ML20113C177
| ML20113C177 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 06/24/1996 |
| From: | Woodard J GEORGIA POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| LCV-0795, LCV-795, NUDOCS 9607010013 | |
| Download: ML20113C177 (8) | |
Text
,
.~.
Georgia Power company 333 Piedmont Avenue At!anta, Georgia 30308 Te% phone 404 526-3195 Malling Address 40 inverness Center Parkway l
Post Office Box 1295 Birmingham. Alabama 35201 Telephone 205 868-5086 J. D. Woodard "we souf'em eiwtre system l
Senior Vice President June 24, 1996 I
LCV-0795 Docket No.: 50-425 U. S. Nuclear Regulatory Commission ATTN.: Document Control Desk Washington, D. C. 20555 i
VOGTLE ELECTRIC GENERATING PLANT RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION, RE: REVISION 7 TO INSERVICE INSPECTION PROGRAM l
Ladies and Gentlemen:
By letter LCV-0668 dated January 22,1996, Georgia Power Company (GPC) submitted Revision 7 of the Vogtle Electric Generating Plant, Unit 2 (VEGP-2) Inservice Inspection (ISI) Program to the NRC for review and approval. Contained therein were revisions to several existing relief requests, the addition of several new relief requests, and minor editorial changes.
Subsequent to the submittal of Revision 7 of the VEGP-2 ISI Program to the NRC, several questions were raised by the NRC reviewer concerning new relief request l
RR-58 and the revision to existing relief request RR-29. The questions involving these two relief requests were identified to GPC by means of a facsimile and a telephone conference call. Relief Request RR-58 pertains to the repair of a steam generator manway l
cover during VEGP-2 Maintenance / Refueling Outage 2R3 and was originally submitted to the NRC by GPC letter LCV-0440 dated October 28,1994. That particular relief request was previously reviewed and approved by the NRC as documented in its April 26,1995
. letter to GPC. Relief Request RR-58 was submitted in Revision 7 of the VEGP-2 ISI Program so that it could be formally incorporated into the ISI program document in order to maintain the document current and requires no additional action from the NRC. Relief Request RR-29 was revised to include two additional welds that were inadvertently omitted from the VEGP-2 ISI Program when it was originally submitted to the NRC.
Geometric limitations due to nozzle configuration prevent full volumetric examination f
coverage from both sides of steam generator nozzle-to-shell welds 21201-B6-001-W18 9607010013 960624 i
PDR ADOCK 05000425
\\
l G
PDR j
i 280081
_= -
l-k L
Georgia Power L U. S. Nuclear Regulatory Commission i
LCV-0795 Page Two and 21201-B6-002-W19. Full volumetric examination coverage can be attained from the l
shell side of these particular welds only. An alternative volumetric examination is not practical for these welds which are also examined using surface examination techniques as required by the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI,1983 Edition with Addenda through Summer 1983 provides information in response to the NRC facsimile of May 23,1996. provides information in response to a telephone conference call with NRC and the reviewer on May 30,1996.
Should there be any questions in this regard, please contact this ofIice.
Sincerely, N
l l
'xJJ Woodard JDW/JAE/jae
Enclosures:
- 1. Response to NRC Facsimile ofMay 23,1996 concerning VEGP-2 ISI Program, Revision 7, Relief Requests RR-29 and RR-58.
- 2. Response (including figure) to NRC Comments during Telephone Conference Call of May 30,1996 concerning VEGP-2 ISI Program, Revision 7, Relief Request RR-29.
xc: Georgia Power Compan_y Mr. J. B. Beasley, Jr. (w/encls.)
Mr. W. L. Burmeister (w/o encls.)
L Mr. M. Sheibani (w/o encls.)
NORMS (w/encls.)
t
?
U. S. Nuclear Regulatory Commission Mr. S. D. Ebneter, Regional Administrator (w/encts.)
{
Mr. C. R. Ogle, Senior Resident Inspector, Vogtle (w/encts.)
j Mr. L. L. Wheeler, Licensing Project Manager, NRR (w/encls.)
k
l l
i ENCLOSURE 1
\\
RESPONSE TO NRC FACSIMILE OF MAY 23,1996 CONCERNING VEGP-2 ISI PROGRAM, REVISION 7 RELIEF REQUESTS RR-29 AND RR-58 INOUIRY l l
" Request for Relief No. RR-29 (Rev 7) - Two Examination Category C-B welds have l
been added to this request in Revision 7. In addition, a third weld (the 6" aux. feedwater nozzle-to-shell weld) appears in this request which was not evaluated in the Safety Evaluation Repon dated December 17,1991. For these three Examination category C-B 1
welds, the information provided in the January 22,1996 submittal is not adequate.
l Provide the Code item number for these welds along with a detailed technical basis and proposed alternative (if appropriate). Include in the basis a technical description of the l
limitations and/or drawings depicting the restrictions. Also discuss the possibility of l
increasing coverage by extending the beam paths and performing a one-sided cxamination."
RESPONSE TO INOUIRY 1 ASME Section XI Code, Category C-B, Item No. C2.21,6" Auxiliary Feedwater (AFW)
Nozzle-to-Shell Weld 21201-B6-004-W26 was added to the VEGP-2 ISI Program by Revision 6. That revision was submitted to the NRC by GPC letter LCV-0248 dated l
March 2,1994. Please refer to pages 1 and 2 of that GPC letter for a discussion on the revision of Relief Request RR-29. The addition of the subject weld to Relief Request RR-29 was reviewed and approved by the NRC as documented in its letter dated February 9,1995 to GPC. Please refer to page 2 of the Safety Evaluation Report and pages 2 and 4 of the Technical Evaluation Report which accompanied the NRC letter to GPC for additional discussion regarding approval of the addition of weld 21201-B6-004-W26 to Relief Request RR-29.
Revision 7 to the VEGP-2 ISI Program as submitted to the NRC by GPC letter l
LCV-0668 dated January 22,1996 included a revision to Relief Request RR-29. The change bar added by Revision 6 for the addition of weld 21201-B6-004-W26 was deleted.
i Welds 21201-B6-001-W18 and 21201-B6-002-W19 were added to Relief Request RR-29 1.
in Revision 7 because these welds were inadvertently omitted when the subject relief request was originally submitted to the NRC. Those welds are also ASME Section XI
[
Code, Category C-B, Item No. C2.21.
El-1 3
L
l-ENCLOSURE 1 l
RESPONSE TO NRC FACSIMILE OF MAY 23,1996 CONCERNING VEGP-2 ISI PROGRAM, REVISION 7 RELIEF REQUESTS RR-29 AND RR-58 (continued)
[ NOTE: VEGP-2 ISI Program page 6-52, the first page of Relief Request RR-29, l
identifies the Item No. for these ASME Section XI Code, Category C-B components.]
For these ASME Section XI Code, Category C-B, Item No. C2.21 components (welds),
i.e., welds 21201-B6-001-Wl8,21201-B6-002-W19, and 21201-B6-004-W26, referenced in Relief Request RR-29, GPC is performing the Code-required surface examination of each weld and a volumetric examination using ultrasonic examination techniques to the extent practical. The ultrasonic examination is limited to the percentages identified in the relief request because of the nozzle geometry. Please refer to ASME Section XI Code, Figure IWC-2500-4(b) for a depiction of the style of nozzle used at VEGP-2. No alternative examination is practical due to the nozzle configuration for these three welds.
Relief Request RR-29 for VEGP-2 as modified by Revisions 6 and 7 to the VEGP-2 ISI Program is virtually identical to the similarly numbered relief request for VEGP-1 except that it also includes weld 21201-86-001-W01. The similarly numbered relief request for VEGP-1 has been reviewed and approved by the NRC as documented in its letter dated l
November 26,1991 to GPC. Please refer to pages 50 through 52 of the Technical Evaluation Report which accompanied the NRC letter to GPC for discussion on VEGP-1 l
Relief Request RR-29.
l INOUIRY 2 l
l
" Request for Relief No. RR-58 (Rev 7)- Reliefis requested from the NDE and j
hydrostatic pressure testing requirements of the 83S83 Code, for a welded repair made on l
a manway cover on the Class 2 portion of a steam generator. Per IWA-4400, certain l
types of repairs are exempt from hydrostatic pressure test requirements (i.e., pressure vessel repairs where the cavity does not exceed 10% of the minimum design wall thickness). Do any of these exemptions apply? If not, what has been done to test the seal and provide reasonable assurance of the operational readiness of the manway cover?"
l RESPONSE TO INOUIRY 2 By GPC letter LCV-0440 dated October 28,1994, Relief Request RR-58 was submitted j
to the NRC for revieve and approval. Because submittal of that relief request was a i
separate submittal to the NRC and was not part of a formal VEGP-2 ISI Program revision El-2 I
I r
1 ENCLOSURE 1 RESPONSE TO NRC FACSIMILE OF MAY 23,1996 CONCERNING VEGP-2 ISI PROGRAM, REVISION 7 RELIEF REQUESTS RR-29 AND RR-58 (continued)
RESPONSE TO INOUIRY 2 (continued) package to the NRC, GPC indicated in letter LCV-0440 that regardless of the results of the NRC review and approval process that GPC would include Relief Request RR-58 in I
the next revision (i.e., Revision 7) of the VEGP-2 ISI Program thereby formally incorporating it into the ISI Program for VEGP-2. By letter dated April 26,1995, the l
NRC notified GPC ofits approval of Relief Request RR-58. The nondestructive examinations that were performed are specifically addressed in the " Basis for Relief" section of the relief request and are consistent with the requirements of the 1989 Edition of ASME Section XI with Addenda through 1990. No alternative examinations were proposed since the repairs performed and their resulting nondestructive examinations met the requirements of the ASME Section XI Code,1989 Edition with Addenda through 1990. Please refer to the Safety Evaluation Report which accompanied the NRC letter for discussion of the adequacy of the relief request and actions taken by GPC. In addition to the foregoing, Relief Request RR-58 was addressed in GPC letter LCV-0668 dated January 22,1996 which transmitted Revision 7 of the VEGP-2 ISI Program to the NRC.
It was noted in the GPC letter that no additional action was being requested of the N'RC for Relief Request RR-58 since it had been previously reviewed and approved by the NRC and that it was being submitted [in Revision 7) in order to formally incorporate the subject relief request into the ISI Program document so that the ISI Program document could be maintained current.
i I
El-3 j
i i
i w
---v,-
n-e - -
n.
,, r
l ENCLOSURE 2 RESPONSE TO NRC COMMENTS DURING TELEPHONE CONFERENCE CALL OF MAY 30,1996 CONCERNING VEGP-2 ISI PROGRAM, REVISION 7, RELIEF REQUEST RR-29 l
Class 2 Nozzle Limitations Certain vessel nozzle configurations hinder ultrasonic examinations. Two such nozzles in the VEGP inspection scope and referenced in the Revision 7 submittal of Relief Request RR-29 are the Steam Generator Main Steam Nozzle-to-Shell Weld (21201-B6-001-W18) which was examined during the preservice inspection (PSI) and during the first period of the first ten-year inspection interval, and Steam Generator Main Feedwater Nozzle-to-l Shell Weld (21201-B6-002-W19) which was examined during the PSI and is scheduled for the third period in the first inspection interval. The weld limitations are consistent with similar VEGP-1 nozzles and are identified in VEGP-1 Relief Request RR-29. Upon review and comparison of Relief Request RR-29 for each respective VEGP unit, the 1
subject welds appear to have been inadvertently omitted when Relief Request RR-29 was originally submitted to the NRC for VEGP-2.
ASME Code Requirements j
Section XI of the ASME Code (IWA-2232) requires that vessel exams meet Anicle 4 of l
ASME Section V. The typical technique requires a 0,45, and 60 degree examination from two directions and scanning both perpendicular to and parallel to the weld (total of 9 scans). For the two welds in question, the required volume to be examined is indicated in ASME Section XI Figure IWC-2500-4 (a), which includes the inner 1/3 t of the weld and 1/4" of the base material.
Volume Limitations For standard piping examinations, one sided examinations (e.g., pipe-to-valve) can generally meet the two directional volume requirements by use of the multiple node technique (reflecting of shear waves). Appendix III of Section XI gives calibration requirements including inside diameter (ID) and outside diameter (OD) notches. However, for vessel welds, only 1/2 node (IT) techniques are utilized with side-drilled holes as per AS'ME Section V.
For this calibration (1/2 node) and volume requirement (two direction), the nozzle taper prohibits the transducer positioning needea to obtain the required code volume from the 4
2 E2-1 4
r
~.
ENCLOSURE 2 RESPONSE TO NRC COMMENTS DURING TELEPHONE CONFERENCE CALL OF MAY 30,1996 CONCERNING VEGP-2 ISI PROGRAM, REVISION 7, RELIEF REQUEST RR-29 (continued)
Class 2 Nozzle Limitations (continued)
Volume Limitations (continued) nozzle side. Full volumetric coverage is usually obtained with the 0 degree transducer and j
45 and 60 degree clockwise (cw) and counter-clockwise (ccw) examinations. Full volumetric coverage in one direction is usually obtained with both the 45 and 60 degree transducers from the shell side.
VEGP Examinations /Documentatiort In the past, if scanning was not permitted from one side due to geometry, the weld was generally given a 50% examination percentage. For vessels, a method which can be used, as allowed by T-441.4.4 of ASME Section V, is to use the recommended techniques and document limitations in the examination report. VEGP currently goes a step farther and documents limitations in the examination report, in the Owner's Report for Inservice Inspection (ASME Form NIS-1 Report), and in relief requests. Using alternate methods (scaled plots and composite angle percentages broken down by scans), a greater composite percentages can be claimed. However, the ultrasonic techniques of the ISI examinations compared to the PSI examinations did not differ. Therefore, for consistency with the previously submitted and approved relief request, the two welds in question were given a conservative 50% code coverage.
Alternate Examinations Using other angles from the shell side provides no additional coverage since 100%
coverage (one directional) is already obtained with the 45 and 60 degree transducers.
Since the 0 degree is already used and obtains 100% coverage from both sides of the weld, additional lower angles (10 or 20 degrees) from the nozzle side would not incnuse the overall validity of the examination. A meaningful examination cannot be performed from the nozzle taper or nozzle barrel due to the metal path required and technique of reflecting from the ID of the nozzle bore into the examination area. A surface exam is performed as required by ASME Section XI for these ALIE Category C-B, Item C2.21 components. (Please refer to accompanying figure depicting locations of nozzle barrel, 4
nozzle bore, and nozzle taper.)
E2-2 i
p 4
! !j N?
TH j.an
$~eU-g
?!?
34 p%pM a
$. Y I s
8
>o 4
i e
~
3lhw 1s e
Q 7
l g
.,I.
gg
~
yQs
- 1:
N
.-a c
l 5y) l'# fi 7k f.-r!
5 v
o e<
$l33
{
r" [2 h 9 i.
l a
s a
l 1E*
e tii; i
48
$5ii i! :
I I;
tu (
~
ii tm 13
$ g.. 3 ri..
l5
[] Z yi i3
- l-Q o i
h a@
l ]
g M
E Q
Q li N
f
?l--
~
E o
4c N
1.
q F. W } a i
o s i
y
. ;;t ame e
? li
~
f 9
Y l'
K i
D l
i x
o 4.!
i Q
lt D
(
R
~
, 's i
i:5
~'
j L
w -
.p 4-i-
2
-6 to 4
48 w
i:
4 t O
)
it! l.
l' i
s g
T,y L
.j L
gg 3,
I y
x i-s is1
's
\\,
=
d p)
-d I
4%
\\
g[
]
h
~-
.sc....,
~
1
', -~
s o h
[.3Yi :.
l_ n J
~
p%
i-E
, 2v m.....
w 3;
n _.._-. %l y
l-o m......;
a
.I g
0
'+
p.>
d, x
8 l
i
- i x
4:
3 y
l-_ y
3 y >u8
- i a :i
+
~
($m%gi M_,, g 4wh M
j n.
1 w
l
[ y I $ '"
'WI l3~'~~T~h
)
g
.V bl s4g
~
J
.,~
i h
p 0 (V
~
s-i,1
-a I
I 84 u,- e QQ q
s a
>t
.ig; '.
f L
~ ' " ' ' ' '
'Ni.f.,
l / ' [k i
--[
n, -
1
. 'L i
ig-ea o
i
-tl.
o
- t w
,,