ML13303B246
| ML13303B246 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/12/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML13303B245 | List: |
| References | |
| NUDOCS 9010250316 | |
| Download: ML13303B246 (6) | |
Text
~ps REGy1ENLOUR 0,
UNITED STATES ENCLOSURE 1 It" NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE INSERVICE TESTING PROGRAM AND REQUESTS FOR RELIEF SAN ONOFRE NUCLEAR GENERATING STATION, UNIT NOS. 2 AND 3 DOCKET NOS. 50-361 AND 50-362
1.0 INTRODUCTION
In general, Technical Specification 4.0.5 for the San Onofre Nuclear Generating Station, Unit Nos. 2 and 3, states that the surveillance requirements for In service Inspection and Testing of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Class 1, 2, and 3 components shall be applicable as follows:
Inservice Inspection of ASME Code Class 1, 2, and 3 components shall be performed in accordance with Section XI of the ASME Code and applicable Addenda as required by 10 CFR 50.55a(g), except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i).
Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the first ten-year interval comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b) on the date twelve months prior to the date of issuance of the operating license, subject to the limitations and modifications listed therein. The components (including supports) may meet the requirements set forth in subsequent editions and addenda of the ASME Code incorporated by reference in 10 CFR 50.55a(b) subject to the limitations and modifications listed therein.
Pursuant to 10 CFR 50.55a(g)(5), if the licensee determines that conformance with an examination requirement of Section XI of the ASME Code is not practical for his facility, information shall be submitted to the Commission in support of that determination and a request made for relief from the ASME Code requirement. After evaluation of the determination, pursuant to 10 CFR 50.55a(g)(6)(i), the Commission may grant relief and may impose alternative requirements that are determined to be authorized by law, will not endanger life or property or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the licensee that would result if the requirements were imposed.
The licensee, Southern California Edison Company, et al., requested approval 901 250316 901012 PDR ADOCK 05000:361 Q
-2 of a common ISI interval start date of August 18, 1983, for both San Onofre Nuclear Generating Station, Unit Nos. 2 and 3. The licensee has also requested that the 1977 Edition, Summer 1979 Addenda of the Code be used for both units.
Based on the September 7, 1982, date of issuance of the operating license for Unit 2, the licensee has prepared the San Onofre Nuclear Generating Station, Unit Nos. 2 and 3, First Ten-Year Interval Inservice Inspection (ISI) Program Plan to meet the requirements of the 1977 Edition, Summer 1979 Addenda of Section XI of the ASME Boiler and Pressure Vessel Code. However, the exami nation of Class 2 piping welds in the residual heat removal, emergency core cooling, and containment heat removal systems have been determined by the 1974 Edition, Summer 1975 Addenda as required by 10 CFR 50.55a(b)(2)(iv)(A).
The staff, with technical assistance from its contractor, Science Applications International Corporation (SAIC), has evaluated the First Ten-Year Interval Inservice Inspection Program Plan, additional information related to the Program Plan, and the requests for relief from certain ASME Code requirements are determined to be impractical for San Onofre Nuclear Generating Station, Unit Nos. 2 and 3, during the first inspection interval.
2.0 EVALUATION The ISI Program Plan has been evaluated for (a) application of the correct Section XI Code edition and addenda, (b) compliance with examination and test requirements of Section XI, (c) acceptability of the examination sample, (d) compliance with prior ISI commitments made by the licensee, (e) correctness of the application of system or component examination exclusion criteria, and (f) adequate information in support of requests for relief from impractical Section XI Code requirements. The staff has determined that the licensee's ISI Program Plan, with the exception of those requests for relief that are denied, reflects compliance with the requirements listed above.
It is noted that augmented ultrasonic examinations of the bores of the low pressure turbine disc have not been included in the ISI Program. The license should confirm that these examination will be performed as required by NUREG-0712, "Safety Evaluation Report Related to the Operation of San Onofre Nuclear Generating Station, Units 2 and 3."
We concur with the evaluation and recommendation for acceptance, in the attached SAIC Technical Evaluation Report SAIC-84/1664, of the licensee's request for a common ISI interval start date of August 18, 1983 and use of the 1977 Edition, Summer 1979 Addenda of the ASME Section XI Code for both units in lieu of using the 1977 Edition, Summer 1979 Addenda for Unit 2 and the 1980 Edition, Summer 1981 Addenda for Unit 3. The application of the earlier edition and addenda of the Code for both San Onofre Units 2 and 3 will not impact the health and safety of the public.
The information provided by the licensee in support of requests for relief from impractical requirements has been evaluated and the bases for granting relief from those requirements are documented in the attached SAIC Technical
-3 Evaluation Report SAIC-84/1664. We concur with the findings and recommendations contained in the subject report with the exception of Relief Request No. B-7.
In that case, the contractor recommended that interim relief be granted with the condition that the licensee either demonstrate that the actual procedure and instrumentation to be used for the proposed examination would detect 0. D.
flaws in the existing configuration, or perform the Code-required surface examination. The staff does not agree that relief should be granted because the licensee has not provided sufficient detailed technical justification and has not demonstrated that the ultrasonic testing instrumentation and procedures are capable of detecting 0. D. surface-connected defects. The increase in safety achieved by performing the required surface examination outweighs the impracticalities cited by the licensee. In order for relief to be considered, the licensee must meet the following conditions: (a) additional information must be provided demonstrating that the Code-required surface examination is impractical to perform; (b) the remote volumetric examination must include the entire weld volume and heat affected zone instead of only the inner one-third of the weld; and (c) the ultrasonic testing instrumentation and procedures must be demonstrated to be capable of detecting 0. D. surface connected defects, in the circumferential orientation, and in laboratory test blocks. The defects in the test blocks should be cracks and not machined notches.
Table 1 presents a summary of the reliefs requested and the status of the requests as determined by the staff.
3.0 CONCLUSION
The staff concludes that the San Onofre Nuclear Generating Station, Unit Nos.
2 and 3, First Ten-Year Interval Inservice Inspection Program Plan, with the additional information provided and the specific written relief, constitutes the basis for compliance with 10 CFR 50.55a(g) and Technical Specification 4.0.5 and is therefore acceptable, with the exception of Relief Request B-7, which is denied.
San Onofre Nuclear Generating Station, Units 2 and 3 Page 1 of 3 TABLE 1
SUMMARY
OF RELIEF REQUESTS Relief Licensee Request System or Exam.
Item Volume or Area Required Proposed Relief Request Number Component Cat.
No.
to be Examined Method Alternative Status B-1 Pressurizer B-D B3.110 Nozzle-to-vessel welds Volumetric Ultrasonic scan Granted and Steam and examination from vessel side Generators B3.130 only using full V-path technique B-4 Class 1 B-J B9.31 Branch connection welds Volumetric 100% surface Relief not Piping greater than 2-inch and surface examination and required diameter examinations ultrasonic examination from the piping side only using full V-path technique B-7 Class 1 B-F 85.50 Safe end welds Volumetric Applicable circ.
Denied and and surface and long. welds Class 2 B-J B9.10 Circ. and long. welds examination will receive Piping 4-inch NPS and greater for 85.50, full volumetric B9.10, examination in 89.20 Circ. and long. welds B9.31, lieu of surface less than 4-inch NPS C5.21, and and volumetric C5.22; examination B9.30 Branch pipe connection required in welds NPS greater than Surface Figure 2 inches (B9.31) and NPS examination IWB-2500-8 2 inches or less (B9.32) for B9.20, B9.32, and B9.40 Socket welds B9.40 C-F C5.21 Circ. and long. piping and welds over 1/2-inch C5.22 nominal wall thickness
San Onofre Nuclear Generating Station, Units 2 and 3 Page 2 of 3 TABLE 1
SUMMARY
OF RELIEF REQUESTS Relief Licensee Request System or Exam.
Item Volume or Area Required Proposed Relief Request Number Component
- Cat, No.
to be Examined Method Alternative Status Section Class 1 B-M-1 B12.30 Valve body welds Volumetric External surface Granted with 3.1.5.1 Valves and surface examination per conditions of TER examination IWB-3518.1(d) stated in TER C-1 Steam C-B C2.20 Class 2 nozzle-to-vessel Volumetric Ultrasonic scan Granted Generator welds and surface from vessel side examinations only using full V-path technique C-3 Class 2 C-F C5.10, Longitudinal welds in Volumetric Volumetric Relief not Piping C5.20, RHR, ECC, and CHR systems and/or and/or surface required C5.30 surface examinations of examinations 2.5T of of 100% of longitudinal length of weld at the longitudinal intersecting weld joint circumferential in pipe weld per 77S79 fittings per 74S75 C-4 Shutdown C-B C2.20 Nozzle-to-vessel welds Volumetric Surface Granted Cooling and surface examination of Heat examinations fillet welds Exchangers attaching saddle-to-vessel and saddle-to-nozzle
San Onofre Nuclear Generating Station, Units 2 and 3 Page 3 of 3 TABLE 1
SUMMARY
OF RELIEF REQUESTS Relief Licensee Request System or Exam.
Item Volume or Area Required Proposed Relief Request Number Component
- Cat, No.
to be Examined Method Alternative Status C-5 Class 2 C-E C3.40, Integrally welded support Surface Surface Relief not (Unit 3
- Piping, C3.70, attachments examination examination of required only)
Pumps, and and per 77S79 welds whose Valves C3.100 support base material design thickness exceeds 3/4 inch per 74S76