ML20216J664
| ML20216J664 | |
| Person / Time | |
|---|---|
| Issue date: | 03/13/1998 |
| From: | Lainas G NRC (Affiliation Not Assigned) |
| To: | Terry C AFFILIATION NOT ASSIGNED |
| References | |
| TAC-M97373, NUDOCS 9803240018 | |
| Download: ML20216J664 (4) | |
Text
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UNITED STATES g
j-NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20556-0001 m
j March 13,1998 1
1 CarlTerry, BWRVIP Chairman l
Niagara Mohawk Power Company f
Post Office Box 63 Lycoming, NY 13093
SUBJECT:
REVIEW OF "BWR VESSEL AND INTERNALS PROJECT, ROLt/ EXPANSION l
REPAIR OF CONTROL ROD DRIVE AND IN-CORE INSTRUMENT PENETRATIONS IN BWR VESSELS (BWRVIP-17)" (TAC NO. M97373)
Dear Mr. Terry:
The NRC staff has completed its review of the Electric Power Research Institute (EPRI) proprietary report TR-106712, "BWR Vessel and Intemals Project, Roll / Expansion Repair of Control Rod Drive [CRD] and in-Core Instrument Penetrations in BWR Vessels (BWRVIP-17),"
dated November 27,1996. The BWRVlP-17 report was submitted as a means of providing a generic technical basis and criteria for performing a non-Code repair to an ASME Code component. The purpose of the report was to allow BWR licenees to reference the report for plant-specific cases where the roll / expansion repair process to mitigate or eliminate leakage from vessel penetrations was proposed as a permanent attemative under 10 CFR 50.55a(a)(3).
i The BWRVIP-17 report referenced three licensee requests for an altemative under 10 CFR 50.55a(3), including one from Nine Mile Point, Unit 1 (NMP1), dated December 11,1986< By letter dated March 25,1987, the NRC provided an evaluation of the NMP110 CFR 50.55a(a)(3) j relief request, which was based on a number of conditions and ongoing licensee activities, including the absence of cracks in the J-weld, leakage inspections, and development of a prototype mechanical seal, associated tooling and investigation of methods of weld repair. The position of the NRC staff was predicated on the specific locations of the cracks at NMP1, the change to the plant technical specifications (TSs) to limit leakage, as well as a licensee commitment to develop a permanent repair that corrects the degradation to the RCS pressure boundary. Thus, the staff did not approve the roll / expansion process for NMP1 as a permanent repair in lieu of meeting ASME Code repair criteria.
V The BWRVIP-17 report does not address whether or not there could be an increase in risk as a result of operating with degraded CRD com.ponents. For instance, no information is provided as to whether there is an increased likelihood of ejecting a component if the cracking were at a less favorable location than at the CRD stub tube location at NMP1 or at a location in a reactor lacking stub tubes where the J-weld would not impinge against the stub tubo and preclude rod ejection (see attached figure). Further, the lack of success with the roll /oxpansion process used in foreign reactor CRD penetrations is attributed, in part, to the leakage allowed for extended periods of time prior to the roll expansion attempt, with possible steam cutting, and/or crud / oxide deposits on the rolling contact surfaces.
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- C. Terry ?.
The NRC staff's position is that the corrective action intended by the ASME Code requirements, upon discovery of a flaw in a Class 1 pressure retainin0 boundary component, is to either repair the flaw or replace the flawed component in order to return it to a condition of Code compliance.
An ASME Code-acceptable repair of a crack in a control rod drive (CRD) stub tube or in-core penetration would require a weld repair. Although the roll / expansion method may for some time period control the symptom of the flaw (leakage), it does not repair the flaw; therefore, it does not meet the criteria or the intent of a permanent repair method. As evidenced from the data on NMP1 included in BWRVIP-17, a significant number of rolled CRD penetrations have required re-rolling to mitigate new leakage at the penetrations, thus the roll / expansion repair is not a long term leakage repair method. Further, in the original SE evaluating the roll / expansion process for
. NMP1 it was approved only until the next outage. Following the outage, the process was approved in a TS change request with the condition that a program be implemented which would investigate mechanical seal concepts and other methods such as weld repair. This is consistent with the staff's understanding that the roll / expansion process is not intended as a permanent repair.
Therefore, the NRC staff has determined that the BWRVIP-17 report does not provide a sufficient basis for an acceptable permanent attemative program to 10CFR50.55a(a)(3). As such, the NRC staff denies the BWRVIP-17 generic application.
Please contact C. E. (Gene) Carpenter, Jr., of my staff at (301) 415-2169 if you have any further questions regarding this subject.
fIh? twt:db'l Gus C. Lainas, Acting Director Division of Engineering Office of Nuclear Reactor Regulation cc: See next page SJCollins/FJMiraglia LCShao/MEMayfield NRR/EMCB Reading BWSheron TECollins PUBLIC RPZimmerman Central File DOCUMENT NAME: G:\\BWRVIP\\BWRVIP17.LTR
- See Previous Concurrence To receive a copy of this document. Ind6cate in the box: "C" = Copy 'N' = No copy EMCB:lNT C
EMCB: LPM C
EMCP:SC C
EMCB:SLS C
UShoop*
CECarpenter*
KRWichman*
RAHermann*
02/23/1998 02/23/1998 02/23/1998 02/23/1998 EMCB:BC C
EMEB BC C
DE:DD C
D$:D C
EJSullivan*
RHWessman*
JRStrosnider*
G nas 03/02/1998 03/03/1998 3/11/98 3/ 1998 OFFICIAL RECORD COPY d
C. Terry e The NRC staff's position is that the corrective action intended by the ASME Code requirements, upon discovery of a flaw in a Class 1 pressure retaining boundary component, is to either repair the flaw or replace the flawed component in order to return it to a condition of Code compliance.
An ASME Code-acceptable repair of a crack in a control rod drive (CRD) stub tube or in-core penetration would require a weld repair. Although the roll / expansion method may for some time /
period control the symptom of the flaw (leakage), it does not repair the flaw; therefore, it does /
not meet the criteria or the intent of a permanent repair method. As evidenced from the data on NMP1 included in BWRVIP-17, a significant number of rolled CRD penetrations have requ' re-rolling to mitigate new leakage at the penetrations, thus the roll / expansion reps.ir is n long term leakage repair method. Further, in the original SE evaluating the roll / expansion ss for NMP1 it was approved only until the next outage. Following the outage, the proces as approved in a TS change request with the condition that a program be implement which would investigate mechanical seal concepts and other methods such as weld repair. T is is consistent with the staff's understanding that the roll / expansion process is not intended a a permanent repair.
Therefore, the NRC staff has determined that the BWRVIP-17 report d not provide a sufficient basis for a generic permanent alternative to the ASME Code. As such, the NRC staff denies the BWRVIP-17 generic application, Please contact.C. E. (Gene) Carpenter, Jr., of my staff at (301) 4 -2169 if you have any further questions regarding this subject.
Sincerely, Gus C. Laina Acting Director Division of E ineering Office of N lear Reactor Regulation cc: See next page SJCollins/FJMiraglia LCShao/MEMayfield NRR/EMCB Reading BWSheron TECollins PUBLIC RPZimmerman Central File DOCUMENT NAME: G:\\BWRVIP\\BWRVIP17.LTR
- See Previous Concurrence l
To receive a copy of this document, indic in the box: "C" = Copy "N" a No copy EMCB: TNT C
EMCB: LPM C
MCB:SC C
EMCB:SLS C
UShoop*
CECarpenter*
KRWichman*
RAHermann*
02/23/1998' 02/23/1998 02/23/1998 02/23/1998 EMCB:BC C
EMEB:BC C
DE:DD fk C
DE:D C
EJSullivan*
RHWessman*
JRStrosnider GClainas 03/02/1998 03/03/1998 03///1998 b
03/ /1998 OFFICIAL RECORD COPY i
1 l
C. Terry
- 1 steam cutting, and/or crud / oxide deposits on the rolling contact surfaces. In addition, the NRC does not find a friction connection from rolling the stub tube against the lower reactor vessel to be equivalent to a welded design.
The NRC staff's position is that the corrective action intended by the ASME Code requirements, upon discovery of a flaw in a Class 1 pressure retaining boundary component, is to either repair the flaw or replace the flawed component in order to return it to a condition of Code compliance. An ASME Code-acceptable repair of a crack in a control rod drive (CRD) stub tube or in-core penetration would require a weld repair.
Although the roll / expansion method may for some time period control the symptom of the j
flaw (leakage), it does not repair the flaw; therefore, it does not meet the criteria or the l
intent of a permanent repeir method. As evidenced from the data on NMP1 included in BWRVIP-17, a significant number of rolled CRD penetrations have required re-rolling to mitigate new leakage at the penetrations, thus the roll / expansion repair is not a long term leakage repair method. Further, in the original SE evaluating the roll / expansion process for NMP1 it was approved only until the next outage. Following the outage, the process was approved in a TS change request with the condition that a program be implemented which I
would investigate mechanical seal concepts and other methods such as weld rppair. This is consistent with the stoff's understanding that the roll / expansion process is not intended as a permanent repair.
Therefore, the NRC staff has determined that the BWRVIP-17 report d s not provide a sufficient basis for a generic permanent alternative to the ASME Cod. As such, the NRC staff denies the BWRVIP-17 generic application. Plant-specific te. orary alternatives that are based on the technical arguments presented in the BWRVIP-report may be submitted for staff review, but additional plant-specific information will b required that addresses the above concerns with the BWRVIP-17 report.
Please contact C. E. (Gene) Carpenter, Jr., of my staff at
- 01) 415-2169 if you have any further questions regarding this subject.
Sincerely, Gus C ainas, Acting Director Divis n of Engineering Off' e of Nuclear Reactor Regulation cc: See next page SJCollins/FJMiraglia LCShao/ME ayfield NRR/EMCB Reading BWSharon TECollins PUBLIC RPZimmerman Central File DOCUMENT NAME: G:\\BWRVIP\\BWRVIP17.t/R j)
- See Previous Concurrence To receive a copy of this doce6 ment, Indicate in the bog:
'C' = Copy *N* = No copy j
EMCB:lNT C
EMCB: LPM C
EMCB Qh)
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USN,op CECarpente!. _ g RAHerman 02/Q1998 UCS O2/h199 02M1998 02831998 EMCB:BC C
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RHWess JRStrosnider GClainas
~T3[t998 O D 998 o
02/ /1998 o2/ /1998 OFFICIAL RECORD COPY gi 3 }"
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cc:
i George Jones, Executive Chairman Dana Covill, Technical Chairman BWRVIP Assessment Task BWRVIP Assessment Task Pennsylvania Power & Light GPU Nuclear-A6-1 1 Upper Pond Road Two North Ninth Street Parsippany, NJ 07054
(
Allentown, PA 18101 Joe Hagan, Executive Chairman Carl Larsen, Technical Chairman BWRVIP inspection Task BWRVIP inspection Task
{
Entergy Yankee Atomic P. O. Box 756 580 Main Street Waterloo Road Bolton, MA 01740 Port Gibson, MS 39150 Paul Bemis, Executive Chairman Vaughn Wagoner, Technical Chairman BWRVIP Integration Task BWRVIP Integration Task Washington Public Power Supply System Carolina Power & Light Company P. O. Box 968 One Hannover Square 9C1
{
North Power Plant Loop P.O. Box 1551 Richland, WA 99352-0968 Raleigh, NC 27612 Lewis Sumner, Executive Chairman John Wilson, Technical Chairman BWRVIP Mitigation Task BWRVIP Mitigation Task Southern Nuclear Operating Co.
Public Service Electric & Gas Co.
40 inverness Center Parkway N51 Birmingham, AL 35201 Post Office Box 236 g
Hancocks Bridge, NJ 08038 John Blomgren, Executive Chairman Bruce McLeod, Technical Chairman BWRVIP Repair Task BWRVIP Repair Task Commonwealth Edison Co.
Southern Nuclear Operating Co.
1400 Opus Place, Suite 600 Post Office Box 1295 I
Downers Grove, IL 60515 5701 40 inverness Center Parkway Birmingham, AL 35201 Bill Campbell, BWRVlP Vice Chairman Warren Bilanin, EPRI BWRVIP Carolina Power & Light Integration Manager P. O. Box 1551 Joe Gilman, EPRI BWRVIP I
Raleigh, NC 27612 Mitigation Manager Ken Wolfe, EPRI BWRVIP Robert Carter, EPRI BWRVIP Repair Manager Assessmont Manager Electric Power Research Institute
{
Greg Selby, EPRI BWRVIP P. O. Box 10412
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inspection Manager 3412 Hillview Ave.
J EPRI NDE Center Palo Alto, CA 94303 i
P. O. Box 217097 1300 W. T. Harris Blvd.
1 Charlotte, NC 28221 j
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