Text

2022 Annual Radiological Environmental Operating Report
	ML23132A130
Person / Time
Site:	LaSalle
Issue date:	05/12/2023
From:	Van Fleet J; Constellation Energy Generation
To:	; Office of Nuclear Reactor Regulation, Document Control Desk
References
	RA23-029
	Download: ML23132A130 (1)
	v • d • e

Constellation~

LaSalle County Station 2601 North 21 " Road Marseilles. IL 61341 815-415-2000 Telephone RA23-029 May 12, 2023 10 CFR 50 Appendix I U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001

Subject:

LaSalle County Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374 2022 Annual Radiological Environmental Operating Report Enclosed is the Constellation Energy Generation, LLC, 2022 Annual Radiological Environmental Operating Report for LaSalle County Station, submitted in accordance with Technical Specification 5.6.2, "Annual Radiological Environmental Operating Report." The enclosed report contains the results of groundwater monitoring conducted in accordance with Constellation's Radiological Groundwater Protection Program, which is a voluntary program implemented in 2006. This information is being reported in accordance with a nuclear industry initiative.

There are no regulatory commitments contained within this letter. Should you have any questions concerning this letter, please contact Mr. Daniel Mearhoff, Regulatory Assurance Manager, at (815) 415-2800.

Respectfully, John Van Fleet Site Vice President LaSalle County Station

Enclosures:

LaSalle County Station Units 1 and 2 Annual Radiological Environmental Operating Report 1 January through 31 December 2022 cc:

Regional Administrator-NRC Region Ill NRC Senior Resident Inspector - LaSalle County Station

Docket No:

50-373 50-374 LASALLE COUNTY STATION UNITS 1 and 2 Annual Radiological Environmental Operating Report 1 January through 31 December 2022 Prepared By Teledyne Brown Engineering Environmental Services Constellation~

LaSalle County Station Marseilles, IL 61341 May 2023

Intentionally left blank

Table Of Contents I. Summary and Conclusions.............................................................................................. 1 II. Introduction...................................................................................................................... 3 A. Objectives of the REMP....................................................................................... 3 B. Implementation of the Objectives........................................................................ 3 Ill. Program Description....................................................................................................... 4 A. Sample Collection................................................................................................ 4 B. Sample Analysis.................................................................................................. 6 C. Data Interpretation............................................................................................... 6 D. Program Exceptions............................................................................................ 7 E. Program Changes............................................................................................... 8 IV. Results and Discussion................................................................................................. 9 A. Aquatic Environment........................................................................................... 9

1. Surface Water........................................................................................... 9

2. Ground/Well Water................................................................................... 9

3. Fish......................................................................................................... 10

4. Sediment................................................................................................. 10 B. Atmospheric Environment................................................................................. 10

1. Airborne.................................................................................................. 10

a. Air Particulates............................................................................. 10

b. Airborne Iodine............................................................................. 11

2. Terrestrial................................................................................................ 11

a. Milk............................................................................................... 11

b. Food Products.............................................................................. 11

c. Vegetation.................................................................................... 11 C. Ambient Gamma Radiation............................................................................... 12 D. Land Use Census.............................................................................................. 12 E. Errata Data........................................................................................................ 13 F. Summary of Results - Inter-laboratory Comparison Program........................... 13

Appendix A Tables Table A-1 Appendix B Tables Table B-1 Table B-2 Figures Figure B-1 Figure B-2 Figure B-3 Appendix C Tables Table C-1.1 Table C-1.2 Table C-1.3 Table C-I1.1 Table C-I1.2 Table C-II1.1 Appendices Radiological Environmental Monitoring Report Annual Summary Radiological Environmental Monitoring Program Annual Summary for the LaSalle County Station, 2022 Location Designation, Distance & Direction, and Sample Collection &

Analytical Methods Radiological Environmental Monitoring Program - Sampling Locations, Distance and Direction, LaSalle County Station, 2022 Radiological Environmental Monitoring Program - Summary of Sample Collection and Analytical Methods, LaSalle County Station, 2022 Inner Ring OSLO Locations of the LaSalle County Station, 2022 Outer Ring OSLO Locations and Fixed Air Sampling Locations of the LaSalle County Station, 2022 Ingestion and Waterborne Exposure Pathway Sample Locations of the LaSalle County Station, 2022 Data Tables and Figures - Primary Laboratory Concentrations of Gross Beta in Surface Water Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Tritium in Surface Water Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Gamma Emitters in Surface Water Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Tritium in Ground/Well Water Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Gamma Emitters in Ground/Well Water Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Gamma Emitters in Fish Samples Collected in the ii

Table C-IV.1 Table C-V.1 Table C-V.2 Table C-V.3 Table C-Vl.1 Table C-Vll.1 Table C-Vll.2 Table C-Vlll.1 Table C-Vlll.2 Table C-IX.1 Figures Figure C-1 Figure C-2 Figure C-3 Figure C-4 Figure C-5 Figure C-6 Figure C-7 Figure C-8 Vicinity of LaSalle County Station, 2022 Concentrations of Gamma Emitters in Sediment Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Gross Beta in Air Particulate Samples Collected in the Vicinity of LaSalle County Station, 2022 Monthly and Yearly Mean Values of Gross Beta Concentrations in Air Particulate Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Gamma Emitters in Air Particulate Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of 1-131 in Air Iodine Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of 1-131 in Milk Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Gamma Emitters in Milk Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Gamma Emitters in Food Product Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Gamma Emitters in Vegetation Samples Collected in the Vicinity of LaSalle County Station, 2022 Quarterly DLR Results for LaSalle County Station, 2022 Surface Water - Gross Beta - Stations L-21 (C) and L-40 Collected in the Vicinity of LSCS, 2005 - 2022 Surface Water - Tritium - Stations L-21 (C) and L-40 Collected in the Vicinity of LSCS, 2005 - 2022 Air Particulate - Gross Beta - Stations L-01 and L-03 Collected in the Vicinity of LSCS, 2005 - 2022 Air Particulate - Gross Beta - Stations L-05 and L-06 Collected in the Vicinity of LSCS, 2005 - 2022 Air Particulate - Gross Beta - Station L-10 (C) Collected in the Vicinity of LSCS, 2005 - 2022 Air Particulate - Gross Beta - Stations L-04 and L-07 Collected in the Vicinity of LSCS, 2005 - 2022 Air Particulate - Gross Beta - Stations L-08 and L-11 Collected in the Vicinity of LSCS, 2005 - 2022 Air Particulate - Gross Beta - Station L-11A Collected in the Vicinity of LSCS, 2016 - 2022 iii

Appendix D Tables Table D-1 Table D-2 Table D-3 Appendix E Appendix F Inter-Laboratory Comparison Program Analytics Environmental Radioactivity Cross Check Program Teledyne Brown Engineering Environmental Services, 2022 DOE's Mixed Analyte Performance Evaluation Program (MAPEP)

Teledyne Brown Engineering Environmental Services, 2022 ERA Environmental Radioactivity Cross Check Program Teledyne Brown Engineering Environmental Services, 2022 Errata Data Annual Radiological Groundwater Protection Program Report (ARGPPR) iv

I.

Summary and Conclusions In 2022, the LaSalle Generating Station released to the environment through the radioactive effluent gaseous pathways approximately 899 curies of noble gas, fission, and activation products and approximately 46.4 curies of tritium. There were no liquid effluent releases beyond the site in 2022. The resultant calculated dose due to solid and gaseous radioactive effluents from LAS were well below regulatory limits of 40 CFR 190 and are summarized below:

Calculated Dose to Members of the Public Whole Body Thyroid Max Other Organ Gaseous 1.2 1.31E-02 1.12E-01 4.64E-02 Liquid 0.00E+00 0.00E+00 0.00E+00 Sky Shine 7.92E-01 Total Site Dose 8.05E+01 1.12E-01 4.64E-02 Total with Other 8.05E-01 1.12E-01 4.64E-02 Nearbv Facilitv 3 Limit 25 mrem 75 mrem 25 mrem

% of Limit 3.22E+00 1.49E-01 1.86E-01 1 Gaseous dose values include organ dose from Noble Gas, Iodine, Tritium. Carbon-14 and particulates with half-lives > 8 days 2 Individual groups with the highest dose are used:

Total Body: all age groups for Noble Gas and the Child for particulates Thyroid: the Infant Max Other Organ: Individual age group sum is lower 3 Other fuel cycle sources within 5 miles of the site do not exist This report on the Radiological Environmental Monitoring Program conducted for the LaSalle County Station (LSCS) by Constellation (formerly Exelon) covers the period 1 January 2022 through 31 December 2022. During that time period, 1,308 analyses were performed on 1,227 samples. In assessing all the data gathered for this report and comparing these results with preoperational data, it was concluded that the operation of LSCS had no adverse radiological impact on the environment.

Surface water samples were analyzed for concentrations of gross beta, tritium and gamma-emitting nuclides. Ground/well water samples were analyzed for concentrations of tritium and gamma-emitting nuclides. No fission or activation products were detected. Gross beta and tritium activities detected were consistent with those detected in previous.

Commercially and recreationally important fish species were sampled and analyzed for concentrations of gamma-emitting nuclides. No fission or activation products were detected in fish.

Sediment samples were analyzed for concentrations of gamma-emitting nuclides.

No fission or activation products were detected.

Air particulate samples were analyzed for concentrations of gross beta and gamma-emitting nuclides. No fission or activation products were detected.

High sensitivity iodine-131 (1-131) analyses were performed on weekly air samples. All results were less than the minimum detectable activity for 1-131.

Cow milk samples were analyzed for concentrations of 1-131 and gamma-emitting nuclides. All I-131 results were below the minimum detectable activity.

Concentrations of naturally occurring potassium-40 (K-40) were consistent with those detected in previous years. No fission or activation products were found.

All nuclides were below the minimum detectable activity.

Food product samples were analyzed for concentrations of gamma-emitting nuclides. No fission or activation products were detected.

Vegetation samples were analyzed for concentrations of gamma-emitting nuclides.

No fission or activation products were detected.

Environmental gamma radiation measurements were performed quarterly using Optically Stimulated Luminescence Dosimeters (OSLO) for the Radiological Environmental Monitoring Program (REMP). The results from the environmental gamma radiation monitoring program were consistent with those detected in previous years.

II.

Introduction The LaSalle County Station (LSCS), consists of two boiling water reactors, each rated for 3,546 MWt. Both units are owned and operated by Constellation Energy and are located in LaSalle County, Illinois. Unit 1 went critical on 16 March 1982.

Unit 2 went critical on 02 December 1983. The site is located in northern Illinois, approximately 75 miles southwest of Chicago, Illinois.

A Radiological Environmental Monitoring Program (REMP) for LSCS was initiated in 1982 (the preoperational period for most media covers the periods 1 January 1979 through 26 December 1981 and was summarized in a separate report.).

This report covers those analyses performed by Teledyne Brown Engineering (TBE) and Landauer on samples collected during the period 1 January 2022 through 31 December 2022.

A.

Objectives of the REMP The objectives of the REMP are to:

1.

Provide data on measurable levels of radiation and radioactive materials in the site environs.

2. Evaluate the relationship between quantities of radioactive material released from the plant and resultant radiation doses to individuals from principal pathways of exposure.

B.

Implementation of the Objectives The implementation of the objectives is accomplished by:

1. Identifying significant exposure pathways.

2. Establishing baseline radiological data of media within those pathways.

3.

Continuously monitoring those media before and during Station operation to assess Station radiological effects (if any) on man and the environment.

Ill.

Program Description A.

Sample Collection Samples for the LSCS REMP were collected for Constellation by Environmental Inc. (Midwest Labs). This section describes the general collection methods used by Environmental Inc. (Midwest Labs) to obtain environmental samples for the LSCS REMP in 2022. Sample locations and descriptions can be found in Tables 8-1 and 8-2, and Figures B-1 through B-3, Appendix B.

Aquatic Environment The aquatic environment was evaluated by performing radiological analyses on samples of surface water, ground/well water, fish, and sediment. Two gallon water samples were collected weekly from two surface water locations (L-21 and L-40) and composited for monthly and quarterly required analyses. Control location was L-21. Two ground/well water locations (L-27 and L-28) were also grab sampled quarterly. Wells 4, 5 and 6 are associated with L-28. L-27 and L-28 Well 6 could be affected by LaSalle's effluent releases. All samples were collected via grab sample.

The samples were then transferred to new unused plastic containers. Both the grab container and the sample containers were rinsed with source water prior to actual sample collection. Fish samples were collected semiannually at three locations, L-34, L-35 and L-36 (Control). Sediment samples composed of recently deposited substrate were collected at three locations semiannually, L-21 (Control), L-40 and L-41.

Atmospheric Environment The atmospheric environment was evaluated by performing radiological analyses on samples of airborne particulate and iodine. Airborne particulate and iodine samples were collected and analyzed weekly at nine locations (L-01, L-03, L-04, L-05, L-06, L-07, L-08, L-10, and L-11A). The control location was L-10. Airborne particulate and iodine samples were obtained at each location, using a vacuum pump to pull air through an iodine cartridge and a glass fiber particulate filter. The pumps were run continuously and sampled air at the rate of approximately one cubic foot per minute. The particulate filters and iodine cartridges were replaced weekly and sent to the laboratory for analysis.

Terrestrial Environment The terrestrial environment was evaluated by performing radiological analyses on samples of milk and food product. Samples are typically collected biweekly at one milk location (L-42) from May through September, and monthly from December through April. The control location was L-42.

All samples, when available, were collected in new unused two gallon plastic bottles from the bulk tank at each location, preserved with sodium bisulfite, and shipped promptly to the laboratory.

Food products were collected during the growing season at four locations (L-42, L-Quad 1, L-Quad 2 and L-Quad 4). The control location was L-42.

Various types of samples were collected and placed in new unused plastic bags and sent to the laboratory for analysis.

Vegetation samples were collected monthly during the growing season from May through October at three locations (L-Veg C, L-ESE1, and L-ESE2).

The control location was L-Veg C and was located in the lowest deposition sector (ENE sector) surrounding LaSalle. Various vegetation samples were also collected in the highest deposition sector (ESE sector) surrounding LaSalle. The samples were collected and placed in new unused plastic bags and sent to the laboratory for analysis.

Ambient Gamma Radiation Beginning in the first quarter of 2012, the type of dosimetry used for the Radiological Environmental Monitoring Program (REMP) was changed.

Optically Stimulated Luminescent Dosimetry (OSLO) were deployed and Thermo-luminescent Dosimetry (TLD) were discontinued. This change may cause step changes in readings, up or down, depending on site characteristics. However, the relative comparison to control locations remains valid. OSLO technology is different than that used in a TLD but has the same purpose (to measure direct radiation).

Each location consisted of 2 OSLO sets. The OSLDs were exchanged quarterly and sent to Landauer for analysis. The OSLO locations were placed on and around the LSCS site as follows:

An inner ring consisting of 16 locations (L-101, L-102, L-103, L-104, L-105, L-106, L-107, L-108, L-109, L-110, L-1118, L-112, L-113A, L-114, L-115 and L-116) near and within the site perimeter representing fence post doses (i.e., at locations where the doses will be potentially greater than maximum annual off-site doses from LSCS releases).

An outer ring consisting of 17 locations (L-201, L-202, L-203, L-204, L-205A, L-2058, L-206, L-207, L-208, L-209, L-210, L-211, L-212, L-213, L-214, L-215 and L-216) extending to approximately 5 miles from the site designed to measure possible exposures to nearby population.

An other set consisting of eight locations (L-01, L-03, L-04, L-05, L-06, L-07, L-08, and L-11A).

The balance of one location (L-10) represe_nting the control area.

The specific OSLO locations were determined by the following criteria:

1. The presence of relatively dense population;

2. Site meteorological data taking into account distance and elevation for each of the sixteen 22 1/2 degree sectors around the site, where estimated annual dose from LSCS, if any, would be most significant;

3.

On hills free from local obstructions and within sight of the vents (where practical);

4.

And near the closest dwelling to the vents in the prevailing downwind direction.

(Two OSLDs were placed at each location approximately six feet above ground level.)

B.

Sample Analysis This section describes the general analytical methodologies used by Environmental Inc. (Midwest Labs) and TBE to collect and analyze, respectively, the environmental samples for radioactivity for the LSCS REMP in 2022. The analytical procedures used by the laboratory are listed in Table B-2.

In order to achieve the stated objectives, the current program includes the following analyses:

1.

Concentrations of beta emitters in surface water and air particulates

2.

Concentrations of gamma emitters in ground/well and surface water, air particulates, milk, fish, sediment and vegetation

3.

Concentrations of tritium in ground/well and surface water

4.

Concentrations of 1-131 in air and milk

5.

Ambient gamma radiation levels at various site environs C.

Data Interpretation The radiological and direct radiation data collected prior to LaSalle County Station becoming operational were used as a baseline with which these operational data were compared. For the purpose of this report, LaSalle County Station was considered operational at initial criticality. In addition, data were compared to previous years' operational data for consistency and trending. Several factors were important in the interpretation of the data:

1.

Lower Limit of Detection and Minimum Detectable Concentration The lower limit of detection (LLD) is defined as the smallest concentration of radioactive material in a sample that would yield a net count (above background) that would be detected with only a 5%

probability of falsely concluding that a blank observation represents a "real" signal. The LLD is intended as a before the fact (a priori) estimate of a system (including instrumentation, procedure and sample type) and not as an after the fact (a posteriori) criteria for the presence of activity. All analyses were designed to achieve the required LSCS detection capabilities for environmental sample analysis.

The minimum detectable concentration (MDC) is defined above with the exception that the measurement is an after the fact estimate of the presence of activity.

2. Net Activity Calculation and Reporting of Results Net activity for a sample was calculated by subtracting background activity from the sample activity. Since the REMP measures extremely small changes in radioactivity in the environment, background variations may result in sample activity being lower than the background activity effecting a negative number. An MDC was reported in all cases where positive activity was not detected.

Gamma spectroscopy results for each type of sample were grouped as follows:

For surface water, food products, and vegetation: 12 nuclides including Mn-54, Co-58, Fe-59, Co-60, Zn-65, Zr-95, Nb-95, 1-131, Cs-134, Cs-137, Ba-140, and La-140 were reported.

For ground/well water, fish, sediment, air particulate and milk:

11 nuclides including Mn-54, Co-58, Fe-59, Co-60, Zn-65, Zr-95, Nb-95, Cs-134, Cs-137, Ba-140, and La-140 were reported.

Means and standard deviations of the results were calculated. The standard deviations represent the variability of measured results for different samples rather than single analysis uncertainty.

D.

Program Exceptions For 2022, the LSCS REMP had a sample recovery rate of >99%. Sample anomalies and missed samples are listed in the following tables:

Table D-1 LISTING OF SAMPLE ANOMALIES Sample Location Collection Reason Type Code Date(s)

AP/Al L-06 01/06/22 Timer indicates approximately 14.7 hrs. less than expected due to 01/12/22 a power outage Timer indicates approximately 27 hrs. less than expected due to a AP/Al L-06 01/20/22 power outage.

NOTE: During the 01/20 collection, the cause of time deficiency was determined to be a faulty timer - timer exchanqed SW L-21 01/12/22 No sample collected - river frozen 01/27/22 01/12/22 01/20/22 SW L40 01/27/22 No sample collected - river frozen 02/03/22 02/18/22 AP/Al L-03 02/09/22 2 weeks run - Collector unable to access the sampler during L-05 02/03/22 collection due to heavy snow accumulation The timer indicates lower reading of 1441.5 hrs. for the 7-day collection period. No power at the station; flow rate estimated AP/Al L-04 03/24/22 based on 03/17 field check; power restored after 2 hrs.

NOTE: During the 03131 collection, the timer indicated 163.0 hrs.

(exoected value for the collection oeriod).

Table D-1 LISTING OF SAMPLE ANOMALIES (cont'd)

Sample Location Collection Reason Type Code Date The timer broke down after 17.3 hrs - the filter appears to be AP/Al L-11A 06/01/22 similar color to the other ones. Run time calculated, timer exchanged.

L-03 The timer indicates lower reading of 159.3 on the 8-day collection AP/Al L-07 07/07/22 period, possibly due to a power outage. Note: During the 07113 collection, the L-03 timer indicated expected value of 144.9 hrs.

AP/Al L-07 07/13/22 The timer broke down indicating O hrs; filter appears to be similar color to others. Timer exchanged.

Timer displayed 10 hrs. less than expected; timer exchanged AP/Al L-03 08/31/22 NOTE: During the 09/08 collection the timer indicated expected value of 190. 8 hrs.

The timer indicates lower value of 119.1 hrs., possibly due to a AP/Al L-04 09/22/23 power outage.

NOTE: During the 09/28 collection, the timer indicated 144.9 hrs (expected value for the 6-dav collection period).

OSLO L-103-2 09/30/22 Sample missing in the field - premises searched unsuccessfully.

OSLO L-03-2 12/31/22 Sample missing in the field - premises searched unsuccessfully.

SW L-21 12/28/22 No sample collected - river frozen L-40 Table D-2 LISTING OF MISSED SAMPLES Sample Location Collection Reason Type Code Date(s)

Ml L-42

>04/07/22 Farmer stopped milking cows.

AP/Al L-03 02/03/22 Locations inaccessible due to heavy snowfall.

L-05 VEG QUA03 July August Unable to collect vegetables from the sector - previous location September abandoned/sold.

Each program exception has been reviewed to understand the causes of the program exception. Occasional equipment breakdowns and power outages were unavoidable.

The overall sample recovery rate indicates that the appropriate procedures and equipment are in place to assure reliable program implementation.

E.

Program Changes There were no program changes in 2022.

IV.

Results and Discussion A

Aquatic Environment

1.

Surface Water Samples were taken weekly and composited monthly at two locations (L-21 and L-40). Of these locations only L-40 located downstream, could be affected by LaSalle's effluent releases. The following analyses were performed:

Gross Beta Samples from all locations were analyzed for concentrations of gross beta (Table C-1.1, Appendix C). Gross beta was detected in 23 out of 24 samples with a range of 2.9 to 13.4 pCi/L. (Figure C-1, Appendix C). The required LLD was met for all samples.

Tritium Quarterly composites of weekly collections were analyzed for tritium activity (Table C-1.2, Appendix C). Tritium was detected in 4 of 8 samples with a range of 197 - 546 pCi/L. Concentrations detected were consistent with those detected in previous years.

(Figure C-2, Appendix C).

Gamma Spectrometry Samples from both locations were analyzed for gamma-emitting nuclides (Table C-1.3, Appendix C). No nuclides were detected, and all required LLDs were met.

2. Ground/Well Water Quarterly grab samples were collected at two locations (L-27 and L-28). Wells 4, 5 and 6 are associated with L-28. L-27 and L-28 Well 6 could be affected by LaSalle's effluent releases. The following analyses were performed:

Tritium Quarterly grab samples from the locations were analyzed for tritium activity (Table C-11.1, Appendix C). No tritium was detected and the contractually-required 200 pCi/L LLDs were met.

Gamma Spectrometry Samples from all locations were analyzed for gamma-emitting nuclides (Table C-11.2, Appendix C). No nuclides were detected, and all required LLDs were met.

3.

Fish Fish samples were collected at three locations (L-34, L-35 and L-36) semiannually. Locations L-34 and L-35 could be affected by LaSalle's effluent releases. The following analysis was performed:

Gamma Spectrometry The edible portion of fish samples from both locations was analyzed for gamma-emitting nuclides (Table C-111.1, Appendix C). Naturally occurring K-40 was found at all stations and ranged from 1,835 to 3,786 pCi/kg wet. No fission or activation products were found.

4.

Sediment Aquatic sediment samples were collected at three locations (L-21, L-40 and L-41) semiannually. Location L-21 is located upstream and is not affected by LaSalle's liquid effluent releases. Locations L-40 and L-41, located downstream, could be affected by LaSalle's effluent releases.

The following analysis was performed:

Gamma Spectrometry Sediment samples from the three locations were analyzed for gamma-emitting nuclides (Table C-IV.1, Appendix C). Naturally occurring Be-7 was found at two stations and ranged from 1,118 to 1,830 pCi/kg dry.

Naturally occurring K-40 was found at all stations and ranged from 8,502 to 17,880 pCi/kg dry. No fission or activation products were found.

B.

Atmospheric Environment

1.

Airborne

a.

Air Particulates Continuous air particulate samples were collected from nine locations on a weekly basis. The nine locations were separated into four groups: Group I (onsite) represents locations within the LSCS site boundary (L-03 and L-05), Group II (near-site) represents the locations near the LSCS site (L-01 and L-06),

Group Ill (far-field) represents the locations at an intermediate distance from LSCS (L-04, L-07, L-08, and L-11A) and Group IV (control) represents the control location at a remote distance (L-10). The following analyses were performed:

Gross Beta Weekly samples were analyzed for concentrations of beta emitters (Table C-V.1 and C-V.2, Appendix C). Detectable gross beta activity was observed at all locations. Comparison of results among the four groups aid in determining the effects, if any, resulting from the operation of LSCS. The results from the onsite locations (Group I) ranged from 8 to 39E-3 pCi/m3 with a mean of 20E-3 pCi/m3. The results from the near-site location (Group II) ranged from 9 to 41 E-3 pCi/m3 with a mean of 21 E-3 pCi/m3.

The results from the far-field locations (Group Ill) ranged from 8 to 42E-3 pCi/m3 with a mean of 22E-3 pCi/m3. The results from the control location (Group IV) ranged from 10 to 40E-3 pCi/m3 with a mean of 22E-3 pCi/m3. Comparison of the 2022 air particulate data with previous years' data indicate no effects from the operation of LSCS (Figures C-3 through C-8, Appendix C). In addition, comparisons of the weekly mean values for 2022 indicate no notable differences among the four groups.

Gamma Spectrometry Weekly samples were composited quarterly and analyzed for gamma-emitting nuclides (Table C-V.3, Appendix C). Naturally occurring Be-7, due to cosmic ray activity, was detected in 36 of 36 samples. These values ranged from 84 to 166E-3 pCi/m3. All other nuclides were less than the MDC.

b.

Airborne Iodine Continuous air samples were collected from ten locations (L-01, L-03, L-04, L-05, L-06, L-07, L-08, L-10, and L-11A) and analyzed weekly for 1-131 (Table C-Vl.1, Appendix C). No 1-131 was detected.

2.

Terrestrial

a.

Milk One sample was collected from one location (L-42) during 2022.

The following analyses were performed:

lodine-131 One sample from the location was analyzed for concentrations of 1-131 (Table C-Vll.1, Appendix C). 1-131 was not detected, and the required LLDs were met.

Gamma Spectrometry One sample was analyzed for concentrations of gamma-emitting nuclides (Table C-Vll.2, Appendix C). Naturally occurring K-40 activity was found in the sample with a concentration of 770 pCi/L.

No other nuclides were detected, and all required LLDs were met.

b.

Food Products Food product samples were collected at four locations (L42, L-Quad 1, L-Quad 2 and L-Quad 4) when available. All locations could be affected by LaSalle's effluent releases. The following analysis was performed:

Gamma Spectrometry Samples from all available locations were analyzed for gamma-emitting nuclides (Table C-Vlll.1, Appendix C). No nuclides were detected, and all required LLDs were met.

c.

Vegetation Vegetation samples were collected monthly during the growing season from May through October at three locations (L-Veg C, L-ESE-1, and L-ESE-2). The control location was L-Veg C and was located in the lowest deposition sector (ENE sector) surrounding LaSalle. Various vegetation samples were also collected in the highest deposition sector (ESE sector) surrounding LaSalle. The following analyses were performed:

Gamma Spectrometry Samples from all available locations were analyzed for gamma-emitting nuclides (Table C-Vlll.2, Appendix C). No nuclides were detected, and all required LLDs were met.

C.

Ambient Gamma Radiation Ambient gamma radiation levels were measured utilizing Optically Stimulated Luminescence Dosimeters (OSLO). Forty-two OSLO locations were established around the site. Results of OSLO measurements are listed in Tables C-IX.1, Appendix C.

All OSLO measurements were below 21 mrem/std. quarter, with a range of 13.0 to 20.5 mrem/quarter. A comparison of the Normalized Annual Dose to the Baseline Background and Minimum Differential Dose indicates that there is no evidence of dose which could be attributed to facility-related direct radiation.

D.

Land Use Census A Land Use Census conducted September 6, 2022, around the LaSalle County Station (LSCS) was performed by Environmental Inc. (Midwest Labs) for Constellation Energy to comply with Radiological Effluent Control 12.5.2 of the LaSalle's Offsite Dose Calculation Manual. The purpose of the survey was to document the nearest resident and milk producing animal in each of the sixteen 22 1/2 degree sectors around the site within 10 km (6.2 miles). The distance and direction of all locations from the LSCS reactor buildings were positioned using Global Positioning System (GPS) technology. Since there were no milk animals within 10 km of LSCS, beef cows were identified. There were no changes required to the LSCS REMP as a result of this survey. The results of this survey are summarized below:

Distance in Miles from the LSCS Reactor Buildings Sector Residence Livestock Milk Farm Miles Miles Miles A

N 3.9 4.0 B

NNE 1.6 1.7 C

NE 2.1 3.5 D

ENE 3.3 4.6 E

E 3.2 14.2 F

ESE 1.4 G

SE 1.7 5.1 H

SSE 1.8 4.7 J

s 1.5 1.5 K

SSW 0.7 L

SW 1.0 5.8 M

WSW 1.5 N

w 1.7 3.0 p

WNW 0.9 3.0 Q

NW 1.7 3.3 R

NNW 1.7 4.5 E.

Errata Data There is no errata data for 2022.

F.

Summary of Results - Inter-Laboratory Comparison Program The TBE Laboratory analyzed Performance Evaluation (PE) samples of air particulate, air iodine, milk, soil, vegetation, and water matrices for various analytes. The PE samples supplied by Analytics Inc., Environmental Resource Associates (ERA) and Department of Energy (DOE) Mixed Analyte Performance Evaluation Program (MAPEP), were evaluated against the following pre-set acceptance criteria:

1.

Analytics Evaluation Criteria Analytics' evaluation report provides a ratio of TBE's result and Analytics' known value. Since flag values are not assigned by Analytics, TBE evaluates the reported ratios based on internal QC requirements based on the DOE MAPEP criteria.

2.

ERA Evaluation Criteria ERA's evaluation report provides an acceptance range for control and warning limits with associated flag values. ERA's acceptance limits are established per the USEPA, National Environmental Laboratory Accreditation Conference (NELAC), state-specific Performance Testing (PT) program requirements or ERA's SOP for the Generation of Performance Acceptance Limits, as applicable.

The acceptance limits are either determined by a regression equation specific to each analyte or a fixed percentage limit promulgated under the appropriate regulatory document.

3.

DOE Evaluation Criteria MAPEP's evaluation report provides an acceptance range with associated flag values. MAPEP defines three levels of performance:

Acceptable (flag = "A") - result within +/- 20% of the reference value Acceptable with Warning (flag = "W') - result falls in the +/- 20% to

+/- 30% of the reference value Not Acceptable (flag = "N") - bias is greater than 30% of the reference value Note: The Department of Energy (DOE) Mixed Analyte Performance Evaluation Program (MAPEP) samples are created to mimic conditions found at DOE sites which do not resemble typical environmental samples obtained at commercial nuclear power facilities.

For the TBE laboratory, laboratory, 142 out of 150 analyses performed met the specified acceptance criteria. Eight analyses did not meet the specified acceptance criteria and were addressed through the TBE Corrective Action Program. NOTE: Two analyses (soil for Tc-99 and U-238) that did not meet acceptance criteria was performed for TBE information and is not on the list of required /GP analyses. A summary is found below:

1.

The Analytics March 2022 AP Ce-141 result was evaluated as Not Acceptable. The reported value for Ce-141 was 60.9 pCi and the known result was 42.0 pCi/L (1.45 ratio of reported result vs. known; TBE's internal acceptance range is 0.70 - 1.30). This sample was used as the workgroup duplicate with a result of 45. 7 (109% of known) and was also counted on a different detector with a result of 50.9 (121 % of known). This was TBE's first failure for AP Ce-141. (NCR 22-04)

2.

The MAPEP February 2022 Urine U-234 & U-238 results were evaluated as Not Acceptable. TBE's reported values of 0.142 and 0.0254 were above the known upper ranges of 0.0096 and 0.0134 respectively for U-234 and U-238. These spiked values were below TBE's typical MDC for urine client samples. The samples were re-prepped using a larger sample aliquot and counted for 60 hours6.944444e-4 days 0.0167 hours 9.920635e-5 weeks 2.283e-5 months as opposed to 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months . The recount results were 0.00732 for U-234 and 0.0119 for U-238 (both within acceptable range). MAPEP urine samples will be flagged to use a larger sample aliquot and counting time than typical client samples. MAPEP did not include any urine cross-check samples in August. (NCR 22-05)

3.

The ERA MRAD September 2022 AP Pu-238 was evaluated as Not Acceptable. The reported value was 38.8 pCi and the known result was 29.9 (acceptance range 22.6 - 36.7). The AP filter was cut in half prior to digestion (shared with Fe-55) but should have been complete digested together and aliquotted afterwards like typical client samples.

This is the first failure for AP Pu-238. (NCR 22-19)

4. The ERA October 2022 water Uranium result was evaluated as Not Acceptable. The reported value was 10.54 pCi/L and the known was 8.53 (acceptance range 6.60 - 9.88) or 124% of the known (acceptable for TBE QC). The 2-sigma error was 3.2, placing the reported result well within the acceptable range. This sample was used as the workgroup duplicate with a result of 8.2 +/- 2.9 pCi/L (also within the acceptable range). All other QA was reviewed with no anomalies.

(NCR 22-20)

5.

The Analytics AP Co-60 result was evaluated as Not Acceptable. The reported value was 207 pCi and the known was 14 7 (141 % of the known). TBE's internal QC acceptance is 70 - 130%. All QA was reviewed with no anomalies. This sample was used as the workgroup duplicate and counted on a different detector with a result of 167 pCi (114% of the known). This is the first failure for AP Co average result ratio compared to the known is 109%. (NCR 22-21)

6.

The MAPEP August 2022 water Tc-99 result was evaluated as Not Acceptable. The reported value was 1.86 +/- 0.414 Bq/L for this "false positive" test. The evaluation of the submitted result to the 3 times the uncertainty indicated a slight positive. This sample was used as the workgroup duplicate with a result of 0.88 +/- 0.374 Bq/L. All QC was reviewed, and no anomalies found. This is the first unacceptable since the resumption of reporting water Tc-99 for the 3rd quarter of 2020.

TBE to known ratios have ranged from 94-109% during this time.

(NCR 22-22)

The Inter-Laboratory Comparison Program provides evidence of "in control" counting systems and methods, and that the laboratories are producing accurate and reliable data.

Intentionally left blank

APPENDIX A RADIOLOGICAL ENVIRONMENTAL MONITORING REPORT ANNUAL

SUMMARY

Intentionally left blank

TABLE A-1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL

SUMMARY

FOR THE LASALLE COUNTY STATION, 2022 NAME OF FACILITY:

LASALLE COUNTY STATION DOCKET NUMBER:

50-373 & 50-374 LOCATION OF FACILITY:

MARSEILLES, IL REPORTING PERIOD:

2022 INDICATOR CONTROL LOCATION WITH HIGHEST ANNUAL MEAN (M)

MEDIUM OR REQUIRED LOCATIONS LOCATION NUMBER OF PATHWAY SAMPLED TYPES OF NUMBER OF LOWER LIMIT MEAN(M)

MEAN(M)

STATION#

NON ROUTINE (UNITOF ANALYSES ANALYSES OF DETECTION (F)

(F)

NAME REPORTED MEASUREMENrJ.

PERFORMED PERFORMED

!LLDl RANGE RANGE RANGE DISTANCE AND DIRECTION MEASUREMENTS SURFACE WATER GR-B 24 4

7.8 7.8 7.8 L-40 INDICATOR 0

(PCI/LITER)

(12/12)

(11/12)

(12/12)

ILLINOIS RIVER - DOWNSTREAM 2.9-13.4 3.9-12.2 2.9-13.4 5.2 MILES NNW OF SITE H-3 8

200 372 360 372 L-40 INDICATOR 0

(2/4)

ILLINOIS RIVER - DOWNSTREAM 197 -546 200-520 197 - 546 5.2 MILES NNW OF SITE GAMMA 24 MN-54 15

<LLD

<LLD 0

CO-58 15

<LLD

<LLD 0

FE-59 30

<LLD

<LLD 0

)>

CO-60 15

<LLD

<LLD 0

I....

ZN-65 30

<LLD

<LLD 0

NB-95 15

<LLD

<LLD 0

ZR-95 30

<LLD

<LLD 0

1-131 15

<LLD

<LLD 0

CS-134 15

<LLD

<LLD 0

CS-137 18

<LLD

<LLD 0

BA-140 60

<LLD

<LLD 0

LA-140 15

<LLD

<LLD 0

GROUND WATER H-3 12 200

<LLD

<LLD 0

(PCIILITER)

GAMMA 12 MN-54 15

<LLD

<LLD 0

CO-58 15

<LLD

<LLD 0

FE-59 30

<LLD

<LLD 0

C0-60 15

<LLD

<LLD 0

ZN-65 30

<LLD

<LLD 0

NB-95 15

<LLD

<LLD 0

ZR-95 30

<LLD

<LLD 0

CS-134 15

<LLD

<LLD 0

CS-137 18

<LLD

<LLD 0

BA-140 60

<LLD

<LLD 0

LA-140 15

<LLD

<LLD 0

(M) The Mean Values are calculated using the positive values (values~ MDC). (F) Fraction of detectable measurement are indicated in parentheses.

TABLE A-1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL

SUMMARY

FOR THE LASALLE COUNTY STATION, 2022 NAME OF FACILITY:

LASALLE COUNTY STATION DOCKET NUMBER:

50-373 & 50-374 LOCATION OF FACILITY:

MARSEILLES, IL REPORTING PERIOD:

2022 INDICATOR CONTROL LOCATION WITH HIGHEST ANNUAL MEAN (M)

MEDIUM OR REQUIRED LOCATIONS LOCATION NUMBER OF PATHWAY SAMPLED TYPES OF NUMBER OF LOWER LIMIT MEAN(M)

MEAN(M)

STATION#

NON ROUTINE (UN/TOF ANALYSES ANALYSES OF DETECTION (F)

(F)

NAME REPORTED MEASUREMENrJ.

PERFORMED PERFORMED

!LLDl RANGE RANGE RANGE DISTANCE AND DIRECTION MEASUREMENTS FISH GAMMA 12 (PCIIKG WE7)

K-40 NA 2897 3146 3146 L-36 CONTROL 0

(8/8)

(4/4)

ILLINOIS RIVER - UPSTREAM 1993 - 3786 1835 -3721 1835 - 3721 4.3 MILES NE OF SITE MN-54 130

<LLD

<LLD 0

CO-58 130

<LLD

<LLD 0

FE-59 260

<LLD

<LLD 0

CO-60 130

<LLD

<LLD 0

ZN-65 260

<LLD

<LLD 0

NB-95 NA

<LLD

<LLD 0

ZR-95 NA

<LLD

<LLD 0

)>

CS-134 130

<LLD

<LLD 0

I CS-137 150

<LLD

<LLD 0

BA-140 NA

<LLD

<LLD 0

LA-140 NA

<LLD

<LLD 0

SEDIMENT GAMMA 6

(PCIIKG ORY)

K-40 NA 11996 17460 17460 L-21 CONTROL 0

(4/4)

(2/2)

ILLINOIS RIVER - UPSTREAM 8502-14450 17040 - 17880 17040- 17880 4.0 MILES NE OF SITE MN-54 NA

<LLD

<LLD 0

C0-58 NA

<LLD

<LLD 0

FE-59 NA

<LLD

<LLD 0

CO-60 NA

<LLD

<LLD 0

ZN-65 NA

<LLD

<LLD 0

NB-95 NA

<LLD

<LLD 0

ZR-95 NA

<LLD

<LLD 0

CS-134 150

<LLD

<LLD 0

CS-137 180

<LLD

<LLD 0

BA-140 NA

<LLD

<LLD 0

LA-140 NA

<LLD

<LLD 0

AIR PARTICULATE GR-8 466 10 21.2 21.5 22.4 L-07 INDICATOR 0

(E-3 PC/ICU.METER)

(4141414)

(52/52)

SENECA 8-42 10-40 9-42 5.2 MILES NNE OF SITE (M) The Mean Values are calculated using the positive values (values,!: MDC). (F) Fraction of detectable measurement are indicated in parentheses.

TABLE A-1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL

SUMMARY

FOR THE LASALLE COUNTY STATION, 2022 NAME OF FACILITY:

LASALLE COUNTY STATION DOCKET NUMBER:

50-373 & 50-374 LOCATION OF FACILITY:

MARSEILLES, IL REPORTING PERIOD:

2022 INDICATOR CONTROL LOCATION WITH HIGHEST ANNUAL MEAN (M)

MEDIUM OR REQUIRED LOCATIONS LOCATION NUMBER OF PATHWAY SAMPLED TYPES OF NUMBER OF LOWER LIMIT MEAN(M)

MEAN(M)

STATION#

NONROUTINE (UNITOF ANALYSES ANALYSES OF DETECTION (F)

(F)

NAME REPORTED MEASUREMEN"!J.

PERFORMED PERFORMED (LLDl RANGE RANGE RANGE DISTANCE AND DIRECTION MEASUREMENTS AIR PARTICULATE GAMMA 36 (E-3 PC/ICU.METER)

Be-7 NA 126 118 140 L-01 INDICATOR 0

(32/32)

(4/4)

NEARSITE 1 85 -166 84 -144 110-166 1.5 MILES NNW OF SITE CO-58 NA

<LLD

<LLD 0

FE-59 NA

<LLD

<LLD 0

CO-60 NA

<LLD

<LLD 0

ZN-65 NA

<LLD

<LLD 0

NB-95 NA

<LLD

<LLD 0

ZR-95 NA

<LLD

<LLD 0

CS-134 50

<LLD

<LLD 0

l>

CS-137 60

<LLD

<LLD 0

I BA-140 NA

<LLD

<LLD 0

(A)

LA-140 NA

<LLD

<LLD 0

AIR IODINE GAMMA 466 (E-3 PC/ICU.METER) 1-131 70

<LLD

<LLD 0

MILK 1-131 1

1 NA

<LLD 0

(PCIA.ITER)

GAMMA K-40 NA NA 770 770 L-42 CONTROL 0

(1/1)

BIOS FARM 14.2 MILES E OF SITE MN-54 NA NA

<LLD 0

CO-58 NA NA

<LLD 0

FE-59 NA NA

<LLD 0

CO-60 NA NA

<LLD 0

ZN-65 NA NA

<LLD 0

NB-95 NA NA

<LLD 0

ZR-95 NA NA

<LLD 0

CS-134 15 NA

<LLD 0

CS-137 18 NA

<LLD 0

BA-140 60 NA

<LLD 0

LA-140 15 NA

<LLD 0

(M) The Mean Values are calculated using the positive values (values~ MDC). (F) Fraction of detectable measurement are indicated in parentheses.

TABLE A-1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL

SUMMARY

FOR THE LASALLE COUNTY STATION, 2022 NAME OF FACILITY:

LASALLE COUNTY STATION DOCKET NUMBER:

50-373 & 50.374 LOCATION OF FACILITY:

MARSEILLES, IL REPORTING PERIOD:

2022 INDICATOR CONTROL LOCATION WITH HIGHEST ANNUAL MEAN (M)

MEDIUM OR REQUIRED LOCATIONS LOCATION NUMBER OF PATHWAY SAMPLED TYPES OF NUMBER OF LOWER LIMIT MEAN(M)

MEAN(M)

STATION#

NONROUTINE (UNITOF ANALYSES ANALYSES OF DETECTION (F)

(F)

NAME REPORTED MEASUREMENT},

PERFORMED PERFORMED

!LLD!

RANGE RANGE RANGE DISTANCE AND DIRECTION MEASUREMENTS FOOD PRODUCTS GAMMA 26 (PCJJKG WET)

MN-54 NA

<LLD

<LLD 0

C0-58 NA

<LLD

<LLD 0

FE-59 NA

<LLD

<LLD 0

CO-60 NA

<LLD

<LLD 0

ZN-65 NA

<LLD

<LLD 0

NB-95 NA

<LLD

<LLD 0

ZR-95 NA

<LLD

<LLD 0

1-131 60

<LLD

<LLD 0

CS-134 60

<LLD

<LLD 0

CS-137 80

<LLD

<LLD 0

BA-140 NA

<LLD

<LLD 0

)>

LA-140 NA

<LLD

<LLD 0

I

.i:,.

VEGETATION GAMMA 46 (PCIIKG WET)

MN-54 NA

<LLD

<LLD 0

CO-58 NA

<LLD

<LLD 0

FE-59 NA

<LLD

<LLD 0

CO-60 NA

<LLD

<LLD 0

ZN-65 NA

<LLD

<LLD 0

NB-95 NA

<LLD

<LLD 0

ZR-95 NA

<LLD

<LLD 0

1-131 60

<LLD

<LLD 0

CS-134 60

<LLD

<LLD 0

CS-137 80

<LLD

<LLD 0

BA-140 NA

<LLD

<LLD 0

LA-140 NA

<LLD

<LLD 0

DIRECT RADIATION OSLD-QUARTERL Y 168 NA 17.5 14.9 19.9 L-102 INDICATOR 0

(MILLI-ROENTGENIQTR.)

(1641164)

(4/4)

(414) 13.5-20.5 13.0-15.B 19.2 - 20.5 0.6 MILES NNE (M) The Mean Values are calculated using the positive values (values 2: MDC). (F) Fraction of detectable measurement are indicated in parentheses.

APPENDIX B LOCATION DESIGNATION, DISTANCE & DIRECTION, AND SAMPLE COLLECTION & ANALYTICAL METHODS

Intentionally left blank

TABLE B-1:

Radiological Environmental Monitoring Program - Sampling Locations, Distance and Direction, LaSalle County Station, 2022 Location A.

Surface Water L-21 L-40 Location Description Illinois River at Seneca, Upstream (control)

Illinois River, Downstream (indicator)

B.

Ground/Well Water L-27 L-28-W4 L-28-W5 L-28-W6 LSCS Onsite Well (indicator)

Marseilles Well (control)

Marseilles Well (indicator)

C.

Milk - bi-weekly/ monthly L-42 Biros Farm (control)

D.

Air Particulates I Air Iodine L-01 L-03 L-04 L-05 L-06 L-07 L-08 L-10 L-11A E.

Fish L-34 L-35 L-36 F.

Sediment L-21 L-40 L-41 G.

Food Products Quadrant 1 Quadrant 1 Quadrant 2 Quadrant 2 Quadrant 4 Control H.

Vegetation L-Veg C L-ESE 1 L-ESE 2 Nearsite 1 (indicator)

Onsite 3 (indicator)

Rte. 170 (indicator)

Onsite 5 (indicator)

Nearsite 6 (indicator)

Seneca (indicator)

Marseilles (indicator)

Streator (control)

Ransom (indicator)

LaSalle Cooling Lake (indicator)

Marseilles Pool of Illinois River, Downstream (indicator)

Illinois River, Upstream of Discharge (control)

Illinois River at Seneca, Upstream (control)

Illinois River, Downstream (indicator)

Illinois River, Downstream (indicator) 171 Valley View, Seneca IL 281 E. Lincoln, Seneca IL 106 W. Thomas, Ransom, IL 205 W. Plumb, Ransom IL 2507 N. 2553 Rd., Marseilles IL Biros Farm Control Indicator Indicator B-1 Distance & Direction From Site 4.0 miles NE 5.2 miles NNW O miles at station 7.0 miles NNW 6.7 miles NNW 4.1 miles N 14.2 miles E 1.5 miles NNW 1.0 miles ENE 3.2 miles E 0.3 miles ESE 0.4 miles W 5.2 miles NNE 6.0 miles NNW 13.5 miles SW 6.0 miles S 2.0 miles E 6.5 miles NNW 4.3 miles NE 4.0 miles NE 5.2 miles NNW 4.6 miles N 5.2 miles NE 5.1 miles NE 6.0 miles S 5.3 miles S 4.3 miles NNW 14.2 miles E 9.5 miles ENE 1.5 miles ESE 6.0 miles ESE

TABLE B-1 :

Radiological Environmental Monitoring Program - Sampling Locations, Distance and Direction, LaSalle County Station, 2022 Location Location Description I.

Environmental Dosimetry - OSLD Inner Ring L-101-1 and -2 L-102-1 and -2 L-103-1 and -2 L-104-1 and -2 L-105-1 and -2 L-106-1 and -2 L-107-1 and -2 L-108-1 and -2 L-109-1 and -2 L-110-1 and -2 L-111 b-1 and -2 L-112-1 and -2 L-113a-1 and-2 L-114-1 and -2 L-115-1 and -2 L-116-1 and -2 Outer Ring L-201-3 and -4 L-202-3 and -4 L-203-1 and -2 L-204-1 and -2 L-205A-1 and -2 L-2058-3 and -4 L-206-1 and -2 L-207-1 and -2 L-208-1 and -2 L-209-1 and -2 L-210-1 and -2 L-211-1 and -2 L-212-1 and -2 L-213-3 and -4 L-214-3 and -4 L-215-3 and -4 L-216-3 and -4 L-01-1 and -2 L-03-1 and -2 L-04-1 and -2 L-05-1 and -2 L-06-1 and -2 L-07-1 and -2 L-08-1 and -2 L-11A-1 and -2 Nearsite 1 (indicator)

Onsite 3 (indicator)

Rte. 170 (indicator)

Onsite 5 (indicator)

Nearsite 6 (indicator)

Seneca (indicator)

Marseilles (indicator)

Ransom (indicator)

Control and Special Interest L-10-1 and -2 Streator B-2 Distance & Direction From Site 0.5 miles N 0.6 miles NNE 0.7 miles NE 0.8 miles ENE 0.7 miles E 1.4 miles ESE 0.8 miles SE 0.5 miles SSE 0.6 miles S 0.6 miles SSW 0.8 miles SW 0.9 miles WSW 0.8 miles W 0.9 miles WNW 0.7miles NW 0.6 miles NNW 4.0 miles N 3.6 miles NNE 4.0 miles NE 3.2 miles ENE 3.2 miles ESE 5.1 miles E 4.3 miles SE 4.5 miles SSE 4.5 miles S 4.0 miles SSW 3.3 miles SW 4.5 miles WSW 4.0 miles W 4.9 miles W 5.1 miles WNW 5.0 miles NW 5.0 miles NNW 1.5 miles NNW 1.0 miles ENE 3.2 miles E 0.3 miles ESE 0.4 miles W 5.2 miles NNE 6.0 miles NNW 6.0 miles S 13.5 miles SW

TABLE 8-2:

Radiological Environmental Monitoring Program - Summary of Sample Collection and Analytical Methods, LaSalle County Station, 2022 Sample Analysis Sampling Method Analytical Procedure Number Medium Surface Water Gamma Monthly composite from TBE, TBE-2007 Gamma-Emitting Radioisotope Analysis Spectroscopy weekly grab samples.

Surface Water Gross Beta Monthly composite from TBE, TBE-2008 Gross Alpha and/or Gross Beta Activity in Various Matrices weekly grab samples.

Surface Water Tritium Quarterly composite from TBE, TBE-2011 Tritium Analysis in Drinking Water by Liquid Scintillation weekly grab samples.

Ground/Well Gamma Quarterly grab samples.

TBE, TBE-2007 Gamma-Emitting Radioisotope Analysis Water Spectroscopy Ground/Well Tritium Quarterly grab samples.

TBE, TBE-2011 Tritium Analysis in Drinking Water by Liquid Scintillation Water Gamma Semi-annual samples TBE-2007 Gamma-Emitting Radioisotope Analysis Fish Spectroscopy collected via electroshocking or other techniques Sediment Gamma Semi-annual TBE, TBE-2007 Gamma-Emitting Radioisotope Analysis Spectroscopy grab samples Air One-week composite of TBE, TBE-2008 Gross Alpha and/or Gross Beta Activity in Various Matrices Particulates Gross Beta continuous air sampling through glass fiber filter paper Air Gamma Quarterly composite of each TBE, TBE-2007 Gamma-Emitting Radioisotope Analysis Particulates Spectroscopy station Gamma Bi-weekly composite of TBE, TBE-2007 Gamma-Emitting Radioisotope Analysis Air Iodine Spectroscopy continuous air sampling through charcoal filter Bi-weekly grab sample when TBE, TBE-2012 Radioiodine in Various Matrices Milk 1-131 cows are on pasture.

Monthly all other times Gamma Bi-weekly grab sample when Milk Spectroscopy cows are on pasture.

TBE, TBE-2007 Gamma-Emitting Radioisotope Analysis Monthly all other times Food Gamma Annual grab samples.

TBE, TBE-2007 Gamma-Emitting Radioisotope Analysis Products Spectroscopy Vegetation Gamma Monthly grab samples during TBE, TBE-2007 Gamma-Emitting Radioisotope Analysis Spectroscopy growing season Optically Quarterly OSLDs comprised Stimulated OSLO Luminescence of two Al2O3:C Landauer Landauer Incorporated Dosimetry Incorporated elements B-3

r.

i' I

B-4 N

N 0

C/lN C

0 C

.;::::; 0 co :.:;

0 (IJ 0.....

_J en C!l Cl~

QJ -l C

... en :::,

5,0 8 Cl LL C ~

c2 ro

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(IJ C -l C

QJ

- £ -

0

Grand Ridge

-**streator

..._*uo 1

)'}.

L-215-3 I I

-I I

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I Marseilles*',.\ *,

L-031 1

1 *,

7r~,

I

\:. ;

I..

~

L-21 t:-3 ',

1 I

Senec,a" L-07,

-. *-... L-215-4 **

. L-2*1 tl-4 11 i'

1,,L-JJ1-::i

,i **i_

t.

'L *y(,,.,-,..

\ L-21J1-4.' -.:..:<*...

- L -~(r' --,

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/ L-202-4..,

-1..*,-..::_..

I I

L-2*14-3 L-214-4..

I L.

1' I

-IJ ',

I I

II 11 11 I

I L-204-1

- L-204-2 I

I

.. \. /.,.,. ---* L-O:: ____________ ----

L-21::-3

*--}~'. -l:- ________

L-U4 L

,,1

., 4

- L-212-1 L-06 *-=tt~---.-

L *)l "i -,

___ ----~.--?,*rt -----

L-X1c:;.::

- -~ ~..:-:------*-

.. ***' i,' ', *, *--:-:,.. -~------

~ -

. L-U5

l-lU:,-4 L-211-1...

L *:.i-1-1 '!

_/

-~---** L-210-1 L-210-2/

L-209-1 1

I I

I 11 11 I

I I

I

\

I I

I I I I I I I

I I I

', I L-209-2 L-2n:=:.1 l-20:::-2 L-11,9 L-11A Ransom Figure B-2 L-207-1 **

L-207-2 L-205-1

. L-205-2 L-2C6-1 Outer Ring OSLD Locations and Fixed Air Sampling Locations of the LaSalle County Station, 2022 B-5

Figure 8-3 Ingestion and Waterborne Exposure Pathway Sample Locations of the LaSalle County Station, 2022 B-6

APPENDIX C DATA TABLES AND FIGURES

Intentionally left blank

Table C-1.1 CONCENTRATIONS OF GROSS BETA IN SURFACE WATER SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 Table C-1.2 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA COLLECTION PERIOD L-21 L-40 01/06/22 - 01/20/22 4.3 +/- 2.1 5.4 +/- 2.1 02/03/22 - 02/24/22 10.8 +/- 2.7 8.8 +/- 2.5 03/02/22 - 03/30/22 6.0 +/- 2.5 8.5 +/- 2.8 04/07/22 - 04/28/22 4.0 +/- 2.5 5.6 +/- 2.6 05/04/22 - 05/26/22 3.9 +/- 2.1 5.2 +/- 2.3 06/01 /22 - 06/29/22 6.7 +/- 2.6 6.6 +/- 2.5 07107122 - 07 /28/22

< 2.6 2.9 +/- 1.9 08/03/22 - 08/31 /22 8.4 +/- 2.8 7.9 +/- 2.8 09/08/22 - 09/28/22 9.3 +/- 3.2 8.6 +/- 3.3 10/06/22 - 10/27 /22 11.0 +/- 3.2 13.4 +/- 3.4 11 /02/22 - 11 /30/22 8.7 +/- 3.0 11.9 +/- 3.3 12/08/22 - 12/22/22 12.2 +/-2.1 8.7 +/- 2.0 (1) MEAN+/- 2 STD DEV 7.8 +/- 5.9 7.8 +/- 5.9 CONCENTRATIONS OF TRITIUM IN SURFACE WATER SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA COLLECTION PERIOD L-21 L-40 01 /06/22 - 03/30/22

< 186

< 182 04/07 /22 - 06/29/22

< 183

< 167 07/07/22 - 09/28/22 200 +/- 123 197 +/- 123 10/06/22 - 12/22/22 520 +/- 133 546 +/- 133 (1) MEAN+/- 2 STD DEV 360 +/- 453 372 +/- 494 (1) THE MEAN AND TWO STANDARD DEVIATION ARE CALCULATED USING THE POSITIVE VALUES (VALUES C-1

Table C-1.3 CONCENTRATIONS OF GAMMA EMITTERS IN SURFACE WATER SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA COLLECTION SITE PERIOD Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 L-21 01/06/22 - 01/20/22

< 2

<6

< 2

<4

< 3

< 5

< 8

< 2

< 16

<6 02/03/22 - 02/24/22

< 3

<4

< 8

< 3

< 6

< 4

<6

< 13

< 3

<4

< 27

< 9 03/02/22 - 03/30/22

< 2

< 5

< 2

<4

< 2

<4

< 11

< 2

< 19

< 6 04/07122 - 04/28/22

< 3

<4

< 9

< 3

< 7

< 4

<6

< 14

<4

< 31

< 8 05/04/22 - 05/26/22

< 2

< 5

< 2

<4

< 2

< 3

< 7

< 2

< 15

< 6 06/01 /22 - 06/29/22

< 2

<4

< 2

<4

< 2

< 3

< 9

< 2

< 17

< 6 07/07/22 - 07/28/22

< 3

<6

< 3

< 5

< 3

< 5

< 11

< 3

< 20

< 6 08/03/22 - 08/31 /22

< 2

< 5

< 2

<4

< 2

<4

< 11

< 2

< 19

< 7 09/08/22 - 09/28/22

< 2

<4

< 2

<4

< 2

<4

< 8

< 2

< 16

< 5 10/06/22 - 10/27 /22

< 2

<4

< 2

<4

< 2

<4

< 8

< 2

< 15

<4 11 /02/22 - 11 /30/22

< 1

< 2

<4

< 2

< 3

< 2

< 3

< 10

< 2

< 18

<6 12/08/22 - 12/22/22

< 2

<6

< 2

< 5

< 3

<4

< 13

< 2

< 23

< 7 MEAN C')

I II,)

L-40 01/06/22 - 01/06/22

< 1

< 3

< 1

< 2

< 1

< 2

< 8

< 1

< 13

<4 02/09/22 - 02/24/22

< 3

< 6

< 3

< 6

< 3

< 5

< 8

< 3

< 19

< 6 03/02/22 - 03/30/22

< 2

< 5

< 2

< 4

< 2

<4

< 11

< 2

< 19

< 6 04/07/22 - 04/28/22

< 3

<4

< 8

< 2

< 6

< 3

< 7

< 12

< 3

<4

< 28

< 8 05/04/22 - 05/26/22

< 2

< 5

< 2

<4

< 2

<4

< 9

< 2

< 18

< 6 06/01/22 - 06/29/22

< 1

< 2

<4

< 2

< 3

< 2

< 3

< 9

< 2

< 16

< 5 07 /07 /22 - 07 /28/22

< 3

< 7

< 3

< 5

< 3

< 5

< 10

< 3

< 21

< 7 08/03/22 - 08/31 /22

< 2

< 5

< 2

< 4

< 2

< 3

< 12

< 2

< 20

< 7 09/08/22 - 09/28/22

< 2

<4

< 2

< 4

< 2

< 3

< 7

< 2

< 14

<4 10/06/22 - 10/27 /22

< 2

<4

< 2

< 4

< 2

<4

< 7

< 2

< 14

<6 11 /02/22 - 11 /30/22

< 2

< 4

< 2

< 3

< 2

< 3

< 12

< 2

< 19

<6 12/08/22 - 12/22/22

< 2

< 5

< 2

< 4

< 2

<4

< 11

< 2

< 21

< 7 MEAN

Table C-I1.1 CONCENTRATIONS OF TRITIUM IN GROUND/WELL WATER SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA COLLECTION PERIOD L-27 L-28-W4 L-28-W5 L-28-W6 01/12/22 - 01/12/22

< 165

< 194

< 186 04/14/22

04/14/22

< 197

< 196

< 199 07/13/22

07/13/22

< 191

< 183

< 187 10/12/22 - 10/12/22

< 198

< 184

< 178 MEAN C-3

Table C-11.2 CONCENTRATIONS OF GAMMA EMITTERS IN GROUND/WELL WATER SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA COLLECTION SITE PERIOD Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 L-27 01/12/22 - 01/12/22

<4

< 8

< 5

< 6

< 5

< 7

< 5

< 4

< 16

< 8 04/14/22 - 04/14/22

< 7

< 6

< 15

< 5

< 13

< 8

< 13

< 6

< 7

< 35

< 10 07/13/22 - 07/13/22

< 9

< 5

< 15

< 8

< 14

< 8

< 15

< 9

< 7

< 34

< 11 10/12/22 - 10/12/22

<4

< 5

< 9

< 5

< 10

< 5

< 8

< 5

< 22

< 7 MEAN L-28-W4 04/14/22 - 04/14/22

< 7

< 6

< 10

< 6

< 10

< 5

< 9

< 7

< 6

< 26

< 10 10/12/22 - 10/12/22

<4

< 3

< 9

<4

< 10

<4

< 6

< 4

<4

< 17

< 6 MEAN L-28-W5 01/12/22 - 01/12/22

<6

< 5

< 12

<6

< 13

<7

< 11

<6

< 5

< 27

< 10 07 /13/22 - 07 /13/22

< 6

< 7

< 17

< 7

< 12

<6

< 12

< 7

< 33

<4 C')

MEAN I

.i:.

L-28-W6 01/12/22 - 01/12/22

<4

< 5

< 10

<4

< 12

< 5

< 9

<6

< 5

< 25

< 8 04/14/22 - 04/14/22

<6

< 8

< 16

< 8

< 14

<6

< 10

< 7

< 8

< 31

< 11 07/13/22 - 07/13/22

< 6

< 7

< 14

< 7

< 13

< 7

< 9

< 7

< 31

< 12 10/12/22 - 10/12/22

< 3

< 4

< 9

< 6

< 7

<4

< 7

< 4

< 17

< 5 MEAN

Table C-111.1 CONCENTRATIONS OF GAMMA EMITTERS IN FISH SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/KG WET+/- 2 SIGMA COLLECTION SITE PERIOD Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 L-34 Common Carp 05/04/22

< 61

< 75

< 126

< 69

< 86

< 54

< 92

< 63

< 54

< 320

< 63 Largemouth Bass 05104122

< 69

< 52

< 138

< 47

< 193

< 90

< 116

< 88

< 74

< 329

< 87 Bluegill 10/14/22

< 78

< 69

< 146

< 71

< 165

< 88

< 101

< 77

< 71

< 342

< 148 Channel Catfish 10/14/22

< 72

< 67

< 154

< 81

< 142

< 66

< 123

< 65

< 367

< 90 MEAN L-35 Freshwater Drum 05/03/22

< 36

< 48

< 104

< 55

< 94

< 41

< 81

< 54

< 47

< 252

< 81 River Carpsucker 05/03/22

< 74

< 90

< 155

< 69

< 197

< 79

< 141

< 96

< 91

< 418

< 132 Smallmouth Bass 10/14/22

< 74

< 63

< 158

< 73

< 146

< 82

< 148

< 79

< 78

< 356

< 86 Smallmouth Buffalo 10/14/22

< 56

< 54

< 60

< 66

< 117

< 40

< 114

< 57

< 49

< 230

< 91 C)

MEAN I

Ul L-36 Channel Catfish 05/03/22

< 58

< 45

< 132

< 61

< 112

< 58

< 97

< 40

< 46

< 351

< 96 Freshwater Drum 05/03/22

< 43

< 51

< 90

< 41

< 110

< 40

< 95

< 30

< 43

< 299

< 78 Channel Catfish 10/14/22

< 63

< 68

< 127

< 73

< 134

< 65

< 125

< 65

< 57

< 312

< 115 Smallmouth Buffalo 10/14/22

< 46

< 57

< 113

< 61

< 116

< 57

< 105

< 50

< 70

< 249

< 75 MEAN

Table C-IV.1 CONCENTRATIONS OF GAMMA EMITTERS IN SEDIMENT SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/KG DRY+/- 2 SIGMA COLLECTION SITE PERIOD Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 L-21 05/17/22

< 68

< 65

< 147

< 75

< 148

< 82

< 125

< 78

< 101

< 332 96 10/29/22

< 71

< 79

< 169

< 100

< 185

< 102

< 126

< 87

< 96

< 302 105 MEAN L-40 05/17/22

< 51

< 52

< 129

< 75

< 119

< 66

< 108

< 59

< 57

< 300

< 65 10/29/22

< 98

< 89

< 190

< 85

< 199

< 112

< 136

< 94

< 89

< 355

< 103 MEAN L-41 05/03/22

< 53

< 60

< 98

< 63

< 117

< 61

< 110

< 74

< 70

< 304

< 101 10/14/22

< 51

< 49

< 105

< 66

< 125

< 60

< 96

< 60

< 55

< 240

< 84 0

MEAN I en

Table C-V.1 CONCENTRATIONS OF GROSS BETA IN AIR PARTICULATE SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF E-3 PCI/CU METER +/- 2 SIGMA COLLECTION GROUP I GROUP II GROUP Ill GROUP IV PERIOD L-03 L-05 L-01 L-06 L-04 L-07 L-08 L-11A L-10 12/29/21 - 01/06/22 29 +/- 5 39 +/- 5 39 +/- 5 41 +/- 5 28 +/- 4 42 +/- 5 38 +/- 5 37 +/- 5 40 +/- 5 01/06/22 - 01/12/22 24 +/- 5 32 +/- 6 31 +/- 6 35 +/- 7 28 +/- 6 27 +/- 6 27 +/- 5 23 +/- 5 24 +/- 5 01/12/22 - 01/20/22 21 +/- 4 21 +/- 4 25 +/- 5 22 +/- 5 22 +/- 5 28 +/- 5 27 +/- 5 26 +/- 5 25 +/- 5 01/20/22 - 01/27/22 21 +/- 5 24 +/- 5 21 +/- 5 19 +/- 5 24 +/- 5 23 +/- 5 26 +/- 5 21 +/- 5 24 +/- 5 01/27/22 - 02/03/22 33 +/- 4 31 +/- 4 28 +/- 5 27 +/- 5 23 +/- 5 28 +/- 5 24 +/- 5 21 +/- 5 21 +/- 4 02/03/22 - 02/09/22 (1)

(1) 36 +/- 6 35 +/- 6 37 +/- 7 30 +/- 6 30 +/- 6 30 +/- 6 35 +/- 6 02/09/22 - 02/17/22 19 +/- 4 20 +/- 4 19 +/- 4 18 +/- 4 22 +/- 4 17 +/- 4 21 +/- 4 16 +/- 4 20 +/- 4 02/17/22 - 02/24/22 17 +/- 5 21 +/- 5 15 +/- 4 15 +/- 4 18 +/- 5 20 +/- 5 22 +/- 5 16 +/- 4 14 +/- 4 02/24/22 - 03/02/22 23 +/- 6 24 +/- 6 22 +/- 5 22 +/- 5 29 +/- 6 30 +/- 6 21 +/- 5 29 +/- 6 28 +/- 6 03/02/22 - 03/09/22 20 +/- 4 21 +/- 5 25 +/- 5 20 +/- 4 20 +/- 4 24 +/- 5 22 +/- 5 22 +/- 5 22 +/- 5 03/09/22 - 03/17/22 24 +/- 5 18 +/- 4 25 +/- 5 23 +/- 4 17 +/- 4 19 +/- 4 18 +/- 4 22 +/- 4 20 +/- 4 03/17/22 - 03/24/22 15 +/- 4 14 +/- 4 12 +/- 4 14 +/- 4 19 +/- 5 13 +/- 4 17 +/- 5 11 +/- 4 15 +/- 4 03/24/22 - 03/31/22 16 +/- 4 12 +/- 4 15 +/- 4 14 +/- 4 14 +/- 4 15 +/- 5 13 +/- 4 13 +/- 4 13 +/- 4 03/30/22 - 04/07/22 11 +/- 4 10 +/- 4 12 +/- 4 10 +/- 4 12 +/- 4 11 +/- 3 12 +/- 4 9 +/- 4 10 +/- 4 04/07/22 - 04/14/22 10 +/- 4 12 +/- 4 11 +/- 4 12 +/- 4 10 +/- 4 11 +/- 4 11 +/- 4 8 +/- 4 11 +/- 4 04/14/22 - 04/21/22 13 +/- 4 8 +/- 4 12 +/- 4 9 +/- 4 10 +/- 4 9+/-4 13 +/- 4 12 +/- 4 14 +/- 4 04/21/22 - 04/28/22 15 +/- 4 12 +/- 4 15 +/- 4 18 +/- 4 15 +/- 4 13 +/- 4 19 +/- 4 17 +/- 4 16 +/- 4 04/28/22 - 05/04/22 11 +/- 4 10 +/- 4 18 +/- 5 15 +/- 5 14 +/- 5 13 +/- 5 12 +/- 5 16 +/- 5 13 +/- 4 05/04/22 - 05/12/22 20 +/- 4 18 +/- 4 19 +/- 4 18 +/- 4 21 +/- 4 17 +/- 4 20 +/- 4 15 +/- 4 19 +/- 4 05/12/22 - 05/19/22 21 +/- 4 22 +/- 4 19 +/- 4 21 +/- 4 18 +/- 4 22 +/- 4 19 +/- 4 20 +/- 4 22 +/- 4 05/19/22 - 05/26/22 18 +/- 4 15 +/- 4 16 +/- 4 15 +/- 4 17 +/- 4 15 +/- 4 17 +/- 4 11 +/- 4 16 +/- 4 05/26/22 - 06/01/22 17 +/- 5 13 +/- 4 18 +/- 5 14 +/- 4 18 +/- 5 17 +/- 5 18 +/- 5 17 +/- 5 18 +/- 5 06/01/22 - 06/09/22 19 +/- 4 14 +/- 4 20 +/- 4 20 +/- 4 18 +/- 4 18 +/- 4 22 +/- 4 18 +/- 4 17 +/- 4 06/09/22 - 06/16/22 22 +/- 5 24 +/- 5 22 +/- 5 26 +/- 5 24 +/- 5 26 +/- 5 25 +/- 5 22 +/- 5 22 +/- 4 06/16/22 - 06/23/22 12 +/- 4 12 +/- 4 12 +/- 4 14 +/- 4 11 +/- 4 12 +/- 4 13 +/- 4 13 +/- 4 13 +/- 4 06/23/22 - 06/29/22 10 +/- 5 8 +/- 4 15 +/- 5 12 +/- 4 12 +/- 5 11 +/- 5 11 +/- 5 11 +/- 5 10 +/- 4 06/29/22 - 07/07/22 22 +/- 5 22 +/- 4 25 +/- 4 27 +/- 4 25 +/- 4 30 +/- 5 25 +/- 4 25 +/- 4 22 +/- 4 07/07/22 - 07/13/22 16 +/- 5 21 +/- 5 22 +/- 5 18 +/- 5 16 +/- 5 26 +/- 5 17 +/- 5 20 +/- 5 16 +/- 5 07/13/22 - 07/21/22 18 +/- 4 17 +/- 4 21 +/- 4 22 +/- 4 23 +/- 4 21 +/- 4 19 +/- 4 22 +/- 4 20 +/- 4 07/21/22 - 07/28/22 16 +/- 4 20 +/- 4 20 +/- 4 15 +/- 4 19 +/- 4 22 +/- 5 18 +/- 4 20 +/- 4 19 +/- 4 07/28/22 - 08/03/22 14 +/- 5 14 +/- 5 19 +/- 5 16 +/- 5 17 +/- 5 17 +/- 5 13 +/- 5 15 +/- 5 19 +/- 5 08/03/22 - 08/11/22 13 +/- 3 16 +/- 4 14 +/- 3 17 +/- 4 15 +/- 3 18 +/- 4 15 +/- 3 15 +/- 3 15 +/- 3 08/11/22 - 08/18/22 21 +/- 4 21 +/- 4 24 +/- 4 21 +/- 4 21 +/- 4 24 +/- 5 27 +/- 5 24 +/- 5 19 +/- 4 08/18/22 - 08/24/22 18 +/- 5 22 +/- 5 26 +/- 5 21 +/- 5 20 +/- 5 24 +/- 5 21 +/- 5 24 +/- 5 24 +/- 5 08/24/22 - 08/31/22 25 +/- 5 22 +/- 5 23 +/- 5 20 +/- 4 27 +/- 5 21 +/- 5 25 +/- 5 22 +/- 5 19 +/- 4 08/31/22 - 09/08/22 18 +/- 4 23 +/- 4 22 +/- 4 19 +/- 4 24 +/- 4 23 +/- 4 23 +/- 4 22 +/- 4 25 +/- 4 09/08/22 - 09/15/22 21 +/- 4 25 +/- 5 23 +/- 4 20 +/- 4 23 +/- 4 28 +/- 5 24 +/- 5 24 +/- 5 24 +/- 5 09/15/22 - 09/22/22 26 +/- 5 26 +/- 5 26 +/- 5 23 +/- 5 38 +/- 7 27 +/- 5 27 +/- 5 25 +/- 5 22 +/- 5 09/22/22 - 09/28/22 12 +/- 4 14 +/- 4 18 +/- 5 14 +/- 4 13 +/- 4 15 +/- 5 12 +/- 4 16 +/- 5 16 +/- 5 09/28/22 - 10/06/22 12 +/- 4 15 +/- 4 14 +/- 4 15 +/- 4 15 +/- 4 15 +/- 4 14 +/- 4 16 +/- 4 18 +/- 4 10/06/22 - 10/12/22 31 +/- 6 28 +/- 6 28 +/- 6 25 +/- 6 28 +/- 6 29 +/- 6 28 +/- 6 31 +/- 6 31 +/- 6 10/12/22 - 10/20/22 12 +/- 4 11 +/- 4 11 +/- 3 15 +/- 4 13 +/- 4 12 +/- 3 14 +/- 4 16 +/- 4 13 +/- 4 10/20/22 - 10/27/22 27 +/- 5 32 +/- 5 23 +/- 5 29 +/- 5 28 +/- 5 31 +/- 5 31 +/- 5 34 +/- 5 29 +/- 5 10/27/22 - 11/02/22 32 +/- 6 33 +/- 6 33 +/- 6 31 +/- 6 42 +/- 6 40 +/- 6 40 +/- 6 42 +/- 6 39 +/- 6 11/02/22 - 11/10/22 24 +/- 4 28 +/- 5 29 +/- 4 26 +/- 4 29 +/- 4 30 +/- 5 31 +/- 5 29 +/- 5 30 +/- 5 11/10/22 - 11/17/22 9 +/- 4 11 +/- 4 12 +/- 4 10 +/- 4 9 +/- 3 11 +/- 4 14 +/- 4 13 +/- 4 15 +/- 4 11/17/22 - 11/23/22 28 +/- 5 31 +/- 6 25 +/- 5 29 +/- 6 34 +/- 6 34 +/- 6 29 +/- 5 25 +/- 5 33 +/- 6 11/23/22 - 11/30/22 31 +/- 5 37 +/- 6 34 +/- 5 30 +/- 5 30 +/- 5 37 +/- 6 42 +/- 6 31 +/- 5 36 +/- 6 11/30/22 - 12/08/22 31 +/- 5 33 +/- 5 34 +/- 5 30 +/- 5 34 +/- 5 35 +/- 5 19 +/- 4 35 +/- 5 35 +/- 5 12/08/22 - 12/15/22 27 +/- 5 25 +/- 5 25 +/- 5 25 +/- 5 23 +/- 4 30 +/- 5 28 +/- 5 27 +/- 5 26 +/- 5 12/15/22 - 12/22/22 31 +/- 5 31 +/- 5 33 +/- 5 31 +/- 5 31 +/- 5 34 +/- 5 37 +/- 5 33 +/- 5 33 +/- 5 12/22/22 - 12/28/22 22 +/- 5 23 +/- 5 18 +/- 5 22 +/- 5 23 +/- 5 21 +/- 5 20 +/- 5 18 +/- 5 24 +/- 5 (2) MEAN+/- 2 STD DEV 20 +/- 13 21 +/- 16 22 +/- 14 21 +/- 14 21 +/- 15 22 +/- 17 22 +/- 15 21 +/- 15 22 +/- 15 (1) SEE PROGRAM EXCEPTIONS SECTION FOR EXPLANATION (2) THE MEAN AND TWO STANDARD DEVIATION ARE CALCULATED USING THE POSITIVE VALUES (VALUES ~ MDC)

C-7

Table C-V.2 MONTHLY AND YEARLY MEAN VALUES OF GROSS BETA CONCENTRATIONS IN AIR PARTICULATE SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF E-3 PCI/CU METER +/- 2 SIGMA GROUP I - ONSITE LOCATIONS GROUP 11-NEAR-SITE LOCATIONS GROUP Ill - FAR-FIELD LOCATIONS GROUP IV-CONTROL LOCATION COLLECTION MIN MAX MEAN +/-

COLLECTION MIN MAX MEAN +/-

COLLECTION MIN MAX MEAN+/-

COLLECTION MIi\ MAX MEAN +/-

PERIOD 2SD PERIOD 2SD PERIOD 2SD PERIOD 2SD 12/29/21 - 01/27/22 21 39 26 +/- 13 12/29/21 - 01/27/22 19 41 29 +/- 17 12/29/21 - 01/27/22 21 42 28 +/- 12 12/29/21 - 01/27/22 24 40 28 +/- 16 01/27/22 - 03/02/22 17 33 23 +/- 11 01/27/22 - 03/02/22 15 36 24 +/- 15 01 /27 /22 - 03/02/22 16 37 24 +/- 12 01/27/22 - 03/02/22 14 35 24 +/- 16 03/02/22 - 03/31 /22 12 24 17 +/- 8 03/02/22 - 03/31 /22 12 25 18 +/- 10 03/02/22 - 03/31 /22 11 24 17 +/- 8 03/02/22 - 03/31 /22 13 22 17 +/- 8 03/31 /22 - 04/28/22 8

15 11 +/- 4 03/31 /22 - 04/28/22 9

18 12 +/- 5 03/30/22 - 04/28/22 8

19 12 +/- 6 03/31/22 - 04/28/22 10 16 13 +/- 6 04/28/22 - 06/01/22 10 22 17 +/- 8 04/28/22 - 06/01 /22 14 21 17 +/- 5 04/28/22 - 06/01/22 11 22 17 +/- 6 04/28/22 - 06/01 /22 13 22 17 +/- 7 06/01/22 - 06/29/22 8

24 15 +/- 12 06/01/22 - 06/29/22 12 26 18 +/- 10 06/01/22 - 06/29/22 11 26 17 +/- 11 06/01/22 - 06/29/22 10 22 16 +/- 10 06/29/22 - 08/03/22 14 22 18 +/- 6 06/29/22 - 08/03/22 15 27 21 +/- 7 06/29/22 - 08/03/22 13 30 21 +/- 9 06/29/22 - 08/03/22 16 22 19 +/- 4 08/03/22 -

08/31 /22 13 25 20 +/- 8 08/03/22 - 08/31 /22 14 26 21 +/- 8 08/03/22 - 08/31/22 15 27 22 +/- 8 08/03/22 - 08/31 /22 15 24 19 +/- 7 08/31 /22 - 09/28/22 12 26 21 +/- 11 08/31 /22 - 09/28/22 14 26 21 +/- 7 08/31 /22 - 09/28/22 12 38 23 +/- 13 08/31/22 - 09/28/22 16 25 22 +/- 8 09/28/22 - 11 /02/22 11 33 23 +/- 19 09/28/22 - 11 /02/22 11 33 23 +/- 16 09/28/22 - 11/02/22 12 42 26 +/- 21 09/28/22 11/02/22 13 39 26 +/- 21 11 /02/22 - 11/30/22 9

37 25 +/- 20 11/02/22 - 11/30/22 10 34 24 +/- 18 11/02/22 - 11/30/22 9

42 27 +/- 19 11/02/22 - 11 /30/22 15 36 28 +/- 19 0

I 11 /30/22 - 12/28/22 22 33 28 +/- 8 11 /30/22 - 12/28/22 18 34 27 +/- 11 11/30/22 - 12/28/22 18 37 28 +/- 13 11/30/22 - 12/28/22 24 35 29 +/- 10 O>

12/29/21 - 12/28/22 8

39 20 +/- 14 12/29/21 - 12/28/22 9

41 21 +/- 14 12/29/21 - 12/28/22 8

42 22 +/- 15 12/29/21 - 12/28/22 10 40 22 +/- 15

Table C-V.3 CONCENTRATIONS OF GAMMA EMITTERS IN AIR PARTICULATE SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF E-3 PCI/CU METER+/- 2 SIGMA COLLECTION SITE PERIOD Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 L-01 12/29/21 - 03/31/22

< 2

<4

< 10

< 2

< 4

< 3

< 6

< 2

< 1

< 284

< 130 03/31 /22 - 06/29/22

< 3

< 5

< 12

< 3

< 6

< 5

< 8

< 4

< 3

< 266

< 106 06/29/22 - 09/28/22

< 3

<4

< 14

<4

< 11

< 6

< 8

< 3

< 321

< 174 09/28/22 - 12/28/22

< 2

<4

< 13

< 3

< 7

< 6

< 10

< 2

< 3

< 313

< 56 MEAN L-03 12/29/21 - 03/31/22

< 2

< 8

< 2

< 5

< 3

<4

< 1

< 333

< 110 03/31 /22 - 06/29/22

<4

< 5

< 21

< 3

< 10

< 7

< 11

<4

< 4

< 297

< 109 06/29/22 - 09/28/22

< 3

< 5

< 16

<4

< 7

<4

< 6

< 2

< 327

< 129 09/28/22 - 12/28/22

< 2

<4

< 11

< 3

< 6

<4

< 7

< 1

< 2

< 212

< 57 MEAN

(')

L-04 12/29/21 - 03/31/22

< 3

< 4

< 7

< 2

< 7

< 5

< 7

< 2

< 286

< 106 I (0 03/31 /22 - 06/29/22

< 2

< 3

< 11

< 3

<6

<4

<6

< 2

< 161

< 72 06/29/22 - 09/28/22

< 3

<4

< 14

< 2

<6

<4

<6

< 2

< 281

< 58 09/28/22 - 12/28/22

< 2

< 4

< 14

< 2

< 7

< 3

< 6

< 2

< 194

< 95 MEAN L-05 12/29/21 - 03/31 /22

< 2

<4

< 6

< 2

< 7

<4

< 2

< 244

< 151 03/31 /22 - 06/29/22

< 2

< 3

< 10

< 3

< 6

<4

< 5

< 2

< 217

< 58 06/29/22 - 09/28/22

< 2

< 4

< 13

< 3

<4

< 3

< 7

< 2

< 1

< 247

< 121 09/28/22 - 12/28/22

< 3

< 5

< 12

< 2

<7

<6

< 10

< 3

< 331

< 98 MEAN L-06 12/29/21 - 03/31 /22

< 2

<4

< 14

< 2

< 5

<4

< 8

< 2

< 248

< 117 03/31/22 06/29/22

< 2

< 5

< 13

< 2

< 7

< 5

< 8

< 3

< 265

< 91 06/29/22 - 09/28/22

< 2

< 3

< 10

< 2

<6

< 4

< 6

< 2

< 250

< 77 09/28/22 - 12/28/22

< 3

< 5

< 15

< 2

< 8

< 5

< 11

< 3

< 379

< 76 MEAN

Table C-V.3 CONCENTRATIONS OF GAMMA EMITTERS IN AIR PARTICULATE SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF E-3 PCI/CU METER+/- 2 SIGMA COLLECTION SITE PERIOD Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 L-07 12/29/21 - 03/30/22

< 2

<4

< 14

< 3

< 7

< 5

< 8

< 3

< 2

< 368

< 156 03/30/22 - 06/29/22

< 2

< 4

< 10

< 2

<6

< 5

<6

< 2

< 198

< 50 06/29/22 - 09/28/22

< 3

< 4

< 13

< 2

< 7

<4

< 6

< 1

< 3

< 282

< 145 09/28/22 - 12/28/22

< 2

< 3

< 12

< 2

< 5

< 4

< 5

< 2

< 215

< 82 MEAN L-08 12/29/21 - 03/30/22

< 2

< 4

< 11

< 3

<4

< 8

< 2

< 302

< 161 03/30/22 - 06/29/22

< 3

< 4

< 22

< 3

< 7

< 6

< 3

<4

< 361

< 91 06/29/22 - 09/28/22

< 2

< 5

< 12

< 2

< 7

< 5

< 9

< 2

< 257

< 127 09/28/22 - 12/28/22

< 2

< 3

< 13

< 3

< 6

< 4

< 7

< 2

< 212

< 129 MEAN

(')

L-10 12/29/21 - 03/31/22

< 2

< 3

< 9

< 1

<4

< 3

< 5

< 2

< 223

< 113 I.....

0 03/31 /22 - 06/29/22

< 2

< 3

< 8

< 2

< 5

<4

< 6

< 3

< 2

< 208

< 67 06/29/22 - 09/28/22

< 2

< 3

< 12

< 2

< 6

< 4

< 6

< 2

< 308

< 71 09/28/22 - 12/28/22

< 3

< 5

< 15

< 3

< 7

< 5

< 10

< 3

< 2

< 310

< 106 MEAN L-11A 12/29/21 - 03/31/22

< 2

< 4

< 11

< 2

<6

< 2

< 7

< 2

< 247

< 84 03/31 /22 - 06/29/22

< 3

< 5

< 14

< 2

< 7

< 4

< 9

< 3

< 2

< 265

< 89 06/29/22 - 09/28/22

< 1

< 3

< 16

< 3

< 6

< 3

< 6

< 2

< 287

< 135 09/28/22 - 12/28/22

< 2

<4

< 9

< 1

< 5

< 3

< 7

< 2

< 179

< 111 MEAN

Table C-Vl.1 CONCENTRATIONS OF I-131 IN AIR IODINE SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF E-3 PCI/CU METER+/- 2 SIGMA COLLECTION GROUP I GROUP II GROUP Ill GROUP IV PERIOD L-03 L-05 L-01 L-06 L-04 L-07 L-08 L-11A L-10 12/29/21 - 01/06/22

< 56

< 57

< 54

< 32

< 57

< 35

< 34

< 35

< 33 01/06/22 - 01/12/22

< 23

< 21

< 12

< 23

< 25

< 24

< 12 01/12/22 - 01/20/22

< 50

< 33

< 51

< 20

< 33

< 32

< 31 01/20/22 - 01/27/22

< 45

< 46

< 29

< 46

< 30

< 28

< 18

< 29 01/27/22 - 02/03/22

< 8

< 19

< 37

< 38

< 18

< 38

< 43

< 41 02/03/22 - 02/09/22 (1)

(1)

< 29

< 26

< 29

< 64

< 60

< 63

< 59 02/09/22 - 02/17/22

< 26

< 41

< 42

< 41

< 51

< 50

< 50 02/17/22 - 02/24/22

< 21

< 35

< 34

< 31

< 13 02/24/22 - 03/02/22

< 64

< 65

< 63

< 53

< 65

< 27

< 54

< 55

< 54 03/02/22 - 03/09/22

< 52

< 26

< 52

< 50

< 51

< 50

< 51

< 25

< 50 03/09/22 - 03/17/22

< 31

< 30

< 43

< 30

< 23

< 44

< 42 03/17/22 - 03/24/22

< 48

< 46

< 44

< 17

< 25

< 33

< 31 03/24/22 - 03/31/22

< 19

< 18

< 12

< 18

< 20

< 19

< 17 7

03/30/22 - 04/07 /22

< 24

< 49

< 48

< 47

< 30

< 32

< 32 04/07/22 - 04/14/22

< 28

< 40

< 43

< 39

< 23

< 47

< 44

< 45 04/14/22 - 04/21/22

< 34

< 49

< 48

< 47

< 50

< 49

< 24

< 48 04/21/22 - 04/28/22

< 18

< 37

< 35

< 36

< 35

< 34

< 21

< 34 04/28/22 - 05/04/22

< 27

< 55

< 56

< 54

< 55

< 53

< 45

< 51 05/04/22 - 05/12/22

< 35

< 21

< 34

< 42

< 21

< 41 05/12/22 - 05/19/22

< 23

< 48

< 47

< 62

< 30

< 61 05/19/22 - 05/26/22

< 24

< 48

< 46

< 37

< 45

< 39

< 38

< 23

< 38 05/26/22 - 06/01 /22

< 27

< 65

< 63

< 65

< 66

< 28

< 65

< 64 06/01 /22 - 06/09/22

< 55

< 56

< 54

< 22

< 42

< 43

< 41 06/09/22 - 06/16/22

< 22

< 46

< 44

< 22

< 44

< 10

< 23

< 22 06/16/22 - 06/23/22

< 48

< 25

< 47

< 45

< 48

< 23

< 47

< 46

< 45 06/23/22 - 06/29/22

< 39

< 56

< 60

< 56

< 66

< 67

< 35

< 63 06/29/22 - 07/07/22

< 31

< 50

< 48

< 40

< 47

< 42

< 44

< 41

< 41 07/07/22 - 07/13/22

< 31

< 30

< 52

< 30

< 24

< 53

< 55

< 54 07/13/22 - 07/21/22

< 40

< 41

< 40

< 50

< 40

< 25

< 50

< 51

< 49 07/21/22 - 07/28/22

< 41

< 59

< 58

< 46

< 58

< 33

< 48

< 47 07/28/22 - 08/03/22

< 58

< 59

< 61

< 25

< 61

< 26

< 60

< 59 08/03/22 - 08/11/22

< 40

< 17

< 37

< 39

< 38

< 32

< 13

< 31 08/11 /22 - 08/18/22

< 23

< 11

< 24

< 23

< 24

< 33

< 33 08/18/22 - 08/24/22

< 59

< 29

< 59

< 52

< 59

< 54

< 34

< 53 08/24/22 - 08/31/22

< 43

< 41

< 40

< 17

< 41

< 33

< 69

< 67 08/31/22 - 09/08/22

< 29

< 12

< 28

< 40

< 47

< 45 09/08/22 - 09/15/22

< 13

< 30

< 28

< 29

< 50

< 48 09/15/22 - 09/22/22

< 33

< 32

< 18

< 25

< 58

< 59

< 58 09/22/22 - 09/28/22

< 66

< 27

< 66

< 32

< 14

< 32

< 31 09/28/22 - 10/06/22

< 62

< 61

< 25

< 61

< 60

< 62

< 25

< 61

< 61 10/06/22 - 10/12/22

< 48

< 40

< 47

< 54

< 52

< 51 10/12/22 - 10/20/22

< 68

< 69

< 67

< 62

< 69

< 61

< 25

< 63

< 60 10/20/22 10/27/22

< 48

< 46

< 52

< 45

< 54

< 55

< 26 10/27/22 11/02/22

< 48

< 49

< 24

< 48

< 49

< 23

< 48

< 48 11/02/22 11/10/22

< 28

< 12

< 27

< 67

< 28

< 69

< 29

< 65 11/10/22 - 11/17/22

< 22

< 12

< 22

< 23

< 11

< 22

< 22 11/17/22 - 11/23/22

< 49

< 24

< 49

< 50

< 49

< 57

< 56

< 57

< 57 11 /23/22 - 11 /30/22

< 30

< 32

< 30

< 16

< 30

< 41

< 38 11/30/22 12/08/22

< 53

< 28

< 53

< 55

< 53

< 53 12/08/22 - 12/15/22

< 49

< 50

< 49

< 24

< 23

< 46

< 47

< 46 12/15/22 - 12/22/22

< 56

< 30

< 55

< 47

< 56

< 24

< 49

< 46 12/22/22 - 12/28/22

< 68

< 69

< 35

< 62

< 69

< 65

< 63

< 31

< 62 MEAN (1) SEE PROGRAM EXCEPTIONS SECTION FOR EXPLANATION C-11

0 I.....

I\)

Table C-Vll.1 Table C-Vll.2 COLLECTION SITE PERIOD L-42 04/07/22 MEAN CONCENTRATIONS OF 1-131 IN MILK SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA COLLECTION PERIOD 04/07/22 MEAN CONTROL FARM L-42

< 0.9 CONCENTRATIONS OF GAMMA EMITTERS IN MILK SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140

< 8

< 7

< 21

< 8

< 21

<7

<13

<7

<9

<53

<10

Table C-Vlll.1 CONCENTRATIONS OF GAMMA EMITTERS IN FOOD PRODUCT SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/KG WET+/- 2 SIGMA COLLECTION SITE PERIOD Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 L-42 Pasturage 01/06/22

< 39

< 33

< 61

< 33

< 86

< 39

< 63

< 55

< 36

< 38

< 133

< 42 Pasturage 02/03/22

< 35

< 29

< 86

< 38

< 95

< 32

< 56

< 38

< 33

< 130

< 30 Pasturage 03/02/22

< 32

< 35

< 69

< 34

< 73

< 34

< 61

< 52

< 40

< 35

< 143

< 37 Pasturage 05/04/22

< 27

< 30

< 57

< 30

< 75

< 32

< 51

< 50

< 36

< 31

< 135

< 32 Pasturage 05/20/22

< 13

< 14

< 35

< 16

< 28

< 14

< 25

< 37

< 15

< 14

< 82

< 17 Pasturage 06/01/22

< 35

< 93

< 38

< 85

< 33

< 61

< 55

< 42

< 30

< 137

< 55 Pasturage 06/16/22

< 38

< 37

< 88

< 56

< 92

< 34

< 65

< 54

< 47

< 42

< 163

< 49 Pasturage 06/29/22

< 35

< 37

< 82

< 42

< 81

< 34

< 58

< 59

< 37

< 30

< 156

< 52 Pasturage 07/13/22

< 30

< 28

< 58

< 30

< 61

< 30

< 44

< 42

< 31

< 26

< 127

< 35 Pasturage 07/28/22

< 37

< 33

< 69

< 34

< 72

< 35

< 49

< 52

< 35

< 40

< 155

< 43 Pasturage 08/11/22

< 33

< 23

< 54

< 33

< 52

< 34

< 62

< 39

< 27

< 28

< 107

< 29 Pasturage 08/24/22

< 37

< 32

< 66

< 40

< 62

< 35

< 60

< 54

< 34

< 137

< 50 Pasturage 09/08/22

< 36

< 31

< 80

< 41

< 85

< 38

< 68

< 56

< 42

< 35

< 163

< 47 Pasturage 09/22/22

< 34

< 43

< 67

< 22

< 74

< 31

< 59

< 53

< 34

< 33

< 140

< 32 Pasturage 10/06/22

< 40

< 87

< 46

< 80

< 37

< 64

< 50

< 39

< 41

< 150

< 48 Pasturage 10/22/22

< 38

< 31

< 79

< 37

< 89

< 36

< 70

< 48

< 54

< 43

< 178

< 41 0

Pasturage 11/02/22

< 28

< 29

< 59

< 33

< 65

< 27

< 49

< 53

< 33

< 29

< 133

< 35 I

~

Pasturage 11/30/22

< 29

< 31

< 64

< 35

< 71

< 39

< 53

< 47

< 26

< 33

< 140

< 39 c,J MEAN L-QUAD 1 Cabbage 08/03/22

< 28

< 37

< 66

< 31

< 74

< 39

< 50

< 53

< 34

< 35

< 167

< 50 Potato 08/03/22

< 16

< 39

< 20

< 41

< 15

< 32

< 25

< 21

< 20

< 75

< 21 MEAN L-QUAD 2 Horseradish 07/13/22

< 27

< 29

< 62

< 28

< 72

< 25

< 50

< 53

< 34

< 29

< 132

< 33 Horseradish leaves 07/13/22

< 25

< 30

< 61

< 34

< 72

< 27

< 55

< 40

< 32

< 28

< 123

< 51 Cabbage 07/21/22

< 25

< 34

< 75

< 44

< 64

< 34

< 61

< 37

< 33

< 30

< 132

< 39 MEAN L-QUAD4 Kohlrabi 07/13/22

< 20

< 51

< 21

< 48

< 20

< 33

< 32

< 25

< 19

< 100

< 26 Cabbage 07/13/22

< 26

< 28

< 75

< 31

< 83

< 34

< 61

< 42

< 38

< 32

< 118

< 34 Carrots 08/11/22

< 27

< 24

< 55

< 28

< 49

< 27

< 46

< 44

< 33

< 27

< 113

< 32 MEAN

Table C-Vlll.2 CONCENTRATIONS OF GAMMA EMITTERS IN VEGETATION SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/KG WET+/- 2 SIGMA COLLECTION SITE PERIOD Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 L-VEG C Grass 05/19/22

< 29

< 27

< 63

< 30

< 65

< 24

< 48

< 44

< 28

< 31

< 129

< 47 Clover 05119/22

< 22

< 48

< 24

< 47

< 22

< 44

< 33

< 22

< 24

< 90

< 27 Mayapple 05119/22

< 24

< 27

< 51

< 26

< 59

< 25

< 38

< 34

< 25

< 113

< 30 Milkweed 06116/22

< 36

< 74

< 43

< 72

< 38

< 54

< 52

< 40

< 165

< 60 Clover 06/16/22

< 34

< 51

< 100

< 59

< 105

< 45

< 79

< 56

< 52

< 45

< 204

< 61 Snakeroot 06/16/22

< 31

< 30

< 61

< 38

< 58

< 34

< 52

< 50

< 33

< 32

< 141

< 42 Turnips 07/13/22

< 34

< 30

< 57

< 46

< 75

< 35

< 55

< 39

< 33

< 143

< 40 Mustard green 07/13/22

< 37

< 28

< 97

< 42

< 120

< 45

< 68

< 53

< 44

< 40

< 163

< 39 Milkweed 07121122

< 33

< 35

< 81

< 35

< 68

< 31

< 56

< 52

< 37

< 34

< 161

< 34 Clover 07/21122

< 17

< 37

< 21

< 44

< 18

< 33

< 28

< 19

< 18

< 83

< 24 Snakeroot 07/21/22

< 39

< 40

< 86

< 37

< 91

< 39

< 65

< 56

< 43

< 166

< 56 Radish 07/28/22

< 34

< 31

< 61

< 34

< 57

< 23

< 42

< 43

< 26

< 30

< 115

< 35 Lettuce 07/28/22

< 30

< 31

< 52

< 33

< 60

< 32

< 51

< 46

< 32

< 30

< 142

< 46 Milkweed 08/18/22

< 39

< 33

< 97

< 36

< 98

< 38

< 64

< 50

< 46

< 37

< 155

< 56 Clover 08/18/22

< 46

< 42

< 90

< 42

< 108

< 52

< 79

< 55

< 51

< 44

< 190

< 56 Milkweed 09/15/22

< 44

< 38

< 80

< 48

< 86

< 44

< 78

< 58

< 42

< 40

< 186

< 48 Clover 09/15/22

< 39

< 31

< 89

< 35

< 77

< 33

< 61

< 53

< 42

< 41

< 131

< 32 Grass 09/15/22

< 43

< 46

< 86

< 42

< 101

< 40

< 71

< 53

< 46

< 44

< 174

< 41 Clover 10/20/22

< 38

< 36

< 73

< 41

< 72

< 42

< 59

< 51

< 32

< 35

< 171

< 45 MEAN C')

L-ESE-1 Clover 05/19/22

< 21

< 19

< 42

< 19

< 45

< 20

< 34

< 23

< 20

< 94

< 27

~

Dandelion 05/19/22

< 37

< 33

< 72

< 35

< 86

< 41

< 69

< 57

< 36

< 34

< 188

< 48 Clover 06/16/22

< 35

< 34

< 71

< 37

< 73

< 38

< 61

< 57

< 37

< 28

< 140

< 48 Dandelion 06/16/22

< 32

< 35

< 74

< 35

< 77

< 39

< 66

< 52

< 38

< 36

< 172

< 44 Clover 07/21/22

< 17

< 36

< 20

< 39

< 18

< 31

< 25

< 18

< 80

< 23 Dandelion 07/21/22

< 40

< 32

< 79

< 53

< 86

< 37

< 63

< 44

< 40

< 36

< 164

< 44 Plantain 07121/22

< 38

< 42

< 91

< 43

< 101

< 38

< 75

< 55

< 44

< 41

< 155

< 49 Plantain 08/18/22

< 34

< 32

< 66

< 35

< 76

< 35

< 63

< 54

< 35

< 144

< 39 Dandelion 08118/22

< 34

< 94

< 46

< 76

< 37

< 56

< 44

< 45

< 37

< 157

< 49 Clover 09115/22

< 41

< 39

< 79

< 37

< 64

< 38

< 60

< 55

< 36

< 38

< 167

< 43 Dandelion 09/15122

< 38

< 35

< 91

< 46

< 79

< 32

< 55

< 53

< 34

< 41

< 137

< 40 Clover 10/20/22

< 32

< 78

< 38

< 76

< 37

< 62

< 50

< 35

< 34

< 158

< 46 MEAN L-ESE-2 Dandelion 05/19/22

< 18

< 20

< 42

< 22

< 36

< 19

< 30

< 29

< 23

< 18

< 83

< 29 Plantain 05/19/22

< 20

< 22

< 41

< 27

< 49

< 24

< 39

< 35

< 22

< 21

< 89

< 27 Clover 05/19/22

< 21

< 24

< 52

< 21

< 47

< 21

< 38

< 30

< 21

< 19

< 90

< 21 Dandelion 06116/22

< 36

< 41

< 95

< 39

< 86

< 35

< 72

< 48

< 41

< 38

< 192

< 44 Plantain 06/16/22

< 47

< 42

< 89

< 37

< 77

< 43

< 75

< 56

< 50

< 40

< 163

< 56 Dandelion 07/21/22

< 18

< 35

< 21

< 36

< 19

< 27

< 26

< 20

< 19

< 77

< 23 Plantain 07121/22

< 44

< 32

< 75

< 42

< 72

< 38

< 69

< 49

< 44

< 42

< 157

< 45 Clover 07121/22

< 18

< 17

< 38

< 22

< 40

< 18

< 33

< 23

< 21

< 19

< 71

< 20 Dandelion 08/18/22

< 29

< 33

< 70

< 34

< 80

< 33

< 51

< 43

< 34

< 130

< 40 Plantain 08/18/22

< 48

< 34

< 104

< 57

< 100

< 37

< 71

< 47

< 41

< 53

< 172

< 20 Clover 08/18/22

< 40

< 39

< 64

< 43

< 90

< 35

< 61

< 58

< 43

< 38

< 166

< 45 Thistle 09115122

< 31

< 29

< 72

< 45

< 69

< 28

< 59

< 46

< 34

< 144

< 30 Plantain 09115122

< 28

< 34

< 42

< 39

< 76

< 37

< 64

< 43

< 42

< 34

< 173

< 36 Clover 09/15/22

< 39

< 46

< 56

< 39

< 103

< 38

< 61

< 41

< 47

< 36

< 184

< 35 Grass 10/20/22

< 35

< 37

< 78

< 33

< 99

< 37

< 74

< 57

< 46

< 43

< 196

< 47 MEAN

Table C-IX.1 QUARTERLY DLR RES UL TS FOR LASALLE COUNTY STATION, 2022 Location L-01 L-03 L-04 L-05 L-06 L-07 L-08 L-10 L-101 L-102 L-103 L-104 L-105 L-106 L-107 L-108 L-109 L-110 L-111 B L-112 L-113A L-114 L-115 L-116 L-11A L-201 L-202 L-203 L-204 L-205A L-205B L-206 L-207 L-208 L-209 L-210 L-211 L-212 L-213 L-214 L-215 L-216 Location Annual Annual Qtrly B0 + 2022 Normalized Net Dose, M0x Normalized BA+

Facility Facility

Baseline, MDD0 (mrem/std. Qtr.)

Annual Dose, Bl1 MDDA'21 Dose, FA

Dose, MA (mrem/yr)

FA >10 B0 (mrem) 1 I

2 I

3 I

4 (mrem) mrem 13.3 22.0 17.3 17.5 17.8 19.1 71.8 53.1 87.3 ND No 11.9 20.6 17.1 16.1 16.6 19.2 68.9 45.3 79.5 ND No 12 20.7 15.8 16.7 16.9 17.6 67.0 45.6 79.8 ND No 11.7 20.4 16.5 16.0 15.5 17.8 65.8 46.8 81.0 ND No 13.2 21.9 16.6 18.4 17.1 17.2 69.2 53.0 87.2 ND No 12.9 21.6 17.9 18.2 17.1 16.7 69.8 51.5 85.7 ND No 12.5 21.2 15.3 14.9 15.1 16.0 61.3 50.1 84.3 ND No 10 18.7 15.8 15.5 15.5 13.0 59.7 39.8 74.0 ND No 13.3 22.0 18.4 18.9 17.5 18.6 73.3 50.4 84.6 ND No 14.9 23.6 19.2 20.3 20.5 19.8 79.8 59.5 93.7 ND No 12.3 21.0 16.4 17.5 16.9 17.1 68.0 49.2 83.4 ND No 11.6 20.3 16.4 17.8 18.0 16.6 68.7 46.3 80.5 ND No 13.3 22.0 18.1 19.7 19.0 19.2 76.0 53.2 87.4 ND No 12.3 21.0 16.8 17.5 17.5 18.1 70.0 49.2 83.4 ND No 12.8 21.5 18.5 18.3 20.0 20.2 76.9 51.2 85.4 ND No 11.1 19.8 20.0 17.0 18.4 18.4 73.8 44.3 78.5 ND No 12.9 21.6 16.1 17.8 15.5 16.1 65.4 51.6 85.8 ND No 12.4 21.1 18.1 18.2 16.5 18.7 71.4 49.7 83.9 ND No 13.1 21.8 18.0 19.4 19.1 17.1 73.6 52.3 86.5 ND No 12.4 21.1 16.6 18.1 18.0 17.5 70.1 49.6 83.8 ND No 13.8 22.5 17.7 19.0 20.2 19.2 76.1 55.2 89.4 ND No 13.1 21.8 17.8 17.9 17.3 17.9 70.9 50.0 84.2 ND No 11.2 19.9 16.1 16.4 16.5 19.0 68.0 44.8 79.0 ND No 11.2 19.9 16.9 16.8 17.4 17.5 68.6 44.8 79.0 ND No 10.3 19.0 17.7 16.8 17.7 17.1 69.2 41.2 75.4 ND No 11 19.7 14.0 13.9 14.5 15.4 57.7 43.8 78.0 ND No 10.2 18.9 13.5 15.2 15.1 16.7 60.5 40.9 75.1 ND No 12.8 21.5 15.8 17.5 16.7 17.2 67.1 51.1 85.3 ND No 13.3 22.0 19.0 18.2 16.2 19.4 72.7 50.7 84.9 ND No 12.2 20.9 16.3 16.7 15.7 18.2 66.7 48.8 83.0 ND No 12 20.7 16.3 16.7 15.7 18.2 66.7 45.7 79.9 ND No 12.9 21.6 19.0 19.4 16.5 19.2 74.0 51.6 85.8 ND No 12.1 20.8 17.3 17.8 17.5 17.4 69.9 48.5 82.7 ND No 13.1 21.8 17.8 19.3 16.5 18.6 72.2 44.6 78.8 ND No 12.4 21.1 17.3 17.6 17.8 18.4 71.0 47.2 81.4 ND No 13.7 22.4 17.4 19.9 20.1 19.7 77.0 51.9 86.1 ND No 13.5 22.2 18.2 18.1 18.5 16.6 71.5 54.1 88.3 ND No 13.3 22.0 18.1 19.1 17.9 19.4 74.4 50.5 84.7 ND No 11.5 20.2 17.2 16.6 17.3 16.8 67.8 41.6 75.8 ND No 11.9 20.6 16.4 18.7 15.5 16.9 67.4 47.6 81.8 ND No 13.6 22.3 17.9 19.1 16.7 18.9 72.6 54.4 88.6 ND No 13.4 22.1 16.7 17.6 18.2 18.6 71.0 53.5 87.7 ND No 111 Baseline background dose (BA): The estimated mean background radiation dose at each field monitoring location annually based on historical measurements. excluding any dose contribution from the monitored facility 121 Minimum differential dose (MDDA): The smallest amount of facility related dose at each monitored location annually above the baseline background dose that can be reliably detected by an environmental dosimetry system C-15

Table C-IX.1 QUARTERLY OSLO RESULTS FOR LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF MILLI REM/QUARTER+/- 2 STANDARD DEVIATIONS STATION MEAN JAN - MAR APR-JUN JUL - SEP OCT-DEC CODE

+/-2 S.D.

L-01 17.9 +/- 1.6 17.3 17.5 17.8 19.1 L-03 17.2 +/- 2.7 17.1 16.1 16.6 19.2 L-04 16.8 +/- 1.5 15.8 16.7 16.9 17.6 L-05 16.5 +/- 2.0 16.5 16.0 15.5 17.8 L-06 17.3 +/- 1.5 16.6 18.4 17.1 17.2 L-07 17.5 +/- 1.4 17.9 18.2 17.1 16.7 L-08 15.3 +/- 0.9 15.3 14.9 15.1 16.0 L-10 14.9 +/- 2.6 15.8 15.5 15.5 13.0 L-11A 17.3 +/- 0.9 17.7 16.8 17.7 17.1 L-101 18.3 +/- 1.1 18.4 18.9 17.5 18.6 L-102 19.9 +/- 1.2 19.2 20.3 20.5 19.8 L-103 17.0 +/- 0.9 16.4 17.5 16.9 17.1 L-104 17.2 +/- 1.6 16.4 17.8 18.0 16.6 L-105 19.0 +/- 1.3 18.1 19.7 19.0 19.2 L-106 17.5 +/- 1.0 16.8 17.5 17.5 18.1 L-107 19.2 +/- 2.0 18.5 18.3 20.0 20.2 L-108 18.5 +/- 2.4 20.0 17.0 18.4 18.4 L-109 16.4 +/- 2.0 16.1 17.8 15.5 16.1 L-110 17.8 +/- 1.9 18.1 18.2 16.5 18.7 L-111 B 18.4 +/- 2.1 18.0 19.4 19.1 17.1 L-112 17.5 +/- 1.3 16.6 18.1 18.0 17.5 L-113A 19.0 +/- 2.1 17.7 19.0 20.2 19.2 L-114 17.7 +/- 0.6 17.8 17.9 17.3 17.9 L-115 17.0 +/- 2.6 16.1 16.4 16.5 19.0 L-116 17.1 +/-0.7 16.9 16.8 17.4 17.5 L-201 14.4 +/- 1.4 14.0 13.9 14.5 15.4 L-202 15.1 +/- 2.6 13.5 15.2 15.1 16.7 L-203 16.8 +/- 1.5 15.8 17.5 16.7 17.2 L-204 18.2 +/- 2.9 19.0 18.2 16.2 19.4 L-205A 16.7+/-2.1 16.3 16.7 15.7 18.2 L-205B 16.7 +/- 2.1 16.3 16.7 15.7 18.2 L-206 18.5 +/- 2.7 19.0 19.4 16.5 19.2 L-207 17.5 +/- 0.5 17.3 17.8 17.5 17.4 L-208 18.1 +/- 2.4 17.8 19.3 16.5 18.6 L-209 17.7 +/- 1.0 17.3 17.6 17.8 18.4 L-210 19.3 +/- 2.5 17.4 19.9 20.1 19.7 L-211 17.9 +/- 1.7 18.2 18.1 18.5 16.6 L-212 18.6 +/- 1.5 18.1 19.1 17.9 19.4 L-213 17.0 +/- 0.7 17.2 16.6 17.3 16.8 L-214 16.9 +/- 2.7 16.4 18.7 15.5 16.9 L-215 18.2 +/- 2.2 17.9 19.1 16.7 18.9 L-216 17.7 +/- 1.6 16.7 17.6 18.2 18.6 C-16

TABLE C-IX.2 MEAN QUARTERLY OSLO RESULTS FOR THE INNER RING, OUTER RING, OTHER AND CONTROL LOCATIONS FOR LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF MILLIREM/QUARTER +/- 2 STANDARD DEVIATIONS OF THE STATION DATA COLLECTION PERIOD JAN-MAR APR-JUN JUL-SEP OCT-DEC Table C-IX.3 LOCATION INNER RING OUTER RING OTHER CONTROL INNER RING OUTER RING OTHER CONTROL

+/-2 S.D.

17.6 +/- 2.1 16.9 +/- 2.9 16.7 +/- 1.8 15.8 +/- 0 18.1 +/- 2.1 18.1 +/- 2.1 16.8 +/- 2.5 15.5 +/- 0 18.0 +/- 2.7 18.0 +/- 2.7 16.6 +/- 1.9 15.5 +/- 0 18.1 +/- 2.2 18.1 +/- 2.2 17.6 +/- 2.4 14.9 +/- 0

SUMMARY

OF THE AMBIENT DOSIMETRY PROGRAM FOR LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF MILLIREM/QUARTER SAMPLES PERIOD PERIOD PERIOD MEAN ANALYZED MINIMUM MAXIMUM

+/- 2 S.D.

68 15.5 20.5 17.9 +/- 2.4 68 13.5 20.1 17.4 +/- 3.0 28 14.9 19.2 16.9 +/- 2.2 4

14.1 16.8 14.9 +/- 2.6 INNER RING STATIONS - L-101-1, L-101-2, L-102-1, L-102-2, L-103-1, L-103-2, L-104-1, L-104-2, L-105-1, L-105-2, L-106-1, L-106-2, L-107-1, L-107-2, L-108-1, L-108-2, L109-1, L109-2, L110-1, L110-2, L-111B-1, L-111B-2, L-112-1, L-112-2, L113A-1, L-113A-2, L114-1, L-114-2, L-115-1, L-115-2, L-116-1. L-116-2 OUTER RING STATIONS - L-201-3, L-201-4, L-202-3, L-202-4, L-203-1, L-203-2, L-204-1, L-204-2, L205-1, L-205-2, L-205-3, L-205-4, L-206-1, L-206-2, L-207-1, L207-2, L208-1, L208-2, L209-1, L209-2, L210-1, L-210-2, L-211-1, L-211-2, L-212-1, L-212-2, L-213-3, L-213-4, L-214-3, L-214-4, L-215-3, L-215-4, L-2016-3, L-216-4 OTHER STATIONS-L-01-1, L-01-2, L-03-1, L-03-2, L-04-1, L-04-2, L-05-1, L-05-2, L-06-1, L-06-2, L-07-1, L-07-2, L-08-1, L-08-2, L-11A-1, L-11A-2 CONTROL STATIONS - L-10-1, L-10-2 C-17

FIGURE C-1 Surface Water - Gross Beta - Stations L-21 (C) and L-40 Collected in the Vicinity of LSCS, 2005 - 2022

~

u C.

14.0 12.0 10.0 8.0 6.0 4.0 2.0 L-21 (C) Illinois River at Seneca 0.0 -------- - ------ --- --4 01 05 01-18-11 01 17 12-30-22 L-40 Illinois River Downstream 16.0 14.0 12.0 10.0 8.0 6.0 4.0 2.0 0.0 01-27-05 01-18-11 01-08-17 12-30-22 C-18

FIGURE C-2 Surface Water - Tritium - Stations L-21 (C) and L-40 Collected in the Vicinity of LSCS, 2005 - 2022 L-21 Illinois River at Seneca 2000 1600 1200

..J i3 CL 800 400 0

03-31-05 09-07-09 02-14-14 07-24-18 12-31-22 L-40 Illinois River Downstream 2000 1600 1200

..J i3 CL 800 400 0

03-31-05 09-07-09 02-14-14 07-24-18 12-31-22 C-19

FIGURE C-3 Air Particulate - Gross Beta - Stations L-01 and L-03 Collected in the Vicinity of LSCS, 2005 - 2022 60.0 50.0 e 4o.o

~

a. 30.0 M

9

~ 20.0 10.0 L-01 Nearsite No. 1 0.0 +-------------------~

01-06-05 60.0 50.0 e

4o.o

~

a.

30.0 M

9

~

20.0 10.0 07-06-09 01-03-14 07-03-18 12-31-22 L-03 Onsite No. 3 0.0 +------+-----+------+-----

01-06-05 07-06-09 01-03-14 07-03-18 12-31-22 C-20

FIGURE C-4 Air Particulate - Gross Beta - Stations L-05 and L-06 Collected in the Vicinity of LSCS, 2005 - 2022 60.0 50.0 e 4o.o

~ 30.0 q

~ 20.0 10.0 L-05 Onsite No. 5 0.0 -------------......... ------1 E

01-06-05 70.0 60.0 50.0

~ 40.0 q 30.0 w

! 20.0 10.0 07-06-09 01-03-14 07-03-18 12-31-22 L-06 Nearsite No. 6 0.0 +------+-----+---------i-----t 01-06-05 07-06-09 01 14 07-03-18 12-31-22 C-21

FIGURE C-5 Air Particulate - Gross Beta - Station L-1 0 (C)

Collected in the Vicinity of LSCS, 2005 - 2022 60.0 50.0 40.0

~

0 c. 30.0 9

~ 20.0

'I""

10.0 L-10 (C) Streator 0.0 -----------------

01-06-05 07-06-09 01-03-14 07-03-18 12-31-22 C-22

FIGURE C-6 Air Particulate - Gross Beta - Stations L-04 and L-07 Collected in the Vicinity of LSCS, 2005 - 2022 M

E

u Q,

M Cjl w

0

'I""

60.0 50.0 40.0 30.0 20.0 10.0 0.0 07-07-05 60.0 50.0 M

40.0

.e 0 a. 30.0 M

Cjl

~ 20.0

'I""

10.0 L-04 Rte. 170 11-19-09 04-03-14 08-16-18 12-29-22 L-07 Seneca 0.0 _____________

07-07-05 11-19-09 04-03-14 08-16-18 12-29-22 C-23

FIGURE C-7 Air Particulate - Gross Beta - Stations L-08 and L-11 Collected in the Vicinity of LSCS, 2005 - 2022 60.0 50.0 i 40.0 u

c. 30.0 M q

~ 20.0 10.0 L-08 Marseilles 0.0 --------------------

07-07-05 60.0 50.0 M

40.0

.e u

c. 30.0 M q

~ 20.0 10.0 11-19-09 04-03-14 08-16-18 12-29-22 L-11 Ransom (1) 0.0 ---------------------

07-07-05 01-14-09 07-24-12 02-01-16 (1) Air monitoring station L-11 was retired on 01121116 C-24

APPENDIX D INTER-LABORATORY COMPARISON PROGRAM

Intentionally left blank

Analytics Environmental Radioactivity Cross Check Program Table D.1 Teledxne Brown Engineering Environmental Services Identification TBE Known Ratio of TBE to Month/Year Number Matrix Nuclide Units Reported Value (a)

Analytics Result Evaluation Cb)

Value March 2022 E13706 Milk Sr-89 pCi/L 80.3 96.8 0.83 A

Sr-90 pCi/L 12.7 12.6 1.01 A

E13707 Milk Ce-141 pCi/L 62.3 65 0.96 A

Co-58 pCi/L 158 164 0.96 A

Co-60 pCi/L 286 302 0.95 A

Cr-51 pCi/L 314 339 0.93 A

Cs-134 pCi/L 155 182 0.85 A

Cs-137 pCi/L 210 223 0.94 A

Fe-59 pCi/L 211 185 1.14 A

1-131 pCi/L 88.0 96.7 0.91 A

Mn-54 pCi/L 169 164 1.03 A

Zn-65 pCi/L 238 246 0.97 A

E13708 Charcoal 1-131 pCi 79.9 87.1 0.92 A

E13709 AP Ce-141 pCi 60.9 42.0 1.45 N< l Co-58 pCi 118 107 1.11 A

Co-60 pCi 218 196 1.11 A

Cr-51 pCi 251 221 1.14 A

Cs-134 pCi 129 118 1.09 A

Cs-137 pCi 156 145.0 1.07 A

Fe-59 pCi 124 120.0 1.03 A

Mn-54 pCi 120 107 1.12 A

Zn-65 pCi 162 160 1.01 A

E13710 Soil Ce-141 pCi/g 0.123 0.103 1.19 A

Co-58 pCi/g 0.254 0.263 0.97 A

Co-60 pCi/g 0.493 0.483 1.02 A

Cr-51 pCi/g 0.603 0.543 1.11 A

Cs-134 pCi/g 0.268 0.292 0.92 A

Cs-137 pCi/g 0.399 0.431 0.93 A

Fe-59 pCi/g 0.320 0.296 1.08 A

Mn-54 pCi/g 0.263 0.263 1.00 A

Zn-65 pCi/g 0.407 0.395 1.03 A

E13711 AP Sr-89 pCi 83.2 97.4 0.85 A

Sr-90 pCi 12.7 12.7 1.00 A

(a) The Analytics known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation (b) Analytics evaluation based on TBE internal QC limits:

A = Acceptable - reported result falls within ratio limits of 0. 80-1. 20 W = Acceptable with warning - reported result falls within 0. 70-0. 80 or 1. 20-1. 30 N = Not Acceptable - reported result falls outside the ratio limits of< 0. 70 and> 1.30 (1) See NCR 22-04 (Page 1 of 2)

Analytics Environmental Radioactivity Cross Check Program Table D.1 Teled~ne Brown Engineering Environmental Services Identification TBE Known Ratio of TBE to Month/Year Number Matrix Nuclide Units Reported Value <al Analytics Result Evaluation (bl Value September 2022 E13712 Milk Sr-89 pCi/L 71.1 89.1 0.80 A

Sr-90 pCi/L 12.0 13.6 0.88 A

E13713 Milk Ce-141 pCi/L 148 161 0.92 A

Co-58 pCi/L 178 189 0.94 A

Co-60 pCi/L 229 260 0.88 A

Cr-51 pCi/L 486 456 1.07 A

Cs-134 pCi/L 220 252 0.87 A

Cs-137 pCi/L 203 222 0.92 A

Fe-59 pCi/L 174 173 1.01 A

1-131 pCi/L 75.9 94.2 0.81 A

Mn-54 pCi/L 269 282 0.95 A

Zn-65 pCi/L 364 373 0.97 A

E13714 Charcoal 1-131 pCi 81.4 83.6 0.97 A

E13715 AP Ce-141 pCi 102 91 1.12 A

Co-58 pCi 118 107 1.11 A

Co-60 pCi 207 147 1.41 Nm Cr-51 pCi 310 257 1.21 w

Cs-134 pCi 148 142 1.04 A

Cs-137 pCi 137 125 1.10 A

Fe-59 pCi 115 98 1.18 A

Mn-54 pCi 168 159 1.05 A

Zn-65 pCi 240 211 1.14 A

E13716 Soil Ce-141 pCi/g 0.288 0.284 1.01 A

Co-58 pCi/g 0.320 0.334 0.96 A

Co-60 pCi/g 0.445 0.459 0.97 A

Cr-51 pCi/g 0.883 0.805 1.10 A

Cs-134 pCi/g 0.410 0.446 0.92 A

Cs-137 pCi/g 0.447 0.465 0.96 A

Fe-59 pCi/g 0.314 0.305 1.03 A

Mn-54 pCi/g 0.489 0.499 0.98 A

Zn-65 pCi/g 0.666 0.660 1.01 A

E13717 AP Sr-89 pCi 87.5 98.3 0.89 A

Sr-90 pCi 12.6 15.0 0.84 A

(a) The Analytics known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation (b) Analytics evaluation based on TBE internal QC limits:

A = Acceptable - reported result falls within ratio limits of 0. 80-1. 20 W = Acceptable with warning-reported result falls within 0. 70-0.80 or 1.20-1.30 N = Not Acceptable - reported result falls outside the ratio limits of< 0. 70 and> 1.30 (2) See NCR 22-21 (Page 2 of 2)

DOE's Mixed Analyte Performance Evaluation Program (MAPEP)

Table D.2 Teledlne Brown Ensineerins Environmental Services Identification TBE Known Acceptance MonthNear Matrix Nuclide Units Reported Evaluation !bl Number Value Value (aJ Range February 2022 22-GrF46 AP Gross Alpha Sq/sample 0.402 1.20 0.36 - 2.04 A

Gross Beta Sq/sample 0.669 0.68 0.341 - 1.022 A

22-MaS46 Soil Ni-63 Bq/kg 645 780 546 - 1014 A

Tc-99 Bq/kg 526 778 545-1011 N<3J 22-MaSU46 Urine Cs-134 Bq/L 1.67 1.77 1.24 - 2.30 A

Cs-137 Bq/L 1.50 1.56 1.09 - 2.03 A

Co-57 Bq/L 4.93 5.39 3.77 - 7.01 A

Co-60 Bq/L 2.13 2.06 1.44 - 2.68 A

Mn-54 Bq/L 4.83 5.08 3.56 - 6.60 A

U-234 Bq/L 0.142 0.0074 0.0052 - 0.0096 N<4l U-238 Bq/L 0.0254 0.0103 0.0072 - 0.0134 N(4l Zn-65 Bq/L 4.71 4.48 3.14 - 5.82 A

22-MaW46 Water Ni-63 Bq/L 28.6 34.0 23.8 - 44.2 A

Tc-99 Bq/L 8.59 7.90 5.5 - 10.3 A

22-RdV46 Vegetation Cs-134 Bq/sample 6.61 7.61 5.33 - 9.89 A

Cs-137 Bq/sample 1.50 1.52 1.06-1.98 A

Co-57 Bq/sample 5.11 5.09 3.56 - 6.62 A

Co-60 Sq/sample 0.0162 (1)

A Mn-54 Sq/sample 2.42 2.59 1.81 - 3.37 A

Sr-90 Bq/sample 0.684 0.789 0.552 - 1.026 A

Zn-65 Bq/sample 1.44 1.47 1.03-1.91 A

August2022 22-MaS47 Soil Ni-63 Bq/kg 14.6 (1)

A Tc-99 Bq/kg 994 1000 700 - 1300 A

22-MaW47 Water Ni-63 Bq/L 24.4 32.9 23.0 - 42.8 A

Tc-99 Bq/L 1.9 (1)

N(S) 25-RdV47 Vegetation Cs-134 Sq/sample 0.032 (1)

A Cs-137 Sq/sample 0.891 1.08

0. 758 - 1.408 A

Co-57 Sq/sample 0.006 (1)

A Co-60 Bq/sample 4.04 4.62 3.23-6.01 A

Mn-54 Bq/sample 2.01 2.43 1.70 - 3.16 A

Sr-90 Sq/sample 1.25 1.60 1.12-2.08 w

Zn-65 Sq/sample 6.16 7.49 5.24 - 9.74 A

(a) The MAPEP known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation (b) DOE/MAPEP evaluation:

A= Acceptable - reported result falls within ratio limits of 0.80-1.20 W= Acceptable with warning-reported result falls within 0.70-0.80 or 1.20-1.30 N = Not Acceptable - reported result falls outside the ratio limits of< 0. 70 and> 1.30 (1) False positive test (2) Sensitivity evaluation (3) Tc-99 soil cross-checks done for TBE infonnation only - not required (4) See NCR 22-05 (5) See NCR 22-22 (Page 1 of 1)

ERA Environmental Radioactivity Cross Check Program Table D.3 Teledyne Brown Engineering Environmental Services Month/Year Identification Matrix Nuclide Units TBE Reported Known Acceptance Evaluation (bl Number Value Value(*>

Limits March 2022 MRAD-36 Water Am-241 pCi/L 68.3 74.6 51.2 - 95.4 A

Fe-55 pCi/L 797 1140 670 - 1660 A

Pu-238 pCi/L 146 147 88.4-190 A

Pu-239 pCi/L 69.9 71.9 44.5 - 88.6 A

Soil Sr-90 pCi/kg 8050 6720 2090 - 10500 A

AP Fe-55 pCi/filter 148 127 46.4 - 203 A

Pu-238 pCi/filter 29.9 29.6 22.3 - 36.4 A

Pu-239 pCi/filter 51.6 49.7 37.2 - 60.0 A

U-234 pCi/filter 59.9 67.3 49.9 - 78.9 A

U-238 pCi/filter 59.0 66.7 50.4 - 79.6 A

GR-A pCi/filter 95.6 94.2 49.2 - 155 A

GR-B pCi/filter 71.2 66.8 40.5-101 A

April 2022 RAD-129 Water Ba-133 pCi/L 61.7 62.9 52.3 - 69.2 A

Cs-134 pCi/L 80.9 81.6 68.8-89.8 A

Cs-137 pCi/L 37.4 36.6 32.1 - 43.3 A

Co-60 pCi/L 103 97.4 87.7-109 A

Zn-65 pCi/L 318 302 272 - 353 A

GR-A pCi/L 26.9 20.8 10.4 - 28.3 A

GR-B pCi/L 49.7 51.0 34.7 - 58.1 A

U-Nat pCi/L 56.3 68.9 56.3 - 75.8 A

H-3 pCi/L 17,000 18,100 15,800 - 19,000 A

Sr-89 pCi/L 65.3 67.9 55.3 - 76.1 A

Sr-90 pCi/L 42.1 42.7 31.5 - 49.0 A

1-131 pCi/L 25.7 26.2 21.8 - 30.9 A

September 2022 MRAD-37 Water Am-241 pCi/L 111 96.2 66.0 - 123 A

Fe-55 pCi/L 850 926 544 - 1350 A

Pu-238 pCi/L 62.1 52.6 31.6 - 68.2 A

Pu-239 pCi/L 139.5 117 72.5 - 144 A

Soil Sr-90 pCi/kg 3350 6270 1950 - 9770 A

U-234 pCi/kg 1684 3350 1570 - 4390 A

U-238 pCi/kg 1658 3320 1820 -4460 Nt"'

AP Fe-55 pCi/filter 71.9 122 44.5-195 A

Pu-238 pCi/filter 38.8 29.9 22.6 - 36.7 Nt11 Pu-239 pCi/filter 14.5 13.0 9.73-15.7 A

U-234 pCi/filter 78.0 71.5 53.0 - 83.8 A

U-238 pCi/filter 79.7 70.9 53.5 - 84.6 A

GR-A pCi/filter 62.8 55.5 29.0 - 91.4 A

GR-B pCi/filter 70.9 64.8 39.3 - 97.9 A

October 2022 RAD-131 Water Ba-133 pCi/L 76.2 79.4 66.6 - 87.3 A

Cs-134 pCi/L 28.0 30.5 23.9 - 33.6 A

Cs-137 pCi/L 202 212 191 -235 A

Co-60 pCi/L 52.4 51.4 46.3 - 59.1 A

Zn-65 pCi/L 216 216 194 - 253 A

GR-A pCi/L 19.7 16.9 8.28 - 23.7 A

GR-B pCi/L 49.8 53.0 36.1 - 60.0 A

U-Nat pCi/L 10.54 8.53 6.60- 9.88 Nl"!

H-3 pCi/L 13,900 15,100 13,200 - 16,600 A

Sr-89 pCi/L 59.7 64.5 52.3 - 72.5 A

Sr-90 pCi/L 32.9 37.3 27.4 - 43.0 A

1-131 pCi/L 26.9 24.4 20.2 - 28.9 A

(a) The ERA known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation.

(b) ERA evaluation:

A = Acceptable - Reported value falls within the Acceptance Limits N = Not Acceptable - Reported value falls outside of the Acceptance Limits (1) See NCR 22-19 (2) U soil cross-checks done for TBE information only - not required (3) See NCR 22-20 (Page 1 of 1)

APPENDIX E ERRATA DATA

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There is no errata data for 2022.

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APPENDIX F ANNUAL RADIOLOGICAL GROUNDWATER PROTECTION PROGRAM REPORT (ARGPPR)

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Docket No:

50-373 50-374 LASALLE COUNTY STATION UNITS 1 and 2 Annual Radiological Groundwater Protection Program Report 1 January through 31 December 2022 Prepared By Teledyne Brown Engineering Environmental Services Constellation LaSalle County Station Marseilles, IL 61341 May 2023

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Table Of Contents I. Summary and Conclusions......................................................................................... 1 II. Introduction................................................................................................................ 2 A. Objectives of the RGPP........................................................................................ 2 B. Implementation of the Objectives......................................................................... 2 C. Program Description............................................................................................. 3 D. Characteristics of Tritium (H-3)............................................................................. 3 Ill. Program Description.................................................................................................. 4 A. Sample Analysis.................................................................................................. 4 B. Data Interpretation.............................................................................................. 4 C. Background Analysis.......................................................................................... 5

1. Background Concentrations of Tritium........................................................... 5 IV. Results and Discussion............................................................................................. 7 A. Groundwater Results.......................................................................................... 7 B. Surface Water Results........................................................................................ 8 C. Drinking Water Well Survey................................................................................ 8 D. Summary of Results - Inter-laboratory Comparison Program............................... 8 E. Leaks, Spills, and Releases.................................................................................. 8 F. Trends.................................................................................................................. 8 G. Investigations....................................................................................................... 8 H. Actions Taken...................................................................................................... 8

Appendix A Tables Table A-1 Figures Figure A-1 Appendix B Tables Table B-1.1 Table B-1.2 Table B-1.3 Appendices Location Designation LaSalle County Station Groundwater Monitoring Sample Point List, 2022 LaSalle County Station Map of Groundwater Monitoring Sampling Locations, 2022 Data Tables Concentrations of Tritium, Strontium, Gross Alpha, and Gross Beta in Groundwater Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Gamma Emitters in Groundwater Samples Collected in the Vicinity of LaSalle County Station, 2022 Concentrations of Hard-to-Detects in Groundwater Samples Collected as Part of the Radiological Groundwater Protection Program, LaSalle County Station, 2022 ii

I.

Summary and Conclusions In 2006, Constellation (formerly Exelon) instituted a comprehensive program to evaluate the impact of station operations on groundwater and surface water in the vicinity of LaSalle County Station. This evaluation involved numerous station personnel and contractor support personnel. Following baseline sampling and subsequent recommendations, LaSalle's Radiological Groundwater Protection Program (RGPP) program now consists of the six surface water and twenty-seven groundwater well sampling locations. The results for LaSalle's RGPP sampling efforts in 2022 are included in this report.

This is the sixteenth in a series of annual reports on the status of the RGPP conducted at LaSalle County Station. This report covers groundwater and surface water samples, collected from the environment, both on and off station property in 2022. During that time period, 144 analyses were performed on 62 samples from 19 groundwater locations. The monitoring was conducted by station personnel.

In assessing all the data gathered for this report, it was concluded that the operation of LaSalle County Station had no adverse radiological impact on the environment, and there are no known active releases into the groundwater at LaSalle County Station.

Strontium-89 (Sr-89) and strontium-90 (Sr-90) were not detected in any groundwater samples during 2022.

In the case of tritium, Constellation specified that its laboratories achieve a lower limit of detection (LLD) 100 times lower than that required by federal regulation.

The United States Environmental Protection Agency (USEPA) drinking water standard (and the Nuclear Regulatory Commission Reporting Limit) is 20,000 pCi/L.

Tritium levels were detected at concentrations greater than the LLD of 200 pCi/L in 19 of 59 groundwater samples analyzed. The tritium concentrations ranged from

<LLD to 5,790 +/- 649 pCi/L. The elevated tritium levels (>200 pCi/L) being observed in groundwater are associated with the U1 CY tank leak that occurred in the June/

July 2010 timeframe, as documented in the Station's 10 CFR 50.75(g) report.

Gamma-emitting nuclides and gross alpha analysis in the dissolved and suspended fractions were not performed in 2022.

Hard-to-detect analyses were performed on 6 of the groundwater sampling locations in accordance with the LaSalle RGPP and to aid in establishing background levels. The analyses included Fe-55, Ni-63, Am-241, Cm-242, Cm-243/244, Pu-238, Pu-239/240, U-234, U-235, and U-238. U-234 was detected in 4 samples, affecting 4 of 6 groundwater locations. The U-234 concentrations ranged from 0.44 to 3.28 pCi/L. U-238 was detected in 4 samples, affecting 4 of 6 groundwater locations. The U-238 concentrations ranged from 0.37 to 1.96 pCi/L.

U-234 and U-238 are commonly found in groundwater at low concentrations due to the naturally occurring Radium (Uranium) Decay Series.

1

II.

Introduction The LaSalle County Station (LSCS), consisting of two boiling water reactors, each rated for 3,546 MWt, owned and operated by Constellation, is located in LaSalle County, Illinois. Unit 1 went critical on March 16, 1982. Unit 2 went critical on December 2, 1983. The site is located in northern Illinois, approximately 75 miles southwest of Chicago, Illinois.

This report covers those analyses performed by Teledyne Brown Engineering (TBE) on samples collected in 2022.

A.

Objectives of the RGPP The long-term objectives of the RGPP are as follows:

1. Identify suitable locations to monitor and evaluate potential impacts from station operations before significant radiological impact to the environment and potential drinking water sources.

2. Understand the local hydrogeologic regime in the vicinity of the station and maintain up-to-date knowledge of flow patterns on the surface and shallow subsurface.

3. Perform routine water sampling and radiological analysis of water from selected locations.

4. Report new leaks, spills, or other detections with potential radiological significance to stakeholders in a timely manner.

5. Regularly assess analytical results to identify adverse trends.

6. Take necessary corrective actions to protect groundwater resources.

B.

Implementation of the Objectives The objectives identified have been implemented at LaSalle County Station as discussed below:

1.

Constellation and its consultant identified locations as described in the 2006 Phase 1 study. Phase 1 studies were conducted by Conestoga Rovers and Associates (CRA) and the results and conclusions were made available to state and federal regulators.

2.

The LaSalle County Station reports describe the local hydrogeologic regime. Periodically, the flow patterns on the surface and shallow subsurface are updated based on ongoing measurements.

3.

LaSalle County Station will continue to perform routine sampling and radiological analysis of water from selected locations.

4.

LaSalle County Station has implemented procedures to identify and report new leaks, spills, or other detections with potential radiological significance in a timely manner.

5.

LaSalle County Station staff and consulting hydrogeologist assess analytical results on an ongoing basis to identify adverse trends.

2

C.

Program Description Sample Collection Sample locations can be found in Figure A-1, Appendix A.

Groundwater and Surface Water Samples of water are collected, managed, transported and analyzed in accordance with approved procedures following EPA methods. Both groundwater and surface samples water are collected. Sample locations, sample collection frequencies and analytical frequencies are controlled in accordance with approved station procedures. Contractor and/or station personnel are trained in the collection, preservation management, and shipment of samples, as well as in documentation of sampling events.

Analytical laboratories are subject to internal quality assurance programs, industry cross-check programs, as well as nuclear industry audits. Station personnel review and evaluate all analytical data deliverables as data are received.

Analytical data results are reviewed by both station personnel and an independent hydrogeologist for adverse trends or changes to hydrogeologic conditions.

D.

Characteristics of Tritium (H-3)

Tritium (chemical symbol H-3) is a radioactive isotope of hydrogen. The most common form of tritium is 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. Tritium can be taken into the body by drinking water, eating food, breathing air, 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 with a clearance rate characterized by an effective biological half-life of about 14 days. Within one month or so after ingestion, essentially all tritium is cleared. 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-? and/or boron-10 are activated to produce tritium. 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 radioactive decay of tritium is the source of the health risk from exposure to tritium. Tritium is one of the least dangerous radionuclides because it emits very weak radiation and leaves the body relatively quickly.

3

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.

Ill.

Program Description A.

Sample Analysis This section describes the general analytical methodologies used by TBE to analyze the environmental samples for radioactivity for the LaSalle County Station RGPP in 2022. Sample and analysis and frequency is based upon well location, assessed risk and site hydrogeology as described in the RGPP.

In order to achieve the stated objectives, the current program includes the following analyses:

1.

Concentrations of gamma emitters in groundwater

2.

Concentrations of strontium in groundwater

3.

Concentrations of tritium in groundwater

4.

Concentrations of gross alpha (dissolved and suspended) in groundwater

5.

Concentrations of Am-241 in groundwater

6.

Concentrations of Cm-242 and Cm-243/244 in groundwater

7.

Concentrations of Pu-238 and Pu-239/240 in groundwater

8.

Concentrations of U-234, U-235 and U-238 in groundwater

9.

Concentrations of Fe-55 in groundwater

10. Concentrations of Ni-63 in groundwater B.

Data Interpretation The radiological data collected prior to LaSalle County Station becoming operational were used as a baseline with which these operational data were compared. For the purpose of this report, LaSalle County Station was considered operational at initial criticality. Several factors were important in the interpretation of the data:

1.

Lower Limit of Detection and Minimum Detectable Concentration The lower limit of detection (LLD) is specified by federal regulation as a minimum sensitivity value that must be achieved routinely by the analytical parameter.

2.

Laboratory Measurements Uncertainty The estimated uncertainty in measurement of tritium in environmental samples is frequently on the order of 50% of the measurement value.

Statistically, the exact value of a measurement is expressed as a range with a stated level of confidence. The convention is to report results with a 95% level of confidence. The uncertainty comes from calibration standards, sample volume or weight measurements, sampling 4

uncertainty and other factors. Constellation reports the uncertainty of a measurement created by statistical process (counting error) as well as all sources of error (Total Propagated Uncertainty or TPU). Each result has two values calculated. Constellation reports the TPU by following the result with plus or minus+/- the estimated sample standard deviation, as TPU, that is obtained by propagating all sources of analytical uncertainty in measurements.

Analytical uncertainties are reported at the 95% confidence level in this report for reporting consistency with the AREOR.

C.

Background Analysis A pre-operational radiological environmental monitoring program (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, precipitation, marine life, and foodstuffs. The results of the monitoring were detailed in the report entitled, Environmental Radiological Monitoring for LaSalle County Nuclear Power Station, Commonwealth Edison Company, Annual Reports for the years 1979 and 1981. The pre-operational REMP contained analytical results from samples collected from the surface water and groundwater.

1.

Background Concentrations of Tritium The purpose of the following discussion is to summarize background measurements of tritium in various media performed by others.

Additional detail may be found by consulting references (CRA 2006).

a.

Tritium Production 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 present in crystalline rocks by neutrons produced by the radioactive decay of naturally abundant 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 and strontium-90 comes from the former atmospheric testing of thermonuclear weapons.

Levels of tritium in precipitation increased significantly during the 1950s and early 1960s, and later with additional testing, resulting in the release of significant amounts of tritium to the atmosphere. The Canadian heavy water nuclear power reactors, other commercial power reactors, nuclear research and weapons production continue to influence tritium concentrations in the environment.

5

b.

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 provide 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 worldwide from 1960 to 2006. RadNet provides tritium precipitation concentration data for samples collected at stations throughout the U.S. from 1960 up to and including 2006. Based on GNIP data for sample stations located in the U.S. Midwest, tritium concentrations peaked around 1963. This peak, which approached 10,000 pCi/L for some stations, coincided with the atmospheric testing of thermonuclear weapons.

Tritium concentrations in surface water 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. LaSalle's 1979 or 1981 pre-operational REMP showed precipitation tritium concentrations >300 pCi/L. Tritium concentrations in wells may still be above the 200 pCi/L detection limit from the external causes described above.

Water from previous years and decades is naturally captured in groundwater, so some well water sources today are affected by the surface water from the 1960s that was elevated in tritium.

c.

Surface Water Data Tritium concentrations are routinely measured in large surface water bodies, including Lake Michigan and the Mississippi River. Illinois surface water data were typically less than 100 pCi/L. Illinois River H-3 results have shown >200 pCi/L, as evidenced in LaSalle's REMP program sample results. This is attributable to sources upstream as measured by the control location.

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% 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.

The radio-analytical laboratory is counting tritium results to a Constellation-specified LLD of 200 pCi/L. Typically, the lowest positive measurement will be reported within a range of 40 - 240 pCi/L or 140 +/- 100 pCi/L. Clearly, these sample results cannot be distinguished as different from background at this concentration.

6

IV.

Results and Discussion A.

Groundwater Results Samples were collected from onsite wells throughout the year in accordance with the station radiological groundwater protection program. Analytical results and anomalies are discussed below.

Tritium Samples from 19 locations were analyzed for tritium activity. Tritium values ranged from <LLD to 5,790 pCi/L. The highest tritium activity was found at well TW-LS-118S. The well is located predominantly in clay till. Based on the hydrogeological study conducted at LaSalle, there is no feasible pathway into a drinking water supply. Based on established aquifer flow paths the location most representative of potential offsite release into groundwater was also less than the detection limit. (Table B-1.1, Appendix B)

Strontium A total of 12 samples from 12 groundwater locations were analyzed for Sr-89 and Sr-90. The results were less than the required detection limit of 10 pCi/L for Sr-89 and less than the required detection limit of 1.0 pCi/liter for Sr-90. (Table B-1.1, Appendix B)

Gross Alpha (dissolved and suspended)

Gross alpha in the dissolved and suspended fractions were not analyzed in 2022. (Table B-1.1, Appendix B)

Gamma Emitters Samples for gamma emitting nuclides were not collected or analyzed in 2022. (Table B-1.2, Appendix B)

Hard-To-Detect Hard-to-detect analyses were performed on 6 of the groundwater sampling locations in accordance with the LaSalle RGPP and to aid in establishing background levels. The analyses included Fe-55, Ni-63, Am-241, Cm-242, Cm-243/244, Pu-238, Pu-239/240, U-234, U-235, and U-238. U-234 was detected in 4 of 6 samples, affecting 4 of 6 locations. U-234 concentrations ranged from 0.44 to 3.28 pCi/L. U-238 was detected in 4 of 6 samples, affecting 4 of 6 locations. The U-238 concentrations ranged from 0.37 to 1.96 pCi/L. U-234 and U-238 are commonly found in groundwater at low concentrations due to the naturally occurring Radium (Uranium) Decay Series. The concentrations of U-234 and U-238 discussed above are considered to be background and are not the result of plant effluents.

(Table B-1.3, Appendix B)

All other hard-to-detect nuclides were not detected at concentrations greater than their respective minimum detectable concentrations.

7

B.

Surface Water Results No surface water samples were collected in 2022.

C.

Drinking Water Well Survey A drinking water well survey was conducted during the summer 2006 by CRA (CRA 2006) around the LaSalle County Station. This survey concluded that no residents in the vicinity of the plant utilize the shallow water aquifer as a drinking water supply. Site hydrological studies of aquifer flow and permeation rates from the shallow aquifer to the deep aquifer concluded that there is no feasible dose receptor via a ground water pathway at LaSalle.

D.

Summary of Results - Inter-Laboratory Comparison Program Inter-Laboratory Comparison Program results for TBE are presented in the AREOR.

E.

Leaks, Spills, and Releases There were no new leaks identified at LaSalle Station during the reporting period.

F.

Trends Analysis results from samples continue to be trended in order to assess impact to groundwater at LaSalle Station. There were no new leaks identified in the reporting period. Sample data from the plume arising from the historic 2010 U1 CY tank leak is being trended per the LaSalle RGPP. The plume had been dispersing with groundwater flow, and extraction wells have been installed to provide additional control of the plume migration (see Section H.3. below). Currently, no tritium has migrated offsite, and tritium migration offsite is not expected.

G.

Investigations No new investigations were carried out during the reporting period.

H.

Actions Taken

1. Compensatory Actions No compensatory actions were taken during the reporting period.

2. Installation of Monitoring Wells No new monitoring wells have been installed during the reporting period.

3. Actions to Recover/Reverse Plumes Two (2) extraction wells (RW-LS-1 00S and RW-LS-101 S) were installed to control the migration of the tritium plume near U1 CY tank. RW-LS-1 00S became operational in October 2012. RW-LS-101 S became operational in April 2014.

8

APPENDIX A LOCATION DESIGNATION

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TABLE A-1 LaSalle County Station Groundwater Monitoring Sample Point List, 2022 Site HP-2 HP-5 HP-7 HP-10 MW-LS-104S MW-LS-105S MW-LS-106S MW-LS-107S MW-LS-111 S RW-LS-100S RW-LS-101S TW-LS-114S TW-LS-116S TW-LS-117S TW-LS-118S TW-LS-119S TW-LS-120S TW-LS-121S Oil Separator A-1 Site Type Monitoring Well Monitoring Well Monitoring Well Monitoring Well Monitoring Well Monitoring Well Monitoring Well Monitoring Well Monitoring Well Extraction Well Extraction Well Monitoring Well Monitoring Well Monitoring Well Monitoring Well Monitoring Well Monitoring Well Monitoring Well

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BB Figure A-1 Ground Water and Surface Water Locations LaSalle County Station, 2022

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EXEi.ON GENERATION a:lttPNtr, U.C LaSALLE GENERATNG STATION MARSEUES, IWNOIS R.EETW1DEASSESSIE<T MOhffOAING YELL LOCATICNS AND SLRFACE WATER FEATURES

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APPENDIX B DATA TABLES

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TABLE B-1.1 CONCENTRATIONS OF TRITIUM AND STRONTIUM IN GROUNDWATER SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA COLLECTION SITE DATE H-3 Sr-89 Sr-90 HP-2 03/05/22

< 188 HP-5 03/05/22

< 193 HP-7 03/04/22

< 198 HP-7 06/15/22

< 176

< 8.2

< 0.8 HP-7 08/17/22

< 191 HP-7 11/09/22

< 187 HP-10 03/05/22

< 184 MW-LS-104S 03/05/22 305 +/- 134 MW-LS-104S 06/14/22 719 +/- 147

< 9.0

< 0.8 MW-LS-104S 08/16/22 619 +/- 139 MW-LS-104S 11/08/22 842 +/- 163 MW-LS-105S 03/04/22

< 186 MW-LS-105S 06/14/22

< 191

< 8.7

< 0.6 MW-LS-105S 08/16/22

< 199 MW-LS-105S 11/10/22

< 180 MW-LS-106S 03/05/22

< 194 MW-LS-107S 03/04/22

< 186 MW-LS-107S 06/14/22

< 182

< 8.0

< 0.9 MW-LS-107S 08/16/22

< 186 MW-LS-107S 11/09/22

< 180 MW-LS-111S 03/05/22

< 186 OIL SEPARATOR 03/05/22

< 194 OIL SEPARATOR 06/14/22

< 195

< 9.1

< 0.9 OIL SEPARATOR 08/17/22

< 186 OIL SEPARATOR 11/09/22

< 193 RW-LS-100S 03/04/22 880 +/- 172 RW-LS-100S 06/14/22 1380 +/- 211

< 9.2

< 0.9 RW-LS-100S 08/16/22 810 +/- 152 RW-LS-100S 11/10/22 450 +/- 138 RW-LS-101S 03/04/22 1320 +/- 204 RW-LS-101S 03/04/22 1360 +/- 204 RW-LS-101S Duplicate 03/04/22 1140 +/- 177 RW-LS-101S 06/14/22 443 +/- 127

< 6.0

< 0.6 RW-LS-101S 08/16/22 557 +/- 134 RW-LS-101S 11/17/22 1400 +/- 215 TW-LS-114S 03/04/22

< 195 TW-LS-114S 06/14/22

< 185 TW-LS-114S 08/16/22

< 188 TW-LS-114S 11/10/22

< 181 TW-LS-116S 03/04/22 2910 +/- 349 TW-LS-116S Duplicate 03/04/22 2670 +/- 324 TW-LS-116S 06/14/22 3350 +/- 395

< 8.8

< 0.6 TW-LS-116S 08/16/22 3550 +/- 417 TW-LS-116S 11/08/22 3000 +/- 372 TW-LS-117S 03/04/22

< 183 TW-LS-117S 06/14/22

< 166

< 9.2

< 0.6 TW-LS-117S 08/16/22

< 197 TW-LS-117S 11/10/22

< 188 TW-LS-118S 03/04/22 5790 +/- 649 TW-LS-118S 06/14/22 4230 +/- 482

< 7.7

< 0.9 TW-LS-118S 08/16/22 3720 +/- 439 TW-LS-118S 11/08/22 2380 +/- 311 TW-LS-119S 03/05/22

< 196 TW-LS-119S 06/15/22

< 179

< 7.0

< 0.8 TW-LS-119S 08/17/22

< 190 TW-LS-119S 11/08/22

< 186 TW-LS-120S 03/04/22

< 195 TW-LS-120S 06/15/22

< 182

< 6.7

< 0.6 TW-LS-120S 08/17/22

< 193 TW-LS-120S 11/10/22

< 188 TW-LS-121S 03/04/22

< 184 TW-LS-121S 08/16/22

< 192 B-1

TABLE B-1.2 Ill I I\)

CONCENTRATIONS OF GAMMA EMITTERS IN GROUNDWATER SAMPLES COLLECTED IN THE VICINITY OF LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA No samples collected or analyzed for gamma emitters in 2022

TABLE B-1.3 CONCENTRATIONS OF HARD-TO-DETECTS IN GROUNDWATER SAMPLES COLLECTED AS PART OF THE GROUNDWATER PROTECTION PROGRAM, LASALLE COUNTY STATION, 2022 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA COLLECTION SITE DATE Am-241 Cm-242 Cm-243/244 Pu-238 Pu-239/240 U-234 U-235 U-238 Fe-55 Ni-63 MW-LS-104S 06/14/22

< 0.13

< 0.03

< 0.04

< 0.13

< 0.09

< 0.07

< 66

< 4.8 MW-LS-107S 06/14/22

< 0.08

< 0.04

< 0.07 3.28 +/- 0.69

< 0.05 1.96 +/- 0.50 OIL SEPARATOR 06/14/22

< 0.03

< 0.06

< 0.03

< 0.19

< 0.07 0.67 +/- 0.32

< 0.11 0.48 +/- 0.26

< 89

< 3.9 RW-LS-100S 06/14/22

< 0.02

< 0.04

< 0.07

< 0.09

< 0.07

< 137

< 4.5 RW-LS-101S 06/14/22

< 0.07

< 0.03

< 0.06

< 0.14

< 0.09 0.44 +/- 0.22

< 0.12 0.37 +/- 0.20

< 149

< 4.2 TW-LS-118S 06/14/22

< 0.03

< 0.05

< 0.04

< 0.12 1.46 +/- 0.41

< 0.05 1.18 +/- 0.36

< 72

< 4.2 Cl I

(A)

Intentionally left bfank.

RA23-029, 2022 Annual Radiological Environmental Operating Report

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RA23-029, 2022 Annual Radiological Environmental Operating Report

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