ML20154R958
| ML20154R958 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/21/1998 |
| From: | Salas P TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9810270236 | |
| Download: ML20154R958 (12) | |
Text
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o IUA Tennessee Valley Authority Post Othce Box 2000 Soddy Daisy Tennestae 37379 October 21, 1998 10 CFR 50.50a (a) (3) (i)
U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Gentleman:
In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PIANT (SQN) - REQUEST FOR APPROVAL OF RELIEF FROM AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) CODE REQUIREMENTS - REQUEST FOR RELIEF ISI INTEGRALLY WELDED ATTACHMENTS OF SUPPORTS AND RESTRAINTS FOR AUXILIARY FEEDWATER (AFW) PIPING - NOMINAL PIPE SIZE (NPS) 1 INCH AND SMALLER.
Reference:
NRC letter to TVA dated April 27, 1998,
" Evaluation of the Second 10-Year Interval Inspection Program Plan and Associated Requests for Relief For Sequoyah Nuclear Plant, Units 1 and 2 (TAC Nos. M94115 and M94116)"
This letter provides a request for relief (ISI-3) for SON l Units 1 and 2. The request for relief provides a proposed I alternative to the requirements contained in the 1989 Edition of the ASME Code,Section XI. The proposed alternative adopts provisions from the 1991 Addenda to the 1989 Edition of the Code that exempts visual inspection of integrally welded attachments of supports and restraints for Class 3 AFW I system piping, NPS 1 inch and smaller. TVA's proposed alternative to adopt provisions of the 1991 Addenda will not reduce the level of quality and safety.
In response to the referenced letter, TVA is resubmitting l ISI-3 for staff approval under the proposed alternative provisions of 10 CFR 50.55a (a) (3) (i) . j
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9810270236 981021 Yn l PDR ADOCK 05000327 G PDR l
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U.S. Nuclear Regulatory Commission Page,2
' October 21, 1998 l
TVA is resubmitting the ISI-3 relief request following ,
discussions with your staff, which suggested that a I comparison between Code requirements from the 1989 l Edition of the Code and the 1991 Addenda be provided. !
Specifically, the exemption for Class 3 AFW piping )
(NPS 1 inch and smaller) is provided in the 1991 Addenda to j the 1989 Edition of ASME,Section XI Code. This exemption i was previously provided by ASME Code prior to the 1980 Edition, Winter 1980 Addenda.
The ISI-3 relief request is applicable to SON's second 10-year inservice inspection interval that began December 16, 1995. NRC review and approval of ISI-3 is requested prior to May 31, 1999. This date supports SQN's schedule for planning inservice inspections during the Cycle 10 refueling outages.
Enclosure 1 provides the Unit 1 request for relief (1-ISI-3) and Enclosure 2 provides the Unit 2 request for relief (2-ISI-3). The justification for 3-ISI-3 and 2-ISI-3 are identical. The relief requests are unit specific to reflect differences between the numbers in piping supports that are applicable to each unit.
If you have any questions regarding this response, please contact me at extension (423) 843-7071 or J. D. Smith at extension (423) 843-6672.
Sincerel ,
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/ Parl s Licensing and Industry Affairs Manager Enclosures cc: See page 2 I
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U.S. Nuclear Regulatory Commission Page 3 October 21, 1998 cc (Enclosures):
Mr. R. W. Hernan, Project Manager Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 NRC Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy-Daisy, Tennessee 37379-3624 Regional Administrator U.S. Nuclear Regulatory Commission Region II Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-3415
ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNITS 1 AND 2 SECOND 10-YEAR INTERVAL REQUEST FOR RELIEF No. 1-ISI-3 Executive Summary: This request for relief is associated with the visual examination requirements for integrally welded attachments of supports and restraints to Auxiliary Feedwater System ( AFWS) piping with Nominal Pipe Size (NPS) 1 inch and smaller.
American Society of Mechanical Engineers (ASME)
Section XI Code editions and addenda prior to the 1980 Edition, Winter 1980 Addenda allowed the exemption of all system component connections, piping, and associated valves of 1-inch NPS and smaller except for steam generator tubing. The NPS exemption for the AFWS was removed in the ASME Section XI Code 1980 Edition, Winter 1980 Addenda.
In the 1989 Edition, 1991 Addenda (and later addenda) of ASME Section XI Code, Paragraph IWD-1220 included a NPS 1 inch and smaller exemption for the AFWS.
TVA's relief request proposes to utilize the NPS 1 inch and smaller exemption criteria for the SON AFWS. This approach is an alternative to the current Code of record for SQN (1989 Edition).
TVA's proposed alternative is consistent with the 1989 Edition, 1991 Addenda of ASME Section XI Code Current Code requirements, along with TVA's Inservice Inspection (ISI) Program, require the examination of the ASME Code Class 3 integrally welded attachments of supports and restraints to AFWS components and piping greater than NPS 1 inch.
TVA's proposed alternative for utilizing the 1991 Addenda of ASME Section XI Code to exempt examination of integrally welded attachments of supports and restraints to AFWS piping NPS 1 inch or less, provides an acceptable level of quality and safety pursuant to 10CFR 50.55a(a) (3) (1) .
Unit : 1 System: Auxiliary Feedwater - System 3 Components: Integrally Welded Attachments of Supports and Restraints to AFWS Piping NPS 1 Inch and Smaller ASME Code Class: ASME Code Class 3 (Equivalent)
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Section XI Edition: 1989 Edition Code Subparagraph: -IWD-1220.1 Code Requirement: Subparagraph IWD-1220.1 of the 1989 Edition of ASME Section XI states; " Integral attachments of supports and restraints to components that are NPS 4 and smaller within the system boundaries of Examination Categories D-A, D-B and D-C of Table IWD-2500-1 shall be exempt from the visual examination VT-3, except for PWR Auxiliary Feedwater Systems."
Code Requirement From Which Relief Is Requested: TVA requests relief from the exemption criteria provided by Subparagraph IWD-1220.1 of the 1989 Edition for visual examination requirements associated with integrally welded attachments of supports and restraints to components that are NPS 1 inch and smaller in SON's AFWS.
List Of Items Associated with The Relief Request: This relief request applies to the integrally welded attachments of supports and restraints to the AFWS piping, NPS 1 inch and smaller. This piping includes drain lines, vent lines, instrument lines, sampling lines and valve leak off lines, and orifice lines within the Code Class 3 boundaries.
There are 159 supports on NPS 1 inch and smaller AFWS piping. Of these, 10 are integrally welded attachments.
Code Case N-491 is currently used for the i examination of supports. Paragraph 1230 of code Case N-491 requires supports to be examined on {
components not exempted. Paragraph 1230 of N-491 states that component supports exempt from the examination requirements of Paragraph 2000 are those connected to components and items exempted from examination under IWB-1220, IWC-1220, IWD-1220, and IWE-1220. In addition, portions of supports that are inaccessible by being encased in concrete, buried underground or encapsulated by guard pipe are also exempt from the examination requirements of Paragraph 2000.
Code Case N-509 is currently used for the selection and examination of Class 1, 2, and 3 integrally welded attachments. The Visual Test (VT) 1 visual examination from Table 2500-1, Examination Category El-2
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I D-A (Code Case N-509), is used in lieu of the VT-3 i examination of Table IWD-2500-1, Examination Categories D-A, D-B, and D-C (1989 Edition of ASME
, Section XI). Paragraph 1.1 of Code Case N-509 4
permits the exemption criteria of IWB-1220, IWC-1220, and IWD-1220 to be applied to Class 1, 2, l and 3 components, respectively, with integrally i a welded attachments required to be examined in i i
accordance with Table 2500-1. l
) Basis for Relief: TVA's proposed request is based on the provisions i of later editions of the Code. The proposed alternative adopts provisions from the 1991 Addenda .
to the 1989 Edition of the Code that exempts visual i
inspection of integrally welded attachments on Class 3 AFWS piping, NPS 1 inch and smaller. TVA' s
, proposed use of the 1991 Addenda as an alternative i
to the 1989 Edition of the code, provides an l acceptable level of quality and safety, t
4 Alternate
- Requirement
- TVA proposes to, in lieu of the Code required
- examination requirements from Paragraph IWD-1220.1 (1989 Edition), apply the exemption criteria of L Paragraph IWD-1220 (1989 Edition, 1991 Addenda) for
- integrally welded attachments on SQN's AFWS piping.
Justification For The Granting Of Relief: ASME Section XI Code 1989 Edition, 1991 Addenda and later addenda, incorporated a NPS 1 inch and smaller exemption requirement for the AFWS.
Subparagraph IWD-1220 of this addenda exempts piping NPS 1 inch and smaller and also exempts vessels, pumps, and valves and their connections in piping NPS 1 inch and smaller.
SON's Code of record (1989 Edition of ASME Section XI Code, Paragraph IWD-1220.1) does not contain a NPS 1 inch and smaller exemption for the AFWS.
The following table is a comparison of the related Code requirements:
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l REIATED REQUIREMENTS COMPARISON 3 1989 Edition. 1991 Addenda cot @ENTS 7WD-1220 Items Exempt From IWD-1220 Components Exempt From Examination Examination IWD-1220.1 Integral attachments The following components or parts of The 1991 Addenda of supports and restraints to components are exemp' ed from the VT- reworded the components that are NPS 4 and 3 visual examination requirements of subparagraph and smaller within the system IWD-2500: incorporated the boundaries of Examination (a) for systems, except Auxiliary Auxiliary Feedwater Categories D-A, D-B, and D-C of Feedwater Systems in pressurized Systems NPS 1 inch Table IWD-2500-1 shall be exempt water reactor plants: exemption.
from the visual examination VT- (1) piping NPS 4 and smaller 3, except for PWR Auxiliary (2) vessels, pumps, and valves Feedwater Systems, and their connections in piping' NPS 4 and smaller (b) for Auxiliary Feedwater Systems in pressurized water reactor plants:
(1) piping NPS 1 and smaller (2) vessels, pumps, and valves and their connections in piping' NPS 1 and smaller IWD-1220.2 Integral attachments (c) components that operate at a The 1991 Addenda of supports and restraints to pressure of 275 psig or less and reworded the components exceeding NPS 4 may at a temperature of 200*F or subparagraph and be exempted from visual less in systems (or portions of clarified which examination VT-3 of Table IWD- systems) whose function is not Class 3 systems are 2500-1 provided: required in support of reactor required to meet (a) the components are located residual heat removal, inservice in systems (or portions of containment heat removal, and examination systems) whose function is emergency core cooling; requirements of I not required in support of Section XI.
reactor residual heat removal, containment heat removal, and emergency core cooling: and (b) the components operate at a pressure of 275 psig or less and at a temperature of 200*F or less.
(d) integral attachments of supports 1991 Addenda added and restraints that are provisions to exempt inaccessible due to being integral attachments encased in concrete, buried that are underground, or encapsulated by inaccessible for guard pipe. inspection.
Footnote 1 1991 Addenda added In piping is defined as having a to clarify that cumulative inlet and a cumulative vessels with outlet pipe cross-sectional area multiple openings neither of which exceeds the nominal are to be exempted OD cross-sectional area of the based on the designated size. cumulative cross section area.
Reference Code Inquiry file # IN95-17.
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Justification For The Granting Of Relief l
, (Continued): The design basis for SQN does not include a {
postulated break for pipe NPS 1 inch or less. It j j
l has been shown by analysis that the consequences ,
from this size pipe failure does not affect the '
plant's ability to achieve and maintain safe shutdown conditions. This analysis is described in Section 3.6.1.2 of the SQN Updated Final Safety ;
- Analysis Report (UFSAR), Amendment 14.
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TVA's proposed use of Paragraph IWD-1220 of the 1989 Edition, 1991 Addenda of the ASME Section XI code exemption for the components and piping NPS 1 I
inch and smaller in SON's AFWS does not decrease the level of quality or safety. SQN's performance of examinations on the ASME Code Class 3 integrally 3
welded attachments of, supports and restraints to l AFWS components and piping greater than NPS 1 inch,
- as required by the ASME Section XI Code, will constitute a representative sample of the system's 1 integrity and will provide reasonable assurance of i an acceptable level of quality and safety.
i 1 Therefore, pursuant to 10 CFR 50.55a (a) (.3) (i) , it j is recommended that relief be granted.
l Implementation Schedule: This request for relief is applicable to the second inspection interval for SON Unit 1.
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ENCLOSURE 2
, TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNITS 1 AND 2 SECOND 10-YEAR INTERVAL l REQUEST FOR RELIEF NO. 2-ISI-3 i
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Executive Summary: This request for relief is associated with the visual examination requirements for integrally i welded attachments of supports and restraints to Auxiliary Feedwater System (AFWS) piping with Nominal Pipe Size (NPS) 1 inch and smaller. ASME Section XI Code editions and addenda prior to the 1980 Edition, Winter 1980 Addenda allowed the exemption of all system component connections, piping, and associated valves of 1-inch NPS and smaller except for steam generator tubing. The NPS exemption for the AFWS was removed in the ASME Section XI Code 1980 Edition, Winter 1980 Addenda.
In the 1989 Edition, 1991 Addenda (and later addenda) of ASME Section XI Code, Paragraph IWD-1220 included a NPS 1 inch and smaller exemption for the AFWS.
TVA's relief request proposes to utilize the NPS 1 inch and smaller exemption criteria for the SQN AFWS. This approach is an alternative to the current Code of record for SQN (1989 Edition).
TVA's proposed alternative is consistent with the 1999 Edition, 1991 Addenda of ASME Section XI Code.
Current Code requirements, along with TVA's Inservice Inspection (ISI) Program, require the examination of the ASME Code Class 3 integrally welded attachments of supports and restraints to AFWS components and piping greater than NPS 1 inch.
TVA's proposed alternative for utilizing the 1991 Addenda of ASME Section XI Code to exempt examination of integrally welded attachments of supports and restraints to AFWS piping NPS 1 inch or less, provides an acceptable level of quality and safety pursuant to 10CFR 50.55a (a) (3) (i) .
Unit: 2 System: Auxiliary Feedwater - System 3 Components: Integrally Welded Attachments of Supports and Restraints to AFWS Piping NPS 1 Inch and Smaller ASME Code Class: ASME Code Class 3 (Equivalent)
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Section XI Edition: 1989 Edition Code Subparagraph: IWD-1220.1 Code Requirement: Subparagraph IWD-1220.1 of the 1989 Edition of ASME Section XI states; " Integral attachments of supports and restraints to components that are NPS 4 and smaller within the system boundaries of Examination Categories D-A, D-B and D-C of Table IWD-2500-1 shall be exempt from the visual examination VT-3, except for PWR Auxiliary Feedwater Systems."
Code Requirement From Which Relief Is Requested: TVA requests relief from the exemption criteria provided by Subparagraph IWD-1220.1 of the 1989 Edition, for visual examination requirements associated with integrally welded attachments of supports and restraints to components that are NPS 1 inch and smaller in SON's AFWS.
List Of Items Associated with The Relief Request: This relief request applies to the integrally welded attachments of supports and restraints to the AFWS piping, NPS 1 inch and smaller. This piping includes drain lines, vent lines, instrument lines, sampling lines and valve leak off lines, and orifice lines within the Code Class 3 boundaries.
There are 153 supports on NPS 1 inch and smaller AFWS piping. Of these, there are 10 integrally welded attachments.
Code Case N-491 is currently being used for the examination of supports. Paragraph 1230 of Code Case N-491 requires supports to be examined on components not exempted. Paragraph 1230 of N-491 states that component supports exempt from the examination requirements of Paragraph 2000 are l those connected to components and items exempted l from examination under IWB-1220, IWC-1220, IWD-1220, and IWE-1220. In addition, portions of
)
supports that are inaccessible by being encased in concrete, buried underground or encapsulated by guard pipe are also exempt from the examination requirements of Paragraph 2000.
i l Code Case N-509 is currently used for the selection l and examination of Class 1, 2, and 3 integrally welded attachments. The VT-1 visual examination from Table 2500-1, Examination Category D-A (Code i
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Case N-5)9), is used in lieu of the VT-3 examinatf.on of Table IWD-2500-1, Examination Categories D-A, D-B, and D-C (1989 Edition of ASME Section XI). Paragraph 1.1 of Code Case N-509 l
permits the exemption criteria of IWB-1220, I IWC-1220, and IWD-1220 to be applied to Class 1, 2, and 3 components, respectively, with integrally welded attachments required to be examined in accordance with Table 2500-1.
l Basis for Relief: TVA's proposed request is based on the provisions of later editions of the Code. The proposed i alternative adopts provisions from the 1991 Addenda l to the 1989 Edition of the Code that exempts visual inspection of integrally welded attachments on !
Class 3 AFWS piping, NPS 1 inch and smaller. TVA's proposed use of the 1991 Addenda as an alternative to the 1989 Edition of the Code, provides an ,
acceptable level of quality and safety. !
Alternate Requirement: TVA proposes to, in lieu of the Code required l examination requirements from Paragraph IWD-1220.1 1 (1989 Edition), apply the exemption criteria of i Paragraph IWD-1220 (1989 Edition, 1991 Addenda) for I integrally welded attachments on SQN's AFWS piping.
1 Justification For The Granting Of Relief: ASME Section XI Code 1989 Edition, 1991 Addenda and later addenda, incorporated a NPS 1 inch and smaller exemption requirement for the AFWS, Subparagraph IWD-1220 of this addenda exempts piping NPS 1 inch and smaller and also exempts vessels, pumps, and valves and their connections in piping NPS 1 inch and smaller.
SON's Code of record (1989 Edition of ASME Section XI Code, Paragraph IWD-1220.1) does not contain a NPS 1 inch and smaller exemption for the AFWS.
The following table is a comparison of the related Code requirements:
E2-3
RELATED REQUIREMENTS COMPARISON 1989 Ed). tion. 1991 Addenda COMMENTS i )
IWD-1220 Items Exempt From IWD-1220 Components Exempt From Examination Examination 1WD-1220.1 Integral attachments The following components or parts of The 1991 Addenda of supports and restraints to components are exempted from the VT- reworded the i components that are NPS 4 and 3 visual examination requirements of subparagraph and
' l smaller within the system IWD-2500: incorporated the boundaries of Examination (a) for systems, except Auxiliary Auxiliary Feedwater Categories D-A, D-B, and D-C of Feedwater Systems in pressurized Systems NPS 1 inch Table IWD-2500-1 shall be exempt water reactor plants: exemption.
i from the visual examination VT- (1) piping NPS 4 and smaller 3, except for PWR Auxiliary (2) vessels, pumps, and valves Feedwater Systems. and their connections in I i piping' NPS 4 and smaller (b) for Auxiliary Feedwater Systems in pressurized water reactor plants:
(1) piping NPS 1 and smaller (2) vessels, pumps, and valves
- and their connections in piping' NPS 1 and smaller IWD-1220.2 Integral attachments (c) components that operate at a The 1991 Addenda of supports and restraints to pressure of 275 psig or less and reworded the components exceeding NPS 4 may at a temperature of 200*F or subparagraph and 3 be exempted from visual less in systems (or portions of clarified which examination VT-3 of Table IWD- systems) whose function is not Class 3 systems are 2500-1 provided
- required in support of reactor required to meet (a) the components are located residual heat removal, inservice in systems (or portions of containment heat removal, and examination systems) whose function is emergency core cooling; requirements of not required in support of Section XI.
reactor residual heat removal, containment heat removal, and emergency core cooling: and (b) the components operate at a pressure of 275 psig or less and at a temperature
- of 200*F or less.
(d) integral attachments of supports 1991 Addenda added and restraints that are provisions to exempt 4 inaccessible due to being integral attachments i encased in concrete, buried that are i underground, or encapsulated by inaccessible for j guard pipe inspection.
Footnote 1 1991 Addenda added In piping is defined as having a to clarify that cumulative inlet and a cumulative vessels with outlet pipe cross-sectional area multiple openings neither of which exceeds the nominal are to be exempted OD cross-sectional area of the based on the designated siz.. cumulative cross section area.
Reference Code Inquiry file # IN95-
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Justification For The Granting Of Relief ^
i (Continued): The design basis for SQN does not include a postulated break for pipe NPS 1 inch or less. It has been shown by analysis that the consequences 4
from this size pipe failure does not affect the plant's ability to achieve and maintain safe j
shutdown conditions. This analysis is described in Section 3.6.1.2 of the SQN UFSAR, Amendment 14.
TVA's proposed use of Paragraph IWD-1220 of the
- 1989 Edition, 1991 Addenda of the ASME Section XI 4
i Code exemption for the components and piping NPS 1 inch and smaller in SON's AFWS does not decrease
- the level of quality or safety. SON's performance i of examinations on the ASME Code Class 3 integrally welded attachments of supports and restraints to AFWS components and piping greater than NPS 1 inch, as required by the ASME Section XI Code, will
' constitute a representative sample of the system's integrity and will provide reasonable assurance of ,
an acceptable level of quality and safety. '
Therefore, pursuant to 10 CFR 50.55a(a) (3) (i), it is recommended that relief be granted.
l Implementation Schedule: This request for relief is applicable to the second ;
inspection interval for SON Unit 2.
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