ML15188A066
| ML15188A066 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley, Indian Point, North Anna, Ginna, Diablo Canyon  |
| Issue date: | 06/25/2015 |
| From: | Wilson T Electric Power Research Institute |
| To: | Document Control Desk, NRC Region 1 |
| References | |
| Download: ML15188A066 (9) | |
Text
06612512015 Pnoo I
.......... S Nulear R.pulatr Com.missio.n Oneratin Center Event Rnrt P, I Non-Agreement State Event # 51181 Rep Org: ELECTRIC POWER RESEARCH INSTITUTE Notification Date / Time: 06/25/2015 15:40 (EDT)
Licensee: ELECTRIC POWER RESEARCH INSTITUTE Event Date / Time: 05/01/2015 (EDT)
Last Modification: 06/25/2015 Region: 1 Docket #:
City: CHARLOTTE Agreement State: Yes County: License #:
State: NC NRC Notified by: TRACY WILSON Notifications: JOHN ROGGE R1DO HQ Ops Officer: DONG HWA PARK KATHLEEN O'DONOHUE R2DO Emergency Class: NON EMERGENCY VIVIAN CAMPBELL R4DO 10 CFR Section:
21.21(a)(2) INTERIM EVAL OF DEVIATION PART 21 - DEVIATION IN NOZZLE MODELING INTERNAL REPORTS The following was received via facsimile:
"[This report pertains] to a deviation in a basic product (EPRI nozzle modeling internal reports) supplied by EPRI (Electric Power Research Institute) regarding Westinghouse Pressurizer Head Nozzle Inner Corner Region Ultrasonic Inspections. EPRI will complete all evaluation efforts and provide a determination of reportability in accordance with 10CFR Part 21 no later than July 24, 2015.
"EPRI has conducted an evaluation to the basic product's actual use and determined that the ASME examination volume coverage for at least one of the pressurizer nozzles has changed and is now 90 percent or less. A 90 percent threshold is required by ASME Boiler & Pressure Vessel Code, Section XI.
"Designpinputs used in EPRI modeling for ultrasonic scanning coverage for nuclear safety related component nozzles may have been inaccurate. In some cases, the upper and lower heads of Westinghouse pressurizers can be offset from the center of each nozzle (spray, safety, relief, surge). This offset results in a change in the thickness of the pressurizer head as compared to an on-axis pressurizer head with the same radial dimensions.
Some of the computer models EPRI used to describe these pressurizer heads did not account for an increase in the thickness due to these offsets. As a result, in some cases the ultrasonic inspection parameters produced by these computer models may have produced inaccuracies in the examination volume coverage calculations.
"In the case of a basic component which contains a defect or falls to comply, the number and location of these components in use at, supplied for, being supplied for, or may be supplied for, manufactured, or being manufactured for one or more facilities or activities subject to the regulations in this part.
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, M5612 5121)#_5 Pn*,p I Nuceat~r Repuladrv Commission Onerationi U.S.205 Cepnter Event R-nnrt Pn"a Utility Name/Plant Name Exelon Corporation / Ginna First Energy Nuclear Operating / Beaver Valley 1 Entergy / Indian Point 2 Entergy / Indian Point 3 Pacific Gas & Electric Co. / Diablo Canyon Unit 2 Dominion Generation / North Anna "EPRI has reviewed the pressurizer upper and lower head drawings for the nozzles that it has modeled and determined if these offsets are present. For those cases that are potentially affected EPRI has recalculate the new examination volume coverage for the nozzle inspection detection techniques and provided this information to the corresponding licensees.
"EPRI staff shall develop a matrix or table to better define the necessary design inputs for computer modeling of nozzles. This should also include a question to the utility regarding any obstructions or thickness changes which would impact the ultrasonic inspection parameters. EPRI staff shall improve its documentation for review and approval of design inputs for computer modeling. Consideration shall also be given to including a review of design inputs by the member along with an acknowledgement from the member that the design inputs are appropriate for use. EPRI staff shall consider methods of including additional conservatism to the modeling results to better accommodate changes which may be observed in the field. The project quality plan and quality project instruction shall be updated as necessary to accommodate or clarify these improvements. Completion commitment date -
10/27/2015 "The coverage calculations indicated in the notification letters would likely increase if the EPRI modeled scan plans are exceeded and or if additional inspection angles were implemented. Conversely, these coverage calculations would likely decrease if physical field limitations prevented the ultrasonic probe from executing the EPRI modeled scan pattern. It is on this basis that recipients of this letter must evaluate the condition pursuant to 10 CFR Part 21.21 to determine if it could represent a substantial safety hazard reportable under 10 CFR Part 21."
No. 0601 P. 1i Jun. 25 2015 3:34PM iiELFef~lJc POWLER of '
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Jun,25. 2015 3'35PM No, 0601 P.2/7 EI~e ~ELECTRIC POWER RESEARCH INSTITUTE NEIL WILMSHURST Vice President and Chief Nuclear Oficer June 25, 2015 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
Subject:
Part 21 60 Day Interim Report Notification:
Westinghouse Pressurizer Head Nozzle Inner Corner Region Ultrasonic Inspections Dear Sir; This letter provides an interim report inaccordance with 10 CFR Part 21.21 pertaining to a deviation ina basic product (EPRI nozzle modeling internal reports) supplied by EPRI (Electric Power Research Institute) regarding Westinghouse Pressurizer Head Nozzle Inner Corner Region Ultrasonic Inspections.
EPRI will complete all evaluation efforts and provide a determination of reportability in accordance with IOCFR Part 21 no later than July 24, 2015.
The information required for this Interim Report per 21.21(a)(2) isprovided inthe following attachments.
Ifyou have any questions, please contact me.
Sincerely, Together . .. Shaping the Future oF Electricity CHARLOrrE orrICE 1300 West W.T. Harris Boulevard, Charlotte, NC 28262-8550 USA
- 704.595.2000 ' Fox 70,4.595.2860 Cuslomer Service 800.313.377A4 u.www.eprt.com
Jun.25. 2015 3:35PM No,0601 P.3/7 Part 21 - 60 Day Interim Report Notification June 25, 2015 Page 2 Attacment Exelon Corporation Ginna First Energy Nuclear Operating Beaver Valley 1 Entergy Indian Point 2 Entergy Indian Point 3 Pacific Gas &Electric Co. Diablo Canyon Unit 2 Dominion .Generation North Anna NOTE: Calculations for another six plants resulted inchanges to certain examination coverage calculations, but not to levels below the 90% threshold. EPRI has sent Information Notices to these plants.
Athird group of plants had no changes.
Together . . . Shaping the Future of Electricity 1300 Wesl W.T. Harris Boulevard, Charlotte, NC 28262-8550 USA
- 704.595.2732
- Mobile 704.490.2653
- nwilmshurst@epri.com
Jun. 25, 2015 3:35PM No. 0601 P. 4/7 Part 21 - 60 Day interim Report Notification June 25, 2015 Page 3 Attachment 2 Potential Part 21 Reporting Information (i) Name and address of the individualor Individuals informing the Commission.
Neil M.Wilmshurst Vice President and CNO Electric Power Research Institute 1300 West WT Harris Blvd ICharlotte NC 28262-2867 (11) Identification of the facility, the activity, or the basic component supplied for such facility which fails to comply or contains a defect.
EPRI has conducted an evaluation to the basic product's actual use and determined that the ASME examination volume coverage for at least one of the pressurizer nozzles identified inthis letter has changed and isnow 90% or less. A90% threshold is required by ASME Boiler &Pressure Vessel Code, Section XA.
(M) Identification of the firm constructingthe facility or supplying the basic component which fails to comply or contains a defect EPRI supplied the basic product (report) to the licensees listed inTable 1 from 2010 to the present.
(iv) Nature of the defect or failure to comply and the safety hazard which Is createdor could be createdby such defect or failure to comply.
Design inputs used inEPRI modeling for ultrasonic scanning coverage for nuclear safety related component nozzles may have been inaccurate, Insome cases, the upper and lower heads of Westinghouse pressudzers can be offset from the center of each nozzle (spray, safety, relief, surge). This offset results ina change inthe thickness of the pressurizer head as compared to an on-axis pressurizer head with the same radial dimensions (see examples inAttachment 3). Some of the computer models EPRI used to describe these pressurizer heads did not account for an increase inthe thickness due to these offsets. As a result, insome cases the ultrasonic inspection parameters produced by these computer models may have produced inaccuracies inthe examination volume coverage calculations.
(v) The date on which the informationof such defector failure to comply was obtained.
An EPRI Corrective Action Report (CAR 2015-0032) was initiated on I May 2015.
(vi) Inthe case of a basic component which contains a defect or falls to comply, the number and location of these components in use at, suppliedfor, being suppliedfor, or may be supplied Together ... Shaping the Future of Electricity 1300 West W.T, Ho'tis Boulevard, Charlivle, NC 28262-8550 USA
- 704.595.2732 ° Mobile 704.490,2653 . nwiimshurst@epri.cvrn
Jun. 25, 2015 3:35PM No. 0601 P. 5/7 Part 21 - 60 Day interim Report Notification June 25, 2015 Page 4 for, manufactured,or being manufacturedfor one or more facilities or activities subject to the regulationsin this part.
See Table 1.
(vii) The corrective action, which has been, is being, or will be taken; the name of the individual or organizationresponsiblefor the action; andthe length of time that has been or will be taken to complete the action.
EPRI has reviewed the pressurizer upper and lower head drawings for the nozzles that ithas modeled and determined ifthese offsets are present. For those cases that are potentially affected EPRI has recalculate the new examination volume coverage for the nozzle inspection detection techniques and provided this information to the corresponding licensees.
EPRI staff shall develop a matrix or table to better define the necessary design inputs for computer modeling of nozzles. This should also include a question to the utility regarding any obstructions or thickness changes which would impact the ultrasonic inspection parameters. EPRI staff shall improve its documentation for review and approval of design inputs for computer modeling. Consideration shall also be given to including a review of design inputs by the member along with an acknowledgement from the member that the design inputs are appropriate for use. EPRI staff shall consider methods of including additional conservatism to the modeling results to better accommodate changes which may be observed In the field, The project quality plan and quality project instruction shall be updated as necessary to accommodate or cladfy these improvements. Completion commitment date - 10127/205 (viii) Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasersor licensees.
The coverage calculations indicated in the notification letters would likely increase ifthe EPRI modeled scan plans are exceeded and or if additional inspection angles were implemented. Conversely, these coverage calculations would likely decrease ifphysical field limitations prevented the ultrasonic probe from executing the EPRI modeled scan pattern. Itis on this basis that recipients of this letter must evaluate the condition pursuant to 10 CFR Part 21.21 to determine ifitcould represent a substantial safety hazard reportable under 10 CFR Part 21.
(ix) In the case of an early site permit, the entities to whom an early site permit was transferred.
This is not an early site permit concern, Together .-. . Shoping the Future of Electricity 1300 West W.T. Harris Boulevard, Charlotte, NC 28262-8550 USA e 704.595.2732 &Mobile 704.490.2653 a nwilmshurleepri.com
Jun. 25, 2015 3:35PM No. 0601 P.6/7 Part 21 - 60 Day Interim Report Notification June 25, 2015 Page 5 Attachment 3 Westinghouse Pressurizer Head Nozzle Inner Corner' Region Ultrasonic Inspections - Supporting Figures' Figure 1 below contains a sketch of a typical Westinghouse, pressurizer upper head indicating that the outside surface isoffset from the center of the inside surface and the center of each safety-relief and spray nozzle. The ASME Section XA Class 1 examination volurneis also identified inthis figure.
Note ChangerInThlmec*kOue to UpperHead Preseurizer$roty-R-r$1,NSenae AEi 91 Cio 1 Ream Yilum.
Upper Head Pmnrsuhzer SprayHonts
.SME XI CIOGea I ExarmVluma C4ntor Pointis)l :f,'
7ý Figure 1. Westinghouse Pressurizer Upper Head Sketch with Offsets Together . . . Shaping the Future of Electricity 1300 West W.T Harris Boulevard, Charlotle, NC 28262-8550 USA
- 704,595,2732
- Mobile 704.490.2653 nwilm:hursl@Oeprixom
Jun. 25. 2015 3:35PM No. 0601 P.7/7 Part 21 - 60 Day Interim Report Notification I I June 25, 2015 I Page 6 Attachment 3 (cont)
Figure 2below contains a sketch of a typical Westinghouse, pressurizer lower head!indicafing that the outside surface is offset from the center of the inside surface and the center of thb sbirge nozzle. The ASME Section Xl Class 1examination volume isalso identified inthis figure.
Lower Head Pressurlzr Burg&Nozzl, ASMEXl M:aan1 Exom VoluMO " I .r .
6irVr POl~s)ran Ha OrS ld* Raal p
Note Change In ThIccese Oua i to Figure 2.Westinghouse Pressurizer Lower Head Sketch with Offsets Together . . Shaping the Future of Electricity 1300 West W.T. Harris Boulevard, Chirlolle, NC 28262-8550 USA 6 704,595.2732
- Mobile 704.490.2653
- mwilVahurst@epri.com