OCRWM Corrective Action Program Page: 1 46 Condition ...
Transcript of OCRWM Corrective Action Program Page: 1 46 Condition ...
Assignment Information
Ownership Organization: Sandia National Lab
Responsible Organization: Sandia National Lab
CRRecordReport
Oversight Organization:
Oversight Lead:
OTM - Sci Division
Fish, Robert
27-Jun-09
4-46 Aro/
OCRWM Corrective Action Program
Condition Report
Record Report
MOL. 20 090630.0014
f#410 4-ctri
Page: 1
QA:QA
CR Num CR Level CR Type Step Entry Date Step Step Resp Step Owner
12799 C QARD 6/26/2009 2:32:22 PM Completed N/A N/A
Condition Information
CR Title: Unexpected Test Results - Heterogeneous Alloy 22 Oxide Thickness
Date Found: 25-Sep-08 CR Initiator: Brown, Neil
Time Found: 10:00 CR Initiating Org: Sandia National Lab
Involve Initiator? Yes
Condition Description:
Corroborative, non-Q, secondary ion mass spectrometry (SIMS) analysis of 5-year Alloy 22 corrosion coupons was performed according to TWP-WIS-MD-000025 and in support of TWP-WIS-MD-000027 and resulted in an unexpected test result. The analyzed coupons had been subjected to general corrosion
conditions and it was anticipated that the oxide thickness on a given sample would not exhibit significant spatial varietion. However, for three examined coupons (DWA132, DWB132, DWB134) it was determined that the region of the coupon covered by a PTFE washer during the corrosion test had a locally
thicker oxide than the remainder of the coupon. There was no evidence to suggest that any form of localized corrosion (e.g., pitting corrosion, crevice corrosion) had occurred under the washer. The area affected by the presence of the washer appears to be on the order of 3% of the total sample area. The small fraction of the sample area affected is insufficient to impact the calculated corrosion rates based on gravimetric analysis. Therefore, these results do not effect the SAR or the underlying models (ANL-EBS-MD-000003), but will require additional investigation.
Supplemental Information:
Routing Notes:
10/02/08 Danika Miller - This CR has been prescreened by a member of the CAP Staff using criteria Technical Information.
Trend Only? No
Requirement Involved? Yes
Requirement: SCI-PRO-002
Business Process:
Business Process ID:
Condition Information
27-Jun-09 Page: 2 OCRWM Corrective Action Program
Condition Report
Record Report slto, Step Resp
N/A
Step Owner
N/A
QA Review Type: No QA Review Required
Quality Assurance Rep (QAR):
Business Process Review Org:
CR Num CR Level CR Type Step Entry Date Step
12799 C QARD 6/26/2009 2:32:22 PM Completed
Assignment Information
Screening Information
CR Level: C
CST / MRC Conclusions:
10/06/08 Danika Miller - Significance Determination established at a Level C using criteria Technical Information.
Screening Information
Review Information
NRC Reportabilitv Review (e.g. Part 21 and 10CFR63.73b)
Potential NRC Reportable CR? No
NRC Reportable Discussion:
Validated NRC Reportable CR?
Self-Revealing Conditions
* Conditions identified outside of formal processes (such as Self Assessments) where
the event/consequence occurred prior to entry of the condition into CAP
Self-Revealing condition? No
10CFR835 - Radiological Protection Program (RPP) Review
Potential RPP issue? No
RPP Category:
RPP Discussion:
Validated RPP issue?
CRRecordReport
Date Submitted: 10/1/2008 Date Issued: 10/6/2008
27-Jun-09
kftri OCRWM Corrective Action Program
Condition Report
Record Report orel ktirl
Page: 3
CR Num CR Level CR Type Step Entry Date Step
12799 C QARD 6/26/2009 2:32:22 PM Completed
10CFR851 - Worker Safety and Health Proaram (WSH131 Review
Potential WSHP issue? No Validated WSHP issue?
WSHP Category:
WSHP Discussion:
Step Resp Step Owner
N/A N/A
Occurrence Reporting and Processing System (ORPS1 Review
Potential ORPS issue? No Validated ORPS issue?
ORPS Criteria:
ORPS Significance:
ORPS Report ID:
ORPS Discussion:
NTS Reportable conditions only
NTS Report ID:
Review Information
Evaluation Information
Immediate/Interim Action Taken? No
Immediate/Interim Action Desc:
Previous Occurrence Review:
Extent of Condition:
CRRecordReport
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41A9
Cause Analysis Information
Plan Information
Plan Due Date: 11/5/2008
Plan Completed Date: 10/30/2008
Original Est Comp Date: 3/20/2009
Current Est Comp Date: 6/18/2009
Date Completed:
Date Closed:
6/26/2009
6/26/2009
Actions Required? Yes
Corrective Action Plan Summary:
10/28/08 - B. Mitcheltree - The unexpected test result will have to be evaluated and analyzed, an action will be created for this.
CRRecordReport
Effectiveness Rev Required? No Effectiveness Rev Days
OCRWM Corrective Action Program
Condition Report
Record Report
CR Num CR Level
12799
CR Type
QARD
Step Entry Date Step
6/26/2009 2:32:22 PM Completed
Step Resp
N/A
Step Owner
N/A
Evaluation Information
Cause Analysis Information
Cause Analysis Type: N/A
Cause Analysis Results:
LL/GI Required?
Reason LL/GI Not Performed:
Cause Analysis Team Members
Team Member Name Team Member Organization
< NO CAUSE ANALYSIS TEAM MEMBERS IDENTIFIED FOR THIS CONDITION REPORT >
Cause Code(s):
A0B0000 - Cause not applicable or required
Event Code(s):
1MT - Measuring and Testing Equipment Program
2DT - Data
Review Information
Stmv Review Plan
Step Completion Date Person that performed review
10/29/2008 1:02:33 PM Brown, Neil
10/30/2008 11:43:27 Brown, Neil
AM
Oversee Implementation
Step Completion Date Person that performed review
6/26/2009 8:09:09 AM Mitcheltree, Wendy
27-Jun-09
or* kftri OCRWM Corrective Action Program
Condition Report
Record Report SAitei NE Amos
Page:
CR Num CR Level
12799
CR Type Step Entry Date
QARD 6/26/2009 2:32:22 PM
Step
Completed
Step Resp Step Owner
N/A N/A '
Discussed Plan with CR Initiator? Yes
Discussed Implementation with CR Initiator? Yes
Action Title
12799-001 Analyze residual oxide thickness
Discussion Results: 10/28/08 - B. Mitcheltree - The initiator agreed with the plan.
Discussion Results: 6/25/09, W. Mitcheltree- Spoke to initiator, he is fine with the resolution of
this CR.
Plan Information
Plan Approval Indicator and Comments, if any
• add oxide in two places
This plan is necessary and sufficient to address this CR. Analyses work is funded.
Neil Brown 10/30/08
Implementation Done Indicator and Comments, if any
6/25/09, W. Mitcheltree- There was one action for this CR, which was resoled as follows: As documented in the report, "Comparison of Oxide Thickness between 5 and 9.5 Year Alloy 22 Gravimetric Sample" dated June 24, 2009 the oxide
thicknesses for samples exposed for 5 and 9.5 year were examined to determine the likely causes and effects of the unexpected oxide heterogeneity. Based upon the work performed to date it is most likely that the increased oxide thickness is due to a deposition process rather than corrosion. This conclusion is based upon the fact that the oxides under the crevice contain much higher quantities of magnesium, silicon and organics than the boldly exposed surfaces. Alloy 22 does not contain these elements, so they likely came from corrosion of other materials tested in the same vessels as the Alloy 22. Also of note is that dark stained regions outside of the washer region contain similar surface product layers to that under the washer region, further suggesting that this is not a corrosion mechanism.
No
Yes
Yes
CRRecordReport
27-Jun-09
451 Page: 6
Step Resp
N/A
Step Owner
N/A
Neil Brown 6/26/09.
Review Information
CR Step History
Step Owner Step Resp Exit Date
Bonano, Evaristo Brown, Neil 10/1/2008
2 Staff Review CR 10/1/2008 Giacomini, Michael Miller, Danika 10/2/2008
Rev # EnteredStep Entry Date
1 Initiate CR 9/30/2008
CRRecordReport
CST Review CR Miller, Danika
Exit To Status
Staff Review CR
User that hit VO'
Brown, Neil
Milestone on Exit # of Days In Step
1
OCRWM Corrective Action Program
Condition Report
Record Report
CR Num CR Level CR Type Step Entry Date Step
12799 C QARD 6/26/2009 2:32:22 PM Completed
Oversee Implementation (continued)
Step Completion Date Person that performed review Implementation Done Indicator and Comments, if any
The oxides under the washer region are considerably thicker for the 9.5 year samples
than for the 5 year samples. This observation further supports the conclusion that
this is not a corrosion mechanism as the corrosion rates for the 9.5 year samples are
lower than for the 5 year samples. Since there is no evidence that this is a corrosion
mechanism, a likely explanation for the thicker regions in the 9.5 year samples is that
the concentrations of the deposition products were increasing with time in the test
vessels. Considering that the corrosion of other materials in the vessels is occurring
as a function of time, it is reasonable that this would result in increasing concentration
of these constituents. Furthermore, increased organics both in terms of quantity and
prevalence were also observed in CR 12868.
Therefore, based upon the available information, the unexpected test condition does
not have an impact on the corrosion rates or mechanism used in the Alloy 22
corrosion models. The action for this CR has been completed and this CR should
therefore be closed.
Sum/ Verify Irnol
Step Completion Date Person that performed review CR Verification Indicator / Comments
6/26/2009 2:08:30 PM Brown, Neil Yes I concur that this CR should be closed. All available evidence indicates that the
unexpected results are due to environmental deposition and not corrosion.
10/6/2008 Plan CR
10/28/2008 Supv Review Plan
Plan CR
Supv Review Plan
Oversee Implementation
Supv Verify Impl
CST Close CR
Miller, Danika
Mitcheltree, Brian
Brown, Neil
Mitcheltree, Brian
Brown, Neil
Mitcheltree, Wendy
Brown, Neil
CR ISSUED 10/6/2008 12:15:02 PM
PLAN COMPLETED 10/30/2008 11:43:27 AM
CAs COMPLETED 6/26/2009 8:09:09 AM
N/A
10/29/2008
10/29/2008
10/30/2008
6/26/2009
6/26/2009
4
22
1
239
0
6/26/2009 Completed Miller, Danika CR CLOSED 6/26/2009 2:32:22 PM
0
Mitcheltree, Brian
Brown, Neil
Bonano, Evaristo
Bonano, Evaristo
10/30/2008 Bonano, Evaristo
6/26/2009
6/26/2009
6/26/2009
Bonano, Evaristo
Pesek, John
N/A
CR Attachments
Filename
CR 12799 Closure Checklist.doc
Size Date
85 kb
27-Jun-09
or* *ri OCRWM Corrective Action Program
Condition Report
Record Report orAti ItY
Page: 7
CR Num CR Level
12799
CR Type Step Entry Date Step
QARD 6/26/2009 2:32:22 PM Completed Step Resp
N/A Step Owner
N/A
10/2/2008 CST Review CR
10/6/2008
Supv Review Plan 10/28/2008
_Q. Plan CR -10/29/2008
Supv Review Plan 10/29/2008
8 Oversee Implementation
Supv Verify Imp!
10 CST Close CR
11 Completed
Giacomini, Michael Miller, Danika
Bonano, Evaristo
Bonano, Evaristo
Mitcheltree, Brian
Brown, Neil
Mitcheltree, Wendy
Brown, Neil
Miller, Danika
N/A
Plan CR
CR Step History
CR Attachments
CRRecordReport
27-Jun-09 Page: 8
04* Ativi
OCRWM Corrective Action Program
Condition Report
Record Report
Corrective Action Report
Step Owner
N/A
Step Resp
N/A CR Num Action Num Step Entry Date Step
12799 12799-001 6/26/2009 8:08:13 Completed
Action Details
Action Number: 12799-001 Current Due Date: 6/11/2009
Original Due Date: 3/13/2009
Accepting Org: Sandia National Lab Bonano, Evaristo
Assigned To Org: Sandia National Lab Bonano, Evaristo
Action Title: Analyze residual oxide thickness
Date Completed: 6/25/2009 Date Closed: 6/26/2009
Action Description:
10/28/08 - B. Mitcheltree - Analyze/evaluate residual oxide thickness for the boldly exposed surfaces and under the crevice region for time-frame other than 5-year exposures. This information will be used to determine if the unexpected heterogenetity under the crevice former increases with time and at what rate. This information will be used to either document no impact or additional actions will be required for this CR.
The objective evidence will be the result of the analyses/evaluation or justification why this was not performed.
Action Taken:
6/25/09- W. Mitcheltree- As documented in the attached report, "Comparison of Oxide Thickness between 5 and 9.5 Year Alloy 22 Gravimetric Samples", dated June 24, 2009 the oxide thicknesses for samples exposed for 5 and 9.5 years were examined to determine the likely causes and effects of the unexpected oxide heterogeneity. Based upon the work performed to date it is most likely that the increased oxide thickness is due to a deposition process rather than corrosion. This conclusion is based upon the fact that the oxides under the crevice contain much higher quantities of magnesium, silicon and organics than the boldly exposed surfaces. Alloy 22 does not contain these elements, so they likely came from corrosion of other materials tested in the same vessels as the Alloy 22. Also of note is that dark stained regions outside of the washer region contain similar surface product layers to that under the washer region, further suggesting that this is not a corrosion mechanism.
The oxides under the washer region are considerably thicker for the 9.5 year samples than for the 5 year samples. This observation further supports the conclusion that this is not a corrosion mechanism as the corrosion rates for the 9.5 year samples are lower than for the 5 year samples. Since there is no evidence that this is a corrosion mechanism, a likely explanation for the thicker regions in the 9.5 year samples is that the concentrations of the deposition
products were increasing with time in the test vessels. Considering that the corrosion of other materials in the vessels is occurring as a function of time, it is reasonable that this would result in increasing concentration of these constituents. Furthermore, increased organics both in terms of quantity and prevalence were also observed in CR 12868.
CRRecordReport
Proposed Due Date
4/10/2009 6/11/2009
Step
Completed Completed
Action Attachments
Filename
Washer Report Ver3.pdf
Size Date
679 kb
27-Jun-09 Pak OCRWM Corrective Action Program
Condition Report
Record Report
Corrective Action Report
f* euø
Page: 9
CR Num
12799 Action Num
12799-001 Step Entry Date Step
6/26/2009 8:08:13 Completed Step Resp
N/A Step Owner
N/A
Therefore, based upon the available information, the unexpected test condition does not have an impact on the corrosion rates or mechanism used in the Alloy 22 corrosion models. This CR action should therefore be closed.
Routing Notes:
Action Details
Action Adjustments
Adjustment Num Adjustment Title
12799-001-001 Due Date Adjustment 12799-001-002 Due Date Adjustment
Action Adjustments
Action Step History
Rev # EnteredStep
1 Plan Action
2 Perform Action
3 Plan Action
4 Perform 'Action
5 Completed
Step Owner
Bonano, Evaristo
Bonano, Evaristo
10/29/2008
10/29/2008 Bonano, Evaristo
6/26/2009 N/A
Step Resp
Mitcheltree, Brian
Mitcheltree, Brian
Mitcheltree, Brian
Mitcheltree, Wendy
N/A
Exit Date Exit To Status
10/28/2008 Perform Action
10/29/2008 Plan Action
10/29/2008 Perform Action
6/26/2009 Completed
User that hit GO'
Mitcheltree, Brian
M itch eltree, Brian
M itch eltree, Brian
M itch eltree, Wendy
# of Days in Step
0
240
N/A
Entry Date
10/28/2008
10/28/2008
Bonano, Evaristo
Action Step History
Action Attachments
CRRecordReport
Step Resp Exit Date
Brown, Neil 1/23/2009
3 Bonano, Evaristo 1/26/2009
Exit To Status
Accept Act
Adjustment
Completed
N/A
User that hit 'GO # of Days in Step
Brown, Neil 0
Bonano, Evaristo
N/A
Rev # EnteredStep Entry Date Step Owner
1 Request Act 1/23/2009 Bona no, Evaristo Adjustment
2 Accept Act 1/23/2009 Bonano, Evaristo Adjustment
3 Completed 1/26/2009 N/A
Action Adjustment Step History
CRRecordReport
Step Owner
N/A
27-Jun-09
CR Num
12799
OCRWM Corrective Action Program
Condition Report
Record Report
CA Adjustment Report
or* Nfitvi
Page: 10
Action Num
12799-001 Step Resp
N/A
Action Adj Num Step Entry Date Step
12799-001-001 1/26/2009 1:41:02 Completed
Action Adjustment Details
Adjustment Number: 12799-001-001
Requested Due Date: 4/10/2009 Date Request Submitted: 1/23/2009 Date Closed: 1/26/2009
Adjustment Title: Due Date Adjustment
Reason for Adjustment:
As a result of many RAls from the NRC, DOE and the Lead Laboratory have agreed that resources planned to address this CR will be moved to RAls. Neil Brown 1/23/09
Adjustment Response:
Tito Bonano - 01/26/09 I approve the extensions.
Routing Notes:
Action Adjustment Details
Action Adjustment Step History
User that hit 'GO'
Mitcheltree, Brian
# of Days in Step
0
Mon, Kevin
Completed 4/28/2009 N/A N/A 3 N/A
Step Owner
N/A
27-Jun-09
CR Num
12799
olitV kli„V
OCRWM Corrective Action Program
Condition Report
Record Report
CA Adjustment Report
oat %fete,
Page: 11
Action Num
12799-001 Step Resp
N/A
Action Adj Num Step Entry Date Step
12799-001-002 4/28/2009 3:52:39 Completed
Action Adjustment Details
Adjustment Number: 12799-001-002
Requested Due Date: 6/11/2009
Adjustment Title: Due Date Adjustment
Reason for Adjustment: •
4/28/09 - B. Mitcheltree - Budget cuts, and RAI resource usage.
Adjustment Response:
04/28/2009 Kevin Mon adjustment accepted for Neil Brown
Routing Notes:
Date Request Submitted: 4/28/2009 Date Closed: 4/28/2009
Action Adjustment Details
Action Adjustment Step History
EnteredStep
Request Act Adjustment
Accept Act 4/28/2009
Adjustment
Step Owner Step Resp
Bonano, Evaristo Mitcheltree, Brian
Bonano, Evaristo Mon, Kevin
Exit Date Exit To Status
4/28/2009 Accept Act
Adjustment
Completed
Rev #
1
Entry Date
4/28/2009
4/28/2009
Action Adjustment Step History
CRRecordReport
SNL Conducted by: Wendy Mitcheltree CR Number: 12799 CR Level: C Resp. Org:
CR Closure Verification Checklist
Personal or sensitive information should not be included in condition reports.
Documentation should provide traceable, verifiable, objective evidence that will demonstrate that each action was completed as stated
in the plan within the CR record. It should be in sufficient detail that uninvolved third-party reviewers can understand the reasons
behind the decisions made, analysis, extent of condition, and corrective actions.
Applicable Yes/No Attribute Comments
To Level(s) NA ,
Miscellaneous CR Fields
If Involve Initiator field is "Yes, does the Disc Plan w/Init and/or the A-D YES
Disc Impl w/lnit field have appropriate wording to affirm?
If the LUG! Required field is "Yes," has a lessons learned been N/A
submitted?
CAQs
Requirement Involved is "Yes' A-C YES
If the Requirement Involved field is "Yes, is the Requirement field YES
completed with something other than TBD?
Trend Onl if a ..licable
Does CR clearly state what was corrected and/or why no further C-D N/A
action is required
Extent of Condition (EoC)
Is documented in the CR A-B N/A
The bounding methodology is appropriate and documented in the N/A
CR
A. . arent or Root Cause
Is clearly stated A-B N/A
Identified Cause(s) are supported by investigative findings N/A 1
Previous Occurrence
Is documented in the CR A-B N/A
Identified similar CRs N/A
1 of 2
12/15/08
Applicable Yes/No Attribute Comments
To Level(s) NA
Corrective Actions
Identify Actions to preclude recurrence A N/A
Address the Cause(s) identified or there was adequate explanation A-B N/A
of why no action was necessary
Is clear enough to identify that the corrective action(s) was A-D YES
completed satisfactorily
Support the correction of the condition identified in the CR YES
If actions were not completed as stated, an explanation was N/A
provided
If no action will be taken, rationale is provided N/A
Documentation
Additional documentation, as referenced, has been attached or its A-D YES
location has been identified
Closing one CR to an existing CR, if applicable
The issue documented within the new CR is already addressed A-D N/A
within the existing CR
The newer CR is closed to an older CR N/A
The higher significance level CRs is not closing to a lower N/A
significance level CR
Closing to another Business Process, if applicable,
The business process(es) is a controlled process, managed by N/A
procedure, periodically assessed, and tracked/trended.
When utilizing other business processes to track the completion of N/A
the action(s):
1) There is a clear statement documents the process that will be N/A
utilized to track action(s),
2) There is a cross-reference to a tracking number(s) within that N/A
process, and
3) There is a clear statement how the process is documented and N/A
periodically assessed
Non -Valid CR if a. • ',cable
Documentation clearly affirms that the original issue was not valid N/A N/A
2 of 2
12/15/08
Comparison of Oxide Thickness between 5 and 9.5 Year Alloy 22 Gravimetric Samples K.R. Zavadil & J.A. Ohlhausen, June 24, 2009
Goal of Analysis The goal of the work described in this report was to determine whether a longer period of corrosion test exposure, 9.5 years vs. 5 years, produced detectable differences in remnant oxide and exposure product layers on Alloy 22 gravimetric samples. Specific emphasis was placed on an annular region surrounding the mounting bore hole of these test coupons originally covered by a Teflon washer. This region of interest was previously , explored for 5 year samples and results were summarized Oxide Thickness Measurements for C22 Weight Loss Samples:
Coupons DWA132 and DWB132 (November 19, 2008). Despite the presence of the Teflon washer covering this region of the surface, micron deep grooves produced by a directional 600 grit polish on the coupon front face allowed for electrolyte penetration and resulting surface chemical processes to take place. Acetone and HC1 cleaned coupons typically show dark staining in this area of the sample, indicating that residual corrosion and exposure related products remain and are factored into the overall gravimetric analysis used to determine a corrosion rate. The work described within this report attempts to evaluate the extent to which gravimetric estimates might be influenced by exposure time.
Approach Surface characterization was conducted on five weight loss, long term corrosion test C22 coupons — two immersed for 5 years and three immersed for 9.5 years in a simulated concentrated water (SCW) electrolyte at 90°C. Analysis was conducted using a combination of time-of-flight secondary ion mass spectrometery (ToF-SIMS) and scanning electron microscopy (SEM) with energy dispersive x-ray analysis. SIMS sputtering was conducted with the incident ion parallel to the 600 grit polishing striations on the samples to minimize shadowing effects in the depth profile. SEM analysis was typically used to examine the SIMS sputter crater and the region around the craters within the washer region to determine the morphological origin of the depth profile data. A minimum of seven sites were analyzed on, each coupon with three located within the region of the washer and four on the openly exposed surface of the coupon. The oxide on a mechanically polished (30 nm alumina) C22 disk that was cleaned in acetone followed by a 12 minute immersion in 1.8 M HC1 served as a calibrant for sputtering rate. Several focused ion beam cross-section samples were prepared and imaged using transmission electron microscopy. The lattice spacing in single crystal silicon was used as a calibrant for the TEM measurements. All of the depth profiles for the weight loss coupons within this report were generated using the same energy and flux of Cs ÷ ions as for the reference C22 disk.
Results Table 1 provides a summary of the description, sputter times and calculated oxide thickness for each of the sites analyzed for the sample set under consideration. This data is further condensed into a set of average oxide thickness values as a function of exposure time and analysis site in Table 2 and Figure 1 to allow for easier comparison. The light and dark site designations in these tables 'make reference to the general optical appearance of the site and, in select cases, represent remnant surface product not removed during the cleaning process. We consider the optically light regions as the baseline for comparisons within this study. The data of Tables 1 and 2 demonstrate that the surface oxide is on average twice as thick within these light regions for 9.5
Comparison of Oxide Thickness between 5 and 9.5 Year Alloy 22 Gravimetric Samples page 2of 8
versus 5 years of exposure. The optically dark regions generally possess thicker surface oxide
Table 1: Comparison of Oxide Thickness Measurements of Select Sites on
Immersed SCW 90°C C22 Weight Loss Coupons
Sample Time (yr) Site Description Sputter Time (s) Thickness (nm) *
DWA132 5 A light 102 9
B light 93 8
C dark 198 17
D dark 203 17
E washer > 3240 273
F washer >4817 506
G washer 656 55
DWB132 5 A light 58 5
B dark 145 12
C dark 167 14
D dark 118 10
E washer 511 43 ,
F washer 331 28
G washer 580 49
, DWB139 9.5 A washer 5633 474
B washer 2520 212
C light 192 16
D light 174 15
E dark >2072 >174
F dark >4720 >397
G dark >4785 >403
H washer 212 18
DWA140 9.5 A light 240 20
B light 220 18
C dark 227 19
D dark 257 22
E washer 10444 880
F washer 5155 434
G washer 10049 846
DWB140 9.5 A washer 2643 223
B washer >4902 >413
C washer >2200 >185
D •dark >2584 >218
E light 216 18
F light 228 19
G light 185 16
with respect to a mechanically polished, HC1 etched C22 disk stored in
N2 and demonstrated to have a 1.6 nm thick oxide via TEM.
layers when compared to light regions for a given exposure time. The 9.5 year DWA140 sites C
5 300
.c 250
•
200
Comparison of Oxide Thickness between 5 and 9.5 Year Alloy 22 Gravimetric Samples page 3of 8
and D appear to be exceptions to this trend and may reflect a degree of arbitrariness to this visual
classification (light, dark) of the sample surface. Note that sputter times for optically dark sites
were occasionally not sufficient in duration to completely breakthrough the surface oxide layer
across the full analysis site. The cumulative ion yield images generated over the course of the
profile show that these incomplete sampled sites are comprised of two components - regions of
thinner and significantly thicker
surface oxide. The resulting depth Table 2: Comparison of Average Oxide Thickness profiles represent a spatial convolution for Various Sites on Alloy 22 Coupons as a of these two components. The
Function of Immersion SCW 90°C Time thickness values for these sites listed Time (yr) Description Thickness (nm) * in Table 1 reflect the minimum values
5 light 7 for the thickest component. The
dark 14 average oxide thickness value
washer 180 displayed in Table 2 and Figure 1
9.5 light 17 should also be thought of as a
dark 204 minimum thickness for the thickest
washer 509 component of a spatially
heterogeneous oxide. Spatially
heterogeneous oxides are also
observed for the washer regions on
500
these coupons. Comparison of the
thickness of these dark regions 450
between the two exposure times shows 400
that the oxide is more likely to be — 350 '—
significantly thicker for the longer
exposure time.
The oxide layer appears to be thicker I — for the longer exposure period samples 150 -
within the washer region. The 5 year loo samples exhibit a range of thickness
50
values from 30 to 50 nm with several
sites in excess of 300 nm. The 9.5 year 5 war 5 year 5 year 9.5 year 9.5 yea, 9 5 year
samples also exhibit large variation light dark washer light dark washer
with one 18 nm thick site (DWA139 Exposure Time and Coupon Site
site H) and the remainder ranging Figure 1. Average oxide thickness as a function of from 200 to 900 nm. This variation in Alloy 22 SCW 90°C immersion exposure time and thickness is a function of where within site (*the average minimum thickness for the the washer region a site is selected for thickest component for a spatially heterogeneous sampling, as both optical and oxide). secondary electron images of these
regions show areas of thick and thin surface deposits. SEM images were used to confirm that the
thin oxide observed for DWA139 site H was the result of sampling a thinner deposit region.
Despite the limited sampling conducted within this study, the measurements suggest a thicker
surface layer remains after cleaning for the longer exposure time of 9.5 year. All of the washer
sites with the thicker surface layers (> 60 nm) show clear evidence of the presence of two surface
Comparison of Oxide Thickness between 5 and 9.5 Year Alloy 22 Gravimetric Samples page 4of 8
layer components, as discussed previously for the optically dark sites, with a large difference in
thickness. 1
I 3.5E+04 1 6E+03 3(0.04 4.0E+03
i DWB139 Site A - Ni (Y1) b DVVB139 Site A -Ni (y1) .
I a _MO (y1) 1.4E+03 3.5E+03 3.0E+04 - 3.0E+04 - -Si (y1)
I
. - Cr0 (y1)
- Ca) (y2)
_ Moo6,02)(y2) 1.2E+03 2.5E+041 -
.•
7
- 190 (y1)
- C2H (y1) • 3 0E+433
I 113E+03
,i. Mg0 (y2)
I
Z. •
T„ 2.0E+04 - ,, ' '• ' 1 • 1
,a" 2 0E+04 - ;
.'
: - 0 (.12)
• 2_5E+03
i,
I 5 I
_ . r
I 8 0E+02 • -
' -2 0E+03 , .E.
I f, 1.5E-iO4 1 g 1.5E+04 -
6.0E+02 - I . 1.5E+03
I
14, 5 1 0E+04 i 1 0E+04 - 1111I,•illial . 4 0E402
, '44111\11111iiiiii,,_ , • 1 0E403
1
I 1
5.0E+03 • ' 1 ̀s-
i ____„_ -. ---M4(...e.,,
2 0E+02 5.0E+03 -71111
.k. 1111111 e,„*„......„..._
I 0 1030 2C00 3000 4110 5C00 6000 7000 8000 9030 00E+03 - .... -.1.-----4-- . 0 0E+00
I 3.0E+04
Sputter Time (e) Spinet Time )s1
2.0E+03 1.0E+05 Ci 1" 2" "CI 4" 61" 6" 7" 61" "3 2 0E+433
I c . DWB139 Site C -Ni (y1)
- Ni0 (y1) 1.3E+03 9 0E404 d DVVB139 Site C
-Ni (y1)
- CI (y1) 1.8E+03
a 2.5E+04 - - 1 e0 (y1) - Si (y1)
I -Cr0 (y1) 1.6E+03 80E.04 r\\ _ TO (y1) 1_6E+03
I - C°° (Y2) 1.4E+03 70E4434 1 4E+03
-- ONIC29HD°:)(Y1) 1 2E+03
I
2, 7
.4 2_0E+04 II MOO (y2)
- 0 (y2) 1.2E+03 4, 6.0E+04
2
i
\ 1.5E404 1.0E+03 2 50E404 I 1.0E+03
I . g
* ,J. ,
900.02 2 4.0E+04 I , 8.0E+02
I ' 1.0E+04
1 6.0E+02 305.434 ; .',. 606.02 1 • I
. ' Ck ■ 4.0E+ . 02 20E4434 , ., , 4.0E+02 ... ..., 5.0E+03 i \A
2.0E+02 1.0E+04
0.0E+00 , ---------- ..,.-'-`-:-"4:4.-:i1-''''''''''''''''''' •••""*"'•• 0 0E+00 0091.03 ' '. ' ------rs= . --L"----- "-'-' -• 0.0E+00
0 203 400 600 600 1000 0 200 4433 600 803 1(03
Simnel- Time (s) Sperm, Time 151
2.5E+04 1 0E+03 6.0E+04 3.0E4413
e DWB139 Site G -rui (y1) f DWB139 Site G -Ni (y1)
Nic) ( y i) -9 0E+02 -CI (yl)
- Fe0 (y1) 513E+04 - -51 (Y 1 ) - 2.5E+133 20E+04 - A - 8.0E+02 • - -310 (y1) - CIO (y1) _ .
- Co0 (y2) . 0E+02 ,1110441/011,Soilli\slisiitt C2H (y1)
7
. . Mo0 (y2) 4 0E+04 - - . • . . MgO (y2) . 2.0E+03
.., 1.5E+04 - • --0 (y2) - 6.0E+02 2.: - 0 (y2)
f . 5.0E+02 (I• 3.0E+04 - .
- 1.5E403 . . ' .
'
1
.
2 10E 4 0E+ 404 - '
•
5.0E403 - k '
.. • ._ .•
. : . .. : : ,. .
. . .. . , .
• 02 2
- 3 0E+02
- 2.0E+02
• .
2.0E+04 -
1.0E404
4. ,Iii
ir min 0 i
• ,
- 5.0E+02
10E+02
0 0E+03 ODE -OWa0E400 0 0E+00
I
0 1000 ZOO 100 4000 5003 6000
Swale, Time IsI
1000 211033300 41300 51:0) 6000
Swale, Time lel
Figure 2. Comparison of ToF-SIMS depth profiles for three sites on sample
DWB139: a,b) unintended crevice site A, c,d) optically light open surface site C, I,
and e,f) optically dark open surface site G. The yl and y2 designations in the plot
legends indicate which ordinate axis a given ion intensity is plotted against (1 -
primary or left, 2 - secondary or right).
Comparison of Oxide Thickness between 5 and 9.5 Year Alloy 22 Gravimetric Samples page 5of 8
The composition of the oxide layer within the washer region is unique when compared to the regions of the coupon that had been effectively cleaned in advance of the material loss measurements. Figure 2 shows representative depth profiles for three sites on DWA139, including: 1) washer site A, 2) optically light site C, and 3) optically dark site G. Two plots are shown for each site that display the primary alloy constituents (as metal oxide ions) and select environmental constituents including Cl, Si (as a silicate), Mg as the Mg0 - ion and C21-1- as an indicator of carbonaceous content in the surface layer. Readily seen in Fig. 2 is the fact that washer region contains high relative levels of Cl, Si, Mg and organic species distributed through the oxide surface layer. These results are contrasted with the thinner oxide at site C (open surface, well cleaned) that show a hydrocarbon terminated oxide surface with substantially lower relative levels of Mg, Cl and Si in the outer section (near electrolyte) of the oxide surface film. Site G (along with sites E & F — not shown) is a special case where staining and residual product layers are evident on the surface as viewed with optical and electron microscopy. Note that the 0 profile exhibits a characteristic hybrid signature comprised of a narrow time period (depth) of intense secondary ion yield followed by an extended period of lower yield. This signature is a convolution of the sputtering of a thin oxide between islands of thicker product layer. Si, Cl and Mg are distributed through the product islands along with a significant amount of carbonaceous species. The fact that similar surface product layers are observed outside of the unintended washer region suggests that the basic compositional nature of the corroded surface product layer that formed underneath the washer may not be significantly different than that which forms out on the open surface. Microstructural or subtle compositional aspects of the film may determine the extent to which it is removed during the cleaning process.
Figure 3. Secondary electron (SE) image of a corner of site E on DWB140. X-ray fluorescence spectra are shown for regions of interest outside and inside the sputter area. Elemental maps for Mg and Si show environmental constituent distribution.
Figure 4. SEM image of SIMS analysis site E
on DWA132
Comparison of Oxide Thickness between 5 and 9.5 Year Alloy 22 Gravimetric Samples page 6of 8
These electrolyte and environmental constituents are also represented in the electron microscopic
data generated for the washer sites. Figure 3 shows regional energy dispersive x-ray analysis spectra along with select images of the corner of the sputter crater at DWB140 site E to highlight
the most probable coupling between morphology and composition of the sputter site based on
proximity. The regions of low secondary electron (SE) emission in Fig. 3 correspond to regions of high x-ray fluorescence from Si, Mg, 0 and C (the latter two not shown). Fluorescence
intensity for Mg and Si correlates with the 600 grit polishing striations showing that the surface product lines the grooves of these original mechanical features; forming channels for electrolyte
entry underneath the Teflon washer. Fluorescence intensity from Si and Mg is largely absent within the sputter crater except along several deeper grooves due to sputter removal highlighting
the variation in oxide layer thickness encountered during this analysis. A comparison of full fluorescence spectra for regions outside and inside the sputter region show that the unsputtered
surface layers contain elevated levels of all of the environmental constituents observed in the
SEWS measurements.
The thickness values reported in Table 1 represent maximum estimates of a morphologically variable surface layer. Measurements appear reasonably accurate for the well-cleaned open surface sites based on the profile shapes and comparisons of topology effects on control C22
samples. Estimates become significantly more problematic when analyzing sites with readily detectable microstructure variations observed by SEM within the washer region of these
samples. Better measurements would be achieved by accounting for the area fractions occupied by the thinner and thicker surface layers within a given analysis site. Such an analysis assumes that the surface layer can be approximated by two components: one thin and one thick. Such an
assumption seems reasonable based on the SEM data of Figure 4 acquired within the washer
region of sample DWA132 surrounding site E. The sputter crater is clearly visible
as the bright 300 x 300 [tm 2 feature, with
SIMS data acquired from the center 50 x
50 g.im2 region of this site. Several levels of product layer morphology variation are evident in the surrounding area — presumed to represent the original
properties of Site E prior to sputtering. Morphological variation includes vertical banding and infilling of polishing grooves, creating the possibility for the presence of
two levels of surface product. Figure 5a-b show the cumulative ion maps (integrated
over the full period of sputtering) for 58Ni"
and C2I-1- . These maps show a general
correlation between regions of high and
low yield for these secondary ions. SIMS profiling is always conducted with the sputter beam aligned parallel to the directional polishing striations on the surface and thicker surface layers
tend to occupy the groove bottoms (see Fig. 4). A complementary mask was generated to define
these two regions as shown in the binary image of Figure Sc. This mask was then used to
Comparison of Oxide Thickness between 5 and 9.5 Year Alloy 22 Gravimetric Samples page 7of 8
recreate complementary depth profiles for these two regions. Note that the binary mask allows for a simple computation of the area fraction for these two regions. The results of this analysis are shown in Figure 6a-f. The result of this analysis is a reasonable separation of an apparent thinner and thicker surface oxide. The thin oxide region shows a narrow peak in ion yield with a
width approaching values observed for the efficiently cleaned open surface of this sample. The
thick oxide region shows a broader distribution of 0 ion yield to substantially longer sputter times (depth). Examination of the profiles for the environmental constituents shows that Si, Mg
and carbonaceous constituents track with thickness showing a broader distribution through the thicker region. The Cl response is more intense for the thicker region but shows broad
distribution in the thinner region. Of note is the fact that the 0 ion yield does not fully decay to zero indicating only partial separation of thin and thick surface layers.
_ . Figure 5. Cumulative secondary ion images for 58Ni" (a) and C21-1- (b) for DWA132
site E and the mask generated from these images (c)
These results were sufficiently encouraging to apply this technique to the full set of washer sites
analyzed in this report. Significant problems were encountered that more frequently produced a poor quality separation between thin and thick regions for this sample set. These depth profiles are run under conditions that optimize mass resolution as opposed to spatial resolution and
improved spatial resolution may aid in determining the analysis area fraction of each component. An additional complication was found in clearly identifying the appropriate constituent secondary ions upon which to base the mask. Additional work would be necessary to refine this
analysis process so as to produce a more consistent and reliable result.
Conclusions A measurable increase in the remnant surface oxide thickness is observed with SCW 90°C immersion time (5 vs. 9.5 year) for chemically cleaned Alloy 22 coupons. The washer region of
these samples, along with select optically dark sites on the coupon front face, contains an oxide surface product layer that is spatially heterogeneous. Results show that the minimum thickness of
the thickest regions of this surface layer can be in excess of 0.5 im thick. Thicker product layers are observed with longer exposure time in this washer region of the coupons. A possible method
for establishing an area weighted estimate for these thickest product layers is demonstrated.
6E4433 35E.04
1 4E403 30E-+04
1 2E403 2 5E404
1 0E403
2 0E404
800.02 I
g 1.5E.04
600.02 -
1 0E404 400402
200.02 500.03
- Ni (y1)
- NO (y1)
- FeO (y1)
-CIO (y1)
- Co° (y2)
- -MoO (y2)
-0 (y2)
3.0E404
2.5E404
2.0E404
; 1.5E+04
10E+04
5.0E403
1.8E400
1.6E400
1.4E+03
1 2040)
1.0E+00
- 0E431
6 0E-01
0 500 1000 1500 2000 2500 3000 3503 41315)
Spinet Time Is)
2.0E400
1.8E+00
1 6E+00
1 4E+00
1 2E+00
42 1 0E+00
2
SUE-U1
6.0E-01
4.0E-01
2 GE-01
000.00
-Ni (y1)
- 510 (y1)
FeO (y1)
- Cr0 (y1)
- Ce0 (y2)
Me0 (y2)
0 (y2)
- NI (y1)
- CI (y1)
- Si (y1)
- 110 (y1)
- C2H (y1)
- MgO (y2)
- 0 (y2)
1.4E-01
1.2E-01
1.0E-01
8.0E-02
6 0E-02
4.0E-02
2.0E-02
0.0E.00
0 3500 4000 1000 1500 2CCIO 2500 3300 0 500 2503 3000 30034025
DWA132 Site E - NI (y1)
- CI (y1)
- Si (y1)
-1)0 (y1)
- C2H (y1)
- Mg0 (y2)
- 0 (y2)
250.04
206.03
5 0E+02
1 5E+03
1 0E403
Comparison of Oxide Thickness between 5 and 9.5 Year Alloy 22 Gravimetric Samples page 8of 8
0.0E.02 0.0E+00
0 500 1000 15D3 2030 • 2500 3115) 3500 4000
Slimier Time 04
0.0E400 I 0.004C0
0 5133 1000 1500 2000 2500 3000 3500 4(03
Spieler lime is)
- Ni (y1)
100(y1)
- FeO (y1)
- Cr° (y1)
- Co0 (y2)
Me0 (y2)
0(y2)
1.2E-01 1.8E-o3
1.664o3
0E-01
1 4E+00
-Ni (y1)
- CI (y1)
- Si (y1)
- (y1)
- C2H (y1)
- MgO (y2)
-0 (y2)
1.2E-01
1 0E-01
El 0E-02
6.0E-02
4.0E-02
2.0E-G2
a 0E.00
C DWA132 Site E, thin oxide
800-02 1 2E4CC
100.03
600-02 :1
13E-01
4 0E-02 6.0E-0
4 CIE-01 VIILINIMILL 1,. I 4 0E-01
2 CIE-02
2 0E-01 2.0E-01
0.0E400 , ( ---"4`.111719111r111411.1 0 0E+00 00E+00
0 500 1000 1500 2000 2500 3000 3500 4000
Sputter Time (s)
I 0E431 2.5E+00
9.0E-02
0E-02 20E400
7 0E-02
SUE-U) 44, 1 5E+00
5 0E-132
400-02 1 0E-400
3.0E-02
20E-02 5.0E-01
1 0E-02
0 0E+00 0.0E400
503 1000 1500 2000
Sputter Thee Is) Swim Time is)
Figure 6. SIMS profiles for DWA132 site E: a,b) full analysis area, c,d) mask
separated region of high ion yield - thin oxide, and e,1) mask separated region of low
ion yield - thick oxide. Ion intensity is normalized to pixel number for c-f.