ML062760004

to Hydrogeologic Investigation Report, Fleetwide Assessment, Braidwood Generating Station.

ML062760004
Person / Time
Site:	Braidwood
Issue date:	09/30/2006
From:	Conestoga-Rovers & Associates
To:	Exelon Generation Co, Office of Nuclear Reactor Regulation
References
045136 (12), FOIA/PA-2010-0209
Download: ML062760004 (801)

Text

Revision 1 Certain figures in this Report contain sensitive, security-related information protected from public disclosure by Federal and State law. This Report is suitable for public disclosure only after these figures are removed.

HYDROGEOLOGIC INVESTIGATION REPORT FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Prepared For:

Exelon Generation Company, LLC DISCLAIMER: Prepared by:

SOME FORMATTING CHANGES MAY HAVE OCCURRED WHEN THE ORIGINAL DOCUMENT WAS PRINTED TO PDF; HOWEVER, Conestoga-Rovers THE ORIGINAL CONTENT REMAINS UNCHANGED. & Associates 651 Colby Drive Waterloo, Ontario Canada N2V 1C2 Office: (519) 884-0510 Fax: (519) 884-0525 SEPTEMBER 2006 web: http:\\www.CRAworld.com REF. NO. 045136 (12)

Worldwide Engineering, Environmental, Construction, and IT Services

Revision 1 TABLE OF CONTENTS Page EXECUTIVE

SUMMARY

.................................................................................................................... i

1.0 INTRODUCTION

...................................................................................................................1 2.0 STATION DESCRIPTION .....................................................................................................2 2.1 STATION LOCATION .......................................................................................2 2.2 OVERVIEW OF COOLING WATER OPERATIONS.....................................2 2.3 SURROUNDING LAND USE ...........................................................................3 2.4 STATION SETTING............................................................................................4 2.4.1 TOPOGRAPHY AND SURFACE WATER FEATURES.................................4 2.4.2 GEOLOGY ............................................................................................................5 2.4.3 HYDROGEOLOGY .............................................................................................7 2.5 AREA GROUNDWATER USE ..........................................................................9 2.6 BRAIDWOOD STATION BLOWDOWN LINE INVESTIGATIONS.........10 3.0 AREAS FOR FURTHER EVALUATION...........................................................................11 3.1 SYSTEMS EVALUATIONS..............................................................................11 3.2 HISTORICAL RELEASES ................................................................................14 3.3 STATION INVESTIGATIONS.........................................................................14 3.3.1 PRE-OPERATIONAL RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM.............................................................................14 3.3.2 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ......15 3.3.3 HISTORIC SITE INVESTIGATIONS ..............................................................16 3.3.3.1 POWER PLANT DOCUMENTS-UFSAR REPORT ......................................16 3.3.3.2 BLOWDOWN LINE INVESTIGATION.........................................................16 3.4 IDENTIFIED AREAS FOR FURTHER EVALUATION ...............................16 4.0 FIELD METHODS.................................................................................................................19 4.1 STAFF GAUGES INSTALLATION ................................................................19 4.2 GROUNDWATER MONITORING WELL INSTALLATION.....................19 4.3 GROUNDWATER MONITORING WELL DEVELOPMENT ....................21 4.4 WELL INVENTORY .........................................................................................21 4.5 SURVEY ..............................................................................................................22 4.6 GROUNDWATER AND SURFACE WATER ELEVATION MEASUREMENTS ............................................................................................22 4.7 GROUNDWATER AND SURFACE WATER SAMPLE COLLECTION ..................................................................................24 4.8 DATA QUALITY OBJECTIVES.......................................................................26 4.9 SAMPLE IDENTIFICATION ...........................................................................26 4.10 CHAIN-OF-CUSTODY RECORD...................................................................27 4.11 QUALITY CONTROL SAMPLES ...................................................................27 4.12 ANALYSES.........................................................................................................27 045136 (12) Braidwood Generation Station CONESTOGA-ROVERS & ASSOCIATES

Revision 1 TABLE OF CONTENTS Page 5.0 RESULTS

SUMMARY

..........................................................................................................28 5.1 STATION GEOLOGY .......................................................................................28 5.2 SITE HYDROGEOLOGY..................................................................................30 5.2.1 GROUNDWATER FLOW DIRECTIONS ......................................................30 5.2.2 MAN-MADE INFLUENCES ON GROUNDWATER FLOW .....................31 5.2.3 VERTICAL HYDRAULIC GRADIENTS........................................................32 5.2.4 LATERAL GROUNDWATER FLOW AND VELOCITY.............................33 5.3 GROUNDWATER QUALITY..........................................................................35 5.3.1

SUMMARY

OF BETA-EMITTING RADIONUCLIDES ANALYTICAL RESULTS.................................................................................35 5.3.2

SUMMARY

OF GAMMA-EMITTING RADIONUCLIDES ANALYTICAL RESULTS.................................................................................36 5.3.3

SUMMARY

OF FIELD MEASUREMENTS ...................................................36 5.4 SURFACE WATER QUALITY.........................................................................37 5.4.1

SUMMARY

OF BETA-EMITTING RADIONUCLIDES ANALYTICAL RESULTS.................................................................................37 5.4.2

SUMMARY

OF GAMMA-EMITTING RADIONUCLIDES ANALYTICAL RESULTS.................................................................................38 6.0 RADIONUCLIDES OF CONCERN AND SOURCE AREAS .........................................39 6.1 GAMMA-EMITTING RADIONUCLIDES.....................................................39 6.2 BETA-EMITTING RADIONUCLIDES ...........................................................39 6.3 TRITIUM.............................................................................................................39 6.3.1 GENERAL CHARACTERISTICS ....................................................................39 6.3.2 DISTRIBUTION IN STATION GROUNDWATER.......................................40 6.3.2.1 UPPER SAND AQUIFER .................................................................................41 6.3.2.2 DEEPER BEDROCK GROUNDWATER ........................................................42 6.3.3 DISTRIBUTION IN STATION SURFACE WATER......................................43 6.3.4 CONCEPTUAL MODEL OF TRITIUM RELEASE AND MIGRATION ...43 6.3.5 ATTENUATION OF TRITIUM WITHIN THE SHALLOW GROUNDWATER SYSTEM..............................................47 7.0 EXPOSURE PATHWAY ASSESSMENT............................................................................49 7.1 HEALTH EFFECTS OF TRITIUM...................................................................49

7.2 BACKGROUND

CONCENTRATIONS OF TRITIUM ................................50 7.2.1 GROUNDWATER.............................................................................................50 7.2.2 PRECIPITATION DATA ..................................................................................50 7.2.3 SURFACE WATER DATA ...............................................................................51 7.2.4 DRINKING WATER DATA ............................................................................52 7.2.5 EXPECTED TRITIUM BACKGROUND FOR THE STATION ...................52 045136 (12) Braidwood Generation Station CONESTOGA-ROVERS & ASSOCIATES

Revision 1 TABLE OF CONTENTS Page 7.3 IDENTIFICATION OF POTENTIAL EXPOSURE PATHWAYS AND POTENTIAL RECEPTORS ............................................53 7.3.1 POTENTIAL GROUNDWATER MIGRATION TO DRINKING WATER USERS OFF THE STATION PROPERTY .................53 7.3.2 POTENTIAL GROUNDWATER MIGRATION TO SURFACE WATER USERS OFF THE STATION PROPERTY ....................54 7.3.3 POTENTIAL EXPOSURE TO SURFACE WATER IN THE PERIMETER DITCH AT THE STATION........................................54 7.4

SUMMARY

OF POTENTIAL TRITIUM EXPOSURE PATHWAYS ..........55 7.5 OTHER RADIONUCLIDES.............................................................................55

8.0 CONCLUSION

S....................................................................................................................56 9.0 RECOMMENDATIONS.......................................................................................................61 9.1 DATA GAPS ......................................................................................................61 9.2 GROUNDWATER MONITORING ................................................................61

10.0 REFERENCES

CITED...........................................................................................................62 045136 (12) Braidwood Generation Station CONESTOGA-ROVERS & ASSOCIATES

Revision 1 LIST OF FIGURES (Following Text)

FIGURE 1.1 STATION LOCATION MAP FIGURE 1.2 STATION BOUNDARIES AND FEATURES FIGURE 1.3 STATION BOUNDARIES INCLUDING BLOWDOWN LINE FIGURE 2.1 STATION BASE MAP FIGURE 2.2 STATION FEATURES AND WELL LOCATIONS FIGURE 2.3 STATION SURFACE WATER FEATURES FIGURE 2.4 STORM WATER DRAINAGE CROSS-SECTION AA-AA' FIGURE 2.5 OIL-WATER SEPARATOR CROSS-SECTION BB-BB' FIGURE 2.6 PERIMETER DITCH CROSS-SECTION CC-CC' FIGURE 2.7 PERIMETER DITCH CROSS-SECTION DD-DD' FIGURE 2.8 LOCAL GEOLOGIC CROSS-SECTION FIGURE 2.9 CONTOUR MAP OF THE WEDRON FORMATION FIGURE 2.10 PRIVATE WELL LOCATIONS AND WELL DEPTHS FIGURE 2.11 GROUNDWATER MONITORING LOCATIONS FIGURE 2.12 REGIONAL HYDROGEOLOGIC CROSS-SECTION LOCATIONS FIGURE 2.13 REGIONAL HYDROGEOLOGIC CROSS-SECTION E-E' FIGURE 2.14 REGIONAL HYDROGEOLOGIC CROSS-SECTION F-F' FIGURE 2.15 PRIVATE WELL AND MONITORING WELL SAMPLE RESULTS FIGURE 3.1 AREAS FOR FURTHER EVALUATION (STATION) 045136 (12) Braidwood Generation Station CONESTOGA-ROVERS & ASSOCIATES

Revision 1 LIST OF FIGURES (Following Text)

FIGURE 3.2 AREAS FOR FURTHER EVALUATION (WEST SIDE OF TURBINE BUILDING)

FIGURE 4.1 SURFACE WATER/STAFF GAUGE MONITORING LOCATIONS FIGURE 4.2 GROUNDWATER MONITORING LOCATIONS (STATION)

FIGURE 4.3 PRESSURE TRANSDUCER AND PRECIPITATION DATA -

JUNE/JULY 2006 FIGURE 5.1 HYDROGEOLOGIC CROSS-SECTION LOCATIONS FIGURE 5.2 HYDROGEOLOGIC CROSS-SECTION A-A' FIGURE 5.3 HYDROGEOLOGIC CROSS-SECTION B-B' FIGURE 5.4 HYDROGEOLOGIC CROSS-SECTION C-C' FIGURE 5.5 HYDROGEOLOGIC CROSS-SECTION D-D' FIGURE 5.6 POTENTIOMETRIC SURFACE CONTOURS - SHALLOW ZONE -

MAY 2006 FIGURE 5.7 POTENTIOMETRIC SURFACE CONTOURS - SHALLOW ZONE -

JULY 2006 FIGURE 5.8 POTENTIOMETRIC SURFACE CONTOURS - DEEP ZONE - MAY 2006 FIGURE 5.9 POTENTIOMETRIC SURFACE CONTOURS - DEEP ZONE - JULY 2006 FIGURE 5.10 TRITIUM CONCENTRATIONS - GROUNDWATER AND SURFACE WATER FIGURE 5.11 RADIONUCLIDE CONCENTRATIONS - GROUNDWATER AND SURFACE WATER FIGURE 6.1 HYDROGEOLOGIC PROFILE-TRITIUM CONCENTRATIONS -

GROUNDWATER FIGURE 6.2 MONITORING WELL TRITIUM SAMPLE RESULTS 045136 (12) Braidwood Generation Station CONESTOGA-ROVERS & ASSOCIATES

Revision 1 LIST OF TABLES (Following Text)

TABLE 4.1

SUMMARY

OF MONITORING WELL INSTALLATION DETAILS TABLE 4.2

SUMMARY

OF MONITORING WELL DEVELOPMENT PARAMETERS TABLE 4.3

SUMMARY

OF GROUNDWATER ELEVATIONS TABLE 4.4

SUMMARY

OF SURFACE WATER ELEVATIONS TABLE 4.5 SAMPLE KEY TABLE 4.6

SUMMARY

OF MONITORING WELL PURGING PARAMETERS TABLE 5.1

SUMMARY

OF CALCULATED VERTICAL HYDRAULIC GRADIENTS TABLE 5.2 ANALYTICAL RESULTS

SUMMARY

- TRITIUM IN GROUNDWATER TABLE 5.3 ANALYTICAL RESULTS

SUMMARY

- RADIONUCLIDES IN GROUNDWATER TABLE 5.4 ANALYTICAL RESULTS

SUMMARY

- TRITIUM IN SURFACE WATER TABLE 5.5 ANALYTICAL RESULTS

SUMMARY

- RADIONUCLIDES IN SURFACE WATER TABLE 5.6 EXISTING ANALYTICAL RESULTS

SUMMARY

- TRITIUM IN GROUNDWATER TABLE 5.7 EXISTING ANALYTICAL RESULTS

SUMMARY

- TRITIUM IN SURFACE WATER 045136 (12) Braidwood Generation Station CONESTOGA-ROVERS & ASSOCIATES

Revision 1 LIST OF APPENDICES APPENDIX A MONITORING WELL LOGS APPENDIX B PRIVATE WATER WELL INVENTORY RECORDS (CRA, MARCH 2006)

APPENDIX C QUALITY ASSURANCE PROGRAM - TELEDYNE BROWN ENGINEERING, INC.

APPENDIX D LABORATORY ANALYTICAL REPORTS APPENDIX E DATA VALIDATION MEMORANDUM 045136 (12) Braidwood Generation Station CONESTOGA-ROVERS & ASSOCIATES

Revision 1 EXECUTIVE

SUMMARY

This Hydrogeologic Investigation Report (HIR) documents the results of Conestoga-Rovers & Associates' (CRA's) May 2006 Hydrogeologic Investigation Work Plan (Work Plan) and associated correspondence pertaining to the Braidwood Generating Station in Braceville, Illinois. CRA prepared this HIR for Exelon as part of its Fleetwide Program to determine whether groundwater at and in the vicinity of its nuclear power generating facilities has been adversely impacted by any releases of radionuclides.

CRA collected and analyzed information on any historical releases, the structures, components, and areas of the Station that have the potential to release tritium or other radioactive liquids to the environment and past hydrogeologic investigations at the Station. CRA used this information, combined with its understanding of groundwater flow and sample locations at the Station to identify the Areas for Further Evaluation (AFEs) for the Station.

CRA collected 45 groundwater samples and six surface water samples at the Station.

CRA also collected a full round of water levels on two occasions from the newly installed and existing wells and measured surface water levels. All groundwater and surface water samples were analyzed for tritium, strontium-89/90, and gamma-emitting radionuclides.

This HIR does not discuss the investigations of tritium in groundwater along the Braidwood Station Blowdown Line. This report focuses on the groundwater conditions in and near the Protected Area (PA). The results of this hydrogeologic investigation are:

• Gamma-emitting radionuclides associated with licensed plant operations were not detected at concentrations greater than their respective Lower Limits of Detection (LLDs) in any of the groundwater or surface water samples obtained and analyzed during the course of this investigation;

• Strontium-89/90 was not detected at a concentration greater than the LLD of 2.0 picoCuries per liter (pCi/L) in any of the groundwater or surface water samples obtained and analyzed during the course of this investigation;

• Tritium was not detected in any of the groundwater or surface water samples obtained during the course of this investigation at concentrations greater than the United States Environmental Protection Agency drinking water standard of 20,000 pCi/L; 045136 (12) Braidwood Generation Station i CONESTOGA-ROVERS & ASSOCIATES

Revision 1

• Low levels of tritium were detected at concentrations greater than the LLD of 200 pCi/L in 15 of 45 groundwater monitoring locations. These tritium concentrations ranged from 204 (+/- 112 pCi/L) to 1,040 (+/- 172 pCi/L);

• Most of the tritium that was detected in groundwater at the Station is on the west side of the Turbine building and is believed to be the result of isolated historical releases;

• Based on the results of this investigation, tritium is not migrating off the Station property at detectable concentrations;

• Based on the results of this investigation, there is no current risk from exposure to radionuclides associated with licensed plant operations through any of the identified potential exposure pathways; and

• Based on the results of this investigation, there are no known active releases into the groundwater at the Station.

Based upon the information collected to date, CRA recommends that Exelon conduct periodic monitoring of selected locations.

045136 (12) Braidwood Generation Station ii CONESTOGA-ROVERS & ASSOCIATES

Revision 1

1.0 INTRODUCTION

Conestoga-Rovers & Associates (CRA) has prepared this Hydrogeologic Investigation Report (HIR) for Exelon Generating Company, LLC (Exelon) as part of its fleetwide program to determine whether groundwater at and near its nuclear power generating facilities has been adversely impacted by any releases of radionuclides. This report documents the results of CRA's May 2006 Hydrogeologic Investigation Work Plan (Work Plan), as well as, several other investigative tasks recommended by CRA during the course of the investigation. These investigations pertain to Exelon's Braidwood Nuclear Power Station in Braceville, Illinois (Station) (see Figure 1.1).

The Station is defined as all property, structures, systems, and components owned and operated by Exelon LLC located at 35100 South Route 53, Braceville, Illinois. The Station boundaries for all areas of the Station are depicted on Figure 1.2 and Figure 1.3.

Pursuant to the Work Plan, CRA assessed groundwater quality at the Station in locations designated as areas for further evaluation (AFEs). The process by which CRA identified AFEs is discussed in Section 3.0 of this report.

Since the spring of 2005, Exelon has performed investigations into the occurrence of tritium along the blowdown line, as discussed in the following Section 2.0. This report does not include discussions of hydrogeologic investigations related to the Braidwood Station's Cooling Lake blowdown line.

The objectives of the Work Plan were to:

• characterize the geologic and hydrogeologic conditions at the Station including subsurface soil types, the presence or absence of confining layers, and the direction and rate of groundwater flow;

• characterize the groundwater/surface water interaction at the Station, including a determination of the surface water flow regime;

• evaluate groundwater quality at the Station including the vertical and horizontal extent, quantity, concentrations, and potential sources of tritium and other radionuclides in the groundwater, if any;

• define the probable sources of any radionuclides released at the Station;

• evaluate potential human, ecological, or environmental receptors of any radionuclides that might have been released to the groundwater; and

• evaluate whether interim response activities are warranted.

045136 (12) Braidwood Generating Station 1 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 2.0 STATION DESCRIPTION The following section presents a general summary of the Station location and definition, overview of Station operations, surrounding land use, and an overview of both regional and Station-specific topography, surface water features, geology, hydrogeology, and groundwater flow conditions. This section also presents an overview of groundwater use in the area.

2.1 STATION LOCATION The Station property consists of approximately 4,450 acres, of which approximately 52 acres are used for the generating facilities. The other approximately 4,400 acres of property encompasses an approximately 2,500-acre Cooling Lake and the land associated with the blowdown line. The Station address is 35100 South Route 53, Braceville, Illinois. The Station is owned and operated by Exelon. Figure 2.1 presents the Station Base Map, which includes the key features.

This HIR excludes land associated with the Cooling Lake and as discussed in Section 1.0, excludes the land associated with the blowdown line and the blowdown line's vacuum breakers. As such, this HIR does not discuss the groundwater investigations performed recently along the Station's blowdown line. These are discussed further in Section 2.5.

2.2 OVERVIEW OF COOLING WATER OPERATIONS The Station contains a two-unit nuclear generating facility capable of generating 1,120 net megawatts of electricity per unit. Units 1 and 2 are pressurized water reactors (PWRs) designed by Westinghouse and began commercial operation in July and October 1988, respectively. A PWR plant consists of three separate loops of fluids. Each loop is designed to avoid mixing the fluids of one loop with the fluids of another. The three loops are called the primary loop, the secondary loop, and the tertiary loop.

The main purpose of the primary loop is to transfer the energy generated from fission in the fuel to the secondary loop steam generators. It is a closed loop system. Nuclear fission creates heat in the fuel. This heat is removed by the flow of reactor coolant water through the reactor vessel and into the steam generators. The heat is transferred to the secondary side where steam is generated. The water is then pumped back to the reactor vessel to cool the fuel again.

045136 (12) Braidwood Generating Station 2 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 The main purpose of the secondary loop is to use the steam generated in the steam generators to turn the turbine generator, which makes electricity. It is also a closed system.

The main purpose of the tertiary loop is to use cooler lake water to condense the steam in the condenser and transfer the heat to the atmosphere. The lake loop needs makeup water to operate properly. Makeup water comes from the Kankakee River.

As the steam is condensed in the condenser, the circulating water becomes hotter. The circulating water is discharged to the Cooling Lake where it loses some of its heat through evaporation. The now cooler water is then pumped back to the condenser to start the loop over again.

The Braidwood Station employs a blowdown line to return water from the Cooling Lake back to the Kankakee River for the purposes of reducing the dissolved mineral concentration in the lake water. This blowdown line also serves as a permitted discharge point for the site's sewage treatment plant and the liquid Radwaste system.

The discharge is approved under the Station's National Pollutant Discharge Elimination System (NPDES) Permit IL 0048321 and Nuclear Regulatory Commission (NRC)

Operating Licenses NPF-72 and NPF-77 for Units 1 and 2, respectively.

2.3 SURROUNDING LAND USE To the north, south, east, and west, land surrounding the Station is primarily for agricultural, residential, and recreational use. Residential lots surround the Station to the north and to the east along Smiley Road and Center Street. Further to the north, there are several ponds or small lakes. The center of the Village of Braidwood is approximately 1.5 miles north of Braidwood Station measured from Smiley Road. To the northwest of the site, there are two main highways (Illinois State Highway 53 and Illinois Route 129) running parallel to each other with a railroad (Southern Pacific Railroad) between them. Within the southern portion of the Station is the Cooling Lake that is designated as a recreational area in the summer for boating and fishing under the auspices of the Illinois Department of Natural Resources (IDNR) (Refer to Figures 1.2 and 1.3). The town of Godley is located west and southwest of the PA.

045136 (12) Braidwood Generating Station 3 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 2.4 STATION SETTING The following sections present a summary of the topography, surface water features, geology, hydrogeology, and groundwater flow conditions in the region surrounding the Station. The information was primarily gathered from Sections 2.1 and 2.5 of the Braidwood Station Updated Final Safety Analysis Report (UFSAR) Revision 10, dated December 2004. The main references the UFSAR relies upon are listed in Section 10.0 of this HIR. CRA checked and verified all UFSAR references that apply to this HIR.

2.4.1 TOPOGRAPHY AND SURFACE WATER FEATURES In general, the topography of the area slopes gently downward to the north toward the Illinois River and is relatively flat (see Figure 1.1 and United States Geological Topographic Quadrangle MapEssex1973, Photo revised 1980).

The Cooling Lake was formed from former coal strip mining operations discussed further in Section 2.4.2. The average depth of the Cooling Lake is about 8 feet (UFSAR, 1994). It is isolated from the adjacent upper water bearing aquifer by a slurry wall constructed during building construction at the PA. The lake bottom consists of mine spoils left behind after strip-mining operations.

There are also remnants of former coal strip mining operations to the north of the PA (ISGS March 2005 and October 2003). There are also a number of ponds located northeast of the PA that were dug originally as sand borrow pits (for highway construction materials) that have subsequently filled with groundwater. These include the ponds located near Center Street and Smiley Road (Figures 1.1 and 2.2). The ponds are evident on the aerial photo presented on Figure 2.2.

Figure 2.3 presents portions of some of the relevant surface water features at the Station such as the Cooling Lake, pond, and perimeter ditch. Surface water drains via the storm water drainage system and man-made ditches (e.g., the perimeter ditch) and flows generally to the north within the PA. Surface water is conveyed away from the Cooling Lake via the perimeter ditch (Figure 2.3). This ditch eventually flows west and south past the PA and past the Village of Godley. This ditch intercepts the shallow groundwater table (CRA, September 2003).

The PA and surrounding land is generally flat and covered by paved areas, roadways, and parking lots. These areas are drained by a storm water drainage system that drains to the northwest corner of the PA (Figure 2.3). The storm water drainage system drains 045136 (12) Braidwood Generating Station 4 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 to an Oil/Water Separator at the north end of the PA. The outfall from the Oil/Water Separator discharges to a small east-west ditch and flows west to the perimeter ditch.

Previous studies have documented that the storm water drainage system intercepts groundwater on the west side of the Turbine Building. These same studies have indicated that the perimeter ditch (Figure 2.3), which flows from the north to the south along the western Station property line, also intercepts the groundwater (CRA, September 2003). Hydrogeologic profiles of the storm water drainage system, Oil/Water Separator, and the perimeter ditch are provided on Figures 2.4 to 2.7. These figures are from the CRA September 2003 report.

2.4.2 GEOLOGY The Natural Resource Conservation Service (NRCS) classifies the shallow soils surrounding the site as primarily fine sands and silt loams; typical soils of an outwash plain. The NRCS classified the soils around the Station in groups that primarily include the following soils: Oakville fine sand, Wateska loamy fine sand, Markham silt loam, and Orthents loamy soil. These soil groups all have similar characteristics and vary by the amount of silt in the material. These soils are moderately to well drained, have moderate to rapid permeability from 0 to 60 inches below ground surface (bgs), and contain 0.5 to 2 percent organic matter.

The local geology is composed of a relatively thin overburden layer overlying the bedrock. Figure 2.8 presents a stratigraphic cross-section of the local geology.

The overburden consists of the Equality Formation (silty sand) and the Wedron Clay Till Formation (glacial outwash and till) (UFSAR, 1994). The Equality Formation is Quaternary age and primarily consists of eolian and lacustrine sands and at the Station it is described as a homogenous, loose, gray to brown sand. This formation is approximately 20 feet thick at the site (Arnold et al., 1999). The Wedron Clay Till consists of glacial till and interbedded discontinuous glacial outwash deposits. At the site, the Wedron Clay Till is predominantly a silty clay. The Wedron Clay Till ranges from 15 to 20 feet thick at the site (Willman et al., 1975). A contour map of the top of the Wedron Clay Till around the Turbine Building and Reactors from the UFSAR is included on Figure 2.9 (UFSAR, 1994).

045136 (12) Braidwood Generating Station 5 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 The important bedrock units in the site area can be divided into these three general sections (Willman and Frye, 1970):

• Pennsylvanian age siltstone, shale, and coal;

• Ordovician shale; and

• Cambrian- Ordovician sandstone and limestone/dolostone.

The Pennsylvanian age units are generally horizontal strata that act as an aquitard and barriers to vertical flow. The coal-bearing Carbondale Formation (Colchester Member) within this group was previously strip-mined in the area of the Station (Figure 2.8). The strip mining removed the overlying units to the bottom of this coal seam (Chapter 2.5.1.2.7, UFSAR, 1994; and ISGS, October 2003). The Carbondale Formation includes the Francis Creek Shale Member and the Colchester Coal Member. It is underlain by the Spoon Formation (Figure 2.8).

Coal was discovered in Braidwood in 1854. Underground mining began in the 1870s.

Strip-mining began in the 1920s. Total production of coal is estimated at over 26 million tons. Approximately 6.2 million tons was produced from underground mines, and about 20.5 million tons from strip mines. Coal was produced mainly from the No. 2 Coal Seam (Figure 2.8). The coal seam is approximately 100 feet bgs. Overlaying the coal is 30 or more feet of the Francis Creek Shale Member of the Pennsylvanian Carbondale Formation. This seam is also known as the Colchester Coal No. 2, which has an average thickness of 3 feet. In the southwestern part of the area thin seams of coal lie closely above and below the Colchester No. 2 seam.

As a result of coal mining, there are several small lakes near the site, which formed when abandoned open-pit mines subsequently filled with groundwater and precipitation. The Cooling Lake south of the facility is one of these lakes (Figure 1.2).

The Cooling Lake is filled with mine spoils consisting of fractured, fragmented deposits of clay shale and other excavated material.

The Ordovician shale is the Maquoketa Shale Group of varying thickness but generally at least 70 feet thick. The Maquoketa Shale separates upper shallower bedrock formations (limestone and dolomite) from the deep sandstone bedrock of Cambrian-Ordovician-Glenwood-St. Peter Formations and the Ironton-Galesville Formations (Figure 2.8).

045136 (12) Braidwood Generating Station 6 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 2.4.3 HYDROGEOLOGY Groundwater in the site area is mainly extracted from two primary aquifers:

• the upper sand aquifer; and

• the deep Cambrian and Ordovician age sandstone formations.

There is some indication, however, based upon well logs from private residences that water supply wells are sometimes completed in the sandstone and limestone of the Carbondale Formation and the Spoon Formation (Figures 2.2 and 2.10). The Carbondale Formation includes the Francis Creek Shale Member, an aquitard, siltstones, conglomerates, shale, and the Colchester No. 2 coal. Beneath the Carbondale Formation is the limestone of the Spoon Formation. Apparently some private wells are installed into the Carbondale Formation above the coal or into the underlying Spoon Formation based upon well depth. Figure 2.10 presents wells completed in the 80- to 120-foot depth that may represent the Spoon Formation.

The upper sand aquifer comprises Quaternary age eolian and lacustrine sands (20 to 30 feet deep) (UFSAR, 1994). There are numerous private wells screened within the surficial sand unit where well yields are highly variable. In general, on a regional scale, well yields range from 20 gallons per minute (gpm) to 100 gpm; the higher yields are in areas where the sand and gravel deposits are thickest. The shallow groundwater flow direction is typically north-northeast but is influenced by surface water bodies.

The deeper bedrock formations used regionally for municipal and private water supplies (depths of 600 to 1,600 feet) are separated from the shallow system by a number of regional aquitards (Visocky, 1985). These barriers include the Wedron Clay Till (located just beneath the shallow sands) and various shale formations including the Scales Shale, which is over 70 feet thick at the Station and found at depths of 400 feet.

Groundwater flow in these deep bedrock formations is expected to be toward the northeast in response to regional pumping centers near Joliet, Illinois (Visocky, 1985).

The groundwater system of most interest at the Station is the upper sand aquifer. This is the zone where previous studies of tritium occurrence have indicated its migration on and off the Braidwood Station property (CRA, March 2006).

The groundwater in the upper sand aquifer occurs under unconfined (water table) conditions and the saturated thickness ranges from 20 to 22 feet. The groundwater in this aquifer is recharged by local precipitation and discharges to local ponds and streams, and to the bedrock near the Kankakee River.

045136 (12) Braidwood Generating Station 7 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 Recently, over 300 permanent and temporary monitoring wells have been installed into the deep and shallow zones (as described in Section 4.0) of the upper sand aquifer at Braidwood Station along the blowdown line (refer to Figure 2.11). Several well nests have been installed in the upper sand aquifer to determine the vertical distribution of impacted groundwater, and also the vertical hydraulic gradient within the aquifer.

Previous investigations along the blowdown line did not indicate a systematic pattern of vertical hydraulic gradients within the upper sand aquifer. The data recently collected as part of the fleetwide investigation has indicated similar vertical hydraulic gradients with one area of exception. Monitoring well clusters located just west of the Turbine Building indicate a downward vertical hydraulic gradient.

Data collected from CRA's previous investigations (CRA, September 2003 and March 2006) indicate there is a significant interaction between the groundwater in the overburden and the surface water bodies such as the perimeter ditch and the ponds to the northeast of the Station (refer to Figures 2.6 and 2.7).

The results from single-well response tests performed as part of the blowdown line investigation indicate that the hydraulic conductivity of the overburden aquifer is in the range of 2.5 x 10-2 centimeters/second (cm/sec) to 3.7 x 10-2 cm/sec (CRA, March 2006).

Average groundwater velocity in the overburden aquifer is 80 feet/year (ft/yr) to 170 ft/yr in the area of the blowdown line.

The Cooling Lake, which is on the upgradient side of the Station, is not in direct contact with the upper sand aquifer, but rather is separated by a slurry wall (a low permeability barrier) that was installed at the time the Station was built. The slurry wall was installed or keyed into the Wedron Clay Till. The Cooling Lake is surrounded by this slurry wall and is, therefore, isolated from the upper sand aquifer at the site.

The Cooling Lake, although on the average is only 8 feet deep, is underlain by mine spoils left over from the coal-strip mining activities discussed previously. These mine spoils typically contain shales, clays, and siltstones that have been excavated and re-deposited. The mine spoil permeability is expected to be extremely low based upon CRA experience with mine spoils in the region. Consequently, the vertical seepage out of the Cooling Lake should not be significant when compared to evaporation losses or the amount of water blown down to the Kankakee River. Finally, although the Colchester Coal No. 2 was mined in this area, the Maquoketa Shale was not disturbed and remains a barrier to vertical flow beneath the Cooling Lake.

045136 (12) Braidwood Generating Station 8 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 Approximately 140 feet of relatively impermeable shale separate the overburden aquifer from the deep bedrock aquifer. The shale units act as aquitards, limiting the hydraulic communication between the groundwater in the overburden and the bedrock aquifer (Visocky, 1985). Most domestic wells in the area are completed within the Glenwood-St. Peter Formation, which is approximately 600 feet bgs.

The Station does not rely on groundwater for any of its water supplies; consequently, there is little information on the deeper groundwater bearing zones at the Station property. However, a review of the water well logs (Appendix A) for private and public supply wells in the area indicate similar groundwater conditions as discussed previously in Section 2.0. Water supply wells in the Station area are completed to depths of approximately 100 feet, 600 feet, and 1,600 feet in order to tap bedrock water bearing formations (refer to Figure 2.10).

Figure 2.12 presents the locations of a local regional cross-section presenting the regional geology, the location of the PA and deeper private and public water supply wells.

Figure 2.13 is a regional cross-section in a southwest to northeast direction. Figure 2.14 is a regional cross-section in a more northerly direction. Both Figures 2.13 and 2.14 indicate the relative depths of PA features, the bedrock aquifers, aquitards and private and public water supply wells.

A former construction water supply well is located in the northeast area of the PA, just east of the Condensate Storage Tanks (Figure 2.1). This well was drilled to a depth of approximately 1,750 feet and is cased to approximately 260 feet bgs. The Braidwood Station does not use this former supply well and there are plans to plug and abandon the well in the near future. The pump inside the well casing restricts access to this well.

2.5 AREA GROUNDWATER USE The groundwater beneath the Station is not used as a potable resource for its operations.

The Station obtains its water from the Kankakee River. There are a number of domestic wells near the Station (see Figures 2.2 and 2.10 for private well locations) that obtain their water from the upper sand aquifer. The groundwater within this upper sand aquifer is under water table conditions with the depth to water ranging from 5 to 15 feet bgs. The shallow aquifer is recharged by precipitation and the shallow aquifer discharges to nearby surface streams and strip mines.

045136 (12) Braidwood Generating Station 9 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 The upper sand aquifer is underlain by Pennsylvanian bedrock composed of siltstone, shale, sandstone, clay, limestone, and coal (Carbondale and Spoon Formations). The Pennsylvanian strata may locally yield up to 20 gpm from the interbedded sandstones.

The Cambrian and Ordovician aquifers in the Station area comprise the Mt. Simon, the Ironton Galesville and the Glenwood-St. Peter Sandstones. These deeper Cambrian and Ordovician aquifers consist of sandstones in contrast to the shallow Pennsylvanian formations, which consist mainly of shale and limestone (Visocky et al, 1985). Water supply wells completed in this aquifer are at depths of over 600 feet (Figures 2.10, 2.13, and 2.14). Most of the groundwater supply wells within the surrounding area of the Braidwood Station are finished within these deeper aquifers (depths of 100 feet, and 600 to 1,600 feet) (Figure 2.10).

The Village of Braidwood, which is approximately 1.5 miles north of the site, provides municipal water via at least one deep bedrock water supply well that has a depth of over 1,600 feet (Figure 2.14). The homeowners and businesses in the Village of Godley generally rely upon shallow sand-point type wells that are constructed into the upper sand aquifer. The Godley Park District uses a deeper bedrock well for its purposes.

2.6 BRAIDWOOD STATION BLOWDOWN LINE INVESTIGATIONS Since the spring of 2005, Exelon has undertaken extensive efforts to investigate tritium impact in areas outside and east of the PA and along the Station's blowdown lines, including extensive sampling of groundwater, surface water, and private wells. The results are presented as follows:

• Tritium Investigation Report (CRA, March 2006);

• Investigation of Tritium in the Groundwater in the Vicinity of VB-4 (CRA, April 2006);

• Investigation of Tritium in the Groundwater in the Vicinity of VB-6 (CRA, April 2006);

• Investigation of Tritium in the Groundwater in the Vicinity of VB-7 (CRA, April 2006);

• Technical memorandum, "Evaluation of the Source of Tritium in Two Private Wells located Along the Kankakee River and Illinois Route 113" (CRA, June 2006); and

• Hydrogeologic investigation Turbine Building/Protected Area (CRA, June 2006).

The above documents have been submitted to the Illinois EPA.

045136 (12) Braidwood Generating Station 10 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 3.0 AREAS FOR FURTHER EVALUATION CRA considered all Station operations in assessing groundwater quality at the Station.

During this process, CRA identified areas at the Station that warranted further evaluation or "AFEs". This section discusses the process by which AFEs were selected.

CRA's identification of AFEs involved the following components:

• Station inspection on March 24, 2006;

• interviews with Station personnel;

• evaluation of Station systems;

• investigation of confirmed and unconfirmed releases of radionuclides; and

• review of previous Station investigations.

CRA analyzed the information collected from these components combined with information obtained from CRA's study of hydrogeologic conditions at the Station to identify those areas where groundwater potentially could be impacted from operations at the Station.

CRA then designed an investigation to determine whether any confirmed or potential releases or any other release of radionuclides adversely affected groundwater. This entailed evaluating whether existing Station groundwater monitoring systems were sufficient to assess the groundwater quality at the AFEs. If the systems were not sufficient to adequately investigate groundwater quality associated with any AFE, additional monitoring wells were installed by CRA.

The following sections describe the above considerations and the identification of AFEs.

The results of CRA's investigation are discussed in Section 5.0.

3.1 SYSTEMS EVALUATIONS Exelon launched an initiative to systematically assess the structures, systems and components that store, use, or convey potentially radioactively contaminated liquids.

Maps depicting each of these systems were developed and provided to CRA for review.

The locations of these systems are presented on Figures 3.1 and 3.2. The Station identified a total of 21 systems that contain or could contain potentially radioactively contaminated liquids. The following presents a list of these systems.

045136 (12) Braidwood Generating Station 11 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 System Identification Description AB Boric Acid Process AS Auxiliary System Steam CD Condensate CP Condensate Cleanup CW Circulation Water Blowdown and Treated Runoff Return Portions FC Fuel Pool Cooling HD Feedwater Drains OG Off Gas OD Equipment/Floor Oil Drain PW Primary Water RF Reactor Building Floor Drains SH Station Heating ST Sewage Treatment SX Essential Service Water TE Turbine Building Floor Drains TF Turbine Building Floor Drains TR Treated Runoff VF Filtered Vents WE Auxiliary Building Equipment Drain WF Auxiliary Building Floor Drain WX Radwaste Disposal After these systems were identified, Exelon developed a list of the various structures, components and areas of the systems (e.g., piping, tanks, process equipment) that handle or could potentially handle any radioactively contaminated liquids. The structures, components, and areas may include:

• aboveground storage tanks;

• condensate vents;

• areas where confirmed or potential historical releases, spills, or accidental discharges may have occurred;

• pipes;

• pools;

• sumps;

• surface water bodies (i.e., basins, pits, ponds, or lagoons);

• trenches;

• underground storage tanks; and

• vaults.

045136 (12) Braidwood Generating Station 12 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 The Station then individually evaluated the various system components to determine the potential for any release of radioactively contaminated liquid to enter the environment. Each structure or identified component was evaluated against the following seven primary criteria:

• location of the component (i.e., basement or second floor of building);

• component construction material (i.e., stainless steel or steel tanks);

• construction methodologies (i.e., welded or mechanical pipe joints);

• concentration of radioactively contaminated liquid stored or conveyed;

• amount of radioactively contaminated liquid stored or conveyed;

• existing controls (i.e., containment and detection); and

• maintenance history.

System components, which were located inside a building or that otherwise had some form of secondary containment, such that a release of radioactively contaminated liquid would not be discharged directly to the environment, were eliminated from further evaluation. System components that are not located within buildings or did not have some other form of secondary containment were retained for further qualitative evaluation of the risk of a release of radioactively contaminated liquid to the environment and the potential magnitude of any release.

Exelon's risk evaluation took into consideration factors such as:

• the potential concentration of radionuclides;

• the volume of liquid stored or managed;

• the probabilities of the systems actually containing radioactively contaminated liquid; and

• the potential for a release of radioactively contaminated liquid from the system component.

These factors were then used to rank the systems and system components according to the risk for a potential release of a radioactively contaminated liquid to the environment.

The evaluation process resulted in the identification of structures, components, and areas to be considered for further evaluation.

045136 (12) Braidwood Generating Station 13 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 3.2 HISTORICAL RELEASES CRA also reviewed information concerning confirmed or potential historical releases of radionuclides at the Station, including reports and documents previously prepared by Exelon and compiled for CRA's review. CRA evaluated this information in identifying the AFEs. Any historical releases identified during the course of this assessment that may have a current impact on Station conditions are further discussed in Section 3.4.

3.3 STATION INVESTIGATIONS CRA also considered previous Station investigations in the process of selecting the AFEs for the Station. This section presents a summary of the pre-operational radiological environmental monitoring program, past station investigations, and the radiological environmental monitoring program.

3.3.1 PRE-OPERATIONAL RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM A pre-operational radiological environmental monitoring program (pre-operational REMP) was conducted to establish background radioactivity levels prior to operation of the Station. The environmental media sampled and analyzed during the pre-operational REMP were atmospheric radiation, fall-out, domestic water, surface water, marine life, and foodstuffs. The results of the monitoring were detailed in the report entitled, Environmental Radiological Monitoring for Braidwood Nuclear Power Station, Commonwealth Edison Company, Annual Report 1986, May 1987.

The pre-operational REMP at Braidwood commenced in July 1983. The fourth annual report in 1986 presented data acquired during the period from January through December 1985. Atmospheric radiation monitoring consisted of gas and air particulate radioactivity measurements; fall-out monitoring consisted of radioactivity measurements of soil, vegetation, and rain water; domestic water monitoring consisted of well water sample analysis; surface water samples were collected from the two Kankakee River locations and two cooling water locations. Foodstuffs were monitored by analyzing samples of cow's milk and vegetables from nearby farms.

The pre-operational REMP contained analytical results from samples collected from the surface water and groundwater. The samples were analyzed for gross beta content and were averaged for each quarter.

045136 (12) Braidwood Generating Station 14 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 Surface water at the Kankakee River downstream collection point, BD-10, had gross beta concentrations that ranged from 2.8 +/- 0.9 picoCuries per liter (pCi/L) to 3.2 +/- 1.4 pCi/L.

At the upstream Kankakee River collection point, BD-7, the average gross beta concentrations for the second and fourth quarters was 3.6 pCi/L and the average gross beta concentration during the third quarter was 18.8 pCi/L. Gross beta concentrations from the cooling water sample points ranged from unspecified LLDs to a maximum detection of 4.9 +/- 1.0 pCi/L.

Monthly composites of weekly sample collections from all surface water locations indicated tritium concentrations were non detect at the LLD (200 pCi/L). Monthly composites of weekly sample collections from all surface water locations indicate (strontium-89, strontium-90, cesium-134, and cesium-137) concentrations less than their specified LLDs.

Groundwater was collected from one off-site well on a quarterly basis. Gross beta, gamma isotopic, radiostrontium, and tritium analyses were performed on all samples.

Strontium-89, strontium-90, tritium and gamma emitters were below their respective LLDs. Gross beta activity was within the expected levels and ranged from 3.7 +/- 1.7 pCi/L to 37.9 +/- 3.2 pCi/L.

3.3.2 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM As part of its NRC operating license, Braidwood Station conducts a REMP. The REMP includes the collection of multi-media samples including air, surface water, groundwater, fish, sediment, and vegetation. The samples are analyzed for beta and gamma emitting radionuclides, tritium, iodine-131, and/or strontium as established in the procedures developed for the REMP. The samples are collected at established locations, identified as stations, so that trends in the data can be monitored.

An annual report is prepared providing a description of the activities performed and the results of the analysis of the samples collected from the various media. The latest report generated was prepared by Station personnel and is entitled Annual Radiological Environmental Operating Report for the Braidwood Station (period from January 1 to December 31, 2005), May 2006. This report concluded that the operation of the Braidwood Station had no adverse radiological impact on the environment.

As part of REMP, surface water samples are collected at two locations and groundwater samples are collected at six locations.

045136 (12) Braidwood Generating Station 15 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 3.3.3 HISTORIC SITE INVESTIGATIONS This section summarizes historic site investigations completed at the Station in regard to releases of radioactively contaminated liquid to the subsurface.

3.3.3.1 POWER PLANT DOCUMENTS-UFSAR REPORT During the construction of the Station, a series of comprehensive investigations of regional and local geology, surface water, and groundwater conditions were conducted.

These studies are documented in the UFSAR Rev. 10, December 2004.

3.3.3.2 BLOWDOWN LINE INVESTIGATION The blowdown line, which runs from the PA and east to the Kankakee River, was previously evaluated by CRA. The results are presented in a series of reports listed in Section 2.6 and Section 10.0. Figure 2.11 presents locations of monitoring wells installed as of May 2006 along the blowdown line and in the PA as part of these previous studies.

3.4 IDENTIFIED AREAS FOR FURTHER EVALUATION CRA used the information presented in the above sections along with its understanding of the hydrogeology at the Station to identify AFEs, which were a primary consideration in the development of the scope of work in the Work Plan. The establishment of AFEs is a standard planning practice in hydrogeologic investigations to focus the investigation activities at areas where there is the greatest potential for impact to groundwater.

Specifically, AFEs were identified based on these six considerations:

• systems evaluations;

• risk evaluations;

• review of confirmed and/or potential releases;

• review of documents;

• review of the hydrogeologic conditions; and

• Station inspection completed on March 24, 2006.

045136 (12) Braidwood Generating Station 16 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 Prior to CRA completing its analysis and determination of AFEs, Station personnel completed an exhaustive review of all historic and current management of systems that may contain potentially radioactively contaminated liquids.

CRA reviewed the systems identified by the Station, which have the potential for the release of radioactively contaminated liquids to the environment, and groundwater flow at the Station. This evaluation allowed CRA to become familiar with Station operations and potential systems that may impact groundwater. CRA then evaluated information concerning historic releases as provided by the Station. This information, along with a review of the results from historic investigations, was used to refine CRA's understanding of areas likely to have the highest possibility of impacting groundwater.

Where at risk systems or identified historical releases were located in close proximity or were located in areas which could not be evaluated separately, the systems and historical releases were combined into a single AFE. At times, during the Station investigation, separate AFEs were combined into one or were otherwise altered based on additional information and consideration.

Finally, CRA used its understanding of known hydrogeologic conditions (prior to this investigation) to identify AFEs. Groundwater flow was an important factor in deciding whether to combine systems or historical releases into a single AFE or create separate AFEs. For example, groundwater beneath several systems that contain radioactively contaminated liquids that flows toward a common discharge point were likely combined into a single AFE. The AFEs were created based on known groundwater flow conditions prior to the work completed during this investigation.

Based upon its review of information concerning confirmed or potential historical releases, historic investigations, and the systems at the Station that have the potential for release of radioactively contaminated liquids to the environment combined with its understanding of groundwater flow at the Station, CRA identified four AFEs (see Figures 3.1 and 3.2).

AFE-Braidwood North of the Slurry Wall This area was identified as an AFE to investigate the possibility that the slurry wall (slurry trench) is not providing sufficient hydraulic control to prevent tritium (if present) from migrating off the site property. Tritium has been detected in the groundwater within the slurry wall on the west side of the Turbine Building. It was necessary to assess if this tritium or other groundwater impacts had the potential to migrate north of the slurry wall and outside the PA.

045136 (12) Braidwood Generating Station 17 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 On March 13, 2006, rain accumulated and mixed with tritiated water within the bermed area surrounding the Frac Tank storage area located on a concrete pad (Refer to Figure 3.2). The berm surrounding the tanks was breached and allowed water to spill over the berm and seep into soils near the pad. Most of the water was recovered.

AFE-Braidwood North/Northeast of Units 1 and 2 This area was identified as an AFE due to its proximity to Units 1 and 2 and the systems near these two units. More specifically, this area was identified as an AFE to monitor groundwater quality on the northeast of the reactors, the fuel handling building, and other systems.

AFE-Braidwood Auxiliary Construction Storage Tank This area comprises the Auxiliary Construction Storage Tank, the blowdown line as it exits the PA, and the sewage treatment plant. This area was selected for groundwater monitoring to evaluate the quality of groundwater in this area of the PA and the potential impacts of historical releases documented by Exelon.

AFE-Braidwood West Side of Turbine Building This area comprises the west side of the Turbine Building. The following five pieces of information provide support to this area being identified as an AFE:

• existing monitoring well data from the Winter of 2006 had indicated tritium impacts in wells located adjacent to the west side of the Turbine Building foundation;

• a seep, occurring intermittently, into the basement of the Turbine Building had indicated concentrations of tritium over the LLD of 200 pCi/L;

• prior to 1992, effluent from Turbine Building Fire and Oil Sump was released to the storm water drainage system;

• in December 1990, some tritiated water may have been periodically discharging to the storm sewer system through a heating system relief valve. The valves discharge to the Oil/Water Separator on the north end of the property. The separator then discharges into the drainage ditch; and

• on April 6, 2006, a release of steam (location is presented on Figure 3.2) from the west side of the Turbine Building discharged onto the ground surface near the waste treatment lagoons and north of the waste treatment plant. The release was partially remediated by collecting all available standing water, pumping water from the storm water drainage system, and blocking drainage paths for some site drainage ditches.

045136 (12) Braidwood Generating Station 18 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 4.0 FIELD METHODS The field investigations completed for this HIR were completed in April, May, and July 2006. CRA supervised the installation of monitoring wells and staff gauges, collected samples from the newly-installed and existing monitoring wells and from surface water locations, and collected a round of groundwater and surface water measurements. The field investigations were completed in accordance with the methodologies presented in the Work Plan (CRA, 2006).

4.1 STAFF GAUGES INSTALLATION Figure 4.1 presents the location of the four new staff gauges and two surface water monitoring points installed as part of this investigation. CRA installed staff gauges at four locations (SG-BW-101 to 104) within the perimeter ditch and established two monitoring points (SG-105 and 106) on the Cooling Lake.

4.2 GROUNDWATER MONITORING WELL INSTALLATION Twelve new monitoring wells were installed for the fleetwide hydrogeologic investigation. Monitoring well construction logs are provided in Appendix A. This included ten wells completed within the upper sand aquifer and two completed within the shallow bedrock. Figure 4.2 presents the location of the new monitoring wells.

These locations were selected based on a review of all data provided, the hydrogeology at the Station, and current understanding of identified AFEs. Table 4.1 summarizes the well completion details.

Prior to completing any ground penetration activities, CRA completed subsurface utility clearance procedures to minimize the potential of injury to workers and/or damage to subsurface utility structures. The subsurface clearance procedures consisted of completing an electronic survey within a minimum of 10-foot radius of the proposed location utilizing electromagnetic and ground penetrating radar technology.

Additionally, an air knife was utilized to verify utilities were not present at the proposed location to a depth to 10 feet bgs.

Specific installation protocols for the ten shallow monitoring wells are described below:

• the borehole was advanced to the target depth using 4.25-inch inside diameter hollow-stem augers (HSA) or Rotosonic techniques; 045136 (12) Braidwood Generating Station 19 CONESTOGA-ROVERS & ASSOCIATES

Revision 1

• a nominal 2-inch diameter (No. 10 slot) PVC screen, 10 feet in length, attached to a sufficient length of 2-inch diameter schedule 40 PVC riser pipe to extend to the surface, was placed into the borehole through the augers;

• a filter sand pack consisting of silica sand was installed to a minimum height of 2 feet above the top of the screen as the augers are removed;

• a minimum 2-foot thick seal consisting of 3/8-inch diameter bentonite pellets or chips was placed on top of the sand pack and hydrated using potable water;

• the remaining borehole annulus was sealed to within 3 feet of the surface using pure bentonite chips;

• the remaining portion of the annulus was filled with concrete and a 6-inch diameter protective above-grade casing. The well head will be fitted with a water-tight, lockable cap; and

• cement-filled bollard posts were installed around selected monitoring well locations.

Shallow monitoring wells included two types of wells completed within the upper sand aquifer. A shallow zone well was completed at depths of approximately 15 feet bgs into the upper sand zone and at the water table. The deep zone wells were completed at depths of approximately 25 to 30 feet bgs and into the lower portions of sand found on top of the Wedron Clay Till.

Specific installation protocols for the two bedrock monitoring wells are described below.

Each shallow bedrock well was drilled to and completed within the first water bearing zone encountered beneath the Francis Creek Shale Member. A sandstone was encountered below these shales and the screened interval for both MW-BW-201BD and MW-BW-208BD was set into this sandstone layer at a depth of approximately 80 to 95 feet bgs at MW-BW-201BD and from 85 to 100 feet bgs at MW-BW-208BD. This sandstone is expected to be part of the underlying Spoon Formation.

MW-BW-201D was installed using 8-inch HSA drilled to a depth of 39 feet bgs. A 6-inch protective casing was then installed through the augers and pushed to a depth of 40 feet bgs to ensure a proper seal into the till. A HQ coring bit was used to drill through the shale and siltstone formations to a depth of 100 feet bgs. Ten-foot core samples were recovered between 70 and 100 feet bgs. The core sample recovered in MW-BW-201BD between 84 and 91 feet bgs appeared to contain highly fractured and weathered sandstone, therefore the monitoring well screen was installed to straddle that zone (i.e., from 80 to 95 feet bgs) as shown on the well construction log. Similar conditions were encountered at MW-BW-208BD. At this location the well screen was 045136 (12) Braidwood Generating Station 20 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 installed between 80 to 100 feet bgs. The monitoring well MW-BW-208BD was installed in July 2006 using Rotosonic drilling techniques.

Sand was installed in the borehole from the bottom of the hole to the bottom of the well screen to provide a base for the 2-inch monitoring well. A sand pack was then installed up to a depth of 2 feet above the top of the screen. Bentonite chips were installed to ensure a hydraulic seal above the sand pack. The protective casing and either the 8-inch augers (in the case of the HSA) or the drill steel (in the case of the Rotosonic) were then removed from the borehole. A bentonite gel and Portland cement slurry was then mixed and added to the borehole to 2 feet bgs. The monitoring wells were then finished with a Pro-cover protective casing.

4.3 GROUNDWATER MONITORING WELL DEVELOPMENT In order to establish good hydraulic communication with the aquifer and reduce the volume of sediment in the monitoring well, monitoring well development was performed in accordance with the procedure outlined below:

• Monitoring wells were surged using a pre-cleaned surge block for a period of at least 20 minutes.

• Water was purged from the monitoring well using a pneumatic submersible pump.

• Groundwater was collected at regular intervals with the pH, temperature, and conductivity measured using field instruments. These instruments were calibrated daily according to the manufacturer's specifications. Additional observations such as color, odor, and turbidity of the purged water were recorded in the field book.

• Development continued until the turbidity and silt content of the monitoring wells was significantly reduced and three consistent readings of pH, temperature, and conductivity were recorded, or a minimum of ten well volumes were purged.

A summary of the well development parameters is provided in Table 4.2.

4.4 WELL INVENTORY CRA performed a comprehensive private well survey/inventory along the length of the blowdown line and in areas north and west of the site. This well inventory was presented in the reports discussed in Section 2.6. The private well logs for wells near and surrounding the Site are provided in Appendix B. These wells are a subset of the 045136 (12) Braidwood Generating Station 21 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 water supply wells sampled by Exelon. Figure 2.15 presents the locations and results for private wells, public wells, and monitoring wells.

4.5 SURVEY The new monitoring wells and staff gauges were surveyed to establish reference elevations relative to mean sea level. The top of each well casing was surveyed to the nearest 0.01 feet relative to the National Geodetic Vertical Datum (NGVD), and the survey point was marked on the well casing. The survey included the ground elevation at each well to the nearest 0.10 feet relative to the NGVD, and the well location to the nearest 1.0 foot. A reference point was also marked on each staff gauge.

4.6 GROUNDWATER AND SURFACE WATER ELEVATION MEASUREMENTS From May 9 to 11, 2006, CRA collected water level measurements from both existing monitoring wells, new monitoring wells, and from surface water locations in accordance with the Work Plan. CRA collected a second round of water levels from both existing and new monitoring wells on July 31, 2006. Based on the measured depth to water from the reference point and the surveyed elevation of the reference point, the groundwater or surface water elevation was calculated. A summary of groundwater elevations for the events is provided in Table 4.3.

Prior to the water level measurements, the wells were correctly identified and located.

Once the well was identified, a thorough inspection of each well was conducted, and any deficiencies were noted. Water level measurements were collected using an electronic depth-to-water probe accurate to +/- 0.01 feet. The measurements were made from the designated location on each of the monitoring wells inner riser or steel casing.

The water level measurements were obtained using the following procedures:

• The proper elevation of the meter was checked by inserting the tip into water and noting if the contact was registering correctly.

• The tip was dried, and then slowly lowered into the well until contact with the water was indicated.

• The tip was slowly raised until the light and/or buzzer just began to activate. This indicated the static water level.

• The reading at the reference point was noted to the nearest hundredth of a foot.

045136 (12) Braidwood Generating Station 22 CONESTOGA-ROVERS & ASSOCIATES

Revision 1

• The reading was then re-checked.

• The water level was then recorded, and the water level meter decontaminated prior to use at the next well location.

In early May 2006, as part of the fleetwide investigation, CRA collected a round of water level measurements from 43 of the Station monitoring wells and six surface water locations on the Station. On July 31, 2006, CRA collected a second round of water level measurements from 45 of the Station monitoring wells (including the two newly installed monitoring wells, MW-BW-207I and MW-BW-208BD). A summary of groundwater elevations for the two events is provided in Table 4.3.

During the May 2006 groundwater sampling program, the following monitoring wells (MW-4, MW-5, TB-1-3D, TW-6, and TW-8) were not measured for depth to water due to problems with the water level indicator meter. CRA subsequently has gone back at a later date to get these water levels. Also, water levels were not measured at TW-8 because TW-8 had broken riser.

Surface water elevations were measured at the four staff gages installed within the perimeter ditch (Figure 4.1) and at two locations on the north side of the Cooling Lake (Figure 4.1). The data from these measurements are provided in Table 4.4.

A pressure transducer was installed by CRA at TB-1-4D for approximately 6 weeks to evaluate water level changes near the Turbine Building close to where leaks have occurred within the basement. The purpose of the continuous monitoring was to determine if the system (pipe) water leaks were creating this basement seep, or, if precipitation/storm water system leaks were affecting flow into the basement.

Water level data were recorded for the period from June 6 to July 21, 2006. Precipitation data were also reviewed for this same period for the Village of Braidwood. Figure 4.3 presents a graphical presentation of the relative head (feet above the transducer) measurements from the transducer. Figure 4.3 also presents the precipitation (inches) for the monitored period. The pressure transducer was set at 10 feet below the top of the well casing. At the time of installation, the water table was 6.9 feet below the top of the well casing.

045136 (12) Braidwood Generating Station 23 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 4.7 GROUNDWATER AND SURFACE WATER SAMPLE COLLECTION CRA conducted two rounds of groundwater sampling during the completion of the Work Plan for these hydrogeologic investigations. A total of 43 monitoring wells were sampled between May 9 and May 22, 2006 and two monitoring wells were sampled on July 28, 2006. Of the 45 monitoring wells sampled, 12 were newly installed. The sampling was scheduled to allow for two weeks to elapse between well development and groundwater sample collection. The existing wells were selected for inclusion in this monitoring program based on their proximity to the AFEs. The new wells were installed to complete the monitoring network near the AFEs.

At the monitoring locations, CRA conducted the sampling using dedicated tubing and peristaltic pumps and employed low-flow purging techniques as described in Puls and Barcelona (1996).

The groundwater in the monitoring wells was sampled by the following low-flow procedures:

• The wells were located and the well identification numbers were verified.

• A water level measurement was taken.

• The well was sounded by carefully lowering the water level tape to the bottom of the well (so as to minimize penetration and disturbance of the well bottom sediment),

and comparing the sounded depth to the installed depth to assess the presence of any excess sediment or drill cuttings.

• The pump or tubing was lowered slowly into the well and fixed into place such that the intake was located at the mid-point of the well screen, or a minimum of 2 feet above the well bottom/sediment level.

• The purging was conducted using a pumping rate between 100 to 500 milliliters per minute (mL/min). Initial purging began using the lower end of this range. The groundwater level was monitored to ensure that a drawdown of less than 0.3 feet occurred. If this criterion was met, the pumping rate was increased dependent on the behavior of the well. During purging, the pumping rate and groundwater level were measured and recorded every 10 minutes.

• The field parameters (pH, temperature, conductivity, oxidation-reduction potential (ORP), dissolved oxygen (DO), and turbidity) were monitored during the purging to evaluate the stabilization of the purged groundwater. Stabilization was considered to be achieved when three consecutive readings for each parameter, taken at 5-minute intervals, were within the following limits:

045136 (12) Braidwood Generating Station 24 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 pH +/- 0.1 pH units of the average value of the three readings; Temperature +/- 3 percent of the average value of the three readings; Conductivity +/- 0.005 milliSiemen per centimeter (mS/cm) of the average value of the three readings for conductivity <1 mS/cm and

+/- 0.01 mS/cm of the average value of the three readings for conductivity >1 mS/cm; ORP +/- 10 millivolts (mV) of the average value of the three readings; DO +/- 10 percent of the average value of the three readings; and Turbidity +/- 10 percent of the average value of the three readings, or a final value of less than 5 nephelometric turbidity units (NTU).

• Once purging was complete, the groundwater samples were collected directly from the pump/tubing directly into the sample containers.

All groundwater samples were labeled with a unique sample number, the date and time, the parameters to be analyzed, the job number, and the sampler's initials. The samples were then screened by the Station for shipment to Teledyne Brown Engineering, Inc.

(Teledyne Brown).

A sample key is presented in Table 4.5; purging parameters for the fleetwide event are presented in Table 4.6.

CRA containerized the water purged from the monitoring wells during the sampling, as well as the water purged from all of the wells during the hydrogeologic investigation.

The water was placed into 55-gallon drums, which will be processed by the Station in accordance with its NPDES permit.

Surface water samples were collected on May 17, 2006 a few days after a storm event.

The surface water samples were collected under dry conditions in order to avoid dilution by rainwater. Six surface water samples were collected, four at staff gauges located on the perimeter ditch and locations on the north end of the Cooling Lake. The surface water sampling locations are presented on Figure 4.1.

The surface water samples were collected by submerging the sample container at the determined sample locations until completely filled. All samples were shipped to Teledyne Brown for analysis.

045136 (12) Braidwood Generating Station 25 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 4.8 DATA QUALITY OBJECTIVES CRA has validated the analytical data to establish the accuracy and completeness of the data reported. Teledyne Brown provided the analytical services. The Quality Assurance Programs for the laboratory is described in Appendix E. Analytical data for groundwater and surface water samples collected in accordance with the Work Plan are presented in Appendix F. Data validation reports are presented in Appendix G. The data validation included the following information and evaluations:

• sample preservation;

• sample holding times;

• laboratory method blanks;

• laboratory control samples;

• laboratory duplicates;

• verification of laboratory qualifiers; and

• field quality control (field blanks and duplicates).

Following the completion of field activities, CRA compiled and reviewed the geologic, hydrogeologic, and analytical data.

The data were reviewed using the following techniques:

• data tables and databox figures;

• hydrogeologic cross-sections; and

• hydraulic analyses.

4.9 SAMPLE IDENTIFICATION Systematic sample identification codes were used to uniquely identify all samples. The identification code format used in the field was: WG - BW - 050806 - MB - 001. A summary of sample identification numbers is presented in Table 4.5.

WG - Sample matrix -groundwater SW - Sample matrix - surface water BW - Station code 050806 - Date MB - Sampler initial 001 - Sample number 045136 (12) Braidwood Generating Station 26 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 4.10 CHAIN-OF-CUSTODY RECORD The samples were delivered to Station personnel under chain-of-custody protocol.

Subsequently, the Station shipped the samples under chain-of-custody protocol to Teledyne Brown for analyses.

4.11 QUALITY CONTROL SAMPLES Quality control samples were collected to evaluate the sampling and analysis process.

Field Duplicates Field duplicates were collected to verify the accuracy of the analytical laboratory by providing two samples collected at the same location and then comparing the analytical results for consistency. Field duplicate samples were collected at a frequency of one duplicate for every ten samples collected. A total of seven duplicate samples were collected. The locations of duplicate samples were selected in the field during the performance of sample collection activities. The duplicate samples were collected simultaneously with the actual sample and were analyzed for the same parameters as the actual samples.

Split Samples Split samples were collected for the NRC for tritium simultaneously with the actual sample at every sample location. Split samples were delivered to the Station personnel and made available to the NRC.

4.12 ANALYSES Groundwater and surface water samples were analyzed for tritium and gamma-emitting radionuclides as listed in NUREG-1301 and strontium-89/90 as listed in 40 CFR 141.25.

045136 (12) Braidwood Generating Station 27 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 5.0 RESULTS

SUMMARY

This section provides a summary of Station-specific geology and hydrogeology, along with a discussion of hydraulic gradients, groundwater elevations, and flow directions in the vicinity of the Station. This section also presents and evaluates the analytical results obtained from activities performed in accordance with the Work Plan.

5.1 STATION GEOLOGY The geology encountered during monitoring well installation is consistent with the geology described in Section 2.4.2 and the geology within areas to the east and along the blowdown line as described in the CRA reports previously listed (refer to Section 2.5).

The geology beneath the site consists of overburden deposits of sand (Equality Formation) and clay (Wedron Clay Till) that overlies alternating layers of shale/siltstone and dolostone (Carbondale Formation) (refer to the site specific stratigraphic column on Figure 2.8). South-north and east-west hydrogeologic profiles (profiles) are presented on Figures 5.1 to 5.5. These profile locations were chosen because of their close proximity to structures potentially influencing groundwater flow patterns.

The three new shallow and seven intermediate depth wells (MW-BW-201S, MW-BW-201I, MW-BW-202S, MW-BW-202I, MW-BW-203S, MW-BW-203I, MW-BW-204I, MW-BW-205I, MW-BW-206I, and MW-BW-207I) were installed within the Equality Formation. The Equality Formation is primarily uniform fine-grained sand.

The monitoring well logs for the new monitoring wells are presented in Appendix A.

The two bedrock wells, MW-BW-201BD and MW-BW-208BD, were installed through the Equality Formation, the Wedron Clay Till, the Francis Creek Shale Member of the Carbondale Formation and into the lower portion of the Francis Creek Shale Member.

Refer to Figure 2.8 for the sequence of formations beneath the site. The top of the Wedron Clay Till was encountered at approximately 24 feet bgs, which is consistent with previous geological investigations. The bottom of the clay was approximately 54 feet bgs where shale bedrock was encountered and is considered to be the Francis Creek Shale Member. At a depth of approximately 85 feet bgs, a sandstone was encountered that was weathered. From 90 to 100 feet, the material included a conglomerate, sandstone, and shale. MW-BW-201BD and MW-BW-208BD were both completed in this lower zone from 80 to 95 feet bgs and 85 to 100 feet bgs, respectively.

This is expected to be the bottom of the Francis Creek Shale Member of the Carbondale Formation and it is located just above the Colchester Coal (Figure 2.8).

045136 (12) Braidwood Generating Station 28 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 Profile A-A' (Figure 5.2) is a west-east profile through the middle of the Station. It begins at the western fence line bordering the Station and terminates near the eastern perimeter ditch approximately 1,200 feet east of the eastern fence line of the site. The profile A-A' presents the relative elevations of the perimeter ditch water levels with groundwater levels on both sides of the PA. Higher water levels are measured in the eastern stretch of the perimeter ditch. The profile also indicates that the buildings extend to the top of the Francis Creek Shale Member (through the Wedron Clay Till) and will act as barriers to lateral flow. The backfilled area around the building is also indicated on this profile. Finally, the slurry wall is projected on this figure based upon information gathered from Station documents. The top of the slurry wall appears to be close to the current water table elevation.

Profile B-B' (Figure 5.3) is a north-south profile and parallels the storm sewer line that runs south-north. The profile B-B' indicates the relative elevation of the groundwater table and the approximate depth of the storm water drainage system. This figure clearly indicates that the storm water drainage system intercepts the water table as reported previously (CRA, August 2002 and September 2003). The limits of the construction excavation are also depicted on this profile along with the expected condition of the slurry wall. During drilling of the intermediate monitoring well MW-BW-207I on July 13, 2006, the Wedron Clay Till was not encountered. The material encountered included sands and other fill type material such as gravels and concrete. These observations indicate that the Station construction excavation went to a depth of approximately 44 to 45 feet bgs at this location. This depth of the excavation is indicated on Figure 5.3. Although the clay was missing in the location of MW-BW-207I, the top of the Francis Creek Shale Member was encountered where expected (45 feet bgs).

Profile C-C (Figure 5.4) is a north-south profile down the center of the PA area to the Cooling Lake. The bedrock well (MW-BW-201BD) is displayed on this figure, as well as the building foundation. The profile C-C' presents a more regional depiction of subsurface conditions from the Cooling Lake in the south to the north end of the PA.

The slurry wall associated with the Cooling Lake and the slurry wall associated with the building construction are depicted on this profile. The depths of the various facility buildings are shown to extend down through the Wedron Clay Till and to the top of the Francis Creek Shale Member. As such, these buildings are barriers to lateral groundwater flow. The shallow bedrock monitoring well (MW-BW-201BD) is presented on this figure and indicates the bottom of the Francis Creek Shale Member.

Profile D-D' (Figure 5.5) is a west-east profile in the northern portion of the PA that transects the CST area. Hydrogeologic profile D-D' presents the locations and relative elevations of the groundwater, storm water drainage system, slurry wall, and 045136 (12) Braidwood Generating Station 29 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 excavation/fill material. This profile is north of the Turbine Building and as such does not present subsurface building structures. The water levels on each side of the slurry wall on the west do indicate a slight difference in elevation. However, this is not as apparent in other areas in the PA.

5.2 SITE HYDROGEOLOGY This section describes groundwater flow in the various hydrogeologic units identified at the site. Figure 5.1 presents the monitoring well network in relationship to the hydrogeologic profile locations. Hydrogeologic profiles are presented on Figures 5.2 to 5.5.

5.2.1 GROUNDWATER FLOW DIRECTIONS Groundwater flow directions in the upper sand aquifer are presented on Figures 5.6 and 5.7 (the shallow zone) and on Figures 5.8 and 5.9 (the deep zone). Figures 5.6 and 5.8 represent water levels measured in May 2006. Figures 5.7 and 5.9 represent water levels measured in July 2006. CRA has identified four areas of differing flow within and around the PA based upon the May and July water levels. These four areas are a result of the man-made features presented in the previous section.

One flow system encompasses the east side of the PA. The second system is found along the west side of the Turbine Building within the perimeter of the slurry wall and within the limits of the former excavation. The third system is to the northwest of the slurry wall near the perimeter ditch. The fourth system includes the area west-southwest of the PA where groundwater flows to the southwest and discharges to the perimeter ditch. The groundwater flow is restricted by the basement walls and, to some degree, the slurry trench. Groundwater flow directions are provided on Figures 5.6 and 5.7 for the shallow zone of the upper sand aquifer and on Figures 5.8 and 5.9 for the deep zone of the upper sand aquifer.

Groundwater in the near west side of the Turbine Building predominantly flows to the north toward a storm water drainage system ditch north of the Oil/Water Separator.

The storm water drainage system ditch is a tributary to the perimeter ditch (Figure 2.3).

To the west and southwest of the PA, the perimeter ditch acts as a discharge point for the shallow groundwater system (CRA, August 2002). Groundwater generally flows to the ditch from east to west. The water elevation within the ditch is measured to be 045136 (12) Braidwood Generating Station 30 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 approximately 586 feet above mean sea level (AMSL) at a location northwest of the PA.

Groundwater elevations are higher than ditch elevations along the length of the perimeter ditch as it flows to the south. There is no shallow groundwater flow to the west of the perimeter ditch under normal flow conditions (CRA, September 2003).

5.2.2 MAN-MADE INFLUENCES ON GROUNDWATER FLOW There are a number of man-made features that influence the flow direction and velocity of groundwater as it moves through the site area. These features include:

• The perimeter ditch (Figures 2.3, 2.6, and 2.7), which was dug at the time of the Station Construction to drain surface water away from the Cooling Lake;

• The storm water drainage system (Figures 2.3, 2.4, and 2.5) located on the west side of the Turbine Building and its associated Oil/Water Separator;

• The slurry wall constructed around the footprint of the buildings in the PA (Figure 2.1;

• The former excavation now backfilled with material located around the current buildings (Figure 2.1);

• The various basements and foundations of the turbine, auxiliary, reactor, fuel handling, and other buildings, many of these extend through the water table (Figures 5.2 to 5.5); and

• The Cooling Lake and the slurry wall, which are located south of the PA (Figures 2.13, 2.14, and 5.4).

The figures listed above and the discussion presented below provide basic observations on the impact of these features on groundwater flow which was discussed previously in Section 5.2.2.

The PA (Figure 1.2) is located at the northwest area of the Station property and is surrounded by the perimeter ditch, which flows from the east, to the north of the PA, and then to the south. The perimeter ditch flows along the western boundary of the Station property (Figure 2.3). The elevation of the water in the ditch drops from about 593 feet AMSL on the east side to 586 feet AMSL on the west side. The water levels continue to drop as the ditch flows to the south and west. As the ditch exits the Braidwood Station Property, its surface water elevation is about 579 feet AMSL.

To the south of the PA is the Cooling Lake, which comprises over 2,500 acres of impounded water. A slurry wall constructed to keep surface water from seeping into 045136 (12) Braidwood Generating Station 31 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 the upper sand aquifer surrounds the Cooling Lake. This is confirmed by the groundwater data monitored by the Station at various locations around the Lake.

During construction of the buildings within the PA, a slurry wall was constructed to minimize groundwater infiltration into the excavation. This excavation was within the confines of the slurry wall and in some areas the depth was greater than 40 feet and into the underlying bedrock shale formation (UFSAR, 1994).

The foundations or basements associated with the Reactors/Auxiliary Building and the Turbine Building extend to depths below the water table. In fact, the foundations were completed through the Wedron Clay Till at this Station, as is shown on the hydrogeologic profiles presented on Figures 5.2 to 5.5 (i.e., the Wedron Clay Till was removed during building excavation). These basements are barriers to groundwater flow in the upper sand aquifer. There are no dewatering systems such as sump pumps used to manage groundwater inflow. As such, the basement walls are assumed to be impermeable to groundwater flow. Consequently, groundwater pressure on these foundations will create an inward gradient into the basement. The Francis Creek Shale Member was not disturbed during building construction and remains in place as an aquitard.

The PA and surrounding land is generally flat and paved areas, roadways, and parking lots now cover it. These areas are drained by a storm water drainage system that drains to the northwest corner of the PA. The storm water drainage system drains to an Oil/Water Separator at the north end of the PA (Figures 2.3 and 2.5). The outfall from the Oil/Water Separator discharges to a small east-west ditch and then flows west to the perimeter ditch.

Previous studies have documented that the storm water drainage system intercepts groundwater on the west side of the Turbine Building. These same studies have indicated that the perimeter ditch, which flows from the north to the south along the western Station property line, also intercepts the groundwater (CRA, August 2002 and September 2003). As such, groundwater flowing near the perimeter ditch will be intercepted by the ditch (Figures 2.6 and 2.7).

5.2.3 VERTICAL HYDRAULIC GRADIENTS Several monitoring well nests have been installed in the upper sand aquifer not only to determine the vertical distribution of impacted groundwater, but also the vertical hydraulic gradient within the aquifer. The calculated hydraulic gradients for the site are 045136 (12) Braidwood Generating Station 32 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 provided in Table 5.1 and the well locations used to calculate hydraulic gradients are shown on Figure 5.1.

Table 5.1 indicates that vertical hydraulic gradients are minor or slightly upward in areas away from the buildings and away from the former construction excavation.

However, a few monitoring well clusters located on the west side of the Turbine Building indicate a downward vertical hydraulic gradient. This gradient varies from 0.005 feet/foot (ft/ft) at TB-1-4D/TW-3 location to 0.167 ft/ft at the TB-1-2D/MW-2 location. The locations with downward vertical hydraulic gradients are also near the storm water drainage system. The cause of the downward vertical hydraulic gradients is likely related to the additional recharge from the nearby storm water drainage system.

Vertical groundwater flow is restricted by the regional aquitards. However, due to the removal of the Wedron Clay Till beneath the buildings, one of the two regional aquitards was locally removed within the PA. Nevertheless, groundwater data indicate that the remaining aquitard (the Francis Creek Shale Member) is preventing vertical migration of tritium downward within the PA.

The downward vertical hydraulic gradients measured along the west side of the Turbine Building are likely caused by increased recharge into the fill material by precipitation that leaks from the storm water drainage system. A review of the precipitation and transducer data on Figure 4.3 suggests that there are small groundwater fluctuations that may be due to precipitation/storm water infiltration. The data presented on Figure 4.3 do not suggest that there are any types of systematic or routine events (i.e., operations) that are causing fluctuations in the water table elevations.

5.2.4 LATERAL GROUNDWATER FLOW AND VELOCITY The groundwater flow directions depicted on Figures 5.6, 5.7, 5.8, and 5.9 for the upper sand aquifer indicate, to some degree, a radial pattern of flow from the center of the PA.

Groundwater flow directions are similar to conditions measured in May and July 2006.

This pattern is better explained by understanding the role of man-made features on the regional flow direction in this upper sand aquifer. Groundwater on a local or regional basis in the upper sand aquifer is to the north and northeast towards the surface waters that drain to the Kankakee and Illinois Rivers (CRA March 2006). This flow direction was confirmed in the blowdown studies discussed in Section 2.6.

Within and nearby the PA the man-made features have modified the local flow system to the north. First, the former construction excavation and the building basements force 045136 (12) Braidwood Generating Station 33 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 a split or divide in flow as groundwater moves from south to north. Second, the perimeter ditch flows from east, to north to south and ultimately to the west around the PA and becomes a discharge point for groundwater. This ditch intercepts the groundwater table and groundwater discharges into this ditch along its whole length.

The surface water elevation of the perimeter ditch as it exits the Braidwood Station property (south of Godley) is approximately 579 feet AMSL (CRA, September 2000).

This is 11 to 16 feet lower than the groundwater elevation in the PA.

Consequently, the combination of structures in the PA and the presence of the perimeter ditch create the appearance of radial flow, but these influences are just a modification to the regional flow direction of south to north.

The average calculated horizontal hydraulic gradient in the upper sand aquifer along the east side of the PA is 0.004 ft/ft. The groundwater flow direction in this area is from the south to north. Figures 5.6 and 5.7 display the groundwater elevation contours in the shallow groundwater zone.

The average calculated horizontal hydraulic gradient in the upper sand aquifer along the west side of the Turbine Building is 0.007 ft/ft. The general groundwater flow direction in this area is from south to north (Figures 5.6, 5.7, 5.8, and 5.9).

The average calculated horizontal hydraulic gradient in the upper sand aquifer west of the slurry wall is 0.005 ft/ft. The general groundwater flow direction in this area is from the southeast to the northwest (Figures 5.6, 5.7, 5.8, and 5.9).

The overall, site-wide, average calculated horizontal hydraulic gradient is approximately 0.007 ft/ft within the upper sand aquifer. Results from previous single-well response tests performed east of the PA and along the blowdown line (previous investigations referred to in Section 1.0) indicate that the hydraulic conductivity of the overburden aquifer is 2.5 x 10-2 cm/s. Assuming an average effective porosity of 0.3, the average groundwater velocity in the upper sand aquifer is approximately 604 ft/yr.

The calculated hydraulic gradients and average groundwater velocity are greater than that observed east of the PA and along the blowdown line. It is likely that the groundwater velocity is influenced by steep hydraulic gradients toward the perimeter ditch flowing to the north and to the west of the PA.

045136 (12) Braidwood Generating Station 34 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 5.3 GROUNDWATER QUALITY CRA personnel collected groundwater samples from 45 of the monitoring wells located on the Station property, including 12 newly installed monitoring wells. This subset included all available existing monitoring wells in the PA but did not include those located along the blowdown line to the east. The groundwater samples were analyzed for tritium and additional radionuclides. Teledyne Brown provided the analytical services. The Quality Assurance Program for the laboratory is described in Appendix E.

The analytical data reports are provided in Appendix F.

Table 5.2 presents a summary of tritium analyses for groundwater samples collected recently in May and July 2006. Table 5.3 presents a summary of radionuclides analyzed in groundwater samples collected in May and July 2006. Tables 5.4 and 5.5 present the tritium and radionuclide analyses for surface water samples, respectively. Table 5.6 presents a summary of groundwater analyses for tritium in samples collected previously at existing monitoring wells. Table 5.7 presents a summary of surface water analyses for tritium in samples collected previously at existing surface water locations.

The analytical data presented herein has been subjected to CRA's data validation process. CRA has used the data with appropriate qualifiers where necessary.

The data reported in the figures and tables does not include the results of recounts that the laboratory completed, except if those results ultimately replaced an initial report.

The tables and figures, therefore, include only the first analysis reported by the laboratory. Where multiple samples were collected over time, then the most recent result has been used in the discussion, below.

5.3.1

SUMMARY

OF BETA-EMITTING RADIONUCLIDES ANALYTICAL RESULTS A summary of the tritium results for the groundwater samples collected during this investigation is provided in Table 5.2 and shown on Figure 5.10. Table 5.6 summarizes analytical results for previous sampling events performed at the site.

All tritium concentrations were below the USEPA drinking water standard of 20,000 pCi/L. Tritium was not detected at concentrations greater than at the LLD of 200 pCi/L in 34 of the 45 groundwater samples collected.

045136 (12) Braidwood Generating Station 35 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 The highest concentrations of tritium (between 200 pCi/L and 1,040 +/- 172 pCi/L) in test wells were predominantly from groundwater samples collected on the west side of the Turbine Building. The highest concentration of tritium at 1,040 +/- 172 pCi/L was found at TW-3, which was installed in the deep upper sand aquifer. At five of these locations, the groundwater analyses indicated tritium concentrations just over 200 pCi/L and less than 250 pCi/L.

The groundwater samples collected from the bedrock monitoring wells MW-BW-201BD and MW-BW-208BD, which were completed to a depth of 95 feet bgs and 100 feet bgs, respectively, did not contain tritium at a concentration exceeding the LLD of 200 pCi/L.

These wells were completed beneath the confining layers of the Wedron Clay Till and the Francis Creek Shale Member.

Strontium-89/90 was not detected in concentrations greater than the LLD of 2.0 pCi/L.

A summary of the strontium-89/90 results for the groundwater samples collected as part of the investigation that is the subject of this HIR is provided in Table 5.3 and shown on Figure 5.11.

5.3.2

SUMMARY

OF GAMMA-EMITTING RADIONUCLIDES ANALYTICAL RESULTS Gamma-emitting target radionuclides were not detected in concentrations greater than their respective LLD. A summary of the gamma-emitting radionuclides results for the groundwater samples collected as part of the investigation that is the subject of this HIR is provided in Table 5.3 and shown on Figure 5.11.

Other non-targeted radionuclides were also included in the tables but excluded from discussion in this report. These radionuclides were either a) naturally occurring and thus not produced by the Station, or b) could be definitively evaluated as being naturally occurring due to the lack of presence of other radionuclides which would otherwise indicate the potential of production from the Station.

5.3.3

SUMMARY

OF FIELD MEASUREMENTS Table 4.6 presents of a summary of field measurements collected during the well purging and sampling activities. These field measurements included pH, dissolved oxygen, conductivity, turbidity and temperature. The field parameters were typical of a shallow sand aquifer with carbonate source rock (i.e., the underlying limestones and 045136 (12) Braidwood Generating Station 36 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 shales). As such the pH values were found to be above 7.0 and the conductivity was indicative of a shallow water table system subject to surface water recharge.

Of note were the slightly elevated temperature readings (above 20 degrees Celsius) at TB-1-9D, which is located south of the wastewater treatment building and the treatment lagoon (Figure 3.1), TB-10-D, which is located adjacent to the Turbine Building, and just east of TB-1-9D, and MW-BW-207I, which is located adjacent to the Turbine Building, and north of TB-1-10D. It should also be noted that the conductivity of the water purged from MW-6, TB-1-3D, and TB-1-8D was an order-of-magnitude higher than the readings from other sampling locations.

5.4 SURFACE WATER QUALITY Six surface water samples were collected from the four staff gauge locations on the perimeter ditch and from two locations along the north end of the Cooling Lake. The locations of the samples are shown on Figure 4.1. The samples were analyzed for tritium, gamma-emitting radionuclides, and strontium-89/90. Teledyne Brown provided the analytical services. The Quality Assurance Program for the laboratory is described in Appendix E. The analytical data reports are provided in Appendix F.

Analytical data for these surface water samples are presented in Tables 5.4 and 5.5.

5.4.1

SUMMARY

OF BETA-EMITTING RADIONUCLIDES ANALYTICAL RESULTS A summary of the tritium results for the surface water samples collected in this investigation is provided in Table 5.4 and shown on Figure 5.10.

Surface water samples SW-101, SW-102, SW-103 had concentrations of tritium of 398 +/- 129, 365 +/- 120, and 230 +/- 114 pCi/L, respectively. These concentrations are greater than the LLD of 200 pCi/L. Surface water samples SW-101 and SW-102 were collected from the perimeter ditch located just northwest of the PA. Surface water sample SW-103 was collected along the perimeter ditch near the northeast corner of the Cooling Lake. A summary of the tritium analytical results from six surface water samples is presented in Table 5.4. Surface water samples collected as part of the blowdown line investigations and as part of the interim routine monitoring program in the PA are provided in Table 5.7.

045136 (12) Braidwood Generating Station 37 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 The results of analyses of numerous surface water samples, which were collected during the spring and summer of 2006, along the perimeter ditch, have shown that no tritium greater than detectable limits have left the Station.

Strontium-89/90 was not detected in concentrations greater than the LLD of 2.0 pCi/L.

A summary of the strontium-89/90 results for the surface water samples collected in this investigation is provided in Table 5.5 and shown on Figure 5.11.

Surface water samples were collected within the perimeter ditch and analyzed for tritium at four monitoring points found north, west, and south of the PA. In addition, surface water was collected at the north end of the Cooling Lake at two locations just off the shoreline. Figure 4.1 presents these locations.

5.4.2

SUMMARY

OF GAMMA-EMITTING RADIONUCLIDES ANALYTICAL RESULTS Gamma-emitting target radionuclides were not detected in concentrations greater than their respective LLD. A summary of the gamma-emitting radionuclides results for the surface water samples collected in this investigation is provided in Table 5.5 and shown on Figure 5.11.

Other non-targeted radionuclides were also included in the tables but excluded from discussion in this report. These radionuclides were either a) naturally occurring and thus not produced by the Station, or b) could be definitively evaluated as being naturally occurring due to the lack of presence of other radionuclides which would otherwise indicate the potential of production from the Station.

045136 (12) Braidwood Generating Station 38 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 6.0 RADIONUCLIDES OF CONCERN AND SOURCE AREAS This section discusses radionuclides evaluated in this investigation, potential sources of the radionuclides detected, and their distribution.

6.1 GAMMA-EMITTING RADIONUCLIDES Gamma-emitting target radionuclides were not detected at concentrations greater than their respective LLD. Other non-targeted radionuclides were also included in the tables but excluded from discussion in this report. These radionuclides were either a) naturally occurring and thus not produced by the Station, or b) could be definitively evaluated as being naturally occurring due to the lack of presence of other radionuclides which would otherwise indicate the potential of production from the Station.

6.2 BETA-EMITTING RADIONUCLIDES Strontium-89/90 was not detected in any of the samples collected at concentrations that were greater than the LLD of 2.0 pCi/L. Concentrations of tritium ranged between 200 pCi/L and 1,040 +/- 172 pCi/L.

Since only tritium was detected at concentrations greater than the LLDs, the following sections focus on tritium; specifically, providing general characteristics of tritium, potential sources, distribution in groundwater, and a conceptual model for migration.

6.3 TRITIUM This section discusses the general characteristics of tritium, the distribution of tritium in groundwater and surface water, and the conceptual model of tritium release and migration.

6.3.1 GENERAL CHARACTERISTICS Tritium (chemical symbol H-3) is a radioactive isotope of hydrogen. The most common forms of tritium are tritium gas and tritium oxide, which is also called "tritiated water."

The chemical properties of tritium are essentially those of ordinary hydrogen. Tritiated water behaves the same as ordinary water in both the environment and the body.

045136 (12) Braidwood Generating Station 39 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 Tritium can be taken into the body by drinking water, breathing air, eating food, or absorption through skin. Once tritium enters the body, it disperses quickly and is uniformly distributed throughout the body. Tritium is excreted primarily through urine within a month or so after ingestion. Organically bound tritium (tritium that is incorporated in organic compounds) can remain in the body for a longer period.

Tritium is produced naturally in the upper atmosphere when cosmic rays strike air molecules. Tritium is also produced during nuclear weapons explosions, as a by-product in reactors producing electricity, and in special production reactors, where the isotopes lithium-7 and/or boron-10 are bombarded to produce tritium.

Although tritium can be a gas, its most common form is in water because, like non-radioactive hydrogen, radioactive tritium reacts with oxygen to form water.

Tritium replaces one of the stable hydrogen atoms in the water molecule and is called tritiated water. Like normal water, tritiated water is colorless and odorless. Tritiated water behaves chemically and physically like non-tritiated water in the subsurface, and therefore tritiated water will travel at the same velocity as the average groundwater velocity.

Tritium has a half-life of approximately 12.3 years. It decays spontaneously to helium-3 (3He). This radioactive decay releases a beta particle (low-energy electron). The radioactivity of tritium is the source of the risk of exposure.

Tritium is one of the least dangerous radionuclides because it emits very weak radiation and leaves the body relatively quickly. Since tritium is almost always found as water, it goes directly into soft tissues and organs. The associated dose to these tissues is generally uniform and is dependent on the water content of the specific tissue.

6.3.2 DISTRIBUTION IN STATION GROUNDWATER This section provides an overview of the lateral and vertical distribution of tritium detected in groundwater within and adjacent to the PA. Tritium has been the only parameter detected in the upper sand aquifer at concentrations exceeding background concentrations. This observation is based upon the studies recently completed within and adjacent to the PA and based upon the extensive studies performed along the blowdown line and reported previously to the Illinois EPA. A hydrogeologic profile of the tritium concentrations in groundwater is presented on Figure 6.1. In addition, a plan view of the tritium concentrations detected in the groundwater samples collected as part of this investigation is presented on Figure 6.2. As discussed later in this section, tritium 045136 (12) Braidwood Generating Station 40 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 has not been detected in the deeper, bedrock groundwater at concentrations greater than the LLD of 200 pCi/L.

The detections of tritium in the shallow or deeper parts of the upper sand aquifer in the Station area, which were greater than the LLD of 200 pCi/L, occur within the confines of the slurry wall.

6.3.2.1 UPPER SAND AQUIFER West Side of the Turbine Building Generally, tritium concentrations that were greater than the LLD of 200 pCi/L are limited to an area along the west side of the Turbine Building, as summarized in Table 5.2 and illustrated on Figures 5.10 and 6.2. The tritium detected in the groundwater samples from monitoring wells located along the west side of the Turbine Building (TB-1-3D, TB-1-4D, TW-3, TW-6, MW-9, TW-21, and TB-1-5D) indicate consistent concentrations of tritium greater than the LLD. Tritium analytical data for groundwater samples collected from these monitoring wells are available back to January 2006 and have been included in Table 5.6.

Groundwater flow within the west side of the Turbine Building has been observed recently and historically to flow from south to north. The monitoring wells on the west side of the Turbine Building are located within the limits of the former excavated area (for Station construction) and are located within 150 feet of the main foundation of the Turbine Building. These wells are also located within 150 feet of the main storm water drainage system, which runs from the south to the north parallel to the Turbine Building (Figure 2.3). This storm water drainage system discharges to the Oil/Water Separator located at the north end of the PA as is shown on Figure 2.3.

The storm water drainage system intercepts groundwater and has been shown to be a preferential pathway for groundwater to migrate to the north (Figures 2.4 and 2.5). The sewer's ability to transmit groundwater and its contaminants was documented in various reports submitted to the Illinois EPA in the past (CRA, September 2003).

The more recent detections of tritium in groundwater samples from monitoring wells installed in the area along the west side of the Turbine Building are found both in the upper portions or shallow zone of the sand aquifer (e.g., TW-3 and TW-6) in the deeper portions (deeper zone) of the upper sand aquifer (e.g., TB-1-4D and TB-1-5D); and within the fill material (MW-BW-207I).

045136 (12) Braidwood Generating Station 41 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 Other Areas There are four monitoring wells where tritium has been detected in groundwater samples at concentrations greater than the LLD of 200 pCi/L in areas not associated with the Turbine Building. These wells are MW-BW-201S/I, MW-BW-205I and TW-24, and at TW-16. The tritium concentrations detected in groundwater samples from MW-BW-201S/I, MW-BW-205I and TW-24 were only slightly greater than the LLD of 200 pCi/L and below 250 pCi/L (refer to Figures 5.10 and 6.2).

The tritium concentration detected in a groundwater sample from TW-16, which is located approximately 300 feet due west of TW-3 (Figures 4.2, 5.10, and 6.2), is situated where water ponded from the April 6, 2006 steam release (Figure 4.2), was 893 +/- 145 pCi/L. In this case, the tritium in the groundwater sample from TW-16 can be explained by the more recent release of tritiated water in the west area of the PA, as is discussed further below. Both TW-3 and TW-16 are located in an area near the point at which the relief valve vents outside of the Turbine Building. As shown on Figure 5.7, the groundwater beneath the western side of the PA generally flows from the south to north-northwest.

6.3.2.2 DEEPER BEDROCK GROUNDWATER The first water bearing zone in the deeper bedrock, the zone below the Wedron Clay Till and the Francis Creek Shale Member of the Carbondale Formation was monitored by MW-BW-201BD and MW-BW-208BD. The screened intervals of these two monitoring wells are completed in the zone of conglomerates and sandstones found at the base of the Francis Creek Shale Member and just above the Colchester Coal No. 2. Some of the private wells located north and east of the PA are also completed in this zone (Figure 2.10). The two deeper bedrock monitoring wells were installed at locations expected to be downgradient of the reactor buildings and fuel handling building. The location of these wells is shown on Figure 4.2. Groundwater samples collected from the two bedrock monitoring wells (including samples and duplicates) indicated tritium concentrations less than the LLD of 200 pCi/L.

Additionally, there are a number of private and public wells located to the north of the PA, which have been sampled as part of the blowdown line investigations. The sample results for tritium from these wells indicated no concentrations greater than the LLD of 200 pCi/L.

045136 (12) Braidwood Generating Station 42 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 Based upon the findings from the recent studies around the PA and those performed in the past along the blowdown line, the groundwater zones found below the Wedron Clay Till and the Francis Creek Shale Member do not indicate tritium impacts from releases within or adjacent to the PA.

6.3.3 DISTRIBUTION IN STATION SURFACE WATER Surface water was collected within the perimeter ditch and analyzed for tritium at four monitoring points found north, west, and south of the PA. In addition, surface water was collected at the north end of the Cooling Lake at two locations just off the shoreline.

Figure 4.1 presents these locations.

Surface water samples SW-101, SW-102, and SW-103 had concentrations of tritium of 398 +/- 129, 365 +/- 120, and 230 +/- 114 pCi/L, respectively. These concentrations exceeded the LLD of 200 pCi/L. Surface water samples SW-101 and SW-102 were collected from the perimeter ditch located just northwest of the PA. Surface water sample SW-103 was collected along the perimeter ditch near the northeast corner of the Cooling Lake. A summary of the tritium analytical results from samples collected from surface water is presented in Table 5.4. Surface water samples collected as part of the blowdown line investigations and as part of the interim routine monitoring program in the PA are provided in Table 5.7.

6.3.4 CONCEPTUAL MODEL OF TRITIUM RELEASE AND MIGRATION This section presents CRA's conceptual model of groundwater and tritium migration at the Station. This model is then used to discuss the historic detections of tritium within the PA and the more recent detections found during the hydrogeologic investigations presented in this report.

Hydrogeologic Framework Groundwater flows within the upper sand aquifer (Equality Formation) at the site in response to regional discharge points located to the north and in response to the perimeter ditch located west and south of the site. Groundwater moving within the upper sand aquifer is separated from the regional bedrock aquifer zones by the Wedron Clay Till, the Francis Creek Shale Member and the Maquoketa Shale. The only exception is where the building basements were constructed through the Wedron Clay Till.

045136 (12) Braidwood Generating Station 43 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 However, these building structures are considered impermeable barriers to flow in or out of their foundations.

As of the date of this report, no tritium has been detected at concentrations greater than the LLD of 200 pCi/L in samples from bedrock monitoring wells, bedrock private wells, or bedrock public wells located downgradient of the PA. These groundwater quality data further support the role of the Wedron Clay Till and the Francis Creek Shale Member as aquitards. As such, the focus of the conceptual hydrogeologic model presented herein is the migration of groundwater and tritium within the upper sand aquifer.

Groundwater flowing in the upper sand aquifer within the PA is restricted by the building foundations which, in some cases, extend through the Wedron Clay Till. As a result, groundwater flowing with the regional gradient from south to north is diverted to the east or west of the building structures (a divide). In addition, groundwater flowing on the west side of the Turbine Building discharges into and out of the storm water drainage system located in this area of the PA. Additional recharge of water from the sewer into groundwater is expected in this area.

The slurry wall, which surrounds the main Station buildings, appears to provide some limited hydraulic control on the west side of the PA. There is a noticeable drop in groundwater levels across the wall on the west side and groundwater flow changes direction from north to northwest in this area (Figures 5.6 and 5.7). However, the slurry wall's impact on groundwater flowing north toward the regional surface water discharge points is still unknown. The lateral hydraulic gradients to the north are consistent across the slurry wall.

To the west and south of the PA, the upper sand aquifer is influenced by the perimeter ditch which flows from north to south on the west side of the Station property. This man-made ditch intercepts the shallow aquifer and under normal flow conditions is a discharge point for groundwater. The water level in the ditch as it exits the Braidwood Station property is 11 to 16 feet lower than groundwater in the PA. As such, the perimeter ditch is acting similar to a gravity drain or "French Drain" within the upper sand aquifer. This is evident in the southwest and west flow of groundwater outside the slurry wall (Figures 5.6 and 5.7).

045136 (12) Braidwood Generating Station 44 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 Sources and Migration of Tritium Tritium has recently been detected at concentrations greater than background in groundwater samples from two areas within the PA and within the confines of the slurry wall:

• Along the west side of the Turbine Building; and

• 300 feet west of the Turbine Building.

Prior to the more recent release of tritium to the surface in the west area of the PA, the tritium detections were limited to the area near the west wall of the Turbine Building.

The current distribution of tritium (both within the shallow water table zone and within the deeper portions of the upper sand aquifer) is likely related to the following tritiated water release history:

• previous releases of tritium to the surface or subsurface; and

• the April 6, 2006 release of steam containing tritiated water.

After April 2006 a number of groundwater samples from the same monitoring wells sampled in early 2006 indicated higher concentrations of tritium. The more recent groundwater sampling data that were collected in May and July 2006 show very good correlation with the release of steam which occurred on April 6, 2006 on the west side of the Turbine Building. The distribution of tritium in May 2006 groundwater samples matches with the location of ponded areas of the April 6 steam release and with groundwater and surface water (e.g., storm water) flow directions in this area of the PA.

Refer to Figures 6.1 and 6.2 for a presentation of the vertical and lateral distribution of tritium in groundwater, respectively.

In the case of both the pre-April 2006 groundwater data and the post-April 2006 groundwater data the role of surface water infiltration and transport within the storm water drainage system is well documented. The previous discussions suggest that the tritium detected in the groundwater on the west side of the Turbine Building is a result of multiple isolated spills or releases to the surface that have occurred over time.

Groundwater samples were collected from the existing monitoring wells within the PA and the new monitoring wells in the first week of May 2006; a month after the April 6 steam release. This was a surface release that allowed tritiated water to both pond on the land surface and also to seep into the storm water drainage system.

045136 (12) Braidwood Generating Station 45 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 The May 2006 groundwater sampling event very clearly shows the impact of the steam release waters as they ponded on the ground and drained into the storm water drainage system (Figure 3.1). Figure 5.10 and Table 5.2 present the May and July 2006 tritium data in groundwater. The highest concentration of tritium detected was in the groundwater sample from the shallow monitoring well TW-3 (1,040 +/- 172 pCi/L), which is near the valve which released the steam with the tritiated water. The concentration of tritium in the groundwater sample from this well in March 2006 was approximately 300 pCi/L. CRA considers the increase in tritium concentrations in TW-3 to be a result of steam/water entering the groundwater through the storm water drainage system, which is located near this well. Similarly, the tritium concentration in the groundwater sample from TW-16, which is directly west of the steam vent and where the tritiated water pooled on the ground, increased from 368 +/- 94 pCi/L to 893 +/- 145 pCi/L. This information indicates that within 30 days the steam release waters had impacted the shallow groundwater zone. The steam release event is also suspected to have affected the groundwater near TW-6, MW-9, and TB-1-5D, which are along or near the storm water drainage system.

Groundwater infiltrating the storm water drainage system will flow to the Oil/Water Separator to the north. This separator discharges water to small ditch which then flows to the west and discharges to the perimeter ditch (Figure 2.3). Surface water samples collected in the perimeter ditch as part of this investigation of the PA (Figure 4.1) and surface water samples collected in the perimeter ditch have indicated concentrations of tritium greater than background at locations north and west of the PA. The main source of the tritium in this area of the perimeter ditch is the plume of tritium migrating from historical releases at vacuum breaker VB-1 into the ditch at that location (CRA, March 2006).

In addition, as a result of the recent steam release, it is expected that some tritiated water has entered the Oil/Water Separator and migrated in the small ditch toward the larger perimeter ditch. Recent sampling of the Oil/Water Separator supports this pathway of tritiated water migration.

Table 5.7 presents the results of previous sampling of surface water in the perimeter ditch and samples from the Oil/Water Separator discharge after the April 6, 2006 steam release.

The following section provides further details supporting the conceptual model of groundwater flow and tritium transport discussed above.

045136 (12) Braidwood Generating Station 46 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 6.3.5 ATTENUATION OF TRITIUM WITHIN THE SHALLOW GROUNDWATER SYSTEM Within the PA consideration must be given to how long ago a release occurred and the effect of precipitation water infiltration on groundwater quality. During the previous hydrogeologic investigations the releases from vacuum breakers along the blowdown line where it became apparent that the distribution of a historical or older release of tritium into the groundwater system would be impacted by the infiltration from "clean" precipitation recharge (CRA, March 2006). This resulted in the upper, water table zone of the sand aquifer appearing to have lower concentrations of tritium from the deeper portions (these zones are only separated by 5 to 15 feet). This "cleaning up" of the shallow zone of the sand aquifer needs to be considered when evaluating the data collected within the PA. Specifically, the location of the storm water drainage system near the Turbine Building and the affected monitoring wells (TB-1-3D, TB-1-4D, TW-3, TW-6, MW-9, TB-1-5D, and MW-BW-207I) likely allows for both the flow in and out of the sewer line of tritiated water and clean precipitation waters.

Table 5.6 presents the history of sampling results in 2006 for the area west of the Turbine Building. Figure 6.2 presents a summary of these data on a plan view map. The highest concentrations detected prior to the April 6, 2006 steam release event are found in monitoring wells TW-6 and TB-1-4D. The detections in TB-1-4D in March 2006 (582 pCi/L) were greater than in the adjacent shallow well TW-3 (330 pCi/L) for the same sampling event. This suggests that the source for this deeper tritium is not recent but historical in nature. The tritium concentrations in March 2006 for groundwater samples collected at TW-6 were in the 600 to 800 pCi/L range and may indicate a more recent release, although of limited in extent. In both cases (TW-6 and TB-1-4D) the extent of tritium impacts in the upper sand aquifer appears to be limited to near these two wells along the west side of the Turbine Building. It has been determined that the vertical limits in the excavated area are restricted by the underlying shale formation (Figure 6.1).

The relatively high groundwater velocities measured in the site area of 600 ft/yr and the permeable nature of the upper sand aquifer also support attenuation of the tritium through lateral groundwater movement. The dispersion of the tritium as it flows through the sand along with its natural decay rate will allow for reduction in concentrations over time and with distance from a release into the groundwater. Simple fate and transport modeling performed for the blowdown line investigations using the USEPA BIOSCREEN Model (CRA, March 2006 and April 2006) provides evidence of the attenuation of tritium through dispersion and decay. Consequently, tritium released 045136 (12) Braidwood Generating Station 47 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 within the west side of the PA and near the Turbine Building would also be expected to attenuate rapidly to lower concentrations as it flowed in the upper sand aquifer.

The natural decay rate of the tritium itself lends to further attenuation of its concentration in the groundwater. Tritium has a half-life of 12.3 years and as such its concentration would be reduced over the time period that it travels in the groundwater system. Consequently, as the tritium migrates with the groundwater, its concentration would be decreased by 50 percent in a 12.3-year time frame.

045136 (12) Braidwood Generating Station 48 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 7.0 EXPOSURE PATHWAY ASSESSMENT This section addresses the groundwater impacts from tritium and other radionuclides at the Station and potential risks to human health and the environment.

Based upon historical knowledge and data related to the Station operations, and based upon radionuclide analyses of groundwater samples, the primary constituent of concern (COC) is tritium. The discussions that follow are restricted to the exposure pathways related to tritium.

Teledyne Brown reports all samples to their statistically derived Minimum Detectable Concentration (MDC) of approximately 150 to 170 pCi/L, which is associated with 95 percent confidence interval on their hardcopy reports. However, the laboratory uses a 99 percent confidence range (+/- 3 sigma) for determining whether to report the sample activity concentration as detected or not. This 3-sigma confidence range typically equates to 150 (+/- 135.75) pCi/L.

Exelon has specified a LLD of 200 pCi/L for the Fleetwide assessment. Exelon has also required the laboratory to report related peaks identified at the 95 percent confidence level (2-sigma).

This HIR, therefore, screens and assesses data using Exelon's LLD of 200 pCi/L. As is outlined below, this concentration is also a reasonable approximation of the background concentration of tritium in groundwater at the Station.

7.1 HEALTH EFFECTS OF TRITIUM Tritium is a radionuclide that decays by emitting a low-energy beta particle that cannot penetrate deeply into tissue or travel far in air. A person's exposure to tritium is primarily through the ingestion of water (drinking water) or through ingestion of water bearing food products. Inhalation of tritium requires the water to be in a vapor form (i.e., through evaporation or vaporization due to heating). Inhalation is a minor exposure route when compared to direct ingestion or drinking of tritiated water.

Absorption of tritium through skin is possible, but tritium exposure is more limited here versus direct ingestion or drinking of tritiated water.

045136 (12) Braidwood Generating Station 49 CONESTOGA-ROVERS & ASSOCIATES

Revision 1

7.2 BACKGROUND

CONCENTRATIONS OF TRITIUM The purpose of the following paragraphs is to establish a background concentration through review of various media.

7.2.1 GROUNDWATER Tritium is created in the environment from naturally occurring processes both cosmic and subterranean, as well as from anthropogenic (i.e., man-made) sources. In the upper atmosphere, "cosmogenic" tritium is produced from the bombardment of stable nuclides and combines with oxygen to form tritiated water, which will then enter the hydrologic cycle. Below ground, "lithogenic" tritium is produced by the bombardment of natural lithium isotopes 6Li (92.5 percent abundance) and 7Li (7.5 percent abundance) present in crystalline rocks by neutrons produced by the radioactive decay of uranium and thorium. Lithogenic production of tritium is usually negligible compared to other sources due to the limited abundance of lithium in rock. The lithogenic tritium is introduced directly to groundwater.

A major anthropogenic source of tritium comes from the former atmospheric testing of thermonuclear weapons. Levels of tritium in precipitation increased during the 1950s and early 1960s, coinciding with the release of significant amounts of tritium to the atmosphere during nuclear weapons testing prior to the signing of the Limited Test Ban Treaty in 1963, which prohibited atmospheric nuclear tests.

7.2.2 PRECIPITATION DATA Precipitation samples are routinely collected at stations around the world for the analysis of tritium and other radionuclides. Two publicly available databases that provided tritium concentrations in precipitation are Global Network of Isotopes in Precipitation (GNIP) and USEPA's RadNet database. GNIP provides tritium precipitation concentration data for samples collected world wide from 1960 to 2006.

RadNet provides tritium precipitation concentration data for samples collected at Stations through the U.S. from 1960 up to and including 2006.

Based on GNIP data for sample stations located in the U.S. Midwest including Chicago, St. Louis and Madison, Wisconsin, as well as Ottawa Ontario, and data from the University of Chicago, tritium concentrations peaked around 1963. This peak, which approached 10,000 pCi/L for some stations, coincided with the atmospheric testing of 045136 (12) Braidwood Generating Station 50 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 thermonuclear weapons. Tritium concentrations showed a sharp decline up until 1975 followed by a gradual decline since that time. Tritium concentrations in Midwest precipitation have typically been below 100 pCi/L since around 1980.

The RadNet database for several stations in the U.S. Midwest (Chicago, Columbus, Indianapolis, Lansing, Madison, Minneapolis, Painesville, Toledo, and Welsch, MN) did not show the same trend, which can attributed to pre-1995 data handling procedures.

The pre-1995 data were rounded to the nearest 100 pCi/L, which damped out variances in the data. The post-1995 RadNet data, where rounding was not applied, exhibit much more scatter, and similar to the GNIP data, the vast majority of the data were less than 100 pCi/L.

CRA constructed a non-parametric upper tolerance limit with a confidence of 95 percent and a coverage of 95 percent based on RadNet data for USEPA Region 5 from 2004 to 2005. The resulting upper tolerance limit is 133 pCi/L, which indicates that CRA is 95 percent confident that 95 percent of the ambient precipitation concentration results are below 133 pCi/L. The statistical confidence, however, must be compared with the limitations of the underlying RadNet data, which does not include the minimum detectable concentration for a majority of the measurements. Some of the RadNet values below 200 pCi/L may be approximated. Nevertheless, these results show a background contribution for precipitation of up to 133 pCi/L.

7.2.3 SURFACE WATER DATA Tritium concentrations are routinely measured in large surface water bodies, including Lake Michigan and the Mississippi River. Surface water data from the RadNet database for Illinois sampling stations include East Moline (Mississippi River), Moline (Mississippi River), Marseilles (Illinois River), Morris (Illinois River), Oregon (Rock River), and Zion (Lake Michigan). As is the case for the RadNet precipitation data, the pre-September 1995 Illinois surface water data was rounded to the nearest 100 pCi/L, creating a dampening of variances in the data. The post-1995 Illinois surface water data, similar to the post-1995 Midwest precipitation data, were less than 100 pCi/L with the exception of the Moline (Mississippi River) station. Tritium surface water concentrations at this location varied between 100 and 800 pCi/L, which may reflect local natural or anthropogenic inputs.

For the Lake Michigan station, the surface water concentrations were less than 100 pCi/L, with the exception of a couple of occasions occurring around 1996 to 1997.

Tritium concentrations in Lake Michigan would be expected to be lower than 045136 (12) Braidwood Generating Station 51 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 precipitation concentrations given the 99-year surface water residence time within Lake Michigan, which corresponds to 8 half-lives of tritium and the dilution provided the large volume of the Lake (1,180 cubic miles) as well as seasonal mixing effects (WDNR, 1999).

The USEPA RadNet surface water data typically has a reported 'Combined Standard Uncertainty' of 35 to 50 pCi/L. According to USEPA, this corresponds to a

+/- 70 to 100 pCi/L 95 percent confidence bound on each given measurement. Therefore, the typical background data provided may be subject to measurement uncertainty of approximately +/- 70 to 100 pCi/L.

7.2.4 DRINKING WATER DATA Tritium concentrations in drinking water from the RadNet database for three Illinois sampling stations (Chicago, Morris, and East Chicago) exhibit similar trends as the precipitation and surface water data. As with the precipitation and surface water data, the pre-1995 data has dampened out variances due to rounding the data to the nearest 100 pCi/L. The post-1995 results show tritium concentrations in drinking water well below 100 pCi/L and less than the tritium concentrations found in precipitation and surface water.

7.2.5 EXPECTED TRITIUM BACKGROUND FOR THE STATION As reported in the GNIP and RadNet databases, tritium concentrations in U.S. Midwest precipitation has typically been less than 100 pCi/L since 1980. Tritium concentrations reported in the RadNet database for Illinois surface water and groundwater, at least since 1995, has typically been less than 100 pCi/L. Based on the USEPA Region 5's 2004 to 2005 RadNet precipitation data, 95 percent of the ambient concentrations of tritiated water in Illinois are expected to be less than 133 pCi/L, based on a 95 percent confidence limit. Tritium concentrations in surface water and drinking water are expected to be comparable or less based on historical data and trends.

Concentrations in groundwater similar to surface water and drinking are expected to be less as compared to precipitation values. The lower groundwater concentrations are related to the age of the groundwater as compared to the half-life of tritium. Deep aquifers in proximity to crystalline basement rock, however, can potentially show elevated concentrations of tritium due to lithogenic sources.

045136 (12) Braidwood Generating Station 52 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 As was noted in Section 7.0, the analytical laboratory is reporting tritium results to a LLD of 200 pCi/L. This concentration also represents a reasonable representation of background groundwater quality, given the data for precipitation, surface water, and drinking water.

Based on the evaluation presented above, the background concentration for tritium at the Station is reasonably represented by the LLD of 200 pCi/L.

7.3 IDENTIFICATION OF POTENTIAL EXPOSURE PATHWAYS AND POTENTIAL RECEPTORS Three potential exposure pathways were considered during the evaluation of tritium in groundwater:

• groundwater migration off the Station Property to private and public groundwater users;

• groundwater migration off the Station Property to a surface water body; and

• potential exposure to surface water in the perimeter ditch at the Station.

The following section provides an overview of each of these three potential exposure pathways for tritium in groundwater.

7.3.1 POTENTIAL GROUNDWATER MIGRATION TO DRINKING WATER USERS OFF THE STATION PROPERTY In this pathway groundwater flows to the north off Exelon's property and onto adjacent private property. There are a number of private landowners to the north that use private wells completed in the upper sand aquifer. These shallow water supply wells are considered potential pathways.

The concentrations of tritium in groundwater (within the upper sand aquifer and the deeper bedrock aquifer) are below the LLD of 200 pCi/L off the Station property.

Consequently, there is no tritium in the groundwater currently migrating off the Station property.

With the exception of the blowdown line investigation there have been no samples collected from private or public water supply wells, to the north or west of the PA, that contained tritium at concentrations that exceed the LLD of 200 pCi/L. Therefore, 045136 (12) Braidwood Generating Station 53 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 although there is a potentially complete exposure pathway, there is no current risk of exposure associated with groundwater ingestion from private wells in the upper sand aquifer.

Groundwater samples collected from private wells in the deep bedrock investigated did not contain tritium that exceeded the LLD of 200 pCi/L. This is to be expected because the vertical movement of tritiated water into deeper formations is restricted by the following three regional aquitards (see Figure 2.8):

• the Wedron Clay Till, which directly underlies the upper sand aquifer;

• the shales of the Carbondale Formation (Francis Creek Shale Member); and

• the Scales Shale of the Maquoketa Group.

The effectiveness of these aquitards is further supported by the recent data collected from the approximately 100 feet deep bedrock monitoring wells MW-BW-201BD and MW-BW-208BD on the Station property. Samples from these wells were from a water bearing zone just beneath the Francis Creek Shale Member and contained tritium at concentrations less than the LLD of 200 pCi/L. Therefore, the exposure pathway is incomplete and there is no current risk of exposure associated with groundwater ingestion from private wells in the deep bedrock aquifer.

7.3.2 POTENTIAL GROUNDWATER MIGRATION TO SURFACE WATER USERS OFF THE STATION PROPERTY There is a potential exposure pathway in the upper sand aquifer to ponds, ditches, and other surface water bodies. Based on the results of this investigation tritium has not been detected at concentrations greater than the LLD 200 pCi/L in groundwater, which might discharge to these surface water bodies.

Although this is a potentially complete exposure pathway, there is no current risk of exposure associated with ingestion and recreational use off the Station property.

7.3.3 POTENTIAL EXPOSURE TO SURFACE WATER IN THE PERIMETER DITCH AT THE STATION The perimeter ditch flows to the south on the west side of the Station Property and does not flow off the property until a point located approximately 2 miles southwest of the PA.

045136 (12) Braidwood Generating Station 54 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 Under this potential exposure pathway, groundwater must migrate to the surface and into the perimeter ditch. Potential exposures could occur if the groundwater discharge to the surface water contains tritium. Although water in the perimeter ditch has contained trace amounts of tritium in the past, Station personnel are protected and monitored by the Radiation Protection Program, which is controlled by Federal guidelines. This is a potentially complete exposure pathway, but there is no current risk of exposure associated with ingestion, inhalation, or absorption on Station property.

7.4

SUMMARY

OF POTENTIAL TRITIUM EXPOSURE PATHWAYS There are three potential exposure pathways for tritium originating in or adjacent to the PA:

• groundwater migration off the Station Property to private and public groundwater users (drinking water exposure);

• groundwater migration off the Station Property to a surface water body (recreational exposure); and

• potential exposure to surface water in the perimeter ditch at the Station.

In summary, based upon the groundwater and surface water data provided and referenced in this investigation, none of the potential receptors are at risk of exposure to concentrations of tritium in excess of USEPA drinking water standards (20,000 pCi/L).

7.5 OTHER RADIONUCLIDES Target radionuclides were not detected at concentrations greater than their respective LLD in the groundwater samples collected. Other non-targeted radionuclides were also included in the tables but excluded from discussion in this report. These radionuclides were either a) naturally occurring and thus not produced by the Station, or b) could be definitively evaluated as being naturally occurring due to the lack of presence of other radionuclides which would otherwise indicate the potential of production from the Station.

045136 (12) Braidwood Generating Station 55 CONESTOGA-ROVERS & ASSOCIATES

Revision 1

8.0 CONCLUSION

S Based on all of the studies completed to date at this site, CRA concludes:

Groundwater Flow

• The deeper bedrock water supply aquifers are separated from the upper sand aquifer system by a number of aquitards, including the Wedron Clay Till and the regionally-identified Francis Creek Shale Member, and the Maquoketa Shale. These aquitards are present beneath the PA and continue to restrict downward vertical movement of groundwater.

• Groundwater at near-by properties is extracted from both the 20- to 30-foot thick upper sand aquifer and deeper bedrock formations at depths of 600 to 1,600 feet.

• Depth to groundwater in the upper sand aquifer ranges from 4 to 12 feet and it flows beneath the PA in a generally south to north manner, flowing from the Cooling Lake toward ponds and streams located north of the Station property.

• Groundwater in the upper sand aquifer flows to the west and southwest at locations west and south of the PA.

• Lateral groundwater flow within the PA is affected by the construction (basements/foundations) of the Reactor, Turbine, and Auxiliary Buildings, which were constructed through the Wedron Clay Till onto the top of the Francis Creek Shale Member. These buildings are barriers to lateral flow.

• Lateral groundwater flow within the PA is controlled by the slurry trench to some degree as is evident by the change in hydraulic gradients on the west side of the PA.

However, the degree of its influence on flow to the north is not known at this time.

• Vertical groundwater flow is restricted by the regional aquitards, however, due to the removal of the Wedron Clay Till beneath the buildings, one of the two regional aquitards has been removed within the PA. Nevertheless, groundwater data indicate that the remaining aquitard (Francis Creek Shale Member) is preventing vertical migration of tritium downward within the PA.

Groundwater Quality

• Tritium concentrations in groundwater were not detected at concentrations greater than the USEPA drinking water standard of 20,000 pCi/L.

• Tritium was not detected at concentrations greater than the LLD (200 pCi/L) in 34 of the 45 samples collected as part of this investigation.

045136 (12) Braidwood Generating Station 56 CONESTOGA-ROVERS & ASSOCIATES

Revision 1

• Gamma-emitting radionuclides associated with licensed plant operations were not detected at concentrations greater than their respective LLDs in 45 of the 45 samples collected as part of this investigation.

• Strontium-89/90 was not detected at a concentration greater than the LLD of 2.0 pCi/L in 45 of the 45 samples collected as part of this investigation.

• In the site area, tritium is not migrating off the Exelon property in the upper sand aquifer at concentrations greater than the LLD of 200 pCi/L.

• Deeper private water supply wells that are located downgradient of the PA contain concentrations of tritium less than the LLD of 200 pCi/L. The regional aquitards act as vertical barriers to migration of tritium from surficial aquifers to deeper bedrock aquifers.

• The depth of the tritium detected within the PA is defined by the top of the Wedron Clay Till with one exception. Along the west side of the Turbine Building and within the formerly excavated area, where the clay was excavated and backfilled, the vertical extent of the tritium is limited by the top of the Francis Creek Shale Member.

• Tritium has not been detected at concentrations greater than the LLD of 200 pCi/L in groundwater located beneath the Francis Creek Shale Member in the vicinity of the PA, downgradient of the buildings, and near the former building excavation.

Surface Water Quality

• Tritium concentrations in surface water were not detected at concentrations greater than the USEPA drinking water standard of 20,000 pCi/L.

• Tritium was not detected at concentrations greater than the LLD (200 pCi/L) in three of the six samples collected as part of this investigation.

• Gamma-emitting radionuclides associated with licensed plant operations were not detected at concentrations greater than their respective LLDs in six of the six samples collected as part of this investigation.

• Strontium-89/90 was not detected at a concentration greater than the LLD of 2.0 pCi/L in six of the six samples collected as part of this investigation.

• In the site area, tritium is not migrating off the Exelon property in surface water at concentrations exceeding the LLD of 200 pCi/L.

• Detections of tritium in the north and east stretches of the perimeter ditch can be attributed to the releases at vacuum breaker VB-1 located to the east along the blowdown line.

045136 (12) Braidwood Generating Station 57 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 AFE-Braidwood North of the Slurry Wall

• Gamma-emitting radionuclides associated with licensed plant operations were not detected at concentrations greater than their respective LLDs in any of the groundwater samples collected from the monitoring wells in the vicinity of AFE-Braidwood-1.

• Strontium-89/90 was not detected at a concentration greater than the LLD of 2.0 pCi/L in any of the groundwater samples collected from the monitoring wells in the vicinity of AFE-Braidwood-1.

• In the area north of the slurry wall, tritium was detected in groundwater samples from the shallow and deeper zones of the upper sand aquifer at concentrations less than 250 pCi/L.

• The concentrations of tritium detected in groundwater samples from north of the slurry wall in the upper sand aquifer are less than or just slightly greater than the LLD of 200 pCi/L.

• The concentrations of tritium detected in groundwater samples from the deeper bedrock monitoring well completed just below the Francis Creek Shale Member was less than the LLD of 200 pCi/L.

• Private well samples collected downgradient of this area provide additional evidence that the deeper bedrock is not impacted by tritium greater than the LLD of 200pCi/L.

• There are currently three monitoring wells (and numerous private wells) located downgradient of this AFE. No additional data are needed in this area of the site.

There have been no impacts to groundwater from AFE-Braidwood-1.

AFE-Braidwood North/Northeast of Units 1 and 2

• Gamma-emitting radionuclides associated with licensed plant operations were not detected at concentrations greater than their respective LLDs in any of the groundwater samples collected from the monitoring wells in the vicinity of AFE-Braidwood-2.

• Strontium-89/90 was not detected at a concentration greater than the LLD of 2.0 pCi/L in any of the groundwater samples collected from the monitoring wells in the vicinity of AFE-Braidwood-2.

• Groundwater samples collected downgradient of the fuel handling building, Units 1 and 2, and other systems on the east side of the PA did not contain tritium at concentrations greater than the LLD of 200 pCi/L.

045136 (12) Braidwood Generating Station 58 CONESTOGA-ROVERS & ASSOCIATES

Revision 1

• There are currently five monitoring wells (and numerous private wells) located downgradient of this AFE. There is no current impact to groundwater from AFE-Braidwood-2.

AFE-Braidwood Auxiliary Condensate Construction Storage Tank

• Gamma-emitting radionuclides associated with licensed plant operations were not detected at concentrations greater than their respective LLDs in any of the groundwater samples collected from the monitoring wells in the vicinity of AFE-Braidwood-3.

• Strontium-89/90 was not detected at a concentration greater than the LLD of 2.0 pCi/L in any of the groundwater samples collected from the monitoring wells in the vicinity of AFE-Braidwood-3.

• Groundwater samples collected from new monitoring wells located near and downgradient of this AFE area did not contain tritium at concentrations greater than the LLD of 200 pCi/L.

• There are two monitoring wells (and numerous private wells) located downgradient of this AFE. There is no current impact to groundwater from AFE-Braidwood-3.

AFE-Braidwood West Side of Turbine Building

• Gamma-emitting radionuclides associated with licensed plant operations were not detected at concentrations greater than their respective LLDs in any of the groundwater samples collected from the monitoring wells in the vicinity of AFE-Braidwood-4.

• Strontium-89/90 was not detected at a concentration greater than the LLD of 2.0 pCi/L in any of the groundwater samples collected from the monitoring wells in the vicinity of AFE-Braidwood-4.

• Tritium has been detected at concentrations greater than the LLD of 200 pCi/L in a localized area found along the west side of the Turbine Building. These detections are within the former excavation used during construction, adjacent to the deep basement of the Turbine Building and next to the storm water sewer.

• The lateral extent of tritium within this area of the Station has been defined by groundwater monitoring data to the north, west, and south, by the building basements to the east. The vertical extent of the tritium is limited by the Wedron Clay Till.

045136 (12) Braidwood Generating Station 59 CONESTOGA-ROVERS & ASSOCIATES

Revision 1

• The vertical extent of tritium within this area of the Station has been defined by groundwater monitoring data where the Wedron Clay Till has not been excavated and has been defined within the formerly excavated area.

• There are over 37 monitoring wells on the west side of the Turbine building that delineate the lateral and vertical extent of tritium in the upper sand unit and within the fill material.

• The source of the tritium detected on the west side of the Turbine Building is likely a result of multiple intermittent surface spills or releases of tritiated water.

Potential Receptors

• Based on the results of this investigation 1 , there is no current risk from exposure to radionuclides associated with licensed plant operations through any of the identified potential exposure pathways.

General Conclusions

• Based on the results of this investigation, tritium is not migrating off the Station property at detectable concentrations.

• Based on the results of this investigation, there are no known active releases into the groundwater at the Station.

1 Using the LLD specified in this HIR.

045136 (12) Braidwood Generating Station 60 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 9.0 RECOMMENDATIONS The following presents CRA's recommendations for proposed activities to be completed at the Braidwood Station 9.1 DATA GAPS Based on the results of this hydrogeologic investigation, there are no data gaps remaining to support CRAs conclusions regarding the characterization of the groundwater regime and potential impacts from radionuclides at the Station.

9.2 GROUNDWATER MONITORING Based upon the information collected to date, CRA recommends that Exelon conduct periodic monitoring of selected sample locations.

045136 (12) Braidwood Generating Station 61 CONESTOGA-ROVERS & ASSOCIATES

Revision 1

10.0 REFERENCES

CITED Arnold, T.L., Sullivan, D.J., Harris, M.A., Fitzpatrick F.A., Scudder, B.C., Ruhl, P.M.,

Hanchar, D.W., and Stewart, J.S., 1999. Environmental Setting of the Upper Illinois River Basin and Implications for Water Quality; Water Resources Report 98-4288.

Bouwer, H. and R.C. Rice, 1976. A slug test method for determining hydraulic conductivity of unconfined aquifers with completely or partially penetrating wells, Water Resources Research, vol. 12, no. 3, pp. 423-428.

CRA, June 2006. Memorandum entitled "Evaluation of the Source of Tritium in Two Private Water Supply Wells located along the Kankakee River and IL-Route 113 Braidwood Nuclear Station".

CRA, April 2006. Investigation of Tritium in the Groundwater in the Vicinity of VB-4.

CRA, April 2006. Investigation of Tritium in the Groundwater in the Vicinity of VB-6.

CRA, April 2006. Investigation of Tritium in the Groundwater in the Vicinity of VB-7.

CRA, August 2002. Results of Stage 2 Investigations, Illinois Site Remediation Program, Exelon Generation - Braidwood Facility.

CRA, March 2006. Tritium Investigation Report.

CRA, May 2006. Hydrogeologic Investigation Work Plan.

CRA, September 2000. Results of Sampling of the Perimeter Ditch, Commonwealth Edison Braidwood Facility, Braceville, Illinois.

CRA, September 2003. Results of Stage 1 Activities, Illinois Site Remediation Program, Exelon Generation Braidwood Facility.

Eisenbud, Merril and Gesell, Thomas, 1997. Environmental Radioactivity From Natural, Industrial, and Military Sources, Fourth Edition.

Exelon, 2004. Updated Final Safety Analysis Report (UFSAR) Revision 10, December 2004.

Exelon, 2005. Braidwood Station Units 1 and 2, 2004 Annual Radiological Environmental Operating Report, Exelon, (January 1 to December 31, 2005),

Braceville, Illinois May 2006.

Illinois Administrative Code Title 35 Part 742, Tiered Approach to Corrective Action Objectives, Illinois Pollution Control Board, effective February 5, 2002.

Illinois Geological Survey, March 2006 and October 2003, Coal Section, Map of Coal Mines - Will County.

045136 (12) Braidwood Generating Station 62 CONESTOGA-ROVERS & ASSOCIATES

Revision 1 Puls, R.W., and M.J. Barcelona, April 1996. Low-Flow (Minimal Drawdown)

Ground-Water Sampling Procedures, EPA Ground Water Issue, EPA/540/S-92/005, R. S. Kerr Environmental Research Center, United States Environmental Protection Agency, Ada, Oklahoma.

Schicht, Richard J., J. Rodger Adams, and John B. Stall, 1976. Water Resources Availability, Quality, and Cost in Northeastern Illinois, Illinois State Water Survey Report of Investigation 83.

Teledyne Isotopes Midwest Laboratory, May 1987. Environmental Radiological Monitoring for Braidwood Nuclear Power Station, Commonwealth Edison Company, Annual Report 1986.

Visocky, Adrian P., 1997. Water-Level Trends and Pumpage in the Deep Bedrock Aquifers in the Chicago Region, 1991-1995, Illinois State Water Survey Circular 182.

Visocky, Adrian P., Marvin G. Sherrill, and Keros Cartwright, 1985. Geology, Hydrogeology, and Water Quality of the Cambrian and Ordovician Systems in Northern Illinois, Illinois State Geological Survey, Illinois State Water Survey, Cooperative Groundwater Report 10.

Willman, H.B. and Frye, J.C., 1970. Pleistocene Stratigraphy of Illinois, Bulletin 94, Illinois State Geological Survey.

Willman, H.B., Atherton E., Buschbach, T.C., Collinson, C., Frye, J.C., Hopkins, M.E.,

Lineback, J.A., Simon, J.A., 1975. Handbook of Illinois Stratigraphy, ISGS Bulletin 95.

045136 (12) Braidwood Generating Station 63 CONESTOGA-ROVERS & ASSOCIATES

0 2000 4000ft STATION PROPERTY BOUNDARY SOURCE: USGS QUADRANGLE MAP; BRAIDWOOD MOSAIC, ILLINOIS - 1973 (PHOTO REVISED 1980) figure 1.1 STATION LOCATION MAP BRAIDWOOD GENERATING STATION EXELON GENERATION COMPANY, LLC 45136-20(012)GN-WA037 AUG 23/2006 REVISION 1

12 53 9

TE TE U U O O R R KA NK AK BRAIDWOOD EE R

0 1000 3000ft VE RI VB4 VB5 VB6 VB8 VB9 VB10 VB7 VB11 VB2 VB3 VB1 EXELON NUCLEAR STATION BRAIDWOOD COOLING LAKE figure 1.3 LEGEND STATION BOUNDARIES INCLUDING BLOWDOWN LINE BLOW DOWN LINE AERIAL PHOTO WITH UBS EXELON GENERATION COMPANY, LLC 45136-20(012)GN-WA038 AUG 23/2006 REVISION 1

0 500 1500ft VB-4 VB-3 VB-2 VB-1 figure 2.2 LEGEND STATION FEATURES AND WELL LOCATIONS BLOW DOWN LINE BRAIDWOOD GENERATING STATION BRAIDWOOD STATION PROPERTY LINE EXELON GENERATION COMPANY, LLC PRIVATE AND PUBLIC WELL LOCATION (APPROXIMATE ONLY) 45136-20(012)GN-WA039 AUG 23/2006 REVISION 1

AA AA' TANK NORTHEAST SOUTHWEST NORTHEAST MP-3 AA' TW-7 602 SB-17 MP-3 SB-16 TW-6 TW-7 598 AA SOUTHWEST N

0 20 40 594 LEGEND TEMPORARY MONITORING WELL IDENTIFIER 590 GROUND SURFACE (APPROXIMATE)

WELL CASING WELL SCREEN GROUNDWATER ELEVATION (FT. AMSL) 586 OCTOBER 9, 2001 APPROXIMATE STORM SEWER LINE APPROXIMATE FUEL LINE figure 2.4 582 STORM WATER DRAINAGE CROSS-SECTION AA-AA' MAIN SITE AREA SOURCE:

RESULTS OF STAGE 1 ACTIVITIES EXELON GENERATION COMPANY, LLC CRA, SEPTEMBER 2003 45136-20(012)GN-WA041 AUG 23/2006 REVISION 1

SB-22 WEST EAST BB BB' 602 OIL/WATER SEPARATOR WEST EAST BB BB' TW-13 SB-21 OIL WATER SEPARATOR 598 MP-2 N

SB-20 0 15 30 594 LEGEND OIL TEMPORARY MONITORING WELL IDENTIFIER 590 GROUND SURFACE (APPROXIMATE)

WELL CASING WATER WELL SCREEN 586 GROUNDWATER ELEVATION (FT. AMSL)

BASE OCTOBER 9, 2001 figure 2.5 582 OIL-WATER SEPARATOR CROSS-SECTION BB-BB' MAIN SITE AREA SOURCE: EXELON GENERATION COMPANY, LLC RESULTS OF STAGE 1 ACTIVITIES CRA, SEPTEMBER 2003 45136-20(012)GN-WA042 AUG 23/2006 REVISION 1

NORTHWEST SOUTHEAST NORTHWEST CC CC' CC MP-1 N

TW-17 0 40 80 598 TW-17 CC' PERIMETER SOUTHEAST DITCH 594 MP-1 LEGEND 590 TEMPORARY MONITORING WELL IDENTIFIER GROUND SURFACE (APPROIXMATE) 586 WELL CASING WELL SCREEN GROUNDWATER ELEVATION (FT. AMSL)

OCTOBER 9, 2001 582 figure 2.6 PERIMETER DITCH CROSS-SECTION CC-CC' MAIN SITE AREA SOURCE: EXELON GENERATION COMPANY, LLC RESULTS OF STAGE 1 ACTIVITIES CRA, SEPTEMBER 2003 45136-20(012)GN-WA043 AUG 23/2006 REVISION 1

598 DD' DD EAST WEST WEST DD TW-19 TW-20 TW-20 594 SG-1 N

PERIMETER 0 40 80 DITCH TW-19 DD' 590 EAST SG-1 586 SOURCE:

582 RESULTS OF STAGE 1 ACTIVITIES CRA, SEPTEMBER 2003 LEGEND TEMPORARY MONITORING WELL IDENTIFIER 578 GROUND SURFACE (APPROXIMATE)

WELL CASING WELL SCREEN OCTOBER 9, 2001 figure 2.7 574 GROUNDWATER ELEVATION (FT. AMSL)

OCTOBER 9, 2001 PERIMETER DITCH CROSS-SECTION DD-DD' MAIN SITE AREA EXELON GENERATION COMPANY, LLC 45136-20(012)GN-WA044 AUG 23/2006 REVISION 1

SOUTHWEST NORTHEAST 620 620 EXISTING GROUND SURFACE OVERBURDEN 600 600 BLOWDOWN LINE EQUALITY FORMATION 580 AQUIFER 580 WEDRON FORMATION 560 560 CHANNEL SANDSTONE DEPOSITS AQUITARD CARBONDALE 540 FRANCIS CREEK SHALE MEMBER 540 FORMATION 520 SILTSTONE CONG LOME 520 PENNSYLVANIA SHALES CO LC RATE H ESTE MEMBER R COA L MEMBER 500 500 480 480 LOCAL SPOON FORMATION USE 460 AQUIFER 460 ELEVATION IN FEET (MSL) 440 440 420 420 400 400 ORDOVICIAN SHALES 380 380 MAQUOKETA SHALE GROUP 360 360 340 REGIONAL USE 340 BEDROCK AQUIFER 320 320 300 300 GALENA AND PLATTEVILLE GROUPS (DEEP BEDROCK AQUIFER) FROM 250 TO 0 ftAMSL ORDOVICIAN GLENWOOD - ST. PETER FORMATION (DEEP BEDROCK AQUIFER) FROM 0 TO -280 ftBMSL 280 280 CAMBRIAN SCALE: HORIZONTAL 1"=400' VERTICAL 1"=40' figure 2.8 LOCAL GEOLOGIC CROSS-SECTION EXELON GENERATION COMPANY, LLC 45136-20(012)GN-WA046 AUG 23/2006 REVISION 1

CONTAINMENT BUILDING No. 2 GATE HOUSE LIMIT OF EXCAVATION W-2 RADWASTE/SERVICE TRAINING FACILITY PERIMETER DITCH E E SLURRY WALL SLURRY WALL LIMIT OF EXCAVATION SLURRY WALL SOUTH NORTH BUILDING COMPLEX PW-14 PW-11 COOLING 600 LAKE PW-10 G-2/D 600 500 500 400 400 ELEVATION (ft. AMSL) ELEVATION (ft. AMSL) 300 300 200 200 100 100 SCALE VERIFICATION THIS BAR MEASURES 1" ON ORIGINAL. ADJUST SCALE ACCORDINGLY.

EXELON GENERATION COMPANY, LLC 0 0 FLEETWIDE ASSESSMENT REGIONAL HYDROGEOLOGIC CROSS-SECTION E-E' BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Source

Reference:

-100 -100 Project Manager: Reviewed By: Date:

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000 S. QUIGLEY M. KELLY AUGUST 2006 DISTANCE (ft.)

Scale: Project N o : Report N o : Drawing N o :

AS SHOWN 45136-20 012 figure 2.13 REVISION 1 45136-20(012)GN-WA028 AUG 23/2006

SLURRY WALL - BOTTOM ELEVATION 575 MW-BW-201BD W-2 REACTOR CONTAINMENT UNIT I REACTOR CONTAINMENT UNIT II MW-BW-201I LIMIT OF EXCAVATION LIMIT OF EXCAVATION BRAIDWOOD MUNICIPAL WELL MW-BW-201S AUXILIARY BUILDING SLURRY WALL F'

MW-BW-204I F SOUTH SLURRY WALL - BOTTOM ELEVATION 575 NORTH

- BOTTOM OF WELL 1647' BGS COOLING LAKE 600 ~594.8 600 500 500 400 400 300 300 200 200 ELEVATION (ft. AMSL) ELEVATION (ft. AMSL) 100 100 0 0 SCALE VERIFICATION THIS BAR MEASURES 1" ON ORIGINAL. ADJUST SCALE ACCORDINGLY.

EXELON GENERATION COMPANY, LLC

-100 -100 FLEETWIDE ASSESSMENT REGIONAL HYDROGEOLOGIC CROSS-SECTION F-F' BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS

-200 -200 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000 8500 9000 9500 10000 Source

Reference:

BOTTOM AT 1647' BGS DISTANCE (ft.)

Project Manager: Reviewed By: Date:

S. QUIGLEY M. KELLY AUGUST 2006 Scale: Project N o : Report N o : Drawing N o :

AS SHOWN 45136-20 012 figure 2.14 REVISION 1 45136-20(012)GN-WA028 AUG 23/2006

0 800 2400ft LEGEND BRAIDWOOD STATION PROPERTY LINE SAMPLE LOCATION WITH TRITIUM figure 2.15 CONCENTRATION BETWEEN 400 AND 2000 pCi/L SAMPLE LOCATION WITH TRITIUM CONCENTRATION LESS THAN 200 pCi/L SAMPLE LOCATION WITH TRITIUM PRIVATE WELL AND MONITORING WELL SAMPLE RESULTS (LESS THAN THE DETECTION LIMIT) CONCENTRATION BETWEEN 2000 AND 20,000 pCi/L BRAIDWOOD GENERATING STATION SAMPLE LOCATION WITH TRITIUM SAMPLE LOCATION WITH TRITIUM EXELON GENERATION COMPANY, LLC CONCENTRATION BETWEEN 200 AND 400 pCi/L CONCENTRATION EXCEEDING 20,000 pCi/L 45136-20(012)GN-WA047 AUG 23/2006 REVISION 1

Transducer (feet of head) 45136-20(012)GN-WA036 AUG 23/2006 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 6/6/06 6/7/06 REVISION 1 6/8/06 6/9/06 6/10/06 6/11/06 6/12/06 6/13/06 6/14/06 6/15/06 6/16/06 6/17/06 6/18/06 6/19/06 6/20/06 6/21/06 6/22/06 6/23/06 6/24/06 6/25/06 6/26/06 6/27/06 6/28/06 Transducer Data from TB-1-4D Date 6/29/06 6/30/06 7/1/06 7/2/06 7/3/06 7/4/06 7/5/06 7/6/06 7/7/06 7/8/06 7/9/06 PRESSURE TRANSDUCER AND PRECIPITATION DATA-JUNE/JULY 2006 Precipitation - Braidwood 7/10/06 7/11/06 7/12/06 7/13/06 7/14/06 7/15/06 7/16/06 7/17/06 7/18/06 7/19/06 7/20/06 BRAIDWOOD GENERATING STATION 7/21/06 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 Precipitation (inches)

EXELON GENERATION COMPANY, LLC figure 4.3

W-2 A A' LIMIT OF EXCAVATION (BOTTOM ~539.0')

LIMIT OF EXCAVATION (BOTTOM ~539.0')

WEST EAST 610 610 593.72 MW-6 BURIED PIPES (APPROXIMATE) REACTOR CONTAINMENT UNIT II FENCE TURBINE/AUXILIARY/

MW-BW-203I REACTOR BUILDING D-1D (O/S 16' NORTH)

TB-1-3D SLURRY WALL SLURRY WALL ROAD MW-BW-203S (O/S 14' NORTH)

RAILROAD D-1 (O/S 14' NORTH)

RAILROAD (BASE OF BUILDING AT 539.0') ROAD MW-107 FENCE FILL FENCE FENCE FENCE DITCH FENCE 600 ROAD ROAD 600 SAND WEDRON CLAY TILL FENCE FRANCIS CREEK SHALE TW-20 DITCH 594.79 594.79 FRANCIS CREEK SILTSTONE/CONGLOMERATE 593 COLCHESTER COAL NO. 2 592.25 SPOON FORMATION 590 590 586 585.06 ELEVATION (ft. AMSL) ELEVATION (ft. AMSL) 580 580 570 570 560 560 550 550 SCALE VERIFICATION THIS BAR MEASURES 1" ON ORIGINAL. ADJUST SCALE ACCORDINGLY.

540 540 EXELON GENERATION COMPANY, LLC FLEETWIDE ASSESSMENT HYDROGEOLOGIC CROSS-SECTION A-A' 530 530 BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Source

Reference:

520 520 Project Manager: Reviewed By: Date:

0 500 1000 1500 2000 2500 3000 3500 4000 S. QUIGLEY M. KELLY AUGUST 2006 Scale: Project N o : Report N o : Drawing N o :

DISTANCE (ft.) AS SHOWN 45136-20 012 figure 5.2 REVISION 1 45136-20(012)GN-WA026 AUG 23/2006

W-2 MW-207I (O/S 51' EAST) (BOTTOM ELEVATION 549.59)

B B' NORTH SOUTH 610 610 593.72 TB-1-8D TB-1-5D (O/S 56' EAST)

FENCE LIMIT OF EXCAVATION MW-7 (O/S 12' WEST) MW-4 (O/S 11' WEST) TB-1-10D (O/S 9' EAST)

TW-3 (O/S 46' EAST) TB-1-3D (O/S 1' EAST)

TB-1-14D (O/S 58' EAST)

LIMIT OF EXCAVATION (BOTTOM FENCE MW-9 ELEVATION ~ 539') SLURRY WALL FENCE FENCE ROAD FILL (BOTTOM ELEVATION ~ 539')

TB-1-4D (O/S 45' EAST)

MW-6 SLURRY WALL FENCE SAND SERVICE BUILDING MW-13 600 600 WEDRON CLAY TILL FRANCIS CREEK SHALE FRANCIS CREEK SILTSTONE/CONGLOMERATE COLCHESTER COAL NO. 2 595.55 595.55 594.5 SPOON FORMATION 594.31 593.8 APPROXIMATE STORMWATER DRAINAGE SYSTEM 590.99 591.48 590.56 590 590 ELEVATION (ft. AMSL) ELEVATION (ft. AMSL) 580 580 570 570 560 560 SCALE VERIFICATION THIS BAR MEASURES 1" ON ORIGINAL. ADJUST SCALE ACCORDINGLY.

550 550 EXELON GENERATION COMPANY, LLC FLEETWIDE ASSESSMENT HYDROGEOLOGIC CROSS-SECTION B-B' BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS 540 540 0 500 1000 1500 Source

Reference:

DISTANCE (ft.)

Project Manager: Reviewed By: Date:

S. QUIGLEY M. KELLY AUGUST 2006 Scale: Project N o : Report N o : Drawing N o :

AS SHOWN 45136-20 012 figure 5.3 REVISION 1 45136-20(012)GN-WA026 AUG 23/2006

REACTOR CONTAINMENT UNIT I REACTOR CONTAINMENT UNIT II W-2 SLURRY WALL -

SLURRY WALL - AUXILIARY BUILDING C C' LIMIT OF EXCAVATION LIMIT OF EXCAVATION NORTH SOUTH 593.72 610 610 BOTTOM ELEVATION 571 BOTTOM ELEVATION 571 RAILROAD

/ FUEL HANDLING BUILDING MW-BW-201BD FENCE FENCE MW-BW-204I FENCE RAILROAD MW-BW-201I FENCE ROAD FENCE MW-BW-201S SLURRY WALL 600 600 COOLING LAKE 592.40 ~594.8 592.40 592.42 FILL 592.27 SAND 590 590 WEDRON CLAY TILL FRANCIS CREEK SHALE FRANCIS CREEK SILTSTONE/CONGLOMERATE 580 580 COLCHESTER COAL NO. 2 SPOON FORMATION MINE SPOIL 570 570 560 560 ELEVATION (ft. AMSL) ELEVATION (ft. AMSL) 550 550 MINE SPOIL 540 540 530 530 520 520 510 510 500 500 490 490 480 480 SCALE VERIFICATION THIS BAR MEASURES 1" ON ORIGINAL. ADJUST SCALE ACCORDINGLY.

470 470 EXELON GENERATION COMPANY, LLC 460 460 FLEETWIDE ASSESSMENT HYDROGEOLOGIC CROSS-SECTION C-C' 450 450 BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS 440 440 Source

Reference:

430 430 Project Manager: Reviewed By: Date:

0 500 1000 1500 2000 2500 3000 3500 S. QUIGLEY M. KELLY AUGUST 2006 Scale: Project N o : Report N o : Drawing N o :

DISTANCE (ft.)

AS SHOWN 45136-20 012 figure 5.4 REVISION 1 45136-20(012)GN-WA026 AUG 23/2006

D D' W-2 STORM SEWER DRAIN NOT TO WEST MW-BW-202I EAST LIMIT OF EXCAVATION LIMIT OF EXCAVATION WEST WALL OF 605 605 SLURRY WALL SCALE AND APPROXIMATE MW-BW-202S (O/S 10' SOUTH) 593.72 RAILROAD RAILROAD WAREHOUSE NO.1 TW-8 (O/S 12' NORTH)

FENCE SLURRY WALL MW-9 ROAD FENCE FENCE FENCE TW-12 600 600 ROAD ROAD TW-24 FILL SAND WEDRON CLAY TILL FRANCIS CREEK SHALE 595 595 FRANCIS CREEK SILTSTONE/CONGLOMERATE 593.90 593.64 593.72 593.74 COLCHESTER COAL NO. 2 593.45 592.95 SPOON FORMATION STORM SEWER 590 590 ELEVATION (ft. AMSL) ELEVATION (ft. AMSL) 585 585 580 580 575 575 570 570 565 565 SCALE VERIFICATION THIS BAR MEASURES 1" ON ORIGINAL. ADJUST SCALE ACCORDINGLY.

560 560 EXELON GENERATION COMPANY, LLC FLEETWIDE ASSESSMENT HYDROGEOLOGIC CROSS-SECTION D-D' BRAIDWOOD GENERATING STATION 555 555 BRACEVILLE, ILLINOIS Source

Reference:

550 550 Project Manager: Reviewed By: Date:

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 S. QUIGLEY M. KELLY AUGUST 2006 DISTANCE (ft.)

Scale: Project N o : Report N o : Drawing N o :

AS SHOWN 45136-20 012 figure 5.5 REVISION 1 45136-20(012)GN-WA026 AUG 23/2006

LIMIT OF EXCAVATION (BOTTOM ELEVATION ~ 539') MW-207I (O/S 51' EAST) (BOTTOM ELEVATION 549.59)

B B' NORTH SOUTH W-2 TB-1-8D 610 610 593.72 TB-1-5D (O/S 56' EAST) FENCE TB-1-10D (O/S 9' EAST)

SLURRY TRENCH MW-7 (O/S 12' WEST) MW-4 (O/S 11' WEST)

TW-3 (O/S 46' EAST) TB-1-3D (O/S 1' EAST)

TB-1-14D (O/S 58' EAST)

MW-9 WELL SCREEN FENCE MW-13 TRITIUM CONCENTRATION LIMIT OF EXCAVATION (BOTTOM ELEVATION ~ 539')

ND FENCE FENCE FENCE ROAD SLURRY TRENCH TB-1-4D (O/S 45' EAST) MW-6 TRITIUM RESULTS GREATER THAN 1,000 (pCi/L)

BUILDING MW-13 TRITIUM RESULTS 500 TO 1,000 (pCi/L) 600 600 TRITIUM RESULTS 200 TO 500 (pCi/L)

TRITIUM RESULTS 0 TO 200 (pCi/L) 595.55 595.55 594.5 594.31 593.8 MW-9 311 MW-7 MW-4 TW-3 214 196 1040 APPROXIMATE STORM DRAIN 590.99 591.48 590.56 590 MW-13 590 ND MW-6 288 ELEVATION (ft. AMSL) ELEVATION (ft. AMSL) 200 TB-1-3D 285 TB-1-14D ND 580 TB-1-4D 580 719 500 TB-1-5D TB-1-8D 172 TB-1-10D ND 3/8/06 200 ND 570 570 MW-BW-207I 471 560 560 555 555 SCALE VERIFICATION THIS BAR MEASURES 1" ON ORIGINAL. ADJUST SCALE ACCORDINGLY.

515 515 EXELON GENERATION COMPANY, LLC FLEETWIDE ASSESSMENT 508 508 HYDROGEOLOGIC PROFILE TRITIUM CONCENTRATIONS - GROUNDWATER BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS 504 504 Source

Reference:

430 430 Project Manager: Reviewed By: Date:

0 500 1000 1500 S. QUIGLEY M. KELLY AUGUST 2006 DISTANCE (ft.)

Scale: Project N o : Report N o : Drawing N o :

AS SHOWN 45136-20 012 figure 6.1 REVISION 1 45136-20(012)GN-WA027 AUG 23/2006

Page 1 of 2 TABLE 4.1

SUMMARY

OF MONITORING WELL INSTALLATION DETAILS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Surface Reference Screened Interval Hydrogeologic Sample X coor. Y coor. Elevation Elevation Top Bottom Top Bottom Well Unit Location (Site-Specific Coordinates) (ft AMSL) 1 (ft AMSL) (ft bgs) 2 (ft AMSL) Construction Screened 3 Existing Monitoring Wells MW-11 65288.1939 84097.4503 600.60 603.83 2.0 12.0 596.00 586.00 2-inch PVC Screen S MW-13 65367.1182 84267.4234 597.50 600.85 2.5 12.5 595.00 585.00 2-inch PVC Screen S MW-14 65103.9949 84342.5513 599.50 602.46 2.0 12.0 597.50 587.50 2-inch PVC Screen S MW-2 65271.3906 83474.2371 599.80 603.00 2.0 12.0 597.80 587.80 2-inch PVC Screen S MW-22 65319.3555 83911.9591 597.70 601.65 7.0 17.0 591.70 581.70 2-inch PVC Screen S MW-4 65409.1225 83750.0194 599.60 599.35 2.0 12.0 597.60 587.60 2-inch PVC Screen S MW-5 65250.5952 83778.1842 599.90 598.64 2.0 12.0 597.90 587.90 2-inch PVC Screen S MW-6 65425.2927 83575.8848 599.10 599.56 5.0 15.0 594.10 584.10 2-inch PVC Screen S MW-9 65412.2272 84020.0972 600.40 603.83 2.0 12.0 598.40 588.40 2-inch PVC Screen S Exelon-Owned Wells MW-BW-201I 65818.6280 84208.5570 600.02 603.21 14 24 586.02 576.02 2-inch PVC Screen I MW-BW-202I 66014.4060 84018.4590 600.72 604.09 15 25 585.72 575.72 2-inch PVC Screen I MW-BW-203I 66327.2810 83422.6210 598.95 602.19 15 25 583.95 573.95 2-inch PVC Screen I MW-BW-204I 66042.0060 82081.7290 600.37 603.17 5 25 595.37 575.37 2-inch PVC Screen I MW-BW-205I 64768.7390 82860.2200 598.04 600.86 15 25 583.04 573.04 2-inch PVC Screen I MW-BW-206I 64330.7570 81803.4620 595.10 598.35 14 24 581.10 571.10 2-inch PVC Screen I MW-BW-207I 66063.7670 83836.3590 599.59 601.59 35 45 564.59 554.59 2-inch PVC Screen I MW-BW-201S 65819.1100 84203.0330 599.97 603.11 5 15 594.97 584.97 2-inch PVC Screen S MW-BW-202S 66013.7490 84009.2920 600.87 604.30 5 15 595.87 585.87 2-inch PVC Screen S MW-BW-203S 66327.6550 83436.7650 599.14 602.33 5 15 594.14 584.14 2-inch PVC Screen S MW-BW-201BD 65825.1430 84203.7530 599.94 603.23 80 95 519.94 504.94 2-inch PVC Screen BD MW-BW-208BD 66063.7670 83836.3590 599.98 601.98 85 100 514.59 499.59 2-inch PVC Screen BD Existing Temporary Wells TB-1-1D 65393.4430 83562.0330 598.50 601.00 15 20 583.50 578.50 1-inch PVC Screen I TB-1-2D 65273.1690 83473.5080 599.41 600.62 19 24 580.41 575.41 1-inch PVC Screen I TB-1-3D 65425.9530 83576.8750 599.70 602.77 10 15 589.70 584.70 1-inch PVC Screen I TB-1-4D 65468.1300 83642.7460 599.45 600.86 17 22 582.45 577.45 1-inch PVC Screen I TB-1-5D 65467.1650 84030.2150 600.71 602.37 23 28 577.71 572.71 1-inch PVC Screen I TB-1-6D 65289.3290 84093.8570 600.34 602.69 22.5 27.5 577.84 572.84 1-inch PVC Screen I TB-1-7D 65143.3310 84097.4860 600.45 601.46 18 23 582.45 577.45 1-inch PVC Screen I CRA 045136 (12) Braidwood Generating Station Revision 1

Page 2 of 2 TABLE 4.1

SUMMARY

OF MONITORING WELL INSTALLATION DETAILS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Surface Reference Screened Interval Hydrogeologic Sample X coor. Y coor. Elevation Elevation Top Bottom Top Bottom Well Unit Location (Site-Specific Coordinates) (ft AMSL) 1 (ft AMSL) (ft bgs) 2 (ft AMSL) Construction Screened 3 TB-1-8D 65618.2450 83005.0640 600.43 602.43 23 28 577.43 572.43 1-inch PVC Screen I TB-1-9D 65293.9090 83362.6330 600.68 603.41 22 27 578.68 573.68 1-inch PVC Screen I TB-1-10D 65490.5850 83409.8970 600.05 604.68 23 28 577.05 572.05 1-inch PVC Screen I TB-1-11D 65532.5070 84328.0420 600.41 604.29 10 25 590.41 575.41 1-inch PVC Screen I TB-1-12D 65621.9120 84412.5880 599.40 603.15 10 25 589.40 574.40 1-inch PVC Screen I TB-1-13D 65517.5830 84403.9470 599.40 602.59 10 25 589.40 574.40 1-inch PVC Screen I TB-1-14D 65425.3930 84345.7930 599.16 602.32 10 25 589.16 574.16 1-inch PVC Screen I TBRW-1 65534.1810 84232.9450 600.58 603.74 4 14 596.58 586.58 2-inch PVC Screen I TBRW-2 65600.3030 84274.6220 600.44 603.72 4 14 596.44 586.44 2-inch PVC Screen I TBRW-3 65571.3530 84346.9090 600.53 603.44 4 14 596.53 586.53 2-inch PVC Screen I TW-8 65465.9498 84031.8836 600.70 600.52 2 12 598.70 588.70 1-inch PVC Screen S TW-16 65187.5681 83650.3472 599.00 601.93 2 12 597.20 587.20 1-inch PVC Screen S TW-6 65459.9085 83827.6580 599.60 599.56 2 12 597.60 587.60 1-inch PVC Screen S TW-23 65288.6581 84140.0696 600.10 603.10 6 16 594.10 584.10 1-inch PVC Screen S TW-3 65469.3170 83648.7042 599.60 599.37 2 12 597.60 587.60 1-inch PVC Screen S TW-10 65403.4913 84146.6207 600.60 602.54 2 12 598.60 588.60 1-inch PVC Screen S TW-15 65099.6209 84260.1475 599.20 601.17 3 13 596.20 586.20 1-inch PVC Screen S TW-12 65134.2956 84008.2068 599.30 601.51 2 12 597.30 587.30 1-inch PVC Screen S TW-21 65466.2133 84104.6516 600.70 600.54 2 12 598.70 588.70 1-inch PVC Screen S TW-18 64856.1143 83653.2073 597.70 599.09 3 13 594.70 584.70 1-inch PVC Screen S TW-24 65099.2125 84010.5879 598.90 601.87 5 15 593.90 583.90 1-inch PVC Screen S TW-25 65142.5107 84100.4868 597.10 600.07 6 16 591.10 581.10 1-inch PVC Screen S TW-26 64958.0854 84223.0321 599.70 602.68 7 17 592.70 582.70 1-inch PVC Screen S Notes:

1 ft AMSL - feet Above Mean Sea Level S, well open to the water table in the shallow aquifer 2

ft bgs - feet below ground surface I, well open to the water table in the intermediate aquifer 3

Hydrogeologic unit screened: BD, well open to the top of the bedrock CRA 045136 (12) Braidwood Generating Station Revision 1

Page 1 of 2 TABLE 4.2

SUMMARY

OF MONITORING WELL DEVELOPMENT PARAMETERS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Well Volume Location Date Volume Purged pH Conductivity Temperature Turbidity Observations (1)

(gallons) (gallons) (Std. Units) (µS/cm ) (2) (° C) (3) (NTU) (4)

MW-BW-201I 5/1/2006 2.6 6 7.17 891 11.7 452 NM (5) 12 7.04 1,014 11.7 175 NM 18 7.00 1,052 11.7 77 NM MW-BW-201S 5/1/2006 1.2 3 7.33 1,006 11.0 180 NM 6 7.11 1,132 11.0 22.0 NM 9 7.07 1,145 11.0 18.6 NM MW-BW-202I 5/1/2006 2.7 6 7.68 167 12.2 555 NM 12 7.34 178 12.3 704 NM 18 7.26 175 12.3 305 NM MW-BW-202S 5/1/2006 1.2 4 6.97 248 12.3 310 NM 8 6.93 221 12.3 85.1 NM 12 6.89 217 12.3 67.5 NM MW-BW-203I 5/1/2006 3.2 7 7.23 1,192 11.7 678 NM 14 7.16 1,201 11.7 177 NM 21 7.14 1,195 11.7 64 NM MW-BW-203S 5/1/2006 1.6 4 9.04 930 10.8 1,248 NM 8 8.30 1,004 10.8 150 NM 12 8.01 1,040 10.8 73.5 NM 16 7.91 1,062 10.8 61.1 NM MW-BW-204I 4/28/2006 2.9 6 8.11 638 13.3 417 Cloudy 12 7.96 612 13.5 337 Slightly cloudy 18 7.85 611 13.3 222 Slightly cloudy 24 7.77 613 13.3 84.2 Slightly cloudy CRA 045136 (12) Braidwood Generating Station Revision 1

Page 2 of 2 TABLE 4.2

SUMMARY

OF MONITORING WELL DEVELOPMENT PARAMETERS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Well Volume Location Date Volume Purged pH Conductivity Temperature Turbidity Observations (1)

(gallons) (gallons) (Std. Units) (µS/cm ) (2) (° C) (3) (NTU) (4)

MW-BW-201I 5/1/2006 2.6 6 7.17 891 11.7 452 NM (5) 12 7.04 1,014 11.7 175 NM 18 7.00 1,052 11.7 77 NM MW-BW-201S 5/1/2006 1.2 3 7.33 1,006 11.0 180 NM 6 7.11 1,132 11.0 22.0 NM 9 7.07 1,145 11.0 18.6 NM MW-BW-205I 4/28/2006 3.1 6 7.78 859 23.5 264 Cloudy 12 7.74 825 23.4 48.5 Slightly cloudy 18 7.72 819 23.3 27.4 Clear MW-BW-206I 4/28/2006 2.7 5 6.89 1,494 20.7 204 Cloudy 10 6.92 1,418 20.5 33.0 Slightly cloudy 15 7.01 1,354 20.6 12.2 Clear MW-BW-207I 7/14/2006 6.5 6 7.19 491 11.7 NM Slightly cloudy 12 7.24 475 12.0 NM Slightly cloudy 18 7.27 469 12.0 NM Slightly cloudy 24 7.31 431 12.1 NM Clear 30 7.35 421 12.0 NM Clear MW-BW-208BD 7/18/2006 14 28 7.91 359 13.1 NM Slightly cloudy 42 7.53 371 12.9 NM Slightly cloudy 56 7.29 385 12.5 NM Slightly cloudy 70 7.13 391 12.3 NM Slightly cloudy Notes:

(1) Std. Units - standard units (2) µS/cm - microsiemens per centimeter (3) ° C - degrees Celsius (4) NTU - nephelometric turbidity units (5) NM - not measured CRA 045136 (12) Braidwood Generating Station Revision 1

Page 1 of 1 TABLE 4.3

SUMMARY

OF GROUNDWATER ELEVATIONS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Reference Depth to Water Groundwater Depth to Water Groundwater Location Elevation (ft Below Elevation (ft Below Elevation (ft AMSL) (1) Reference) (ft AMSL) Reference) (ft AMSL)

May 9-11, 06 May 9-11, 06 July 31, 06 July 31, 06 MW-11 603.83 10.49 593.34 10.79 593.04 MW-13 600.85 9.86 590.99 9.95 590.90 MW-14 602.46 12.69 589.77 12.78 589.68 MW-2 603 NM NM 6.93 596.07 MW-22 601.65 8.60 593.05 8.15 593.50 MW-4 599.35 4.89 594.46 4.73 594.62 MW-5 599.9 5.40 594.50 4.23 595.67 MW-6 599.1 5.42 593.68 3.41 595.69 MW-9 603.83 10.03 593.80 10.40 593.43 MW-BW-201BD 603.23 10.96 592.27 11.45 591.78 MW-BW-201I 603.21 10.79 592.42 11.89 591.32 MW-BW-201S 603.11 10.71 592.40 10.75 592.36 MW-BW-202I 604.09 10.37 593.72 10.38 593.71 MW-BW-202S 604.3 10.56 593.74 10.55 593.75 MW-BW-203I 602.19 7.39 594.80 7.49 594.70 MW-BW-203S 602.33 7.55 594.78 7.65 594.68 MW-BW-204I 603.173 8.51 594.66 8.94 594.23 MW-BW-205I 600.859 8.13 592.73 8.30 592.56 MW-BW-206I 598.349 10.74 587.61 11.11 587.24 MW-BW-207I 599.59 NM NM 7.35 592.24 MW-BW-208BD 601.98 NM NM 13.05 588.93*

TB-1-10D 604.68 9.35 595.33 9.03 595.65 TB-1-1D 601 6.61 594.39 5.91 595.09 TB-1-2D 600.62 6.22 594.40 7.04 593.58 TB-1-3D 602.77 8.64 594.13 6.94 595.83 TB-1-4D 600.86 6.60 594.26 5.38 595.48 TB-1-5D 602.37 10.89 591.48 11.40 590.97 TB-1-6D 602.69 11.14 591.55 11.28 591.41 TB-1-7D 601.46 9.65 591.81 9.55 591.91 TB-1-8D 602.43 6.88 595.55 7.00 595.43 TB-1-9D 603.41 8.03 595.38 7.40 596.01 TW-10 602.54 10.42 592.12 10.76 591.78 TW-12 601.51 9.16 592.35 9.06 592.45 TW-15 601.17 10.92 590.25 11.00 590.17 TW-16 601.93 7.14 594.79 6.56 595.37 TW-18 599.09 7.65 591.44 8.61 590.48 TW-21 600.54 4.79 595.75 7.25 593.29 TW-23 603.1 11.80 591.30 11.90 591.20 TW-24 601.87 10.51 591.36 10.48 591.39 TW-25 600.07 8.14 591.93 8.06 592.01 TW-26 602.68 12.53 590.15 12.77 589.91 TW-3 599.37 4.51 594.86 3.82 595.55 TW-6 599.56 6.73 592.83 5.00 594.56 TW-84 600.52 6.13 594.39 7.10 593.42 Notes:

(1) - ft AMSL - feet above mean sea level.

NM - Not Measured.

• - A water elevation of 592.74 ft AMSL was measured at MW-BW-208BD on August 15, 2006.

CRA 045136 (12) Braidwood Generating Station Revision 1

Page 1 of 1 TABLE 4.4

SUMMARY

OF SURFACE WATER ELEVATIONS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Reference Depth to Water Groundwater Location Elevation (ft Below Elevation (ft AMSL) Reference) (ft AMSL)

SG-BW-101 588.36 1.00 587.36 SG-BW-102 587.61 1.00 586.61 SG-BW-103 580.03 1.00 579.03 SG-BW-104 567.38 1.00 566.38 SG-BW-105 595.92 1.42 594.50 SG-BW-106 596.44 2.03 594.41 Notes:

All elevations were measured May 17, 2006.

ft AMSL - feet above mean sea level.

CRA 045136 (12) Braidwood Generating Station

Page 1 of 1 TABLE 4.5 SAMPLE KEY FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Date Location Sample Identification QC Sample Collected Matrix Analyses TB-1-9D WG-BW-050906-JL-001 5/9/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-6 WG-BW-050906-MS-002 5/9/2006 Groundwater Tritium/Strontium/Gamma Spectrum TB-1-5D WG-BW-050906-JL-003 5/9/2006 Groundwater Tritium/Strontium/Gamma Spectrum TB-1-3D WG-BW-050906-MS-004 5/9/2006 Groundwater Tritium/Strontium/Gamma Spectrum TB-1-1D WG-BW-050906-JL-005 5/9/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-8 WG-BW-050906-MS-006 5/9/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-16 WG-BW-050906-JL-007 5/9/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-6 WG-BW-050906-MS-008 5/9/2006 Groundwater Tritium/Strontium/Gamma Spectrum TB-1-10D WG-BW-051006-JL-009 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-5 WG-BW-050906-MS-010 5/9/2006 Groundwater Tritium/Strontium/Gamma Spectrum TB-1-10D WG-BW-051006-JL-011 Duplicate (009) 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-11 WG-BW-051006-MS-012 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum TB-1-4D WG-BW-051006-JL-013 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-23 WG-BW-051006-MS-014 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-3 WG-BW-051006-JL-015 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-10 WG-BW-051006-MS-016 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-2 WG-BW-051006-JL-017 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-13 WG-BW-051006-MS-018 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum TB-1-2D WG-BW-051006-JL-019 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-15 WG-BW-051006-MS-020 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum TB-1-7D WG-BW-051006-JL-021 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-15 WG-BW-051006-MS-022 Duplicate (020) 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-14 WG-BW-051006-MS-024 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum TB-1-8D WG-BW-051006-JL-025 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-12 WG-BW-051006-MS-026 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-22 WG-BW-051106-JL-027 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-24 WG-BW-051006-MS-028 5/10/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-9 WG-BW-051106-JL-029 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-4 WG-BW-051106-MS-030 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-9 WG-BW-051106-JL-031 Duplicate (029) 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-7 WG-BW-051106-MS-032 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum TB-1-6D WG-BW-051106-JL-033 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-21 WG-BW-051106-MS-034 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-202I WG-BW-051106-JL-035 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-203S WG-BW-051106-MS-036 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-202S WG-BW-051106-JL-037 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-203I WG-BW-051106-MS-038 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-201S WG-BW-051106-JL-039 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-201I WG-BW-051106-MS-040 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-204I WG-BW-051206-JL-041 5/12/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-201I WG-BW-051106-MS-042 Duplicate (040) 5/11/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-205I WG-BW-051206-JL-043 5/12/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-26 WG-BW-051206-MS-044 5/12/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-18 WG-BW-051206-MS-046 5/12/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-206I WG-BW-051206-MS-048 5/12/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-24 WG-BW-051506-MB-050 5/15/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-24 WG-BW-051506-MB-052 Duplicate (050) 5/15/2006 Groundwater Tritium/Strontium/Gamma Spectrum SG-BW-101 SW-BW-051706-MB-101 5/17/2006 Surface Water Tritium/Strontium/Gamma Spectrum SG-BW-102 SW-BW-051706-MB-102 5/17/2006 Surface Water Tritium/Strontium/Gamma Spectrum SG-BW-103 SW-BW-051706-MB-103 5/17/2006 Surface Water Tritium/Strontium/Gamma Spectrum SG-BW-104 SW-BW-051706-MB-104 5/17/2006 Surface Water Tritium/Strontium/Gamma Spectrum SG-BW-105 SW-BW-051706-MB-105 5/17/2006 Surface Water Tritium/Strontium/Gamma Spectrum SG-BW-106 SW-BW-051706-MB-106 5/17/2006 Surface Water Tritium/Strontium/Gamma Spectrum TW-25 WG-BW-051906-MB-054 5/19/2006 Groundwater Tritium/Strontium/Gamma Spectrum TW-26 WG-BW-051906-MB-055 5/19/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-201BD WG-BW-052206-MB-056 5/22/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-201BD WG-BW-052206-MB-057 Duplicate (056) 5/22/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-208BD WG-BW-MW-208BD-072806-JL-100 7/28/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-207I WG-BW-MW-207I-072806-JL-101 7/28/2006 Groundwater Tritium/Strontium/Gamma Spectrum MW-BW-207I WG-BW-MW-207I-072806-JL-102 Duplicate (101) 7/28/2006 Groundwater Tritium/Strontium/Gamma Spectrum Notes:

QC - Quality Control Gamma Spectrum - Barium-140, Cesium-134, Cesium-137, Cobalt-58, Cobalt-60, Iron-59, Lanthanum-140, Manganese-54, Niobium-95, Zinc-65, Zirconium-95 CRA 045136 (12) Braidwood Generating Station Revision 1

Page 1 of 9 TABLE 4.6

SUMMARY

OF MONITORING WELL PURGING PARAMETERS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Minutes Pumping Volume (5)

Location Date Purged Rate pH Temperature Conductivity ORP DO (7) Turbidity Purged (1) (2)

(mL/min) (Std. Units) (°C) (3) (µS/cm) (4) (mV) (6)

(mg/L) (8) (NTU) (9) (gallons)

TB-1-9D 5/9/2006 5 200 7.18 22.01 1600 NA 0.80 95 10 200 7.19 22.35 1590 NA 0.24 40 15 200 7.20 22.47 1580 NA 0.16 37 20 200 7.21 22.55 1560 NA 0.13 35 25 200 7.22 22.62 1560 NA 0.12 20 30 200 7.24 22.62 1550 NA 0.09 20 35 200 7.25 22.64 1540 NA 0.10 17 2 gallons MW-6 5/9/2006 5 250 7.51 16.25 19990 281 0.73 141 10 250 7.31 16.14 20020 277 0.55 62.5 15 250 7.22 15.98 21000 275 0.58 16.4 20 250 7.16 16.01 22200 275 0.55 34.9 25 250 7.11 15.91 24300 275 0.51 32.8 2 gallons TB-1-5D 5/9/2006 5 200 7.76 13.74 763 NA 1.55 100 10 200 7.56 14.19 828 NA 2.05 55 15 200 7.54 14.77 898 NA 4.68 45 20 200 7.52 14.93 907 NA 7.47 29 25 200 7.42 14.97 929 NA 7.41 9.2 30 200 7.34 15.09 939 NA 7.31 7.6 35 200 7.29 15.13 942 NA 7.30 5.7 40 200 7.30 15.10 941 NA 7.34 6 2 gallons TB-3D 5/9/2006 5 200 7.06 16.19 23500 142 0.46 76.7 10 200 7.08 15.99 24000 90 0.37 14.1 15 200 7.05 16.04 24000 66 0.33 5.98 20 200 7.04 15.93 23800 45 0.32 5.11 25 200 7.02 15.92 23700 29 0.31 2.96 1 gallon TB-1D 5/9/2006 5 200 7.48 14.22 889 NA 1.67 190 10 200 7.44 14.33 894 NA 1.03 60 15 200 7.46 14.30 892 NA 0.12 27 20 200 7.47 14.33 889 NA 0.10 28 25 200 7.44 14.37 891 NA 0.09 18 30 200 7.45 14.33 891 NA 0.08 23 1.5 gallons CRA 045136 (12) Braidwood Generating Station Revision 1

Page 2 of 9 TABLE 4.6

SUMMARY

OF MONITORING WELL PURGING PARAMETERS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Minutes Pumping Volume (5)

Location Date Purged Rate pH Temperature Conductivity ORP DO (7) Turbidity Purged (1) (2)

(mL/min) (Std. Units) (°C) (3) (µS/cm) (4) (mV) (6)

(mg/L) (8) (NTU) (9) (gallons)

TW-8 5/9/2006 5 200 7.98 13.32 8040 217 0.86 13.7 10 200 7.17 13.19 7840 222.0 0.62 8.09 15 200 6.88 13.18 7650 226 0.52 4.94 20 200 6.81 13.16 7540 229 0.48 4.84 25 200 6.78 13.01 7330 231 0.48 3.25 1 gallon TW-16 5/9/2006 5 200 7.14 13.75 437 NA 1.24 5.3 10 200 6.98 13.66 435 NA 1.12 3.4 15 200 6.90 13.64 432 NA 0.90 2.8 20 200 6.83 13.62 438 NA 0.73 1.7 25 200 6.83 13.61 439 NA 0.65 2 30 200 6.81 13.59 443 NA 0.63 1.4 1.5 gallons TW-6 5/9/2006 5 200 8.16 16.88 925 123 0.77 16 10 200 7.66 17.26 872 112 0.62 16.1 15 200 7.39 17.38 781 107 0.70 7.67 20 200 7.31 16.70 694 94 0.55 4.44 25 200 7.22 16.65 695 89 0.52 2.45 1 gallon TB-1-10D 5/10/2006 5 200 7.09 19.37 2690 NA 1.01 15 10 200 7.15 19.81 2280 NA 6.12 18 15 200 7.18 20.11 2060 NA 6.72 4.8 20 200 7.10 20.09 1970 NA 5.26 2.2 25 200 7.11 20.08 1960 NA 5.84 1.6 30 200 7.17 20.10 1940 NA 5.87 1.4 1.5 gallons MW-5 5/9/2006 5 200 8.68 12.48 553 168 7.76 19.1 10 200 8.10 12.52 551 198 7.87 13 15 200 7.90 12.64 550 220 7.84 6.43 20 200 7.82 12.51 550 231 7.94 5.49 25 200 7.77 12.51 556 242 8.06 4.3 1 gallon CRA 045136 (12) Braidwood Generating Station Revision 1

Page 3 of 9 TABLE 4.6

SUMMARY

OF MONITORING WELL PURGING PARAMETERS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Minutes Pumping Volume (5)

Location Date Purged Rate pH Temperature Conductivity ORP DO (7) Turbidity Purged (1) (2)

(mL/min) (Std. Units) (°C) (3) (µS/cm) (4) (mV) (6)

(mg/L) (8) (NTU) (9) (gallons)

TB-1-4D 5/10/2006 5 200 7.54 16.14 7730 NA 0.19 310 10 200 7.56 16.11 7140 NA 0.14 110 15 200 7.58 16.03 6990 NA 0.11 60 20 200 7.60 16.04 6770 NA 0.11 31 25 200 7.58 16.10 6680 NA 0.11 36 30 200 7.60 16.08 6650 NA 0.15 33 1.5 gallons MW-11 5/10/2006 5 200 8.83 13.26 6600 380.0 6.51 6.18 10 200 7.89 13.21 6560 382.0 6.53 5.6 15 200 7.38 13.18 6470 384.0 6.42 3.83 20 200 7.15 13.21 6330 385.0 6.37 2.16 25 200 7.05 13.16 6230 386.0 6.41 1.41 1 gallon TW-3 5/10/2006 5 200 8.58 16.28 2210 NA 0.58 95 10 200 9.31 16.16 2730 NA 0.48 100 15 200 9.58 16.14 3070 NA 0.28 390 20 200 9.76 16.01 3340 NA 0.25 400 25 200 10.06 16.01 3690 NA 0.29 350 1 gallon TW-23 5/10/2006 5 200 8.31 13.42 2160 303.0 1.57 8.78 10 200 7.54 13.02 1710 315.0 3.42 8.75 15 200 7.32 12.88 1670 321 3.69 4.65 20 200 7.19 12.89 1680 325 3.51 2.77 25 200 7.14 12.87 1650 328 3.50 1.72 1 gallon MW-2 5/10/2006 5 200 7.32 13.40 401 NA 2.43 16 10 200 7.26 13.51 400 NA 1.34 8.9 15 200 7.23 13.55 398 NA 0.67 4.9 20 200 7.21 13.49 397 NA 0.46 3.8 25 200 7.19 13.44 397 NA 0.37 2.9 1 gallon TW-10 5/10/2006 5 200 8.78 14.10 772 282 7.18 47.2 10 200 8.63 13.93 772 290 7.31 45.1 15 200 8.56 13.92 774 296 7.35 42.3 20 200 8.53 13.92 776 301 7.40 39.5 1 gallon CRA 045136 (12) Braidwood Generating Station Revision 1

Page 4 of 9 TABLE 4.6

SUMMARY

OF MONITORING WELL PURGING PARAMETERS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Minutes Pumping Volume (5)

Location Date Purged Rate pH Temperature Conductivity ORP DO (7) Turbidity Purged (1) (2)

(mL/min) (Std. Units) (°C) (3) (µS/cm) (4) (mV) (6)

(mg/L) (8) (NTU) (9) (gallons)

TB-1-2D 5/10/2006 5 200 7.68 14.49 493 NA 2.49 75 10 200 7.66 14.87 488 NA 2.53 32 15 200 7.57 14.99 486 NA 1.82 26 20 200 7.54 14.96 482 NA 2.08 15 25 200 7.52 14.96 482 NA 2.20 16 1 gallon MW-13 5/10/2006 5 200 7.92 14.57 2190 284 2.13 295 10 200 7.47 14.49 2780 295 1.86 169 15 200 7.18 14.46 3820 304 1.35 89.7 20 200 7.06 14.31 4620 309 1.07 62.3 25 200 6.95 14.19 5040 302 0.96 43 1 gallon TB-1-7D 5/10/2006 5 200 7.60 13.30 1660 NA 1.81 55 10 200 7.56 13.24 1650 NA 1.50 100 15 200 7.53 13.32 1640 NA 1.24 120 20 200 7.55 13.21 1630 NA 1.79 23 25 200 7.53 13.55 1640 NA 1.74 12 30 200 7.55 13.28 1630 NA 1.51 24 1.5 gallons TW-15 5/10/2006 5 200 8.69 12.57 662 283 6.89 3.75 10 200 7.68 12.40 645 293 7.01 1.67 15 200 7.28 12.40 650 303 7.01 1.46 1 gallon TW-25 5/10/2006 5 200 7.19 12.91 7200 NA 4.97 6.1 10 200 7.18 12.97 6550 NA 4.39 3.2 15 200 7.20 12.92 6100 NA 4.01 2.7 20 200 7.21 12.94 5940 NA 3.94 2.4 25 200 7.21 12.98 5860 NA 3.83 2.5 1 gallon MW-14 5/10/2006 5 200 9.21 11.88 563 288 8.92 2.39 10 200 7.97 11.66 524 305 8.90 1.97 15 200 7.83 11.59 522 309 8.90 1.46 20 200 7.61 11.55 517 314 9.10 1.33 1 gallon CRA 045136 (12) Braidwood Generating Station Revision 1

Page 5 of 9 TABLE 4.6

SUMMARY

OF MONITORING WELL PURGING PARAMETERS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Minutes Pumping Volume (5)

Location Date Purged Rate pH Temperature Conductivity ORP DO (7) Turbidity Purged (1) (2)

(mL/min) (Std. Units) (°C) (3) (µS/cm) (4) (mV) (6)

(mg/L) (8) (NTU) (9) (gallons)

TB-1-8D 5/10/2006 5 250 7.22 14.51 11580 NA 2.11 160 10 200 7.21 14.49 11560 NA 1.38 40 15 200 7.20 14.54 11460 NA 0.74 16 20 200 7.20 14.51 11470 NA 0.41 13 25 200 7.19 14.52 11520 NA 0.37 7.3 1.5 gallons TW-12 5/10/2006 5 200 7.90 14.89 2440 317 7.17 3.01 10 200 7.34 14.68 2440 322 7.35 4.95 15 200 7.13 14.63 2520 328 7.42 5.93 20 200 7.01 14.58 2840 332 7.60 4.02 25 200 6.95 14.54 3090 335 7.13 2.01 1 gallon MW-22 5/10/2006 5 250 7.79 14.44 717 NA 3.57 7.2 10 200 7.78 14.44 732 NA 2.72 4.5 15 200 7.76 14.89 740 NA 2.66 4.7 20 200 7.74 14.50 738 NA 2.76 2.4 1 gallon TW-24 5/12/2006 5 250 7.25 16.59 2 301 8.55 2.91 10 200 7.21 16.32 2 311 8.60 2.81 15 200 7.20 16.30 1 319 8.63 1.79 1 gallon MW-9 5/10/2006 5 200 7.53 12.00 2520 NA 1.21 2.6 10 200 7.53 11.99 2550 NA 1.05 2 15 200 7.52 11.95 2570 NA 1.01 1.9 1 gallon MW-4 5/11/2006 5 200 7.68 13.00 2610 334 0.94 11.1 10 200 7.08 13.02 2610 306 0.78 10 15 200 6.88 13.14 2630 271 0.74 6.94 20 200 6.82 13.01 2620 251 0.69 4.42 1 gallon TB-1-6D 5/11/2006 5 200 8.10 12.72 807 NA 3.05 19 10 200 8.05 12.65 851 NA 3.85 25 15 150 7.97 12.72 927 NA 3.33 19 20 150 7.90 12.73 928 NA 3.16 11 25 150 8.11 12.68 930 NA 3.85 5.4 1 gallon CRA 045136 (12) Braidwood Generating Station Revision 1

Page 6 of 9 TABLE 4.6

SUMMARY

OF MONITORING WELL PURGING PARAMETERS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Minutes Pumping Volume (5)

Location Date Purged Rate pH Temperature Conductivity ORP DO (7) Turbidity Purged (1) (2)

(mL/min) (Std. Units) (°C) (3) (µS/cm) (4) (mV) (6)

(mg/L) (8) (NTU) (9) (gallons)

MW-7 5/11/2006 5 200 7.08 14.56 4320 265 1.83 98.7 10 200 7.09 14.79 4050 267 1.57 94.2 15 200 7.20 14.83 3290 271 2.87 86.2 20 200 7.16 14.82 3110 276 2.92 48.3 1 gallon MW-BW-202 5/11/2006 5 250 7.55 12.01 1480 NA 1.47 85 10 250 7.54 12.02 1510 NA 1.46 27 15 250 7.55 12.00 1520 NA 0.68 13 20 250 7.54 12.02 1540 NA 0.51 6.9 25 250 7.54 12.01 1540 NA 0.88 4.6 1.5 gallons TW-21 5/11/2006 5 250 7.19 13.32 3040 303 3.10 64.1 10 200 7.16 13.19 3080 305 3.11 31.5 15 200 7.08 13.06 3090 307 3.38 13 20 200 7.03 12.02 2820 309 3.43 11 1 gallon MW-BW-202S 5/11/2006 5 250 7.48 12.42 3480 NA 1.56 24 10 250 7.35 12.38 3400 NA 0.81 13 15 250 7.34 12.39 3130 NA 0.55 7.9 20 250 7.35 12.39 2850 NA 0.39 6.7 25 250 7.35 12.36 2620 NA 0.38 4.7 30 250 7.35 12.31 2590 NA 0.36 3.7 MW-BW-203S 5/11/2006 5 200 7.54 11.02 962 317 4.64 129 10 200 7.54 11.08 997 318 4.27 60.2 15 200 7.53 11.12 1005 318 4.20 32.8 20 200 7.51 11.15 1025 320 3.99 13.11 25 200 7.51 11.16 1032 321 3.90 7.89 1 gallon MW-BW-201S 5/11/2006 5 250 7.62 11.07 893 NA 4.94 5.1 10 250 7.59 11.10 904 NA 4.73 3.6 15 250 7.58 11.09 915 NA 4.67 3.4 20 250 7.58 11.09 914 NA 4.68 1.7 1 gallon CRA 045136 (12) Braidwood Generating Station Revision 1

Page 7 of 9 TABLE 4.6

SUMMARY

OF MONITORING WELL PURGING PARAMETERS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Minutes Pumping Volume (5)

Location Date Purged Rate pH Temperature Conductivity ORP DO (7) Turbidity Purged (1) (2)

(mL/min) (Std. Units) (°C) (3) (µS/cm) (4) (mV) (6)

(mg/L) (8) (NTU) (9) (gallons)

MW-BW-203I 5/11/2006 5 200 8.24 11.68 1332 217 1.02 764 10 200 7.61 11.53 1324 216 0.77 113 15 200 7.30 11.50 1326 209 0.71 37.5 20 200 7.14 11.50 1332 207 0.65 26.2 25 200 7.07 11.48 1329 203 0.63 12.4 1 gallon MW-BW-201I 5/11/2006 5 200 7.20 12.42 1 267 9.31 na 10 200 7.19 11.54 1630 267 1.32 534 15 200 7.20 11.50 1680 271 0.85 57.5 20 200 7.17 11.47 1700 272 0.70 27.1 25 200 7.13 11.46 1710 274 0.62 11.2 1 gallon MW-BW-204I 5/12/2006 5 250 7.36 10.44 512 NA 2.27 900 10 250 7.34 10.35 510 NA 1.43 130 15 250 7.33 10.30 514 NA 0.96 60 20 250 7.33 10.33 520 NA 0.62 55 25 250 7.32 10.36 522 NA 0.45 31 30 250 7.31 10.35 523 NA 0.32 24 35 250 7.31 10.34 525 NA 0.34 18 2 gallons TW-26 5/12/2006 5 200 7.81 11.28 949 305 5.66 29.5 10 200 7.36 11.29 1043 314 5.51 21.5 15 200 7.17 11.34 1092 321 5.52 16.2 20 200 7.05 11.32 1113 325 5.51 11.6 1 gallon TW-18 5/12/2006 5 200 7.17 10.57 1780 341 1.06 10.73 10 200 7.16 10.64 1770 340 0.93 8.13 15 200 7.13 10.68 1760 326 0.77 4.47 1 gallon MW-BW-205I 5/12/2006 5 250 7.87 20.43 944 NA 0.19 16 10 250 7.88 20.37 944 NA 0.12 8.8 15 250 7.86 20.63 943 NA 0.10 5.4 20 250 7.87 20.74 941 NA 0.09 6.2 1 gallon CRA 045136 (12) Braidwood Generating Station Revision 1

Page 8 of 9 TABLE 4.6

SUMMARY

OF MONITORING WELL PURGING PARAMETERS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Minutes Pumping Volume (5)

Location Date Purged Rate pH Temperature Conductivity ORP DO (7) Turbidity Purged (1) (2)

(mL/min) (Std. Units) (°C) (3) (µS/cm) (4) (mV) (6)

(mg/L) (8) (NTU) (9) (gallons)

MW-BW-206I 5/12/2006 5 200 6.78 16.55 3580 233 1.11 na 10 200 6.61 16.06 3570 213 0.94 na 15 200 6.60 16.34 3580 208 0.88 799 20 200 6.54 16.21 3590 197 0.77 287 25 200 6.54 16.30 3600 189 0.72 147 1 gallon TW-24 5/15/2006 5 200 7.25 16.59 2000 303 8.55 2.91 10 200 7.21 16.32 2000 310 8.60 2.81 15 200 7.20 16.30 100 313 8.63 1.79 1 gallon TW-25 5/19/2006 5 200 6.89 12.90 457 310 6.21 45.7 10 200 6.87 12.80 463 316 6.15 32.1 15 200 6.85 12.90 471 318 6.13 19.6 1 gallon TW-26 5/19/2006 5 200 7.71 11.32 949 307 5.65 30.2 10 200 7.32 11.32 1010 310 5.62 24.1 15 200 7.05 11.33 1015 313 5.61 20.9 20 200 7.01 11.35 1023 315 5.61 14.6 1 gallon MW-BW-201BD 5/22/2006 5 200 7.59 12.00 432 732 1.56 1000 10 200 7.54 12.30 452 315 2.15 1000 15 200 7.55 12.20 455 217 3.19 929 20 200 7.37 12.50 432 214 3.27 572 25 200 7.28 12.70 415 210 3.33 453 30 200 7.27 12.90 417 208 3.34 193 1.5 gallons MW-BW-208BD 7/28/2006 10 250 7.15 19.53 419 333 2.17 cloudy 15 250 7.39 17.75 429 319 2.71 cloudy 20 250 7.41 17.06 422 311 2.53 cloudy 25 250 7.50 17.70 411 305 3.18 cloudy 30 250 7.46 17.09 408 307 2.76 cloudy 35 250 7.58 17.10 400 302 2.70 cloudy 40 250 7.57 17.05 400 302 2.40 cloudy 45 250 7.60 17.66 402 301 2.65 cloudy 50 250 7.64 17.09 401 299 2.72 cloudy 55 250 7.63 17.13 403 302 2.61 slightly cloudy 3 gallons MW-BW-207I 7/28/2006 10 250 8.20 24.73 1290 245 0.18 cloudy CRA 045136 (12) Braidwood Generating Station Revision 1

Page 9 of 9 TABLE 4.6

SUMMARY

OF MONITORING WELL PURGING PARAMETERS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Minutes Pumping Volume (5)

Location Date Purged Rate pH Temperature Conductivity ORP DO (7) Turbidity Purged (1) (2)

(mL/min) (Std. Units) (°C) (3) (µS/cm) (4) (mV) (6)

(mg/L) (8) (NTU) (9) (gallons) 15 250 8.25 24.83 1292 230 0.16 slightly cloudy 20 250 8.31 24.98 1295 216 0.15 slightly cloudy 25 250 8.32 24.93 1293 190 0.15 clear 30 250 8.30 24.93 1289 185 0.14 clear 1.5 gallons Notes:

(1) mL/min - milliliters per minute (6) mV - millivolts (2) Std. Units - standard units (7) DO - dissolved oxygen (3) °C - degrees Celsius (8) mg/L - milligrams per liter (4) µS/cm - microsiemens per centimet (9) NTU - nephelometric turbidity units (5) ORP - oxidation-reduction potential The last three readings are provided in the table CRA 045136 (12) Braidwood Generating Station Revision 1

Page 1 of 1 TABLE 5.1

SUMMARY

OF CALCULATED VERTICAL GRADIENTS FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Top of Bottom of Mid-Point 31-Jul-06 Sample Screen Screen of Screen Water Vertical Location Elevation Elevation Elevation Level Gradient (ft AMSL) (ft AMSL) (ft AMSL) (ft AMSL) (ft/ft) (1)

MW-BW-201S 594.97 584.97 589.97 592.36 0.116 MW-BW-201I 586.02 576.02 581.02 591.32 MW-BW-202S 595.87 585.87 590.87 593.75 0.004 MW-BW-202I 585.72 575.72 580.72 593.71 MW-BW-203S 594.14 584.14 589.14 594.68 -0.002 MW-BW-203I 583.95 573.95 578.95 594.70 TB-1-4D 582.45 577.45 579.45 595.48 0.005 TW-3 597.60 587.60 592.6 595.55 TB-1-2D 580.41 575.41 577.91 593.58 0.167 MW-2 597.80 587.80 592.8 596.07 MW-11 594.10 584.10 589.1 593.04 0.118 TB-1-6D 577.84 572.84 575.34 591.41 MW-6 594.10 584.10 589.1 595.69 -0.074 TB-1-3D 589.70 584.70 587.2 595.83 MW-BW-207I 564.59 554.59 559.59 592.24 0.100 TW-3 597.60 587.60 592.6 595.55 Notes:

ft AMSL feet above mean sea level.

(1) Positive value denotes downward vertical gradient; negative value denotes upward vertical gradient.

CRA 045136 (12) Braidwood Generating Station Revision 1

Page 1 of 1 TABLE 5.2 ANALYTICAL RESULTS

SUMMARY

- TRITIUM IN GROUNDWATER FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Location Sample Identification QC Sample Sample Date Tritium (pCi/L) Result Error MW-2 WG-BW-051006-JL-017 5/10/2006 ND (200) -

MW-4 WG-BW-051106-MS-030 5/11/2006 ND (200) -

MW-5 WG-BW-050906-MS-010 5/9/2006 ND (200) -

MW-6 WG-BW-050906-MS-002 5/9/2006 288 +/-121 MW-7 WG-BW-051106-MS-032 5/11/2006 214 +/-101 MW-9 WG-BW-051106-JL-029 5/11/2006 311 +/-118 MW-9 WG-BW-051106-JL-031 Duplicate (029) 5/11/2006 441 +/-131 MW-11 WG-BW-051006-MS-012 5/10/2006 ND (200) -

MW-13 WG-BW-051006-MS-018 5/10/2006 ND (200) -

MW-14 WG-BW-051006-MS-024 5/10/2006 ND (200) -

MW-22 WG-BW-051106-JL-027 5/11/2006 ND (200) -

MW-BW-201BD WG-BW-052206-MB-056 5/22/2006 ND (200) -

MW-BW-201BD WG-BW-052206-MB-057 Duplicate (056) 5/22/2006 ND (200) -

MW-BW-201I WG-BW-051106-MS-040 5/11/2006 261 +/-104 MW-BW-201I WG-BW-051106-MS-042 Duplicate (040) 5/11/2006 ND (200) -

MW-BW-201S WG-BW-051106-JL-039 5/11/2006 244 +/-100 MW-BW-202I WG-BW-051106-JL-035 5/11/2006 ND (200) -

MW-BW-202S WG-BW-051106-JL-037 5/11/2006 ND (200) -

MW-BW-203I WG-BW-051106-MS-038 5/11/2006 ND (200) -

MW-BW-203S WG-BW-051106-MS-036 5/11/2006 ND (200) -

MW-BW-204I WG-BW-051206-JL-041 5/12/2006 ND (200) -

MW-BW-205I WG-BW-051206-JL-043 5/12/2006 221 +/-102 MW-BW-206I WG-BW-051206-MS-048 5/12/2006 ND (200) -

MW-BW-207I WG-BW-207-072806-JL-101 7/28/2006 438 +/-133 MW-BW-207I WG-BW-207-072806-JL-102 Duplicate (101) 7/28/2006 471 +/-137 MW-BW-208BD WG-BW-208D-072806-JL-100 7/28/2006 ND (200) -

TB-1-1D WG-BW-050906-JL-005 5/9/2006 ND (200) -

TB-1-2D WG-BW-051006-JL-019 5/10/2006 ND (200) -

TB-1-3D WG-BW-050906-MS-004 5/9/2006 285 +/-120 TB-1-4D WG-BW-051006-JL-013 5/10/2006 719 +/-150 TB-1-5D WG-BW-050906-JL-003 5/9/2006 443 +/-122 TB-1-6D WG-BW-051106-JL-033 5/11/2006 ND (200) -

TB-1-7D WG-BW-051006-JL-021 5/10/2006 ND (200) -

TB-1-8D WG-BW-051006-JL-025 5/10/2006 ND (200) -

TB-1-9D WG-BW-050906-JL-001 5/9/2006 ND (200) -

TB-1-10D WG-BW-051006-JL-011 Duplicate (009) (1) 5/10/2006 ND (200) -

TW-3 WG-BW-051006-JL-015 5/10/2006 1040 +/-172 TW-6 WG-BW-050906-MS-008 5/9/2006 775 +/-136 TW-8 WG-BW-050906-MS-006 5/9/2006 ND (200) -

TW-10 WG-BW-051006-MS-016 5/10/2006 ND (200) -

TW-12 WG-BW-051006-MS-026 5/10/2006 ND (200) -

TW-15 WG-BW-051006-MS-020 5/10/2006 ND (200) -

TW-15 WG-BW-051006-MS-022 Duplicate (020) 5/10/2006 ND (200) -

TW-16 WG-BW-050906-JL-007 5/9/2006 893 +/-145 TW-18 WG-BW-051206-MS-046 5/12/2006 ND (200) -

TW-21 WG-BW-051106-MS-034 5/11/2006 211 +/-95.6 TW-23 WG-BW-051006-MS-014 5/10/2006 ND (200) -

TW-24 WG-BW-051506-MB-050 5/15/2006 204 +/-112 TW-24 WG-BW-051506-MB-052 Duplicate (050) 5/15/2006 200 +/-111 TW-25 WG-BW-051906-MB-054 5/19/2006 ND (200) -

TW-26 WG-BW-051206-MS-044 5/12/2006 ND (200) -

TW-26 WG-BW-051906-MB-055 5/19/2006 ND (200) -

Notes:

Samples analyzed by: Teledyne Brown Engineering, Inc.

QC - Quality Control (1) - Sample container for original tritium analysis lost in transit.

ND ( ) - Non-detect; value in parentheses is the LLD.

LLD - Lower limit of detection.

- - Non-detect value, +/- value not reported.

q014AI-XT2-WG WS-0506 0706 Groundwater Surface Water-37-TH 8/9/2006 CRA 045136 (12) Braidwood Generating Station Revision 1

Page 1 of 1 TABLE 5.4 ANALYTICAL RESULTS

SUMMARY

- TRITIUM IN SURFACE WATER FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Location Sample Identification Sample Date Tritium (pCi/L) Result Error SG-BW-101 SW-BW-051706-MB-101 5/17/2006 398 +/-129 SG-BW-102 SW-BW-051706-MB-102 5/17/2006 365 +/-120 SG-BW-103 SW-BW-051706-MB-103 5/17/2006 230 +/-114 SG-BW-104 SW-BW-051706-MB-104 5/17/2006 ND (200) -

SG-BW-105 SW-BW-051706-MB-105 5/17/2006 ND (200) -

SG-BW-106 SW-BW-051706-MB-106 5/17/2006 ND (200) -

Notes:

Samples analyzed by: Teledyne Brown Engineering, Inc.

ND ( ) - Non-detect; value in parentheses is the LLD.

LLD - Lower limit of detection.

- - Non-detect value, +/- value not reported.

q014AI-XT2-WG WS-0506 0706 Groundwater Surface Water-37-TH 8/9/2006 CRA 045136 (12) Braidwood Generating Station Revision 1

Page 1 of 2 TABLE 5.6 EXISTING ANALYTICAL RESULTS

SUMMARY

- TRITIUM IN GROUNDWATER FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Location Sample Identification QC Sample Laboratory Analysis Laboratory Sample Date Tritium (pCi/L) Result Error MW-2 GW-030806-MB-MW-2 EI 3/8/2006 ND (200) -

MW-2 WG-BW-051006-JL-017 TBE 5/10/2006 ND (200) -

MW-4 GW-030806-MB-MW-4 EI 3/8/2006 ND (200) -

MW-4 GW-050206-MB-MW-4 EI 5/2/2006 390 +/-95 MW-4 WG-BW-051106-MS-030 TBE 5/11/2006 ND (200) -

MW-5 GW-050206-MB-MW-5 EI 5/2/2006 206 +/-87 MW-5 WG-BW-050906-MS-010 TBE 5/9/2006 ND (200) -

MW-6 GW-030806-MB-MW-6 EI 3/8/2006 348 +/-107 MW-6 WG-BW-050906-MS-002 TBE 5/9/2006 288 +/-121 MW-7 WG-BW-051106-MS-032 TBE 5/11/2006 214 +/-101 MW-9 WG-BW-051106-JL-029 TBE 5/11/2006 311 +/-118 MW-9 WG-BW-051106-JL-031 Duplicate (029) TBE 5/11/2006 441 +/-131 MW-11 WG-BW-051006-MS-012 TBE 5/10/2006 ND (200) -

MW-13 WG-BW-051006-MS-018 TBE 5/10/2006 ND (200) -

MW-14 WG-BW-051006-MS-024 TBE 5/10/2006 ND (200) -

MW-22 WG-BW-051106-JL-027 TBE 5/11/2006 ND (200) -

MW-BW-201BD WG-BW-052206-MB-056 TBE 5/22/2006 ND (200) -

MW-BW-201BD WG-BW-052206-MB-057 Duplicate (056) TBE 5/22/2006 ND (200) -

MW-BW-201I WG-BW-051106-MS-040 TBE 5/11/2006 261 +/-104 MW-BW-201I WG-BW-051106-MS-042 Duplicate (040) TBE 5/11/2006 ND (200) -

MW-BW-201S WG-BW-051106-JL-039 TBE 5/11/2006 244 +/-100 MW-BW-202I WG-BW-051106-JL-035 TBE 5/11/2006 ND (200) -

MW-BW-202S WG-BW-051106-JL-037 TBE 5/11/2006 ND (200) -

MW-BW-203I WG-BW-051106-MS-038 TBE 5/11/2006 ND (200) -

MW-BW-203S WG-BW-051106-MS-036 TBE 5/11/2006 ND (200) -

MW-BW-204I WG-BW-051206-JL-041 TBE 5/12/2006 ND (200) -

MW-BW-205I WG-BW-051206-JL-043 TBE 5/12/2006 221 +/-102 MW-BW-206I WG-BW-051206-MS-048 TBE 5/12/2006 ND (200) -

TB-1-1D GW-011106-MB-TB-1D EI 1/11/2006 ND (200) -

TB-1-1D GW-030806-MB-TB-1D EI 3/8/2006 ND (200) -

TB-1-1D WG-BW-050906-JL-005 TBE 5/9/2006 ND (200) -

TB-1-2D GW-011106-MB-TB-2D EI 1/11/2006 ND (200) -

TB-1-2D GW-030806-MB-TB-2D EI 3/8/2006 ND (200) -

TB-1-2D WG-BW-051006-JL-019 TBE 5/10/2006 ND (200) -

TB-1-3D GW-011106-MB-TB-3D EI 1/11/2006 265 +/-117 TB-1-3D GW-030806-MB-TB-3D EI 3/8/2006 301 +/-90 TB-1-3D WG-BW-050906-MS-004 TBE 5/9/2006 285 +/-120 TB-1-4D GW-011106-MB-TB-4D EI 1/11/2006 622 +/-128 TB-1-4D GW-030806-EV-TB-4D EI 3/8/2006 582 +/-111 TB-1-4D WG-BW-051006-JL-013 TBE 5/10/2006 719 +/-150 TB-1-5D GW-011106-MB-TB-5D EI 1/11/2006 ND (200) -

TB-1-5D GW-030806-MB-TB-5D EI 3/8/2006 ND (200) -

TB-1-5D WG-BW-050906-JL-003 TBE 5/9/2006 443 +/-122 TB-1-6D GW-011106-MB-TB-6D EI 1/11/2006 ND (200) -

TB-1-6D GW-030806-MB-TB-6D EI 3/8/2006 ND (200) -

TB-1-6D WG-BW-051106-JL-033 TBE 5/11/2006 ND (200) -

TB-1-7D GW-011106-MB-TB-7D EI 1/11/2006 ND (200) -

TB-1-7D GW-030806-EV-TB-7D EI 3/8/2006 ND (200) -

TB-1-7D WG-BW-051006-JL-021 TBE 5/10/2006 ND (200) -

TB-1-8D GW-022406-MB-TB1-8D EI 2/24/2006 ND (200) -

TB-1-8D GW-030806-MB-TB-8D EI 3/8/2006 ND (200) -

TB-1-8D WG-BW-051006-JL-025 TBE 5/10/2006 ND (200) -

TB-1-9D GW-022406-MB-TB1-9D EI 2/24/2006 ND (200) -

TB-1-9D GW-030806-EV-TB1-9D EI 3/8/2006 ND (200) -

TB-1-9D WG-BW-050906-JL-001 TBE 5/9/2006 ND (200) -

TB-1-10D GW-022406-MB-TB1-10D EI 2/24/2006 ND (200) -

CRA 045136 (12) Braidwood Generating Station

Page 2 of 2 TABLE 5.6 EXISTING ANALYTICAL RESULTS

SUMMARY

- TRITIUM IN GROUNDWATER FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Location Sample Identification QC Sample Laboratory Analysis Laboratory Sample Date Tritium (pCi/L) Result Error TB-1-10D GW-030806-EV-TB-1-10D EI 3/8/2006 ND (200) -

TB-1-10D WG-BW-051006-JL-011 Duplicate (009) (1) TBE 5/10/2006 ND (200) -

TB-1-11D GW-031706-MB-TB1-11D EI 3/17/2006 ND (200) -

TB-1-12D GW-031606-MB-TB1-12D EI 3/16/2006 ND (200) -

TB-1-13D GW-031606-MB-TB1-13D EI 3/16/2006 ND (200) -

TB-1-14D GW-031706-MB-TB1-14D EI 3/17/2006 ND (200) -

TBRW-1 GW-031706-MB-TBRW-1 EI 3/17/2006 ND (200) -

TBRW-1 GW-050206-MB-TBRW-1 EI 5/2/2006 ND (200) -

TBRW-2 GW-031706-MB-TBRW-2 EI 3/17/2006 ND (200) -

TBRW-2 GW-050206-MB-TBRW-2 EI 5/2/2006 ND (200) -

TBRW-3 GW-031706-MB-TBRW-3 EI 3/17/2006 ND (200) -

TBRW-3 GW-050206-MB-TBRW-3 EI 5/2/2006 ND (200) -

TW-3 GW-030806-EV-TW-3 EI 3/8/2006 302 +/-101 TW-3 GW-030806-EV-TW-3-recount Recount EI 3/8/2006 330 +/-103 TW-3 WG-BW-051006-JL-015 TBE 5/10/2006 1040 +/-172 TW-6 GW-030806-EV-TW-6 EI 3/8/2006 880 +/-110 TW-6 GW-030806-EV-TW-6-recount Recount EI 3/8/2006 676 +/-117 TW-6 WG-BW-050906-MS-008 TBE 5/9/2006 775 +/-136 TW-8 GW-030806-EV-TW-8 EI 3/8/2006 ND (200) -

TW-8 WG-BW-050906-MS-006 TBE 5/9/2006 ND (200) -

TW-10 WG-BW-051006-MS-016 TBE 5/10/2006 ND (200) -

TW-12 WG-BW-051006-MS-026 TBE 5/10/2006 ND (200) -

TW-15 WG-BW-051006-MS-020 TBE 5/10/2006 ND (200) -

TW-15 WG-BW-051006-MS-022 Duplicate (020) TBE 5/10/2006 ND (200) -

TW-16 GW-050206-MB-TW-16 EI 5/2/2006 368 +/-94 TW-16 WG-BW-050906-JL-007 TBE 5/9/2006 893 +/-145 TW-18 WG-BW-051206-MS-046 TBE 5/12/2006 ND (200) -

TW-21 WG-BW-051106-MS-034 TBE 5/11/2006 211 +/-95.6 TW-23 WG-BW-051006-MS-014 TBE 5/10/2006 ND (200) -

TW-24 WG-BW-051506-MB-050 TBE 5/15/2006 204 +/-112 TW-24 WG-BW-051506-MB-052 Duplicate (050) TBE 5/15/2006 200 +/-111 TW-25 GW-030806-EV-TW-25 EI 3/8/2006 ND (200) -

TW-25 WG-BW-051906-MB-054 TBE 5/19/2006 ND (200) -

TW-26 WG-BW-051206-MS-044 TBE 5/12/2006 ND (200) -

TW-26 WG-BW-051906-MB-055 TBE 5/19/2006 ND (200) -

Seep* Turbine Building Basement EI 12/13/2005 2,825 +/-181 Notes:

EI - Environmental, Inc.

TBE - Teledyne Brown Engineering, Inc.

QC - Quality Control (1) - Sample container for original tritium analysis lost in transit.

ND - Non-detect at associated value.

- Non-detect value, +/- value not reported.

• This seep sample was collected from the west side of the Turbine Building within the basement. The water seeps into the basement on an intermittent basis. This water sample may not represent groundwater.

CRA 045136 (12) Braidwood Generating Station

Page 1 of 1 TABLE 5.7 EXISTING ANALYTICAL RESULTS

SUMMARY

- TRITIUM IN SURFACE WATER FLEETWIDE ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Sample Location Sample Date Sample Identification Tritium (pCi/L) Result Error Ditch at Culvert 12/22/2005 Ditch at Culvert~12/22/05 1007 +/-128 Ditch at Culvert 2/15/2006 GW-021506-MB-Ditch at Culvert 468 +/-99 Ditch at Culvert 2/22/2006 GW-022206-MB-Ditch at Culvert 306 +/-95 Ditch at Culvert 3/1/2006 GW-030106-MB-Ditch at Culvert 670 +/-119 Ditch at Culvert 3/7/2006 GW-030706-MB-Ditch at Culvert 311 +/-91 Ditch at Culvert 3/15/2006 GW-031506-MB-Ditch at Culvert 458 +/-96 Ditch at Culvert 3/22/2006 GW-032206-MB-Ditch at Culvert 889 +/-119 Ditch at Culvert 3/29/2006 GW-032906-MB-Ditch at Culvert 598 +/-109 Ditch at Culvert 4/5/2006 GW-040506-MB-Ditch at Culvert 704 +/-110 Ditch at Culvert 4/12/2006 GW-041206-MB-Ditch at Culvert 664 +/-102 Ditch at Culvert 4/19/2006 GW-041906-MB-Ditch at Culvert 423 +/-90 Ditch at Culvert 4/26/2006 GW-042606-JL-Ditch at Culvert 633 +/-104 Ditch at Culvert 5/17/2006 GW-051706-MB-Ditch at Culvert 368 +/-101 Ditch by Alpha Gate 12/15/2005 Ditch by Alpha Gate~12/15/05 1 +/-82 Ditch by Alpha Gate 12/22/2005 Ditch by Alpha Gate~12/22/05 13 +/-82 Ditch by Alpha Gate 12/29/2005 Ditch by Alpha Gate~12/29/05 11 +/-93 Ditch by Alpha Gate 1/5/2006 Ditch by Alpha Gate~1/5/06 7 +/-93 Ditch by Alpha Gate 1/12/2006 Ditch by Alpha Gate~1/12/06 -30 +/-95 Ditch by Alpha Gate 1/19/2006 Ditch by Alpha Gate~1/19/06 107 +/-100 Ditch by Alpha Gate 1/26/2006 Ditch by Alpha Gate~1/26/06 77 +/-98 Ditch by Alpha Gate 2/2/2006 Ditch by Alpha Gate~2/2/06 23 +/-96 Ditch by Alpha Gate 2/9/2006 Ditch by Alpha Gate~2/9/06 201 +/-86 Ditch by Alpha Gate 2/16/2006 Ditch by Alpha Gate~2/16/06 123 +/-100 Ditch by Alpha Gate 2/23/2006 Ditch by Alpha Gate~2/23/06 166 +/-84 Ditch by GW-1 2/15/2006 GW-021506-MB-Ditch by GW-1 36 +/-82 Ditch by GW-1 2/22/2006 GW-022206-MB-Ditch by GW-1 100 +/-91 Ditch by GW-1 3/1/2006 GW-030106-MB-Ditch by GW-1 -10 +/-80 Ditch by GW-1 3/7/2006 GW-030706-MB-Ditch by GW-1 56 +/-80 Ditch by GW-1 3/15/2006 GW-031506-MB-Ditch by GW-1 96 +/-81 Ditch by GW-1 3/22/2006 GW-032206-MB-Ditch by GW-1 70 +/-82 Ditch by GW-1 3/29/2006 GW-032906-MB-Ditch by GW-1 -166 +/-79 Ditch by GW-1 4/5/2006 GW-040506-MB-Ditch by GW-1 122 +/-89 Ditch by GW-1 4/12/2006 GW-041206-MB-Ditch by GW-1 89 +/-79 Ditch by GW-1 4/19/2006 GW-041906-MB-Ditch by GW-1 -30 +/-97 Ditch by GW-1 4/26/2006 GW-042606-JL-Ditch at GW-1 152 +/-85 Ditch by GW-1 5/17/2006 GW-051706-MB-DITCHBYGW-1 105 +/-108 Oil Water Sep 4/19/2006 GW-041906-MB-Oil Water Sep 86 +/-75 Oil Water Sep 5/2/2006 GW-050206-MB-OILWATERSEP 368 +/-94 Oil Water Sep 5/18/2006 Oil Separator~051806 394 +/-99 Oil Water Sep 6/2/2006 Oil Separator~060206 199 +/-85 Note:

Samples analyzed by Environmental, Inc.

CRA 045136 (12) Braidwood Generating Station

Revision 1 APPENDIX A MONITORING WELL LOGS 045136 (12) Braidwood Generating Station

STRATIGRAPHIC AND INSTRUMENTATION LOG (OVERBURDEN) Page 1 of 2 PROJECT NAME: BRAIDWOOD GENERATING STATION HOLE DESIGNATION: MW-BW-207I PROJECT NUMBER: 45136-20 DATE COMPLETED: July 13, 2006 CLIENT: EXELON GENERATION COMPANY LLC DRILLING METHOD: Sonic LOCATION: BRAIDWOOD, ILLINOIS FIELD PERSONNEL: N. KUHL ELEV. SAMPLE DEPTH STRATIGRAPHIC DESCRIPTION & REMARKS ft Monitoring Well ft BGS NUMBER INTERVAL 'N' VALUE AMSL REC (%)

GROUND SURFACE 599.59 Asphalt 599.09 SP - Sand, brown 2

4

- saturated at 5.0ft BGS 6

8 10 589.59 Fill, gray, poorly graded, medium grained sand, saturated 12 14 Grout 16 18 20 22 OVERBURDEN LOG 45136-20.GPJ CRA_CORP.GDT 8/9/06 24

- brown at 25.0ft BGS 26 28 Bentonite Chips NOTES: MEASURING POINT ELEVATIONS MAY CHANGE; REFER TO CURRENT ELEVATION TABLE

STRATIGRAPHIC AND INSTRUMENTATION LOG (OVERBURDEN) Page 2 of 2 PROJECT NAME: BRAIDWOOD GENERATING STATION HOLE DESIGNATION: MW-BW-207I PROJECT NUMBER: 45136-20 DATE COMPLETED: July 13, 2006 CLIENT: EXELON GENERATION COMPANY LLC DRILLING METHOD: Sonic LOCATION: BRAIDWOOD, ILLINOIS FIELD PERSONNEL: N. KUHL ELEV. SAMPLE DEPTH STRATIGRAPHIC DESCRIPTION & REMARKS ft Monitoring Well ft BGS NUMBER INTERVAL 'N' VALUE AMSL REC (%)

- cobble seam at 30.0ft BGS 32 34 Sand 36 38 40 559.59 Sand/gravel fill, dry concrete 42 2" 0/ PVC Well Screen 44 555.59 CL - Clay, silty 554.09 Shale, hard 46 48 50 549.59 END OF BOREHOLE @ 50.0ft BGS WELL DETAILS Screened interval:

564.59 to 554.59ft AMSL 52 35.00 to 45.00ft BGS OVERBURDEN LOG 45136-20.GPJ CRA_CORP.GDT 8/9/06 Length: 10ft Diameter: 2in Slot Size: 10 54 Material: PVC Sand Pack:

567.59 to 549.59ft AMSL 32.00 to 50.00ft BGS 56 Material: Sand 58 NOTES: MEASURING POINT ELEVATIONS MAY CHANGE; REFER TO CURRENT ELEVATION TABLE

STRATIGRAPHIC AND INSTRUMENTATION LOG (OVERBURDEN) Page 1 of 5 PROJECT NAME: BRAIDWOOD GENERATING STATION HOLE DESIGNATION: MW-BW-208BD PROJECT NUMBER: 45136-20 DATE COMPLETED: July 13, 2006 CLIENT: EXELON GENERATION COMPANY LLC DRILLING METHOD: Sonic LOCATION: BRAIDWOOD, ILLINOIS FIELD PERSONNEL: N. KUHL DEPTH DEPTH SAMPLE STRATIGRAPHIC DESCRIPTION & REMARKS Monitoring Well ft BGS ft BGS NUMBER INTERVAL REC (%) 'N' VALUE TOP OF CASING 601.98 SP - Sand, brown 2

4 6

8 10 12 14 16 18 20 Grout 22 OVERBURDEN LOG 45136-20.GPJ CRA_CORP.GDT 8/9/06 24 26 28 NOTES: MEASURING POINT ELEVATIONS MAY CHANGE; REFER TO CURRENT ELEVATION TABLE

STRATIGRAPHIC AND INSTRUMENTATION LOG (OVERBURDEN) Page 2 of 5 PROJECT NAME: BRAIDWOOD GENERATING STATION HOLE DESIGNATION: MW-BW-208BD PROJECT NUMBER: 45136-20 DATE COMPLETED: July 13, 2006 CLIENT: EXELON GENERATION COMPANY LLC DRILLING METHOD: Sonic LOCATION: BRAIDWOOD, ILLINOIS FIELD PERSONNEL: N. KUHL DEPTH DEPTH SAMPLE STRATIGRAPHIC DESCRIPTION & REMARKS Monitoring Well ft BGS ft BGS NUMBER INTERVAL REC (%) 'N' VALUE CL - clay, silty, gray 30.00 32 34 36 38 40 END OF OVERBURDEN HOLE @ 40.0ft BGS 42 44 46 48 50 52 OVERBURDEN LOG 45136-20.GPJ CRA_CORP.GDT 8/9/06 54 56 58 NOTES: MEASURING POINT ELEVATIONS MAY CHANGE; REFER TO CURRENT ELEVATION TABLE

STRATIGRAPHIC AND INSTRUMENTATION LOG (BEDROCK) Page 3 of 5 PROJECT NAME: BRAIDWOOD GENERATING STATION HOLE DESIGNATION: MW-BW-208BD PROJECT NUMBER: 45136-20 DATE COMPLETED: July 13, 2006 CLIENT: EXELON GENERATION COMPANY LLC DRILLING METHOD: Sonic LOCATION: BRAIDWOOD, ILLINOIS FIELD PERSONNEL: N. KUHL CORE DEPTH DEPTH STRATIGRAPHIC DESCRIPTION & REMARKS Monitoring Well ft BGS ft BGS RUN RQD %

NUMBER RECOVERY %

40 40.00 Shale, gray 42 44 46 48 50 52 54 56 58 60 Grout BEDROCK LOG 45136-20.GPJ CRA_CORP.GDT 8/9/06 62 64 66 NOTES: MEASURING POINT ELEVATIONS MAY CHANGE; REFER TO CURRENT ELEVATION TABLE

STRATIGRAPHIC AND INSTRUMENTATION LOG (BEDROCK) Page 4 of 5 PROJECT NAME: BRAIDWOOD GENERATING STATION HOLE DESIGNATION: MW-BW-208BD PROJECT NUMBER: 45136-20 DATE COMPLETED: July 13, 2006 CLIENT: EXELON GENERATION COMPANY LLC DRILLING METHOD: Sonic LOCATION: BRAIDWOOD, ILLINOIS FIELD PERSONNEL: N. KUHL CORE DEPTH DEPTH STRATIGRAPHIC DESCRIPTION & REMARKS Monitoring Well ft BGS ft BGS RUN RQD %

NUMBER RECOVERY %

70 72 74 76 78 80 Bentonite Chips 82 84 Sand 86 88 90 2" 0/ PVC Well Screen BEDROCK LOG 45136-20.GPJ CRA_CORP.GDT 8/9/06 92 94 96 NOTES: MEASURING POINT ELEVATIONS MAY CHANGE; REFER TO CURRENT ELEVATION TABLE

STRATIGRAPHIC AND INSTRUMENTATION LOG (BEDROCK) Page 5 of 5 PROJECT NAME: BRAIDWOOD GENERATING STATION HOLE DESIGNATION: MW-BW-208BD PROJECT NUMBER: 45136-20 DATE COMPLETED: July 13, 2006 CLIENT: EXELON GENERATION COMPANY LLC DRILLING METHOD: Sonic LOCATION: BRAIDWOOD, ILLINOIS FIELD PERSONNEL: N. KUHL CORE DEPTH DEPTH STRATIGRAPHIC DESCRIPTION & REMARKS Monitoring Well ft BGS ft BGS RUN RQD %

NUMBER RECOVERY %

- trace sandstone at 98.0ft BGS 100 102 102.00 END OF BOREHOLE @ 102.0ft BGS WELL DETAILS Screened interval:

85.00 to 100.00ft BGS 104 Length: 15ft Diameter: 2in Slot Size: 10 Material: PVC 106 Sand Pack:

82.00 to 102.00ft BGS Material: Sand 108 110 112 114 116 118 120 BEDROCK LOG 45136-20.GPJ CRA_CORP.GDT 8/9/06 122 124 126 NOTES: MEASURING POINT ELEVATIONS MAY CHANGE; REFER TO CURRENT ELEVATION TABLE

Revision 0 APPENDIX B PRIVATE WATER WELL INVENTORY RECORDS (CRA, MARCH 2006) 045136 (12) Braidwood Generating Station

TABLE B.1 Page 1 of 5

SUMMARY

OF PRIVATE WELL LOCATIONS FLEETWIDE TRITIUM ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Location X-coord Y-coord PW-8 69990.437 86292.616 PWS-105 72609.760 84740.620 PWS-201B 72599.192 84017.487 PWS-104 72321.130 84616.820 PWN-103 72237.120 85936.930 PWS-101 72171.640 85070.240 PW-409 72106.054 85345.562 PWN-102 72073.780 85953.130 PW-411 72044.983 84695.237 PW-410 72029.555 85013.795 PWS-102 71952.970 84886.930 PWS-103 71940.060 84650.450 PWN-202 71931.210 86935.330 PWN-101 71858.950 85920.420 PW-403 71852.715 87016.198 PW-406 71852.715 86649.659 PW-407 71848.974 86567.375 PW-416 71845.234 86862.850 PW-900 71802.536 86662.790 PW-600 71801.847 88801.973 PWN-201 71701.864 85717.075 PW-408 71643.264 86500.052 PW-418 71643.264 86088.631 PW-419 71639.524 85763.235 PW-405 71624.563 86806.747 PW-6 71605.796 85391.696 PW-420 71602.122 85254.570 PW-12 71587.852 86707.365 PW-404 71583.421 87132.143 PW-13 71546.472 86841.803 PW-6P 71388.441 85039.761 PW-401 71385.191 88665.620 PW-402 71329.088 88014.827 PW-530 71289.638 88990.609 PW-5 71067.841 85419.750 PW-414 71011.173 88710.502 PW-415 70996.212 88863.850 PW-7 70885.511 86008.244 PW-422-Pond 70708.217 87846.519 SW-7 70580.707 88711.098 PW-422 70405.262 88033.528 PW-400 70337.939 88673.100 PW-3 69587.058 84332.752 PW-2 69372.937 84385.856 PW-11 69334.651 86909.209 PW-1 69272.431 84296.473 PW-9 69244.481 86394.565 CRA 45136 (12) Braidwood Generating Station

TABLE B.1 Page 2 of 5

SUMMARY

OF PRIVATE WELL LOCATIONS FLEETWIDE TRITIUM ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Location X-coord Y-coord PW-413 69163.521 88609.517 PW-604-Pond 69024.152 93493.943 PW-603 69024.152 93493.943 PW-602 69024.152 93512.320 PW-431 68697.487 84158.754 PW-423-Trailer 68580.051 86803.007 PW-10 68549.643 86613.142 PW-423 68381.822 88669.360 PW-15 68374.868 85430.394 PW-4 68105.605 85295.707 PW-14 68000.667 85361.724 PWG-005 67790.817 90404.436 PW-614 66594.462 87475.150 PW-540 66064.576 87131.387 PWG-184 63950.203 81324.681 PWG-080 63943.422 81783.803 PWG-143 63914.529 81998.729 PWG-142 63892.440 82101.811 PWG-096 63882.426 81783.803 PWG-182 63871.101 81333.470 PWG-181 63859.382 81506.324 PWG-105 63848.878 82351.066 PWG-104 63845.829 82457.809 PWG-041 63832.868 83173.340 PWG-095 63824.480 81780.753 PWG-141 63821.264 81992.593 PWG-031 63808.704 82699.370 PWG-600 63781.890 82113.025 PWG-180 63780.279 81330.540 PWG-102 63772.633 82451.710 PWG-094 63754.335 81777.703 PWG-179 63753.912 81491.675 PWG-038 63748.755 83174.927 PWG-027 63682.535 82703.958 PWG-026 63680.241 82839.302 PWG-139 63677.686 81982.776 PWG-099 63668.940 82360.216 PWG-093 63665.890 81768.554 PWG-176 63663.090 81491.675 PWG-177 63660.161 81318.822 PWG-138 63650.688 82095.675 PWG-025 63643.538 82706.252 PWG-022 63636.656 82850.772 PWG-091 63598.795 81762.454 PWG-136 63595.466 81972.959 PWG-234 63595.438 81888.498 PWG-032 63595.364 83169.634 CRA 45136 (12) Braidwood Generating Station

TABLE B.1 Page 3 of 5

SUMMARY

OF PRIVATE WELL LOCATIONS FLEETWIDE TRITIUM ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Location X-coord Y-coord PWG-135 63593.012 82096.903 PWG-227 63588.720 82096.765 PWG-229 63588.720 82161.708 PWG-228 63588.720 82159.469 PWG-097 63586.595 82348.016 PWG-024 63581.601 82701.664 PWG-023 63572.425 82832.420 PWG-232 63564.086 83292.621 PWG-233 63555.128 83568.071 PWG-174 63551.761 81491.675 PWG-175 63551.761 81310.032 PWG-090 63525.599 81759.404 PWG-230 63494.664 82237.849 PWG-187 63490.780 84164.240 PWG-172 63481.448 81491.675 PWG-173 63481.448 81310.032 PWG-089 63452.404 81750.255 PWG-171 63440.432 81307.103 PWG-170 63414.064 81488.745 PWG-087 63363.960 81768.554 PWG-185 63361.329 81280.735 PWG-156 63361.329 81280.735 PWG-186 63358.399 81482.886 PWG-088 63342.611 81930.193 PWG-199 63324.066 82912.177 PWG-198-1 63324.002 82912.876 PWG-122 63309.063 82421.212 PWG-169 63273.437 81479.956 PWG-189 63269.049 83305.923 PWG-086 63266.366 81771.603 PWG-237 63265.453 83313.127 PWG-168 63255.859 81307.103 PWG-120 63226.718 82280.921 PWG-085 63180.971 81762.454 PWG-198-2 63177.091 83054.698 PWG-200 63172.637 82907.723 PWG-166 63170.897 81304.173 PWG-167 63170.897 81465.308 PWG-121 63162.673 82430.361 PWG-126 63150.473 82283.970 PWG-084 63110.826 81759.404 PWG-164 63083.005 81304.173 PWG-163 63071.287 81465.308 PWG-007 63047.106 82281.973 PWG-119 63043.730 82277.871 PWG-009 63026.460 82121.289 PWG-083 63022.382 81756.354 CRA 45136 (12) Braidwood Generating Station

TABLE B.1 Page 4 of 5

SUMMARY

OF PRIVATE WELL LOCATIONS FLEETWIDE TRITIUM ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Location X-coord Y-coord PWG-162 62995.114 81304.173 PWG-161 62980.465 81453.589 PWG-008 62953.053 82167.169 PWG-082 62936.987 81756.354 PWG-006 62934.701 82295.684 PWG-129 62912.589 82433.411 PWG-131 62909.539 82433.411 PWG-160 62872.065 81274.876 PWG-116 62863.792 82283.970 PWG-081 62857.692 81753.305 PWG-159 62848.628 81441.870 PWG-130 62833.294 82430.361 PWG-133 62833.294 82430.361 PWG-157 62792.963 81269.016 PWG-115 62790.596 82265.672 PWG-114 62787.547 82268.721 PWG-158 62769.525 81447.729 PWG-079 62766.198 81744.155 PWG-145 62758.451 82130.765 PWG-188 62754.058 82740.864 PWG-113 62753.999 82393.763 PWG-112 62753.999 82396.813 PWG-109 62753.999 82396.813 PWG-110 62753.999 82396.813 PWG-144 62752.826 82220.766 PWG-124 62750.949 82393.763 PWG-125 62750.949 82393.763 PWG-132 62747.899 82396.813 PWG-192 62746.906 82748.017 PWG-147 62653.450 81842.011 PWG-146 62649.700 82142.015 PWG-034 62629.564 81644.013 PWG-149 62627.199 81643.259 PWG-014 62407.088 81082.121 PWG-015 62404.794 81004.126 PWG-021 62400.206 80669.206 PWG-020 62395.618 80747.201 PWG-017 62395.618 80889.427 PWG-018 62393.324 80838.960 PWG-019 62322.211 80721.967 PWG-013 62319.917 81194.525 PW-535 62316.016 81977.041 PWG-012 62310.741 81267.932 PWG-064 62244.682 80856.662 PWG-213 62197.256 80297.800 PWG-108 62192.835 82073.534 PWG-107 62189.785 81902.745 CRA 45136 (12) Braidwood Generating Station

TABLE B.1 Page 5 of 5

SUMMARY

OF PRIVATE WELL LOCATIONS FLEETWIDE TRITIUM ASSESSMENT BRAIDWOOD GENERATING STATION BRACEVILLE, ILLINOIS Location X-coord Y-coord PWG-062 62162.337 80856.662 PWG-210 62117.088 80627.381 PWG-206 62108.180 81090.575 PWG-203 62108.180 81331.080 PWG-202 62103.727 81429.064 PWG-208 62014.651 80979.230 PWG-071 61939.701 80444.939 PWG-061 61918.352 80756.019 PWG-205 61912.214 81126.206 PWG-003 61872.603 81240.813 PWG-070 61848.207 80444.939 PWG-069 61848.207 80344.295 PWG-002 61829.919 81115.274 PWG-068 61784.161 80341.245 PWG-224 61778.600 80685.280 PWG-001 61759.617 81110.252 PWG-221 61756.331 81420.156 PWG-223 61756.331 80930.239 PWG-222 61756.331 81001.499 PWG-225 61640.532 80645.196 PWG-004 61631.567 81243.324 PWG-067 61616.422 80826.164 PWG-072 61573.725 80447.988 PWG-066 61534.077 80734.670 PWG-190 61516.651 81467.694 PWG-190-Pond 61516.376 81471.908 PWG-193 61509.499 81467.694 PWG-065 61476.131 80829.214 PWG-052-Pond 61425.969 79697.474 PWG-591 61425.953 81080.151 PWG-049 61417.429 80490.904 PWG-042 61414.176 81226.180 PWG-048 61404.415 80617.788 PWG-047 61404.415 80708.884 PWG-045 61340.567 83003.772 PWG-054 61328.366 79636.472 PWG-053 61328.366 79689.341 PWG-046 61313.319 80725.151 PWG-051 61312.099 79827.611 PWG-050 61303.966 79913.014 PWG-059 61280.545 80190.231 PWG-056 61280.545 86566.046 PWG-542 61204.623 82476.990 PWG-043 61181.962 83007.839 CRA 45136 (12) Braidwood Generating Station

Revision 0 APPENDIX C QUALITY ASSURANCE PROGRAM - TELEDYNE BROWN ENGINEERING, INC.

045136 (12) Braidwood Generating Station

TABLE OF CONTENTS Section Title Page 1.0 KNOXVILLE QAM SECTION INTRODUCTION 7 2.0 QUALITY SYSTEM 10 2.1 Policy 10 2.2 Quality System Structure 10 2.3 Quality System Objectives 10 2.4 Personnel Orientation, Training, and Qualification 11 3.0 ORGANIZATION, AUTHORITY, AND RESPONSIBILITY 12 4.0 PERSONNEL ORIENTATION, DATA INTEGRITY, TRAINING, AND QUALIFICATION 13 4.1 Orientation 13 4.2 Data Integrity 13 4.3 Training 13 4.4 Qualification 13 4.5 Records 13 5.0 CUSTOMER INTERFACES 14 5.1 Interface Personnel 14 5.2 Bid Requests and Tenders 14 5.3 Contracts 14 5.4 TBEs Expectation of Customers 14 5.5 Customer Satisfaction 15 5.5.1 Customer Complaints 15 5.5.2 Customer Confidentiality 15 6.0 DOCUMENTATION GENERATION AND CONTROL 16 6.1 General 16 6.2 New Documentation 16 6.3 Documentation Changes 16 Page 2 of 32

TABLE OF CONTENTS - Continued 6.4 Documentation Lists and Distributions 16 6.5 Other Documentation 16 6.6 Documentation Reviews 16 7.0 DESIGN OF LABORATORY CONTROLS 17 7.1 General 17 7.2 Facility 17 7.3 Technical Processes and Methods 17 7.3.1 Operational Flow 17 7.3.2 Methods 18 7.3.3 Data Reduction and Analysis 18 7.4 Verification of Technical Processes, Methods, and Software 18 7.4.1 Operational Flow Verification 18 7.4.2 Method Verifications 18 7.4.3 Data Reduction and Analysis Verification 18 7.5 Design of Quality Controls 18 7.5.1 General 19 7.5.2 Demonstration of Capability (D of C) 19 7.5.3 Process Control Checks 19 7.6 Counting Instrument Controls 20 8.0 PURCHASING AND SUBCONTRACT CONTROLS 21 8.1 General 21 8.2 Source Selection 21 8.3 Procurement of Supplies and Support Services 21 8.3.1 Catalog Supplies 21 8.3.2 Support Services 21 8.3.3 Equipment and Software 22 8.4 Subcontracting of Analytical Services 22 8.5 Acceptance of Items or Services 22 Page 3 of 32

TABLE OF CONTENTS - Continued 9.0 TEST SAMPLE IDENTIFICATION AND CONTROL 23 9.1 Sample Identification 23 9.2 LIMS 23 9.3 Sample Control 23 10.0 SPECIAL PROCESSES, INSPECTION, AND TEST 24 10.1 Special Processes 24 10.2 Inspections and Tests 24 10.2.1 Intra Laboratory Checks (QC Checks) 24 10.2.2 Inter Laboratory Checks 24 10.2.3 Data Reviews 24 10.3 Control of Sampling of Samples 24 10.4 Reference Standards / Material 24 10.4.1 Weights and Temperatures 25 10.4.2 Radioactive Materials 25 11.0 EQUIPMENT MAINTENANCE AND CALIBRATION 26 11.1 General 26 11.2 Support Equipment 26 11.3 Instruments 26 11.4 Nonconformances and Corrective Actions 26 11.5 Records 27 12.0 NONCONFORMANCE CONTROLS 28 12.1 General 28 12.2 Responsibility and Authority 28 12.3 10CFR21 Reporting 28 Page 4 of 32

TABLE OF CONTENTS - Continued 13.0 CORRECTIVE AND PREVENTIVE ACTIONS 29 13.1 General 29 13.2 Corrective Actions 29 13.3 Preventive Actions 29 14.0 RESULTS ANALYSIS AND REPORTING 30 14.1 General 30 14.2 Results Review 30 14.3 Reports 30 15.0 RECORDS 31 15.1 General 31 15.2 Type of Records 31 15.3 Storage and Retention 31 15.4 Destruction or Disposal 31 16.0 ASSESSMENTS 32 16.1 General 32 16.2 Audits 32 16.3 Management Reviews 32 Page 5 of 32

REVISION HISTORY Revision 7 Complete re-write January 1, 2005 Bill Meyer Revision 8 Updated organization chart, minor change to 1.0, 4.4, 7.5.3.2, 10.2.3, and 12.3 Page 6 of 32

1.0 Knoxville QAM Section Introduction This Quality Assurance Manual (QAM) and related Procedures describes the Knoxville Environmental Services Laboratorys QA system. This system is designed to meet multiple quality standards imposed by Customers and regulatory agencies including:

NRCs 10 CFR 50 Appendix B NRCs Regulatory Guide 4.15 DOEs Order 414.1 DOEs QSAS ANSI N 42.23 ANSI N 13.30 NELAC Standard, Chapter 5 The Environmental Services (ES) Laboratory does low level radioactivity analyses for Power Plants and other customers. It primarily analyzes environmental samples (natural products from around plants such as milk), in-plant samples (air filters, waters), bioassay samples from customers employees, and waste disposal samples (liquids and solids).

Potable and non-potable water samples are tested using methods based on EPA standards as cited in State licenses (see Procedure 4010). The listing [current as of initial printing of this Manual - see current index for revision status and additions / deletions] of implementing Procedures (SOPs) covering Administration, Methods, Counting Instruments, Technical, Miscellaneous, and LIMS is shown in Table 1-1. Reference to these Procedures by number is made throughout this QAM.

Table 1-1 Number Title Part 1 Administrative Procedures Validation and Verification of Computer Programs for Radiochemistry Data 1001 Reduction 1002 Organization and Responsibility 1003 Control, Retention, and Disposal of Quality Assurance Records 1004 Definitions 1005 Data Integrity 1006 Job Descriptions 1007 Training and Certifications 1008 Procedure and Document Control 1009 Calibration System 1010 Nonconformance Controls 1011 10CFR21 Reporting 1012 Corrective Action and Preventive Action Page 7 of 32

Number Title 1013 Internal Audits and Management Reviews 1014 RFP, Contract Review, and Order Entry (formerly 4001) 1015 Procurement Controls Part 2 Method Procedures 2001 Alpha Isotopic and Plutonium-241 2002 Carbon-14 Activity in Various Matrices Carbon-14 and Tritium in Soils, Solids, and Biological Samples; Harvey 2003 Oxidizer Method 2004 Cerium-141 and Cerium-144 by Radiochemical Separation 2005 Cesium-137 by Radiochemical Separation 2006 Iron-55 Activity in Various Matrices 2007 Gamma Emitting Radioisotope Analysis 2008 Gross Alpha and/or Gross Beta Activity in Various Matrices 2009 Gross Beta Minus Potassium-40 Activity in Urine and Fecal Samples 2010 Tritium and Carbon-14 Analysis by Liquid Scintillation 2011 Tritium Analysis in Drinking Water by Liquid Scintillation 2012 Radioiodine in Various Matrices 2013 Radionickel Activity in Various Matrices 2014 Phosphorus-32 Activity in Various Matrices 2015 Lead-210 Activity in Various Matrices 2016 Radium-226 Analysis in Various Matrices 2017 Total Radium in Water Samples 2018 Radiostrontium Analysis by Chemical Separation 2019 Radiostrontium Analysis by Ion Exchange 2020 Sulfur-35 Analysis 2021 Technetium-99 Analysis by Eichrom Resin Separation 2022 Total Uranium Analysis by KPA 2023 Compositing of Samples 2024 Dry Ashing of Environmental Samples 2025 Preparation and Standardization of Carrier Solutions 2026 Radioactive Reference Standard Solutions and Records 2027 Glassware Washing and Storage 2028 Moisture Content of Various Matrices 2029 Polonium-210 Activity in Various Matrices 2030 Promethium-147 Analysis Page 8 of 32

Number Title Part 3 Instrument Procedures 3001 Calibration and Control of Gamma-Ray Spectrometers 3002 Calibration of Alpha Spectrometers 3003 Calibration and Control of Alpha and Beta Counting Instruments 3004 Calibration and Control of Liquid Scintillation Counters 3005 Calibration and Operation of pH Meters 3006 Balance Calibration and Check 3008 Negative Results Evaluation Policy 3009 Use and Maintenance of Mechanical Pipettors 3010 Microwave Digestion System Use and Maintenance Part 4 Technical Procedures 4001 Not Used 4002 QC Checks on Data 4003 Sample Regent and Control 4004 Data Package Preparation and Reporting 4005 Blank, Spike, and Duplicate Controls 4006 Inter-Laboratory Comparison Study Process 4007 Method Basis and Initial Validation Process 4008 Not Used 4009 MDL Controls 4010 State Certification Process 4011 Accuracy, Precision, Efficiency, and Bias Controls and Data Quality Objectives 4012 Not Used 4013 Not Used 4014 Facility Operation and Control 4015 Documentation of Analytical Laboratory Logbooks (formerly 1002) 4016 Total Propagated Uncertainty (formerly 1004) 4017 LIMS Operation 4018 Instrument Calibration System 4019 Radioactive Reference Material Standards Part 5 Miscellaneous Procedures 5001 Laboratory Hood Operations 5002 Operation and Maintenance of Deionized Water System 5003 Waste Management 5004 Acid Neutralization and Purification System Operation Procedure Page 9 of 32

Part 6 LIMS 6001 LIMS Raw Data Processing and Reporting 6002 Software Development and/or Pilots of COTS Packages 6003 Software Change and Version Control 6004 Backup of Data and System Files 6005 Disaster Recovery Plan 6006 LIMS Hardware 6007 LIMS User Access 6008 LIMS Training 6009 LIMS Security 2.0 QUALITY SYSTEM The TBE-ES QA system is designed to comply with multiple customer- and regulatory agency-imposed specifications related to quality. This quality system applies to all activities of TBE-ES that affect the quality of analyses performed by the laboratory.

2.1 Policy The TBE quality policy, given in Company Policy P-501, is TBE will continually improve our processes and effectiveness in providing products and services that exceed our customers expectations.

This policy is amplified by this Laboratorys commitment, as attested to by the title page signatures, to perform all work to good professional practices and to deliver high quality services to our customers with full data integrity. (See Section 4.0 and Procedure 1005).

2.2 Quality System Structure The Quality System is operated by the organizations described in Section 3.0 of this Manual. The Quality System is described in this Manual and in the Procedures Manual, both of which are maintained by the QA Manager. Procedures are divided into 6 sections - Administrative, Methods, Equipments, Technical, Miscellaneous, and LIMS. This Manual is structured as shown in the Table of Contents and refers to Procedures when applicable. Cross references to the various imposed quality specifications are contained in Appendices to this Manual.

2.3 Quality System Objectives The Quality System is established to meet the objective of assuring all operations are planned and executed in accordance with system requirements. The Quality System also assures that performance evaluations are performed (see Procedure 4006), and that appropriate verifications are performed (see Procedures in the 1000 and 4000 series) to further assure compliance. Verification includes Page 10 of 32

examination of final reports (prior to submittal to customers) to determine their quality (see Procedure 4004).

To further these objectives, various in-process assessments of data, as well as assessments of the system, via internal audits and management reviews, are performed. Both internal experts and customer / regulatory agencies perform further assessments of the system and compliance to requirements.

2.4 Personnel Orientation, Training, and Qualification TBE provides indoctrination and training to employees and performs proficiency evaluation of technical personnel. This effort is described in Section 4.0.

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3.0 ORGANIZATION, AUTHORITY, AND RESPONSIBILITY TBE has established an effective organization for conducting laboratory analyses at the Knoxville Environmental Services Laboratory. The basic organization is shown in Figure 3-1. Detail organization charts with names, authorities, and responsibilities are given in Procedure 1002. Job descriptions are given in Procedure 1006.

This organization provides clearly established Quality Assurance authorities, duties, and functions. QA has the organizational freedom needed to:

(1) Identify problems (2) Stop nonconforming work (3) Initiate investigations (4) Recommend corrective and preventive actions (5) Provide solutions or recommend solutions (6) Verify implementation of actions All Laboratory personnel have the authority and resources to do their assigned duties and have the freedom to act on problems. The QA personnel have direct, independent access to Company management as shown in Figure 3-1.

President VP VP Administration & QA Environmental Product Assurance Director Lab QA Manager Lab Operations Manager Program Lab Administration Managers Supervisor Staff Figure 3.1. Laboratory Organization Page 12 of 32

4.0 PERSONNEL ORIENTATION, DATA INTEGRITY, TRAINING, AND QUALIFICATION 4.1 Orientation All laboratory personnel must receive orientation to the quality program if their work can affect quality. Orientation includes a brief review of customer- and regulatory agency-imposed quality requirements, the structure of the QAM, and the implementing procedures. The goal of orientation is to cover the nature and goals of the QA program.

4.2 Data Integrity The primary output of the Laboratory is data. Special emphasis and training in data integrity is given to all personnel whose work provides or supports data delivery. The Laboratory Data Integrity Procedure (Procedure 1005) describes training, personnel attestations, and monitoring operations. Annual reviews are required.

4.3 Training The Quality Assurance Manager (QAM) maintains a training matrix indicating which laboratory personnel need training in which specific Procedures. This matrix is updated when personnel change or change assignments. All personnel are trained per these requirements and procedures. This training program is described in Procedure 1007. The assigned responsibilities for employees are described in Procedure 1002 (See Section 3.0) on Organization and in Procedure 1006, Job Descriptions. Refresher training or re-training is given annually as appropriate.

4.4 Qualification Personnel are qualified as required by their job description. Management and non-analysts are evaluated based on past experience, education, and managements assessment of their capabilities. Formal qualification is required of analysts and related technical personnel who perform laboratory functions. Each applicable person is given training and then formally evaluated by the Operations Manager (or his designees) and by QA. Each analyst must initially demonstrate capability to perform each assigned analytical effort. Each year, thereafter, he or she must perform similar analyses on Interlab Comparison Samples (see Procedure 4006) or on equivalent blanks and spikes samples. Acceptable results extend qualifications (certification). Unacceptable results require retraining in the subject method / Procedures. (See Procedure 1007 for added information, records, forms, etc. used.)

4.5 Records Records of training subjects, contents, attendees, instructors, and certifications are maintained by QA.

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5.0 CUSTOMER INTERFACES 5.1 Interface Personnel The Laboratory has designated Program Managers as the primary interface with all customers. Other interfaces may be the QA Manager or the Lab Operations Manager.

5.2 Bid Requests and Tenders The Program Managers respond to customer requests for bids and proposals per Procedure 1014 for bids, proposals, and contract reviews. They clarify customer requests so both the customer and the lab staff understand requests. As responses are developed, internal reviews are conducted to ensure that requirements are adequately defined and documented and to verify that the Laboratory has adequate resources in physical capabilities, personal skills, and technical information to perform the work. Accreditation needs are reviewed. If subcontracts are required to perform any analysis, the subcontractor is similarly evaluated and the client notified in writing of the effort. Most qualifications are routine with standard pricing and the review of these quotes is performed by the Program Manager. Larger or more complex quotes are reviewed by the Operations Manager and the QA Manager (or designees). Evidence of review is by initialing and dating applicable papers, signatures on quotations, or by memo.

5.3 Contracts The Program Managers receive contract awards (oral or written) and generate the work planning for initiation preparation (charge numbers, data structure or contents in LIMS, etc.). They review contracts for possible differences from quotations and, if acceptable, contracts are processed. Documentation of the review is by initials and date as a minimum. Contract changes receive similar reviews and planning.

5.4 TBEs Expectation of Customers TBE expects customers to provide samples suitable for lab analysis. These expectations include:

Accurate and unambiguous identification of samples Proper collection and preservation of samples Use of appropriate containers free from external and internal contamination Integrity preservation during shipment and timely delivery of samples that are age sensitive Adequate sized samples that allow for retest, if needed Specification of unique MOA/MDC requirements Alerting the lab about abnormal samples (high activity, different chemical contents, etc.)

Chain of custody initiation, when required.

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5.5 Customer Satisfaction TBEs quality policy centers on customer satisfaction (See 2.0). TBE will work to satisfy customers through full compliance with contract requirements, providing accurate data and properly responding to any questions or complaints.

Customers are provided full cooperation in their monitoring of Laboratory performance. Customers are notified if any applicable State Accreditation is withdrawn, revoked, or suspended.

5.5.1 Customer Complaints Any customer complaints are documented and tracked to closure. Most complaints concern analysis data and are received by Program Managers. They log each such complaint, order retests for verification, and provide documented results to customers. Complaints may also be received by QA or Operations.

If complaints are other than re-test type, the nonconformance and corrective action systems (Sections 12 and 13) are used to resolve them and record all actions taken.

5.5.2 Customer Confidentiality All laboratory personnel maintain confidentiality of customer-unique information.

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6.0 DOCUMENTATION GENERATION & CONTROL 6.1 General The documentation generation and control system is detailed in Procedure 1008. An overview is given below. The basic quality system documents are described in Section 2.0.

6.2 New Documentation Each Procedure and this QAM is written by appropriate personnel, validated if applicable (see Section 7.0), reviewed for adequacy, completeness, and correctness, and, if acceptable, accepted by the authorized approver [QA Manager, Operations Manager (or their designee)]. Both approvals are required if a Procedure affects both QA and Operations. (See Responsibilities in Section 3.0). These procedures control the quality measurements and their accuracy.

Each document carries a unique identification number, a revision level, dates, page numbers and total page count, and approver identification and sign off. If TBE writes code for software, the software is version identified and issued after Verification and Validation per Section 7.0.

6.3 Documentation Changes Each change is reviewed in the same manner and by the same people as new documentation. Revision identifications are updated and changes indicated by side bars, italicized words, or by revision description when practical. Obsolete revisions are maintained by QA after being identified as obsolete.

6.4 Documentation Lists and Distributions Computer indexes of documents are maintained by Quality showing the current authorized revision level of each document. These revisions are placed on the Laboratory server and obsolete ones are removed so that all personnel have only the current documents. If hard copies are produced and distributed, separate distribution lists are maintained indicating who has them and their revision level(s).

Copies downloaded off the server are uncontrolled unless verified by the user (on the computer) to be the latest revision.

6.5 Other Documentation In addition to TBE-generated documentation, QA maintains copies of applicable specifications, regulations, and standard methods.

6.6 Documentation Reviews Each issued document is reviewed at least every third year by the approving personnel. This review determines continued suitability for use and compliance with requirements.

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7.0 DESIGN OF LABORATORY CONTROLS 7.1 General The Laboratory and its operating procedures are designed specifically for low level (environmental and in-plant) radioactive sample analysis. The various aspects of the laboratory design include the following which are discussed in subsequent paragraphs of this Section:

(a) Facility (b) Technical Processes and Methods (c) Verification of Design of Processes, Methods, and Software.

(d) Design of Quality Controls (e) Counting Instrument Controls 7.2 Facility The facility was designed and built in 2000 to facilitate correct performance of operations in accordance with good laboratory practices and regulatory requirements. It provides security for operations and samples. It separates sample storage areas based on activity levels, separates wet chemistry from counting instrumentation for contamination control, and provides space and electronic systems for documentation, analysis, and record storage. Procedure 4014 describes the facility, room uses, layouts, etc.

7.3 Technical Processes and Methods 7.3.1 Operational Flow The laboratory design provides for sample receipt and storage (including special environmental provisions for perishable items) where samples are received from clients and other labs (see Section 9.0). The samples are logged into the computer based Laboratory Information Management System (LIMS) and receive unique identification numbers and bar code labels. (See Procedure 4017 for LIMS description and user procedures). The Program Managers then plan the work and assure LIMS contains any special instructions to analysts. Samples then go to sample preparation, wet chemistry (for chemical separation), and counting based on the radionuclides. See Procedures in the 2000 and 3000 series. Analysts perform the required tasks with data being entered into logbooks, LIMS, and counting equipment data systems as appropriate. Results are collected and reviewed by the Operations Manager and Program Managers and reports to clients are generated (See Section 14.0). All records (electronic or hard copy) are maintained in files or in back-up electronic copies (see Section 15.0). After the required hold periods and client notification and approval, samples are disposed of in compliance with regulatory requirements (see Procedures 5003 and 5004).

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7.3.2 Methods The laboratory methods documented in the 2000 and 3000 series of Procedures were primarily developed by senior TBE laboratory personnel based on years of experience at our prior facility in New Jersey. They have been improved, supplemented and implemented here. Where EPA or other accepted national methods exist (primarily for water analyses under State certification programs - see Procedure 4010), the TBE methods conform to the imposed requirements or State accepted alternate requirements. Any method modifications are documented and described in the Procedure. There are no nationally recognized methods for most other analysis methods but references to other method documents are noted where applicable.

7.3.3 Data Reduction and Analysis Whenever possible automatic data capture and computerized data reduction programs are used. Calculations are either performed using commercial software (counting system operating systems) or TBE developed and validated software is used (see 7.4 below). Analysis of reduced data is performed as described in Section 14.0 and Procedure 4004.

7.4 Verification of Technical Processes, Methods, and Software 7.4.1 Operational Flow Verification The entire QA Manual and related procedures describe the verification of elements of the technical process flow and the establishment of quality check points, reviews, and controls.

7.4.2 Method Verifications Methods are verified and validated per Procedure 4007 prior to use unless otherwise agreed to by the client. For most TBE methods initial validation occurred well in the past. New or significantly revised Methods receive initial validation by demonstration of their performance using known analytes (NIST traceable) in appropriate matrices. Sufficient samples are run to obtain statistical data that provides evidence of process capability and control, establishes detection levels (see procedure 4009), bias and precision data (see Procedure 4011). All method procedures and validation data are available to respective clients. Also see Section 7.5 below for the Demonstration of Capability program.

7.4.3 Data Reduction and Analysis Verification Data reduction and analysis verification is performed by personnel who did not generate the data. (See Section 14.0).

7.5 Design of Quality Controls Page 18 of 32

7.5.1 General There are multiple quality controls designed into the laboratory operations.

Many of these are described elsewhere in this manual and include personnel qualification (Section 4.0), Document control (6.0), Sample identification and control (9.0), Use of reference standards (10.0), intra- and inter- laboratory tests (10.0), etc.

This Section describes the basic quality control systems used to verify Method capability and performance.

7.5.2 Demonstration of Capability (D of C)

The demonstration of capability system verifies and documents that the method, analyst, and the equipment can perform within acceptable limits. The D of C is certified for each combination of analyte, method, and instrument type. D of C's are certified based on objective evidence at least annually. This program is combined with the analyst D of C program (See Section 4.0). Initial D of C's use the method validation effort as covered above. Subsequent D of C's use Inter-Laboratory samples (Procedure 4006) or, if necessary, laboratory generated samples using NIST traceable standards. If results are outside of control limits, re-demonstration is required after investigation and corrective action is accomplished (See Sections 12.0 and 13.0) 7.5.3 Process Control Checks Process control checks are designed to include Inter-Lab samples, Intra-lab QC check samples, and customer provided check samples. 10% of laboratory analysis samples are for process control purposes.

7.5.3.1 Inter- Lab Samples. Inter-lab samples are procured or obtained from sources providing analytes of interest in matrices similar to normal client samples. These samples may be used for Demonstration of Capability of analyst's, equipment and methods. They also provide for independent insight into the lab's process capabilities. Any value reported as being in the warning zone (over 2 sigma) is reviewed and improvements taken. Any value failing (over 3 sigma) is documented on an NCR and formal investigation per Section 12.0 and 13.0 is performed. If root causes are not clearly understood and fixed, re-tests are required using lab prepared samples (See Procedure 4006).

7.5.3.2 QC Samples. QC samples, along with Inter-lab samples and customer check samples, are 10% of the annual lab workload for the applicable analyte and method. If batch processing is used, some specifications require specific checks with each batch or each day rather than as continuous process controls.

(See Procedure 4005)

QC samples consist of multiple types of samples including:

(a) Method blanks (b) Blank spikes (c) Matrix spikes Page 19 of 32

(d) Duplicates (e) Tracers and carriers Acceptance limits for these samples are given in Procedures or in lab standards. The number, frequency, and use of these sample types varies with the method, matrix, and supplemental requirements. The patterns of use versus method and the use of the resulting test data is described in Procedure 4005.

7.5.3.3 Customer Provided Check Samples. Customers may provide blind check samples and duplicates to aid in their evaluation of the Laboratory. When the lab is notified that samples are check samples their results are included in the QC sample percentage counts. Any reported problems are treated as formal complaints and investigated per Section 5.

7.6 Counting Instrument Controls The calibration of instruments is their primary control and is described in Section 11.0. In addition, counting procedures (3000 series) also specify use of background checks (method blank data is not used for this) to evaluate possible counting equipment contamination. Instrument calibration checks using a lab standard from a different source than the one used for calibration are also used.

Background data can be used to adjust client and test data. Checks with lab standards indicate potential calibration changes.

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8.0 PURCHASING AND SUBCONTRACT CONTROLS 8.1 General Procurement and Subcontracts efforts use the Huntsville-based Cost Point computer system to process orders. The Laboratory-generated Purchase Requisitions are electronically copied into Purchase Orders in Huntsville. The Laboratory also specifies sources to be used. Procured items and services are received at the Laboratory where receiving checks and inspections are made.

Laboratory Procedure 1015 provides details on the procurement control system at the Laboratory and references the Huntsville procedures as applicable.

8.2 Source Selection Sources for procurements of items and services are evaluated and approved by QA as described in Procedure 1015. Nationally recognized catalog item sources are approved by the QA Manager based on reputation. Maintenance services by an approved distributor or the equipment manufacturing company are pre-approved.

Sources for other services are evaluated by QA, based on service criticality to the quality system, by phone, mail out, or site visit.

Subcontract sources for laboratory analysis services are only placed with accredited laboratories (by NELAP, NUPIC, State, Client, etc.) as applicable for the type of analysis to be performed. QA maintains lists of approved vendors and records of evaluations performed.

8.3 Procurement of Supplies and Support Services 8.3.1 Catalog Supplies The Laboratory procures reagents, processing chemicals, laboratory glassware, consumables, and other catalog items from nationally known vendors and to applicable laboratory grades, purities, concentrations, accuracy levels, etc.

Purchase Requisitions for these items specify catalog numbers or similar call-outs for these off-the-shelf items. Requisitions are generated by the personnel in the lab needing the item and are approved by the Operations or Production Manager.

Reagents are analytical reagent grade only.

8.3.2 Support Services Purchase Requisitions for support services (such as balance calibration, equipment maintenance, etc.) are processed as in 8.3.1 but technical requirements are specified and reviewed before approvals are given.

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8.3.3 Equipment and Software Purchase Requisitions for new equipment, software programs, and major facility modifications affecting the quality system are reviewed and approved by the Operations Manager and the QA Manager.

8.4 Subcontracting of Analytical Services When necessary, the Laboratory may subcontract analytical services required by a client. This may be because of special needs, infrequency of analysis, etc.

Applicable quality and regulatory requirements are imposed in the Purchase Requisition and undergo a technical review by QA. TBE reserves the right of access by TBE and our client for verification purposes.

8.5 Acceptance of Items or Services Items and services affecting the quality system are verified at receipt based on objective evidence supplied by the vendor. Supply items are reviewed by the requisitioner and, if acceptable, are accepted via annotation on the vendor packing list or similar document. Similarly, equipment services are accepted by the requisitioning lab person. Calibration services are accepted by QA based on certification reviews. (See Section 11.0.)

Data reports from analytical subcontractors are evaluated by Program Managers and subsequently by the Operations Manager (or designee) as part of client report reviews.

Items are not used until accepted and if items or services are rejected, QA is notified and nonconformance controls per Section 12.0 are followed. Vendors may be removed from the approved vendors list if their performance is unacceptable.

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9.0 TEST SAMPLE IDENTIFICATION AND CONTROL 9.1 Sample Identification Incoming samples are inspected for customer identification, container condition, chain of custody forms, and radioactivity levels. If acceptable, the sample information is entered into LIMS which generates bar coded labels for attachment to the sample(s). The labels are attached and samples stored in the assigned location.

If environmental controls are needed (refrigeration, freezing, etc.), the samples are placed in these storage locations. If not acceptable, the Program Manager is notified, the customer contacted, and the problem resolved (return of sample, added data receipts, etc.). See Procedure 4003 for more information on sample receipt.

9.2 LIMS The LIMS is used to schedule work, provide special information to analysts, and record all actions taken on samples. See Procedure 4017 and the 6000 series of procedures for more information on LIMS operations.

9.3 Sample Control The sample, with its bar coded label, is logged out to the applicable lab operation where the sample is processed per the applicable methods (Procedures 2000 and 3000). The LIMS-assigned numbers are used for identification through all operations to record data. Data is entered into LIMS, log books (kept by the analysts) or equipment data systems to record data. The combination of LIMS, logbooks, and equipment data systems provide the Chain of Custody data and document all actions taken on samples. Unused sample portions are returned to its storage area for possible verification use. Samples are discarded after required time limits are passed and after client notification and approval, if required.

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10.0 SPECIAL PROCESSES, INSPECTION, AND TEST 10.1 Special Processes The Laboratorys special processes are the methods used to analyze a sample and control equipment. These methods are defined in Procedures in the 2000 and 3000 series. These processes are performed to the qualified methods (see Section 7.0) by qualified people (see 4.0).

10.2 Inspections and Tests The quality of the process is monitored by indirect means. This program involves calibration checks on counting equipments (see Section 11.0), intra-laboratory checks, and inter-laboratory checks. In addition, some customers submit quality control check samples (blinds, duplicates, external reference standards). All generated data gets independent reviews.

10.2.1 Intra Laboratory Checks (QC Checks)

The quantity and types of checks varies with the method, but basic checks which may include blanks, spiked blanks, matrix spikes, matrix spike duplicates, and duplicates are used as appropriate for customer samples. This process is described in Procedure 4005 and in Section 7.0.

10.2.2 Inter Laboratory Checks TBE participates in Inter-lab performance evaluation (check) programs with multiple higher level labs. These programs provide blind matrices for the types of matrix/analyte combinations routinely processed by the Lab, if available. This program is described in Procedure 4006.

10.2.3 Data Reviews Raw data and reports are reviewed by the Operations Manager, or designees. This review checks for data logic, expected results, procedure compliance, etc. (See Section 14.0).

10.3 Control of Sampling of Samples Samples for analysis are supplied by customers preferably in quantities sufficient to allow re-verification analyses if needed. The samples are prepared for analysis by analysts and then an aliquot (partial sample extraction) is taken from the homogeneous customer sample for the initial analysis. Methods specify standard volumes of sample material required. Sampling data is recorded in LIMS and/or logbooks.

10.4 Reference Standards / Material Page 24 of 32

10.4.1 Weights and Temperatures Reference standards are used by the Laboratorys calibration vendor to calibrate the Labs working instruments measuring weights and thermometers.

10.4.2 Radioactive Materials Reference radioactive standards, traceable to NIST, are procured from higher level laboratories. These reference materials are maintained in the standards area and are diluted down for use by laboratory analysts. All original and diluted volumes are fully traceable to source, procedure, analyst, dilution, and acquisition dates. See Section 11.0 and Procedure 1009.

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11.0 EQUIPMENT MAINTENANCE AND CALIBRATION 11.1 General There are two types of equipment used by the Laboratory: support equipment (scales, glassware, weights, thermometers, etc.) and instruments for counting. Standards traceable to NIST are used for calibration and are of the needed accuracy for laboratory operations. Procedures 1009, 4018, and 4019 describe the calibration and maintenance programs.

11.2 Support Equipment Analytical support equipment is purchased with the necessary accuracies and appropriate calibration data. If needed, initial calibration by the Laboratory or its calibration vendor is performed. Recalibration schedules are established and equipment recalibrated by the scheduled date by a calibration vendor or by Laboratory personnel. Maintenance is performed, as needed, per manufacturers manuals or lab procedures.

In addition to calibrations and recalibrations, checks are made on the continued accuracy of items as described in Procedure 1009. Records are maintained of calibration and specified checks.

11.3 Instruments Instruments receive initial calibration using radioactive sources traceable to NIST. The initial calibration establishes statistical limits of variation that are used to set control limits for future checks and recalibration. This process is described in Procedure 4018. Instruments are maintained per Instrument Manual requirements.

Recalibrations are performed per the Procedure.

Between calibrations, check sources are used to assure no significant changes have occurred in the calibration of items. Background checks are performed to check for possible radioactive contamination. Background values are used to adjust sample results. Hardware and software are safeguarded from adjustments that could invalidate calibrations or results.

11.4 Nonconformances and Corrective Actions If calibrations or checks indicate a problem, the nonconformance system (Section 12.0) and corrective action system (Section 13.0) are initiated to document the problem and its resolution. Equipment is promptly removed from service if questionable.

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11.5 Records Records of calibrations are maintained. Calibration certificates from calibration vendors are maintained by QA. Other calibration data and check data is maintained in log books, LIMS, or instrument software as appropriate and as described in Procedures 1009, 4018, and 4019.

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12.0 NONCONFORMANCE CONTROLS 12.1 General The nonconformance control system is implemented whenever a nonconforming condition on any aspect of Laboratory analysis, testing, or results exist. The system takes graded actions based on the nature and severity of the nonconformance. Nonconforming items or processes are controlled to prevent inadvertent use. Nonconformances are documented and dispositioned. Notification is made to affected organizations, including clients. Procedure 1010 describes the procedures followed. Sample results are only reported after resolution.

12.2 Responsibility and Authority Each Laboratory employee has the responsibility to report nonconformances and the authority to stop performing nonconforming work or using nonconforming equipment. Laboratory supervision can disposition and take corrective actions on minor problems. Any significant problem is documented by QA using the Laboratorys NCR system per Procedure 1010. QA conducts or assures the conduct of cause analyses, disposition of items or data, and initiation of corrective action if the nonconformance could recur.

12.3 10CFR21 Reporting The QA Manager reviews NCRs for possible need of customer and/or NRC notification per the requirements of 10CFR21. Procedure 1011 is followed in this review and for any required reporting.

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13.0 CORRECTIVE AND PREVENTIVE ACTIONS 13.1 General The Laboratory takes corrective actions on significant nonconformances (see Section 12.0). It also initiates preventive and improvement actions per the Company Quality Policy (see Section 2.0). The procedures for Corrective Action/Preventive Action systems are contained in Procedure 1012.

13.2 Corrective Actions Corrective actions are taken by Operations and Quality to promptly correct significant conditions adverse to quality. The condition is identified and cause analysis is performed to identify root causes. Solutions are evaluated and the optimum one selected that will prevent recurrence, can be implemented by the Laboratory, allows the Laboratory to meet its other goals, and is commensurate with the significance of the problem. All steps are documented, action plans developed for major efforts, and reports made to Management. QA verifies the implementation effectiveness. Procedure 1012 provides instructions and designates authorities and responsibilities.

13.3 Preventive Actions Preventive actions are improvements intended to reduce the potential for nonconformances. Possible preventive actions are developed from suggestions from employees and from analysis of Laboratory technical and quality systems by management. If preventive actions or improvements are selected for investigation, the issues, investigation, recommendations, and implementation actions are documented. Follow up verifies effectiveness.

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14.0 RESULTS ANALYSIS AND REPORTING 14.1 General The Laboratorys role is to provide measurement-based information to clients that is technically valid, legally defensible, and of known quality.

14.2 Results Review The results obtained from analytical efforts are collected and reviewed by the Operations Manager and the Program Manager. This review verifies the reasonableness and consistency of the results. It includes review of sample and the related QC activity data. Procedure 4002 describes the process. Any deficiencies are corrected by re-analyses, recalculations, or corrective actions per Sections 12.0 and 13.0. Use of the LIMS with its automatic data loading features (see Procedure 4017) minimizes the possibility of transcription or calculation errors.

14.3 Reports Reports range from simple results reporting to elaborate analytical reports based on the client requirements and imposed specifications and standards. (See Procedure 4004.) Reports present results accurately, clearly, unambiguously, objectively, and as required by the applicable Method(s). Reports include reproduction restrictions, information on any deviations from methods, and any needed data qualifiers based on QC data. If any data is supplied by analytical subcontractors (see Section 8.0), it is clearly identified and attributed to that Laboratory by either name or accreditation number.

If results are faxed or transmitted electronically, confidentiality statements are included in case of receipt by other than the intended client.

Reports are approved by the Program Manager and Operations Manager and record copies kept in file (See Section 15.0).

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15.0 RECORDS 15.1 General The Laboratory collects generated data and information related to quality or technical data and maintains them as records. Records are identified, prepared, reviewed, placed in storage, and maintained as set forth in Procedure 1003.

15.2 Type of Records All original observations, calculations, derived data, calibration data, and test reports are included. In addition QA data such as audits, management reviews, corrective and preventive actions, manuals, and procedures are included.

15.3 Storage and Retention Records are stored in files after completion in the lab. Files are in specified locations and under the control of custodians. Filing systems provide for retrieval.

Electronic files are kept on Company servers (with regular back up) or on media stored in fireproof file cabinets. Records are kept in Laboratory files for at least 2 years after the last entry and then in Company files for another year as a minimum.

Some customers specify larger periods - up to 7 years - which is also met. Generic records supporting multiple customers are kept for the longest applicable period.

15.4 Destruction or Disposal Records may be destroyed after the retention period and after client notification and acceptance, if required. If the Laboratory closes, records will go in to company storage in Huntsville unless otherwise directed by customers. If the Laboratory is sold, either the new owner will accept record ownership or the records will go into Company storage as stated above.

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16.0 ASSESSMENTS 16.1 General Assessments consist of internal audits and management reviews as set forth in Procedure 1013.

16.2 Audits Internal audits are planned, performed at least annually on all areas of the quality system, and are performed by qualified people who are as independent as possible from the activity audited. (The Laboratorys small size inhibits full independence in some technical areas.) Audits are coordinated by the Quality Manager who assures audit plans and checklists are generated and the results documented. Reports include descriptions of any findings and provide the auditors assessment of the effectiveness of the audited activity. Report data includes personnel contacted.

Audit findings are reviewed with management and corrective actions agreed to and scheduled. Follow up is performed by QA to verify accomplishment and effectiveness of the corrective action.

16.3 Management Reviews The Annual Quality Assurance Report, prepared for some clients, is the Management Review vehicle. These reports cover audit results, corrective and preventive actions, external assessments, and QC and inter-laboratory performance checks. The report is reviewed with Management by the QA Manager for the continued suitability of the Quality Program and its effectiveness. Any needed improvements are defined, documented, and implemented. Follow ups are made to verify implementation and effectiveness.

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Revision 1 APPENDIX D LABORATORY ANALYTICAL REPORTS 045136 (12) Braidwood Generating Station

L28597 1 of 111 L28597 2 of 111 L28597 3 of 111 L28597 4 of 111 L28597 5 of 111 L28597 6 of 111 L28597 7 of 111 L28597 8 of 111 L28597 9 of 111 L28597 10 of 111 L28597 11 of 111 L28597 12 of 111 L28597 13 of 111 L28597 14 of 111 L28597 15 of 111 L28597 16 of 111 L28597 17 of 111 L28597 18 of 111 L28597 19 of 111 L28597 20 of 111 L28597 21 of 111 L28597 22 of 111 L28597 23 of 111 L28597 24 of 111 L28597 25 of 111 L28597 26 of 111 L28597 27 of 111 L28597 28 of 111 L28597 29 of 111 L28597 30 of 111 L28597 31 of 111 L28597 32 of 111 L28597 33 of 111 L28597 34 of 111 L28597 35 of 111 L28597 36 of 111 L28597 37 of 111 L28597 38 of 111 L28597 39 of 111 L28597 40 of 111 L28597 41 of 111 L28597 42 of 111 L28597 43 of 111 L28597 44 of 111 L28597 45 of 111 L28597 46 of 111 L28597 47 of 111 L28597 48 of 111 L28597 49 of 111 L28597 50 of 111 L28597 51 of 111 L28597 52 of 111 L28597 53 of 111 L28597 54 of 111 L28597 55 of 111 L28597 56 of 111 L28597 57 of 111 L28597 58 of 111 L28597 59 of 111 L28597 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123 L28671 24 of 123 L28671 25 of 123 L28671 26 of 123 L28671 27 of 123 L28671 28 of 123 L28671 29 of 123 L28671 30 of 123 L28671 31 of 123 L28671 32 of 123 L28671 33 of 123 L28671 34 of 123 L28671 35 of 123 L28671 36 of 123 L28671 37 of 123 L28671 38 of 123 L28671 39 of 123 L28671 40 of 123 L28671 41 of 123 L28671 42 of 123 L28671 43 of 123 L28671 44 of 123 L28671 45 of 123 L28671 46 of 123 L28671 47 of 123 L28671 48 of 123 L28671 49 of 123 L28671 50 of 123 L28671 51 of 123 L28671 52 of 123 L28671 53 of 123 L28671 54 of 123 L28671 55 of 123 L28671 56 of 123 L28671 57 of 123 L28671 58 of 123 L28671 59 of 123 L28671 60 of 123 L28671 61 of 123 L28671 62 of 123 L28671 63 of 123 L28671 64 of 123 L28671 65 of 123 L28671 66 of 123 L28671 67 of 123 L28671 68 of 123 L28671 69 of 123 L28671 70 of 123 L28671 71 of 123 L28671 72 of 123 L28671 73 of 123 L28671 74 of 123 L28671 75 of 123 L28671 76 of 123 L28671 77 of 123 L28671 78 of 123 L28671 79 of 123 L28671 80 of 123 L28671 81 of 123 L28671 82 of 123 L28671 83 of 123 L28671 84 of 123 L28671 85 of 123 L28671 86 of 123 L28671 87 of 123 L28671 88 of 123 L28671 89 of 123 L28671 90 of 123 L28671 91 of 123 L28671 92 of 123 L28671 93 of 123 L28671 94 of 123 L28671 95 of 123 L28671 96 of 123 L28671 97 of 123 L28671 98 of 123 L28671 99 of 123 L28671 100 of 123 L28671 101 of 123 L28671 102 of 123 L28671 103 of 123 L28671 104 of 123 L28671 105 of 123 L28671 106 of 123 L28671 107 of 123 L28671 108 of 123 L28671 109 of 123 L28671 110 of 123 L28671 111 of 123 L28671 112 of 123 L28671 113 of 123 L28671 114 of 123 L28671 115 of 123 L28671 116 of 123 L28671 117 of 123 L28671 118 of 123 L28671 119 of 123 L28671 120 of 123 L28671 121 of 123 L28671 122 of 123 L28671 123 of 123 L28784 1 of 141 L28784 2 of 141 L28784 3 of 141 L28784 4 of 141 L28784 5 of 141 L28784 6 of 141 L28784 7 of 141 L28784 8 of 141 L28784 9 of 141 L28784 10 of 141 L28784 11 of 141 L28784 12 of 141 L28784 13 of 141 L28784 14 of 141 L28784 15 of 141 L28784 16 of 141 L28784 17 of 141 L28784 18 of 141 L28784 19 of 141 L28784 20 of 141 L28784 21 of 141 L28784 22 of 141 L28784 23 of 141 L28784 24 of 141 L28784 25 of 141 L28784 26 of 141 L28784 27 of 141 L28784 28 of 141 L28784 29 of 141 L28784 30 of 141 L28784 31 of 141 L28784 32 of 141 L28784 33 of 141 L28784 34 of 141 L28784 35 of 141 L28784 36 of 141 L28784 37 of 141 L28784 38 of 141 L28784 39 of 141 L28784 40 of 141 L28784 41 of 141 L28784 42 of 141 L28784 43 of 141 L28784 44 of 141 L28784 45 of 141 L28784 46 of 141 L28784 47 of 141 L28784 48 of 141 L28784 49 of 141 L28784 50 of 141 L28784 51 of 141 L28784 52 of 141 L28784 53 of 141 L28784 54 of 141 L28784 55 of 141 L28784 56 of 141 L28784 57 of 141 L28784 58 of 141 L28784 59 of 141 L28784 60 of 141 L28784 61 of 141 L28784 62 of 141 L28784 63 of 141 L28784 64 of 141 L28784 65 of 141 L28784 66 of 141 L28784 67 of 141 L28784 68 of 141 L28784 69 of 141 L28784 70 of 141 L28784 71 of 141 L28784 72 of 141 L28784 73 of 141 L28784 74 of 141 L28784 75 of 141 L28784 76 of 141 L28784 77 of 141 L28784 78 of 141 L28784 79 of 141 L28784 80 of 141 L28784 81 of 141 L28784 82 of 141 L28784 83 of 141 L28784 84 of 141 L28784 85 of 141 L28784 86 of 141 L28784 87 of 141 L28784 88 of 141 L28784 89 of 141 L28784 90 of 141 L28784 91 of 141 L28784 92 of 141 L28784 93 of 141 L28784 94 of 141 L28784 95 of 141 L28784 96 of 141 L28784 97 of 141 L28784 98 of 141 L28784 99 of 141 L28784 100 of 141 L28784 101 of 141 L28784 102 of 141 L28784 103 of 141 L28784 104 of 141 L28784 105 of 141 L28784 106 of 141 L28784 107 of 141 L28784 108 of 141 L28784 109 of 141 L28784 110 of 141 L28784 111 of 141 L28784 112 of 141 L28784 113 of 141 L28784 114 of 141 L28784 115 of 141 L28784 116 of 141 L28784 117 of 141 L28784 118 of 141 L28784 119 of 141 L28784 120 of 141 L28784 121 of 141 L28784 122 of 141 L28784 123 of 141 L28784 124 of 141 L28784 125 of 141 L28784 126 of 141 L28784 127 of 141 L28784 128 of 141 L28784 129 of 141 L28784 130 of 141 L28784 131 of 141 L28784 132 of 141 L28784 133 of 141 L28784 134 of 141 L28784 135 of 141 L28784 136 of 141 L28784 137 of 141 L28784 138 of 141 L28784 139 of 141 L28784 140 of 141 L28784 141 of 141 L29406 1 of 37 L29406 2 of 37 L29406 3 of 37 L29406 4 of 37 L29406 5 of 37 L29406 6 of 37 L29406 7 of 37 L29406 8 of 37 L29406 9 of 37 L29406 10 of 37 L29406 11 of 37 L29406 12 of 37 L29406 13 of 37 L29406 14 of 37 L29406 15 of 37 L29406 16 of 37 L29406 17 of 37 L29406 18 of 37 L29406 19 of 37 L29406 20 of 37 L29406 21 of 37 L29406 22 of 37 L29406 23 of 37 L29406 24 of 37 L29406 25 of 37 L29406 26 of 37 L29406 27 of 37 L29406 28 of 37 L29406 29 of 37 L29406 30 of 37 L29406 31 of 37 L29406 32 of 37 L29406 33 of 37 L29406 34 of 37 L29406 35 of 37 L29406 36 of 37 L29406 37 of 37 Revision 1 APPENDIX E DATA VALIDATION MEMORANDUM 045136 (12) Braidwood Generating Station