ML20067E616
| ML20067E616 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/25/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20067E615 | List: |
| References | |
| NUDOCS 9102150221 | |
| Download: ML20067E616 (9) | |
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UN!TED STATES i
NUCLEAR REGULATORY COMMISSION j
j WASHINGTON, t>. C. 20555 E
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ENCLOSURE SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION FIRST 10-YEAR INTERVAL INSERVICE INSPECTION PROGRAM, REVISION 14 AND THIRTEEN ASSOCIATED REQUESTS FOR RELIEF TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT, UNIT 1 DOCKET NO. 50-327
1.0 INTRODUCTION
Technical Specification 4.0.5 for the Sequoyah Nuclear Plant, Unit 1, states that the surveillance requirements for inservice ins Vessel Code (Code) y for Mechanical Engineers (ASME)pec the American Societ Boiler and Pressure 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 Boiler and Pressure Vessel Code and applicable Addenda as required by 10 CFR 50.55a(g),
except where a specific re pursuant to 10 CFR 50.55a(quest for relief has been granted by the Commission g)(6)(1) or 10 CFR 50.55a(a)(3).
pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components (includingsupports)shallmeettherequirements,exceptthedesignand access provisions and the preservice examination requirements, set forth in the Code,Section XI, of editions and addenda that become effective in the future, to the extent practical within the limits of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components shall comply with the latest edition and addenda of Section XI of the Code incorporated by reference in 10 CFR 50.55a(b) on the date 12 months prior to the date of issuance of the operating license.
Pursuantto10CFR50.55a(g)(5),ifthelicense9determinesthatconformance with an examination requirement of Section XI r,f the Code is not practical for its facility, information shall be submitted to the Commission in support for the determination (s) and a request made for relief from the Code requirement. After evaluation of the detennination(s), pursuant to 10 CFR 50.55a(g)(6)(1), the Comission 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 otheivise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed.
Pursuant to 10 CFR 50.55a(a)(3), if the licensee determines that an alterna-tive to the ASME Code requirements would provide an acceptable level of quality and safety, information shall be submitted to the Commission in support of the 9102150221 910207 PDR ADOCK 05000327 P
pon
detemir ation(s) and a request made for relief from the Code requirements.
Af ter evaluation of the determinations, pursuant to 10 CFR 50.55a(a)(3)(i), the Ccmission may grant relief from the Code.
In'a letter dated May 5,1989, the Tennessee Valley Authority. (TVA), foniarded the Sequoyah Nuclear Plant, Unit 1, first 10-year interval Inservice Inspec-tion (ISI) Program, Revision 14. This program is to meet the requirements of the 1977 Edition, Sumer 1978 Addenda of Section XI of the Code with the following exception:
the axtent of excmination for Code Class 1 piping welds have been detennined by the 1974 Edition through Sumer 1975 Addenda as required by 10 CFR 50.55a(b).
The staff, with technical assistance from its contractor, Science Applications International Corporation (SAIC), has reviewed (1) the Unit I first 10-year inter-val ISI Program, Revision 14, including additional information related to the
- program in TVA letters dated January 25, and July 12, 1990, and (2) the requests for relief from certain ASME Code requirements for Unit 1 during the first inspection interval.
The Sequoyah Nuclear Plant, Units 1 and 2, were built and licensed to the same edition / addenda of the Code. Accordingly, the first 10-year Interval ISI Program for ttcse two units are almost identical. The additional information in TVA't :<cter dated July 12, 1990, concerned (1) the Unit 2' relief requests granted by NRC letter. dated April 19, 1990 and (2) the Unit I relief requests.
The additional information for Unit 2 relief requests will be the subject of a separate evaluation on Unit 2.
2.0 EVALUATION The ISI Program has been evaluated for (a) application of the correct sectior. XI Code edition and addenda, (b) conipliance with examinatiun and test requirements of Section XI, (c) acceptability of the examination samale, (d) compliance with prior ISI comitraents made by TVA, (e) correctness of.the application of. system or component exclusion' criteria, and (f) adequate information to support recuests for relief from Section XI code requirements. The information pro-vided by TVA in support of requests for relief from Section XI Code require-ments has been evaluated and the bases for granting relief from the require-ments are documented in the attached SAIC Technical Evaluation Report (TER)
SAIC-89/1474 dated May 1990. A list of the TVA submittals reviewed by SAIC is given in the TER. The NRC staff concurs with the findings and recomendations contained in the TER with the exceptions.of the relief granted for ISI-6 and the changes generated by the additional information supplied by TVA in its letter j
dated July 12, 1990.
The changes generated by-the TVA letter of July 12,1990 and the evaluations by the ' staff are as follows:
2.1 Relief Requests 151-1 and ISI-8 Relief Request ISI-1, Pump Internal Pressure Boundary Surface, Category B-L-2, ItemB12.20,page26.to28oftheattachedTER, phrase (c)andReliefRequestISI-8,
' Pressure Retaining Welds on Pump Casirsgs, Category B-L-1, Item B12.10, pages 24
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. and 25 of reference (1), phrase (d); both of the phrases " periodic inservice testing of pumps is conducted in accordance with IKP." are to be deleted, as are all text references to IWP on pages 27 and 24 of the attached TER, respectively.
The 1977 Edition with addenda through Sunner 1978 ASME Code,Section XI, IWP-1100 defines the scope of IWP as applying to pumps installed in light water cooled nuclear power plants and which are proviced with an eurgency power source. The reactor coolant pumps at Sequoyah Unit 1 (and 2) are not in its IWP program.
2.2 Relief Request ISI-2 Relief Request 151-2, V61ve Internal Pressure Boundary Surface, Category B-M-2 Item D12.40, pages 29 to 31 of the attac'hed TER; phrase (b): /,dd the phrase "as applicable" between "IWV" and ", and".
The 1977 Edition with adderdt through Sumer 1978, ASKI Code Section XI, IWY-1100 defines the scope of IWV as applyirp to valves in light-water cooled nuclear power plants which are required to perform a specific function its shutting down a reactor to cold shutdown condition or in mitigating the conse-quences of cn accident. TVA has described the vehes presently included in relief request 151-2 as being within the scopt: of IWV in their letter of July 12, 1990. However, when additional valves are included in this relief request in the future, a valve is not to be added to the Dly prcgram solely on the basis thet it is subject to Category B-M-2 visual examination.
2.3 Relief Request 151-0 Relief Request ISI-6, Steam Generator Nozzle Inside Radius Section, Category B-0, Item 83.140, pages 15 to 17 of the atteched TER is not granted as proposed.
The licenste had proposed not aerforining the volumetric examinatiorcs until the second inspection interval. The justification was based upon the Electric Power Research Institute (EPRI) Report NP-4242, 'Long Term Inspection Requirements for Nuclear Power Plants." This report recomended that the inner radius of these nozzles be examined no sooner than at half the plant !1ife, and subsequently, at the established code inspection intervals. The EPRI Report Ha-4242 has not been received or reviewed by the NRC staff. Upon reviewing the relief requested under ISI-6, we have concluded that delaying the inspection required by the Code from the first 10-year interval to the second 10-year interval is inadequately justified. The reasons for our position are as follows:
(a) There is no assurance that the original flaw size assumed in the EpRI report was not exceeded. This plant predates the requirements for preservice examinations. TVA's preservice inspection results were not noted in the original request.
(b) The techniques used for this preservice ultrasonic inspection need to have demonstrated adequate sensitivity to detect the allowable reference flaw size.
4-The provision for relief in 10 CFR 50.55a(g) is designed for situations where the liniits of design, geomctry, or matericls of ;onstruction of the components makes it 1mpractical to physically. perform the inspections.
Another avenue for changes of inspection requirements under the regulations is provided in 10 CFR50.55a(a)(3). Here, the licensee proposes alternatives whici must either 3
(1) provide an ecceptable level of quality and safety, or (2 compliance with the specif fef. taquirements would result in hardship-or enusua)l difficulties without a compensating increase in the level of quality and safety.
If there is a compellirg reason for ctanging the Ccde requirements, there are niechanisms within the Code to effect the necessery changes. The staff het con luded that c
. performing the code required volunetric exaninations of Item B3.140 in the first 10-year interval is required.
Sequoyah Nuclear Plant Unit l's comercial cperating date is July 1,1981.
1 The code requirement in B3.140 for inspection of at least 25 percent of this itix in the first inspection period wu rot performed. It is imposs'Ible (i.e.,
impractical) to.perfom the inspections requiret in the first 40 month inspection period as it ended November,1984 Accordingly, relief is needed from the re by the end' quiretrent in B3.140 of performing at least 25 percent of the itenis of the first inspection period because none of the items were inspected in the first inspection period of the first inspection interval.
The request for r.clief ISI-6 was submitted to the staff in TVA letter dated August 23, 1983 prior to the end of the first inspection period. Ther fore, e
the st6ff censidered if relief from this requirement would be acceptable, o
The develop'nent of cracks at the inner nozzle radius of these nor21es at the beginning-of their life is remote, as indicated by the iPRI Report NP-4242, and delay of E5 percent of thess inspections frcm the end of the first 40-taonth
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period to thtt end of the first 1tbyear inspection interval poses no threat to s6fety. - In subsequent 10-year intervals, the requirer.t.nts of the code shall be met. Therefore, delaying the volumetric examination of the nozzle sections until the third inspection perho of tise first inspection intervtl and then following the code requirements is acceptable.
2.4 Relief Requests Sumary Table 1 presents a sumary a id status of the reli_ef requests as determined 'by the steff. Thirteen relief. requests have been reviewed and nine Dre a cceptr.ble.
Of the nine acceptable requcsts, for on9,151-9, ve have determined that the proposed alternatives to the Code requirennts will provide an acce of-quality and safety at Unit 1 pursuant to 10 CFR 50.55a(a)(3)(i).ptable level For the remaining eight requests.. ISI-1, ISI-3. to 151 5 have determined that the Code requirnents are Im.I5148.151-10, and 151-13, we prcctical t, perfor1n at Unit 1 and the alternative requirenents will not endanger life or property'ing the or the comon defense and security, and are a the public interest consider-burden that could result on TVA if.the Code requirements were imposed on Unit 1-pursuantto-10CFR50.55a(g)(6)(i),
for the four rL11ef requests which we could not grcrt approval, one,his time 151-11 was withdrawn. Tw; requests were determined as not heing necessary at t e.nd are postponed (ISI-2 and ISI-7) and one request 151-12. is not needed.
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-S-The table lists the restrictions; if any, for each relief request that is acceptabic. Whcre the relitf requegs' status is " Granted with alternative requirements", the alternative requirr.ments are as recomended in the SAIC TER except as amended above (i.e.,151-1, !bl-2, ISI-6, and 151-8). The granting of relief requests as provided in this SE it contingent upon all other requirements of Section XI being met for inst vice examinations, inservice tests and system pressure tests of the componrots affected by these relief req tests.
Th0 BC imposed augmented and accelerated fie'.d weld inspections generated a relhi,equart for Unit ? because these inspections were reouired to be performed within te nixt two refueling outages (i.e., Unit T. Cycle 3 and Unit 2 Cycle 4),
both oi uich feil within the second inspection period for the 10-year inspection y
inte rv al.
the Code spell' out that there is to be a maximum peretntage of 67%
for given upection categories to be completed in the second period and relief f rom this 4 equ(seinent was granted for Unit 2 in the staff's letter dated April
- 9,1990.
ibis 1s. relief request ISI-14 for Unit 2.
For Unit 1, the applicable efuclins Jtages Unit 1 Cycle 4 and Unit 1 Cycle ' fall within the second snd tMrd inspectIch periods, respectively. Theret s ; the Code specified requirements can be met, and accordingly, relief is wt 7' quired or granted for Unit 1 for the NRC imposed inspections, 1,
3.0 @tl.USICNS For Ltc Unf5 1 ISI Program, TVA submitted 13 requests for re!"f from the requ'en mts ?.' the Code:
151-1 to 151-13. As discussed ;b e, wc have dete m N d thAt these requests may be granted except in the friNwing four requests (
1ST. ;, ISI-7, ISI-11 and 151-12. Of these four repw, one was Mithdrawn (151 c 1) fore, nine requests for reliof should be grantedone is not ne and151-7). Th :re For requut 'SI-9, we have deternined that the proposed alternatives to the Code requirements will provide ar, acceptable level of quality and.',afety at Unit 1.
For the remaining eight reouests, ISI-1, ISI-3 to ISI-6, ISI-8,151-10, and 151-13, we have detemined'that the Code requirements are impractical to perform at Unit I and the alternative rruirements will not endanger life or property, w De punon defense and secur f, and are in the public interest considering -
the btr,fec that could result on (VA if the Code requirements were imposed on -
Unit 1.
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The NRC imposec ',ugmente( and accelerated field weld inspections generated a relief request f t bit 2 which is not needed for Unit 1 because these inspec-tions were required w be perfomed within the next two refueling outages (Unit '2 Cycle 3 ar.d W2 Cycle 4) both of which fell within the second inspection period. The ude spells out that there is to be a maximum percent-6ge of 67% for given ins x ction categories to be complettd in the second period and relief from ti requirement was granted.
For Unit 1, the ap)1ic-able ref ue71ng outages, Vr t 1 Cycle 4 and Unit 1 Cycle S, fall within t1e second and third inspection periods, respectively. Therefore, the Code speci-fied requirensnts can be me at Unit 1, and accordingly, relief is not required for the NRC imposed inspect'ons at Unit 1.
. Granting relief from Code requirements is authorized by law where (1) the l
roposed alternative would p(pursuant to 10 CFR 50.55a(provide an at a table level of quality and safety a)(3)(1)), (2l compliance with the specified requirements would result in hardship or unusual difficulties without a compensating increase in the level of quality and saft.ty (pursuant to 10 CFR 50.55a(a)(3)(ii)), or (3) the Code requirement is impractical and the L1 terne-5 f
tive requirement will not endanger life or property, or the common defense and security, and is in the public interest (pursuant to 10 CFR 50.55a(g)(6)(1)).
Therefore,pursuantto10CFR50.55a(a)(3)(1)and10CFR50.55a(g)(6)(1)ofthe Commission's regulations, TVA should be granted the following requerts for relief from the Code:
ISI-1,151-3 to ISI-6.151-8 to 151-10, and 151-13.
Where the relief status is " Granted with alternative requirements," the alter-native requirements are as recommended in the attached TER except as ioted in this SER. The granting of these relief requests will be contingent up1n all other requirements of Section XI being met for inservice examinations, inservice y
tests, and system pressure tests of the components affected by these re:ief requests.
The staff concludes that the Sequoyah Nuclear Plant, Unit 1, first 10-Year Interval ISI Program, Revision 14, with the additional information arovided in References 3 and 4 and the specific written reliefs constitute the ) asis for compliance with 10 CFR 50.55a(g) and the Technical Specification 4.0.5 and is, therefore, acceptable.
4.0 REFERENCES
1.
Science Applications International Corporation, "First' Interval Inservice Inspection Program, Sequoyah Nuclear Station Unit 1, " Technical Evaluation Report SAIC-89/1474," Idaho Falls, Idaho, dated May 1990.
2.
LetterfromC,H. Fox (TVA)toNRC,
Subject:
Augmented and Accelerated Inservice Inspection Program for Unit 1, dated May 5,1989.
3.
Letter from M. J. Ray (TVA) to NRC,
Subject:
Response to NRC Request for Information, Inservice Inspection Progra:a, dated January 25, 1990.
4 Letter from E. G. Wallace (TVA) to NRC,
Subject:
NRC Safety Evaluation Report for the First 10-Year Interval Inservice Inspection Program, dated July 12, l')90.
Enclosures:
As Stated Principal Contributor:
D. E. Smith Dated: October 25, 1990 1
SEQUOYAH NUCLEAR PLANT - UNIT 1
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PAGE 1 of 3 TABLE 1 SUf9'ARY OF RELIEF REQUESTS (SYSTEM /C0ftPONENTS)
LICENSEE RELIEF RELIEF REQUEST ITEM EXAM SYSTEF CR VOLU?tE OR AREA REQUIRED PROPOSED REQUI.ST HUMBER NO.
CAT.
C0h?0NENT TO BE EXA!!!NED METHOD ALTERNATIVE STATts l
10 CFR 50.55a(g)(6)(i) Requests 151-1 B12.20 B-L-2 Pirmps Internal Pressure Visual Visual exam of Granted with Foundary Surfaces surfaces if purp alternative opened for maint. requirements If not, UT thick-ness from ex-terior 151-2 B12.40 B -M-2 Valves Internal Pressure Visual None Postpor,ed Boundary Surfaces until speci-fic relief requests are presented towards end of interval ISI-3 B5.50 8-F Bioctal Pressure retain-Surface Inspect to ex-Granted with Welds ing bimetallic Volumetric tent possible alternative welds in piping requirements B9.10 B-J Welds Pressure retain-Surface Inspect to ex-Granted with B9.20 ings welds in Volunetric tent possible alternative 89.30 piping requirements i
C5.10 C-F C5.20 C5.30 ISY-4 C1-10 C-A Steam Class 2 Circum.
Volumetric Inspect to ex-Grar
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- Generator shell welds tent possible ISI-5 Bl.21 B-A Reactor Bottom head Volumetric Inspect to ex
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.n Yessel Circum. weld tent possible alb
.e r-
,ents
m-iSEQUOYAH NUCLEAR PLANT - UNIT ~1 PAGE 2 of 3 '
' TABLE 1
.5LHMARY OF RELIEF REQUESTS (SYSTEM / COMPONENTS)
RELIEF LICENSEE RELIEF REQUEST
_ ITEM EXAM
- SYSTEI4 OR -
VOLUME OR AREA.,
REQUICD
~ NUMBER NO.
. C AT.-
COMPONENT
.TO BE EXAMINED METHOD.
PROPOSED
- REQUEST ALTERNATIVE STATUS 151-6
.B3.140 A-D
_ Steam
-Nozzle inside-
-Volumetric Postpone until Granted with-Generator-radius section next intarval alternative requirements 151-7
.B0.10 B-J Piping Reactor. coolant Volumetric-None Pestponed loop piping welds until fourth interval 151-8 B12.10 B-t-1 Pumps
-Pressure retain.
. Surface Surface exam Granted with ing welds'on pump Volumetric Only alternative.
casings requirements' 151-10 Bl.30 B-A
. Reactor Flange to upper Volumetric Delay volume-Grcnted vessel-shell~ weld at Table tric to end of IWB-2412-1 interval.
frequency IST-11 Withdrawn 151-12 C1.10 C-A
' Pressure Shell weld at Volumetric Nene Relief not C1.20 C-C vessels structural dis-Volumetric required ~
C1.30 C-C continuities Volumetric C3.10 C-E' attachments Surface 151-13 C2.20 C-B Pressure RHR HTEX nozzel Surface Forface exam Granted vessels to vessel welds Volumetric only
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.SEQUOYAH NUCLEAR PLANT - UNITji'
~ PAGE-3 of 3:
- TABLEil:
'SIMtAR' 0F* RELIEF REQUESTS (SYSTEM /COMFCNENTS) 1--
~
LICENSEE RELIEF
- RELIEF --
- REQUEST ITEM EXAM
-5YSTEM OR~~
V0LtME OR AREA
' REQUIRED-PROPOSED-REQUEST'
.NO.
': CAT.
COMP 0 MENT
. TO BE EXAMIMED METHOD 1p'.TERNATIVE ~
STATUS-NtEBER~
- 10 CFR 50.55a(a)(3)(1) Requests' ISI-9
-UT cali-Use:of 5-percent
-. Continue use of. Granting pro--
bration notches'in' lieu existing blocks vided alter-of: side-drilled
' native -
holes existing; blocks meet
. applicable i
l Code re -
quirements l
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