ML20058N884
| ML20058N884 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 12/16/1993 |
| From: | Hebert J Maine Yankee |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| JRH-93-261, MN-93-118, NUDOCS 9312220317 | |
| Download: ML20058N884 (9) | |
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EDISON DR VE
- AUGUSTA MAINE 04330 * (207) 622-4868 December 16, 1993 MN-93-118 JRH-93-261 UNITED STATES NUCLEAR REGULATORY COMMISSION l
Attention: Document Control Desk l
Washington, DC 20555
References:
(a)
License No. DPR-36 (Docket No. 50-309) l (b) USNRC Letter to MYAPCo dated October 23, 1991, Inspection Report No. 91-16 I
l
Subject:
Inservice Inspection (ISI) Program Relief Request Gentlemen:
The attachment to this letter provides a basis for the ISI change request that will finalize Maine Yankee's ISI program for the second interval.
Relief Request number sixteen (16) is in response to Reference (b). The ISI program relief change requests have been reviewed and approved by Maine Yankee's Plant Operation Review Committee (PORC).
We trust this information is satisfactory.
Please contact us should you have any questions regarding this matter.
Very truly yours,
~w h Y James R. Hebert, Manager Licensing & Engineering Support Department JVW/ jag Attachment c:
Mr. Thomas T. Martin Mr. J. T. Yerokun Mr. E. H. Trottier Mr. Patrick J. Dostie 210002 9312220317 931216 h
PDR ADOCK 05000309 3
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RELTEF REQUEST Number 16 System:
Reactor Coolant Safety Class:
1 t
Category / Item:
B-A, Pressure Retaining Welds in Reactor Vessel, Items 81.10 Components:
RPV-A - Shell to Flange weld Transverse Examination - Cumulative Coverage - 35%
Examination from Top - Cumulative Coverage - 95%
t RPV-VCl - Lower Shell Vertical Weld Parallel Examination - Cumulative Coverage - 72%
CW, 96% CCW Transverse Examination - Cumulative Coverage - 88%
Requirement:
Perform a volumetric examination on each selected weld for essentially 100% of the length, once each L
interval.
i Relief Request:
Relief is requested from the requirement to examine essentially 100% of the weld.
l Basis for Relief:
Physical limitations and geometric configurations prevent the examination of the entire length of these welds.
l For RPV-A, the configuration (ID Taper) of the upper half of the examination volume limited the transverse scan. The scan from the vessel flange essentially covered 100% of the volume.
t for RPV-VC1, a combination of permanent physical obstructions exist.
These obstructions (core stabilizing lug at 80 for 14" and a surveillance capsule at 83 for 26.83") limited the clockwise direction of the parallel scan.
The counterclockwise direction of the parallel scan essentially covered 100% of this volume.
The transverse scan was limited due to the above stated obstructions and also the flow skirt.
This scan achieved 88% cumulative coverage.
Alternate Testing:
- 1) Partial exam as described above and,
- 2) each of these welds is subjected to a leakage test before startup after each refueling outage.
l 16-1 i
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RELIEF RE0 VEST Number:
17 System:
Reactor Coolant Safety Class:
1 Category / Item:
B-J, Pressure Retaining Welds in Piping, Item B9.10 Components:
Circumferential welds in the 33%" main coolant i
lines and their associated long seams:
Line 33 %" RC-3, Weld CEC 1-3 Line 33 %" RC-9, Weld CEC 2-3 Line 33 %" RC-14, Weld CEC 3-3 Requirement:
Perform a surface and volumetric examination on each selected weld, once each interval.
Relief Request:
Relief is requested from the requirement to examine essentially 100% of the weld.
Basis for Relief:
The subject welds are located in the middle of penetrations through the primary shield wall (see attached sketch).
Due to the curvature of the primary shield wall and interference from integral whip restraints within the penetrations, part of each circumferential weld was accessible from the loop area (located at 3 o' clock), part of each weld was accessible from the annular area (located at 9 o' clock) and other parts of each weld had limited accessibility from both sides.
For the associated long seams (4 for each circumferential weld), the upstream and downstream welds at 3:00 were accessible.
The downstream weld at 9:00 was limited and the upstream weld at l
9:00 was not accessible.
The use of automated scanners was investigated and ruled out due to the limited clearance (3%"
maximum) between the pipe and the penetration and the interference of integral whip restraints.
Manual examinations were performed on the OD, from the loop area and the annulus area on a best l
effort basis as follows:
17-1 R:\\ PED \\PJM\\93 42 1
Number:
17 i
CEC 1-3 Circ Weld Surface Exam Completed 47%
Volumetric Exar Completed 73%
Long Seams LS @ 3:00 Upstream Surface Exam 100%
Volumetric Exam 100%
LS @ 3:00 Downstream Surface Exam 100%
Volumetric Exam 100%
LS @ 9:00 Downstream Surface Exam 100%
Volumetric Exam 100%
LS @ 9:00 Upstream No access, no coverage i
CEC 2-3 Circ Welds Surface Exam Completed 47%
Volumetric Exam Completed 75%
Long Seams LS @ 3:00 Upstream Surface Exam 100%
Volumetric Exam 100%
LS 9 3:00 Downstream Surface Exam 100%
l Volumetric Exam 100%
l LS @ 9:00 Downstream Surface 50% - Limited Access l
Volumetric 100% (blind scan) l LS @ 9:00 Upstream No access, no coverage CEC 3-3 Circ Welds i
l Surface Exam Completed 45%
l Volumetric Exam Completed 75%
l l
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17 i R:\\ PED \\PJM\\93-42 l
l l
l RELIEF REQUESI Number:
17 Long Seams LS @ 3:00 Upstream Surface Exam 100%
Volumetric Exam 100%
LS @ 3:00 Downstream Surface Exam 100%
Volumetric Exam 100%
LS @ 9:00 Downstream Surface 33% - Limited Access Volumetric 100%
LS @ 9:00 Upstream No access, no coverage Alternate Examination:
1)
Partial exams as described above and, 2) each of these welds is subjected to a leakage test before startup after each refueling outage.
l 2
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l 17-3 R:\\ PED \\P.M\\93-42 l
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3 0' CLOCK q
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LOOP l
AREA
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[9 0' CLOCK f
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i PRIMARY
_7 SUBJECT WELD
[SHEILDWALL l
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REACTOR i
VESSEL i
i TYPICAL CEC WELDS PLAN VIEW N.T.S.
17-4 j
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RELIEF REQUEST l
Number:
18 i
System:
Reactor Coolant-j f
Safety Class:
1 j
Category / Item:
B-F Pressure Retaining Dissimilar Metal Welds, 4
i Item B5.50 i
J i
Component:
i J
[
Requirement:
Perform a surface and volumetric examination on each dissimilar metal weld once per interval.
1 t
i For Interval 2, Relief (RR No. 5) was granted from l
l performici the volumetric examination on the cast j
stainlen steel portion of the subject dissimilar j
i metal weld.
t Alternate testing provided for performing an l
ultrasonic examination from the carbon side of the l
weld and performing a high energy radiographic examination if the line is drained.
Relief Request:
Relief is requested from performing the ultrasonic l
examination on the carbon steel portion of the l
a above stated weld.
)
Basis for Relief:
Attempts were made to perform the ultrasonic exam 3
from the carbon steel side however, due to the configuration of the nozzle at SE 29 (see attached profile), the ultrasonic beam cannot be directed into the area of interest. Angles from 45 to 70 were plotted without success.
Ultrasonic i
examination of this weld from the carbon steel l
side would not provide suitable results.
1 L
Maine Yankee believes that attempting to l
ultrasonically examine the subject weld from the i
nozzle side withou. the possibility of suitable l
results is neither reasonable nor feasible and I
would increase personnel exposure and' cost without a compensating increase in the level of quality or safety.
Alternate Testing:
Perform the required surface examination
-1 (completed).
This line is subjected to a system leakage test before start-up from each refueling outage.
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C /S N0ZZLE 5
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l N0ZZLE TO SAFE END CONFIGURATION 18-2
\\
e RELIEF RE0 VEST Number:
19 System:
Safety Injection Class:
1 Category / Item:
B-M-1/B12.40 Components:
Stainless steel valve body welds Valve 10 SIA-M-ll SIA-M-21 SIA-M-31 Requirement:
Perform a volumetric examination once each interval.
Relief Request:
Relief is requested from the schedule requirement.
Basis for Relief:
Due to the geometry of the valve body, it is not possible to get the ultrasonic wave into the required volume area of the component.
The valve is not isolable from the reactor vessel, and therefore it remains water filled throughout a j
normal refueling outage. This line would only -
become drained if the reactor vessel was drained below the loop nozzles or if a nozzle plug was installed. Therefore, radiography of this weld during a normal refueling would not be possible.
Maine Yankee believes that reducing the reactor vessel water level or installing a nozzle plug solely for the radiography of these valve welds is an undue hardship without a compensating increase in the level of safety or quality.
Alternate Testing:
Perform a surface examination on the OD during the regular schedule, and perform the required volumetric examination if the associated loop piping is drained during a scheduled refueling outage.
l 19-1 s
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