ML20076B589
| ML20076B589 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry, 05000000 |
| Issue date: | 07/30/1982 |
| From: | SCIENCE APPLICATIONS INTERNATIONAL CORP. (FORMERLY |
| To: | NRC |
| Shared Package | |
| ML20076B592 | List: |
| References | |
| CON-NRC-03-82-096, CON-NRC-3-82-96 SAI-186-028-16, SAI-186-28-16, NUDOCS 8208040170 | |
| Download: ML20076B589 (49) | |
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SAI Report No. 186-028-16 BROWNS FERRY NUCLEAR POWER PLANT UNITS 1, 2 AND 3 INSERVICE INSPECTION PROGRAM TECHNICAL EVALUATION REPORT Submitted to:
U. S. Nuclear Regulatory Commission Contract No. 03-82-096 Science Applications, Inc.
McLean, Virginia 22102 l
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l July 30, 1982 XA Copy Has Been Sent to PDR Science Applications,Inc.
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i CONTENTS INTRODUCTION.............................
1 I.
CLASS 1 COMPONENTS.......................
4 A.
Reactor Vessel.......................
4 1.
Request for Relief ISI-2; Pressure Retaining Welds, Categories B-A and B-8, Items Bl.1 and Bl.2 4
2.
Request for Relief ISI-3; Reactor Pressure Vessel Support Skirt, Category B-H, Item Bl.12 7
3.
Request for Relief ISI-6; Pressure Retaining Welds in Control Rod Drive Housings, Category C-0, Item Bl.18.................-
9 B.
Pressurizer (does not apply to BWRs)
C.
Heat Exchangers and Steam Generators (no relief requests)
D.
Piping Pressure Boundary.
11 1.
Request for Relief ISI-7; Pressure Retaining Welds i n P i p i n g, C a tego ry B.J, I tem B4. 5...........
11 2.
Request for Relief 151-12; Pressure Retaining Longi-tudinal Welds in Piping, Category B-J, Item B4.5....
15 3.
Pequest fcr Relief ISI-8; Pressure Retaining Welds in Piping, Category B-J; Pressure Retaining Dissimilar Metal Welds, Category B-F; and Pressure Retaining Welds in Valve Bodies, Category B-M-1 la 4.
Request for Relief ISI-9; Support Members for Piping and Valves, Category B-K-1, Item B4.9 22 l
E.
Pump Pressure Boundary..
24 l
1.
Request for Relief ISI-4; Reactor Recirculation Pumps, Category B-L-2, Item B5.7............
24 F.
Valve Pressure Boundary 27 1.
Relief Request ISI-9; Support Members for Valves, Category B-K-1, Item B6.4 27 2.
Relief Request ISI-8; Pressure Retaining Welds in Valve Bodies, Category B-M-1, Item B6.6 27 3.
Request for Relief ISI-5; Valve Bodies, Category B-M-2, Item B6.7....................
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CLASS 2 C0tiPONENTS........................
31 A.
Pressure Yessels.......................
31 1.
P.equest for Relief ISI-13; Pressure Retaining Nozzle Welds in RHR Heat Exchangers, Category C-B, Item C1.2 31 2.
Request for Relief 151-14; Pressure Retaining Bolting Exceeding 1-Inch Diameter, Category C-D, (all items) 33 B.
Piping.............................
35 1.
Request for Relief 151-14; Bolting, Category C-D.....
35 2.
Request for Relief ISI-8; Pressure Retaining Welds in Piping, Category C-F, Items C2.1, C2.2 and C3.3 (Unit 3 only) 35 3.
Request for Relief ISI-11; Support Members for Piping, Category C-E-1, Item C2.5 37 C.
Pumps 33 1.
Request for Relief 151-14; Bolting, Category C-D.....
38 D.
Valves............................
38 1.
Request for Relief 151-14; Bolting, Category C-D.....
38 III.
CLASS 3 COMPONENTS (no relief requests)
IV.
PRESSURE TESTS (no relief requests)
V.
GENERAL 39 A.
Ultrasonic Examination Techniques 39 1.
Request for Relief 151-10; Ultrasonic Calibration Standards, Class 1 and 2.................
39 2.
Request for Relief ISI-15; Ultrasonic Examination Technique of Pipir.g Welds, Class 1 and 2.........
41 B.
Exempted Components 43 1.
Code Exemption per IUC-1220(a), Components Exempted from Examination Based on Pressure and Temperature....
43 2.
Class 2 Components and Piping Exemptions Based on Chemistry Control per IWC-1220(c) 44 C.
Other(none)
REFERENCES..............................
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TECHNICAL EVALUATION REPORT BROWNS FERRY NUCLEAR PLANT UNITS 1. 2 AND 3 INSERVICE INSPECTION PROGRAM INTRODUCTION The revision to 10 CFR 50.55a, published in February 1976, required that Inservice Inspection (ISI) Programs be updated to meet the requirements (to the extent practical) of the Edition and Addenda of Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code
- incorporated in the Regulation by reference in paragraph (b). This updat4ng of the programs was required to be done every 40 months to reflect the new requirements of the later editions of Section XI.
A: specified in the February 1976 revision, for plants with Operating Licenses issued prior to March 1, 1976, the regulations became effective after September 1,1976,at the start of the next regular 40-month inspection period.
The initial inservice examinations conducted during the first 40-month period were to comply with the requirements in editions of Section XI and addenda in effect no more than six months prior to the date of start of facility comercial operation.
The Regulation recognized that the requirements of the later editions and addenda of the Section XI might not be practical to implement at facilities because of limitations of design, geometry, and materials of construction of components and systems.
It therefore permitted determinations of impractical examination or testing requirements to be evaluated.
Relief from these require-ments could be granted provided health and safety of the public were not endan-gered giving due consideration to the burden placed on the licensee if the requirements were imposed.
This report provides evaluations of the various requests for relief by the licensee, Tennessee Valley Authority (TVA), of the Browns Ferry Nuclear Plant Units 1, 2 and 3.
It deals only with inservice examinations of components and with system pressure tests.
Inservice tests of pumps and valves (IST programs) are being evaluated separately.
- Hereinafter referred to asSection XI or Code. Science Appheations,inc.
The revision to 10 CFR 50.55a, effective November 1,1979, modified the time interval for updating ISI programs and incorporated by reference a later edition and addenda of Section XI. The updating intervals were extended from 40 months to 120 months to be consistent with intervals as defined in Section XI.
For plants with Operating Licenses issued prior to March 1, 1976, the provisions of the November 1,1979 revision are effective after September 1, 1976,at the start of the next one-third of the 120-month interval. During the one-third of an interval and throughout the remainder of the interval, inservice examinations shall comply with the latest edition and addenda of Section XI, incorporated by reference in the Regulation, on the date 12 months prior to the start of that one-third of an interval.
For Browns Ferry Nuclear Plant Units 1, 2 and 3 the ISI program, and the relief requests evaluated in this report, cover the last 80 months of the current 120-month inspection in-terval, i.e., from July 1, 1980 to March 1, 1987. This orogram was based upon the 1974 Edition of Section XI of the AS!1E Boiler and Pressure Vessel Code with Addenda through the Summer of 1975.
The November 1979 revision of the Regulation also provides that ISI programs may meet the requirements of subsequent code editions and addenda, incorporated by reference in paragraph (b) and subject to Nuclear Regulatory Commission (NRC) approval.
Portions of such editions or addenda may be used provided that all related' requirements of the respective editions or addenda are met.
These instances are addressed on a case-by-case basis in the body of this report.
Finally,Section XI of the code provides for certain components and systems to be exempted from its requirements.
In some instances, these exemptions are not acceptable to NRC or are only acceptable with restrictions. As appropriate, these instances are also discussed in this report.
References (1) to (22) listed at the end of this report pertain to previous transmittals on ISI between the licensee and the Commission. By letters of September 15 and November 22,1976,(1,3) the Commission provided general ISI guidance to all licensees. Submittals in response to that guidance were made by the licensee on October 20,1976,(2) and January 28,1977.I4) On February 25, 1977,(5) the Connission granted approval to postpone implementation of the ISI program for Unit #3 to July 31, 1977. Additional submittals(6,7) were made science Appucations. ine-l 1
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by the licensee to the Cor: mission. By letters of May 31,1978,(8) and August 8, 1978,(9) the Commission requested additional information to complete the review of the ISI program submitted for Unit 3.(7) This infonnation was furnished by the licensee on November 3,1978,(10) and December 11,1976,(11) respectively.
Additional submittals were made by the licensee on March 29, 1979(12) and April 24, 1979.(13) On May 8, 1979,(14) the licensee submitted a revised ISI program for Unit 3.
On July 11,1979,(15) the, licensee proposed to start Units 1, 2 and 3 on the same ISI interval and the same program. Additional sub-mittals(16,17) were cade for Unit 3 by the licensee.
On December 24,1980(1d) the licensee submitted a proposal for a comon start cate of' July 1,1980 for
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the second 40-month cycle for Units 1, 2 and 3.
On November 16,1981,(19 the licensee submitted a revised ISI program for Units 1, 2 and 3.
On November 17,
,1931,(20) the licensee submitted revised technical specifications for Units 1 and 2.
By. letter of February 24, 1982,(21) the Comission requested additional information to complete the review of.the ISI prograin submitted for Units 1, 2 and 3.(19) This information.was furnished by the licensee on April 14, 1932.(22)
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From these submittals 4 total of 16 requests (a) for relief from code requirements, (b) for updating to a later code, and (c) for exemptions not necessarily acceptable to the ~ Commission were identified.
These requests are evaluated in the following sections of this report.
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CLASS 1 COMPONENTS A.
Reactor Vessel 1.
Request for Relief ISI-2, Pressure Retaining Welds, Categories B-A and B-B, Items Bl.1 and Bl.2 Code Requirement Category B-A (In Reactor Vessel Beltline Region):
Volumetric examination of the shell longitudinal and cir-cumferential welds during each inspection interval shall cover at least 10% of the length of each longitudinal weld, and 5%
of the length of each circumferential weld, with the minimum length of weld examined equal to one wall thickness. The exami-nation may be performed at or near the end of each inspection interval.
Category B-B (In Vessels):
Volumetric examinations shall be performed during eacn inspec-tion interval and shall cover at least 10% of the length of each longitudinal shell weld and meridional head weld and 5% of the length of each circumferential shell weld and head weld.
Code Relief Request Relief is requested from the volumetric examination of the following reactor pressure vessel welds, for Units 1, 2 and 3:
1 Weld Identification Category C-S-BH (Circ. Seam approximately 54 feet long)
B-B V-BH-2 (Long. Seam approximately 6.5 feet long)
B-B V-BH-3 (Long. Seam approximately 6.5 feet long)
B-B V-BH-4 (Long. Seam approximately 6.5 feet long)
B-B V-BH-5 (Long. Seam approximately 6.5 feet long)
B-B V-BH-6 (Long. Seam approximately 6.5 feet long)
B-B V-BH-1 (Long. Seam approximately 6.5 feet long)
B-B C-BH-1 (Cire. Seam approximately 69 feet long)
B-B V-1-B (Long. Seam approximately 11 feet, 1 inch long)
B-A V-1-A (Long. Seam approximately 11 feet, 1 inch long)
B-A V-1-C (Long. Seam approximately 11 feet, 1 inch long)
B-A C-1-2 (Circ. Seam approximately 69 feet long)
B-A V-2-B (Long. Seam approximately 11 feet, 1 inch long)
B-A V-2-A (Long. Seam approximately 11 feet, 1 inch long)
B-A V-2-C (Long. Seam approximately 11 feet, 1 inch long)
B-A C-2-3 (Circ. Seam approximately 69 feet long)
B-A V-2-C (Long. Seam approximately 11 feet, 1 inch long)
B-B V-3-B (Long. Seam approyimately 11 feet,1 inch long)
B-B SClence ApphCationS,Inc. '
i Lower head bottom section to lower head center section circum-ferential seam weld (approximately 39 feet long), Category B-B.
The lower head center section contains four longitudinal welds (approximately 2.5 feet long each), Category B-B.
Proposed Alternative Examination None Licensee's Basis for Requesting Relief The Browns Ferry Nuclear Plant was designed and under construction before the issuance of Section XI. As a result, only those welds above the sacrificial shield are accessible for inservice inspection. Access has not been provided in f.the sacrificial shield area for external examinations nor does Ithe BWR design permit internal examinations in this area.
g Only those welds above the sacrificial shield and portions of welds as may be accessible at nozzle access points will be examined during thE inservice inspection intervals.
Evaluation Imposition of the Code requirements would necessitate the removal of portions of the concrete biological shield and the permanently installed insulation to perform the required ex-amination of the welds listed from the vessel exterior.
The vessel internals, shroud and jet pumps preclude volumetric examination of almost all the beltline weld volume from the vessel interior.
The reactor vessel is presently monitored for radiation damage in the beltline region by a surveillance program in accordance with ASTM-E185-70 to the extent possible and there-fore conforms to the intent of 10 CFR 50, Appendix H.
In addition, the vessel was designed and fabricated in accordance with the rules of Section III of the 1965 Edition and Addenda through the Summer 1966 of the ASME Boiler and Pressure Vessel Code.
This examination requirement is impractical due to the existing design and geometry for the above welds.
Certain longitudinal and circumferential welds, not in the core region, are partially or wholly accessible for inservice examination, In response to a request for additional information, the licensee has summarized the weld accessibility as follows:
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I Accessible Length Code Required Weld Code Required Weld Not Required By Code Category Length Accessible Length Inaccessible Code B-A None 6.6 ft. Long. Seau None 6.9 ft. Circ. Seam l
B-B 5.9 ft. Long. Seam 7.1 ft. Long. Seam 31.9 ft. Long. Seam 7.0 ft. Circ. Stam 8.1 ft. Circ. Seam 24.5 ft. Circ. Seam To maintain the extent of examination, an alternative inservice inspection program would be required.
The examination of the accessible Category B-B welds could be increased to achieve an exanination sample equivalent to the Category B-A and B-B welds for which relief was requested.
Based on the above summary, examination of 13.7 ft of longitudinal welds (of the 31.9 ft not required by the Code), and 15.0 ft of circumferential welds (of the 24.5 ft not required by the Code) would meet this aug-mented program.
In addition, visual inspections of the identified welds for which code relief was requested, to the extent possible, could be performed during system leakage and hydrostatic tests.
Such examinations should furnish sufficient information to evaluate the structural reliability of the welds.
Conclusions and Recommendations Based on the above evaluation, it is concluded that for the welds discussed above, the code requirements are imoractical.
It is further concluded that the alternative examination dis-cussed above will provide necessary added assurance of structural reliability. Therefore, the following is recommended:
Relie# should be granted from the volumetric examination of the icentified welds with the following provisions:
The exaninations of the accessible Category 3-B welds e
are increased to achieve an examination sample equivalent to the Category B-A and B-B welds for which relief is requested.
e Visual inspection of the accessible portions of the identified welds are conducted for evidence of leakage during system hydrostatic tests when performed as required by IWB-5000.
References References 19, 21 and 22.
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2.
Request for Relief ISI-3; Reactor Pressure Vessel Support Skirt, Category B-H, Item Bl.12 Code Requirement For vessel support skirts, volumetric examination shall be performed during each inspection interval and shall cover at least 10" of the circumference of the weld to the vessel.
Code Relief Request Relief is requested from performing 100% of the required volumetric examination of the support skirt attachment weld to the reactor pressure vessel. Approximately 67E-of the required examination can be completed.
Proposed Alternative Examination None Licensee's Basis for Requesting Relief Approximately 6 feet of the atta.nment weld would require examination to meet Code requirements.
However, nonremovable reactor-vessel insulation limits inservice examination. Two access ports, approximately 180 degrees apart, provide access for examination of two 2-foot lengths.
Four feet of the support skirt-to-reactor vessel weld will be ultrasonically examined during each inspection interval.
Evaluation Access to this weld is limited by the nonremovable vessel insulation. The licensee, however, is able to perform the examinations required to a limited extent (approximately 67" of the requirement).
Surface examinations can be performed only on the sane 4 feet of weld that will be volumetrically examined.
- Hence, supplemental surface examinations would not contribute any additional information.
Examination of 4 feet of the weld should furnish suffi-cient information to enable a judgment to be made on the structural reliability of the weld.
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Conclusions and Recommendations Based on the above evaluation, it is concluded that for the weld discussed above, the code requirements are impractical.
It is further concluded that the partial examination discussed above will provide necessary assurance of structural reliability.
Therefore, the following is recommended:
Relief should be granted to limit the required volumetric examination to the accessible 4 feet of the circumference of the skirt-to-vessel weld.
References _
References 19, 21 and 22.
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Request for Relief ISI-6; Pressure Retaining Welds in Control Rod Drive Housings, Category B-0, Item Bl.18 Code Requirement Volumetric weld examinations shall t;e performed during each inspection interval and shall include 100% of the welds in 10% of the peripheral control rod drive (CRD) housings.
The examinations may be perfomed at or near the end of the in-spection interval.
Code Relief Recuest Relief is requested from the volumetric exa_mination of the peripheral CRD housing welds.
Proposed Alternative Examination All peripheral CRD housing welds shall be visually examined during the system hydrostatic pressure tests in accordance with IWB-1220(c).
Licensee's Basis for Requesting Relief Should the CRD housing weld fail, the leakage path to the failure meets the makeup exclusion criteria, maximum 3 in.
diameter pipe, and is therefore excluded from volumetric examina-tion in accordance with IWB-1220(b)(1). The makeup supply system is equivalent to 4-in, nominal pipe size. The largest leakage path area would be realized between the guide cap and thermal sleeve. The total leakage path area is 0.83 sq. in., which is substantially less than 7.39 sq. in. (flow path area of a 3-in.
diameter pipe).
Evaluation The licensee has shown that the maximum flow path resulting from a complete failure of the CR0 housing weld is less than that of a pipe of 3 in. diameter and has stated that the makeuo system has sufficient capacity to shut down and cool the reactor in an orderly manner. The control rod drive weld is greater than 3 in. diameter but, due to the internal housing mechanisms and the stop on each housing, the unobstructed flow path is much smaller. The requirements of paragraph IWB-1220(b)(1) are satisfied and the examinations required for Code-exempted com-ponents will be performed by the licensee.
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Conclusions and Recomendations Based on the above evaluation, it is concluded that for the welds discussed above, the code requirements for exemption of volumetric examinations have been satisfied.
It is further con-cluded that the alternative examination discussed above will provide necessary added assurance of structural reliability.
Therefore, the following is recomended:
Relief should be granted from the volumetric examination of 100% of the welds in 10% of the peripheral CRD housings, with the following provision:
All peripheral CRD housing welds are visually examined during the system hydrostatic pressure tests in accord-ance with IWD-1220(c), as proposed by the licensee.
Reference Reference 19.
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B.
Pressurizer Does not apply to BWRs.
C.
Heat Exchangers and Steam Generators No code relief requests.
D.
Piping Pressure Scundary 1.
Request for Relief ISI-7; Pressure Retaining Welds in Piping; Category B-J, Item B4.5 Code Requirement Volumetric weld examinations shall be performed during each inspection interval and shall cover all the area of 25% of the circumferential joints including the adjoining I ft, sections of longitudinal joints and 25% of the pipe branch connection joints.
Code Relief Request Relief is requested from the volumetric examination of the following pressure retaining welds:
(a) Penetration Flued Head to Process Pioe Welds (Units 1, 2 and 3)
No. Welds System 2
Main Steam Residual Heat Removal (RHR) 4 2
Reactor Water Cleanun 1
High Pressure Coolant Injection (HPCI)
(b) Main Steam Welds (Units 1, 2 and 3)
KMS-1 KMS-29 KMS-56 KMS-81 (c) Feedwater Welds (Units 1, 2 and 3)
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Feedwater Walds (Unit 3)
KFW-41 KFW-42 KFW-43 KFW-45 Proposed Alternative Examination A "best effort" visual examination will be performed during system leakage and hydrostatic pressure tests.
Licensee's Basis for Requesting Relief The penetration flued head to process pipe welds are inaccessible for any type of examination. The four main steam welds and the two feedwater welds on each unit are located under rigid pipe restraints and are inaccessibtf for volumetric examination. The four feedwater welds on Unit 3 are located under pipe supoorts.
Evaluation The identified welds are completely inaccessible for volumetric or surface examination because the welds are either located inside a containment penetration or are covered by rigid pipe restraints.
(a) Penetration Flued Heat to Process Pipe Welds, Units 1, 2 and 3 Each primary containment penetration assembly, due to its design, leaves one pressure retaining piping weld inaccessible for examination by either surface or volu-metric means.
The welds can only be examined by inspecting for evidence of leakage during system hydrotests.
The initial design of the assemblies did not provide for accessibility for inservice examinations.
If it is assumed, though, that the workmanship and gaality assurance of the welding as well as the preservice examinations were adequate, then an examination of the first pressure boundary weld (process piping to flued head) outside the containment should reflect service-induced failures for that particular piping section. Thus, the first pressure boundary weld outside the containment on each of these process pipes would be volumetrically examined, where practical, over 100% of its length during each inspection interval. Such an examination would maintain sample size. The licensee could also conduct visual examinations at these penetrations as proposed.
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(b) Main Steam Weld- (Units 1, 2 and 3)
Feedwater Welds (Units 1, 2 and 3)
Because these welds are completely inaccessible, examina-tion is not practical and relief from the examination could be granted on that basis. However, the number of inaccessible welds is sufficiently small and random, compared with the total number of welds in Category 3-J (or in either of the two affected systems) that none of these welds needs to be included in the 25% sample to be examined during this inspection interval.
For subsequent inspection intervals, the licensee has the option of updating to subsequent code versions or of staying with the 1974 Edition and addenda through the Summer 1975 Addenda, pursuant to 10 CFR 50.$ta(b)(2)(ii).
Updating would allow the licensee to examine the same 25%
sample, if the provisions of the Summer 1978 Addenda of the 1977 Edition continue to prevail (see Footnote (2) of Cate-gory B-J in Table IW8-2500-1). By adopting 10 CFR 50.55a (b)(2)(ii) the Commission was offering an option whereby
" operating facilities with ongoing inservice inspection programs would have continuity in the extent and frequency of examinations for pipe welds" (see 44 FR 57913).
Based on these considerations, relief from these requirements is not required at this time for these welds.
It is preferable to defer a decision until the next inspec-tion interval after the licensee has determined which of the above options he wishes to exercise.
In addition, visual examination of the welds for which code relief is requested could be performed in the interim.
Those welds covered by the pipe restraints could also be examined if the pipe restraints need to be disassembled for maintenance.
Conclusions and Recommendations (a) Penetration Flued Head to Process Pipe Welds, Units 1, 2 and 3 Based on the above evaluation, it is concluded that for It is fur-these welds, the code requirements are inpractical.
ther concluded that the alternative examination ' discussed above will provide necessary added assurance of structural reliability.
Therefore, the following is recommended:
Relief should be granted from the volumetric examination of the identified welds, with the following provisions:
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i e The first pressure bouncary weld outside the containment on each of these process pipes should be volumetrically examined, where practical, over 100% of its length during each inspection interval.
e The proposed visual examinations should be performed on the containment penetration assemblies when leakage and hydrostatic tests are conducted in accordance with IUB-1220(c).
(b) Main Steam Welds (Units 1, 2 and 3)
Feedwater Welds (Units 1, 2 and 3)
Based on the above evaluation, it is concluded that for these tvelds, there is not presently enGUgh justification for granting relief from the impractical code requirements.
Therefore, the following is recommended:
(a) Relief from volumetric examination should not be granted at this time.
(b) The identified welds should be visually examined during the system hydrostatic pressure tests in accordance with IWB-1220(c).
(c) In the event that the pipe restraints are disassembled for maintenance and the welds are accessible for exami-nation, the code-required examination should be performed.
References References 19 and 22.
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Request for Relief ISI-12; Pressure Retaining Lonoitudinal Welds in Piping, Category B-J, Item B4.5 Code Requirement Volumetric weld examinations shall be performed during each inspection interval and shall cover all of the area of 25% of the circumferential joints including the adjoining 1-ft sections of longitudinal joints and 25% of the pipe branch connection joints.
Code Relief Request Relief is requested from performing 100% of the required volumetric examination of the following pressuTF-retaining longitudinal welds in piping (Unit 3):
Longitudinal Seam Adjacent to Weld n Inspection Limitation GR-3-62 0
Prohibited by support lug KR-3-51 50 Scan limited to 6" by support DCS-3-4 25 Scan limited to 5" by support DCS-3-5 65 Scan limited to 8" by support DCS-3-13 50 Scan limited to 6" by penetra tion GMS-3-2 16 Scan limited to 2" by penetration GMS-3-3 50 Scan limited to 6" by support GMS-3-9 50 Scan limited to 6" by penetration GMS-3-10 15 Scan limited to 2" by penetration GMS-3-11 50 Scan limited to 6" by penetration GMS-3-15 15 Partial scan limited by insulation ring GMS-3-32 15 Partial scan limited by insulation ring GMS-3-18 50 Scan limited to 6" by penetration GMS-3-19 25 Scan limited to 3" by penetration GMS-3-20 15 Scan limited to 2" by penetration GMS-3-27 50 Scan limited to 6" by penetration
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e Longitudinal Seam Adjacent to Weld
% Inspection Limitation l
GMS-3-28 15 Scan limited to 2" by penetration GMS-3-29 50 Scan limited to 6" by penetration DSRHR-3-9 35 Scan limited to 4" by support DSRHR-3-7 35 Scan limited to 4" by support DSRHR-3-6 35 Scan limited to 4" by support DSRHR-3-5A 10 Scan limited to 1" by elbow radius DSCS-3-4 75 Scan limited by elbow curvature DRHR-3-18 75 Scan limited to 9" by support ORHR-3-13 50 Scan limited to 6" by penetration KMS-3-105 75 Partial scan limited by support lug Proposed Alternative Examination A surface examination will be performed on the accessible Code-required length of the weld.
Licensee's Basis for Requesting Relief These are longitudinal pipe welds only partly accessible for inservice examination. The limitations to performing a full volumetric examination of each weld are listed above with the identified weld.
Evaluation Because of the design of the components or locations of the circumferential weld, it is considered impossible to obtain meaningful examination results on 100% of the longitudinal seam required to be examined by the Code.
This request involves welds on only one unit.
In essentially all instances, at least some portion of the sean adjacent to the circumferential weld is accessible to volumetric examination.
For these welds, a best-effort volumetric examination could be maintained to the volume percentages estimated in the relief request.
Surface examination would augment the volumetric examination. Visual examinations should be per-formed during system leakage and hydrostatic tests.
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l Conclusions and Recommendations Based on the above evaluation, it is concluded that for the welds discussed above, the code requirements are impractical.
It is further concluded that the alternative examination dis-cussed above will provide necessary added assurance of structural reliability. Therefore, the following is recommended:
Relief should be granted from the volumetric examination of the identified welds provided that the following examinations are performed:
e a best effort volumetric examination of the volumes estimated in the relief request; e a surface examination, as proposed by the licensee; and e visual examinations during system hydrostatic pressure tests in accordance with IWB-1220(c).
References References 19 and 22.
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Request for Relief 151-8; Pressure Retaining Welds in Piping, Category B-J; Pressure Retaining Dissimilar Metal Welds, Category B-F; and Pressure Retaining Welds in Valve Bodies, Category B-M-1 Code Requirement e Category B-J; Itams 84.5 and B4.6 Volumetric weld examinations shall be performed during each inspection interval and shall cover all of the area of 25% of the circumferential joints including the adjoining 1-ft sections of longitudinal joints and 25% of the pipe branch connection joints.
o Category B-F Volumetric and surface examinations shall be performed dur-ing each inspection interval and shall cover the circumference of 100% of the welds.
e Category B-M-1; Item B6.6 Volumetric weld examinations shall be performed during each inspection interval and shall include 100% of the pressure-retain-ing welds in at least one valve within each group of valves that are of the same constructional design, (e.g., globe, gate, or check valve), manufacturing method and manufacturer and that are performing similar functions in the system (e.g., containment isolation, system overpressure protection, etc.).
The examinations may be performed at or near the end of the inspection interval.
Code Relief Request Relief is requested from performing 1005 of the required volumetric examination of the following pressure retaining welds:
Class 1 Welds Unit 1 Weld Identification
% Inspection Limitation DCS-1-8 65 Valve Configuration -
Branch Conn.
DCS-1-15 70 Valve Configuration - Support DCS-1-17 65 Valve Configuration -
Branch Conn.
ORWC-1-3 70 Valve Configuration -
Branch Conn.
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l Weld Identification
% Inspection Limitation TRWC-1-3 65 Valve / Bonnet Configuration TRWC-1-4 70 Valve Configuration - Branch Conn.
Unit 2 Weld Identification
% Inspection Limitation KR-2-1 25 Branch Conn. Weld Configuration KR-2-4 50 Branch Conn. Weld Configuration GMS-2-19 50 Valve Configuration -
Penetration DHS-2-6 65 Valve Configuration - Elbow.
Curvrture KFW-2-26 75 Support Lug on Weld KMS-2-25 75 Support Lug on Weld i
XMS-2-63 50 Branch Conn. Weld Configuration KMS-2-76 80 Support Lug KMS-2-105 75 Support Lug on Weld RWC-2-3 70 Nozzle Configuration - Support Lug TCS-2-406 65 Valve Configuration - Support Lug DRWC-2-2 40 Valve Configuration - Support Lug and Branch Conn.
DRWC-2-3 60 Valve Configuration - Branch Conn.
RCRD-2-31 50 Valve Configuration-Support DSRHR-2-4 50 Support on Weld DSRHR-2-9 50 Support on Weld RCRDS-2-2 50 Branch Conn. Weld Configuration RCRDS-2-3 80 Tee - Reducer Configuration THPCI-2-72 65 Valve Configuration - Support Lug THPCI-2-82 50 Valve Configuration -
Penetration Unit 3 Weld Identification
% Inspection Limitation N4C-S/E 70 Nozzle Configuration - Branch Conn.
N4D-S/E 70 Nozzle Configuration - Branch Conn.
N4F-S/E 70 Nozzle Configuration - Branch Conn.
NSA-S/E 25 Nozzle Configuration -
Metallurgical Properties AVI science Appucaons.inc.
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Weld Identification
% Inspection Limitation N5B-S/E 25 Nozzle Configuration -
Metallurgical Properties GR-3-56 70 Valve Configuration - Support Lug DCS-3-8 70 Valve Configuration - Branch Conn.
DCS-3-17 70 Valve Configuration - Branch Conn.
GFW-3-7 50 Fitting Configuration (Both Sides)
GFW-3-23
/0 Fitting Configuration - Branch Conn.
GFW-3-24 50 Fitting Configuration (Both-94 des)
KMS-3-25 85 Support Lug KMS-3-63 50 Branch Conn. Configuration TCS-3-421 80 Duct Work TCS-3-423 80 Duct Work DRWC-3-1A 60 Valve Configuration - Branch Conn.
DRWC-3-3 70 Drain Line 'onn.
DSCS-3-8 70 Elbow Curvature - Branch Conn.
DSCS-3-10 65 Hanger - Elbow Curvature RCRD-3-22 70 Valve Configuration - Branch Conn.
TSCS-3-424 80 Duct Work Proposed Alternative Examination In addition to the visual examination performed during system leakage and hydrostatic pressure tests, a "best effort" ultrasonic examination will be performed. Also, a surface examination will be performec on accessible areas of the weld (s).
Licensee's Basis for Requesting Relief In some cases it will be impractical to inspect all welds in accordance with paragraph T-532 of Article 5,Section V, of the ASME Code, i.e., nonremovable hanger interference or valve and pump casings adjoining the welds.
Evaluation Because of the geometric configuration of the fittings, cr location of the welds,it is considered impossible to obtain mean-ingful examination results on 100% of the volume required to be examined by the Code. No more than 20 partially inaccessible welds are involved in any of the three units and no more than a small percentage of the welds in any one system. On essentially all these welds, more than half the weld volume is accessible to ultra-sonic examination.
A science Aconcations inc.
_ _ _ _ _ _ _ _ ~ _ _ _ _ _ _ _ _ _ _ _ _ _ _
4 As proposed by the licensce, a best-effort ultrasonic examination and surface examination on the accessible areas of 'the welds is practical for the above Category B-F, B-J, and B-M-1 welds. The ultrasonic examination should cover the estimated weld volume percentages given in the relief requests.
(The proposed surface examination is code-required for the Category B-F welds, but not for the other two cate-gories.) Visual examinations could also be performed during system leakage and hydrostatic tests.
Conclusions and Recommendations Based on the above evaluation, it is concluded that for certain Category B-F, B-J, and B-M-1 welds (discussed above),
the code requirements are impractical.
It is further ccncluded that the alternative examination discussed above will provide necessary added assurance of structural reliability.
Therefore, the following is recommended:
Relief should be granted from the volumetric examination of the identified welds provided that the following alternative examinations (proposed by the licensee) are performed:
(a) a best-effort ultrasonic examination of the accessible weld volume percentages estimated in the relief request (b) a surface examination (c) visual examinations during system hydrostatic pressure tests in accordance with IWB-1220(c).
1 l
References References 19 and 22.
JE science Apphcahons,Inc.
4.
Request for Relief ISI-9; Support Members for Fiping and Valves, Category B-K-1, Item Bd.9 Code Requirement The volumetric examination performed during each inspection interval shall cover 25% of the integrally welded supports. The areas shall include the integrally delded external support attachments. This includes the welds to the pressure-retaining boundary and the base metal beneath the weld zone and along the support attachment member for a distance of two support thick-nesses.
Code Relief Reouest Relief is requested from the volumetric examination of all intecrally welded external support attachments for piping, and valves, except welds KR-1-54 and KR-1-55 (Unit 1).
Proposed Alternative Examination Class 1 integrally welded supports will be liquid penetrant examined in place of ultrasonic examinations. The liquid pene-trant examinations performed during each inspection interval will cover 25% of the integrally welded supports.
Licensee's Basis for Requesting Relief During the first Browns Ferry baseline inspection, the ultrasonic examinations of the integrally welded Class 1 supports were meaningless because of the lack of penetration indications that existed for the full length of the support welds. The supports were fabricated to ANSI B31.1.0 and General Electric Company specification 21A2100. The GE specification required a full penetration weld and surface examination requirements, which would no.t verify penetration. The TVA Division of Engineering Cesign has taken actual weld dimensions of randomly-chosen piping supports and compared the load capabilities of these welds as installed to the loads based on design the supports would see during operation. As indicated in this analysis, all supports studied have high factors of safety in their load-carrying capability; therefore, the licensee feels that the inte-grally welded supports on the primary coolant piping are acceptable as installed.
Future ultrasonic examinations of these supports would be meaningless.
Evaluation Because of the weld design, ultrasonic examination required 2 science Aponcations.inc.
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by the Code is impractical as determined during the baseline inspection. As an alternative examination, the licensee has committed to surface examination of these welds.
Based on the loading conditions of these types of welds, any flaws would most likely be generated at the weld surface and thus be detectable by surface examination.
The licensee analyzed a selection of integral supports and found that the welds would tolerate a substantially higher stress than that predicted to be required. A minimum safety factor of 8.3 was calculated.
Welds KR-1-54 and KR-1-55 will be fully inspected per the Code.
Conclusions and Recommendations Based on the above evaluation, it is concluded that for the welds discussed above, the code requirements are impractical.
It is further concluded that the alternative examination dis-cussed above will provide necessary added assurance of structural reliability.
Therefore, the following is recommended:
Relief should be granted from the volumetric examination i
of all integrally welded external support attachments for piping i
and valves, except welds KR-1-54 and KR-1-55, provided that:
l e the welds be liquid penetrant examined e such examinations cover 25% of the integrally welded supports during each inspection interval, as proposed by the licensee.
l References Reference 19.
1 A
science Apphcations,Inc.
E.
Pump Pressure Boundary 1.
Request for Relief ISI-4; Reactor Recircuiation pumps, Category B-L-2, Item B5.7 Code Requirement Visual examination of pump internal pressure boundary surfaces.
One pump in each of the group of pumps performing similar functions in the system shall be examined during each inspection interval. The examinations may be per-formed at or near the end of the inspection intqrval. '
Code Relief Request Relief is requested from the visual examination of the internal surfaces of the reactor recirculation pump at the pressure boundary.
Proposed Alternative Examination The internal surfaces of the recirculation pump casing will be visually examined whenever the. surfaces are made accessible when a pump from any unit is disassembled for maintenance purposes.
If during the 10-year interval a pump from any unit is not disassembled, a pump from one unit shall be examined from the exterior. This shall be accomplished by taking ultrasonic thickness measurements of the pump casing.
Licensee's Basis for Requesting Relief In absence of required maintenance, disassembly of a re-circulation pump solely to perform a visual examination of internal surfaces is impractical. This would represent un-necessary exposure of employees to high radiation and con-tamination areas and excessive expense to TVA.
Disassembly of this pump could require transport of the motor outside of containment; consequently, a possibility of damage to the pump, pump motor, or other safety-related equipment exists. The time required for this major task of disassembly, examination, and reassembly would consume at least three weeks of 24-hours-per-day work. Radiation dose rates of the pump exterior will average 100-300 mrem / hour, and pump internal dose rates will average 10-20 rem / hour.
This would result in a cumulative dose of between.100 and 300 man-rem.
The benefit received from this major effort is minimal considering employee exposure, potential damage to safety-related equipment, and cost in dollars.
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24 science Apphcations.Inc.
e In addition, the multiple units at' Browns Ferry Nuclear Plant operate under similar conditions. Therefore, we feel that if a pump from one of the multiple units is disassembled for maintenance during a 10-year interval, the visual examina-tion performed will be representative of the pump condition for each unit. This would avoid unnecessary exposure of employees to high radiation dose rates noted. We conclude that if one pump is disassembled for maintenance during the 10-year interval, the visual examination performed satisfies Examination Category B-L-2 requirements for the three multiple units. Disassembly of the pump solely for visual examinatinn is marginal.
Evaluation The visual examination is to determine whether unanticipated severe degradation of the casing is occurring due to phenomena such as erosion, corrosion, or cracking. However, previous experi-ence during examinations of pumps at other plants has not shown any significant degradation of casings.
The disassembly of the reactor recirculation pumps.o the t
degree necessary to inspect the internal pressure retaining sur-faces is a major effort, involving large personnel exposures and the generation of large amounts of radioactive waste.
In view of the effort required to disassemble a pump, the information returned from visual examination of its internal surfaces would be marginal.
The licensee has committed to the concept of visual examina-tion if the pump is disassembled for maintenance. Meanwhile, pressure and flow are monitored during pump operation to' assess performance.
The licensee contends that if a pump from one of the three Browns Ferry units is disassembled for maintenance during the 10-year interval, the visual examination performed will satisfy the examination. requirements of all three units at the site, This contention is not consistent with the requirements of 10 CFR l
50.55a(g).
Each licensed unit at the plant site must meet the requirements of 10 CFR 50.55a(g). The inservice inspection performed at a specific unit cannot be used to fulfill examina-tion requirements of another similar unit.
In the event that a recirculation pump is not disassembled for maintenance during the interval, the licensee proposes to Such measurements, perform ultrasonic wall thickness measurements.
using the minimum wall thickness requirements of Section III of the ASME Code as the acceptance standard and done to paragraph T-560,Section V, 1977 Edition, Winter 1978 Addenda, are potentially an acceptable alternative examination. However, detailed procedures establishing such parameters as frequency and location of measure-ments would have to be developed.
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The visual examination of the internal pressure boundary may be performed at or near the end of the 10-year inspection interval. Therefore, relief from examination requirements is not necessary until then because the licensee will be in compli-ance with the Regulation up to that time. The Code committee and the Electric Power Research Institute (EPRI) are under-taking a program to assemble and evaluate results of visual examination of internal pump casing surfaces. Within the next two years, this program should provide a more definitive basis for the Code committee and HRC for upholding or modify-ing this Code requirement.
Since so many licensees consider this requirement impractical and an undue burden, it is reasonable to postpone a decision to grant relief until that program is completed.
The licensee could submit a new relief request at that time.
Conclusions and Recommendations Based on the above evaluation, it is concluded that for the Code-required internal visual examination discussed above, a more definitive technical basis is needed. Therefore, the following is recannended:
(a) Relief should not be granted at this time from the visual examination of the internal surfaces of the reactor recirculation pump at the pressure boundary.
(b) The licensee's proposal to perform a visual examination whenever the surfaces are made accessible because a pump is disassembled for maintenance purposes should be accepted.
(c) A decision on the licensee's proposal to perform ultrasonic thickness measurements on pump casings should be deferred pending development of detailed procedures.
References Reference 19.
II Jl JF science Appiications,inc.
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F.
Valve Pressure Boundary 1.
Relief Request ISI-9; Support Members for Valves, Category B-K-1, Item B6.4 The request for relief from volumetric examination of integrally welded external support attachments for valves (see I.D.4 of this report) applies here. Therefore, the following is recommended:
Relief should be granted from the volumetric examination of all integrally welded external support attachments for valves, provided that:
e the weids be liquid penetrant examined
~~
e such examinations cover 25% of the integrally s
welded supports during each inspection interval, as proposed by the licensee.
2.
Relief Request ISI-8; Pressure Retaining Welds in Valve Bodies, Category B-M-1. Item B6.6 The request for relief from volumetric examination of valve body welds (see I.D.3 of this report) applies here.
Therefore, the following is recommended:
Relief should be granted from the volumetric examination of the identified welds provided that the following alternative examinations (proposed by the licensee) are performed:
(a) a best-effort ultrasonic examination of the accessible weld volume percentages estimated in the relief request (b) a surface examination (c) visual examinations done during system hydrostatic pressure tests in accordance with IWB-1220(c).
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3.
Request for Relief ICI-5, Valve Bodies, Category B-M-2, Item B6.7 Code Requirement Visual inspection of the internal pressure boundary surfaces, on valves exceeding 4 in nominal pipe size.
One valve in each group of valves of the same constructional design, e.g., globe, gate, or check valve, manufacturing method and manufacturer that performs similar functions in the system shall be examined during each inspection interva1.
The examinations may be performed at or near the end of the inspection interval.
Code Relief Request Relief is requested from the visual examination of the internal surfaces at the pressure boundary of the Class 1 valves exceeding 4 inch diameter nominal pipe size.
Proposed Alternative Examination If a valve from a particular classification has not been disassembled as the end of the inspection interval approaches, a case-by-case study will be made to determine the practi-cality of disassembling a valve from one of the multiple units solely for visual examination (determine if draining the vessel would be required, etc.).
If necessary, a request for relief will be issued at that time.
l Licensee's Basis for Requesting Relief During routine maintenance, visual examinations of valve i
body internal pressure boundary surfaces are performed and documented under existing plant administrative procedures.
Most Class 1 valves, particularly cnntainment isolation valves, are disassembled frequently for maintenance.
In addition, the multiple units at Browns Ferry operate under similar conditions.
If a valve from one of the multiple units is disassembled for maintenance within a 10-year interval, the visual examination performed would be representative of all three units and would be sufficient to satisfy the examination requirements for all three units for that particular valve classification as defined in Examination Category B-M-2.
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There are 26 groups of valves which are of the same design and manufacturer and perform similar functions on each i
unit. To meet the code requirement would require one valve from each of the 26 groups to be disassembled.
It is estimated that it would take an average of 30 man-hours to disassemble, examine, and reassemble each valve with a total dose of three man-rem per valve. The time and exposure involved would be much greater for valves (such as the recirculation valves) which require unloading the core and draining the vessel before they can be disassembled.
Evaluation The disassembly of large valves to the degree necessary to inspect the internal pressure retaining surfaces (casing) is a major effort, involving large personnel! exposures To do this u
disassembly solely to perform a visual exsmination of the internal casing is impractical.
g The licensee has committed to the concept af visual examina-tion if the valve is disassembled for maintenarce. The visual examination specified is to determine whether unanticipated severe degradation of the casing is occurring due to phenomena such as erosion or corrosion.
The visual examination of the internal pressure boundary may be performed at or near the end of the 10-year inspection interval.
The licensee contends that the intent of Category B-M-2 is met if one valve in eacn group of valves of the some con-structional design and manufacture from any unit is examined during the inspection interval.
This contention is not con-sistent with the requirements of 10 CFR 50.55a(g). Each licensed facility at the plant site should meet the requirements of 10 CFR 50.55a(g). The inservice inspection performed at a specific facility cannot be used to fulfill the examination requirements of another similar plant.
In addition, for this contention to be valid, the operating histories of the three units would have to be identical.
This cannot be guaranteed by the licensee.
Under the terms of 10 CFR 50.55a(g)(5)(iv), the licensee may, as he has requested, postpone specific relief requests from internal surface inspection on any of the 26 Code-required valves in each unit until near the end of the inspection inter-val. Submitting such relief requests as soon as possible after the next-to-last scheduled outage of the inspection interval and at least six months before the scheduled start of the last outage would minimize delays and outage time.
For those inspection periods when valve maintenance does not occur, visual examinations could be performed when the 2 science Apphcahons,Inc.
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i system pressure tests (IWA-5000) are conducted in accordance with the requirements for Category.B-P.
Conclusions and Recommendations Based on the above evaluation, it is concluded that for the valves discussed above, there is not presently enough justification for granting relief from the impractical Code requirements. Therefore, the following is recommended:
(a) Relief should not be granted at this time from visual examination of the internal pressure boundary surfaces on valves exceeding 4-in. nominal pipe size.
(b) The licensee's proposal to perform the Code-required examinations whenever the valves are opened because of maintenance should be accepted.
(c) During other inspection periods, the licensee should perform visual examinations for leakage when the system pressure tests (IWA-5000) are conducted in accordance with the requirements for Category B-P.
(d) The licensee should submit specific relief requests as the end of the inspection interval approaches for each valve classification for which a valve has not been disassembled and examined in each unit.
References References 19 and 22.
Science Apphcations,Inc.
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p.
I II. CLASS 2 COMPONENTS A.
Pressure Vessels 1.
Request for_ Relief 151-13; Pressure Retaining Nozzle Welds in the RHR Heat Exchanqors, Category C-B, Item C1.2 r
Cod _eJequirement_
~ Volumetric examination of 100% of the no2zle-to-vessel a,tta'chnent wilds for the equivalent of one Residual Heat
- Removal (RHR) h.ett exchanger, among four, shall be performed over the 40-year service lifetime of the system.
Code Rc_ lief Request Relief is requested from the volumetric examination of two nozzle-to-vessel welds among eacn of four RHR Heat Exchanners for Units 1, 2 and 3.
x Proposed Alternative Examinat. ton s
~
There are four Residual Heat Removal Heat Exchangers for each unit. There are two reinforcement ring welds on tach of the RHR Heat Ex-hangers.
These welds'are' accessible and can be given a surface examination. Two reinforcement ring helds among the four RHR Heat Exchangers f,nr each unit will be sur-
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face examined over the 40-year service lifetime in accordance with IWC-2411 of ASME Section XI.
w s
Licensee's Basis for Requesting Relief The RHR Heat Exchangers nozzle-to-vessel attachment weld is' covered by a reinforcement ring which does not allow access to any of thc attachment weld.
Evaluation The welds required to be examined are completely covered by a 1 1/2-in.-thick reinforcing ring that prevents
.1 a volumetric examination as required by the Code. The ring is welded to the shell and to the nozzle with fillet welds.
The licensee proposes to perform a surface extmination on the reinforcing ring welds which are completely accessible.
' ~
Weld cracking would be detected by the surface examination.
Visual examinations of the welds during periodic hydro-static testing would provide additional assurance that an adequate level of safety will be maintained.
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Conclusions and Recomendations Based on the above evaluation, it is concluded that for the welds discussed above, the Code requirements are impracti-cal.
It is further concluded that the alternative examination discussed above will provide necessary added assurance of struc-tural reliability. Therefore, the following is recomended:
Relief should be granted from performing vnlumetric examination of two nozzle-to-vessel welds among the RHR heat exchangers for each unit, provided that:
(a) The proposed alternative surface examination is performed on the reinforcement ring welds that make the nozzle-to-vessel welds inaccessible.
4 (b) Visual examination of the welds for l'eakage is
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g performed during periodic hydrostatic testing in accordance with IWC-5000.
Reference _
Reference 19.
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2.
Request for Relief 151-14; Pressure Retaining Bolting Exceeding 1-Inch in Diameter, Category C-0 (all items)
Code Requirement Visual examinations performed during each inspection interval shall cover 100% of the bolts, studs, nuts, bushings, and threads in base material and flange ligaments between threaded stud holes. Surface or volumetric examinations shall be performed on 10% of the bolting in each joint, but not less than two bolts or studs per joint.
Code Relief Request Licensee requests permission to use the_l977 Edition.
Sumer 1979 Addenda of Section XI.
Proposed Alternative Examination Licensee would comply with the more recent edition of the code.
Licensee's Basis for Requesting Relief Examination of Class 2 pressure-retaining bolting in accor-dance with the Summer 1975 Addenda of Section XI exceeds inspec-tion requirements for class 1 pressure-retaining bolting. An examination program for class 2 pressure-retaining bolting similar to that for class 1 would be desirable.
This type of examination has been incorporated in the 1977 Edition, Summer 1978 and Summer 1979 Addenda of Section XI.
Evaluation The 1977 Edition of Section XI has been referenced in 10 CFR 50.55a, and inservice examinations may meet the requirements of this edition in lieu of those from previous editions with the following provisions:
(a) Comission approval is required to update to the more recent edition (pursuant to 10 CFR 50.55a(g)(4)(iv));
(b) When applying the 1977 Edition, all of the addenda through Sumer 1978 Addenda must be used; (c) Any requirement of the more recent edition which is related to the one(s) under consideration must also be met.
Updating to the 1977 Edition, Summer 1978 Addenda for Category C-D items exempts all Class 2 bolting, 2-in, in diameter or less, from examination but substitutes volumetric for visual examination of bolts and studs of larger diameters.
On this scienc. 4poucationsanc.
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i provision, the Sumer 1978 Addenda is identical to the Sumer 1979 Addenda (version licensee requests updating to).
Recomendations Pursuant to 10 CFR 50.55a(g)(4)(iv), approval should be granted to update to the requirements of the 1977 Edition, Sumer 1978 Addenda for Category C-D items. This approval would exempt all Class 2 bolting, 2-in in diameter or less, from examination.
References
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Reference 19.
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e B.
Piping 1.
Request for Relief ISI-14; Bolting, Category C-D The request to update to the Summer 1978 Addenda applies here (see II.A.2 of this report). Therefore, the following is recommended:
Pursuant to 10 CFR 50.55a(g)(4)(iv), approval should be granted to update to the requirements of the Summer 1978 Addenda for Category C-D items. This approval would exempt all Class 2 bolting, 2-in, in diameter or less, from examination.
2.
Recuest for Relief ISI-8; Pressure-Retaining Welds in Piping,,
Category C-F, Items C2.1, C2.2 and C2.3 (Unit 3 only)
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i Code Requirement Voltmetric weld examinations shall cover 1007, of the welds. This examination shall be scheduled over the lifetime of the plant (four intervals with three periods within each interval).
Code Relief Reouest Relief is requested from performing 100% of the required volumetric examination of the following pressure-retaining welds:
Unit 3 Weld Identification
% Inspection Limitation DMS-3-9 70 Valve Configuration -
Branch Conn.
l DMS-3-17 70 Valve Configuration -
l Branch Conn.
TRHR-3-53 90 Support Lugs t
TRHR-3-204 95 Support Lugs l
Proposed Alternative Examination In addition to the visual examination performed during system leakage and hydrostatic pressure tests, a "best effort" ultrasonic examination will be performed. Also, a surface examination will be perforned on accessible areas of the l
weld (s),
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i Licensee's Basis for Requesting Relief In some cases it will be impractical to inspect all welds in accordance with paragraph T-532 of Article 5,Section V, of the ASMT. Code, i.e., nonremovable hanger interference or valve i
and pump casings adjoining the welds. These welds will be noted on the ultrasonic examination data sheets.
I Evaluation Because of the geometric configuration of the fitting or location of the weld, meaningful examination results cannot be obtained on the entire code-required volume of just four welds in this category.
)
For Category C-F welds, a best effort volumetric examina-tion to the volune percentage estimated in the relief request seems practical.
Surface examination would augment the volumetric examination.
Visual examinations could also be performed during system leakage and hydrostatic tests.
Conclusions and Recommendations Based on the above evaluation, it is concluded that for the welds discussed above, the code requirements are impracti-cal.
It is further concluded that the alternative examination discussed above will provide necessary added assurance of structural reliability. Therefore, the following is reconmended:
Relief should be granted from the volumetric examination of the identified welds with the following provisions:
(a) A best effort volumetric examination should be performed to the volume percentage estimated in the relief request; (b) A surface examination should be performed; (c) Visual examination of the welds should be performed during periodic hydrostatic testing in accordance with IWC-5000.
References References 19 and 22.
2l J science Appiicanons.ine.
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f 3.
Request for Relief ISI-11; Support Members for Piping, Category C-E-1 Item C2.5 Code Requirement Surface examination shall be performed of the external support attachments including the welds to the pressure-retaining boundary and along the support attachment nember for a distance of two support thicknesses. The examination perfomed during each inspection interval shall cover 100%
of the major load-bearing elements of the support structure and hanger.
Code Relief Request Relief is requested from the surface examination of 12 guide lugs which are welded to the process pipe of the main steaa system in each of four special restraints.
Proposed Alternative Examination None.
l.icensee's Bacis for Reouesting Relief The main steam system includes four special restraints, each of which is partly embedded in a wall. Each embedded restraint includes 12 guide lugs which are welded to the process pipe. These welds are inaccessible for examination. Each restraint also includes 12 stop plates welded to the process pipe which are accessible for examination, and they will be surface examined during the inspection intervals.
Evaluation The design of the component makes the surface examination of the 12 guide lugs on each steam line impractical. Examina-tion of the lugs can only be done by dismantling the restraint.
The accessible welds on the 12 stop plates will be examined.
Forces developed in the restraint will tend to stress the stop plate welds rather than the guide lug welds. Hence, any stress-induced weld failures in the restraints should be detectable by the planned surface examinations. If any of the restraints are dismantled for maintenance, the lug welds could be examined.
Conclusions and Recommendations Based on the above evaluation, it is concluded that for the welds discussed above, the code requirements are impractical.
It is further concluded that the alternative examination discussed above will provide necessary added assurance of struc-tural reliability.
Therefore, the following is recommended:
A 37 science 4poucanons. inc.
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Relief should be granted from the surface examination of the identified welds, with the provision that whenever the restraints are dismantled for maintenance, the guide lug-to-pipe welds sr.ould be examined.
References Reference 19.
I C.
Pumps 1.
Request fof' Relief ISI-14; Bolting, Category C-D The request to update to the Summer 1978 Addenda applies here (see II.A.2 of this report). Therefore, the following is recommended:
Pursuant to 10 CFR 50.55a(g)(4)(iv), approval should be granted to update to the requirements of the Summer 1978 Addenda for Category C-D items.
This approval would exempt all Class 2 bolting, 2-in. in diameter or less, from exanination.
D.
Valves 1.
Request for Relief ISI-14 Bolting, Category C-D The request to update to the Sumer 1978 Addenda applies here (see II.A.2 of this report). Therefore, the following is recomended:
Pursuant to 19 CFR 50.55a(g)(4)(iv), approval ~should be granted to update to the requirements of the Sumer 1978 Addenda for Category C-D items. This approval would exempt all Class 2 bolting, 2-in. in diameter or less, from examination.
III. CLASS 3 COMPONENTS (No code relief requests)
IV.
PRESSURE TESTS 4
(No code relief requests)
A Science Applications,Inc. -
V.
GENERAL A.
Ultrasonic Examination Techniques 1.
Request for Relief ISI-10; Ultrasonic Calibration Standards Class 1 and 2 Code Requirement IWA-2232:
Ultrasonic examination shall be conducted in accordance with the provisions of Appendix I.
Where Appendix I (I-1200) is not applicable, the provisions of Article 5 of Section V shall apply.
Code Relief Request Relief is requested from the calibratio'n block require-
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ments of the 1974 Edition including Addenda through Sumer 1975 for ultrasonic examinations of Class 1 and 2 piping and vessel welds.
Proposed Alternative Examination Future examinations which require fabrication of new calibration blocks will be perfonned using calibration blocks which will meet the 1974 Edition, Summer 1975 Addenda of Section XI, except for piping blocks which will as a minimum meet the 1977 Edition, Sumer 1978 Addenda of ASME Section XI.
Licensee's Basis for Requesting Relief Ultrasonic calibration blocks employed for the Browns l
Ferry baseline examination were fabricated to the 1971 Edition of Section XI. These blocks will continue to be used for future examinations to ensure the repeatability of data. The pipe blocks have 5% T sawtooth notches running circumferentially around the inside and outside diameters. One side-drilled hole is placed in the side of the block parallel to the longitudinal axis of the curved blocks.
Pipeblock curvature is within 0.9 to 1.5 times the diameter of the pipe examined; and thickness and hole size are according to ASME Section III, Figure IX-3432.1 of the 1971 Edition, Summer 1971 Addenda. Material for all blocks was the same or equivalent "P" number except as discussed in the file note and shown in the mill test report submitted by the licensee.
Evaluation The licensee has provided test data that demonstrates the similarity in acoustic velocity and identifies differences in attenuation between the basic calibration blocks used for the science Aconications.ine-
1 preservice ultrasonic examinations and either the actual component or the material from which the component was manu-factured. The data were presented for blocks fabricated from materials that were not the same or equivalent "P" number. Based on the data, the licensee provided assurance that the calibration, based on attentuation considerations, provided an examination at least equivalent to that required by the applicable Code.
The licensee has utilized 5% T sawtooth notches as the reference reflectors for basic calibration for piping exami-nations. The 5% T sawtooth notches were used rather than drilled holes specified in Article 5 of ASME Section V. With the use of sawtooth notches, approximately 10% T is con-sidered acceptable in later Editions of Section XI (Appendix III, 1977 Edition). The use of the 5% T notch, providing calibration is conducted from the direction M own in Figure III-3430-1 of Appendix III of Section XI (1977 Edi 'on),is considered an acceptable alternative.
The use of the baseline calibration blocks for in-service inspections fabricated to the 1971 Edition of Section XI, will provide a level of sensitivity equivalent to that obtained if the calibration blocks met the exact requirements of the applicable Code, i.e.,Section XI,1974 Edition, including Sumer 1975 Addenda.
Conclusions and Recomendations Based on the above evaluation, it is concluded that for the calibration blocks discussed above, the code requirements are impractical.
It is further concluded that the alternative examination discussed above will provide necessary added assur-ance of examination reliability.
Therefore, the following is recomended:
Relief should be granted from the calibration block requirements of the 1974 Edition, including addenda through Summer 1975 of Section XI, for ultrasonic examinations of Class 1 and 2 piping and vessel welds.
The following alternative proposed by the licensee should be approved: Future examinations requiring fabrication of new calibration blocks would be performed using calibration blocks which would meet the 1974 Edition, Summer 1975 Addenda of Section XI, except for piping blocks which would, as a minimum, meet the 1977 Edition, Summer 1978 Addenda of Section XI.
l References Reference 19.
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t 2.
Request for Relief ISI-15; Ultrasonic Examination Technique of Piping Welds, Class 1 and 2 Code Requirement IWA-2232:
Ultrasonic Examination Appendix III:
Ultrasonic Examination IWA-3000:
Evaluations Code Relief Request Licensee requests approval to update the ultrasonic exami-nation and evaluation of piping welds to the 1977. Edition, Summer 1978 Addenda of Section XI to provide state-of-the-art methods for both.
Proposed Alternative Examination Perfnrm ultrasonic examination of piping welds according to IWA-2232(b), IWA-2232(c), and Apoendix III and evaluate according to IWA-3000, all of the 1977 Edition, Summer 1978 Addenda.
Licensee's Basis for Recuesting Relief In accordance with 10 CFR 50.55a(g)(4)(iv), the licensee requests approval to update the ultrasonic examination and evaluation of piping welds to the 1977 Edition, Summer 1978 Addenda of Section XI to provide state-of-the-art methods for both.
There are existing requests for relief (addressed to the 1974 Edition of the ASME Code) from the requirements of III-3410, III-3430 and III-4450 of Appendix III. The licensee does not believe that the existing requests for relief (ISI-8 and ISI-10) affect the overall purpose of updating the examination and evaluation techniques.
Evaluation The 1977 Edition of Section XI has been referenced in 10 CFR 50.55a and inservice examinations may meet the requirements of this edition in lieu of those from previous editions with the following provisions:
(a) Commission approval is required to update to the more recent edition (pursuant to 10 CFR 50.55a(g)(4)(iv));
(b) When applying the 1977 Edition, all of the addenda through Summer 1978 Addenda must be used; science Aconcanons.inc.
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Exempted Components 1.
Code Exemption per IWC-1220(a), Components Exempted from Examination Based on Pressure and Temperature Code Requirement 1974 Edition Section XI (Sumer 1975 Addenda)-IWC-1220(a):
The following components may be exempted from the examination requirements of IWC-2520:
(a) Components in systems where both the design pressure and temperature are equal to or less than 275 psig and 2000F, respectively.
1977 Edition Section XI (Sumner 1978 Addenda) - IWC-1220(b):
The following conponents shall be exempted from the inservice examination requirements of IWC-2500:
(b) Components of systems or portions of system, other than Residual Heat Removal Systems and Emergency Core Cooling Systems, that are not required to operate above a pressure 0
of 275 psig (1900 KPa) or above a temperature of 200 F (930C).
Exemption Exemption from examination of Class 2 piping welds is claimed according to IWC-1220(a), 1974 Edition of Section XI.
Evaluation Paragraph IWC-1220(b) of Section XI, Summer 1978 Addenda, does not permit the exemption from exanination of components in0 the ECCS and the RHRS that operate below 275 psig or below 200 F.
Hence, low operating pressure and temperature are not acceptable as a basis for exempting ECCS and RHRS components from inservice ei?mination.
Components in the RHRS and the ECCS cannot be exempted under IWC-1220(a).
It is required that a representative sample of welds on these components be examined.
Conclusions and Recommendations Based on the above evaluation, it is concluded that components in the RHRS and the ECCS should not be exempted. The licensee should include a representative saraple of welds on the RHRS and ECCS components in the Inservice Inspection Program.
References Reference 19.
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2.
Class 2 Components and Piping Exemptions Based on Chemistry Control per IWC-1220(c)
Code Requirement IWC-1220(c) Exempted Components: Components which perform an emergency core cooling function, provided the control of the chemis-try (to minimize corrosive effects) of the contained fluid is verified by periodic sampling and testing.
Exemption Licensee claims exemption from inspection of Class 2 Emergency Core Cooling System (ECCS) components and piping based on IWC-1220(c).
Evaluation The chemistry control provision was deleted from paragraph IWC-1220 in the 1977 Edition of Section XI because practical evalu-ation, review, and acceptance standards could not be defined. Hence, water chemistry control to minimize stress corrosion described in Paragraph IWC-1220(c) of Section XI, 1974 Edition, is not an acceptable basis for exempting ECCS components from inservice examination.
Conclusions and Reconsnendations Based on the above evaluation, it is concluded that for Class 2 ECCS components and piping systems claims for exemp-tion from examination per IWC-1220(c) should not be allowed.
It is recomended that the licensee revite the inservice inspection program for Browns Ferry fluclear Plant to include examination of those portions of the ECCS that were deleted from the current ISI program based on exemptions allowed by IWC-1220(c).
References Reference 19.
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Other (None) l bl science Appncations.inc.
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i REFERENCES 1.
J. F. Stolz (NRC) to G. Williams (TVA), Docket #50-296, Browns Ferry Nuclear Plant, Unit 3, Confonnance to 10 CFR 50.55a(g), September 15, 1976.
2.
J, E. Gilleland (TVA) to J. F. Stolz (NRC), October 20, 1976.
3.
J. F. Stolz (NRC) to G. Williams (TVA), Docket #50-296, Compliance with 10 CFR 50.55a(g) for Brown Ferry Unit 3, November 22, 1976.
4 G. Williains (TVA) to B. Rusche (NRC)
License Amendment to Change Technical Specifications, January 28, 1977.
5.
R. S. Boyd (NRC) to G. Williams (TVA), Browns Ferry Unit 3 - Exemption from 10 CFR 50.55a(g), February 25, 1977.
6.
J. E. Gilleland (TVA) to E. G. Case (NRC), Technical Specifications Change for Browns Ferry Nuclear Plant, Unit 3, July 29,1977.
7.
J. E. Gilleland iTVA) to E. G. Case (NRC), Revised Browns Ferry Unit 3 Inservice Inspection Program, July 29, 1977.
8.
G. Lear (NRC) to N. B. Hughes (TVA), Request for Additional Information, Browns Ferry Nuclear Plant Unit 3, May 31,1978.
9.
T. A. Ippolito (NRC) to N. B. Hughes (TVA), Hydrostatic Pressure Testing, Browns Ferry Nuclear Plant Unit 3, August 8,1978.
10.
J. E. Gilleland (TVA), to T. A. Ippolito (NRC), Hydrostatic Pressure Testing, Browns Ferry Nuclear Plant Unit 3, November 3,1978.
11.
J. E. Gilleland (TVA) to T. A. Ippolito (NRC), Relief Request, Browns Ferry Nuclear Plant Unit 3, December 11, 1978.
12.
J. E. Gilleland (TVA) to T. A. Ippolito (NRC), March 29, 1979.
13.
J. E. Gilleland (TVA) to T. A. Ippolito (NRC), Termination of TVA BFNP TS 77, Continuation of TVA BFNP TS 89, April 24, 1979.
14.
J. E. Gilleland (TVA) to T. A. Ippolito (NRC), Revised ISI of July 29, 1977,*
May 8, 1979.
15.
L. M. Mills (TVA) to T. A. Ippolito (NRC), Proposal Allowing TVA to Start l
All Browns Ferry Units on January 1, 1980 ISI Interval, July 11, 1979.
16.
L. M. Mills (TVA) to H. R. Denton (NRC), Further Revisions to Technical Specifications, Browns Ferry Nuclear Plant Unit 3, July 20, 1979.
17.
L. M. Mills (TVA) to T. A. Ippolito (NRC), Additional Relief Request ISI-9, October 16,1:f79.
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18.
L. M. Mills (TVA) to T. A. Ippolito (NRC), Request to Establish Concurrent Cycles for ASME Section XI Inservice Inspections and Tests, December 24, 1980.
19.
L. M. Mills (TVA) to H. R. Denton (NRC), Complete Inservice Inspection Program, Browns Ferry Nuclear Plant Units 1, 2 and 5, November 16, 1981.
20.
L. M. Mills (TVA) to H. R. Denton (NRC), Technical Specification Changes for Browns Ferry Nuclear Plant Units 1 and 2, November 17, 1981.
21.
D. B. Vassallo (NRC) to H. G. Parris (TVA), Inservice Inspection Program, Browns Ferry Nuclear Plant, Units 1, 2 and 3, February 24, 1982.
22.
L. M. Mills (TVA) to D. B. Vassallo (NRC), Reply to Request for Additional Informa tion, April 14, 1982.
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