ML20236N140
| ML20236N140 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 02/06/1998 |
| From: | Howe A NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Kobetz T, Leeds E, Sturz F NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| Shared Package | |
| ML20236J176 | List: |
| References | |
| FOIA-98-164 NUDOCS 9807150024 | |
| Download: ML20236N140 (18) | |
Text
_ _ _ _ _ _ _ - _ - - - - - - - - - - - - - - - - - - - - - - ' - ' ~ ~ ~ ~
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4
?;
I From:
Allen Howe eJJ f
I To:
TJK1, EJL, FCS 7g
,u Date:
2/6/98 2:16pm
Subject:
SNC Phone Calls I called ANO, Keller & Dosa and discussed my trip next week.
I am scheduled to be at ANO 2/10 and 2/11.
I called SNC, Moekel, wrt the trip next week and the 2/237 inspection. I also discussed the items in the letter regarding the 15 day clock for the proprietary affidavit and the notification of GTAW weld process qualification. His only question was why was the inspection a SNC inspection? I basically told him it related to a SNC CAL corrective action verification,
(
9807150024 900630 PDR FOIA co DUMS98-164 PDR W_---__
___-___-_---__-___________________________________Q
s t
i Mall Envelope Info:
(34DB61.Sc.A46 : 17 : 42080)
Subject:
SMC Phone Calls Croation Date:
2/6/98 2:16pm From:
Allen Howe Created By:
WND1.WNP7:AGH1 Recipients Action Date & Time Post Office WND1.WNP7 EJL (Eric Leeds) 1 FCS (Frederick Sturz)
TJK1 (Timothy Kobetz)
Domain. Post Office Delivered Route WNDI.WNP7 Pending WND1.WNP7 Files Size Date & Time MESSAGE 483 02/06/98 02:16pm View 4109 02/06/98 09:16am Options Auto Delete:
No Expiration Date:
None Notify Recipients:
No Priority:
Normal Reply Requested:
No Return Notification::
None Concealed
Subject:
No Security:
Normal To Be Delivereo:
Immediate Status Tracking:
All information i
____a._--------____
f Quick UT Questions:
SCANNING:
MSB in VCC, MTC, either or both?
MSB in rest position or lifted / skewed /otherwise specially positioned for examination?
Scan from top / side, exclusively / combination expected % coverage of weld, by volume / length Transducers: Straight (0 degree) or angle beam (30 degree,45 degree, etc.)
Single scan with multiple transducers, or multiple scans?
Any difference in scanning casks to be loaded, or ones already on the pad?
Differences between dry run conditions and actual conditions?
Acceptance criteria for inspection?
What would prohibit them from doing UT inspection?
ALARA:
Estimated dose for entire exam?
Dose rates?
Scan times?
DOCUMENTATION:
Baseline scan of MSB mockup before flaw implantation?
l Flaw data books?
Physical sample of lack of penetration removed from mockup?
l Detailed, written procedure for examination? Differences between mockup and actual casks?
l Differences between ANO/ Point Beach / Palisades?
l SCHEDULE:
Will they meet proposed schedule (NRC Demo week of 2/23/98)?
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'o at Decision on inspection approach for the weld crown grinding:
l On the subject of grinding the entire weld crown off of the mockup, the Owners Group l
wants to seriously pursue this option as a part of their development process. There is the possibility that this examination approach may involve less dose, and yield better examination results than the current " side view" method. However, that call cannot be made without trying out this approach.
From the regulatory and inspection logistics perspective, there are concems. It is my understanding that the UT response for the weld with a crown will differ from the reshaped weld. If the Owners Group proposes the use both examination methods (a decision that remains to be made by the Owners Group), then:
- a.. What do we need to inspect?
l
- b. Can we review "before" and "after" data for the " side view" exam? If so, what?
)
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- c. Do we need to directly observe both examination methods? If so what is the basis?
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Beyond the UT aspects, there are other grinding issues:
- 1) a.
Removal of weld reinforcement. This is not credited in the structural analysis but it provides additional margin.
l l
- b. Is this a 72.48 allowed design change i
I I
- 2) What is the grinding process (manual / auto)? How is it controlled? What are the
{
variables?
j 1
- 3) How will this process affect dose? Safety?
- 4) For loaded casks Where will they be ground (pad vs. Rx bldg)?
a.
b.
There is a potential for exposure of near subsurface flaws.
l c.
Removal of PT'd area.
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Root Mean Square Error Calculation for Flaw Sizing 0 Degree,200 Degr 0 Degree LongitudinalScan l
FlawTech VSC-24 Mockup Flaw # True Length Measured Length (1-m)
(m-1)^2 True Depth Measured Depth (t-m)
(m-1)^2 1
0.5
-0.5 0.2500 0.050
-0.05 0.0025 2
0.5
-0.5 0.2500 0.075 0.0056 I
3 0.75
-0.75 0.5625 0.100
-0.1 0.0100 t
4 0.5 0.6 0.1 0.0100 0.150 0.19 0.04 0.0016 5
0.5 0.4
-0.1 0.0100 0.200 0.19
-0.01 0.0001 6
1.5 1.3
-0.2 0.0400 0.250 0.3 0.05 0.0025 7
0.5
-0.5 0.2500 0.100
-0.1 0.0100 8
0.5
-0.5 0.2500 0.050
-0.05 0.0025 9
0.5 0.5 0.2500 0.075
-0.075 0.0056 l
10 0.75 0.6
-0.15 0.0225 0.100 0.12 0.02 0.0004 11 0.5 0.7 0.2 0.0400 0.150 0.12
-0.03 0.0009 12 0.5 0.8 0.3 0.0900 0.200 0.22 0.02 0.0004 13 1.5 1.5 0 0.0000 0.250 0.26 0.01 0.0001 14 0.5 0.6 0.1 0.0100 0.050 0.11 0.06 0.0036 15 0.5 0.65 0.15 0.0225 0.075 0.075 0
0.0000 16 0.75 0.8 0.05 0.0025 0.100 0.11 0.01 0.0001 17 0.5 0.8 0.3 0.0900 0.150 0.22 0.07 0.0049 18 0.5 1
0.5 0.2500 0.200 0.19
-0.01 0.0001 19 1.5 1.3
-0.2 0.0400 0.250 0.27 0.02 0.0004 20 0.5
-0.5 0.2500 0.050
-0.05 0.0025 21 0.5
-0.5 0.2500 0.075
-0.075 0.0056 22 0.75 0.8 0.05 0.0025 0.100 0.15 0.05 0.0025 23 0.5 0.6 0.1 0.0100 0.150 0.15 0
0.0000 24 0.5 0.6 0.1 0.0100 0.200 0.19
-0.01 0.0001 25 1.5 1.4
-0.1 0.0100 0.250 0.3 0.05 0.0025 26 0.5 0.75 0.25 0.0625 0.100 0.15 0.05 0.0025 27 0.5 0.75 0.25 0.0625 0.100 0.18 0.08 0.0064 28 0.5 1
0.5 0.2500 0.300 0.34 0.04 0.0016 29 0.5 1
0.5 0.2500 0.400 0.34 0.06 0.0036 30 0.5 05 0 0.0000 0.500 0.46
-0.04 0.0016 31 NA NA 0 0.0000 NA NA 0
0.0000 32 NA NA 0 0.0000 NA NA 0
0.0000 33 NA NA 0 0.0000 NA NA 0
0.0000 3.5975 0.0803 Number of FI 30 Number of Flaws, n 30 RMS Length Error:
0.346 RMS Depth Error:
0.052 Max. ASME RMS Error Flaw Length:
0.75in Max. ASME RMS Error Depth :
0.1251n Maximum allowable RMS error per ASME Section XI, Appendix Vill, Supplement 2 RMS Error = sum {[(m-t)^2]/n)^1/2, m = Measured Flaw Size, t = True Flaw Size, n = number of flaws measured Calculations Diameter of Transducer, 0.5 inches Frequency, F [MHz) 10 MHz Velocity in Steel, F [in/se 232,000 inches /second Near Field 2.69 inches
= [(D^2 x F) / (4 x V)]
Beam Spread 1.33 degrees = arcsin [(0.5 x V) / (F x D)]
j Wavelength 0.023 inches
=V/F t'
(,
J l
Root Mean Square Error Calculation for Flaw Sizing 45 Degree,200 Degr45 Degree Shear Wave Scan, UP FlawTech VSC-24 Mockup Flaw # True Length Measured Length (1-m)
(m-1)^2 True Depth Measured Depth (t-m)
(m-1)^2 1
0.5
-0.5 0.2500 0.050
-0.05 0.0025 __
2 0.5
-0.5 0.2500 0.075 0.0056 3
0.75
-0.75 0.5625 0.100
-0.1 0.0100 4
0.5
-0.5 0.2500 0.150
-0.15 0.0225 5
0.5
-0.5 0.2500 0.200
-0.2 0.0400 6
1.5
-1.5 2.2500 0.250
-0.25 0.0625 7
0.5
-0.5 0.2500 0.100
-0.1 0.0100 8
0.5
-0.5 0.2500 0.050
-0.05 0.0025 l
9 0.5 0.65 0.15 0.0225 0.075 0.2 0.125 0.0156 10 0.75 0.75 0 0.0000 0.100 0.17 0.07 0.0049 11 0.5 0.7 0.2 0.0400 0.150 0.12
-0.03 0.0009 12 0.5 0.65 0.15 0.0225 0.200 0.3 0.1 0.0100 13 1.5 G:46 t. 7
-c.5-t-ST 44424 c M 0.250 0.25 0
0.0000 14 0.5 0.5 0 0.0000 0.050 0.14 0.09 0.0081 15 0.5 0.6 0.1 0.0100 0.075 0.1 0.025 0.0006 16 0.75 0.45
-0.3 0.0900 0.100 0.07
-0.03 0.0009 17 0.5 0.5 0.2500 0.150
-0.15 0.0225 18 0.5
-0.5 0.2500 0.200
-0.2 0.0400 19 1.5
-1.5 2.2500 0.250
-0.25 0.0625 20 0.5 0.9 0.4 0.1600 0.050 0.17 0.12 0.0144 21 0.5 0.9 0.4 0.1600 0.075 0.24 0.165 0.0272 22 0.75 1.2 0.45 0.2025 0.100 0.2 0.1 0.0100 23 0.5 0.9 0.4 0.1600 0.150 0.2 0.05 0.0025 24 0.5 0.8 0.3 0.0900 0.200 0.17
-0.03 0.0009
]
25 1.5 2
0.5 0.2500 0.250 0.27 0.02 0.0004 26 0.5
-0.5 0.2500 0.100
-0.1 0.0100 27 0.5 0.4
-0.1 0.0100 0.100 0.14 0.04 0.0016 28 0.5 0.4
-0.1 0.0100 0.300 0.3 0.0900 l
29 0.5 0.4 0.1 0.0100 0.400 0.25
-0.15 0.0225 30 0.5 0.6 0.1 0.0100 0.500 0.3
-0.2 0.0400 31 NA NA 0 0.0000 NA NA 0
0.0000 32 NA NA 0 0.0000 NA NA 0
0.0000 33 NA NA 0 0.0000 NA NA 0
0.0000 g
03 24--
0.5412 Numberof Fla 30 Number of Flaws, n 0.s37 RMS Length Error:
ASWB RMS Depth Error:
0.134 Max. ASME RMS Error Flaw Length:
0.751n Max. ASME RMS Error Depth :
0.1 in Maximum allowable RMS error per ASME Section XI, Appendix Vill, Supplement 2 RMS Error = sum {[(m-1)^2]/n}^1/2, m = Measured Flaw Size, t = True Flaw Size, n = number of flaws measured Calculations Diameter of Transducer, 0.375 inches Frequency, F [MHz) 10 MHz Velocity in Steel, F [in/se 128,000 inches /second Near Field 2.75 inches
= [ (D^2 x F) / (4 x V)]
Beam Spread 0.98 degrees = arcsin [ (0.5 x V) / (F x D) }
Wavelength 0.013 inches
= V/F L
s j
. Root Mean Square Error Calculation for Flaw Sizing
-45 Degree,200 De 45 Degree Shearwave scan, CIRC
' FlawTech VSC-24 Mockup Flaw # True Length Measured Length (1-m)
(m-t)^2 l True Depth Measured Depth (t-m)
(m-1)^2 1
NA 0 - 0.0000 NA C
0.0000 2
NA 0 0.0000 NA 0
0.0000 3
' NA '
0 0.0000' NA 0
0.0000 4-NA 0 0.0000 NA 0
0.0000 5
NA 0 0.0000
-NA 0
0.0000 6
NA 0 0.0000 NA 0
0.0000 7
.NA 0 0.0000 NA 0
0.0000 8
NA:
0 0.0000 NA 0
0.0000 9-NA 0 0.0000 NA 0
0.0000 l
10 NA 0 0.0000 NA 0
0.0000 11
-NA 0 0.0000 NA 0
0.0000 12 NA 0 0.0000 NA 0
.0.0000 13 NA 0 0.0000 NA 0
0.0000 14 NA 0 0.0000 NA 0
0.0000 16 NA 0 0.0000 NA 0
0.0000 16 NA 0 0.0000 NA 0
0.0000 17 NA 0 0.0000 NA
~0 0.0000 18 NA 0 0.0000 NA 0
0.0000 19 NA 0 ' O.0000 NA 0
0.0000 20 NA 0 0.0000 NA-0 0.0000 21-NA 0 0.0000 NA 0
0.0000 22 NA 0 0.0000 NA 0
0.0000 23 NA 0 0.0000 NA 0.
0.0000 24 NA 0 0.0000 NA 0
0.0000 26 NA 0 0.0000 NA 0
0.0000 26 NA 0 0.0000 NA 0
0.0000 27 NA 0 0.0000 NA 0'
O.0000 28 NA-0 0.0000 NA 0
0.0000.
l--
29 NA 0 0.0000 NA' O
0.0000 l
30 NA-
~0 0.0000 NA 0
0.0000 31 0.375 0.5 0.125 0.0156 0.1 0.07
-0.03 0.0009 32 0.375 0.4 0.025 0.0006 0.2 0.14
-0.06 0.0036 33 0.375 0.5 0.125 0.0156 0.3 0.17
-0.13 0.0169 0.0319 0.0214 Number of Fla 3
Number of Flaws, n 3
' RMS Length Error:
0.103 RMS Depth Error:
0.084 Max. ASME RMS Error Flaw Length:
0.75ln Max. ASME RMS Error Depth :
0.125in Maximum allowable RMS error per ASME Section XI, Appendix Vill, Supplement 2
~
RMS Error = sum {[(m t)^2]/n}^1/2, m = Measured Flaw Size, t = True Flaw Size, n = number of flaws measured Calculations Diameter of Transducer,
' 0.5 inches Frequency, F [MHz)
S MHz Velocity M Steel, F [in/s 128,000 inches /second
- Near Field 2.44 inches
= [ (D^2 x F) / (4 x V) ]
Beam Spread 1.47 degrees = arcsin [(0.5 x V) /(F x D)]
Wavelength 0.026 inches
=V/F-
A, Root Mean Square Error Calculation for Flaw Sizing Per ASME Section XI, Appendix Vill l
l True Flaw Size is Depth of Flaws for FlawTech VSC-24 Mockup l
Flaw Number True Flaw Size, t Measured Flaw Size, m (m-t)^2 j
1 0.050 0.000 0.0025
[
2 0.075 0.000 0.0056 l
3 0.100 0.000 0.0100 l
4 0.150 0.000 0.0225 l
5 0.200 0.000 0.0400 l
6 0.250 0.000 0.0625 7
0.100 0.000 0.0100 8
0.050 0.000 0.0025 9
0.075 0.000 0.0056 l
10 0.100 0.000 0.0100 l
11 0.150 0.000 0.0225 l
12 0.200 0.000 0.0400 13 0.250 0.000 0.0625
(
14 0.050 0.000 0.0025 l
15 0.075 0.000 0.0056 16 0.100 0.000 0.0100 17 0.150 0.000 0.0225 18 0.200 0.000 0.0400 l
19 0.250 0.000 0.0625 20 0.050 0.000 0.0025 l.
21 0.075 0.000 0.0056 22 0.100 0.000 0.0100 l
23 0.150 0.000 0.0225 24 0.200 0.000 0.0400 25 0.250 0.000 0.0625 26 0.100 0.000 0.0100 i
27 0.100 0.000 0.0100 l
28 0.300 0.000 0.0900 29 0.400 0.000 0.1600 30 0.500 0.000 0.2500 31 0.100 0.000 0.0100 32 0.200 0.000 0.0400 33 0.300 0.000 0.0900 1.2425 Number of Flaws, n 33 Sum RMS Error 0.194 RMS Error = sum ([(m-t)^2]/n)^1/2 m = Measured Flaw Size ASME Section XI, Appendix Vill, Supplement 2:
1 = True Flaw Size Max. RMS Error Flaw Length: 0.75in n = number of flaws measured Max. RMS Error Depth Length: 0.1251n C:lculations Diameter of Transducer, D [in]
0.5 inches Frequency, F [MHz) 10 MHz Velocity in Steel, F [in/sec]
232,000 inches /second N;ar Field
= [ (Da2 x F) / (4 x V)]
2.69 inches Beam Spread
= arcsin [ (0.5 x V) / (F x D) ]
1.33 dyrees Wavelength
= V/ F 0.023 inches C6 u------------
l l
(
q
Root Mean Square Error Calculation for Flaw Sizing 45 Degree,200 Degrs5 Degree ShearWave Scan, UP FlawTech VSC-24 Mockup l
i Flaw # True Length Measured Length (1-m)
(m-1)^2 True Depth Measured Depth (1-m)
(m-1)^2 I
1 0.5
-0.5 0.2500 0.050
-0.05 0.0025 2
0.5
-0.5 0.2500 0.075
-0.075 0.0056 3
0.75
-0.75 0.5625 0.100
-0.1 0.0100 l
4 0.5
-0.5 0.2500 0.150
-0.15 0.0225 5
0.5 -
-0.5 0.2500 0.200
-0.2 0.0400 6
1.5
-1.5 2.2500 0.250
-0.25 0.0625 7
0.5
-0.5 0.2500 0.100
-0.1 0.0100 8
0.5
-0.5 0.2500 0.050
-0.05 0.0025 9
0.5 0.65 0.15 0.0225 0.075 0.2 0.125 0.0156 10 0.75 0.75 0 0.0000 0.100 0.17 0.07 0.0049 11 0.5 0.7 0.2 0.0400 0.150 0.12
-0.03 0.0009 l
12 0.5 0.65 0.15 0.0225 0.200 0.3 0.1 0.0100 13 1.5 1.8 0.3 0.0900 0.250 0.25 0
0.0000 14 0.5 0.5 0 0.0000 0.050 0.14 0.09 0.0081 l
15 0.5 0.6 0.1 0.0100 0.075 0.1 0.025 0.0006 16 0.75 0.45
-0.3 0.0900 0.100 0.07
-0.03 0.0009 17 0.5
-0.5 0.2500 0.150
-0.15 0.0225 18-0.5
-0.5 0.2500 0.200
-0.2 0.0400 19 1.5
-1.5 2.2500 0.250
-0.25 0.0625 j
20 0.5 0.9 0.4 0.1600 0.050 0.17 0.12 0.0144 21 0.5 0.9 -
0.4 0.1600 0.075 0.24 0.165 0.0272 22 0.75 1.2 0.45 0.2025 0.100 0.2 0.1 0.0100 23 0.5 0.9 0.4 0.1600 0.150 02 0.05 0.0025 24 0.5 0.8 0.3 0.0900 0.200 0.17
-0.03 0.0009 25 1.5 2
0.5 0.2500 0.250 0.27 0.02 0.0004 24 0.5
-0.5 0.2500 0.100
-0.1 0.0100 l
27 0.5 -
0.4 0.1 0.0100 0.100 0.14 0.04 0.0016 28 0.5 0.4
-0.1 0.0100 0.300
-0.3 0.0900 29 0.5 0.4
-0.1 0.0100 0.400 0.25
-0.15 0.0225 30 0.5 0.6 0.1 0.0100 0.500 0.3
-0.2 0.0400 l
31 NA NA 0 0.0000 NA NA 0
0.0000 l
32 NA NA 0 0.0000 NA NA 0
0.0000 33 NA NA 0 0.0000 NA NA 0
0.0000 8.6500 0.5412 I
- of Flaws 30
- of Flaws 30 RMS Length Error:
0.537 RMS Depth Error:
0.134 l
Max. ASME RMS Error Flaw Length:
0.751n Max. ASME RMs Error Depth :
0.125ln Maximum allowable RMS error per ASME Section XI, Appendix Vill, Supplement 2 q
RMS Error = sum ([(m-t)^2}/n}^1/2, m = Measured Flaw Size, t = True Flaw Size, n = number of flaws measured Calculations Diameter of Transducer, D 0.375 inches Frequency, F [MHz]
10 MHz V;locity in Steel, F [in/sec 128,000 inches /second Near Field 2.75 inches
= [ (D^2 x F) / (4 x V) ]
l l
l l
I i
l
~* Beam Spread 0.98 degrees = arcsin [ (0.5 x V) / (F x D)]
Wavelength 0.013 inches
=V/F l
l l
l l
l l
l
M
. Root Mean Square Error Calculation for Flaw Sizing
- 0 Dogt ee, 200 Degre 0 Degree Longitudinal Scan Fl:wTech VSC-24 Mockup Flaw # ' True Length Measured Lenath (t-m)
(m-t)^2 True Depth Measured Depth (t-m)
(m-t)^2 0.5
-0.5 0.2500 0.050
-0.05 0.0025 2
0.5
-0.5 0.2500 0.075
-0.075 0.0036 3
. 0.75
-0.75 0.5625 0.100
-0.1 0.0025 4'
O.5 0.6 0.1 0.0100 0.150 0.19 0.04 0.0025 5.
0.5 0.4
-0.1 0.0100 0.200 0.19
-0.01 0.0056 6
1.' 5 1.3 -
-0.2 0.0400 0.250 0.3 0.05 0.0056 0.5 l
7
' 0.5 0.2500 0.100
-0.1 0.0000 i
8 0.5
-0.5 0.2500 0.050
-0.05 0.0056 l.
9 0.5
-0.5 0.2500 0.075
-0.075 0.0001 l
10 0.75 0.6
-0.15 0.0225 0.100' O.12 0.02 0.0025 I
11 0.5 0.7 0.2 0.0400 0.150 0.12
-0.03 0.0025 I
12 0.5 0.8 0.3 0.0900 0.200 0.22 ~
0.02 0.0100 13-1.5 1.5 0 0.0000 0.250 0.26 0.01 0.0100 14 0.5 0.6 0.1 0.0100 0.050 0.11 0.06 0.0064 18 0.5 0.65 0.15 0.0225 0.075 0.075 0
0.0004 l
l 14-0.75 0.8 0.05 0.0025 0.100 0.11 0.01 0.0049 17 0.5 0.8 0.3 0.0900 0.150 0.22 0.07 0.0000 l
18 0.5 1
0.5 0.2500 0.200 0.19
-0.01 0.0016 19 1.5 1.3 '
-0.2 0.0400 0.250 0.27 0.02 0.0009
- 20 ;
0.5
-0.5 0.2500 0.050
-0.05 0.0001 21 0.5
-0.5 0.2500 0.075
-0.075 0.0001 22 0.75 0.8
.0.05 0.0025 0.100 0.15 0.05 0.0004 23 '
O.5 0.6 0.1 0.0100 0.150 0.15 0
0.0001 L
.24 0.5 -
0.6
- 0.1 0.0100 0.200 0.19-
-0.01 0.0025 i
'25
' 1.5 1.4
-0.1 0.0100 0.250 0.3 0.05 0.0025 26 0.5 0.75 0.25 0.0625 0.100 0.15-0.05 0.0001 27 0.5 0.75 0.25 0.0625 0.100 0.18 0.08 0.0004 28-0.5 1
0.5 0.2500 0.300 0.34 0.04 '
O.0016 i
29 0.5
'1 0.5 0.2500 0.400 0.34
-0.06 0.0036 30 0.5 0.5 0 -0.0000 0.500 0.46
-0.04 0.0016 31 NA NA 0 0.0000 NA NA 0
0.0000 32 NA.
NA 0 0.0000 NA NA-0 0.0000 l
33 NA NA 0 0.0000 NA NA 0
0.0000 l
3.5975 0.0803 H
. # of Flaws 30
- of Flaws 30 l
1
' RMS Length Error:
0.346 RMS Depth Error:
0.052 l
Max. ASME RMS Error Flaw Length:
0.75in Max. ASME RMS Error Depth :
0.1251n
. Maximum allowable RMS error per ASME Section XI, Appendix Vill, Supplement 2 j
RMS Error = sum ([(m-t)a2)/n}^1/2 m = Measured Flaw Size, t = True Flaw Size, n = number of flaws measured l-Calculations 4
Diameter of Transducer, D 0.5 inches Frequency, F [MHz]
10 MHz V;locity in Steel, F [in/sec 232,000 inches /second j
Near Field 2.69 inches
= [ (D^2 x F) / (4 x V) ]
1'
\\
~
Be:m Spread 1,33 degrees = arcsin [(0.5 x V) / (F x D)]
Wavelength 0.023 inches
=V/F l
1 i
l 1
l 1
i
.-s
~
Root Mean Square Error Calculation for Flaw Sizing 45 Degree, 200 Dog 45 Degree Shear wave Scan, clRC FlawTech VSC-24 Mockup i
Flaw # True Length Measured Length (t-m)
(m-t)^2 l True Depth Measured Depth (1-m)
(m-t)^2 1
NA 0 0.0000 NA 0
0.0000 2
NA 0 0.0000 NA 0
0.0000 3
NA 0 0.0000 NA 0
0.0000 4
NA 0 0.0000 NA 0
0.0000 8
NA 0 0.0000 NA 0
0.0000 6
NA 0 0.0000-NA 0
0.0000 7
NA 0 0.0000 NA 0
0.0000 8
NA 0 0.0000 NA 0
0.0000 9
NA 0 0.0000 NA 0
0.0000 10 NA 0 0.0000 NA 0
0.0000 11 NA 0 0.0000 NA 0
0.0000 12 NA 0 0.0000 NA 0
0.0000 13 NA 0 0.0000 NA 0
0.0000 14 NA 0 0.0000 NA 0
0.0000 15.
NA 0 0.0000 NA 0
0.0000 16 NA 0 0.0000 NA 0
0.0000 17 NA 0 0.0000 NA 0
0.0000 18 NA 0 0.0000 NA 0
0.0000 19 NA 0 0.0000 NA 0
0.0000 20 NA 0 0.0000 NA 0
0.0000 21 NA 0 0.0000 NA 0
0.0000 22 NA 0 0.0000 NA 0
0.0000 23 NA 0 0.0000 NA 0
0.0000 24 NA 0 0.0000 NA 0
0.0000 25 NA 0 0.0000 NA 0
0.0000 26 NA 0 0.0000 NA 0
0.0000 27 NA 0 0.0000 NA 0
0.0000 j
28 NA 0 0.0000 NA 0
0.0000 29 NA 0 0.0000 NA 0
0.0000 30 NA 0 0.0000 NA 0
0.0000 21 0.375 0.5 0.125 0.0156 0.1 0.07
-0.03 0.0009 32 0.375.
0.4 0.025 0.0006 0.2 0.14
-0.06 0.0036 33 0.375 0.5 0.125 0.0156 0.3 0.17
-0.13 0.0169 0.0319 0.0214
- of Flaws 3
- of Flaws 3
l l
RMS Length Error:
0.103 RMS Depth Error:
0.084 Max. ASME RMS Error Flaw Length:
0.75in Max. ASME RMS Error Depth :
0.1251n Maximum allowable RMS error per ASME Section XI, Appendix Vill, Supplement 2 RMS Error = sum {[(m t)^2]/n}^1/2, m = Measured Flaw Size, t = True Flaw Size, n = number of flaws measured C lculations Diameter of Transducer, 0.5 inches Frequency, F [MHz) 5 MHz V;iocity in Steel, F [in/se 128,000 inches /second Near Field 2.44 inches
= [ (D^2 x F) / (4 x V) J
Beam Spread 1.47 degrees = arcsin [(0.5 x V) / (F x D)]
W:velength 0.026 inches
=V/F l
l l
r' f-y 1
i i-l' ll-Regression Output:
0.0266666666666665
(
Std Err of Y Est 0.0163299316185545 R Squared 0.949367088607595 No. of Observations 3
Degrees of Freedom 1
.' X Coefficient (s) 0.500000000000001 Std Err of Coef.
0.115470053837925 l
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l-From:-
Allen HowejMMJ.S 5
To s '-
ARD1.ARP1.JVE, ARD1.ARP1.DBS, CHD1.CHP2.BLJ, CHD1....
E'
/
Date:
3/26/98 7:34am f /EL hgf9f g A_V subject:
VSC-24 Weld Issues Status gQe,g
.I am providing you the attached status on the VSC-24 weld issues for your information. As always, future events and dates are subject to change. This does, however, provide a general outline of SFPO's internal plan to complete the CAL items. As this is an internal planning guide, I request that you maintain it.as one.
Please contact me or Tim Kobetz if you have any q
questions.
Thanks Allen-CC:
emhl, tjkl, ckbl..
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VSC-24 FABRICATION AND WELDING ISSUES TAC # L21140 Last Update: March 25,1998 Project Manager: Tim Kobetz Weld Team:
A. Howe (Team Leader), K. Battige, G.Homseth, M.Vassilaros, H. Lee, R.Parkhill, C.Interrante. E.Hackett T= Target; C= Complete: TBD=To be determined MILESTONES DATE TEAM lssue supplemental CALs to utilities 9/5/97C Kobetz Receive Consumers Energy's CAL response (Palisades) 9/19/97C Receive Sierra Nuclear Corporation's (SNC) RAI response 9/19/97C Receive WEPCo's CAL response (Point Beach) 9/22/97C Receive Entergy's CAL response (ANO) 3/12/98C NRC review CAL responses and initiate RAls to resolve questions 9/19/97 -
Weld Team 11/6/97 l
VSC-24 Owners Group verbally commits to perform UT 11/13/97C l
I NRC issues letter to SNC describing commitments made to VSC-24 12/09/97C Kobetz Owners Group at a meeting December 4,1997 SNC submits revised calculation for allowable flaw definition in structural 12/17/97C lid weld SNC submits schedule to qualify UT process 12/23/97C NRC completes review of revised allowable flaw size definition and 2/12/98C Weld Team notifies SNC that it is acceptable.
NRC observation of implementation of flaws into MSB mock-up 1/28/98C Battige & Parkhill NRC inspection of P-Scan UT qualification process at ANO 3/20/98C Howe, Battige, Contractors NRC inspechon of " Time of Flight" UT qualification process at Palisades 4/24/98T Howe, Battige, Contractors NRC completes independent fracture toughness testing and venfication Spring /98T Weld Team - RES of allowable flaw definition SNC submits revised calculation for allowable flaw definition in structural Spnng/98T lid weld using fracture toughness testing results. Also SNC submits flaw size acceptance criteria.
NRC completes technical review of all outstanding RAI and CAL issues Late Weld Team issue Closeout Evaluation Report Spring /98T Perform inspections at ANO 6/98T Howe, Battige, Homseth, Region IV lasue ANO Inspection Report; Lift CAL 6/98T Howe, Battige, Homseth, Region IV Perform inspections at Point Beach 7/98T Kobetz, Battige Region til MILESTONES DATE TEAM lasue Point Beach inspection Report; Lift CAL 7/98T Kobetz, Battige Region lli Perform inspections at Palisades Fall /98T Kobetz, Battige Region lli lasue Palisades inspection Report; Lift CAL Falt/98T Kobetz, Battige Region lil Inspect Point Beach cask loading (1st load since H2 ignition)
TBD TBD inspection ANO cask loading TBD TBD inspection Palisades cask loading TBD TBD inspect Point Beach UT of previously loaded casks TBD TBD j
l Inspection Palisades UT of previously loaded casks TBD TBD l
Inspection ANO UT of previously loaded casks TBD TBD
e.
s Brief
Description:
Since 1992 NRC has continued to identify QA problems with SNC. In Spring 1997 NRC identified significant failures by SNC to perform effective corrective actions. One of the failures involved inadequate follow up to weld cracking problems encountered at ANO and Palisades during the loading of casks. In response, in May 1997 CALs were issued to SNC and the user utilities (Palisades, Point Beach and ANO) to resolve the welding problems before loading additional casks (the CALs were supplemented in September). During the investigation into the welding problems, SNC became aware that March Metalfab (MMI), a subcontractor, had not documented all welding performed on the casks during fabrication. The investigation also revealed that hydrogen induced cracking appeared to be the most likely contributor to the weld problems at ANO. At Palisades, the weld crack was caused by an existing condition in the shell material which opened up during the shield-lid welding process. The crack propagated along grain boundaries of a pre-existing weld of unknown origin. Cracking identified at Point Beach was attributed to poor joint fit-up.
Currently, three primary problems exist; (1) welding procedures must be developed to inhibit hydrogen induced cracking, (2) due to the uncertainty of SNC's QA program and the identification of undocumented welds, licensees must certify the integrity of casks to be loaded in the future, and (3) NRC must confirm the integrity of previously loaded casks or require the casks be unloaded.
Current Status: Transducer failures delayed completion of P. Scan demonstration at ANO. ". Time of Flight" planned for Palisades during the week of 4/20/98. Fracture toughness testing of weld specimens by the licensees is ongoing.
Potential Problem / Resolution: NONE i
Resource Expenditure: Approximately 0.5 FTE l
i t