ML063450050

Oyster Creek: Licensee Final Document - IR 546049 Assignment 02, Reference A/R A2152754 Eval 06, Engineering Response on Drywell NDE and Other Evaluations (Pre-PORC Draft) (PD)

ML063450050
Person / Time
Site:	Oyster Creek
Issue date:	11/03/2006
From:	- No Known Affiliation
To:	Office of Nuclear Reactor Regulation
References
%dam200701, TAC 8261
Download: ML063450050 (131)

Text

IR 546049 Assignment 02

Reference:

A/R A2152754 Eval 06 Engineering Response This evaluation is being prepared as a technical eval in accordance with procedure CC-AA-309-101, rev 7, and will be submitted to document control for retention. The evaluation resolves concerns identified under IR 546049.

1.0 SCOPE Evaluate the current acceptability of the Oyster Creek drywell shell below elevation 10'-

3" considering the standing water found in the Bay #5 inspection trench and the moisture identified in the Bay #17 inspection trenches. This evaluation will demonstrate that adequate margin exists in the drywell shell to support plant start-up through the next plant operating cycle. Additionally, the as-found conditions will be demonstrated to not adversely impact current design or licensing bases requirements. The inspection trenches are located inside the drywell.

This evaluation will include:

• Results from drywell shell non-destructive examination (NDE) inspections

• Chemistry analysis of the water samples taken from the drywell sump, the sub-pile room (room below the reactor vessel) drainage trough and the Bay #5 trench

• The water migration tracer test results

• The drywell shell corrosion evaluation

• Visual inspection of drywell sump 1-8 2.0 EVALUATION

2.1 Background

In 1980, Oyster Creek Generating Station observed water coming from the sand bed region drains. Investigation conducted between 1980 and 1986 determined the source of water was from the reactor cavity during refueling outages. Ultrasonic Testing (UT) thickness measurements taken in 1986 confirmed that the drywell shell was thinner than expected and that wall thinning in the sand bed region was greater than locations above the sand bed.

As a result of the 1986 UT readings, a program was initiated to obtain detailed measurements in order to determine the extent and characterization of the thinning.

Measurements were taken from inside the drywell and around its perimeter, in accessible locations corresponding to the sand bed region.

To determine the vertical profile of wall thinning within the sand bed region (the bottom elevation of the sand bed region is 8'- 11.25", the top elevation of the sand bed region is 1

12'-3"), two trenches were excavated in elevation 10'-3" concrete floor slab inside the drywell in 1986. One trench is located in Bay #5 and the other in Bay #17. The approximate bottom elevation of the trenches is 8'-9" and 9'-3" respectively. The basis for selectingthe two bays is that Bay #5 exhibited less wall thinning, while Bay #17 experienced greater wall thinning. Following the specified inspections/examinations the exposed steel in the trenches was prepped and coated, and the trenches were filled with an easily removable material, (Dow Coming 3-6548 silicone RTV foam topped with a protective sealing layer of promatic low density silicone elastomer), to the height of the 10'-3 floor slab surface.

In 1988 the sand bed drains were cleared to allow for proper drainage of the sand bed region.

Additional UT thickness measurements taken in 1987, 1988, and 1989 showed that corrosion in the sand bed region continued to occur despite removal of water from the region. Furthermore, the cathodic protection system installed in two bays was not effective in arresting corrosion. Thus, removal of the sand was pursued, as the potential solution for mitigating corrosion in the sand bed region. Actions to remove the sand were initiated in 1988.

Again in 1991 UT measurements were obtained and evaluated as documented in Calculation C-1302-187-5300-021.

In 1992 sand was completely removed for the sand bed region. The external surface of the shell was cleaned in preparation for coating. The multi-layered epoxy coating of the shell, in the sand bed region, was completed in January 1993.

Numerous detailed inspections of the drywell have been performed since 1980. The engineering documentation associated with these inspections indicated evidence of water in the Bay #5 and #17 trenches during inspections during the 12R outage and the 15R outage (Sept 1994). The 1998 structural monitoring walkdown documented no water at the trenches. The documentation and the engineering evaluation for these findings are included as attachment 7.1.

2.2 1R21 Findings The 1R21 outage scope included removal of the filler material and NDE inspection of the drywell shell in the Bay #5 and #17 trenches. This is the first time since 1988 that the filler material has been removed.

Removal of the filler material during 1R21 revealed water in the trenches. Specifically approximately 5" depth of standing water was found in the Bay #5 trench, and dampness was noted in the Bay #17 trench. The approximate elevation of the top of the water in the Bay #5 trench (elevation 9'-2"), is near the bottom of the Bay #17 trench (approximate elevation 9'-3").

2

The standing water was removed from the Bay #5 trench via a wet-vac. Following the initial removal, additional water was observed entering the trench. The water level returned to its initial 5" depth. On-going dewatering via the wet-vac was initiated and continued until the water level was lowered to the bottom of the trench. The entire dewatering process removed at least 25 gallons of water from the Bay #5 trench. (see attached "Oyster Creek Trench Pump Out Schedule" for a summary of actions. See section 7.2 of this eval)

No water was removed from the Bay #17 trench since this area was damp only with no standing water found. The bottom of this trench is approximately at the same height as the top of the water level found in trench #5.

2.3 Additional Actions The following actions, associated with the identification and evaluation of the water found in the elevation 10'-3" concrete slab, were initiated:

• Performed a detailed drawing review to identify potential sources of the water in the trenches

• Obtained water samples and sent to lab for detailed analysis

• Performed an engineering field walkdown of the drywell interior at 10'-3" elevation to identify potential water in-leakage paths and water system leaks

• Added a tracer element to water in the sub-pile room drainage trough to determine if trough leakage was a potential source of the Bay #5 trench water

• Removed additional concrete from the bottom of the Bay #5 trench and performed additional UT exams to determine any potential impact to the drywell shell

• Initiated an engineering analysis to evaluate impact of the water on the drywell shell integrity

• Initiated field repairs and modifications to mitigate/minimize future water intrusion into the elev 10'-3" concrete slab. (ECR 06-00879) 2.4 Identification of Potential Water Sources The detailed drawing review confirmed that the only water bearing commodities in the drywell basement slab (elev 10'-3" and 10'-9") are the drywell sump 1-8, the sub-pile room drainage trough, and the trough-to-sump drain pipes. A preliminary field inspection of these commodities indicated potential leakage points in the trough, and at the trough-to-sump drainpipes. The elevation of these potential leakage points was above the 5" water level in the Bay #5 trench. External sources of water were ruled out based on the visual and UT examinations performed in the sandbed region of the drywell shell.

See section 5.0 for a list of the drawings reviewed.

Other potential water sources were also determined based on the field walkdowns.

Sources such as equipment leakage/condensation that either fell to the floor or washed down the inside of the drywell shell and traveled to the basement concrete-to-wall joint were identified.

3

2.5 Water Samples A series of water samples were obtained from the drywell sump, the sub-pile room drainage trough, and Bay #5 trench. The initial water samples taken from the Bay #5 trench, upon discovery of the water, were performed by the Oyster Creek chemistry personnel. The ph of these initial samples were greater than 10.5. These initial samples provided the earliest and most accurate pH indication of the water in contact with the drywell shell at the time of discovery. Comparisons were also made with other above floor water sources such as the RBCCW, Condensate and Feedwater systems. (For a complete listing of water samples used see the Section 7.3 attached report.) These samples were taken to assist in determining sources of the water in the Bay #5 trench, and the possible migration path of the water. Water samples were obtained from the Bay #5 trench and the sub-pile room trough and were sent to an off-site lab for analysis. OC and corporate chemistry personnel then evaluated the lab results. As part of this evaluation, a list of the water systems in the drywell was compiled. A matrix was developed defining the chemical composition of the potential water sources. The chemistry evaluation compared the lab results with the potential sources in order to identify/eliminate any contributing systems.

The evaluation concludes, "The source(s) of water in the trench cannot be conclusively determined from chemistry analysis. We can conclude that it is not the result of CCW leakage as there is no evidence of closed cooling water corrosion inhibitor in the trench.

Furthermore, it is not the direct result of recent reactor coolant leakage because there are no short-lived radionuclides in the trench samples. It is also unlikely that the source of water is due to an external source. The radionuclides present in the trench water are indicative of CRD water that has been allowed to decay such that only longer-lived radionuclides are present in the trench samples. The difference between the radionuclides present in the trough and the trench is due to the tortuous path the water takes migrating from the trough to the trench. Migration of water from the trough to the trench has a relatively long transit time as evidenced by the fact that there are no short-lived radionuclides in the trench. The two samples containing dye indicate that water is migrating, albeit slowly, from the trough where the fluorescein solution was added on Monday, October 23, to the trench. Therefore, the most probable source of water in the Bay 5 trench is Control Rod Drive water."

See the attached chemistry evaluation, section 7.3 of this eval, for complete details.

2.6 Field Walkdowns Engineering and maintenance personnel performed numerous field walkdowns and inspections. These inspections looked at the concrete surfaces at elevation 10'-3", the sub-pile room floor, the sub-pile room drainage trough, and the upper visible area of the drywell sump pit 1-8. These inspections:

• Confirmed, through the 2006 structural monitoring walkdown that the elev 10'-3 floor slab concrete outside of the sub pile room was in generally good condition.

4

" Did not identify any defects in the sump 1-8 liner plate when viewed from above, and during a detailed visual exam, (See section 2.7.2 for visual examination of the sump pit 1-8).

" Identified several defects, (i.e. cracks and voids) at the interface of the drainage trough and its drainpipes to the 1-8 sump.

" Identified a glass object embedded in a void at the bottom of the drainage trough near the discharge pipes to the sump. This condition was confirmed to be a direct water entry path into the drywell elevation 10'-3"/10'-9" concrete slab. This condition is believed to have existed since the original plant construction. It is unknown if the associated void has degraded since that time.

" Confirmed that no caulk or other sealant material currently exists at the curb-to-drywell shell interface at elev 10'-3".

(Note: the 2006 drywell maintenance rule structural monitoring walkdown write-up is attached for information, section 7.6) 2.7 Water Migration Potential migration paths identified from the drawing reviews and field walkdowns were investigated. It was determined that water migration could occur during plant operation or during outage periods. See the attached sketches in section 7.8 for the drywell elevation 10'-3" configuration. The credible paths investigated included:

• Water/condensation washing down the inside face of the drywell shell and into the unsealed circumferential gap between the shell and the elev 10'-3" slab

• Water migration through degraded surfaces of the elevation 10'-3" and 10'-9" floor slabs

• Leakage from the drywell sump 1-8

• Leakage from the sub-pile room drainage trough/drain into the concrete and through sub surface cracks or between concrete pour layers

• Water migration from water on the elevation 10'-3" slab

• Any combinations of the above pathways Based on the drawing review and the field inspections, engineering concluded that leakage from the sub-pile room drainage trough/drain appeared to be a highly likely source of the trench water.

To confirm this hypothesis, a tracer test plan was developed and implemented, (see attachment 7.4, tracer test plan, for more information.). The test commenced 10/23/06 at approximately 04:30 and continued throughout the day. Based on the scheduled control rod drive (CRD) exchange, which would cause water to enter the sub-pile room, the drainage trough drainpipe plugs were removed on 10/23/06 at approximately 21:20. (see the attachment 7.2, "Oyster Creek Trench Pump Out Schedule" for a summary of the actions.) At the time of the drain plug removal, approximately 15 gallons of water was lost from the trough, but no tracer element had been identified in the Bay #5 trench. This was not unexpected, since the water migration rate through concrete is small and the slab 5

had been "de-watered" to the bottom of the Bay #5 trench. Monitoring of the Bay #5 trench continued for the next several days.

On 10/25/06 at approximately 08:00, a small amount of water was observed in the Bay #5 trench. Inspection of the water with a black light provided initial confirmation that tracer element was present in the water. A sample was extracted and confirmatory testing was performed in the hot lab. This testing confirmed the presence of the tracer element in the sample.

The 10/25/06 positive identification of tracer element in the Bay #5 trench confirms that some, if not all, of the water that migrated to the Bay #5 trench is from the sub-pile room drainage trough and associated drains. Engineering continues to consider the drywell-to-concrete curb interface as another credible water entry path based on the observations of water dripping down the wall during early outage walkdowns, and the gap at the concrete-to-shell interface.

As noted in the maintenance rule structural monitoring walkdowns, (attachment 7.6),

discussed above, the structural inspection of the elevation 10'-3"/10'-9" floor slab surface condition was in generally good condition. The as-found condition is not conducive to significant water intrusion.

2.8 Engineering Evaluation of the Drywell Shell Steel Corrosion An engineering evaluation was prepared by an independent structural engineering and corrosion expert from Structural Integrity Associates (SIA). The evaluation reviewed the impact of the as-found water on the continued integrity of the drywell shell. The engineering evaluation utilized the results of the above discussed water chemical analysis and NDE examinations. The engineering evaluation concluded: These measured water chemistry values, plus the lack of any indications of rebar degradation, suggest that the protective passive film established during concrete installation at the embedded steel/concrete interface is still intact and significant corrosion of the drywell steel would not be anticipated as long as this benign environment is maintained. Therefore, since the concrete environment complies with the EPRI concrete structure guidelines, corrosion would not be considered "an applicable aging mechanism for nuclear power plant concrete structures and structural members" at Oyster Creek. More specifically, the results of this engineering evaluation indicate that no significant corrosion of the inside surface of drywell steel shell would be anticipated for the following reasons:

• The concrete floor water inside the drywell is characterized by corrosion-inhibiting high pH with low impurity levels that are significantly below the EPRI embedded steel guidelines action level recommendations. Therefore, drywell steel integrity can be maintained indefinitely as long as the high pH and low impurity levels in the water at the concrete-to-drywell shell interface are maintained.

• Any subsequent water (such as reactor coolant) entering the concrete floor-to-drywell shell interface will increase in pH due to its migration through and 6

contact with the concrete. This will reduce its corrosivity compared to neutral pH.

" The corrosion of drywell steel surfaces in contact with water at the concrete floor-to-drywell shell interface is expected to occur only during outages when oxygen is present. Corrosion during operation is expected to be almost nil since the drywell operates inerted and no oxygen is present to drive the corrosion reaction. During outages, shell corrosion losses in the interface are expected to be small since the exposure time is very limited and the water pH is expected to be relatively high.

" The expected low corrosion losses in the concrete-to-drywell shell interface have been confirmed by examinations of steel surfaces in the trenches, which have revealed only superficial corrosion of the drywell shell.

Therefore, the water identified in contact with the inside surface of the drywell steel has not been and is not, an engineering concern for the structural integrity of the drywell as long as the environmental conditions (e.g., pH and water purity) are maintained.

The SIA engineering evaluation is included as attachment 7.5.

In addition to the review performed by SIA, a review of the 10CFR50 Appendix J, Type A testing results was performed to confirm that the area of the shell encased in concrete is not breached. Attachment 7.0 was prepared to evaluate this configuration. The last type A test was performed successfully in November 2000.

2.9 NDE Inspections 2.9.1 UT Examinations The scope of the 1R21 outage included numerous NDE exams of the drywell shell.

Additional drywell shell NDE exams were also performed as a result of the water found in the Bay #5 and #17 trenches. The results of these NDE exams were reviewed and evaluated by engineering in technical evaluation A/R A2152754 eval 09. that tech eval concludes: The plates exposed by the two trenches exhibit signs of material loss. It is concluded that all the material loss occurred between 1986 and 1992. Assumed corrosion rates for this mechanism between 1986 and 1994 are consistent with as found measured corrosion rates previously established for these bays for this period in time.

Additional concrete was removed from Bay 5 trench and UT readings taken on the newly exposed 6 inches of drywell shell below the previous 1986 and 2006 readings. This newly excavated area represents shell thicknesses of the embedded region (on both sides) of the vessel in Bay 5 of sandbed region. The average Drywell shell thickness measured was 1.113 inches and the minimum reading was 1.052 inches. The UT Data Sheet is of a/r a2152754 eval 09. The shell thickness in this area meets the general uniform thickness criteria of .736 inches with considerable margin. This area will be used to repeat these UT measurements in 1R22.

7

Evaluation of the NDE examination results at and below the elevation 10'3" concrete slab concludes that the drywell shell has sufficient thickness to withstand all design requirements.

2.9.2 Visual Inspection of Drywell Sump 1-8 A visual inspection was performed on the drywell sump 1-8. the inspection was performed to confirm the stainless steel sump liner remains structurally adequate and leak tight. The inspection looked for pitting, corrosion, cracks, and other defects. The visual inspection confirmed the liner remains structurally adequate and leak tight. The inspection results are included in attachment 7.7.

2.10 Field Repairs/Rework ECR 06-00879 has been developed to mitigate the introduction of water into and/or below the drywell elevation 10'-3" slab through inspections, repairs, and rework of associated components during 1R21. Specifically the ECR implements the following actions:

" Clean and inspect the sub-pile room drainage trough.

• Verify drainage trough is properly sloped to the sump

" Repair/re-surface the trough and discharge points as required to return the trough to its design intent

• Clean and dewater the drywell sump 1-8 to verify integrity.

• Perform visual inspection of the drywell sump 1-8

" Repair significant leak paths, if any, in the drywell sump 1-8, as required (Note: as documented in section 2.9.2. above, the sump did not require any repairs.)

• Clean and prep the top surface of the elevation 10'-3" slab curb at the drywell shell interface.

" Seal the joint at the curb-to-drywell shell interface with approved caulking material

" Excavate additional concrete at the base of the Bay #5 trench to provide sufficient space for new UT exams of the shell below the current trench bottom

" Perform UT exams at additional drywell shell locations at the newly exposed portions of the drywell shell

" Caulk the concrete-to-shell interface in the Bay #5 and #17 trenches 2.11 Drywell Leakage Monitoring In addition to the above described actions implemented during 1R21, on-line procedures minimize potential water available for water migration below the elevation 10'-3"/10'9" floor slab. Plant operating procedures require on-line monitoring of known and unidentified drywell leakage. This process maintains the drywell leakage to an acceptable amount, and provides a rapid indication of significant drywell leakage during plant operation.

8

2.12 Structural Adequacy of the Elevation 10'-3" Concrete Slab The fill slab is reinforced concrete placed in the bottom of the drywell vessel up to El.

10'-3" to provide a working base for supporting the reactor pedestal and other loads from the internal structures and equipment. The fill slab transfers all imposed loads to the drywell vessel foundation through direct bearing only, (Ref., Section 3.8.3.1.1 of the UFSAR). Typically, cracking of concrete elements within reasonable limits will not affect the structural capacity of concrete members provided the overall integrity of the element remains intact. Given the structural configuration of the fill slab as confined by the steel shell and exterior drywell support and that the primary load transfer mechanism is by direct bearing, nominal cracking in the slab will not affect its load carrying capacity.

The concrete material removed from the Bay #5 and Bay #17 trenches has no impact on the drywell shell analysis.

.The original concrete fill inside the drywell was specified to have a minimum compressive strength of 3000 psi at 28 days. The concrete was placed in three (3) layers with specific requirements for strength and time between pours, (

Reference:

Drawing BR 4059-2 sheet 2 of 3).

From a structural standpoint, the presence of water in cracks or porosities will not impact the strength of the fill slab. It should be noted that the Bay #5 and Bay #17 trenches were excavated in areas that are completely outside the concrete bearing area required to support the reactor vessel pedestal.

The concrete slab is inspected each outage as part of the Maintenance Rule Structural Monitoring Program. The Maintenance Rule Structural Monitoring walkdowns to date have reported the concrete surface sound, with no spalling or cracking that would indicate reinforcing steel corrosion in the slab.

Therefore, the concrete floor slab integrity is maintained and the presence of water in the inspection trenches has no detrimental impact on the drywell internal concrete's structural design function.

3.0 CONCLUSION

3.1 Based on the detailed drawing reviews, field inspections, chemical analysis, and monitoring, the source of a portion of the water in the Bay #5 trench is confirmed to have originated from the degraded areas in the sub-pile room drainage trough drain. There still remains a potential leak path from the unsealed area between the drywell shell and the concrete curb at elevation 10'-3". Based on the drywell elevation 10'-3" construction details and the relative bottom elevation of the Bay #5 and Bay #17 trenches, the source of the Bay #5 water is also likely to be the source of the dampness noted, in the Bay #17 trench. water or moisture may continue to exist below the drywell interior elevation 10'-

3" floor slab.

9

3.2 The attached SIA engineering evaluation indicates that no significant corrosion of the inside surface of drywell steel shell occurs as long as the current environmental conditions inside the drywell are maintained for the following reasons:

" The water at the concrete floor-to-drywell shell interface inside the drywell is characterized by corrosion-inhibiting high pH with low impurity levels that are significantly below the EPRI embedded steel guidelines action level recommendations. Therefore, drywell steel integrity can be maintained indefinitely as long as the high pH and low impurity levels in the water at the concrete floor-to-drywell shell interface is maintained.

" Any subsequent water (such as reactor coolant) entering the concrete floor-to-drywell shell interface will increase in pH due to its migration through and contact with the concrete. This will reduce its corrosivity compared to neutral pH.

" The corrosion of drywell steel surfaces in contact with water at the concrete floor-to-drywell shell interface is expected to occur only during outages when oxygen is present. Corrosion during operation is expected to be almost nil since the drywell operates inerted and no oxygen is present to drive the corrosion reaction. During outages, shell corrosion losses in the interface are expected to be small since the exposure time is very limited and the water pH is expected to be relatively high.

• The expected low corrosion losses in the concrete-to-drywell shell interface have been confirmed by examinations of steel surfaces in the trenches, which have revealed only superficial corrosion of the drywell shell.

Therefore, the water identified in contact with the inside surface of the drywell steel has not been and is not, an engineering concern for the structural integrity of the drywell as long as the environmental conditions (e.g., pH and water purity) are maintained.

3.3 The evaluation of the NDE examination results at and below the elev 10'-3" concrete slab concluded that the drywell shell has sufficient thickness to withstand all design requirements.

3.4 ECR 06-00879 has been generated to implement a series of actions to mitigate further water intrusion into and below the drywell elevation 10'-3" concrete slab. These actions will greatly reduce or eliminate future water migration below the surface of the elevation 10'-3"/10'-9" concrete slab.

3.5 Overall Conclusion Significant engineering, maintenance, and NDE effort was employed during the 1R21 outage to address the cause, source, and impact of the standing water in the Bay #5 inspection trench and the dampness in the Bay #17 inspection trench at drywell elevation 10'-3". The investigations concluded that the likely entry point for the water was a deteriorated connection at the sub-pile room drainage trough drainpipes, at the void in the bottom of the sub-pile room drainage trough, and at the unsealed gap at the elev 10'-3" concrete slab curb and the interior surface of the drywell shell. A design change was implemented to remediate these entry paths. In addition, detailed inspections confirmed 10

the structural adequacy of the drywell sump. NDE exams confirmed that the drywell shell thickness maintains adequate margin by exceeding the required minimum wall thickness. The SIA engineering report established that the drywell shell structural integrity is not impacted by continued water in the drywell elevation 10'-3" concrete.

Therefore it is concluded that the drywell structural integrity is maintained and the drywell continues to meet all of its design bases requirements until the next scheduled refueling outage at which time additional inspections will be performed.

4.0 RECOMMENDATIONS 4.1 Perform UT and visual examinations of the drywell shell in the Bay #5 and #17 trenches (interior shell surface) and the sand bed region inspection points below the as-found Bay #5 trench water level (exterior shell surface) in the next refueling outage to confirm that the conclusions of this evaluation remains valid. See action tracking item IR 546049, assignment 06.

4.2 Include the sub-pile room drainage trough and the drywell shell-to-concrete curb caulk in the structural monitoring program. Inspection should be performed each refueling outage. The inspections will be part of ER-OC-450. Reference ECR 06-00879, and ER-OC-450

5.0 REFERENCES

IR 546049 Cc-AA-309-101, rev 7 Dwg 3e-153-02-001, rev 7 Dwg 3e-153-02-009, rev 4 Dwg BR 2134, rev 8 Dwg BR 2135, rev 8 Dwg BR 2145, rev 12 Dwg BR 2146, rev 14 Dwg BR 2184, rev 7 Dwg BR 2186, rev 9 Dwg BR 4049, rev 7 Dwg BR 4050, rev 2 Dwg BR 4058, rev 2 Dwg BR 4059, sheet 1, rev 1 Dwg BR 4059, sheet 2, rev 2 Dwg BR 4070, sheet 1, rev 4 Dwg BR 4070, sheet 2, rev 3 Dwg BR 3136, rev 15 Dwg 9-097 1, sheet 11, rev 2 (CB&I)

UFSAR Section 3.8 Calculation C- 1302-187-5300-021.

11

6.0 REVIEWS This eval has been prepared as a technical evaluation in accordance with procedure CC-AA-309-101. Based on a review of CC-AA-102, this eval has no procedure, program, or other documentation impacts.

Based on a review of HU-AA-1212, a risk rank of 2 was assigned to this product, and the appropriate pre-job brief was performed. This evaluation shall receive an independent review, and an independent third party review.

7.0 ATTACHMENTS 7.1 Plant Structure Walkdown/Monitoring Reports, (20 pages). Attachment includes: Report dated 03/26/97 for walkdown performed in 1996 (contains letter describing conditions found in 1994); Report dated 11/12/98 for walkdown performed in 1998.

7.2 Oyster Creek Trench Pump Out Schedule (3 pages) 7.3 OC Drywell Chemistry Sample Results and Analysis, rev 6. (13 pages)

Attachment also includes embedded file (BWXT Report "Examination of Water Samples From Oyster Creek, rev 0, dated 10/22/06) (32 pages) 7.4 Tracer Test Plan, rev 2 (3 pages) 7.5 Structural Integrity Associates, Inc. "Corrosion Evaluation of the Oyster Creek Drywell Shell Steel - ECR 06-00879", dated 11/02/06 (11 pages) 7.6 2006 Drywell Maintenance Rule Structural Monitoring Walkdown Write-up (20 pages) Attachment includes #R2091380-01-01, and #R2091380-01-02 7.7 GE Visual Examination Report #21R-158 - Sump 1-8 Visual Inspection (3 pages) 7.8 Simplified sketches (5 pages) 7.9 Evaluation of the Ability of Type A Integrated Leak Rate Test to Detect Through Wall Breach in the Concrete Encased Area of the Drywell Shell, 10/31/06 (5 pages) 7.10 MPR Associates Letter, "Third Party Independent Review of Oyster Creek Drywell Water Evaluation, dated 11/03/06 (3 pages)

Preparer: DP Knepper - PEDM Independent Reviewer Comments:

An independent review of this document was performed in accordance with CC-AA-309-101. I performed a detailed review of the inputs, attachments and reference documents, with emphasis being applied to evaluations performed or referenced in Section 2.0. I performed a walkdown of the concrete slab and verified that the concrete slab is in good 12

condition. I provided comments to the preparer and all comments have been satisfactory resolved. I agree with the conclusion that the structural integrity of the containment shell is not impacted by continued water in the drywell Elevation 10'-3" concrete slab, or its adjacent interface with the containment shell.

Independent review Performed by Dan Fiorello, Corporate Design Engineering Independent Third Party Reviewer:

ITPR was performed by MPR Associates. The documentation of this review is included as Attachment 7.10 of this eval.

Manager Comments:

The preparer and multiple reviewers of this technical evaluation had the appropriate knowledge and experience and are qualified to perform this task. The Independent Third Party Review (ITPR) was performed by MPR who was selected as a subject matter expert based on their expertise and industry experience on this topic. This document has been rigorously challenged and addresses the adequacy of the as-found water conditions and potential impacts to demonstrate the drywell vessel maintains its design and licensing bases requirements to support restart from 1R21.

The ITPR has been completed and comments adequately resolved as documented in 0.

Manager Approval: F.H. Ray 11/3/2006 13

1-?- S o4,* ttr _*7~,

7"[ iAcI1At/fi 0-0.

Attachment 7.1 Plant Structure Walkdown /Monitoring Reports A) Report dated 03/26/97 for walkdown performed in 1996 and contains letter describing condition found in 1994 B) Report dated 11/12/98 for walkdown performed in 1998 (20 Pages)

• ~~ (4- 0(2 7 AM44-4I-el1-(-~uOYSTER. CREEX NUCLAR ISTATI0 NUCLE PON..

AREXERATINO U

Nuibber j21v 126.6 TitleJRevision N6,,

Building Structure Monitor~ing Plan 0

SYSTEM: 4f~

.~~ ~~ mhTV9 DjwI_'ý3/A.df/! TnZMS.

WALKDOW? ENGINER SIGNATURE.

2Silii o sal-ing Con~crete 11 *. d R

3. a *Car ~ .On, 4~~~~~~O eea~~roia~K I, S Wt tt*~a

~f qf~.~L Q' A Ai*~L~

TVW N' i-a.- ~..

f~ s"-,

r

-;A~~AUP4IV i.4

S.

7.S.

C)w

~.

Jk~4I 1 1 Ii df.0 . ~sW~kw A'r-A~~ ~ *IVI~~JA e4WAIAr 4 p.~ 0o~dz ~~~VWA.

/*v k#

a £~d/ A4. MW~

- ~ se~ ~viJAW (1256/S3) 81-1

-r-7,/

Page lof 2 S16R STRUCTURAL WALKDOWN REPORT INSIDE THE DRYWELL

• t1. GENERAL STATEMENT As required per plant Procedure 125.6, a walkdown was performed in the morning of September 22, 1996 by Tom Quintenz and T.H. Chang Inside the Drywall. This walkdown is to provide visual inspection to the structural elements at that area in accordance with the NRC's New Maintenance Rule. The accessible locations from El. 82' on top of the biological shield wall to platforms at EL 46' and 25', to El. 10' concrete floor and under the Reactor vessel were inspected.

2.

2.1 El. 62' on Too of Blolouical Shield Wall

- The general appearance of the Reactor vessel stabilizers, the star truss that connects the biological shield wall to the Drywall steel liner, and the surface condition of the Drywall, the steel platform underneath the Reactor cavity which was flooded during this Inspection.

. General condition of the pipe supports and duct supports.

2.2 El. 46' Gratlna Platform

- The general condition of the platform structure.

- The platform steel beams and beam connections, if visible.

. The surface condition of Drywall liner.

0 - The supports for Drywall cooling fans.

- The general condition of the pipe/equipment supports.

2.3 El. 23' Gratina Platform Same as for El. 46' platform except there are no Drywall cooling fans on El. 23'.

2.4 Concrete Floor at El. 10'

- The Drywall surface condition.

- The concrete floor surface condition.

The ring corbel that supports the Reactor vessel looking up from underneath the vessel.

3. RESULTS AND CONCLUSIONS Some of these conditions were documented in the attached pictures. There are no obvious structural deficiencies found during this walkdown except the following:

3.1 Any temporary, heavy laydown load shall be placed on top of the steel beam, particularly the radial beams where the structural strength Is greater. Due to the very tight space condition, some of the steel plates removed from the pipe penetration ware laid on the grating. This condition was inspected, and no sign of structural failure nor excessive displacement at this location was found.

p:.\Docs.96MEI0.96W.REPOTSCHANO.16RDWD

12 S4-to o4ý - o I. 4TfACW~.~r 7~1

• ,h Page 2 of 2 t6R STRUCTURAL WALKDOWN REPORT 0 INSIDE THE DRYWELL 3.2 On El. 10', at the sand bed region where the concrete curb protects the Drywall liner, there are two locations where concrete curbs were removed about one foot long. The two locations are near the drain tank and near the ladder. GPUN performed UT to monitor the Drywell liner corrosion condition at the sand bed region at those two locations. During this walkdown, floor water accumulation at those two locations was identified. The possible Impact to the Drywall liner due to the water has been addressed by Sam Saha (Memo 5340-98-002, January 3, 1998).

eV 0

P:M0McS96E310.9G6JREP7tVCKMANO.6RDWD

ui 54toWc ot. A-r-rAcy1Yqevr -7,1 EMNucrears Memorandum jams, INSPECTION OF DRYVELL COATING AND Dt, January 3, 1995 CONCRETE TRENCHES @ EL: 10'-30, O.

S. K.

S~, Saha - Engineer, Engineering and Design Lmetust Morris Corp. Center Us, Distribution on September 29, 1994 the writer, along with Bill Quinlan, made an entry into the dryvell to inspect and observe coating condition on,the inside surfaces of drywell shell from elevation 10'-30 to elevation 53f. As a part

• of the same effort, an inspection of two trenches at -elevation 10-30 in Bays'5 and 17, excavated and filled during 21R outage, was also performael.

The results of this inspection are detailed below:

Dry ell Coatrn=:

The inside surface of the'drywell shell between elevations 10-3* to 94'-10 Is coated, with CarboZinc 11 coating, manufactured by Carboline Company.

During construction, the individual shell plates were precoated in the shop with CarboZine 11 over an abrasive blasted surface (SSPC*,SP5/SP6) to a.dry film thickness. (DFT) of 3-6 mile except 2 to 3 inches of the edges'which were masked off for field welding (Ref 1). During field erection, the Individual drywell shell plates were welded to form the pressure boundary.

The weld crowns were ground flush and touched up (probably by brush) with CarboZine 11 (Ref. 1). During the last 25 years of plant operation, various system modifications/repairs 'have required removal of this coating for welding and/or fitting. Upon completion of repair/modiflcatIon, CarbonZinc 11 was reapplied by brush over a SP-3 (power brush cleaned) AX SP-11 (power tool cleaned) surface.

The walkdown inspection was carried out from. the platforms located inside drywe.1l at elevations 10'-3", 23',60 and 461-10. The visual inspection did not reveal any coating distress such am-blisters, disbotding, chalking.

spelling. etc. Some fading of luster and accumulation of dust were seen on the.coating surface which was expected considering the coating type and its age. The coating showed good adhesion to the drywell shell when tapped with a'20W& wooden bar. In short, nothing was observed on the coating to change any technical basis of its failure mode during LOCA or to cause strainer blockage, as evaluated under Reference 2.

Concrete Trenches:

During l2R, two trenches were dug where the concrete floor meets the drywell shell ((Figure 1) to evaluate shell thickness and to remove plug samples in Bays S and 17. After evaluation and repair, the shell was spray coated in the trench areas, filled up with Dow Corning 3-6548 Silicone RTV Foam and sealed at the top by pouring a protective sealing layer of Promatee Low Density Silicone Elastoner. It was evident after a 12R inspection of the .

area. that water was seeping into the trenches. Probable sources of water may be (a): various component (e.g. valve) leakages, (b): spills from drain

• Disiributio lan4, ~-7 Jhnuary 3, 1995 . -.

5340-95-002 Page 2 tanks, and (c): excess water from outage-activities (e.g. CRD changes). In April. 1994. the trench areas were visually inspected again when a valkdown wad, conducted to check fixed point radiation monitors during a forced outage. The areas were totally dry (Figures 2 and 3)..

To evaluate corrosion potential of trench water on the drywell shell, It WAs decided to collect water samples from the trench areas during 15R outage ind analyze for pH, conductivity and halogen content as specified in Reference

3. The writer found the trench areas wet/moist during 9/29/94 dryetll walkdown but no water accumulation was seen (Figures 4 and 5), Wfhen the elastomeric filler/sealer was vigorously tapped with a 20x6u wooden bar, water. was seen spewing out of the joint connecting elastomeric tilloer/sealer to the dryvell shell (Figures 6 and 7). However, theamount of water was inadequate. in quantity for the planned analysis and no sampling wp"4 performed. A band of rust 1 to 1.51 wide wa" seen on the drywell shell above sealer shell interface indicating the level of water accumulation -on the conciete floor. No visually observed localized corrpsion attack was seen In the rusted band and the depth of oxide layer was visually estimated to be. in 2-3 mils range.

The above observation indicates that (a): Prometec LDSE is no longer acting as a seal to prevent intrusion of surface water, and (b): Dow Corning RTV foam is retaining the water reaching the trenches. It is. likely that the subject areas dry out rapidly once the reactor starts but nonetheless, water reaching the trenches do remain in contact with concrete and drywell shell until it drles'out. Concerns have been expressed on long and short term effect of this water Intrusion on drywell shell corrosion. 'The writer's evaluation of the subject concerns are summarized below:

Although no water sample analysis was performed; it. is bel-ieved that such analyses would have shown low corrosion potential for the drywell shell in trench areas because of:

a) expected'high pH value of trench water due. to contact with concrete.

The pH of a saturated Ca(OH)3 solution is about 12.5. At such high pH value and in the presence of moisture and oxygen (outage condition),

carbon steel shell will be passivated by formation of thin-FeOOH oxide film. WThen oxygen Is depleted and concrete is dry (plant operation),

this film may be disrupted but still-amount of corrosion will bq very low (Ref. 4)-.

b) low contaminants leaching out of (I)-RTV foam (Ref. 5), (2) LDSE sealer (Ref. 6), and (3)-concrete. The leach rate should not increase corrosion potential of the trapped water by any substantial margin.

c) nitrogen Inerting of drywell during plant operation. Nitrogen blanket will keep the shell corrosion to a very low level.

Therefore, the writer does not expect any significant shell corrosion from Infrequent trapping and drying of moisture under filler/sealer and shell

• k Interface at the subject trenches.

Iwi:PJM'&G95 002

.T.-~- 0 jov

- @rczr

~,Dis tribution Mc ~

january 3, 1995 5340-95-002 Fage 3 Technically, the condition of the subject trenches is not desirable. In addition to collecting water, they also trap various contaminants includin&

radioactive, particles. Rectification of the situation will require either prevention of water from reaching the trenches or removal of existing filler oaterials and resealing the trenches with proven material(s). Any such rectification will involve significant exposure of. radiation to work personnel. The conceptual estimate for this job is 10-15 Person-RflI based upon similar work In 12R (Ref. 7). Therefore. desirability of rectification.

work must be evaluated against practicality, of high Person-REN exposure before any final decision is made.

Please feel free to call me at extension 7684 if you have any questions on the evaluation.

S. K. Saha Extension 7684

/kv Attachments

• 7 (Figures 1 thiu 7)

Distribution:

J. D. Abraovicl - Mechanical Components Manager

j. J. Colit, - Director. Engineering and Design W. M. Connor , Manager, Nucir Matrls/Cheu Engineering W. J. Cooper'- Manager Red Engineering. OC R.F. Croll - Engineer. Engineering and Design D. K. Croneberger - Director Special Projects D. H. Reppert - Tech Analyst. Red Engineering, OG

• - Tech Function Site Director, OC S. L. Schwartxz - Engineer, Systems Engineering,. 00 C. R. Tracy - Engrg Projects Director (OC) 31VPsINM"IoI0 9-o

0?- -4TX-cWC>-ýa I-AZ546,41 Distribution JanuaryZ 3,,1995 5340-95-002 Page 4 REFERE?

Technical Data Report No. 503 - "Dryvell Coating Evaluation ..

1. *FUNC 2;. GFUC Safety Evaluation SE-328245-001 "Dryvell Shell Coating Touch Up, Inspection and Minor Repaft of

3. GPuNC Specification - SP-1302-32-035 -

Coating on Concrete and Drywall Shell Surfaces in the Sandbed Regiono

4. ASM Handbook - Volume 13 'Corrosion" - 9th Edition Chapter Corrosion iIn Structures- Page 1301.

5. Dov Corning Product Information Bulletin on 6548 Silicone RTV foam 1.36 I 6. Personal Com-unleation with Clenn Kruse of Promatec on Reg.,Cuide Test on Promatec LDSE materials.

7. GFUWC Memo 5340-95-001 - "Drywall Floor Trench Repair" from R. F. Croll to S. X. Saha Aj

DThtributiou t~z544~ t4j -~~-- 4n-4c~'t-~e~/r -

'January 3, 1995 5340-95-002 M~9 Page 5 I I' LI6#T DfN5Iv~j31I!1e!l!Jg v,t&Aar@ICAAlVTfAtI^7X..

/ 'MeC.

9LA. VA AIZS

• I-p 1MICA TCl Irf^ ASAVICb 1 I&L @D' KATCAIALS 05ftA C?0ASS-SECTlON AT'AR(AS OFT<EPAIR (BAT -S 1~ 17)

A cross section of excavated dryvell concrete trench @

I mLSIWpjMW,4Oq3,ýOl Elev. 10#-3"

, /$*istribution January 3, 1995 12 Sto4+1 -0Z-5340-95-002 A-lT~c--'9 1- 7,2 Page 6 I) 7I, /

Repaired concrete trench area in Bay 5 during April '94 Ps1-sIwi)cc,'fl 5 -os*t walkdown showing the area totally dry. Note crack at the sealer - concrete-shell interface.

4 Distribution-January 3,. 1995 5340-95-002 Page 8

• f i flM k.-

Bay 5 trench repair ares shoving Adigns of Wetness and' moisture during September 194 ralkdowv

.1 LLLUe-.j: Same as Figure 4 but in Bay 17

AWAO te4A4'~btArncwi~w fz. K!,'.

-o 0.11 4W¶S0, 44 - A

~ al#

'PA-Ars

YT- 544, 04q~ -02 4 1 ~17f RA 2..&

'FARM ~

W&, r I r' T

dAR ,,Ael-wA4 ,a,.,AOw.V

£12- S44~O4'j -p2- - ,#7746 frA cMT 1,'/

A4¶tCA(  ?~4 ~4-

] ,'

I 4"i ~*C4t d~.i or di 4t~ 'SA4 vs ii(f '-fr~SAeVfl .,' n-sr *'E~ 9A~4

, '*1 40,0W',,4'Oat ..

p 146if loley,41444

-L?- 'ý;4-lp Do - O-L -4T~41-~qeYr 7,

. . . . ý ý 2 it 1.

1,

)

- ~ 'Mv~L.

I.

0

- ~ ~r~sTh'.

I 0&

~ ~ 41.q44 4 lp*AwN'~ i

,T1",.AC/y F n7.~.3fl -T 64 o4ý o -L 17,1 OYSTER CREEK NUCLEAR GENERATING Number STATION PROCEDURE j 125.-6 NUCLEAR Title Revision No.

9uilding Structure Monitoring Plan 0 0 ________________________________________________________________________________

AATTArmRETR 125.6-1

.1. ~

PLANT! S'acTPUTLYR2 WALXDOOLVMONITOR-ING REPORT qV~t~!M 9~'* 0,,- Ar*# zs'vvw(6JAz'/296TM____

LOCATIONJ: 1-wIALKDOWN ENGINEER SIGNATURE:-

?tNAGER OF THE WALKI)OWN ENGINEER S IGNATURE:_____________

OTHERS ON YVAWSWUMN: (~'U) ',.../

r"Spoe-jor- TremM z" He Nah L=9Aa+/-n Ogeri-ntrpr'g 1 Major Concrete Crack 0 99 0 2 ,Spalliq or Scaling Concrete 03 a Ii Rebar ExpoSure 03 CS 0 Rebar Corrosion, 03 M 03 Water intrusion 0 im 0 6 water Stain 0) o a 7 Rust Stain 0 o3 es Disintegrating Concrete 0 g 03 9 Structural Sectlemenc 03 99 0 Disrorted Structural Member 0, 0 03 No:iceable Block Wall Defect (3 13 9

.o.iceable Structural Steel Defect aw a 0.

CONDTION/PROBLEMS NOTED ODING WALKOOWN AND ACTIONS INITIATED (1256/S3) EI-1

36:320 la/L3t/060)7 Nov 6, 1998 17 R Structural Walk-down Reoor Inside the drvwell

Background:

Under the requirement of 'The structural monitoring plan", GPUN shall perform a structural inspection inside the drywell during every re-fueling outage. The scope of the inspection is to visually examine the condition of the supporting frames, the connections, the surface of the drywell, the general out-look of the pipe and equipment supports, the concrete condition at elevation 10'. To some extent, the temporary loading condition including the rigging, the radiation shielding, the location of the temporary equipment loading on the existing structural elements are also inspected.

During this inspection on September 30, 1993, the engineer used the 16R walk-down report and compared to the current condition. The engineer went through elevation 46', 23' and 10' but not elevation 82' on top of the biological shield wall due to the access unavailability at the time of this inspection. Since there was no activity on el. 82', the engineer believed that inspection to that location was not important. The star truss and the reactor vessel stabilizers are massive and therefore a development of unaware structural defect is not likely to happen on elevation 82'.

Results of the 17R inspection:

(1) The surface of the drywell looked in good material condition. There was no sign of corrosion, crack or other structural defects.

(2) The radial beams and the secondary beams for the platforms are in good shape. The engineer also checked few bolted connections and found no evidence of 'structural defect or failure'.

(3) The engineer did not observe any temporary over load that may fail the existing structural elements.

(4) On elevation 10', the engineer inspected the reactor pedestal fiom the room underneath the Rx vessel, and the floor condition. They were all in good condition. The two cutout areas at the curb were dry although standing water at few locations was presented at the tinte of this iospection.

As a result of this 17R walk-down, the engineer concluded that the structural adequacy inside the drywell was ensured.

10/183/06 )7:36:30 SA44f~ AW"~94 A 7ev

• jg.

1)0/13106 07:36:30 TO-- 54,041 -0 A-V<4 &* tý 4%~. 4~'

7~#1 ,004VMe.~

~pws-

/*%~ A.yAVdGd

-4 I. ..

.0 sea A-AVA OL.4 **e.v

i01Z8106 07:36:30 iý- 04L41 -o0r~c~wd MrM4.V*46 2 f i##SzP~

Ii p /

I it I AO _ __ _ __ _

40vaaW i3' I

SeecW 4*,oW -w ~9 sbf

540,41i -0 z Attachment 7.2 Oyster Creek Trench Pump Out Schedule (oae- pagej nijoi.

A41b"4 f~g~ 2-OYSTER CREEK TRENCH PUMP OUT Trench Level (Top Level of of Floor to Vacuum Water in Water A Trough B Trough C Trough D Trough Running Vacuum 1-8 Sump Date Time Level) Level Level Level Level In Trench Container Water Level Notes 24" down from top of 1012112006 10:45 No sum p Manually_________________

Manually drained 1.8 Sump, Sump inspected, no obvious 1012112006 11:55 holes, debris In comers Vacuum Pump Off, only Input 1012112006 12:00 V-6118"lieNo 0-- 1/4" 200 mlimmn 10121/2006 16:40 1V6-6 112" No 8" Vacuum Pump Off 10121/2006 16:45 No Water Yes 8" Started Vacuum Pump 10/21/2006 17:15 No W ater No No 21n2e 2 112" Not Vacuu m Not Vacuum hose disconnected, 1012112006 21:51 11'- 112" Dry 1116" 112" Dry No Measured water not being removed 2 5/5' before Not Vacuum container emptied, 10121/2006 22:30 V- 6 1/2" Yes emptying Measured vacuum restarted Time noted on stop watch 1 114" resulting In 1 1/4" level In Dry/No before vacuum container was 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 1012212006 2:15 Water Dry 1116" 2" 1116" Yes emptying 13" 23 minutes wimn vacuum pump oTn for is minutes, water was observed; however, rate at which water Water was entering trench has visible In slowed. Vacuum pump lowest restarted after this 10/22/2006 2:30 point I No I observation.

wir, vacuum pump ofr for 1I minutes, I drop of water was observed; new hose to 1-8 Sump added for CRD drives, Dry/No 3" did not no flow. Flow from 2 112 pipe 10/22/2006 10:32 Water Dry 112" 1" 114" Yes empty 19" still about 200ml.

Under vessel work (pulling Dry/No 3" did not tubes) Is getting water In the 10122)2006 13:15 Water Dr 1/2" 718" 1/4" Yes empty 21.5" area.

Dry/No 3" did not 10/23/2006 4:30 Water 3" 3.5" 4" 3 114" Yes empty 36" Dye added to trough Vacuum ran all night long, Is Dry/No Did not No dye in not turned off. No sign of dye 1012312006 9:40 Water 2 1/2" 2 314" 3" 2 1/2" Yes look sump migration.

r~- s4~,o4~j A rTc /1. - . 7-7~A~

Dry/No Did not No sign of dye in sump or 10/2312006 12:09 Water 2" 2 314" 3 114" 2 112" No look 31" trench Dry/No 3" did not Dye visible past pipe plug in 10/23/2006 16:45 Water 1 718" 2 518" 3" 2 112" NO empty 32 112" quad a and in sump.

Looked at pipe plugs Dry/No 3" did not with no Removed pipe plugs, flushed 10/23/2006 21:20 Water 2" 2 1/2" 3" 2 1/2" No empty conclusion trough.

- - a - -L

IEq. 544oW'-oZ-

.1--f,-ver7,3 Pik o 1--/13 Attachment 7.3 Chemistry Analysis Report Includes printout of embedded file containing BWXT report (Lji* Pages)

I-rr,4_- lqe~J fW OC Drywell Chemistry Sample Results and Analysis Rev 6 Back2round In 1986 two trenches were excavated in Bays # 5 and 17 at elevation 10' 3" of the Drywell to allow access to the interior surface of the Drywell shell in order to perform ultrasonic testing measurements and to collect core samples. At the time, the exterior of the Drywell shell at that elevation was inaccessible because it was filled with sand.

During a planned inspection during 1R21 standing water was observed in the Bay # 5 trench. No standing water was observed in the Bay # 17 trench. An initial sample of approximately two liters of that standing water was obtained on October 18, 2006 at 02:50 to determine if the source of water could be determined by on-site analysis. The on-site analysis of this initial sample was an isotopic analysis only versus chemical analysis. The concrete above the surface of the water was dry. After removing two liters of water from the Drywell Bay #5 trench and lowering its level, the water returned to its initial level. Subsequent discussions identified that additional analyses would be required in order to identify the source of water in the trench.

On October 19, 2006 at 02:05, both the Drywell Bay #5 trench and a 1-8 Drywell Sump local sample (Sample #6 or BWXT RACL #0610012-06) were obtained. These samples were counted on-site for isotopic analysis.

The following night shift, October 20, 2006 at 00:20, the Drywell Bay # 5 trench (Sample #4 or BWXT RACL #0610012-04) and the Drywell trough (Sample #2 or BWXT RACL #0610012-02) were sampled at 00:20 for off-site analysis by GPL Laboratories. iOn-site analysis of these samples consisted of chlorides, sulfates, isoiopic activity, pH, conductivity and molybdate. Due to the high activity levels of these samples, two of these samples were decanted to prepare for shipment at a lower dose rate. This was challenged internally and the decision was made to ship those same samples out again without decanting in a smaller volume to ensure a representative sample for all analysis.

Later on October 20, 2006 at 18:20 samples were obtained from the Drywell Bay # 5 Trench (Sample #3 or BWXT RACL #0610012-03) and the Drywell trough (Sample #1 or BWXT RACL #0610012-01), later at 19:15 a sample of Drywell Control Rod Drive (CRD) leak (Sample #5 or BWXT RACL I

5.4(A4'jt, -c, --

.,*,1r* I'C4 3,-1"

1. 0610012-05) also was obtained for analysis. It was determined that off-site analysis for elemental analysis that could not be performed at Oyster Creek would also be required for these samples. These three samples were combined with the new aliquots from the three previously shipped samples so that no interlaboratory bias would be seen in the data.

Therefore, six sets of two samples each were sent to BWXT labs on October.

21, 2006 for analysis. The report of that analysis is found in Attachment 1.

All samples for analysis by BWXT were prepared by one chemist to reduce the chance of error and no decanting was performed. It is for those reasons that only the BWXT samples should be used for outside vendor data analysis.

2

Summary of Data RACL Chain-Constituents Date Time of-Custody pH pH Isotopes Tritium Iron Copper Zinc Nickel Units XX/XX/XX YY:YY none none uCi/mL uCi/mL ug/L ug/L ug/L ugIL Samples ________________ §1Ijf <- <-

Mn-54: 2.23e-4 Co-58: 5.91e-5 Fe-59: 1.01e-4 Co-60: 9.07e-5 Numerous Zn-65: 2.04e-5 Reactor Water Dates, See Mo-99: 2.82e-5 (Base) Notes Cs-137: none 1.11E-02 0.874 0.072 1.87 0.08 Numerous Condensate Dates, See (Base) Notes Mn-54:1.17e-7 29.928 0.142 0.084 <0.032 Numerous Feedwater Dates, See (Base) Notes 3.46 0.016 0.44 0.017 Reactor Bldg Closed Co-60: 4.09e-6 Cooling Water 9/6/2006 9:00:00 Cs-134: 8.25e-7 (Base) AM, See Notes 9.52 Cs-137:1.28e-5 245 28 Turbine Bldg Closed Cooling Water 9/5/2006 9:00:00 (Base) AM, See Notes 9.49 Cs-1 37: 2.32E-06 79 221 I H 3

Constituents Date Time Cobalt Conductivity Sulfates Nitrates Chlorides Calcium Potassium Fluoride Magnesium Chromium Units XX/XX/XX YY:YY ug uS/cm uL uL ug/L u/L Samples ._____m________ 7. . - . ..... _..

Reactor Numerous Dates, Water (Base) See Notes 0.061 0.5-1.1 0.1 Condensate Numerous Dates, (Base) See Notes <0.528 0.063 <0.2 <0.3 <0.4 Feedwater Numerous Dates, (Base) See Notes 0.053 Reactor Bldg Closed Cooling 9/6/2006 9:00:00 Water (Base) AM, See Notes 600 1000 900 " < 5000 Turbine Bldg Closed Cooling 9/5/2006 9:00:00 Water (Base) AM, See Notes 1030 2930 1360 < 5000 (N

4

Constituents Date Time Molybdate Sulfur Trace Elements Notes Units XX/XX/XX YY:YY m___

Sa 77-77-7 77...7,*....

p esam.ples. "..................... ... ...*...............

Nickel, Copper, Iron, Zinc data is the average of 5 September samples. Chlorides and Sulfates data is for October. Isotopic &

conductivity data from September Reactor Water Numerous Dates, 15, 2006. Tritium Data from (Base) See Notes October 13, 2006.

Cobalt, Copper, Iron, Nickel, Zinc data is the average of 5 October samples. Sulfates, Nitrates, Chlorides data is the average of Condensate Numerous Dates, the last 4 samples. Isotopic &

(Base) See Notes Conductivity Data from 9/12/06.

Copper, Iron, Nickel & Zinc data is the September average for these Feedwater Numerous Dates, samples. Conductivity Data from (Base) See Notes 9/1 2/06.

Reactor Bldg Closed All data from 9/6/06 sample except Cooling Water 916/2006 9:00:00 Benzotriazole: Total Gamma is from 10/18/06 (Base) AM, See Notes 371 39 sample.

Turbine Bldg Closed All data from 9/5/06 sample except Cooling Water 9/5/2006 9:00:00 Benzotriazole: Total Gamma is from 10/20/06 (Base) AM, See Notes 389 29 sample.

~rj 5

RACL Chain-Constituents Date Time of-Custody pH Isotopes Tritium iron Copper Zinc Nickel BWXT BWXT @ 21.2 Oyster Units XX/XX/XX YY:YY Assigned deg C Creek pCi/mL pCi/mL ug/L ug/L ug/L ug/L Mn-54: 9.74e+0 Sample #1 - Co-60: 3.98e+0 Drywell Trough 10/20/06 18:20 0610012-01 7.02 7.50 Cs-I 37: 3.00e+0 1.93E+03 2900 38.2 571 29.2 Mn-54: 7.97e+2 Co-58:1.91e+1 Co-60: 4.1 le+3 Sample #2 - Zn-65: 1.48e+2 Drywell Trough 10/20/06 00:20 0610012-02 7.43 7.95 Cs-137: 3.07e+1 7.95E+03 41500 426 7350 231 Sample #3 -

Drywell Bay # 5 Co-60: 2.60e+0 trench 10/20/06 18:20 0610012-03 8.40 9.30 Cs-137:1.66e+1 5.51E+03 1720 43.2 136 13.2 Sample #4 -

Drywell Bay # 5 trench 10/20/06 00:20 0610012-04 10.21 10.35 Cs-137:1.64e+1 5.63E+03 1600 49.3 235 12.3 Mn-54: 6.55e+1 Co-58: 5.56e+0 Sample #5 - Co-60: 2.84e+1 Drywell CRD Leak 10/20/06 19:15 0610012-05 6.35 6.19 Zn-65: 3.18e+1. 7.47E+03 244 10.7 348 17.8 Mn-54:1.17e+2 Co-58: 2.15e+1 Fe-59: 4.45e+0 H Co-60: 6.19e+1 Zn-65:1.60e+1 Sample #6 - Mo-99: 1.97e+0 Drywell 1-8 Sump 10/19/06 2:55 0610012-06 7.34 7.62 Cs-137:1.06e+1 4.85E+03 199 597 749 2.9 6

RACL Chain-Constituents Date Time of-Custody Cobalt Conductivity Sulfates Nitrates Chlorides Calcium Potassium Fluoride BWXT Units XX/XX/XX YY:YY Assigned ug/L uS/cm ug/l ug/L ug/L ug/L Iu/L Sample #1 -

Drywell trough 10/20/06 18:20 0610012-01 3.0 150 19900 3200 4530 494 Sample #2 -

Drywell trough 10/20/06 00:20 0610012-02 33.3 104 15000 3500 < 2000 15700 1780 Sample #3 -

Drywell Bay # 5 not trench 10/20/06 18:20 0610012-03 detected 656 230,000 14600 83500 29400 Sample #4 -

Drywell Bay # 5 trench 10/20/06 00:20 0610012-04 1.9 672 228,000 13600 96600 29800 Sample #5 -

Drywell CRD not Leak 10/20/06 19:15 0610012-05 0.339 6.32 6700 700 detected 111 Sample #6-Drywell 1-8 Sump 10/19/06 2:55 0610012-06 0.178 151 171,000 16,300 1780 534 7

RACL Chain-of-Constituents Date Time Custody Magnesium Chromium Molybdate Sulfur Notes Units XX/XX/XX YY:YY BWXT Assigned mg/L ug/L Sample #1 -

Drywell trough 10/20/06 18:20 0610012-01 not detected Sample #2 -

Drywell trough 10/20/06 00:20 0610012-02 <15 2850 Sample #3 -

Drywell Bay # 5 trench 10/20/06 18:20 0610012-03 41700 Sample #4 -

Drywell Bay # 5 trench 10/20(06 00:20 0610012-04 < 15 42700 Sample #5 -

Drywell CRD Leak 10/20/06 19:15 0610012-05 not detected Sample #6 -

Drywell 1-8 Sump 10/19/06 2:55 0610012-06 1460 8

" 5Z

• 4604 - Z.

1q.T-jfe'*P7 7 Analysis of Spreadsheet Data Chemistry was asked to determine the source of water in the Drywell Bay #5 trench. Following is an analysis of in-house and vendor laboratory data.

1. The Reactor Building and Turbine Building Closed Cooling Water (CCW) systems at Oyster Creek are treated with a molybdate solution (-375 ppm).

The absence of molybdate (< 15 ppm) in the Drywell samples indicates there is no leakage of CCW into these samples. (Note: One cannot measure a zero value for a parameter. There is a Lower Limit of Quantification. For molybdate, that value is < 15 ppm.) This result indicates there is no significant leak from the CCW system to the trough or the trench.

2. The tritium data from the six samples range from 1.95E+3 to 7.95E+3 pCi/mL. Since the tritium level is higher in the trough than the trench, there is no direct rapid communication between the trough and trench.

3. Between 00:20 and 18:20 on October 25, 2005 chloride and sulfate concentrations in the trough decreased. This indicates that impurity concentrations in the trough were diluted most likely from the CRD leakage during the time period between samples because the water in the trough did not have time to pick up impurities. During the same time period, there was no dilution in the trench.

4. Between the two time periods of 00:20 and 18:20 the water in the trough is diluted while the water in the trench is relatively constant as indicated by the relatively constant values for chloride, sulfate, calcium and potassium in the two trench samples. This conclusion is also based upon copper, zinc and nickel data. This also supports the findings in No. 2 and 3 above that there is no free flow of water between the trough and the trench during that 18-hour time period.

5. The first sample taken from the trough showed the presence of short-lived radionuclides as well as a peak at 511 keV. The presence of short-lived radionuclides and a 511 keV peak in the trough sample and their absence in the trench samples indicates that the trough water is fresher and the trench water is "older." The 511 keV peak is due likely to fluorine-18 that has a 1.8-hour half-life. The trench samples are four orders of magnitude lower in activity than the trough samples. This indicates the water in the trench is not refreshed with short-lived radionuclides, as is the water in the trough. This is also consistent with No. 2 above in terms of lack of direct rapid communication from the trough to the trench.

6. The pH values are consistent with other chemistry values. Elevated pH in the trench is the result of high levels of calcium that the water picked up as a result of it being in contact with concrete for a longer time. Calcium in water 9

7EP 4 6 049 -o7-2 4 If A VTr 7. 3 raises its pH. The first sample taken from the Bay 5 trench on October 19 had a pH of 10.72. This elevated pH is consistent with water being in contact with concrete for a relatively long time.

7. Low iron in the trench sample indicates there is minimal carbon steel corrosion in the vicinity of the trench.

8. On October 23, 2006 at 0438 sodium fluorescein dye was added to the trough.

At approximately 09:00 on October 25, water was spotted in the Drywell Bay 5 trench. The = 30 mL of sample had Mn-54, Co-60 and Cs-137 present along with fluorescein.

A second sample, consisting of 100 mL of water obtained October 26, also showed Mn-54, Co-60 and Cs-137. It too was positive for fluorescein but was more dilute than the previous day's sample. These two results indicate that water is migrating, albeit slowly, from the trough where the fluorescein solution was added on Monday, October 23, to the trench.

CONCLUSION The source(s) of water in the trench cannot be conclusively determined from chemistry analysis. We can conclude that it is not the result of CCW leakage as there is no evidence of closed cooling water corrosion inhibitor in the trench. Furthermore, it is not the direct result of recent reactor coolant leakage because there are no short-lived radionuclides in the trench samples. It is also unlikely that the source of water is due to an external source.

The radionuclides present in the trench water are indicative of CRD water that has been allowed to decay such that only longer-lived radionuclides are present in the trench samples. The difference between the radionuclides present in the trough and the trench is due to the tortuous path the water takes migrating from the trough to the trench.

Migration of water from the trough to the trench has a relatively long transit time as evidenced by the fact that there are no short-lived radionuclides in the trench. The two samples containing dye indicate that water is migrating, albeit slowly, from the trough where the fluorescein solution was added on Monday, October 23, to the trench.

Therefore, the most probable source of water in the Bay 5 trench is Control Rod Drive water.

Preparer/Reviewers:

Michael Ford Oyster Creek Robert Artz Oyster Creek 10

1?.5 460 D"4 A-r~cH'IJ~r7, MA7V.CAl Fý4f 12 Scott Giacobbe EXELON Power Labs John Diletto EXELON Power Labs Tom Wait EXELON Power Labs David Morey EXELON Corporate Chemistry 11

ATTACHMENTS - BWXT Examination of Water Samples from Oyster Creek Oyster Creek Report.pdf - Michelle Mura (Amergen) e-mail to Rick Devault (BWXT) dated October 21, 11:23 pm r.., , .-.- *... . l .. *gie .. .. ,I __.___, . A.-- . .. . -W*:,'*...* . ...

Cen. OAMWI3tsý~m.t DAtft~bsti itPd, Ndtue*ftt;dý teOarta obtu*o LeWMI y

sublft Oytrce~w amswo Per proposal number RACL-O57 section 2.4 ICP Analysis, the elements that can be eliminated from the list to be analyzed per the project team (J. ORourke) are tin, barium, A

cadmium, silver, arsenic, mercury, selenium, and vanadium. I willverify with the team the need for chloride, fluoride, and sulfate. I understand that these analyses would not te able to be performed until next week. Thank you Michelle R. Mum OpJftf Crek GmraSt Dativ Pilo~nPfI'woa Chesnw bhoqg609.971-4070 0qff 60941yS-y62

-j A~.Ib ~2 4 ~ Ec* U~11~AA~J ~ ~f~i Ii~i S 12

Ar-Tb-s 2 3M BWXT $ervices, Inc.

To: John Diletto, Exelon Power Laboratory From: Kevin Hour, BWXT Services, Inc.

Date: October 22, 2006 Re: Examination of Water Samples from Oyster Creek Ref: Rev. 0 Introduction Per Exelon Power Lab's request, BWXT Services (BWXS), Inc. Lynchburg Technology Center (LTC) was to provide expedited service to analyze two water samples from the Oyster Creek Nuclear Power Station. This work scope was authorized under Exelon Power Labs Purchase Order 00059971-00001, authorization 2006100258, dated October 20, 2006. This work was designated safety-related and was conducted in accordance with Radioisotope and Analytical Chemistry Laboratory (RACL) Quality Assurance Plan.

BWXS received the shipment around 7:00 pm on October 21 and the LTC HP released the specimens to RACL personnel around 8:00 pm. Upon opening of the two packages, RACL personnel found a total of six plastic bags and each one of them had a unique description and identification. Inside each bag, there were two 125 ml plastic containers (one is preserved and one is not). Since this was not consistent with purchase order specifications, RACL personnel contacted the reactor site people.

Michelle Mura, a chemist at Oyster Creek, confirmed for us that all six samples needed to be analyzed. Based on this instruction, RACL personnel proceeded with the preparation. Further discrepancies between the purchase order and the BWXS proposal were identified; both sides discussed and reached the following conclusion (documented in an email from Michelle Mura to Rick Devault, dated October 21 11:23pm).

kic. a Mc~ermw aoconny BWX TadhnoJO~imB

Memo Hour to Diletto Examination of Water Samples from Oyster Creek October 22, 2006

1. The following elements are removed from the list of elements to be analyzed: tin, barium, cadmium, silver, arsenic, mercury, selenium, and vanadium.

2. Per the Purchase Order, chloride, fluoride, and sulfate are to be analyzed. BWXS did not mobilize a qualified analyst to perform this task as BWXS did not include this task in its proposal. Either the analysis is to be performed at Oyster Creek or BWXS will perform the analysis in the coming week.

BWXS management decided to proceed with the agreed upon statement of work and will submit revised proposal later to Exelon Power Labs to revise its Purchase Order.

Methods and Test Results Specimen Identification and Traceability.

Six specimens were received and their identifications are summarized as follow:

Oyster Creek Identification RACL Chain-of-Custody Dry Well Trough (10/20/06 18:20) 0610012-01 Dry Well Trough (10/20/06 00:20) 0610012-02 Dry Well Hole#5 Bay (10/20/06 18:20) 0610012-03 Dry Well Hole #5 Bay (10/20/06 00:20) 0610012-04 Dry Well CRD Leak (10/20/06 19:15) 0610012-05 Dry Well 1-8 Pump (10/19/06 02:55) 0610012-06 For each specimen, there were two 125 ml plastic containers (one was preserved with nitric acid and designated as "A"sample and one was not and designated as uB" sample). An aliquot of specimen was taken from these bottles for various analyses and specimen identification was written on the bottle or vial to preserve the specimen traceability.

pH Measurement pH measurement was conducted in accordance with LTC Technical Procedure TP-312, Rev. 11 "Measurements of pH in Soil and Water Based on SW846 Methods:

9040B (Water) and 9045C (Soil/Waste). Unpreserved specimens show pH ranging from 6.35 to 10.21 and preserved specimens (with nitric acid) are verified to have pH below 2. Detailed results are shown in Appendix A.

Gamma Scan Due to the limited amount of material received, only 20 cc of specimen was used for gamma scan. All six non-preserved specimens were prepared in accordance with LTC Technical Procedure TP-398, Rev. 8 "Sample Dissolution, Actinide Separations and Gamma Spectroscopy Preparation. All six specimens were counted in accordance

5460~6A-ewr t;V.,4Trl4,, 7.3 Memo Hour to Diletto Examination of Water Samples from Oyster Creek October 22, 2006 with LTC Technical Procedure TP-852, Rev. 2 "QC Operations, Calibration and Sample Counting Procedure for the Genie 2000 Counting System" for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Cobalt-6,0, manganese-54 and cesium-137 are the main isotopes identified in the specimens.

Detailed results are shown in Appendix B.

ICP/MS Per the discussion with customer, the unpreserved specimens were used for calcium and potassium analysis and the preserved specimens were analyzed for the remaining metals. All specimens were prepared in accordance with LTC Technical Procedure TP-1 474, Rev. 1 "Microwave Assisted Acid Digestion of Aqueous Samples, Sediments, Sludge, Soils & Oil Extracts (SW 846 3015, 3051)". Analysis was performed in accordance with LTC Technical Procedure TP-873, Rev. 1 "Inductively Coupled Plasma-Mass Spectrometry SW846-6020A". Detailed results are shown in Appendix C..

Tritium Analysis An aliquot was taken from each of the six unpreserved specimens for tritium analysis.

Specimens were prepared in accordance with LTC Technical Procedure TP-642, Rev.

3 "Analysis of Tritium Samples" and counting was conducted in accordance with LTC Technical Procedure TP-619, Rev. 2C "General Counting Procedure for the Model 2550TR/LL Liquid Scintillation Counting System". Detailed results are shown in Appendix D.

Independent Review and QA Review All data were subjected to an independent technical review. Additionally, the Laboratory QA Manager performed a review of the project and concluded that it was performed in accordance with customer's purchase order requirement except for those discrepancies documented in the Introduction section of this report. A certificate of conformance is shown in Appendix E.

ý6qý-ol- hrAcvAs~ PmP- -7 Memo Hour to Diletto Examination of Water Samples from Oyster Creek October 22, 2006 Summary pH measurement, gamma scan, elemental analysis, and tritium analyses were conducted on six water specimens removed from the Oyster Creek Nuclear Power Station. If further information regarding this data report is required, please contact any of the following personnel.

Kevin Y. Hour (434)-426-6881 Kevin Bull (434) 426-6124 Virginia Gibson (434) 369-6258 Rick Devault Project Engineer

r-?- 540p4ý-c-TT 4-e-167 A

to Diletto Oyster Creek Memo Hour of Water Samples from Examination 2006 October 22, Appendix A pH Measurements

5ý4,,0'".- Olz.

TFP-31! '/2 2 ,

,4j-dcHAqew4r 1.3

. ?me g LOGBOOK #: LB763 q pH Worksheet 9040B/9045C/Method 150.1 Rev. 3-83 I pH Meter ID:

I- o04- 0011 Intr. Seria No. 0 11.033 I Temp. Compensated: (ONo Analysis DatejTime: (Of P-0 Thermometer 11):

(0 02"'ý Calibration Due Date: 'A' S01 os:--0-3 Balance W Calibration Due Date:

I Buffer 4 FUt MFG O

Lot # " DateHEx.

I.II;o10sc o

. VSloVe Value

-ON Temp.

all~ac, I 7Rerun(!C 0- -310" o100 a I Temperature  % Moisture <20% (Y/N) Mass of I Sample H) 0C pH Value , 90 Sample Vol. Water OP,&OI L4- 4N iA,,/--

I o 2toi*-8367.*

4II,O__

o ,-_  ?*m ____i __-I_

I Chk Buffer (CCV) .----

U I

I I Final Buffe~r (CMv (Duplicaft I In20 samples required) e i. A't 7 0 0 1 -* -

iol Exp.

I QC True Value Element Batch ID)

Ii,70 Range ,- ,_ Date Rec. _l_____

Notes: WNA Gtlbfofio0 Otlri nertirrmd wilt, O,1r-Inog am I A5.Z;ý 11)100. P&Ad 6&Sev- L1, 4S

.... , - 1 ...

64AAIML fx 1i~f~Sw Performed by:"/A,N Al."k C Date/Time: 1qP406 0300 I 1A Reviewed by:, &I Va'f Date:

/ f I 000023

tvL 5 4-L,Q4ki -o -

74fcjqA'fe$/T1 7-3 Memo Hour to Diletto M¶C~PKZ 4 2w Examination of Water Samples from Oyster Creek October 22, 2006 Appendix B Gamma Scan Results

BWXT Services, Inc. Gamma Data Report for Oyster Creek lO2/202oo6 SixG 0610012 Customer NmLS Preparation Analydo Sample ID Sample ID Method 2 Sigma U--tably MDA Date Date Dry Well Trough 10/20/06 18.20 0610012-01 EPA901.1 9.74E+00 1.34E+00 9.97&-01 pCi/m-L 10/21/06 10/22/06 Dry Well Trough 10/20/06 18:20 0610012-01 EPA901.1 MDA NA 1.03E+00 pci/mL 10/21/06 10/22/06 Dry Well Trough 10/20/06 18".20 0610012-01 EPA901.1 MDA NA 1.56E+00 pai/mL 10/21/06 10/22/06 Dry Well Trough 10/20/06 1M20 0610012-01 EPA901.1 ca-0 3.98E+00 9.46E-01 9.24M.O1 pci/mL 10/21/06 10/22/06 Dry Well Trough 10/20/06 18:20 0610012-01 EPA9O1.1 Zn-65 MDA NA 2.M3E+00 pcl/mL 10/21/06 10/22/06 Dry Well Trough 10/20/06 18:20 0610012-01 EPA901.1 Mo-99 MDA NA 6.43E-01 Pqi/mL 10/21/06 10/22/06 Dry Well Trough 10/20106 15:20 0610012-01 EPAg1.1 Co-137 3.00E+00 7.00B-01 &01M-01 10/21/06 10/22/06 Ca-D7 pCi/ndL Dry Well Trough 10/20/06 00:20 0610012-02 EPA901.1 7.97E+02 620E+01 1.23E+01 10/21/06 10/22/06 Pci/niL Dry Well Trough 10/20/06 00:20 0610012-02 EPA901.1 CO-58 1.91E+01 728E+00 1.15E+01 10/21/06 10/22/06 Dry Well Trough 10/20/06 00:20 0610012-02 EPA901.1 Fe-59 MDA NA 2.69E+01 pCi/mL 10/21/06 10/22/06 Dry Well Trough 10/20/06 00:20 0610012-02 EPA901.1 Co-60 4.11E+03 9.81E+00 10/21/06 10/22/06 1.32E+02 pCi/mL Dry Well Trough 10/20/06 00.20 0610012-02 EPA901.1 Zjw-65 1.48E+02 Z14E+01 3.19E+01 10/22/06 pCi/ -L 10/22/06 Dry WeUlTrough 10/20/06 00:20 0610012-02 EPA9O1.1 Mo-99 MDA NA 4.38E+00 pCi/niL 10/21/06 10/22/06 Dry Well Trough 10/20/06 00:20 0610012-02 EPA901.1 C&-137 3.07E+01 5.32E+00 7.73E+00 10/21/06 10/22/&6 pCi/niL Dry Well Hole #5 Bay 10/20/06 18:20 0610012-03 EPA901.1 Mn*54 MDA NA 8.93E-01 10/21/06 10/22/06 pCi/niL Dry Well Hole #5 Bay 10/20/06 18:20 0610012-03 EPA9O1.1 MDA NA 7.17E-01 10/21/06 10/22/06 Dry Well Hole #5 Bay 10/20/06 18"20 0610012-03 EPA901.1 Fe-59 MDA NA 1.38E+00 pCi/niL 10/21/06 10/22/06 Dry Well Hole #5 Bay 10/20/06 18:20 0610012-03 EPA9On.1 Co-60 7.06E-01 7.03B-01 Z60E+00 10/21/06 10/22/ 06 Zn-65 pci/mL Dry Well Hole #5 Bay 10/20/06 18:20 0610012-03 EPA901.1 MDA NA 1.78E+00 10/21/06 10/22/06 pci/niL Dry Well Hole #5 Bay 10/20/06 18:20 0610012-03 EPA901.1 Mo.99 MDA NA 8.08E-01 10/21/06 10/22/06 Dry Well Hole #5 Bay 10/20/06 18:20 0610012-03 EPA9011 C9-137 1.66E+01 1.47E+00 9.878-01 pCi/mL 10/21/06 10/22/06 r

Dry Well Hole #5 Bay 10/20/06 00:20 0610012-04 EPA901.1 Mn-54 MDA NA - 9.928-01 10/21/06 10/22106 Dry Well Hole #5 Bay 10/20/06 00:20 0610012-04 BPA9O1.1 MDA NA 9.98E-01 10/21/06 10/22/06 EPA901.1 pci/niL Dry Well Hole #5 Bay 10/20/06 00.20 0610012-04 Fe-59 MDA NA 1.71E+00 10/22/06 EPA9OI.1 10/21/06 Atj pCi/mi?

Dry Wel Hole #5 Bay 10/20/06 00:20 0610012-04 (X)-60 MDA NA 2040+00 10/21/06 10/22/06 Dry Well Hole #5 Bay 10/20/06 00:20 zn-65 jpCI/nLr 10/21/06 10/22/06 0610012-04 EPA901.1 MDA NA 2.02E+00

BWXT Services, Inc. Gamma Data Report for Oyster Creek 10/22/2006 SDG 0610012 Customer NENS PrepDa-I Analysis Sample ID Sample ID Method Emult 2 SAIPma Uaesrtiniy MDA Dkat Date Dry Well Hole #5 Bay 10/20/06 00:20 0610012-04 EPA901.1 M(>-9 MDA NA - 9.04"-01 pCi/mL 10/21/06 10/22/06 Dry Well Hole #5 Bay 10/20/06 O0-20 0610012-04 EPA901.1 Cs-137 1.64E+01 1.42E+00 7.9*E-01 pCi/mL 10/21/06 10/22/06 Dry Well CRD Leak 10/20/06 19.15 0610012-05 EPA901.1 MP_% 6-55E+01 5.66E+00 1.63E+00 pCi/mL 10/21/06 10/22/06 Dry Well CRD Leak 10/20/06 1915 0610012-05 EPA901.1 co-% 5.56E+00 1.10E+00 126"+00 p(-i/mL 10/21/06 10/22/06 Dry Well CRD Leak 10/20/06 19:15 0610012-05 EPA90"11 Fe-89 MDA NA 2.55E+00 pCi/mnL 10/21/06 10/22/06 Dry Well CRD Leak 10/20/06 19:15 0610012-05 EPA9O1.1 Co-60 2.84E+01 2.28E+00 1.13E+00 pCi/mL 10/21/06 10/22/06 Dry Well CRD Leak 10/20/06 19:15 0610012-05 EPA901.1 Zn-5 3.18E+01 3.78E+00 3.59E+00 pCi/mL 10/21/06 10/22/06 Dry Well CRD Leak 10/20/06 19:15 0610012-05 EPA901.1 Mo-99 MDA NA 7.99F-01 pCi/mL 10/21/06 10/22/06 Dry Well CRD Leak 10/20/06 19-.15 0610012-05 EPA901.1 Cs-137 MDA NA 1.77E+00 pCI/mL 10/21/06 10/22/06 Dry Well 1-8 Sump 10/19/06 02.55 0610012-06 EPA901.1 Mn1% 1.17E+02 1.03E+01 1.82E+00 pCi/mL 10/21/06 10/22/06 Dry Well 1-8 Sump 10/19/06 02:55 0610012-06 EPA901.1 Co-68 2.15E+01 2.46E+00 2.09E+00 pci/mL 10/21/06 10/22/06 Dry Well 1-8 Sump 10/19/06 02.55 0610012-06 EPA901.1 4.45E+00 2.74E+00 434E+00 pci/ML 10/21/06 10/22/06 Dry Well 1-8 Sump 10/19/06 0255 0610012-06 EPA9O1.1 6.19E+01 4.14E+00 1.24+00 pCi/mL 10/21/06 10/22/06 Dry Well 1-8 Sump 10/19/06 02:55 0610012-06 EPA9O1.1 1.60E+01 3.20*+00 4.14B+00 pQi/mL 10/21/06 10/22/06 Dry Well 1-8 Sump 10/19/06 0255 0610012-06 EPA9O.1 MO-99 1.97E+00 1.07E+00 1.70E+00 pcA/mL 10/21/06 10/22/06 Dry Well 1-8 Sump 10/19/06 02.55 0610012-06 EPA9OM.1 Cs-137 1.06E+01 1.73E+00 2.34E+00 pck/mL 10/21/06 10/22/06 X~kL~

eV- 5 -604A '1-O

-0 4 rr.4c f~e% '

Memo Hour to Diletto Examination of Water Samples from Oyster Creek October 22, 2006 Appendix C ICP-MS Results

a 1ooejVr& Analytical Chemistry B WXT Services, Inc.

INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ED: 0610012-01A DI Client ID: Dry Well Trough 18:20 Matrix: WATER Date Received: Level: LOW

% Solids: Sample WI/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL DI! Date Time Lithium 7439-93-2 84.4 ug/L U MS 84.4 10.00 10/22/2006 03:20:59 Boron 7440-42-8 39.0 ug/L B MS 4.0 10.00 10/22/2006 03:20:59 Sodium 7440-23-5 3040 ug/L MS 33.2 10.00 10/22/2006 03:20:59 Magnesium 7439-95-4 1430 ug/L MS 6.0 10.00 10/22/2006 03:20:59 Aluminum 7429-90-5 456 ug.L MS 7.5 10.00 10/22/2006 03:20:59 Silica 7440-21-3 999 ugtL MS 11.1 10.00 10/22/2006 03:20:59 Phosphorus 7723-14-0 89.5 ug/L MS 10.00 10/22/2006 03:20:59 Potassium 7440-09-7 521 ug/L MS 10.2 10.00 10/22=2006 03:20:59 Caldum 7440-70-2 3860 ug/L MS 376 10.00 10/22/2006 03:20:59 Titanium 7440-32-6 38.2 ug/L MS 1.0 10.00 10/22/2006 03:20:59 Chromium 7440-47-3 15.2 ug/L MS 0.611 10.00 10/22/2006 03:20:59 Iron 7439-89-6 2900 ug/L MS 19.2 10.00 10/22/2006 03:20:59 Manganese 7439-96-5 37.7 ugIL MS 0.911 10.00 10/22/2006 03:20:59 Cobalt 7440-48-4 3.0 ug/L MS 0.233 10.00 10/22/2006 03:20:59 Nickel 7440-02-0 29.2 ug/L MS 3.2 10.00 10/22/2006 03:20:59 Copper 7440-58 38.2 ug'L MS 1.7 10.00 10/22/2006 03:20:52 Zinc 7440-66-4 571 ug/L MS 92.1 10.00 10/22/2006 03:20:59 Strontium 7440-24-6 .45.1 ug/L MS 2.5 10.00 10/22/2006 03:20:59 Zirconium 7440-67-7 1.2 ug(L MS 0.222 10.00 10/22/2006 03:20:59 Molybdenum 7439-98-7 1580 ug/L MS 2.0 10.00 10/22/2006 03:20:59 Tin 7440-31-5 1.4 ug/L MS 0.158 10.00 10/22/2006 03:20:59 Antimony 7440-36-0 1.5 ug/L MS 0.267 10.00 10/22)2006 03:20:59 Barium 7440-39-3 8.7 ug/L MS 0.878 10.00 10/22/2006 03:20:59 MS 7440-33-7 11.1 ug/L 11.1 10.00 10/22/2006 03:20:59 MS Lead 7439-92-1 115 ug/L 0.967 10.00 10/22/2006 03:20:59 Qualifier Descriptions: U - Nop-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution Is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry z044.o41 - o-z-. 4-rf1#~t,-1(tr 7.3 INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-02A Client ID: Dry Well Trough 00:20 Matrix: WATER Date Received: Level: LOW

% Solids: Sample Wt/Voh: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/2212006 Analytical Analyte CAS No. Concentration Units C Qual M DL Dil Date Time Lithium 7439-93-2 42.2 uu/L U MS 42.2 5.00 10/22/2006 04:19:31 Boron 7440-42-8 121 ugIL MS 2.0 5.00 10/22/2006 04:19:33 Sodium 7440-23-5 8890 ug/L MS 16.6 5.00 10/22/2006 04:19:33 Magnesium 7439-95-4 7490 ug/L MS 3.0 5.00 10/22/2006 04:19".33 Aluminum 7429-90-S 5580 ug/L MS 3.7 5.00 10/22/2006 04:19:33 Siles 7440-21-3 10600 ug/L MS 22.2 20.00 10/22/2006 05:06:25 Phosphorus 7723-14-0 746 ug/L MS 5.6 5.00 10/22/2006 04:19:33 Potassium 7440-09-7 1710 ug/L MS 5.1 5.00 10/22o200 04:19"33 Caldum 7440-70-2 13500 ug/L MS 188 5.00 10/22/2006 04:19:33 Titanium 7440-32-6 529 ug/L MS 0.500 5.00 10/22/2006 04:19:33 Chromium 7440-47-3 226 ug/L MS 0.306 5.00 10/22/2006 04:19"33 Iron 7439-89-6 41500 ug/L MS 9.6 5.00 10/22/2006 04:19.33 Manganese 7439-96-S 497 ug/L MS 0.456 5.00 10/22/200" 04:19.33 Cobalt 7440-48-4 33.3 ug/L B MS 0.117 5.00 10/22/2006 04:19"33 Nickel 7440-02-0 231 ug/L MS 1.6 5.00 10/27/2006 04:19:.33 Copper 7440-50-8 426 ug/L MS 0.872 5.00 10/22=006 04:19:33 Zinc 7440-66-6 7350 ug/L MS 184 20.00 10/22/2006 05:06:25 Strontium 7440-24-6 160 ug/L MS 1.3 5.00 10/22/2006 04:19.33 Zirconium 7440-67-7 17.6 ug/L B MS 0.111 5.00 10/22/2006 04:19"33 Molybdenum 7439-98-7 5030 ug/L MS 1.0 5.00 10/22/2006 04:19-.33 Tin 7440-31-5 9.7 ug/L B MS 0.079 5.00 10/22/2006 04:19:33 Antimony 7440-36-0 6.1 ug/L B MS 0.133 5.00 10/22/2006 04:19:33 Barium 7440-39-3 73.7 ug/L MS 0.439 5.00 10/2212006 04:19.33 7440-33-7 7.1 ug/L B MS 5.6 5.00 10/22/2006 04:19-33 Lead 7439-92-1 1530 ug/L MS 0.483 5.00 10/22/2006 04:19.33 Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

BWXT Services, Inc. Radioisotope & Analytical Chemistry MLz 544&o4-Aý- O-L 4TC7'1 INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A

/

Sample ID: 0610012-03A Client ID: Dry Well Hole #5 Bay 18:20 Matrix: WATER Date Received: Level: LOW

% Solids: Sample Wt/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Quai M DL Dil Date Time Lithium 7439-93-2 42.2 ug/L U MS 42.2 5.00 10/22/2006 04:23:42 Boron 7440-42-8 578 ug/L MS 2.0 5.00 10/22/2006 04:23:42 Sodium 7440-23-5 52500 ug/L MS 16.6 5.00 10/22/2006 04:23:42 Magnesium 7439-95-4 580 ug/L MS 3.0 5.00 10/22/2006 04:23:42 Aluminum 7429-90-5 119 ugIL MS 3.7 5.00 10/22/2006 04:23:42 Sinea 7440-21-3 9380 ug/L MS 22.2 20.00 10/22/2006 05:10:25 Phosphorus 7723-14-0 98.1 ugtL MS 5.6 5.00 10/22/2006 04:23:42 Potassium 7440-09-7 26200 ugIL MS 5.1 5.00 10/22/2006 04:23:42 Calcium 7440-70-2 73000 ug/L MS 188 5.00 10/22/2006 04:23:42 Titanium 7440-32-6 0.500 ug/L U MS 0.500 5.00 10/22/2006 04:23:42 Chromium 7440-47-3 12.7 ug/L MS 0.306 5.00 10/22/2006 04:23:42 Iron 7439-89-6 1720 ugIL MS 9.6 5.00 10/22/2006 04:23:42 Manganese 7439-96-5 53.6 ug/L MS 0.456 5.00 10/22/2006 04:23:42 Cobalt 7440-48-4 0.117 ug/L U MS 0.117 5.00 10/22/2006 04:23:42 Nickel 7440-02-0 13.2 ugIL B MS 1.6 5.00 10/22/2006 04:23:42 Copper 7440-50-8 43.2 _ug/L B MS 0.872 5.00 10/22/2006 04:23:42 Zinc 7440-66-6 136 ug/L MS 46.1 5.00 10/22/2006 04:23:42 Strontium 7440-24" 2470 ug/L MS 1.3 5.00 10/22/2006 04:23:42 Zirconium 7440-67-7 1.0 ugIL B MS 0.111 5.00 10/22/2006 04:23:42 Molybdenum 7439-98-7 1960 ug/L MS 1.0 5.00 10/22/2006 04:23:42 Tin 7440-31-S 2.2 ugIL B MS 0.079 5.00 10/22/2006 04:23:42 Antimony 7440-36-0 6.0 ug/L B MS 0.133 5.00 10/22/2006 04:23:42 Barium 7440-39-3 16.0 ug/L B MS 0.439 5.00 10/22/2006 04:23:42 7440-33-7 5.6 ug/l. U MS 5.6 5.00 10/22/2006 04:23:42 Lead 7439-924 24.8 ug/L B MS 0.483 5.00 10/22/2006 04:23:42 Qualifier Descriptions: U - Nop-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution Is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry

-1"-

INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 301516020A Sample ID: 0610012-04A Client ID: Dry Well Hole #5 Bay 00:20 Matrix: WATER Date Received: Level:' LOW

% Solids: Sample Wt/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL Dil Date Time Lithium 7439-93-2 42.9 ug/L B MS 42.2 5.00 10/22/2006 04:28:01 Boron 7440-42-8 557 nu/L MS 2.0 5.00 10/22/2006 04:28:07 Sodium 7440-23-5 51300 ug/L MS 16.6 5.00 10/22/2006 04:28:07 Magnesium 7439-95-4 564 ug/L MS 3.0 5.00 10/22/2006 04:28:07 Aluminum 7429-90-5 199 ug/L MS 3.7 5.00 10/22/2006 04:28:07 Silica 7440-21-3 12900 uglL MS 22.2 20.00 10/22/2006 05:14:36 Phosphorus 7723-14-0 105 ug[L MS 5.6 5.00 10/2212006 04:28:07 Potassium 7440-09-7 26300 ug/L MS 5.1 5.00 10/22/2006 04:28:07 Calcium 7440-70-2 85300 ug/L MS 188 5.00 10/22/2006 04:28:07 Titanium 7440-32-6 2.2 ug/L B MS 0.500 5.00 10/22/2006 04:28:07 Chromium 7440-47-3 24.6 ugIL MS 0.306 5.00 10/22/2006 04:28:07 Iron 7439-89-6 1600 ugfL MS 9.6 5.00 10/22/2006 04:28:07 Manganese 7439-96-5 34.6 ug/L MS 0.456 5.00 10/22/2006 04:28:07 Cobalt 7440-48-4 1.9 ug/L B MS 0.117 5.00 10/22/2006 04:28:07 Nickel 7440-02-0 12.3 ug/L B MS 1.6 5.00 10/22/2006 04:28:07 Copper 7440-50" 49.3 nugL B MS 0.872 5.00 10/22/2006 04:28:07 Zinc 7440-66-6 235 ug/L MS 46.1 5.00 10/22/2006 04:28:07 Strontium 7440-24-6 2730 ug/L MS 1.3 5.00 10/22/2006 04:28:07 Zirconium 7440-67-7 0.528 ug/L B MS 0.111 5.00 10/22/2006 04:28:07 Molybdenum 7439-98-7 1890 ug/L MS 1.0 5.00 10/22/2006 04:28:07 Tin 7440-31-5 2A uglL B MS 0.079 5.00 10/22=2006 04:28:07 Antimony 7440-36-0 5.7 ug/L B MS 0.133 5.00 10/22/2006 04:28:07 Barium 7440-39-3 15.4 ug/L B MS 0.439 5.00 10/22/2006 04:28:07 7440-33-7 5.6 ug/L U MS 5.6 5.00 10/22/2006 04:28:07 Lead 7439-92-1 36.0 ug/L B MS 0.483 5.00 10/22/2006 04:28:07 Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry "tr . s441,, -ot *.,* cr/,q*,ew/

INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-05A DI Client ID: Dry Well CRD Leak Matrix: WATER Date Received: Level: LOW

% Solids: Sample Wt/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL DII Date Time Lithium 7439-93-2 42.2 ug/L U MS 42.2 5.00 10/22/2006 04:57:15 Boron 7440-42-8 13.4 B MS 2.0 5.00 10/22/2006 04:57:15 ug/L Sodium 7440-23-5 613 MS 16.6 5.00 10/22/2006 04:57:15 Magnesium 7439-95-4 136 ugtL ug/L MS 3.0 5.00 10/22/2006 04:57:15 Aluminum 7429-90-5 58.1 uWeL MS 3.7 5.00 10/22/2006 04:57:15 Silica 7440-21-3 103 ug/L MS 5.6 5.00 10/22/2006 04:57:15 Phosphorus 7723-14-0 44.1 ug/L MS 5.6 5.00 10/22/2006 04:57:15 Potassium 7440-09-7 194 MS 5.1 5.00 10/22/2006 04:57:15 Calcium 7440-70-2 333 ug/L MS 188 5.00 10/22/2006 04:57:15 Titanium 7440-32-6 0.872" ug/L MS 0.500 5.00 10/22/2006 04:57:15 Chromium 7440-47-3 2.6 ugWL MS 0.306 5.00 10/22/2006 04:57:15 Iron 7439-89" 244 ugL MS 9.6 5.00 10/22/2006 04:57:15 Manganese 7439-96-5 4.1 ugtL MS 0.456 5.00 10/22/2006 04:57:15 Cobalt 7440-48-4 0.339 nulL MS 0.i17 5.00 10/22/2006 04:57:15 Nickel 7440-02-0 17.8 nulL MS 1.6 5.00 10/22/2006 04:57:15 Copper 7440-504 10.7 ug(L MS 0.872 5.00 10/22/2006 04:57:15 Zinc 7440-66-6 348 ug/L MS 46.1 5.00 10/22/2006 04:57:15 Strontium 7440-24-6 1.8 ugIL MS 1.3 5.00 10/22/2006 04:57:15 Zirconium 7440-67-7 0.467 ugtL MS 0.111 5.00 10/22/2006 04:57:15 Molybdenum 7439-98-7 3.1 ug/L MS 1.0 5.00 10/22/2006 04:57:15 Tin 7440-31-5 0.778 ugtL MS 0.079 5.00 10/22/2006 04:57:15 Antimony 7440-36-0 1.4 ugtL MS 0.133 5.00 10/22/2006 04:57:15 Barium 7440-39-3 3.2 ug/L MS 0.439 5.00 10/22/2006 04:57:15 MS 7440-33-7 5.6 ug/L 5.6 5.00 10/22/2006 04:57:15 MS Lead 7439-92-1 40.9 ugL 0A83 5.00 10/22/2006 04:57:15 Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution Is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry r 9- 'S46 0 4A - .4TTr,,Ic t"'7 INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-06A Client ID: Dry Well 1-8 Sump Matrix: WATER Date Received: Level: LOW

% Solids: Sample Wt/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL DIU Date Time Lithium 7439-93-2 42.2 ug/L U MS 42.2 5.00 10/22/2006 05:01:11 Boron 7440-42-8 54.2 ug/L B MS 2.0 5.00 10/22/2006 05:01:17 Sodium 7440-23-5 29000 ug/L MS 16.6 5.00 10/22/2006 05:01:17 Magnesium 7439-95-4 54.2 ugIL MS 3.0 5.00 10/22/2006 05:01:17 Aluminum 7429-90-5 64.2 ug1L MS 3.7 5.00 10/22/2006 05:01:17 Silica 7440-21-3 426 ug/L MS 5.6 5.00 10/22/2006 05:01:17 Phosphorus 7723-14-0 24.5 ug/L MS 5.6 5.00 10/22/2006 05:01:17 Potassium 7440-09-7 492 ug1L MS 5.1 5.00 10/22/2006 05:01:17 Calcium 7440-70-2 1380 ug/L MS 188 5.00 10/22/2006 05:01:17 Titanium 7440-32-6 0.500 ug/L MS 0.500 5.00 10/22/2006 05:01:17 Chromium 7440-47-3 1.1 ug/L MS 0.306 5.00 10/22/2006 05:01:17 Iron 7439-89-6 199 ug/L MS 9.6 5.00 10/22/2006 05:01:17 Manganese 7439-96-5 35.5 ug1L MS 0.456 5.00 10/22/2006 05:01:17 Cobalt 7440-40-4 0.178 ug1L MS 0.117 5.00 10/22/2006 05:01:17 Nickel 7440-02-0 2.9 ug/L MS 1.6 5.00 10/22/2006 05:01:17 Copper 7440-50" 597 ugfL M& 0.872 5.00 10/22/2006 05:01:17 Zinc 7440-66-6 749 ug/L MS 46.1 5.00 10/22/2006 05:01:17 Strontium 7440-24-6 15.5 ug/L MS 1.3 5.00 10/22/2006 05:01:17 Zirconium 7440-67-7 0.117 ugtL MS 0.111 5.00 10/22/2006 05:01:17 Molybdenum 7439-98-7 38600 ug/L MS 10.2 50.00 10/22/2006 05:19:05 Tin 7440-31-5 0.883 ug/L MS 0.079 5.00 10/22/2006 05:01:17 Antimony 7440-36-0 0.894 ug/L MS 0.133 5.00 10/22/2006 05:01:17 Barium 7440-39-3 1.5 ug/L MS 0.439 5.00 10/22/2006 05:01:17 7440-33-7 5.6 ug/L MS 5.6 5.00 10/22/2006 05:01:17 Lead 7439-92-1 4.3 ug/L MS 0.483 5.00 10/22/2006 05:01:17 Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry

-n-e- Fq 30 INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-O1B D! Client ID: Dry Well Trough 18:20 Matrix: WATER Date Received: Level: LOW

% Solids: Sample Wt/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-22 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qua] M DL DIH Date Time Potassium 7440-09-7 494 ug/L MS 25.6 25.00 10/22/2006 06:01:12 Calcium 7440-70-2 4530 ug/L MS 939 25.00 10/22/2006 06:01:12 Comments:

Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry 3VL 54{o4'~-q-oi 1tr ,4tqi~eir Mt<CA1/4 f INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-02B DI Client ID: Dry Well Trough 00:20 Matrix: WATER Date Received: Level: LOW

% Solids: Sample Wt/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-22 Prep Date: 10/2212006 Analytical Analyte CAS No. Concentration Units C Qual M DL Dil Date Time Potassium 7440-09-7 1780 ugIL MS 25.6 25.00 10/22/2006 06:05:15 Calcium 7440-70-2 1$100 ug/L iMS 939 25.00 10/22/2006 06:05:15 Comments:

Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry

.7-INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-03B DI Client ID: Dry Well Hole #5 Bay 18:20 Matrix: WATER Date Received: Level: LOW

% Solids: Sample Wt/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-22 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL DI! Date Time Potassium 7440-09-7 29400 ug/L MS 25.6 25.00 10/22/2006 06:09:13 Calcium 7440-70-2 83500 ug/L MS 939 25.00 10122/2006 06:09:13 Comments:

Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-04B DI Client ID: Dry Well Hole #5 Bay 00:20 Matrix: WATER Date Received: Level: LOW

% Solids: Sample Wt/Voi: 45.0 Final Vol: 50.0 Prep Batch ID: 841-22 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL Dii Date Time Potassium 7440-09-7 29800 ug/L MS 25.6 25.00 10/22/2006 06:13:17 Calcium 7440-70-2 96600 ag/L MS 939 25.00 10/22J7006 06:13:17 Comments:

Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike Is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

B RXT Services, Inc Radioisotope & Analytical Chemistry INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-05BDI Client ID: Dry Well CRD Leak Matrix: WATER Date Received: Level: LOW

% Solidi: Sample Wt/Voi: 45.0 Final Vol: 50.0 Prep Batch ID: 841-22 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL DII Date Time Potassium 7440-09-7 111 ug/L B MS 25.6 25.00 10/22/2006 06:21:31 Calcium 7440-70-2 939 ug/L U MS 939 25.00 10/22/2006 06:21:31 Comments:

Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution Is outside percent difference quality control criteria

B WXT Services, Inc Radioisotope & Analytical Chemistry INORGANIC ANALYSIS DATA PACKAGE * * .

Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-06B D! Client ID: Dry Well 1-8 Sump Matrix: WATER Date Received: Level: LOW

%Solids: Sample Wt/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-22 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL DRI Date Time Potassium 7440-09-7 534 ugAL iMS 25.6 25.00 10/22/2006 06:17:33 Calcium 7440-70-2 1780 ug/L NMS 939 25.00 10/2212006 06:17:33 Comments:

Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

BWXT Services, Inc. Radioisotope & Analytical Chemistry t2ff-

• 4eto4 - 07.- , .4f-A C,,,cvAr?".

2 7 -

INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-OIA Dl Client ID: Dry Well Trough 18:20 Matrix: WATER Date Received: Level: LOW

% Solids: Sample WtIVol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL DU Date Time Sulphur 7704-34-9 1110 ug/L U MS 1110 10.00 10/22/2006 09:23:51 Commentw:

Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry JL5449 4A74'0-17.- Ot INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-02A DI Client ID: Dry Well Trough 00:20 Matrix: WATER Date Received: Level: LOW

% Solids: Sample Wt/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL DU Date Time Sulphur 7704-34-9 2850 ug/IL MS 556 5.00 10/22/2006 09:48:17 Comments:

Qualifier Descriptions: U - Non-Detected Concentration B - Concentration Is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

BWXT Services, Inc. Radioisotope & Analytical Chemistry INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-03A D3 Client ID: Dry Well Hole #5 Bay 18:20 Matrix: WATER Date Received: Level: LOW

% Solids: Sample Wt/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL DRi Date Time Sulphur 7704-34-9 41700 ug/L MS 11100 100.00 10/22/2006 10:00:35 Comments:

Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry

-tl-Z A Ki 3q INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-04A D3 Client ID: Dry Well Hole #5 Bay 00:20 Matrix: WATER Date Received: Level: LOW

% Solids: Sample Wt/Vol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL Dil Date Time Sulphur 7704-34-9 42700 ug/L MS 11100 100.00 10/22/1006 10:04:39 I

Comments:

Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry L-2. S4Loo, - -i- 7-'/?.Jr-

~ ~ ~ Ar k OMKrF)1E qo INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A Sample ID: 0610012-05A DI Client ID: Dry Well CRD Leak Matrix: WATER Date Received: Level: LOW

% Solids: Sample WtfVol: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/22)2006 Analytical Analyte CAS No. Concentration Units C Qual M DL DU Date Time Sulphur 7704-34-9 556 ug/L U MS 556 5.00 10/22/2006 10:12:52 Comments:

Qualifier Descriptions: U - Non-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution Is outside percent difference quality control criteria

B WXT Services, Inc. Radioisotope & Analytical Chemistry INORGANIC ANALYSIS DATA PACKAGE Client: Exelon -Oyster Creek Site SDG No.: 0610012 Method Type: 3015/6020A

/

Sample ID: 0610012-06A DI Client ID: Dry Well 1-8 Sump Matrix: WATER Date Received: Level: LOW

% Solids: Sample WtIVoh: 45.0 Final Vol: 50.0 Prep Batch ID: 841-21 Prep Date: 10/22/2006 Analytical Analyte CAS No. Concentration Units C Qual M DL DU Date Time Sulphur 7704-34-9 1460 ugIL MS 556 5.00 10/2212006 10:16:59 Comments:

Qualifier Descriptions: U - Noh-Detected Concentration B - Concentration is between MDL and CRDL N - Associated Matrix Spike is outside percent recovery quality control criteria

• - Associated Duplicate is outside relative percent difference quality control criteria E - Associated Serial Dilution is outside percent difference quality control criteria

T-ýL '54-(o o4P, - 0 1- A'T74cA404 r 'I Memo Hour to Diletto M9CiqS 9 L/4 Examination of Water Samples from Oyster Creek October 22, 2006 Appendix D Tritium Measurements

BWXT Services, Inc. Tritium Data Report for Oyster Creek 10/22/2006 SDG 0610012 Customer NE[S Analysis 2 Sigma Analysis Sample ID Sample ID Method Analyte Resul Uncedainty MDA units Vi Date Date Dry Well Trough 10/20/06 18.20 0610012-01 EPA 906.0 H-3 1.93E+03 1.76E+02 5.77E-01 pCi/mL 10/21/06 10/22/06 Dry Well Trough 10/20/06 00.20 0610012-02 EPA 906.0 H-3 7.95E+03 7.27E+02 5.77B6-1 pCi/mL 10/21/06 10/22/06 Dry Well Hole #5 Bay 10/20/06 18:20 0610012-03 EPA 906.0 H-3 5.51E+03 5.040+02 5.77E-01 pCi/mL 10/21/06 10/22/06 Dry Well Hole #5 Bay 10/20/06 00:20 0610012-04 EPA 906.0 H-3 5.63E+03 5.15E+02 5.77E-01 pCi/mL 10/21/06 10/22/06 Dry Well CRD Leak 10/20/06 19:15 0610012-05 EPA 906.0 H-3 7.47E+03 6.83E+02 5.77E-01 pCi/mL 10/21/06 10/22/06 Dry Well 1-8 Sumpl 0/19/06 02-55 0610012-06 EPA 906.0 H-3 4S&5ET+3 4.44E+02 5.77E-01 pCi/mL 10/21/06 10/22/06

-9'

T42- 54iO4A -o0Z-ATmcli*104 r 7,3 x~~xA1?We Memo Hour to Diletto Examination of Water Samples from Oyster Creek October 22, 2000 Appendix E Certificate of Comformance

'Tir-4ekveN7 7. 3 BW*XT Services, Inc.

Lynchburg Technology Center Quality Assurance Certification of Conformance BWXS Contract Charge No. S-1211-150 Exelon PowerLabs Purchase Order 0005997 1-00001, Authorization 2006100258 BWXT Services, Inc. hereby certifies that the item(s) or service(s) provided on this order are in accordance with the requirements of the above-specified Exelon PowerLabs purchase order, dated 10/20/06, and amendments summarized in BWXT Services, Inc.

report to John Diletto from Kevin Hour, "Examination of Water Samples from Oyster Creek," dated 10/22/06. This project was conducted on 10/21/06-10/22/06 in accordance with the requirements of the BWXT Services, Inc., Radioisotope and Analytical Chemistry Laboratory QA Plan, Revision 0, dated 10/24/05, and applicable requirements of the Nuclear Materials and Inspection Services, Standard Practice QA Plan, Revision 7, dated 10/1/05, for the project titled "Examination of Water Samples from Oyster Creek."

Date Don L. Hindman.

Manager, Laboratory QA

.4 Tracer Test Plan (Wpages)/l-eo/

3

54-(006Aod DRYWELL WATER MITIGATION PROJECT TRACER TEST, Rev. 2 Purpose Establish required actions to implement the proposed tracer test Back2round Water has been identified in the Bay 5 and Bay 17 trenches in the Drywell, elevation 10'-3". The suspected source of the water is leakage from the Sub-pile Room drainage trough. To confirm/refute the suspected cause, tracer solution is to be added to the Sub-pile Room drainage trough while monitoring the Bay 5 and Bay 17 trench for the tracer element.

Implementation Process

1. Prepare adequate tracer solution (Chemistry)

2. Identify all current water inputs to the trough (Engineering)

3. Re-direct water entering the trough directly to the sump to the extent possible (Operations)

4. Install temporary pipe plugs in the two 4 inch diameter trough discharge pipes. Plugs should be installed on the sump pit end of the pipes (PM/FIN).

5. Install temporary pipe plugs in the four 4 inch diameter drain pipes in the Sub-pile Room wall that input to the trough (PM/FIN).

6. Fill the trough with water to approximately 3 inch depth (approximately 50 gallons) (PM/FIN).

7. Disperse tracer solution (0.5 liter) into the trough. Dispersion should be as uniform as possible (PM/FIN).

8. Record date and time of tracer introduction and the depth of trough water at reference points A, B, C and D (PM/FIN).

9. Periodically monitor water in the trough for the duration of the test. If possible, station a vacuum or pump in the Sub-pile Room to remove water from the trough if the water depth reaches 6 inches. If water depth cannot be maintained at 6 inches or less due to inputs into the trough, remove the sump plug to release water into the sump to prevent the trough from overflowing. Note: If water level increases in the trough but is less than 6 inches, more tracer may be added to the trough as long as no water has entered the 1-8 sump from removal of any plugs - Contact Engineering at extension 4133 before adding more tracer.

10. Continue to monitor the trench at Bay 5 for water at the scheduled 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> interval.

11. Use black light, if necessary, to determine presence of tracer in the trench.

12. Record date and time of first observed tracer in the trench.

s-12 s 6 cGD,41 -o'--

13. At first observation of tracer and recording of date and time, the test is concluded. Demob may commence immediately.

Parts/Equipment

1. 0.5 liter of tracer solution. Solution available from Chemistry (Artz/Mura)

2. 6 - 4 inch diameter temporary pipe plugs

3. Water (approximately 50 gallons)

4. Black light for tracer detection in trench.

Prepared by: Knepper/O'Rourke October 23, 2006, 0205 hours0.00237 days <br />0.0569 hours <br />3.38955e-4 weeks <br />7.80025e-5 months <br />

rV S4-,o4' -o*.r Attachment 7.5 Structural Evaluation Structural Integrity Associated, Inc report for the Corrosion Evaluation of the Oyster Creek Drywell Steel Shell

( Pages)

5~4(04'1 - 07 A -r~tck-1 7. 7 Inc. !7idlr StructuralIntegrity Associates, 3315 Almaden Expressway Suite 24 San Jose, CA 95118-1557 Phone: 408-978-8200 Fax: 408-978-8964 www.structntcom bgordon@structntcom November 2, 2006 SIR-06-436, Rev. 1 BMG-06-016 Mr. Howard Ray AmerGen Energy Company, LLC Oyster Creek Generating Station P. 0. Box 388 Route 9S Forked River, NJ 08731

Subject:

Corrosion Evaluation of the Oyster Creek Drywell Shell Steel - ECR 06-00879

Dear Mr. Ray:

The results of this engineering evaluation indicate that no significant corrosion of the inside surface of drywell steel shell as long as the current environmental conditions inside the drywell are maintained for the following reasons:

1. The concrete floor pore water inside the drywell is characterized by corrosion-inhibiting high pH with low impurity levels that are significantly below the EPRI embedded steel guidelines action level recommendations. Therefore, drywell steel integrity can be maintained indefinitely as long as the high pH and low impurity levels in the concrete pore water are maintained.

2. Any subsequent water ingress into the concrete floor will also become high pH concrete pore water and will have the same corrosion inhibiting characteristics.

3. Corrosion of the steel shell that is not wetted by the concrete pore water will be mitigated by the inerting of the inside of the drywell with nitrogen during plant operation.

4. The only negligible corrosion that would occur during outages and briefly (hours) after the outage would be due to the dissolved oxygen in water that may have migrated into the two trenches, one each in Bays 5 and 17. Once the cathodic reactant dissolved oxygen is consumed in the brief corrosion reaction and/or effervesced from the water during heat up, however, corrosion even in these two locations will cease.

Therefore, the water identified in contact with the inside surface of the drywell steel has not been and is not, an engineering concern for the structural integrity of the drywell as long as the environmental conditions (e.g., pH and water purity) are maintained.

Austin, TX Centeenni, CO Charlotte, NC Stordngton, CT Slvy gprinq, MO Sunrise, FL UnlontoVn, OH WhNtt,CA Ontaio, CANADA 512-533-9191 303-792-0077 704-597-5564 860-536-3982 301-445-8200 954-572-2902 330-899-9753 562.944-8210 905-829-9817

-rt2- c54 o4,o4'.4J*lf4,-,&

"S ttw*ifr2-.7,,3ý Mr. Howard Ray/AmerGen November 2, 2006 SIR-06-436. Rev. I/BMG-06-016 Page 2 of 7 I thank you for the opportunity to provide this report to AmerGen and enjoyed visiting your site.

If you have any questions on the content of this report please do not hesitate to contact me.

Very truly yours, Barry M. Gordon, P. E.

Associate

/nnn Attachment cc: M. Herrera, SI IIF-"r

_C9- .C¢.e'*4,,°M S44,o$4-oL - 7.. r Corrosion Evaluation of the Oyster Creek Drywell Shell Steel - ECR 06-00879 Introduction The degree that concrete pore water will provide corrosion protection for embedded steel depends on the chemical quality of the concrete, the quality of the water used for mixing the concrete, and the depth of concrete in contact with the steel. The permeability of the concrete is also an important factor affecting the embedded steel's corrosion propensities [1]. Low permeability concrete contains less water under a given exposure and is more likely to have high electrical resistance and, thus, will reduce the rate of the corrosion process of any steel in contact with the concrete. High quality concrete also resists the absorption of impurities and their migration to an embedded steel surface and provides a barrier to oxygen, the most common cathodic reactant in aqueous corrosion reactions. Finally, low water-to-cement ratios and adequate air entrainment increases the resistance to water penetration and will also mitigate corrosion [I].

Environmental Factors Affecting Corrosion in Concrete When a freshly-mixed concrete is placed on steel, the mixing water contacting the steel surface forms hydrated calcium ferrite (4CaO.Fe20 3.13H 20). This mixing water also reacts with steel and creates a thin layer of iron hydroxide [Fe(OH) 2] and calcium hydroxides [Ca(OH) 21. The presence of abundant amount of calcium hydroxide and relatively small amounts of alkali elements, such as sodium and potassium, gives concrete pore solution a very high alkalinity with pH of 12 to 13.

This pH range is where steel (iron) is either thermodynamically "immune" to corrosion or where a protective passive film is thermodynamically stable on the steel surface regardless of the corrosion potential of the steel as affected by the dissolved oxygen content of the water, as illustrated in a pH

- potential diagram or Pourbaix diagram, Figure 1 [2). Although the pH of exposed concrete pore water may decrease, i.e., become more acidic, when exposed to air containing carbon dioxide (C0 2 ) due to carbonation, the pH of the water will still be sufficiently high to maintain a passive film on the steel surface. Therefore, steel in contact with low impurity concrete pore water will not suffer significant corrosion even if sufficient moisture and oxygen are available due to the spontaneous formation of this thin protective passive film [3). Such corrosion resistance can be degraded if the alkaline concrete pore solution disappears (e.g. when large cracks reach the steel surface) or the ingress of detrimental species such as chloride (ClI), sulfate (S0 4 -2) or carbon dioxide (CO 2) can occur.

Corrosion of the steel surface in contact with concrete pore water typically occurs in two stages.

The first initiation stage is characterized by aggressive species present in the surrounding medium, penetrating the concrete. The second stage starts when these aggressive species reach sufficient concentrations at the steel surface to degrade the passive film on the steel surface. Chloride and sulfate degrade passive films on most metals surfaces while carbon dioxide dissolved in water (carbonation) forms carbonic acid (H2C0 3 ), which could lower the pH to a range where dissolution, i.e., corrosion, of steel can occur, Figure 1.

C n ,TOA , -. ,r StructuralIntearitv Associates Inc

However, the corrosion of this steel is not significant if the concrete is not exposed to an aggressive environment as defined by the Electric Power Research Institute (EPRI). These guidelines suggest that an environment characterized by a pH < 11.5 or chlorides >500 ppm or sulfate > 1500 ppm can result in the degradation of embedded steel [11. However, it should be noted that this pH corrosion "threshold" is clearly conservative since corrosion of steel (e.g.,

iron) can only thermodynamically occur when the pH <10, Figure 1, and actually remains kinetically insignificant until the pH is truly in the acidic range (e.g., pH <5.5) as noted in this EPRI evaluation [1]. It is important to note that the Pourbaix diagram only reflects a thermodynamic evaluation of corrosion reactions and implies nothing concerning the kinetics of the same corrosion reactions.

In the case of corrosion of steel rebar embedded in concrete, the non-passive corrosion film formed on the rebar steel surface has a volume of approximately three times the volume of the steel that has corroded. This results in a loss of bond between the embedded rebar and the concrete and leads to delamination and spalling of the concrete. Delamination and spalling would thus be indicators of the presence of an aggressive environment.

Oyster Creek Concrete-Drywell Shell Steel Evaluation For the specific case of the Oyster Creek drywell shell in contact with the poured concrete floor inside the drywell, no gross degradation of the drywell shell appears to have occurred, which is completely consistent with the Pourbaix diagram. This conclusion is supported by: (1) the lack of visible significant corrosion on the drywell shell steel surfaces aside from superficial rusting of the steel in the trenches where the steel is no longer in contact with the concrete pore water; (2) the nominal ultrasonic testing (UT) thickness measurements taken by AmerGen during Oyster Creek's 2006 refueling outage; and (3) the lack of any indication of rebar degradation in the concrete inside the drywell.

This near lack of drywell steel corrosion on the interior drywell shell surface is most likely due to the very low concentrations of chloride (13.6 - 14.6 ppm) and sulfate (228 - 230 ppm) plus the high pH (8.40 - 10.21), despite carbonation, of the drywell trench water in Bay 5 as independently measured by BWX Technologies (BWXT) during the 2006 refueling outage, Table 1 [4]. Therefore, corrosion of the steel exposed in the trench that is in contact with good quality concrete pore water will be mitigated. Any corrosion of the trench steel not in contact with concrete pore water will be mitigated by the inerting of the drywell during operations, due to the lack of dissolved oxygen in the water in contact with the steel.

Some corrosion can occur On this exposed steel when the drywell is not inerted during outages and briefly (hours) after inerting as will be discussed in the next section. Again, this small amount of corrosion would be due to the dissolved oxygen in the trench water. Once the cathodic reactant dissolved oxygen is consumed in the brief corrosion reaction and/or effervesced from the water during heat up, corrosion will cease.

BWXT investigators suggest that the high pH and calcium content of the trench water indicates that this water has been in contact with the concrete over a significant period of time since the calcium concentration is significantly higher in the trench water (83.5 and 96.6 ppm) compared Att'.C MMCA) .- ' r% -

SIFT st hrfuI~ Intrn~ifu ACCnj'!Dfta. In^

4 4C,rfcfe"AT 7_5I to the trough water (4.53 and 15.7 ppm), which is believed to be a source of the water in the trench [4].

Again, since these trench water chemistry values comply with the EPRI embedded steel guidelines action level recommendations for maintaining embedded steel integrity in concrete, the structural integrity of the embedded steel is assured as long as the corrosion mitigating concrete pore water chemistry is maintained [Il].

Calculated Amount of Corrosion under Non-Inerted Conditions inside the Drywell As an exercise, a calculation will be performed to determine how much additional corrosion could occur on a unit area of drywell surface prior to the inerting of the drywell, i.e., how much corrosion would occur in a closed, non-refreshed with oxygen, system. To accomplish this objective, several conservative, i.e., worst-case, assumptions will be made:,

1. Assume the worst case temperature for the highest corrosion rate. The maximum temperature of the drywell was 140 'F (60 °C), which nearly coincides with the maximum corrosion rate for carbon steel in open systems, Figure 2. There is a linear increase in corrosion rate of carbon steel with temperature in a closed system from which oxygen cannot escape that corresponds with the increase in the oxygen diffusion coefficient. In an open system where dissolved oxygen can effervesce from the water such as the case with the drywell, the corrosion rate initially follows that for a closed system. However, the corrosion rate starts to rapidly decrease at approximately 158 'F (70 'C) due to the decrease in the solubility of the cathodic reactant oxygen in the water, which at that temperature becomes more significant than the increase in the oxygen diffusion coefficient [5].

2. Assume that the form of corrosion product formed on the drywell steel is non-adherent and non-protective Fe 20 3 , i.e., red rust.

3. Assume that one cubic centimeter (cm 3) of water contacts every square centimeter (cm 2 )

of drywell shell steel.

4. The water contacting the drywell steel is assumed to be pure water since pure water can retain the greatest amount of dissolved oxygen and there is no inhibiting effect of high pH. Note that the presence of impurities in the water will only affect the kinetics of the corrosion reaction, not the total amount of corrosion, which depends only on the quantity of the dissolved oxygen in the solution. Neither sulfate or chloride appear in the corrosion reactions in this system.

5. Assume that all the dissolved oxygen molecules in the water are not homogeneously distributed inside the unit volume of water, but are all biased and in contact with the drywell steel ready for cathodic reduction.

TT% .. Str~lltlraIlIntanrii Aclintao Inn

,4 e-H14wr -7, 65-Corrosion Calculation The following calculation determines the amount of steel that will be corroded if all the dissolved oxygen in the water reacts with the steel.

CalculationData Inputs Density of water at 140 °F (60 °C) = 0.983 g/cm 3 [61 Weight of a unit volume (1 cm 3) of water at 140 °F (60 IC) = 0.983 g Dissolved oxygen concentration in the water at 140 IF (60 IC) = 4.7 parts per million (ppm) [7]

Weight of dissolved oxygen in a unit volume of water = 4.7 x 10-6 x 0.983 g = 4.62 x 10-6 g Moles of dissolved oxygen in a unit volume = 4.62 x 10-6 g/32 g/mole = 1.44 x 10-7 moles CorrosionCalculation Moles of iron corroded into Fe20 3 (red rust) per unit volume of water:

Since the "rusting reaction" is 4Fe + 302 ") 2Fe2 0 3, then 3 moles of dissolved oxygen form two moles of Fe 20 3 rust 2/3 x 1.44 x 10-7 moles of dissolved oxygen = 9.6 x 10-8 moles of Fe20 3 Grams of iron corroded into Fe 20 3 (red rust) per unit volume:

9.6 x 10s moles of Fe2 0 3 x 160 g/mole = 1.54 x 10-5 g of Fe2 03 2 2 Average Fe 20 3 lost per cm = 1.54 x 10-5 g/cm Thickness of steel lost due to corrosion this corrosion would be:

1.54 x 10-5 g/cm 2/density of steel = 1.54 x 10,5 g/cm 2/7.85 g/cm 3 = 1.96 x 10-6 cm or - 0.02 Aim=

0.0008 mils = 8 x 10-7 inches Summary These measured water chemistry values, plus the lack of any indications of rebar degradation, suggest that the protective passive film established during concrete installation at the embedded steel/concrete interface is still intact and significant corrosion of the drywell steel would not be anticipated as long as this benign environment is maintained. Therefore, since the concrete environment complies with the EPRI concrete structure guidelines, corrosion would not be considered "an applicable aging mechanism for nuclear power plant concrete structures and structural members" at Oyster Creek [ 11.

IPF reituimr2Ifntonrilu Acent-intne In^

More specifically, the results of this engineering evaluation indicate that no significant corrosion of the inside surface of drywell steel shell would be anticipated for the following reasons:

1. The concrete floor pore water inside the drywell is characterized by corrosion-inhibiting high pH with low impurity levels that are significantly below the EPRI embedded steel guidelines action level recommendations. Therefore, drywell steel integrity can be maintained indefinitely as long as the high pH and low impurity levels in the concrete pore water are maintained.

2. Any subsequent water ingress into the concrete floor will also become high pH concrete pore water and will have the same corrosion inhibiting characteristics.

3. Corrosion of the steel shell that is not wetted by the concrete pore water will be mitigated by the inerting of the inside of the drywell with nitrogen during plant operation.

4. The only negligible corrosion that would occur during outages and briefly (hours) after the outage would be due to the dissolved oxygen in water that may have migrated into the two trenches, one each in Bays 5 and 17. Once the cathodic reactant dissolved oxygen is consumed in the brief corrosion reaction and/or effervesced from the water during heat up, however, corrosion even in these two locations will cease.

Therefore, the water identified in contact with the inside surface of the drywell steel has not been and is not, an engineering concern for the structural integrity of the drywell as long as the environmental conditions (e.g., pH and water purity) are maintained.

References

1. "Aging Effects for Structures and Structural Components (Structural Tools), Revision 1,"

EPRI, Palo Alto, CA, August 2003. 1002950.

2. EpH Web www.crct.polymtl.ca/ephweb.php.

3. S. Jiggi, H. Bohni and B. Elsener, "Macrocell Corrosion of Steel in Concrete - Experiments and Numerical Modeling," paper presented at Eurocorr 2001, Riva di Gardi, Italy, October, 1-4, 2001.

4. OC Drywell Chemistry Sample Results Summary - Revision 3, BWX Technologies, Lynchburg, VA, October 29, 2006.

5. F. Speller, Corrosion, Causes and Prevention, McGraw-Hill, New York, NY, 1951.

6. Water Density Calculator, http://www.csgnetwork.com/h2odenscalc.html

7. Oxygen Solubility Calculator, http://pointfour.com/cgi/pfscalc.cgi

• ý

Table 1: Oyster Creek Bay 5 Trench Water Chemistry Analyses [41 Sample BWXT ID Date Time BWXT Oyster Cond., SO4"2, C', Ca, Comments Description pH@21.2 °C Creek pH ILS/cm ppm ppm PPM Bay 5 Trench CI- and S0 2 below 4

Sample #3 0610012-03 10/20/06 18:20 8.40 9.30 656 230 14.6 83.5 EPRI thresholds Bay 5 Trench Cl and S0 4 2 below Sample #4 0610012-04 10/20/06 00:20 10.21 10.35 672 228 13.6 96.6 EPRI thresholds Notes: The original BWXT report reported the concentrations of sulfate, chloride and calcium in micrograms/liter, pig/1, which is equivalent to a part per billion, ppb.

Since the reporting of chemical units in reactor waters are typically parts per million, ppm, the concentrations of sulfate, chloride and calcium are reported in ppm in Table 1. For example, the chloride concentration reported by BWXT was 14,600 jIg/l = 14,600 ppb = 14.6 ppm since 1000 ppb = I ppm.

03

~~.-- .l~ - - - fl,-y-~ tx, - -

li;ý? Ctrijobdr-21 lnfanribý Aven^i,3tan hiý

n-A., %k f',~ 0

~2.:AIfl~

Fe-H20, 298.15 K m= le-6 1.6 1.4 1.2 1.0 0.8 0.6 0.4

[,iJ 0.2 0

-0.2

-0.4

-0.6

-0.8

-1.0

-1.2

-2 0 2 4 6 8 10 12 14 16 pH Figure 1: Iron - Water Pourbaix Diagram at 25 *C Indicating the Regions of Thermodynamic Stability for the Fe Ion (Corrosion), Passivity (Fe Oxides) and Corrosion Immunity (Fe) [2]

A rt1,4e}1A4FAI;f '7, kA-r.e4m FO-~46 // oic //

14 12 E

0.

0.

X 0

V 8

0 0.8 C 4

.2 2

0 0 20 40 60 80 100 120 140 160 180 20C Temperature, F Figure 2. Effect of Temperature on the Corrosion Rate of Carbon Steel and Dissolved Oxygen Concentration

4Lz?4 rA "4.,o4l" -oz (;

,4*,,.e-,\ 7 1, Y_.-.

Attachment 7.6 2006 Drywell maintenance rule structural monitoring walkdown write-up

-r

• a4 -- 0 ER-OC-450 Exelon , fr, e7.1r -7,4, Revision 0 Page 1 of 3 Nuclear ATTACHMENT 8 Structures and Components Monitoring Forms Form #P2o../ C(J9o

- 01/-o Sheet 1 of 8 AREA: Inside the Drywell Responsible Engineer/Examiner: Suwit Nioi/ Suiit Nioqi & Dan Fiorello Date-1 0/19/06 Element Type Examination Criteria Template # S-01 "Reinforced Concrete" Attachment 2, Section 1 Template # S-02 "Structural Steel" Attachment 2, Section 2 Template # S-03 "Masonry Walls" Attachment 2, Section 3 Template # S-04 "Equipment and Component Foundations" Attachment 2, Section 4 Template # S-05 "Roofing" Attachment 2, Section 5 Template # S-06 "Component Supports" Attachment 2, Section 6 Template # S-07 "Seismic Gaps" Attachment 2, Section 7 Template # S-08 "Doors (secondary containment, Attachment 2, Section 8 watertight, steam barrier)"

Template # S-09 "Building Siding and Metal Deck" Attachment 2, Section 9 Template # S-10 "Exterior Surfaces-Mechanical Components" Attachment 2, Section 10 Template # S-1I "Panels and Enclosures" Attachment 2, Section 11 Template # S-12 "Wooden Piles & Sheeting" Attachment 2, Section 12 Template # S-13 "Earthen Structures & Embankments" Attachment 2, Section 13 Template # S-14 "Penetration Seals and Structural Seals" Attachment 2, Section 14 Template # S-15 "Permall Shielding Blocks" .Attachment 2, Section 15 Scope of inspection- The inspection includes visual inspection concrete Floor at elevation 10'-3" and pedestal, condition of the floor under the vessel, trough and sump, condition of the support frames, condition of the pipe and equipment supports, general condition of the Drywell surface (Shell) up to elevation 23'. This inspection was performed at elevation 10'-3" of the Drywell

ER-OC-450 Exelon. ,4 t1ef/t'6-T , Revision 0 Page 2 of 3 Nuclear ATTACHMENT 8 Structures and Components Monitoring Forms Form# K2O9I3,{O cI/-O/ Sheet 2 of___

AREA: -Inside the Drywell OBSERVATIONS Seq. # Item Item # I Observation Description/

Type Location Observed Condition 1 Concrete El. 10'-3" The concrete floor outside the pedestal Floor and pedestal are in good condition with no Outside visible evidence of cracking, spalling or Pedestal other structural defects. The floor was stained and dirty Concrete edge of the curb where it meets the steel shell was uneven. Some concrete had chipped off due to sharp edge. This resulted in small gap at the top of the curb where it meets the steel shell.

This is not a structural concern, but possible path of water intrusion to interface surface between concrete slab and the steel shell. Two cutout areas at the curb were inspected. The cutout at bay 17 was dry but cutout at bay 5 was partially filled with water approximately 5 inches deep.

2. Concrete Inspection of the Reactor Pedestal Wall Floor Inside and the floor under the Reactor Vessel Pedestal, found to be in good condition. The slab Trough & within the pedestal (under the vessel) is Sump covered with an additional approximately 6" of concrete over lay. This over lay is crowned at the center and slopes gradually to the trough. The top surface of this over lay slab has exposed aggregate and some small chips on the floor. None of these are structural concern and is in good condition. The trough was partially filled with water and water was dripping from the overhead near the sump. There

In? ~5 1, 0 4,q-a z ER-OC-450 Exelkn, 4-r7-cr

,43C~

~

"e 4 -7.C. Revision 0 Page 3 of 3 Nuclear P5 31c:) pa K~Q*01 o.3 -

were some standing water maximum 1/*"

deep few locations around the outside of the pedestal. At the time of inspection some water was dripping into the area from above the Drywell hatch area. The inside surfaces of the sump were not inspected as they were not accessible.

3. Structural El. 23' The underside of the radial beams and the Steel secondary beams are in good shape.

Some minor rust stains are noticed.

These stains were observed during previous inspections. No temporary overloads that may fail the existing structure were observed.

4. Component El. 10' Component supports and equipment Supports & supports are generally in good condition-Equipment no issues.

Supports Evaluation of Results: X Acceptable; Seq. # 1, 2, 3 and 4 E] Acceptable with Deficiencies; Seq.

[] Unacceptable; Seq. #

Responsible Engineer: X / ,A -VrI Date: /_/_/___

Responsible Manager: Date: / 7'

ATa 5+(,&o4- 7, 4 ER-OC-450 ExelOn., Revision 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Forms Form # -J/---I Sheet 4 of 8 AREA: Inside the Drywell Concrete Edge of the Curb and the Shell

4T7P'/#okqJ 7-o-z-ER-OC-45C Exelon,. Revision (

Nuclear ATTACHMENT 8 Structures and Components Monitoring Forms FormEA: Ins )6 We0l /2-- / Sheet 5 of S8 AREA: Inside the Drywell Water on the Floor EI.10'-3" Outside of Pedestal

/ R.,1 -.l-r" 7, ER-OC-450 Exelkn0. Revision 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Forms Form # A-/- / Sheet 6 of 8 AREA: Inside the Drywell Water Outside Pedestal El. 10'-3" Near the Sleeve

112- 54t,04'i 2

~4 -rr4 qfI r 7,C,,

PT7~AsGw (k 4&d 0 Exelon. ER-OC-450 Revision 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Forms Form # ___ /____-___ /- Sheet 7 of _8_

AREA: Inside the Drywell Trench @ Bay No 5 Inside Drywell El 10'3"

• 41fCk-~E~l-7, 4 ER-OC-45(

Exelon.. Revision 4 Nuclear ATTACHMENT 8 Structures and Components Monitoring Forms Form# 2 i/4-2 ' -

)/-0/ Sheet 8_ of 8 AREA: Inside the Drywell Trough and =6" Thick Over Lay Concrete Floor Inside Pedestal (Under the Vessel)

l n

ExeloER-OC-450 5~24(,,o4AA -OL 4-T-r,,*#/*/f4c r 7, Revision 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Report Form# A"2/3-6/-, Sheet 1 of 11 AREA_: inspection of the area inside the reactor concrete pedestal was performed at Elevation 10'-10 During 1R21, an inspection of the area inside the reactor concrete pedestal was performed at Elevation 10'-10". The inspection was performed during a scheduled window within the CRD replacements when the area was wet and water was streaming from some of the de-torqued CRD flanges. The area had adequate light. The trough was cleaned and prepped for the inspection and a flashlight was used to inspect the internal condition of the trough.

OBSERVATIONS Seq. # Item Item # I Observation Description/

Type Location Observed Condition 1 Concrete EL 10'-10" During the visual examination of the Trough trough, the as-found general condition of the trough was good. There were no signs of significant cracks in the trough. Some signs of erosion and localized minor degradations were observed around the floor drain holes from the area outside the reactor pedestal to the trough. Other minor degradations and localized erosion around the drain holes from the trough to 1-8 sump were also observed. The trough bottom surface is sloped to divert the collected water from the highest point around Azimuth 180 deg to the lowest at Azimuth 0 deg (1-8 Sump). The drainage slope is non-uniform, which was confirmed

~4~,

6- o4'j-02.

Exel4n

_ __ _ e _ _ .A r * /4/

6 ER-OC-450

-I7, R ev is io n 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Report Form # Sheet 2 of 11 by field measurements for the water surface height in the trough with respect to the bottom of the trough. A depressed area in the trough bottom elevation was observed at Azimuth 270. The bottom of the trough is in good condition. The inner surface of the pedestal inside the trough showed some minor hair surface cracks at the construction joints. None of these wall cracks are through cracks. An area of slab corner was observed chipped away for approximately 2" deep by 12" long between Azimuth 0 deg and 90 deg. The surface stain color is similar to the surrounding concrete. As such, the degradation does not appear recent and could be since original construction. It should be noted that the chipped corner is in an area in the raised floor and has no structural contribution to the pedestal supporting structure.

cj~2~4~o4j -OL ER-OC-450 Exelon. /2.

Revision 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Report Form # '. *ii/3 -O/-6 Sheet 3 of 1/

Concrete Floor at El The surface of the floor inside the Floor 10'-1i0" pedestal at El 10'-10" has exposed gravel.

However, no loose gravel was observed except for the small amount that was removed by the field for the inspection prepping. The exposed gravel could be caused by water leakage from the above equipment such as the CRD's over the past years of operations. No signs of significant surface craks were observed.

Generally, the floor surface is in fair condition Steel 10'-10" The steel structure was inspected and Structure some minor surface corrosion was observed at approximately Azimuth 90 deg. No material loss was observed as expected due to the drywell being inerted with nitrogen (no oxygen) at power and the water leakage from the reactor CRD is not aggressive to steel.

ER-OC-450 Exelon. AWMA44 fk'e 1-3 Revision 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Report Form # )ZoY?/3E9Cij3 -io.(J Sheet 4 of 11 4 1-8 Sump The 1-8 sump piping, pipe supports, and cover plates appear in good condition. The

/" S.S linear appears also in good condition based on the inspection of the pictures provided by the FIN group.

Evaluation of Results: Acceptable; Seq. # _1, 2, 3, and 4 fl Acceptable with Deficiencies; Seq. #

El Unacceptable; Seq. #

Responsible Engineer: / Date: lo 27,/b

" W" Responsible Manager: / *' / & Date: _ 7*

A-- -/- ?2- ER-OC-450 Exelon. 54, o 49 r-A&r?-,"6?VT Revision 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Report Form # A2"J)h32%>c): 'v2- Sheet 5 of 11 urain mole to the I-U bump.

ER-OC-450 Exelon., M7,.4k p~~ 3 Revision 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Report Form # A 9i1-330 .Q-cOz(-) " Sheet 6 of 11 Chipped Corner In the Tough.

rTLv s;44o41 -oz.

ER-OC-450 Exeln . ,1-7f,T~~q.1erA,77,4

'1Aqc-* fjN(4 /4 Revision 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Report Form# i.,SY) -OI-'Y2* Sheet 7 of 11 i

-. ~ ~1/42~

drain hole in the pedestal shows some minor degradation.

Exelon. ,*,~i-~-7,

,4-rrA-c ER-OC-450 Revision 0 Nuclear h~wPwiA ke /2 ATTACHMENT 8 Structures and Components Monitoring Report Form # ,*Z£.,*1/031> -L'i..."Sheet 8 of 11 Minor surface cracks in the pedestal construction joint.

good condition.

TLZ- 546 04q - 02Z ER-OC-450 Exelkn. Revision 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Report Form # " -('t-o. Sheet 9 of I/..1.

Azimuth 90 deg., the bottom of the trough is in good condition.

minor surface corrosion.

0

ER-OC-450 Exelkn., /1 r&o~ -o-L~r2 Revision 0 Nuclear ATTACHMENT 8 Structures and Components Monitoring Report Form # /,.. / 3, ) -O.- Sheet 10 of 11 Some surface corrosion, but no material loss. Picture was taken prior to cleaning the area.

sq- G:4.(po44 -,>7 ER-OC-450 Exelkn . 4.qp<AV&,(

24-7 (Ntý 7-0 C~, Revision 0

ýcz Nuclear ATTACHMENT 8 Structures and Components Monitoring Report Form # As2*)//&) ,)/-)2 Sheet 11 of 11 1-8 Sump appears in good condition.

7,7 Attachment 7.7 Sump 1-8 VT-1 Inspection results & report

E-7O WGE Nuclear Energy VISUAL EXAMINATION REPORT Site.. O - k e*C_* 4 Unit ,t ReportNumber ,e../ Sheet / of ,2.

Outage: / Procedure V' /At/ersion / Rev 3 DRRt ,ý}

Camp / Weld No. Configuration: Acceptance CriteriL ..-" , /,

- p DWG: / Ss stem Surface Condition:,4S fgf4-IO Moterial - S Item: ,.*, ,

Visual Inspecion System Technique:- /-/ Resolution Verified by:. ira*/*, .A .

Equipment Used: Mirror [. Magnifier 0. Remote B/W Video 0, Remote Color Video 0. Other 0 if so explain in "Comments"section. eA- -,OJ-4 .T77e,,o--0 Lighting Used: Ambient 0. Flashlight toJ. Other 0 if so explain in "Comments*section.

Tools Used: Six Inch Scale rD. Binoculars 0. Welding GougeQ. Thread Gouge 0. Other 0 if so explain in "Commentso section.

Examinamion Results Item No. Classification Description Accept / Reject

-1P -1P rd i7" (94 _ _ ,

Commentm.t r-ýR Q£tl)~ Or-: 17/-& ý5 4'V-'ý2 S SWztI 4W0 WO'7e Signatures Examiner Name & Lev Date.-

GE Review Name &Level: Date:

D ate: /0 1 - L IUtility Review.

ANII/ANI Review Date:.

I VIUr. EXAINATIONj

. REPOR

,GE Nuclear Energy

""tl I* VJ VISUAL EXAMINATION REPORT Site: dty'TEjZ e-ECEK I Unit / I ReportNumber 21/R'./5 Sheet of /

Outage: 2 1 X Procedures.t.-Yr Version / Rev 3 DRR: N A Comp / Weld No. Configuration: ,6-p. Criteria:

Acceptance Ir& " 1//3

,P m DWG: MID 1. 2,1 Systerm :81 Surface Condition: 45 ,Iowv I Material: 55. Iterrm D;*S'eA*'. SAi.p visual inspectionSystem Technique: VTr- I Resolution Verified by:. -T"E1-r 6AgD Equipment Used: Mirror 0. Magnifier []. Remote BAN Video [j.Remote Color Video El. Other 0 ifso explain in

'Comments" section.

Lighting Used: Ambient i]. Flashlight Ef, Other 0] if so explain in "Comments, section.

Tools Used: Six Inch Scale 0. Binoculars 0. Welding Gauge~J Thread Gouge 0. Other 0 if so explain in

'Comments' section.

Examination Results Item No. Classification Description Accept I Reject

/ /NA /-*a .p Lw,, 2' 2" -*. ,-__ _4_-

Al Commentxs,4 VT- V wes Pd*FS*'-FjpD AA& DOC.UMC?4TE-D OW' 7AN9 I-koA 2r

.0. 714E -jrr7jr~Z~G D~~lAELA.. VIARPZL.f -51,4&P ST,1A/XI -SEPj 'Z'i*

L0C4-rXoW: DW16, s&u.&P-L-a goo^", AZoao.

w~e)Y# e2013773Z 0-64 / AfA`M Signatures Examiner Name& Level: D -'-./.9Z.06 Date.

GEReviewNome&Level: Dote:10. -i Utility Review: Dote:_

ANII/ANI Review _Date._______

c-4f,-o;v 7oZ Attachment 7.8 Simplified sketch showing inspection trenches, sump pit, sub-pile room trough and drywell shell

SKETCH SHOWING LOWER DRYWELL-SAND BED, TRENCH &SUMP

-I-us. 8'-! 5ECTION "15 - 03 L.P. &--r LOOKING WE5T DRAJNAGE CHANNEL 0

Trench Detail Sketch INW.

DRTWELL VARIES CROSS-SECT ION AREA 0 OF TRENCHES IN BAYS 5 & 17 "'I

Plan View of Trough and Trenches

-A 4-'

SE:E DETA1it'-

CROSS SECTIO M04AEA 10123/20( OF -TtiN~m~ 11 KEY LANE 6

1.

Top View - Drywell Floor Sketch LW TO i-Tag 12

Attachment 7.9 Type A Testing Evaluation (b<Pages)

4(ooi--- oz..

A r-r.,c #,-f'i1 7 October 31, 2006 Evaluation of the Ability of Type A Integrated Leak Rate Test to Detect Through Wall Breach in the Concrete Encased Area of the Drywell Shell The Type A test or Integrated Leak Rate Test (ILRT) is an extremely sensitive test in detecting leakage paths from the containment pressure boundary. ANSI/ANS 56.8-1994 requires pressure instrumentation that is accurate to +/- 0.02 psi and repeatable to 0.005 psi, temperature instrumentation accurate to +/- 1.00 F and repeatable to 0.20 F, and relative humidity instrumentation accurate to +/- 3.5% RH and repeatable to 1%RH. Repeatability is an important parameter since calculation of the leakage rate is a function of change in readings rather than the absolute value of the reading.

At Oyster Creek, the maximum allowable leakage rate (L.) is 1% by weight per day, the calculated design basis accident pressure (Pa) is 35 psig and the containment net free volume is 302,400 cubic feet. For the Type A test, the allowable leakage rate is 75% of L, or 0.75% by weight per day. This leakage value would be exceeded through an orifice slightly larger than 3/32 of an inch.

The last 10CFR50 Appendix J Type A test at Oyster Creek was completed on November 8, 2000 with a measured integrated leakage rate of 0.3658 % by weight per day, which substantiated the integrity of the drywell shell. At the upper 95% confidence level, the integrated leakage rate is 0.3767 % by weight per day (from "Oyster Creek Integrated Leakage Rate Test November 8, 2000 Final Test Report'). The close agreement between the measured leakage rate and the 95% upper confidence leakage rate Is a good indication of the quality of the data and a stable leakage rate as indicated on the attached graph. In addition, the measured integrated leakage rate is well below the test acceptable leakage rate of 0.75 % by weight per day and the maximum allowable leakage rate of 1% by weight per day.

Concrete is a porous substance and during the conduct of the test, as the containment is being pressurized, air is forced into the concrete. This phenomenon Is referred to as "in-gassing.'

During many pre-operatlonal tests, when the structural integrity test was performed at a higher test pressure and the pressure reduced to the design basis accident pressure, the air that was forced into the concrete at the structural integrity pressure 'out-gassed" back into the containment. As a result, ANSI/ANS 56.8-1994 Section 5.4 now contains a requirement if the containment pressure is above the Type A test pressure, it must be reduced to 85% of the Type A test pressure for a period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to re-pressurizing to the Type A test pressure.

Empirical evidence also exists that the Type A test would detect leakage through a breach in the containment liner. EPRI Report No. 1009325, Risk Impact Assessment of Extending Integrated Leak Rate Testing Intervals, Appendix A identifies excessive containment leakage paths that were identified during the Type A (ILRT) Test. These include items such as holes that were inadvertently drilled through the liner, vent pipes not capped, tubing plugs not installed and bellows cracks.

Thus, if the shell were breached at the bottom, even with a layer of concrete above and below the breach, a leakage path would exist. If that leakage path exceeded the equivalent of a 3/32-inch orifice, the Type A test would fail. If the voids in the concrete were filled with water that leaked through the breach, the Type A test pressure would force the water back through the breach and the leakage would be detected by the Type A test.

I

gOctober 31, 2006 If the voids in the concrete inside containment above the shell were filled with water, but no breach existed in the shell, there would be no impact to the conduct or validity of the Type A test. Humidity or dewpoint instrument sensors are used for the conduct of the Type A test to measure the amount of water vapor in the air. This compensates for the changes in the total air pressure that are due to changes in water vapor (evaporation or condensation) and are not indications of containment leakage. The torus or suppression pools of BWRs contain a large amount of water during the conduct of Type A testing that do not negatively impact the conduct or validity of the Type A test.

Since calculations of the Type A test leakage rate depend upon changes in the weight of air, the calculated leakage rate is independent of the absolute value of the containment net free volume.

From ANSI/ANS 56.8-1994, the Type A leakage rate is calculated from the following equation:

La, = -2400 A/B [Eqn 1]

Where:

Lam is the measured integrated leakage rate A is the slope of the least squares fit line B is the Intercept of the least squares fit line The slope of the least squares fit line can be expressed as:

A = WA- A-Where W1 is the containment air mass at time t= t4and W, is the containment air mass at time t=0 The intercept of the least squares fit line B = W, From ANSI/ANS 56.8-1994 W, 144V [(PP )1 and W =44v [(P.-PPo1 R and R[ T where:

V = containment net free volume R = ideal gas constant P = total absolute pressure in containment P, = containment weighted vapor pressure T = containment weighted absolute temperature Substituting into Eqn 1:

La -2400T, A[ R J( TR J S144V(P.- PE 2

TV~- 944,004q -OZ, October 31, 2006 Lam =-2400[To .Ti (Po (PiPPJ')I] I or L.m =24 Ti (Po -P.

1T(P0P0)

Thus the measured Type Atest or ILRT leakage rate depends only upon the containment total pressure, partial pressure of water vapor and containment temperature and not on the absolute value of the containment net free volume.

==

Conclusion:==

A breach in the concrete encased area of the drywell shell, slightly in excess of an equivalent 3/32-inch orifice, would have been identified by the Type A test as a change in pressure and/or temperature that would have resulted in a leakage rate in excess of the test allowable value of 0.75 % by weight per day. This was not identified in the November 2000 Type Atest at Oyster Creek.

Prepared ByZ> Date: IoA3 Reviewed By: Date:

3

October 31, 2006 OYSTER CREEK ILRT November 8,2000 1.0000 ---

0.9000 0.8000 ACCEPTANCE CRITERIA= 75%La 0.7000 0.60G0Laaeat0-,C 0.5000 0.3767wt%/day 0.4000 0.3000 Measured Leakage, La .

02000-0.1000 -

4Q

S~t

~4c4q -0o Attachment 7.10 MPR Third Party Review

( - Pages)

- MPR ASSOCIATES1 INC..

Ns 1-i1 Privileged and Confidential November 3, 2006 Mr. F. Howie Ray Manager, Mech/Struct Design Oyster Creek Generating Station AmerGen Energy Company, LLC U.S. Route 09 Forked River, NJ 08731-0388

Subject:

Third Party Tndependent Review of Oyster Creek Drywell Water Evaluation

Dear Mr. Ray:

MPR has completed a HU-AA-1212 Independent Third Party Review of the Oyster Creek drywell evaluation concerning standing water found in dryweli shell inspection trenches in the 101 31' concrete floor in the drywell. This review included the following documents:

" Technical Evaluation A/R A2152754 E06, with attachments

" Technical Evaluation A/R A2152754 E09, with attachments

• ECR 06-00879 Based on this review, we generated two comments, one concerning reported local wall thinning in Bay 17 possibly exceeding limiting dimensions for being considered local, and one concerning the relatively low pH value (and possible corrosivity) of trench/drywell gap water during outages when the migration of CRD water through the concrete pad to the inspection trenches and drywell wall occurs. Those were transmitted to you via email on November 2. Both comments have been resolved as follows:

Local wall thinning in Bay 17: "technicalEvaluation AiR A2152754 E09 has been revised to include another local thinning acceptance criterion documented in Oyster

("reek calculation C-4302-187-5320-024. The UT measurements of concern meet this acceptance criterion and this issue is considered resolved.

a Characterization of the water in the drywell: Section 2.8 of Technical Evaluation

,AR A2152754 E06 has been revised to clarify the tbllowing points:

-- Any subsequent water (such as reactor coolant) entering the concrete floor-to-drywell gap will increase in pH due to its migration through and contact with the concrete. l'his will reduce its corrosivity compared to neutral p[-[ water.

.i20 KINGSRE .dXCANGRIA. VA 22314-:12:30 A .0-t-~O

!01-519-6200 A:735912 FAX: 703-519-0224 t lw lrcr

!dfp:{h`d,,w.mpr.com

• rT-fL 54 H. A-r 7, Mr. F. Howie Ray November 3, 2006

- The corrosion of drywell steel surfaces in contact with gap water is expected to occur only during outages when oxygen is present. Corrosion during operation is expected to be almost nil since the drywell operates inerted and no oxygen is present to drive the corrosion reaction. During outages, shell corrosion losses in the gap are expected to be small since the exposure time is very limited and the water pH is expected to be relatively high.

- The expected low corrosion losses in the concrete-to-drywell gap area have been confirmed by examination of steel surfaces in the trenches which has revealed only superficial corrosion of the drywell shell.

With the resolution of these concerns, we consider that the Technical Evaluations and attachments successfully address:

• The structural integrity of the concrete and drywell shell, The adequacy of repairs, and the effect of the repairs on the assumptions or inputs used for safety and other analyses, and The impacts of past water migration and current repairs on design and the licensing bases.

We also reviewed the technical bases for the Technical Evaluation and conclude that all inputs are accurate or conservative, assumptions are conservative, chemical analysis results are used appropriately, and corrosion evaluations are correct and results used accurately.

Please let me know if you have any questions about this letter.

Sincerely, J. E. Nestell, PhD