AECM-88-0104, Forwards Requests for Relief from Inservice Insp Plan Requirements of ASME Section Xi,Including Rev 1 to Relief Request I-00007 Re Amount of Exam Coverage Obtainable,Rev 2 to I-00010 & Rev 0 to I-00019
| ML20154L872 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 05/24/1988 |
| From: | Kingsley O SYSTEM ENERGY RESOURCES, INC. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| AECM-88-0104, AECM-88-104, NUDOCS 8806010088 | |
| Download: ML20154L872 (25) | |
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EYETEM ENERGY REEOtJRCEE, INC.
OJ.m D , ',RW D yJyyy May 24, 1988 U. S. Nuclear Regulatory Corrmission Mail Statien P1-137 Washington, D. C. 20555 Attention: Document Control Desk Gentlemen:
SUBJECT:
Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 Inservice Inspection Plan Relief Request AECM-88/0104 This submittal provides requests for relief from the requirements of ASME Section XI. This relief is requested in accordance with 10CFR 50.55a(g)5(iii).
While performing inservice examinations during Refueling Outage 2 several conditions were identified where ASME Section XI required volumes were inaccessible. ASME Section XI, 1977 Edition, Summer 1979 Addenda, specifies specific volumes of weld and base materials that require examination. ASME Section XI does not provide any allowances for material volumes that may be inaccessible due to geometric or access restrictions.
Attachea are two revised Relief Requests (I-00U07, Revision 1 and I-00010, Revision 2) and one new Relief Request (I-00019, Revision 0).
The purpose of Relief Request I-00007 Revision 1 is to provide l clarification to the contents of Table 1 by changing the title of the column originally i h tified as "limited area" to "EXAMINABLE VOLUMETRIC AREA" and adding another column "EXAMINABLE SURFACE AREA". This revision clarifies and I corrects the information pertaining to the amount of examination coverage that ;
is obtainable. l Relief Request I-00010, Revision 2 provides the same changes as discussed for Relief Request I-00007, Revision 1. In addition, welds have been added that require relief from the full volumetric examination and also limitations in the required surface examinations are identified.
Relief Request I-00019, Revision 0 identifies specific areas of the Reactor Pressure Vessel that require relief from ASME Section XI required examinations.
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AECM-88/0104 Page 2 Your expeditious review and approval is requested. prior to October 31 1988, since this is the completion of Grand Gulf Nuclear Station's first forty month period. If additional information is required to support your review, please contact this office.
Yours truly, t ent cc: Mr. T. H. Cloninger (w/a)
Mr. R. B. McGehee (w/a)
Mr. N. S. Reynolds (w/a)
Mr. H. L. Thomas (w/o)
Mr. R. C. Butcher (w/a)
Dr. J. Nelson Grace, Regional Administrator (w/a)
U. S. Nuclear Regulatory Commission Region II 101 Marietta St., N. W., Suite 2900 Atlanta, Georgia 30323 Mr. L. L. Kintner, Project Manager (w/a)
Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 14B20 Washington, D.C. 20555 i
I J16AECM88051001 - 2 L
l GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIREMENTS ,
INSERVICE INSPECTION SECTION 4 I TEN YEAR PROGRAM RELIEF REQUEST l I
l GRAND GULF NUCLEAR STATION UNIT 1 i RELIEFREQUESTNO.I-00007 REVISION 1 1 PAGE 1 of 4 l I
INSERVICE INSPECTION l PIPINGWELDSWblNGUARDPIPES l
I. Component: ASME Section III, Class 1 pressure retaining I circumferential welds located in Feedwater Loops A and B (B21), Main Steam (821), Reactor Core Isolation Cooling (E51), Residual Heat Removal (E12), and Reactor Water Cinn-up (G33) piping. !
These welds are located on system piping inside I guard pipes, which extend beyond the containment. The applicable welds are listed in Table 1.
II. Code: These welds were designed and fabricated to ASME Section III, Class 1 requirements. Applicable I inservice inspection is to be performed in I accordance with ASME Section XI, 1977 Edition !
through and including Summer of 1979 Addenda. !
III. Code Requirements: Class 1 pressure retaining piping welds are i required to be volumetrically and surface ;
examined once each ten year inspection interval I in accordance with ASME Section XI, Table IWB-2500-1, Examination Category B-J.
IV. Information to The circumferential welds joining the flued head support the and the process pipe are encapsulated by the determination that portion of the guard pipe which protrudes beyond the code the containment. To comply with the inservice requirements are inspection requirements of ASME Section XI, two impractical: 4" x 6" elliptical access ports spaced 1800 apart are provided for access to the welds.
During the development of the access port design, the inservice -antractor had indicated that the ports were aa uate to permit performance of surface and ults onic examination of the entire weld.
After fabrication and installation of the process pipe, guard pipe and the flued head, it was determined that the entire length of the weld is not accessible through the two access ports.
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GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 RELIEFREQUESTNO.I-00007 REVISION 1 l
PAGE 2 of 4 V. Specific relief Permission is requested to perform ultrasonic requested:
examination of the welds listed in Table I to the extent possible through the 4" x 6" access ports. Also, permission is requested to perform the code required surface examinations on the
" same welds to the extent possible through the access ports. The percentage of each weld examined will be recorded during the inservice examination.
VI. Reasons why relief Exemption is requested for the inservice should be granted: inspection of inaccessible portions of welds located inside guard pipes for the following reasons:
- 1. All but two of these lines were designed to high energy pipe break criteria. The exceptions are QlE12G012W47 and QlE51G00lW12 which are classified as moderate energy pipes.
- 2. These welds were designed and fabricated in accordance with ASME Section III, Class I requirements and were examined by radiographic and liquid penetrant techniques.
- 3. These welds have satisfactorily passed both liquid penetrant and ultrasonic examinations in accordance with ASME Section XI, Class 1 requirements (preservice relief request No.
00001).
- 4. Class 1 isolation valves in the process pipe on both sides of the guard pipes are capable of completely isolating each pipe in the event of a pipe failure.
- 5. The guard pipes have been designed and constructed in accordance with ASME Section III, Class 2 requirements and were hydrostatically tested in accordance with ASME Section III, Class 2 requirements.
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GRAND GULF NUCLEAR STATION INSERVICC INSPECTION REQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GPN 0 GULF NUCLEAR STATION UNIT 1 RELIEF REQUEST NO. I-00007 REVISION 1 PAGE 3 of 4 VI. Reasons why relief 6. The guard pipes are open to the drywell should be granted: environment; thus, any leakage due to weld
, (continued) failure will be contained within the drywell. The guard pipes will prevent any leakage from escaping to the Containment Building.
I 7. The process pipes inside the guard pipes were hydrostatically tested in accordance with ASME Section III, Class 1 requirements.
- 8. The process piping inside each guard pipe assembly will be subject to periodic pressure tests in accordance with ASME Section XI, Table IWB-2500-1, Category B-P, requirements. I l VII. Alternative testing: The accessible length of each weld will be l ultrasonically and surface examined in accordance i with ASME Section XI, Table IWB-2500-1, l Examination Category B-J. Should signs of weld deterioration or discrepancies be noted during l regular inspections, evaluation of the conditions will be made.
NOTE: In addition, a relief request (No.
00001) based on the above logic for four (4) welds on main steam pipes was submitted earlier with the Unit 1 preservice inspection. The Nuclear Regulatory Commission accepted this request for relief in GGNS Safety )
Evaluation Report, Supplement #2.
VIII. NRC Discussion The following statements, conclusions, 1 Statements (Revision recommendations, etc. have been adopted by the '
- 0) NRC and are to be considered part of this request for relief approval.
Therefore, relief is recommended as requested provided:
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GRANo GULF NUCLEAR STATION INSERVICE INSPF.CTION REQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 RELIEF REQUEST NO. I-00007 REVISION 1 PAGE 4 of 4 VIII. NRC Discussion (a) the volumetric and surface examinations are Statements (Revision performed to the maximum extent practical
- 0) continued and (b) the Code-required surface examinations and system pressure tests are performed, and visually inspected.
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e GRANE> GULF NUCLEAR STATION INSERVICE INSPECTION REQUIRENENTS INSERVICE INSPECTION SECTION 4
- TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 [
RELIEF REQUEST NO. I-00007 REVISION 1 TABLE 1 EXAMINABLE EXAMINABLE ITEM SYSTEM VELD ISO PIPE VOLUMETRIC TYPE SURFACE VELD REASON FOR NO NO NO NO SIZE COMPONENT AREA SCAN AREA CLASS TYPE LIMITATIONS 1 B21 G12-C1-A MS-11-9 28" PIPE TO PIPE 27% T NOTE 1 1 CIRC GUARD PIPE 2 B21 G12-Al-A MS-11-3 28" PIPE TO PIPE 27% T NOTE 1 1 CIRC GUARD PIPE 3 ESI G12-DI-A MS-11-12 28" PIPE TO PIPE 27% T NOTE 1 1 CIRC GUARD PIPE 4 821 G12-B1-A MS-11-6 28" PIPE TO PIPE 27% T NOTE 1 1 CIRC GUARD PIPE 5 B21 W2 FV-11-1 24" PIPE TO PIPE 24% T NOTE 1 1 CIRC GUARD PIPE l
I 6 B21 VIA FV-11-7 24" PIPE TO PIPE 24% T NOTE I 1 CIRC GUARD PIPE 7 DELETED 8 E12 V47 RH-11-1 20" PIPE TO PIPE 19% T NOTE 1 1 CIRC GUARD PIPE 9 E51 VI2 RI-8-9 6" PIPE TO PIPE 50% T NOTE 1 1 CIRC GUARD PIPE 1
10 E51 V7 RI-11-3 10" PIPE TO PIFE 100% T NOTE 1 1 CIRC GUARD PIPE 11 G33 V18 CU-11-3 6" PIPE TO PIPE 50% T NOTE 1 1 CIRC GUARD PIPE NOTE 1: The percentage of each weld that is accessible for surface examination will be recorded during the inservice examination.
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GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST .
l GRAND GULF NUCLEAR STATION UNIT 1 RELIEF REQUEST NO. I-00010 REVISION 2 PAGE 1 of 4 INSERVICE EXAMINATION PRESSURE RE INING WELDS I. Component: Inaccessible portions of ASME Section III, Class 1 and 2 pressure retaining and integral attachment piping welds listed in table 1 (see attached).
II. Code: These portions of the pressure retaining and integral attachment piping welds were designed and fabricated to ASME Section III, Class 1 and Class 2 requirements. Applicable inservice inspections are to be performed in accordance with the ASME Section XI, 1977 Edition, through and including the Suminer 1979 Addenda.
III. Code Requirements: Class 1 and Class 2 pressure retaining piping welds are required to be volumetrically and surface examined, essentially 100% of the weld, once every ten year interval in accordance with ASME Section XI, Table IWB-2500-1, Category B-J, Table IWC-2500-1, Category C-F. The Class 1 integral attachment welds depicted in table 1 are required to be surface examined once each ten year interval in accordance with ASME Section XI, Table IWB-2500-1, Category B-K-1.
IV. Information to Portions of welds that were preservice examined support the have physical obstructions due to design. Due to determination that this limited accessibility, it is impractical to the code perform the surface and volumetric examination requirements are for 100% of the required examination volume as impractical: 'idicated for the welds listed in Table 1.
V. Specific relief Permission is requested to perform the Code i requested: required examinations to the extent described in Table 1.
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GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIRENENTS l INSERVICE INSPECTION SECTION 4 1 TEN YEAR PROGRAM RELIEF REQUEST l
i GRAND GULF NUCLEAR STATION UNIT 1 RELIEF REQUEST NO. I-00010 REVISION 2 PAGE 2 of 4 VI. Reasons why relief Request for permission to limit the code required l should be granted: examination to the accessible areas should be j granted for the following reasons: !
- 1. The inaccessible portions of listed pressure retaining welds were examined by radiography, passed in accordance with ASME Section III, Class 1 and 2 requirements.
- 2. The inaccessible portions of the pressure retaining and integral attachment welds were surface examined (magnetic particle or liquid penetrant), passed in accordance with ASME III and/or XI, Class 1 and Class 2 requirements.
- 3. The inaccessible portions of listed piping )
welds will be subject to a system leakage i test after each refueling outage for Class 1, and each inspection period for Class 2 in accordance with ASME Section XI requirements.
- 4. The inaccessible portions of listed piping 1 welds will be sub.iect to a system !
hydrostatic test each inspection interval in !
accordance with ASME Section XI, Class 1 and 2 requirements.
- 5. Accessible portions of listed welds will be volumetrically and surface examined each inspection interval in accordance with ASME Section XI, Should indications be found, an engineering evaluation will be made to determine if the inaccessible portions of the listed welds have been affected.
- 6. Leak detection is provided, by way of the leakage detection system with continuous monitoring, for the RHR, RCIC, MS, RWCU, RECIRC and FW systems.
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GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 RELIEFRF.QUESTNO.I-00010 REVISION 2 PAGE 3 of 4 VI. Reasons why relief 7. The failure of any one of taese pressure should be granted: retaining piping welds would have no adverse (continued) effect on plant safety as there is isolation capability and/or shut down ca,nability as part of the plant design.
- 8. The calculated maximum piping stresses and usage factor at the integral attachments on the piping, including consideration of the local pipe wall stresses, have been determined in the class 1 stress report and are equal to the following:
a) Primary plus secondary (equation 10);
32,775 psi (1.72 Sm)$
b) usage factor is 0.0442.
Circumferential and longitudinal welds in piping with stress levels below 2.4 S m and usage factors below 0.4 are excluded from from ISI examinations, in accordance with Table IWB-2500 1, Category 5-J
- 9. Examinations at GGNS of category B-J, B-K-1 and C-F welds have not identified any flaws or evidence of service induced degradation.
VII. Alternative testing: All the welds identified in Table 1 will be
'nspected twice by volumetric or surface
- amination, as applicable, during the 10 year interval as discussed in GGNS Safety Evaluation Report, Supplement #2.
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- l GRAND Gutr NUCLEAR STATION INSERVICE INSPECTION REQUIREMENTS I INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND C4JLF NUCLEAR STATION UNIT 1 RELIEF REQUEST NO. I-00010 REVISION 2 l PAGE 4 of 4 NRC Discussion As reported in the Safety Evaluation Report dated VIII. statement (for July 22: 1985, all of the subject welds will revision 1): receive volumetric examination of the accessible portions during the inspection interval. The Licensee has also com;ni tted to conduct an engineering evaluation of the entire weld condition if indications are found during the volumetric examinations. The Code-required surface examination and pressure tests will be conducted on all the welds.
The licensee has also stated failure of any of the subject welds would not have an adverse affect on plant safety since all of the areas can be isolated or the system can be shutdown in a manner consistent with plant design. In addition, contiruous leak detection monitoring is <
provided on all of the systems containing inaccessible welds.
Based on the review of Revision 1 of Relief Request I-00010 (Rev. 1) and the SER dated July 22, 1986, it is concluded that the limited i Section XI volumetric examination, along with the l Code-required Section XI surface examination and the hydrostatic test, ensure an acceptable level i of inservice structural integrity and that I compliance with the specific requirements of section XI would result in hardship or unusual difficulties without a compensating increase in the l evel of quality and safety. Therefore, relief is granted as requested.
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GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIRENENTS INSERVICE INSPECTION
- SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 RELIEF REQUEST NO. I-00010 REVISION 2 TABLE 1 EXAMINABLE EXAMINABLE ITCM SYSTEM WELD 150 PIPE VOLUMETRIC TYPE SURFACE WELO REAS0*H TOR NO NO NO NO SIZE COMPONENT AREA SCAN AREA CLASS TYPE LIMITATI0'S 1 E12 G014-FW-44 RH-8-8 6" VALVE TO ELBOW SS% T 100% 1 CIRC ELBOW RADIUS 2 821 G9-Cl-B-L/B MS-11-8 28" ELBOW SEAM 38% T 38% 1 LONG PIPE RESTRAINT 3 ESI G004-8-8-1 RI-8-2 6" ELBOW TO ELBOW 70% T 100% 2 CIRC ELBOW RADIUS
- 4 B21 G11-01-B-L/B MS-11-11 28' ELBOW SEAM 38% T 38% 1 LONG PIPE RESTRAINT S B21 G8-Al-B-L/* MS-11-2 28" ELBOW SEAM 38% T 38% 1 LONG PIPE RESTRAINT 6 821 G030-FW-23 FW-8-2 24" VALVE TO PIPE 93% T 100% 1 CIRC SOCK-0-LET 7 821 G030-FW-36 FV-8-4 24" VALVE TO PIPE 93% T 100% 1 CIRC SOCK-0-LET 8 821 6026-FW-17 FV-11-7 6" P!PE TO TEE 93% T 100% 1 CIRC SOCK-0-LET I
9 B21 G001-W4 MS-11-3 28" VALVE TO PIPE 82% T 100% 1 CIRC PIPE RESTRAINT i
10 B21 G001-W4 MS-11-9 28" VALVE TO ELBOW 82% T 100% 1 CIRC PIPE RESTRAINT 11 B21 G9-Cl-B-L/A MS-11-8 28" ELBOW SEAM 38% T 38% 1 LONG PIPE RESTRAINT 12 B33 G5-B1-E RR-11-9 4"/24" SWEEP TO PIPE 69% T 100% 1 BRANCH SWEEP-0-LET I
GRAND GULF NilCLEAR STATION INSERVICE INSPECTION REQUIRENENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 RELIEF REQUEST NO. I-00010 REVISION 2 TABLE 1 EXAMINABLE EXAMINABLE ITEM SYSTEM WELD ISO PIPE VOLUMETRIC TYPE SURFACE WELD REASON FOR NO NO NO NO SIZE COMPONENT AREA SCAN AREA CLASS TYPE LIMITATIONS 13 ESI G004-7-8-4 RI-8-1 10" REDUCER TO TEE 71% T 100% 2 CIRC TEE 14 E51 G004-7-o-9 RI-8-1 10" REDUCER TO TEE 71% T 100% 2 CIRC TEE 15 E51 G004-7-8-8 RI-8-1 10" REDUCER TO TEE 71% T 100% 2 CIRC TEE 16 B33 G024-W2 RR-11-19 4" ELBOW TO TEE 62% T 100% 1 CIRC TEE 17 G33 G002-W179 CU-8-7 4" ELBOW TO FITT. 63% T NA 1 CIRC ELBOW RADIUS 18 B21 Gil-DI-B-L/A MS-11-11 28" ELBOW SEAM 38% T 38% 1 LONG PIPE RESTRAINT 19 B21 G001-W9 MS-11-12 28" VALVE TO PIPE 82% T 100% 1 CIRC PIPE RESTRAINT ,
20 B21 G8-Al-B-L/A MS-11-2 28" ELBOW SEAN 38% T 38% 1 LONG PIPE RESTRAINT RI-8-12 6" VALVE TO ELBOW f~
21 E51 G001-W1 73% T 100% 2 CIRC j ELBOW RADIUS 22 E51 G001-W40 RI-11-4 6" VALVE TO ELBOW 73% ! 100% 1 CIRC ELTIA.' RAf"JS 23 833 G001-W5 RR-11-2 24" ELBOW TO PUMP 73% see note 1 T 1007 1 C1EC Pur'P 24 B33 G001-W6 RR-11-2 24" PIPE TO PUMP 58% see note 1 T 100% 1 CIRC PUMP
GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIRENENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 RELIEF REQUEST NO. I-00010 REVISION 2 TABLE 1 EXAMINABLE EXAMINABLE ITEM SYSTEM WELD ISO PIPE V0tuMETRIC TYPE SURFACE WELD REASON FOR M0 NO NO NO SIZE COMPONENT AREA SCAN AREA CLASS TYPE LIMITATIONS 25 B33 G001-W8 RR-11-3 24" VALVE TO PIPE 50% see note 2 T 100% 1 CIRC VALVE 26 B33 G001-V28 RR-11-9 24" ELBOW TO PUMP 62% see note 1 T 100% 1 CIRC PUMP 27 B33 G001-V29 RR-11-9 24" PUMP TO PIPE 61% see note 1 T 100% 1 CIRC PUMP 28 B13 G001-V31 RR-11-10 b" VALVE TO PIPE 50%see note 1&2 T 100% 1 CIRC VALVE 29 833 GS-B1-B RR-11-9 4"/24" SVEEP TO PIPE 59% see note 1 T 100% 1 BRANCH SWEEP-0-LET 30 B33 G5-B1-E RR-11-9 4"/24" SWEEP TO PIPE 63% see note 1 T 100% 1 BRANCH SWEEP-0-LET 31 B33 G023-V37 RR-11-15 20" TEE TO PIPE 65% see note 1 T 100% 1 CIRC TEE 32 B33 G024-V8 RR-11-16 4" PIPE TO SWEEP 50% see note 2 T 100% 1 CIRC SWEEP-0-LET 33 B33 G024-V27 RR-11-17 4" PIPE TO SWEEP 50% see note 2 T 100% 1 CIRC SWEEP-0-LET 34 833 G10-B1-L RR-11-11 12"/16" SWEEP TO PIPE 50% see note 3 P 100% 1 BRANCH SWEEP-0-LET 35 B33 G10-81-K RR-11-11 12"/16" SWEEP TO PIPE 50% see note 3 P 100% 1 BRANCH SWEEP-0-LET 36 B33 G10-B1-J RR-11-11 12"/16" SWEEP TO PIPE 50% see note 3 P 100% 1 BRANCH SVEEP-0-LET r
GRAND Gulf NUCLEAR STATION INSERVICE INSPECTION REQUIRENENTS INSERVICE INSPECTION SECTION 4 TE" YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT I RELIEF REQUEST NO. I-000IO REVISION 2 TABLE I EXAMINABLE EXAMINABLE ITEM SYSTEM VELD ISO PIPE VOLUMETRIC TYPE SURFACE WELD REASON FOR NO NO NO NO SIZE COMPONENT AREA SCAN AREA CLASS TYPE LIMITATIONS n
37 B33 G10-B1-H RR-11-11 12"/16" SVEEP TO PIPE SO% see note 3 P 100% 1 BRANCH SVEEP-0-LET 38 B33 G10-B1-G RR-11-11 12"/16" SWEEP TO PIPE S0% see note 3 P 100% 1 BRANCH SVEEP-0-LET 39 B33 GIO-BI-F RR-11-11 12"/16" SVEEP TO PIPE S0% see note 3 P 100% 1 BRANCH SVEEP-0-LET 40 B33 G001-V34 RR-11-11 24" PIPE TO CROSS 50% see note 3 P 100% 1 CIRC CROSS 41 B33 G10-B1-A RR-11-11 16" PIPE TO CROSS 50% see note 3 P 100% 1 CIRC CROSS 42 B33 G10-B1-B RR-11-11 16" PIPE TO CROSS 50% see note 3 P 100% 1 CIRC CROSS 43 B21 G8-Al-C MS-11-2 8"/28" SWEEP TO PIPE 100% T 98% 1 BRANCH PIPE SUPPORT 44 B21 G026-V36 FV-11-1 24" PIPE TO VALVE 95% T 100% 1 CIRC PIPE SUPPORT 45 B21 G8-Al-L.M,N,P MS-11-2 28" LUGS TO PIPE N/A N/A 49% 1 INT ATT PIPE RESTRAINT 46 B21 G10-B1-L.M.N.P MS-11-S 28" LUGS TO PIPE N/A N/A 49% 1 INT ATT PIPE RESTRAINT 47 B21 G9-Cl-L,M,N.P MS-11-8 28" LUGS TO PIPE N/A N/A 49% 1 INT ATT PIPE RESTRAINT 48 821 G11-01-L.M,N,P MS-11-11 28" LUGS TO PIPE N/A N/A 49% 1 INT ATT PIPE RESTRAINT
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GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIREMENTS INSERVICE INSPECTION TEN YEAR PROGRAM GRAND GULF NUCLEAR STATION UNIT 1 RELIEF REQUEST NO. I-00010 REVISION 2 TABLE I LEGEND:
P = SCAN PARALLEL TO THE WELD T = SCAN TANGENT (PERPENDICULAR) TO THE WELD NOTES:
- 1. In addition to the "T" scan limitation, these welds are augmented by the requirements of NUREG 0313 and therefore are examined with a parallel scan that is not required by ASME Section XI. The parallel scan is limited to one side of the weld (50%) due to the fittings being joined by the weld.
- 2. 100% coverage was obtained in one direction only, using refracted longitudinal wave.
- 3. The "P" scan is performed for empliance with NUREG 0313, 100% of ASME Section XI coverage is obtained without limitation.
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GRAho GULF NUCLEAR STATION INSERVICE INSPECTION REQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION l UNIT 1 RELIEF REQUEST NO. I-00019 REVISION O PAGE 1 of 6 INSERVICE EXAMINATION REACTOR PRESS VESSEL ITEMS
- 1. Component: Inaccessible portions of the Reactor Pressure Vessel (RPV) as listed below.
- 1. Jet Pump Instrument Nozzles (N-9 A&B), safe end to penetration seal welds (see figure 1).
figure 2).
II. Code: 1. The Jet Pump Instrument Nozzle assemblies were designed and fabricated to ASME Section i III, Class 1 requirements. Applicable inservice inspections are to be performed in accordance with the ASME Section XI, 1977 Edition, through and including the Summer 1979 Addenda, Table IWB-2500, Category B-J.
- 2. The RPV flange assembly is designed and fabricated to ASME Section III, Class 1 requirements. Applicable inservice l inspections are to be performed in accordance with the ASME Section XI, 1977 Edition, through and including the Summer 1979 Addenda, Table IWB-2500, Category B-G-1.
j III. Code Requirements: 1. ASME Section XI, Table IWB-2500, Category B-J, requires the safe end to penetration :
seal weld to be volumetrically and surface l examined. The examinations are to be performed once e&ch inspection interval.
- 2. ASME Section XI, Table IWB-2500, Category B-G-1, requires the threads in the RPV flange stud hole, and one inch of base material around the stud hole, to be volumetrically 1
- examined for a depth equal to the diameter of I the stud. The examinations are to be i performed once each inspection interval. I npe msg /rri-19r0
GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 RELIEFREQUESTNO.I-00019REVISIONO PAGE 2 of 6 IV. Information to 1. The welds requiring relief attach the support the penetration seal to the safe end. The determination that penetration seal is a forged item allowing the code 14 socket welded connections for each of the requirements are two N9 nozzles. The configuration of the impractical: penetration seal and the installing weld limits the access required for obtaining full code coverage of the weld and associated base material.
The weld is volumetrically examined from the safe end obtaining 44.7% coverage of the code volume. Examination from the weld and from the penetration seal side of the weld is prohibited due to component configuration and weld geometry (see figure 1).
- 2. The area of the RPV flange requiring relief is located between the stud hole and the RPV inside diameter (ligament area). The ligament area also contains the sealing surface that makes contact with the RPV head fl ange. The seal surface is comprised of deposited weld material, and raised approximately 1/2 inch above the flange face creating a geometrical obstruction.
A code volume of 96% is volumetrically examined without interference with the seal surface. The remaining 4% is contained within the restricted area associated with the seal surface (see figure 2).
V. Specific relief Permission is requested to perform the Code requested: required volumetric examinations to the extent described above and shown in figures 1 and 2.
VI. Reasons why relief Request for permission to limit the code required should be granted: examination to the accessible areas should be ;
granted for the following reasons: l npe msg /rri-19r0 1
1
. l GRAND GULF NucLdAR STATION INSERVICE INSPECTION REQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 RELIEF REQUEST NO. I-00019 REVISION O PAGE 3 of 6 VI. Reasons why relief 1. N9 N0ZZLE TO PENETRATION SEAL should be granted:
(continued) a. The subject welds were installed, radiographed, surface examined and hydrostatically tested to the requirements of ASME Section III, Class 1.
- b. The subject welds are completely surface examined during inservice activities once each inspection interval.
- c. The welds are subject to a system leakage test at completion of each refueling outage and a system hydrostatic test once each inspection interval.
- d. The safe end material is SA 336-F8 (304) stainless steel, and the penetration seal is 304L stainless steel. Due to the geometric configuration of the weld joint, the examination can only be conducted from the safe end side of the joint, and therefore, not obtaining full coverage. The examination is able to obtain 44.7% of the code required volume. The examineable area includes the inside surface of the safe end (304 stainless steel material) including the heat affected zone.
The primary degradation mechanism at this location is intergranular stress corrosion cracking (IGSCC). Fatigue is not a significant factor due to the limited fatigue loading at this location. Therefore, the potential for cracking at this location should npe msg /rri-19r0
GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 RELIEFREQUESTNO.I-00019REVISIONO PAGE 4 of 6 VI. Reasons why relief consider IGSCC only. The occurrence of should be granted: IGSCC is caused by the simultaneous (continued) presence of three factors; 1) high stress, 2) aggressive environment, and
- 3) susceptible material . The safe end and penetration seal side of the weld both see essentially the same stress and environmental conditions. However, l there is a significant difference in material susceptibility between the 304 SS safe end and the 304L penetration seal. Generic Letter 88-01, NUREG 0313 l Revision 2, recognizes 304L type i materials as being IGSCC resistant. :
The 304 portion of the assembly )
including that side of the weld root is ;
examined from one direction utilizing '
IGSCC techniques and qu ali fied personnel. In addition, Generic letter 88-01 excludes all piping smaller than 4 inches in nominal diameter. The N9 A&B safe ends are less than four inches in nominal diameter, and therefore, under the rules of the generic letter, the safe ends are not susceptible to IGSCC.
- e. The accessible portions of the subject welds will be volumetrically examined and the complete weld and adjacent base material will be surface examined in accordance with ASME Section XI.
Should indications be found, an engineering evaluation will be made to determine if the inaccessible portions of the subject welds have been affected.
- f. Any leakage occurring from the N9 nozzles would be detected be the existing leakage detection system.
npe msg /rri-19r0
=
. I GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 RELIEF REQUEST No. I-00019 REVISION O PAGE 5 of 6 VI. Reasons why relief g. Mechanical preparation of the wald should be granted: would allow additional coverage to be (continued) obtained by facilitating transducer placement on top of the weld. The efforts necessary for obtaining the improved coverage would require a man rem expenditure of approximately 21.2 whole body and 37.2 for the extremities. The total man rem exposure required to obtain the additional examination coverage is not justified based on the low probability of IGSCC occurrence and the limited fatigue loading at the subject welds,
- h. Examination history at GGNS has not recorded any fl aws or evidence of service induced degradation in category B-J welds.
- i. The limited examination of the two N-9 nozzles (A&B) is considered to be sufficient to determine the structural integrity of welded assemblies.
- a. The RPV flange was fabricated as part of the RPV assembly and tested to the requirements of ASME Section III, Class 1.
- b. The RPV, including the flange assembly, is subject to a system leakage test at completion of each refueling outage and a system hydrostatic test once each inspection interval, npe msg /rri-19r0
GRAND GULF NUCLEAR STATION INSERVICE INSPECTION RCQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST GRAND GULF NUCLEAR STATION UNIT 1 RELIEF REQUEST NO. I-00019 REVISION 0 PAGE 6 of 6 VI. Reasons why relief c. The entire code volume around the stud should be granted: hole is examined except for the area (continued) associated with the sealing surface.
This area is examined for a distance of 1/2 inch from the stud hole before interference from the seal surface is encountered. With the RPV head in pl ace, and fastened with the studs to the RPV shell flange, the seal surface and underlying material is subjected to I compressional loads. The material in l the vicinity of the threads or adjacent to the stud hole is subjected to shear loading with the head in place.
l Therefore, the limiting location with respect to applied stress is the material nearest the stud hole threads.
Since this limited area is examined, any anticipated flaw initiation will be detected,
- d. The amount of obtained volumetric coverage that includes the bounded area l 1s adequate to ensure structural integrity of the stud hole regions of the RPV flange.
VII. Alternate testing None l 1
npe msg /rri-19r0
GRAND GULF NUCLEAR STATION INSERVICE INSPECTION REQUIRENENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PRCGRAM RELIEF REQUEST N9 A 8 8 SAFE END TO PENETRATION SEAL 44.7% EXAMINED IN ONE DIRECTION l HUMP AT ( OF WELD PREVENTS SCANNING COMPLETELY ACROSS WELD WELD g MACHINED EDGE
.68",
i 10* SLOPE SAFE END PENETRATION SEAL F -1
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[.~.~_'_',~,']CODE VOLUME FOR VOLUMETRIC EX AMINATION : .228 lN
((/2 EXAMINABLE VOLUME FOR VOLUMETRIC EXAMIN ATION =.102 IN or 44.7 %
FIGURE I
GRAND Gulf NUCLEAR STATION INSER\' ICE INSPECTION REQUIREMENTS INSERVICE INSPECTION SECTION 4 TEN YEAR PROGRAM RELIEF REQUEST CODE EXAMINATION VOLUME FOR 3GO' OF STUD RPV CLOSURE STUD
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STAINLESS STEEL $'
I VESSEL 1D OVERLAY WELD METAL SEALING SURFACE ,
f SEALING i # N SURFACE 2 $
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RP V STU D -
I"CODE EXAMINATION VOLUME s . 5" k 3
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RPV FLANGE TOP VIEW OF SHELL FLANGE UNABLE TO SCAN FULL I"CIRCLE AROUNO STUD HOLE
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