEM/COMPONENT(S) FOR WHICH RELIEF IS REQUESTED:
All Class MC, Paragraphs IWE-2420(b) and -IWE-2420(c) successive examination requirements for components found acceptable for continued service.
CODE REQUIREMENT(S):
Paragraphs IWE-2420(b) and IWE-2420(c) of the 1992 Edition, 1992 Addenda of ASME Section XI require that when component examination results require evaluation of flaws, evaluation of areas of degradation, or repairs in accordance with Article IWE-3000, and the component is found to be acceptable for continued service, the areas containing such flaws, degradation, or repairs shall be reexamined during the next inspection period listed in the schedule of the inspection program of Paragraph IWE-2411 or Paragraph IWE-2412, in accordance with Table IWE-2500-1, Examination Category E-C.
CODE REQUIREMENT FROM WHICH RELIEF IS REQUESTED:
Relief is requested from the requirement of Paragraphs IWE-2420(b) and IWE-2420(c) to perform successive examination of repairs.
BASIS FOR RELIEF:
The purpose of a repair is to restore the component to an acceptable condition for continued service in accordance with the acceptance standards of Article IWE-3000.
Paragraph IWA-4150 requires the owner to conduct an evaluation of the suitability of the repair including consideration of the cause of failure.
If the repair has restored the component to an acceptable condition, successive examinations are not warranted. If the repair was not suitable, then the repair does not meet code requirements and the component is not acceptable for continued service.
Neither Paragraph IWB-2420(b), Paragraph IWC-2420(b), nor Paragraph IWD-2420(b) requires a repair to be subject to successive examination requirements. Furthermore, if the repair area is subject to accelerated degradation, it would still require augmented examination in accordance with Table IWE-2500-1, Examination Category E-C. The successive examination of repairs in accordance with Paragraphs IWE-2420(b) and IWE-2420(c) constitutes a burden without a compensating increase in quality or safety.
e e
In their resolution to public comment #3.3, the NRG stated, "The purpose of IWE-2420(b) is to manage components found to be acceptable for continued service (meaning no Tepair or replacement at this time) as an Examination Category E-C component... If the component had been repaired or replaced, then the more frequent examination would not be needed."
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii).
Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Successive. examinations in accordance with Paragraphs IWE-2420(b) and IWE-2420(c) are not required for repairs made in accordance with Article IWA-4000.
I~
Virginia Electric & Power Company Surry Power Station Unit 1 First Containment Inspection Interval Relief Request RR-IWES SYSTEMS/COMPONENTS FOR WHICH RELIEF IS REQUESTED:
Class MC pressure retaining bolting.
CODE REQUIREMENT(S):
ASME Section XI 1992 Edition with the 1992 Addenda, Table IWE-2500-1, Examination Category E-G, Pressure Retaining Bolting, Item 8.20.
CODE REQUIREMENT FROM WHICH RELIEF IS REQUESTED:
Relief is requested from ASME Section XI 1992 Edition with the 1992 Addenda, Table IWE-2500-1 Examination Category E-G, Pressure Retaining Bolting, Item 8.20. Bolt torque or tension testing is required on bolted connections that have not been disassembled and reassembled during the inspection interval.
BASIS FOR RELIEF:
Bolt torque or tension testing is required on bolted connections that have not been disassembled and reassembled during the inspection interval.
Determination of the torque or tension value would require that the bolting be de-torqued and then re-torqued or re-tensioned.
Each penetration receives a 1 OCFR50 Appendix J Type B test in accordance with the testing frequencies specified in Appendix J. As noted in 1 OCFR50 Appendix J, the purpose of Type B tests is to measure leakage of containment penetrations whose design incorporates resilient seals, gaskets, sealant compounds, and electrical penetrations fitted with flexible metal seal assemblies. The performance of the Type B test itself proves that the bolt torque or tension remains adequate to provide a leak rate that is within acceptable limits. The torque or tension value of bolting only becomes an issue if the leak rate is excessive. Once a bolt is torqued or tensioned, it should not be subject to any dynamic loading that could cause it to experience significant change.
Appendix J testing and visual inspection is adequate to demonstrate that the design function is met. Torque or tension testing is not required on any other ASME Section XI Class 1, 2, or 3 bolted connections or their supports as part of the inservice inspection program.
-f.
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii). Bolt torque or tension testing of bolted connections which are verified not to experience unacceptable leakage through 1 OCFR50 Appendix J Type B testing is considered to be a hardship or unusual difficulty without a compensating increase in the level of quality and safety.
ALTERNATE EXAMINATION(S):
The following examinations and tests required by Subsection IWE ensure the structural integrity and the leak-tightness of Class MC pressure retaining bolting, and, therefore, no additional alternative examinations are proposed:
(1)
Exposed surfaces of bolted connections shall be visually examined in accordance with requirements of Table IWE-2500-1, Examination Category E-G, Pressure Retaining Bolting, Item No. ES.10, and (2)
Bolted connections shall meet the pressure test requirements of Table IWE-2500-1, Examination Category E-P, All Pressure Retaining Components, Item E9.40.
- t e
e Virginia Electric & Power Company Surry Power Station Unit 1 First Containment Inspection Interval Relief Request RR-IWE6 SYSTEM/COMPONENT($) FOR WHICH RELIEF IS REQUESTED:
Surface areas subject to augmented examination in accordance with Subsection IWE of the 1992 Edition, 1992 Addenda of ASME Section XI.
CODE REQUIREMENTS:
ASME Section XI 1992 Edition, 1992 Addenda, Subarticle IWE-2500(c)(3) requires one foot square grids be used when ultrasonic thickness measurements are performed on augmented examination surface areas.
The number and location of the grids is determined by the Owner.
Subarticle IWE-2500(c)(4) requires the minimum wall thickness within each grid be determined.
CODE REQUIREMENTS FROM WHICH RELIEF IS REQUESTED:
Relief is requested from using one-foot square grids for augmented examination areas and the requirement to determine the minimum wall thickness within each grid.
BASIS FOR RELIEF:
Subarticles IWE-2500(c)(3) and IWE-2500(c)(4) of the 1992 Edition, 1992 Addenda of ASME Section XI requires that the minimum thickness within each one foot square grid of surface areas requiring augmented examination be marked such that periodic reexamination of that location can be performed.
Thickness readings are point readings. Numerous readings are necessary to identify the minimum thickness within each grid. This only identifies the thinnest area. Periodic examination of the minimum thickness point only monitors that point.
It may not be the area that is the most susceptible to accelerated degradation.
Table RR-IWE6 (attached) provides an alternative to the one foot square grid area required by IWE-2500(c)(3).
Table RR-IWE6 requires examination at the grid line intersections. The grid line intersections may not exceed 12 inches and may be as small as 2 inches.
For a sample area of 50 square feet, Table RR-IWE6 requires a minimum of 100 locations to be monitored. For a sample area of 50 square feet, IWE-2500(c)(3) would require only 50 locations to be monitored.
In this instance, utilizing Table RR-IWE6 monitors more locations than required by IWE-2500(c)(3).
I~
e For sample areas greater than 100 square feet, Table RR-IWE6 requires that sufficient points be monitored to ensure at least a 95% confidence level that the thickness of the base metal is reduced by no more than 10% of the nominal plate thickness at 95% of the grid line intersections. Table RR-IWE6 also requires additional examinations when any measurements reveal wall thickness is reduced by more than 10% of the nominal plate thickness.
For all examination areas, should the measurements at a grid line intersection reveal that the base material is reduced by more than 10% of the nominal plate thickness, Table RR-IWE6 requires the minimum wall thickness within each adjoining grid be determined. This is similar to the examination requirements of IWE-2500(c)(4) except that Table RR-IWE6 focuses resources on areas that have exhibited degradation rather than areas that have not exhibited degradation.
The Flow Accelerated Corrosion programs presently in place have proven that thickness readings taken at grid intersections are effective in monitoring wall thinning of piping.
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii).
Taking numerous ultrasonic thickness readings within a grid that had not exhibited degradation results in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Alternative Examination(s):
Table RR-IWE6 will be used to determine examination requirements for ultrasonic thickness measurements of areas requiring augmented examination.
Notes:
TABLE RR-IWE6 ULTRASONIC THICKNESS MEASUREMENTS FOR AUGMENTED EXAMINATIONS Augmented Examination Area Size (Contiguous)
Examination Requirements
~100 square feet 100% of Grid Line Intersections 1*2*3*5*6
>1.00 square feet 100% of Grid Line Intersections 1*2*4*5*6
- 1.
The number, location and size of areas to be examined shall be determined by the Owner.
- 2.
Grid line spacing shall not exceed 12 inches, and need not be less than 2 inches.
- 3.
Grid line spacing shall be selected such that a minimum of 100 measurements are obtained from within each augmented examination area, unless this requires selecting a grid line spacing of less than 2 inches.
- 4.
In lieu of examining 100% of the grid line intersections within the augmented examination area, an alternate examination plan may be developed as follows:
(a) A sample area frbm within the augmented examination area may be selected for examination. The location and size of the sample area shall be determined by the Owner, but shall consist of areas subject to the most severe service conditions within the larger augmented examination area.
100% of the gri~ line intersections within the sample area shall be examined, and grid line spacing shall be selected such that a minimum of 100 measurements is obtained from within the sample areas.
(b) If the sample area exceeds 100 contiguous square feet, the Owner may develop a sampling plan for examination of grid line intersections within the sample area. Locations of ultrasonic thickness measurements to be taken at grid line intersections shall be selected at random throughout the sample area. The minimum number of measurements shall be 100, or shall be sufficient to ensure at least a 95% confidence level that the thickness of the base metal is reduced by no more than 10% of the nominal plate thickness at 95% of the grid line intersections within the sample area, whichever is greater.
(c) If any ultrasonic thickness measurements within the sample area reveal that the thickness of the base metal is reduced by more than 10% of the nominal plate thickness, all remaining grid line intersections within the sample area shall be examined, and additional UT examinations from outside of the sample area shall be required. These additional UT examinations shall be performed on another area from within the larger augmented examination area that is at least as large as the initial sample area. If any of these subsequent examinations reveal that the thickness of the base metal is reduced by more than 10% of the nominal plate thickness, additional areas from within the larger augmented examination area shall be examined until subsequent examinations of additional areas reveal no measurements where metal loss exceeds 10% of the nominal plate thickness, or until the entire augmented examination area has been examined.
- 5.
When an ultrasonic thickness measurement performed at a grid line intersection reveals that the thickness of the base metal is reduced by more than 10%
of the nominal plate thickness, the minimum wall thickness shall be determined and located within each adjoining grid.
- 6.
Measurements need not be obtained at locations where obstructions interfere with grid line intersections.
e
Virginia Electric & Power Company Surry Power Station Unit 1 First Containment Inspection Interval Relief Request RR-IWL2 SYSTEM/COMPONENT(S) FOR WHICH RELIEF IS REQUESTED:
All components subject to examination in accordance with Subsection IWL of the 1992 Edition, 1992 Addenda of ASME Section XI.
CODE REQUIREMENTS:
Subarticle IWA-2210 provides requirements for visual examination procedures.
CODE REQUIREMENTS FROM WHICH RELIEF IS REQUESTED:
Relief is requested from the provisions of Table IWA-2210-1.
Direct visual VT-3 examinations require a minimum illumination of 50 fc, and a maximum examination distance of 4 feet.
The procedure must be demonstrated to resolve a lower case character height of 0.105 inches.
BASIS FOR RELIEF:
In addition to the requirements of Subsection IWL, the requirements of the 1992 Edition, 1992 Addenda of Subsection IWA for containment examinations are applicable.
For VT-3C examinations performed in accordance with Subsection IWL, the examination distance and illumination requirements are the same as for that specified for VT-3 in Table IWA-2210-1.
For remote examination of IWE components, 1 OCFR50.55a permits the maximum direct examination distance specified in Table IWA-2210-1 to be extended and the minimum illumination requirements specified in Table IWA-2210-1 to be decreased provided that the conditions or indications for which the visual examination is performed can be detected at the chosen distance and illumination. This amendment to the requirements of Table IWA-2210-1 can be extended to examination. of IWL items provided the indications for which the visual examination is performed can be detected at the chosen distance and illumination.
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii).
Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Alternative Examination(s):
VT-3C
- visual examinations will be performed under distance and illumination requirements necessary to detect the conditions or indications for which the visual examination is performed. The procedure will be demonstrated capable of detecting conditions or indications for which the examination is being performed.
ASME Code Subsections IWE and IWL Relief Requests IWE-2, 4 through 6 and IWL-2 e
Virginia Electric and Power Company Surry Power Station Unit 2
e e
Virginia Electric & Power Company Surry Power Station Unit 2 First Containment Inspection Interval Relief Request RR-IWE2 SYSTEM/COMPONENT(S) FOR WHICH RELIEF IS REQUESTED Seals and gaskets of Class MC pressure retaining components, Examination Category E-D, Item Numbers E5.10 and E5.20 of IWE-2500, Table IWE-2500-1, ASME Section XI, 1992 Edition, and 1992 Addenda.
CODE REQUIREMENT(S):
IWE-2500, Table IWE-2500-1 requires seals and gaskets on airlocks, hatches, and other devices to be visually examined, VT-3, once each interval to assure containment leak-tight integrity.
CODE REQUIREMENT FROM WHICH RELIEF IS REQUESTED:
Relief is requested from performing the Code-required visual examination, VT-3, on the above identified metal containment seals and gaskets.
BASIS FOR RELIEF:
The components discussed below contain seals and gaskets.
Electrical Penetrations Electrical penetrations use a header plate attached to a containment penetration nozzle flange with redundant 0-rings between the header plate and flange face.
Modules through which electrical conductors pass are installed in the header plate.
One type, manufactured by Amphenol, uses seals and gaskets to assure leak tight integrity.
A second type, manufactured by Conax, uses a set of compression fittings. Replacement modules for the Amphenol penetrations use a combination of 0-rings and compression fittings. These seals and gaskets cannot be inspected without disassembly of the penetration to gain access to the seals and gaskets.
Containment Personnel, Equipment, and Emergency Escape Hatches The personnel, equipment, and emergency escape hatches utilize an inner and outer door with gasketed surfaces to ensure a leak tight integrity. These hatches also contain other gaskets and seals such as electrical penetrations and equalizing
pressure connections that require disassembly to gain access to the gaskets and seals.
Fuel Transfer Tube The fuel transfer tube utilizes a blank flange inside containment with redundant 0-rings between the header plate and flange face.
Per 1 OCFR50 Appendix J, seals and gaskets receive a Type B test. As noted in the CFR, the purpose of Type B tests is to measure leakage of containment or penetrations whose design incorporates resilient seals, gaskets, sealant compounds, and electrical penetrations fitted with flexible metal seal assemblies. For those penetrations that are routinely disassembled, a Type B test is required upon final assembly and prior to start-up.
For those penetrations that are not routinely disassembled, Table IWE-2500-1, Category E-D, Note 1 (1993 Addenda and later) states "Sealed or gasketed connections need not be disassembled solely for the purpose of examination." Therefore, these seals and gaskets would not be visually examined.
Table IWE-2500-1, Category E-P, Item E9.40, requires performance of an Appendix J Type B test for seals and gaskets. Since the Type B test will assure the leak tight integrity of primary containment at the same frequency as that of the Code visual exams, the performance of the visual examination is redundant and will not increase the level of safety or quality.
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii).
Compliance with the visual examination of seals and gaskets in accordance with IWE-2500, Table IWE-2500-1, Category E-D is a burden without any compensating increase in the level of safety or quality. Visual examination of seals and gaskets will not ensure leak tight integrity.
Implementing an ASME Section XI Code program to perform these examinations is the unnecessary administrative burden. Testing the seals and gaskets in accordance with 1 OCFR50 Appendix J is superior to performing a visual examination and provides assurance of the leak-tight integrity of the seals and gaskets.
The Appendix J testing frequency is greater than that of ASME Section XI and, therefore, is more conservative and provides a greater level of safety.
Appendix J testing is a superior alternative method of establishing seal integrity.
ALTERNATIVE EXAMINATION(S):
The leak-tightness of seals and gaskets will be tested in accordance with 1 OCFR50 Appendix J. The 1 OCFR50 Appendix J Type B testing is performed at least once each inspection interval.
e Virginia Electric & Power Company Surry Power Station Unit 2 First Containment Inspection Interval Relief Request RR-IWE4 SYSTEM/COMPONENT(S) FOR WHICH RELIEF IS REQUESTED:
All Class MC, Paragraphs IWE-2420(b) and IWE-2420(c) successive examination requirements for components found acceptable for continued service.
CODE REQUIREMENT(S):
Paragraphs IWE-2420(b) and IWE-2420(c) of the 1992 Edition, 1992 Addenda of ASME Section XI require that when component examination results require evaluation of flaws, evaluation of areas of degradation, or repairs in accordance with Article IWE-3000, and the component is found to be acceptable for continued service, the areas containing such flaws, degradation, or repairs shall be reexamined during the next inspection period listed in the schedule of the inspection program of Paragraph IWE-2411 or Paragraph IWE-2412, in accordance with Table IWE-2500-1, Examination Category E-C.
CODE REQUIREMENT FROM WHICH RELIEF IS REQUESTED:
Relief is requested from the requirement of Paragraphs IWE-2420(b) and IWE-2420(c) to perform successive examination of repairs.
BASIS FOR RELIEF:
The purpose of a repair is to restore the component to an acceptable condition for continued service in accordance with the acceptance standards of Article IWE-3000.
Paragraph IWA-4150 requires the owner to conduct an evaluation of the suitability of the repair including consideration of the cause of failure.
If the repair has restored the component to an acceptable condition, successive examinations are not warranted. If the repair was not suitable, then the repair does not meet code requirements and the component is not acceptable for continued service.
Neither Paragraph IWB-2420(b), Paragraph IWC-2420(b), nor Paragraph IWD-2420(b) requires a repair to be subject to successive examination requirements. Furthermore, if the repair area is subject to accelerated degradation, it would still require augmented examination in accordance with Table IWE-2500-1, Examination Category E-C. The successive examination of repairs in accordance with Paragraphs IWE-2420(b) and IWE-2420(c) constitutes a burden without a compensating increase in quality or safety.
e In their resolution to public comment #3.3, the NRG stated, "The purpose of IWE-2420(b) is to manage components found to be acceptable for continued service (meaniflg no *repair or replacement at this time) as an Examination Category E-C component... If the component had been repaired or replaced, then the more frequent examination would not be needed."
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii).
Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
ALTERNATE EXAMINATION(S):
Successive examinations in accordance with Paragraphs IWE-2420(b) and IWE-2420(c) are not required for repairs made in accordance with Article IWA-4000.
Virginia Electric & Power Company Surry Power Station Unit 2 First Containment Inspection Interval Relief Request RR-IWES SYSTEMS/COMPONENTS FOR WHICH RELIEF IS REQUESTED:
Class MC pressure retaining bolting.
CODE REQUIREMENT(S):
ASME Section XI 1992 Edition with the 1992 Addenda, Table IWE-2500-1, Examination Category E-G, Pressure Retaining Bolting, Item 8.20.
CODE REQUIREMENT FROM WHICH RELIEF IS REQUESTED:
Relief is requested from ASME Section XI 1992 Edition with the 1992 Addenda, Table IWE-2500-1 Examination Category E-G, Pressure Retaining Bolting, Item 8.20.
Bolt torque or tension testing is required on bolted connections that have not been disassembled and reassembled during the inspection interval.
BASIS FOR RELIEF:
Bolt torque or tension testing is required on bolted connections that have not been disassembled and reassembled during the inspection interval.
Determination of the torque or tension value would require that the bolting be de-torqued and then re-torqued or re-tensioned.
Each penetration receives a 1 OCFR50 Appendix J Type B test in accordance with the testing frequencies specified in Appendix J. As noted in 1 OCFR50 Appendix J, the purpose of Type B tests is to measure leakage of containment penetrations whose design incorporates resilient seals, gaskets, sealant compounds, and electrical penetrations fitted with flexible metal seal assemblies. The performance of the Type B test itself proves that the bolt torque or tension remains adequate to provide a leak rate that is within acceptable limits. The torque or tension value of bolting only becomes an issue if the leak rate is excessive. Once a bolt is torqued or tensioned, it should not be subject to any dynamic loading that could cause it to experience significant change.
Appendix J testing and visual inspection is adequate to demonstrate that the design function is met. Torque or tension testing is not required on any other ASME Section XI Class 1, 2, or 3 bolted connections or their supports as part of the inservice inspection program.
e Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii). Bolt torque or tension testing of bolted connections which are verified not to experience unacceptable leakage through 1 OCFR50 Appendix J Type B testing is considered to be a hardship or unusual difficulty without a compensating increase in the level of quality and safety.
ALTERNATE EXAMINATION(S):
The following examinations and tests required by Subsection IWE ensure the structural integrity and the leak-tightness of Class MC pressure retaining bolting, and, therefore, no additional alternative examinations are proposed:
(1)
Exposed surfaces of bolted connections shall be visually examined in accordance with requirements of Table IWE-2500-1, Examination Category E-G, Pressure Retaining Bolting, Item No. E8.10, and (2)
Bolted connections shall meet the pressure test requirements of Table IWE-2500-1, Examination Category E-P, All Pressure Retaining Components, Item E9.40.
(
Virginia Electric & Power Company Surry Power Station Unit 2 First Containment Inspection Interval Relief Request RR-IWE6 SYSTEM/COMPONENT(S) FOR WHICH RELIEF IS REQUESTED:
Surface areas subject to augmented examination in accordance with Subsection IWE of the 1992 Edition, 1992 Addenda of ASME Section *x1.
CODE REQUIREMENTS:
ASME Section XI 1992 Edition, 1992 Addenda, Subarticle IWE-2500(c)(3) requires one foot square grids be used when ultrasonic thickness measurements are performed on augmented examination surface areas.
The number and location of the grids is determined by the Owner.
Subarticle IWE-2500(c)(4) requires the minimum wall thickness within each grid be determined.
CODE REQUIREMENTS FROM WHICH RELIEF IS REQUESTED:
Relief is requested from using one-foot square grids for augmented examination areas and the requirement to determine the minimum wall thickness within each grid.
BASIS FOR RELIEF:
Subarticles IWE-2500(c)(3) and IWE-2500(c)(4) of the 1992 Edition, 1992 Addenda of ASME Section XI requires that the minimum thickness within each one foot square grid of surface areas requiring augmented examination be marked such that periodic reexamination of that location can be performed.
Thickness readings are point readings. Numerous readings are necessary to identify the minimum thickness within each grid. This only identifies the thinnest area. Periodic examination of the minimum thickness point only monitors that point.
It may not be the area that is the most susceptible to accelerated degradation.
Table RR-IWE6 (attached) provides an alternative to the one foot square grid area required by IWE-2500(c)(3).
Table RR-IWE6 requires examination at the grid line intersections. The grid line intersections may not exceed 12 inches and may be as small as 2 inches.
For a sample area of 50 square feet, Table RR-IWE6 requires a mm1mum of 100 locations to be monitored. For a sample area of 50 square feet, IWE-2500(c)(3) would require only 50 locations to be monitored.
In this instance, utilizing Table RR-IWE6 monitors more locations than required by IWE-2500(c)(3).
-~
r For sample areas greater than 100 square feet, Table RR-IWE6 requires that sufficient points l::>e monitored to ensure at least a 95% confidence level that the thickness of the base metal is reduced by no more than 10% of the nominal plate thickness at 95% of
- the grid line intersections. Table RR-IWE6 also requires additional examinations when any measurements reveal wall thickness is reduced by more than 10% of the nominal plate thickness.
For all examination areas, should the measurements at a grid line intersection reveal that the base material is reduced by more than 10% of the nominal plate thickness, Table RR-IWE6 requires the minimum wall thickness within each adjoining grid be determined. This is similar to the examination requirements of IWE-2500(c)(4) except that Table RR-IWE6 focuses resources on areas that have exhibited degradation rather than areas that have not exhibited degradation.
The Flow Accelerated Corrosion programs presently in place have proven that thickness readings taken at grid intersections are effective in monitoring wall thinning of piping.
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii).
Taking numerous ultrasonic thickness readings within a grid that had not exhibited degradation results in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Alternative Examination(s):
Table RR-IWE6 will be used to determine examination requirements for ultrasonic thickness measurements of areas requiring augmented examination.
Notes:
TABLE RR-IWE6 ULTRASONIC THICKNESS MEASUREMENTS FOR AUGMENTED EXAMINATIONS Augmented Examination Area Size (Contiguous)
Examination Requirements
- s;100 square feet 100% of Grid Line Intersections 1*2*3*5*6
>1.00 square feet 100% of Grid Line Intersections 1*2*4*5*6
- 5.
The number, location and size of areas to be examined shall be determined by the Owner.
- 6.
Grid line spacing shall not exceed 12 inches, and need not be less than 2 inches.
- 7.
Grid line spacing shall be selected such that a minimum of 100 measurements are obtained from within each augmented examination area, unless this requires selecting a grid line spacing of less than 2 inches.
- 8.
In lieu of examining 100%1 of the grid line intersections within the augmented examination area, an alternate examination plan may be developed as follows:
(d) A sample area from within the augmented examination area may be selected for examination. The location and size of the sample area shall be determined by th'e Owner, but shall consist of areas subject to the most severe service conditions within the larger augmented examination area.
100% of the grid line intersections within the sample area shall be examined, and grid line spacing shall be selected such that a minimum of 100 measurements is obtained from within the sample areas.
(e) If the sample area exceeds 100 contiguous square feet, the Owner may develop a sampling plan for examination of grid line intersections within the sample area. Locations of ultrasonic thickness measurements to be taken at grid line intersections shall be selected at random throughout the sample area. The minimum number of measurements shall be 100, or shall be sufficient to ensure at least a 95% confidence level that the thickness of the base metal is reduced by no more than 10% of the nominal plate thickness at 95% of the grid line intersections within the sample area, whichever is greater.
(f) If any ultrasonic thickness measurements within the sample area reveal that the thickness of the base metal is reduced by more than 10% of the nominal plate thickness, all remaining grid line intersections within the sample area shall be examined, and additional UT examinations from outside of the sample area shall be required. These* additional UT examinations shall be performed on another area from within the larger augmented examination area that is at least as large as the initial sample area. If any of these subsequent examinations reveal that the thickness of the base metal is reduced by more than 10% of the nominal plate thickness, additional areas from within the larger augmented examination area shall be examined until subsequent examinations of additional areas reveal no measurements where metal loss exceeds 10% of the nominal plate thickness, or until the entire augmented examination area has been examined.
- 7.
When an ultrasonic thickness measurement performed at a grid line intersection reveals that the thickness of the base metal is reduced by more than 10%
of the nominal plate thickness, the minimum wall thickness shall be determined and located within each adjoining grid.
- 8.
Measurements need not be obtained at locations where obstructions interfere with grid line intersections.
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Virginia Electric & Power Company Surry Power Station Unit 2 First Containment Inspection Interval Relief Request RR-IWL2 SYSTEM/COMPONENT(S) FOR WHICH RELIEF IS REQUESTED:
All components subject to examination in accordance with Subsection IWL of the 1992 Edition, 1992 Addenda of ASME Section XI.
CODE REQUIREMENTS:
Subarticle IWA-2210 provides requirements for visual examination procedures.
CODE REQUIREMENTS FROM WHICH RELIEF IS REQUESTED:
Relief is requested from the provisions of Table IWA-2210-1.
Direct visual VT-3 examinations require a minimum illumination of 50 fc, and a maximum examination distance of 4 feet.
The procedure must be demonstrated to resolve a lower case character height of 0.105 inches.
BASIS FOR RELIEF:
In addition to the requirements of Subsection IWL, the requirements of the 1992 Edition, 1992 Addenda of Subsection IWA for containment examinations are applicable.
For VT-3C examinations performed in accordance with Subsection IWL, the examination distance and illumination requirements are the same as for that specified for VT-3 in Table IWA-2210-1.
For remote examination of IWE components, 10 CFR 50.55a permits the maximum direct examination distance specified in Table IWA-2210-1 to be extended and the minimum illumination requirements specified in Table IWA-2210-1 to be decreased provided that the conditions or indications for which the visual examination is performed can be detected at the chosen distance and illumination. This amendment to the requirements of Table IWA-2210-1 can be extended to examination of IWL items provided the indications for which the visual examination is performed can be detected at the chosen distance and illumination.
Relief is requested in accordance with 1 OCFR50.55a(a)(3)(ii).
Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
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Alternative Examination{s):
VT-3C
- visual examinations will be performed under distance and illumination requirements necessary to detect the conditions or indications for which the visual examination is performed. The procedure will be demonstrated capable of detecting conditions or indications for which the examination is being performed.