ML20149L211
| ML20149L211 | |
| Person / Time | |
|---|---|
| Issue date: | 07/29/1997 |
| From: | Sheron B NRC (Affiliation Not Assigned) |
| To: | Modeen D NUCLEAR ENERGY INSTITUTE (FORMERLY NUCLEAR MGMT & |
| References | |
| GL-95-05, GL-95-5, NUDOCS 9707310195 | |
| Download: ML20149L211 (3) | |
Text
__
Mau
.0 4
UNITED STATES g
NUCLEAR REGULATORY COMMISSION f
WASHINGTON. D.C. 20666 4001 o*%
5 l
e.
July 29, 1997 l
Mr. David Modeen Director, Engineering Nuclear Energy Institute 1776 I Street, NW Suite 400 i
Washington, DC 20006-3708
)
SUBJECT:
PROBE VARIABILITY CRITERIA j
Dear Mr.,
K h 6 The Nuclear Energy Institute (NEI) has been acting on the industry's behalf to inform NRC of industry's proposal related to probe variability in order to satisfy the guidance in NRC Generic Letter (GL) 95-05, " Voltage-Based Repair 4
Criteria for Westinghouse Steam Generator Tubes Affected by Outside Diameter Stress Corrosion Cracking." The following information documents our review and conclusions on the subject of probe variability.
GL 95-05 provides guidance on implementing voltage-based repair criteria for certain degraded steam generator tubes.
The repair criteria allow degraded tubes having outside diameter stress corrosion cracking that is predominately axially oriented and confined within the tube support plates to remain in service on the basis of, in part, acceptable bobbin coil voltage response.
In L
view of potential manufacturing variability in new bobbin probes, Section i
3.c.2 of Attachment I to GL 95-05 recommends certain criteria to limit the variability in probes prior to their service in the field.
l In a letter dated January 23, 1996, NEI provided to NRC a proposed approach for addressing probe variability for the eddy current inspection of steam generator tubes. After reviewing NEI's proposal, the staff concluded, in its letter to NEI dated February 9, 1996, that the industry proposed probe variability criteria satisfy GL 95-05. However, the staff requested NEI I
submit for staff information (1) the results of a one-time performance demonstration for bobbin probes showing that new probes satisfy the i
variability criteria in GL 95-05 at the primary frequency and mixed frequencies; and (2) nominal voltage responses for the bobbin probes to be used in the application of GL 95-05 for future reference and inspection activities.
Cy a letter dated October 15, 1996, HEI provided information to respond to the above two staff requests regarding probe variability.
With respect to ites (1), NEI previously recommended that the primary 1
frequency voltage response of a new probe be compared to the nominal responses determined by the vendor to ensure that the new probe is within il0 percent of the nominal response as recommended by GL 95-05. However, after reviewing the recent test data, it was found that voltage responses of probes using mixed y%/
7867 Ok H
9707310195 970729 PDR REVGP ER C
W M W @ M b D gy-/g 510032 i
oPk
_ ~. _.. _... _
l l
Mr. David Modeen letter, NEI provided test data for probes manufactured by Westinghouse and Zetec. On the basis of this data, the staff finds the revised proposal acceptable.
With respect to item (2), NEI stated that to date only Westinghouse and Zetec manufactured probes are acceptable for use in applying alternate repair criteria in accordance with GL 95-05. As requested, NEI has provided the nominal voltage responses and a description of the procedures used to determine the nominal voltage responses.
Based on information provided in the October 15, 1996 letter, the staff has determined that NEI has provided sufficient informat' ion in response to the staff request in the February 9, 1996 letter.
Should you have any questions, please contact me at 301-415-2722 or Mr. Edmund Sullivan at 301-415-3266.
S)ncerely,
/
,/ Brian W. Sheron, Director
[/
Division of Engineering Office of Nuclear Reactor Regulation
/
Distribution:
PUBLIC EMCB RF Central Files TMartin
/
Glainas
/
CBeardslee
/
PRush
/
SCoffin KKarwoski
/
g[
DOCUMENT NAME:
G:\\TSA0 NEIPROBE.R1 To receive a copy of thle document, Indicate in the box: 'C" = Copy without attachtnant/ enclosure "E' = Copy with attachtnent/ enclosure
- N* = No copy 0FFICE DE:EMCB
/
E DE:EMCB cc DE:EMCB N
DE:EMCB NAME JTsao c9tJ/ /
ESullivan %\\
JStrosnider)4 BSheron DATE 9///797
/
1/ W,/97 0
7 /l9 /97/
/
/97
~
0FFICIAL RECORD COPY
,~
d Mr g v,id Modeen i
frequencies had shown higher variability than those from tests performed with the primary frequency.
Therefore, NEI proposed that probos be tested at the primary frequency and mixed frequencies as a part of the one-time performance demcnstration of the voltage response of new probes.
In its October 15, 1996 letter, NEI provided test data for probes manufactured by Westinghouse and Zetec.
On the basis of this data, the staff finds the revised proposal acceptable.
With respect to item (2), NEI stated that to date only Westinghouse and Zetec
)
manufactured probes are acceptable for use in applying alternate repair criteria in accordance with GL 95-05. As requested, NEI has provided the nominal voltage responses and a description of the procedures used to i
determine the nominal voltage responses.
Based on information provided in the October 15, 1996 letter, the staff has determined that NEI has provided sufficient information in response to the l
staff request in the February 9,1996 letter.
Should you have any questions, please contact me at 301-415-2722 or Mr. Edmund i
Sullivan at 301-415-3266.
Sincerely, f
tv&nww3W Brian W. Sheron, Director Division of Engineering Office of Nuclear Reactor Regulation I
Distribution:
5 PUBLIC EMCB RF I
Central < Files i
TMartin GLainas i
CBeardslee PRush SCoffin KKarwoski DOCUMENT NAME:
G:\\TSA0\\NEIPROBE.R1
- See previous concurrence To receive a copy of thee document. indicate in the box: "C" = Copy without attachmentsenclosure *F/)= Copy with attach.
t/9 w sure
- N* = No copy 10FFICE DE:EMCB E
DE:EMCB l E DE:EMCB
[hypDD DE:D :R)
NAME JTsao*
ESullivan*
JStrosnider* GMina,s BShe'ron DATE 7/18 /97 7/18 /97 7/19/97
> '/ //j/97
'7/21/97 0FFICIAL RECORD COPY b-
$hd "fk