ML20114D541
| ML20114D541 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 09/01/1992 |
| From: | Devine J GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-0619, RTR-NUREG-619 5000-92-3062, C321-92-2240, NUDOCS 9209090128 | |
| Download: ML20114D541 (8) | |
Text
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GPU Nuclear Corporation f
One Upper Pond R=d Pwtdppany, New Jersey 07054 201 316 7000 TELEX 136-482 Wnter'a Dwect Otal Nurnter September 1, 1992 5000-92-3062 C321 92-2240 U. S. Nuclear Regulatory Commission
'Att: Document Control Desk Washington, DC 20555
Dear Sir:
Subject:
Oyster Creek Nuclear Generating Station (OCNGS)
Docket No. 50-219 Revision to NUREG-0619 Routine Inspection Criteria for feedwater and Control Rod Drive Return Line Nozzles By letter dated July 8, 1992, the staff requested that GPU Nuclear review and address the issues identified in the their safety evaluation and provide a schedule indicating when the capability to detect thermal fatigue cracks with the phased-array VT technique would be available.
In response to these requests, a meeting was held with the staff on July 23, 1992, A meeting summary and a request for the following additional information was issued by the staff cn July 30, 1992:
1.
The inspections.uPUN has performed on the feedwater nozzles and control rod return line nozzle including safe ends and to what extent they were inspected.
The inspections performed should be compared to NUREG 0619, in addition, the number of startup and shutdown cycles Oyster Creek has experienced during its operation since Cycle 7 should also be included.
3, Provide the results of the phased-array UT performed on the Oyster Creek mock-up including thermal fatigue cracks.
In response to request number 1, Enclosure 1 identifies the inspections performed during past refueling outages (7R through 13R).
Enclosures 2 and 3 summarize the GPU Nuclear correspondence regarding the schedules for liquid penetrant and ultrasonic testing, respectively.
The number of start-up/ shut-down cycles between 7R outage and the present is 94.
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GOU Nuclem Corpo'ation a a sut'siciary of General Pubhc Utn des Corporation
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- With respect to request number 2, the demonstration of'the phased-array UT
- technique to detect thermal-fatigue cracks has been scheduled and the staff
-has been invited 10 observe the demonstration process.
The results and acceptability-of the phased-array UT technique to detect and caaractaize
' thermal fatigue cracks should be apparent at that time.
As identified in the July 30, 1992-meeting summary, GPU has proposed the following:
1.
Utilize the phased-array ultrasonic test (UT) technique as a primary method to detect, characterize and monitor flaws in the feedwater and control rod drive return line nozzles.
2.
Eliminate routine.. liquid penetrant-(PT) examinations of feedwater and control rod drive return line nozzles.
3.
Defer feedwater nozzle UT from 14R (November 1992) to 15R t
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'(October 1994) so feedwater and control rod drive return line nozzles are inspected in the same outage with a fully Appendix Vlli,Section XI, ASME qualified procedure.
Following. successful-Appendix Vill UT gnilificatlon,
- 4..
demonstration of adequate sensitivity for Gyster Creek specific assumed flaw sizes and successful 15R examination with no cracks, perform UT inspections once each Inservice Inspection (ISI) interval (every 10 years) in accordance with the ASME Code.
i During the July 23, 1992 meeting with the staff, GPU Nuclear was informed that a decision on the above proposals could not be made at that time because of the generic-implications and. impact on the inspection methods and frequency established by NUREG-0619,;"BWR Feedwater-(FW) Nozzle and Control Rod Drive Retur_n Line (CRDRL) Nozzle. Cracking".
The.14R outage is currently scheduled to start-on November 28, 1992.. In order to support.this schedule, we request _a timely response to items 1, 2 and 3.
A-response.to item number 4 is not necessary at this time to support the upcoming outage.
If there are any questions please contact Mr. Michael Laggart.at
-(201) 31G-7968.-
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-J. C. DeVine Vice President and Dir?ctor
-Technical Functions JCDV/EJP:lga attachments cc: Administrator, Region I l-Senior Resident inspector
- .0yster Creek NRC Project Manager
ENCLOSURE I Page 1 of 2 0YSTER' CREEK P.EFUELING OUTAGE EXAMINATIONS 1, m
_ m.m REFUELING NUREG-p619 OUTAGE WORK COMPLETED
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7R 04/23/77-08/04/77 PT - FW Nozzles (See Note 1.)
PT - CRDRL Nozzle - No indications FW Nozzle Repairs Installed improved FW sparger and thermal sleeve Assembly having a single piston ring seal and flow baffles for FL' nozzles.
Installed new thermal sleeve and baffle design for the CRDRL nozzle.
8R 09/16/78 12/08/78 Visual -:FW St.arger 9R 01/05/80-07/16/80 Visual - FW Sparger
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10R
'02/12/83-11/03/84 Visual - FW Sparger Visual CRDRL Nazzle llR 04/11/86-12/21/86 Visual --FW Spaigor 12R 09/30/88-05/11/89 UI - Feedwater Nozzles (See Note 2.)
Visual - FW Sparger Visual - CRDRL Nozzle 13R i
02/16/91 06/28/91 UT - Control Rod Drive Peturn Line Nozzle Visual - FW Sparger l-L Visual - CRDRL Nozzlc
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.i 0YSTER CREEK Page 2 of 2 REFUELING OUTAGE EXAMINATIONS 4
L uring the 7R refueling outage, the extent of the liquid NOTE 1:
D penetrant examination coverage was the cladded surface.
This area extended into the nozzle approximately 8 inches, measured from the vessel's_ID wall, During the actual examinations, liquid penetrant interpretations were made in the adjacent uncladded bore region, where the extent of coverage was limited to approximately 3-4 inches.
NOTE 2:
NUPEG 0619, sect'on 4.3.2.3 (UT Inspection and Subsequent PI of Recordable Indications) requires an external UT examination of all feedwater nozzle safe enda, bores and inside blend radii.
During the 12R refueling outage, an external ultrasonic examination was performed for
= detecting both axial and circumferential fluus in the four feedwater nozzles.
The extent of coverage was the nozzle nafe-end to nozzle weld on the entire surface from the nozzle boss transition to the safe-end transition, the inside blend radii, the nozzle bore region and tn'e vessel shell. to nozzle weld.. A small Lsegment of the safe end, approximately 3 inches of the outboard side, was not examined during the 12R inspection, No reportable indications were detected' s
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EE11SJLRJ_2 OYSTER CREEK Page 1 of 2 A
ROUTINE PT INSPECTIONS OF FW/CRDRL N0ZZLES CHRONOLOGY OF CORRESPONDENCE LETTER REFERENCE
SUMMARY
COMMENT 04/09/81 GPUN commits to perform Original commitment to routine PT during Cycle 13 NUREG-0619 refueling outage.
08/25/81 GPUN coafirms commitment to As a result of NRC 7/20/81 inspect CRDRL nozzle at frequency request and by method in NUREG-0619, Paragraph 8.2(5) 11/29/82 PT moved up from Cycle 13 to More efficient use of personnel Cycle 11 retueling outage, for both economic and ALARA considerations 07/26/84 NRC informed that GPUN would not GPUN believes UT tospection will plan on proceeding with internal substantiate l>;K of significant PT inspections, nozzle cracking.
11/20/85 GPUN states that PT examinations UT inepecticn should be able to will only-be performed-during_
detect flaws which would Cycle 12 refueling outage should compromise nozzle integrity. An flaws be detected by UT evaluation of findings would examination which would determine if PT is necessary for compromise nozzle integrity further investigation.
GPUN also informed NRC that, Based on successful application based upon the sensitivity of the of the Phased-Array UT UT technique during 12R, it will techniques, be determined as to whether a.PT exam is required-during 13R.
- 01/18/90 GPUN informs NRC -that UT is a Based on successful application suitable alternative to PT exams of_ UT on FW nozzles during 12R and that it would provide the and FW mock-up testing.
basis for eliminating the 13R PT exam for.FW/CRDRL nozzles in a separate submittal.
GPUN also informed NRC that no PT Based on finding no reportable examinations of the internal indications during the 12R UT diameters of-the nozzles were inspection.
performed.
[NCLDIRRE 2 (CONT'D) 0YSTER CREEK Page 2 of 2 ROUTINE PT INSPECTIONS OF FW/CRDRL N0ZZLES CHRONOLOGY OF CORRESPONDENCE LETTER REFERENCE
SUMMARY
COMMENT
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07/12/90 GPUN informs NRC of proposal to Based on successful application defer the 13R PT exam for FW of UT on FW nozzles during 12R, Nozzles, future PT exam of CRDRL FW meck-up testing, CRDRL mock up Nozzles, replace routine PT exams
- testing, of FW nozzles.with U1 exams.
GPUN states that PT examinations Based on sensitivity and will only be performed should successful application of Phased-flaws be detected by UT Array technique during upcoming examination which would 13R.
compromise nozzle integrity.
04/18/91 GPUN informs NRC that there is a Based on successful applicati,
technical basis to revise the of VI on FW & CRORL Nozzles i NUREG-0619 inspection intervals service and with FW & CRDRL mock-for nozzles.
up tests.
04/08/92 GPUN proposes changes to NUREG-Based on successful application 0619 inspection intervals, of UT technique, use of fracture Specifically, to delete routine mechanics and commitment to PT, unless flaws which would demonstrate UT can detect thermal compromise nozzle integrity are fatigue cracks.
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EtCLOSURE 3 J
J OYSTER CREEK Page 1 of 2 i
UT EXAMINATION OF FW/CRDRL N0ZZLES CHRONOLOGY OF CORRESPONDENCE LETTER REFERENCE
SUMMARY
JUSTIFICATION 1
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-m 04/09/81 UT inspection to begin during Original commitment Cycle 10 refueling outage.
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11/29/82 GPUN revises UT of FW no7:tes Due to analysis showing tendency i
from Cycle 10 to Cycle 'l reload toward further cracking would be
- outage, eliminated per design changes, visual inspection results of spargers during Cycles 8 & 9 reload outages, expected crack l
giowth limitations.
1 07/26/85 GPUN revises UT inspection of FW To reduce Cycle 11 refueling 11/20/85 nozzles from Cycle 11 to Cycle 12 outage scope and because the refueling outage.
results of tests and analyses L
which demonstrate that any previously undetected flaws in the FW nozzles will not grow to an unacceptable size, 01/18/90-GPUN reports that during 12R it Reported FW UT inspection completed a UT examination of results.
weld,' inner radii and inner bore of:FW nozzle.
07/12/90 GPUN proposes to replace PT of This is based ' n the successful o
CRORL nozzle.with UT during 13R, demonstration of the UT technique defer the 13R PT exam for~ FW on FW and CRDRL mock-ups and-l nozzles, replace future PT exams inservice FW UT inspection.
of FW/CRDRL nozzles with UT exams.
04/18/91-GPUN informs the NRC that there Based on successful application is a technical basis to revise of UT on FW & CRDRL nozzles in the NUREG-0619 inspection service and with FW & CRDRL mock-intervals for nozzles, up tests.
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OYSTER CREEK Page 2 of 2 UT FXAMINATION OF FW/CRDRL N0ZZLES CHRONOLOGY OF CORRESPONDENCE
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LETTER
- REFERENCE
SUMMARY
JUSilflCATION
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04/08/92 GPUN proposes to eliminate future This is based on the successful routine PT inspections and demonstration of the UT technique i
perform UT. inspections of FW and on FW & CRDRL nozzles and mock-CRDRL nozzles once each ISI ups, the upcoming demonstration
- period, of UT to detect thermal fatigue cracks and fracture Mechanics analysis.
GPUN proposes to defer the FW UT This is based on Fracture inspection from 14R to 15R.
Mechanics analysis which shows that a sniall flaw will not grow-significantly by ISR, i-nam
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