ML20203G436

Safety Evaluation Re Inservice Insp Program & Requests for Relief from Certain Inservice Insp Requirements.Inservice Insp Plan Acceptable for Implementation

ML20203G436
Person / Time
Site:	Grand Gulf
Issue date:	07/22/1986
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20202J461	List: ML20202J455 ML20203G425 ML20203G436
References
TAC-55522, TAC-55524, TAC-57222, NUDOCS 8608010151
Download: ML20203G436 (8)

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[(. m *kg NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 3- ?j

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE INSERVICE INSPECTION PROGRAM AND RE00ESTS FOR RELIEF FROM CERTAIN INSERVICE INSPECTION REQUIREMENTS MISSISSIPPI POWER AND LIGHT COMPANY GRAND GULF NUCLEAR STATION UNIT 1 DOCKET NO. 50-416 INTRODUCTION The Technical Specification for the Grand Gulf Nuclear Station Unit 1 (GGNS-1) states that inservice examination of ASME Code Class 1, 2, and 3 components shall be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable Addenda as required by 10 CFR 50.55(g) except where specific written relief has been granted by the Commission.

Some plants were designed in conformance to early editions of this Code Section, consequently certain requirements of later editions and addenda of .

Section XI are impractical to perform because of the plants' design, component geometry, and materials of construction. Regulation 10 CFR 50.55a(g)(6)(i) authorizes the Commission to grant relief from those requirements upon making ,

the necessary findings. s ._.> ^..

a By letters dated May 11, June 3, June 29, July 25, September 20, 1984, and -

October 31, 1985, Mississippi Power and Light Company (MP&L) submitted its inservice inspection program, and additional information related to requests _

for relief from certain Code requirements determined to be impractical to perform on the Grand Gulf Nuclear Station Unit 1 during the f.irst inspection interval. The program is based on the requirements of the 1977 Edition through Summer,1979 Addenda of Section XI of the ASME Code, and remains in effect until July 1, 1995, unless the program is modified or changed prior to the interval end dates.

EVALUATION The inservice inspection program and the requests for relief from the require-ments of Section XI that have been determined to be impractical to perform have been reviewed by the Staff's contractor, Science Applications International Presented in attachment 2 is the contractor's Technical Corporation (SAIC)(.TER), which is their evaluation of the licensee's inservice Evaluation Report inspection program plan and relief requests. Also included in the TER are their conclusions and recommendations. The staff has reviewed the TER and agrees with the evaluations and conclusions, and adopts the TER evaluations and con-clusions, except those relating to the sampling selection plan for the examination of pipe supports. As part of the program evaluation, the sampling selection 8608010151 860722 6 PDR ADOCK 0500 G

plan for examination of pipe supports was reviewed. In lieu of using the methodology provided in Code Articles IWF, IWB, IWC and IWD, GGNS-1 developed an alternate selection plan.

The selection is based upon statistical sampling to detect degradation of more than 10% of the supports with a 95% confidence level. The staff agrees with

" the licensee that this selection method is adequate for determining the status of the pipe supports. Under some interpretations of the guidance provided in the Code statistical sample selection would permit a smaller initial sample size. However, in the plan proposed by the licensee, a much smaller number of degraded supports in the population will initiate the examination of 100%

of the supports. A summary of the relief request determinations made by the staff is presented in the tables of attachment 1.

CONCLUSION Based on the review of the inservice inspection program and relief requests summarized, the staff concludes that relief granted from the examination and testing requirements and alternate methods imposed through this document give reasonable assurance of the piping and component pressure boundary and support structural integrity. The staff has determined that the Code requirements are impractical and, pursuant to 10 CFR 50.55a(g)(6)(f), the granting of the requested relief is authorized by law and will not endanger life or property, or the common defense and security, and is otherwise in the public interest considering the burden that could result if the requirements were imposed on the facility. The staff further concludes, the proposed statistical sampling selection plan is a suitable alternate sample selection method, is adequate

for the detection of significant degradation of pipe supports, is conservative. .-

The statistical sampling plan is thus acceptable. During the review of the a licensee's inservice inspection plan the staff has not identified any signifi-cant misinterpretation or omissions of Code requirements. Thus the inservice inspection plan is acceptable for implementation. .

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ATTACHMENT 1 TABLE 1

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CLASS 1 COMPONENTS LICENSEE PROPOSED IWB-2500-1 IWB-2500-1 SYSTEM OR AREA TO BE REQUIRED ALTERNATIVE RELIEF REQUEST ITEM NO. EXAM. CAT. COMPONENT EXAMINED METHOD EXAMINATION STATUS Bl.11& B-A Reactor B1.11: Volumetric Volumetric Granted Bl.21 Vessel Vessel of Sections Provided

. Circum- Containing Volumetric ferential Three Record- Exam of an Shell Welds, able Indica- Additional Bl.21: tions 12" by 12" Circum- Section of ferential Weld is Head Welds Performed (Lower Weld A-A)

B.1.11 B-A Reactor Circum- Volumetric Volumetric Granted Vessel ferential of Sections -

Shell Welds Containing (Lower Weld Four Recorda-A-B) ble Indications B.1.11 B-A Reactor Circum- Volumetric Volumetric Granted Vessel ferential to Extent ..

Shell Weld Practical J.

(Weld A-C)  ; 'j:

B7.10& B7.10: Reactor B7.10: 87.10: Code-Required Granted 814.10 B-G-2 Vessel Bolts, Studs Visual, System Provided ,

B14.10: & Nuts, VT-1 Pressure Code-B-0 B14.10: 814.10: Tests Required Welds in Volumetric Exam is CRD Housing or Surface Performed

. if CRD is Removed for Maintenance 9

TABLE 1 CLASS 1 COMPONENTS (CONTINUED)

LICENSEE PROPOSED IWB-2500-1 IWB-2500-1 SYSTEM OR AREA TO BE REQUIRED ALTERNATIVE RELIEF REQUEST ITEM NO. EXAM. CAT. COMPONENT EXAMINED METHOD EXAMINATION ' STATUS B9.11& B-J Piping Circum- B9.11: Volumetric Granted 89.21 ferential Surface & to Extent Provided Welds, 89.11: Volumetric Practical Code-Nominal Pipe 89.21: Required Size 4 in. Surface Surface

& Greater, Exam is 89.21: Performed Nominal Pipe -

Size Less Than 4 in.,

(Welds within Guard Pipes)

B9.11 & 89.12 B-J Piping Nominal Pipe Surface & Volumetric Granted ,

(RHR, Size 4 in. Volumetric to Extent

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RCIC, MS, & Greater, Practical RECIRC, B9.11: Twice Ouring

& RWCU)

• Circumferential Inspection Welds, B9.12: Interval Longitudinal & Code-Required Welds,(Inaccess- Surface

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ible Portions of .m ,

Welds)

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6 TABLE 2 CLASS 2 COMPONENTS i

LICENSEE I

PROPOSED IWC-2500-1 IWC-2500-1 SYSTEM OR AREA TO BE REQUIRED ALTERNATIVE RELIEF REQUEST ITEM NO. EXAM. CAT. COMPONENT EXAMINED METHOD EXAMINATION STATUS f C5.21 C-F Scraa Circum- Surface & Surface Granted 4

Discharge ferential Volumetric Provided

[1 Volume Weld, Piping Volumetric j Piping Welds Over. Exam is

! in. Nominal Performed

) Wali Thickness to Extent

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(Inaccessible Practical Portion of -

] Weld No. 91)

!J li C5.21 C-F RCIC Circum- Surface & Code-Required Granted j Turbine ferential Volumetric Exam if

.j Exhaust Weld, Piping Suppression j Sparger Welds Over Pool is _

i in. Nominal Drained j _ Wall Thickness 4 (Weld FW-13) e C5.21 C-F Reactor Circum- Surface & Volumetric Granted j Core ferential Volumetric to Extent .,

i Isolation s Weld, Piping Practical ,,..

g Cooling Welds over Twice During 9

(RCIC) in. Nominal Inspection 2 v System Wall Thickness Interval &

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(Inaccessible Code-Required 1 Portions of Surface

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Welds) 4 l

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TABLE 2 CLASS 2 COMPONENTS (CONTINUED)

LICENSEE PROPOSED IWC-2500-1 IWC-2500-1 SYSTEM OR AREA TO BE REQUIRED ALTERNATIVE RELIEF REQUEST

ITEM NO. EXAM. CAT. COMPONENT EXAMINED METHOD EXAMINATION STATUS C5.21 C-F RHR Circum- Surface & Surface Granted Return ferential Volumetric - (Magnetic to RWCU Weld, Piping Particle)

Line Welds Over in. Nominal Wall Thickness (Thermal Sleeve Welds 0011-A-1 ~

& D011-B-1) -

' C6.10 C-G Pumps Pump Casing Surface Surface to Granted Welds Extent Provided (Inaccessible Practical Surface Portion of Exam is -

Welds) Performed From Internal

, Surface if Pump is Disassembled for Maintenance

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. TABLE 3 COMPONENT SUPPORTS LICENSEE PROPOSED IWF-2500-1 IWF-2500-1 SYSTEM OR ITEM TO BE REQUIRED ALTERNATIVE RELIEF REQUEST ITEM NO. EXAM. CAT. COMPONENT EXAMINED METHOD EXAMINATION

• STATUS F-2 F-C Reactor Component Visual, None Granted Core Standard VT-4 Cooling, Supports Main Steam (Within -

to RCIC, Guard Reactor Pipes)

Water Cleanup, Main Steam -

Drain, &

Main Steam 7

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e TABLE 4 PRESSURE TESTS NO RELIEF REQUESTS M

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