ML111920258

Facility Cpp Report (Final) - Structural Inspection of Horizontal Storage Modules Pad

ML111920258
Person / Time
Site:	Three Mile Island, 07200020
Issue date:	07/31/2009
From:	Krauss P, Lawler J Wiss, Janney, Elstner Associates
To:	Wilberg M CH2M-WG Idaho, NRC/NMSS/SFST
Allen W NMSS/SFST 492-3148
References
Download: ML111920258 (234)

Text

THREE MILE ISLAND FACILITY CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad Idaho Falls, ID RFP No. 00713089 TMI 2 HSM and Pad CPP-1774 Inspection July 31, 2009 WJE No. 2008.1917 Prepared for:

Mr. Michael Wilberg CH2M-WG Idaho, LLC 1580 Sawtelle Street P.O. Box 1625 Idaho Falls, ID 83415-2503 Prepared by:

Wiss, Janney, Elstner Associates, Inc.

330 Pfingsten Road Northbrook, Illinois 60062 847.272.7400 tel l 847.291.9599 fax

THREE MILE ISLAND FACILITY CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad Idaho Falls, ID John S. Lawler, Ph.D., P.E.

Senior Associate Paul D. Krauss, P.E.

Principal, Project Manager RFP No. 00713089 - TMI 2 HSM and Pad CPP-1774 Inspection July 31, 2008 WJE No. 2008.1973 Prepared for:

Mr. Michael Wilberg CH2M-WG Idaho, LLC 1580 Sawtelle Street P.O. Box 1625 Idaho Falls, ID 83415-2503 Prepared by:

Wiss, Janney, Elstner Associates, Inc.

330 Pfingsten Road Northbrook, Illinois 60062 847.272.7400 tel l 847.291.9599 fax

TABLE OF CONTENTS Introduction ................................................................................................................................................... 1 Background ................................................................................................................................................... 2 Investigation Approach ................................................................................................................................. 3 Field Investigation .................................................................................................................................. 4 Laboratory Testing ................................................................................................................................. 4 Analyze Results and Report Findings .................................................................................................... 4 Field Investigation ........................................................................................................................................ 4 Visual Survey ......................................................................................................................................... 5 Percolation Testing ................................................................................................................................. 8 Ground Penetrating Radar ...................................................................................................................... 9 Core Location Identification................................................................................................................. 10 Laboratory Investigation ............................................................................................................................. 10 Petrographic Examinations................................................................................................................... 10 Concrete Compressive Strength ........................................................................................................... 11 Chloride Content .................................................................................................................................. 12 Structural Analysis ...................................................................................................................................... 12 Discussion Of Findings And Durability Potential ...................................................................................... 13 Preliminary Repair Recommendations ....................................................................................................... 14 Conclusions ................................................................................................................................................. 15 Bibliography ............................................................................................................................................... 15 Figures ........................................................................................................................................................ 16 Appendix A - Comparison of HSM Appearance in 2008 and 2009 Appendix B - Petrographic Analyses Appendix C - Compressive Strength Testing Appendix D - HSM Design Information

THREE MILE ISLAND FACILITY CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad Idaho Falls, ID Wiss, Janney, Elstner Associates (WJE) recently completed a site investigation and laboratory studies to determine the extent and causes of deterioration occurring to the Horizontal Storage Modules (HSMs) at the Three Mile Island (TMI) Facility CPP 1774 at the Idaho Nuclear Technology and Engineering Center (INTEC). The work was completed in response to the CH2M-WG IDAHO, LLC (CWI) Request For Proposal (RFP) No. 00713089 TMI 2 HSM and Pad CPP-1774 Inspection. This report presents the site inspection and laboratory testing results and conclusions related to the primary causes of deterioration in the HSMs. General conceptual recommendations to address existing damage and prolong the life of the structures are presented.

INTRODUCTION The following information was provided by CH2M-WG (Wilberg, 2008):

The Three Mile Island (TMI) Facility CPP 1774 at the Idaho Nuclear Technology and Engineering Center (INTEC) is an Independent Spent Fuel Storage Installation (ISFSI) licensed by the United States Nuclear Regulatory Commission (NRC). The purpose of this facility is to store nuclear material regulated by the NRC. This facility comprises a concrete pad (Base Mat) with a security fence to enclose thirty (30) concrete Horizontal Storage Modules (HSMs). These HSMs house metal TMI Dry Shielded Canisters (DSCs). The HSM function is to provide radiological shielding and elemental (adverse natural phenomena) protection for the DSCs. Because these HSMs provide the shielding and protection for the DSC it is important that the concrete HSMs maintain their designed service life requirements. It has recently been noted that some of the HSMs are beginning to experience cracking and spalling of the concrete. The HSMs were designed to have a fifty (50) year service life. The HSMs are considered important to safety and are approximately ten (10) years old. It is a concern that this cracking and spalling are indications that the concrete may be breaking down prematurely. It is necessary that the HSMs maintain their designed function for the design service life of the HSM and meet their license requirements. The purpose of this study is to determine the extent and causes of deterioration occurring to the Horizontal Storage Modules (HSMs) at the TMI Facility CPP 1774 (INTEC) and to design repairs that will allow these structures and the Base Mat on which they are support to achieve their 50 year design service lives. The HSMs house metal TMI Dry Shielded Canisters (DSCs).

In 2000, it was noted that some of the HSMs had developed cracking and a cursory site survey was performed. The conclusion of the site survey was that the cracking was not significant. Another survey was performed in 2007 because of concern over continued cracking and efflorescence staining on the HSMs. The conclusion of this survey was also that the cracking and efflorescence was again insignificant and cosmetic. Since deterioration was continuing and these cursory visual surveys performed in 2000 and 2007 were not adequate to establish a sound baseline for the condition assessment of the units, a condition survey of all the 30 HSMs was performed in June and July 2008 by M. D. Wilberg (report dated October 15, 2008, Rev. 15). This study provided documentation of the extent of visual degradation and was used during this current survey to assess the rate of ongoing deterioration.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 2 Our current study did not reproduce the overall condition assessment of the HSMs performed in 2008 but focused on determining the cause of the distress. Site work and laboratory studies were focused on issues related to concrete material quality, strength, and the long-term durability potential. The purpose of this work was to determine the cause of the current distress and assess its significance to the structural integrity and durability of the HSMs. Additionally, recommendations for repair/retrofit and conceptual level recommendations to achieve a 50-year service life have been included. Specific repair details, development of cost estimates for the recommended repairs, preparation of material and construction specifications for the repairs, and maintenance and monitoring recommendations to preserve the HSMs and Base Mat through the design service life will be presented separately.

BACKGROUND The following background information was provided by CH2M-WG (Wilberg, 2008).

The construction of the CPP-1774 was managed by Lockheed Martin for DOE. The design agent for the HSMs was Transnuclear West (TNW), Inc., San Jose, California and the precast builder of the HSM was Yakima Precast, Inc., Yakima, Washington. Lockheed Martin accepted the HSMs for use in 1999.

2.0 DESCRIPTION

OF STRUCTURE The HSM is a prefabricated reinforced concrete vault that is 10-3 wide by 18-2 long by 14-6 high (nominal dimensions). The HSM serves to provide shielding for the DSC to minimize the radiation dose rate from the ISFSI facility. The NUHOMS HSM provides for horizontal storage of the DSC to remove the heat load from the DSC. The HSM includes a steel lined door which is removed for insertion and retrieval of the DSC. For the TMI-2 ISFSI, the HSM is modified from the standard NUHOMS system to provide an access door on the back wall for monitoring and maintenance of the DSC vent and purge HEPA filters. A drain is provided to remove any moisture that may get into the HSM. The HSMs are set on a base mat 205 feet by 110 feet. The long axis of the HSM runs in the north south direction. Fifteen (15) HSMs are placed side by side with a 6 inch gap forming two rows of HSMs in the east west direction on the base mat.

The prefabricated modules are installed in two pieces: the roof (lid) and the body. The body consists of four walls and floor. All sections are a minimum of two feet thick.

The HSM contains no cooling air vents as they are not required to remove the decay heat generated by the TMI-2 canisters. The cooling air flows around the DSC to the top of the HSM. Air warmed by the DSC transfers heat to the HSM walls and roof slab. Adjacent modules are spaced to provide adequate natural convection flow and shielding. This passive system provides an effective means for spent fuel decay heat removal.

The HSM wall and roof thicknesses are primarily dictated by shielding requirements. The massive walls combined with the shield walls on the outer most HSMs adequately protect the DSCs against tornado missiles and other adverse natural phenomena. The tornado generated missile effects are considered to bound any other probable impact-type accident.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 3 The DSC is slid into position in the HSM using parallel structural steel beams supported by the front and back HSM concrete walls. Once in its storage locations, the weight of the DSC is transmitted directly to the HSM front and rear walls. The front and rear wall access opening into the HSM are covered by thick steel doors which provide protection against tornado missiles. The door assembly includes a solid concrete core which acts as a combined gamma and neutron shield. The rear wall HEPA filter access opening is covered by a thick steel plate door hinged on one edge and padlocked, for security, on the other.

The HSM design documented in the TMI-2 ISFSI Safety Analysis Report (SAR) is constructed of 5,000 psi 28 day compressive strength normal weight concrete with Type II Portland cement meeting the requirements of ASTM C150. The concrete aggregate meets the specifications of ASTM C33. The concrete is reinforced with ASTM A615 or A706 Grade 60 deformed bar placed vertically and horizontally in each face of the walls, roof, and floor. The maximum HSM concrete temperature for normal, off-normal, and accident conditions is less than 200°F and meets the requirements of ACI 349-85 for normal concrete. Therefore, no special provisions are required for the NUHOMS-12T HSM concrete aggregates.

6.0 MATERIALS OF CONSTRUCTION According to the approved vendor data the concrete specification requirements were approved as being met. The concrete was specified as a 28-day compressive strength concrete, fc = 5,000psi (min). The water-cement ratio, by weight, is 0.45. When the mix contains a high range water-reducer or other super plasticizers, the maximum slump shall be 8. When a conventional mix without a high range water-reducer or other super plasticizer is used, the maximum slump shall be 4. The concrete unit weight shall have a minimum value of 145 pcf and maximum value of 152 pcf. The air content of the concrete shall be between 3.5% and 5.75%. The water soluble chloride ion (CI) content of the concrete shall not exceed 0.15% by weight of the cement. Cement shall be Type II and shall conform to the requirements of ASTM C150. Both fine and coarse aggregates shall conform to the requirements of ASTM C33.

Drawings of the HSM units showing wall thicknesses and dimensions specified are shown in Figures 1 and 2. The detail of the roof attachment anchor bolt is given in Figure 3. The typical mild steel reinforcing is No. 8 bars at 8 in. each way on each face (E.W.E.F) on the front and No. 9 bars at 8 in. E.W.E.F in rear wall of the base units and No. 8 bars at 8 in. E.W.E.F in the roof (lid) units. Representative photos of the HSMs are given in Figure 4 to Figure 7.

INVESTIGATION APPROACH Prior to commencing the field investigation, a meeting was held at WJEs Northbrook, IL offices with Michael Wilberg of CH2M-WG to discuss the scope of the work and the findings of his initial investigation. A report titled TMI-2 HSM 2008 Evaluation Report - ACI 349.3R7 (Wilberg, 2008) was provided to us and this included the June/July 2008 survey results. This report was reviewed prior to our field investigation.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 4 Field Investigation The following general tasks were completed as part of the field investigation:

• Attend Hazards Training (6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />).

• Attend daily site safety and operations meetings.

• Visual inspection of readily visible and accessible sections of HSMs and Base Mat. Document observations and photograph the nature and extent of distress.

• Examination of the extent and distribution of cracking.

• Hammer sounding delamination survey of representative accessible concrete surfaces.

• Reinforcing steel surveys using covermeters and ground penetrating radar at representative locations to determine cover and location of embedded reinforcing steel.

• Water percolation testing at anchor bolt blockouts in roof slabs.

• Identification of twelve locations for removal of concrete core samples for subsequent drilling and laboratory testing.

• Non-destructive evaluation surveys to evaluate condition and uniformity of concrete of the HSM wall and roof elements.

Corrosion potential surveys were initially planned but could not be completed since approval to drill 5/8-in. diameter holes through the 1-1/2-in. concrete cover to the reinforcing steel was not obtained prior to the completion of our field investigation. Further, no concrete spalling was removed and no inspection openings were made in the concrete since approval for these investigations were also not received during our site visit Laboratory Testing Subsequent our investigation, twelve core samples of concrete were received for evaluation. The laboratory work on these samples included the following:

• Receive and log samples.

• Photograph samples and select samples for testing.

• Test all cores for depth of carbonation (loss of alkalinity).

• Perform petrographic examination of selected core samples.

• Determine chloride content of selected cores.

• Test compressive strength of selected cores.

Analyze Results and Report Findings The results of the document review, site investigation and laboratory analysis were analyzed to determine the primary causes of the distress and to develop general repair concepts. Analysis of the data formed the basis for the assessment of the overall structural condition, cause of existing deterioration, and future durability potential of the concrete.

FIELD INVESTIGATION The field investigation was performed by Paul Krauss, John Lawler and Nathaniel Rende of WJE on April 27 to 30, 2009. Weather conditions were generally cool with intermittent rain showers. Michael Wilberg was present during the site investigation and assisted with coordination of the work. Corrosion

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 5 surveys, exploratory openings and sampling of concrete spalls could not be performed due to lack of required approvals for this work.

Visual Survey Close visual inspections characterized the distress in the HSMs into several categories. These include the following:

(1) Corner cracking and spalling in the roof slab near anchor holes (2) Map cracking on the vertical wall surfaces (3) Random and radial cracking at door edges in base units (4) Spalling at the bottom edge of Shield Walls (5) Efflorescence and water staining A complete inventory of all distress or complete comparison with the 2008 Survey by Wilberg was not the intent of our investigation. However, the photographs and descriptions provided in the 2008 Survey were very useful as benchmark information for the areas we examined in detail. A side-by-side comparison of photos taken by Wilberg in 2008 and photos by WJE in 2009 is given in Appendix A for selected HSMs. The extent of deterioration increased noticeably on the roof slabs over this period and was most pronounced in the northern corners of the roof slabs where severe deterioration had been present in 2008. In general, little change was observed in the base deterioration of the base units.

(1) Corner cracking and spalling in the roof slab and top of base unit Corner cracking and spalling in the HSMs roof slabs make up the most apparent and common type of distress. Dislodged pieces, loss of concrete (fine spalls), wide cracks, and efflorescence all exist at the most distressed locations. Photographs in Figure 8 to Figure 11 show the range of typical distress on the top slab corners. The cracking on the top surface of the lid appear radial to the hole. Cracking on the sides of the roof slab occurred where the radial cracking was severe and was typically, but not always, vertical in nature (Figure 12 to Figure 14). In some cases, vertical cracks were also observed in top corners of the base slabs (Figure 15). These cracks rarely aligned with cracks in the roof slab, but also appeared to be oriented around the anchor bolt. Pieces offset from the original plane of the concrete make up the worst distress locations.

Our examination of this distress was limited to visual and NDE-based investigation, since the spalling and loose concrete could not be removed to examine the origin of the distress. Therefore, further evaluations should be performed of the interior regions of the concrete after the loose concrete pieces are removed during repair operations. Based on this more in-depth examination, the conclusions and recommendations of this report may need to be modified.

Removal of roof slab anchor bolts and washer plates on selected HSMs allowed inspection of the anchor holes and top surface of the base unit at the hole (Figure 16 and Figure 17). During this process, it was noted that the anchor bolts were not uniformly tight - some could be loosened by hand. In addition, some washer plates as found were not positioned to cover the blockout opening (Figure 18). Typically, the portion of the top of the base unit exposed in this manner was covered in mastic.

(2) Map cracking on the vertical wall surfaces A visual inspection of the surfaces of the HSMs was conducted from the ground on the front and back faces of each HSM unit. Table 1 and Table 2 list the results of the visual survey for the front and back

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 6 faces, respectively. The cracking in the base units was graded on a general scale from 0 to 3 in 0.5 increments, with 0 being no visible distress and 3 being severe visible distress. Comments related to the distress observed are noted in the tables. A photograph of the map cracking, which generally fine in nature, is shown in Figure 19. The front and back surfaces of the base units were rated as to the presence of map cracking observed with notations of map cracking (mc), fine map cracking (fmc), very fine map cracking (vfmc) and very, very fine map cracking (vvfmc). Generally, this close-up inspection for map cracking was done at approximate elevations of 4 to 7 feet from the bottom of the HSM units. Figure 18 shows a base surface having highlighted map cracking. The vertical faces of the roof slabs at the front and back of the HSMs, as observed visually from the ground, were also rated on the same scale from 0 to 3, but no attempt to observe map cracking of the roof slabs was made.

Table 1. General Visual Ratings of Front Faces of HSMs Map Roof HSM No. Base Unit Comment*

Cracking** Slab 1 1.5 rh fmc 3.0 2 1.5 ve vfmc 3.0 3 2.0 rve vfmc 3.0 4 1.5 rv vfmc 2.0 5 1.5 rv fmc 3.0 6 1.5 rve vfmc 3.0 7 2.0 rv vfmc 3.0 8 1.0 r vfmc 0.5 9 1.0 -- vvfmc 3.0 10 2.0 rve vfmc 2.5 11 2.0 ve vfmc 1.5 12 2.5 rveh vfmc 3.0 13 2.0 rveh vfmc 2.0 14 1.5 rveh vfmc 2.5 15 1.5 rveh vfmc 2.5 16 0.5 -- vvfmc 0 17 0.5 h vvfmc 1.5 18 0.5 vh vfmc 0 19 0.5 -- vvfmc 0 20 0.5 h vfmc 1.0 21 0.5 vh fmc 1.0 22 0.5 h fmc 1.0 23 0.5 h vfmc 1.5 24 0.5 v vfmc 0.5 25 1.0 rvh fmc 1.0 26 1.0 rvh fmc 2.0 27 1.0 veh fmc 1.5 28 1.0 rv fmc 0.5 29 2.0 rve mc 0.5 30 1.5 rve vfmc 1.0

• h=horizontal cracks, v=vertical cracks, e=efflorescence, r=radial crack

• • mc=map cracking, fmc=fine map cracking, vfmc=very fine map cracking, vvfmc = very very fine map cracking

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 7 Table 2. General Visual Rating of Back Faces of HSMs Map Roof HSM No. Base Unit Comment*

Cracking** Slab 1 1.0 hve fmc 0 2 0.5 hve fmc 0 3 0.5 hv fmc 1.0 4 0.5 hve cc fmc 0.5 5 0.5 he cc fmc 0.5 6 0.5 h fmc 0.5 7 1.0 h mc 0.5 8 0.5 h fmc 0.5 9 0.5 e cc vfmc 1.0 10 0.5 -- mc 0.5 11 0.5 v mc 1.0 12 0.5 h mc 0.5 13 0.5 e vfmc 0.5 14 0.5 h fmc 0 15 0.5 -- mc 0.5 16 0.5 cc --- 0.5 17 0.5 h vvfmc 0.5 18 1.0 ve vvfmc 0.5 19 1.5 hve cc vvfmc 0.5 20 1.0 ve cc vvfmc 1.0 21 1.0 hve vfmc 0 22 1.0 e cc --- 0 23 1.0 he vvfmc 0.5 24 1.5 e cc vvfmc 1.0 25 1.0 h --- 1.0 26 1.0 ve vvfmc 0.5 27 1.0 he vvfmc 2.0 28 1.0 hve cc vvfmc 1.5 29 1.5 he cc vvfmc 1.0 30 1.5 he cc vvfmc 0.5

• h=horizontal cracks, v=vertical cracks, e=efflorescence, r=radial crack, cc =corner cracks (not recorded for front faces)

• • mc=map cracking, fmc=fine map cracking, vfmc=very fine map cracking, vvfmc = very very fine map cracking (3) Random cracking and radial cracking at door edges in base units The HSM base units exhibited horizontal cracks, vertical cracks, radial cracks (usually originating near the front door opening), and efflorescence at many of these crack locations was noted. A photo of horizontal cracks observed on the corners of the base unit is shown in Figure 20. This cracking typically coincided with the spacing of the horizontal reinforcing steel, as confirmed using GPR scanning technique (discussed below). An example of the radial cracks is shown in Figure 21.

The base units had a wide range of distress conditions with many HSMs in good condition but others with moderately widespread cracking. Generally, the worst cracking was along the front faces of HSM base units 1 to 15, but conditions varied. The cracking in the base units was generally not as severe as the cracking noted in the roof slabs.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 8 (4) Spalling at the bottom edge of shield walls The shield walls adjacent to HSM 1 and HSM 30 exhibited spalling (Figure 22). This damage was apparently caused by point loading, likely due to irregularities on the slab or shield wall surface, when the shield wall was installed. This does not appear indicative of on-going deterioration; however, additional investigation would be required to determine its cause.

(5) Efflorescence and water staining Efflorescence and water staining was common around cracks near the top corners of the HSMs (Figure 15, Figure 23, and Figure 24). Efflorescence typically is calcium carbonate formed when calcium hydroxide in the concrete is dissolved by moisture and carried to the surface of the concrete where it reacts with carbon dioxide. It is a strong indicator of persistent moisture moving through the concrete.

Water staining was also visible around the front and rear doors and below the drains at the rear of the HSMs. This indicates that the structures are not water-tight and that precipitation is entering the HSMs.

Percolation Testing To determine whether the mastic installed between the roof slabs and base units was trapping water in the anchor blockout holes, a water percolation test was conducted at eight anchor holes on random HSMs.

For this test, 24 oz. of water was poured into the hole and the time required for the water to drain so that the bottom of the holes was visible was measured. This time-to-drain is compared to a visual rating of cracking and deterioration (from 0 [no cracking] to 3 [cracking and spalling]) in Table 3. The test sites are identified by the HSM number and then the ordinal direction of the corner where the anchor hole was located.

Table 3. Water Percolation Test of Roof Slab Anchor Blockout Holes Time-to-drain Deterioration Test site (min:sec) Rating 5 NW 9:10 Severe (3) 5 NE > 15:00 Severe (3) 5 SE 1:30 Minor (1) 5 SW 0:25 None (0) 18 SW 0:45 None (0) 18 NW 0:10 Minor (1) 12 NE > 15:00 Severe (3) 13 NE > 15:00 Moderate (2)

Anchor blockout holes near corners that had severe cracking and distress drained much more slowly than blockout holes near corners that are currently in good condition. This suggests that water can become trapped in some holes and then freeze, causing the cracking and spalling. When water drained quickly, the water did not typically show up on the outside of the HSM but drained into the inside and over time appeared in the drain outlet on the backwall. When cracks were present at the top corner of the base unit near the anchor location, water sometimes leaked through the crack after the percolation test, as shown in Figure 24.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 9 Ground Penetrating Radar Ground Penetrating Radar (GPR) was used to locate reinforcing steel in the HSMs. GPR surveys performed on concrete elements allow for the detection of embedded objects, such as steel reinforcement, material interfaces, such as a slab to sub-base interface, and internal characteristics, such as voiding and flaws. The technique uses a high-frequency radar antenna, which transmits electromagnetic radar pulses along a longitudinal scan at the surface of a structural element. Electromagnetic signals are optically reflected from material interfaces of varying dielectric constant along the propagation path of the wave.

The reflected signals are collected by the antennae, amplified and displayed for subsequent interpretation.

The contrast between the electromagnetic properties of embedded steel and that of cured concrete provides a distinct direct reflection from the reinforcing bars. The magnitude and phase of these reflections are analyzed to determine the location of the reinforcing.

A Sir-3000 GPR unit and a 2600 MHz frequency antennae manufactured by Geophysical Survey Systems, Inc. (GSSI) was used on this project to locate the exterior layer of reinforcing bars in the walls and roof slab of selected HSM units. Table 4 to Table 6 list the findings of GPR surveys conducted on the front, rear and top surfaces of the HSMs. A reference is given to a figure for each scan in which the GPR scan output is graphically depicted.

The front face of HSM-05 was surveyed, indicating horizontal reinforcement at 8 in. spacing and an average depth of 2 in. and vertical reinforcement at 8 in. spacing and an average depth of 2.5 in. The rear face of HSM-15 was surveyed, indicating horizontal reinforcement at 7 to 8 in. spacing and an average depth of 1.5 in. and vertical reinforcement at 6 to 7 in. spacing and an average depth of 2.3 in. The top surface of the roof slab of HSM-27 was surveyed, indicating north-south reinforcement at 8 in. spacing and an average depth of 2.4 in. and east-west reinforcement at 6 to 7 in. spacing and an average depth of 1.7 in. Additional GPR scans were collected near each core location to locate and avoid the exterior layer of reinforcement prior to coring.

Table 4. Reinforcing Steel in Front Face of HSM-5 Scan ID / Bar Average Depth Range Average Depth Figure Found Direction Spacing (in.) (in.) (in.)

F003 / 10 bars over 6-Figure 27 8 1.7-2.3 2.0 Horizontal 0 scan F006 / 16 bars over 10-Figure 28 8 1.7-2.8 2.5 Vertical 0 scan Front Face Design: Wall thickness: 2-8, Reinforcing: #8 @ 8 in. each way/each face Table 5. Reinforcing Steel in Rear Face of HSM-15 Scan ID / Bar Average Depth Range Average Depth Figure Found Direction Spacing (in.) (in.) (in.)

F027 / 21 bars over 12-Figure 30 7 to 8 1.1-1.9 1.5 Horizontal 0 scan F026 / 20 bars over 10-Figure 29 6 to 7 1.4-2.6 2.3 Vertical 0 scan Rear Face Design: Wall thickness: 3-0, Reinforcing: #9 @ 8 in. each way/each face

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 10 Table 6. Reinforcing Steel in Top Surface of Roof Slab of HSM-27 Scan ID / Bar Average Depth Range Average Depth Figure Found Direction Spacing (in.) (in.) (in.)

F009 / 16 bars over 10-Figure 31 8 2.1-2.6 2.4 North-south 0 scan F012 / 25 bars over 16-Figure 32 6 to 7 1.5-1.8 1.7 East-west 6 scan Roof Slab Design: Slab thickness: 2-2 to 2-6, Reinforcing: #8 @ 8 in. each way/top & bottom Core Location Identification The location of twelve cores were selected and marked out with the objective of obtaining samples of concrete representative of the observed deterioration. The location of near surface reinforcing steel was determined prior to the coring using GPR. Because the coring could not be scheduled at the time of the investigation, WJE did not witness the coring or core hole repair operations. Core 15A was taken at a location about 8 in. above the location marked by WJE. The locations of the cores are shown on the drawings given in Appendix A.

LABORATORY INVESTIGATION Twelve core samples were received for laboratory evaluation and testing. The cores were logged and examined for general characteristics. Based on the sample locations and core conditions, six cores were selected for petrographic examinations.

Petrographic Examinations Petrographic studies were conducted on the concrete cores to determine the general composition and condition of the concrete, with specific attention to possible causes of cracking and concrete characteristics that might increase the propensity for cracking to occur or cause a decrease in the concrete durability. Detailed petrographic studies were performed for two HSM roof slab cores and for two HSM base cores. Partial petrographic examinations (comparative studies without thin sections) were performed for two additional cores. The cores chosen for the petrographic studies are listed in Table 7. Details of the petrographic studies and the core logs and photographs of the as-received cores are presented in Appendix B.

Table 7. Concrete Cores Examined Petrographically Portion of Core ID Significant Features Petrographic Examination Storage Module 5B Roof slab/front Cracking Comparative examination 7A Base/front No visible distress Comparative examination 9A Roof slab/front Cracking Detailed study with thin section 12A Base/front Radial crack Detailed study with thin section 27B Roof slab/top Pour line Detailed study with thin section 29B Base/rear Crack with efflorescence Detailed study with thin section Petrographic studies were conducted in accordance with the methods and procedures outlined in ASTM C 856, Standard Practice for Petrographic Examination of Hardened Concrete. The cores were cut in half perpendicular to the exterior surface and polished to accentuate the appearance of individual constituents and the structure of the concrete. Fresh fracture surfaces, thin sections, and immersion mounts were also prepared to aid in the study.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 11 The concrete represented by the cores examined is generally hard, dense, and well-consolidated. No significant differences were observed between the cores that contain major cracks and those that contain only minor cracks. Crack surfaces and air voids in the vicinity of the major cracks are coated with ettringite (calcium sulfoaluminate hydrate). This feature and efflorescence on the exterior surface of some cores are evidence of water infiltration and long-term exposure to moist conditions. Overall, secondary deposits are not abundant in the body of the concrete suggesting that water migration has occurred predominantly along the cracks. Limited evidence of alkali silica reaction, specifically two reactive particles in Core 27B, was observed, but no damage was directly associated with these occurrences.

Evidence of delayed ettringite formation was not observed.

The concrete contains siliceous natural gravel coarse aggregate and siliceous natural sand fine aggregate dispersed in an air-entrained portland cement paste (except Core 9A is not air-entrained). The paste is medium gray, hard, and dense. Estimated water-cement ratio (w/c) is typically 0.48 to 0.53; except the estimated w/c of Core 29B is 0.50 to 0.55. Estimates of w/c may be biased somewhat high, based on the advanced extent of cement hydration. No supplementary cementitious materials were observed in the paste. Air contents are variable (Table 8) and air-void distribution is mostly non-uniform. Exterior surfaces and crack surfaces are only minimally carbonated.

Table 8. Estimated Air Contents and Average Depth of Surface Carbonation of Cores from TMI Storage Modules Core ID Estimated Air Content Air-Void Distribution Carbonation Depth (in.)

5B - roof slab 3 to 4 percent Non-uniform 0.04 7A - base 5 to 6 percent Non-uniform 0.02 9A -roof slab 2 to 3 percent Not air entrained 0.03 12A -base 5 to 6 percent Non-uniform <0.01 27B -roof slab 4 to 5 percent Non-uniform 0.02 29B - base 4 to 5 percent Non-uniform 0.03 The gravel mainly consists of fresh and altered volcanic rocks, granitic rocks, schist and quartzite. The sand consists of rock types observed in the gravel, along with minerals that are individually present in these rock types. Overall, paste-aggregate bond is moderately weak to weak; fresh fractures mostly pass around aggregate particles. This is mainly due to the hard, smooth surfaces of the aggregates and not any defect in the concrete. Aggregate top size is 3/4 inch. The aggregate is generally well graded, but some cores were observed to be deficient in larger-size aggregate particles. Aggregate distribution in somewhat non-uniform in cores 7A, 9A, 12A, and 29B, but no specific distress was observed in regions of high or low aggregate volume. In most of the cores, a small proportion of the coarse aggregate particles are encircled by light-colored rims of carbonated high w/c paste suggesting these particles were wet when the concrete was batched. The paste-aggregate bond in these areas may also be reduced.

The paste content of the cores is moderately high and microcracking was found in the paste, often between coarse aggregate particles. This internal cracking may be due to early shrinkage stresses in the paste rich mix.

Concrete Compressive Strength The compressive strength of five cores was determined in accordance with ASTM C42 Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete. The test results are summarized in Table 9, and the test data is presented in Appendix C.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 12 The average compressive strength of the five cores is 7,570 psi with a range from 6,190 to 8,680 psi. The original 28-day design compressive strength was 5,000 psi minimum. The strengths measured in the aged concrete are consistent with the design strength.

Table 9. Compressive Strength of Core Samples Sample Length Avg. Diameter Compressive ID (in.) (in.) Strength (psi) 5A 7.468 3.710 7,520 15A 7.377 3.710 7,670 18A 7.376 3.705 6,190 27B 7.329 3.704 8,680 29A 7.470 3.703 7,780 Chloride Content Acid-soluble chloride analysis was performed at two depths in Core samples 7A and 27A, essentially according to ASTM C 1152, Method for Acid-Soluble Chloride in Mortar and Concrete. Core 7A is from the front of a base unit, while Core 27A is from the top of a roof slab. Chloride contents above 0.020 to 0.030 percent by mass of concrete, depending on cement content, can promote corrosion of embedded steel in non-carbonated concrete. The results can be found in Table 10. Very low chloride contents, near the minimum sensitivity of the test, were measured at depth averaging 3/8 and 11/2 in. in both cores.

Table 10. Chloride Contents in Concrete Core Samples Acid-Soluble Chloride, Core Depth, (in) percent by mass of sample 0.125-0.625 0.003 7A 1.25-1.75 0.006 0.125-0.625 0.005 27A 1.25-1.75 0.005 STRUCTURAL ANALYSIS WJE performed a limited structural analysis to study the effect of the deterioration on the strength of the HSM structures. CH2M-WG provided information describing design loadings, a load combination methodology and bending moments and shear forces (provided in Appendix D). Maximum bending moments and shear forces are given for dead, live, tornado wind, tornado missile, seismic, and thermal loads. It is uncertain if these maximum loads are factored or not and also where the maximum loads occur. It is recommended that the basis for these values be determined and a review of the structural calculations be made.

Assuming that the deterioration of the roof slabs is limited to the cracking and spalling that was visually observable over the base unit walls and outside the outer mat of reinforcing steel, the structural capacity of the roof is essentially unaffected. Similarly, the structural capacity of the base units is also essentially unaffected, assuming the deterioration to the walls of the base units is limited to the observed cracking and top corner spalls. Note that an investigation of the inside of the structures was not possible during this investigation.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 13 DISCUSSION OF FINDINGS AND DURABILITY POTENTIAL The initial investigation focused on deleterious reactions within the concrete, such as Alkali-silica reaction (ASR) and Delayed ettringite formation (DEF), which can cause slow but long-term and progressive failure of the concrete. Alkali-silica reaction (ASR) results when reactive silica present in the aggregate comes in contact with the alkali environment produced in the concrete by the portland cement and other cementitious admixtures. The product of this reaction, ASR gel, is expansive when wet and can cause concrete to self-destruct over time. In advanced cases of ASR, widespread cracking and concrete spalling may develop. Aggregates susceptible to ASR are not uncommon in the northwest United States.

Delayed ettringite formation (DEF) is a reaction that causes expansion of the concrete over time that occurs in concrete that has been heat-cured or which encountered a hot environment during curing. High temperatures break down ettringite, which normally forms immediately after water and cement first come into contact. The components that make up ettringite remain in the system and reform ettringite in the presence of moisture. Ettringite is expansive and produces internal pressures in the concrete leading to long-term damage. Additional symptoms of DEF include the presence of microcrystalline ettringite gel gaps around aggregate that develop as the cementitious matrix expands around the inert aggregate particles. Only one core examined from the HSMs exhibited gel deposits due to alkali-silica reaction (ASR), but the gel reaction products were not sufficient to cause any concrete cracking or distress at this time. ASR and DEF do not appear to be a factor in the current distress.

The chloride content measured in two core samples was very low and not sufficient to promote corrosion of embedded metals. Corrosion is also not a factor in the current distress.

Variable and sometimes low entrained air contents were found in some core samples and may cause the concrete to be prone to cyclic freezing damage. However, evidence of damage caused by cyclic freezing-thawing of internally saturated concrete was not observed in any of the core samples, even the core that did not contain entrained air.

Cracking in the base units appears to be primarily caused by shrinkage of the concrete that is internally restrained by the structure, though the most severe cracking and spalling appears related to freezing of trapped water within anchor bolt blockouts in the lids. Some map cracking or crazing cracking is also present and may be a result of the high paste content in the mix and drying shrinkage of the surface layer of concrete. The bond between the aggregate and paste is judged to be weak, due to the round, hard, and smooth aggregate surfaces of the river gravel that was used and the observed high water-cement ratio paste at the interface, possibly due to casting concrete with very wet aggregates. The concrete contains widespread microcracking likely related to the high paste content, variable water-cement ratio and maybe other factors related to curing. These factors contribute to the sensitivity of the structures to shrinkage cracking.

The severe corner cracking in the roof slabs appears to be primarily due to physical forces produced by freezing of water trapped in the anchor blockout holes, resulting in corner cracking and spalling. A major factor in the severity of damage appears to be whether or not the mastic installed between the base units and roof slab created a seal around the bottom of the anchor hole. Based on a limited testing program, water drained readily from roof slab anchor blockout holes that did not show distress but drained slowly from anchor holes that showed distress. Therefore, it appears that if water is able to drain quickly, the water does not have time to freeze and build up within the holes. Water poured into the anchor holes usually drained into the interior of the HSM. The existing anchor blockouts and through wall cracking

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 14 allows water to enter the HSMs and it was not uncommon to see water flow from the inside drain pipes or even water staining below the front door. This water could promote corrosion of the interior steel elements. Additional study is needed to assess the possible risk of corrosion of exposed metals within the HSMs.

Provided that the access of water to the anchor bolt blockout space is minimized during repair operations, the development of new cracking and associated deterioration at the corners of the roof slab should be reduced. The presence of existing cracks makes the structures susceptible to additional freezing and thawing related damage as water fills the cracks and freezes. The other deterioration mechanisms, such as efflorescence, leaching and cyclic freezing damage, are also related to the presence of large amounts of water and will be reduced if the concrete cracks are repaired or protected from water.

The repair approach should include: 1) sealing the anchor blockouts, 2) repair areas where cracks and spalls have developed, and 3) limit moisture exposure of the concrete.

PRELIMINARY REPAIR RECOMMENDATIONS Cracking and spalling at the corners of the roof slabs appear primarily due to freezing of water trapped in the roof slab anchor bolt holes. Therefore, preventing water infiltration into these holes and providing free drainage out of these holes should be a first priority. To address the anchor bolt holes, the following repair options should be considered:

• Fill the void within the anchor bolt blockout with polyurethane or silicone foam to prevent the accumulation of water within the holes.

• Seal the top surface of the roof slab, anchor bolt and washer plate to prevent water from entering the blockout void by applying a bead of silicone sealant between the bolt and washer and the washer plate and roof slab. Ensure that the outside circumference of the plastic (pvc) sleeve and the lid concrete is also sealed with sealant.

• Install a protective cap (plastic, preformed silicone or stainless steel) over the bolt, washer plate, and anchor bolt opening. Seal this cap to the surface of the concrete using silicone sealant.

• To allow monitoring of the effectiveness of the foam fill and sealant and to provide a secondary level of protection allowing any trapped water to drain freely to the outside of the HSM, provide a drain hole at the bottom of the blockout hole, at the interface with the base (optional).

To reduce the potential for additional deterioration at areas where cracking has occurred, the indicated repair is the removal of deteriorated concrete to behind the reinforcing steel, followed by patching.

Concrete removal should be done using small (15 lbs.) chipping hammers until sound concrete is encountered and extend at least 3/4 in. behind the existing reinforcing steel. The repair areas should be saw cut 4 to 6 in. back from the affected area and the edges of the patch left square. Repairs of incipient spalling or severe cracking are indicated on approximately 18 roof slab corners. Cracks and possible spalls were noted on about 11 upper corners of base units. Cracked areas that have not been dislodged can be repaired by resin injection followed by the application of a surface coating.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 15 The service life of the structures would be augmented by minimizing the exposure to moisture. To accomplish this goal, the following options may be considered:

• Treatment of vertical base unit concrete surfaces with breathable, water-repellant silane sealer.

Barrier coatings should not be used on the sides since water and water vapor may be trapped within the concrete.

• Treatment of top and side surfaces of the lids with UV-resistant waterproofing membrane type coating. Due to the risk of ponding, penetrating sealers will not be as effective on the top surfaces as waterproof membranes. As an alternative to the membrane, construct a braced-frame or similar structure over the HSMs to provide shelter from the elements.

CONCLUSIONS Based on the information collected during our site investigation and laboratory studies, the following conclusions can be made:

• Overall, the concrete quality is adequate, but does have some properties (high paste content, variable water-cement ratio, weak paste-aggregate bond) that make it prone to surface shrinkage cracking, which is widespread in the roof slabs and base units. However, no serious deleterious internal reactions were found, and ASR, DEF and corrosion are not considered factors in the current distress.

• The concrete had local areas of variable or low entrained air contents making it susceptible to cyclic freezing damage in localized areas. No evidence of cyclic freezing damage was noted at this time.

• Cracking in the roof slabs appears to be primarily due to physical forces of freezing water trapped in the anchor blockout holes.

• For the structure to remain serviceable over time, the long-term durability of the reinforced concrete requires enhancement. The repair effort should include:

o Sealing the anchor bolt blockout holes o Repair of deteriorated concrete and cracking o Use preservation techniques that might include surface sealers, membrane, or protective structure control the water exposure Bibliography Wilberg, M. D. (2008). TMI-2 HSM 2008 Evaluation Report - ACI 349.3R7. Idaho Falls: ISFSI Management.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 16 FIGURES

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 17 Figure 1. Drawing- Base Unit (Reproduced from drawing by Transnuclear, Inc.)

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 18 Figure 2. Drawing- Roof Slab (Reproduced from drawing by Transnuclear, Inc.)

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 19 Figure 3. Drawing- Roof Attachment Bolt (Reproduced from drawing by Transnuclear, Inc.).

Figure 4. HSMs on pad showing rear and shield wall (foreground) of HSM on south row and front of HSM s (background) of north row.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 20 Figure 5. Front of HSM

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 21 Figure 6. Rear of HSM

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 22 Figure 7. Top of row of HSMs Figure 8. Radial cracking around anchor bolt in roof slab

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 23 Figure 9. Radial cracking around anchor bolt in roof slab Figure 10. Radial cracking around anchor bolt in roof slab

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 24 Figure 11. Radial cracking around anchor bolt in roof slab

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 25 Figure 12. Extension of radial cracking on vertical faces of roof slabs

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 26 Figure 13. Extension of radial cracking on vertical faces of roof slabs

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 27 Figure 14. Extension of radial cracking on vertical faces of roof slabs Figure 15. Cracking at top exterior corner of base unit

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 28 Figure 16. Anchor bolt with washer plate and nut removed Figure 17. View of bottom of anchor bolt hole.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 29 Figure 18. Offset washer plate Figure 19. Map cracking highlighted with yellow

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 30 Figure 20. Cracking along vertical edge of base unit.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 31 Figure 21. Radial cracking around front door Figure 22. Spalling of shield wall adjacent to HSM 1.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 32 Figure 23. Efflorescence present at crack in base unit.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 33 Figure 24. Water leakage through cracks at upper corner of base unit after water percolation test in roof anchor blockout hole.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 34 Figure 25. Water staining below front door.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 35 Figure 26. Water staining below rear drain and ventilation door

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 36 Figure 27. GPR scan F003 collected on front face of HSM-05 showing horizontal reinforcement at 8 in.

spacing and an average depth of 2 in.

Figure 28. GPR scan F006 collected on front face of HSM-05 showing vertical reinforcement at 8 in.

spacing and an average depth of 2.5 in.

Figure 29. GPR scan F026 collected on rear face of HSM-15 showing vertical reinforcement at 6-7 in.

spacing and an average depth of 2.3 in.

Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad July 31, 2009 Page 37 Figure 30. GPR scan F027 collected on rear face of HSM-15 showing vertical reinforcement at 7-8 in.

spacing and an average depth of 1.5 in.

Figure 31. GPR scan F009 collected east on the top surface of the roof slab (middle of slab) of HSM-27 showing north-south reinforcement at 8 in. spacing and an average depth of 2.4 in.

Figure 32. Partial GPR scan F012 collected south on the top surface of the roof slab (middle of slab) of HSM-27 showing east-west reinforcement at 6-7 in. spacing and an average depth of 1.7 in.

APPENDIX A - COMPARISON OF HSM APPEARANCE IN 2008 AND 2009 Legend Core Crack Roof Slab Base Unit Drain (Rear Only)

Crack widths shown on drawings measured at yellow line

HSM No. 4 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 17, 2008 Photo ID: P 1 0.060 in.

0.100 in.

UP 0.003 in. 0.016 in.

Date: April 28, 2009 Photo ID: WJE 98

HSM No. 4 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 17, 2008 Photo ID: P 2 0.060 in.

0.100 in.

UP 0.003 in.

0.016 in.

Date: April 28, 2009 Photo ID: WJE 99

HSM No. 4 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 17, 2008 Photo ID: P 3 0.025 in.

0.060 in.

UP 0.100 in.

Date: April 28, 2009 Photo ID: WJE 101

HSM No. 4 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 17, 2008 Photo ID: P 5 UP Date: April 28, 2009 Photo ID: WJE 102

HSM No. 4 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 17, 2008 Photo ID: P 6 UP Date: April 28, 2009 Photo ID: WJE 103

HSM No. 4 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 17, 2008 Photo ID: P 7 UP Date: April 28, 2009 Photo ID: WJE 104

HSM No. 4 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 17, 2008 Photo ID: P 8 0.005 in.

UP Date: April 28, 2009 Photo ID: WJE 105

HSM No. 4 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 17, 2008 Photo ID: P 9 UP Date: April 28, 2009 Photo ID: WJE 106

HSM No. 4 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 12, 2008 Photo ID: P 10 UP Date: April 28, 2009 Photo ID: WJE 82

HSM No. 4 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 12, 2008 Photo ID: P 11 UP 0.035 in.

0.030 in. 0.010 in.

Date: April 28, 2009 Photo ID: WJE 83

HSM No. 4 WJE No. 2008.1917 Location: Base Unit, NE UP Date: June 12, 2008 Photo ID: P 12 UP Date: April 28, 2009 Photo ID: WJE 84

HSM No. 4 WJE No. 2008.1917 Location: Base Unit, North Face UP Date: June 12, 2008 Photo ID: P 13 UP 0.015 in.

Date: April 28, 2009 Photo ID: WJE 85

HSM No. 4 WJE No. 2008.1917 Location: Base Unit, North Face UP Date: June 12, 2008 Photo ID: P 14 0.005 in.

UP 0.010 in.

Date: April 28, 2009 Photo ID: WJE 86

HSM No. 5 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 17, 2008 Photo ID: P 1 0.015 in.

UP Date: April 28, 2009 Photo ID: WJE 107

HSM No. 5 WJE No. 2008.1917 Location: Base Unit, SW UP Date: July 31, 2008 Photo ID: P 2 UP 0.003 in.

Date: April 28, 2009 Photo ID: WJE 108

HSM No. 5 WJE No. 2008.1917 Location: Base Unit, SW UP Date: July 31, 2008 Photo ID: P 3 UP 0.003 in.

Date: April 28, 2009 Photo ID: WJE 109

HSM No. 5 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 17, 2008 Photo ID: P 4 UP Date: April 28, 2009 Photo ID: WJE 110

HSM No. 5 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 17, 2008 Photo ID: P 5 0.005 in.

UP 0.005 in. 0.005 in.

Date: April 28, 2009 Photo ID: WJE 111

HSM No. 5 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: July 31, 2008 Photo ID: P 6 0.005 in.

UP Date: April 28, 2009 Photo ID: WJE 113

HSM No. 5 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 12, 2008 Photo ID: P 7 UP 0.100 in.

Date: April 28, 2009 Photo ID: WJE 87

HSM No. 5 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: July 31, 2008 Photo ID: P 8 0.100 in.

UP Date: April 28, 2009 Photo ID: WJE 88

HSM No. 5 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 12, 2008 Photo ID: P 9 0.030 in.

UP 0.060 in.

Date: April 28, 2009 Photo ID: WJE 90

HSM No. 5 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 12, 2008 Photo ID: P 10 UP Date: April 28, 2009 Photo ID: WJE 91

HSM No. 5 WJE No. 2008.1917 Location: Base Unit, North Face UP Date: June 12, 2008 Photo ID: P 11 UP Date: April 28, 2009 Photo ID: WJE 92

HSM No. 5 WJE No. 2008.1917 Location: Base Unit, North Face UP Date: June 12, 2008 Photo ID: P 12 UP 0.005 in.

Date: April 28, 2009 Photo ID: WJE 94

HSM No. 5 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 12, 2008 Photo ID: P 13 UP Date: April 28, 2009 Photo ID: WJE 95

HSM No. 5 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: July 31, 2008 Photo ID: P 14 UP 0.100 in. 0.130 in.

0.080 in.

Date: April 28, 2009 Photo ID: WJE 97

HSM No. 7 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 17, 2008 Photo ID: P 1 UP Date: April 28, 2009 Photo ID: WJE 114

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 17, 2008 Photo ID: P 2 UP Date: April 28, 2009 Photo ID: WJE 115

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 17, 2008 Photo ID: P 3 UP Date: April 28, 2009 Photo ID: WJE 116

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 17, 2008 Photo ID: P 4 UP Date: April 28, 2009 Photo ID: WJE 117

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 17, 2008 Photo ID: P 5 UP Date: April 28, 2009 Photo ID: WJE 118

HSM No. 7 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 17, 2008 Photo ID: P 6 UP Date: April 28, 2009 Photo ID: WJE 119

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 17, 2008 Photo ID: P 7 UP Date: April 28, 2009 Photo ID: WJE 120

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 17, 2008 Photo ID: P 8 UP Date: April 28, 2009 Photo ID: WJE 121

HSM No. 7 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 17, 2008 Photo ID: P 9 UP Date: April 28, 2009 Photo ID: WJE 124

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 17, 2008 Photo ID: P 10 UP Date: April 28, 2009 Photo ID: WJE 125

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 12, 2008 Photo ID: P 11 UP Date: April 28, 2009 Photo ID: WJE 147

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 12, 2008 Photo ID: P 12 UP Date: April 28, 2009 Photo ID: WJE 148

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab and Base Unit, NW UP Date: June 12, 2008 Photo ID: P 14 UP Date: April 28, 2009 Photo ID: WJE 151

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 12, 2008 Photo ID: P 15 0.010 in.

0.005 in.

UP Date: April 28, 2009 Photo ID: WJE 152

HSM No. 7 WJE No. 2008.1917 Location: Roof Slab, Top/NE Lifting Embed UP Date: June 12, 2008 Photo ID: P 16 UP Date: April 28, 2009 Photo ID: WJE 153

HSM No. 9 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 17, 2008 Photo ID: P 1 UP Date: April 28, 2009 Photo ID: WJE 126

HSM No. 9 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 17, 2008 Photo ID: P 2 UP 0.005 in.

0.010 in.

Date: April 28, 2009 Photo ID: WJE 127

HSM No. 9 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 17, 2008 Photo ID: P 3 UP Date: April 28, 2009 Photo ID: WJE 128

HSM No. 9 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 17, 2008 Photo ID: P 4 0.010 in.

UP Date: April 28, 2009 Photo ID: WJE 129

HSM No. 9 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 17, 2008 Photo ID: P 5 0.010 in.

UP Date: April 28, 2009 Photo ID: WJE 131

HSM No. 9 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 17, 2008 Photo ID: P 6 UP Date: April 28, 2009 Photo ID: WJE 132

HSM No. 9 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 17, 2008 Photo ID: P 7 UP Date: April 28, 2009 Photo ID: WJE 133

HSM No. 9 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 12, 2008 Photo ID: P 8 UP 0.020 in.

Date: April 28, 2009 Photo ID: WJE 140

HSM No. 9 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 12, 2008 Photo ID: P 9 UP 0.040 in.

0.050 in.

0.050 in.

Date: April 28, 2009 Photo ID: WJE 141

HSM No. 9 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 12, 2008 Photo ID: P 10 UP 0.050 in.

0.020 in. 0.040 in.

Date: April 28, 2009 Photo ID: WJE 143

HSM No. 9 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 12, 2008 Photo ID: P 11 UP Date: April 28, 2009 Photo ID: WJE 144

HSM No. 9 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 12, 2008 Photo ID: P 12 UP Date: April 28, 2009 Photo ID: WJE 146

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 23, 2008 Photo ID: P 1 UP Date: April 29, 2009 Photo ID: WJE 231

HSM No. 10 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 23, 2008 Photo ID: P 2 UP Date: April 29, 2009 Photo ID: WJE 232

HSM No. 10 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 23, 2008 Photo ID: P 3 UP Date: April 29, 2009 Photo ID: WJE 233

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 23, 2008 Photo ID: P 4 UP Date: April 29, 2009 Photo ID: WJE 234

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: July 31, 2008 Photo ID: P 5 UP 0.010 in.

Date: April 29, 2009 Photo ID: WJE 236

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 23, 2008 Photo ID: P 6 0.010 in.

0.005 in.

UP 0.005 in.

Date: April 29, 2009 Photo ID: WJE 237

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: July 31, 2008 Photo ID: P 7 UP Date: April 29, 2009 Photo ID: WJE 238 Note: Paste over bar removed by WJE after 2009 photo

HSM No. 10 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 23, 2008 Photo ID: P 8 UP Date: April 29, 2009 Photo ID: WJE 240

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 23, 2008 Photo ID: P 9 UP Date: April 29, 2009 Photo ID: WJE 242

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, SW corner/face UP Date: June 23, 2008 Photo ID: P 10 0.002 in. 0.005 in.

UP Date: April 28, 2009 Photo ID: WJE 243

HSM No. 10 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 23, 2008 Photo ID: P 11 UP Date: April 29, 2009 Photo ID: WJE 244

HSM No. 10 WJE No. 2008.1917 Location: Base Unit, SW corner/face UP Date: June 23, 2008 Photo ID: P 12 UP Date: April 29, 2009 Photo ID: WJE 245

HSM No. 10 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 23, 2008 Photo ID: P 13 UP Date: April 29, 2009 Photo ID: WJE 246

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 16, 2008 Photo ID: P 14 UP 0.188 in.

Date: April 29, 2009 Photo ID: WJE 247

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: July 31, 2008 Photo ID: P 15 UP Date: April 29, 2009 Photo ID: WJE 249

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 16, 2008 Photo ID: P 16 0.075 in.

0.188 in.

UP Date: April 29, 2009 Photo ID: WJE 250

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 16, 2008 Photo ID: P 17 0.075 in.

UP 0.015 in.

0.060 in.

0.005 in.

Date: April 29, 2009 Photo ID: WJE 251

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 16, 2008 Photo ID: P 18 0.075 in.

0.060 in.

UP Date: April 29, 2009 Photo ID: WJE 252

HSM No. 10 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 16, 2008 Photo ID: P 19 UP Date: April 29, 2009 Photo ID: WJE 253

HSM No. 10 WJE No. 2008.1917 Location: Base Unit, North Face UP Date: June 12, 2008 Photo ID: P 20 0.050 in.

0.008 in.

UP Date: April 29, 2009 Photo ID: WJE 254

HSM No. 10 WJE No. 2008.1917 Location: Base Unit, NE UP Date: June 12, 2008 Photo ID: P 21 UP Date: April 29, 2009 Photo ID: WJE 255

HSM No. 10 WJE No. 2008.1917 Location: Base Unit, North Face UP Date: June 12, 2008 Photo ID: P 22 0.008 in.

UP Date: April 29, 2009 Photo ID: WJE 256

HSM No. 10 WJE No. 2008.1917 Location: Base Unit, NW UP Date: June 12, 2008 Photo ID: P 23 UP Date: April 29, 2009 Photo ID: WJE 257

HSM No. 10 WJE No. 2008.1917 Location: Base Unit, NW UP Date: June 16, 2008 Photo ID: P 24 UP Date: April 29, 2009 Photo ID: WJE 258

HSM No. 12 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 23, 2008 Photo ID: P 1 UP Date: April 28, 2009 Photo ID: WJE 134

HSM No. 12 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 23, 2008 Photo ID: P 2 UP Date: April 28, 2009 Photo ID: WJE 135

HSM No. 12 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 23, 2008 Photo ID: P 3 UP Date: April 28, 2009 Photo ID: WJE 137

HSM No. 12 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 23, 2008 Photo ID: P 3 UP Date: April 28, 2009 Photo ID: WJE 136

HSM No. 12 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 23, 2008 Photo ID: P 4 UP Date: April 28, 2009 Photo ID: WJE 138

HSM No. 12 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 16, 2008 Photo ID: P 5 0.025 in.

UP Date: April 28, 2009 Photo ID: WJE 157

HSM No. 12 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 16, 2008 Photo ID: P 6 0.100 in.

UP 0.075 in. 0.035 in.

0.100 in.

offset Date: April 28, 2009 Photo ID: WJE 158

HSM No. 12 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 16, 2008 Photo ID: P 7 UP 0.035 in.

Date: April 28, 2009 Photo ID: WJE 160

HSM No. 12 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 16, 2008 Photo ID: P 8 UP Date: April 28, 2009 Photo ID: WJE 162

HSM No. 12 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 16, 2008 Photo ID: P 9 UP 0.020 in.

0.050 in.

0.015 in.

Date: April 28, 2009 Photo ID: WJE 163

HSM No. 12 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 16, 2008 Photo ID: P 10 UP 0.050 in.

Date: April 28, 2009 Photo ID: WJE 164

HSM No. 12 WJE No. 2008.1917 Location: Base Unit, North Face UP Date: June 16, 2008 Photo ID: P 11 UP 0.010 in.

Date: April 28, 2009 Photo ID: WJE 165

HSM No. 12 WJE No. 2008.1917 Location: Base Unit, North Face UP Date: June 16, 2008 Photo ID: P 12 0.010 in.

UP 0.005 in.

Date: April 28, 2009 Photo ID: WJE 166

HSM No. 18 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 17, 2008 Photo ID: P 1 UP 0.005 in.

Date: April 29, 2009 Photo ID: WJE 205

HSM No. 18 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 17, 2008 Photo ID: P 2 UP Date: April 29, 2009 Photo ID: WJE 206

HSM No. 18 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 17, 2008 Photo ID: P 3 UP 0.005 in.

Date: April 29, 2009 Photo ID: WJE 207

HSM No. 18 WJE No. 2008.1917 Location: Base Unit, NE UP Date: June 23, 2008 Photo ID: P 4 UP 0.010 in.

Date: April 29, 2009 Photo ID: WJE 215

HSM No. 18 WJE No. 2008.1917 Location: Base Unit, NW UP Date: June 23, 2008 Photo ID: P 5 UP Date: April 29, 2009 Photo ID: WJE 216

HSM No. 19 WJE No. 2008.1917 Location: Base Unit, NE UP Date: June 23, 2008 Photo ID: P 1 0.015 in.

UP Date: April 29, 2009 Photo ID: WJE 219

HSM No. 19 WJE No. 2008.1917 Location: Base Unit, NE UP Date: June 23, 2008 Photo ID: P 2 UP 0.005 in.

Date: April 29, 2009 Photo ID: WJE 220

HSM No. 19 WJE No. 2008.1917 Location: Base Unit, NW UP Date: June 23, 2008 Photo ID: P 3 0.020 in.

0.015 in. 0.060 in.

0.015 in.

UP Date: April 29, 2009 Photo ID: WJE 221

HSM No. 19 WJE No. 2008.1917 Location: Base Unit, NW UP Date: June 23, 2008 Photo ID: P 4 0.060 in.

UP 0.060 in.

0.040 in.

Date: April 29, 2009 Photo ID: WJE 223

HSM No. 19 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 23, 2008 Photo ID: P 5 UP Date: April 29, 2009 Photo ID: WJE 224

HSM No. 19 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 23, 2008 Photo ID: P 6 UP Date: April 29, 2009 Photo ID: WJE 225

HSM No. 19 WJE No. 2008.1917 Location: Base Unit, NW UP Date: June 23, 2008 Photo ID: P 7 UP Date: April 29, 2009 Photo ID: WJE 226

HSM No. 24 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 17, 2008 Photo ID: P 1 UP Date: April 29, 2009 Photo ID: WJE 259

HSM No. 24 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 17, 2008 Photo ID: P 2 UP Date: April 29, 2009 Photo ID: WJE 260

HSM No. 24 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 17, 2008 Photo ID: P 3 UP Date: April 29, 2009 Photo ID: WJE 261

HSM No. 24 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 17, 2008 Photo ID: P 4 0.008 in.

0.008 in.

UP Date: April 29, 2009 Photo ID: WJE 262

HSM No. 24 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 17, 2008 Photo ID: P 6 UP Date: April 29, 2009 Photo ID: WJE 263

HSM No. 24 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 17, 2008 Photo ID: P 7 UP 0.005 in.

Date: April 29, 2009 Photo ID: WJE 264

HSM No. 24 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 17, 2008 Photo ID: P 8 UP Date: April 29, 2009 Photo ID: WJE 265

HSM No. 24 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 23, 2008 Photo ID: P 9 UP Date: April 28, 2009 Photo ID: WJE 196

HSM No. 24 WJE No. 2008.1917 Location: Base Unit, NE UP Date: June 23, 2008 Photo ID: P 10

~0.15 in.

0.015 in.

UP 0.060 in.

Date: April 28, 2009 Photo ID: WJE 197

HSM No. 24 WJE No. 2008.1917 Location: Base Unit, NE UP Date: June 23, 2008 Photo ID: P 11 UP Date: April 28, 2009 Photo ID: WJE 198

HSM No. 24 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 23, 2008 Photo ID: P 12 0.015 in.

UP Date: April 28, 2009 Photo ID: WJE 199

HSM No. 24 WJE No. 2008.1917 Location: Base Unit, NW UP Date: June 23, 2008 Photo ID: P 13 0.025 in.

UP Date: April 28, 2009 Photo ID: WJE 200

HSM No. 24 WJE No. 2008.1917 Location: Base Unit, NW UP Date: June 23, 2008 Photo ID: P 14 0.040 in.

UP Date: April 28, 2009 Photo ID: WJE 201

HSM No. 24 WJE No. 2008.1917 Location: Base Unit, NW UP Date: June 23, 2008 Photo ID: P 15 UP Date: April 28, 2009 Photo ID: WJE 202

HSM No. 24 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 23, 2008 Photo ID: P 16 UP Date: April 28, 2009 Photo ID: WJE 203

HSM No. 24 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: June 23, 2008 Photo ID: P 17 UP Date: April 28, 2009 Photo ID: WJE 204

HSM No. 27 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 16, 2008 Photo ID: P 1 UP 0.005 in.

Date: April 29, 2009 Photo ID: WJE 266

HSM No. 27 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 16, 2008 Photo ID: P 2 UP 0.008 in.

0.003 in.

0.008 in.

Date: April 29, 2009 Photo ID: WJE 267

HSM No. 27 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 16, 2008 Photo ID: P 3 UP Date: April 29, 2009 Photo ID: WJE 268

HSM No. 27 WJE No. 2008.1917 Location: Base Unit, SE UP Date: June 16, 2008 Photo ID: P 4 UP Date: April 29, 2009 Photo ID: WJE 269

HSM No. 27 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 16, 2008 Photo ID: P 5 UP Date: April 29, 2009 Photo ID: WJE 270

HSM No. 27 WJE No. 2008.1917 Location: Base Unit, SW UP Date: June 16, 2008 Photo ID: P 6 UP Date: April 29, 2009 Photo ID: WJE 271

HSM No. 27 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 23, 2008 Photo ID: P 7 UP 0.015 in.

0.005 in.

Date: April 28, 2009 Photo ID: WJE 182

HSM No. 27 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 23, 2008 Photo ID: P 8 UP Date: April 28, 2009 Photo ID: WJE 183

HSM No. 27 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: June 23, 2008 Photo ID: P 9 UP Date: April 28, 2009 Photo ID: WJE 184

HSM No. 27 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: July 23, 2008 Photo ID: P 10 UP Date: April 28, 2009 Photo ID: WJE 185

HSM No. 27 WJE No. 2008.1917 Location: Base Unit, NE UP Date: June 23, 2008 Photo ID: P 11 UP Date: April 28, 2009 Photo ID: WJE 186

HSM No. 27 WJE No. 2008.1917 Location: Base Unit, NE UP Date: July 23, 2008 Photo ID: P 12 UP Date: April 28, 2009 Photo ID: WJE 188

HSM No. 27 WJE No. 2008.1917 Location: Base Unit, NE UP Date: June 23, 2008 Photo ID: P13 0.010 in.

UP Date: April 28, 2009 Photo ID: WJE 190

HSM No. 27 WJE No. 2008.1917 Location: Base Unit, NE UP Date: June 23, 2008 Photo ID: P 14 UP Date: April 28, 2009 Photo ID: WJE 191

HSM No. 27 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: July 23, 2008 Photo ID: P 15 UP Date: April 28, 2009 Photo ID: WJE 192

HSM No. 27 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: July 23, 2008 Photo ID: P 16 0.005 in.

UP 0.005 in.

0.005 in.

Date: April 28, 2009 Photo ID: WJE 193

HSM No. 27 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: July 23, 2008 Photo ID: P 17 UP Date: April 28, 2009 Photo ID: WJE 195

HSM No. 29 WJE No. 2008.1917 Location: Roof Slab, SE UP Date: June 16, 2008 Photo ID: P 1 UP Date: April 28, 2009 Photo ID: WJE 167

HSM No. 29 WJE No. 2008.1917 Location: Base Unit, South Face UP Date: June 16, 2008 Photo ID: P 2 0.010 in.

UP 0.005 in.

Date: April 28, 2009 Photo ID: WJE 168

HSM No. 29 WJE No. 2008.1917 Location: Base Unit, South Face UP Date: June 16, 2008 Photo ID: P 3 0.010 in.

UP 0.010 in.

Date: April 28, 2009 Photo ID: WJE 169

HSM No. 29 WJE No. 2008.1917 Location: Base Unit, South Face UP Date: June 16, 2008 Photo ID: P 4 UP Date: April 28, 2009 Photo ID: WJE 170

HSM No. 29 WJE No. 2008.1917 Location: Base Unit, South Face UP Date: June 16, 2008 Photo ID: P 5 0.005 in.

UP Date: April 28, 2009 Photo ID: WJE 171

HSM No. 29 WJE No. 2008.1917 Location: Roof Slab, SW UP Date: June 16, 2008 Photo ID: P 6 UP Date: April 28, 2009 Photo ID: WJE 174

HSM No. 29 WJE No. 2008.1917 Location: Roof Slab, NE UP Date: July 23, 2008 Photo ID: P 7 0.005 in.

UP 0.005 in.

Date: April 28, 2009 Photo ID: WJE 175

HSM No. 29 WJE No. 2008.1917 Location: Base Unit, NE UP Date: July 23, 2008 Photo ID: P 8 UP Date: April 28, 2009 Photo ID: WJE 176

HSM No. 29 WJE No. 2008.1917 Location: Base Unit, NE UP Date: July 23, 2008 Photo ID: P 9 0.015 in. 0.010 in.

UP Date: April 28, 2009 Photo ID: WJE 177

HSM No. 29 WJE No. 2008.1917 Location: Base Unit, NW UP Date: July 23, 2008 Photo ID: P 10 UP Date: April 28, 2009 Photo ID: WJE 178

HSM No. 29 WJE No. 2008.1917 Location: Roof Slab, NW UP Date: July 23, 2008 Photo ID: P 11 UP 0.005 in.

0.010 in.

Date: April 28, 2009 Photo ID: WJE 179

HSM No. 29 WJE No. 2008.1917 Location: Base Unit, NW UP Date: July 23, 2008 Photo ID: P 12 UP 0.015 in.

Date: April 28, 2009 Photo ID: WJE 180

APPENDIX B - PETROGRAPHIC ANALYSES Wiss, Janney, Elstner Associates, Inc.

330 Pfingsten Road Northbrook, Illinois 60062 847.272.7400 tel l 847.291.5189 fax www.wje.com PETROGRAPHIC STUDIES OF CONCRETE CORE SAMPLES Date: June 8, 2009 Project: Three Mile Island Storage Modules WJE No. 2008.1917

Subject:

Petrographic Studies Laura Powers, Petrographer Petrographic studies have been conducted on six concrete cores to determine the general composition and condition of the concrete, with specific attention to possible causes of cracking and concrete characteristics that might increase the propensity for cracking to occur or cause a decrease in the concrete durability. Detailed petrographic studies were performed for two HSM roof slab cores and for two HSM base cores. Partial petrographic examinations (comparative studies without thin sections) were performed for the two remaining cores. The cores chosen for the petrographic studies are listed in Table 1. Core logs and photographs of the as-received cores are present in Appendix I.

Table 1. Concrete Cores Portion of Core ID Significant Features Petrographic Examination Storage Module 5B Roof slab/front Cracking Comparative examination 7A Base/front No visible distress Comparative examination 9A Roof slab/front Cracking Detailed study with thin section 12A Base/front Radial crack Detailed study with thin section 27B Roof slab/top Pour line Detailed study with thin section 29B Base/rear Crack with efflorescence Detailed study with thin section Methods Petrographic studies were conducted in accordance with the methods and procedures outlined in ASTM C 856, Standard Practice for Petrographic Examination of Hardened Concrete. The cores were cut in half perpendicular to the exterior surface. One half of each core was lapped using successively finer grits to achieve a fine, matte finish suitable for examination at stereomicroscope magnifications (up to approximately 50X ). The lapped surface accentuates the appearance of individual constituents and structures. Fresh fracture surfaces were also prepared to study the physical characteristics of the materials.

For detailed analyses, thin sections and immersion mounts were prepared from areas of interest and these were examined at magnifications up to 500X using a petrographic (polarized-light) microscope to study the composition and microstructure of the concrete and its constituents. Thin sections preserve the microstructure and the relationships between the constituents, and allow the petrographer to assess condition and determine composition more definitively than is possible by other petrographic methods.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 2 PETROGRAPHIC OBSERVATIONS Detailed Studies Core 9A (Roof slab/front)

Core diameter is 3.7 inches. Core length is approximately 16.4 inches. The core was taken over a crack, and was received separated at the crack and broken diagonally from the exterior surface to a depth of 9 to 11.5 inches. Crack width could not be determined. The intact portions of the outside surface of the concrete are smooth, hard, and flat; portions of the outside surface adjacent to the crack are missing.

Surface paste color is light beige-gray. The concrete is well consolidated. The lapped surface of the core is shown in Figure 1.

Aggregates: Coarse and fine aggregates are siliceous natural sand and gravel. Aggregate particles are rounded to occasionally angular, and have smooth hard surfaces. The aggregates are generally well graded; all sizes are represented, but No. 4 to 3/8-inch particles are over-represented and larger-size particles are under-represented. Top size is 3/4 inch. Aggregate distribution is non-uniform, but not problematic. Aggregate volume appears typical.

Coarse aggregate consists of a variety of fresh and altered volcanic rocks (in order of decreasing abundance: basalt, andesite, trachyte, and volcaniclastic rocks), granitic rocks (including granodiorite), schist, quartzite, sandstone-graywacke, and minor amounts of other siliceous metamorphic rock types. Fine aggregate consists of rock types similar to those observed in the coarse aggregate, but with larger proportions of quartz, feldspars, hornblende, opaque mineral grains, meta-chert, and other minerals individually present in the various rock types represented.

The aggregates appear physically sound and chemically stable, based on absence of evidence of physical deterioration and chemical reactions.

Paste-Aggregate Bond: Paste-aggregate bond is moderate weak to weak. The aggregate type (predominantly hard, dense, fine-grained igneous rock) and smooth surface texture are mainly responsible for the bond quality. Fresh fractures pass around most aggregate particles. Granitic rocks, schist, and several minor rock types tend to be broken by fresh fractures. Hard, dense volcanic rocks are rarely broken.

Paste: The paste is medium gray, hard, and dense, and exhibits subvitreous luster on fresh fracture surfaces. Rarely, thin zones of pale buff paste were observed around aggregate particles.

Paste volume is estimated at 30 to 32 percent. No differences in paste characteristics were observed across the crack.

The paste contains moderate amounts of partially hydrated portland cement and unhydrated cement particles, estimated at 7 to 10 percent by volume of paste. Cement hydration characteristics appear normal. Extent of cement hydration is advanced. Calcium hydroxide is mostly uniformly distributed throughout the paste, and occurs as tabular and irregularly shaped crystals up to 35 µm in diameter. Estimated calcium hydroxide content is 6 to 8 percent by volume of paste. No supplementary cementitious materials, such as fly ash, silica fume, or slag, were detected.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 3 Water-Cement Ratio (w/c): Estimated w/c is 0.48 to 0.53, based on physical characteristics and microscopical observations of the paste. This estimate is biased high for concrete that has been heat cured; heat curing influences rate and extent of cement hydration. Micro-scale variability in w/c was observed.

Air-Void System: The concrete is not air entrained, based on the low abundance of small spherical air voids. Estimated total air content is 2 to 3 percent. Regions of significant size (more than 1 inch across) do not contain entrained air voids. The concrete contains scattered irregularly shaped entrapped air voids up to 0.5 inch in diameter. Large entrapped air voids are uncommon.

Cracking: The crack on exterior surface extends diagonally into the concrete (core was reassembled with epoxy after surfaces were examined). The crack passes around aggregate particles and exits the core at a depth of 6 inches. The diagonal fracture between 9 and 11.5 inches also passed around aggregate particles. Several long microcracks parallel to the major fracture were observed in the interior portion of the core.

Adhesion cracks (micro-separation between paste and aggregate) were observed around many coarse aggregate particles. Adhesion cracks were likely caused by shrinkage and weak paste-aggregate bond. Microcracks passing between coarse aggregate particles are common and likely resulted from shrinkage.

Paste Carbonation: Paste at the outside surface of the concrete is carbonated to a depth of 0.020 to 0.035 inch; 0.030 inch average depth. Crack walls are carbonated and zones of high w/c paste surrounding a few coarse aggregate particles are also carbonated.

Secondary Deposits: Crack walls are locally coated with ettringite deposits (white, felty masses of acicular crystals). Ettringite also coats the aggregate surfaces in proximity to the crack diagonal crack. No secondary deposits were observed in air voids.

Deleterious Reactions: Evidence of deleterious reactions, such as gel and microcracks associated with alkali-silica reaction, was not observed. Thin zones of pale buff paste that were observed around a few coarse aggregate particles are associated with locally high w/c.

Core 12A (Base/front)

Core diameter is 3.7 inches. Core length is 15.8 inches. The outside surface of the concrete is smooth, hard, and flat. Surface paste color is light beige-gray and dark beige over hairline cracks. The concrete is well consolidated. No rebar is present in the core; however, a rebar impression is present on the interior end of the core where a No. 11 rebar was removed before core was cut for petrographic examination. No corrosion was observed on the impression or on the rebar. The lapped surface of the core is shown in Figure 2.

Aggregates: Coarse and fine aggregates are siliceous natural sand and gravel. Aggregate particles are rounded to occasionally angular, and have smooth hard surfaces. The aggregates are well graded; all sizes are represented. Top size is 3/4 inch. Aggregate distribution is slightly non-

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 4 uniform. Aggregate volume appears typical. Aggregate constituents are essentially identical to those described for Core 9A.

The aggregates appear physically sound and chemically stable, based on absence of evidence of physical deterioration and chemical reactions.

Paste-Aggregate Bond: Paste-aggregate bond is moderate weak to weak. Fresh fractures pass around the aggregate particles.

Paste: The paste is medium gray, hard, and dense, and exhibits subvitreous luster on fresh fracture surfaces. Lighter gray paste was observed in the outer 0.5 inch of the core. Thin zones of pale buff paste, maximum thickness 0.01-inch, were observed partially encircling a few aggregate particles. Paste volume is estimated at 30 to 32 percent.

The paste contains moderate amounts of partially hydrated portland cement and unhydrated cement particles, estimated at 7 to 10 percent by volume of paste. Cement hydration characteristics appear normal. Extent of cement hydration is advanced. Calcium hydroxide is mostly uniformly distributed throughout the paste (frequent thin rims of calcium hydroxide around fine aggregate particles), and occurs as tabular and irregularly shaped crystals up to 35 µm in diameter. Estimated calcium hydroxide content in the body of the concrete is 6 to 8 percent by volume of paste, and 7 to 10 percent by volume of paste in the outer 0.5 inch of the concrete.

Calcium hydroxide was not observed in the vicinity of the cracks. No supplementary cementitious materials were detected.

Water-Cement Ratio (w/c): Estimated w/c is 0.48 to 0.53, based on physical characteristics and microscopical observations of the paste. Lighter gray paste in the outer 0.5 inch of the core appears to have a slightly higher w/c, 0.050 to 0.55, based on estimates of a greater abundance of calcium hydroxide in this region. As noted for Core 9A, these estimates are biased high for concrete that has been heat cured. Minor micro-scale variability in w/c was observed.

Air-Void System: The concrete is air entrained, based on the abundance and distribution of small spherical air voids. Estimated air content is 5 to 6 percent. The air voids are non-uniformly distributed; some regions of paste contain 2 to 3 percent air and some regions near coarse aggregate particles contain 6 to 8 percent air. The concrete contains scattered irregularly shaped entrapped air voids up to 0.4 inch in diameter (compaction voids). Most entrapped air voids are 0.1 to 0.2 inch across.

Cracking: Hairline cracks on the outside surface of the core extend to depths of 5.2 inches.

Maximum crack width is 0.005 inch. The cracks pass around the coarse aggregate particles.

Adhesion cracks (micro-separation between paste and aggregate) were observed around many coarse aggregate particles. Microcracks passing between coarse aggregate particles are common in the body of the concrete.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 5 Paste Carbonation: Paste at the outside surface of the concrete is carbonated to a depth of less than 0.005 inch. Crack walls are surficially carbonated and thin zones of high w/c paste surrounding a few coarse aggregate particles are also carbonated.

Secondary Deposits: No secondary deposits were observed in air voids or in cracks.

Deleterious Reactions: Evidence of deleterious reactions, such as gel and microcracks associated with alkali-silica reaction, was not observed. Thin zones of pale buff paste were observed around several coarse aggregate particles, but these are attributed to locally high w/c.

Core 27B (Roof slab/top)

Core diameter is 3.7 inches. Core length is 19 inches. The outside surface of the concrete is smooth, hard, and flat. Surface paste color is mottled light and medium beige to dark beige over cracks. A 0.015-inch wide crack extends across the exterior surface and extends vertically through the full depth of the core.

The core was received broken transversely into three segments; one side of both the exterior and interior fracture is coated with ettringite deposits. The concrete is well consolidated. The lapped surface of the core is shown in Figure 3.

Aggregates: Coarse and fine aggregates are siliceous natural sand and gravel. Aggregate particles are rounded to occasionally angular, and have smooth hard surfaces. The aggregates are well graded; all sizes are represented. Top size is 3/4 inch. Aggregate distribution is generally uniform.

Aggregate volume appears typical.

Aggregate constituents are essentially identical to those described for Core 9A.

The aggregates appear physically sound and chemically stable, based on absence of evidence of physical deterioration and only minor, limited occurrence of chemical reactions (ASR, refer to secondary deposits below).

Paste-Aggregate Bond: Paste-aggregate bond is moderate weak to weak. Fresh fractures pass around the aggregate particles.

Paste: The paste is medium gray, hard, and dense, and exhibits subvitreous luster on fresh fracture surfaces. Thin zones of pale buff paste were only occasionally observed partially encircling aggregate particles. No differences in paste characteristics were observed across the longitudinal crack. Paste volume is estimated at 30 to 32 percent.

The paste contains moderate amounts of partially hydrated portland cement and unhydrated cement particles, estimated at 7 to 10 percent by volume of paste. Cement hydration characteristics appear normal. Extent of cement hydration is advanced. Calcium hydroxide is generally uniformly distributed throughout the paste, and occurs as tabular and irregularly shaped crystals 5 to 30 µm in diameter. Estimated calcium hydroxide content is 5 to 7 percent by volume of paste. Calcium hydroxide was not observed in the vicinity of the crack; the paste is nearly isotropic (evidence of leaching). No supplementary cementitious materials were detected.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 6 Water-Cement Ratio (w/c): Estimated w/c is 0.48 to 0.53, based on physical characteristics and microscopical observations of the paste. As noted for Core 9A, this estimate is biased high for concrete that has been heat cured.

Air-Void System: The concrete is air entrained, based on the abundance and distribution of small spherical air voids. Estimated air content is 4 to 5 percent. The air voids are non-uniformly distributed; some regions of paste contain 2 to 3 percent air and some regions, especially near coarse aggregate particles, contain 6 to 8 percent air. The concrete contains scattered irregularly shaped entrapped air voids up to 0.6 inch in diameter (compaction voids). Most entrapped air voids are less than 0.2 inch across.

Cracking: The main crack on the outside end of the core extends the full depth of the core and appears to occur along a pour line; however, no differences in paste characteristics or air content were observed across the separation. The walls of the crack are carbonated and locally coated with ettringite deposits. Maximum crack width at the outside end is 0.015 inch. The crack or separation passes mostly around coarse aggregate particles.

Several long (continuous for more than 1 inch) randomly oriented microcracks filled with calcite were observed in the outer 5 inches of the concrete. None of the microcracks approaches the exterior surface. These microcracks are not obviously associated with any particular distress mechanism.

Adhesion cracks (micro-separation between paste and aggregate) were observed around some coarse aggregate particles. Microcracks passing between coarse aggregate particles are common in the body of the concrete.

Paste Carbonation: Paste at the outside surface of the concrete is carbonated to a depth of 0.005 to 0.040 inch; average depth 0.020 inch. Crack walls are carbonated.

Secondary Deposits: Ettringite deposits, locally heavy, coat the walls of the longitudinal crack and the interior and exterior fracture surfaces. Small amounts of ettringite were observed in air voids; larger amounts closest to cracks/fractures. Large amounts of water movement through the crack likely created these deposits and not any deleterious reactions within the concrete or paste.

Deleterious Reactions: Minor evidence of alkali-silica reaction was observed on the interior fracture surface of the core; isolated small patches of white ASR gel were observed on the inboard edges of two coarse aggregate particles. The amount of gel observed does not appear to be sufficient to cause cracking.

Core 29B (Base/rear)

Core diameter is 3.7 inches. Core length is approximately 19 inches. The outside surface of the concrete is smooth, hard, and flat. Surface paste color is mottled beige-gray. A narrow crack on the exterior surface is heavily coated with buff, scaly deposits of carbonate efflorescence. The concrete is well consolidated. A group of seven-wire strands were embedded in the concrete at between 7 and 9 inches depth from the exterior surface. The lapped surface of the upper 7.5 inches of the core is shown in Figure 4.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 7 Aggregates: Coarse and fine aggregates are siliceous natural sand and gravel. Aggregate particles are rounded to occasionally angular, and have smooth hard surfaces. The aggregates are well graded; all sizes are represented. Top size is 3/4 inch. Aggregate distribution is slightly non-uniform. Aggregate volume appears typical.

Aggregate constituents are essentially identical to those described for Core 9A.

The aggregates appear physically sound and chemically stable, based on absence of evidence of physical deterioration and chemical reactions.

Paste-Aggregate Bond: Paste-aggregate bond is moderate weak to weak. Fresh fractures pass around the aggregate particles.

Paste: The paste is medium gray, hard, and dense, and exhibits subvitreous luster on fresh fracture surfaces. Thin zones of pale buff paste were observed around several coarse aggregate particles indicating elevated initial water contents. Estimated paste volume is 30 to 32 percent.

The paste contains moderate amounts of partially hydrated portland cement and unhydrated cement particles, estimated at 5 to 7 percent by volume of paste. Cement hydration characteristics appear normal. Extent of cement hydration is advanced. Calcium hydroxide is mostly uniformly distributed throughout the paste (frequent thin rims of calcium hydroxide around fine aggregate particles), and occurs as tabular and irregularly shaped crystals 5 to 30 µm in diameter. Estimated calcium hydroxide content is 7 to 10 percent by volume of paste. Calcium hydroxide was not observed in the vicinity of the crack; the paste is nearly isotropic (leaching has removed calcium hydroxide). No supplementary cementitious materials were detected.

Water-Cement Ratio (w/c): Estimated w/c is 0.50 to 0.55, based on physical characteristics and microscopical observations of the paste. As noted for Core 9A, this estimate may be biased high for concrete that has been heat cured. Minor micro-scale variability in w/c was observed.

Air-Void System: The concrete is air entrained, based on the abundance and distribution of small spherical air voids. Estimated air content is 4 to 5 percent. The air voids are non-uniformly distributed; some regions of paste contain no air voids and some regions, especially near coarse aggregate particles, contain higher amounts of air and frequent clusters of voids. The concrete contains scattered irregularly shaped entrapped air voids that are mostly less than 0.2 inch across.

Cracking: The crack on the exterior surface extends to a depth of 1 inch parallel to the core axis, and exits the core at a depth of 2 inches as a diagonal crack. Maximum crack width is 0.010 inch.

The crack passes around the coarse aggregate particles.

Adhesion cracks (micro-separation between paste and aggregate) were observed around many coarse aggregate particles. Microcracks passing between coarse aggregate particles are common in the body of the concrete.

Paste Carbonation: Paste at the outside surface of the concrete is carbonated to a depth of 0.005 to 0.035 inch; average depth is 0.030 inch. Crack walls are carbonated.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 8 Secondary Deposits: Small amounts of ettringite were observed in air voids throughout the outer 7.5 inches of the concrete. Air voids in the vicinity of the crack contain greater amounts of ettringite. Crack walls are locally coated with ettringite crystals.

Deleterious Reactions: Evidence of deleterious reactions, such as gel and microcracks associated with alkali-silica reaction, was not observed. Thin zones of pale buff paste were observed around some coarse aggregate particles, but these are attributed to locally high w/c.

Comparative Studies Core 5B (Roof slab/front)

Core diameter is 3.7 inches. Core length is approximately 19 inches. The core was received broken at a depth of 10 inches. The outside surface of the concrete is smooth, hard, and flat, with several bug holes (the largest, 0.5 inch in diameter). Surface paste color is mottled light and dark beige-gray. A crack up to 0.015 inch wide on the exterior surface extends diagonally into the concrete. The concrete is well consolidated. The lapped surface of the core is shown in Figure 5.

Aggregates: Coarse and fine aggregates are siliceous natural sand and gravel. Aggregate particles are rounded to occasionally angular, and have smooth hard surfaces. The aggregates are generally well graded; all sizes are represented, but the aggregate is deficient in larger size particles. Top size is 3/4 inch. Aggregate distribution is uniform. Aggregate volume appears typical.

Coarse aggregate consists of a variety of fresh and altered volcanic rocks, granitic rocks (including granodiorite), schist, and quartzite. Fine aggregate consists of rock types similar to those observed in the coarse aggregate, but with larger proportions of quartz, feldspars, hornblende, opaque mineral grains, and other minerals individually present in the various rock types represented.

The aggregates appear physically sound and chemically stable, based on absence of evidence of physical deterioration and chemical reactions.

Paste-Aggregate Bond: Paste-aggregate bond is moderate weak to weak. Fresh fractures pass around the aggregate particles.

Paste: The paste is medium to dark gray, hard, and dense, and exhibits subvitreous luster on fresh fracture surfaces. Thin zones of pale buff paste surround a few aggregate particles. Paste volume appears typical. No differences in paste characteristics were observed across the crack.

Air-Void System: The concrete is air entrained, based on the abundance and distribution of small spherical air voids. Estimated air content is 3 to 4 percent. The air voids are non-uniformly distributed; some regions of paste contain 1 to 2 percent air and some regions near coarse aggregate particles contain 4 to 6 percent air. The concrete contains scattered irregularly shaped entrapped air voids mostly less than 0.3 inch in diameter.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 9 Cracking: The crack on exterior surface extends diagonally into the concrete and is open to a depth of 10 inches. On one side of the core, the crack exits at a depth of 5 inches. On the opposite side of the core, the crack extends to 10 inches (the depth at which the core broke during coring).

The crack passes around aggregate particles, except between 6 and 8 inches depth where the crack branches and transects several coarse aggregate particles.

Adhesion cracks (micro-separation between paste and aggregate) were observed around many coarse aggregate particles. Microcracks passing between coarse aggregate particles are common.

Paste Carbonation: Paste at the outside surface of the concrete is carbonated to a depth of 0.04 to 0.15 inch; 0.04 inch average depth. Crack walls are carbonated and zones of high w/c paste surrounding a few coarse aggregate particles are also carbonated.

Secondary Deposits: Ettringite deposits, locally heavy, coat the crack walls. No secondary deposits were observed in air voids.

Deleterious Reactions: Evidence of deleterious reactions, such as gel and microcracks associated with alkali-silica reaction, was not observed. Thin zones of pale buff paste were observed around several coarse aggregate particles, but these are attributed to locally high w/c.

Core 7A (Base/front)

Core diameter is 3.7 inches. Core length is 14.5 inches. The outside surface of the concrete is smooth, hard, and flat. Surface paste color is mottled shades of beige-gray, and is dark beige-gray around hairline cracks. The concrete is well consolidated. No rebar is present in the core; however, a rebar impression is present on the interior end of the core. No corrosion was observed on the impression. The lapped surface of the core is shown in Figure 6.

Aggregates: Coarse and fine aggregates are siliceous natural sand and gravel. Aggregate particles are rounded to occasionally angular, and have smooth hard surfaces. The aggregates are generally well graded; all sizes are represented, but the aggregate is deficient in larger size particles. Top size is 3/4 inch. Aggregate distribution is non-uniform, but not problematic. Aggregate volume appears typical.

Coarse aggregate consists of a variety of fresh and altered volcanic rocks, granitic rocks (including granodiorite), schist, and quartzite. Fine aggregate consists of rock types similar to those observed in the coarse aggregate, but with larger proportions of quartz, feldspars, hornblende, opaque mineral grains, and other minerals individually present in the various rock types represented.

The aggregates appear physically sound and chemically stable, based on absence of evidence of physical deterioration and chemical reactions.

Paste-Aggregate Bond: Paste-aggregate bond is moderate weak to weak. Fresh fractures pass around the aggregate particles.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 10 Paste: The paste is medium to dark gray, hard, and dense, and exhibits subvitreous luster on fresh fracture surfaces. Thin zones of pale buff paste surround a few aggregate particles. Paste volume is similar to the other cores (estimated 30 to 32 percent paste volume).

Air-Void System: The concrete is air entrained, based on the abundance and distribution of small spherical air voids. Estimated air content is 5 to 6 percent. The air voids are non-uniformly distributed; some regions of paste contain 2 to 3 percent air and some regions near coarse aggregate particles contain 6 to 8 percent air. The concrete contains scattered irregularly shaped entrapped air voids up to 1 inch long (compaction voids). Most entrapped air voids are less than 0.4 inch across.

Cracking: Adhesion cracks (micro-separation between paste and aggregate) were observed around many coarse aggregate particles. Hairline cracks on the outside surface of the core extend to depths of 2.5 to 3.5 inches. Maximum crack width is 0.005 inch. The cracks mostly pass around the coarse aggregate particles; two weak aggregate particles were transected by cracks.

Paste Carbonation: Paste at the outside surface of the concrete is carbonated to a depth of 0.02 to 0.03 inch; 0.02 inch average depth. Crack walls are carbonated and zones of high w/c paste surrounding a few coarse aggregate particles are also carbonated.

Secondary Deposits: No secondary deposits were observed in air voids or in cracks.

Deleterious Reactions: Evidence of deleterious reactions, such as gel and microcracks associated with alkali-silica reaction, was not observed. Thin zones of pale buff paste were observed around several coarse aggregate particles, but these are attributed to locally high w/c.

SUMMARY

The concrete represented by the cores examined is generally hard, dense, and well consolidated. No significant differences were observed between concrete that contains major cracks (5B, 27B, 9A, and 29B) and concrete that contains only minor cracks (7A and 12A). Crack surfaces and air voids in the vicinity of the major cracks are coated with ettringite (calcium sulfoaluminate hydrate) derived from calcium, aluminum, and sulfur leached from the cement paste. Efflorescence on the exterior surface of the concrete consists of scaly deposits of calcium carbonate; calcium leached from the cement paste and deposited on the outer surface. Efflorescence and secondary ettringite are evidence of water infiltration and long-term exposure to moist conditions. Overall, secondary deposits are not abundant in the body of the concrete suggesting that water migration has occurred predominantly along the cracks. Limited evidence of alkali silica reaction, two reactive particles in Core 27B, was observed, and no damage was directly associated with these occurrences. Evidence of delayed ettringite formation was not observed.

The concrete contains siliceous natural gravel coarse aggregate and siliceous natural sand fine aggregate dispersed in an air-entrained portland cement paste (except Core 9A is not air-entrained). The paste is medium gray, hard, and dense. Estimated water-cement ratio (w/c) is typically 0.48 to 0.53; except the estimated w/c of Core 29B is 0.50 to 0.55. Estimates of w/c may be biased somewhat high, based on the advanced extent of cement hydration (Figures 7 and 8). No supplementary cementitious materials were

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 11 observed in the paste. Air contents are variable (Table 2) and air-void distribution is mostly non-uniform.

Exterior surfaces and crack surfaces are only minimally carbonated.

Table 2. Estimated Air Contents of Cores from TMI Storage Modules Core ID Estimated Air Content Air-Void Distribution 5B - lid 3 to 4 percent Non-uniform 7A - base 5 to 6 percent Non-uniform 9A -lid 2 to 3 percent Not air entrained 12A -base 5 to 6 percent Non-uniform 27B -lid 4 to 5 percent Non-uniform 29B - base 4 to 5 percent Non-uniform The gravel mainly consists of fresh and altered volcanic rocks, granitic rocks, schist and quartzite. The sand consists of rock types observed in the gravel, along with minerals that are individually present in these rock types. Overall, paste-aggregate bond is moderately weak to weak; fresh fractures mostly pass around aggregate particles. This is mainly due to the hard, smooth surfaces of the aggregates and not any defect in the concrete. Aggregate top size is 3/4 inch. The aggregate is generally well graded, but some cores were observed to be deficient in larger-size aggregate particles. Aggregate distribution in somewhat non-uniform in cores 7A, 9A, 12A, and 29B, but no specific distress was observed in regions of high or low aggregate volume. In most of the cores, a small proportion of the coarse aggregate particles are encircled by light-colored rims of carbonated high w/c paste (Figures 9 and 10), suggesting these particles were overly wet when the concrete was batched. The paste-aggregate bond in these areas may also be reduced.

The paste content of the cores is moderately high and microcracking was observed in the paste, often between coarse aggregate particles. This internal cracking may be due to early shrinkage stresses in the paste rich mix.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 12 Figure 1. Core 9A - Lapped surface. The core was received broken diagonally into two major segments and the outer portion of the core was broken at a steep diagonal crack (shown reassembled with epoxy).

The exterior and interior ends are labeled.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 13 Figure 2. Core 12A - Lapped surface. The core was cut in half transversely to facilitate sample preparation. The exterior and interior ends are labeled. Arrow show impression of large diameter steel rebar at interior end.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 14 Figure 3. Core 27B - Lapped surface. The exterior and interior ends are labeled.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 15 Figure 4. Core 29B - Lapped surface, outer 7.5 inches of core. Note lighter colored paste around aggregate particles (red arrows).

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 16 Figure 5. Core 5B - Lapped surface. The core was received broken into two segments. The exterior and interior ends are labeled. The diagonal to sub-vertical crack is outlined with dark green marker.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 17 Figure 6. Core 7A - Lapped surface. The core was cut in half transversely to facilitate sample preparation. Interior and exterior ends are labeled.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 18 60 µm Figure 7. Core 9A - Thin-section micrograph showing well hydrated portland cement particles (examples shown with arrows). Plane-polarized light.

Figure 8. Large crystals of calcium hydroxide normally associated with moderate and high w/c, in the field shown in Figure 7. Cross-polarized light with upper polar slightly uncrossed.

Three Mile Island Storage Modules Petrographic Studies June 8, 2009 Page 19 Figure 9. Lapped surface of Core 5B showing white rims around many aggregate particles. Magnification is approximately 10X Figure 10. Core 5B - Closer view of microcrack and adhesion crack at aggregate interface. Magnification is approximately 25X.

APPENDIX C - COMPRESSIVE STRENGTH TESTING Three Mile Island Facility CPP-1774 Structural Inspection of Horizontal Storage Modules and Pad April 30, 2008 ASTM C-42 Compressive Strength of Concrete Cores Job Number: 2008.1917 Project Coordinator: Paul Krauss Cast Date: unknown Capping: X Sulfur Unbonded Type of Curing Prior to Testing: As Received X Wet Dry Mitutoyo: 18" Span Mitutoyo (Black Case) Mitutoyo (White Case)

Calipers:

X Serial No: 0014816 Serial No. 0324426 Serial No. 0484673 Test Mark Baldwin ID: Satec 120,000 lbf Test Machine:

X Serial No. 11005 60BTEC6827300 ID: 120HLVC1240 Temperature: 71 Humidity: 47 Operator: L. ZEGLER Initals: lz Date: 6/10/2009 Checked by: P. Krauss Initals: pk Date: 6/17/2009

• Length must be reported when L/D is less than 1.8 or greater than 2.2.

• • Specimens are capped, thus diameter tolerances do not apply.

• • • These correction factors apply to lightweight concrete weighing between 100 and 120 lb/ft3 and to normal weight concrete. The correction factors are applicable for nominal concrete strengths from 2000 to 6000 psi.

• • • • If other than cone.

Diameter, (in.) Diameter (Avg. Correction Max. Load Compressive Corrected Strength Fracture Sample ID Length (in.) Area (in.2)

D1 D2 in.) L/D Factor (lbs.) Strength (psi) (psi) Type 5A 7.468 3.710 3.710 3.710 10.81 2.01 none 81,310 7,520 7,520 CONE 15A 7.377 3.713 3.706 3.710 10.81 1.99 none 82,880 7,670 7,670 CONE 18A 7.376 3.704 3.706 3.705 10.78 1.99 none 66,760 6,190 6,190 CONE 27B 7.329 3.705 3.703 3.704 10.78 1.98 none 93,580 8,680 8,680 C/S 29A 7.470 3.704 3.701 3.703 10.77 2.02 none 83,750 7,780 7,780 CONE NOTES/COMMENTS

APPENDIX D - HSM DESIGN INFORMATION