Text

2021 Annual Radiological Environmental Operating Report
	ML22119A279
Person / Time
Site:	Seabrook
Issue date:	04/29/2022
From:	; Framatome, NextEra Energy Seabrook
To:	; Office of Nuclear Reactor Regulation
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ML22119A277	List: ML22119A278; SBK-L-22043, 2021 Annual Radiological Environmental Operating Report;
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	SBK-L-22043
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2021 Annual Radiological Environmental Operating Report April 2022

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SEABROOK STATION ANNUAL RAOIOLOGICAL ENVIRONMENTAL OPERATING REPORT For the Period January - December 2021 Docket No. 50-443 Prepared By:

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NextEra Energy Seabrook, LLC Chemistry Department Seabrook station And Framatome Inc.

Fluence Radiological Group Lynchburg, VA 24506 Prepared By: V,.,A~ a. 'lY} IMlt1/

t Date:

Theodore A. Messier- Framatome Inc.

Date:

Andreas Glotas, NextEra Energy Seabrook, LLC Approwdeyl ~~~ ~

David Robinson, NextEra Energy Seabrook, LLC

SEABROOK STATION ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT For the Period January - December 2021 April 2022 Docket No. 50-443 Prepared By:

NextEra Energy Seabrook, LLC Chemistry Department Seabrook Station And Framatome Inc.

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TABLE OF CONTENTS EXECUTIVE

SUMMARY

............................................................................................................................................................ IV LIST OF TABLES ........................................................................................................................................................................ VII LIST OF FIGURES .................................................................................................................................................................... VIII

1.0 INTRODUCTION

.................................................................................................................................................................. 1 2.0 PLANT OPERATIONS ENVIRONMENTAL MONITORING PROGRAM .................................................................. 2 3.0

SUMMARY

OF PLANT OPERATIONS RADIOLOGICAL ENVIRONMENTAL MONITORING DATA ............ 13 3.1 AIR PARTICULATE ............................................................................................................................................................... 14 3.2 CHARCOAL FILTERS............................................................................................................................................................. 23 3.3 MILK.................................................................................................................................................................................... 26 3.4 SURFACE WATER ................................................................................................................................................................. 32 3.5 GROUND WATER ................................................................................................................................................................. 36 3.6 SEDIMENT ............................................................................................................................................................................ 42 3.7 FISH ..................................................................................................................................................................................... 46 3.8 LOBSTERS ............................................................................................................................................................................ 50 3.9 SHELLFISH ........................................................................................................................................................................... 54 3.10 IRISH MOSS .......................................................................................................................................................................... 59 3.11 FOOD CROP .......................................................................................................................................................................... 63 3.12 VEGETATION........................................................................................................................................................................ 66 3.13 DIRECT RADIATION ............................................................................................................................................................. 69 4.0 DRY FUEL STORAGE REMP & DATA

SUMMARY

.................................................................................................... 95 4.1 DIRECT RADIATION FROM DFS............................................................................................................................................ 95 5.0 PROGRAM DEVIATIONS AND REPORTING ............................................................................................................ 108 5.1 SAMPLING PROGRAM DEVIATIONS .................................................................................................................................... 108 5.2 COMPARISON OF ACHIEVED LLDS WITH REQUIREMENTS ................................................................................................. 108 5.3 COMPARISON OF RESULTS AGAINST REPORTING LEVELS .................................................................................................. 109 6.0 QUALITY ASSURANCE PROGRAM ............................................................................................................................ 112 6.1 GEL LABORATORIES QA ................................................................................................................................................... 112 6.2 ENVIRONMENTAL TLD QA ............................................................................................................................................... 147 7.0 LAND USE CENSUS ......................................................................................................................................................... 150 ATTACHMENT 1: SAMPLE ANALYSIS DATA LIST FOR 2021 ....................................................................................... 152 iii

Executive Summary Both the plant operations and Dry Fuel Storage Radiological Environmental Monitoring Programs (REMP) for Seabrook Station operated successfully for the period of January through December 2021. This report describes the REMP and its implementation as required by Technical Specifications and as defined in the Offsite Dose Calculation Manual (ODCM). It also contains analytical results, data evaluation, dose assessment (as needed), and data trends for each environmental sample medium. Also included are the results of the Land Use Census, historical data, and the environmental laboratory performance in the Quality Assurance Inter-comparison Program required by the ODCM.

Radioactivity levels in the vicinity of Seabrook Station from January 1 through December 31, 2021 in air, water, sediment, milk, fish, food crops, and vegetation, as well as direct radiation measurements have been analyzed, evaluated, and summarized. The results of the REMP are intended to supplement the results of the radiological effluent monitoring by verifying that any measurable concentration of radioactive materials and levels of radiation are not higher than expected on the basis of the effluent measurement and modeling of the environmental exposure pathways.

Radiation and radioactivity in the environment is monitored within a 10-mile radius of the site. Two types of samples are taken. The first type, control samples, is collected from areas that are beyond measurable influence of Seabrook Station. These samples are used as reference data. Normal background radiation levels, or radiation present due to causes other than Seabrook Station, can thus be compared to the environment surrounding the nuclear power station. Indicator samples are the second sample type obtained.

These samples show how much measureable radiation or radioactivity (if any) is contributed to the environment by the site. Indicator samples are taken from areas close to the station where any plant contribution will be at the highest potential concentration. The ODCM minimum required plant operations REMP included the collection for 2021 of at least 576 samples, with a total of 2416 individual measurement analyses. In 2021, the total number of sample analysis sets (both required and non-required) equaled 822 taken from 98 locations around Seabrook Station. These were collected from aquatic, atmospheric, and terrestrial environments. An estimated 4952 individual measurement analyses were performed on these samples. The plant operations radiological environmental monitoring program is outlined in Table 2.0-1.

Radiation environmental monitoring associated with Dry Fuel Storage (DFS) in 2021 included an additional 18 TLD direct radiation measurements beyond those listed as being part of the REMP. The DFS environmental monitoring program is shown on Table 4.0-1.

Prior to station operation, samples were collected and analyzed to determine the amount of radioactivity present in the area. The resulting values are used as a "pre-operational baseline." Current analysis results from the indicator samples are compared to both current control sample values and the pre-operational baseline to determine if changes in radioactivity levels are attributable to station operations.

A report is required to be submitted to the Nuclear Regulatory Commission when the level of radioactivity as a result of plant operations in an environmental sampling medium at a specified location exceeds the reporting level limits specified in the ODCM when averaged over any calendar quarter. Also, when more than one of the radionuclides is detected in the sampling medium, this report shall be submitted if:

Concentration (1) + Concentration (2) + ... 1.0 Limit Level (1) Limit Level (2)

Based on the analytical results of environmental samples during 2021, Seabrook Station reporting levels were not exceeded.

All off-site radioactivity detected was attributable to either naturally-occurring radionuclides, previous nuclear weapons tests, the Fukushima Daiichi nuclear accident in Japan on March 11, 2011, or other man-made sources.

In 2021, the maximum whole body dose to the hypothetically exposed individual due to Seabrook Station effluents and operations was estimated to be 0.109 mrem. This whole body dose is the sum of all the exposure pathways for liquid and gaseous effluents, plus the direct whole body dose from station sources.

This total represents approximately 0.437% of the whole body dose limits for a member of the public as set forth in 40CFR190.

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The average effective dose per individual in the U.S. population from ubiquitous or background radiation sources is about 3.11 mSv/yr (311 mrem/yr), with another 3.00 mSv/yr (300 mrem/yr) resulting from medical procedures and imaging (NCRP Report No. 160, "Ionizing Radiation Exposure of the Population of the United States" (2009)). The estimate for natural background includes radon gas which has always been present but has not always been included in previous estimates. In some regions of the country, the amount of natural radiation is significantly higher. Residents of Colorado, for example, receive an additional 60 mrem/yr due to the increase in cosmic and terrestrial radiation levels. In fact, for every 100 feet above sea level, a person will receive an additional 1 mrem/yr from cosmic radiation. In several regions of the world, naturally high concentrations of uranium and radium deposits result in doses of several thousand mrem/yr to their residents (CRC Handbook. "Radioecology: Nuclear Energy and the Environment", F. Ward Whicker and Vincent Schultz, Volume I, 1982).

Analytical results are divided into four categories based on exposure pathways: Airborne, direct radiation, ingestion, and waterborne. Each of these pathways is described below:

The airborne exposure pathway includes airborne iodine and airborne particulate. The 2021 results were similar to previous years, excluding the Fukushima Daiichi event in 2011. There was no notable increase in natural products and no detectable fission products or other plant-related radionuclides in the airborne particulate media during the year.

The direct exposure pathway measures environmental radiation exposures by use of thermoluminescent dosimeters (TLDs). TLD results have indicated a trend that compares with previous years which reflect the natural variability of background radiation from one location to another. The exposure rate response at some individual monitoring stations has exhibited step changes at some point in the past that appear to be related to changes in local conditions in the area of the dosimeter measurement. These step observations have been noted at various locations (both control and indicator stations) with no correlation with distance from Seabrook Station, leading to the conclusion that the changes in local TLD responses are not related to Seabrook operations. As a result, no detectable radiation contribution from Seabrook Station sources was identified via TLD environmental measurements off-site during the course of 2021 from either plant operations or from the spent fuel in the Dry Fuel Storage Facility.

The ingestion exposure pathway includes milk, fish, shellfish, terrestrial food products and leafy vegetation samples. The gamma spectroscopy analyses indicated the most prominent positive results were for potassium-40 (K-40) at average environmental levels. Other naturally-occurring radionuclides were also periodically detected. However, past world-wide nuclear events such as atmospheric testing of nuclear weapons and the Fukushima Daiichi nuclear accident did result in detectable fallout of fission related radioactivity (Cs-137) in milk. Neither fish, shellfish, nor terrestrial food products (strawberries, blueberries and tomatoes) had any detectable fission product related radioactivity. No radionuclides related to plant effluents were detected in any of these sample media during 2021. For the one fission product (Cs-137) detected in milk, the concentration falls within the range of past and pre-operational measurements and can be attributed to past weapons testing fallout.

The waterborne exposure pathway includes surface (ocean) water, drinking water supply, shallow well water, sea algae (Irish Moss) and sediment. Water samples were analyzed for tritium, gross-beta and gamma-emitting radionuclides. Irish Moss was analyzed for gamma-emitting radionuclides.

Tritium was not identified in the water samples analyzed. For groundwater, the gross beta activity detected at all locations is similar to what was detected in the pre-operational program and is consistent with results from previous years of commercial operations. Gamma analysis of samples indicated no plant-related gamma-emitting radionuclides above detection limits.

The results of the 2021 REMP continue to clearly demonstrate that there is no significant short term or chronic long-term radiological impact on the environment in the vicinity of Seabrook Station from plant operations and that there is no detectable impact to members of the public associated with the DFS facility.

The REMP monitoring did detect local area fallout related to past global nuclear events, such as atmospheric weapons testing and the Japanese nuclear accident in March 2011, thereby demonstrating the sensitivity and capability of the REMP to detect low level radiological changes in the environment and the likely source. The v

REMP confirmed that plant effluents in 2021 did not contribute measurable radiation exposure to the general public. This finding is consistent with previous years monitoring conclusions. As a result, no increasing or changing trends in plant related radiological impacts on the environment are found.

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LIST OF TABLES Number Title Page 2.0-1 Plant Operations Radiological Environmental Monitoring Program.. ............................... . 3 2.0-2 Plant Operations Radiological Environmental Monitoring Locations ............................... 4 3.1-1 REMP Summary (Medium: Air Particulates). .. 21 3.2-1 REMP Summary (Medium: Charcoal Cartridge) . . 24 3.3-1 REMP Summary (Medium: Milk) .. 30 3.4-1 REMP Summary (Medium: Sea Water) .. 33 3.5-1 REMP Summary (Medium: Ground Water) . .. 39 3.6-1 REMP Summary (Medium: Sediment) . ... 43 3.7-1 REMP Summary (Medium: Fish) . 47 3.8-1 REMP Summary (Medium: American Lobster) . 51 3.9-1 REMP Summary (Medium: Mussel Body) . .... 55 3.9-2 REMP Summary (Medium: Mussel Shell) . . 58 3.10-1 REMP Summary (Medium: Irish Moss) . . 60 3.11-1 REMP Summary (Medium: Food Crops) . ... 64 3.12-1 REMP Summary (Medium: Vegetation) .. 67 3.13-1 Environmental TLD Measurements .................................................................................. 71 3.13-2 Pre-Operational Environmental TLD Measurements . .. 73 3.13-3 Facility Related Dose using ANSI/HPS N13.37-2014 Methodology ................................ 74 4.0-1 Dry Fuel Storage (DFS) TLD Monitoring Locations.. . 98 4.1-1 DFS Environmental TLD Measurements (2021) .... 99 4.1-2 DFS Facility Related Dose using ANSI/HPS N13.37-2014 Methodology 100 5.2-1 Detection Capabilities for Environmental Sample Analysis.............................................. 110 5.3-1 Reporting Levels for Radioactivity Concentrations in Environmental Samples ............... 111 6.1-1 2021 Inter-Lab Radiological Proficiency Testing Results and Acceptance Criteria ......... 118 6.1-2 2021 Eckert & Ziegler Analytics Performance Evaluation Results .................................. 130 6.1-3 REMP Intra-Laboratory Data Summary: Bias & Precision by Matrix . .... ...... 133 6.1-4 All Radiological Intra-Lab Data Summary: Bias and Precision Matrix . 135 6.1-5 2021 Corrective Action Report Summary .......... 143 6.2-1 Percentage of Individual Dosimeters That Passed EDC Internal Criteria . 147 6.2-2 Mean Dosimeter Analyses (N=6) 148 6.2-3 Summary of Independent Dosimeter Blind Spike Testing ... 148 6.2-4 Summary of Independent Blind Duplicate Dosimeter Testing . 149 7.0-1 2021 Land Use Census Results . 151 vii

LIST OF FIGURES Number Title Page Figure 2.1 Radiological Environmental Monitoring Locations within 4 Km of Seabrook Station. 7 Figure 2.2 Radiological Environmental Monitoring Locations Between 4 & 12 Km of Seabrook Station.. 8 Figure 2.3 Radiological Environmental Monitoring Locations Outside 12 Km of Seabrook Station.. 9 Figure 2.4 Direct Radiation Monitoring Locations Within 4 Km of Seabrook Station......... 10 Figure 2.5 Direct Radiation Monitoring Locations Between 4 & 12 Km of Seabrook Station. 11 Figure 2.6 Direction Radiation Monitoring Locations Outside 12 Km of Seabrook Station 12 Figure 3.1 Gross-Beta Measurements of Air Particulate Filters. 16 Figure 3.1.1 Gross-Beta Measurements of Air Particulate Filters Quarterly Averages. 17 Figure 3.1.2 Gross-Beta Measurements of Air Particulate Filters Quarterly Averages. 18 Figure 3.1.3 Gross-Beta Measurements of Air Particulate Filters Quarterly Averages. 19 Figure 3.1.4 Gross-Beta on Air Particulate Filters Quarterly Averages 20 Figure 3.2 I-131 Measurements of Air Charcoal Cartridges . 25 Figure 3.3 Cesium-137 in Milk 27 Figure 3.3.1 Cesium-137 in Milk Annual Average Concentrations. 28 Figure 3.3.2 Cesium-137 in Milk Annual Average Concentrations..... 29 Figure 3.5 Gross-Beta Measurements of Ground Water 37 Figure 3.5.1 Gross-Beta Measurements of Ground Water Semi-Annual Averages..... 38 Figure 3.6 Environmental Radiation Measurements (Using TLDs)............. 77 Figure 3.6.1 Environmental Radiation Measurements (Using TLDs)... 78 Figure 3.7 Environmental Radiation Measurements (Using TLDs). . 79 Figure 3.7.1 Environmental Radiation Measurements (Using TLDs).... . 80 Figure 3.8 Environmental Radiation Measurements (Using TLDs)... 81 Figure 3.8.1 Environmental Radiation Measurements (Using TLDs).............. 82 Figure 3.9 Environmental Radiation Measurements (Using TLDs) 83 Figure 3.9.1 Environmental Radiation Measurements (Using TLDs) 84 Figure 3.10 Environmental Radiation Measurements (Using TLDs) 85 Figure 3.10.1 Environmental Radiation Measurements (Using TLDs) 86 viii

LIST OF FIGURES (Continued)

Figure 3.11 Environmental Radiation Measurements (Using TLDs).. 87 Figure 3.11.1 Environmental Radiation Measurements (Using TLDs).. 88 Figure 3.12 Environmental Radiation Measurements (Using TLDs).. 89 Figure 3.12.1 Environmental Radiation Measurements (Using TLDs).. 90 Figure 3.13 Environmental Radiation Measurements (Using TLDs).. 91 Figure 3.13.1 Environmental Radiation Measurements (Using TLDs).. 92 Figure 3.14 Environmental Radiation Measurements (Using TLDs).. 93 Figure 3.14.1 Environmental Radiation Measurements (Using TLDs).. 94 Figure 4.0.1 Dry Fuel Storage TLD Environmental Monitoring Locations .... 97 Figure 4.1 DFS Control Radiation Measurements (Using TLDs)... 102 Figure 4.2 DFS Environmental Radiation Measurements (Using TLDs). 103 Figure 4.3 DFS Environmental Radiation Measurements (Using TLDs) 104 Figure 4.4 DFS Environmental Radiation Measurements (Using TLDs) 105 Figure 4.5 DFS Environmental Radiation Measurements (Using TLDs) 106 Figure 4.6 DFS Environmental Radiation Measurements (Using TLDs) 107 ix

ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT 1.0 Introduction NextEra Energy Seabrook, LLCs Radiological Environmental Monitoring Program (REMP) consists of two interconnected sample collection and measurement schedules that look for environmental influences from: (1) plant operations which release to the environment radioactive materials in liquid and gaseous effluents, and direct radiation from plant facilities inside the power block Protected Area, and (2) direct radiation from used fuel placed in the Dry Fuel Storage (DFS) facility located in the West Southwest sector approximately 0.38 miles from the Containment Building. Several monitoring locations provide data that are shared or used in the assessment of both plant and DFS operations.

The plant operations REMP at Seabrook Station has been designed and carried out to achieve the following specific objectives:

To provide an indication of the appearance or accumulation of any radioactive material in the environment caused by the operation of the nuclear power station.

To provide assurance to regulatory agencies and the public that the station's environmental impact is known and within anticipated limits.

To verify the adequacy and proper functioning of station effluent controls and monitoring systems.

To provide standby monitoring capability for rapid assessment of risk to the general public in the event of unanticipated or accidental releases of radioactive material.

In July 2008, the plant operations REMP was supplemented with the DFS environmental monitoring for direct radiation when used nuclear fuel assemblies were for the first time transferred to the on-site DFS facility located WSW of the power block.

NextEra Energy Seabrook, LLC staff collected the terrestrial samples. Normandeau Associates, Inc.

collected the marine and sediment samples. After initial sample preparation for shipment, the samples were sent to GEL Laboratories, Inc. of Charleston, SC for analysis. The Environmental Dosimetry Company located in Sterling, MA processed the environmental TLDs for the entire year.

This report is a summary of the findings of the REMP for 2021. It is being provided in compliance with Part A of Seabrook Stations ODCM and Technical Specification 6.8.1.3.

2.0 Plant Operations Environmental Monitoring Program Table 2.0-1 outlines the plant operations monitoring program as specified in the Seabrook Station ODCM, Part B, Section 4. Table 2.0-2 lists the operational sampling stations and their specific locations (distances are measured from the center of the Unit 1 Containment Building). The sampling locations are shown on maps in Figures 2.1 through 2.6. The sampling and analysis program as described above fulfills the minimum requirements for environmental sample collection and analysis as contained in ODCM Table A.9.1-1, and includes additional sampling of various pathways and locations beyond the minimum requirements.

Below are listed the two-letter media codes and what they represent:

AP Air Particulate CF Charcoal Filter TM Milk WG Ground Water WS Surface (Sea) Water SE Sediment FH Fish HA Lobsters MU Mussels (Shellfish - edible portion only)

MS Mussels (Shellfish - shell portion only)

TL Direct Radiation (TLD)

AL Irish Moss (algae)

TF Food Crop TG Vegetation (broad-leaf)

Table 2.0-1 Plant Operations Radiological Environmental Monitoring Program Media Sampling Frequency Required Analyses Air Particulate (AP) -Bi-Weekly Gross Beta

-Quarterly Composite Gamma spectroscopy Charcoal Filter (CF) -Bi-Weekly I-131 Milk (TM)* -Monthly (Semimonthly Gamma spectroscopy when animals I-131 are on pasture)

Surface (Sea) Water (WS) -Monthly Gamma spectroscopy

-Quarterly Composite H-3 (composite)

Sediment (SE) -Semiannually Gamma spectroscopy Fish & Invertebrates -Quarterly or Gamma spectroscopy (FH, HA, MU) -Semiannually Direct Radiation (TL) -Quarterly Integrated gamma exposure Irish Moss (AL) -Semiannually Gamma spectroscopy Ground Water (WG) -Quarterly Gamma spectroscopy Gross Beta H-3 Food Crops (TF) -Monthly/Growing Season Gamma spectroscopy Vegetation (TG) -Monthly/Growing Season Gamma spectroscopy I-131

Note that broad leaf vegetation is substituted for milk due to insufficient number of required milk sampling locations in the site area.

Table 2.0-2 Plant Operations Radiological Environmental Monitoring Locations(a) (b) 2021 Approx.

Distance From Direction Station Code Station Plant From (Media - Sta. No.) Description Zone (km) Plant AP/CF-01+ PSNH Barge Landing Area 1 2.6 ESE AP/CF-02+ Hampton Marina (Harbor Rd) 1 2.5 E AP/CF-03+ Southwest Boundary (Rock Pile) 1 1.0 SW AP/CF-04+ West Boundary (Plate Yard) 1 1.2 W AP/CF-05 Winnacunnet High School 1 4.0 NNE AP/CF-07+ PSNH Substation 1 5.7 NNW AP/CF-08 E&H Substation 1 3.4 SSE AP/CF-09+ Georgetown Electric Light Co. 2 21.4 SSW TM-15 Hampton Falls, NH 1 6.9 NW WG-01 Seabrook Town Wells 1 5.6 W WG-13 Seabrook Station Well No.13 1 1.0 N WG-14 Brimmers Lane 1 1.3 NNW WS-01+ Hampton-Discharge Area 1 5.1 E WS-51+ Ipswich Bay 2 26.2 SSE WS-10

Seabrook Marsh 1 0.18 SSE SE-02 Hampton-Discharge Area 1 5.2 E SE-07 Hampton Beach 1 3.3 E SE-08+ Seabrook Beach 1 3.3 ESE SE-52 Ipswich Bay 2 26.2 SSE SE-57 Plum Island Beach 2 22.4 SSE FH-03+ Hampton-Discharge Area 1 5.0 ESE FH-53+ Ipswich Bay 2 23.3 SSE FH-06 Hampton-Discharge Area 1 5.2 E HA-04+ Hampton-Discharge Area 1 5.1 E HA-54+ Ipswich Bay 2 27.9 SSE MU-06+ Hampton-Discharge Area 1 5.2 E MU-09 Hampton Harbor 1 2.5 E MU-56+ Ipswich Bay 2 28.6 SSE MU-59 Plum Island 2 22.0 SSE MS-06 Hampton-Discharge Area 1 5.2 E MS-56 Ipswich Bay 2 28.6 SSE AL-05 Hampton-Discharge Area 1 5.2 E AL-55 Ipswich Bay 2 28.7 SSE TF-02 Hampton Falls, NH 1 5.0 WNW TF-03 Salisbury, MA 1 5.1 SW TF-06 Ipswich, MA 2 26.0 S Table 2.0-2 (Cont'd)

Plant Operations Radiological Environmental Monitoring Locations(a) (b) 2021 Approx.

Distance From Direction Station Code Station Plant From (Media - Sta. No.) Description Zone (km) Plant TG-08+ North Access Rd, Site Boundary 1 1.05 W TG-09+ General Office Bld. Site Boundary 1 0.97 SW TG-10+ Georgetown Electric Light Co. 2 21.4 SSW TL-01+ Brimmer's Lane, Hampton Falls I 0.97 N TL-02+ Landing Road, Hampton I 3.0 NNE TL-03+ Glade Path, Hampton Beach I 2.9 NE TL-04+ Island Path, Hampton Beach I 2.3 ENE TL-05+ Harbor Road, Hampton Beach I 2.5 E TL-06+ PSNH Barge Landing Area I 2.7 ESE TL-07+ Cross Road, Seabrook Beach I 2.6 SE TL-08+ Farm Lane, Seabrook I 1.3 SSE TL-09+ Farm Lane, Seabrook I 1.3 S TL-10+ Site Boundary Fence I 1.1 SSW TL-11+ Site Boundary Fence I 1.0 SW TL-12+ Site Boundary Fence I 1.2 WSW TL-13+ Inside Site Boundary I 1.2 W TL-14+ Trailer Park, Seabrook I 1.3 WNW TL-15+ Brimmer's Lane, I 1.4 NW Hampton Falls TL-16+ Brimmer's Lane I 1.2 NNW Hampton Falls TL-17+ South Road, North Hampton 0 7.8 N TL-18+ Mill Road, North Hampton 0 7.6 NNE TL-19+ Appledore Avenue, 0 7.7 NE North Hampton TL-20+ Ashworth Avenue, 0 3.2 ENE Hampton Beach TL-21+ Route 1A, Seabrook Beach 0 3.7 SE TL-22+ Cable Avenue, Salisbury 0 7.6 SSE Beach TL-23+ Ferry Road, Salisbury 0 8.1 S TL-24+ Ferry Lots Lane, 0 7.2 SSW Salisbury TL-25+ Elm Street, Amesbury 0 7.6 SW TL-26+ Route 107A, Amesbury 0 8.1 WSW TL-27+ Highland St. S. Hampton 0 7.5 W TL-28+ Rte. 150, Kensington 0 7.5 WNW TL-29+ Frying Pan Ln., Hampton Falls 0 7.2 NW TL-30+ Route 27, Hampton 0 7.6 NNW Table 2.0-2 (Cont'd)

Plant Operations Radiological Environmental Monitoring Locations(a) (b) 2021 Approx.

Distance From Direction Station Code Station Plant From (Media - Sta. No.) Description Zone (km) Plant TL-31+ Alumni Drive, Hampton S 3.8 NNE TL-32+ Seabrook Elementary School S 2.0 S TL-33+ Dock Area, Newburyport S 9.8 S TL-34+ Bow Street, Exeter S 12.0 NW TL-35+ Lincoln Ackerman School S 2.3 NNW TL-36+ Route 97, Georgetown 2 22.6 SSW TL-37+ Post Office Plaistow, NH 2 21.5 WSW TL-38+ Emerson St. Hampstead, NH 2 27.7 W TL-39+ Fremont, NH 2 27.0 WNW TL-40+ Newmarket, NH 2 21.6 NNW TL-41 Portsmouth, NH 2 21.0 NNE TL-42 Ipswich, MA 2 22.8 SSE TL-44 Education (Science & Nature) Center S 0.6 SW TL-45 Hampton Fire Station S 4.4 NE TL-46 Seabrook Beach (near Police Station) S 2.8 ESE TL-47 Hampton Falls, NH S 4.1 WNW Zone indices are: 1 = Indicator Stations; 2 = Control Stations; 0 = Outer Ring TLD; I = Inner Ring TLD; S = Special Interest TLD

+ = Sample Locations required by the Off-Site Dose Calculation Manual (ODCM)

Note that WS-10 is the same location as WS-02 reported in previous reports.

(a) Dry Fuel Storage (DFS) locations are listed on Table 4.0-1.

(b) Table reflects those locations included in the 2021 sample collection program.

Figure 2.1 Radiological Environmental Monitoring Locations Within 4 Km of Seabrook Station Figure 2.2 Radiological Environmental Monitoring Locations Between 4 & 12 Km of Seabrook Station Figure 2.3 Radiological Environmental Monitoring Locations Outside 12 Km of Seabrook Station Legend 0 AUFH/HA/MUIMS/SEJWS

TG TF APfCf

SEABROOK

'STATION N

A TG-1 0 ..

APICf-09 MU.:S9/SE-57 t1Fli-53 0 S~5ZIWS..S1 0 TH)6' HA"54 0 0 AL* 55.'MU*56JMS-56

.~

~

0 2.5 5 10 15 20 25

- -==:::::i**-===***Kilomoters

Figure 2.4 Direct Radiation Monitoring Locations Within 4 Km of Seabrook Station Figure 2.5 Direct Radiation Monitoring Locations Between 4 & 12 Km of Seabrook Station Figure 2.6 Direct Radiation Monitoring Locations Outside 12 Km of Seabrook Station 3.0 Summary of Plant Operations Radiological Environmental Monitoring Data The following pages summarize the analytical results of the plant operations environmental samples collected in 2021. Each environmental media category is presented as a separate subsection. A table that summarizes the data follows a discussion of the sampling requirements and results for each media type. Listed at the top of each table are the units of measurement for each medium. The left-hand column contains the radionuclide which is being reported, total number of analyses of that radionuclide, and the number of measurements that exceed the required reporting level as documented in Table A.9.1-3 of the ODCM. The latter are classified as "non-routine" measurements. The next column lists the Lower Limit of Detection (LLD) for those radionuclides that have detection capability requirements specified in the ODCM.

Those sampling stations which are adjacent to the plant and which could conceivably be affected by the operation of Seabrook Station are called "Indicator" or "Zone 1" stations. Distant stations, which are beyond potential plant influences, are called "Control" or "Zone 2" stations.

A set of statistical parameters is calculated for each radionuclide. This set of statistical parameters includes separate analyses for (1) the indicator stations, (2) the station having the highest annual mean concentration for that radionuclide, and (3) control stations. For each of the three groups of data, these parameters are as follows:

The mean value of all concentrations,

The range of values and

The number of positive measurements (a concentration which is greater than the MDC for the measurement) divided by the total number of measurements.

Each radioactivity measurement datum in this report is based on a single measurement and is reported as a concentration plus or minus a one standard deviation uncertainty. The quoted uncertainty term represents only the random uncertainty associated with the radioactive decay process (counting statistics), and not the propagation of all possible uncertainties in the analytical procedure. contains the data for the samples collected in 2021. The results are organized as follows:

(1) by sample type; (2) within each sample type the data are alphabetical by nuclide; and (3) within each radionuclide listing the data are chronologically arranged by end date (date of sample collection).

The radionuclide value concentrations have been corrected for radioactive decay. For composite samples, such as air particulates and airborne iodine, the GEL laboratory uses the mid-point of the collection period as the reference for decay correction until time of analysis.

3.1 Air Particulate Air monitoring stations were established at a total of eight locations, six locations required by the ODCM, Table A.9.1-1, and two additional sites included to supplement the program. Seven of the locations are indicators, while the remaining one is a control station located more than 21 km away from the plant.

Airborne particulates (AP) are collected by passing the air through a glass-fiber filter. In 2021, these filters were typically collected bi-weekly and held for a period (typically 100 hours0.00116 days 0.0278 hours 1.653439e-4 weeks 3.805e-5 months or more) before being analyzed for gross-beta activity (indicated as BETA in Table 3.1-1) to allow for the decay of Radon and Thoron daughter products. Continuous automated and real-time remote monitoring of vital air sampling system parameters is performed with telemetry that detects power outages, pump failures, filter degradation, tubing failures and excessive filter loading. The telemetry communicates by cellular transmission to a web server that communicates to a shift technicians pager when set-point thresholds are reached, providing 24/7 alert notification. This capability provides for timely identification of problems and corrective actions that reduce the potential loss of air sampling. If periods of high dust loading during the collection period cause a higher than normal differential pressure drop across the collection filters, the collection period may be reduced to weekly cycles to reduce the dust loading. There were no recorded collection cycle reductions due to dust loading in 2021. For the year, 208 particulate filters were collected and analyzed for gross beta activity.

The 2021 gross beta activity analyses for the indicator locations were found to be statistically equivalent to that seen at the control station (positive activity for all samples). The gross beta results are also similar to what was seen in the pre-operational program and for the last thirty years of commercial operation, with the exception of the Fukushima Daiichi related spike in 2011. All filter samples from all stations showed similar trends lines (see Figure 3.1) over the course of the year and from previous years (see Figures 3.1.1, 3.1.2, and 3.1.3). Figure 3.1.4 compares the quarterly average gross beta response of all indicator air sampling stations to the control location over the last 28 years and shows no significant difference in the two data sets. It is also noted that no plant-related radionuclides (by gamma spectroscopy) were identified in any of the quarterly filter composite samples for 2021. The overall fluctuations at all stations seen in the gross beta activity throughout the year can be attributed to changes in environmental conditions unrelated to plant operations. Natural environmental processes such as wind direction, precipitation, snow cover, and soil temperature and moisture affect concentrations of naturally-occurring radionuclides in the atmosphere directly above land.

Gamma isotopic analyses of particulate filters are summarized on Table 3.1-1. The only radionuclides detected were naturally-occurring Be-7, which indicated positive in all air particulate samples, and Th-228, which was positive in three samples. Be-7 is of cosmogenic origin, and its presence is consistent with previous years in both the pre-operational and operational periods.

Near the end of 2010, analysis of environmental samples was changed from the AREVA Environmental Laboratory to GEL Laboratory after the AREVA lab discontinued operations. In comparing long term trends in gross beta activity, the results since 2011 appear to reflect a step increase at the time of the transition between labs. The reason for the step increase is related to the change in the gross beta counting equipment configurations and reference calibration standards used by the AREVA lab and GEL.

Both labs use(d) gas proportional counting of the filter element. However, AREVA applied a Cs-137 calibration source while the GEL lab uses a Tc-99 calibration source. In the case of the AREVA data record, the Cs-137 detection efficiency (typically 34%) was applied to the gross counts to determine the apparent activity. This inherently presumes that the radioactivity in a field sample is all Cs-137. In the case of the GEL data record, the Tc-99 efficiency (20.6%), is applied to the same gross counts as if all the radioactivity in this case is Tc-99. The end result is two different gross beta radioactivity determinations for the same level of environmental activity. In application, this is not an adverse condition in that the gross beta counting is used as a qualitative indicator of changes in environmental conditions, not as a quantitative measure of the actual radioactivity. Since the comparison of the response curves for each monitoring station, including the control station, are similar over time, the curves indicate that there is no detectable influence from a single nearby point source such as Seabrook Station.

The air particulate sampling program demonstrated no off-site dose to the public or impact to the environment from this pathway as the result of plant operations. This is consistent with previous years and the pre-operational program. The REMP Summary Table 3.1-1 lists the range of analysis results by radionuclide for Indicator and Control Stations for the air particulate environmental media. Attachment 1 to this report lists the individual analysis results for each measurement of air particulates under the Sample Type code AP.

Air particulate sample collection and analysis deviations from the ODCM required program (if any) are described in Section 5.

FIGURE 3.1 GROSS-BETA MEASUREMENTS OF AIR PARTICULATE FILTERS SEABROOK STATION 0.12 0.12 0.11 0.11 0.10 0.10 0.09 0.09 pCi/cubic meter 0.08 0.08 0.07 0.07 0.06 0.06 0.05 0.05 0.04 0.04 0.03 0.03 0.02 0.02 0.01 0.01 0.00 0.00 January February March April May June July August September October November December 2021 AP-01 Barge Landing Area AP-02 Hampton Marina AP-03 SW Boundary AP-04 W Boundary AP-05 Winnacunnet High School AP-09 Georgetown (Control)

AP-07 PSNH Substation, Hampton AP-08 Exeter & Hampton Electric Co.

FIGURE 3.1.1 GROSS-BETA MEASUREMENTS OF AIR PARTICULATE FILTERS QUARTERLY AVERAGES SEABROOK STATION 0.16 Chernobyl 0.14 May, 1986 0.12 pCi/cubic meter 0.1 0.08 Fukushima-Daichii Event 5% Criticality March 2011 0.06 June, 1989 Full Power 0.04 May, 1990 0.02 0

1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 AP-01 Barge Landing Area AP-02 Hampton Marina AP-03 SW Boundary AP-06/09 Georgetown Substation (Control)

FIGURE 3.1.2 GROSS-BETA MEASUREMENTS OF AIR PARTICULATE FILTERS QUARTERLY AVERAGES SEABROOK STATION 0.16 Chernobyl 0.14 May, 1986 0.12 pCi/cubic meter 0.1 Fukushima-Daichii Event 0.08 March 2011 0.06 5% Criticality June, 1989 Full Power 0.04 May, 1990 0.02 0

1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 AP-04 W Boundary AP-05 Winnacunnet High School AP-06/09 Georgetown Substation (Control)

FIGURE 3.1.3 GROSS-BETA MEASUREMENTS OF AIR PARTICULATE FILTERS QUARTERLY AVERAGES SEABROOK STATION 0.16 Chernobyl 0.14 May, 1986 0.12 pCi/cubic meter 0.1 Fukushima-0.08 Daichii Event March 2011 5% Criticality 0.06 June, 1989 Full Power 0.04 May, 1990 0.02 0

1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 AP-06/09 Georgetown Substation (Control)

AP-07 PSNH Substation, Hampton AP-08 Exeter & Hampton Electric Co.

FIGURE 3.1.4 GROSS-BETA ON AIR PARTICULATE FILTERS QUARTERLY AVERAGES SEABROOK STATION 0.08 0.08 Fukushima-0.06 Daichii Event 0.06 March 2011 pCi/cubic meter 0.04 0.04 0.02 0.02 0 0 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 Indicators Control Table 3.1-1 Radiological Environmental Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Air Particulates (AP) UNITS: pCi/cubic meter Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

BETA (208) 0.01 2.7E -2 09 3.1E -2 3.1E -2 (0) ( 3.3 - 57.7)E -3 ( 1.6 - 4.8)E -2 ( 1.6 - 4.8)E -2 (182/ 182) (26/ 26) (26/ 26)

Be-7 (32) 1.3E -1 03 1.5E -1 1.4E -1 (0) ( 8.0 - 24.2)E -2 ( 8.0 - 24.2)E -2 ( 1.1 - 1.9)E -1 (28/ 28) (4/ 4) (4/ 4)

K-40 (32) 8.5E -4 05 2.6E -3 1.5E -3 (0) ( -4.0 - 4.6)E -3 ( 1.1 - 4.6)E -3 ( 2.3 - 25.4)E -4 (0/ 28) (0/ 4) (0/ 4)

Cr-51 (32) 3.2E -5 04 4.2E -3 8.4E -4 (0) ( -1.0 - 1.3)E -2 ( -2.5 - 12.7)E -3 ( -1.0 - 1.4)E -2 (0/ 28) (0/ 4) (0/ 4)

Mn-54 (32) 2.2E -5 01 5.0E -5 -5.2E -5 (0) ( -1.6 - 2.3)E -4 ( -8.6 - 131.0)E -6 ( -3.1 - 0.8)E -4 (0/ 28) (0/ 4) (0/ 4)

Co-57 (32) 0.0E 0 02 6.3E -5 0.0E 0 (0) ( -1.1 - 1.3)E -4 ( 3.7 - 13.4)E -5 ( -3.6 - 3.4)E -5 (0/ 28) (0/ 4) (0/ 4)

Co-58 (32) -3.2E -5 07 1.6E -4 -7.5E -5 (0) ( -5.7 - 3.1)E -4 ( 3.0 - 28.7)E -5 ( -2.7 - 1.2)E -4 (0/ 28) (0/ 4) (0/ 4)

Fe-59 (32) 1.1E -4 01 3.9E -4 -1.0E -4 (0) ( -1.2 - 1.2)E -3 ( -4.1 - 10.2)E -4 ( -7.5 - 4.8)E -4 (0/ 28) (0/ 4) (0/ 4)

Co-60 (32) 5.9E -5 02 1.6E -4 -7.3E -5 (0) ( -1.5 - 6.5)E -4 ( -1.1 - 6.5)E -4 ( -5.0 - 3.0)E -4 (0/ 28) (0/ 4) (0/ 4)

Zn-65 (32) -6.4E -5 09 1.9E -4 1.9E -4 (0) ( -8.6 - 6.1)E -4 ( 9.5 - 45.7)E -5 ( 9.5 - 45.7)E -5 (0/ 28) (0/ 4) (0/ 4)

Se-75 (32) 0.0E 0 01 1.3E -4 -4.2E -5 (0) ( -4.0 - 3.2)E -4 ( 9.9 - 322.0)E -6 ( -3.3 - 3.3)E -4 (0/ 28) (0/ 4) (0/ 4)

Nb-95 (32) 4.4E -5 03 1.9E -4 2.2E -5 (0) ( -4.9 - 7.0)E -4 ( -4.9 - 51.9)E -5 ( -3.0 - 2.9)E -4 (0/ 28) (0/ 4) (0/ 4)

Zr-95 (32) 1.4E -4 01 4.3E -4 6.3E -5 (0) ( -6.4 - 12.2)E -4 ( -1.1 - 12.2)E -4 ( -5.4 - 3.4)E -4 (0/ 28) (0/ 4) (0/ 4)

Ru-103 (32) -1.2E -4 02 4.8E -5 -2.1E -4 (0) ( -8.6 - 9.5)E -4 ( -5.2 - 9.5)E -4 ( -9.7 - 1.0)E -4 (0/ 28) (0/ 4) (0/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.1-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Air Particulates (AP) UNITS: pCi/cubic meter Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ru-106 (32) 1.9E -4 09 6.7E -4 6.7E -4 (0) ( -1.5 - 1.2)E -3 ( -6.8 - 29.9)E -4 ( -6.8 - 29.9)E -4 (0/ 28) (0/ 4) (0/ 4)

Ag-108m (32) 0.0E 0 04 2.9E -5 0.0E 0 (0) ( -1.5 - 2.2)E -4 ( -1.5 - 2.2)E -4 ( -7.5 - 9.9)E -5 (0/ 28) (0/ 4) (0/ 4)

Ag-110m (32) 0.0E 0 03 2.0E -4 0.0E 0 (0) ( -9.4 - 3.9)E -4 ( -2.2 - 393.0)E -6 ( -2.4 - 2.8)E -5 (0/ 28) (0/ 4) (0/ 4)

Sb-124 (32) -1.8E -4 03 6.9E -5 2.2E -5 (0) ( -1.1 - 1.5)E -3 ( -6.1 - 14.8)E -4 ( -3.4 - 7.5)E -4 (0/ 28) (0/ 4) (0/ 4)

Sb-125 (32) -6.4E -5 04 1.5E -4 1.4E -4 (0) ( -6.4 - 6.7)E -4 ( -1.9 - 6.7)E -4 ( -2.6 - 3.3)E -4 (0/ 28) (0/ 4) (0/ 4)

I-131 (32) -2.9E -2 07 3.0E -2 -6.4E -2 (0) ( -3.8 - 1.2)E -1 ( 0.0 - 1.2)E -1 ( -1.9 - 0.0)E -1 (0/ 28) (0/ 4) (0/ 4)

Cs-134 (32) 0.05 5.4E -5 04 1.1E -4 0.0E 0 (0) ( -1.5 - 4.6)E -4 ( -6.2 - 45.5)E -5 ( -2.5 - 4.0)E -4 (0/ 28) (0/ 4) (0/ 4)

Cs-137 (32) 0.06 4.8E -5 01 9.7E -5 5.4E -5 (0) ( -1.4 - 2.0)E -4 ( 2.9 - 16.0)E -5 ( -1.7 - 8.9)E -5 (0/ 28) (0/ 4) (0/ 4)

Ba-140 (32) -9.3E -3 05 1.3E -2 1.2E -2 (0) ( -9.2 - 4.0)E -2 ( -3.6 - 40.3)E -3 ( -2.8 - 36.2)E -3 (0/ 28) (0/ 4) (0/ 4)

La-140 (32) -1.7E -3 09 1.5E -2 1.5E -2 (0) ( -2.2 - 2.1)E -2 ( 7.0 - 28.6)E -3 ( 7.0 - 28.6)E -3 (0/ 28) (0/ 4) (0/ 4)

Ce-141 (32) -2.4E -4 01 1.9E -4 -1.7E -4 (0) ( -2.0 - 0.8)E -3 ( -1.8 - 5.7)E -4 ( -8.7 - 10.0)E -4 (0/ 28) (0/ 4) (0/ 4)

Ce-144 (32) 1.1E -4 07 3.7E -4 -7.3E -5 (0) ( -8.8 - 16.1)E -4 ( -1.2 - 61.5)E -5 ( -3.4 - 2.5)E -4 (0/ 28) (0/ 4) (0/ 4)

Ac-228 (32) 3.8E -4 01 5.7E -4 3.6E -4 (0) ( -4.0 - 15.4)E -4 ( -1.9 - 13.4)E -4 ( -7.7 - 13.7)E -4 (0/ 28) (0/ 4) (0/ 4)

Th-228 (32) 3.5E -4 05 5.5E -4 2.2E -4 (0) ( 0.0 - 9.9)E -4 ( 0.0 - 9.9)E -4 ( 0.0 - 4.6)E -4 (3/ 28) (1/ 4) (0/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

3.2 Charcoal Filters Charcoal filter (CF) cartridges are placed in series behind the air particulate glass-fiber filters at each of the air sampling locations. Monitoring stations were established at a total of eight locations. Seven of these are indicators and one is a control. Charcoal filters from the air sampling stations were collected and analyzed for I-131 activity to a lower limit of detection (LLD) of 0.07 pCi/m3 or lower.

During 2021, a total of 208 charcoal cartridges from eight locations were analyzed. As described for the air particulate samplers (see Section 3.1), the collection cycles for the charcoal filters were biweekly during 2021.

Off-normal conditions, such as observed high differential pressure across the associated particulate filter (none detected in 2021) which might be indicative of excessive dust loading, could prompt switching to a temporary weekly cycle (see Section 3.1).

No sample analyses indicated a detectable level for I-131 that was statistically relevant (positive) at any of the air sampling locations during the year. Figure 3.2 shows the I-131 measurement responses in 2021 for all air sampling stations. All analyses were below their respective measurement minimum detectable concentrations (MDC).

From initial criticality in June 1989 to the Fukushima Daiichi accident in March 2011, the Seabrook REMP program had not detected I-131 at any offsite air sample locations. Following the March - April 2011 air concentration spikes of I-131 related to the Fukushima Daiichi accident releases, no detectable I-131 has been observed. The pre-operational data for I-131 are consistent with present (2021) data. Therefore, there are no increasing or decreasing trends related to Seabrook Station operations for airborne I-131. The potential organ doses from I-131 in gaseous effluents, if assumed to be released at the MDA, are well below the 10CFR50, Appendix I dose criteria.

The REMP Summary Table 3.2-1 list the range of analysis results for iodine (I-131) at both Indicator and Control Stations. Attachment 1 to this report lists the individual analysis results for each air sample measurement under the Sample Type code CF.

Charcoal filter sample collection and analysis deviations from the ODCM required program (if any) are described in Section 5.

Table 3.2-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Charcoal Cartridge (CF) UNITS: pCi/cubic meter Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

I-131 (208) 0.07 2.1E -4 05 1.1E -3 7.0E -4 (0) ( -9.7 - 11.9)E -3 ( -2.3 - 6.6)E -3 ( -3.3 - 9.4)E -3 (0/ 182) (0/ 26) (0/ 26)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

FIGURE 3.2 I-131 MEASUREMENTS OF AIR CHARCOAL CARTRIDGES SEABROOK STATION 0.10 0.10 0.08 0.08 0.06 0.06 pCi/cubic meter 0.04 0.04 Data > Other data MDC < MDC 0.02 0.02 0.00 0.00

-0.02 -0.02

-0.04 -0.04 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2021 CF-01 Barge Landing Area CF-02 Hampton Marina CF-03 SW Boundary CF-04 W Boundary CF-05 Winnacunnet High School CF-08 Exeter & Hampton Electric Co.

CF-09 Georgetown (Control) CF-07 PSNH Substation, Hampton 3.3 Milk Milk samples (TM) were collected semi-monthly during the pasture season and monthly at other times. Samples are analyzed for low level I-131 and gamma-emitting radionuclides.

The ODCM (Table A.9.1-1) requires that milk samples be collected from three locations within 5 km of the plant having the highest dose potential. If there are none, then one sample is required from milking animals in each of three areas between 5 to 8 km from the plant where the doses are calculated to be greater than 1 mrem/yr. Due to the limited inventory of milk animals in the site area, as reconfirmed by the 2021 Land Use Census, the number of available sample locations required by the ODCM sampling program could not be met (insufficient numbers of milk animals within 5 km, and only one milk location [designated TM-15] between 5 and 8 km). The ODCM allows for broad leaf vegetation samples to be collected if milk sampling cannot be performed in accordance to the REMP requirements. As a result, two site boundary locations and one control vegetation location are sampled to compensate for the limited milk availability (see Section 3.12).

A total of 17 milk samples were collected during the year from one available location. Each sample was analyzed for gamma emitting radionuclides. In addition, all samples were evaluated for low levels of I-131 through an iodine extraction process. The gamma analyses on samples indicated that naturally-occurring K-40 was detectable in all milk samples. Also detected in three milk samples was Cs-137 at an average concentration of 3.53 pCi/kg (positive measurements only) which falls in the range of past and pre-operational measurements. The highest single Cs-137 analysis result in 2021 was 4.68 pCi/kg. Though the Fukushima Daiichi event in March 2011 may have contributed to the Cs-137 levels observed in milk in 2021, Cs-137 has historically been detected at similar levels in milk before the nuclear accident in Japan. Residual Cs-137 from past weapons testing fallout has been the major contributor attributed to the currently observed values in milk. Figures 3.3, 3.3.1 and 3.3.2 illustrate the analysis results (without regard to whether individual analysis indicated detectable or statistically not detectable concentrations) for Cs-137 in milk over the current period (2021) and previous years.

Iodine-131 was not positively identified at any location for the year. This is consistent with previous years for both the pre-operational and operational phases of the program. One sample did not meet the Lower Limit of Detection (LLD) requirements (1 pCi/kg) for I-131 in milk (LSN 55014001). No increasing or decreasing trends in the radioactivity content of milk were observed.

The REMP Summary Table 3.3-1 lists the range of analysis results by radionuclide for the Indicator station (Historical Control Stations for the milk have ceased operations). Attachment 1 to this report lists the individual analysis results for each measurement of milk under the Sample Type code TM. Section 5 identifies deviations in the sample measurement program (if any), such as missed lower limits of detection (LLD) requirements.

FIGURE 3.3 CESIUM-137 IN MILK SEABROOK STATION 30 25 20 15 Cs-137 > MDC pCi/kg 10 5

0

-5

-10 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2021 TM-15, Hampton Falls NH (Goats)

FIGURE 3.3.1 CESIUM-137 IN MILK ANNUAL AVERAGE CONCENTRATIONS 30 30 25 25 20 20 Chernobyl May, 1986 pCi/kg 15 Fukushima- 15 Daichii Event March 2011 SB 5% Criticality June, 1989 SB Full Power 10 May, 1990 10 5 5 0 0 TM-04, Salisbury MA TM-08, Hampton Falls NH (prior to 1995 TM-10)

TM-09, Hampton NH TM-15, Hampton Falls NH FIGURE 3.3.2 CESIUM-137 IN MILK ANNUAL AVERAGE CONCENTRA TIONS 30 30 Chernobyl May, 1986 25 25 SB 5% Criticality June, 1989 20 20 Fukushima-15 SB Full Power Daichii Event 15 May, 1990 March 2011 pCi/kg 10 10 5 5 0 0 TM-16, Kensington NH TM-21, North Andover MA (Control)

TM-23, Newbury, MA TM-24, North Hampton NH TM-20, Rowley MA (Control)

Table 3.3-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Milk (TM) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Be-7 (17) 1.7E 0 15 1.7E 0 NO DATA (0) ( -7.7 - 8.4)E 0 ( -7.7 - 8.4)E 0 (0/ 17) (0/ 17)

K-40 (17) 1.7E 3 15 1.7E 3 NO DATA (0) ( 1.5 - 2.0)E 3 ( 1.5 - 2.0)E 3 (17/ 17) (17/ 17)

Cr-51 (17) -3.2E -1 15 -3.2E -1 NO DATA (0) ( -2.2 - 1.4)E 1 ( -2.2 - 1.4)E 1 (0/ 17) (0/ 17)

Mn-54 (17) -8.0E -2 15 -8.0E -2 NO DATA (0) ( -8.9 - 10.5)E -1 ( -8.9 - 10.5)E -1 (0/ 17) (0/ 17)

Co-57 (17) 7.1E -2 15 7.1E -2 NO DATA (0) ( -9.5 - 6.3)E -1 ( -9.5 - 6.3)E -1 (0/ 17) (0/ 17)

Co-58 (17) 5.1E -2 15 5.1E -2 NO DATA (0) ( -1.7 - 1.3)E 0 ( -1.7 - 1.3)E 0 (0/ 17) (0/ 17)

Fe-59 (17) -6.9E -2 15 -6.9E -2 NO DATA (0) ( -1.6 - 1.4)E 0 ( -1.6 - 1.4)E 0 (0/ 17) (0/ 17)

Co-60 (17) -5.7E -2 15 -5.7E -2 NO DATA (0) ( -2.7 - 1.9)E 0 ( -2.7 - 1.9)E 0 (0/ 17) (0/ 17)

Zn-65 (17) -5.5E -1 15 -5.5E -1 NO DATA (0) ( -4.7 - 3.0)E 0 ( -4.7 - 3.0)E 0 (0/ 17) (0/ 17)

Se-75 (17) -9.6E -2 15 -9.6E -2 NO DATA (0) ( -1.1 - 0.9)E 0 ( -1.1 - 0.9)E 0 (0/ 17) (0/ 17)

Nb-95 (17) -1.6E -2 15 -1.6E -2 NO DATA (0) ( -2.1 - 1.1)E 0 ( -2.1 - 1.1)E 0 (0/ 17) (0/ 17)

Zr-95 (17) -6.0E -1 15 -6.0E -1 NO DATA (0) ( -3.2 - 1.1)E 0 ( -3.2 - 1.1)E 0 (0/ 17) (0/ 17)

Ru-103 (17) -4.7E -1 15 -4.7E -1 NO DATA (0) ( -1.6 - 0.4)E 0 ( -1.6 - 0.4)E 0 (0/ 17) (0/ 17)

Ru-106 (17) -1.9E 0 15 -1.9E 0 NO DATA (0) ( -9.5 - 4.8)E 0 ( -9.5 - 4.8)E 0 (0/ 17) (0/ 17)

Ag-108m (17) 4.4E -2 15 4.4E -2 NO DATA (0) ( -5.7 - 10.2)E -1 ( -5.7 - 10.2)E -1 (0/ 17) (0/ 17)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.3-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Milk (TM) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ag-110m (17) 8.6E -2 15 8.6E -2 NO DATA (0) ( -1.4 - 1.6)E 0 ( -1.4 - 1.6)E 0 (0/ 17) (0/ 17)

Sb-124 (17) -4.1E -1 15 -4.1E -1 NO DATA (0) ( -2.1 - 1.7)E 0 ( -2.1 - 1.7)E 0 (0/ 17) (0/ 17)

Sb-125 (17) -4.4E -1 15 -4.4E -1 NO DATA (0) ( -1.7 - 1.4)E 0 ( -1.7 - 1.4)E 0 (0/ 17) (0/ 17)

I-131 (17) 1 4.6E -2 15 4.6E -2 NO DATA (0) ( -3.9 - 5.3)E -1 ( -3.9 - 5.3)E -1 (0/ 17) (0/ 17)

Cs-134 (17) 15 1.1E -1 15 1.1E -1 NO DATA (0) ( -2.5 - 1.3)E 0 ( -2.5 - 1.3)E 0 (0/ 17) (0/ 17)

Cs-137 (17) 18 1.3E 0 15 1.3E 0 NO DATA (0) ( 0.0 - 4.7)E 0 ( 0.0 - 4.7)E 0 (3/ 17) (3/ 17)

Ba-140 (17) 15 -3.3E -1 15 -3.3E -1 NO DATA (0) ( -8.9 - 6.7)E 0 ( -8.9 - 6.7)E 0 (0/ 17) (0/ 17)

La-140 (17) 15 -3.8E -2 15 -3.8E -2 NO DATA (0) ( -1.2 - 1.6)E 0 ( -1.2 - 1.6)E 0 (0/ 17) (0/ 17)

Ce-141 (17) 1.4E -1 15 1.4E -1 NO DATA (0) ( -1.9 - 2.8)E 0 ( -1.9 - 2.8)E 0 (0/ 17) (0/ 17)

Ce-144 (17) -4.6E -1 15 -4.6E -1 NO DATA (0) ( -6.4 - 5.2)E 0 ( -6.4 - 5.2)E 0 (0/ 17) (0/ 17)

Pb-212 (17) 6.8E -1 15 6.8E -1 NO DATA (0) ( -2.1 - 3.3)E 0 ( -2.1 - 3.3)E 0 (0/ 17) (0/ 17)

Pb-214 (17) 1.1E 0 15 1.1E 0 NO DATA (0) ( -3.5 - 4.7)E 0 ( -3.5 - 4.7)E 0 (0/ 17) (0/ 17)

Bi-214 (17) 1.2E 0 15 1.2E 0 NO DATA (0) ( -4.2 - 5.2)E 0 ( -4.2 - 5.2)E 0 (0/ 17) (0/ 17)

Ac-228 (17) 8.1E -2 15 8.1E -2 NO DATA (0) ( -8.3 - 11.3)E 0 ( -8.3 - 11.3)E 0 (0/ 17) (0/ 17)

Th-228 (17) 6.8E -1 15 6.8E -1 NO DATA (0) ( -2.1 - 3.3)E 0 ( -2.1 - 3.3)E 0 (0/ 17) (0/ 17)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

3.4 Surface Water Surface water (seawater - WS) grab samples are required at two locations (control and indicator) monthly. The indicator (WS-01) is over the vicinity of the plants submerged discharge structure. The control location (WS-

51) is situated in Ipswich Bay, MA, approximately 26.2 km from the plant. A gamma analysis is performed on each sample. A tritium analysis is performed on the quarterly composite of samples from each ODCM required location. Additional samples were collected from the Seabrook Marsh (WS-10) which borders the immediate plant property. The marsh samples are intended to provide indication of any ground water movement across the site area that might carry contamination into the surface waters of the marsh. Each of these samples is analyzed for both gamma emitters and tritium.

For 2021, a total of 26 gamma analyses were performed on surface water samples. The only radionuclides detected were naturally-occurring K-40, which was detected in all 26 samples, and naturally-occurring Bi-214, which was detected in one sample. The laboratory detected Ba-140 in one sample but identified it as a false positive. No plant-related nuclides were detected. The present data for gamma emitters in seawater is consistent with that of the pre-operational program and previous years of operations. Therefore, no increasing or decreasing trends were observed.

Quarterly composites for the required off-shore locations (Stations WS-01 and WS-51) were analyzed for tritium. A total of 8 off-shore samples (composites) were analyzed in 2021. The quarterly composite samples showed no indication of tritium. All samples met the required minimum LLD (3000 pCi/kg) for tritium in seawater. These results are consistent with pre-operational tritium data. The achieved tritium Minimum Detectable Concentration (MDC) for the quarterly off-shore composite samples averaged 610 pCi/kg.

The calculated dose as the result of plant effluents is not evaluated due to the fact that no plant-related radionuclides were or have been detected in the past. Therefore, no increasing or decreasing trends in dose were observed. This sampling program demonstrates that there is no impact to the public or environment, through this pathway from plant operations.

The REMP Summary Table 3.4-1 lists the range of analysis results by radionuclide for Indicator and Control Stations for the sea water environmental media. Attachment 1 to this report lists the individual analysis results for each measurement of sea water under the Sample Type code WS.

Any sample collection and analysis deviations from the ODCM required program or reportable concentrations that may have occurred during the year are described in Section 5.

Table 3.4-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Sea Water (WS) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

H-3 (8) 3000 -1.4E 2 01 -1.4E 2 -1.5E 2 (0) ( -2.8 - -0.5)E 2 ( -2.8 - -0.5)E 2 ( -3.8 - -0.1)E 2 (0/ 4) (0/ 4) (0/ 4)

Be-7 (26) 1.3E -1 51 2.1E 0 2.1E 0 (0) ( -1.5 - 1.2)E 1 ( -4.1 - 17.0)E 0 ( -4.1 - 17.0)E 0 (0/ 14) (0/ 12) (0/ 12)

K-40 (26) 30 3.0E 2 01 3.3E 2 3.1E 2 (0) ( 1.1 - 3.6)E 2 ( 2.8 - 3.6)E 2 ( 2.2 - 3.6)E 2 (14/ 14) (12/ 12) (12/ 12)

Cr-51 (26) -2.0E 0 51 1.6E 0 1.6E 0 (0) ( -1.0 - 0.8)E 1 ( -1.1 - 1.0)E 1 ( -1.1 - 1.0)E 1 (0/ 14) (0/ 12) (0/ 12)

Mn-54 (26) 15 1.1E -1 01 2.5E -1 -1.4E -1 (0) ( -1.4 - 1.2)E 0 ( -3.3 - 11.5)E -1 ( -1.0 - 0.8)E 0 (0/ 14) (0/ 12) (0/ 12)

Co-57 (26) 2.5E -2 10 5.5E -1 -1.1E -1 (0) ( -8.9 - 12.6)E -1 ( 5.0 - 5.9)E -1 ( -9.4 - 6.2)E -1 (0/ 14) (0/ 2) (0/ 12)

Co-58 (26) 15 -2.8E -1 51 7.1E -2 7.1E -2 (0) ( -7.3 - 1.5)E -1 ( -6.5 - 9.6)E -1 ( -6.5 - 9.6)E -1 (0/ 14) (0/ 12) (0/ 12)

Fe-59 (26) 30 -5.4E -2 10 7.8E -1 -1.2E -1 (0) ( -2.5 - 2.6)E 0 ( -4.2 - 19.7)E -1 ( -2.0 - 3.4)E 0 (0/ 14) (0/ 2) (0/ 12)

Co-60 (26) 15 -9.3E -2 01 -5.6E -2 -1.7E -1 (0) ( -6.7 - 9.2)E -1 ( -6.7 - 9.2)E -1 ( -1.4 - 1.7)E 0 (0/ 14) (0/ 12) (0/ 12)

Zn-65 (26) 30 1.1E -1 01 2.3E -1 1.4E -1 (0) ( -2.2 - 2.5)E 0 ( -2.2 - 2.5)E 0 ( -2.7 - 2.6)E 0 (0/ 14) (0/ 12) (0/ 12)

Se-75 (26) 3.6E -1 10 4.3E -1 2.8E -1 (0) ( -5.9 - 12.9)E -1 ( -1.3 - 87.7)E -2 ( -1.6 - 2.2)E 0 (0/ 14) (0/ 2) (0/ 12)

Nb-95 (26) 15 1.7E -1 10 1.2E 0 -2.1E -1 (0) ( -3.8 - 1.7)E 0 ( 6.4 - 17.3)E -1 ( -1.0 - 0.6)E 0 (0/ 14) (0/ 2) (0/ 12)

Zr-95 (26) 15 -2.9E -1 01 -2.0E -1 -5.1E -1 (0) ( -1.5 - 1.5)E 0 ( -1.5 - 1.5)E 0 ( -3.1 - 1.2)E 0 (0/ 14) (0/ 12) (0/ 12)

Ru-103 (26) -3.6E -1 10 -1.5E -2 -5.8E -1 (0) ( -1.2 - 0.3)E 0 ( -3.0 - 2.7)E -1 ( -1.9 - 0.0)E 0 (0/ 14) (0/ 2) (0/ 12)

Ru-106 (26) 3.3E 0 01 3.3E 0 7.5E -1 (0) ( -6.2 - 9.5)E 0 ( -6.2 - 9.5)E 0 ( -7.0 - 6.4)E 0 (0/ 14) (0/ 12) (0/ 12)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.4-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Sea Water (WS) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ag-108m (26) -3.9E -2 51 5.4E -2 5.4E -2 (0) ( -5.4 - 8.2)E -1 ( -1.3 - 0.8)E 0 ( -1.3 - 0.8)E 0 (0/ 14) (0/ 12) (0/ 12)

Ag-110m (26) -2.0E -3 10 5.8E -1 -5.7E -1 (0) ( -9.6 - 8.7)E -1 ( 5.5 - 6.0)E -1 ( -2.2 - 0.4)E 0 (0/ 14) (0/ 2) (0/ 12)

Sb-124 (26) 1.6E -1 10 1.4E 0 1.3E -1 (0) ( -1.8 - 3.1)E 0 ( 8.7 - 19.9)E -1 ( -3.1 - 2.8)E 0 (0/ 14) (0/ 2) (0/ 12)

Sb-125 (26) -2.7E -1 10 -1.8E -2 -4.6E -1 (0) ( -1.7 - 1.9)E 0 ( -5.4 - 5.0)E -1 ( -2.4 - 1.3)E 0 (0/ 14) (0/ 2) (0/ 12)

I-131 (26) 15 -3.2E -1 01 1.6E -1 -3.6E -1 (0) ( -6.8 - 3.6)E 0 ( -1.6 - 3.6)E 0 ( -1.3 - 1.8)E 0 (0/ 14) (0/ 12) (0/ 12)

Cs-134 (26) 15 1.3E -1 10 3.4E -1 3.3E -1 (0) ( -2.1 - 1.8)E 0 ( 1.1 - 5.6)E -1 ( -4.5 - 11.4)E -1 (0/ 14) (0/ 2) (0/ 12)

Cs-137 (26) 18 5.5E -2 51 3.1E -1 3.1E -1 (0) ( -1.4 - 0.8)E 0 ( -3.4 - 13.0)E -1 ( -3.4 - 13.0)E -1 (0/ 14) (0/ 12) (0/ 12)

Ba-140 (26) 15 -9.2E -1 51 1.3E 0 1.3E 0 (0) ( -1.9 - 0.4)E 1 ( -1.4 - 8.9)E 0 ( -1.4 - 8.9)E 0 (0/ 14) (0/ 12) (0/ 12)

La-140 (26) 15 -1.4E -1 01 -6.2E -2 -9.0E -1 (0) ( -1.1 - 1.7)E 0 ( -1.1 - 1.7)E 0 ( -4.0 - 0.9)E 0 (0/ 14) (0/ 12) (0/ 12)

Ce-141 (26) -3.0E -1 01 -2.8E -1 -1.7E 0 (0) ( -3.2 - 2.4)E 0 ( -3.2 - 2.4)E 0 ( -6.9 - 2.1)E 0 (0/ 14) (0/ 12) (0/ 12)

Ce-144 (26) 6.3E -1 10 1.7E 0 4.4E -1 (0) ( -2.8 - 4.5)E 0 ( 7.6 - 27.4)E -1 ( -4.4 - 6.7)E 0 (0/ 14) (0/ 2) (0/ 12)

Pb-212 (26) 6.6E -1 10 1.9E 0 -3.3E -1 (0) ( -1.5 - 3.0)E 0 ( 9.7 - 27.5)E -1 ( -3.7 - 2.7)E 0 (0/ 14) (0/ 2) (0/ 12)

Pb-214 (26) 1.7E 0 10 2.8E 0 2.8E -1 (0) ( -1.9 - 4.7)E 0 ( 2.2 - 3.3)E 0 ( -3.1 - 4.6)E 0 (0/ 14) (0/ 2) (0/ 12)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses Table 3.4-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Sea Water (WS) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Bi-214 (26) -8.3E -2 51 9.8E -1 9.8E -1 (0) ( -3.2 - 2.9)E 0 ( -5.4 - 8.5)E 0 ( -5.4 - 8.5)E 0 (0/ 14) (1/ 12) (1/ 12)

Ac-228 (26) -1.4E 0 51 1.2E 0 1.2E 0 (0) ( -5.3 - 4.9)E 0 ( -4.1 - 10.1)E 0 ( -4.1 - 10.1)E 0 (0/ 14) (0/ 12) (0/ 12)

Th-228 (26) 6.6E -1 10 1.9E 0 -3.3E -1 (0) ( -1.5 - 3.0)E 0 ( 9.7 - 27.5)E -1 ( -3.7 - 2.7)E 0 (0/ 14) (0/ 2) (0/ 12)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

3.5 Ground Water There is no requirement in the ODCM to collect ground water (WG) samples. For the year, quarterly ground water samples were collected when available from three locations. These samples were collected from the town water line (WG-01) supplied to the Site (by the Town of Seabrook), from an inactive well (WG-13) located approximately 1 km north of the plant, and from a private well 1.3 km NNW (WG-14). For 2021, a total of 12 samples were collected. All samples were analyzed for gross-beta activity, gamma-emitters and tritium.

Gross beta activity was detected in six of the twelve samples due to naturally-occurring radium and its daughter products. The gross beta activity is consistent with results from previous years of commercial operations. Figures 3.5 and 3.5.1 indicate the current year (2021) and the long-term measurement history for gross beta in well waters. No tritium or plant-related gamma emitters were detected in any of the ground water samples collected during the year. Table 3.5-1 identifies the results of the search for radionuclides of which only naturally-occurring Pb-212 was detected in two samples, Pb-214 in seven samples, Bi-214 in eight samples, and Th-228 was detected in two of 12 samples.

The dose potential to the public from drinking ground water is not evaluated due to the fact that plant-related radionuclides have not been detected. Therefore, no increasing or decreasing trends were observed. There is no impact to the public, through this pathway, from plant operations.

The REMP Summary Table 3.5-1 lists the range of analysis results by radionuclide for all ground water environmental samples. Attachment 1 to this report lists the individual analysis results for each measurement of ground water under the Sample Type code WG.

Any reportable sample concentrations that may have occurred during the year are described in Section 5.

FIGURE 3.5 GROSS-BETA MEASUREMENTS OF GROUND WATER SEABROOK STATION 20 18 16 14 12 10 pCi/kg 8

6 4

2 0

-2 Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2021 WG-0 1 Seabrook Town Wells WG-1 3 Seabrook Station Well No. 13 WG-1 4 Brimmer's Lane FIGURE 3.5.1 GROSS-BETA MEASUREMENTS OF GROUND WATER SEMI-ANNUAL AVERAGES SEABROOK STATION 18 13 pCi/kg 8

3

-2 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 WG-01 Seabrook Town Wells WG-14 Brimmer's Lane WG-13 Seabrook Station Well No. 13 Table 3.5-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Ground Water (WG) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

BETA (12) 4 5.4E 0 01 7.2E 0 NO DATA (0) ( 1.7 - 17.2)E 0 ( 3.4 - 14.1)E 0 (6/ 12) (3/ 4)

H-3 (12) 3000 1.2E 2 14 1.7E 2 NO DATA (0) ( -5.2 - 30.4)E 1 ( -4.4 - 304.0)E 0 (0/ 12) (0/ 4)

Be-7 (12) -1.1E 0 13 2.0E 0 NO DATA (0) ( -9.2 - 7.2)E 0 ( -2.4 - 7.2)E 0 (0/ 12) (0/ 4)

K-40 (12) 30 -1.3E 0 01 4.3E 0 NO DATA (0) ( -1.4 - 1.4)E 1 ( 0.0 - 1.4)E 1 (0/ 12) (0/ 4)

Cr-51 (12) -4.6E -2 01 1.9E 0 NO DATA (0) ( -7.0 - 11.0)E 0 ( -2.3 - 5.7)E 0 (0/ 12) (0/ 4)

Mn-54 (12) 15 -2.1E -1 13 1.6E -1 NO DATA (0) ( -2.1 - 1.3)E 0 ( -7.0 - 11.0)E -1 (0/ 12) (0/ 4)

Co-57 (12) 1.8E -3 01 1.3E -1 NO DATA (0) ( -4.6 - 2.5)E -1 ( -9.7 - 23.4)E -2 (0/ 12) (0/ 4)

Co-58 (12) 15 1.8E -1 14 2.7E -1 NO DATA (0) ( -4.3 - 14.4)E -1 ( -4.3 - 14.4)E -1 (0/ 12) (0/ 4)

Fe-59 (12) 30 -2.9E -1 14 -1.0E -2 NO DATA (0) ( -2.1 - 1.8)E 0 ( -1.8 - 1.8)E 0 (0/ 12) (0/ 4)

Co-60 (12) 15 4.4E -1 13 9.7E -1 NO DATA (0) ( -1.0 - 2.1)E 0 ( -5.9 - 20.9)E -1 (0/ 12) (0/ 4)

Zn-65 (12) 30 5.0E -1 13 6.6E -1 NO DATA (0) ( -1.1 - 1.7)E 0 ( -3.6 - 17.2)E -1 (0/ 12) (0/ 4)

Se-75 (12) 5.1E -2 14 2.4E -1 NO DATA (0) ( -9.0 - 11.1)E -1 ( -9.0 - 11.1)E -1 (0/ 12) (0/ 4)

Nb-95 (12) 15 7.0E -2 14 7.6E -1 NO DATA (0) ( -1.6 - 1.7)E 0 ( -5.2 - 17.2)E -1 (0/ 12) (0/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.5-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Ground Water (WG) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Zr-95 (12) 15 -1.0E -1 01 1.7E -1 NO DATA (0) ( -2.2 - 2.4)E 0 ( -1.7 - 1.6)E 0 (0/ 12) (0/ 4)

Ru-103 (12) -3.0E -1 01 -2.5E -1 NO DATA (0) ( -1.2 - 0.3)E 0 ( -1.2 - 0.1)E 0 (0/ 12) (0/ 4)

Ru-106 (12) 2.0E -1 14 2.5E 0 NO DATA (0) ( -7.9 - 10.9)E 0 ( -4.7 - 10.9)E 0 (0/ 12) (0/ 4)

Ag-108m (12) -7.4E -2 14 9.3E -2 NO DATA (0) ( -8.9 - 4.2)E -1 ( -2.8 - 4.1)E -1 (0/ 12) (0/ 4)

Ag-110m (12) -1.0E -2 01 1.8E -1 NO DATA (0) ( -5.6 - 5.3)E -1 ( -3.2 - 4.7)E -1 (0/ 12) (0/ 4)

Sb-124 (12) -1.1E -1 13 3.0E -1 NO DATA (0) ( -2.7 - 1.7)E 0 ( -2.7 - 1.7)E 0 (0/ 12) (0/ 4)

Sb-125 (12) -3.1E -1 14 3.6E -1 NO DATA (0) ( -2.2 - 1.6)E 0 ( -1.9 - 1.6)E 0 (0/ 12) (0/ 4)

I-131 (12) 15 -7.5E -1 13 1.6E -1 NO DATA (0) ( -3.6 - 2.0)E 0 ( -1.2 - 2.0)E 0 (0/ 12) (0/ 4)

Cs-134 (12) 15 2.0E -1 14 5.5E -1 NO DATA (0) ( -7.8 - 10.4)E -1 ( 3.5 - 7.8)E -1 (0/ 12) (0/ 4)

Cs-137 (12) 18 2.1E -1 14 5.2E -1 NO DATA (0) ( -7.1 - 13.5)E -1 ( -7.1 - 13.5)E -1 (0/ 12) (0/ 4)

Ba-140 (12) 15 -1.1E 0 01 -2.3E -2 NO DATA (0) ( -9.4 - 2.8)E 0 ( -3.0 - 2.2)E 0 (0/ 12) (0/ 4)

La-140 (12) 15 -5.3E -1 13 -5.1E -2 NO DATA (0) ( -2.3 - 1.0)E 0 ( -1.3 - 1.0)E 0 (0/ 12) (0/ 4)

Ce-141 (12) -8.8E -1 13 1.1E -1 NO DATA (0) ( -6.0 - 1.7)E 0 ( -1.2 - 1.7)E 0 (0/ 12) (0/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., >3 standard deviations with no uncertain identification) is shown in parentheses.

Table 3.5-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Ground Water (WG) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ce-144 (12) -1.3E -1 01 1.1E 0 NO DATA (0) ( -5.5 - 6.9)E 0 ( -2.9 - 5.1)E 0 (0/ 12) (0/ 4)

Pb-212 (12) -6.5E -3 14 1.5E 0 NO DATA (0) ( -5.7 - 5.6)E 0 ( -2.3 - 3.2)E 0 (2/ 12) (1/ 4)

Pb-214 (12) 3.0E 1 14 8.0E 1 NO DATA (0) ( -3.4 - 166.0)E 0 ( 2.7 - 16.6)E 1 (7/ 12) (4/ 4)

Bi-214 (12) 3.3E 1 14 8.0E 1 NO DATA (0) ( 0.0 - 1.7)E 2 ( 2.8 - 16.8)E 1 (8/ 12) (4/ 4)

Ac-228 (12) 1.7E -1 13 2.5E 0 NO DATA (0) ( -6.5 - 6.3)E 0 ( -1.1 - 6.3)E 0 (0/ 12) (0/ 4)

Th-228 (12) -6.5E -3 14 1.5E 0 NO DATA (0) ( -5.7 - 5.6)E 0 ( -2.3 - 3.2)E 0 (2/ 12) (1/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

3.6 Sediment Semiannual sediment sampling is required at one indicator location, although a total of five locations, three indicators and two controls, are collected. The indicator stations are comprised of two sets of beach sediment cores from Hampton Beach (SE-07) and Seabrook Beach (SE-08), plus two sub-tidal sediment cores taken from near the discharge structure (SE-02). The control locations, Plum Island Beach (SE-57) and sub-tidal Ipswich Bay (SE-52), are both located within Ipswich Bay. A total of 10 samples were collected for the year from all locations. All cores were analyzed as single or whole samples without segmenting. A gamma analysis was performed on each core.

Table 3.6-1 identifies the results of the search for radionuclides of which several naturally-occurring were detected. The naturally-occurring radionuclides include K-40 and nuclides of the Uranium-238 decay chain (Th-230, Ra-226, Pb-214 and Bi-214) and the Thorium-232 decay chain (Ac-228, Th-228, Pb-212, and Tl-208). No plant-related radionuclides were detected in any core. No increasing or decreasing trends were observed. This is consistent with the pre-operational program and with previous years of plant operations. There is no plant related dose to the public or impact to the environment from any pathways associated with this media.

The REMP Summary Table 3.6-1 lists the range of analysis results by radionuclide for Indicator and Control Stations for the sediment environmental media. Attachment 1 to this report lists the individual analysis results for each measurement of sediment under the Sample Type code SE.

Any sample collection and analysis deviations from the ODCM required program, or reportable concentrations that may have occurred during the year are described in Section 5.

Table 3.6-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Sediment (SE) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Be-7 (10) 7.1E 0 52 1.2E 2 1.2E 2 (0) ( -1.8 - 3.5)E 2 ( 1.1 - 1.3)E 2 ( 4.6 - 17.1)E 1 (0/ 6) (0/ 2) (0/ 4)

K-40 (10) 1.4E 4 07 2.0E 4 1.5E 4 (0) ( 0.0 - 2.1)E 4 ( 1.9 - 2.1)E 4 ( 1.2 - 2.4)E 4 (5/ 6) (2/ 2) (4/ 4)

Cr-51 (10) -1.4E 1 08 8.9E 1 -7.9E 1 (0) ( -1.9 - 1.6)E 2 ( 1.7 - 16.0)E 1 ( -1.4 - 0.2)E 2 (0/ 6) (0/ 2) (0/ 4)

Mn-54 (10) 1.3E 1 02 2.3E 1 -1.6E 1 (0) ( -4.9 - 25.0)E 0 ( 2.1 - 2.5)E 1 ( -4.1 - -0.1)E 1 (0/ 6) (0/ 2) (0/ 4)

Co-57 (10) -2.6E 0 02 3.5E 0 -8.3E -1 (0) ( -1.1 - 1.1)E 1 ( -3.6 - 10.5)E 0 ( -9.3 - 8.7)E 0 (0/ 6) (0/ 2) (0/ 4)

Co-58 (10) -1.7E 0 52 1.3E 1 5.6E 0 (0) ( -1.7 - 1.8)E 1 ( 9.4 - 15.8)E 0 ( -5.0 - 15.8)E 0 (0/ 6) (0/ 2) (0/ 4)

Fe-59 (10) 6.7E 0 57 2.1E 1 1.8E 1 (0) ( -4.3 - 4.7)E 1 ( 7.8 - 406.0)E -1 ( 7.8 - 406.0)E -1 (0/ 6) (0/ 2) (0/ 4)

Co-60 (10) -7.5E 0 52 2.9E 1 4.3E 0 (0) ( -1.7 - 0.1)E 1 ( 1.3 - 4.6)E 1 ( -2.8 - 4.6)E 1 (0/ 6) (0/ 2) (0/ 4)

Zn-65 (10) 2.0E 0 52 2.1E 1 -5.5E 0 (0) ( -2.4 - 2.1)E 1 ( 2.1 - 40.3)E 0 ( -4.5 - 4.0)E 1 (0/ 6) (0/ 2) (0/ 4)

Se-75 (10) 8.7E 0 08 1.1E 1 6.0E 0 (0) ( 3.9 - 15.8)E 0 ( 5.4 - 15.8)E 0 ( -2.4 - 12.6)E 0 (0/ 6) (0/ 2) (0/ 4)

Nb-95 (10) 1.2E 1 02 1.9E 1 -1.6E 1 (0) ( -9.5 - 30.8)E 0 ( 1.9 - 2.0)E 1 ( -2.8 - -0.2)E 1 (0/ 6) (0/ 2) (0/ 4)

Zr-95 (10) 4.9E 0 52 6.9E 1 5.2E 1 (0) ( -8.0 - 3.9)E 1 ( 6.8 - 7.1)E 1 ( 1.1 - 7.1)E 1 (0/ 6) (0/ 2) (0/ 4)

Ru-103 (10) -6.3E 0 08 -4.6E -1 -9.5E 0 (0) ( -2.3 - 1.5)E 1 ( -4.3 - 3.4)E 0 ( -1.8 - 0.9)E 1 (0/ 6) (0/ 2) (0/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.6-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Sediment (SE) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ru-106 (10) -2.5E 1 07 7.5E 1 -1.0E 2 (0) ( -2.9 - 0.9)E 2 ( 5.9 - 9.0)E 1 ( -3.0 - 0.6)E 2 (0/ 6) (0/ 2) (0/ 4)

Ag-108m (10) 3.6E 0 08 6.3E 0 -7.7E 0 (0) ( -8.4 - 20.9)E 0 ( -8.4 - 20.9)E 0 ( -2.2 - 0.2)E 1 (0/ 6) (0/ 2) (0/ 4)

Ag-110m (10) 3.1E 0 08 3.7E 1 -7.3E 0 (0) ( -5.2 - 4.7)E 1 ( 2.8 - 4.7)E 1 ( -1.6 - 0.2)E 1 (0/ 6) (0/ 2) (0/ 4)

Sb-124 (10) 6.6E 0 02 4.9E 1 1.2E 1 (0) ( -4.1 - 7.6)E 1 ( 2.1 - 7.6)E 1 ( -1.8 - 3.6)E 1 (0/ 6) (0/ 2) (0/ 4)

Sb-125 (10) 1.9E 1 02 4.0E 1 -3.0E 0 (0) ( -7.4 - 45.9)E 0 ( 3.4 - 4.6)E 1 ( -1.6 - 1.2)E 1 (0/ 6) (0/ 2) (0/ 4)

I-131 (10) 6.1E 0 57 1.7E 1 2.8E 0 (0) ( -3.2 - 3.1)E 1 ( 5.3 - 326.0)E -1 ( -2.1 - 3.3)E 1 (0/ 6) (0/ 2) (0/ 4)

Cs-134 (10) 150 2.9E 1 02 4.5E 1 2.0E 1 (0) ( 2.9 - 47.3)E 0 ( 4.2 - 4.7)E 1 ( 0.0 - 3.6)E 1 (0/ 6) (0/ 2) (0/ 4)

Cs-137 (10) 180 1.4E 1 02 1.9E 1 -6.4E 0 (0) ( 7.5 - 319.0)E -1 ( 6.4 - 31.9)E 0 ( -2.1 - 1.5)E 1 (0/ 6) (0/ 2) (0/ 4)

Ba-140 (10) 2.7E 1 52 1.0E 2 4.3E 1 (0) ( -3.7 - 16.1)E 1 ( 8.8 - 11.4)E 1 ( -1.2 - 1.1)E 2 (0/ 6) (0/ 2) (0/ 4)

La-140 (10) -5.8E 0 52 4.6E 1 1.9E 1 (0) ( -3.1 - 2.6)E 1 ( 9.8 - 81.6)E 0 ( -1.1 - 8.2)E 1 (0/ 6) (0/ 2) (0/ 4)

Ce-141 (10) -9.6E 0 57 -5.4E 0 -8.2E 0 (0) ( -2.6 - 1.2)E 1 ( -1.2 - 0.1)E 1 ( -1.4 - 0.1)E 1 (0/ 6) (0/ 2) (0/ 4)

Ce-144 (10) -1.6E 1 07 5.6E 1 7.5E -1 (0) ( -2.0 - 0.8)E 2 ( 3.3 - 7.9)E 1 ( -4.2 - 2.4)E 1 (0/ 6) (0/ 2) (0/ 4)

Tl-208 (10) 1.6E 2 52 4.1E 2 2.5E 2 (0) ( 9.3 - 38.2)E 1 ( 2.8 - 5.4)E 2 ( 9.1 - 53.8)E 1 (6/ 6) (2/ 2) (4/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.6-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Sediment (SE) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Pb-212 (10) 5.9E 2 52 1.5E 3 9.4E 2 (0) ( 2.8 - 13.8)E 2 ( 1.2 - 1.7)E 3 ( 3.3 - 17.4)E 2 (6/ 6) (2/ 2) (4/ 4)

Pb-214 (10) 4.2E 2 52 1.1E 3 6.9E 2 (0) ( 0.0 - 1.1)E 3 ( 9.3 - 12.9)E 2 ( 2.1 - 12.9)E 2 (5/ 6) (2/ 2) (4/ 4)

Bi-214 (10) 3.2E 2 52 9.4E 2 6.1E 2 (0) ( 0.0 - 1.2)E 3 ( 7.7 - 11.0)E 2 ( 2.7 - 11.0)E 2 (4/ 6) (2/ 2) (4/ 4)

Ra-226 (10) 3.2E 2 52 9.4E 2 6.1E 2 (0) ( 0.0 - 1.2)E 3 ( 7.7 - 11.0)E 2 ( 2.7 - 11.0)E 2 (4/ 6) (2/ 2) (4/ 4)

Ac-228 (10) 4.6E 2 52 1.3E 3 7.7E 2 (0) ( 0.0 - 1.5)E 3 ( 9.4 - 16.7)E 2 ( 0.0 - 1.7)E 3 (4/ 6) (2/ 2) (3/ 4)

Th-228 (10) 5.9E 2 52 1.5E 3 9.4E 2 (0) ( 2.8 - 13.8)E 2 ( 1.2 - 1.7)E 3 ( 3.3 - 17.4)E 2 (6/ 6) (2/ 2) (4/ 4)

Th-230 (10) 3.2E 2 52 9.4E 2 6.1E 2 (0) ( 0.0 - 1.2)E 3 ( 7.7 - 11.0)E 2 ( 2.7 - 11.0)E 2 (4/ 6) (2/ 2) (4/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

3.7 Fish Semiannual fish (FH) and invertebrate samples are required by the ODCM REMP from two locations.

Quarterly collections are attempted to ensure the sampling requirements are met. This section presents the results for fish sampling only. Invertebrate results may be found in Sections 3.8 and 3.9, entitled Lobsters and Shellfish, respectively.

During the year, a total of 9 fish samples were collected. The fish species available from Station FH-03 (indicator station) and Station FH-53 (control station) were dominated by Winter Flounder which are bottom dwelling species. One sample each of Cunner, Silver Hake, and Smelt were also collected from sample location FH-03 (Hampton Bay in the area of the plants discharge). One sample of Cod fish was collected from sample location FH-53 (control station).

A gamma analysis was performed on the edible portion of each sample collected. In 2021, the only radionuclides detected were naturally-occurring K-40 (8 of 9 samples). Table 3.7-1 summarizes the results for radionuclides in fish. Similar to past years, no plant-related radionuclides were detected in any samples. As a result, no increasing or decreasing trends were observed. Subsequently, there is no dose to the public or impact to the environment through this pathway due to plant operations. This is consistent with previous years of plant operations, as well as the pre-operational program.

In addition to the required program for fish as defined in the ODCM, sampling was attempted to collect a local fish species (Cunner fish) that resides in the upper regions of the water column using an alternate collection method from that used for the more prevalent bottom species (Flounder). For 2021, one Cunner sample was collected from Hampton Bay. The results are listed in Attachment 1 as laboratory number 545141003 (05/17/2021). No plant radionuclides were detected in the Cunner fish sample, with only naturally-occurring K-40 being found.

The REMP Summary Table 3.7-1 also lists the range of analysis results by radionuclide for Indicator and Control Stations for all fish environmental media. Attachment 1 to this report lists the individual analysis results for each measurement of fish under the Sample Type code FH.

Any sample collection and analysis deviations from the ODCM required program, or reportable concentrations that may have occurred during the year are described in Section 5.

Table 3.7-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Fish (FH) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Be-7 (9) -1.7E 1 53 -1.2E 1 -1.2E 1 (0) ( -5.8 - 0.2)E 1 ( -3.6 - 2.5)E 1 ( -3.6 - 2.5)E 1 (0/ 5) (0/ 4) (0/ 4)

K-40 (9) 2.6E 3 53 3.5E 3 3.5E 3 (0) ( 0.0 - 4.0)E 3 ( 3.4 - 3.6)E 3 ( 3.4 - 3.6)E 3 (4/ 5) (4/ 4) (4/ 4)

Cr-51 (9) -2.2E 1 53 -5.3E 0 -5.3E 0 (0) ( -1.2 - 0.3)E 2 ( -1.8 - 1.2)E 1 ( -1.8 - 1.2)E 1 (0/ 5) (0/ 4) (0/ 4)

Mn-54 (9) 130 -9.9E -1 53 -6.4E -1 -6.4E -1 (0) ( -5.6 - 5.5)E 0 ( -5.0 - 1.2)E 0 ( -5.0 - 1.2)E 0 (0/ 5) (0/ 4) (0/ 4)

Co-57 (9) 7.9E -1 03 7.9E -1 2.0E -1 (0) ( -4.8 - 4.3)E 0 ( -4.8 - 4.3)E 0 ( -2.1 - 2.3)E 0 (0/ 5) (0/ 5) (0/ 4)

Co-58 (9) 130 -7.1E 0 53 -7.5E -1 -7.5E -1 (0) ( -3.1 - 0.0)E 1 ( -2.5 - 0.2)E 0 ( -2.5 - 0.2)E 0 (0/ 5) (0/ 4) (0/ 4)

Fe-59 (9) 260 -3.6E 0 53 7.4E 0 7.4E 0 (0) ( -6.8 - 1.0)E 0 ( 3.9 - 11.8)E 0 ( 3.9 - 11.8)E 0 (0/ 5) (0/ 4) (0/ 4)

Co-60 (9) 130 3.2E 0 03 3.2E 0 4.2E -3 (0) ( -1.4 - 11.7)E 0 ( -1.4 - 11.7)E 0 ( -7.8 - 10.6)E -1 (0/ 5) (0/ 5) (0/ 4)

Zn-65 (9) 260 -2.4E 0 53 3.2E -1 3.2E -1 (0) ( -1.0 - 1.6)E 1 ( -2.7 - 5.0)E 0 ( -2.7 - 5.0)E 0 (0/ 5) (0/ 4) (0/ 4)

Se-75 (9) -4.0E -1 03 -4.0E -1 -7.5E -1 (0) ( -2.2 - 2.2)E 0 ( -2.2 - 2.2)E 0 ( -2.1 - 0.0)E 0 (0/ 5) (0/ 5) (0/ 4)

Nb-95 (9) 5.7E 0 03 5.7E 0 -2.0E 0 (0) ( -6.2 - 30.7)E 0 ( -6.2 - 30.7)E 0 ( -9.8 - 2.6)E 0 (0/ 5) (0/ 5) (0/ 4)

Zr-95 (9) 7.4E -1 53 2.7E 0 2.7E 0 (0) ( -2.1 - 2.9)E 1 ( 2.0 - 4.4)E 0 ( 2.0 - 4.4)E 0 (0/ 5) (0/ 4) (0/ 4)

Ru-103 (9) 4.6E 0 03 4.6E 0 1.8E 0 (0) ( -5.3 - 206.0)E -1 ( -5.3 - 206.0)E -1 ( 6.6 - 29.6)E -1 (0/ 5) (0/ 5) (0/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.7-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Fish (FH) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ru-106 (9) 5.0E 1 03 5.0E 1 -3.8E 0 (0) ( -1.7 - 13.5)E 1 ( -1.7 - 13.5)E 1 ( -2.2 - 1.2)E 1 (0/ 5) (0/ 5) (0/ 4)

Ag-108m (9) 1.7E 0 53 2.1E 0 2.1E 0 (0) ( -2.3 - 48.6)E -1 ( 6.8 - 47.4)E -1 ( 6.8 - 47.4)E -1 (0/ 5) (0/ 4) (0/ 4)

Ag-110m (9) -3.2E 0 53 -1.8E -2 -1.8E -2 (0) ( -1.5 - 1.0)E 1 ( -3.0 - 3.1)E 0 ( -3.0 - 3.1)E 0 (0/ 5) (0/ 4) (0/ 4)

Sb-124 (9) 2.8E 0 03 2.8E 0 -4.0E 0 (0) ( -2.2 - 18.0)E 0 ( -2.2 - 18.0)E 0 ( -1.2 - 0.3)E 1 (0/ 5) (0/ 5) (0/ 4)

Sb-125 (9) -2.0E 0 53 1.6E 0 1.6E 0 (0) ( -2.3 - 1.2)E 1 ( -4.1 - 27.8)E -1 ( -4.1 - 27.8)E -1 (0/ 5) (0/ 4) (0/ 4)

I-131 (9) -9.8E 0 03 -9.8E 0 -1.5E 1 (0) ( -7.8 - 2.9)E 1 ( -7.8 - 2.9)E 1 ( -7.0 - 1.4)E 1 (0/ 5) (0/ 5) (0/ 4)

Cs-134 (9) 130 -6.1E -1 53 8.9E -1 8.9E -1 (0) ( -3.3 - 3.3)E 0 ( -1.4 - 3.1)E 0 ( -1.4 - 3.1)E 0 (0/ 5) (0/ 4) (0/ 4)

Cs-137 (9) 150 2.5E 0 03 2.5E 0 -1.1E 0 (0) ( 0.0 - 6.4)E 0 ( 0.0 - 6.4)E 0 ( -2.4 - 0.6)E 0 (0/ 5) (0/ 5) (0/ 4)

Ba-140 (9) 1.6E 1 03 1.6E 1 -8.4E 0 (0) ( -8.2 - 9.8)E 1 ( -8.2 - 9.8)E 1 ( -1.8 - 0.6)E 1 (0/ 5) (0/ 5) (0/ 4)

La-140 (9) -1.3E 1 53 3.9E 0 3.9E 0 (0) ( -3.2 - 0.1)E 1 ( -1.8 - 123.0)E -1 ( -1.8 - 123.0)E -1 (0/ 5) (0/ 4) (0/ 4)

Ce-141 (9) -7.7E 0 53 -4.0E 0 -4.0E 0 (0) ( -3.2 - 0.3)E 1 ( -7.4 - -0.6)E 0 ( -7.4 - -0.6)E 0 (0/ 5) (0/ 4) (0/ 4)

Ce-144 (9) 1.1E 1 03 1.1E 1 3.1E 0 (0) ( -4.5 - 8.7)E 1 ( -4.5 - 8.7)E 1 ( -1.1 - 1.8)E 1 (0/ 5) (0/ 5) (0/ 4)

Tl-208 (9) 1.0E -1 03 1.0E -1 -5.3E -1 (0) ( -2.1 - 4.9)E 0 ( -2.1 - 4.9)E 0 ( -3.3 - 1.4)E 0 (0/ 5) (0/ 5) (0/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.7-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Fish (FH) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Pb-212 (9) 1.4E 1 03 1.4E 1 2.7E 0 (0) ( 0.0 - 4.0)E 1 ( 0.0 - 4.0)E 1 ( -2.6 - 7.1)E 0 (0/ 5) (0/ 5) (0/ 4)

Pb-214 (9) -1.8E 1 53 -8.0E -1 -8.0E -1 (0) ( -5.6 - 0.6)E 1 ( -5.1 - 4.4)E 0 ( -5.1 - 4.4)E 0 (0/ 5) (0/ 4) (0/ 4)

Bi-214 (9) 2.8E -1 53 4.9E 0 4.9E 0 (0) ( -3.0 - 1.8)E 1 ( -4.4 - 13.3)E 0 ( -4.4 - 13.3)E 0 (0/ 5) (0/ 4) (0/ 4)

Ra-226 (9) 2.8E -1 53 4.9E 0 4.9E 0 (0) ( -3.0 - 1.8)E 1 ( -4.4 - 13.3)E 0 ( -4.4 - 13.3)E 0 (0/ 5) (0/ 4) (0/ 4)

Ac-228 (9) -2.5E 1 53 -1.5E 0 -1.5E 0 (0) ( -1.5 - 0.3)E 2 ( -8.3 - 2.4)E 0 ( -8.3 - 2.4)E 0 (0/ 5) (0/ 4) (0/ 4)

Th-228 (9) 1.4E 1 03 1.4E 1 2.7E 0 (0) ( 0.0 - 4.0)E 1 ( 0.0 - 4.0)E 1 ( -2.6 - 7.1)E 0 (0/ 5) (0/ 5) (0/ 4)

Th-230 (9) 2.8E -1 53 4.9E 0 4.9E 0 (0) ( -3.0 - 1.8)E 1 ( -4.4 - 13.3)E 0 ( -4.4 - 13.3)E 0 (0/ 5) (0/ 4) (0/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

3.8 Lobsters Semiannual fish and invertebrate samples were required from two locations. This section provides the results for one type of invertebrate - Homarus americanus (American lobsters) which is an important commercial food species from local waters. Lobsters (HA) were collected from an indicator location near the discharge (HA-04) and from a control location (HA-54) within Ipswich Bay. A total of four samples were collected for the year.

Fish and shellfish results may be found in Sections 3.7 and 3.9, respectively.

A gamma analysis was performed on each sample. The only radionuclide detected in lobster samples in 2021 was naturally-occurring K-40 (all samples). Similar to past years, no plant-related radionuclides were detected in any sample. Therefore, no increasing or decreasing trends were observed. Consequently, there is no dose to the public or impact to the environment from this pathway due to plant operations. This is consistent with previous years as well as the pre-operational program.

The REMP Summary Table 3.8-1 also lists the range of analysis results by radionuclide for Indicator and Control Stations for all lobster samples. Attachment 1 to this report lists the individual analysis results for each measurement of lobsters under the Sample Type code HA.

Any sample collection and analysis deviations from the ODCM required program, or reportable concentrations that may have occurred during the year are described in Section 5.

Table 3.8-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: American Lobster (HA) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Be-7 (4) 9.2E 0 04 1.1E 1 9.2E 0 (0) ( -6.9 - 29.8)E 0 ( -6.9 - 29.8)E 0 (0/ 3) (0/ 2) (0/ 1)

K-40 (4) 2.5E 3 04 2.5E 3 2.5E 3 (0) ( 2.3 - 2.7)E 3 ( 2.3 - 2.7)E 3 (3/ 3) (2/ 2) (1/ 1)

Cr-51 (4) 2.3E 1 04 2.9E 1 -2.6E 1 (0) ( 1.1 - 3.2)E 1 ( 2.5 - 3.2)E 1 (0/ 3) (0/ 2) (0/ 1)

Mn-54 (4) 130 -1.9E 0 54 -7.2E -1 -7.2E -1 (0) ( -4.4 - 0.1)E 0 (0/ 3) (0/ 1) (0/ 1)

Co-57 (4) 1.4E 0 04 1.6E 0 1.1E -1 (0) ( 1.2 - 1.8)E 0 ( 1.3 - 1.8)E 0 (0/ 3) (0/ 2) (0/ 1)

Co-58 (4) 130 -1.2E 0 04 -1.2E 0 -1.5E 0 (0) ( -2.4 - 0.1)E 0 ( -2.4 - 0.1)E 0 (0/ 3) (0/ 2) (0/ 1)

Fe-59 (4) 260 4.0E -1 54 5.7E 0 5.7E 0 (0) ( -2.9 - 3.0)E 0 (0/ 3) (0/ 1) (0/ 1)

Co-60 (4) 130 -6.3E -1 04 8.5E -2 -3.0E 0 (0) ( -7.2 - 7.4)E 0 ( -7.2 - 7.4)E 0 (0/ 3) (0/ 2) (0/ 1)

Zn-65 (4) 260 -2.1E 0 54 1.3E 0 1.3E 0 (0) ( -5.1 - 1.0)E 0 (0/ 3) (0/ 1) (0/ 1)

Se-75 (4) -7.5E -1 54 6.3E -1 6.3E -1 (0) ( -1.5 - 0.1)E 0 (0/ 3) (0/ 1) (0/ 1)

Nb-95 (4) -1.2E 0 52 2.3E 0 -2.8E 0 (0) ( -5.2 - 2.3)E 0 (0/ 3) (0/ 1) (0/ 1)

Zr-95 (4) -2.9E 0 04 -2.3E 0 -6.5E 0 (0) ( -5.5 - 0.9)E 0 ( -5.5 - 0.9)E 0 (0/ 3) (0/ 2) (0/ 1)

Ru-103 (4) -9.0E -1 52 1.5E 0 -1.6E -1 (0) ( -2.6 - 1.5)E 0 (0/ 3) (0/ 1) (0/ 1)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.8-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: American Lobster (HA) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ru-106 (4) 1.9E 1 52 4.6E 1 3.6E 1 (0) ( 5.1 - 46.3)E 0 (0/ 3) (0/ 1) (0/ 1)

Ag-108m (4) 1.4E 0 04 2.0E 0 -1.5E 0 (0) ( 3.5 - 24.7)E -1 ( 1.5 - 2.5)E 0 (0/ 3) (0/ 2) (0/ 1)

Ag-110m (4) -1.6E 0 54 1.5E 0 1.5E 0 (0) ( -2.7 - 0.3)E 0 (0/ 3) (0/ 1) (0/ 1)

Sb-124 (4) -3.3E -1 04 4.9E -1 -5.4E 0 (0) ( -2.0 - 1.9)E 0 ( -9.3 - 19.2)E -1 (0/ 3) (0/ 2) (0/ 1)

Sb-125 (4) -8.6E -1 04 -7.4E -1 -9.2E -1 (0) ( -6.0 - 4.5)E 0 ( -6.0 - 4.5)E 0 (0/ 3) (0/ 2) (0/ 1)

I-131 (4) -3.5E 0 52 1.6E 1 -2.3E 0 (0) ( -2.5 - 1.6)E 1 (0/ 3) (0/ 1) (0/ 1)

Cs-134 (4) 130 2.2E 0 52 2.3E 0 -3.9E 0 (0) ( 1.2 - 3.2)E 0 (0/ 3) (0/ 1) (0/ 1)

Cs-137 (4) 150 -5.2E -2 54 2.8E 0 2.8E 0 (0) ( -2.4 - 2.3)E 0 (0/ 3) (0/ 1) (0/ 1)

Ba-140 (4) -1.7E 1 52 1.1E 1 -1.4E 1 (0) ( -6.0 - 1.1)E 1 (0/ 3) (0/ 1) (0/ 1)

La-140 (4) 6.2E -1 52 5.2E 0 1.1E 0 (0) ( -2.7 - 5.2)E 0 (0/ 3) (0/ 1) (0/ 1)

Ce-141 (4) -9.6E -1 52 5.6E -1 -2.6E 0 (0) ( -4.7 - 1.2)E 0 (0/ 3) (0/ 1) (0/ 1)

Ce-144 (4) -1.2E 1 52 2.3E 0 -3.2E 0 (0) ( -4.1 - 0.2)E 1 (0/ 3) (0/ 1) (0/ 1)

Tl-208 (4) 6.3E -1 04 9.4E -1 -1.7E 0 (0) ( -3.2 - 5.1)E 0 ( -3.2 - 5.1)E 0 (0/ 3) (0/ 2) (0/ 1)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.8-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: American Lobster (HA) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Pb-212 (4) 6.7E 0 04 7.0E 0 1.1E 0 (0) ( 6.0 - 7.5)E 0 ( 6.5 - 7.5)E 0 (0/ 3) (0/ 2) (0/ 1)

Pb-214 (4) 5.9E 0 04 7.8E 0 0.0E 0 (0) ( 0.0 - 1.6)E 1 ( 0.0 - 1.6)E 1 (0/ 3) (0/ 2) (0/ 1)

Bi-214 (4) 1.3E 1 04 1.3E 1 -3.3E -1 (0) ( 1.9 - 258.0)E -1 ( 1.9 - 258.0)E -1 (0/ 3) (0/ 2) (0/ 1)

Ra-226 (4) 1.3E 1 04 1.3E 1 -3.3E -1 (0) ( 1.9 - 258.0)E -1 ( 1.9 - 258.0)E -1 (0/ 3) (0/ 2) (0/ 1)

Ac-228 (4) 2.7E -1 04 6.0E 0 -1.1E 1 (0) ( -1.1 - 1.6)E 1 ( -4.1 - 16.1)E 0 (0/ 3) (0/ 2) (0/ 1)

Th-228 (4) 6.7E 0 04 7.0E 0 1.1E 0 (0) ( 6.0 - 7.5)E 0 ( 6.5 - 7.5)E 0 (0/ 3) (0/ 2) (0/ 1)

Th-230 (4) 1.3E 1 04 1.3E 1 -3.3E -1 (0) ( 1.9 - 258.0)E -1 ( 1.9 - 258.0)E -1 (0/ 3) (0/ 2) (0/ 1)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

3.9 Shellfish Semiannual fish and invertebrate samples are required by the ODCM from two locations. This section provides the results for shellfish (MU) samples only. In 2021, four locations (two indicators and two controls) were included in the sample collections. Fish and lobster results may be found in the Sections 3.7 and 3.8, entitled Fish and Lobsters, respectively.

During the year there were two species of mussels (MU) harvested for analysis. Modiolus (horse mussels) was collected by divers from near the discharge outfall (indicator station MU-06) and from Ipswich Bay (control MU-56). Mytilus (blue mussels) were collected from the intertidal areas of Hampton Harbor (indicator MU-09) and Plum Island (control MU-59). A total of eight samples were collected in 2021 and analyzed for radioactivity in the edible portion or meat of the shellfish.

The only radionuclides detected in edible shellfish body samples in 2021 were naturally-occurring K-40 (all 8 samples), Be-7 (one of 8 samples), Pb-212 (one of 8 samples), Bi-214 (two of 8 samples), Ac-228 (one of 8 samples), Ra-226 (two of 8 samples), Th-228 (one of 8 samples), and Th-230 (two of 8 samples). Similar to past years, no plant-related gamma emitting radionuclides were detected in any sample. Therefore, no increasing or decreasing trends were observed. Consequently, there is no dose to the public or impact to the environment from this pathway due to plant operations. This is consistent with the pre-operational program and with previous years of plant operations.

Additional analyses were conducted on the May and November shellfish collections from both indicator (MS-

06) and control (MS-56) locations. Mussel shells (MS) were analyzed for Strontium 89 and 90 (four samples) to see if there was any indication of strontium uptake into the shell. For 2021, no Sr-89/90 was detected in any sample. No shell analyses are required by the REMP as defined in the ODCM.

The REMP Summary Table 3.9-1 (mussel bodies) and Table 3.9-2 (mussel shells) list the range of analysis results by radionuclide for Indicator and Control Stations for all shellfish samples. Attachment 1 to this report lists the individual analysis results for each measurement of shellfish under the Sample Type code MU for the edible portions and MS for shells only.

Any sample collection and analysis deviations from the ODCM required program, or reportable concentrations that may have occurred during the year, are described in Section 5.

Table 3.9-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Mussel Body (MU) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Be-7 (8) 3.3E 1 06 3.6E 1 1.2E 1 (0) ( 0.0 - 6.2)E 1 ( 3.3 - 3.8)E 1 ( 0.0 - 3.8)E 1 (1/ 4) (0/ 2) (0/ 4)

K-40 (8) 1.3E 3 09 1.5E 3 1.3E 3 (0) ( 8.8 - 17.1)E 2 ( 1.3 - 1.7)E 3 ( 9.8 - 17.6)E 2 (4/ 4) (2/ 2) (4/ 4)

Cr-51 (8) -7.3E 0 56 1.8E 1 -9.0E -1 (0) ( -2.9 - 1.4)E 1 ( -1.5 - 5.2)E 1 ( -2.8 - 5.2)E 1 (0/ 4) (0/ 2) (0/ 4)

Mn-54 (8) 130 -5.1E -1 56 4.8E 0 3.8E 0 (0) ( -1.9 - 1.0)E 0 ( -5.1 - 102.0)E -1 ( -5.1 - 102.0)E -1 (0/ 4) (0/ 2) (0/ 4)

Co-57 (8) 8.8E -1 09 1.4E 0 -5.9E -2 (0) ( -6.5 - 21.5)E -1 ( 6.3 - 21.5)E -1 ( -1.1 - 1.0)E 0 (0/ 4) (0/ 2) (0/ 4)

Co-58 (8) 130 -3.3E -1 56 1.1E 0 5.1E -1 (0) ( -1.1 - 0.6)E 0 ( 3.0 - 18.0)E -1 ( -1.2 - 1.8)E 0 (0/ 4) (0/ 2) (0/ 4)

Fe-59 (8) 260 4.1E -1 56 4.5E 0 1.8E 0 (0) ( -5.6 - 4.3)E 0 ( 2.3 - 6.7)E 0 ( -7.5 - 6.7)E 0 (0/ 4) (0/ 2) (0/ 4)

Co-60 (8) 130 -4.5E -1 56 1.1E 0 2.3E -1 (0) ( -2.9 - 2.7)E 0 ( 1.7 - 20.0)E -1 ( -1.4 - 2.0)E 0 (0/ 4) (0/ 2) (0/ 4)

Zn-65 (8) 260 -7.3E 0 56 1.1E 0 -4.1E 0 (0) ( -3.1 - 0.7)E 1 ( -2.8 - 5.1)E 0 ( -1.9 - 0.5)E 1 (0/ 4) (0/ 2) (0/ 4)

Se-75 (8) -7.2E -1 59 2.1E 0 1.0E 0 (0) ( -3.1 - 1.5)E 0 ( 1.1 - 3.2)E 0 ( -1.1 - 3.2)E 0 (0/ 4) (0/ 2) (0/ 4)

Nb-95 (8) -1.3E 0 56 1.1E 0 1.7E -1 (0) ( -2.5 - 0.0)E 0 ( -2.9 - 25.4)E -1 ( -3.1 - 2.5)E 0 (0/ 4) (0/ 2) (0/ 4)

Zr-95 (8) -1.9E -1 56 2.0E 0 3.5E -1 (0) ( -2.6 - 3.5)E 0 ( 1.6 - 2.3)E 0 ( -3.6 - 2.3)E 0 (0/ 4) (0/ 2) (0/ 4)

Ru-103 (8) 1.7E -1 09 1.1E 0 -1.8E 0 (0) ( -2.4 - 1.2)E 0 ( 1.0 - 1.2)E 0 ( -4.1 - 1.6)E 0 (0/ 4) (0/ 2) (0/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.9-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Mussel Body (MU) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ru-106 (8) -2.5E 1 56 7.4E 0 2.4E 0 (0) ( -7.8 - 0.7)E 1 ( 4.8 - 9.9)E 0 ( -9.6 - 9.9)E 0 (0/ 4) (0/ 2) (0/ 4)

Ag-108m (8) 4.1E 0 06 6.9E 0 3.1E -1 (0) ( -5.1 - 120.0)E -1 ( 1.7 - 12.0)E 0 ( -1.4 - 1.9)E 0 (0/ 4) (0/ 2) (0/ 4)

Ag-110m (8) -2.5E 0 59 2.3E 0 9.7E -1 (0) ( -7.7 - -0.5)E 0 ( 1.2 - 3.4)E 0 ( -8.5 - 34.0)E -1 (0/ 4) (0/ 2) (0/ 4)

Sb-124 (8) -1.1E 0 56 2.4E 0 5.7E -1 (0) ( -9.0 - 2.7)E 0 ( -4.2 - 9.1)E 0 ( -4.2 - 9.1)E 0 (0/ 4) (0/ 2) (0/ 4)

Sb-125 (8) 1.6E 0 06 5.1E 0 -5.1E 0 (0) ( -9.2 - 9.0)E 0 ( 1.3 - 9.0)E 0 ( -1.7 - 0.0)E 1 (0/ 4) (0/ 2) (0/ 4)

I-131 (8) -3.6E 0 59 2.0E 0 -3.7E -1 (0) ( -1.2 - 0.6)E 1 ( -2.1 - 4100.0)E -3 ( -5.3 - 4.1)E 0 (0/ 4) (0/ 2) (0/ 4)

Cs-134 (8) 130 4.0E -1 06 1.9E 0 -2.1E -1 (0) ( -5.4 - 3.3)E 0 ( 1.1 - 2.7)E 0 ( -4.0 - 2.1)E 0 (0/ 4) (0/ 2) (0/ 4)

Cs-137 (8) 150 -1.8E 0 59 1.3E 0 4.1E -1 (0) ( -4.2 - 0.1)E 0 ( -2.8 - 28.3)E -1 ( -2.9 - 2.8)E 0 (0/ 4) (0/ 2) (0/ 4)

Ba-140 (8) 2.0E 1 06 2.3E 1 3.3E 0 (0) ( -1.3 - 4.8)E 1 ( 3.9 - 42.5)E 0 ( -5.9 - 9.9)E 0 (0/ 4) (0/ 2) (0/ 4)

La-140 (8) -2.8E 0 59 1.4E 0 -7.9E -1 (0) ( -6.0 - 3.4)E 0 ( 8.3 - 19.5)E -1 ( -3.6 - 2.0)E 0 (0/ 4) (0/ 2) (0/ 4)

Ce-141 (8) -3.7E 0 06 -9.7E -1 -5.5E 0 (0) ( -8.2 - 3.3)E 0 ( -5.2 - 3.3)E 0 ( -8.1 - -2.2)E 0 (0/ 4) (0/ 2) (0/ 4)

Ce-144 (8) -8.1E 0 56 6.1E 0 9.0E -1 (0) ( -1.7 - 0.7)E 1 ( -6.4 - 128.0)E -1 ( -1.0 - 1.3)E 1 (0/ 4) (0/ 2) (0/ 4)

Tl-208 (8) 1.4E 0 56 2.3E 0 8.3E -1 (0) ( -2.4 - 5.7)E 0 ( 1.4 - 3.1)E 0 ( -1.6 - 3.1)E 0 (0/ 4) (0/ 2) (0/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.9-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Mussel Body (MU) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Pb-212 (8) 3.5E 0 56 9.3E 0 6.9E 0 (0) ( -1.5 - 8.5)E 0 ( 6.9 - 11.8)E 0 ( 3.5 - 11.8)E 0 (1/ 4) (0/ 2) (0/ 4)

Pb-214 (8) 1.1E 1 56 2.0E 1 1.4E 1 (0) ( 1.5 - 20.1)E 0 ( 4.3 - 36.6)E 0 ( 2.4 - 36.6)E 0 (0/ 4) (0/ 2) (0/ 4)

Bi-214 (8) 1.3E 1 06 1.6E 1 9.0E 0 (0) ( 8.9 - 20.7)E 0 ( 1.2 - 2.1)E 1 ( -6.6 - 28.1)E 0 (1/ 4) (0/ 2) (1/ 4)

Ra-226 (8) 1.3E 1 06 1.6E 1 9.0E 0 (0) ( 8.9 - 20.7)E 0 ( 1.2 - 2.1)E 1 ( -6.6 - 28.1)E 0 (1/ 4) (0/ 2) (1/ 4)

Ac-228 (8) 1.3E 1 56 3.1E 1 3.0E 1 (0) ( 0.0 - 1.8)E 1 ( 4.1 - 57.3)E 0 ( 4.1 - 57.3)E 0 (1/ 4) (0/ 2) (0/ 4)

Th-228 (8) 3.5E 0 56 9.3E 0 6.9E 0 (0) ( -1.5 - 8.5)E 0 ( 6.9 - 11.8)E 0 ( 3.5 - 11.8)E 0 (1/ 4) (0/ 2) (0/ 4)

Th-230 (8) 1.3E 1 06 1.6E 1 9.0E 0 (0) ( 8.9 - 20.7)E 0 ( 1.2 - 2.1)E 1 ( -6.6 - 28.1)E 0 (1/ 4) (0/ 2) (1/ 4)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.9-2 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Mussel Shell (MS) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Sr-89 (4) 300 1.3E 1 06 1.3E 1 -1.3E 1 (0) ( -3.8 - 29.5)E 0 ( -3.8 - 29.5)E 0 ( -2.8 - 0.1)E 1 (0/ 2) (0/ 2) (0/ 2)

Sr-90 (4) 300 4.1E 1 06 4.1E 1 2.1E -1 (0) ( 2.0 - 6.1)E 1 ( 2.0 - 6.1)E 1 ( -2.1 - 2.5)E 0 (0/ 2) (0/ 2) (0/ 2)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

3.10 Irish Moss There is no REMP technical requirement defined in the ODCM to collect Irish Moss (algae) samples. As a supplement to the required REMP, semiannual Chondrus (Irish Moss) samples were collected from an indicator area (AL-05) near the plant discharge and a control location (AL-55) within Ipswich Bay. If plant-related radionuclides were re-concentrating in the aquatic environment, an early indication of this might be shown in this type of environmental species. Four routine samples (two indicators and two controls) were collected for the year.

A gamma analysis was performed on each sample. Although not required by Table 5.2-1, the LLDs associated with food products were applied to ensure adequate counting statistics. Naturally-occurring K-40 and Be-7 were detected in both indicator and control samples. For the off-shore indicator station (AL-05), no plant-related radionuclides were detected in any sample. Therefore, no plant-related increasing or decreasing trends were observed. Subsequently, there is no dose or impact to the environment from plant operations. This is consistent with the pre-operational program and previous years of plant operations.

The REMP Summary Table 3.10-1 lists the range of analysis results by radionuclide for Indicator and Control Stations for Irish Moss samples. Attachment 1 lists the individual analysis results for each measurement of Irish moss under the Sample Type code AL.

Any sample collection and analysis deviations from the ODCM defined program, or reportable concentrations that may have occurred during the year, are described in Section 5.

Table 3.10-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Irish Moss (AL) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Be-7 (4) 2.2E 2 55 3.6E 2 3.6E 2 (0) ( 2.0 - 2.3)E 2 ( 3.3 - 4.0)E 2 ( 3.3 - 4.0)E 2 (2/ 2) (2/ 2) (2/ 2)

K-40 (4) 7.1E 3 05 7.1E 3 6.8E 3 (0) ( 6.7 - 7.6)E 3 ( 6.7 - 7.6)E 3 ( 6.2 - 7.4)E 3 (2/ 2) (2/ 2) (2/ 2)

Cr-51 (4) -4.2E 0 55 2.0E 1 2.0E 1 (0) ( -3.6 - 2.8)E 1 ( -5.1 - 44.2)E 0 ( -5.1 - 44.2)E 0 (0/ 2) (0/ 2) (0/ 2)

Mn-54 (4) 7.9E -1 05 7.9E -1 -1.3E 0 (0) ( -1.0 - 2.6)E 0 ( -1.0 - 2.6)E 0 ( -3.9 - 1.4)E 0 (0/ 2) (0/ 2) (0/ 2)

Co-57 (4) -1.8E 0 55 1.0E 0 1.0E 0 (0) ( -2.9 - -0.8)E 0 ( 5.0 - 15.9)E -1 ( 5.0 - 15.9)E -1 (0/ 2) (0/ 2) (0/ 2)

Co-58 (4) -2.4E 0 55 6.5E -1 6.5E -1 (0) ( -5.3 - 0.4)E 0 ( -2.1 - 15.0)E -1 ( -2.1 - 15.0)E -1 (0/ 2) (0/ 2) (0/ 2)

Fe-59 (4) 3.1E 0 55 1.4E 1 1.4E 1 (0) ( 3.1 - 58.6)E -1 ( 1.6 - 26.5)E 0 ( 1.6 - 26.5)E 0 (0/ 2) (0/ 2) (0/ 2)

Co-60 (4) -4.5E -2 55 7.6E -1 7.6E -1 (0) ( -3.0 - 2.9)E 0 ( -2.3 - 3.8)E 0 ( -2.3 - 3.8)E 0 (0/ 2) (0/ 2) (0/ 2)

Zn-65 (4) 1.1E 1 05 1.1E 1 2.4E 0 (0) ( 1.1 - 1.1)E 1 ( 1.1 - 1.1)E 1 ( 8.0 - 39.2)E -1 (0/ 2) (0/ 2) (0/ 2)

Se-75 (4) -5.2E 0 55 -3.0E 0 -3.0E 0 (0) ( -5.6 - -4.9)E 0 ( -6.9 - 0.8)E 0 ( -6.9 - 0.8)E 0 (0/ 2) (0/ 2) (0/ 2)

Nb-95 (4) -7.7E 0 55 -2.1E 0 -2.1E 0 (0) ( -1.6 - 0.0)E 1 ( -2.2 - -2.0)E 0 ( -2.2 - -2.0)E 0 (0/ 2) (0/ 2) (0/ 2)

Zr-95 (4) 3.4E 0 05 3.4E 0 -4.0E 0 (0) ( -2.5 - 9.3)E 0 ( -2.5 - 9.3)E 0 ( -4.0 - -4.0)E 0 (0/ 2) (0/ 2) (0/ 2)

Ru-103 (4) 6.5E -1 05 6.5E -1 -4.0E 0 (0) ( -2.3 - 3.6)E 0 ( -2.3 - 3.6)E 0 ( -5.1 - -3.0)E 0 (0/ 2) (0/ 2) (0/ 2)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.10-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Irish Moss (AL) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ru-106 (4) -4.1E 1 55 2.4E 1 2.4E 1 (0) ( -5.1 - -3.1)E 1 ( -2.0 - 6.7)E 1 ( -2.0 - 6.7)E 1 (0/ 2) (0/ 2) (0/ 2)

Ag-108m (4) -1.8E 0 55 -4.1E -1 -4.1E -1 (0) ( -3.0 - -0.6)E 0 ( -6.4 - -1.8)E -1 ( -6.4 - -1.8)E -1 (0/ 2) (0/ 2) (0/ 2)

Ag-110m (4) -4.6E 0 55 -2.8E 0 -2.8E 0 (0) ( -8.7 - -0.4)E 0 ( -6.9 - 1.2)E 0 ( -6.9 - 1.2)E 0 (0/ 2) (0/ 2) (0/ 2)

Sb-124 (4) 1.3E 0 05 1.3E 0 -3.6E 0 (0) ( -1.3 - 3.9)E 0 ( -1.3 - 3.9)E 0 ( -8.8 - 1.5)E 0 (0/ 2) (0/ 2) (0/ 2)

Sb-125 (4) -4.3E 0 55 3.4E 0 3.4E 0 (0) ( -1.5 - 0.6)E 1 ( -1.1 - 1.7)E 1 ( -1.1 - 1.7)E 1 (0/ 2) (0/ 2) (0/ 2)

I-131 (4) 60 1.3E 1 05 1.3E 1 2.7E 0 (0) ( 7.8 - 18.2)E 0 ( 7.8 - 18.2)E 0 ( 0.0 - 5.4)E 0 (0/ 2) (0/ 2) (0/ 2)

Cs-134 (4) 60 1.5E 0 55 3.6E 0 3.6E 0 (0) ( -4.1 - 34.0)E -1 ( 2.6 - 70.3)E -1 ( 2.6 - 70.3)E -1 (0/ 2) (0/ 2) (0/ 2)

Cs-137 (4) 80 4.7E 0 05 4.7E 0 1.9E 0 (0) ( 2.9 - 6.5)E 0 ( 2.9 - 6.5)E 0 ( 6.5 - 31.1)E -1 (0/ 2) (0/ 2) (0/ 2)

Ba-140 (4) -1.5E 1 55 -5.0E 0 -5.0E 0 (0) ( -4.5 - 1.5)E 1 ( -8.4 - -1.7)E 0 ( -8.4 - -1.7)E 0 (0/ 2) (0/ 2) (0/ 2)

La-140 (4) -8.4E 0 55 5.5E 0 5.5E 0 (0) ( -1.5 - -0.2)E 1 ( 4.1 - 6.9)E 0 ( 4.1 - 6.9)E 0 (0/ 2) (0/ 2) (0/ 2)

Ce-141 (4) -3.6E 0 55 9.9E 0 9.9E 0 (0) ( -8.2 - 1.1)E 0 ( 4.4 - 15.4)E 0 ( 4.4 - 15.4)E 0 (0/ 2) (0/ 2) (0/ 2)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.10-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Irish Moss (AL) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ce-144 (4) -1.4E 1 05 -1.4E 1 -2.9E 1 (0) ( -2.7 - 0.0)E 1 ( -2.7 - 0.0)E 1 ( -3.4 - -2.4)E 1 (0/ 2) (0/ 2) (0/ 2)

Ac-228 (4) -6.8E 0 55 2.2E 1 2.2E 1 (0) ( -2.5 - 1.2)E 1 ( 1.3 - 3.1)E 1 ( 1.3 - 3.1)E 1 (0/ 2) (0/ 2) (0/ 2)

Th-228 (4) 3.3E 0 05 3.3E 0 0.0E 0 (0) ( 0.0 - 6.6)E 0 ( 0.0 - 6.6)E 0 ( 0.0 - 0.0)E 0 (0/ 2) (0/ 2) (0/ 2)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

3.11 Food Crop There is no requirement for food crop or vegetation samples as long as the required milk locations are available. As noted in Section 3.3, milk sampling at the minimum required number of locations in 2021 was not possible due to the limited inventory of milk animal sites in the plant vicinity. To compensate for this, vegetation samples were collected as part of the REMP. Section 3.12 describes the alternate broad leafy vegetation (TG) collections.

In addition to the broad leafy vegetation sampling, nine food crop (TF) samples were collected from three locations listed on Table 2.0-2 (two indicator stations, TF-02 and TF-03, and one control station, TF-06) during the growing season months (June, July and August). These included strawberries in June (Lab numbers 547919004, 5, & 6), blueberries, waxed beans, and lettuce in July (Lab numbers 549905004, 5, & 6), and blueberries and tomatoes in August (Lab numbers 552744004, 5 and 6).

A gamma analysis was performed on each sample. Naturally-occurring K-40 was detected in all samples for both indicator and control stations and naturally-occurring Be-7 was detected in one sample for the control station. Similar to past years, no plant-related radionuclides were detected in any samples. Therefore, no increasing or decreasing trends are identified. Subsequently, there is no dose to the public or impact on the environment through this pathway due to plant operations. This is consistent with the pre-operational program and with previous years of plant operations.

The following REMP Summary (Table 3.11-1) lists the range of analysis results by radionuclide for indicator and control stations for the Food Crop environmental media. Attachment 1 to this report lists the individual analysis results for each measurement of Food Crops under the Sample Type code TF.

Any sample collection and analysis deviations from the ODCM defined program, or reportable concentrations that may have occurred during the year, are described in Section 5.

Table 3.11-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Food Crop (TF) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Be-7 (9) 2.2E 1 06 9.4E 1 9.4E 1 (0) ( -4.5 - 5.5)E 1 ( -2.5 - 195.0)E 0 ( -2.5 - 195.0)E 0 (0/ 6) (1/ 3) (1/ 3)

K-40 (9) 1.4E 3 06 1.9E 3 1.9E 3 (0) ( 5.8 - 24.2)E 2 ( 7.3 - 30.4)E 2 ( 7.3 - 30.4)E 2 (6/ 6) (3/ 3) (3/ 3)

Cr-51 (9) 2.3E 0 02 8.5E 0 -2.3E 0 (0) ( -1.2 - 2.9)E 1 ( -6.3 - 28.7)E 0 ( -2.0 - 3.2)E 1 (0/ 6) (0/ 3) (0/ 3)

Mn-54 (9) 2.3E -2 03 3.5E -1 -3.4E 0 (0) ( -4.1 - 5.3)E 0 ( -4.1 - 5.3)E 0 ( -6.2 - 0.5)E 0 (0/ 6) (0/ 3) (0/ 3)

Co-57 (9) 3.2E -1 06 1.3E 0 1.3E 0 (0) ( -1.5 - 1.5)E 0 ( 4.3 - 235.0)E -2 ( 4.3 - 235.0)E -2 (0/ 6) (0/ 3) (0/ 3)

Co-58 (9) -2.3E 0 06 7.5E -1 7.5E -1 (0) ( -8.1 - 0.5)E 0 ( -1.2 - 3.4)E 0 ( -1.2 - 3.4)E 0 (0/ 6) (0/ 3) (0/ 3)

Fe-59 (9) -2.7E 0 06 4.8E 0 4.8E 0 (0) ( -1.4 - 0.4)E 1 ( 3.2 - 5.8)E 0 ( 3.2 - 5.8)E 0 (0/ 6) (0/ 3) (0/ 3)

Co-60 (9) 5.0E -1 06 2.0E 0 2.0E 0 (0) ( -2.0 - 2.1)E 0 ( 6.5 - 41.2)E -1 ( 6.5 - 41.2)E -1 (0/ 6) (0/ 3) (0/ 3)

Zn-65 (9) -2.6E -1 03 -8.3E -2 -7.1E 0 (0) ( -7.3 - 6.1)E 0 ( -3.8 - 5.1)E 0 ( -1.4 - -0.4)E 1 (0/ 6) (0/ 3) (0/ 3)

Se-75 (9) -3.8E -1 03 5.4E -1 5.4E -1 (0) ( -3.6 - 1.5)E 0 ( -3.8 - 14.9)E -1 ( -2.3 - 3.8)E 0 (0/ 6) (0/ 3) (0/ 3)

Nb-95 (9) 4.7E -1 03 1.2E 0 9.5E -1 (0) ( -1.1 - 5.9)E 0 ( -1.1 - 5.9)E 0 ( -1.1 - 3.5)E 0 (0/ 6) (0/ 3) (0/ 3)

Zr-95 (9) -1.6E 0 03 4.8E -1 -1.6E 0 (0) ( -8.3 - 3.8)E 0 ( -3.7 - 2.9)E 0 ( -3.4 - 1.9)E 0 (0/ 6) (0/ 3) (0/ 3)

Ru-103 (9) -4.4E -1 06 2.5E 0 2.5E 0 (0) ( -3.8 - 1.8)E 0 ( 5.0 - 51.8)E -1 ( 5.0 - 51.8)E -1 (0/ 6) (0/ 3) (0/ 3)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.11-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Food Crop (TF) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ru-106 (9) 2.7E 0 03 1.6E 1 -9.1E 0 (0) ( -2.6 - 5.6)E 1 ( -8.8 - 55.6)E 0 ( -1.8 - 0.3)E 1 (0/ 6) (0/ 3) (0/ 3)

Ag-108m (9) -4.7E -1 02 1.2E 0 2.2E -1 (0) ( -3.6 - 4.8)E 0 ( -7.1 - 48.2)E -1 ( -2.4 - 3.7)E 0 (0/ 6) (0/ 3) (0/ 3)

Ag-110m (9) -3.6E -1 06 4.2E 0 4.2E 0 (0) ( -4.0 - 4.9)E 0 ( 6.3 - 83.4)E -1 ( 6.3 - 83.4)E -1 (0/ 6) (0/ 3) (0/ 3)

Sb-124 (9) -1.4E 0 06 3.9E 0 3.9E 0 (0) ( -8.2 - 2.5)E 0 ( -1.3 - 6.8)E 0 ( -1.3 - 6.8)E 0 (0/ 6) (0/ 3) (0/ 3)

Sb-125 (9) -9.9E -1 06 2.2E 0 2.2E 0 (0) ( -7.4 - 7.3)E 0 ( -9.1 - 10.2)E 0 ( -9.1 - 10.2)E 0 (0/ 6) (0/ 3) (0/ 3)

I-131 (9) 60 3.3E 0 03 4.8E 0 -3.7E -1 (0) ( -8.1 - 81.0)E -1 ( 2.1 - 81.0)E -1 ( -4.9 - 2.1)E 0 (0/ 6) (0/ 3) (0/ 3)

Cs-134 (9) 60 3.5E 0 06 5.2E 0 5.2E 0 (0) ( -5.3 - 93.9)E -1 ( 2.7 - 7.9)E 0 ( 2.7 - 7.9)E 0 (0/ 6) (0/ 3) (0/ 3)

Cs-137 (9) 80 2.2E 0 02 3.3E 0 -8.7E -1 (0) ( -1.5 - 6.0)E 0 ( 1.5 - 6.0)E 0 ( -3.8 - 1.5)E 0 (0/ 6) (0/ 3) (0/ 3)

Ba-140 (9) 7.2E 0 03 1.5E 1 3.9E 0 (0) ( -5.8 - 26.4)E 0 ( -5.8 - 26.4)E 0 ( -1.5 - 2.3)E 1 (0/ 6) (0/ 3) (0/ 3)

La-140 (9) -2.5E 0 03 2.5E 0 -3.2E -1 (0) ( -1.0 - 0.4)E 1 ( 1.6 - 3.5)E 0 ( -9.0 - 5.0)E 0 (0/ 6) (0/ 3) (0/ 3)

Ce-141 (9) -2.1E 0 02 7.7E -1 -3.2E 0 (0) ( -1.3 - 0.4)E 1 ( -1.6 - 4.5)E 0 ( -4.6 - -2.3)E 0 (0/ 6) (0/ 3) (0/ 3)

Ce-144 (9) 6.6E 0 03 1.2E 1 -1.6E 1 (0) ( -4.5 - 215.0)E -1 ( 6.4 - 21.5)E 0 ( -4.2 - -0.1)E 1 (0/ 6) (0/ 3) (0/ 3)

Ac-228 (9) 5.0E 0 03 1.1E 1 -7.9E 0 (0) ( -1.6 - 2.9)E 1 ( -1.6 - 2.9)E 1 ( -1.2 - 0.0)E 1 (0/ 6) (0/ 3) (0/ 3)

Th-228 (9) -7.5E -2 03 3.2E 0 2.7E 0 (0) ( -8.9 - 6.9)E 0 ( 2.9 - 68.5)E -1 ( -1.7 - 7.3)E 0 (0/ 6) (0/ 3) (0/ 3)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

3.12 Vegetation In lieu of milk sampling, the ODCM, Table A.9.1-1, requires that broad leafy vegetation (TG) samples grown in the nearest of two different offsite locations with the highest D/Q, and from one control location 15-30 km distant in the least prevalent wind direction, be collected when available (growing season).

Offsite locations are defined in the UFSAR as the land beyond a 3000-foot radius of the two Containment Building centerlines. The analysis of garden locations in the Land Use Census provides a ranking of potential sampling sites for use in determining sampling locations in the general population. Since sampling of broad leaf garden vegetables at high D/Q locations is not feasible due to uncertain availability, other types of broad leafy vegetation were utilized.

Two locations at the site boundary with a maximum D/Q (higher values than determined in the 2021 Land Use Census garden listing) were selected over ranked D/Q gardens in the general population. These two Indicator locations (TG-08 and TG-09) are on site property in areas with available sample media. A third far-field control location (TG-10) was selected in Georgetown, MA. Samples consisted of tree leaves, as broad leaf vegetation provides increased reliability for sample availability. For 2021, a total of 15 monthly (growing season) broad leaf vegetation samples were collected and analyzed by gamma spectroscopy.

A gamma analysis was performed on each sample. Naturally-occurring Be-7 and K-40 were detected in all samples for both indicator and control stations. Cesium-137 was not detected in 2021, but has been detected in broad leafy vegetation in the past and evaluated as to the source. The conclusion of the assessment was that world-wide fallout from events un-related to Seabrook operations, such as the March 11, 2011 Fukushima Daiichi accident in Japan and past atmospheric nuclear weapons testing, have led to Cs-137 being deposited on the ground surface in the northeast United States with subsequent root uptake into leaves of long-lived vegetation. This conclusion continues to be supported by the fact that Seabrook Station had no detectable Cs-137 in any gaseous effluents in recent years, including 2021, and by the prevalence of detectable Cs-137 at the control location compared to in-close indicator sampling points. Utilizing the results of broad leaf vegetation sampling for broad leaf food products, it is concluded that there was no dose impact to the public or to the environment through this food ingestion pathway from Seabrook plant operations.

The following REMP Summary (Table 3.12-1) lists the range of analysis results by radionuclide for indicator and control stations for the broad leaf vegetation environmental media. Attachment 1 to this report lists the individual analysis results for each measurement of broad leaf vegetation under the Sample Type code TG.

Any sample collection and analysis deviations from the ODCM required program, or reportable concentrations that may have occurred during the year, are described in Section 5.

Table 3.12-1 Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Vegetation (TG) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Be-7 (15) 9.7E 2 10 1.2E 3 1.2E 3 (0) ( 3.4 - 22.4)E 2 ( 4.2 - 22.6)E 2 ( 4.2 - 22.6)E 2 (10/ 10) (5/ 5) (5/ 5)

K-40 (15) 4.4E 3 09 4.4E 3 4.2E 3 (0) ( 2.2 - 6.1)E 3 ( 2.4 - 6.1)E 3 ( 2.1 - 6.1)E 3 (10/ 10) (5/ 5) (5/ 5)

Cr-51 (15) -2.1E 0 10 6.6E 0 6.6E 0 (0) ( -5.1 - 10.4)E 1 ( -3.6 - 5.7)E 1 ( -3.6 - 5.7)E 1 (0/ 10) (0/ 5) (0/ 5)

Mn-54 (15) 1.1E 0 10 4.7E 0 4.7E 0 (0) ( -3.8 - 7.8)E 0 ( -4.4 - 25.3)E 0 ( -4.4 - 25.3)E 0 (0/ 10) (0/ 5) (0/ 5)

Co-57 (15) 1.3E 0 10 1.9E 0 1.9E 0 (0) ( -5.5 - 7.1)E 0 ( -4.0 - 14.3)E 0 ( -4.0 - 14.3)E 0 (0/ 10) (0/ 5) (0/ 5)

Co-58 (15) 4.0E 0 09 4.9E 0 3.5E 0 (0) ( -7.4 - 20.2)E 0 ( -7.4 - 20.2)E 0 ( -2.0 - 9.2)E 0 (0/ 10) (0/ 5) (0/ 5)

Fe-59 (15) 1.2E -1 09 4.1E 0 -1.5E 1 (0) ( -1.3 - 3.2)E 1 ( -1.3 - 3.2)E 1 ( -3.8 - 0.1)E 1 (0/ 10) (0/ 5) (0/ 5)

Co-60 (15) 2.7E 0 10 3.2E 0 3.2E 0 (0) ( -5.7 - 14.9)E 0 ( -4.0 - 58.4)E -1 ( -4.0 - 58.4)E -1 (0/ 10) (0/ 5) (0/ 5)

Zn-65 (15) -5.9E -1 10 8.3E 0 8.3E 0 (0) ( -2.2 - 1.5)E 1 ( -7.5 - 45.8)E 0 ( -7.5 - 45.8)E 0 (0/ 10) (0/ 5) (0/ 5)

Se-75 (15) 1.3E 0 10 5.0E 0 5.0E 0 (0) ( -1.4 - 1.2)E 1 ( -6.3 - 11.9)E 0 ( -6.3 - 11.9)E 0 (0/ 10) (0/ 5) (0/ 5)

Nb-95 (15) -1.3E 0 09 9.3E -1 -5.1E -1 (0) ( -9.0 - 9.0)E 0 ( -6.7 - 9.0)E 0 ( -1.2 - 1.4)E 1 (0/ 10) (0/ 5) (0/ 5)

Zr-95 (15) 1.9E 0 08 6.1E 0 -1.5E -1 (0) ( -1.0 - 1.3)E 1 ( -1.2 - 13.0)E 0 ( -6.5 - 10.2)E 0 (0/ 10) (0/ 5) (0/ 5)

Ru-103 (15) 4.8E -2 08 1.3E 0 -6.8E 0 (0) ( -6.5 - 4.9)E 0 ( -1.3 - 4.9)E 0 ( -1.5 - -0.3)E 1 (0/ 10) (0/ 5) (0/ 5)

Ru-106 (15) 1.2E -1 09 1.0E 1 -5.2E 1 (0) ( -9.9 - 12.4)E 1 ( -9.9 - 12.4)E 1 ( -1.4 - 0.0)E 2 (0/ 10) (0/ 5) (0/ 5)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

Table 3.12-1 (Continued)

Radiological Environmental Monitoring Program Summary Seabrook Nuclear Power Station, Seabrook, NH (January - December 2021)

MEDIUM: Vegetation (TG) UNITS: pCi/kg Indicator Stations Station With Highest Mean Control Stations Radionuclides Mean Station Mean Mean (No. Analyses) Required Range Range Range (Non-Routine*) LLD (No. Detected**) (No. Detected**) (No. Detected**)

Ag-108m (15) -3.2E 0 08 -1.2E 0 -1.3E 0 (0) ( -8.5 - 1.8)E 0 ( -3.9 - 1.8)E 0 ( -6.5 - 2.7)E 0 (0/ 10) (0/ 5) (0/ 5)

Ag-110m (15) -4.6E -1 10 5.7E -2 5.7E -2 (0) ( -9.7 - 11.5)E 0 ( -3.0 - 6.3)E 0 ( -3.0 - 6.3)E 0 (0/ 10) (0/ 5) (0/ 5)

Sb-124 (15) 4.6E 0 08 6.9E 0 5.3E 0 (0) ( -8.7 - 24.4)E 0 ( -6.8 - 24.4)E 0 ( -1.4 - 2.2)E 1 (0/ 10) (0/ 5) (0/ 5)

Sb-125 (15) 2.6E 0 08 6.7E 0 -2.2E 0 (0) ( -1.8 - 5.2)E 1 ( -1.8 - 5.2)E 1 ( -1.8 - 1.4)E 1 (0/ 10) (0/ 5) (0/ 5)

I-131 (15) 60 -3.8E 0 09 4.5E 0 -2.8E 0 (0) ( -3.2 - 1.6)E 1 ( -1.1 - 1.6)E 1 ( -8.4 - 6.8)E 0 (0/ 10) (0/ 5) (0/ 5)

Cs-134 (15) 60 4.2E 0 09 5.8E 0 -3.5E 0 (0) ( -8.5 - 24.1)E 0 ( -5.0 - 13.5)E 0 ( -1.2 - 0.3)E 1 (0/ 10) (0/ 5) (0/ 5)

Cs-137 (15) 80 1.0E 0 10 5.2E 0 5.2E 0 (0) ( -1.3 - 2.7)E 1 ( 0.0 - 2.3)E 1 ( 0.0 - 2.3)E 1 (0/ 10) (0/ 5) (0/ 5)

Ba-140 (15) 4.7E 0 09 1.1E 1 7.6E 0 (0) ( -5.6 - 4.5)E 1 ( -1.3 - 4.5)E 1 ( -1.8 - 3.0)E 1 (0/ 10) (0/ 5) (0/ 5)

La-140 (15) -3.6E 0 10 2.8E 0 2.8E 0 (0) ( -2.1 - 1.7)E 1 ( -4.2 - 11.2)E 0 ( -4.2 - 11.2)E 0 (0/ 10) (0/ 5) (0/ 5)

Ce-141 (15) -3.7E 0 10 1.5E 0 1.5E 0 (0) ( -1.9 - 0.7)E 1 ( -1.5 - 1.2)E 1 ( -1.5 - 1.2)E 1 (0/ 10) (0/ 5) (0/ 5)

Ce-144 (15) 1.1E 1 08 2.1E 1 -1.5E 1 (0) ( -2.8 - 6.2)E 1 ( -1.4 - 6.2)E 1 ( -5.9 - 1.2)E 1 (0/ 10) (0/ 5) (0/ 5)

Ac-228 (15) 1.8E 1 08 2.2E 1 6.3E 0 (0) ( -2.1 - 8.2)E 1 ( -9.7 - 81.7)E 0 ( -6.1 - 3.9)E 1 (0/ 10) (0/ 5) (0/ 5)

Th-228 (15) 6.2E 0 08 1.6E 1 8.3E 0 (0) ( -1.6 - 3.6)E 1 ( 8.8 - 363.0)E -1 ( -2.8 - 2.1)E 1 (0/ 10) (0/ 5) (0/ 5)

Non-Routine refers to those radionuclides that exceeded the Reporting Levels in ODCM Table A.9.1-3.

- The fraction of detectable measurements (i.e., > MDC with no uncertain identification) is shown in parentheses.

3.13 Direct Radiation Direct gamma radiation exposure was measured with thermoluminescent dosimeters (TLDs). Two TLD badges are placed at each of the designated monitoring stations. Each TLD badge has three CaSO4:Tm elements. The badges were collected and read on a quarterly schedule. A location result is an average of six independent readings per quarter. A total of forty-six stations are located offsite, thirty-seven of which are required by the ODCM.

The exposure rates were normalized to a standard 91-day quarter so that quarterly results from any monitoring location can be compared to another location based on an equivalent time period of exposure.

A summary of the 2021 data for the plant operational REMP is shown in Table 3.13-1. Figures 3.6 through 3.14 provide a comparison of quarterly TLD location responses in 2021 and illustrate the naturally variation in exposure rates quarter to quarter. Figures 3.6.1 through 3.14.1 provide a long term trend line for each of the environmental TLD locations.

The exposure rate response at individual monitoring stations have occasionally exhibited step changes at some point in the past that are related to changes in local conditions in the area of the dosimeter measurement. As an example, the outer ring TL-33 (a parking lot located 9.8 km south of the plant) was observed for several quarters during 2011 through 2016 to approach or exceed the normal expected environmental fluctuations based on observed history. The average TLD exposure rate from the 2nd quarter 2011 through the 4th quarter of 2013 is reported as 21.8 mR/quarter. For the seven prior quarters (3rd quarter 2009 to the 1st quarter 2011), the average TLD response was 18.6 mR/quarter, or approximately 17% lower than the most recent trend history. Since no other TLDs in the same sector or closer to the plant showed an average increase in measured response above the expected, the change at TL-33 was attributed to a local change in the background radiation associated with parking lot modifications and not with Seabrook Station operations. Field investigations of TL-33 indicated that the parking lot appeared to be re-graded with new fill/gravel material which could have increased the natural concentration of background radiation that the TLD measures. The expected background exposure level for location TL-33 was re-indexed to 20.6 mR/quarter in 2013 to reflect the observed change in background radiation. Three other locations (TL-01, TL-69 and TL-18) also indicated changes in background exposure rates trends over time (un-related to Seabrook operations) and had their expected background exposure levels re-indexed to 17.4 mR/quarter, 13.7 mR/quarter, and 16.3 mR/quarter respectively, in 2013 (for TL-01 and TL-69) and 2019 (for TL-18).

Overall, the REMP direct radiation program showed no statistically significant indication of increased direct radiation above the variable background measured exposure rate in unrestricted areas. This is demonstrated by the fact that indicator location results (as a group) are statistically the same as control locations. The 2021 annual mean of all indicator locations was 16.8 mR/91-day quarter while the mean of all control locations was 17.7 mR/91-day quarter. This indicates that collectively there is no statistical difference in the annual direct dose as a function of distance from the plant. As a result, no direct radiation dose beyond the site boundary was attributed to station operation during 2021.

Starting in 2015, a supplemental analytical method was implemented to evaluate the TLD measurements.

Using the method described in ANSI/HPS N13.37-2014, quarterly and annual baseline dose for each TLD location was determined using appropriate statistical analytical methods considering data from 2004 through 2014. Quarterly and annual dose for 2021 was compared to baseline values to determine if an Investigation Level had been exceeded for evaluation of potential dose to a member of the public. An Investigation Level is considered to be exceeded under the following conditions:

Quarterly: If MQ > (BQ + MDDQ), then FQ = MQ - BQ Where:

MQ is the normalized quarterly field measurement result BQ is the quarterly baseline background dose MDDQ is the quarterly minimum differential dose and FQ is the quarterly facility related dose Or: Annually: If MA > (BA + MDDA), then FA = MA - BA Where:

MA is the sum of the four normalized quarterly measurement values BA is the annual baseline background dose MDDA is the annual minimum differential dose FA is the annual facility related dose Table 3.13-3 summarizes the evaluation of the TLD measurements using the methodology described in ANSI/HPS N13.37-2014. As noted in Table 3.13-3, a quarterly dose of 8.0 mR and 7.3 mR was calculated for location TL-25 during the 1st and 2nd quarters of 2021 using the ANSI/HPS N13.37-2014 methodology and the baseline values calculated using data from 2004 to 2014. However, this dose was determined not to be facility related due to the distance of this TLD location with respect to the plant (7.6 km) and the lack of any observed dose for TLD locations closer to the plant. The observed dose is likely a result of a change in the environment at the TLD location. Figure 3.10.1 shows a step increase in the quarterly TLD values for this location starting in 2020. For this reason, the location will continue to be monitored and the quarterly and annual baseline values for this location will be adjusted, as necessary.

The direct radiation-monitoring program demonstrated that no increasing or decreasing trends were detected. Therefore, there was no offsite dose to the public or impact to the environment from the operation of the plant.

Any TLD collection and analysis deviations from the ODCM required program that may have occurred during the year are described in Section 5.

Table 3.13-1 Environmental TLD Measurements Net Exposure in mR/Standard Quarter (91 days) 2021 Qtr Sta. 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Ave.

No. Description Exp. S.D. Exp. S.D. Exp. S.D. Exp. S.D. Exp.

TL-01 Brimmer's Lane 17.9 + 0.7 19.2 + 0.9 17.9 + 0.8 20.1 + 0.9 18.8 TL-02 Landing Road 14.0 + 0.7 14.4 + 0.7 13.7 + 0.6 15.5 + 0.7 14.4 TL-03 Glade Path 15.2 + 0.6 14.9 + 0.7 14.2 + 0.6 15.5 + 0.6 15.0 TL-04 Island Path 15.4 + 0.9 16.3 + 0.9 15.3 + 0.8 17.3 + 0.7 16.1 TL-05 Harbor Road 15.2 + 0.6 15.0 + 0.6 14.3 + 0.7 16.3 + 0.9 15.2 TL-06 Barge Landing 14.2 + 0.7 14.7 + 0.8 13.8 + 0.6 15.8 + 0.8 14.6 TL-07 Cross Road 13.4 + 0.7 13.5 + 0.5 12.2 + 0.6 14.7 + 0.6 13.5 TL-08 Farm Lane 15.1 + 0.6 16.0 + 0.5 14.7 + 0.7 16.5 + 0.8 15.6 TL-09 Farm Lane 15.8 + 0.8 17.6 + 0.6 15.4 + 0.8 18.1 + 0.8 16.7 TL-10 Site Boundary 14.3 + 0.7 16.7 + 0.6 15.1 + 0.7 18.5 + 0.9 16.2 TL-11 Site Boundary 16.5 + 0.8 19.0 + 0.7 17.4 + 0.9 21.0 + 0.8 18.5 TL-12 Site Boundary 17.4 + 0.7 19.1 + 0.9 17.8 + 0.8 20.0 + 0.9 18.6 TL-13 Inside Site Boundary 17.7 + 1.1 19.6 + 0.9 18.0 + 0.8 20.6 + 0.9 19.0 TL-14 Trailer Park 15.8 + 0.7 16.6 + 0.8 15.5 + 0.7 17.8 + 1.0 16.4 TL-15 Brimmer's Lane 18.1 + 0.7 19.5 + 0.7 18.1 + 0.9 20.2 + 1.0 19.0 TL-16 Brimmer's Lane 16.5 + 0.9 17.4 + 0.7 16.3 + 0.7 18.9 + 0.9 17.3 TL-17 South Road 13.9 + 0.7 14.4 + 0.7 14.3 + 0.6 15.5 + 0.7 14.5 TL-18 Mill Road 17.4 + 0.7 18.0 + 0.7 17.5 + 0.8 19.6 + 0.8 18.1 TL-19 Appledore Avenue 15.1 + 0.7 15.3 + 0.7 14.9 + 0.7 17.0 + 0.7 15.6 TL-20 Ashworth Avenue 16.5 + 0.9 16.8 + 0.6 15.7 + 0.7 18.9 + 0.8 17.0 TL-21 Route 1A 17.8 + 0.9 18.5 + 0.8 17.7 + 0.8 19.8 + 0.7 18.5 TL-22 Cable Avenue 15.7 + 0.6 16.4 + 0.7 15.7 + 0.7 18.3 + 0.9 16.5 TL-23 Ferry Road 15.3 + 0.6 15.6 + 0.5 15.1 + 0.7 17.4 + 0.8 15.9 TL-24 Ferry Lots Lane 16.3 + 0.8 17.1 + 0.7 16.3 + 0.9 18.6 + 0.9 17.1 TL-25 Elm Street 23.6 + 1.0 22.9 + 0.8 (1) 19.5 + 0.9 22.0 TL-26 Route 107A 14.9 + 0.7 15.1 + 0.8 14.9 + 0.7 16.8 + 0.8 15.4 TL-27 Highland Street 16.1 + 0.9 16.3 + 0.7 16.0 + 0.9 19.9 + 0.7 17.1 TL-28 Route 150 17.0 + 0.7 17.5 + 0.8 16.5 + 1.1 19.6 + 0.8 17.7 TL-29 Frying Pan Lane 15.3 + 0.8 16.4 + 0.7 15.3 + 0.7 17.4 + 0.7 16.1 TL-30 Route 27 16.2 + 0.7 16.9 + 0.8 16.3 + 0.7 18.1 + 0.8 16.9 TL-31 Alumni Drive 13.9 + 0.6 14.8 + 0.6 13.9 + 0.8 15.6 + 0.8 14.6 TL-32 SB Elementary School 17.6 + 0.7 18.6 + 0.9 17.8 + 0.8 19.9 + 0.8 18.5 TL-33 Dock Area 11.8 + 0.9 11.7 + 0.6 11.4 + 0.8 12.8 + 0.7 11.9 TL-34 Bow Street 20.5 + 0.9 20.9 + 0.9 20.5 + 0.8 22.7 + 1.0 21.2 TL-35 Lincoln Ack. School 17.2 + 0.8 18.6 + 0.6 18.2 + 1.0 19.2 + 0.6 18.3 TL-36 Route 97(Control) 15.5 + 0.7 15.3 + 0.8 15.1 + 0.7 16.3 + 0.8 15.6 TL-37 Plaistow, NH (Control) 17.3 + 0.9 18.2 + 0.8 18.4 + 1.1 19.8 + 1.0 18.4 TL-38 Hampstead, NH (Control) 18.6 + 1.1 18.4 + 0.6 18.3 + 1.1 20.1 + 0.9 18.9 Table 3.13-1 (Continued)

Environmental TLD Measurements Net Exposure in mR/Standard Quarter (91 days) 2021 Qtr.

Sta. 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Ave.

No. Description Exp. S.D. Exp. S.D. Exp. S.D. Exp. S.D. Exp.

TL-39 Fremont, NH (Control) 20.8 + 0.9 21.3 + 0.6 20.1 + 1.1 22.7 + 0.9 21.2 TL-40 Newmarket, NH (Control) 16.1 + 0.8 17.5 + 0.5 17.7 + 0.9 19.3 + 0.9 17.7 TL-41 Portsmouth, NH (Control) 16.3 + 0.7 16.5 + 0.8 16.3 + 1.0 17.5 + 0.9 16.7 TL-42 Ipswich, MA (Control) 15.0 + 0.6 15.1 + 0.5 14.9 + 0.7 16.6 + 0.8 15.4 TL-44 SB Education Center 13.9 + 0.8 16.5 + 0.9 13.9 + 0.7 18.0 + 1.0 15.6 TL-45 Hampton Fire Station 15.0 + 1.0 17.0 + 1.0 16.0 + 0.9 18.4 + 1.1 16.6 TL-46 SB Police Station 16.4 + 0.8 17.1 + 0.6 16.4 + 1.0 18.4 + 0.9 17.1 TL-47 Route 84 16.5 + 0.9 17.1 + 0.9 16.3 + 0.9 18.8 + 0.9 17.2 Mean of Indicators 16.1 16.9 15.8 18.1 16.8 Mean of Controls 17.1 17.5 17.3 18.9 17.7 (1) TLD missing at time of collection.

Table 3.13-2 Pre-Operational Environmental TLD Measurements Net Exposure in mR/Standard Quarter (91 days)

Qtr Ave 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Over Yr Exp. Exp. Exp. Exp. Exp.

1982 Mean of Indicators -- 17.1 18.1 17.5 17.6 Mean of Controls -- 16.9 18.1 17.9 16.8 1983 Mean of Indicators 16.7 17.1 18.8 17.9 17.6 Mean of Controls 16.9 17.5 18.7 18.4 17.9 1984 Mean of Indicators 16.1 17.1 16.9 17.5 17.0 Mean of Controls 17.6 17.4 15.8 18.7 17.4 1985 Mean of Indicators 16.9 18.0 18.9 16.1 17.4 Mean of Controls 16.8 17.7 18.9 16.1 17.4 1986 Mean of Indicators 14.0 15.5 15.3 15.0 15.0 Mean of Controls 13.9 18.0 16.8 15.1 16.0 1987 Mean of Indicators 12.7 14.8 15.0 14.4 14.2 Mean of Controls 13.0 14.8 15.3 15.0 14.6 1988 Mean of Indicators 13.5 14.1 14.7 14.9 14.3 Mean of Controls 13.3 14.4 18.1 14.6 15.1 1989 Mean of Indicators 14.4 14.3 -- -- 14.4 Mean of Controls 14.0 14.4 -- -- 14.2 All Pre-Operational Mean of Indicators 14.9 16.0 16.8 16.2 15.9 Mean of Controls 15.1 16.4 17.4 16.5 16.2 Table 3.13-3 Facility Related Dose using ANSI/HPS N13.37-2014 Methodology Quarterly Ave. Quarterly Facility Dose Annual 2021 Annual Facility Dose Annual 2021 Quarterly Monitoring Data, Baseline, Baseline, TLD MQ (mR/qtr)

BQ FQ = MQ - (BQ+MDDQ) BA Data, MA FA = MA - (BA+MDDA) mR 1 2 3 4 1 2 3 4 mR mR TL-01 Brimmer's Lane 18.6 17.9 19.2 17.9 20.1 ND ND ND ND 74.5 75.1 ND TL-02 Landing Road 13.8 14.0 14.4 13.7 15.5 ND ND ND ND 55.1 57.6 ND TL-03 Glade Path 14.9 15.2 14.9 14.2 15.5 ND ND ND ND 59.5 59.9 ND TL-04 Island Path 15.9 15.4 16.3 15.3 17.3 ND ND ND ND 63.7 64.3 ND TL-05 Harbor Road 14.6 15.2 15.0 14.3 16.3 ND ND ND ND 58.1 60.9 ND TL-06 Barge Landing 14.6 14.2 14.7 13.8 15.8 ND ND ND ND 58.6 58.5 ND TL-07 Cross Road 12.5 13.4 13.5 12.2 14.7 ND ND ND ND 50.0 53.7 ND TL-08 Farm Lane 15.8 15.1 16.0 14.7 16.5 ND ND ND ND 63.1 62.3 ND TL-09 Farm Lane 16.3 15.8 17.6 15.4 18.1 ND ND ND ND 65.3 67.0 ND TL-10 Site Boundary 17.2 14.3 16.7 15.1 18.5 ND ND ND ND 68.7 64.7 ND TL-11 Site Boundary 17.5 16.5 19.0 17.4 21.0 ND ND ND ND 69.9 73.9 ND TL-12 Site Boundary 18.2 17.4 19.1 17.8 20.0 ND ND ND ND 72.6 74.2 ND TL-13 Inside Site Boundary 19.2 17.7 19.6 18.0 20.6 ND ND ND ND 77.0 76.0 ND TL-14 Trailer Park 15.9 15.8 16.6 15.5 17.8 ND ND ND ND 63.5 65.8 ND TL-15 Brimmer's Lane 18.8 18.1 19.5 18.1 20.2 ND ND ND ND 75.0 75.9 ND TL-16 Brimmer's Lane 16.2 16.5 17.4 16.3 18.9 ND ND ND ND 64.8 69.1 ND TL-17 South Road 16.3 13.9 14.4 14.3 15.5 ND ND ND ND 65.2 58.0 ND TL-18 Mill Road 15.5 17.4 18.0 17.5 19.6 ND ND ND ND 65.0 72.4 ND TL-19 Appledore Avenue 15.5 15.1 15.3 14.9 17.0 ND ND ND ND 62.1 62.3 ND TL-20 Ashworth Avenue 17.5 16.5 16.8 15.7 18.9 ND ND ND ND 70.2 67.9 ND TL-21 Route 1A 16.6 17.8 18.5 17.7 19.8 ND ND ND ND 66.3 73.8 ND TL-22 Cable Avenue 16.3 15.7 16.4 15.7 18.3 ND ND ND ND 65.4 66.1 ND TL-23 Ferry Road 15.7 15.3 15.6 15.1 17.4 ND ND ND ND 62.7 63.4 ND Table 3.13-3 (Continued)

Facility Related Dose using ANSI/HPS N13.37-2014 Methodology Annual Facility Quarterly Ave. Quarterly Facility Dose Annual 2021 Dose Annual 2021 Quarterly Monitoring Data, MQ Baseline Baseline TLD FA = MA -

(mR/qtr)

BQ FQ = MQ - (BQ+MDDQ) BA Data, MA (BA+MDDA) mR 1 2 3 4 1 2 3 4 mR mR TL-24 Ferry Lots Lane 16.0 16.3 17.1 16.3 18.6 ND ND ND ND 63.9 68.3 ND TL-25 Elm Street 15.6 23.6 22.9 (1) 19.5 8.0(2) 7.3(2) ND ND 62.3 66.1 14.61 TL-26 Route 107A 15.4 14.9 15.1 14.9 16.8 ND ND ND ND 61.8 61.6 ND TL-27 Highland Street 16.1 16.1 16.3 16.0 19.9 ND ND ND ND 64.3 68.3 ND TL-28 Route 150 16.2 17.0 17.5 16.5 19.6 ND ND ND ND 64.9 70.7 ND TL-29 Frying Pan Lane 15.4 15.3 16.4 15.3 17.4 ND ND ND ND 61.6 64.4 ND TL-30 Route 27 15.7 16.2 16.9 16.3 18.1 ND ND ND ND 62.9 67.6 ND TL-31 Alumni Drive 14.3 13.9 14.8 13.9 15.6 ND ND ND ND 57.0 58.1 ND TL-32 SB Elementary School 17.8 17.6 18.6 17.8 19.9 ND ND ND ND 71.2 73.9 ND TL-33 Dock Area 21.4 11.8 11.7 11.4 12.8 ND ND ND ND 84.4 47.7 ND TL-34 Bow Street 19.5 20.5 20.9 20.5 22.7 ND ND ND ND 78.2 84.6 ND TL-35 Lincoln Ack. School 18.2 17.2 18.6 18.2 19.2 ND ND ND ND 72.6 73.3 ND TL-36 Route 97(Control) 15.4 15.5 15.3 15.1 16.3 ND ND ND ND 61.9 62.2 ND TL-37 Plaistow, NH (Control) 18.0 17.3 18.2 18.4 19.8 ND ND ND ND 72.0 73.8 ND TL-38 Hampstead, NH (Control) 19.8 18.6 18.4 18.3 20.1 ND ND ND ND 79.3 75.4 ND TL-39 Fremont, NH (Control) 21.3 20.8 21.3 20.1 22.7 ND ND ND ND 85.2 84.8 ND TL-40 Newmarket, NH (Control) 16.7 16.1 17.5 17.7 19.3 ND ND ND ND 66.9 70.6 ND TL-41 Portsmouth, NH (Control) 16.9 16.3 16.5 16.3 17.5 ND ND ND ND 67.6 66.6 ND TL-42 Ipswich, MA (Control) 14.3 15.0 15.1 14.9 16.6 ND ND ND ND 57.2 61.6 ND TL-44 SB Education Center 14.8 13.9 16.5 13.9 18.0 ND ND ND ND 59.0 62.3 ND Table 3.13-3 (Continued)

Facility Related Dose using ANSI/HPS N13.37-2014 Methodology Annual Facility Quarterly Ave. Quarterly Facility Dose Annual 2021 Dose Annual 2021 Quarterly Monitoring Data, MQ Baseline Baseline TLD FA = MA -

(mR/qtr)

BQ FQ = MQ - (BQ+MDDQ) BA Data, MA (BA+MDDA) mR 1 2 3 4 1 2 3 4 mR mR Hampton Fire TL-45 Station 16.9 15.0 17.0 16.0 18.4 ND ND ND ND 67.7 66.4 ND TL-46 SB Police Station 16.7 16.4 17.1 16.4 18.4 ND ND ND ND 66.7 68.3 ND TL-47 Route 84 15.6 16.5 17.1 16.3 18.8 ND ND ND ND 62.4 68.7 ND MDDQ = 4.55 = minimum differential exposure, quarterly, 3 times 90th percentile S Q determined from analysis in mR.

MDDA = 8.97 = minimum differential exposure, annual, 3 times 90th percentile S A determined from analysis in mR.

BQ = Quarterly baseline exposure (mR).

MQ = location's 91 day standard quarterly exposure (mR).

LQ = Quarterly Investigative Level exposure (mR).

BA = Quarterly baseline background average exposure (mR).

MA = Annual monitoring data, determined by summing the quarterly data over all four quarters (mR).

LA = Annual Investigative Level exposure (mR).

ND = Facility contribution to exposure "Not Detected" (1) TLD missing at time of collection (2) A quarterly dose of 8.0 mR and 7.3 mR was calculated for location TL-25 for quarters 1 and 2 using the ANSI/HPS N13.37-2014 methodology and the baseline values calculated using data from 2004 to 2014. However, this dose was determined not to be facility related due to the distance of this TLD location with respect to the plant (7.6 km) and the lack of any observed dose for TLD locations closer to the plant. The observed dose is likely a result of a change in the environment at the TLD location. Figure 3.10.1 shows a step increase in the quarterly TLD values for this location starting in 2020. For this reason, the location will continue to be monitored and the quarterly and annual baseline values for this location will be adjusted, as necessary.

FIGURE 3.6 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs) SEABROOK STATION 40 40 30 30 mR per Quarter 20 20 10 10 0 0 Qtr. 1 Qtr. 2 Qtr. 3 Qtr. 4 2021 TL-01 Brimmer's Lane TL-02 Landing Road TL-03 Glade Path TL-04 Island Path TL-05 Harbor Road FIGURE 3.6.1 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATI ON

~

20 20 t"'

"':J 0

~

"'a.

a::

E 10 10 0 0 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 201 6 2018 2020 2022

~ TL-01 Brimmer's Lane

-e- TL-02 Landing Road

-...- TL-03 Glade Path

- - TL-04 Island Path

~ TL-05 Harbor Road FIGURE 3.7 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 40.0 40.0 30.0 30.0 mR per Quarter 20.0 20.0 10.0 10.0 0.0 0.0 Qtr-1 Qtr-2 Qtr-3 Qtr-4 2021 TL-06 Barge Landing TL-07 Cross Road TL-08 Farm Lane TL-09 Farm Lane TL-10 Site Boundary FIGURE 3.7.1 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 30 30 20 20 mR per Quarter 10 10 0 0 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 TL-06 Barge Landing TL-07 Cross Road TL-08 Farm Lane TL-09 Farm Lane TL-10 Site Boundary FIGURE 3.8 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 40 40 30 30 mR per Quarter 20 20 10 10 0 0 Qtr. 1 Qtr. 2 Qtr. 3 Qtr. 4 2021 TL-11 Site Boundary TL-12 Site Boundary TL-13 Inside Site Boundary TL-14 Trailer Park TL-15 Brimmer's Lane FIGURE 3.8.1 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 30 30 20 20 mR per Quarter 10 10 0 0 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 TL-11 Site Boundary TL-12 Site Boundary TL-13 Inside Site Boundary TL-14 Trailer Park TL-15 Brimmer's Lane FIGURE 3.9 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs) SEABROOK STATION 40 40 30 30 mR per Quarter 20 20 10 10 0 0 Qtr. 1 Qtr. 2 Qtr. 3 Qtr. 4 2021 TL-16 Brimmer's Lane TL-17 South Road TL-18 Mill Road TL-19 Appledore Avenue TL-20 Ashworth Avenue FIGURE 3.9.1 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs) SEABROOK STATION 30 30 20 20 mR per Quarter 10 10 0 0 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 TL-16 Brimmer's Lane TL-17 South Road TL-18 Mill Road TL-19 Appledore Avenue TL-20 Ashworth Avenue FIGURE 3.10 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 40 40 30 30 mR per Quarter 20 20 10 10 0 0 Qtr. 1 Qtr. 2 Qtr. 3 Qtr. 4 2021 TL-21 Route 1A TL-22 Cable Avenue TL-23 Ferry Road TL-24 Ferry Lots Lane TL-25 Elm Street FIGURE 3.10.1 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 30 30 20 20 mR per Quarter 10 10 0 0 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 TL-21 Route 1A TL-22 Cable Avenue TL-23 Ferry Road TL-24 Ferry Lots Lane TL-25 Elm Street FIGURE 3.11 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs) SEABROOK STATION 40 40 30 30 mR per Quarter 20 20 10 10 0 0 Qtr. 1 Qtr. 2 Qtr. 3 Qtr. 4 2021 TL-26 Route 107A TL-27 Highland Street TL-28 Route 150 TL-29 Frying Pan Lane TL-30 Route 27 FIGURE 3.11.1 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 30 30 20 20 mR per Quarter 10 10 0 0 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 TL-26 Route 107A TL-27 Highland Street TL-28 Route 150 TL-29 Frying Pan Lane TL-30 Route 27 FIGURE 3.12 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 40 40 30 30 mR per Quarter 20 20 10 10 0 0 Qtr. 1 Qtr. 2 Qtr. 3 Qtr. 4 2021 TL-31 Alumni Drive TL-32 SB Elementarty School TL-33 Dock Area TL-34 Bow Street TL-35 Lincoln Ackerman School FIGURE 3.12.1 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 30 30 20 20 mR per Quarter 10 10 0 0 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 TL-31 Alumni Drive TL-32 SB Elementary School TL-33 Dock Area TL-34 Bow Street TL-35 Lincoln Ackerman School FIGURE 3.13 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs) SEABROOK STATION 40 40 30 30 mR per Quarter 20 20 10 10 0 0 Qtr. 1 Qtr. 2 Qtr. 3 Qtr. 4 2021 TL-36 Route 97 (Control)

TL-37 Plaistow, NH (Control)

TL-38 Hampstead NH (Control)

TL-39 Fremont, NH (Control)

TL-40 Newmarket, NH (Control)

FIGURE 3.13.1 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 30 30 20 20 mR per Quarter 10 10 0 0 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 TL-36 Route 97 (Control)

TL-37 Plaistow, NH (Control)

TL-38 Hampstead NH (Control)

TL-39 Fremont, NH (Control)

TL-40 Newmarket, NH (Control)

FIGURE 3.14 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 40 40 30 30 mR per Quarter 20 20 10 10 0 0 Qtr. 1 Qtr. 2 Qtr. 3 Qtr. 4 2021 TL-41 Portsmouth, NH (Control)

TL-42 Ipswich, MA (Control)

TL-44 SB Education Center TL-45 Hampton Fire Station TL-46 SB Beach Police Station TL-47 Hampton Falls, Route 84 FIGURE 3.14.1 ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 30 30 20 20 mR per Quarter 10 10 0 0 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 TL-41 Portsmouth, NH (Control)

TL-42 Ipswich, MA (Control)

TL-43 Rocks Road Landing TL-44 SB Education Center TL-45 Hampton Fire Station TL-46 SB Beach Police Station TL-47 Hampton Falls, Route 84 4.0 Dry Fuel Storage REMP & Data Summary The Dry Fuel Storage (DFS) radiological environmental monitoring program required by ODCM Control C.9.4.1 provides representative measurements of direct (including scattered) radiation exposure at those locations that have the highest potential for dose to members of the public resulting from dry fuel storage operations. The design of the storage facility is such that there are no liquid or gaseous effluents released to the environment from DFS and, therefore, no associated exposure pathways for liquids and gases requiring the collection and analysis of such sample media. As a result, only direct (including scattered) radiation from the DFS modules need to be monitored for integrated exposures in areas where doses to members of the public need to be limited.

At locations near the DFS where members of the public might be present (off-site areas near the site boundary and on-site special use locations, i.e., the Science and Nature Center, the new Fitness Center located in the High Rise office building east of the DFS facility and the Firing Range located on the west site boundary), TLDs were placed at least 1 year (4 quarterly measurements) prior to used fuel being placed into storage. The DFS received its first load of fuel for storage on July 28, 2008. A total of 6 fuel canisters were placed in the NUHOMS© Horizontal Storage Modules (HSM) on the DFS pad during 2008 with the last one being loaded on September 4, 2008. A second fuel transfer campaign was conducted during August and September, 2013, with an additional 8 fuel canisters placed into storage, and a third fuel transfer campaign during August - October 2017 with an additional 8 fuel canisters bringing the total to 22 canisters in storage.

The DFS radiological environmental monitoring stations are listed in Table 4.0-1. At the end of 2013, TLD location SB-35, which was located inside the old Fitness Center, and location TL-67 (first quarter of 2014), which was located outside the old Fitness Center south of the DFS, were removed from the program due to the relocation of the fitness center to the High Rise Office Building. TLD locations SB-32 and SB-33 now provide monitoring for the new Fitness Center location. The measurement locations with respect to the Seabrook site area are shown on Figure 4.0.1.

4.1 Direct Radiation from DFS As with the plant operations TLD program described in Section 3.13, the DFS TLD exposure rates were normalized to a standard 91-day quarter. A summary of the 2021 data for the DFS REMP is shown in Table 4.1-1. Figures 4.1, 4.2 and 4.3 show the quarterly 2021 TLD trend lines for the control and indicator monitoring locations. Figures 4.4, 4.5 and 4.6 provide a comparison of long term trend lines (12 years) for the same control locations, site boundary and special use sites.

Overall, the direct radiation program showed no statistically significant indication of increased direct radiation above the variable background measured exposure rate in unrestricted areas. The 2021 annual mean of all indicator locations for the DFS was 17.5 mR/91-day quarter while the mean of all control locations was 17.7 mR/91-day quarter. There was no notable difference detected in the annual exposure rates in areas where members of the public could occupy (site boundary and inside special use locations) and the control locations. Starting in the 4th quarter of 2013, location TL-67 indicated a notable measurement increase in exposure rate following the expansion of fuel storage in the DFS facility in the third quarter of 2013. However, by late November 2013, the fitness center operations had been transferred from its original location south of the DFS to the High Rise Office Building east of the DFS, thereby ending use of the original fitness center facility and its parking lot by members of the public.

Starting in 2015, an additional analytical method was implemented to evaluate the TLD measurements.

Using the method described in ANSI/HPS N13.37-2014, quarterly and annual baseline dose for each DFS TLD location was determined using appropriate statistical analytical methods considering data from 2004 through 2014. Quarterly and annual dose for 2021 was compared to baseline values to determine if an Investigation Level had been exceeded for evaluation of potential dose to a member of the public. An Investigation Level is considered to be exceeded under the following conditions:

Quarterly: If MQ > (BQ + MDDQ), then FQ = MQ - BQ Where:

MQ is the normalized quarterly field measurement result BQ is the quarterly baseline background dose MDDQ is the quarterly minimum differential dose and FQ is the quarterly facility related dose or: Annually: If MA > (BA + MDDA), then FA = MA - BA Where:

MA is the sum of the four normalized quarterly measurement values BA is the annual baseline background dose MDDA is the annual minimum differential dose FA is the annual facility related dose Table 4.1-2 summarizes the evaluation of the TLD measurements using the methodology described in ANSI/HPS N13.37-2014. As noted in Table 4.1-2, TLD location SB-33 (High-Rise Building 1st floor, Fitness Center) was found to have a calculated annual facility related dose of 23.3 mR when comparing the measured TLD value against the annual baseline values. However, as this is an onsite fitness center under Station control, an annual occupancy factor for this location of 0.0416 (1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months per day x 7 days a week x 52 weeks per year / 8760 hours0.101 days 2.433 hours 0.0145 weeks 0.00333 months ) can be applied. This results in an annual dose of 1.0 mR.

Any sample collection and analysis deviations from the ODCM required program, or reportable concentrations that may have occurred during the year are described in Section 5.

Figure 4.0.1 Dry Fuel Storage TLD Environmental Monitoring Locations Table 4.0-1 Dry Fuel Storage (DFS) TLD Monitoring Locations TLD Sample Location Distance From Direction From Site Designation Code DFS Pad DFS Pad Description(3)

(km)

TL-44 On-site, outside Science & Nature Center (1)(2) 0.21 ESE SB-36 On-site, inside Science & Nature Center 0.24 SE SB-32 High-Rise Building, 3rd Floor(1) 0.23 E SB-33 High-Rise Building, 1st Floor (new Fitness Center)(1) 0.23 E TL-68 Nearby site boundary (firing range) to DFS 0.45 W TL-69 Nearby site boundary (Rocks Rd) to DFS 0.47 W TL-10 Site Boundary Fence (2) 0.77 S TL-11 Site Boundary Fence (2) 0.52 SSW TL-12 Site Boundary fence (2) 0.53 WSW TL-13 Inside Site Boundary (2) 0.61 WNW TL-14 Trailer Park, Seabrook (2) 0.94 NW TL-36 Rt 97, Georgetown (Control) (2) 22 SSW TL-37 Plaistow, NH (Control) (2) 21 WSW TL-38 Hampstead, NH (Control) (2) 27 W TL-39 Fremont, NH (Control) (2) 27 WNW TL-40 Newmarket, NH (Control) (2) 22 NNW TL-41 Portsmouth, NH (Control) (1)(2) 22 NNE TL-42 Ipswich, MA (Control) (1)(2) 22 SSE (1) This location is not part of the required DFS radiological monitoring program as defined in Table A.9.4-1 of the Seabrook ODCM.

(2) Shared environmental monitoring locations for both Seabrook Station REMP and DFS monitoring.

(3) TL-67 and SB-35 locations were removed in 2014 due to relocation of the Fitness Center to the High Rise office building.

Table 4.1-1 DFS Environmental TLD Measurements Net Exposures in mR/Standard Quarter (91 days) 2021 Sta. 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Qtr Ave No. Description Exp. S.D. Exp. S.D. Exp. S.D. Exp. S.D. Exp.

TL-44 Outside Science & Nature C.(1) 13.9 + 0.8 16.5 + 0.9 13.9 + 0.7 18.0 + 1.0 15.6 SB-36 Inside Science & Nature C. 16.4 + 0.6 17.1 + 0.9 16.5 + 0.8 18.7 + 1.2 17.2 SB-32 High-Rise 3rd Floor (1) 14.0 + 0.6 13.6 + 0.7 13.9 + 0.7 16.6 + 2.0 14.5 SB-33 High-Rise 1st Fl.(Fitness Cntr)(1) 22.8 + 0.7 22.3 + 0.9 22.4 + 0.8 24.9 + 1.6 23.1 TL-68 Nearby Site Boundary to DFS 17.6 + 1.2 18.1 + 0.8 17.7 + 0.8 19.4 + 0.9 18.2 TL-69 Nearby Site Boundary to DFS 14.2 + 0.8 14.5 + 0.7 14.1 + 1.0 16.3 + 0.7 14.8 TL-10 Site Boundary Fence (2) 14.3 + 0.7 16.7 + 0.6 15.1 + 0.7 18.5 + 0.9 16.2 TL-11 Site Boundary Fence (2) 16.5 + 0.8 19.0 + 0.7 17.4 + 0.9 21.0 + 0.8 18.5 TL-12 Site Boundary Fence (2) 17.4 + 0.7 19.1 + 0.9 17.8 + 0.8 20.0 + 0.9 18.6 TL-13 Inside Site Boundary (2) 17.7 + 1.1 19.6 + 0.9 18.0 + 0.8 20.6 + 0.9 19.0 TL-14 Trailer Park Seabrook (2) 15.8 + 0.7 16.6 + 0.8 15.5 + 0.7 17.8 + 1.0 16.4 TL-36 Rt 97, Georgetow n (control)(2) 15.5 + 0.7 15.3 + 0.8 15.1 + 0.7 16.3 + 0.8 15.6 TL-37 Plaistow , NH (Control)(2) 17.3 + 0.9 18.2 + 0.8 18.4 + 1.1 19.8 + 1.0 18.4 TL-38 Hampstead, NH (Control)(2) 18.6 + 1.1 18.4 + 0.6 18.3 + 1.1 20.1 + 0.9 18.9 TL-39 Fremont, NH (Control)(2) 20.8 + 0.9 21.3 + 0.6 20.1 + 1.1 22.7 + 0.9 21.2 TL-40 New market, NH (Control)(2) 16.1 + 0.8 17.5 + 0.5 17.7 + 0.9 19.3 + 0.9 17.7 TL-41 Portsmouth, NH (Control)(1)(2) 16.3 + 0.7 16.5 + 0.8 16.3 + 1.0 17.5 + 0.9 16.7 TL-42 Ipsw ich, MA (Control)(1)(2) 15.0 + 0.6 15.1 + 0.5 14.9 + 0.7 16.6 + 0.8 15.4 Mean of Indicators 16.4 17.6 16.6 19.3 17.5 Mean of Controls 17.1 17.5 17.3 18.9 17.7 (1) This location is not part of the DFS required program defined by the ODCM.

(2) Shared environmental monitoring locations for both plant REMP and DFS monitoring.

Table 4.1-2 DFS Facility Related Dose using ANSI/HPS N13.37-2014 Methodology Annual Quarterly 2021 Facility 2021 Quarterly Monitoring Ave. Annual Annual Dose Data, MQ (mR/qtr)

Baseline, Quarterly Facility Dose Baseline, TLD FA = MA -

BQ FQ = MQ - (BQ+MDDQ) BA Data, MA (BA+MDDA) mR 1 2 3 4 1 2 3 4 mR mR On-site, outside Science &

TL-44 Nature Center 14.8 13.9 16.5 13.9 18.0 ND ND ND ND 59.0 62.3 ND On-site, inside Science &

SB-36 Nature Center 16.2 16.4 17.1 16.5 18.7 ND ND ND ND 64.7 68.6 ND High-Rise Building, 3rd SB-32 floor 14.0 14.0 13.6 13.9 16.6 ND ND ND ND 55.7 58.1 ND High-Rise Building 1st SB-33 floor, Fitness Center 17.5 22.8 22.3 22.4 24.9 ND ND ND ND 69.2 92.5 23.3(1)

Nearby site boundary TL-68 (firing Range) 17.7 17.6 18.1 17.7 19.4 ND ND ND ND 70.8 72.8 ND Nearby site boundary TL-69 (Rocks Rd) 14.6 14.2 14.5 14.1 16.3 ND ND ND ND 58.2 59.0 ND TL-10 Site Boundary 17.2 14.3 16.7 15.1 18.5 ND ND ND ND 68.7 64.7 ND TL-11 Site Boundary 17.5 16.5 19.0 17.4 21.0 ND ND ND ND 69.9 73.9 ND TL-12 Site Boundary 18.2 17.4 19.1 17.8 20.0 ND ND ND ND 72.6 74.2 ND TL-13 Inside Site Boundary 19.2 17.7 19.6 18.0 20.6 ND ND ND ND 77.0 76.0 ND TL-14 Trailer Park 15.9 15.8 16.6 15.5 17.8 ND ND ND ND 63.5 65.8 ND TL-36 Route 97(Control) 15.4 15.5 15.3 15.1 16.3 ND ND ND ND 61.9 62.2 ND TL-37 Plaistow, NH (Control) 18.0 17.3 18.2 18.4 19.8 ND ND ND ND 72.0 73.8 ND TL-38 Hampstead, NH (Control) 19.8 18.6 18.4 18.3 20.1 ND ND ND ND 79.3 75.4 ND TL-39 Fremont, NH (Control) 21.3 20.8 21.3 20.1 22.7 ND ND ND ND 85.2 84.8 ND TL-40 Newmarket, NH (Control) 16.7 16.1 17.5 17.7 19.3 ND ND ND ND 66.9 70.6 ND TL-41 Portsmouth, NH (Control) 16.9 16.3 16.5 16.3 17.5 ND ND ND ND 67.6 66.6 ND TL-42 Ipswich, MA (Control) 14.3 15.0 15.1 14.9 16.6 ND ND ND ND 57.2 61.6 ND

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Table 4.1-2 (contd)

DFS Facility Related Dose using ANSI/HPS N13.37-2014 Methodology MDDQ = 4.48 = minimum differential exposure, quarterly, 3 times 90th percentile S Q determined from analysis in mR.

MDDA = 10.17 = minimum differential exposure, annual, 3 times 90th percentile S A determined from analysis in mR.

BQ = Quarterly baseline exposure (mR).

MQ = location's 91 day standard quarterly exposure (mR).

LQ = Quarterly Investigative Level exposure (mR).

BA = Quarterly baseline background average exposure (mR).

MA = Annual monitoring data, determined by summing the quarterly data over all four quarters (mR).

LA = Annual Investigative Level exposure (mR).

ND = Facility contribution to exposure "Not Detected" 1 Note that this location is a fitness center and is not occupied full time. Applying an annual occupancy factor for this location of 0.0416 (1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months per day x 7 days a week x 52 weeks per year / 8760 hours0.101 days 2.433 hours 0.0145 weeks 0.00333 months ), results in an annual dose of 1.0 mR.

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FIGURE 4.1 DFS CONTROL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 40 40 30 30 mR per Quarter 20 20 10 10 0 0 Qtr. 1 Qtr. 2 Qtr. 3 Qtr. 4 2021 TL-41 Portsmouth, NH (Control)

TL-42 Ipswich, MA (Control)

TL-36 Route 97 (Control)

TL-37 Plaistow, NH (Control)

TL-38 Hampstead NH (Control)

TL-39 Fremont, NH (Control)

Control Average 7 stations TL-40 Newmarket, NH (Control)

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FIGURE 4.2 DFS ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 40.0 40 30.0 30 mR per Quarter 20.0 20 10.0 10 0.0 0 Qtr. 1 Qtr. 2 Qtr. 3 Qtr. 4 2021 TL-10 Site Boundary Fence TL-12 Site Boundary Fence TL-13 Inside Site Boundary TL-14 Trailer Park Control Average 7 stations TL-11 Site Boundary Fence

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FIGURE 4.3 DFS ENVIRONMENTAL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 40 40 30 30 mR per Quarter 20 20 10 10 0 0 Qtr. 1 Qtr. 2 Qtr. 3 Qtr. 4 2021 TL-44 Outside Science & Nature Center SB-36 Inside Science & Nature Center TL-68 Near Site Boundary to DFS TL-69 Near Site Boundary to DFS Control Average 7 stations SB-32 High-Rise 3rd Fl.

SB-33 High-Rise 1st Fl. (new Fitness Cntr.)

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FIGURE 4.4 DFS CONTROL RADIATION MEASUREMENTS (USING TLDs)

SEABROOK STATION 30 30 First DFS loading, July 2008 20 20 mR per Quarter 10 10 2nd DFS loading, Completed Sept. 3rd DFS loading, 2013 Completed Oct.

2017 0 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 years TL-41 Portsmouth, NH (Control)

TL-42 Ipswich, MA (Control)

TL-36 Route 97 (Control)

TL-37 Plaistow, NH (Control)

TL-38 Hampstead NH (Control)

TL-39 Fremont, NH (Control)

Control Average 7 stations TL-40 Newmarket, NH (Control)

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FIGURE 4.5 DFS RADIATION MEASUREMENTS TRENDS (USING TLDs)

SEABROOK STATION 30 First DFS loading, 30 July 2008 20 20 mR per Quarter 10 10 2nd DFS loading, Completed 3rd DFS loading, Completed Oct.

2017 0 0 2000200120022003200420052006200720082009201020112012201320142015201620172018201920202021 years TL-10 Site Boundary Fence TL-11 Site Boundary Fence TL-12 Site Boundary Fence TL-13 Inside Site Boundary TL-14 Trailer Park TL-39 Fremont, NH (Control)

Control Average 7 stations TL-40 Newmarket, NH (Control)

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FIGURE 4.6 DFS RADIATION MEASUREMENTS TRENDS (USING TLDs)

SEABROOK STATION 30 30 First DFS loading, July 2008 20 20 mR per Quarter 10 10 2nd DFS loading, 3rd DFS loading, Completed Sept. Completed 2013 Oct. 2017 0 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 years TL-44 Outside Science & Nature Center SB-36 Inside Science & Nature Center TL-67 Outside Old Fitness Center SB-35 Inside Old Fitness Center TL-68 Near Site Boundary to DFS TL-69 Near Site Boundary to DFS Control Average 7 stations TL-40 Newmarket, NH (Control)

TL-39 Fremont, NH (Control) SB-32 High-Rise 3rd Fl.

SB-33 High-Rise 1st Fl. (new Fitness Cntr.)

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5.0 Program Deviations and Reporting 5.1 Sampling Program Deviations Table A.9.1-1 of the Offsite Dose Calculation Manual (ODCM) allows for deviations in the REMP sampling schedule "if specimens are unobtainable due to circumstances such as hazardous conditions, seasonal unavailability and malfunction of automatic sampling equipment." All deviations from the sampling schedule shall be documented each year in the Radiological Environmental Operating Report. The deviations for 2021 are as follows:

On February 17, 2021, the REMP air sampling stations in Exeter/Hampton (AP/CF-08), the Rock Pile (AP/CF-03), and Barge Landing (AP/CF-01) lost AC power. The out of service time did not impact the ability to collect sufficient sample volume over the collection cycle for this analysis. AR 02384329 was written to document and track this issue.

On March 2, 2021, the REMP air sampling stations in Exeter/Hampton (AP/CF-08), and Barge Landing (AP/CF-01) lost AC power. The out of service time did not impact the ability to collect sufficient sample volume over the collection cycle for this analysis. AR 02385673 was written to document and track this issue.

The REMP milk sample was not obtained for February due to difficulty obtaining formaldehyde from the manufacturer. The formaldehyde was ordered in January, but the package was damaged during delivery and had to be reordered. AR 02385897 was written to document and track this issue.

On May 15, 2021, the REMP air sampling station in the plateyard (AP/CF-04) lost AC power. The out of service time did not impact the ability to collect sufficient sample volume over the collection cycle for this analysis. AR 02393369 was written to document and track this issue.

On May 28, 2021, the REMP air sampling stations in Exeter/Hampton (AP/CF-08), the Rock Pile (AP/CF-03), and Barge Landing (AP/CF-01) lost AC power. The out of service time did not impact the ability to collect sufficient sample volume over the collection cycle for this analysis. AR 02394442 was written to document and track this issue.

On July 23, 2021, the REMP air sampling station in the plateyard (AP/CF-04) lost AC power. The out of service time did not impact the ability to collect sufficient sample volume over the collection cycle for this analysis. AR 02399303 was written to document and track this issue.

On September 18, 2021, the REMP air sampler station at the Hampton Marina (AP/CF-02) lost AC power. The out of service time did not impact the ability to collect sufficient sample volume over the collection cycle for this analysis. AR 02404533 was written to document and track this issue.

The third quarter TLD TL-25 (Elm Street Amesbury, MA) was found to be missing. AR 02405925 was written to document and track this issue.

5.2 Comparison of Achieved LLDs with Requirements Table A.9.1-2 of the ODCM indicates the required Lower Limits of Detection (LLDs) for environmental sample analyses. (This table is duplicated in Table 5.2-1 of this report.) Occasionally an LLD for short-lived radionuclides is not achieved due to low sample volume or delays between sample collection and time of analysis. In such cases, ODCM Table A.9.1-2 requires a discussion of the event in the annual Radiological Environmental Operating Report.

For each analysis having an LLD requirement in ODCM Table A.9.1-2, the a posteriori (after the fact)

Minimum Detectable Concentration (MDC) calculated for that analysis was compared with the required LLD. During 2021, 1422 analyses had an LLD requirement listed in Table 5.2-1, and in all cases except four (one missed LLD for I-131 in milk, three missed LLDs for Ba-140 in surface water), the LLD requirements were met.

For the missed LLDs, the following explanations are provided:

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LSN 550014001 (missed LLD for I-131 in milk) - Due to the short half-life of the isotope being analyzed.

LSN 565202001 and 565202002 (missed LLD for Ba-140 in surface water) - Due to short half-life of the isotope being analyzed.

LSN 548321002 (missed LLD for Ba-140 in surface water) - Due to short half-life of the isotope being analyzed.

The issue has been added into the laboratory NCR system for communication within the lab and process improvement.

5.3 Comparison of Results against Reporting Levels Seabrook Station ODCM Section 10.1 requires the notification of the NRC by special report within 30 days of receipt from the environmental laboratory whenever a Reporting Level in Table 5.3-1 is exceeded.

Reporting Levels are the environmental concentrations that relate to the ALARA design dose objectives of 10 CFR 50, Appendix I. It should be noted that environmental concentrations are averaged over calendar quarters for the purposes of this comparison, and that Reporting Levels apply only to measured levels of radioactivity due to plant effluents. During 2021, no Reporting Levels were exceeded.

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Table 5.2-1 DETECTION CAPABILITIES FOR ENVIRONMENTAL SAMPLE ANALYSISa Lower Limit of Detection (LLD)

Fish and Water Airborne Particulate or Invertebrates Milk Food Products Sediment Analysis (pCi/kg) Gas (pCi/m3) (pCi/kg, wet) (pCi/kg) (pCi/kg, wet) (pCi/kg, dry)

Gross Beta 4 0.01 H-3 3,000 Mn-54 15 130 Fe-59 30 260 Co-58, 60 15 130 Zn-65 30 260 Zr-Nb-95 15c I-131 15 0.07 1 60b Cs-134 15 0.05 130 15 60 150 Cs-137 18 0.06 150 18 80 180 Ba-La-140 15c 15

a. Reference Seabrook Station ODCM, Table A.9.1-2 for clarifications.

b. Broad leaf vegetation only.

c. Parent only.

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Table 5.3-1 REPORTING LEVELS FOR RADIOACTIVITY CONCENTRATIONS IN ENVIRONMENTAL SAMPLESa Analysis Water Airborne Particulate or Gas Fish and Milk Food Products (pCi/kg) (pCi/m3) Invertebrates (pCi/kg) (pCi/kg, wet)

(pCi/kg, wet)

H-3 30,000 Mn-54 1,000 30,000 Fe-59 400 10,000 Co-58 1,000 30,000 Co-60 300 10,000 Zn-65 300 20,000 Zr-Nb-95 400 I-131 100 0.9 3 100b Cs-134 30 10 1,000 60 1,000 Cs-137 50 20 2,000 70 2,000 Ba-La-140 200 300

a. Reference Seabrook Station ODCM Table A.9.1-3 for clarifications.

b. Broad leaf vegetation only.

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6.0 QUALITY ASSURANCE PROGRAM 6.1 GEL Laboratories QA GELs primary goals are to ensure that all measurement data generated are scientifically and legally defensible, of known and acceptable quality per the data quality objectives (DQOs), and thoroughly documented to provide sound support for environmental decisions. In addition, GEL continues to ensure compliance with all contractual requirements, environmental standards, and regulations established by local, state and federal authorities.

GEL administers the QA program in accordance with their Quality Assurance Plan, GL-QS-B-001. The Quality Systems include all quality assurance (QA) policies and quality control (QC) procedures necessary to plan, implement, and assess the work that GEL performs. GELs QA Program establishes a quality management system (QMS) that governs all of the activities of the organization.

The results of GELs assessment of their laboratory activities listed in this section entails their quality assurance program for the proficiency testing (PT) and environmental monitoring aspects of GEL for 2021. GELs QA Program is designed to monitor the quality of analytical processing associated with environmental, radiobioassay, effluent (10 CFR Part 50), and waste (10 CFR Part 61) sample analysis.

This summary was extracted from GEL Laboratories report entitled 2021 Annual Quality Assurance Report for the Radiological Environmental Monitoring Program (REMP), dated March 1, 2022, and includes:

Intra-laboratory QC results analyzed during 2021.

Inter-laboratory QC results analyzed during 2021 where known values were available.

Quality Assurance Programs for Inter-laboratory, Intra-laboratory and Third Party Cross Check In addition to internal and client audits, GELs laboratory participates in annual performance evaluation studies conducted by independent providers. GEL routinely participates in the following types of performance audits:

Proficiency testing and other inter-laboratory comparisons

Performance requirements necessary to retain Certifications

Evaluation of recoveries of certified reference and in-house secondary reference materials using statistical process control data.

Evaluation of relative percent difference between measurements through statistical process control (SPC) data.

GEL also participate in a number of proficiency testing programs for federal and state agencies and as required by contracts. It is GELs policy that no proficiency evaluation samples be analyzed in any special manner. GELs annual performance evaluation participation generally includes a combination of studies that support the following:

US Environmental Protection Agency (EPA) Discharge Monitoring Report, Quality Assurance Program (DMR-QA) - An annual national program sponsored by the EPA for laboratories engaged in the analysis of samples associated with the NPDES monitoring program. Participation is mandatory for all holders of NPDES permits. The permit holder must analyze for all of the parameters listed on the discharge permit. Parameters include general chemistry, metals, BOD/COD, oil and grease, ammonia, nitrates, etc.

Department of Energy (DOE) Mixed Analyte Performance Evaluation Program (MAPEP) - A semiannual program developed by DOE in support of DOE contractors performing waste

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analyses. Participation is required for all laboratories that perform environmental analytical measurements in support of environmental management activities. This program includes radioactive isotopes in water, soil, vegetation and air filters.

ERAs MRAD-Multimedia Radiochemistry Proficiency test program - This program is for labs seeking certification for radionuclides in wastewater and solid waste. The program is conducted in strict compliance with USEPA National Standards for Water Proficiency study.

ERAs InterLab RadChem Proficiency Testing Program for radiological analyses - This program completes the process of replacing the USEPA EMSL-LV Nuclear Radiation Assessment Division program discontinued in 1998. Laboratories seeking certification for radionuclide analysis in drinking water also use the study. This program is conducted in strict compliance with the USEPA National Standards for Water Proficiency Testing Studies. This program encompasses Uranium by EPA method 200.8 (for drinking water certification in Utah/Primary NELAP), gamma emitters, Gross Alpha/Beta, Iodine-131, naturally-occurring radioactive isotopes, Strontium-89/90, and Tritium.

ERAs Water Pollution (WP) biannual program for waste methodologies, which includes parameters for both organic and inorganic analytes.

ERAs Water Supply (WS) biannual program for drinking water methodologies, which includes parameters for organic and inorganic analytes.

Environmental Cross-Check Program administered by Eckert & Ziegler Analytics, Inc. - This program encompasses radionuclides in water, soil, milk, naturally-occurring radioactive isotopes in soil and air filters.

GEL procures single-blind performance evaluation samples from Eckert & Ziegler Analytics to verify the analysis of sample matrices processed at GEL. Samples are received on a quarterly basis. GELs Third-Party Cross-Check Program provides environmental matrices encountered in a typical nuclear utility REMP. The Third-Party Cross-Check Program is intended to meet or exceed the inter-laboratory comparison program requirements discussed in NRC Regulatory Guide 4.15. Once performance evaluation samples have been prepared in accordance with the instructions provided by the program test (PT) provider, samples are managed and analyzed in the same manner as environmental samples from GELs clients.

Quality Assurance Program for Internal and External Audits During each annual reporting period, at least one internal assessment of each area of the laboratory is conducted in accordance with the pre-established schedule from Standard Operating Procedure for the Conduct of Quality Audits, GL-QS-E-001. The annual internal audit plan is reviewed for adequacy and includes the scheduled frequency and scope of quality control actions necessary to GELs QA program.

Internal audits are conducted at least annually in accordance with a schedule approved by the Quality Systems Director. Supplier audits are contingent upon the categorization of the supplier, and may or may not be conducted prior to the use of a supplier or subcontractor. Type I suppliers and subcontractors, regardless of how they were initially qualified, are re-evaluated at least once every three years.

In addition, prospective customers audit GEL during pre-contract audits. GEL hosts several external audits each year for both our clients and other programs. These programs include environmental monitoring, waste characterization, and radiobioassay. The following list of programs may audit GEL at least annually or up to every three years depending on the program.

TNI, The NELAC Institute, National Environmental Laboratory Accreditation Program (NELAP)

DOECAP, U.S. Department of Energy Consolidated Audit Program

DOELAP, U.S. Department of Energy Laboratory Accreditation Program

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DOE QSAS, U.S. Department of Energy, Quality Systems for Analytical Services

ISO/IEC 17025:2005

A2LA, American Association for Laboratory Accreditation

DOD ELAP, US Department of Defense Environmental Accreditation Program

NUPIC, Nuclear Procurement Issues Committee

South Carolina Department of Health and Environmental Control (SC DHEC)

The annual radiochemistry laboratory internal audit (20-RAD-001) was conducted in June, 2021. There were no findings or observations, and four recommendations for improvements from this assessment.

Performance Evaluation Acceptance Criteria for Environmental Sample Analysis GEL utilized an acceptance protocol based upon two performance models. For those inter-laboratory programs that already have established performance criteria for bias (i.e., MAPEP, and ERA/ELAP), GEL will utilize the criteria for the specific program. For intra-laboratory or third party quality control programs that do not have a specific acceptance criteria (i.e. the Eckert-Ziegler Analytics Environmental Cross-check Program), results will be evaluated in accordance with GELs internal acceptance criteria.

Performance Evaluation Samples Performance Evaluation (PE) results and internal quality control sample results are evaluated in accordance with GEL acceptance criteria. The first criterion concerns bias, which is defined as the deviation of any one result from the known value. The second criterion concerns precision, which deals with the ability of the measurement to be replicated by comparison of an individual result with the mean of all results for a given sample set.

GEL also evaluates its analytical performance on a regular basis through statistical process control (SPC) acceptance criteria. Where feasible, this criterion is applied to both measures of precision and accuracy and is specific to sample matrix. GEL establishes environmental process control limits at least annually.

For Radiochemistry analysis, quality control evaluation is based on static limits rather than those that are statistically derived. Current process control limits are maintained in GELs AlphaLIMS. GEL also measures precision with matrix duplicates and/or matrix spike duplicates. The upper and lower control limits (UCL and LCL respectively) for precision are plus or minus three times the standard deviation from the mean of a series of relative percent differences. The static precision criteria for radiochemical analyses are 0 - 20%, for activity levels exceeding the contract required detection limit (CRDL).

Quality Control Program for Environmental Sample Analysis GELs internal QA Program is designed to include QC functions such as instrumentation calibration checks (to insure proper instrument response), blank samples, instrumentation backgrounds, duplicates, as well as overall staff qualification analyses and statistical process controls. Both quality control and qualification analyses samples are used to be as similar as the matrix type of those samples submitted for analysis by the various laboratory clients. These performance test samples (or performance evaluation samples) are either actual samples submitted in duplicate in order to evaluate the precision of laboratory measurements, or fortified blank samples, which have been given a known quantity of a radioisotope that is in the interest to GELs clients.

Accuracy (or Bias) is measured through laboratory control samples and/or matrix spikes, as well as surrogates and internal standards. The UCLs and LCLs for accuracy are plus or minus three times the standard deviation from the mean of a series of recoveries. The static limit for radiochemical analyses is 75 - 125%. Specific instructions for out-of-control situations are provided in the applicable analytical SOP.

GELs Laboratory Control Standard (LCS) is an aliquot of reagent water or other blank matrix to which known quantities of the method analytes are added in the laboratory. The LCS is analyzed exactly like a

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sample, and its purpose is to determine whether the methodology is in control, and whether the laboratory is capable of making accurate and precise measurements. Some methods may refer to these samples as Laboratory Fortified Blanks (LFB). The requirement for recovery is between 75 and 125% for radiological analyses excluding drinking water matrix.

Bias (%) = (observed concentration)

100 %

(known concentration)

Precision is a data quality indicator of the agreement between measurements of the same property, obtained under similar conditions, and how well they conform to themselves. Precision is usually expressed as standard deviation, variance or range in either absolute or relative (percentage) terms.

GELs laboratory duplicate (DUP or LCSD) is an aliquot of a sample taken from the same container and processed in the same manner under identical laboratory conditions. The aliquot is analyzed independently from the parent sample and the results are compared to measure precision and accuracy.

If a sample duplicate is analyzed, it will be reported as Relative Percent Difference (RPD). The RPD must be 20 percent or less, if both samples are greater than 5 times the MDC. If both results are less than 5 times MDC, then the RPD must be equal to or less than 100%. If one result is above the MDC and the other is below the MDC, then the RPD can be calculated using the MDC for the result of the one below the MDC. The RPD must be 100% or less. In the situation where both results are above the MDC but one result is greater than 5 times the MDC and the other is less than 5 times the MDC, the RPD must be less than or equal to 20%. If both results are below MDC, then the limits on % RPD are not applicable.

Difference (%) = (high duplicate result - low duplicate result)

100 %

(average of results)

Summary of Data Results During 2021, forty-five (45) radioisotopes associated with seven (7) matrix types were analyzed under GELs Performance Evaluation program in participation with ERA, MAPEP, and Eckert & Ziegler Analytics. Matrix types were representative of client analyses performed during 2021. Of the four hundred thirty-three (433) total results reported, 96.5% (418 of 433) were found to be acceptable. The list below contains the type of matrix evaluated by GEL.

Air Filter

Cartridge

Water

Milk

Soil

Liquid

Vegetation A summary list of all Inter-laboratory radiological proficiency test results and their evaluation against their acceptance criteria is provided in Table 6.1-1. This list reflects GELs participation in the MAPEP Monitoring Program, the ERA MRaD PT Program, the ERA PT Program, and the Eckert & Ziegler Analytics Environmental Cross-Check Program.

Summaries of GELs Intra-laboratory test result for bias and precision by sample matrix are provided in Table 6.1-3 (REMP Related) and Table 6.1-4 (All Samples).

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Summary of Participation in the Eckert & Ziegler Analytics Environmental Cross-Check Program Eckert & Ziegler Analytics provided samples for one hundred thirty (89) individual environmental analyses. The accuracy of each result reported to Eckert & Ziegler Analytics, Inc. is measured by the ratio of GELs result to the known value. All results fell within GELs acceptance criteria (100%). Table 6.1-2 list the results specific to the Eckert & Ziegler Analytics sample provided in 2021. No corrective action reports were noted for these results.

Summary of Participation in the MAPEP Monitoring Program MAPEP Series 44 and 45 were analyzed by the laboratory. Of the one hundred thirty (130) analyses, 96.1% (125 out of 130) of all results fell within the PT providers acceptance criteria. Three isotope failures occurred in Series 44: Antimony, Cesium-134, and Strontium-90. Five isotope failures occurred in Series 45: Gross Alpha, Uranium-234, Neptunium-237, Radium-226, and Strontium-90.

For the corrective actions associated with MAPEP Series 44 and 45, refer to corrective actions CARR 210723-1339 and CARR 211216-1360, respectively (Table 6.1-5).

Summary of Participation in the ERA MRaD PT Program The ERA MRad program provided samples (MRAD-34 and MRAD-35) for one hundred seventy-one (171) individual environmental analyses. One hundred sixty-six (166) of the 171 analyses fell within the PT providers acceptance criteria (97.1%). Three isotope failures occurred in MRAD-34: Gross Alpha in air filter, Gross Alpha in water, and Iron-55 in water. Two isotope failures occurred in MRAD-35: Uranium-234 in air filter and Uranium-234 in water.

For the corrective actions associated with MRAD 34 and MRAD 35, refer to corrective actions CARR 210603-1329 and CARR 211215-1358, respectively (Table 6.1-5).

Summary of Participation in the ERA PT Program The ERA program provided samples (RAD-124, RAD-125, RAD-126, RAD-127) for forty-three (43) individual environmental analyses. Of the 43 analyses, 88.4% (38 out of 43) of all results fell within the PT providers acceptance criteria. Three isotope failures occurred in RAD-124: Radium-226, Radium-228, and Strontium-89 in water. One failure occurred in RAD-125: Radium-226 in water. One failure occurred in RAD-126: Strontium-90 in water.

For the corrective actions associated with RAD-124, RAD-125, and RAD-126, refer to corrective actions CARR 210311-1305, CARR 210524-1327 and CARR210830-1343, respectively (Table 6.1-5).

Corrective Action Request and Report (CARR)

There are two categories of corrective action at GEL. One is corrective action implemented at the analytical and data review level in accordance with the analytical standard operating procedures (SOP).

The other is formal corrective action documented by the Quality Systems Team in accordance with GELs standard operating procedure GL-QS-E-002. A formal corrective action is initiated when a nonconformance reoccurs or is so significant that permanent elimination or prevention of the problem is required. Formal corrective action investigations include root cause analysis.

GEL includes quality requirements in most analytical standard operating procedures to ensure that data are reported only if the quality control criteria are met or the quality control measures that did not meet the acceptance criteria are documented. A formal corrective action is implemented according to GELs standard operating procedure GL-QS-E-002 for Conducting Corrective/Preventive Action and Identifying Opportunities for Improvement. Recording and documentation is performed following guidelines stated in GELs standard operating procedure GL-QS-E-012 for Client NCR Database Operation.

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Any employee at GEL can identify and report a nonconformance and request that corrective action be taken. Any GEL employee can participate on a corrective action team as requested by the QS team or Group Leaders. The steps for conducting corrective action are detailed in GELs standard operating procedure GL-QS-E-002. In the event that correctness or validity of the laboratorys test results in doubt, the laboratory will take corrective action. If investigations show that the results have been impacted, affected clients will be informed of the issue in writing within five (5) calendar days of the discovery.

Table 6.1-5 provides the status of CARRs for radiological performance testing during 2021. GEL has determined that causes of the failures did not impact any data reported to its clients.

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TABLE 6.1-1 2021 INTER-LAB RADIOLOGICAL PROFICIENCY TESTING RESULTS AND ACCEPTANCE CRITERIA PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Barium-133 22.3 23.8 18.4 - 27.4 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Cesium-134 46.8 42.8 34.2 - 47.1 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Cesium-137 148 148 133 - 165 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Cesium-137 148 148 133 - 165 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Cobalt-60 36.7 34.6 30.8 - 40.8 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Zinc-65 68.2 61.6 54.6 - 75.0 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Gross Alpha 69.6 63.3 33.2 - 78.5 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Gross Beta 38.8 39.8 26.4 - 47.3 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Radium-226 8.42* 15.5 11.5 - 17.8 Not Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Radium-228 19.5* 12.9 8.54 - 15.8 Not Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Radium-228 14.6 12.9 8.54 - 15.8 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Uranium (Nat) 29.4 30.1 24.4 - 33.4 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Uranium (Nat) mass 44.6 43.9 35.5 - 48.7 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Tritium 2000 2120 1750 - 2350 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Tritium 2020 2120 1750 - 2350 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Strontium-89 74.6 61.3 49.4 - 69.2 Not Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Strontium-89 65.7 61.3 49.4 - 69.2 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Strontium-90 32.5 40.6 29.9 - 46.7 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Strontium-90 38.2 40.6 29.9 - 46.7 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Iodine-131 30.2 27.9 23.2 - 32.8 Acceptable ERA 1st/2021 03/02/21 RAD-124 Water pCi/L Iodine-131 31.7 27.9 23.2 - 32.8 Acceptable EZA 1st/2021 03/11/21 E13356 Cartridge pCi Iodine-131 9.34E+01 8.80E+01 1.06 Acceptable EZA 1st/2021 03/11/21 E13357 Milk pCi/L Strontium-89 9.55E+01 8.71E+01 1.1 Acceptable EZA 1st/2021 03/11/21 E13357 Milk pCi/L Strontium-90 1.14E+01 1.26E+01 0.9 Acceptable EZA 1st/2021 03/11/21 E13358 Milk pCi/L Cerium-141 1.32E+02 1.25E+02 1.05 Acceptable EZA 1st/2021 03/11/21 E13358 Milk pCi/L Cobalt-58 1.33E+02 1.28E+02 1.04 Acceptable EZA 1st/2021 03/11/21 E13358 Milk pCi/L Cobalt-60 1.57E+02 1.54E+02 1.02 Acceptable EZA 1st/2021 03/11/21 E13358 Milk pCi/L Chromium-51 2.33E+02 2.42E+02 0.96 Acceptable EZA 1st/2021 03/11/21 E13358 Milk pCi/L Cesium-134 1.37E+02 1.51E+02 0.9 Acceptable EZA 1st/2021 03/11/21 E13358 Milk pCi/L Cesium-137 1.12E+02 1.10E+02 1.02 Acceptable EZA 1st/2021 03/11/21 E13358 Milk pCi/L Manganese-54 1.15E+02 1.12E+02 1.02 Acceptable EZA 1st/2021 03/11/21 E13358 Milk pCi/L Iron-59 1.21E+02 1.09E+02 1.11 Acceptable

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PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio EZA 1st/2021 03/11/21 E13358 Milk pCi/L Iodine-131 8.39E+01 8.69E+01 0.97 Acceptable EZA 1st/2021 03/11/21 E13358 Milk pCi/L Zinc-65 2.38E+02 2.11E+02 1.13 Acceptable EZA 1st/2021 03/11/21 E13359 Water pCi/L Cerium-141 1.26E+02 1.24E+02 1.02 Acceptable EZA 1st/2021 03/11/21 E13359 Water pCi/L Cobalt-58 1.34E+02 1.26E+02 1.06 Acceptable EZA 1st/2021 03/11/21 E13359 Water pCi/L Cobalt-60 1.54E+02 1.52E+02 1.01 Acceptable EZA 1st/2021 03/11/21 E13359 Water pCi/L Cesium-134 1.35E+02 1.50E+02 0.9 Acceptable EZA 1st/2021 03/11/21 E13359 Water pCi/L Cesium-137 1.15E+02 1.09E+02 1.06 Acceptable EZA 1st/2021 03/11/21 E13359 Water pCi/L Iodine-131 9.64E+01 8.79E+01 1.1 Acceptable EZA 1st/2021 03/11/21 E13359 Water pCi/L Iron-59 1.12E+02 1.08E+02 1.04 Acceptable EZA 1st/2021 03/11/21 E13359 Water pCi/L Manganese-54 1.17E+02 1.11E+02 1.05 Acceptable EZA 1st/2021 03/11/21 E13359 Water pCi/L Zinc-65 2.24E+02 2.08E+02 1.08 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Actinium-228 3260 3170 2090 - 3990 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Americium-241 1580 1620 875 - 2290 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Bismuth-212 3300 3280 939 - 4890 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Bismuth-214 1370 1380 662 - 2050 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Cesium-134 5380 5920 4050 - 7080 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Cesium-137 7580 7570 5720 - 9570 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Cobalt-60 4660 5060 3980 - 6250 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Lead-212 3830 3350 2340 - 4240 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Lead-212 3830 3350 2340 - 4240 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Lead-214 1760 1440 605 - 2260 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Manganese-54 <28.3 <1000 <1000 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Plutonium-238 1810 1930 963 - 2930 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Plutonium-239 1610 1720 937 - 2480 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Potassium-40 24400 24700 17000 - 29500 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Strontium-90 10200 9190 2860 - 14300 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Thorium-234 4870 4020 1520 - 6880 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Uranium-234 3650 4060 1900 - 5320 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Uranium-234 3740 4060 1900 - 5320 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Uranium-238 3480 4020 2210 - 5400 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Uranium-238 3320 4020 2210 - 5400 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Uranium-Total 7300 8260 4580 - 10700 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Uranium-Total 7060 8260 4580 - 10700 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil µg/kg Uranium-Total (mass) 10400 12000 5420 - 16200 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Soil µg/kg Uranium-Total (mass) 9950 12000 5420 - 16200 Acceptable

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PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio ERA 2nd/2021 5/25/2021 MRAD 34 Soil pCi/kg Zinc-65 7090 7040 5620 - 9600 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Americium-241 2210 2460 1520 - 3470 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Cesium-134 1920 2350 1560 - 3130 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Cesium-137 2590 2720 2090 - 3660 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Cobalt-60 1640 1610 1260 - 2100 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Curium-244 3260 3750 2110 - 4660 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Manganese-54 <26.8 <300 <300 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Plutonium-238 3450 3610 2500 - 4660 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Plutonium-239 1750 1820 1260 - 2300 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Potassium-40 36700 33300 25000 - 42200 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Strontium-90 986 1260 710 - 1640 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Strontium-90 986 1260 710 - 1640 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Uranium-234 1370 1420 998 - 1810 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Uranium-238 1380 1410 996 - 1760 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Uranium-Total 2830 2900 1850 - 3910 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg µg/kg Uranium-Total (mass) 4150 4230 3250 - 5240 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/kg Zinc-65 797 766 572 - 1140 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 veg pCi/Filter Americium-241 61.8 60.2 43.0 - 80.3 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Cesium-134 958 1030 668 - 1260 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Cesium-134 958 1030 668 - 1260 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Cesium-137 159 163 134 - 214 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Cesium-137 159 163 134 - 214 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Cobalt-60 1280 1220 1040 - 1550 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Iron-55 103 121 44.2 - 193 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Manganese-54 <6.46 <50.0 <50.0 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Plutonium-238 35.9 35.4 26.7 - 43.5 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Plutonium-239 20.1 20.5 15.3 - 24.7 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Strontium-90 181 189 120 - 257 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Uranium-234 24.1 25.5 18.9 - 29.9 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Uranium-234 26.4 25.5 18.9 - 29.9 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Uranium-238 24.6 25.3 19.1 - 30.2 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Uranium-238 23.5 25.3 19.1 - 30.2 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Uranium-Total 50 52 38.0 - 61.7 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Uranium-Total 49.9 52 38.0 - 61.7 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter µg/Filter Uranium-Total (mass) 73.8 75.9 60.9 - 88.9 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter µg/Filter Uranium-Total (mass) 70.5 75.9 60.9 - 88.9 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Zinc-65 840 771 632 - 1180 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Gross Alpha 391* 96.1 50.2 - 158 Not Acceptable

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PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio ERA 2nd/2021 5/25/2021 MRAD 34 Filter pCi/Filter Gross Beta 71.5 62.6 38.0 - 94.6 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Americium-241 160 157 108 - 201 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Cesium-134 1550 1610 1220 - 1770 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Cesium-137 595 578 495 - 657 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Cobalt-60 2310 2180 1880 - 2500 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Cobalt-60 2310 2180 1880 - 2500 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Cobalt-60 2310 2180 1880 - 2500 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Iron-55 494 275 162 - 400 Not Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Manganese-54 <6.01 <100 <100 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Plutonium-238 115 171 103 - 222 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Plutonium-239 95.2 142 87.9 - 175 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Strontium-90 736 671 483 - 829 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Uranium-234 140 160 122 - 183 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Uranium-234 162 160 122 - 183 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Uranium-234 152 160 122 - 183 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Uranium-238 146 158 122 - 186 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Uranium-238 158 158 122 - 186 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Uranium-238 145 158 122 - 186 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Uranium-Total 292 325 254 - 370 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Uranium-Total 297 325 254 - 370 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water µg/L Uranium-Total (mass) 436 474 384 - 538 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water µg/L Uranium-Total (mass) 433 474 384 - 538 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Zinc-65 1900 1720 1530 - 2170 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Gross Alpha 87.8 62.2 22.7 - 85.8 Not Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Gross Beta 73.7 103 51.5 - 142 Acceptable ERA 2nd/2021 5/25/2021 MRAD 34 Water pCi/L Tritium 24900 22800 17200 - 27800 Acceptable ERA 2nd/2021 5/25/2021 RAD 125 Water pCi/L Radium-226 14.2 19.3 14.3 - 22.0 Not Acceptable ERA 2nd/2021 5/25/2021 RAD 125 Water pCi/L Radium-228 9.98 10.3 6.71 - 12.8 Acceptable ERA 2nd/2021 5/25/2021 RAD 125 Water pCi/L Strontium-89 59.3 63.5 51.4 - 71.5 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-GrF44 Filter Bq/smpl Gross Alpha 0.864 1.77 0.53-3.01 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-GrF44 Filter Bq/smpl Gross Beta 0.639 0.649 0.325-0.974 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-GrF44 Water Bq/L Gross Alpha 0.782 0.87 0.26-1.48 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-GrF44 Water Bq/L Gross Beta 2.40 2.50 1.25-3.75 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Americium-241 89.6 88 62-114 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Cesium-134 2.92 False pos. test Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Cesium-137 1590 1550 1085-2015 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Cobalt-57 1010 920 644-1196 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Cobalt-60 1320 1370 959-1781 Acceptable

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PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Iron-55 1150 910 637-1183 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Manganese-54 1.84 False pos. test Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Nickel-63 597 689 482-896 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Plutonium-238 51.2 49.1 34.4-63.8 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Plutonium-239/240 -0.819 False pos. test Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Potassium-40 618 618 433-803 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Strontium-90 313 272 190-354 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Technetium-99 576 638 447-829 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg U-234/233 57.1 59 41-77 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Uranium-238 194 208 146-270 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaS44 Soil Bq/Kg Zinc-65 627 604 423-785 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Americium-241 0.0145 False pos. test Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Cesium-134 10.6 11.5 8.1-15.0 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Cesium-137 8.54 7.9 5.5-10.3 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Cobalt-57 12.2 11.4 8.0-14.8 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Cobalt-60 0.146 False pos. test Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Hydrogen-3 2.27 False pos. test Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Iron-55 27.1 26.9 18.8-35.0 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Manganese-54 16.7 15.5 10.9-20.2 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Nickel-63 10.4 8.2 5.7-10.7 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Plutonium-238 0.515 0.577 0.404-0.750 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Plutonium-239/240 0.564 0.649 0.454-0.844 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Potassium-40 -0.886 False pos. test Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Radium-226 0.538 0.632 0.442-0.822 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Strontium-90 4.95 4.47 3.13-5.81 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Technetium-99 3.69 4.01 2.81-5.21 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Uranium-234/233 0.884 0.85 0.60-1.11 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Uranium-238 0.913 0.86 0.60-1.12 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-MaW44 Water Bq/L Zinc-65 11.6 10.5 7.4-13.7 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter ug/smpl Uranium-235 0.0366 0.0353 0.0247-0.0459 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter ug/smpl Uranium-238 5.19 5.03 3.52-6.54 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter ug/smpl Uranium-Total 5.22 5.07 3.55-6.59 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Americium-241 0.0385 0.037 0.026-0.048 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Cesium-134 2.12 2.14 1.50-2.78 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Cesium-137 -0.0168 False pos. test Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Cobalt-57 0.74 0.686 0.480-0.892 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Cobalt-60 0.0325 False pos. test Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Manganese-54 0.368 0.312 0.218-0.406 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Plutonium-238 0.0207 0.0228 0.0160-0.0296 Acceptable

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PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Plutonium-239/240 0.0417 0.0453 0.0317-0.0589 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Strontium-90 0.89 0.749 0.524-0.974 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Uranium-234/233 0.063 0.06 0.04-0.08 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Uranium-238 0.0617 0.063 0.044-0.082 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdF44 Filter Bq/smpl Zinc-65 0.457 0.352 0.246-0.458 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Americium-241 0.0605 0.0586 0.0410-0.0762 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Cesium-134 2.51 3.6 2.52-4.68 Not Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Cesium-137 3.75 4.69 3.28-6.10 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Cobalt-57 3.73 5.05 3.54-6.57 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Cobalt-60 2.36 2.99 2.09-3.89 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Manganese-54 4.13 5.25 3.68-6.83 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Plutonium-238 0.0467 0.0446 0.0312-0.058 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Plutonium-239/240 0.0912 0.0912 0.0645-0.1197 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Strontium-90 0.444 0.673 0.471-0.875 Not Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Uranium-234/233 0.136 0.138 0.097-0.179 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Uranium-238 0.143 0.143 0.100-0.186 Acceptable MAPEP 2nd/2021 06/22/21 MAPEP-21-RdV44 veg Bq/smpl Zinc-65 -0.0042 False pos. test Acceptable EZA 2nd/2021 08/06/21 E13360 Cartridge pCi Iodine-131 9.99E+01 9.08E+01 1.10 Acceptable EZA 2nd/2021 08/06/21 E13362 Milk pCi/L Cerium-141 2.12E+02 2.17E+02 0.98 Acceptable EZA 2nd/2021 08/06/21 E13362 Milk pCi/L Cobalt-58 2.09E+02 2.16E+02 0.97 Acceptable EZA 2nd/2021 08/06/21 E13362 Milk pCi/L Cobalt-60 2.62E+02 2.60E+02 1.01 Acceptable EZA 2nd/2021 08/06/21 E13362 Milk pCi/L Chromium-51 2.66E+02 6.42E+02 1.02 Acceptable EZA 2nd/2021 08/06/21 E13362 Milk pCi/L Cesium-134 2.34E+02 2.57E+02 0.91 Acceptable EZA 2nd/2021 08/06/21 E13362 Milk pCi/L Cesium-137 2.32E+02 2.26E+02 1.03 Acceptable EZA 2nd/2021 08/06/21 E13362 Milk pCi/L Iron-59 2.50E+02 2.21E+02 1.13 Acceptable EZA 2nd/2021 08/06/21 E13362 Milk pCi/L Iodine-131 8.04E+01 8.38E+01 0.96 Acceptable EZA 2nd/2021 08/06/21 E13362 Milk pCi/L Manganese-54 3.05E+02 3.00E+02 1.02 Acceptable EZA 2nd/2021 08/06/21 E13362 Milk pCi/L Zinc-65 3.93E+02 3.62E+02 1.09 Acceptable EZA 2nd/2021 08/06/21 E13363 Water pCi/L Cerium-141 1.96E+02 1.80E+02 1.09 Acceptable EZA 2nd/2021 08/06/21 E13174 Water pCi/L Cobalt-58 1.84E+02 1.79E+02 1.03 Acceptable EZA 2nd/2021 08/06/21 E13174 Water pCi/L Cobalt-60 2.20E+02 2.15E+02 1.02 Acceptable EZA 2nd/2021 08/06/21 E13174 Water pCi/L Chromium-51 5.65E+02 5.33E+02 1.06 Acceptable EZA 2nd/2021 08/06/21 E13174 Water pCi/L Cesium-134 2.02E+02 2.13E+02 0.95 Acceptable EZA 2nd/2021 08/06/21 E13174 Water pCi/L Cesium-137 2.00E+02 1.88E+02 1.07 Acceptable EZA 2nd/2021 08/06/21 E13174 Water pCi/L Iron-59 2.12E+02 1.83E+02 1.16 Acceptable EZA 2nd/2021 08/06/21 E13174 Water pCi/L Iodine-131 9.21E+01 9.20E+01 1.00 Acceptable EZA 2nd/2021 08/06/21 E13174 Water pCi/L Manganese-54 2.75E+02 2.49E+02 1.10 Acceptable EZA 2nd/2021 08/06/21 E13174 Water pCi/L Zinc-65 3.35E+02 3.00E+02 1.12 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Barium-133 48.9 45.5 37.2 - 50.6 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Cesium-134 84.4 87.5 71.8 - 96.2 Acceptable

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PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Cesium-137 211 208 187 - 230 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Cobalt-60 93 87.1 78.4 - 98.1 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Zinc-65 108 102 91.8 - 122 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Gross Alpha 39.1 49.1 25.6 - 61.7 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Gross Alpha 40.3 49.1 25.6 - 61.7 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Gross Beta 30.4 31.5 20.3 - 39.2 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Radium-226 11.2 13.4 9.99 - 15.4 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Radium-228 6.8 7.59 4.81 - 9.68 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Radium-228 6.69 7.59 4.81 - 9.68 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Uranium (Nat) 59.6 62.3 50.9 - 68.5 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water µg/L Uranium (Nat) mass 94 90.9 74.2 - 100 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Tritium 9820 10400 9050 - 11400 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Tritium 10300 10400 9050 - 11400 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Strontium-89 50.3 55.9 44.6 - 63.6 Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Strontium-90 46.2 40.1 29.5 - 46.1 Not Acceptable ERA 3rd /2021 08/30/21 RAD-126 Water pCi/L Iodine-131 17.6 20.8 17.2 - 25.0 Acceptable EZA 3rd/2021 11/08/21 E13364 Cartridge pCi Iodine-131 1.02E+02 9.08E+01 112 Acceptable EZA 3rd/2021 11/08/21 E13365 Milk pCi/L Strontium-89 8.92E+01 8.54E+01 1.04 Acceptable EZA 3rd/2021 11/08/21 E13365 Milk pCi/L Strontium-90 1.01E+01 1.40E+01 0.72 Acceptable EZA 3rd/2021 11/08/21 E13366 Milk pCi/L Cerium-141 1.17E+02 1.14E+02 1.02 Acceptable EZA 3rd/2021 11/08/21 E13366 Milk pCi/L Cobalt-58 1.25E+02 1.18E+02 1.06 Acceptable EZA 3rd/2021 11/08/21 E13366 Milk pCi/L Cobalt-60 1.46E+02 1.45E+02 1.01 Acceptable EZA 3rd/2021 11/08/21 E13366 Milk pCi/L Chromium-51 2.69E+02 2.36E+02 1.14 Acceptable EZA 3rd/2021 11/08/21 E13366 Milk pCi/L Cesium-134 9.00E+01 9.31E+01 0.97 Acceptable EZA 3rd/2021 11/08/21 E13366 Milk pCi/L Cesium-137 1.14E+02 1.12E+02 1.02 Acceptable EZA 3rd/2021 11/08/21 E13366 Milk pCi/L Iron-59 1.23E+02 1.02E+02 1.21 Acceptable EZA 3rd/2021 11/08/21 E13366 Milk pCi/L Iodine-131 9.08E+01 8.56E+01 1.06 Acceptable EZA 3rd/2021 11/08/21 E13366 Milk pCi/L Manganese-54 1.31E+02 1.28E+02 1.02 Acceptable EZA 3rd/2021 11/08/21 E13366 Milk pCi/L Zinc-65 1.65E+02 1.53E+02 1.08 Acceptable EZA 3rd/2021 11/08/21 E13367 Water pCi/L Cerium-141 1.54E+02 1.51E+02 1.02 Acceptable EZA 3rd/2021 11/08/21 E13367 Water pCi/L Cobalt-58 1.62E+02 1.56E+02 1.04 Acceptable EZA 3rd/2021 11/08/21 E13367 Water pCi/L Cobalt-60 2.07E+02 1.91E+02 1.08 Acceptable EZA 3rd/2021 11/08/21 E13367 Water pCi/L Chromium-51 3.30E+02 3.12E+02 1.06 Acceptable EZA 3rd/2021 11/08/21 E13367 Water pCi/L Cesium-134 1.13E+02 1.23E+02 0.92 Acceptable EZA 3rd/2021 11/08/21 E13367 Water pCi/L Cesium-137 1.57E+02 1.48E+02 1.06 Acceptable EZA 3rd/2021 11/08/21 E13367 Water pCi/L Iron-59 1.52E+02 1.35E+02 1.13 Acceptable EZA 3rd/2021 11/08/21 E13367 Water pCi/L Iodine-131 2.71E+02 2.47E+02 1.10 Acceptable EZA 3rd/2021 11/08/21 E13367 Water pCi/L Manganese-54 1.83E+02 1.70E+02 1.08 Acceptable EZA 3rd/2021 11/08/21 E13367 Water pCi/L Zinc-65 2.33E+02 2.02E+02 1.15 Acceptable

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PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio MAPEP 4th/2021 12/16/21 MAPEP-21-GrF45 Filter Bq/sample Gross Alpha 1.73 0.98 0.288-1.632 Not Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-GrF45 Filter Bq/sample Gross Beta 0.642 0.553 0.277-0.830 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-GrW45 Water Bq/L Gross Alpha 0.226 0.232 0.070-0.394 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-GrW45 Water Bq/L Gross Beta 2.73 2.8707 1.404-4.211 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Americium-241 106.0 98.0 69-127 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Cesium-134 993 1170 819-1521 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Cesium-137 579.00 572 400-744 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Cobalt-57 0.375 False Pos Test Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Cobalt-60 692 722 505-939 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Iron-55 994 1020 714-1326 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Manganese-54 412 410 287-533 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Nickel-63 1170 1280 896-1664 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Plutonium-238 55.9 59.8 41.9-77.7 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Plutonium-239/240 66.3 71.3 49.9-92.7 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Potassium-40 612 607 425-789 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Strontium-90 0.161 False Pos Test Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Technetium-99 747 777 544-1010 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg U-234/233 80 51 36.0-66.8 Not Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Uranium-238 177 168 118-218 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaS45 Soil Bq/Kg Zinc-65 945 907 635-1179 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Americium-241 0.407 0.426 0.298-0.554 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Cesium-134 9.5 10.4 7.3-13.5 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Cesium-137 -0.04 False Pos Test Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Cobalt-57 14 13.9 9.7-18.1 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Cobalt-60 14.5 14.0 9.8-18.2 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Hydrogen-3 231 250 175-325 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Iron-55 47.9 49.8 34.9-64.7 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Manganese-54 9.47 9.0 6.3-11.7 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Nickel-63 41.4 39.5 27.7-51.4 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Plutonium-238 -0.00169 0.0096 Sens. Evaluation Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Plutonium-239/240 0.470 0.528 0.370-0.689 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Potassium-40 0.005 False Pos Test Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Radium-226 0.310 0.226 0.158-0.294 Not Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Strontium-90 3.50 3.86 2.70-5.02 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Technetium-99 3.79 3.71 2.60-4.82 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Uranium-234/233 0.0203 0.0215 Sens. Evaluation Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Uranium-238 0.00975 0.0123 Sens. Evaluation Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-MaW45 Water Bq/L Zinc-65 0.122 False Pos Test Acceptable

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PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter ug/sample Uranium-235 0.0594 0.0588 0.0412-0.0764 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter ug/sample Uranium-238 8.5 8.3 5.8-10.8 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter ug/sample Uranium-Total 8.579 8.4 5.9-10.9 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Americium-241 0.109 0.119 0.083-0.155 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Cesium-134 1.23 1.32 0.92-1.72 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Cesium-137 1.31 1.280 0.90-1.66 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Cobalt-57 0.82800 0.83 0.58-1.08 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Cobalt-60 2.37 2.28 1.60-2.96 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Manganese-54 1.60 1.46 1.02-1.90 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Plutonium-238 0.0023 0.0030 Sens. Evaluation Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Plutonium-239/240 0.0574 0.0609 0.0426-0.0792 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Strontium-90 0.195 0.273 0.191-0.355 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Uranium-234/233 0.101 0.100 0.070-0.130 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Uranium-238 0.107 0.104 0.073-0.135 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdF45 Filter Bq/sample Zinc-65 0.0579 False Pos Test Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Americium-241 0.0724 0.0747 0.0523-0.0971 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Cesium-134 4.02 4.34 3.04-5.64 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Cesium-137 2.28 2.21 1.55-2.87 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Cobalt-57 4.56 4.66 3.26-6.06 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Cobalt-60 3.44 3.51 2.46-4.56 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Manganese-54 -0.0404 False Pos Test Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Plutonium-238 0.0603 0.0655 0.0459-0.0852 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Plutonium-239/240 0.00140 False Pos Test Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Strontium-90 1.10 1.32 0.92-1.72 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Uranium-234/233 0.1740 0.1830 0.128-0.238 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Uranium-238 0.1770 0.1760 1.123-0.229 Acceptable MAPEP 4th/2021 12/16/21 MAPEP-21-RdV45 Vegetation Bq/sample Zinc-65 2.57 2.43 1.70-3.16 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Actinium-228 3370 3240 2140 - 4080 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Americium-241 922 891 481 - 1260 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Bismuth-212 3320 3350 959 - 4990 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Bismuth-214 1140 1370 658 - 2040 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Cesium-134 2410 2650 1810 - 3170 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Cesium-134 2410 2650 1810 - 3170 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Cesium-137 3720 3660 2770 - 4630 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Cobalt-60 4680 4730 3720 - 5840 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Lead-212 3840 3420 2390 - 4320 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Lead-214 1480 1490 626 - 2340 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Manganese-54 <27.4 <1000 <1000 Acceptable

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PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Plutonium-238 1230 1250 623 - 1900 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Plutonium-239 1440 1450 790 - 2090 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Potassium-40 25600 24700 17000 - 29500 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Strontium-90 8770 6090 1900 - 9490 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Thorium-234 3350 2720 1030 - 4660 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Uranium-234 2620 2740 1280 - 3590 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Uranium-234 3260 2740 1280 - 3590 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Uranium-238 2870 2720 1490 - 3650 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Uranium-238 3400 2720 1490 - 3650 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Uranium-Total 5670 5580 3100 - 7210 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Uranium-Total 5670 5580 3100 - 7210 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Uranium-Total 6817 5580 3100 - 7210 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil µg/kg Uranium (mass) 8630 8140 3670 - 11000 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil µg/kg Uranium (mass) 10200 8140 3670 - 11000 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Soil pCi/kg Zinc-65 5540 4860 3880 - 6630 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Americium-241 4040 4040 2500 - 5710 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Cesium-134 918 923 613 - 1230 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Cesium-137 2180 2210 1700 - 2980 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Cobalt-60 1670 1590 1250 - 2080 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Cobalt-60 1670 1590 1250 - 2080 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Curium-244 2830 2840 1600 - 3530 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Manganese-54 <47.1 <300 <300 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Plutonium-238 1730 1620 1120 - 2090 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Plutonium-239 1620 1440 995 - 1820 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Potassium-40 30200 33300 25000 - 42200 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Strontium-90 5760 5720 3220 - 7450 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Uranium-234 1410 1350 948 - 1720 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Uranium-238 1420 1340 946 - 1680 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Uranium-Total 2900 2750 1760 - 3710 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg µg/kg Uranium (mass) 4250 4010 3080 - 4970 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Veg pCi/kg Zinc-65 1340 1200 896 - 1780 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Americium-241 28.1 27.7 19.8 - 36.9 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Cesium-134 217 241 156 - 296 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Cesium-137 187 187 154 - 245 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Cobalt-60 324 310 264 - 394 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Cobalt-60 324 310 264 - 394 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Iron-55 508 548 200 - 874 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Manganese-54 <3.06 <50.0 <50.0 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Plutonium-238 27.8 28.5 21.5 - 35.0 Acceptable

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PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Plutonium-239 22.6 21.6 16.1 - 26.1 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Strontium-90 23.4* 19.2 12.1 - 26.1 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Uranium-234 7.96 7.76 5.75 - 9.09 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Uranium-234 9.62* 7.76 5.75 - 9.09 Not Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Uranium-238 7.35 7.69 5.81 - 9.17 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Uranium-238 7.38 7.69 5.81 - 9.17 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Uranium-Total 15.8 15.8 11.5 - 18.7 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Uranium-Total 17 15.8 11.5 - 18.7 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter µg/Filter Uranium (mass) 22.1 23.1 18.5 - 27.1 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter µg/Filter Uranium (mass) 22.1 23.1 18.5 - 27.1 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Zinc-65 414 366 300 - 559 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Gross Alpha 95.4 77.6 40.5 - 128 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Filter pCi/Filter Gross Beta 87 80.6 48.9 - 122 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Americium-241 70.5 63.7 43.7 - 81.5 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Cesium-134 626 649 490 - 714 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Cesium-137 2210 2170 1860 - 2470 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Cobalt-60 1040 964 831 - 1110 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Iron-55 339* 246 145 - 358 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Plutonium-238 74.1 114 68.5 - 148 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Plutonium-239 21.3 34.3 21.2 - 42.3 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Strontium-90 915 936 674 - 1160 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Uranium-234 39.9 40.8 31.1 - 46.7 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Uranium-234 49.8* 40.8 31.1 - 46.7 Not Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Uranium-238 40.3 40.5 31.4 - 47.7 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Uranium-238 41.2 40.5 31.4 - 47.7 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Uranium-Total 83.1 83.2 64.9 - 94.8 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Uranium-Total 92.9* 83.2 64.9 - 94.8 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water µg/L Uranium (mass) 121 121 98.0 - 137 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water µg/L Uranium (mass) 123 121 98.0 - 137 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Zinc-65 449 394 351 - 497 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Gross Alpha 74.7 93.9 34.3 - 129 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Gross Beta 96.1 97 48.5 - 133 Acceptable ERA 4th/2021 11/23/21 MRAD-35 Water pCi/L Tritium 12600 12800 9650 - 15600 Acceptable ERA 4th/2021 11/27/21 RAD-127 Water pCi/L Strontium-90 28.5 29.3 21.3 - 34.0 Acceptable EZA 4th/2021 02/02/22 E13368 Cartridge pCi Iodine-131 9.78E+01 9.35E+01 1.05 Acceptable EZA 4th/2021 02/02/22 E13370 Milk pCi/L Strontium-89 7.54E+01 9.08E+01 0.83 Acceptable EZA 4th/2021 02/02/22 E13370 Milk pCi/L Strontium-90 1.10E+01 1.30E+01 0.85 Acceptable EZA 4th/2021 02/02/22 E13366 Milk pCi/L Cerium-141 1.32E+02 1.32E+02 1.00 Acceptable EZA 4th/2021 02/02/22 E13366 Milk pCi/L Cobalt-58 1.14E+02 1.14E+02 1.00 Acceptable EZA 4th/2021 02/02/22 E13366 Milk pCi/L Cobalt-60 2.27E+02 2.23E+02 1.02 Acceptable

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PT Quarter / Analytical Sample GEL Known Acceptance Range/

Sample Number Unit Analyte / Nuclide Evaluation Provider Year Date Media Value value Ratio EZA 4th/2021 02/02/22 E13366 Milk pCi/L Chromium-51 2.84E+02 2.93E+02 0.97 Acceptable EZA 4th/2021 02/02/22 E13366 Milk pCi/L Cesium-134 1.51E+02 1.66E+02 0.91 Acceptable EZA 4th/2021 02/02/22 E13366 Milk pCi/L Cesium-137 1.15E+02 1.17E+02 0.98 Acceptable EZA 4th/2021 02/02/22 E13366 Milk pCi/L Iron-59 1.27E+02 1.13E+02 1.13 Acceptable EZA 4th/2021 02/02/22 E13366 Milk pCi/L Iodine-131 9.28E+01 9.03E+01 1.03 Acceptable EZA 4th/2021 02/02/22 E13366 Milk pCi/L Manganese-54 1.60E+02 1.52E+02 1.06 Acceptable EZA 4th/2021 02/02/22 E13366 Milk pCi/L Zinc-65 2.87E+02 2.57E+02 1.12 Acceptable EZA 4th/2021 02/02/22 E13367 Water pCi/L Cerium-141 1.53E+02 1.54E+02 0.99 Acceptable EZA 4th/2021 02/02/22 E13367 Water pCi/L Cobalt-58 1.42E+02 1.34E+02 1.06 Acceptable EZA 4th/2021 02/02/22 E13367 Water pCi/L Cobalt-60 2.82E+02 2.61E+02 1.08 Acceptable EZA 4th/2021 02/02/22 E13367 Water pCi/L Chromium-51 3.75E+02 3.42E+02 1.1 Acceptable EZA 4th/2021 02/02/22 E13367 Water pCi/L Cesium-134 1.82E+02 1.94E+02 0.94 Acceptable EZA 4th/2021 02/02/22 E13367 Water pCi/L Cesium-137 1.41E+02 1.37E+02 1.03 Acceptable EZA 4th/2021 02/02/22 E13367 Water pCi/L Iron-59 1.44E+02 1.32E+02 1.09 Acceptable EZA 4th/2021 02/02/22 E13367 Water pCi/L Iodine-131 9.66E+01 9.13E+01 1.06 Acceptable EZA 4th/2021 02/02/22 E13367 Water pCi/L Manganese-54 1.88E+02 1.77E+02 1.06 Acceptable EZA 4th/2021 02/02/22 E13367 Water pCi/L Zinc-65 3.45E+02 3.01E+02 1.15 Acceptable

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Table 6.1-2 2021 ECKERT & ZIEGLER ANALYTICS PERFORMANCE EVALUATION RESULTS Report Sample Sample GEL Acceptance Date Number Media Unit Analyte / Nuclide Value Known value Range/ Ratio Evaluation 03/11/21 E13356 Cartridge pCi Iodine-131 9.34E+01 8.80E+01 1.06 Acceptable 03/11/21 E13357 Milk pCi/L Strontium-89 9.55E+01 8.71E+01 1.1 Acceptable 03/11/21 E13357 Milk pCi/L Strontium-90 1.14E+01 1.26E+01 0.9 Acceptable 03/11/21 E13358 Milk pCi/L Cerium-141 1.32E+02 1.25E+02 1.05 Acceptable 03/11/21 E13358 Milk pCi/L Cobalt-58 1.33E+02 1.28E+02 1.04 Acceptable 03/11/21 E13358 Milk pCi/L Cobalt-60 1.57E+02 1.54E+02 1.02 Acceptable 03/11/21 E13358 Milk pCi/L Chromium-51 2.33E+02 2.42E+02 0.96 Acceptable 03/11/21 E13358 Milk pCi/L Cesium-134 1.37E+02 1.51E+02 0.9 Acceptable 03/11/21 E13358 Milk pCi/L Cesium-137 1.12E+02 1.10E+02 1.02 Acceptable 03/11/21 E13358 Milk pCi/L Manganese-54 1.15E+02 1.12E+02 1.02 Acceptable 03/11/21 E13358 Milk pCi/L Iron-59 1.21E+02 1.09E+02 1.11 Acceptable 03/11/21 E13358 Milk pCi/L Iodine-131 8.39E+01 8.69E+01 0.97 Acceptable 03/11/21 E13358 Milk pCi/L Zinc-65 2.38E+02 2.11E+02 1.13 Acceptable 03/11/21 E13359 Water pCi/L Cerium-141 1.26E+02 1.24E+02 1.02 Acceptable 03/11/21 E13359 Water pCi/L Cobalt-58 1.34E+02 1.26E+02 1.06 Acceptable 03/11/21 E13359 Water pCi/L Cobalt-60 1.54E+02 1.52E+02 1.01 Acceptable 03/11/21 E13359 Water pCi/L Cesium-134 1.35E+02 1.50E+02 0.9 Acceptable 03/11/21 E13359 Water pCi/L Cesium-137 1.15E+02 1.09E+02 1.06 Acceptable 03/11/21 E13359 Water pCi/L Iodine-131 9.64E+01 8.79E+01 1.1 Acceptable 03/11/21 E13359 Water pCi/L Iron-59 1.12E+02 1.08E+02 1.04 Acceptable 03/11/21 E13359 Water pCi/L Manganese-54 1.17E+02 1.11E+02 1.05 Acceptable 03/11/21 E13359 Water pCi/L Zinc-65 2.24E+02 2.08E+02 1.08 Acceptable 08/06/21 E13360 Cartridge pCi Iodine-131 9.99E+01 9.08E+01 1.10 Acceptable 08/06/21 E13362 Milk pCi/L Cerium-141 2.12E+02 2.17E+02 0.98 Acceptable 08/06/21 E13362 Milk pCi/L Cobalt-58 2.09E+02 2.16E+02 0.97 Acceptable 08/06/21 E13362 Milk pCi/L Cobalt-60 2.62E+02 2.60E+02 1.01 Acceptable 08/06/21 E13362 Milk pCi/L Chromium-51 2.66E+02 6.42E+02 1.02 Acceptable 08/06/21 E13362 Milk pCi/L Cesium-134 2.34E+02 2.57E+02 0.91 Acceptable 08/06/21 E13362 Milk pCi/L Cesium-137 2.32E+02 2.26E+02 1.03 Acceptable 08/06/21 E13362 Milk pCi/L Iron-59 2.50E+02 2.21E+02 1.13 Acceptable 08/06/21 E13362 Milk pCi/L Iodine-131 8.04E+01 8.38E+01 0.96 Acceptable

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Report Sample Sample GEL Acceptance Date Number Media Unit Analyte / Nuclide Value Known value Range/ Ratio Evaluation 08/06/21 E13362 Milk pCi/L Manganese-54 3.05E+02 3.00E+02 1.02 Acceptable 08/06/21 E13362 Milk pCi/L Zinc-65 3.93E+02 3.62E+02 1.09 Acceptable 08/06/21 E13363 Water pCi/L Cerium-141 1.96E+02 1.80E+02 1.09 Acceptable 08/06/21 E13174 Water pCi/L Cobalt-58 1.84E+02 1.79E+02 1.03 Acceptable 08/06/21 E13174 Water pCi/L Cobalt-60 2.20E+02 2.15E+02 1.02 Acceptable 08/06/21 E13174 Water pCi/L Chromium-51 5.65E+02 5.33E+02 1.06 Acceptable 08/06/21 E13174 Water pCi/L Cesium-134 2.02E+02 2.13E+02 0.95 Acceptable 08/06/21 E13174 Water pCi/L Cesium-137 2.00E+02 1.88E+02 1.07 Acceptable 08/06/21 E13174 Water pCi/L Iron-59 2.12E+02 1.83E+02 1.16 Acceptable 08/06/21 E13174 Water pCi/L Iodine-131 9.21E+01 9.20E+01 1.00 Acceptable 08/06/21 E13174 Water pCi/L Manganese-54 2.75E+02 2.49E+02 1.10 Acceptable 08/06/21 E13174 Water pCi/L Zinc-65 3.35E+02 3.00E+02 1.12 Acceptable 11/08/21 E13364 Cartridge pCi Iodine-131 1.02E+02 9.08E+01 112 Acceptable 11/08/21 E13365 Milk pCi/L Strontium-89 8.92E+01 8.54E+01 1.04 Acceptable 11/08/21 E13365 Milk pCi/L Strontium-90 1.01E+01 1.40E+01 0.72 Acceptable 11/08/21 E13366 Milk pCi/L Cerium-141 1.17E+02 1.14E+02 1.02 Acceptable 11/08/21 E13366 Milk pCi/L Cobalt-58 1.25E+02 1.18E+02 1.06 Acceptable 11/08/21 E13366 Milk pCi/L Cobalt-60 1.46E+02 1.45E+02 1.01 Acceptable 11/08/21 E13366 Milk pCi/L Chromium-51 2.69E+02 2.36E+02 1.14 Acceptable 11/08/21 E13366 Milk pCi/L Cesium-134 9.00E+01 9.31E+01 0.97 Acceptable 11/08/21 E13366 Milk pCi/L Cesium-137 1.14E+02 1.12E+02 1.02 Acceptable 11/08/21 E13366 Milk pCi/L Iron-59 1.23E+02 1.02E+02 1.21 Acceptable 11/08/21 E13366 Milk pCi/L Iodine-131 9.08E+01 8.56E+01 1.06 Acceptable 11/08/21 E13366 Milk pCi/L Manganese-54 1.31E+02 1.28E+02 1.02 Acceptable 11/08/21 E13366 Milk pCi/L Zinc-65 1.65E+02 1.53E+02 1.08 Acceptable 11/08/21 E13367 Water pCi/L Cerium-141 1.54E+02 1.51E+02 1.02 Acceptable 11/08/21 E13367 Water pCi/L Cobalt-58 1.62E+02 1.56E+02 1.04 Acceptable 11/08/21 E13367 Water pCi/L Cobalt-60 2.07E+02 1.91E+02 1.08 Acceptable 11/08/21 E13367 Water pCi/L Chromium-51 3.30E+02 3.12E+02 1.06 Acceptable 11/08/21 E13367 Water pCi/L Cesium-134 1.13E+02 1.23E+02 0.92 Acceptable 11/08/21 E13367 Water pCi/L Cesium-137 1.57E+02 1.48E+02 1.06 Acceptable 11/08/21 E13367 Water pCi/L Iron-59 1.52E+02 1.35E+02 1.13 Acceptable 11/08/21 E13367 Water pCi/L Iodine-131 2.71E+02 2.47E+02 1.10 Acceptable 11/08/21 E13367 Water pCi/L Manganese-54 1.83E+02 1.70E+02 1.08 Acceptable 11/08/21 E13367 Water pCi/L Zinc-65 2.33E+02 2.02E+02 1.15 Acceptable 02/02/22 E13368 Cartridge pCi Iodine-131 9.78E+01 9.35E+01 1.05 Acceptable

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Report Sample Sample GEL Acceptance Date Number Media Unit Analyte / Nuclide Value Known value Range/ Ratio Evaluation 02/02/22 E13370 Milk pCi/L Strontium-89 7.54E+01 9.08E+01 0.83 Acceptable 02/02/22 E13370 Milk pCi/L Strontium-90 1.10E+01 1.30E+01 0.85 Acceptable 02/02/22 E13366 Milk pCi/L Cerium-141 1.32E+02 1.32E+02 1.00 Acceptable 02/02/22 E13366 Milk pCi/L Cobalt-58 1.14E+02 1.14E+02 1.00 Acceptable 02/02/22 E13366 Milk pCi/L Cobalt-60 2.27E+02 2.23E+02 1.02 Acceptable 02/02/22 E13366 Milk pCi/L Chromium-51 2.84E+02 2.93E+02 0.97 Acceptable 02/02/22 E13366 Milk pCi/L Cesium-134 1.51E+02 1.66E+02 0.91 Acceptable 02/02/22 E13366 Milk pCi/L Cesium-137 1.15E+02 1.17E+02 0.98 Acceptable 02/02/22 E13366 Milk pCi/L Iron-59 1.27E+02 1.13E+02 1.13 Acceptable 02/02/22 E13366 Milk pCi/L Iodine-131 9.28E+01 9.03E+01 1.03 Acceptable 02/02/22 E13366 Milk pCi/L Manganese-54 1.60E+02 1.52E+02 1.06 Acceptable 02/02/22 E13366 Milk pCi/L Zinc-65 2.87E+02 2.57E+02 1.12 Acceptable 02/02/22 E13367 Water pCi/L Cerium-141 1.53E+02 1.54E+02 0.99 Acceptable 02/02/22 E13367 Water pCi/L Cobalt-58 1.42E+02 1.34E+02 1.06 Acceptable 02/02/22 E13367 Water pCi/L Cobalt-60 2.82E+02 2.61E+02 1.08 Acceptable 02/02/22 E13367 Water pCi/L Chromium-51 3.75E+02 3.42E+02 1.1 Acceptable 02/02/22 E13367 Water pCi/L Cesium-134 1.82E+02 1.94E+02 0.94 Acceptable 02/02/22 E13367 Water pCi/L Cesium-137 1.41E+02 1.37E+02 1.03 Acceptable 02/02/22 E13367 Water pCi/L Iron-59 1.44E+02 1.32E+02 1.09 Acceptable 02/02/22 E13367 Water pCi/L Iodine-131 9.66E+01 9.13E+01 1.06 Acceptable 02/02/22 E13367 Water pCi/L Manganese-54 1.88E+02 1.77E+02 1.06 Acceptable 02/02/22 E13367 Water pCi/L Zinc-65 3.45E+02 3.01E+02 1.15 Acceptable

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TABLE 6.1-3 REMP INTRA-LABORATORY DATA

SUMMARY

BIAS AND PRECISION BY MATRIX Bias Criteria Precision Criteria

(+ / - 25%) (Note 1)

WITHIN OUTSIDE WITHIN OUTSIDE REMP 2021 CRITERIA CRITERIA CRITERIA CRITERIA MILK Gas Flow Sr 2nd count 54 0 59 1 Gas Flow Total Strontium 12 0 13 0 Gamma Spec Liquid RAD A-013 with Ba, La 32 0 105 0 Gamma Spec Liquid RAD A-013 with Iodine 0 0 2 0 SOLID Gamma Spec Solid RAD A-013 6 0 9 0 LSC Nickel 63 3 0 3 0 Gas Flow Sr 2nd count 5 0 8 0 Gas Flow Total Strontium 3 0 3 0 Gamma Spec Solid RAD A-013 with Iodine 16 0 37 0 FILTER Gross A & B 388 0 248 0 Gamma Spec Filter 35 0 78 0 LIQUID Tritium 192 0 249 0 LSC Iron-55 14 0 14 0 LSC Nickel 63 14 0 14 0 Gamma Iodine-131 1 0 1 0 Gas Flow Sr 2nd count 6 0 5 0 Gas Flow Total Strontium 13 0 15 0 Gross Alpha Non Vol Beta 23 0 71 0 Gamma Spec Liquid RAD A-013 with Ba, La 74 0 146 0 Gamma Spec Liquid RAD A-013 with Iodine 17 0 74 0 TISSUE Gas Flow Sr 2nd count 9 0 11 0 Gas Flow Total Strontium 5 0 5 0 Gamma Spec Solid RAD A-013 with Iodine 15 0 15 0 VEGETATION Gamma Spec Solid RAD A-013 10 0 10 0 Gas Flow Sr 2nd count 10 0 8 0 Gamma Spec Solid RAD A-013 with Iodine 73 0 102 0 AIR CHARCOAL Carbon-14 (Ascarite/Soda Lime Filter per Liter) 29 0 28 0 DRINKING WATER Tritium 23 0 24 0 LSC Iron-55 7 0 7 0 LSC Nickel 63 8 0 8 0

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Bias Criteria Precision Criteria

(+ / - 25%) (Note 1)

WITHIN OUTSIDE WITHIN OUTSIDE REMP 2021 CRITERIA CRITERIA CRITERIA CRITERIA Gamma Iodine-131 16 0 14 0 Gas Flow Sr 2nd count 9 0 10 0 Gas Flow Total Strontium 10 0 8 0 Gross Alpha Non Vol Beta 64 0 58 0 Gamma Spec Liquid RAD A-013 with Ba, La 20 0 60 0 Gamma Spec Liquid RAD A-013 with Iodine 0 0 4 0 Total 1245 1557 Note 1: The RPD must be 20 percent or less, if both samples are greater than 5 times the MDC. If both results are less than 5 times MDC, then the RPD must be equal to or less than 100%. If one result is above the MDC and the other is below the MDC, then the RPD can be calculated using the MDC for the result of the one below the MDC. The RPD must be 100% or less. In the situation where both results are above the MDC but one result is greater than 5 times the MDC and the other is less than 5 times the MDC, the RPD must be less than or equal to 20%. If both results are below MDC, then the limits on %

RPD are not applicable.

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Table 6.1-4 ALL RADIOLOGICAL INTRA-LABORATORY DATA

SUMMARY

BIAS AND PRECISION BY MATRIX Bias Criteria (+ / - 25% Precision Criteria (Note 1)

WITHIN OUTSIDE WITHIN OUTSIDE Total Radiological 2021 CRITERIA CRITERIA CRITERIA CRITERIA MILK Gamma Spec Liquid RAD A-013 4 0 4 0 Gamma Iodine-129 5 0 5 0 Gamma Iodine-131 8 0 119 0 LSC Sulfur 35 1 0 2 0 Gas Flow Sr 2nd count 54 0 59 0 Gas Flow Strontium 90 8 0 8 0 Gas Flow Total Strontium 12 0 13 0 Gamma Spec Liquid RAD A-013 with Ba, La 32 0 105 0 Gamma Spec Liquid RAD A-013 with Iodine 4 0 4 0 SOLID Gamma Percent Leach 6 0 0 0 Gas Flow Radium 228 93 0 100 0 Alpha Spec Neptunium 680 0 685 0 Tritium 398 0 479 0 Tritium by Pyrolysis 0 0 1 0 Carbon-14 250 0 334 0 Carbon-14 by Pyrolysis 0 0 1 0 LSC Iron-55 110 0 115 0 Alpha Spec Polonium Solid 23 0 28 0 Gamma Nickel 59 RAD A-022 145 0 149 0 Gamma Spec Ra226 RAD A-013 10 0 9 0 Gamma Spec Solid RAD A-013 1448 0 1867 0 LSC Nickel 63 256 0 279 0 LSC Plutonium 207 0 222 0 Technetium-99 667 0 764 0 Gamma Spec Liquid RAD A-013 1 0 1 0 Gross Alpha Beta Soil Leach 80 0 86 0 ICP-MS Technetium-99 in Soil 3 0 3 0 LSC Selenium 79 31 0 33 0 Total Activity, 6 0 9 0 Tritium 32 0 33 0 Alpha Spec Am243 96 0 110 0 Gamma Iodine-129 103 0 159 0 Gross Alpha/Beta 1 0 1 0 Gas Flow Lead 210 32 0 34 0 Alpha Spec Uranium 814 0 942 0 LSC Promethium 147 4 0 5 0

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Bias Criteria (+ / - 25% Precision Criteria (Note 1)

WITHIN OUTSIDE WITHIN OUTSIDE Total Radiological 2021 CRITERIA CRITERIA CRITERIA CRITERIA LSC, Rapid Strontium 89 and 90 55 0 57 0 Alpha Spec Thorium 898 0 1017 0 ICP-MS Uranium-233, 234 in Solid 49 0 52 0 LSC Sulfur 35 3 0 3 0 Alpha Spec Neptunium (pCi/Sample) 1 0 1 0 Alpha Spec Plutonium 759 0 762 0 ICP-MS Technetium-99 Prep in Soil 4 0 3 0 LSC Calcium 45 0 0 1 0 Alpha Spec Plutonium 162 0 174 0 Alpha Spec Radium 226 37 0 46 0 Gas Flow Sr 2nd count 17 0 24 0 Gas Flow Strontium 90 359 0 365 0 Lucas Cell Radium 226 225 0 261 0 Total Activity Screen 1 0 1 0 Alpha Spec Am241 Curium 613 0 602 0 Alpha Spec Total Uranium 81 0 93 0 Gas Flow Total Strontium 105 0 103 0 ICP-MS Uranium-233, 234 Prep in Solid 48 0 52 0 ICP-MS Uranium-235, 236, 238 in Solid 53 0 55 0 Alpha Spec Polonium Solid 14 0 14 0 Gamma Spec Solid RAD A-013 with Iodine 16 0 37 0 GFC Chlorine-36 in Solids 17 0 19 0 Gamma Spec Solid RAD A-013 (pCi/Sample) 1 0 2 0 Technetium-99 1 0 1 0 Tritium 10 0 10 0 Alpha Spec Am241 (pCi/Sample) 1 0 1 0 ICP-MS Uranium-234, 235, 236, 238 in Solid 350 0 361 0 ICP-MS Uranium-235, 236, 238 Prep in Solid 51 0 55 0 Alpha Spec Thorium 1 0 1 0 Gross Alpha/Beta (Am/Cs Calibration) Solid 2 0 3 0 ICP-MS U-234, 235, 236, 238 Prep per sample 8 0 8 0 Gross Alpha/Beta 493 0 592 0 Alpha Spec Plutonium 1 0 1 0 Gas Flow Strontium 90 1 0 1 0 Gross Alpha/Beta (Americium Calibration) Solid 2 0 2 0 ICP-MS Uranium-234, 235, 236, 238 Prep in Solid 181 0 176 0 Gross Alpha Beta (F,U) 17 0 18 0 FILTER Alpha Spec Polonium 1 0 10 0 Gamma I-131, filter 4 0 4 0 Alpha Spec Neptunium 73 0 94 0

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Bias Criteria (+ / - 25% Precision Criteria (Note 1)

WITHIN OUTSIDE WITHIN OUTSIDE Total Radiological 2021 CRITERIA CRITERIA CRITERIA CRITERIA LSC Plutonium Filter 88 0 125 0 Tritium 28 0 157 0 Alpha Spec Californium 2 0 3 0 Carbon-14 Direct Count 0 0 9 0 Carbon-14 0 0 75 0 ICP-MS Tc-99 in Filter 0 0 5 0 Nickel-63 0 0 20 0 LSC Iron-55 56 0 65 0 Gamma Nickel 59 RAD A-022 77 0 83 0 Alpha Spec Californium FPL 10 0 12 0 LSC Nickel 63 63 0 75 0 Technetium-99 9 0 101 0 Gamma Spec Filter RAD A-013 165 0 220 0 ICP-MS Tc-99 Prep in Filter 0 0 5 0 LSC Selenium 79 4 0 5 0 Alphaspec Np Filter per Liter 5 0 19 0 Alphaspec Pu Filter per Liter 10 0 18 0 Gamma Iodine-129 10 0 63 0 Alpha Spec Am243 17 0 32 0 Gas Flow Lead 210 1 0 2 0 Alpha Spec Uranium 85 0 119 0 LSC, Rapid Strontium 89 and 90 76 0 84 0 Alpha Spec Thorium 45 0 78 0 Gas Flow Radium 228 6 0 10 0 Alpha Spec Plutonium 66 0 142 0 ICP-MS Uranium-233, 234 in Filter 1 0 7 0 Alpha Spec Plutonium 79 0 118 0 Alpha Spec Plutonium 3 0 3 0 Alpha Spec Polonium,(Filter/Liter) 0 0 2 0 Alpha Spec Radium 226 3 0 10 0 Gas Flow Sr 2nd Count 25 0 45 0 Gas Flow Strontium 90 61 0 110 1 Gas Flow Total Radium 2 0 5 0 LSC Plutonium 241 Filter per Liter 7 0 29 0 Lucas Cell Radium-226 5 0 6 0 Alpha Spec Am241Curium 122 0 195 0 Gas Flow Total Strontium 0 0 1 0 ICP-MS Uranium-233, 234 Prep in Filter 1 0 7 0 ICP-MS Uranium-235, 236, 238 in Filter 11 0 15 0 Total Activity in Filter, 0 0 9 0 Alphaspec Am241 Curium Filter per Liter 13 0 45 0

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Bias Criteria (+ / - 25% Precision Criteria (Note 1)

WITHIN OUTSIDE WITHIN OUTSIDE Total Radiological 2021 CRITERIA CRITERIA CRITERIA CRITERIA Tritium 91 0 125 0 GFC Chlorine-36 in Filters 1 0 9 0 Gamma Spec Filter RAD A-013 Direct Count 3 0 9 0 Carbon-14 15 0 25 0 Gross A & B (Americium Calibration) Liquid 2 0 36 0 Direct Count-Gross Alpha/Beta 74 0 0 0 Gross Alpha/Beta 23 0 37 0 ICP-MS Uranium-234, 235, 236, 238 in Filter 12 0 60 0 ICP-MS Uranium-235, 236, 238 Prep in Filter 8 0 15 0 Alpha Spec U 19 0 51 0 Gross A & B 418 0 314 0 LSC Iron-55 11 0 17 0 Technetium-99 14 0 32 0 Gas Flow Sr-90 8 0 31 0 LSC Nickel 63 31 0 38 0 Gamma Spec Charcoal 2 0 2 0 Gas Flow Pb-210 0 0 17 0 Gas Flow Ra-228 0 0 18 0 Gross Alpha Beta (Flame, Unflame) 11 0 12 0 Gamma Iodine 129 16 0 16 0 ICP-MS Uranium-234, 235, 236, 238 Prep in Filter 6 0 30 0 Gamma Spec Filter 86 0 137 0 Lucas Cell Ra-226 5 0 24 0 Alpha Spec Thorium 6 0 31 0 LIQUID Alpha Spec Uranium 550 0 811 0 Alpha Spec Polonium 9 0 13 0 Alpha Spec Neptunium 230 0 332 0 Tritium 1216 0 1259 0 Carbon-14 156 0 185 0 Plutonium 100 0 118 0 Chlorine-36 in Liquids 1 0 1 0 Iodine-131 4 0 4 0 LSC Iron-55 68 0 124 0 Gamma Nickel 59 RAD A-022 21 0 27 0 Gamma Iodine 131 RAD A-013 1 0 3 0 LSC Nickel 63 114 0 157 0 LSC Radon 222 10 0 10 0 Technetium-99 601 0 714 0 Gamma Spec Liquid RAD A-013 815 0 914 0 Alpha Spec Total U RAD A-011 55 0 72 0 LSC Selenium 79 40 0 40 0

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Bias Criteria (+ / - 25% Precision Criteria (Note 1)

WITHIN OUTSIDE WITHIN OUTSIDE Total Radiological 2021 CRITERIA CRITERIA CRITERIA CRITERIA Total Activity, 8 0 9 0 Alpha Spec Am243 10 0 25 0 Gamma Iodine-129 184 0 199 0 Gamma Iodine-131 1 0 1 0 ICP-MS Technetium-99 in Water 3 0 8 0 Gas Flow Lead 210 9 0 20 0 Gross Alpha, Beta 3 0 3 0 LSC Promethium 147 17 0 17 0 LSC, Rapid Strontium 89 and 90 9 0 9 0 Alpha Spec Polonium 2 0 5 0 Alpha Spec Thorium 250 0 393 0 Gas Flow Radium 228 6 0 5 0 Gas Flow Radium 228 537 0 645 0 Alpha Spec Plutonium 401 0 545 0 LSC Sulfur 35 16 0 15 0 Alpha Spec Plutonium 27 0 40 0 Alpha Spec Radium 226 45 0 46 0 Gas Flow Sr 2nd count 65 0 108 0 Gas Flow Strontium 90 318 0 387 0 Gas Flow Strontium 90 10 0 10 0 Gas Flow Total Radium 333 0 281 0 ICP-MS Technetium-99 Prep in Water 3 0 8 0 ICP-MS Uranium-233, 234 in Liquid 7 0 11 0 LSC Calcium 45 13 0 13 0 Lucas Cell Radium 226 317 0 502 0 Lucas Cell Radium-226 7 0 10 0 Total Activity Screen 0 0 1 0 Chlorine-36 in Liquids 19 0 21 0 Gamma Spec Drinking Water RAD A-013 8 0 6 0 Alpha Spec Am241 Curium 353 0 463 0 Gas Flow Total Strontium 118 0 125 0 Gross Alpha Non Vol Beta 722 0 974 0 LSC Phosphorus-32 6 0 8 0 ICP-MS Uranium-233, 234 Prep in Liquid 7 0 11 0 Tritium in Drinking Water by EPA 906.0 9 0 6 0 Gamma Spec Liquid RAD A-013 with Ba, La 76 0 155 0 Gamma Spec Liquid RAD A-013 with Iodine 76 0 157 0 Gas Flow Strontium 89 & 90 6 0 5 0 ICP-MS Uranium-235, 236, 238 in Liquid 10 0 19 0 Gas Flow Total Alpha Radium 9 0 9 0

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Bias Criteria (+ / - 25% Precision Criteria (Note 1)

WITHIN OUTSIDE WITHIN OUTSIDE Total Radiological 2021 CRITERIA CRITERIA CRITERIA CRITERIA Gross Alpha Co-precipitation 5 0 9 0 ICP-MS Uranium-235, 236, 238 Prep in Liquid 9 0 19 0 Gross Alpha/Beta 1 0 5 0 ICP-MS Uranium-234, 235, 236, 238 in Liquid 108 0 104 0 Gross Alpha Beta (Flame, Unflame) 253 0 269 0 Gross Alpha Beta (Americium Calibration) Liquid 32 0 74 0 ICP-MS Uranium-234, 235, 236, 238 Prep in Liquid 52 0 56 0 Alpha/Beta (Americium Calibration) Drinking Water 35 0 27 0 ECLS-R-GA NJ 48 Hr Rapid Gross Alpha 1 0 1 0 TISSUE Alpha Spec Neptunium 0 0 13 0 Tritium 7 0 19 0 Carbon-14 2 0 13 0 Gamma Nickel 59 RAD A-022 2 0 2 0 Gamma Spec Solid RAD A-013 54 0 77 0 LSC Nickel 63 2 0 2 0 LSC Plutonium 2 0 2 0 Technetium-99 2 0 15 0 Gamma Iodine-129 6 0 19 0 Gas Flow Lead 210 2 0 13 0 Alpha Spec Uranium 8 0 24 0 Alpha Spec Thorium 2 0 14 0 Alpha Spec Plutonium 5 0 19 0 Alpha Spec Plutonium 2 0 2 0 Gas Flow Sr 2nd count 9 0 11 0 Gas Flow Strontium 90 10 0 23 0 Lucas Cell Radium 226 3 0 12 0 Alpha Spec Am241 Curium 3 0 17 0 Gas Flow Total Strontium 5 0 5 0 Gamma Spec Solid RAD A-013 with Iodine 15 0 15 0 GFC Chlorine-36 in Solids 0 0 11 0 Gross Alpha/Beta 3 0 5 0 VEGETATION Carbon-14 3 0 3 0 Gamma Spec Solid RAD A-013 29 0 24 0 Technetium-99 1 0 1 0 Tritium 2 0 2 0 Gas Flow Lead 210 3 0 4 0 Alpha Spec Uranium 21 0 24 0 Alpha Spec Thorium 9 0 10 0

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Bias Criteria (+ / - 25% Precision Criteria (Note 1)

WITHIN OUTSIDE WITHIN OUTSIDE Total Radiological 2021 CRITERIA CRITERIA CRITERIA CRITERIA Alpha Spec Plutonium 21 0 14 0 Gas Flow Sr 2nd count 10 0 8 0 Gas Flow Strontium 90 22 0 16 0 Gas Flow Total Radium 3 0 4 0 Alpha Spec Am241 Curium 9 0 7 0 Gamma Spec Solid RAD A-013 with Iodine 73 0 102 0 Gamma Spec Solid RAD A-013 (pCi/Sample) 2 0 2 0 Alpha Spec Am241 (pCi/Sample) 0 0 2 0 Alpha Spec Uranium 0 0 2 0 Gross Alpha/Beta 7 0 6 0 Alpha Spec Plutonium 0 0 2 0 Gas Flow Strontium 90 4 0 2 0 AIR CHARCOAL Gamma Iodine-129 23 0 8 0 Carbon-14 11 0 11 0 Carbon-14 (Ascarite/Soda Lime Filter per Liter) 29 0 28 0 Gamma Spec Charcoal 14 0 14 0 Gamma Iodine 129 14 0 14 0 DRINKING WATER Alpha Spec Uranium 1 0 1 0 Tritium 23 0 24 0 Iodine-131 1 0 0 0 LSC Iron-55 7 0 7 0 LSC Nickel 63 8 0 8 0 LSC Radon 222 17 0 20 0 Gamma Spec Liquid RAD A-013 3 0 3 0 Gamma Iodine-129 2 0 3 0 Gamma Iodine-131 16 0 14 0 Gas Flow Radium 228 41 0 37 0 Gas Flow Sr 2nd count 9 0 10 0 Gas Flow Strontium 90 9 0 8 0 Lucas Cell Radium 226 3 0 4 0 Lucas Cell Radium-226 46 0 46 0 Gamma Spec Drinking Water RAD A-013 37 0 48 0 Gas Flow Total Strontium 10 0 8 0 Gross Alpha Non Vol Beta 159 0 138 0 Tritium in Drinking Water by EPA 906.0 41 0 42 0 Gamma Spec Liquid RAD A-013 with Ba, La 20 0 60 0 Gamma Spec Liquid RAD A-013 with Iodine 2 0 6 0 Gas Flow Strontium 89 & 90 11 0 7 0 Alpha/Beta (Americium Calibration) Drinking Water 11 0 12 0 ECLS-R-GA NJ 48 Hr Rapid Gross Alpha 2 0 2 0

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Bias Criteria (+ / - 25% Precision Criteria (Note 1)

WITHIN OUTSIDE WITHIN OUTSIDE Total Radiological 2021 CRITERIA CRITERIA CRITERIA CRITERIA Total 21797 26844 Note 1: The RPD must be 20 percent or less, if both samples are greater than 5 times the MDC. If both results are less than 5 times MDC, then the RPD must be equal to or less than 100%. If one result is above the MDC and the other is below the MDC, then the RPD can be calculated using the MDC for the result of the one below the MDC. The RPD must be 100% or less. In the situation where both results are above the MDC but one result is greater than 5 times the MDC and the other is less than 5 times the MDC, the RPD must be less than or equal to 20%. If both results are below MDC, then the limits on % RPD are not applicable.

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Table 6.1-5 2021 CORRECTIVE ACTION REPORT

SUMMARY

CORRECTIVE ACTION ID#

& DISPOSITION PE FAILURE CARR 210311-1305 Root Cause Analysis ISO Documentation of PT Failures in Upon receipt of the PT report, an investigation was initiated by the RAD 124 in drinking water for: Quality Department and a Corrective Action (CARR) team assembled. The team consisted of representatives from the Ra-226 affected areas. The sample preparation and analytical processes Ra-228 were reviewed. This included review of reagents and standards Sr-89 used in the sample preparation steps, calibration records, process control samples, and interviews with the analysts.

The investigation determined that the laboratory met all quality control criteria specified in the method. Additionally, all internal procedures and policies were performed as required. These failures were tracked through GELs internal non-conformance system.

Ra-226:

The laboratory reviewed the data, and no anomalies were noted.

A review of the sample preparation processes, and data set did not reveal any gross errors or possible contributors to the low bias. It is possible that an unknown systematic error must have occurred during the precipitation steps of the procedure resulting in the low bias.

Ra-228:

The Batch data were reviewed and low gravimetric yields were identified. The Ra-228 drinking water method includes two gravimetric yields and both yields were lower than normal for this method. It is apparent that the low yields, which are multiplied together to determine the final yield for the analysis, biased the result high. Original reported data was calculated with "typical" method yields obtaining result of 11.9 pCi/L (92% of known value).

The low yields were not sample specific with MB and LCS yields being similar to the samples in the batch; therefore, an unknown systematic error must have occurred during the precipitation steps of the procedure that resulted in low yields.

Sr-89:

The result for Strontium-89 was 122% of the known value with the acceptance range limit of 114%. The Group Leader reviewed the method to identify the bias. The method LCS trend was reviewed for the method and no anomalies were identified. The calibration used for the analysis was compared to the new calibration performed recently and the original reported data were processed with both calibrations for comparison. Data were comparable. Instrument run logs were reviewed and there was no indication of possible bias.

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CORRECTIVE ACTION ID#

& DISPOSITION PE FAILURE Sr89/90 drinking water method includes two gravimetric yields. Both gravimetric batch yields were reviewed, and it was noted that the Yttrium yields appeared to be slightly higher than expected for this method. It is possible that the Yttrium yields were biased high due to analyst error during the drying process. The original reported data were processed with typically recovered Yttrium method yields and the Sr-89 value (65.8 pCi/L) was within the acceptance range at 108%.

Permanent Corrective/Preventive Actions or Improvements None at this time. The laboratory will continue to monitor the recoveries of these parameters to ensure that there are no continued issues in the processes.

CARR 210524-1327 Root Cause Analysis ISO Documentation of PT Failure in The laboratory reviewed the data, and no anomalies were noted. A review RAD 125 in drinking water for: of the sample preparation processes, and data set did not reveal any gross errors or possible contributors to the low bias. It is possible that an unknown systematic error must have occurred during the precipitation steps of the

Ra-226 procedure resulting in the low bias.

Permanent Corrective/Preventive Actions or Improvements None at this time. The laboratory will continue to monitor the recoveries of these parameters to ensure that there are no continued issues in the processes CARR 210603-1329 Root Cause Analysis ISO Documentation of PT Failure in The results for this analysis were reviewed and it was noted that the result MRAD 34 in air filter and water for: for the in-batch duplicate would have been acceptable recovering at 96% of the known value and met replication criteria. The laboratory investigated the transfer rig that was used to prep the unacceptable sample and noted loose

Gross fittings and cracked tubing. These may have contributed to the low bias in Alpha the sample preparation. The transfer rig was rebuilt, and the other rigs inspected for possible wear issues that may need to be rebuilt or replaced.

ISO Documentation of PT Failure in MRAD-34 in water for: Permanent Corrective/Preventive Actions or Improvements

Fe-55 None at this time. The laboratory will continue to monitor the recovery of this parameter to ensure that there are no continued issues in the processes.

CARR 210723-1339 Root Cause Analysis ISO Documentation of PT Failures in The antimony sample was prepared using standard hot-acid leach per MAPEP 44 for: section 7.5 of SW-846 3050B. More rigorous digestions were used in an attempt to increase solubility without success. It is suspected that the low bias in the result is due to an unidentified matrix interferant.

Sb

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CORRECTIVE ACTION ID#

& DISPOSITION PE FAILURE

Ce-134 The data have been reviewed for these analyses and no errors were noted.

Sr-90 The Cesium-134 and Strontium-90 failed with a low bias compared to the known. It was noted that several other reported isotopes had a low bias but were within the acceptance ranges for their parameters. It is suspected that the sample preparation had an unidentified error during the digestion process.

Permanent Corrective/Preventive Actions or Improvements None at this time. The laboratory will continue to monitor the recovery of this parameter to ensure that there are no continued issues in the processes.

CARR 210830-1343 Root Cause Analysis ISO Documentation of PT Failures in The data have been reviewed for this analysis and no errors were noted. The RAD-126 for: Strontium-90 failed with a high bias compared to the known.

Permanent Corrective/Preventive Actions or Improvements

Sr-90 None at this time. The laboratory will continue to monitor the recovery of this parameter to ensure that there are no continued issues in the processes.

CARR 211216-1360 Root Cause Analysis ISO Documentation of PT Failures in Gross Alpha: The data for this analysis has been reviewed and no errors MAPEP 45 for: were noted. It was found that the result from the original count for the sample preparation was within the acceptance limits of the study. The sample initially did not meet replication criteria for the in-batch duplicate and

Gross Alpha was recounted. The duplicate sample was not recounted during the

U-234 process.

Np-237

Ra-226 U-234: The laboratory preparation and counting procedures were

Sr-90 evaluated for potential contributors to the high bias of these results. None were noted and the batches met QC criteria for recovery and duplication.

Np-237: Upon review, it is suspected that the bias in the Np result is due to an unidentified matrix interferant. The sample should have been returned to the lab for additional clean up steps. The Sr warning result recovered at 72.5% of the known value. The laboratory evaluated both the prep and instrument processes for possible causes for the low bias. A definitive cause was not determined.

Ra-226: The data has been reviewed and no errors were found. It was noted that the in-batch duplicate sample result was within acceptance limits for the study. The samples met RER replication criteria.

Sr-90: This warning result recovered at 71% of the known value. The laboratory evaluated both the prep and instrument processes for possible causes for the low bias. A definitive source was not determined. This Sr warning result was analyzed in a separate laboratory than the synthetic fecal sample which uses an entirely separate processes for analysis.

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CORRECTIVE ACTION ID#

& DISPOSITION PE FAILURE Permanent Corrective/Preventive Actions or Improvements None at this time. The laboratory will continue to monitor the recoveries of these parameters to ensure that there are no continued issues in the processes.

CARR 211215-1358 Root Cause Analysis ISO Documentation of PT Failures in The laboratory reviewed the data and found no errors. It was noted that the MRAD 35 air filter and water for: sample was replicated in the analysis batch and met replication criteria. For the water analysis, the result of the duplicate sample was within the acceptance range of the study. All analysis data met the acceptance QC

U-234 criteria and procedures for initial calibration, continuing calibration, instrument controls and process controls were met.

Permanent Corrective/Preventive Actions or Improvements None at this time. The laboratory will continue to monitor the recoveries of these parameters to ensure that there are no continued issues in the processes.

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6.2 Environmental TLD QA Environmental dosimetry services for the reporting period of January - December 2021 were provided through Stanford Dosimetry, with TLD processing by the Environmental Dosimetry Company (EDC), Sterling, Massachusetts. The TLD systems at the Environmental Dosimetry Company (EDC) are calibrated and operated to ensure consistent and accurate evaluation of TLDs. The quality of the dosimetric results reported to EDC clients is ensured by in-house performance testing and independent performance testing by EDC clients.

The purpose of the dosimetry quality assurance program is to provide performance documentation of the routine processing of EDC dosimeters. Performance testing provides a statistical measure of the bias and precision of dosimetry processing against a reliable standard, which in turn points out any trends or performance changes. Dosimetry quality control tests are performed on EDC Panasonic 814 Environmental dosimeters. These tests include: (1) the in-house testing program conducted by the EDC QA Officer; and (2) independent tests perform by EDC clients. In-house tests are performed using six pairs of 814 dosimeters.

A pair is reported as an individual result and six pairs are reported as the mean result.

Excluded from this report are instrumentation checks. Although instrumentation checks represent an important aspect of the quality assurance program, they are not included as process checks in this report.

Instrumentation checks represent between 5-10% of the TLDs processed.

Table 6.2-1 provides a summary of individual dosimeter results evaluated against the EDC internal acceptance criteria for high-energy photons (Cs-137) only. The internal acceptance (tolerance) criteria for the Panasonic Environmental dosimeters are: +/- 15% for bias and +/- 12.8% for precision. During this period, 100% (72/72) of the individual dosimeters evaluated against these criteria met the tolerance limits for accuracy and 100% (72/72) met the criterion for precision.

Table 6.2-2 provides the Bias + Standard deviation results for each group (N=6) of dosimeters evaluated against the internal tolerance criteria. Overall, 100% (12/12) of the dosimeter sets evaluated against the internal tolerance performance criteria met these criteria.

Table 6.2-3 presents the independent blind spike results for irradiated dosimeters provided by client utilities during this annual period. All results passed the performance acceptance criterion.

Table 6.2-4 presents the independent blind duplicate results for dosimeters co-located with field dosimeters provided by the client utility (Seabrook Station) during the annual period. All results passed the performance criteria of agreement to within 20% (within 3-sigma) of the field dosimeter.

TABLE 6.2-1 PERCENTAGE OF INDIVIDUAL DOSIMETERS THAT PASSED EDC INTERNAL CRITERIA JANUARY - DECEMBER 2021(1), (2)

Number % Passed Precision Dosimeter Type % Passed Bias Criteria Tested Criteria Panasonic Environmental 72 100 100 (1)This table summarizes results of tests conducted by EDC.

(2)Environmental dosimeter results are free in air.

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TABLE 6.2-2 MEAN DOSIMETER ANALYSES (N=6)

JANUARY - DECEMBER 2021(1), (2)

Exposure Standard Tolerance Process Date Mean Bias %

Level Deviation % Limit +/-15%

5/04/2021 33 0.6 0.9 Pass 5/06/2021 120 -0.2 1.4 Pass 5/26/2021 53 -3.8 1.6 Pass 7/27/2021 67 2.8 1.4 Pass 8/04/2021 91 -1.8 2.3 Pass 9/14/2021 47 -0.2 2.3 Pass 11/01/2021 28 3.7 0.6 Pass 11/03/2021 74 1.9 1.9 Pass 11/09/2021 103 1.1 1.1 Pass 01/26/2022 37 2.6 1.9 Pass 01/30/2022 85 -4.2 1.1 Pass 02/06/2022 58 2.9 1.2 Pass (1) This table summarizes results of tests conducted by EDC for TLDs issued in 2021.

(2) Environmental dosimeter results are free in air.

TABLE 6.2-3

SUMMARY

OF INDEPENDENT DOSIMETER TESTING JANUARY - DECEMBER 2021(1), (2)

Standard Issuance Period Client Mean Bias % Pass / Fail Deviation %

1st Qtr. 2021 SONGS -3.8 1.4 Pass 1st Qtr. 2021 SONGS -4.7 1.1 Pass 2nd Qtr.2021 Seabrook 3.1 1.0 Pass 3rd Qtr. 2021 Millstone -4.7 1.4 Pass 4th Qtr.2021 PSEG(PNNL) 50mR 1.3 0.8 Pass 4th Qtr.2021 PSEG(PNNL) 100mR 1.8 0.8 Pass 4th Qtr.2021 PSEG(PNNL) 150mR -0.6 0.5 Pass 4th Qtr.2021 PSEG(PNNL) 200mR -2.6 2.0 Pass 4th Qtr.2021 Seabrook 2.6 1.4 Pass (1) Performance criterion is +/- 15%.

(2) Blind spike irradiations using Cs-137

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TABLE 6.2-4

SUMMARY

OF INDEPENDENT BLIND DUPLICATE DOSIMETER TESTING JANUARY - DECEMBER 2021(1)

Standard % Passed Number Mean Bias Issuance Period Client Deviation Precision Tested %

% Criteria 1st Qtr. 2021 Seabrook 12 0.7 3.7 Pass 2nd Qtr.2021 Seabrook 6 0.7 3.3 Pass 3rd Qtr. 2021 Seabrook 12 -4.6 2.9 Pass 4th Qtr.2021 Seabrook 6 -0.2 3.7 Pass (1) Performance criterion is Bias % within +/- 20% for each test dosimeter.

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7.0 Land Use Census The Offsite Dose Calculation Manual (ODCM Control 9.2.1) requires that a Land Use Census be conducted annually to identify the location of the nearest residence, milk animal and nearest garden of greater than 50 square meters producing broad leaf vegetation in each of the 16 meteorological sectors within five miles of the plant. The 2021 census was completed in accordance with the requirements of the ODCM. In 2021, a global positioning system was used to determine locations in the off-site environs with respect to the center of the site (Unit 1 Containment).

The nearest resident, garden and milk animal locations identified in the 2021 Land Use Census and their distances are shown in Table 7.0-1. There were slight changes in the measured distances for residences in the NNE, NE, ENE, E, ESE, SE, SSE, SW and WSW sectors due to the specific location where the GPS measurement was taken. There were no changes in the locations of nearest gardens from last years census.

There were no new milk producing locations identified within the required 5 miles (8 km) of the plant that were different from those reported in the last years land use census. As a result, there still remains an insufficient number of milk producing locations to qualify milk sampling as a REMP media per the requirements of ODCM Table A.9.1-1.

The results of this years census also showed that the sampling locations used in the REMP continue to have the highest calculated dose commitments of available locations. In 2021, broad leaf vegetation continued as part of the sample collection and analysis program due to the absence of sufficient milk producing locations to provide REMP samples. Sampling locations for broad leaf vegetation are at the site boundary near points of highest predicted D/Q. This option continues, as opposed to public owned vegetable gardens located by the land use census, in order to ensure adequate availability of samples for REMP analysis from locations with the highest potential for detecting plant effluents.

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Table 7.0-1 2021 Land Use Census Results (Within 5 Miles)

Sector Nearest Residence Nearest Garden Nearest Milk Animal (km) (km) (km)

N 2.78 3.99 NNE 3.09 3.20 NE 2.92 4.24 ENE 2.31 2.53 E 2.56 -----

ESE 2.43 -----

SE 2.36 4.69 SSE 1.65 -----

S 1.21 1.25 SSW 1.12 1.22 SW 1.13 1.73 WSW 1.87 2.33 W 1.25 1.55 WNW 1.11 3.08 NW 1.22 3.14 6.93 NNW 1.04 2.07 5.32a a No milking goats at this time.

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Attachment 1: Sample Analysis Data List for 2021 FLAGS A blank Flag field indicates that the measured activity is considered positive as it is greater than the MDC and has no other qualifiers noted.

U: Target isotope was analyzed for but not detected above the MDC and LLD.

UI: Uncertain identification for gamma spectroscopy.

X: Lab-specific qualifier:

(1) False positive due to the presence of radon gas in the water.

M: Reported result is less than the LLD and greater than the MDC.

DL: Measured MDC is greater than the LLD.

DL*: Near miss of MDC being within round-off difference of being greater than the LLD.

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

AL 05 545134001 5/11/2021 Ac-228 1.17E+01 1.38E+01 3.83E+01 U AL 05 545134001 5/11/2021 Ag-108m -3.02E+00 2.14E+00 6.32E+00 U AL 05 545134001 5/11/2021 Ag-110m -4.11E-01 3.84E+00 1.22E+01 U AL 05 545134001 5/11/2021 Ba-140 1.48E+01 1.67E+01 5.66E+01 U AL 05 545134001 5/11/2021 Be-7 2.31E+02 5.65E+01 7.16E+01 AL 05 545134001 5/11/2021 Ce-141 1.05E+00 3.89E+00 1.27E+01 U AL 05 545134001 5/11/2021 Ce-144 -2.70E+01 1.53E+01 4.21E+01 U AL 05 545134001 5/11/2021 Co-57 -7.50E-01 1.95E+00 6.24E+00 U AL 05 545134001 5/11/2021 Co-58 4.31E-01 2.78E+00 9.04E+00 U AL 05 545134001 5/11/2021 Co-60 -3.02E+00 3.09E+00 9.29E+00 U AL 05 545134001 5/11/2021 Cr-51 -3.59E+01 2.41E+01 7.24E+01 U AL 05 545134001 5/11/2021 Cs-134 -4.08E-01 2.87E+00 9.17E+00 U AL 05 545134001 5/11/2021 Cs-137 6.45E+00 2.91E+00 9.30E+00 U AL 05 545134001 5/11/2021 Fe-59 3.10E-01 7.45E+00 2.53E+01 U AL 05 545134001 5/11/2021 I-131 7.83E+00 6.62E+00 2.26E+01 U AL 05 545134001 5/11/2021 K-40 6.66E+03 4.00E+02 6.36E+01 AL 05 545134001 5/11/2021 La-140 -1.54E+00 4.77E+00 1.51E+01 U AL 05 545134001 5/11/2021 Mn-54 2.60E+00 2.75E+00 9.12E+00 U AL 05 545134001 5/11/2021 Nb-95 1.52E-01 2.57E+00 8.37E+00 U AL 05 545134001 5/11/2021 Ru-103 -2.29E+00 2.62E+00 8.17E+00 U AL 05 545134001 5/11/2021 Ru-106 -3.10E+01 2.46E+01 7.18E+01 U AL 05 545134001 5/11/2021 Sb-124 -1.26E+00 6.02E+00 1.66E+01 U AL 05 545134001 5/11/2021 Sb-125 6.18E+00 6.73E+00 2.30E+01 U AL 05 545134001 5/11/2021 Se-75 -5.64E+00 3.55E+00 9.52E+00 U AL 05 545134001 5/11/2021 Th-228 0.00E+00 8.76E+00 1.77E+01 U AL 05 545134001 5/11/2021 Zn-65 1.06E+01 8.06E+00 2.76E+01 U AL 05 545134001 5/11/2021 Zr-95 -2.48E+00 5.12E+00 1.60E+01 U AL 05 562686001 11/17/2021 Ac-228 -2.52E+01 2.47E+01 6.34E+01 U AL 05 562686001 11/17/2021 Ag-108m -5.76E-01 3.09E+00 1.01E+01 U AL 05 562686001 11/17/2021 Ag-110m -8.71E+00 6.21E+00 1.77E+01 U AL 05 562686001 11/17/2021 Ba-140 -4.45E+01 3.06E+01 8.51E+01 U AL 05 562686001 11/17/2021 Be-7 2.01E+02 7.03E+01 1.10E+02 AL 05 562686001 11/17/2021 Ce-141 -8.18E+00 1.00E+01 2.15E+01 U AL 05 562686001 11/17/2021 Ce-144 0.00E+00 3.23E+01 6.72E+01 U AL 05 562686001 11/17/2021 Co-57 -2.93E+00 2.82E+00 8.49E+00 U AL 05 562686001 11/17/2021 Co-58 -5.28E+00 4.71E+00 1.43E+01 U AL 05 562686001 11/17/2021 Co-60 2.93E+00 5.08E+00 1.72E+01 U AL 05 562686001 11/17/2021 Cr-51 2.75E+01 3.72E+01 1.28E+02 U AL 05 562686001 11/17/2021 Cs-134 3.40E+00 4.77E+00 1.67E+01 U AL 05 562686001 11/17/2021 Cs-137 2.93E+00 4.61E+00 1.46E+01 U AL 05 562686001 11/17/2021 Fe-59 5.86E+00 1.22E+01 4.12E+01 U AL 05 562686001 11/17/2021 I-131 1.82E+01 1.18E+01 3.97E+01 U AL 05 562686001 11/17/2021 K-40 7.62E+03 4.70E+02 1.65E+02 AL 05 562686001 11/17/2021 La-140 -1.53E+01 1.27E+01 3.04E+01 U AL 05 562686001 11/17/2021 Mn-54 -1.02E+00 3.96E+00 1.31E+01 U AL 05 562686001 11/17/2021 Nb-95 -1.55E+01 7.61E+00 1.65E+01 U AL 05 562686001 11/17/2021 Ru-103 3.58E+00 4.68E+00 1.57E+01 U AL 05 562686001 11/17/2021 Ru-106 -5.11E+01 4.15E+01 1.18E+02 U AL 05 562686001 11/17/2021 Sb-124 3.93E+00 8.80E+00 3.12E+01 U AL 05 562686001 11/17/2021 Sb-125 -1.48E+01 1.02E+01 2.88E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

AL 05 562686001 11/17/2021 Se-75 -4.85E+00 4.67E+00 1.48E+01 U AL 05 562686001 11/17/2021 Th-228 6.64E+00 8.32E+00 2.50E+01 U AL 05 562686001 11/17/2021 Zn-65 1.08E+01 1.20E+01 4.11E+01 U AL 05 562686001 11/17/2021 Zr-95 9.26E+00 8.31E+00 2.77E+01 U AL 55 545134002 5/11/2021 Ac-228 1.31E+01 1.79E+01 5.44E+01 U AL 55 545134002 5/11/2021 Ag-108m -6.44E-01 2.68E+00 8.49E+00 U AL 55 545134002 5/11/2021 Ag-110m -6.85E+00 5.03E+00 1.45E+01 U AL 55 545134002 5/11/2021 Ba-140 -1.73E+00 2.37E+01 7.48E+01 U AL 55 545134002 5/11/2021 Be-7 3.32E+02 6.14E+01 9.98E+01 AL 55 545134002 5/11/2021 Ce-141 1.54E+01 1.01E+01 1.70E+01 U AL 55 545134002 5/11/2021 Ce-144 -2.38E+01 1.95E+01 6.15E+01 U AL 55 545134002 5/11/2021 Co-57 1.59E+00 2.41E+00 8.23E+00 U AL 55 545134002 5/11/2021 Co-58 -2.07E-01 3.57E+00 1.18E+01 U AL 55 545134002 5/11/2021 Co-60 3.76E+00 4.22E+00 1.41E+01 U AL 55 545134002 5/11/2021 Cr-51 -5.06E+00 3.29E+01 1.07E+02 U AL 55 545134002 5/11/2021 Cs-134 2.59E-01 4.70E+00 1.44E+01 U AL 55 545134002 5/11/2021 Cs-137 6.52E-01 3.38E+00 1.15E+01 U AL 55 545134002 5/11/2021 Fe-59 2.65E+01 1.86E+01 3.18E+01 U AL 55 545134002 5/11/2021 I-131 5.37E+00 9.51E+00 3.13E+01 U AL 55 545134002 5/11/2021 K-40 7.40E+03 4.12E+02 1.03E+02 AL 55 545134002 5/11/2021 La-140 6.94E+00 5.55E+00 1.89E+01 U AL 55 545134002 5/11/2021 Mn-54 -3.92E+00 4.45E+00 1.13E+01 U AL 55 545134002 5/11/2021 Nb-95 -2.15E+00 3.97E+00 1.11E+01 U AL 55 545134002 5/11/2021 Ru-103 -2.99E+00 4.10E+00 1.25E+01 U AL 55 545134002 5/11/2021 Ru-106 6.70E+01 4.87E+01 9.08E+01 U AL 55 545134002 5/11/2021 Sb-124 -8.81E+00 7.74E+00 2.19E+01 U AL 55 545134002 5/11/2021 Sb-125 -1.05E+01 8.62E+00 2.50E+01 U AL 55 545134002 5/11/2021 Se-75 8.26E-01 4.35E+00 1.30E+01 U AL 55 545134002 5/11/2021 Th-228 0.00E+00 1.47E+01 2.09E+01 U AL 55 545134002 5/11/2021 Zn-65 3.92E+00 9.61E+00 3.18E+01 U AL 55 545134002 5/11/2021 Zr-95 -4.01E+00 7.68E+00 2.16E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

AL 55 562686002 11/17/2021 Ac-228 3.07E+01 2.48E+01 5.78E+01 U AL 55 562686002 11/17/2021 Ag-108m -1.83E-01 2.03E+00 6.44E+00 U AL 55 562686002 11/17/2021 Ag-110m 1.16E+00 4.32E+00 1.40E+01 U AL 55 562686002 11/17/2021 Ba-140 -8.35E+00 1.76E+01 5.58E+01 U AL 55 562686002 11/17/2021 Be-7 3.96E+02 6.10E+01 8.64E+01 AL 55 562686002 11/17/2021 Ce-141 4.40E+00 4.79E+00 1.55E+01 U AL 55 562686002 11/17/2021 Ce-144 -3.37E+01 1.82E+01 4.85E+01 U AL 55 562686002 11/17/2021 Co-57 5.01E-01 1.97E+00 6.40E+00 U AL 55 562686002 11/17/2021 Co-58 1.50E+00 3.65E+00 1.20E+01 U AL 55 562686002 11/17/2021 Co-60 -2.25E+00 3.52E+00 9.27E+00 U AL 55 562686002 11/17/2021 Cr-51 4.42E+01 2.88E+01 9.76E+01 U AL 55 562686002 11/17/2021 Cs-134 7.03E+00 6.91E+00 1.02E+01 U AL 55 562686002 11/17/2021 Cs-137 3.11E+00 3.25E+00 1.09E+01 U AL 55 562686002 11/17/2021 Fe-59 1.59E+00 8.09E+00 2.75E+01 U AL 55 562686002 11/17/2021 I-131 0.00E+00 8.98E+00 2.15E+01 U AL 55 562686002 11/17/2021 K-40 6.21E+03 3.53E+02 1.13E+02 AL 55 562686002 11/17/2021 La-140 4.10E+00 5.28E+00 1.88E+01 U AL 55 562686002 11/17/2021 Mn-54 1.36E+00 3.16E+00 1.04E+01 U AL 55 562686002 11/17/2021 Nb-95 -2.03E+00 3.87E+00 1.20E+01 U AL 55 562686002 11/17/2021 Ru-103 -5.09E+00 3.41E+00 9.67E+00 U AL 55 562686002 11/17/2021 Ru-106 -1.96E+01 2.73E+01 8.40E+01 U AL 55 562686002 11/17/2021 Sb-124 1.54E+00 6.77E+00 2.27E+01 U AL 55 562686002 11/17/2021 Sb-125 1.72E+01 8.34E+00 2.71E+01 U AL 55 562686002 11/17/2021 Se-75 -6.88E+00 4.19E+00 1.11E+01 U AL 55 562686002 11/17/2021 Th-228 0.00E+00 1.02E+01 1.63E+01 U AL 55 562686002 11/17/2021 Zn-65 8.03E-01 8.18E+00 2.77E+01 U AL 55 562686002 11/17/2021 Zr-95 -3.99E+00 6.33E+00 1.93E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 01 532372001 1/13/2021 BETA 2.47E-02 1.08E-03 8.27E-04 AP 01 533687001 1/27/2021 BETA 2.07E-02 1.01E-03 8.66E-04 AP 01 535173001 2/10/2021 BETA 2.20E-02 1.08E-03 1.01E-03 AP 01 536335001 2/25/2021 BETA 2.56E-02 9.97E-04 7.03E-04 AP 01 537636001 3/10/2021 BETA 2.55E-02 1.09E-03 8.32E-04 AP 01 539006001 3/24/2021 BETA 2.43E-02 1.02E-03 7.33E-04 AP 01 543395001 3/24/2021 Ac-228 1.34E-03 6.57E-04 1.66E-03 U AP 01 543395001 3/24/2021 Ag-108m -8.89E-05 8.09E-05 2.48E-04 U AP 01 543395001 3/24/2021 Ag-110m 1.18E-04 1.49E-04 5.10E-04 U AP 01 543395001 3/24/2021 Ba-140 -7.32E-02 3.48E-02 8.59E-02 U AP 01 543395001 3/24/2021 Be-7 1.13E-01 8.34E-03 7.23E-03 AP 01 543395001 3/24/2021 Ce-141 -1.80E-04 6.70E-04 2.23E-03 U AP 01 543395001 3/24/2021 Ce-144 1.03E-03 1.15E-03 1.72E-03 U AP 01 543395001 3/24/2021 Co-57 -2.10E-05 6.85E-05 2.31E-04 U AP 01 543395001 3/24/2021 Co-58 1.87E-04 2.05E-04 7.01E-04 U AP 01 543395001 3/24/2021 Co-60 -6.78E-05 1.11E-04 3.49E-04 U AP 01 543395001 3/24/2021 Cr-51 -2.76E-03 5.81E-03 1.80E-02 U AP 01 543395001 3/24/2021 Cs-134 2.84E-04 1.20E-04 3.84E-04 U AP 01 543395001 3/24/2021 Cs-137 1.60E-04 1.04E-04 3.09E-04 U AP 01 543395001 3/24/2021 Fe-59 9.96E-04 9.94E-04 2.37E-03 U AP 01 543395001 3/24/2021 I-131 0.00E+00 1.36E-01 0.00E+00 UI AP 01 543395001 3/24/2021 K-40 8.87E-04 2.22E-03 3.40E-03 U AP 01 543395001 3/24/2021 La-140 -7.12E-03 1.29E-02 3.98E-02 U AP 01 543395001 3/24/2021 Mn-54 -4.38E-06 1.06E-04 3.52E-04 U AP 01 543395001 3/24/2021 Nb-95 3.37E-04 2.36E-04 7.99E-04 U AP 01 543395001 3/24/2021 Ru-103 1.85E-04 3.19E-04 1.07E-03 U AP 01 543395001 3/24/2021 Ru-106 4.11E-04 9.44E-04 3.10E-03 U AP 01 543395001 3/24/2021 Sb-124 -9.68E-04 5.80E-04 1.35E-03 U AP 01 543395001 3/24/2021 Sb-125 1.64E-04 2.53E-04 8.56E-04 U AP 01 543395001 3/24/2021 Se-75 3.22E-04 2.85E-04 5.91E-04 U AP 01 543395001 3/24/2021 Th-228 2.65E-04 2.71E-04 6.20E-04 U AP 01 543395001 3/24/2021 Zn-65 -3.64E-04 2.86E-04 7.95E-04 U AP 01 543395001 3/24/2021 Zr-95 6.02E-04 4.09E-04 1.39E-03 U AP 01 540404001 4/7/2021 BETA 1.77E-02 9.11E-04 8.10E-04 AP 01 541857001 4/21/2021 BETA 9.13E-03 6.81E-04 8.29E-04 M AP 01 544029001 5/5/2021 BETA 2.22E-02 1.04E-03 9.98E-04 AP 01 545432001 5/19/2021 BETA 1.81E-02 9.33E-04 8.54E-04 AP 01 546369001 6/2/2021 BETA 1.55E-02 8.75E-04 8.71E-04 AP 01 547926001 6/16/2021 BETA 2.22E-02 1.03E-03 8.20E-04 AP 01 548743001 6/29/2021 BETA 2.23E-02 1.10E-03 9.67E-04 AP 01 552139001 6/29/2021 Ac-228 -1.26E-04 2.97E-04 9.40E-04 U AP 01 552139001 6/29/2021 Ag-108m -1.68E-06 5.62E-05 1.89E-04 U AP 01 552139001 6/29/2021 Ag-110m 1.43E-04 1.33E-04 5.00E-04 U AP 01 552139001 6/29/2021 Ba-140 -1.18E-03 3.40E-02 1.12E-01 U AP 01 552139001 6/29/2021 Be-7 1.22E-01 9.35E-03 5.21E-03 AP 01 552139001 6/29/2021 Ce-141 1.16E-04 3.82E-04 1.29E-03 U AP 01 552139001 6/29/2021 Ce-144 4.97E-05 3.18E-04 9.93E-04 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 01 552139001 6/29/2021 Co-57 -1.22E-05 3.12E-05 1.01E-04 U AP 01 552139001 6/29/2021 Co-58 2.22E-04 1.62E-04 6.07E-04 U AP 01 552139001 6/29/2021 Co-60 4.33E-05 8.64E-05 3.11E-04 U AP 01 552139001 6/29/2021 Cr-51 -5.60E-03 5.09E-03 1.37E-02 U AP 01 552139001 6/29/2021 Cs-134 2.79E-05 1.01E-04 3.36E-04 U AP 01 552139001 6/29/2021 Cs-137 2.90E-05 8.53E-05 3.00E-04 U AP 01 552139001 6/29/2021 Fe-59 -3.91E-05 5.72E-04 1.88E-03 U AP 01 552139001 6/29/2021 I-131 0.00E+00 1.53E-01 0.00E+00 UI AP 01 552139001 6/29/2021 K-40 9.27E-04 1.43E-03 4.89E-03 U AP 01 552139001 6/29/2021 La-140 1.12E-02 1.61E-02 5.84E-02 U AP 01 552139001 6/29/2021 Mn-54 8.34E-05 9.64E-05 3.40E-04 U AP 01 552139001 6/29/2021 Nb-95 1.57E-04 1.68E-04 6.08E-04 U AP 01 552139001 6/29/2021 Ru-103 -2.16E-04 3.42E-04 1.06E-03 U AP 01 552139001 6/29/2021 Ru-106 -6.58E-04 8.91E-04 2.63E-03 U AP 01 552139001 6/29/2021 Sb-124 5.41E-04 5.41E-04 2.16E-03 U AP 01 552139001 6/29/2021 Sb-125 -4.42E-04 2.25E-04 4.15E-04 U AP 01 552139001 6/29/2021 Se-75 9.89E-06 1.26E-04 4.01E-04 U AP 01 552139001 6/29/2021 Th-228 3.47E-04 1.53E-04 3.00E-04 UI AP 01 552139001 6/29/2021 Zn-65 -6.17E-05 3.38E-04 1.10E-03 U AP 01 552139001 6/29/2021 Zr-95 1.22E-03 6.10E-04 1.25E-03 U AP 01 549925001 7/13/2021 BETA 1.36E-02 8.39E-04 8.95E-04 AP 01 551091001 7/28/2021 BETA 2.51E-02 1.10E-03 9.79E-04 AP 01 552841001 8/11/2021 BETA 2.46E-02 1.13E-03 1.05E-03 AP 01 554155001 8/25/2021 BETA 2.21E-02 1.07E-03 8.98E-04 AP 01 555720001 9/9/2021 BETA 3.10E-02 1.22E-03 8.15E-04 AP 01 556805001 9/22/2021 BETA 2.70E-02 1.26E-03 1.01E-03 AP 01 560825001 9/22/2021 Ac-228 1.26E-03 6.70E-04 1.58E-03 U AP 01 560825001 9/22/2021 Ag-108m -3.29E-05 6.54E-05 2.16E-04 U AP 01 560825001 9/22/2021 Ag-110m -9.36E-05 1.42E-04 4.49E-04 U AP 01 560825001 9/22/2021 Ba-140 -1.95E-02 2.86E-02 9.04E-02 U AP 01 560825001 9/22/2021 Be-7 1.09E-01 8.01E-03 5.79E-03 AP 01 560825001 9/22/2021 Ce-141 2.57E-04 6.11E-04 1.80E-03 U AP 01 560825001 9/22/2021 Ce-144 3.59E-04 5.27E-04 1.69E-03 U AP 01 560825001 9/22/2021 Co-57 4.55E-05 6.82E-05 2.20E-04 U AP 01 560825001 9/22/2021 Co-58 2.92E-05 1.94E-04 6.29E-04 U AP 01 560825001 9/22/2021 Co-60 -1.14E-04 8.90E-05 2.24E-04 U AP 01 560825001 9/22/2021 Cr-51 -1.19E-03 4.57E-03 1.46E-02 U AP 01 560825001 9/22/2021 Cs-134 6.37E-05 1.02E-04 3.40E-04 U AP 01 560825001 9/22/2021 Cs-137 9.72E-05 9.77E-05 2.98E-04 U AP 01 560825001 9/22/2021 Fe-59 1.02E-03 6.82E-04 2.37E-03 U AP 01 560825001 9/22/2021 I-131 0.00E+00 1.21E-01 0.00E+00 UI AP 01 560825001 9/22/2021 K-40 0.00E+00 2.10E-03 2.60E-03 U AP 01 560825001 9/22/2021 La-140 2.07E-02 1.49E-02 5.26E-02 U AP 01 560825001 9/22/2021 Mn-54 1.31E-04 1.18E-04 3.57E-04 U AP 01 560825001 9/22/2021 Nb-95 -3.98E-05 2.17E-04 6.90E-04 U AP 01 560825001 9/22/2021 Ru-103 2.27E-04 4.39E-04 9.69E-04 U AP 01 560825001 9/22/2021 Ru-106 4.18E-04 7.77E-04 2.63E-03 U AP 01 560825001 9/22/2021 Sb-124 3.95E-05 4.47E-04 1.49E-03 U AP 01 560825001 9/22/2021 Sb-125 7.66E-05 2.28E-04 7.36E-04 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 01 560825001 9/22/2021 Se-75 1.59E-04 1.53E-04 5.14E-04 U AP 01 560825001 9/22/2021 Th-228 1.58E-04 2.42E-04 6.11E-04 U AP 01 560825001 9/22/2021 Zn-65 2.83E-04 2.43E-04 7.75E-04 U AP 01 560825001 9/22/2021 Zr-95 -1.13E-04 3.36E-04 1.05E-03 U AP 01 558373001 10/6/2021 BETA 2.46E-02 1.22E-03 1.04E-03 AP 01 560124001 10/21/2021 BETA 2.68E-02 1.28E-03 1.16E-03 AP 01 561299001 11/2/2021 BETA 2.52E-02 1.38E-03 1.39E-03 AP 01 562487001 11/17/2021 BETA 2.60E-02 1.00E-03 6.68E-04 AP 01 563880001 12/1/2021 BETA 2.05E-02 8.95E-04 6.71E-04 AP 01 565211001 12/15/2021 BETA 2.80E-02 1.11E-03 7.93E-04 AP 01 566442001 12/29/2021 BETA 3.28E-02 1.20E-03 8.05E-04 AP 01 568408001 12/29/2021 Ac-228 -1.85E-04 3.90E-04 1.23E-03 U AP 01 568408001 12/29/2021 Ag-108m -1.95E-05 4.98E-05 1.61E-04 U AP 01 568408001 12/29/2021 Ag-110m -4.43E-05 1.09E-04 3.26E-04 U AP 01 568408001 12/29/2021 Ba-140 0.00E+00 4.44E-02 4.22E-02 U AP 01 568408001 12/29/2021 Be-7 9.90E-02 7.50E-03 4.51E-03 AP 01 568408001 12/29/2021 Ce-141 5.68E-04 7.79E-04 1.08E-03 U AP 01 568408001 12/29/2021 Ce-144 -2.83E-04 3.42E-04 1.04E-03 U AP 01 568408001 12/29/2021 Co-57 3.15E-05 4.71E-05 1.57E-04 U AP 01 568408001 12/29/2021 Co-58 9.64E-06 1.29E-04 4.17E-04 U AP 01 568408001 12/29/2021 Co-60 -3.95E-05 8.14E-05 2.50E-04 U AP 01 568408001 12/29/2021 Cr-51 6.53E-03 3.71E-03 1.26E-02 U AP 01 568408001 12/29/2021 Cs-134 -1.62E-05 7.52E-05 2.35E-04 U AP 01 568408001 12/29/2021 Cs-137 1.02E-04 8.07E-05 2.77E-04 U AP 01 568408001 12/29/2021 Fe-59 -4.05E-04 4.47E-04 1.31E-03 U AP 01 568408001 12/29/2021 I-131 2.61E-02 4.75E-02 1.65E-01 U AP 01 568408001 12/29/2021 K-40 1.51E-03 1.37E-03 2.26E-03 U AP 01 568408001 12/29/2021 La-140 -2.19E-03 6.09E-03 1.87E-02 U AP 01 568408001 12/29/2021 Mn-54 -8.62E-06 7.63E-05 2.41E-04 U AP 01 568408001 12/29/2021 Nb-95 -1.63E-05 1.47E-04 4.68E-04 U AP 01 568408001 12/29/2021 Ru-103 -6.74E-05 2.23E-04 7.22E-04 U AP 01 568408001 12/29/2021 Ru-106 4.95E-04 6.80E-04 2.33E-03 U AP 01 568408001 12/29/2021 Sb-124 -3.63E-04 4.75E-04 1.33E-03 U AP 01 568408001 12/29/2021 Sb-125 -1.58E-05 1.64E-04 5.45E-04 U AP 01 568408001 12/29/2021 Se-75 3.08E-05 1.24E-04 3.93E-04 U AP 01 568408001 12/29/2021 Th-228 0.00E+00 2.98E-04 4.72E-04 U AP 01 568408001 12/29/2021 Zn-65 -2.28E-04 2.03E-04 5.72E-04 U AP 01 568408001 12/29/2021 Zr-95 -4.13E-06 2.05E-04 6.59E-04 U AP 02 532372002 1/13/2021 BETA 2.00E-02 1.03E-03 9.19E-04 AP 02 533687002 1/27/2021 BETA 1.16E-02 8.06E-04 9.04E-04 AP 02 535173002 2/10/2021 BETA 1.66E-02 9.71E-04 1.04E-03 AP 02 536335002 2/25/2021 BETA 2.54E-02 1.16E-03 9.32E-04 AP 02 537636002 3/10/2021 BETA 2.52E-02 1.24E-03 1.06E-03 AP 02 539006002 3/24/2021 BETA 2.95E-02 1.19E-03 8.49E-04 AP 02 543395002 3/24/2021 Ac-228 4.20E-04 5.09E-04 1.53E-03 U AP 02 543395002 3/24/2021 Ag-108m -1.52E-04 6.82E-05 1.39E-04 U

-158-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 02 543395002 3/24/2021 Ag-110m 2.65E-04 1.85E-04 6.72E-04 U AP 02 543395002 3/24/2021 Ba-140 3.14E-02 6.59E-02 2.24E-01 U AP 02 543395002 3/24/2021 Be-7 1.07E-01 9.60E-03 7.63E-03 AP 02 543395002 3/24/2021 Ce-141 -3.93E-04 7.39E-04 2.31E-03 U AP 02 543395002 3/24/2021 Ce-144 7.79E-04 5.13E-04 1.70E-03 U AP 02 543395002 3/24/2021 Co-57 3.87E-05 5.93E-05 2.00E-04 U AP 02 543395002 3/24/2021 Co-58 -3.44E-04 2.70E-04 6.81E-04 U AP 02 543395002 3/24/2021 Co-60 -1.05E-04 1.19E-04 3.24E-04 U AP 02 543395002 3/24/2021 Cr-51 7.01E-03 7.37E-03 2.58E-02 U AP 02 543395002 3/24/2021 Cs-134 2.70E-04 1.28E-04 4.49E-04 U AP 02 543395002 3/24/2021 Cs-137 3.49E-05 9.98E-05 3.33E-04 U AP 02 543395002 3/24/2021 Fe-59 -1.16E-03 8.57E-04 2.14E-03 U AP 02 543395002 3/24/2021 I-131 -1.36E-01 3.26E-01 0.00E+00 U AP 02 543395002 3/24/2021 K-40 2.03E-03 2.07E-03 3.62E-03 U AP 02 543395002 3/24/2021 La-140 2.31E-03 2.85E-02 9.29E-02 U AP 02 543395002 3/24/2021 Mn-54 -6.47E-05 1.20E-04 3.50E-04 U AP 02 543395002 3/24/2021 Nb-95 7.02E-04 4.73E-04 9.63E-04 U AP 02 543395002 3/24/2021 Ru-103 9.53E-04 4.39E-04 1.25E-03 U AP 02 543395002 3/24/2021 Ru-106 1.34E-04 1.09E-03 3.21E-03 U AP 02 543395002 3/24/2021 Sb-124 1.63E-04 7.28E-04 2.43E-03 U AP 02 543395002 3/24/2021 Sb-125 -5.39E-04 2.71E-04 6.59E-04 U AP 02 543395002 3/24/2021 Se-75 2.01E-05 1.67E-04 5.24E-04 U AP 02 543395002 3/24/2021 Th-228 3.63E-04 2.70E-04 4.33E-04 U AP 02 543395002 3/24/2021 Zn-65 -4.92E-05 2.13E-04 6.81E-04 U AP 02 543395002 3/24/2021 Zr-95 -6.14E-04 4.74E-04 1.07E-03 U AP 02 540404002 4/7/2021 BETA 1.59E-02 8.81E-04 8.35E-04 AP 02 541857002 4/21/2021 BETA 1.15E-02 7.63E-04 8.72E-04 AP 02 544029002 5/5/2021 BETA 2.30E-02 1.09E-03 9.14E-04 AP 02 545432002 5/19/2021 BETA 1.95E-02 1.01E-03 8.84E-04 AP 02 546369002 6/2/2021 BETA 2.07E-02 1.03E-03 9.17E-04 AP 02 547926002 6/16/2021 BETA 2.41E-02 1.15E-03 1.01E-03 AP 02 548743002 6/29/2021 BETA 2.40E-02 1.17E-03 9.80E-04 AP 02 552139002 6/29/2021 Ac-228 -1.31E-04 4.09E-04 1.33E-03 U AP 02 552139002 6/29/2021 Ag-108m 1.99E-06 7.13E-05 2.38E-04 U AP 02 552139002 6/29/2021 Ag-110m -1.28E-04 1.48E-04 4.50E-04 U AP 02 552139002 6/29/2021 Ba-140 1.78E-02 3.51E-02 1.17E-01 U AP 02 552139002 6/29/2021 Be-7 1.32E-01 8.49E-03 6.84E-03 AP 02 552139002 6/29/2021 Ce-141 -6.19E-04 6.76E-04 2.16E-03 U AP 02 552139002 6/29/2021 Ce-144 -3.09E-04 5.04E-04 1.66E-03 U AP 02 552139002 6/29/2021 Co-57 3.73E-05 6.44E-05 2.21E-04 U AP 02 552139002 6/29/2021 Co-58 1.27E-04 1.82E-04 6.24E-04 U AP 02 552139002 6/29/2021 Co-60 1.73E-04 1.01E-04 3.54E-04 U AP 02 552139002 6/29/2021 Cr-51 -4.78E-03 6.86E-03 2.09E-02 U AP 02 552139002 6/29/2021 Cs-134 9.00E-05 1.04E-04 3.56E-04 U AP 02 552139002 6/29/2021 Cs-137 -4.89E-05 8.74E-05 2.68E-04 U AP 02 552139002 6/29/2021 Fe-59 5.83E-04 7.03E-04 2.37E-03 U AP 02 552139002 6/29/2021 I-131 0.00E+00 1.77E-01 0.00E+00 UI AP 02 552139002 6/29/2021 K-40 -7.29E-04 1.53E-03 5.25E-03 U AP 02 552139002 6/29/2021 La-140 -2.64E-03 1.41E-02 4.51E-02 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 02 552139002 6/29/2021 Mn-54 9.46E-06 1.05E-04 3.49E-04 U AP 02 552139002 6/29/2021 Nb-95 -1.85E-07 2.17E-04 7.27E-04 U AP 02 552139002 6/29/2021 Ru-103 -5.19E-04 3.55E-04 1.01E-03 U AP 02 552139002 6/29/2021 Ru-106 1.12E-03 1.01E-03 2.98E-03 U AP 02 552139002 6/29/2021 Sb-124 -7.70E-04 5.96E-04 1.56E-03 U AP 02 552139002 6/29/2021 Sb-125 -1.22E-04 2.32E-04 7.49E-04 U AP 02 552139002 6/29/2021 Se-75 -3.48E-04 1.96E-04 5.32E-04 U AP 02 552139002 6/29/2021 Th-228 5.22E-04 2.74E-04 6.26E-04 U AP 02 552139002 6/29/2021 Zn-65 -2.43E-04 2.55E-04 7.40E-04 U AP 02 552139002 6/29/2021 Zr-95 1.17E-04 3.62E-04 1.23E-03 U AP 02 549925002 7/13/2021 BETA 1.39E-02 9.20E-04 1.14E-03 AP 02 551091002 7/28/2021 BETA 2.69E-02 1.21E-03 8.96E-04 AP 02 552841002 8/11/2021 BETA 3.06E-02 1.34E-03 9.75E-04 AP 02 554155002 8/25/2021 BETA 2.17E-02 1.13E-03 9.98E-04 AP 02 555720002 9/9/2021 BETA 3.32E-02 1.38E-03 1.13E-03 AP 02 556805002 9/22/2021 BETA 2.78E-02 1.38E-03 1.28E-03 AP 02 560825002 9/22/2021 Ac-228 1.21E-03 1.21E-03 3.57E-03 U AP 02 560825002 9/22/2021 Ag-108m -5.09E-05 1.25E-04 4.06E-04 U AP 02 560825002 9/22/2021 Ag-110m -9.42E-04 3.97E-04 5.98E-04 U AP 02 560825002 9/22/2021 Ba-140 -9.15E-02 5.88E-02 1.50E-01 U AP 02 560825002 9/22/2021 Be-7 1.20E-01 1.24E-02 1.32E-02 AP 02 560825002 9/22/2021 Ce-141 -2.41E-05 1.03E-03 3.36E-03 U AP 02 560825002 9/22/2021 Ce-144 -5.48E-05 7.77E-04 2.54E-03 U AP 02 560825002 9/22/2021 Co-57 1.34E-04 1.04E-04 3.47E-04 U AP 02 560825002 9/22/2021 Co-58 -4.23E-04 4.51E-04 1.26E-03 U AP 02 560825002 9/22/2021 Co-60 6.47E-04 2.57E-04 7.44E-04 U AP 02 560825002 9/22/2021 Cr-51 -2.95E-03 8.87E-03 2.97E-02 U AP 02 560825002 9/22/2021 Cs-134 -3.75E-05 2.12E-04 6.64E-04 U AP 02 560825002 9/22/2021 Cs-137 1.86E-04 2.12E-04 7.24E-04 U AP 02 560825002 9/22/2021 Fe-59 9.22E-04 1.03E-03 3.55E-03 U AP 02 560825002 9/22/2021 I-131 -1.00E-01 2.47E-01 0.00E+00 U AP 02 560825002 9/22/2021 K-40 -4.02E-03 3.01E-03 8.73E-03 U AP 02 560825002 9/22/2021 La-140 8.41E-03 2.85E-02 9.62E-02 U AP 02 560825002 9/22/2021 Mn-54 1.57E-04 1.85E-04 6.40E-04 U AP 02 560825002 9/22/2021 Nb-95 -2.72E-04 5.42E-04 1.66E-03 U AP 02 560825002 9/22/2021 Ru-103 2.11E-05 6.01E-04 2.01E-03 U AP 02 560825002 9/22/2021 Ru-106 -1.11E-03 1.82E-03 5.55E-03 U AP 02 560825002 9/22/2021 Sb-124 -1.29E-04 1.14E-03 3.61E-03 U AP 02 560825002 9/22/2021 Sb-125 -6.36E-04 4.45E-04 1.25E-03 U AP 02 560825002 9/22/2021 Se-75 -3.71E-04 3.09E-04 8.49E-04 U AP 02 560825002 9/22/2021 Th-228 5.33E-04 5.46E-04 1.15E-03 U AP 02 560825002 9/22/2021 Zn-65 4.85E-04 5.65E-04 2.01E-03 U AP 02 560825002 9/22/2021 Zr-95 4.73E-04 8.34E-04 2.81E-03 U AP 02 558373002 10/6/2021 BETA 2.30E-02 1.23E-03 1.12E-03 AP 02 560124002 10/21/2021 BETA 3.21E-02 1.44E-03 1.11E-03 AP 02 561299002 11/2/2021 BETA 2.77E-02 1.54E-03 1.42E-03

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 02 562487002 11/17/2021 BETA 2.82E-02 1.11E-03 7.91E-04 AP 02 563880002 12/1/2021 BETA 2.11E-02 9.82E-04 7.80E-04 AP 02 565211002 12/15/2021 BETA 2.82E-02 1.14E-03 8.72E-04 AP 02 566442002 12/29/2021 BETA 3.21E-02 1.24E-03 8.86E-04 AP 02 568408002 12/29/2021 Ac-228 1.40E-04 4.63E-04 1.57E-03 U AP 02 568408002 12/29/2021 Ag-108m 1.83E-04 8.63E-05 2.33E-04 U AP 02 568408002 12/29/2021 Ag-110m 1.48E-04 1.36E-04 4.94E-04 U AP 02 568408002 12/29/2021 Ba-140 -1.72E-02 1.81E-02 5.20E-02 U AP 02 568408002 12/29/2021 Be-7 9.81E-02 7.50E-03 6.20E-03 AP 02 568408002 12/29/2021 Ce-141 -7.92E-04 5.67E-04 1.50E-03 U AP 02 568408002 12/29/2021 Ce-144 1.11E-04 4.84E-04 1.45E-03 U AP 02 568408002 12/29/2021 Co-57 4.26E-05 5.07E-05 1.69E-04 U AP 02 568408002 12/29/2021 Co-58 1.40E-04 1.48E-04 5.42E-04 U AP 02 568408002 12/29/2021 Co-60 -5.99E-05 7.80E-05 2.06E-04 U AP 02 568408002 12/29/2021 Cr-51 2.03E-03 3.65E-03 1.27E-02 U AP 02 568408002 12/29/2021 Cs-134 8.36E-05 1.08E-04 3.84E-04 U AP 02 568408002 12/29/2021 Cs-137 1.47E-04 8.16E-05 2.89E-04 U AP 02 568408002 12/29/2021 Fe-59 1.11E-04 5.09E-04 1.55E-03 U AP 02 568408002 12/29/2021 I-131 2.12E-02 5.53E-02 1.72E-01 U AP 02 568408002 12/29/2021 K-40 7.44E-04 1.45E-03 5.29E-03 U AP 02 568408002 12/29/2021 La-140 -1.17E-03 7.41E-03 2.30E-02 U AP 02 568408002 12/29/2021 Mn-54 -4.27E-05 8.57E-05 2.72E-04 U AP 02 568408002 12/29/2021 Nb-95 -2.55E-05 1.64E-04 5.10E-04 U AP 02 568408002 12/29/2021 Ru-103 -2.63E-04 2.91E-04 8.60E-04 U AP 02 568408002 12/29/2021 Ru-106 5.25E-04 8.12E-04 2.76E-03 U AP 02 568408002 12/29/2021 Sb-124 -7.59E-04 5.47E-04 1.27E-03 U AP 02 568408002 12/29/2021 Sb-125 4.78E-05 1.99E-04 6.71E-04 U AP 02 568408002 12/29/2021 Se-75 7.23E-06 1.37E-04 4.70E-04 U AP 02 568408002 12/29/2021 Th-228 1.85E-04 2.96E-04 5.55E-04 U AP 02 568408002 12/29/2021 Zn-65 4.09E-06 2.36E-04 7.83E-04 U AP 02 568408002 12/29/2021 Zr-95 9.47E-05 3.48E-04 1.13E-03 U AP 03 532372003 1/13/2021 BETA 1.89E-02 1.05E-03 1.02E-03 AP 03 533687003 1/27/2021 BETA 2.23E-02 1.13E-03 1.02E-03 AP 03 535173003 2/10/2021 BETA 2.10E-02 1.08E-03 9.88E-04 AP 03 536335003 2/25/2021 BETA 2.55E-02 1.17E-03 9.50E-04 AP 03 537636003 3/10/2021 BETA 4.09E-02 1.49E-03 9.72E-04 AP 03 539006003 3/24/2021 BETA 5.77E-02 1.75E-03 9.77E-04 AP 03 543395003 3/24/2021 Ac-228 1.37E-04 6.52E-04 2.09E-03 U AP 03 543395003 3/24/2021 Ag-108m -4.22E-05 1.01E-04 3.03E-04 U AP 03 543395003 3/24/2021 Ag-110m 3.56E-04 2.17E-04 7.24E-04 U AP 03 543395003 3/24/2021 Ba-140 -2.31E-02 4.00E-02 1.21E-01 U AP 03 543395003 3/24/2021 Be-7 1.78E-01 1.20E-02 8.55E-03 AP 03 543395003 3/24/2021 Ce-141 -1.18E-03 8.62E-04 2.63E-03 U AP 03 543395003 3/24/2021 Ce-144 -5.41E-04 6.86E-04 2.23E-03 U AP 03 543395003 3/24/2021 Co-57 -3.62E-05 8.86E-05 2.97E-04 U AP 03 543395003 3/24/2021 Co-58 -2.27E-04 2.37E-04 7.23E-04 U AP 03 543395003 3/24/2021 Co-60 1.52E-04 1.33E-04 4.50E-04 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 03 543395003 3/24/2021 Cr-51 -2.34E-03 7.52E-03 2.35E-02 U AP 03 543395003 3/24/2021 Cs-134 3.62E-04 2.42E-04 5.11E-04 U AP 03 543395003 3/24/2021 Cs-137 2.31E-05 1.13E-04 3.68E-04 U AP 03 543395003 3/24/2021 Fe-59 -2.08E-05 1.02E-03 2.83E-03 U AP 03 543395003 3/24/2021 I-131 0.00E+00 1.45E-01 0.00E+00 UI AP 03 543395003 3/24/2021 K-40 0.00E+00 2.07E-03 3.02E-03 U AP 03 543395003 3/24/2021 La-140 -7.16E-03 1.32E-02 4.04E-02 U AP 03 543395003 3/24/2021 Mn-54 -4.45E-05 1.39E-04 4.52E-04 U AP 03 543395003 3/24/2021 Nb-95 1.88E-05 2.43E-04 8.17E-04 U AP 03 543395003 3/24/2021 Ru-103 7.13E-05 4.14E-04 1.37E-03 U AP 03 543395003 3/24/2021 Ru-106 -2.70E-04 1.11E-03 3.54E-03 U AP 03 543395003 3/24/2021 Sb-124 -6.12E-04 5.75E-04 1.53E-03 U AP 03 543395003 3/24/2021 Sb-125 -5.65E-04 3.19E-04 8.85E-04 U AP 03 543395003 3/24/2021 Se-75 1.30E-04 2.23E-04 7.27E-04 U AP 03 543395003 3/24/2021 Th-228 5.13E-04 3.47E-04 6.10E-04 U AP 03 543395003 3/24/2021 Zn-65 -1.70E-04 3.72E-04 1.16E-03 U AP 03 543395003 3/24/2021 Zr-95 1.83E-04 4.68E-04 1.60E-03 U AP 03 540404003 4/7/2021 BETA 3.23E-02 1.30E-03 9.43E-04 AP 03 541857003 4/21/2021 BETA 2.10E-02 1.08E-03 1.02E-03 AP 03 544029003 5/5/2021 BETA 4.60E-02 1.59E-03 1.02E-03 AP 03 545432003 5/19/2021 BETA 3.11E-02 1.32E-03 9.99E-04 AP 03 546369003 6/2/2021 BETA 3.38E-02 1.35E-03 1.01E-03 AP 03 547926003 6/16/2021 BETA 4.67E-02 1.65E-03 1.08E-03 AP 03 548743003 6/29/2021 BETA 4.11E-02 1.60E-03 1.16E-03 AP 03 552139003 6/29/2021 Ac-228 -1.67E-04 5.31E-04 1.73E-03 U AP 03 552139003 6/29/2021 Ag-108m 6.41E-05 7.85E-05 2.66E-04 U AP 03 552139003 6/29/2021 Ag-110m -2.24E-06 1.66E-04 5.47E-04 U AP 03 552139003 6/29/2021 Ba-140 -6.02E-02 4.61E-02 1.33E-01 U AP 03 552139003 6/29/2021 Be-7 2.42E-01 1.47E-02 7.65E-03 AP 03 552139003 6/29/2021 Ce-141 5.23E-04 8.30E-04 2.82E-03 U AP 03 552139003 6/29/2021 Ce-144 -1.95E-04 6.34E-04 2.12E-03 U AP 03 552139003 6/29/2021 Co-57 -2.31E-05 7.46E-05 2.51E-04 U AP 03 552139003 6/29/2021 Co-58 1.93E-05 1.92E-04 6.45E-04 U AP 03 552139003 6/29/2021 Co-60 1.31E-04 1.12E-04 3.91E-04 U AP 03 552139003 6/29/2021 Cr-51 -1.56E-03 7.54E-03 2.37E-02 U AP 03 552139003 6/29/2021 Cs-134 -1.50E-04 1.18E-04 3.45E-04 U AP 03 552139003 6/29/2021 Cs-137 -1.29E-04 1.04E-04 2.94E-04 U AP 03 552139003 6/29/2021 Fe-59 1.07E-03 7.92E-04 2.68E-03 U AP 03 552139003 6/29/2021 I-131 -2.20E-01 3.28E-01 0.00E+00 U AP 03 552139003 6/29/2021 K-40 0.00E+00 2.10E-03 3.47E-03 U AP 03 552139003 6/29/2021 La-140 -2.12E-02 1.76E-02 4.86E-02 U AP 03 552139003 6/29/2021 Mn-54 1.15E-04 1.30E-04 3.94E-04 U AP 03 552139003 6/29/2021 Nb-95 5.19E-04 2.71E-04 8.96E-04 U AP 03 552139003 6/29/2021 Ru-103 -6.67E-04 4.30E-04 1.21E-03 U AP 03 552139003 6/29/2021 Ru-106 1.03E-03 9.63E-04 3.20E-03 U AP 03 552139003 6/29/2021 Sb-124 1.48E-03 6.38E-04 2.26E-03 U AP 03 552139003 6/29/2021 Sb-125 5.21E-04 2.79E-04 9.07E-04 U AP 03 552139003 6/29/2021 Se-75 -4.04E-04 2.27E-04 6.17E-04 U AP 03 552139003 6/29/2021 Th-228 3.56E-05 3.34E-04 6.54E-04 U

-162-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 03 552139003 6/29/2021 Zn-65 -7.04E-05 2.98E-04 9.44E-04 U AP 03 552139003 6/29/2021 Zr-95 -4.41E-04 4.21E-04 1.28E-03 U AP 03 549925003 7/13/2021 BETA 3.27E-02 1.40E-03 1.09E-03 AP 03 551091003 7/28/2021 BETA 4.41E-02 1.59E-03 9.93E-04 AP 03 552841003 8/11/2021 BETA 1.94E-02 9.35E-04 7.68E-04 AP 03 554155003 8/25/2021 BETA 1.82E-02 9.51E-04 9.82E-04 AP 03 555720003 9/9/2021 BETA 2.76E-02 1.16E-03 8.48E-04 AP 03 556805003 9/22/2021 BETA 2.66E-02 1.22E-03 9.35E-04 AP 03 560825003 9/22/2021 Ac-228 3.49E-04 4.79E-04 1.55E-03 U AP 03 560825003 9/22/2021 Ag-108m 0.00E+00 0.00E+00 2.11E-04 U AP 03 560825003 9/22/2021 Ag-110m 6.60E-05 1.51E-04 4.91E-04 U AP 03 560825003 9/22/2021 Ba-140 4.04E-02 3.29E-02 1.03E-01 U AP 03 560825003 9/22/2021 Be-7 1.00E-01 7.69E-03 5.83E-03 AP 03 560825003 9/22/2021 Ce-141 -6.43E-04 5.96E-04 1.47E-03 U AP 03 560825003 9/22/2021 Ce-144 -8.76E-04 4.81E-04 1.20E-03 U AP 03 560825003 9/22/2021 Co-57 5.88E-05 5.49E-05 1.77E-04 U AP 03 560825003 9/22/2021 Co-58 -1.55E-04 1.68E-04 4.98E-04 U AP 03 560825003 9/22/2021 Co-60 7.69E-05 1.05E-04 3.68E-04 U AP 03 560825003 9/22/2021 Cr-51 -1.99E-04 4.82E-03 1.59E-02 U AP 03 560825003 9/22/2021 Cs-134 -1.24E-04 1.08E-04 3.15E-04 U AP 03 560825003 9/22/2021 Cs-137 1.25E-06 7.83E-05 2.49E-04 U AP 03 560825003 9/22/2021 Fe-59 3.97E-04 6.50E-04 2.26E-03 U AP 03 560825003 9/22/2021 I-131 -9.26E-03 1.12E-01 0.00E+00 U AP 03 560825003 9/22/2021 K-40 1.58E-03 1.32E-03 4.75E-03 U AP 03 560825003 9/22/2021 La-140 -1.33E-02 1.20E-02 3.27E-02 U AP 03 560825003 9/22/2021 Mn-54 -1.11E-04 1.11E-04 3.29E-04 U AP 03 560825003 9/22/2021 Nb-95 2.73E-04 2.25E-04 7.33E-04 U AP 03 560825003 9/22/2021 Ru-103 -6.62E-04 4.01E-04 8.46E-04 U AP 03 560825003 9/22/2021 Ru-106 -4.91E-04 8.09E-04 2.40E-03 U AP 03 560825003 9/22/2021 Sb-124 -3.95E-04 5.07E-04 1.45E-03 U AP 03 560825003 9/22/2021 Sb-125 2.15E-04 2.22E-04 7.53E-04 U AP 03 560825003 9/22/2021 Se-75 1.44E-05 1.17E-04 3.94E-04 U AP 03 560825003 9/22/2021 Th-228 4.22E-04 2.78E-04 5.13E-04 U AP 03 560825003 9/22/2021 Zn-65 1.43E-04 2.66E-04 9.14E-04 U AP 03 560825003 9/22/2021 Zr-95 -2.53E-04 3.03E-04 7.56E-04 U AP 03 558373003 10/6/2021 BETA 2.09E-02 1.04E-03 9.28E-04 AP 03 560124003 10/21/2021 BETA 2.36E-02 1.09E-03 8.94E-04 AP 03 561299003 11/2/2021 BETA 2.35E-02 1.25E-03 1.17E-03 AP 03 562487003 11/17/2021 BETA 3.11E-02 1.31E-03 1.05E-03 AP 03 563880003 12/1/2021 BETA 2.54E-02 1.27E-03 1.27E-03 AP 03 565211003 12/15/2021 BETA 2.46E-02 1.21E-03 1.06E-03 AP 03 566442003 12/29/2021 BETA 3.08E-02 1.39E-03 1.11E-03 AP 03 568408003 12/29/2021 Ac-228 1.45E-03 6.20E-04 1.75E-03 U AP 03 568408003 12/29/2021 Ag-108m -1.31E-04 9.46E-05 2.62E-04 U AP 03 568408003 12/29/2021 Ag-110m 3.93E-04 4.02E-04 6.04E-04 U AP 03 568408003 12/29/2021 Ba-140 -8.41E-03 2.13E-02 6.86E-02 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 03 568408003 12/29/2021 Be-7 8.02E-02 6.97E-03 6.38E-03 AP 03 568408003 12/29/2021 Ce-141 2.72E-04 4.41E-04 1.45E-03 U AP 03 568408003 12/29/2021 Ce-144 5.91E-05 4.41E-04 1.44E-03 U AP 03 568408003 12/29/2021 Co-57 -1.01E-04 6.23E-05 1.71E-04 U AP 03 568408003 12/29/2021 Co-58 -1.69E-04 1.72E-04 4.77E-04 U AP 03 568408003 12/29/2021 Co-60 2.00E-04 1.20E-04 4.40E-04 U AP 03 568408003 12/29/2021 Cr-51 -7.04E-03 4.45E-03 1.29E-02 U AP 03 568408003 12/29/2021 Cs-134 0.00E+00 2.14E-04 4.10E-04 U AP 03 568408003 12/29/2021 Cs-137 1.14E-04 9.28E-05 3.22E-04 U AP 03 568408003 12/29/2021 Fe-59 -1.37E-04 5.66E-04 1.87E-03 U AP 03 568408003 12/29/2021 I-131 -7.16E-02 6.48E-02 1.88E-01 U AP 03 568408003 12/29/2021 K-40 0.00E+00 1.61E-03 1.74E-03 U AP 03 568408003 12/29/2021 La-140 3.12E-03 8.78E-03 3.01E-02 U AP 03 568408003 12/29/2021 Mn-54 2.25E-04 1.41E-04 4.77E-04 U AP 03 568408003 12/29/2021 Nb-95 -4.86E-05 1.95E-04 6.16E-04 U AP 03 568408003 12/29/2021 Ru-103 -9.87E-05 2.95E-04 9.58E-04 U AP 03 568408003 12/29/2021 Ru-106 8.18E-04 9.74E-04 3.34E-03 U AP 03 568408003 12/29/2021 Sb-124 -1.98E-04 4.99E-04 1.52E-03 U AP 03 568408003 12/29/2021 Sb-125 8.04E-05 2.11E-04 7.27E-04 U AP 03 568408003 12/29/2021 Se-75 1.08E-04 1.49E-04 4.80E-04 U AP 03 568408003 12/29/2021 Th-228 4.86E-04 2.02E-04 5.75E-04 U AP 03 568408003 12/29/2021 Zn-65 1.32E-04 2.22E-04 7.23E-04 U AP 03 568408003 12/29/2021 Zr-95 1.37E-04 2.95E-04 1.00E-03 U AP 04 532372004 1/13/2021 BETA 2.31E-02 1.07E-03 8.77E-04 AP 04 533687004 1/27/2021 BETA 2.68E-02 1.15E-03 8.61E-04 AP 04 535173004 2/10/2021 BETA 2.60E-02 1.12E-03 9.19E-04 AP 04 536335004 2/25/2021 BETA 3.07E-02 1.03E-03 6.25E-04 AP 04 537636004 3/10/2021 BETA 2.80E-02 1.07E-03 7.72E-04 AP 04 539006004 3/24/2021 BETA 3.53E-02 1.24E-03 7.68E-04 AP 04 543395004 3/24/2021 Ac-228 1.54E-03 9.99E-04 2.53E-03 U AP 04 543395004 3/24/2021 Ag-108m 5.91E-05 1.11E-04 3.53E-04 U AP 04 543395004 3/24/2021 Ag-110m -6.45E-05 2.03E-04 6.22E-04 U AP 04 543395004 3/24/2021 Ba-140 -1.65E-02 4.15E-02 1.34E-01 U AP 04 543395004 3/24/2021 Be-7 1.39E-01 1.15E-02 9.76E-03 AP 04 543395004 3/24/2021 Ce-141 -6.43E-04 7.43E-04 2.31E-03 U AP 04 543395004 3/24/2021 Ce-144 -4.77E-05 5.24E-04 1.73E-03 U AP 04 543395004 3/24/2021 Co-57 -3.27E-05 6.84E-05 2.22E-04 U AP 04 543395004 3/24/2021 Co-58 1.28E-04 2.95E-04 9.93E-04 U AP 04 543395004 3/24/2021 Co-60 2.86E-04 1.99E-04 6.96E-04 U AP 04 543395004 3/24/2021 Cr-51 4.40E-03 7.65E-03 2.47E-02 U AP 04 543395004 3/24/2021 Cs-134 1.11E-04 1.63E-04 5.57E-04 U AP 04 543395004 3/24/2021 Cs-137 1.72E-04 1.44E-04 5.01E-04 U AP 04 543395004 3/24/2021 Fe-59 3.21E-04 1.04E-03 3.62E-03 U AP 04 543395004 3/24/2021 I-131 0.00E+00 1.70E-01 0.00E+00 UI AP 04 543395004 3/24/2021 K-40 2.75E-03 2.15E-03 3.53E-03 U AP 04 543395004 3/24/2021 La-140 -6.29E-03 1.82E-02 5.60E-02 U AP 04 543395004 3/24/2021 Mn-54 0.00E+00 2.06E-04 5.35E-04 U AP 04 543395004 3/24/2021 Nb-95 1.45E-04 3.15E-04 1.06E-03 U AP 04 543395004 3/24/2021 Ru-103 2.79E-04 4.32E-04 1.51E-03 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 04 543395004 3/24/2021 Ru-106 -4.17E-04 1.46E-03 4.69E-03 U AP 04 543395004 3/24/2021 Sb-124 -6.41E-04 7.53E-04 1.92E-03 U AP 04 543395004 3/24/2021 Sb-125 6.68E-04 3.66E-04 1.19E-03 U AP 04 543395004 3/24/2021 Se-75 -5.57E-05 2.26E-04 7.07E-04 U AP 04 543395004 3/24/2021 Th-228 2.19E-04 3.27E-04 8.30E-04 U AP 04 543395004 3/24/2021 Zn-65 -8.61E-04 5.67E-04 1.23E-03 U AP 04 543395004 3/24/2021 Zr-95 -4.78E-04 5.27E-04 1.49E-03 U AP 04 540404004 4/7/2021 BETA 2.07E-02 1.02E-03 8.84E-04 AP 04 541857004 4/21/2021 BETA 1.79E-02 9.93E-04 9.72E-04 AP 04 544029004 5/5/2021 BETA 3.79E-02 1.72E-03 1.33E-03 AP 04 545432004 5/19/2021 BETA 2.31E-02 1.27E-03 1.17E-03 AP 04 546369004 6/2/2021 BETA 2.59E-02 1.24E-03 1.12E-03 AP 04 547926004 6/16/2021 BETA 3.30E-02 1.41E-03 1.08E-03 AP 04 548743004 6/29/2021 BETA 3.13E-02 1.35E-03 1.06E-03 AP 04 552139004 6/29/2021 Ac-228 1.47E-04 8.46E-04 2.85E-03 U AP 04 552139004 6/29/2021 Ag-108m -1.23E-05 1.10E-04 3.67E-04 U AP 04 552139004 6/29/2021 Ag-110m 2.89E-04 2.67E-04 9.30E-04 U AP 04 552139004 6/29/2021 Ba-140 -1.94E-02 6.52E-02 2.10E-01 U AP 04 552139004 6/29/2021 Be-7 1.64E-01 1.47E-02 1.17E-02 AP 04 552139004 6/29/2021 Ce-141 -1.38E-03 1.04E-03 2.97E-03 U AP 04 552139004 6/29/2021 Ce-144 -7.76E-04 7.41E-04 2.22E-03 U AP 04 552139004 6/29/2021 Co-57 -5.90E-05 8.49E-05 2.66E-04 U AP 04 552139004 6/29/2021 Co-58 -3.01E-05 3.54E-04 1.12E-03 U AP 04 552139004 6/29/2021 Co-60 -5.97E-05 2.20E-04 6.97E-04 U AP 04 552139004 6/29/2021 Cr-51 1.27E-02 8.95E-03 3.05E-02 U AP 04 552139004 6/29/2021 Cs-134 4.55E-04 3.78E-04 7.07E-04 U AP 04 552139004 6/29/2021 Cs-137 -2.35E-05 1.73E-04 4.92E-04 U AP 04 552139004 6/29/2021 Fe-59 8.83E-04 1.26E-03 4.10E-03 U AP 04 552139004 6/29/2021 I-131 -3.77E-01 3.10E-01 0.00E+00 U AP 04 552139004 6/29/2021 K-40 -2.14E-03 2.04E-03 6.28E-03 U AP 04 552139004 6/29/2021 La-140 4.69E-03 3.29E-02 1.09E-01 U AP 04 552139004 6/29/2021 Mn-54 -1.55E-04 2.32E-04 6.84E-04 U AP 04 552139004 6/29/2021 Nb-95 5.11E-04 4.15E-04 1.44E-03 U AP 04 552139004 6/29/2021 Ru-103 -7.12E-05 6.72E-04 1.98E-03 U AP 04 552139004 6/29/2021 Ru-106 9.88E-04 1.77E-03 6.01E-03 U AP 04 552139004 6/29/2021 Sb-124 -1.07E-03 1.19E-03 3.11E-03 U AP 04 552139004 6/29/2021 Sb-125 -1.90E-04 4.54E-04 1.48E-03 U AP 04 552139004 6/29/2021 Se-75 2.65E-04 2.47E-04 8.09E-04 U AP 04 552139004 6/29/2021 Th-228 0.00E+00 6.04E-04 1.00E-03 U AP 04 552139004 6/29/2021 Zn-65 6.12E-04 4.73E-04 1.72E-03 U AP 04 552139004 6/29/2021 Zr-95 8.55E-04 6.79E-04 2.39E-03 U AP 04 549925004 7/13/2021 BETA 2.56E-02 1.19E-03 1.02E-03 AP 04 551091004 7/28/2021 BETA 2.96E-02 1.31E-03 9.86E-04 AP 04 552841004 8/11/2021 BETA 3.63E-02 1.36E-03 8.79E-04 AP 04 554155004 8/25/2021 BETA 3.63E-02 1.42E-03 9.93E-04 AP 04 555720004 9/9/2021 BETA 4.71E-02 1.54E-03 8.68E-04 AP 04 556805004 9/22/2021 BETA 3.99E-02 1.48E-03 9.36E-04

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 04 560825004 9/22/2021 Ac-228 -4.01E-04 5.50E-04 1.59E-03 U AP 04 560825004 9/22/2021 Ag-108m -1.46E-04 7.64E-05 1.82E-04 U AP 04 560825004 9/22/2021 Ag-110m 9.62E-05 1.57E-04 5.58E-04 U AP 04 560825004 9/22/2021 Ba-140 8.53E-03 3.12E-02 9.47E-02 U AP 04 560825004 9/22/2021 Be-7 1.56E-01 1.16E-02 7.64E-03 AP 04 560825004 9/22/2021 Ce-141 -1.74E-04 4.71E-04 1.51E-03 U AP 04 560825004 9/22/2021 Ce-144 4.20E-04 4.69E-04 1.61E-03 U AP 04 560825004 9/22/2021 Co-57 -4.23E-05 5.94E-05 1.89E-04 U AP 04 560825004 9/22/2021 Co-58 1.59E-04 2.27E-04 7.37E-04 U AP 04 560825004 9/22/2021 Co-60 8.95E-05 1.27E-04 4.46E-04 U AP 04 560825004 9/22/2021 Cr-51 -2.49E-03 5.61E-03 1.86E-02 U AP 04 560825004 9/22/2021 Cs-134 -6.15E-05 1.11E-04 3.48E-04 U AP 04 560825004 9/22/2021 Cs-137 1.50E-04 1.12E-04 3.87E-04 U AP 04 560825004 9/22/2021 Fe-59 -3.97E-05 7.51E-04 2.44E-03 U AP 04 560825004 9/22/2021 I-131 0.00E+00 1.44E-01 0.00E+00 UI AP 04 560825004 9/22/2021 K-40 3.84E-03 1.83E-03 6.56E-03 U AP 04 560825004 9/22/2021 La-140 7.33E-04 1.34E-02 4.49E-02 U AP 04 560825004 9/22/2021 Mn-54 3.53E-05 1.25E-04 4.04E-04 U AP 04 560825004 9/22/2021 Nb-95 -5.55E-05 2.45E-04 8.13E-04 U AP 04 560825004 9/22/2021 Ru-103 2.44E-04 3.57E-04 1.13E-03 U AP 04 560825004 9/22/2021 Ru-106 7.94E-04 9.44E-04 3.25E-03 U AP 04 560825004 9/22/2021 Sb-124 7.06E-04 8.15E-04 2.97E-03 U AP 04 560825004 9/22/2021 Sb-125 5.56E-05 2.52E-04 8.32E-04 U AP 04 560825004 9/22/2021 Se-75 -2.03E-04 1.90E-04 5.34E-04 U AP 04 560825004 9/22/2021 Th-228 3.56E-04 3.29E-04 5.68E-04 U AP 04 560825004 9/22/2021 Zn-65 -1.51E-04 3.08E-04 9.34E-04 U AP 04 560825004 9/22/2021 Zr-95 -5.91E-05 3.98E-04 1.33E-03 U AP 04 558373004 10/6/2021 BETA 2.77E-02 1.20E-03 1.02E-03 AP 04 560124004 10/21/2021 BETA 3.48E-02 1.26E-03 8.12E-04 AP 04 561299004 11/2/2021 BETA 3.24E-02 1.36E-03 1.01E-03 AP 04 562487004 11/17/2021 BETA 4.18E-02 1.43E-03 8.82E-04 AP 04 563880004 12/1/2021 BETA 3.10E-02 1.29E-03 9.24E-04 AP 04 565211004 12/15/2021 BETA 3.43E-02 1.32E-03 9.33E-04 AP 04 566442004 12/29/2021 BETA 3.90E-02 1.42E-03 1.03E-03 AP 04 568408004 12/29/2021 Ac-228 3.88E-04 4.54E-04 1.44E-03 U AP 04 568408004 12/29/2021 Ag-108m 2.15E-04 1.08E-04 2.36E-04 U AP 04 568408004 12/29/2021 Ag-110m -2.03E-04 1.73E-04 3.93E-04 U AP 04 568408004 12/29/2021 Ba-140 -1.26E-02 2.07E-02 5.79E-02 U AP 04 568408004 12/29/2021 Be-7 1.18E-01 8.69E-03 4.82E-03 AP 04 568408004 12/29/2021 Ce-141 8.03E-04 6.36E-04 1.21E-03 U AP 04 568408004 12/29/2021 Ce-144 -4.39E-04 3.12E-04 8.78E-04 U AP 04 568408004 12/29/2021 Co-57 5.06E-05 4.66E-05 1.61E-04 U AP 04 568408004 12/29/2021 Co-58 -2.96E-04 1.81E-04 4.55E-04 U AP 04 568408004 12/29/2021 Co-60 1.36E-04 1.49E-04 4.70E-04 U AP 04 568408004 12/29/2021 Cr-51 2.10E-03 3.44E-03 1.21E-02 U AP 04 568408004 12/29/2021 Cs-134 -5.69E-05 9.25E-05 2.89E-04 U AP 04 568408004 12/29/2021 Cs-137 -2.38E-05 7.56E-05 2.32E-04 U AP 04 568408004 12/29/2021 Fe-59 -3.82E-04 4.90E-04 1.38E-03 U

-166-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 04 568408004 12/29/2021 I-131 -3.93E-02 5.77E-02 1.85E-01 U AP 04 568408004 12/29/2021 K-40 2.66E-03 2.08E-03 3.21E-03 U AP 04 568408004 12/29/2021 La-140 -4.18E-03 8.23E-03 2.51E-02 U AP 04 568408004 12/29/2021 Mn-54 1.04E-04 1.05E-04 3.74E-04 U AP 04 568408004 12/29/2021 Nb-95 9.52E-05 1.89E-04 6.65E-04 U AP 04 568408004 12/29/2021 Ru-103 -4.27E-04 2.73E-04 7.00E-04 U AP 04 568408004 12/29/2021 Ru-106 -4.25E-04 8.65E-04 2.64E-03 U AP 04 568408004 12/29/2021 Sb-124 -7.21E-04 5.23E-04 1.14E-03 U AP 04 568408004 12/29/2021 Sb-125 6.10E-05 2.16E-04 6.64E-04 U AP 04 568408004 12/29/2021 Se-75 5.73E-05 1.45E-04 4.65E-04 U AP 04 568408004 12/29/2021 Th-228 3.88E-04 2.15E-04 5.41E-04 U AP 04 568408004 12/29/2021 Zn-65 5.23E-05 2.48E-04 8.29E-04 U AP 04 568408004 12/29/2021 Zr-95 5.23E-04 3.52E-04 1.27E-03 U AP 05 532372005 1/13/2021 BETA 2.02E-02 1.06E-03 9.54E-04 AP 05 533687005 1/27/2021 BETA 2.34E-02 1.14E-03 9.95E-04 AP 05 535173005 2/10/2021 BETA 1.87E-02 1.06E-03 1.12E-03 AP 05 536335005 2/25/2021 BETA 2.92E-02 1.24E-03 9.43E-04 AP 05 537636005 3/10/2021 BETA 2.61E-02 1.28E-03 1.11E-03 AP 05 539006005 3/24/2021 BETA 3.44E-02 1.21E-03 7.33E-04 AP 05 543395005 3/24/2021 Ac-228 -1.54E-04 4.92E-04 1.57E-03 U AP 05 543395005 3/24/2021 Ag-108m -3.51E-05 6.75E-05 2.11E-04 U AP 05 543395005 3/24/2021 Ag-110m -1.57E-04 1.66E-04 4.94E-04 U AP 05 543395005 3/24/2021 Ba-140 0.00E+00 3.84E-02 9.12E-02 U AP 05 543395005 3/24/2021 Be-7 1.38E-01 1.08E-02 6.73E-03 AP 05 543395005 3/24/2021 Ce-141 -2.25E-04 5.85E-04 1.79E-03 U AP 05 543395005 3/24/2021 Ce-144 1.89E-04 4.02E-04 1.29E-03 U AP 05 543395005 3/24/2021 Co-57 -4.57E-05 5.02E-05 1.46E-04 U AP 05 543395005 3/24/2021 Co-58 0.00E+00 0.00E+00 7.19E-04 U AP 05 543395005 3/24/2021 Co-60 2.98E-05 1.34E-04 4.50E-04 U AP 05 543395005 3/24/2021 Cr-51 -1.03E-02 5.71E-03 1.53E-02 U AP 05 543395005 3/24/2021 Cs-134 1.11E-04 1.19E-04 4.26E-04 U AP 05 543395005 3/24/2021 Cs-137 5.90E-05 9.61E-05 3.23E-04 U AP 05 543395005 3/24/2021 Fe-59 -1.56E-04 7.60E-04 2.47E-03 U AP 05 543395005 3/24/2021 I-131 0.00E+00 1.22E-01 0.00E+00 UI AP 05 543395005 3/24/2021 K-40 1.09E-03 1.63E-03 5.77E-03 U AP 05 543395005 3/24/2021 La-140 2.92E-03 1.04E-02 3.53E-02 U AP 05 543395005 3/24/2021 Mn-54 6.71E-05 1.28E-04 4.49E-04 U AP 05 543395005 3/24/2021 Nb-95 -4.94E-04 3.21E-04 6.47E-04 U AP 05 543395005 3/24/2021 Ru-103 -9.03E-06 3.15E-04 1.03E-03 U AP 05 543395005 3/24/2021 Ru-106 -1.46E-03 1.13E-03 2.93E-03 U AP 05 543395005 3/24/2021 Sb-124 2.01E-04 4.85E-04 1.70E-03 U AP 05 543395005 3/24/2021 Sb-125 -2.60E-04 2.29E-04 6.60E-04 U AP 05 543395005 3/24/2021 Se-75 1.33E-04 1.56E-04 5.26E-04 U AP 05 543395005 3/24/2021 Th-228 0.00E+00 2.25E-04 3.98E-04 U AP 05 543395005 3/24/2021 Zn-65 -2.36E-04 2.77E-04 8.09E-04 U AP 05 543395005 3/24/2021 Zr-95 -1.65E-04 4.04E-04 1.22E-03 U AP 05 540404005 4/7/2021 BETA 2.17E-02 1.00E-03 8.09E-04 AP 05 541857005 4/21/2021 BETA 1.33E-02 7.91E-04 8.13E-04

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 05 544029005 5/5/2021 BETA 2.60E-02 1.12E-03 1.01E-03 AP 05 545432005 5/19/2021 BETA 2.05E-02 9.96E-04 8.73E-04 AP 05 546369005 6/2/2021 BETA 2.34E-02 1.10E-03 9.50E-04 AP 05 547926005 6/16/2021 BETA 2.32E-02 1.08E-03 8.67E-04 AP 05 548743005 6/29/2021 BETA 2.50E-02 1.20E-03 1.04E-03 AP 05 552139005 6/29/2021 Ac-228 2.31E-04 4.36E-04 1.38E-03 U AP 05 552139005 6/29/2021 Ag-108m -6.49E-07 6.68E-05 2.22E-04 U AP 05 552139005 6/29/2021 Ag-110m -1.48E-04 1.40E-04 4.13E-04 U AP 05 552139005 6/29/2021 Ba-140 4.03E-02 3.57E-02 1.20E-01 U AP 05 552139005 6/29/2021 Be-7 1.25E-01 8.85E-03 6.04E-03 AP 05 552139005 6/29/2021 Ce-141 6.60E-04 7.07E-04 2.39E-03 U AP 05 552139005 6/29/2021 Ce-144 -3.07E-04 4.83E-04 1.58E-03 U AP 05 552139005 6/29/2021 Co-57 -7.13E-06 6.18E-05 2.10E-04 U AP 05 552139005 6/29/2021 Co-58 7.74E-05 1.74E-04 5.94E-04 U AP 05 552139005 6/29/2021 Co-60 -2.51E-05 9.59E-05 3.11E-04 U AP 05 552139005 6/29/2021 Cr-51 -8.73E-03 7.55E-03 1.91E-02 U AP 05 552139005 6/29/2021 Cs-134 3.15E-05 9.86E-05 3.34E-04 U AP 05 552139005 6/29/2021 Cs-137 -1.54E-05 8.74E-05 2.77E-04 U AP 05 552139005 6/29/2021 Fe-59 -9.56E-04 7.05E-04 1.91E-03 U AP 05 552139005 6/29/2021 I-131 0.00E+00 1.91E-01 0.00E+00 UI AP 05 552139005 6/29/2021 K-40 2.59E-03 2.26E-03 2.80E-03 U AP 05 552139005 6/29/2021 La-140 2.36E-03 1.60E-02 5.29E-02 U AP 05 552139005 6/29/2021 Mn-54 1.60E-04 1.13E-04 3.82E-04 U AP 05 552139005 6/29/2021 Nb-95 8.45E-05 2.08E-04 6.91E-04 U AP 05 552139005 6/29/2021 Ru-103 -4.68E-04 3.77E-04 1.11E-03 U AP 05 552139005 6/29/2021 Ru-106 1.23E-03 9.38E-04 3.08E-03 U AP 05 552139005 6/29/2021 Sb-124 3.37E-04 6.35E-04 1.89E-03 U AP 05 552139005 6/29/2021 Sb-125 2.37E-04 2.29E-04 7.73E-04 U AP 05 552139005 6/29/2021 Se-75 -8.17E-05 1.64E-04 5.14E-04 U AP 05 552139005 6/29/2021 Th-228 5.37E-04 3.07E-04 6.16E-04 U AP 05 552139005 6/29/2021 Zn-65 -6.41E-04 3.02E-04 6.89E-04 U AP 05 552139005 6/29/2021 Zr-95 0.00E+00 8.79E-04 1.24E-03 U AP 05 549925005 7/13/2021 BETA 1.85E-02 9.99E-04 9.54E-04 AP 05 551091005 7/28/2021 BETA 2.45E-02 1.13E-03 1.06E-03 AP 05 552841005 8/11/2021 BETA 3.18E-02 1.33E-03 1.14E-03 AP 05 554155005 8/25/2021 BETA 2.54E-02 1.19E-03 9.66E-04 AP 05 555720005 9/9/2021 BETA 3.47E-02 1.32E-03 8.59E-04 AP 05 556805005 9/22/2021 BETA 3.37E-02 1.40E-03 1.01E-03 AP 05 560825005 9/22/2021 Ac-228 8.04E-04 8.09E-04 1.78E-03 U AP 05 560825005 9/22/2021 Ag-108m -6.84E-06 7.62E-05 2.40E-04 U AP 05 560825005 9/22/2021 Ag-110m 1.38E-04 1.94E-04 6.58E-04 U AP 05 560825005 9/22/2021 Ba-140 -3.63E-03 3.39E-02 1.13E-01 U AP 05 560825005 9/22/2021 Be-7 1.27E-01 9.71E-03 6.09E-03 AP 05 560825005 9/22/2021 Ce-141 8.26E-04 7.98E-04 1.87E-03 U AP 05 560825005 9/22/2021 Ce-144 -5.84E-04 5.17E-04 1.60E-03 U AP 05 560825005 9/22/2021 Co-57 5.13E-06 6.35E-05 2.15E-04 U AP 05 560825005 9/22/2021 Co-58 -1.96E-04 2.05E-04 5.91E-04 U AP 05 560825005 9/22/2021 Co-60 7.64E-05 1.12E-04 3.99E-04 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 05 560825005 9/22/2021 Cr-51 -6.24E-03 5.62E-03 1.63E-02 U AP 05 560825005 9/22/2021 Cs-134 8.87E-06 1.34E-04 4.19E-04 U AP 05 560825005 9/22/2021 Cs-137 1.96E-04 1.67E-04 3.22E-04 U AP 05 560825005 9/22/2021 Fe-59 -1.21E-03 7.77E-04 1.83E-03 U AP 05 560825005 9/22/2021 I-131 0.00E+00 1.32E-01 0.00E+00 UI AP 05 560825005 9/22/2021 K-40 2.08E-03 2.31E-03 3.97E-03 U AP 05 560825005 9/22/2021 La-140 -1.68E-02 1.41E-02 3.70E-02 U AP 05 560825005 9/22/2021 Mn-54 6.53E-05 1.32E-04 4.44E-04 U AP 05 560825005 9/22/2021 Nb-95 -6.07E-06 2.43E-04 7.00E-04 U AP 05 560825005 9/22/2021 Ru-103 -2.75E-04 3.79E-04 1.21E-03 U AP 05 560825005 9/22/2021 Ru-106 9.00E-04 1.05E-03 3.62E-03 U AP 05 560825005 9/22/2021 Sb-124 -4.34E-04 6.15E-04 1.77E-03 U AP 05 560825005 9/22/2021 Sb-125 6.06E-06 2.48E-04 7.89E-04 U AP 05 560825005 9/22/2021 Se-75 -9.70E-06 1.80E-04 5.87E-04 U AP 05 560825005 9/22/2021 Th-228 6.81E-04 2.67E-04 4.30E-04 AP 05 560825005 9/22/2021 Zn-65 5.39E-04 3.46E-04 1.11E-03 U AP 05 560825005 9/22/2021 Zr-95 -1.59E-05 5.57E-04 1.60E-03 U AP 05 558373005 10/6/2021 BETA 2.48E-02 1.25E-03 1.10E-03 AP 05 560124005 10/21/2021 BETA 2.73E-02 1.21E-03 1.02E-03 AP 05 561299005 11/2/2021 BETA 2.82E-02 1.40E-03 1.30E-03 AP 05 562487005 11/17/2021 BETA 3.00E-02 1.29E-03 9.41E-04 AP 05 563880005 12/1/2021 BETA 2.64E-02 1.26E-03 1.03E-03 AP 05 565211005 12/15/2021 BETA 3.02E-02 1.39E-03 1.14E-03 AP 05 566442005 12/29/2021 BETA 3.40E-02 1.49E-03 1.19E-03 AP 05 568408005 12/29/2021 Ac-228 1.12E-03 9.34E-04 3.19E-03 U AP 05 568408005 12/29/2021 Ag-108m -8.77E-05 1.15E-04 3.58E-04 U AP 05 568408005 12/29/2021 Ag-110m -4.58E-05 2.91E-04 9.08E-04 U AP 05 568408005 12/29/2021 Ba-140 1.73E-02 4.09E-02 1.17E-01 U AP 05 568408005 12/29/2021 Be-7 1.13E-01 1.05E-02 9.48E-03 AP 05 568408005 12/29/2021 Ce-141 -1.99E-03 8.80E-04 2.07E-03 U AP 05 568408005 12/29/2021 Ce-144 1.61E-03 1.11E-03 2.33E-03 U AP 05 568408005 12/29/2021 Co-57 5.25E-05 8.69E-05 2.91E-04 U AP 05 568408005 12/29/2021 Co-58 -5.69E-04 3.80E-04 9.26E-04 U AP 05 568408005 12/29/2021 Co-60 2.52E-07 2.13E-04 7.03E-04 U AP 05 568408005 12/29/2021 Cr-51 3.85E-03 6.62E-03 2.32E-02 U AP 05 568408005 12/29/2021 Cs-134 -5.31E-05 2.11E-04 6.57E-04 U AP 05 568408005 12/29/2021 Cs-137 -1.08E-05 1.41E-04 4.56E-04 U AP 05 568408005 12/29/2021 Fe-59 1.06E-03 9.25E-04 3.41E-03 U AP 05 568408005 12/29/2021 I-131 -3.54E-02 1.00E-01 3.32E-01 U AP 05 568408005 12/29/2021 K-40 4.55E-03 2.94E-03 5.79E-03 U AP 05 568408005 12/29/2021 La-140 -2.24E-02 1.28E-02 1.96E-02 U AP 05 568408005 12/29/2021 Mn-54 -1.57E-04 1.97E-04 5.61E-04 U AP 05 568408005 12/29/2021 Nb-95 -4.06E-04 2.92E-04 6.91E-04 U AP 05 568408005 12/29/2021 Ru-103 -2.49E-04 5.32E-04 1.49E-03 U AP 05 568408005 12/29/2021 Ru-106 -6.94E-04 1.79E-03 5.66E-03 U AP 05 568408005 12/29/2021 Sb-124 -1.04E-04 1.14E-03 3.62E-03 U AP 05 568408005 12/29/2021 Sb-125 7.60E-06 4.07E-04 1.37E-03 U AP 05 568408005 12/29/2021 Se-75 5.05E-05 2.31E-04 7.35E-04 U AP 05 568408005 12/29/2021 Th-228 9.90E-04 4.37E-04 1.02E-03 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 05 568408005 12/29/2021 Zn-65 -3.40E-04 4.87E-04 1.49E-03 U AP 05 568408005 12/29/2021 Zr-95 4.35E-04 6.59E-04 2.23E-03 U AP 07 532372006 1/13/2021 BETA 2.13E-02 1.07E-03 9.33E-04 AP 07 533687006 1/27/2021 BETA 2.43E-02 1.14E-03 9.29E-04 AP 07 535173006 2/10/2021 BETA 2.02E-02 1.09E-03 1.10E-03 AP 07 536335006 2/25/2021 BETA 2.94E-02 1.28E-03 9.86E-04 AP 07 537636006 3/10/2021 BETA 2.26E-02 1.26E-03 1.19E-03 AP 07 539006006 3/24/2021 BETA 3.21E-02 1.20E-03 8.00E-04 AP 07 543395006 3/24/2021 Ac-228 5.09E-04 6.12E-04 2.05E-03 U AP 07 543395006 3/24/2021 Ag-108m -1.86E-05 8.09E-05 2.51E-04 U AP 07 543395006 3/24/2021 Ag-110m 1.04E-04 2.04E-04 7.02E-04 U AP 07 543395006 3/24/2021 Ba-140 -2.73E-02 3.01E-02 8.92E-02 U AP 07 543395006 3/24/2021 Be-7 1.13E-01 9.48E-03 6.70E-03 AP 07 543395006 3/24/2021 Ce-141 -6.87E-05 5.26E-04 1.68E-03 U AP 07 543395006 3/24/2021 Ce-144 3.96E-04 3.97E-04 1.34E-03 U AP 07 543395006 3/24/2021 Co-57 1.10E-04 8.37E-05 1.81E-04 U AP 07 543395006 3/24/2021 Co-58 3.02E-05 2.22E-04 7.54E-04 U AP 07 543395006 3/24/2021 Co-60 -1.46E-04 1.15E-04 2.84E-04 U AP 07 543395006 3/24/2021 Cr-51 -8.15E-04 4.75E-03 1.54E-02 U AP 07 543395006 3/24/2021 Cs-134 -4.42E-05 1.21E-04 3.91E-04 U AP 07 543395006 3/24/2021 Cs-137 2.04E-04 1.21E-04 4.14E-04 U AP 07 543395006 3/24/2021 Fe-59 1.20E-03 8.47E-04 3.01E-03 U AP 07 543395006 3/24/2021 I-131 0.00E+00 1.29E-01 0.00E+00 UI AP 07 543395006 3/24/2021 K-40 3.09E-03 2.37E-03 4.88E-03 U AP 07 543395006 3/24/2021 La-140 1.16E-02 1.44E-02 5.13E-02 U AP 07 543395006 3/24/2021 Mn-54 -1.92E-05 1.45E-04 4.14E-04 U AP 07 543395006 3/24/2021 Nb-95 1.13E-04 3.48E-04 1.05E-03 U AP 07 543395006 3/24/2021 Ru-103 -3.42E-04 3.98E-04 1.21E-03 U AP 07 543395006 3/24/2021 Ru-106 9.22E-04 1.08E-03 3.71E-03 U AP 07 543395006 3/24/2021 Sb-124 -7.46E-04 8.26E-04 2.36E-03 U AP 07 543395006 3/24/2021 Sb-125 -1.07E-04 2.33E-04 7.04E-04 U AP 07 543395006 3/24/2021 Se-75 -7.65E-05 1.38E-04 4.43E-04 U AP 07 543395006 3/24/2021 Th-228 6.26E-04 2.04E-04 3.55E-04 AP 07 543395006 3/24/2021 Zn-65 3.23E-04 3.16E-04 1.11E-03 U AP 07 543395006 3/24/2021 Zr-95 1.22E-03 5.48E-04 1.52E-03 U AP 07 540404006 4/7/2021 BETA 2.04E-02 9.75E-04 8.17E-04 AP 07 541857006 4/21/2021 BETA 1.17E-02 7.51E-04 8.35E-04 AP 07 544029006 5/5/2021 BETA 2.91E-02 1.21E-03 9.04E-04 AP 07 545432006 5/19/2021 BETA 2.14E-02 1.05E-03 8.91E-04 AP 07 546369006 6/2/2021 BETA 2.13E-02 1.06E-03 9.48E-04 AP 07 547926006 6/16/2021 BETA 2.59E-02 1.20E-03 1.04E-03 AP 07 548743006 6/29/2021 BETA 2.47E-02 1.24E-03 1.07E-03 AP 07 552139006 6/29/2021 Ac-228 0.00E+00 7.32E-04 1.38E-03 U AP 07 552139006 6/29/2021 Ag-108m 1.09E-04 6.18E-05 2.09E-04 U AP 07 552139006 6/29/2021 Ag-110m -3.01E-04 1.33E-04 2.87E-04 U AP 07 552139006 6/29/2021 Ba-140 1.41E-02 3.25E-02 1.11E-01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 07 552139006 6/29/2021 Be-7 1.30E-01 8.59E-03 4.99E-03 AP 07 552139006 6/29/2021 Ce-141 -6.21E-04 5.90E-04 1.69E-03 U AP 07 552139006 6/29/2021 Ce-144 -1.17E-05 4.41E-04 1.39E-03 U AP 07 552139006 6/29/2021 Co-57 -2.20E-05 5.55E-05 1.72E-04 U AP 07 552139006 6/29/2021 Co-58 1.21E-04 1.79E-04 5.95E-04 U AP 07 552139006 6/29/2021 Co-60 1.29E-05 9.16E-05 3.00E-04 U AP 07 552139006 6/29/2021 Cr-51 4.80E-03 5.34E-03 1.77E-02 U AP 07 552139006 6/29/2021 Cs-134 -4.70E-05 9.74E-05 2.69E-04 U AP 07 552139006 6/29/2021 Cs-137 -9.56E-05 7.69E-05 2.19E-04 U AP 07 552139006 6/29/2021 Fe-59 -9.74E-05 5.12E-04 1.66E-03 U AP 07 552139006 6/29/2021 I-131 0.00E+00 1.49E-01 0.00E+00 UI AP 07 552139006 6/29/2021 K-40 2.22E-03 1.91E-03 2.96E-03 U AP 07 552139006 6/29/2021 La-140 -3.27E-03 1.48E-02 4.82E-02 U AP 07 552139006 6/29/2021 Mn-54 1.07E-04 1.03E-04 3.42E-04 U AP 07 552139006 6/29/2021 Nb-95 -4.12E-04 2.45E-04 5.73E-04 U AP 07 552139006 6/29/2021 Ru-103 3.17E-04 2.92E-04 1.01E-03 U AP 07 552139006 6/29/2021 Ru-106 -8.78E-05 7.41E-04 2.43E-03 U AP 07 552139006 6/29/2021 Sb-124 -4.81E-05 4.83E-04 1.58E-03 U AP 07 552139006 6/29/2021 Sb-125 -2.59E-04 1.82E-04 4.86E-04 U AP 07 552139006 6/29/2021 Se-75 -3.15E-05 1.36E-04 4.23E-04 U AP 07 552139006 6/29/2021 Th-228 6.99E-04 2.34E-04 3.28E-04 AP 07 552139006 6/29/2021 Zn-65 -5.39E-04 3.08E-04 6.22E-04 U AP 07 552139006 6/29/2021 Zr-95 -1.54E-04 3.15E-04 9.71E-04 U AP 07 549925006 7/13/2021 BETA 1.84E-02 1.03E-03 1.00E-03 AP 07 551091006 7/28/2021 BETA 2.82E-02 1.27E-03 9.40E-04 AP 07 552841006 8/11/2021 BETA 3.67E-02 1.52E-03 1.05E-03 AP 07 554155006 8/25/2021 BETA 2.93E-02 1.36E-03 1.08E-03 AP 07 555720006 9/9/2021 BETA 4.00E-02 1.40E-03 9.79E-04 AP 07 556805006 9/22/2021 BETA 3.96E-02 1.48E-03 1.07E-03 AP 07 560825006 9/22/2021 Ac-228 -2.23E-04 5.29E-04 1.63E-03 U AP 07 560825006 9/22/2021 Ag-108m 4.52E-05 7.71E-05 2.66E-04 U AP 07 560825006 9/22/2021 Ag-110m -5.07E-05 1.44E-04 4.36E-04 U AP 07 560825006 9/22/2021 Ba-140 -1.31E-02 3.92E-02 1.20E-01 U AP 07 560825006 9/22/2021 Be-7 1.50E-01 1.12E-02 5.79E-03 AP 07 560825006 9/22/2021 Ce-141 -1.25E-03 7.87E-04 2.01E-03 U AP 07 560825006 9/22/2021 Ce-144 4.81E-04 5.06E-04 1.68E-03 U AP 07 560825006 9/22/2021 Co-57 2.86E-05 5.82E-05 1.94E-04 U AP 07 560825006 9/22/2021 Co-58 2.87E-04 2.12E-04 7.43E-04 U AP 07 560825006 9/22/2021 Co-60 3.31E-05 8.98E-05 3.14E-04 U AP 07 560825006 9/22/2021 Cr-51 3.48E-03 6.21E-03 2.16E-02 U AP 07 560825006 9/22/2021 Cs-134 -1.61E-05 1.15E-04 3.77E-04 U AP 07 560825006 9/22/2021 Cs-137 1.14E-04 9.11E-05 3.19E-04 U AP 07 560825006 9/22/2021 Fe-59 5.74E-05 5.47E-04 1.87E-03 U AP 07 560825006 9/22/2021 I-131 0.00E+00 1.38E-01 0.00E+00 UI AP 07 560825006 9/22/2021 K-40 -1.12E-03 1.68E-03 5.89E-03 U AP 07 560825006 9/22/2021 La-140 -9.20E-03 1.42E-02 4.13E-02 U AP 07 560825006 9/22/2021 Mn-54 -3.81E-05 1.15E-04 3.53E-04 U AP 07 560825006 9/22/2021 Nb-95 -3.89E-05 2.64E-04 8.39E-04 U AP 07 560825006 9/22/2021 Ru-103 1.81E-05 3.58E-04 1.20E-03 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 07 560825006 9/22/2021 Ru-106 -6.59E-04 8.56E-04 2.53E-03 U AP 07 560825006 9/22/2021 Sb-124 1.26E-04 5.38E-04 1.83E-03 U AP 07 560825006 9/22/2021 Sb-125 -2.56E-05 2.05E-04 6.83E-04 U AP 07 560825006 9/22/2021 Se-75 -1.37E-04 1.83E-04 5.35E-04 U AP 07 560825006 9/22/2021 Th-228 0.00E+00 3.22E-04 6.30E-04 U AP 07 560825006 9/22/2021 Zn-65 -2.88E-04 3.55E-04 9.03E-04 U AP 07 560825006 9/22/2021 Zr-95 6.63E-04 4.77E-04 1.64E-03 U AP 07 558373006 10/6/2021 BETA 3.02E-02 1.23E-03 8.80E-04 AP 07 560124006 10/21/2021 BETA 3.72E-02 1.32E-03 8.20E-04 AP 07 561299006 11/2/2021 BETA 3.35E-02 1.41E-03 1.02E-03 AP 07 562487006 11/17/2021 BETA 3.57E-02 1.27E-03 8.09E-04 AP 07 563880006 12/1/2021 BETA 3.08E-02 1.22E-03 8.40E-04 AP 07 565211006 12/15/2021 BETA 4.02E-02 1.54E-03 1.11E-03 AP 07 566442006 12/29/2021 BETA 4.17E-02 1.45E-03 9.44E-04 AP 07 568408006 12/29/2021 Ac-228 8.38E-05 5.08E-04 1.42E-03 U AP 07 568408006 12/29/2021 Ag-108m -1.22E-04 6.62E-05 1.65E-04 U AP 07 568408006 12/29/2021 Ag-110m 2.53E-05 1.39E-04 4.67E-04 U AP 07 568408006 12/29/2021 Ba-140 3.94E-03 1.47E-02 4.93E-02 U AP 07 568408006 12/29/2021 Be-7 1.03E-01 7.09E-03 4.16E-03 AP 07 568408006 12/29/2021 Ce-141 -5.78E-05 3.79E-04 1.22E-03 U AP 07 568408006 12/29/2021 Ce-144 6.15E-04 3.87E-04 1.29E-03 U AP 07 568408006 12/29/2021 Co-57 3.53E-05 4.71E-05 1.59E-04 U AP 07 568408006 12/29/2021 Co-58 1.94E-04 1.50E-04 5.46E-04 U AP 07 568408006 12/29/2021 Co-60 4.28E-05 9.30E-05 3.20E-04 U AP 07 568408006 12/29/2021 Cr-51 -3.75E-04 3.17E-03 1.07E-02 U AP 07 568408006 12/29/2021 Cs-134 -3.27E-05 8.65E-05 2.81E-04 U AP 07 568408006 12/29/2021 Cs-137 -1.36E-04 8.81E-05 1.86E-04 U AP 07 568408006 12/29/2021 Fe-59 -4.91E-04 4.76E-04 1.29E-03 U AP 07 568408006 12/29/2021 I-131 1.19E-01 5.96E-02 2.01E-01 U AP 07 568408006 12/29/2021 K-40 7.68E-04 1.48E-03 5.40E-03 U AP 07 568408006 12/29/2021 La-140 -1.06E-03 6.72E-03 2.21E-02 U AP 07 568408006 12/29/2021 Mn-54 4.47E-05 6.65E-05 2.40E-04 U AP 07 568408006 12/29/2021 Nb-95 -1.62E-04 1.68E-04 5.05E-04 U AP 07 568408006 12/29/2021 Ru-103 3.98E-05 2.43E-04 8.09E-04 U AP 07 568408006 12/29/2021 Ru-106 8.99E-04 8.58E-04 2.92E-03 U AP 07 568408006 12/29/2021 Sb-124 3.32E-04 3.83E-04 1.46E-03 U AP 07 568408006 12/29/2021 Sb-125 -2.23E-04 1.69E-04 4.63E-04 U AP 07 568408006 12/29/2021 Se-75 -9.98E-05 1.15E-04 3.69E-04 U AP 07 568408006 12/29/2021 Th-228 2.58E-04 2.18E-04 4.92E-04 U AP 07 568408006 12/29/2021 Zn-65 -3.13E-04 2.08E-04 4.84E-04 U AP 07 568408006 12/29/2021 Zr-95 -1.91E-04 3.14E-04 9.13E-04 U AP 08 532372007 1/13/2021 BETA 2.38E-02 1.14E-03 9.82E-04 AP 08 533687007 1/27/2021 BETA 2.92E-02 1.27E-03 1.00E-03 AP 08 535173007 2/10/2021 BETA 1.57E-02 9.44E-04 9.91E-04 AP 08 536335007 2/25/2021 BETA 3.10E-02 1.29E-03 9.53E-04 AP 08 537636007 3/10/2021 BETA 2.17E-02 8.50E-04 5.97E-04 AP 08 539006007 3/24/2021 BETA 2.96E-02 1.14E-03 7.94E-04

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 08 543395007 3/24/2021 Ac-228 2.97E-04 3.97E-04 1.36E-03 U AP 08 543395007 3/24/2021 Ag-108m -3.04E-05 7.03E-05 2.30E-04 U AP 08 543395007 3/24/2021 Ag-110m 3.38E-04 1.92E-04 6.71E-04 U AP 08 543395007 3/24/2021 Ba-140 -6.30E-03 2.81E-02 9.19E-02 U AP 08 543395007 3/24/2021 Be-7 1.23E-01 8.82E-03 5.22E-03 AP 08 543395007 3/24/2021 Ce-141 -2.56E-04 6.13E-04 1.94E-03 U AP 08 543395007 3/24/2021 Ce-144 7.44E-04 5.28E-04 1.74E-03 U AP 08 543395007 3/24/2021 Co-57 9.71E-05 6.59E-05 2.19E-04 U AP 08 543395007 3/24/2021 Co-58 -2.47E-04 2.24E-04 6.15E-04 U AP 08 543395007 3/24/2021 Co-60 2.77E-04 2.03E-04 6.47E-04 U AP 08 543395007 3/24/2021 Cr-51 2.27E-03 6.30E-03 1.85E-02 U AP 08 543395007 3/24/2021 Cs-134 1.18E-04 1.32E-04 4.53E-04 U AP 08 543395007 3/24/2021 Cs-137 -4.19E-05 8.76E-05 2.73E-04 U AP 08 543395007 3/24/2021 Fe-59 7.54E-04 6.10E-04 2.21E-03 U AP 08 543395007 3/24/2021 I-131 0.00E+00 1.29E-01 0.00E+00 UI AP 08 543395007 3/24/2021 K-40 -3.24E-03 1.83E-03 5.61E-03 U AP 08 543395007 3/24/2021 La-140 -3.28E-03 1.39E-02 4.45E-02 U AP 08 543395007 3/24/2021 Mn-54 7.13E-05 9.26E-05 3.24E-04 U AP 08 543395007 3/24/2021 Nb-95 3.70E-05 2.29E-04 7.58E-04 U AP 08 543395007 3/24/2021 Ru-103 3.27E-04 3.25E-04 1.15E-03 U AP 08 543395007 3/24/2021 Ru-106 -6.20E-04 8.88E-04 2.71E-03 U AP 08 543395007 3/24/2021 Sb-124 -8.39E-04 7.41E-04 1.91E-03 U AP 08 543395007 3/24/2021 Sb-125 -2.51E-05 2.28E-04 7.65E-04 U AP 08 543395007 3/24/2021 Se-75 2.88E-05 1.61E-04 5.11E-04 U AP 08 543395007 3/24/2021 Th-228 2.11E-04 3.32E-04 4.72E-04 U AP 08 543395007 3/24/2021 Zn-65 -1.37E-04 2.55E-04 7.34E-04 U AP 08 543395007 3/24/2021 Zr-95 2.69E-04 3.56E-04 1.24E-03 U AP 08 540404007 4/7/2021 BETA 1.59E-02 8.37E-04 7.69E-04 AP 08 541857007 4/21/2021 BETA 1.13E-02 7.44E-04 8.55E-04 AP 08 544029007 5/5/2021 BETA 2.46E-02 1.07E-03 8.41E-04 AP 08 545432007 5/19/2021 BETA 1.82E-02 9.26E-04 8.24E-04 AP 08 546369007 6/2/2021 BETA 1.94E-02 9.52E-04 8.45E-04 AP 08 547926007 6/16/2021 BETA 2.50E-02 1.12E-03 9.08E-04 AP 08 548743007 6/29/2021 BETA 3.34E-03 5.20E-04 9.97E-04 M AP 08 552139007 6/29/2021 Ac-228 -1.31E-05 4.22E-04 1.39E-03 U AP 08 552139007 6/29/2021 Ag-108m 2.86E-05 6.80E-05 2.30E-04 U AP 08 552139007 6/29/2021 Ag-110m -2.50E-04 1.57E-04 4.25E-04 U AP 08 552139007 6/29/2021 Ba-140 -4.07E-02 3.82E-02 1.14E-01 U AP 08 552139007 6/29/2021 Be-7 9.61E-02 7.45E-03 6.29E-03 AP 08 552139007 6/29/2021 Ce-141 2.05E-05 1.09E-03 2.16E-03 U AP 08 552139007 6/29/2021 Ce-144 3.63E-04 4.91E-04 1.68E-03 U AP 08 552139007 6/29/2021 Co-57 -1.05E-04 6.76E-05 2.03E-04 U AP 08 552139007 6/29/2021 Co-58 -8.82E-06 1.98E-04 6.56E-04 U AP 08 552139007 6/29/2021 Co-60 -5.54E-05 7.79E-05 2.37E-04 U AP 08 552139007 6/29/2021 Cr-51 8.33E-03 7.04E-03 2.04E-02 U AP 08 552139007 6/29/2021 Cs-134 -1.50E-04 9.90E-05 2.77E-04 U AP 08 552139007 6/29/2021 Cs-137 5.48E-05 8.05E-05 2.66E-04 U AP 08 552139007 6/29/2021 Fe-59 -4.16E-04 7.96E-04 2.31E-03 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 08 552139007 6/29/2021 I-131 0.00E+00 1.90E-01 0.00E+00 UI AP 08 552139007 6/29/2021 K-40 1.96E-03 1.54E-03 2.63E-03 U AP 08 552139007 6/29/2021 La-140 -4.59E-04 1.18E-02 3.84E-02 U AP 08 552139007 6/29/2021 Mn-54 -5.16E-05 9.21E-05 2.93E-04 U AP 08 552139007 6/29/2021 Nb-95 2.53E-04 2.45E-04 7.47E-04 U AP 08 552139007 6/29/2021 Ru-103 -3.33E-04 3.41E-04 1.03E-03 U AP 08 552139007 6/29/2021 Ru-106 7.16E-04 8.69E-04 2.87E-03 U AP 08 552139007 6/29/2021 Sb-124 2.68E-05 4.44E-04 1.45E-03 U AP 08 552139007 6/29/2021 Sb-125 -1.41E-04 2.15E-04 6.86E-04 U AP 08 552139007 6/29/2021 Se-75 -4.41E-05 1.60E-04 5.08E-04 U AP 08 552139007 6/29/2021 Th-228 0.00E+00 2.58E-04 4.12E-04 U AP 08 552139007 6/29/2021 Zn-65 1.83E-04 2.24E-04 7.56E-04 U AP 08 552139007 6/29/2021 Zr-95 1.02E-04 3.72E-04 1.26E-03 U AP 08 549925007 7/13/2021 BETA 1.67E-02 9.32E-04 9.17E-04 AP 08 551091007 7/28/2021 BETA 2.41E-02 1.07E-03 8.14E-04 AP 08 552841007 8/11/2021 BETA 3.03E-02 1.25E-03 8.89E-04 AP 08 554155007 8/25/2021 BETA 2.60E-02 1.20E-03 1.11E-03 AP 08 555720007 9/9/2021 BETA 4.03E-02 1.44E-03 9.11E-04 AP 08 556805007 9/22/2021 BETA 3.52E-02 1.45E-03 1.02E-03 AP 08 560825007 9/22/2021 Ac-228 3.81E-04 4.61E-04 1.48E-03 U AP 08 560825007 9/22/2021 Ag-108m 1.79E-05 5.28E-05 1.81E-04 U AP 08 560825007 9/22/2021 Ag-110m -6.43E-05 1.59E-04 4.86E-04 U AP 08 560825007 9/22/2021 Ba-140 -1.40E-02 2.88E-02 9.13E-02 U AP 08 560825007 9/22/2021 Be-7 1.13E-01 8.42E-03 5.74E-03 AP 08 560825007 9/22/2021 Ce-141 -5.36E-04 5.40E-04 1.44E-03 U AP 08 560825007 9/22/2021 Ce-144 4.32E-04 3.93E-04 1.24E-03 U AP 08 560825007 9/22/2021 Co-57 -5.55E-05 5.10E-05 1.49E-04 U AP 08 560825007 9/22/2021 Co-58 3.08E-04 1.73E-04 6.16E-04 U AP 08 560825007 9/22/2021 Co-60 -2.98E-05 9.44E-05 3.02E-04 U AP 08 560825007 9/22/2021 Cr-51 4.58E-04 4.39E-03 1.51E-02 U AP 08 560825007 9/22/2021 Cs-134 1.45E-04 1.08E-04 3.73E-04 U AP 08 560825007 9/22/2021 Cs-137 6.75E-06 9.02E-05 2.66E-04 U AP 08 560825007 9/22/2021 Fe-59 -6.72E-04 5.44E-04 1.46E-03 U AP 08 560825007 9/22/2021 I-131 0.00E+00 1.02E-01 0.00E+00 UI AP 08 560825007 9/22/2021 K-40 1.41E-03 1.47E-03 2.01E-03 U AP 08 560825007 9/22/2021 La-140 9.28E-03 1.14E-02 4.13E-02 U AP 08 560825007 9/22/2021 Mn-54 3.06E-05 1.06E-04 3.15E-04 U AP 08 560825007 9/22/2021 Nb-95 4.68E-05 1.91E-04 6.32E-04 U AP 08 560825007 9/22/2021 Ru-103 -4.15E-04 2.84E-04 7.65E-04 U AP 08 560825007 9/22/2021 Ru-106 3.33E-04 8.48E-04 2.86E-03 U AP 08 560825007 9/22/2021 Sb-124 -3.60E-04 5.00E-04 1.39E-03 U AP 08 560825007 9/22/2021 Sb-125 1.06E-05 1.76E-04 5.94E-04 U AP 08 560825007 9/22/2021 Se-75 5.32E-05 1.25E-04 4.00E-04 U AP 08 560825007 9/22/2021 Th-228 4.95E-04 3.23E-04 5.48E-04 U AP 08 560825007 9/22/2021 Zn-65 1.53E-05 2.61E-04 7.87E-04 U AP 08 560825007 9/22/2021 Zr-95 -6.36E-04 3.76E-04 8.83E-04 U AP 08 558373007 10/6/2021 BETA 2.26E-02 1.12E-03 9.81E-04 AP 08 560124007 10/21/2021 BETA 3.16E-02 1.30E-03 9.63E-04

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 08 561299007 11/2/2021 BETA 2.82E-02 1.40E-03 1.22E-03 AP 08 562487007 11/17/2021 BETA 3.23E-02 1.35E-03 1.08E-03 AP 08 563880007 12/1/2021 BETA 2.64E-02 1.30E-03 1.28E-03 AP 08 565211007 12/15/2021 BETA 2.74E-02 1.29E-03 1.08E-03 AP 08 566442007 12/29/2021 BETA 3.53E-02 1.50E-03 1.13E-03 AP 08 568408007 12/29/2021 Ac-228 3.29E-04 6.64E-04 1.86E-03 U AP 08 568408007 12/29/2021 Ag-108m -1.18E-05 7.63E-05 2.41E-04 U AP 08 568408007 12/29/2021 Ag-110m -7.25E-05 1.91E-04 5.15E-04 U AP 08 568408007 12/29/2021 Ba-140 1.33E-02 2.24E-02 7.84E-02 U AP 08 568408007 12/29/2021 Be-7 9.17E-02 7.87E-03 6.50E-03 AP 08 568408007 12/29/2021 Ce-141 3.64E-04 5.78E-04 1.81E-03 U AP 08 568408007 12/29/2021 Ce-144 -2.05E-04 5.23E-04 1.56E-03 U AP 08 568408007 12/29/2021 Co-57 -2.19E-05 6.01E-05 2.01E-04 U AP 08 568408007 12/29/2021 Co-58 -2.77E-04 1.87E-04 4.67E-04 U AP 08 568408007 12/29/2021 Co-60 -6.40E-05 1.16E-04 3.59E-04 U AP 08 568408007 12/29/2021 Cr-51 3.15E-04 5.35E-03 1.56E-02 U AP 08 568408007 12/29/2021 Cs-134 1.33E-04 1.20E-04 4.23E-04 U AP 08 568408007 12/29/2021 Cs-137 2.95E-05 1.08E-04 3.09E-04 U AP 08 568408007 12/29/2021 Fe-59 -2.10E-04 6.46E-04 1.99E-03 U AP 08 568408007 12/29/2021 I-131 -2.19E-04 6.44E-02 2.08E-01 U AP 08 568408007 12/29/2021 K-40 -1.77E-03 1.60E-03 4.92E-03 U AP 08 568408007 12/29/2021 La-140 -2.13E-03 9.74E-03 3.13E-02 U AP 08 568408007 12/29/2021 Mn-54 -8.87E-05 1.14E-04 3.39E-04 U AP 08 568408007 12/29/2021 Nb-95 -8.30E-05 2.72E-04 8.77E-04 U AP 08 568408007 12/29/2021 Ru-103 -8.62E-04 4.41E-04 1.02E-03 U AP 08 568408007 12/29/2021 Ru-106 5.29E-04 9.80E-04 3.40E-03 U AP 08 568408007 12/29/2021 Sb-124 1.82E-04 7.05E-04 2.12E-03 U AP 08 568408007 12/29/2021 Sb-125 -3.96E-04 2.61E-04 6.74E-04 U AP 08 568408007 12/29/2021 Se-75 2.22E-04 1.76E-04 5.90E-04 U AP 08 568408007 12/29/2021 Th-228 4.02E-04 3.02E-04 7.19E-04 U AP 08 568408007 12/29/2021 Zn-65 1.33E-04 2.49E-04 8.50E-04 U AP 08 568408007 12/29/2021 Zr-95 1.30E-04 3.64E-04 1.11E-03 U AP 09 532372008 1/13/2021 BETA 2.31E-02 9.56E-04 7.09E-04 AP 09 533687008 1/27/2021 BETA 2.94E-02 1.19E-03 8.49E-04 AP 09 535173008 2/10/2021 BETA 2.17E-02 1.05E-03 9.41E-04 AP 09 536335008 2/25/2021 BETA 3.12E-02 1.19E-03 8.22E-04 AP 09 537636008 3/10/2021 BETA 2.63E-02 1.17E-03 9.73E-04 AP 09 539006008 3/24/2021 BETA 4.04E-02 1.45E-03 9.23E-04 AP 09 543395008 3/24/2021 Ac-228 6.18E-04 4.44E-04 1.58E-03 U AP 09 543395008 3/24/2021 Ag-108m -7.51E-05 7.02E-05 2.08E-04 U AP 09 543395008 3/24/2021 Ag-110m -1.64E-05 1.41E-04 4.71E-04 U AP 09 543395008 3/24/2021 Ba-140 -2.75E-03 3.09E-02 9.11E-02 U AP 09 543395008 3/24/2021 Be-7 1.29E-01 9.82E-03 6.34E-03 AP 09 543395008 3/24/2021 Ce-141 -8.66E-04 6.87E-04 1.64E-03 U AP 09 543395008 3/24/2021 Ce-144 -3.35E-04 4.53E-04 1.39E-03 U AP 09 543395008 3/24/2021 Co-57 3.36E-05 6.23E-05 2.08E-04 U AP 09 543395008 3/24/2021 Co-58 1.19E-04 1.72E-04 5.86E-04 U AP 09 543395008 3/24/2021 Co-60 2.98E-04 1.41E-04 5.09E-04 U

-175-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 09 543395008 3/24/2021 Cr-51 -2.05E-03 5.46E-03 1.82E-02 U AP 09 543395008 3/24/2021 Cs-134 -2.47E-04 1.18E-04 2.12E-04 U AP 09 543395008 3/24/2021 Cs-137 7.20E-05 8.30E-05 2.86E-04 U AP 09 543395008 3/24/2021 Fe-59 -3.14E-04 6.75E-04 2.10E-03 U AP 09 543395008 3/24/2021 I-131 -4.08E-02 1.33E-01 0.00E+00 U AP 09 543395008 3/24/2021 K-40 1.26E-03 1.63E-03 6.20E-03 U AP 09 543395008 3/24/2021 La-140 1.61E-02 1.20E-02 4.50E-02 U AP 09 543395008 3/24/2021 Mn-54 0.00E+00 9.93E-05 3.11E-04 U AP 09 543395008 3/24/2021 Nb-95 3.09E-05 2.05E-04 6.63E-04 U AP 09 543395008 3/24/2021 Ru-103 1.02E-04 2.64E-04 9.01E-04 U AP 09 543395008 3/24/2021 Ru-106 1.89E-04 9.58E-04 3.01E-03 U AP 09 543395008 3/24/2021 Sb-124 1.05E-05 7.48E-04 2.53E-03 U AP 09 543395008 3/24/2021 Sb-125 -2.55E-04 2.39E-04 7.13E-04 U AP 09 543395008 3/24/2021 Se-75 -2.89E-05 1.42E-04 4.34E-04 U AP 09 543395008 3/24/2021 Th-228 4.55E-04 2.32E-04 5.64E-04 U AP 09 543395008 3/24/2021 Zn-65 1.22E-04 2.59E-04 8.99E-04 U AP 09 543395008 3/24/2021 Zr-95 3.08E-04 3.84E-04 1.31E-03 U AP 09 540404008 4/7/2021 BETA 2.24E-02 1.13E-03 9.94E-04 AP 09 541857008 4/21/2021 BETA 1.57E-02 1.00E-03 1.09E-03 AP 09 544029008 5/5/2021 BETA 2.86E-02 1.30E-03 1.01E-03 AP 09 545432008 5/19/2021 BETA 1.98E-02 1.03E-03 9.10E-04 AP 09 546369008 6/2/2021 BETA 2.36E-02 1.18E-03 1.10E-03 AP 09 547926008 6/16/2021 BETA 3.05E-02 1.37E-03 1.10E-03 AP 09 548743008 6/29/2021 BETA 3.09E-02 1.34E-03 1.07E-03 AP 09 552139008 6/29/2021 Ac-228 1.37E-03 6.00E-04 1.64E-03 U AP 09 552139008 6/29/2021 Ag-108m -2.56E-05 5.88E-05 1.92E-04 U AP 09 552139008 6/29/2021 Ag-110m 2.78E-05 1.47E-04 4.82E-04 U AP 09 552139008 6/29/2021 Ba-140 3.62E-02 3.51E-02 1.23E-01 U AP 09 552139008 6/29/2021 Be-7 1.45E-01 1.05E-02 6.42E-03 AP 09 552139008 6/29/2021 Ce-141 1.00E-03 7.35E-04 2.12E-03 U AP 09 552139008 6/29/2021 Ce-144 2.46E-04 4.43E-04 1.47E-03 U AP 09 552139008 6/29/2021 Co-57 -3.53E-05 6.08E-05 1.91E-04 U AP 09 552139008 6/29/2021 Co-58 -2.63E-04 2.00E-04 5.29E-04 U AP 09 552139008 6/29/2021 Co-60 -2.25E-05 1.09E-04 3.60E-04 U AP 09 552139008 6/29/2021 Cr-51 -1.01E-02 5.96E-03 1.46E-02 U AP 09 552139008 6/29/2021 Cs-134 -1.66E-04 1.07E-04 2.71E-04 U AP 09 552139008 6/29/2021 Cs-137 -1.74E-05 1.07E-04 3.21E-04 U AP 09 552139008 6/29/2021 Fe-59 -7.46E-04 7.33E-04 1.97E-03 U AP 09 552139008 6/29/2021 I-131 0.00E+00 1.86E-01 0.00E+00 UI AP 09 552139008 6/29/2021 K-40 2.54E-03 1.59E-03 2.87E-03 U AP 09 552139008 6/29/2021 La-140 2.86E-02 1.72E-02 6.36E-02 U AP 09 552139008 6/29/2021 Mn-54 1.84E-05 9.43E-05 3.12E-04 U AP 09 552139008 6/29/2021 Nb-95 6.59E-05 1.90E-04 6.40E-04 U AP 09 552139008 6/29/2021 Ru-103 2.31E-05 3.11E-04 1.05E-03 U AP 09 552139008 6/29/2021 Ru-106 1.71E-04 7.69E-04 2.59E-03 U AP 09 552139008 6/29/2021 Sb-124 -3.28E-04 4.87E-04 1.39E-03 U AP 09 552139008 6/29/2021 Sb-125 2.49E-04 2.11E-04 7.39E-04 U AP 09 552139008 6/29/2021 Se-75 -1.38E-04 1.56E-04 4.53E-04 U AP 09 552139008 6/29/2021 Th-228 0.00E+00 2.47E-04 5.08E-04 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 09 552139008 6/29/2021 Zn-65 4.57E-04 2.33E-04 8.37E-04 U AP 09 552139008 6/29/2021 Zr-95 3.40E-04 3.60E-04 1.25E-03 U AP 09 549925008 7/13/2021 BETA 2.44E-02 1.18E-03 1.05E-03 AP 09 551091008 7/28/2021 BETA 3.11E-02 1.25E-03 8.60E-04 AP 09 552841008 8/11/2021 BETA 4.01E-02 1.51E-03 9.89E-04 AP 09 554155008 8/25/2021 BETA 3.83E-02 1.45E-03 9.89E-04 AP 09 555720008 9/9/2021 BETA 4.84E-02 1.60E-03 9.08E-04 AP 09 556805008 9/22/2021 BETA 4.58E-02 1.62E-03 9.82E-04 AP 09 560825008 9/22/2021 Ac-228 -7.65E-04 1.08E-03 3.17E-03 U AP 09 560825008 9/22/2021 Ag-108m -2.51E-05 1.19E-04 3.95E-04 U AP 09 560825008 9/22/2021 Ag-110m -2.39E-06 3.41E-04 1.08E-03 U AP 09 560825008 9/22/2021 Ba-140 8.40E-03 6.16E-02 2.06E-01 U AP 09 560825008 9/22/2021 Be-7 1.88E-01 1.51E-02 1.10E-02 AP 09 560825008 9/22/2021 Ce-141 -6.28E-04 1.05E-03 3.30E-03 U AP 09 560825008 9/22/2021 Ce-144 -2.72E-04 7.56E-04 2.42E-03 U AP 09 560825008 9/22/2021 Co-57 -3.64E-05 9.70E-05 3.12E-04 U AP 09 560825008 9/22/2021 Co-58 -2.69E-04 4.08E-04 1.20E-03 U AP 09 560825008 9/22/2021 Co-60 -4.99E-04 3.31E-04 7.79E-04 U AP 09 560825008 9/22/2021 Cr-51 1.35E-02 9.11E-03 3.19E-02 U AP 09 560825008 9/22/2021 Cs-134 3.95E-04 2.11E-04 7.42E-04 U AP 09 560825008 9/22/2021 Cs-137 7.15E-05 2.13E-04 7.10E-04 U AP 09 560825008 9/22/2021 Fe-59 1.84E-04 1.24E-03 4.22E-03 U AP 09 560825008 9/22/2021 I-131 -1.94E-01 2.29E-01 0.00E+00 U AP 09 560825008 9/22/2021 K-40 2.03E-03 3.76E-03 6.24E-03 U AP 09 560825008 9/22/2021 La-140 9.20E-03 2.33E-02 8.01E-02 U AP 09 560825008 9/22/2021 Mn-54 -3.10E-04 2.56E-04 6.82E-04 U AP 09 560825008 9/22/2021 Nb-95 2.89E-04 4.81E-04 1.62E-03 U AP 09 560825008 9/22/2021 Ru-103 -9.74E-04 6.68E-04 1.82E-03 U AP 09 560825008 9/22/2021 Ru-106 2.99E-03 1.80E-03 6.26E-03 U AP 09 560825008 9/22/2021 Sb-124 7.48E-04 9.70E-04 3.55E-03 U AP 09 560825008 9/22/2021 Sb-125 3.30E-04 4.09E-04 1.43E-03 U AP 09 560825008 9/22/2021 Se-75 -3.32E-04 2.84E-04 7.82E-04 U AP 09 560825008 9/22/2021 Th-228 4.29E-04 4.70E-04 1.07E-03 U AP 09 560825008 9/22/2021 Zn-65 1.03E-04 5.17E-04 1.77E-03 U AP 09 560825008 9/22/2021 Zr-95 1.44E-04 9.63E-04 3.14E-03 U AP 09 558373008 10/6/2021 BETA 4.53E-02 1.79E-03 1.40E-03 AP 09 560124008 10/21/2021 BETA 4.38E-02 1.51E-03 9.32E-04 AP 09 561299008 11/2/2021 BETA 4.15E-02 1.68E-03 1.20E-03 AP 09 562487008 11/17/2021 BETA 2.65E-02 9.76E-04 6.49E-04 AP 09 563880008 12/1/2021 BETA 2.61E-02 1.07E-03 7.65E-04 AP 09 565211008 12/15/2021 BETA 2.87E-02 1.13E-03 8.18E-04 AP 09 566442008 12/29/2021 BETA 3.42E-02 1.23E-03 8.80E-04 AP 09 568408008 12/29/2021 Ac-228 2.20E-04 3.60E-04 1.13E-03 U AP 09 568408008 12/29/2021 Ag-108m 9.88E-05 6.95E-05 2.39E-04 U AP 09 568408008 12/29/2021 Ag-110m -2.37E-05 9.33E-05 2.83E-04 U AP 09 568408008 12/29/2021 Ba-140 7.81E-03 1.62E-02 5.04E-02 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

AP 09 568408008 12/29/2021 Be-7 1.12E-01 7.73E-03 5.37E-03 AP 09 568408008 12/29/2021 Ce-141 -1.96E-04 3.95E-04 1.22E-03 U AP 09 568408008 12/29/2021 Ce-144 7.05E-05 3.27E-04 1.06E-03 U AP 09 568408008 12/29/2021 Co-57 -6.83E-07 4.22E-05 1.36E-04 U AP 09 568408008 12/29/2021 Co-58 1.13E-04 1.37E-04 4.75E-04 U AP 09 568408008 12/29/2021 Co-60 -6.90E-05 6.80E-05 1.72E-04 U AP 09 568408008 12/29/2021 Cr-51 2.01E-03 3.21E-03 1.12E-02 U AP 09 568408008 12/29/2021 Cs-134 2.99E-05 7.24E-05 2.44E-04 U AP 09 568408008 12/29/2021 Cs-137 8.93E-05 8.06E-05 2.80E-04 U AP 09 568408008 12/29/2021 Fe-59 4.76E-04 4.79E-04 1.63E-03 U AP 09 568408008 12/29/2021 I-131 -2.16E-02 5.00E-02 1.63E-01 U AP 09 568408008 12/29/2021 K-40 2.32E-04 1.33E-03 4.66E-03 U AP 09 568408008 12/29/2021 La-140 6.95E-03 5.14E-03 2.04E-02 U AP 09 568408008 12/29/2021 Mn-54 8.24E-05 8.10E-05 2.84E-04 U AP 09 568408008 12/29/2021 Nb-95 -2.96E-04 1.64E-04 3.43E-04 U AP 09 568408008 12/29/2021 Ru-103 2.20E-06 2.36E-04 7.83E-04 U AP 09 568408008 12/29/2021 Ru-106 -6.76E-04 7.47E-04 2.17E-03 U AP 09 568408008 12/29/2021 Sb-124 -3.43E-04 4.55E-04 1.24E-03 U AP 09 568408008 12/29/2021 Sb-125 2.36E-04 1.94E-04 6.77E-04 U AP 09 568408008 12/29/2021 Se-75 3.30E-04 2.16E-04 3.95E-04 U AP 09 568408008 12/29/2021 Th-228 8.86E-06 2.61E-04 4.02E-04 U AP 09 568408008 12/29/2021 Zn-65 9.48E-05 1.81E-04 6.43E-04 U AP 09 568408008 12/29/2021 Zr-95 -5.41E-04 3.67E-04 9.33E-04 U

-178-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

CF 01 532372009 1/13/2021 I-131 -1.60E-03 2.38E-03 6.93E-03 U CF 01 533687009 1/27/2021 I-131 3.86E-04 2.54E-03 8.70E-03 U CF 01 535173009 2/10/2021 I-131 -5.12E-04 1.72E-03 5.68E-03 U CF 01 536335009 2/25/2021 I-131 -2.66E-03 2.20E-03 6.16E-03 U CF 01 537636009 3/10/2021 I-131 -1.49E-04 2.21E-03 7.47E-03 U CF 01 539006009 3/24/2021 I-131 2.86E-04 1.23E-03 4.07E-03 U CF 01 540404009 4/7/2021 I-131 -1.98E-03 2.80E-03 8.85E-03 U CF 01 541857009 4/21/2021 I-131 1.96E-03 4.30E-03 1.47E-02 U CF 01 544029009 5/5/2021 I-131 3.94E-04 3.30E-03 1.13E-02 U CF 01 545432009 5/19/2021 I-131 9.30E-04 3.33E-03 1.17E-02 U CF 01 546369009 6/2/2021 I-131 -2.65E-04 3.59E-03 1.18E-02 U CF 01 547926009 6/16/2021 I-131 2.80E-04 2.56E-03 8.43E-03 U CF 01 548743009 6/29/2021 I-131 1.90E-03 2.43E-03 8.77E-03 U CF 01 549925009 7/13/2021 I-131 -5.59E-03 3.09E-03 6.88E-03 U CF 01 551091009 7/28/2021 I-131 5.64E-03 2.88E-03 9.66E-03 U CF 01 552841009 8/11/2021 I-131 -2.26E-03 2.07E-03 5.95E-03 U CF 01 554155009 8/25/2021 I-131 2.22E-04 2.12E-03 7.04E-03 U CF 01 555720009 9/9/2021 I-131 2.69E-03 3.28E-03 1.14E-02 U CF 01 556805009 9/22/2021 I-131 1.14E-03 2.10E-03 7.34E-03 U CF 01 558373009 10/6/2021 I-131 -2.70E-03 2.33E-03 6.57E-03 U CF 01 560124009 10/21/2021 I-131 1.02E-03 3.60E-03 1.15E-02 U CF 01 561299009 11/2/2021 I-131 -2.49E-03 3.51E-03 1.05E-02 U CF 01 562487009 11/17/2021 I-131 -7.27E-04 9.60E-04 2.82E-03 U CF 01 563880009 12/1/2021 I-131 8.87E-04 1.25E-03 4.48E-03 U CF 01 565211009 12/15/2021 I-131 7.56E-04 1.01E-03 3.65E-03 U CF 01 566442009 12/29/2021 I-131 3.40E-03 1.54E-03 6.13E-03 U CF 02 532372010 1/13/2021 I-131 9.75E-04 2.33E-03 7.99E-03 U CF 02 533687010 1/27/2021 I-131 -2.55E-03 2.54E-03 7.07E-03 U CF 02 535173010 2/10/2021 I-131 2.61E-04 3.64E-03 1.26E-02 U CF 02 536335010 2/25/2021 I-131 5.52E-03 2.53E-03 5.73E-03 U CF 02 537636010 3/10/2021 I-131 -3.22E-03 2.04E-03 5.29E-03 U CF 02 539006010 3/24/2021 I-131 0.00E+00 2.64E-03 3.71E-03 U CF 02 540404010 4/7/2021 I-131 -3.24E-03 3.67E-03 1.14E-02 U CF 02 541857010 4/21/2021 I-131 3.03E-03 4.75E-03 1.70E-02 U CF 02 544029010 5/5/2021 I-131 0.00E+00 3.27E-03 5.40E-03 U CF 02 545432010 5/19/2021 I-131 -4.35E-03 3.59E-03 7.96E-03 U CF 02 546369010 6/2/2021 I-131 4.01E-03 2.53E-03 9.95E-03 U CF 02 547926010 6/16/2021 I-131 1.12E-03 3.08E-03 1.07E-02 U CF 02 548743010 6/29/2021 I-131 1.39E-03 1.89E-03 6.97E-03 U CF 02 549925010 7/13/2021 I-131 -1.18E-03 3.30E-03 1.08E-02 U CF 02 551091010 7/28/2021 I-131 -2.28E-04 3.98E-03 1.30E-02 U CF 02 552841010 8/11/2021 I-131 -2.70E-03 2.70E-03 7.52E-03 U CF 02 554155010 8/25/2021 I-131 2.32E-03 2.41E-03 8.62E-03 U CF 02 555720010 9/9/2021 I-131 3.95E-03 3.08E-03 1.06E-02 U CF 02 556805010 9/22/2021 I-131 -8.42E-04 2.42E-03 7.63E-03 U CF 02 558373010 10/6/2021 I-131 1.12E-03 3.53E-03 1.18E-02 U CF 02 560124010 10/21/2021 I-131 -2.13E-03 2.19E-03 6.28E-03 U CF 02 561299010 11/2/2021 I-131 -7.04E-04 4.24E-03 1.41E-02 U CF 02 562487010 11/17/2021 I-131 -6.51E-04 1.39E-03 4.50E-03 U CF 02 563880010 12/1/2021 I-131 -4.86E-04 1.53E-03 4.76E-03 U

-179-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

CF 02 565211010 12/15/2021 I-131 -9.41E-04 1.61E-03 4.94E-03 U CF 02 566442010 12/29/2021 I-131 -2.05E-05 1.86E-03 5.64E-03 U CF 03 532372011 1/13/2021 I-131 4.80E-04 3.28E-03 1.11E-02 U CF 03 533687011 1/27/2021 I-131 5.43E-05 2.06E-03 6.44E-03 U CF 03 535173011 2/10/2021 I-131 -3.98E-03 2.91E-03 6.66E-03 U CF 03 536335011 2/25/2021 I-131 -5.83E-03 2.91E-03 6.43E-03 U CF 03 537636011 3/10/2021 I-131 -1.64E-03 3.15E-03 1.01E-02 U CF 03 539006011 3/24/2021 I-131 -3.06E-03 2.15E-03 6.08E-03 U CF 03 540404011 4/7/2021 I-131 5.57E-04 2.67E-03 9.15E-03 U CF 03 541857011 4/21/2021 I-131 2.01E-03 3.71E-03 1.34E-02 U CF 03 544029011 5/5/2021 I-131 9.99E-04 4.59E-03 1.57E-02 U CF 03 545432011 5/19/2021 I-131 2.00E-03 3.12E-03 7.34E-03 U CF 03 546369011 6/2/2021 I-131 -2.12E-03 4.23E-03 1.19E-02 U CF 03 547926011 6/16/2021 I-131 -3.89E-03 3.73E-03 1.15E-02 U CF 03 548743011 6/29/2021 I-131 3.00E-04 2.63E-03 9.09E-03 U CF 03 549925011 7/13/2021 I-131 3.80E-03 3.20E-03 1.16E-02 U CF 03 551091011 7/28/2021 I-131 -4.99E-05 3.40E-03 1.15E-02 U CF 03 552841011 8/11/2021 I-131 2.09E-03 1.98E-03 7.05E-03 U CF 03 554155011 8/25/2021 I-131 6.55E-04 1.83E-03 5.82E-03 U CF 03 555720011 9/9/2021 I-131 -1.85E-03 2.76E-03 8.30E-03 U CF 03 556805011 9/22/2021 I-131 -3.39E-03 2.49E-03 6.63E-03 U CF 03 558373011 10/6/2021 I-131 1.96E-03 3.51E-03 9.57E-03 U CF 03 560124011 10/21/2021 I-131 2.08E-03 2.19E-03 7.69E-03 U CF 03 561299011 11/2/2021 I-131 -8.03E-04 2.85E-03 9.21E-03 U CF 03 562487011 11/17/2021 I-131 -1.02E-03 2.02E-03 6.43E-03 U CF 03 563880011 12/1/2021 I-131 -1.98E-04 1.91E-03 6.42E-03 U CF 03 565211011 12/15/2021 I-131 1.65E-04 1.58E-03 5.13E-03 U CF 03 566442011 12/29/2021 I-131 0.00E+00 5.67E-03 1.20E-02 U CF 04 532372012 1/13/2021 I-131 -7.05E-04 2.00E-03 6.49E-03 U CF 04 533687012 1/27/2021 I-131 -2.11E-03 1.79E-03 5.02E-03 U CF 04 535173012 2/10/2021 I-131 2.33E-03 2.54E-03 8.71E-03 U CF 04 536335012 2/25/2021 I-131 1.14E-03 1.70E-03 5.96E-03 U CF 04 537636012 3/10/2021 I-131 3.38E-03 1.82E-03 6.51E-03 U CF 04 539006012 3/24/2021 I-131 1.05E-03 1.56E-03 5.38E-03 U CF 04 540404012 4/7/2021 I-131 -4.23E-04 3.27E-03 9.97E-03 U CF 04 541857012 4/21/2021 I-131 -2.10E-03 5.83E-03 1.59E-02 U CF 04 544029012 5/5/2021 I-131 -3.76E-03 7.18E-03 2.26E-02 U CF 04 545432012 5/19/2021 I-131 -2.60E-03 4.15E-03 1.24E-02 U CF 04 546369012 6/2/2021 I-131 -7.59E-04 4.61E-03 1.53E-02 U CF 04 547926012 6/16/2021 I-131 -1.63E-04 2.19E-03 7.35E-03 U CF 04 548743012 6/29/2021 I-131 1.16E-03 1.81E-03 6.62E-03 U CF 04 549925012 7/13/2021 I-131 6.02E-04 4.02E-03 1.33E-02 U CF 04 551091012 7/28/2021 I-131 8.39E-03 6.50E-03 2.32E-02 U CF 04 552841012 8/11/2021 I-131 -9.07E-04 2.64E-03 8.33E-03 U CF 04 554155012 8/25/2021 I-131 -6.00E-03 3.63E-03 9.33E-03 U CF 04 555720012 9/9/2021 I-131 -2.00E-03 2.54E-03 7.71E-03 U CF 04 556805012 9/22/2021 I-131 -1.65E-03 1.73E-03 4.87E-03 U CF 04 558373012 10/6/2021 I-131 -3.61E-04 2.44E-03 8.16E-03 U CF 04 560124012 10/21/2021 I-131 -1.26E-03 1.75E-03 5.57E-03 U

-180-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

CF 04 561299012 11/2/2021 I-131 5.87E-03 2.72E-03 9.41E-03 U CF 04 562487012 11/17/2021 I-131 -9.62E-04 1.17E-03 3.41E-03 U CF 04 563880012 12/1/2021 I-131 5.25E-04 1.54E-03 5.22E-03 U CF 04 565211012 12/15/2021 I-131 7.28E-04 1.48E-03 5.08E-03 U CF 04 566442012 12/29/2021 I-131 -3.98E-03 3.25E-03 9.26E-03 U CF 05 532372013 1/13/2021 I-131 3.76E-04 2.39E-03 7.98E-03 U CF 05 533687013 1/27/2021 I-131 -2.29E-03 2.66E-03 8.34E-03 U CF 05 535173013 2/10/2021 I-131 3.39E-03 2.11E-03 7.86E-03 U CF 05 536335013 2/25/2021 I-131 3.57E-03 2.66E-03 9.60E-03 U CF 05 537636013 3/10/2021 I-131 1.35E-03 2.55E-03 9.06E-03 U CF 05 539006013 3/24/2021 I-131 -1.08E-04 1.30E-03 3.96E-03 U CF 05 540404013 4/7/2021 I-131 4.02E-04 2.67E-03 9.23E-03 U CF 05 541857013 4/21/2021 I-131 -4.91E-04 3.89E-03 1.16E-02 U CF 05 544029013 5/5/2021 I-131 1.39E-04 4.41E-03 1.51E-02 U CF 05 545432013 5/19/2021 I-131 3.04E-03 3.02E-03 1.10E-02 U CF 05 546369013 6/2/2021 I-131 -1.57E-03 3.94E-03 1.27E-02 U CF 05 547926013 6/16/2021 I-131 2.49E-03 2.01E-03 7.38E-03 U CF 05 548743013 6/29/2021 I-131 7.13E-04 2.30E-03 8.02E-03 U CF 05 549925013 7/13/2021 I-131 2.86E-03 2.12E-03 7.49E-03 U CF 05 551091013 7/28/2021 I-131 3.99E-03 5.24E-03 1.73E-02 U CF 05 552841013 8/11/2021 I-131 3.60E-03 2.64E-03 8.98E-03 U CF 05 554155013 8/25/2021 I-131 -1.54E-03 2.22E-03 6.76E-03 U CF 05 555720013 9/9/2021 I-131 6.55E-03 3.03E-03 1.02E-02 U CF 05 556805013 9/22/2021 I-131 3.32E-04 2.68E-03 8.07E-03 U CF 05 558373013 10/6/2021 I-131 -6.83E-04 2.14E-03 6.98E-03 U CF 05 560124013 10/21/2021 I-131 -1.04E-03 2.07E-03 6.68E-03 U CF 05 561299013 11/2/2021 I-131 2.09E-04 2.19E-03 7.46E-03 U CF 05 562487013 11/17/2021 I-131 -7.79E-04 1.81E-03 5.86E-03 U CF 05 563880013 12/1/2021 I-131 4.91E-03 2.13E-03 7.51E-03 U CF 05 565211013 12/15/2021 I-131 9.08E-04 2.52E-03 8.12E-03 U CF 05 566442013 12/29/2021 I-131 -9.83E-04 4.16E-03 1.33E-02 U CF 07 532372014 1/13/2021 I-131 1.19E-02 3.03E-03 8.78E-03 UI M CF 07 533687014 1/27/2021 I-131 -4.57E-03 2.31E-03 4.92E-03 U CF 07 535173014 2/10/2021 I-131 -3.09E-05 2.50E-03 8.43E-03 U CF 07 536335014 2/25/2021 I-131 2.69E-03 4.94E-03 1.75E-02 U CF 07 537636014 3/10/2021 I-131 -3.76E-03 2.80E-03 7.15E-03 U CF 07 539006014 3/24/2021 I-131 2.57E-03 1.99E-03 6.92E-03 U CF 07 540404014 4/7/2021 I-131 -1.89E-03 2.38E-03 6.89E-03 U CF 07 541857014 4/21/2021 I-131 5.73E-03 4.65E-03 1.65E-02 U CF 07 544029014 5/5/2021 I-131 4.90E-03 4.05E-03 1.00E-02 U CF 07 545432014 5/19/2021 I-131 1.12E-03 2.85E-03 1.01E-02 U CF 07 546369014 6/2/2021 I-131 -4.48E-03 2.81E-03 5.65E-03 U CF 07 547926014 6/16/2021 I-131 1.43E-03 4.32E-03 1.51E-02 U CF 07 548743014 6/29/2021 I-131 3.33E-03 2.79E-03 1.02E-02 U CF 07 549925014 7/13/2021 I-131 1.18E-03 3.25E-03 1.10E-02 U CF 07 551091014 7/28/2021 I-131 4.07E-04 2.89E-03 9.42E-03 U CF 07 552841014 8/11/2021 I-131 -5.73E-04 3.02E-03 9.57E-03 U CF 07 554155014 8/25/2021 I-131 2.74E-03 3.44E-03 1.17E-02 U CF 07 555720014 9/9/2021 I-131 8.90E-04 2.39E-03 8.32E-03 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

CF 07 556805014 9/22/2021 I-131 -2.04E-03 2.29E-03 7.03E-03 U CF 07 558373014 10/6/2021 I-131 4.88E-03 3.10E-03 1.17E-02 U CF 07 560124014 10/21/2021 I-131 -6.35E-04 2.06E-03 6.77E-03 U CF 07 561299014 11/2/2021 I-131 1.10E-04 2.66E-03 8.97E-03 U CF 07 562487014 11/17/2021 I-131 -1.33E-03 2.06E-03 6.51E-03 U CF 07 563880014 12/1/2021 I-131 -2.18E-03 2.07E-03 6.30E-03 U CF 07 565211014 12/15/2021 I-131 3.48E-04 1.32E-03 4.16E-03 U CF 07 566442014 12/29/2021 I-131 3.92E-04 2.49E-03 8.31E-03 U CF 08 532372015 1/13/2021 I-131 2.63E-03 2.10E-03 7.62E-03 U CF 08 533687015 1/27/2021 I-131 2.38E-03 2.81E-03 1.00E-02 U CF 08 535173015 2/10/2021 I-131 2.84E-03 2.65E-03 9.37E-03 U CF 08 536335015 2/25/2021 I-131 -4.88E-03 3.40E-03 9.90E-03 U CF 08 537636015 3/10/2021 I-131 1.33E-03 1.70E-03 5.70E-03 U CF 08 539006015 3/24/2021 I-131 1.12E-03 1.81E-03 6.24E-03 U CF 08 540404015 4/7/2021 I-131 1.15E-03 3.03E-03 9.11E-03 U CF 08 541857015 4/21/2021 I-131 -5.89E-03 4.62E-03 8.59E-03 U CF 08 544029015 5/5/2021 I-131 -3.51E-03 3.49E-03 1.02E-02 U CF 08 545432015 5/19/2021 I-131 8.76E-03 5.43E-03 1.61E-02 U CF 08 546369015 6/2/2021 I-131 1.55E-03 3.14E-03 1.08E-02 U CF 08 547926015 6/16/2021 I-131 -1.36E-03 2.42E-03 7.76E-03 U CF 08 548743015 6/29/2021 I-131 9.02E-04 2.62E-03 8.54E-03 U CF 08 549925015 7/13/2021 I-131 -1.08E-03 2.43E-03 7.06E-03 U CF 08 551091015 7/28/2021 I-131 -9.73E-03 4.49E-03 1.10E-02 U CF 08 552841015 8/11/2021 I-131 1.29E-03 2.47E-03 8.64E-03 U CF 08 554155015 8/25/2021 I-131 -2.39E-03 2.39E-03 7.17E-03 U CF 08 555720015 9/9/2021 I-131 2.15E-03 2.56E-03 9.12E-03 U CF 08 556805015 9/22/2021 I-131 1.23E-03 2.23E-03 7.80E-03 U CF 08 558373015 10/6/2021 I-131 6.12E-04 2.94E-03 1.01E-02 U CF 08 560124015 10/21/2021 I-131 -1.98E-03 3.62E-03 1.16E-02 U CF 08 561299015 11/2/2021 I-131 -1.81E-03 3.25E-03 9.15E-03 U CF 08 562487015 11/17/2021 I-131 1.19E-04 1.31E-03 4.49E-03 U CF 08 563880015 12/1/2021 I-131 2.66E-03 2.08E-03 7.11E-03 U CF 08 565211015 12/15/2021 I-131 2.25E-03 2.03E-03 7.60E-03 U CF 08 566442015 12/29/2021 I-131 -5.70E-04 3.16E-03 1.04E-02 U CF 09 532372016 1/13/2021 I-131 -2.38E-03 1.37E-03 3.29E-03 U CF 09 533687016 1/27/2021 I-131 -1.57E-03 1.83E-03 5.62E-03 U CF 09 535173016 2/10/2021 I-131 -2.41E-03 1.79E-03 4.96E-03 U CF 09 536335016 2/25/2021 I-131 0.00E+00 3.47E-03 6.70E-03 U CF 09 537636016 3/10/2021 I-131 -1.25E-03 1.99E-03 6.22E-03 U CF 09 539006016 3/24/2021 I-131 1.63E-03 2.10E-03 6.88E-03 U CF 09 540404016 4/7/2021 I-131 -3.33E-03 3.82E-03 1.06E-02 U CF 09 541857016 4/21/2021 I-131 -3.01E-03 4.63E-03 1.41E-02 U CF 09 544029016 5/5/2021 I-131 -2.12E-03 5.34E-03 1.67E-02 U CF 09 545432016 5/19/2021 I-131 -1.13E-03 3.58E-03 1.15E-02 U CF 09 546369016 6/2/2021 I-131 9.39E-03 5.36E-03 1.92E-02 U CF 09 547926016 6/16/2021 I-131 4.39E-03 3.99E-03 1.37E-02 U CF 09 548743016 6/29/2021 I-131 2.37E-03 2.30E-03 8.45E-03 U CF 09 549925016 7/13/2021 I-131 4.61E-03 3.51E-03 8.87E-03 U CF 09 551091016 7/28/2021 I-131 -2.81E-04 2.36E-03 7.87E-03 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/m3) (pCi/m3) (pCi/m3)

CF 09 552841016 8/11/2021 I-131 2.19E-03 2.72E-03 9.72E-03 U CF 09 554155016 8/25/2021 I-131 -1.78E-04 2.40E-03 7.83E-03 U CF 09 555720016 9/9/2021 I-131 9.66E-04 2.45E-03 8.57E-03 U CF 09 556805016 9/22/2021 I-131 2.60E-03 2.20E-03 7.87E-03 U CF 09 558373016 10/6/2021 I-131 3.19E-03 3.18E-03 1.14E-02 U CF 09 560124016 10/21/2021 I-131 2.77E-03 2.06E-03 7.27E-03 U CF 09 561299016 11/2/2021 I-131 1.89E-03 2.45E-03 8.78E-03 U CF 09 562487016 11/17/2021 I-131 -1.12E-04 8.30E-04 2.63E-03 U CF 09 563880016 12/1/2021 I-131 4.67E-04 1.37E-03 4.53E-03 U CF 09 565211016 12/15/2021 I-131 6.96E-04 1.10E-03 3.86E-03 U CF 09 566442016 12/29/2021 I-131 -1.15E-03 2.98E-03 8.14E-03 U

-183-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

FH 03 545141001 5/17/2021 Ac-228 -1.38E+01 1.09E+01 3.15E+01 U FH 03 545141001 5/17/2021 Ag-108m 3.81E-01 1.49E+00 5.11E+00 U FH 03 545141001 5/17/2021 Ag-110m 1.57E+00 2.99E+00 1.00E+01 U FH 03 545141001 5/17/2021 Ba-140 3.72E+00 7.71E+00 2.66E+01 U FH 03 545141001 5/17/2021 Be-7 -1.88E+00 1.72E+01 5.74E+01 U FH 03 545141001 5/17/2021 Bi-214 4.28E+00 8.79E+00 1.81E+01 U FH 03 545141001 5/17/2021 Ce-141 -1.59E+00 3.34E+00 1.05E+01 U FH 03 545141001 5/17/2021 Ce-144 0.00E+00 2.04E+01 3.54E+01 U FH 03 545141001 5/17/2021 Co-57 4.47E-01 1.48E+00 4.88E+00 U FH 03 545141001 5/17/2021 Co-58 3.62E-01 2.01E+00 6.64E+00 U FH 03 545141001 5/17/2021 Co-60 7.75E-01 1.91E+00 6.72E+00 U FH 03 545141001 5/17/2021 Cr-51 2.55E+01 1.92E+01 6.16E+01 U FH 03 545141001 5/17/2021 Cs-134 -2.97E+00 2.38E+00 6.54E+00 U FH 03 545141001 5/17/2021 Cs-137 2.78E+00 2.09E+00 7.24E+00 U FH 03 545141001 5/17/2021 Fe-59 -5.93E-01 5.98E+00 1.67E+01 U FH 03 545141001 5/17/2021 I-131 -2.03E+00 2.83E+00 9.14E+00 U FH 03 545141001 5/17/2021 K-40 2.92E+03 1.86E+02 6.58E+01 FH 03 545141001 5/17/2021 La-140 -6.27E+00 3.34E+00 6.67E+00 U FH 03 545141001 5/17/2021 Mn-54 -3.62E+00 2.32E+00 5.99E+00 U FH 03 545141001 5/17/2021 Nb-95 -6.49E-01 2.25E+00 7.17E+00 U FH 03 545141001 5/17/2021 Pb-212 9.02E+00 6.80E+00 1.30E+01 U FH 03 545141001 5/17/2021 Pb-214 4.79E+00 4.62E+00 1.57E+01 U FH 03 545141001 5/17/2021 Ra-226 4.28E+00 8.79E+00 1.81E+01 U FH 03 545141001 5/17/2021 Ru-103 -5.27E-01 2.37E+00 7.08E+00 U FH 03 545141001 5/17/2021 Ru-106 -6.19E+00 1.67E+01 5.37E+01 U FH 03 545141001 5/17/2021 Sb-124 1.37E+00 3.42E+00 1.21E+01 U FH 03 545141001 5/17/2021 Sb-125 1.17E+01 1.34E+01 1.68E+01 U FH 03 545141001 5/17/2021 Se-75 -2.15E+00 2.68E+00 7.88E+00 U FH 03 545141001 5/17/2021 Th-228 9.02E+00 6.80E+00 1.30E+01 U FH 03 545141001 5/17/2021 Th-230 4.28E+00 8.79E+00 1.81E+01 U FH 03 545141001 5/17/2021 Tl-208 -2.08E+00 2.36E+00 7.08E+00 U FH 03 545141001 5/17/2021 Zn-65 -2.65E+00 5.08E+00 1.52E+01 U FH 03 545141001 5/17/2021 Zr-95 -1.78E+00 2.91E+00 8.78E+00 U FH 03 554690001 8/10/2021 Ac-228 1.56E+01 1.54E+01 4.26E+01 U FH 03 554690001 8/10/2021 Ag-108m 2.49E+00 2.00E+00 6.55E+00 U FH 03 554690001 8/10/2021 Ag-110m 9.75E+00 6.25E+00 1.38E+01 U FH 03 554690001 8/10/2021 Ba-140 4.32E+01 3.07E+01 1.06E+02 U FH 03 554690001 8/10/2021 Be-7 -1.08E+01 2.27E+01 7.46E+01 U FH 03 554690001 8/10/2021 Bi-214 0.00E+00 7.60E+00 1.67E+01 U FH 03 554690001 8/10/2021 Ce-141 0.00E+00 8.85E+00 1.42E+01 U FH 03 554690001 8/10/2021 Ce-144 1.58E+01 1.34E+01 4.51E+01 U FH 03 554690001 8/10/2021 Co-57 1.39E+00 1.58E+00 5.40E+00 U FH 03 554690001 8/10/2021 Co-58 1.33E-01 2.71E+00 8.93E+00 U FH 03 554690001 8/10/2021 Co-60 2.10E+00 3.20E+00 1.11E+01 U FH 03 554690001 8/10/2021 Cr-51 -1.95E+01 3.27E+01 1.01E+02 U FH 03 554690001 8/10/2021 Cs-134 -3.27E+00 2.99E+00 8.75E+00 U FH 03 554690001 8/10/2021 Cs-137 6.38E+00 3.13E+00 1.03E+01 U FH 03 554690001 8/10/2021 Fe-59 1.02E+00 6.56E+00 2.13E+01 U FH 03 554690001 8/10/2021 I-131 6.69E+00 1.56E+01 5.11E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

FH 03 554690001 8/10/2021 K-40 3.96E+03 2.45E+02 6.79E+01 FH 03 554690001 8/10/2021 La-140 1.45E+00 8.14E+00 2.75E+01 U FH 03 554690001 8/10/2021 Mn-54 -2.80E+00 2.45E+00 6.99E+00 U FH 03 554690001 8/10/2021 Nb-95 4.99E+00 5.56E+00 8.57E+00 U FH 03 554690001 8/10/2021 Pb-212 9.96E+00 5.61E+00 1.39E+01 U FH 03 554690001 8/10/2021 Pb-214 4.46E+00 5.56E+00 1.82E+01 U FH 03 554690001 8/10/2021 Ra-226 0.00E+00 7.60E+00 1.67E+01 U FH 03 554690001 8/10/2021 Ru-103 3.92E-01 3.14E+00 1.07E+01 U FH 03 554690001 8/10/2021 Ru-106 -1.73E+01 2.17E+01 6.76E+01 U FH 03 554690001 8/10/2021 Sb-124 -2.20E+00 5.89E+00 1.82E+01 U FH 03 554690001 8/10/2021 Sb-125 6.06E+00 6.59E+00 2.15E+01 U FH 03 554690001 8/10/2021 Se-75 2.19E+00 2.90E+00 9.65E+00 U FH 03 554690001 8/10/2021 Th-228 9.96E+00 5.61E+00 1.39E+01 U FH 03 554690001 8/10/2021 Th-230 0.00E+00 7.60E+00 1.67E+01 U FH 03 554690001 8/10/2021 Tl-208 -1.15E+00 2.64E+00 8.36E+00 U FH 03 554690001 8/10/2021 Zn-65 -1.02E+01 8.05E+00 2.24E+01 U FH 03 554690001 8/10/2021 Zr-95 1.86E+00 4.77E+00 1.61E+01 U FH 53 545141002 5/11/2021 Ac-228 2.40E+00 9.38E+00 3.21E+01 U FH 53 545141002 5/11/2021 Ag-108m 8.95E-01 1.36E+00 4.74E+00 U FH 53 545141002 5/11/2021 Ag-110m 3.13E+00 2.86E+00 9.77E+00 U FH 53 545141002 5/11/2021 Ba-140 -1.27E+01 1.29E+01 3.88E+01 U FH 53 545141002 5/11/2021 Be-7 -1.09E+01 1.47E+01 4.58E+01 U FH 53 545141002 5/11/2021 Bi-214 -4.43E+00 4.95E+00 1.46E+01 U FH 53 545141002 5/11/2021 Ce-141 -5.85E-01 2.89E+00 9.19E+00 U FH 53 545141002 5/11/2021 Ce-144 -3.31E-01 1.01E+01 3.23E+01 U FH 53 545141002 5/11/2021 Co-57 2.28E+00 1.38E+00 4.46E+00 U FH 53 545141002 5/11/2021 Co-58 1.52E-01 1.76E+00 5.75E+00 U FH 53 545141002 5/11/2021 Co-60 -5.93E-02 1.92E+00 6.44E+00 U FH 53 545141002 5/11/2021 Cr-51 -1.83E+01 1.64E+01 5.06E+01 U FH 53 545141002 5/11/2021 Cs-134 3.71E-02 2.12E+00 6.87E+00 U FH 53 545141002 5/11/2021 Cs-137 6.46E-01 1.74E+00 5.87E+00 U FH 53 545141002 5/11/2021 Fe-59 3.85E+00 4.47E+00 1.52E+01 U FH 53 545141002 5/11/2021 I-131 -1.54E+00 4.22E+00 1.40E+01 U FH 53 545141002 5/11/2021 K-40 3.44E+03 1.98E+02 4.67E+01 FH 53 545141002 5/11/2021 La-140 -1.77E-01 3.43E+00 1.13E+01 U FH 53 545141002 5/11/2021 Mn-54 7.65E-01 1.89E+00 6.30E+00 U FH 53 545141002 5/11/2021 Nb-95 -9.97E-02 2.14E+00 6.92E+00 U FH 53 545141002 5/11/2021 Pb-212 7.06E+00 5.92E+00 1.14E+01 U FH 53 545141002 5/11/2021 Pb-214 -2.55E+00 4.19E+00 1.32E+01 U FH 53 545141002 5/11/2021 Ra-226 -4.43E+00 4.95E+00 1.46E+01 U FH 53 545141002 5/11/2021 Ru-103 2.51E+00 1.88E+00 6.54E+00 U FH 53 545141002 5/11/2021 Ru-106 9.06E+00 1.70E+01 5.78E+01 U FH 53 545141002 5/11/2021 Sb-124 -2.44E+00 4.65E+00 1.40E+01 U FH 53 545141002 5/11/2021 Sb-125 1.10E+00 4.41E+00 1.51E+01 U FH 53 545141002 5/11/2021 Se-75 -2.14E+00 2.25E+00 6.38E+00 U FH 53 545141002 5/11/2021 Th-228 7.06E+00 5.92E+00 1.14E+01 U FH 53 545141002 5/11/2021 Th-230 -4.43E+00 4.95E+00 1.46E+01 U FH 53 545141002 5/11/2021 Tl-208 1.20E+00 3.10E+00 6.24E+00 U FH 53 545141002 5/11/2021 Zn-65 -2.05E-01 5.24E+00 1.78E+01 U FH 53 545141002 5/11/2021 Zr-95 2.35E+00 3.39E+00 1.16E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

FH 53 554690002 8/25/2021 Ac-228 1.84E+00 1.02E+01 3.43E+01 U FH 53 554690002 8/25/2021 Ag-108m 1.89E+00 1.97E+00 4.96E+00 U FH 53 554690002 8/25/2021 Ag-110m -2.62E+00 2.72E+00 8.00E+00 U FH 53 554690002 8/25/2021 Ba-140 -9.03E+00 1.16E+01 3.44E+01 U FH 53 554690002 8/25/2021 Be-7 -3.55E+01 2.02E+01 5.26E+01 U FH 53 554690002 8/25/2021 Bi-214 -3.52E-01 5.15E+00 1.66E+01 U FH 53 554690002 8/25/2021 Ce-141 -2.83E+00 3.41E+00 1.03E+01 U FH 53 554690002 8/25/2021 Ce-144 4.91E+00 1.06E+01 3.44E+01 U FH 53 554690002 8/25/2021 Co-57 -6.44E-01 1.27E+00 3.98E+00 U FH 53 554690002 8/25/2021 Co-58 -4.44E-01 2.27E+00 7.40E+00 U FH 53 554690002 8/25/2021 Co-60 -2.00E-01 2.67E+00 8.85E+00 U FH 53 554690002 8/25/2021 Cr-51 1.18E+01 1.81E+01 6.12E+01 U FH 53 554690002 8/25/2021 Cs-134 1.81E+00 2.27E+00 7.77E+00 U FH 53 554690002 8/25/2021 Cs-137 -2.35E+00 2.39E+00 7.11E+00 U FH 53 554690002 8/25/2021 Fe-59 1.18E+01 6.16E+00 2.02E+01 U FH 53 554690002 8/25/2021 I-131 -1.86E+00 4.23E+00 1.35E+01 U FH 53 554690002 8/25/2021 K-40 3.55E+03 2.13E+02 7.64E+01 FH 53 554690002 8/25/2021 La-140 2.21E+00 4.40E+00 1.34E+01 U FH 53 554690002 8/25/2021 Mn-54 -4.99E+00 2.45E+00 5.93E+00 U FH 53 554690002 8/25/2021 Nb-95 2.57E+00 2.53E+00 8.62E+00 U FH 53 554690002 8/25/2021 Pb-212 -2.55E+00 3.70E+00 1.21E+01 U FH 53 554690002 8/25/2021 Pb-214 4.44E+00 6.36E+00 1.63E+01 U FH 53 554690002 8/25/2021 Ra-226 -3.52E-01 5.15E+00 1.66E+01 U FH 53 554690002 8/25/2021 Ru-103 6.60E-01 2.30E+00 6.69E+00 U FH 53 554690002 8/25/2021 Ru-106 1.19E+01 1.89E+01 6.51E+01 U FH 53 554690002 8/25/2021 Sb-124 -4.04E+00 4.97E+00 1.42E+01 U FH 53 554690002 8/25/2021 Sb-125 -4.07E-01 5.62E+00 1.62E+01 U FH 53 554690002 8/25/2021 Se-75 -5.63E-01 2.32E+00 7.72E+00 U FH 53 554690002 8/25/2021 Th-228 -2.55E+00 3.70E+00 1.21E+01 U FH 53 554690002 8/25/2021 Th-230 -3.52E-01 5.15E+00 1.66E+01 U FH 53 554690002 8/25/2021 Tl-208 1.41E+00 2.49E+00 8.22E+00 U FH 53 554690002 8/25/2021 Zn-65 -8.73E-01 6.70E+00 1.85E+01 U FH 53 554690002 8/25/2021 Zr-95 2.04E+00 4.32E+00 1.47E+01 U FH 53 562703001 11/17/2021 Ac-228 -8.26E+00 1.21E+01 3.78E+01 U FH 53 562703001 11/17/2021 Ag-108m 4.74E+00 2.55E+00 7.98E+00 U FH 53 562703001 11/17/2021 Ag-110m -3.01E+00 3.99E+00 1.18E+01 U FH 53 562703001 11/17/2021 Ba-140 6.16E+00 1.67E+01 5.64E+01 U FH 53 562703001 11/17/2021 Be-7 2.49E+01 2.08E+01 7.15E+01 U FH 53 562703001 11/17/2021 Bi-214 1.11E+01 7.88E+00 1.46E+01 U FH 53 562703001 11/17/2021 Ce-141 -5.19E+00 4.00E+00 1.16E+01 U FH 53 562703001 11/17/2021 Ce-144 1.84E+01 1.27E+01 4.15E+01 U FH 53 562703001 11/17/2021 Co-57 1.24E+00 1.60E+00 5.30E+00 U FH 53 562703001 11/17/2021 Co-58 -1.93E-01 2.89E+00 9.23E+00 U FH 53 562703001 11/17/2021 Co-60 -7.84E-01 2.46E+00 7.88E+00 U FH 53 562703001 11/17/2021 Cr-51 -4.17E+00 2.31E+01 7.84E+01 U FH 53 562703001 11/17/2021 Cs-134 3.07E+00 2.71E+00 9.19E+00 U FH 53 562703001 11/17/2021 Cs-137 -2.03E+00 2.39E+00 7.12E+00 U FH 53 562703001 11/17/2021 Fe-59 5.57E+00 7.39E+00 2.57E+01 U FH 53 562703001 11/17/2021 I-131 1.37E+01 7.75E+00 2.61E+01 U FH 53 562703001 11/17/2021 K-40 3.55E+03 2.16E+02 6.08E+01

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

FH 53 562703001 11/17/2021 La-140 1.34E+00 4.61E+00 1.57E+01 U FH 53 562703001 11/17/2021 Mn-54 1.20E+00 2.41E+00 8.00E+00 U FH 53 562703001 11/17/2021 Nb-95 -9.80E+00 4.25E+00 7.79E+00 U FH 53 562703001 11/17/2021 Pb-212 4.46E+00 7.30E+00 1.49E+01 U FH 53 562703001 11/17/2021 Pb-214 0.00E+00 1.25E+01 1.90E+01 U FH 53 562703001 11/17/2021 Ra-226 1.11E+01 7.88E+00 1.46E+01 U FH 53 562703001 11/17/2021 Ru-103 8.84E-01 2.63E+00 8.91E+00 U FH 53 562703001 11/17/2021 Ru-106 -2.19E+01 2.20E+01 6.51E+01 U FH 53 562703001 11/17/2021 Sb-124 2.88E+00 4.53E+00 1.62E+01 U FH 53 562703001 11/17/2021 Sb-125 2.78E+00 5.81E+00 1.99E+01 U FH 53 562703001 11/17/2021 Se-75 -4.38E-02 2.95E+00 9.19E+00 U FH 53 562703001 11/17/2021 Th-228 4.46E+00 7.30E+00 1.49E+01 U FH 53 562703001 11/17/2021 Th-230 1.11E+01 7.88E+00 1.46E+01 U FH 53 562703001 11/17/2021 Tl-208 -3.28E+00 2.75E+00 8.10E+00 U FH 53 562703001 11/17/2021 Zn-65 -2.67E+00 6.00E+00 1.95E+01 U FH 53 562703001 11/17/2021 Zr-95 1.95E+00 5.26E+00 1.74E+01 U FH 03 564101001 11/29/2021 Ac-228 -2.35E-01 1.01E+01 3.02E+01 U FH 03 564101001 11/29/2021 Ag-108m -2.30E-01 1.59E+00 4.53E+00 U FH 03 564101001 11/29/2021 Ag-110m -3.81E+00 2.65E+00 7.40E+00 U FH 03 564101001 11/29/2021 Ba-140 1.53E+01 1.47E+01 3.28E+01 U FH 03 564101001 11/29/2021 Be-7 2.29E+00 1.40E+01 4.53E+01 U FH 03 564101001 11/29/2021 Bi-214 8.83E+00 5.73E+00 1.04E+01 U FH 03 564101001 11/29/2021 Ce-141 2.77E+00 4.64E+00 8.93E+00 U FH 03 564101001 11/29/2021 Ce-144 -2.19E+00 1.08E+01 3.08E+01 U FH 03 564101001 11/29/2021 Co-57 2.65E+00 1.50E+00 4.58E+00 U FH 03 564101001 11/29/2021 Co-58 -4.85E-02 1.75E+00 5.81E+00 U FH 03 564101001 11/29/2021 Co-60 -1.43E+00 1.78E+00 5.46E+00 U FH 03 564101001 11/29/2021 Cr-51 -1.24E+01 1.63E+01 5.11E+01 U FH 03 564101001 11/29/2021 Cs-134 -2.50E-01 2.09E+00 6.89E+00 U FH 03 564101001 11/29/2021 Cs-137 0.00E+00 4.62E+00 6.20E+00 U FH 03 564101001 11/29/2021 Fe-59 -6.78E+00 5.06E+00 1.26E+01 U FH 03 564101001 11/29/2021 I-131 -4.30E+00 3.96E+00 1.19E+01 U FH 03 564101001 11/29/2021 K-40 2.59E+03 1.61E+02 4.20E+01 FH 03 564101001 11/29/2021 La-140 -4.63E+00 3.62E+00 9.81E+00 U FH 03 564101001 11/29/2021 Mn-54 1.53E+00 1.85E+00 6.30E+00 U FH 03 564101001 11/29/2021 Nb-95 -1.80E-01 2.03E+00 6.29E+00 U FH 03 564101001 11/29/2021 Pb-212 0.00E+00 6.52E+00 9.13E+00 U FH 03 564101001 11/29/2021 Pb-214 5.69E+00 7.01E+00 1.19E+01 U FH 03 564101001 11/29/2021 Ra-226 8.83E+00 5.73E+00 1.04E+01 U FH 03 564101001 11/29/2021 Ru-103 6.65E-01 2.00E+00 6.48E+00 U FH 03 564101001 11/29/2021 Ru-106 7.33E+00 1.39E+01 4.81E+01 U FH 03 564101001 11/29/2021 Sb-124 -7.59E-01 4.24E+00 1.37E+01 U FH 03 564101001 11/29/2021 Sb-125 -5.34E+00 4.38E+00 1.26E+01 U FH 03 564101001 11/29/2021 Se-75 -1.79E+00 2.12E+00 6.71E+00 U FH 03 564101001 11/29/2021 Th-228 0.00E+00 6.52E+00 9.13E+00 U FH 03 564101001 11/29/2021 Th-230 8.83E+00 5.73E+00 1.04E+01 U FH 03 564101001 11/29/2021 Tl-208 -1.18E+00 2.20E+00 6.67E+00 U FH 03 564101001 11/29/2021 Zn-65 -5.23E+00 5.04E+00 1.23E+01 U FH 03 564101001 11/29/2021 Zr-95 -3.69E+00 3.19E+00 9.42E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

FH 03 545141003 5/17/2021 Ac-228 -1.52E+02 8.96E+01 2.32E+02 U FH 03 545141003 5/17/2021 Ag-108m 1.23E+00 1.26E+01 4.00E+01 U FH 03 545141003 5/17/2021 Ag-110m -8.40E+00 2.10E+01 6.20E+01 U FH 03 545141003 5/17/2021 Ba-140 -8.16E+01 8.05E+01 2.03E+02 U FH 03 545141003 5/17/2021 Be-7 -5.76E+01 1.24E+02 3.79E+02 U FH 03 545141003 5/17/2021 Bi-214 1.81E+01 4.94E+01 1.30E+02 U FH 03 545141003 5/17/2021 Ce-141 -3.16E+01 2.23E+01 5.82E+01 U FH 03 545141003 5/17/2021 Ce-144 8.69E+01 7.38E+01 2.20E+02 U FH 03 545141003 5/17/2021 Co-57 4.25E+00 1.01E+01 3.01E+01 U FH 03 545141003 5/17/2021 Co-58 -3.12E+01 1.71E+01 3.63E+01 U FH 03 545141003 5/17/2021 Co-60 1.17E+01 1.63E+01 5.55E+01 U FH 03 545141003 5/17/2021 Cr-51 -1.19E+02 1.26E+02 3.78E+02 U FH 03 545141003 5/17/2021 Cs-134 3.25E+00 1.70E+01 5.33E+01 U FH 03 545141003 5/17/2021 Cs-137 2.53E+00 1.45E+01 4.58E+01 U FH 03 545141003 5/17/2021 Fe-59 -5.90E+00 2.98E+01 9.60E+01 U FH 03 545141003 5/17/2021 I-131 2.89E+01 2.21E+01 7.16E+01 U FH 03 545141003 5/17/2021 K-40 3.50E+03 4.56E+02 4.93E+02 FH 03 545141003 5/17/2021 La-140 -3.21E+01 2.87E+01 7.82E+01 U FH 03 545141003 5/17/2021 Mn-54 5.48E+00 1.43E+01 4.53E+01 U FH 03 545141003 5/17/2021 Nb-95 3.07E+01 1.76E+01 5.23E+01 U FH 03 545141003 5/17/2021 Pb-212 4.01E+01 3.98E+01 9.91E+01 U FH 03 545141003 5/17/2021 Pb-214 -4.99E+01 4.67E+01 1.11E+02 U FH 03 545141003 5/17/2021 Ra-226 1.81E+01 4.94E+01 1.30E+02 U FH 03 545141003 5/17/2021 Ru-103 2.06E+01 1.53E+01 4.92E+01 U FH 03 545141003 5/17/2021 Ru-106 1.35E+02 1.82E+02 4.33E+02 U FH 03 545141003 5/17/2021 Sb-124 1.80E+01 2.76E+01 9.57E+01 U FH 03 545141003 5/17/2021 Sb-125 -2.32E+01 3.95E+01 1.21E+02 U FH 03 545141003 5/17/2021 Se-75 -1.25E+00 1.54E+01 4.94E+01 U FH 03 545141003 5/17/2021 Th-228 4.01E+01 3.98E+01 9.91E+01 U FH 03 545141003 5/17/2021 Th-230 1.81E+01 4.94E+01 1.30E+02 U FH 03 545141003 5/17/2021 Tl-208 0.00E+00 2.94E+01 3.96E+01 U FH 03 545141003 5/17/2021 Zn-65 -9.74E+00 3.01E+01 9.54E+01 U FH 03 545141003 5/17/2021 Zr-95 -2.14E+01 3.26E+01 7.83E+01 U FH 53 537622002 2/8/2021 Ac-228 -2.10E+00 1.15E+01 3.54E+01 U FH 53 537622002 2/8/2021 Ag-108m 6.80E-01 1.45E+00 5.00E+00 U FH 53 537622002 2/8/2021 Ag-110m 2.43E+00 3.17E+00 1.08E+01 U FH 53 537622002 2/8/2021 Ba-140 -1.81E+01 4.23E+01 1.37E+02 U FH 53 537622002 2/8/2021 Be-7 -2.47E+01 2.48E+01 7.61E+01 U FH 53 537622002 2/8/2021 Bi-214 1.33E+01 8.61E+00 1.67E+01 U FH 53 537622002 2/8/2021 Ce-141 -7.43E+00 6.20E+00 1.81E+01 U FH 53 537622002 2/8/2021 Ce-144 -1.06E+01 1.26E+01 3.80E+01 U FH 53 537622002 2/8/2021 Co-57 -2.08E+00 1.91E+00 5.32E+00 U FH 53 537622002 2/8/2021 Co-58 -2.52E+00 2.59E+00 7.49E+00 U FH 53 537622002 2/8/2021 Co-60 1.06E+00 2.40E+00 8.38E+00 U FH 53 537622002 2/8/2021 Cr-51 -1.07E+01 3.37E+01 1.14E+02 U FH 53 537622002 2/8/2021 Cs-134 -1.35E+00 2.29E+00 7.06E+00 U FH 53 537622002 2/8/2021 Cs-137 -5.19E-01 2.44E+00 7.23E+00 U FH 53 537622002 2/8/2021 Fe-59 8.56E+00 7.59E+00 2.57E+01 U FH 53 537622002 2/8/2021 I-131 -6.95E+01 4.07E+01 1.15E+02 U FH 53 537622002 2/8/2021 K-40 3.51E+03 2.12E+02 6.36E+01

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

FH 53 537622002 2/8/2021 La-140 1.23E+01 1.26E+01 4.68E+01 U FH 53 537622002 2/8/2021 Mn-54 4.73E-01 2.57E+00 7.58E+00 U FH 53 537622002 2/8/2021 Nb-95 -5.85E-01 2.75E+00 8.83E+00 U FH 53 537622002 2/8/2021 Pb-212 1.64E+00 5.26E+00 1.24E+01 U FH 53 537622002 2/8/2021 Pb-214 -5.09E+00 4.69E+00 1.40E+01 U FH 53 537622002 2/8/2021 Ra-226 1.33E+01 8.61E+00 1.67E+01 U FH 53 537622002 2/8/2021 Ru-103 2.96E+00 3.31E+00 1.14E+01 U FH 53 537622002 2/8/2021 Ru-106 -1.44E+01 1.72E+01 5.23E+01 U FH 53 537622002 2/8/2021 Sb-124 -1.22E+01 7.17E+00 1.62E+01 U FH 53 537622002 2/8/2021 Sb-125 2.73E+00 4.37E+00 1.52E+01 U FH 53 537622002 2/8/2021 Se-75 -2.60E-01 2.75E+00 8.54E+00 U FH 53 537622002 2/8/2021 Th-228 1.64E+00 5.26E+00 1.24E+01 U FH 53 537622002 2/8/2021 Th-230 1.33E+01 8.61E+00 1.67E+01 U FH 53 537622002 2/8/2021 Tl-208 -1.43E+00 2.30E+00 6.99E+00 U FH 53 537622002 2/8/2021 Zn-65 5.04E+00 5.61E+00 1.89E+01 U FH 53 537622002 2/8/2021 Zr-95 4.37E+00 4.90E+00 1.68E+01 U FH 03 537622001 2/23/2021 Ac-228 2.71E+01 5.69E+01 1.19E+02 U FH 03 537622001 2/23/2021 Ag-108m 4.86E+00 7.17E+00 2.50E+01 U FH 03 537622001 2/23/2021 Ag-110m -1.50E+01 1.41E+01 3.56E+01 U FH 03 537622001 2/23/2021 Ba-140 9.75E+01 8.90E+01 3.04E+02 U FH 03 537622001 2/23/2021 Be-7 -1.46E+01 7.74E+01 2.60E+02 U FH 03 537622001 2/23/2021 Bi-214 -2.98E+01 2.43E+01 7.05E+01 U FH 03 537622001 2/23/2021 Ce-141 -8.12E+00 1.61E+01 5.59E+01 U FH 03 537622001 2/23/2021 Ce-144 -4.45E+01 4.89E+01 1.66E+02 U FH 03 537622001 2/23/2021 Co-57 -4.77E+00 6.08E+00 2.10E+01 U FH 03 537622001 2/23/2021 Co-58 -4.54E+00 8.94E+00 2.92E+01 U FH 03 537622001 2/23/2021 Co-60 2.86E+00 8.28E+00 2.84E+01 U FH 03 537622001 2/23/2021 Cr-51 1.69E+01 1.16E+02 3.82E+02 U FH 03 537622001 2/23/2021 Cs-134 2.12E-01 8.47E+00 2.88E+01 U FH 03 537622001 2/23/2021 Cs-137 9.14E-01 8.72E+00 2.87E+01 U FH 03 537622001 2/23/2021 Fe-59 -5.86E+00 1.90E+01 6.04E+01 U FH 03 537622001 2/23/2021 I-131 -7.83E+01 5.11E+01 1.56E+02 U FH 03 537622001 2/23/2021 K-40 0.00E+00 3.04E+02 2.63E+02 U FH 03 537622001 2/23/2021 La-140 -2.41E+01 2.70E+01 7.85E+01 U FH 03 537622001 2/23/2021 Mn-54 -5.55E+00 7.60E+00 2.41E+01 U FH 03 537622001 2/23/2021 Nb-95 -6.23E+00 1.10E+01 3.11E+01 U FH 03 537622001 2/23/2021 Pb-212 9.84E+00 2.53E+01 6.01E+01 U FH 03 537622001 2/23/2021 Pb-214 -5.61E+01 2.51E+01 6.35E+01 U FH 03 537622001 2/23/2021 Ra-226 -2.98E+01 2.43E+01 7.05E+01 U FH 03 537622001 2/23/2021 Ru-103 1.82E+00 1.08E+01 3.67E+01 U FH 03 537622001 2/23/2021 Ru-106 1.31E+02 8.09E+01 2.10E+02 U FH 03 537622001 2/23/2021 Sb-124 -2.24E+00 2.03E+01 6.50E+01 U FH 03 537622001 2/23/2021 Sb-125 7.91E-01 2.20E+01 7.58E+01 U FH 03 537622001 2/23/2021 Se-75 1.01E+00 1.22E+01 4.09E+01 U FH 03 537622001 2/23/2021 Th-228 9.84E+00 2.53E+01 6.01E+01 U FH 03 537622001 2/23/2021 Th-230 -2.98E+01 2.43E+01 7.05E+01 U FH 03 537622001 2/23/2021 Tl-208 4.93E+00 1.69E+01 2.69E+01 U FH 03 537622001 2/23/2021 Zn-65 1.56E+01 1.91E+01 6.48E+01 U FH 03 537622001 2/23/2021 Zr-95 2.87E+01 1.75E+01 6.03E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

HA 04 545580001 5/21/2021 Ac-228 -4.08E+00 9.61E+00 2.46E+01 U HA 04 545580001 5/21/2021 Ag-108m 2.47E+00 1.63E+00 5.37E+00 U HA 04 545580001 5/21/2021 Ag-110m 3.08E-01 2.70E+00 9.16E+00 U HA 04 545580001 5/21/2021 Ba-140 -2.94E+00 1.08E+01 2.97E+01 U HA 04 545580001 5/21/2021 Be-7 -6.91E+00 1.44E+01 4.56E+01 U HA 04 545580001 5/21/2021 Bi-214 1.90E-01 9.26E+00 1.14E+01 U HA 04 545580001 5/21/2021 Ce-141 -4.65E+00 3.05E+00 7.26E+00 U HA 04 545580001 5/21/2021 Ce-144 1.47E+00 8.91E+00 2.81E+01 U HA 04 545580001 5/21/2021 Co-57 1.84E+00 1.39E+00 3.49E+00 U HA 04 545580001 5/21/2021 Co-58 6.17E-02 1.90E+00 6.13E+00 U HA 04 545580001 5/21/2021 Co-60 7.36E+00 4.87E+00 7.66E+00 U HA 04 545580001 5/21/2021 Cr-51 2.54E+01 2.06E+01 4.84E+01 U HA 04 545580001 5/21/2021 Cs-134 1.19E+00 2.12E+00 7.34E+00 U HA 04 545580001 5/21/2021 Cs-137 2.34E+00 2.04E+00 6.73E+00 U HA 04 545580001 5/21/2021 Fe-59 2.98E+00 4.04E+00 1.39E+01 U HA 04 545580001 5/21/2021 I-131 -6.38E-01 2.52E+00 8.24E+00 U HA 04 545580001 5/21/2021 K-40 2.71E+03 1.63E+02 5.91E+01 HA 04 545580001 5/21/2021 La-140 -2.74E+00 2.50E+00 6.57E+00 U HA 04 545580001 5/21/2021 Mn-54 9.28E-02 1.94E+00 6.58E+00 U HA 04 545580001 5/21/2021 Nb-95 -5.21E+00 2.55E+00 5.41E+00 U HA 04 545580001 5/21/2021 Pb-212 6.47E+00 5.62E+00 1.05E+01 U HA 04 545580001 5/21/2021 Pb-214 0.00E+00 1.00E+01 1.42E+01 U HA 04 545580001 5/21/2021 Ra-226 1.90E-01 9.26E+00 1.14E+01 U HA 04 545580001 5/21/2021 Ru-103 -2.60E+00 1.74E+00 4.82E+00 U HA 04 545580001 5/21/2021 Ru-106 6.60E+00 1.64E+01 5.39E+01 U HA 04 545580001 5/21/2021 Sb-124 1.92E+00 4.10E+00 1.39E+01 U HA 04 545580001 5/21/2021 Sb-125 4.49E+00 4.72E+00 1.58E+01 U HA 04 545580001 5/21/2021 Se-75 8.14E-02 1.89E+00 6.40E+00 U HA 04 545580001 5/21/2021 Th-228 6.47E+00 5.62E+00 1.05E+01 U HA 04 545580001 5/21/2021 Th-230 1.90E-01 9.26E+00 1.14E+01 U HA 04 545580001 5/21/2021 Tl-208 5.05E+00 2.87E+00 5.75E+00 U HA 04 545580001 5/21/2021 Zn-65 9.89E-01 4.50E+00 1.51E+01 U HA 04 545580001 5/21/2021 Zr-95 9.03E-01 3.54E+00 1.14E+01 U HA 04 562688001 11/17/2021 Ac-228 1.61E+01 2.73E+01 5.22E+01 U HA 04 562688001 11/17/2021 Ag-108m 1.47E+00 2.29E+00 7.86E+00 U HA 04 562688001 11/17/2021 Ag-110m -2.72E+00 4.22E+00 1.32E+01 U HA 04 562688001 11/17/2021 Ba-140 -5.95E+01 2.65E+01 5.83E+01 U HA 04 562688001 11/17/2021 Be-7 2.98E+01 2.55E+01 8.85E+01 U HA 04 562688001 11/17/2021 Bi-214 2.58E+01 1.18E+01 2.88E+01 U HA 04 562688001 11/17/2021 Ce-141 1.20E+00 4.31E+00 1.29E+01 U HA 04 562688001 11/17/2021 Ce-144 -4.06E+01 1.62E+01 3.45E+01 U HA 04 562688001 11/17/2021 Co-57 1.29E+00 1.62E+00 5.36E+00 U HA 04 562688001 11/17/2021 Co-58 -2.37E+00 2.55E+00 7.47E+00 U HA 04 562688001 11/17/2021 Co-60 -7.19E+00 4.20E+00 9.41E+00 U HA 04 562688001 11/17/2021 Cr-51 3.17E+01 2.83E+01 9.82E+01 U HA 04 562688001 11/17/2021 Cs-134 3.16E+00 3.38E+00 1.16E+01 U HA 04 562688001 11/17/2021 Cs-137 -2.39E+00 3.21E+00 9.41E+00 U HA 04 562688001 11/17/2021 Fe-59 -2.94E+00 8.17E+00 2.61E+01 U HA 04 562688001 11/17/2021 I-131 -2.53E+01 1.03E+01 2.22E+01 U HA 04 562688001 11/17/2021 K-40 2.27E+03 1.81E+02 9.54E+01

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

HA 04 562688001 11/17/2021 La-140 -5.95E-01 8.31E+00 2.64E+01 U HA 04 562688001 11/17/2021 Mn-54 -4.35E+00 3.89E+00 9.98E+00 U HA 04 562688001 11/17/2021 Nb-95 -6.95E-01 3.35E+00 1.04E+01 U HA 04 562688001 11/17/2021 Pb-212 7.54E+00 5.41E+00 1.19E+01 U HA 04 562688001 11/17/2021 Pb-214 1.56E+01 9.83E+00 2.38E+01 U HA 04 562688001 11/17/2021 Ra-226 2.58E+01 1.18E+01 2.88E+01 U HA 04 562688001 11/17/2021 Ru-103 -1.62E+00 3.14E+00 9.79E+00 U HA 04 562688001 11/17/2021 Ru-106 5.08E+00 2.97E+01 9.71E+01 U HA 04 562688001 11/17/2021 Sb-124 -9.31E-01 6.82E+00 2.12E+01 U HA 04 562688001 11/17/2021 Sb-125 -5.97E+00 7.12E+00 2.16E+01 U HA 04 562688001 11/17/2021 Se-75 -1.50E+00 2.91E+00 9.56E+00 U HA 04 562688001 11/17/2021 Th-228 7.54E+00 5.41E+00 1.19E+01 U HA 04 562688001 11/17/2021 Th-230 2.58E+01 1.18E+01 2.88E+01 U HA 04 562688001 11/17/2021 Tl-208 -3.17E+00 3.38E+00 8.54E+00 U HA 04 562688001 11/17/2021 Zn-65 -2.16E+00 7.83E+00 2.52E+01 U HA 04 562688001 11/17/2021 Zr-95 -5.49E+00 6.80E+00 1.95E+01 U HA 52 562688002 11/15/2021 Ac-228 -1.12E+01 1.29E+01 3.64E+01 U HA 52 562688002 11/15/2021 Ag-108m 3.46E-01 1.73E+00 5.96E+00 U HA 52 562688002 11/15/2021 Ag-110m -2.31E+00 3.58E+00 1.07E+01 U HA 52 562688002 11/15/2021 Ba-140 1.14E+01 1.74E+01 6.05E+01 U HA 52 562688002 11/15/2021 Be-7 4.63E+00 1.91E+01 6.58E+01 U HA 52 562688002 11/15/2021 Bi-214 1.17E+01 7.50E+00 1.39E+01 U HA 52 562688002 11/15/2021 Ce-141 5.64E-01 3.78E+00 1.26E+01 U HA 52 562688002 11/15/2021 Ce-144 2.30E+00 1.15E+01 3.83E+01 U HA 52 562688002 11/15/2021 Co-57 1.18E+00 1.40E+00 4.76E+00 U HA 52 562688002 11/15/2021 Co-58 -1.39E+00 2.86E+00 8.84E+00 U HA 52 562688002 11/15/2021 Co-60 -2.07E+00 3.48E+00 9.31E+00 U HA 52 562688002 11/15/2021 Cr-51 1.10E+01 2.35E+01 7.59E+01 U HA 52 562688002 11/15/2021 Cs-134 2.29E+00 2.34E+00 8.20E+00 U HA 52 562688002 11/15/2021 Cs-137 -1.06E-01 2.44E+00 8.04E+00 U HA 52 562688002 11/15/2021 Fe-59 1.15E+00 5.58E+00 1.81E+01 U HA 52 562688002 11/15/2021 I-131 1.55E+01 1.19E+01 2.21E+01 U HA 52 562688002 11/15/2021 K-40 2.39E+03 1.67E+02 6.43E+01 HA 52 562688002 11/15/2021 La-140 5.20E+00 6.49E+00 2.33E+01 U HA 52 562688002 11/15/2021 Mn-54 -1.54E+00 2.59E+00 6.79E+00 U HA 52 562688002 11/15/2021 Nb-95 2.25E+00 2.55E+00 8.84E+00 U HA 52 562688002 11/15/2021 Pb-212 6.02E+00 5.41E+00 1.09E+01 U HA 52 562688002 11/15/2021 Pb-214 2.04E+00 5.35E+00 1.72E+01 U HA 52 562688002 11/15/2021 Ra-226 1.17E+01 7.50E+00 1.39E+01 U HA 52 562688002 11/15/2021 Ru-103 1.52E+00 2.77E+00 9.59E+00 U HA 52 562688002 11/15/2021 Ru-106 4.63E+01 2.35E+01 8.05E+01 U HA 52 562688002 11/15/2021 Sb-124 -1.97E+00 4.29E+00 1.25E+01 U HA 52 562688002 11/15/2021 Sb-125 -1.11E+00 5.58E+00 1.88E+01 U HA 52 562688002 11/15/2021 Se-75 -8.44E-01 2.62E+00 8.12E+00 U HA 52 562688002 11/15/2021 Th-228 6.02E+00 5.41E+00 1.09E+01 U HA 52 562688002 11/15/2021 Th-230 1.17E+01 7.50E+00 1.39E+01 U HA 52 562688002 11/15/2021 Tl-208 0.00E+00 4.29E+00 5.58E+00 U HA 52 562688002 11/15/2021 Zn-65 -5.14E+00 5.73E+00 1.75E+01 U HA 52 562688002 11/15/2021 Zr-95 -4.11E+00 5.16E+00 1.54E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

HA 54 545580002 5/23/2021 Ac-228 -1.14E+01 1.04E+01 3.02E+01 U HA 54 545580002 5/23/2021 Ag-108m -1.46E+00 1.87E+00 5.59E+00 U HA 54 545580002 5/23/2021 Ag-110m 1.53E+00 3.04E+00 1.03E+01 U HA 54 545580002 5/23/2021 Ba-140 -1.37E+01 1.01E+01 2.60E+01 U HA 54 545580002 5/23/2021 Be-7 9.18E+00 1.46E+01 5.02E+01 U HA 54 545580002 5/23/2021 Bi-214 -3.25E-01 5.98E+00 1.63E+01 U HA 54 545580002 5/23/2021 Ce-141 -2.55E+00 2.47E+00 7.37E+00 U HA 54 545580002 5/23/2021 Ce-144 -3.23E+00 9.49E+00 3.04E+01 U HA 54 545580002 5/23/2021 Co-57 1.06E-01 1.13E+00 3.71E+00 U HA 54 545580002 5/23/2021 Co-58 -1.46E+00 1.85E+00 5.77E+00 U HA 54 545580002 5/23/2021 Co-60 -2.99E+00 2.58E+00 7.44E+00 U HA 54 545580002 5/23/2021 Cr-51 -2.57E+01 1.58E+01 4.39E+01 U HA 54 545580002 5/23/2021 Cs-134 -3.92E+00 2.44E+00 6.78E+00 U HA 54 545580002 5/23/2021 Cs-137 2.81E+00 2.47E+00 8.19E+00 U HA 54 545580002 5/23/2021 Fe-59 5.68E+00 5.50E+00 1.84E+01 U HA 54 545580002 5/23/2021 I-131 -2.33E+00 2.45E+00 7.30E+00 U HA 54 545580002 5/23/2021 K-40 2.45E+03 1.63E+02 7.88E+01 HA 54 545580002 5/23/2021 La-140 1.09E+00 2.72E+00 9.19E+00 U HA 54 545580002 5/23/2021 Mn-54 -7.21E-01 2.19E+00 7.16E+00 U HA 54 545580002 5/23/2021 Nb-95 -2.78E+00 2.10E+00 6.18E+00 U HA 54 545580002 5/23/2021 Pb-212 1.11E+00 3.90E+00 1.17E+01 U HA 54 545580002 5/23/2021 Pb-214 0.00E+00 8.78E+00 1.39E+01 U HA 54 545580002 5/23/2021 Ra-226 -3.25E-01 5.98E+00 1.63E+01 U HA 54 545580002 5/23/2021 Ru-103 -1.57E-01 1.91E+00 6.37E+00 U HA 54 545580002 5/23/2021 Ru-106 3.60E+01 1.92E+01 6.27E+01 U HA 54 545580002 5/23/2021 Sb-124 -5.41E+00 5.22E+00 1.51E+01 U HA 54 545580002 5/23/2021 Sb-125 -9.22E-01 5.13E+00 1.61E+01 U HA 54 545580002 5/23/2021 Se-75 6.28E-01 2.09E+00 7.05E+00 U HA 54 545580002 5/23/2021 Th-228 1.11E+00 3.90E+00 1.17E+01 U HA 54 545580002 5/23/2021 Th-230 -3.25E-01 5.98E+00 1.63E+01 U HA 54 545580002 5/23/2021 Tl-208 -1.68E+00 2.93E+00 7.58E+00 U HA 54 545580002 5/23/2021 Zn-65 1.31E+00 5.69E+00 1.86E+01 U HA 54 545580002 5/23/2021 Zr-95 -6.54E+00 4.16E+00 1.19E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

MU 06 545135001 5/11/2021 Ac-228 0.00E+00 1.22E+01 2.44E+01 U MU 06 545135001 5/11/2021 Ag-108m 1.74E+00 1.11E+00 3.83E+00 U MU 06 545135001 5/11/2021 Ag-110m -5.68E-01 1.84E+00 5.80E+00 U MU 06 545135001 5/11/2021 Ba-140 3.86E+00 7.86E+00 2.71E+01 U MU 06 545135001 5/11/2021 Be-7 3.81E+01 1.78E+01 4.18E+01 U MU 06 545135001 5/11/2021 Bi-214 1.17E+01 5.25E+00 1.21E+01 U MU 06 545135001 5/11/2021 Ce-141 3.28E+00 2.50E+00 8.19E+00 U MU 06 545135001 5/11/2021 Ce-144 7.24E+00 7.41E+00 2.48E+01 U MU 06 545135001 5/11/2021 Co-57 -6.45E-01 9.47E-01 3.02E+00 U MU 06 545135001 5/11/2021 Co-58 4.39E-02 1.62E+00 5.32E+00 U MU 06 545135001 5/11/2021 Co-60 -8.92E-02 1.74E+00 5.86E+00 U MU 06 545135001 5/11/2021 Cr-51 -1.98E+01 1.73E+01 4.46E+01 U MU 06 545135001 5/11/2021 Cs-134 2.67E+00 1.70E+00 5.78E+00 U MU 06 545135001 5/11/2021 Cs-137 6.29E-02 1.44E+00 4.79E+00 U MU 06 545135001 5/11/2021 Fe-59 4.27E+00 3.53E+00 1.20E+01 U MU 06 545135001 5/11/2021 I-131 -4.24E+00 4.30E+00 1.23E+01 U MU 06 545135001 5/11/2021 K-40 1.19E+03 8.85E+01 5.40E+01 MU 06 545135001 5/11/2021 La-140 -4.68E+00 3.38E+00 8.80E+00 U MU 06 545135001 5/11/2021 Mn-54 1.01E+00 1.43E+00 4.83E+00 U MU 06 545135001 5/11/2021 Nb-95 4.47E-02 1.39E+00 4.58E+00 U MU 06 545135001 5/11/2021 Pb-212 8.54E+00 5.38E+00 9.80E+00 U MU 06 545135001 5/11/2021 Pb-214 1.49E+00 3.76E+00 1.11E+01 U MU 06 545135001 5/11/2021 Ra-226 1.17E+01 5.25E+00 1.21E+01 U MU 06 545135001 5/11/2021 Ru-103 8.43E-01 1.45E+00 5.02E+00 U MU 06 545135001 5/11/2021 Ru-106 7.48E+00 1.03E+01 3.28E+01 U MU 06 545135001 5/11/2021 Sb-124 2.71E+00 3.16E+00 1.14E+01 U MU 06 545135001 5/11/2021 Sb-125 1.26E+00 3.15E+00 1.10E+01 U MU 06 545135001 5/11/2021 Se-75 -9.52E-01 1.80E+00 5.54E+00 U MU 06 545135001 5/11/2021 Th-228 8.54E+00 5.38E+00 9.80E+00 U MU 06 545135001 5/11/2021 Th-230 1.17E+01 5.25E+00 1.21E+01 U MU 06 545135001 5/11/2021 Tl-208 -1.85E+00 2.07E+00 5.25E+00 U MU 06 545135001 5/11/2021 Zn-65 4.27E+00 3.33E+00 1.13E+01 U MU 06 545135001 5/11/2021 Zr-95 0.00E+00 6.28E+00 8.79E+00 U MU 09 545140001 5/13/2021 Ac-228 1.84E+01 3.20E+01 1.12E+01 M MU 09 545140001 5/13/2021 Ag-108m -5.08E-01 3.08E+00 2.56E+00 U MU 09 545140001 5/13/2021 Ag-110m -1.08E+00 6.30E+00 4.92E+00 U MU 09 545140001 5/13/2021 Ba-140 -1.32E+01 2.57E+01 1.83E+01 U MU 09 545140001 5/13/2021 Be-7 6.23E+01 4.93E+01 4.01E+01 M MU 09 545140001 5/13/2021 Bi-214 1.24E+01 2.29E+01 9.62E+00 M MU 09 545140001 5/13/2021 Ce-141 -4.77E+00 8.25E+00 5.60E+00 U MU 09 545140001 5/13/2021 Ce-144 -1.69E+01 2.54E+01 1.85E+01 U MU 09 545140001 5/13/2021 Co-57 6.27E-01 3.08E+00 2.60E+00 U MU 09 545140001 5/13/2021 Co-58 -1.06E+00 4.47E+00 3.46E+00 U MU 09 545140001 5/13/2021 Co-60 2.71E+00 4.18E+00 3.94E+00 U MU 09 545140001 5/13/2021 Cr-51 -2.92E+01 4.35E+01 3.24E+01 U MU 09 545140001 5/13/2021 Cs-134 3.26E+00 4.14E+00 3.54E+00 U MU 09 545140001 5/13/2021 Cs-137 -4.24E+00 5.34E+00 3.49E+00 U MU 09 545140001 5/13/2021 Fe-59 4.17E+00 9.12E+00 8.33E+00 U MU 09 545140001 5/13/2021 I-131 5.52E+00 1.00E+01 8.92E+00 U MU 09 545140001 5/13/2021 K-40 1.71E+03 2.79E+02 3.58E+01

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

MU 09 545140001 5/13/2021 La-140 3.42E+00 9.79E+00 8.74E+00 U MU 09 545140001 5/13/2021 Mn-54 0.00E+00 1.00E+01 3.16E+00 U MU 09 545140001 5/13/2021 Nb-95 -1.35E+00 4.35E+00 3.31E+00 U MU 09 545140001 5/13/2021 Pb-212 8.37E+00 1.32E+01 7.46E+00 M MU 09 545140001 5/13/2021 Pb-214 4.73E+00 1.04E+01 8.61E+00 U MU 09 545140001 5/13/2021 Ra-226 1.24E+01 2.29E+01 9.62E+00 M MU 09 545140001 5/13/2021 Ru-103 1.20E+00 4.51E+00 3.93E+00 U MU 09 545140001 5/13/2021 Ru-106 -4.60E+00 3.24E+01 2.62E+01 U MU 09 545140001 5/13/2021 Sb-124 1.43E+00 7.30E+00 6.53E+00 U MU 09 545140001 5/13/2021 Sb-125 5.13E+00 9.57E+00 8.55E+00 U MU 09 545140001 5/13/2021 Se-75 1.53E+00 5.22E+00 4.28E+00 U MU 09 545140001 5/13/2021 Th-228 8.37E+00 1.32E+01 7.46E+00 M MU 09 545140001 5/13/2021 Th-230 1.24E+01 2.29E+01 9.62E+00 M MU 09 545140001 5/13/2021 Tl-208 -2.39E+00 5.63E+00 4.18E+00 U MU 09 545140001 5/13/2021 Zn-65 -9.63E+00 1.12E+01 7.27E+00 U MU 09 545140001 5/13/2021 Zr-95 3.45E+00 6.93E+00 6.14E+00 U MU 56 545135002 5/11/2021 Ac-228 4.12E+00 1.23E+01 2.89E+01 U MU 56 545135002 5/11/2021 Ag-108m -1.36E+00 1.33E+00 4.02E+00 U MU 56 545135002 5/11/2021 Ag-110m 1.93E-01 2.22E+00 7.45E+00 U MU 56 545135002 5/11/2021 Ba-140 8.73E+00 1.10E+01 3.67E+01 U MU 56 545135002 5/11/2021 Be-7 3.82E+01 1.74E+01 5.48E+01 U MU 56 545135002 5/11/2021 Bi-214 2.81E+01 7.31E+00 1.07E+01 MU 56 545135002 5/11/2021 Ce-141 -2.18E+00 3.30E+00 9.37E+00 U MU 56 545135002 5/11/2021 Ce-144 1.28E+01 1.00E+01 3.22E+01 U MU 56 545135002 5/11/2021 Co-57 -4.52E-01 1.25E+00 3.99E+00 U MU 56 545135002 5/11/2021 Co-58 3.01E-01 1.71E+00 5.79E+00 U MU 56 545135002 5/11/2021 Co-60 1.72E-01 1.90E+00 6.17E+00 U MU 56 545135002 5/11/2021 Cr-51 -1.52E+01 1.67E+01 5.31E+01 U MU 56 545135002 5/11/2021 Cs-134 1.02E-01 1.61E+00 5.44E+00 U MU 56 545135002 5/11/2021 Cs-137 2.01E+00 1.77E+00 5.83E+00 U MU 56 545135002 5/11/2021 Fe-59 2.25E+00 3.85E+00 1.30E+01 U MU 56 545135002 5/11/2021 I-131 -2.43E-01 4.39E+00 1.46E+01 U MU 56 545135002 5/11/2021 K-40 1.76E+03 1.15E+02 3.81E+01 MU 56 545135002 5/11/2021 La-140 -2.36E+00 3.62E+00 1.12E+01 U MU 56 545135002 5/11/2021 Mn-54 -5.09E-01 1.86E+00 6.13E+00 U MU 56 545135002 5/11/2021 Nb-95 2.54E+00 1.94E+00 6.68E+00 U MU 56 545135002 5/11/2021 Pb-212 1.18E+01 7.20E+00 1.21E+01 U MU 56 545135002 5/11/2021 Pb-214 4.33E+00 6.24E+00 1.32E+01 U MU 56 545135002 5/11/2021 Ra-226 2.81E+01 7.31E+00 1.07E+01 MU 56 545135002 5/11/2021 Ru-103 1.60E+00 1.89E+00 6.29E+00 U MU 56 545135002 5/11/2021 Ru-106 4.78E+00 1.43E+01 4.65E+01 U MU 56 545135002 5/11/2021 Sb-124 -4.19E+00 4.34E+00 1.26E+01 U MU 56 545135002 5/11/2021 Sb-125 2.47E-01 4.09E+00 1.35E+01 U MU 56 545135002 5/11/2021 Se-75 8.72E-01 1.91E+00 6.57E+00 U MU 56 545135002 5/11/2021 Th-228 1.18E+01 7.20E+00 1.21E+01 U MU 56 545135002 5/11/2021 Th-230 2.81E+01 7.31E+00 1.07E+01 MU 56 545135002 5/11/2021 Tl-208 3.11E+00 2.52E+00 5.02E+00 U MU 56 545135002 5/11/2021 Zn-65 5.08E+00 4.40E+00 1.49E+01 U MU 56 545135002 5/11/2021 Zr-95 2.27E+00 3.41E+00 1.18E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

MU 59 545579001 5/23/2021 Ac-228 2.97E+01 1.69E+01 4.37E+01 U MU 59 545579001 5/23/2021 Ag-108m 1.92E+00 1.97E+00 6.89E+00 U MU 59 545579001 5/23/2021 Ag-110m 3.40E+00 3.19E+00 1.10E+01 U MU 59 545579001 5/23/2021 Ba-140 3.70E-01 9.86E+00 3.31E+01 U MU 59 545579001 5/23/2021 Be-7 1.08E+01 1.96E+01 6.75E+01 U MU 59 545579001 5/23/2021 Bi-214 -6.62E+00 7.16E+00 2.09E+01 U MU 59 545579001 5/23/2021 Ce-141 -4.39E+00 3.52E+00 9.70E+00 U MU 59 545579001 5/23/2021 Ce-144 1.83E+00 1.24E+01 4.15E+01 U MU 59 545579001 5/23/2021 Co-57 -1.11E+00 1.60E+00 5.14E+00 U MU 59 545579001 5/23/2021 Co-58 1.14E+00 2.48E+00 8.31E+00 U MU 59 545579001 5/23/2021 Co-60 -1.44E+00 2.18E+00 6.52E+00 U MU 59 545579001 5/23/2021 Cr-51 -1.22E+01 1.93E+01 5.75E+01 U MU 59 545579001 5/23/2021 Cs-134 -3.97E+00 2.66E+00 6.78E+00 U MU 59 545579001 5/23/2021 Cs-137 2.83E+00 2.67E+00 9.18E+00 U MU 59 545579001 5/23/2021 Fe-59 5.84E+00 4.83E+00 1.75E+01 U MU 59 545579001 5/23/2021 I-131 4.10E+00 3.41E+00 1.10E+01 U MU 59 545579001 5/23/2021 K-40 1.24E+03 1.20E+02 7.25E+01 MU 59 545579001 5/23/2021 La-140 1.95E+00 4.18E+00 1.44E+01 U MU 59 545579001 5/23/2021 Mn-54 3.92E+00 2.63E+00 8.99E+00 U MU 59 545579001 5/23/2021 Nb-95 -3.12E+00 2.73E+00 6.55E+00 U MU 59 545579001 5/23/2021 Pb-212 5.50E+00 6.97E+00 1.20E+01 U MU 59 545579001 5/23/2021 Pb-214 2.36E+00 7.46E+00 2.15E+01 U MU 59 545579001 5/23/2021 Ra-226 -6.62E+00 7.16E+00 2.09E+01 U MU 59 545579001 5/23/2021 Ru-103 -1.96E+00 2.33E+00 6.89E+00 U MU 59 545579001 5/23/2021 Ru-106 -9.64E+00 2.20E+01 7.03E+01 U MU 59 545579001 5/23/2021 Sb-124 -1.60E-01 4.12E+00 1.34E+01 U MU 59 545579001 5/23/2021 Sb-125 -2.58E+00 5.72E+00 1.89E+01 U MU 59 545579001 5/23/2021 Se-75 3.20E+00 3.00E+00 9.73E+00 U MU 59 545579001 5/23/2021 Th-228 5.50E+00 6.97E+00 1.20E+01 U MU 59 545579001 5/23/2021 Th-230 -6.62E+00 7.16E+00 2.09E+01 U MU 59 545579001 5/23/2021 Tl-208 3.64E-01 4.23E+00 8.61E+00 U MU 59 545579001 5/23/2021 Zn-65 -1.89E+01 7.43E+00 1.47E+01 U MU 59 545579001 5/23/2021 Zr-95 1.13E+00 3.73E+00 1.25E+01 U MU 06 562727001 11/17/2021 Ac-228 1.84E+01 2.40E+01 6.02E+01 U MU 06 562727001 11/17/2021 Ag-108m 1.20E+01 5.28E+00 1.28E+01 U MU 06 562727001 11/17/2021 Ag-110m -7.68E+00 6.10E+00 1.46E+01 U MU 06 562727001 11/17/2021 Ba-140 4.25E+01 2.89E+01 1.04E+02 U MU 06 562727001 11/17/2021 Be-7 3.30E+01 4.16E+01 1.46E+02 U MU 06 562727001 11/17/2021 Bi-214 2.07E+01 2.10E+01 4.83E+01 U MU 06 562727001 11/17/2021 Ce-141 -5.22E+00 7.97E+00 2.38E+01 U MU 06 562727001 11/17/2021 Ce-144 -9.25E+00 2.32E+01 7.28E+01 U MU 06 562727001 11/17/2021 Co-57 1.37E+00 3.36E+00 1.12E+01 U MU 06 562727001 11/17/2021 Co-58 -9.32E-01 3.76E+00 1.16E+01 U MU 06 562727001 11/17/2021 Co-60 -2.88E+00 3.86E+00 1.06E+01 U MU 06 562727001 11/17/2021 Cr-51 5.37E+00 4.32E+01 1.49E+02 U MU 06 562727001 11/17/2021 Cs-134 1.06E+00 2.75E+00 9.61E+00 U MU 06 562727001 11/17/2021 Cs-137 -7.93E-01 3.97E+00 1.27E+01 U MU 06 562727001 11/17/2021 Fe-59 -1.22E+00 9.84E+00 3.28E+01 U MU 06 562727001 11/17/2021 I-131 -3.24E+00 1.09E+01 3.62E+01 U MU 06 562727001 11/17/2021 K-40 8.83E+02 1.62E+02 9.42E+01

-195-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

MU 06 562727001 11/17/2021 La-140 -3.99E+00 8.85E+00 2.58E+01 U MU 06 562727001 11/17/2021 Mn-54 -1.89E+00 4.38E+00 1.32E+01 U MU 06 562727001 11/17/2021 Nb-95 -1.44E+00 4.80E+00 1.49E+01 U MU 06 562727001 11/17/2021 Pb-212 -1.24E+00 8.15E+00 2.59E+01 U MU 06 562727001 11/17/2021 Pb-214 2.01E+01 1.81E+01 4.51E+01 U MU 06 562727001 11/17/2021 Ra-226 2.07E+01 2.10E+01 4.83E+01 U MU 06 562727001 11/17/2021 Ru-103 -2.36E+00 4.00E+00 1.23E+01 U MU 06 562727001 11/17/2021 Ru-106 -7.81E+01 4.55E+01 1.08E+02 U MU 06 562727001 11/17/2021 Sb-124 4.63E-01 6.86E+00 2.30E+01 U MU 06 562727001 11/17/2021 Sb-125 9.00E+00 9.57E+00 3.21E+01 U MU 06 562727001 11/17/2021 Se-75 -3.02E-01 5.89E+00 1.83E+01 U MU 06 562727001 11/17/2021 Th-228 -1.24E+00 8.15E+00 2.59E+01 U MU 06 562727001 11/17/2021 Th-230 2.07E+01 2.10E+01 4.83E+01 U MU 06 562727001 11/17/2021 Tl-208 4.33E+00 4.09E+00 1.11E+01 U MU 06 562727001 11/17/2021 Zn-65 -3.11E+01 1.23E+01 1.54E+01 U MU 06 562727001 11/17/2021 Zr-95 -1.61E+00 7.71E+00 2.42E+01 U MU 56 562727002 11/17/2021 Ac-228 5.73E+01 3.51E+01 8.18E+01 U MU 56 562727002 11/17/2021 Ag-108m 1.13E+00 3.21E+00 1.08E+01 U MU 56 562727002 11/17/2021 Ag-110m -8.53E-01 4.38E+00 1.19E+01 U MU 56 562727002 11/17/2021 Ba-140 -5.86E+00 2.27E+01 6.92E+01 U MU 56 562727002 11/17/2021 Be-7 0.00E+00 5.60E+01 1.05E+02 U MU 56 562727002 11/17/2021 Bi-214 2.97E+00 1.09E+01 3.88E+01 U MU 56 562727002 11/17/2021 Ce-141 -7.19E+00 8.14E+00 2.33E+01 U MU 56 562727002 11/17/2021 Ce-144 -6.43E-01 2.80E+01 8.04E+01 U MU 56 562727002 11/17/2021 Co-57 3.26E-01 3.31E+00 1.05E+01 U MU 56 562727002 11/17/2021 Co-58 1.80E+00 4.23E+00 1.48E+01 U MU 56 562727002 11/17/2021 Co-60 2.00E+00 4.11E+00 1.49E+01 U MU 56 562727002 11/17/2021 Cr-51 5.15E+01 4.22E+01 1.47E+02 U MU 56 562727002 11/17/2021 Cs-134 9.38E-01 4.46E+00 1.52E+01 U MU 56 562727002 11/17/2021 Cs-137 -2.91E+00 3.91E+00 1.17E+01 U MU 56 562727002 11/17/2021 Fe-59 6.69E+00 1.16E+01 4.01E+01 U MU 56 562727002 11/17/2021 I-131 -5.34E+00 1.21E+01 3.29E+01 U MU 56 562727002 11/17/2021 K-40 1.14E+03 1.54E+02 1.88E+02 MU 56 562727002 11/17/2021 La-140 -3.58E+00 1.03E+01 2.94E+01 U MU 56 562727002 11/17/2021 Mn-54 1.02E+01 4.08E+00 1.54E+01 U MU 56 562727002 11/17/2021 Nb-95 -2.88E-01 4.42E+00 1.48E+01 U MU 56 562727002 11/17/2021 Pb-212 6.87E+00 9.13E+00 3.15E+01 U MU 56 562727002 11/17/2021 Pb-214 3.66E+01 1.64E+01 3.74E+01 U MU 56 562727002 11/17/2021 Ra-226 2.97E+00 1.09E+01 3.88E+01 U MU 56 562727002 11/17/2021 Ru-103 -4.05E+00 4.30E+00 1.17E+01 U MU 56 562727002 11/17/2021 Ru-106 9.92E+00 3.91E+01 1.35E+02 U MU 56 562727002 11/17/2021 Sb-124 9.08E+00 6.85E+00 3.03E+01 U MU 56 562727002 11/17/2021 Sb-125 -1.73E+01 1.12E+01 2.71E+01 U MU 56 562727002 11/17/2021 Se-75 -1.14E+00 5.40E+00 1.78E+01 U MU 56 562727002 11/17/2021 Th-228 6.87E+00 9.13E+00 3.15E+01 U MU 56 562727002 11/17/2021 Th-230 2.97E+00 1.09E+01 3.88E+01 U MU 56 562727002 11/17/2021 Tl-208 1.42E+00 4.92E+00 1.70E+01 U MU 56 562727002 11/17/2021 Zn-65 -2.79E+00 1.07E+01 3.32E+01 U MU 56 562727002 11/17/2021 Zr-95 1.64E+00 5.85E+00 2.04E+01 U

-196-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

MU 09 562681001 11/15/2021 Ac-228 1.59E+01 2.58E+01 5.08E+01 U MU 09 562681001 11/15/2021 Ag-108m 3.14E+00 2.39E+00 8.07E+00 U MU 09 562681001 11/15/2021 Ag-110m -4.84E-01 3.42E+00 1.11E+01 U MU 09 562681001 11/15/2021 Ba-140 4.77E+01 2.59E+01 8.54E+01 U MU 09 562681001 11/15/2021 Be-7 0.00E+00 4.56E+01 8.26E+01 U MU 09 562681001 11/15/2021 Bi-214 8.90E+00 7.37E+00 2.48E+01 U MU 09 562681001 11/15/2021 Ce-141 -8.16E+00 6.04E+00 1.57E+01 U MU 09 562681001 11/15/2021 Ce-144 -1.34E+01 1.81E+01 5.37E+01 U MU 09 562681001 11/15/2021 Co-57 2.15E+00 2.27E+00 7.27E+00 U MU 09 562681001 11/15/2021 Co-58 6.31E-01 2.94E+00 9.92E+00 U MU 09 562681001 11/15/2021 Co-60 -1.55E+00 2.84E+00 8.83E+00 U MU 09 562681001 11/15/2021 Cr-51 1.44E+01 2.79E+01 9.43E+01 U MU 09 562681001 11/15/2021 Cs-134 -5.40E+00 3.23E+00 6.99E+00 U MU 09 562681001 11/15/2021 Cs-137 -2.27E+00 2.53E+00 7.66E+00 U MU 09 562681001 11/15/2021 Fe-59 -5.57E+00 7.49E+00 2.20E+01 U MU 09 562681001 11/15/2021 I-131 -1.23E+01 9.23E+00 2.57E+01 U MU 09 562681001 11/15/2021 K-40 1.25E+03 1.24E+02 8.65E+01 MU 09 562681001 11/15/2021 La-140 -6.00E+00 9.00E+00 2.13E+01 U MU 09 562681001 11/15/2021 Mn-54 -1.14E+00 2.43E+00 7.63E+00 U MU 09 562681001 11/15/2021 Nb-95 -2.53E+00 3.62E+00 1.06E+01 U MU 09 562681001 11/15/2021 Pb-212 -1.51E+00 5.81E+00 1.83E+01 U MU 09 562681001 11/15/2021 Pb-214 1.85E+01 9.71E+00 2.44E+01 U MU 09 562681001 11/15/2021 Ra-226 8.90E+00 7.37E+00 2.48E+01 U MU 09 562681001 11/15/2021 Ru-103 9.96E-01 3.16E+00 1.03E+01 U MU 09 562681001 11/15/2021 Ru-106 -2.32E+01 2.30E+01 6.93E+01 U MU 09 562681001 11/15/2021 Sb-124 -9.04E+00 7.05E+00 1.67E+01 U MU 09 562681001 11/15/2021 Sb-125 -9.18E+00 6.67E+00 1.79E+01 U MU 09 562681001 11/15/2021 Se-75 -3.14E+00 3.29E+00 1.01E+01 U MU 09 562681001 11/15/2021 Th-228 -1.51E+00 5.81E+00 1.83E+01 U MU 09 562681001 11/15/2021 Th-230 8.89E+00 7.37E+00 2.48E+01 U MU 09 562681001 11/15/2021 Tl-208 5.68E+00 5.68E+00 6.91E+00 U MU 09 562681001 11/15/2021 Zn-65 7.20E+00 5.85E+00 1.94E+01 U MU 09 562681001 11/15/2021 Zr-95 -2.61E+00 3.99E+00 1.21E+01 U MU 59 562681002 11/15/2021 Ac-228 2.89E+01 1.28E+01 3.36E+01 U MU 59 562681002 11/15/2021 Ag-108m -4.36E-01 1.65E+00 5.35E+00 U MU 59 562681002 11/15/2021 Ag-110m 1.15E+00 2.82E+00 9.79E+00 U MU 59 562681002 11/15/2021 Ba-140 9.91E+00 1.60E+01 5.43E+01 U MU 59 562681002 11/15/2021 Be-7 0.00E+00 3.51E+01 6.37E+01 U MU 59 562681002 11/15/2021 Bi-214 1.14E+01 6.22E+00 2.02E+01 U MU 59 562681002 11/15/2021 Ce-141 -8.06E+00 4.36E+00 9.74E+00 U MU 59 562681002 11/15/2021 Ce-144 -1.04E+01 1.16E+01 3.50E+01 U MU 59 562681002 11/15/2021 Co-57 1.00E+00 1.39E+00 4.68E+00 U MU 59 562681002 11/15/2021 Co-58 -1.19E+00 2.11E+00 6.69E+00 U MU 59 562681002 11/15/2021 Co-60 1.87E-01 2.00E+00 6.64E+00 U MU 59 562681002 11/15/2021 Cr-51 -2.77E+01 1.95E+01 5.56E+01 U MU 59 562681002 11/15/2021 Cs-134 2.09E+00 2.16E+00 7.77E+00 U MU 59 562681002 11/15/2021 Cs-137 -2.84E-01 1.86E+00 5.84E+00 U MU 59 562681002 11/15/2021 Fe-59 -7.51E+00 5.44E+00 1.40E+01 U MU 59 562681002 11/15/2021 I-131 -2.05E-03 6.55E+00 2.20E+01 U MU 59 562681002 11/15/2021 K-40 9.82E+02 1.05E+02 6.49E+01

-197-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

MU 59 562681002 11/15/2021 La-140 8.29E-01 5.50E+00 1.89E+01 U MU 59 562681002 11/15/2021 Mn-54 1.75E+00 1.89E+00 6.80E+00 U MU 59 562681002 11/15/2021 Nb-95 1.53E+00 2.15E+00 7.64E+00 U MU 59 562681002 11/15/2021 Pb-212 3.45E+00 6.49E+00 1.27E+01 U MU 59 562681002 11/15/2021 Pb-214 1.13E+01 9.48E+00 1.92E+01 U MU 59 562681002 11/15/2021 Ra-226 1.14E+01 6.22E+00 2.02E+01 U MU 59 562681002 11/15/2021 Ru-103 -2.97E+00 2.32E+00 6.41E+00 U MU 59 562681002 11/15/2021 Ru-106 4.55E+00 1.91E+01 6.29E+01 U MU 59 562681002 11/15/2021 Sb-124 -2.46E+00 4.42E+00 1.41E+01 U MU 59 562681002 11/15/2021 Sb-125 -6.88E-01 4.80E+00 1.58E+01 U MU 59 562681002 11/15/2021 Se-75 1.08E+00 2.27E+00 7.98E+00 U MU 59 562681002 11/15/2021 Th-228 3.45E+00 6.49E+00 1.27E+01 U MU 59 562681002 11/15/2021 Th-230 1.14E+01 6.22E+00 2.02E+01 U MU 59 562681002 11/15/2021 Tl-208 -1.57E+00 2.48E+00 6.51E+00 U MU 59 562681002 11/15/2021 Zn-65 3.16E-01 6.01E+00 1.75E+01 U MU 59 562681002 11/15/2021 Zr-95 -3.64E+00 5.02E+00 1.42E+01 U MS 06 545135004 5/11/2021 Sr-89 2.95E+01 4.62E+01 7.97E+01 U MS 06 545135004 5/11/2021 Sr-90 6.14E+01 5.58E+01 1.72E+02 U MS 56 545135005 5/11/2021 Sr-89 1.11E+00 3.48E+01 8.43E+01 U MS 56 545135005 5/11/2021 Sr-90 2.50E+00 2.67E+01 8.72E+01 U MS 06 562727004 11/17/2021 Sr-89 -3.78E+00 5.87E+01 1.49E+02 U MS 06 562727004 11/17/2021 Sr-90 2.01E+01 3.27E+01 1.02E+02 U MS 56 562727005 11/17/2021 Sr-89 -2.77E+01 5.48E+01 1.42E+02 U MS 56 562727005 11/17/2021 Sr-90 -2.08E+00 3.11E+01 1.03E+02 U

-198-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

SE 02 545145001 5/11/2021 Ac-228 5.58E+02 1.51E+02 1.48E+02 SE 02 545145001 5/11/2021 Ag-108m 5.13E+00 8.43E+00 3.06E+01 U SE 02 545145001 5/11/2021 Ag-110m -1.29E+01 1.80E+01 5.84E+01 U SE 02 545145001 5/11/2021 Ba-140 -1.20E+01 7.76E+01 2.64E+02 U SE 02 545145001 5/11/2021 Be-7 -1.79E+02 9.23E+01 2.39E+02 U SE 02 545145001 5/11/2021 Bi-214 4.12E+02 6.63E+01 7.21E+01 SE 02 545145001 5/11/2021 Ce-141 -8.80E+00 1.53E+01 5.37E+01 U SE 02 545145001 5/11/2021 Ce-144 0.00E+00 9.56E+01 1.69E+02 U SE 02 545145001 5/11/2021 Co-57 -3.56E+00 6.31E+00 2.27E+01 U SE 02 545145001 5/11/2021 Co-58 1.83E+01 1.38E+01 4.98E+01 U SE 02 545145001 5/11/2021 Co-60 1.13E+00 1.21E+01 3.98E+01 U SE 02 545145001 5/11/2021 Cr-51 -1.92E+02 1.06E+02 3.18E+02 U SE 02 545145001 5/11/2021 Cs-134 4.73E+01 1.85E+01 6.08E+01 U SE 02 545145001 5/11/2021 Cs-137 3.19E+01 1.38E+01 4.64E+01 U SE 02 545145001 5/11/2021 Fe-59 1.20E+01 3.13E+01 1.08E+02 U SE 02 545145001 5/11/2021 I-131 -3.15E+01 2.95E+01 9.74E+01 U SE 02 545145001 5/11/2021 K-40 1.50E+04 1.01E+03 4.62E+02 SE 02 545145001 5/11/2021 La-140 8.90E+00 1.70E+01 6.18E+01 U SE 02 545145001 5/11/2021 Mn-54 2.09E+01 1.38E+01 4.54E+01 U SE 02 545145001 5/11/2021 Nb-95 2.02E+01 1.39E+01 5.00E+01 U SE 02 545145001 5/11/2021 Pb-212 6.06E+02 5.20E+01 5.91E+01 SE 02 545145001 5/11/2021 Pb-214 6.40E+02 6.61E+01 1.84E+02 SE 02 545145001 5/11/2021 Ra-226 4.12E+02 6.63E+01 7.21E+01 SE 02 545145001 5/11/2021 Ru-103 1.49E+01 1.28E+01 4.59E+01 U SE 02 545145001 5/11/2021 Ru-106 -4.42E+01 9.80E+01 3.17E+02 U SE 02 545145001 5/11/2021 Sb-124 2.14E+01 2.53E+01 9.29E+01 U SE 02 545145001 5/11/2021 Sb-125 4.59E+01 2.91E+01 1.05E+02 U SE 02 545145001 5/11/2021 Se-75 1.40E+01 1.22E+01 4.26E+01 U SE 02 545145001 5/11/2021 Th-228 6.06E+02 5.20E+01 5.91E+01 SE 02 545145001 5/11/2021 Th-230 4.12E+02 6.63E+01 7.21E+01 SE 02 545145001 5/11/2021 Tl-208 1.83E+02 2.73E+01 4.58E+01 SE 02 545145001 5/11/2021 Zn-65 1.53E+01 2.97E+01 9.19E+01 U SE 02 545145001 5/11/2021 Zr-95 3.38E+01 2.32E+01 8.44E+01 U SE 02 562731001 11/17/2021 Ac-228 1.51E+03 3.26E+02 3.50E+02 SE 02 562731001 11/17/2021 Ag-108m -4.66E+00 1.70E+01 5.97E+01 U SE 02 562731001 11/17/2021 Ag-110m -5.15E+01 3.19E+01 7.20E+01 U SE 02 562731001 11/17/2021 Ba-140 4.92E+01 1.42E+02 5.10E+02 U SE 02 562731001 11/17/2021 Be-7 3.53E+02 2.19E+02 8.07E+02 U SE 02 562731001 11/17/2021 Bi-214 1.15E+03 1.36E+02 1.43E+02 SE 02 562731001 11/17/2021 Ce-141 -1.86E+01 3.69E+01 1.30E+02 U SE 02 562731001 11/17/2021 Ce-144 -1.95E+02 1.22E+02 3.81E+02 U SE 02 562731001 11/17/2021 Co-57 1.05E+01 1.48E+01 5.52E+01 U SE 02 562731001 11/17/2021 Co-58 -1.71E+01 2.74E+01 8.42E+01 U SE 02 562731001 11/17/2021 Co-60 -5.92E-01 3.11E+01 1.07E+02 U SE 02 562731001 11/17/2021 Cr-51 0.00E+00 6.17E+02 7.24E+02 U SE 02 562731001 11/17/2021 Cs-134 4.18E+01 2.81E+01 1.02E+02 U SE 02 562731001 11/17/2021 Cs-137 6.39E+00 2.41E+01 8.42E+01 U SE 02 562731001 11/17/2021 Fe-59 -4.26E+01 6.75E+01 1.84E+02 U SE 02 562731001 11/17/2021 I-131 2.49E+01 6.26E+01 2.33E+02 U SE 02 562731001 11/17/2021 K-40 1.28E+04 1.21E+03 7.86E+02

-199-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

SE 02 562731001 11/17/2021 La-140 -2.28E+01 5.60E+01 1.71E+02 U SE 02 562731001 11/17/2021 Mn-54 2.50E+01 2.62E+01 8.98E+01 U SE 02 562731001 11/17/2021 Nb-95 1.85E+01 2.90E+01 1.02E+02 U SE 02 562731001 11/17/2021 Pb-212 1.38E+03 1.52E+02 1.61E+02 SE 02 562731001 11/17/2021 Pb-214 1.12E+03 1.47E+02 1.49E+02 SE 02 562731001 11/17/2021 Ra-226 1.15E+03 1.36E+02 1.43E+02 SE 02 562731001 11/17/2021 Ru-103 -2.29E+01 2.68E+01 8.70E+01 U SE 02 562731001 11/17/2021 Ru-106 -2.90E+02 2.04E+02 5.61E+02 U SE 02 562731001 11/17/2021 Sb-124 7.64E+01 5.17E+01 2.06E+02 U SE 02 562731001 11/17/2021 Sb-125 3.43E+01 5.57E+01 2.07E+02 U SE 02 562731001 11/17/2021 Se-75 4.91E+00 2.37E+01 8.22E+01 U SE 02 562731001 11/17/2021 Th-228 1.38E+03 1.52E+02 1.61E+02 SE 02 562731001 11/17/2021 Th-230 1.15E+03 1.36E+02 1.43E+02 SE 02 562731001 11/17/2021 Tl-208 3.82E+02 7.14E+01 9.46E+01 SE 02 562731001 11/17/2021 Zn-65 -1.63E+01 9.75E+01 2.06E+02 U SE 02 562731001 11/17/2021 Zr-95 -7.98E+01 5.08E+01 1.29E+02 U SE 07 545146001 5/13/2021 Ac-228 0.00E+00 1.49E+02 2.86E+02 U SE 07 545146001 5/13/2021 Ag-108m -7.54E+00 9.09E+00 2.46E+01 U SE 07 545146001 5/13/2021 Ag-110m 7.90E+00 1.95E+01 6.01E+01 U SE 07 545146001 5/13/2021 Ba-140 -1.56E+01 6.91E+01 2.36E+02 U SE 07 545146001 5/13/2021 Be-7 -2.46E+01 8.73E+01 3.07E+02 U SE 07 545146001 5/13/2021 Bi-214 0.00E+00 8.93E+01 1.42E+02 U SE 07 545146001 5/13/2021 Ce-141 1.15E+01 1.40E+01 5.05E+01 U SE 07 545146001 5/13/2021 Ce-144 7.89E+01 5.06E+01 1.81E+02 U SE 07 545146001 5/13/2021 Co-57 2.69E+00 5.95E+00 2.20E+01 U SE 07 545146001 5/13/2021 Co-58 -7.69E+00 1.14E+01 3.74E+01 U SE 07 545146001 5/13/2021 Co-60 -5.36E+00 1.50E+01 4.92E+01 U SE 07 545146001 5/13/2021 Cr-51 -7.62E+01 9.62E+01 3.21E+02 U SE 07 545146001 5/13/2021 Cs-134 2.88E+00 1.34E+01 4.74E+01 U SE 07 545146001 5/13/2021 Cs-137 1.36E+01 1.20E+01 4.10E+01 U SE 07 545146001 5/13/2021 Fe-59 -4.95E+00 3.88E+01 1.10E+02 U SE 07 545146001 5/13/2021 I-131 -2.17E+00 2.48E+01 8.52E+01 U SE 07 545146001 5/13/2021 K-40 2.09E+04 1.29E+03 2.73E+02 SE 07 545146001 5/13/2021 La-140 2.58E+01 2.49E+01 8.84E+01 U SE 07 545146001 5/13/2021 Mn-54 1.08E+01 1.11E+01 3.99E+01 U SE 07 545146001 5/13/2021 Nb-95 3.55E-01 1.34E+01 4.73E+01 U SE 07 545146001 5/13/2021 Pb-212 2.81E+02 4.39E+01 6.02E+01 SE 07 545146001 5/13/2021 Pb-214 2.12E+02 5.94E+01 6.84E+01 SE 07 545146001 5/13/2021 Ra-226 0.00E+00 8.93E+01 1.42E+02 U SE 07 545146001 5/13/2021 Ru-103 -7.04E+00 1.06E+01 3.56E+01 U SE 07 545146001 5/13/2021 Ru-106 9.04E+01 9.60E+01 3.40E+02 U SE 07 545146001 5/13/2021 Sb-124 -8.26E+00 2.69E+01 8.77E+01 U SE 07 545146001 5/13/2021 Sb-125 -6.39E+00 2.45E+01 8.13E+01 U SE 07 545146001 5/13/2021 Se-75 3.94E+00 1.22E+01 4.46E+01 U SE 07 545146001 5/13/2021 Th-228 2.81E+02 4.39E+01 6.02E+01 SE 07 545146001 5/13/2021 Th-230 0.00E+00 8.93E+01 1.42E+02 U SE 07 545146001 5/13/2021 Tl-208 9.26E+01 1.90E+01 3.39E+01 SE 07 545146001 5/13/2021 Zn-65 -2.39E+01 3.84E+01 1.22E+02 U SE 07 545146001 5/13/2021 Zr-95 2.35E+01 2.13E+01 7.71E+01 U

-200-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

SE 07 562730001 11/15/2021 Ac-228 0.00E+00 1.48E+02 2.97E+02 U SE 07 562730001 11/15/2021 Ag-108m 1.61E+01 9.82E+00 3.54E+01 U SE 07 562730001 11/15/2021 Ag-110m 5.24E-01 1.66E+01 5.72E+01 U SE 07 562730001 11/15/2021 Ba-140 1.61E+02 9.28E+01 3.28E+02 U SE 07 562730001 11/15/2021 Be-7 4.07E+01 1.12E+02 3.98E+02 U SE 07 562730001 11/15/2021 Bi-214 2.50E+02 5.62E+01 8.21E+01 SE 07 562730001 11/15/2021 Ce-141 -2.56E+01 2.18E+01 6.42E+01 U SE 07 562730001 11/15/2021 Ce-144 3.25E+01 7.03E+01 2.42E+02 U SE 07 562730001 11/15/2021 Co-57 -1.03E+01 9.37E+00 2.91E+01 U SE 07 562730001 11/15/2021 Co-58 -1.42E+00 1.29E+01 4.20E+01 U SE 07 562730001 11/15/2021 Co-60 -1.22E+01 1.61E+01 4.80E+01 U SE 07 562730001 11/15/2021 Cr-51 5.66E+00 1.19E+02 4.10E+02 U SE 07 562730001 11/15/2021 Cs-134 1.40E+01 1.62E+01 5.55E+01 U SE 07 562730001 11/15/2021 Cs-137 6.53E+00 1.29E+01 4.48E+01 U SE 07 562730001 11/15/2021 Fe-59 3.45E+01 4.18E+01 9.77E+01 U SE 07 562730001 11/15/2021 I-131 3.09E+01 3.97E+01 1.26E+02 U SE 07 562730001 11/15/2021 K-40 1.89E+04 1.23E+03 3.60E+02 SE 07 562730001 11/15/2021 La-140 -5.19E+00 2.70E+01 8.78E+01 U SE 07 562730001 11/15/2021 Mn-54 1.51E+01 1.37E+01 4.46E+01 U SE 07 562730001 11/15/2021 Nb-95 1.21E+01 1.22E+01 4.29E+01 U SE 07 562730001 11/15/2021 Pb-212 4.30E+02 4.84E+01 6.31E+01 SE 07 562730001 11/15/2021 Pb-214 2.00E+02 5.99E+01 1.49E+02 SE 07 562730001 11/15/2021 Ra-226 2.50E+02 5.62E+01 8.21E+01 SE 07 562730001 11/15/2021 Ru-103 -2.17E+01 1.16E+01 3.01E+01 U SE 07 562730001 11/15/2021 Ru-106 5.89E+01 1.07E+02 3.76E+02 U SE 07 562730001 11/15/2021 Sb-124 -4.05E+01 2.42E+01 4.58E+01 U SE 07 562730001 11/15/2021 Sb-125 2.15E+01 3.04E+01 1.04E+02 U SE 07 562730001 11/15/2021 Se-75 7.95E+00 1.43E+01 5.10E+01 U SE 07 562730001 11/15/2021 Th-228 4.30E+02 4.84E+01 6.31E+01 SE 07 562730001 11/15/2021 Th-230 2.50E+02 5.62E+01 8.21E+01 SE 07 562730001 11/15/2021 Tl-208 1.19E+02 2.87E+01 3.74E+01 SE 07 562730001 11/15/2021 Zn-65 1.07E+01 2.90E+01 8.79E+01 U SE 07 562730001 11/15/2021 Zr-95 3.92E+01 2.58E+01 8.98E+01 U SE 08 545146002 5/13/2021 Ac-228 3.21E+02 9.97E+01 1.12E+02 SE 08 545146002 5/13/2021 Ag-108m -8.40E+00 7.48E+00 2.18E+01 U SE 08 545146002 5/13/2021 Ag-110m 2.79E+01 1.50E+01 5.19E+01 U SE 08 545146002 5/13/2021 Ba-140 1.85E+01 4.60E+01 1.67E+02 U SE 08 545146002 5/13/2021 Be-7 -6.54E+00 6.94E+01 2.49E+02 U SE 08 545146002 5/13/2021 Bi-214 1.27E+02 4.42E+01 6.93E+01 SE 08 545146002 5/13/2021 Ce-141 -9.26E+00 1.38E+01 4.42E+01 U SE 08 545146002 5/13/2021 Ce-144 -8.67E+00 4.31E+01 1.55E+02 U SE 08 545146002 5/13/2021 Co-57 -4.00E+00 5.07E+00 1.77E+01 U SE 08 545146002 5/13/2021 Co-58 9.49E+00 9.77E+00 3.47E+01 U SE 08 545146002 5/13/2021 Co-60 -1.67E+01 1.18E+01 3.05E+01 U SE 08 545146002 5/13/2021 Cr-51 1.70E+01 8.07E+01 2.75E+02 U SE 08 545146002 5/13/2021 Cs-134 2.65E+01 2.25E+01 3.75E+01 U SE 08 545146002 5/13/2021 Cs-137 7.50E-01 1.05E+01 3.04E+01 U SE 08 545146002 5/13/2021 Fe-59 -5.56E+00 2.35E+01 7.64E+01 U SE 08 545146002 5/13/2021 I-131 -8.39E+00 2.01E+01 6.51E+01 U SE 08 545146002 5/13/2021 K-40 1.87E+04 1.04E+03 1.88E+02

-201-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

SE 08 545146002 5/13/2021 La-140 -3.07E+01 2.80E+01 5.62E+01 U SE 08 545146002 5/13/2021 Mn-54 -4.90E+00 8.78E+00 2.85E+01 U SE 08 545146002 5/13/2021 Nb-95 -9.45E+00 1.05E+01 3.12E+01 U SE 08 545146002 5/13/2021 Pb-212 3.27E+02 3.83E+01 4.63E+01 SE 08 545146002 5/13/2021 Pb-214 3.48E+02 5.35E+01 5.77E+01 SE 08 545146002 5/13/2021 Ra-226 1.27E+02 4.42E+01 6.93E+01 SE 08 545146002 5/13/2021 Ru-103 3.41E+00 9.02E+00 3.29E+01 U SE 08 545146002 5/13/2021 Ru-106 -2.49E+01 6.50E+01 2.21E+02 U SE 08 545146002 5/13/2021 Sb-124 -3.33E+00 1.56E+01 5.08E+01 U SE 08 545146002 5/13/2021 Sb-125 -7.40E+00 2.21E+01 7.08E+01 U SE 08 545146002 5/13/2021 Se-75 1.58E+01 1.08E+01 3.74E+01 U SE 08 545146002 5/13/2021 Th-228 3.27E+02 3.83E+01 4.63E+01 SE 08 545146002 5/13/2021 Th-230 1.27E+02 4.42E+01 6.93E+01 SE 08 545146002 5/13/2021 Tl-208 1.04E+02 2.29E+01 3.02E+01 SE 08 545146002 5/13/2021 Zn-65 4.73E+00 2.30E+01 7.35E+01 U SE 08 545146002 5/13/2021 Zr-95 -3.41E+00 1.62E+01 4.89E+01 U SE 08 562730002 11/15/2021 Ac-228 3.43E+02 1.34E+02 2.25E+02 SE 08 562730002 11/15/2021 Ag-108m 2.09E+01 1.31E+01 4.58E+01 U SE 08 562730002 11/15/2021 Ag-110m 4.65E+01 5.39E+01 7.14E+01 U SE 08 562730002 11/15/2021 Ba-140 -3.69E+01 9.92E+01 3.28E+02 U SE 08 562730002 11/15/2021 Be-7 -1.41E+02 1.45E+02 3.91E+02 U SE 08 562730002 11/15/2021 Bi-214 0.00E+00 6.39E+01 9.15E+01 U SE 08 562730002 11/15/2021 Ce-141 -7.02E+00 2.33E+01 8.53E+01 U SE 08 562730002 11/15/2021 Ce-144 -1.89E+00 7.53E+01 2.81E+02 U SE 08 562730002 11/15/2021 Co-57 -1.12E+01 9.90E+00 3.45E+01 U SE 08 562730002 11/15/2021 Co-58 -1.15E+01 1.53E+01 4.85E+01 U SE 08 562730002 11/15/2021 Co-60 -1.10E+01 1.85E+01 5.81E+01 U SE 08 562730002 11/15/2021 Cr-51 1.60E+02 1.47E+02 5.38E+02 U SE 08 562730002 11/15/2021 Cs-134 4.30E+01 1.99E+01 6.62E+01 U SE 08 562730002 11/15/2021 Cs-137 2.66E+01 2.88E+01 4.84E+01 U SE 08 562730002 11/15/2021 Fe-59 4.68E+01 4.48E+01 1.40E+02 U SE 08 562730002 11/15/2021 I-131 2.27E+01 4.62E+01 1.68E+02 U SE 08 562730002 11/15/2021 K-40 0.00E+00 1.40E+03 3.97E+02 U SE 08 562730002 11/15/2021 La-140 -1.06E+01 2.99E+01 9.64E+01 U SE 08 562730002 11/15/2021 Mn-54 1.35E+01 1.62E+01 5.64E+01 U SE 08 562730002 11/15/2021 Nb-95 3.08E+01 1.79E+01 6.18E+01 U SE 08 562730002 11/15/2021 Pb-212 4.90E+02 6.06E+01 8.34E+01 SE 08 562730002 11/15/2021 Pb-214 0.00E+00 6.88E+01 1.66E+02 U SE 08 562730002 11/15/2021 Ra-226 0.00E+00 6.39E+01 9.15E+01 U SE 08 562730002 11/15/2021 Ru-103 -4.33E+00 1.60E+01 5.41E+01 U SE 08 562730002 11/15/2021 Ru-106 5.85E+01 1.22E+02 4.37E+02 U SE 08 562730002 11/15/2021 Sb-124 -6.00E+00 3.18E+01 1.04E+02 U SE 08 562730002 11/15/2021 Sb-125 2.42E+01 3.38E+01 1.21E+02 U SE 08 562730002 11/15/2021 Se-75 5.40E+00 2.15E+01 6.70E+01 U SE 08 562730002 11/15/2021 Th-228 4.90E+02 6.06E+01 8.34E+01 SE 08 562730002 11/15/2021 Th-230 0.00E+00 6.39E+01 9.15E+01 U SE 08 562730002 11/15/2021 Tl-208 1.07E+02 3.08E+01 4.23E+01 SE 08 562730002 11/15/2021 Zn-65 2.13E+01 4.61E+01 1.43E+02 U SE 08 562730002 11/15/2021 Zr-95 1.59E+01 2.57E+01 9.10E+01 U

-202-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

SE 52 545145002 5/11/2021 Ac-228 9.38E+02 1.75E+02 2.34E+02 SE 52 545145002 5/11/2021 Ag-108m -2.16E+01 1.63E+01 4.99E+01 U SE 52 545145002 5/11/2021 Ag-110m 1.57E+00 3.07E+01 9.97E+01 U SE 52 545145002 5/11/2021 Ba-140 1.14E+02 1.37E+02 4.81E+02 U SE 52 545145002 5/11/2021 Be-7 1.14E+02 1.68E+02 5.71E+02 U SE 52 545145002 5/11/2021 Bi-214 7.72E+02 1.08E+02 1.37E+02 SE 52 545145002 5/11/2021 Ce-141 -7.89E+00 2.90E+01 9.94E+01 U SE 52 545145002 5/11/2021 Ce-144 -4.23E+01 9.05E+01 3.09E+02 U SE 52 545145002 5/11/2021 Co-57 -9.26E+00 1.15E+01 3.87E+01 U SE 52 545145002 5/11/2021 Co-58 9.37E+00 2.08E+01 7.01E+01 U SE 52 545145002 5/11/2021 Co-60 4.58E+01 2.57E+01 9.05E+01 U SE 52 545145002 5/11/2021 Cr-51 -6.46E+01 1.59E+02 5.56E+02 U SE 52 545145002 5/11/2021 Cs-134 0.00E+00 5.04E+01 1.03E+02 U SE 52 545145002 5/11/2021 Cs-137 1.45E+01 2.35E+01 8.07E+01 U SE 52 545145002 5/11/2021 Fe-59 1.68E+01 4.45E+01 1.55E+02 U SE 52 545145002 5/11/2021 I-131 -2.06E+01 4.53E+01 1.56E+02 U SE 52 545145002 5/11/2021 K-40 1.35E+04 9.74E+02 4.04E+02 SE 52 545145002 5/11/2021 La-140 8.16E+01 4.52E+01 1.49E+02 U SE 52 545145002 5/11/2021 Mn-54 -4.13E+01 2.28E+01 5.58E+01 U SE 52 545145002 5/11/2021 Nb-95 -1.31E+01 2.45E+01 7.70E+01 U SE 52 545145002 5/11/2021 Pb-212 1.24E+03 8.77E+01 9.98E+01 SE 52 545145002 5/11/2021 Pb-214 9.34E+02 1.04E+02 1.16E+02 SE 52 545145002 5/11/2021 Ra-226 7.72E+02 1.08E+02 1.37E+02 SE 52 545145002 5/11/2021 Ru-103 -1.83E+01 2.11E+01 6.73E+01 U SE 52 545145002 5/11/2021 Ru-106 -1.47E+02 1.81E+02 5.63E+02 U SE 52 545145002 5/11/2021 Sb-124 9.97E-01 4.19E+01 1.36E+02 U SE 52 545145002 5/11/2021 Sb-125 1.22E+01 4.64E+01 1.64E+02 U SE 52 545145002 5/11/2021 Se-75 1.48E+00 2.25E+01 7.43E+01 U SE 52 545145002 5/11/2021 Th-228 1.24E+03 8.77E+01 9.98E+01 SE 52 545145002 5/11/2021 Th-230 7.72E+02 1.08E+02 1.37E+02 SE 52 545145002 5/11/2021 Tl-208 2.83E+02 4.96E+01 6.17E+01 SE 52 545145002 5/11/2021 Zn-65 2.11E+00 4.56E+01 1.37E+02 U SE 52 545145002 5/11/2021 Zr-95 6.79E+01 4.54E+01 1.44E+02 U SE 52 562731002 11/17/2021 Ac-228 1.67E+03 1.85E+02 1.71E+02 SE 52 562731002 11/17/2021 Ag-108m -5.18E+00 1.11E+01 3.83E+01 U SE 52 562731002 11/17/2021 Ag-110m -1.62E+01 1.88E+01 5.52E+01 U SE 52 562731002 11/17/2021 Ba-140 8.75E+01 1.00E+02 3.65E+02 U SE 52 562731002 11/17/2021 Be-7 1.34E+02 1.33E+02 4.86E+02 U SE 52 562731002 11/17/2021 Bi-214 1.10E+03 1.26E+02 1.01E+02 SE 52 562731002 11/17/2021 Ce-141 -1.42E+01 2.73E+01 9.43E+01 U SE 52 562731002 11/17/2021 Ce-144 2.13E+01 8.31E+01 3.00E+02 U SE 52 562731002 11/17/2021 Co-57 8.67E+00 1.16E+01 4.22E+01 U SE 52 562731002 11/17/2021 Co-58 1.58E+01 1.36E+01 4.81E+01 U SE 52 562731002 11/17/2021 Co-60 1.28E+01 1.89E+01 6.15E+01 U SE 52 562731002 11/17/2021 Cr-51 -1.35E+02 1.44E+02 4.94E+02 U SE 52 562731002 11/17/2021 Cs-134 1.79E+01 1.87E+01 6.60E+01 U SE 52 562731002 11/17/2021 Cs-137 -2.11E+01 1.81E+01 5.48E+01 U SE 52 562731002 11/17/2021 Fe-59 1.44E+01 3.45E+01 1.12E+02 U SE 52 562731002 11/17/2021 I-131 -1.47E+00 4.25E+01 1.39E+02 U SE 52 562731002 11/17/2021 K-40 1.15E+04 8.92E+02 5.67E+02

-203-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

SE 52 562731002 11/17/2021 La-140 9.78E+00 3.90E+01 1.34E+02 U SE 52 562731002 11/17/2021 Mn-54 -1.32E+00 1.75E+01 5.82E+01 U SE 52 562731002 11/17/2021 Nb-95 -2.81E+01 2.33E+01 6.93E+01 U SE 52 562731002 11/17/2021 Pb-212 1.74E+03 1.09E+02 8.22E+01 SE 52 562731002 11/17/2021 Pb-214 1.29E+03 1.19E+02 3.12E+02 SE 52 562731002 11/17/2021 Ra-226 1.10E+03 1.26E+02 1.01E+02 SE 52 562731002 11/17/2021 Ru-103 -1.77E+01 1.62E+01 5.10E+01 U SE 52 562731002 11/17/2021 Ru-106 -3.03E+02 1.52E+02 3.82E+02 U SE 52 562731002 11/17/2021 Sb-124 3.10E+01 3.26E+01 1.21E+02 U SE 52 562731002 11/17/2021 Sb-125 -1.48E+01 3.78E+01 1.32E+02 U SE 52 562731002 11/17/2021 Se-75 1.24E+01 2.07E+01 6.62E+01 U SE 52 562731002 11/17/2021 Th-228 1.74E+03 1.09E+02 8.22E+01 SE 52 562731002 11/17/2021 Th-230 1.10E+03 1.26E+02 1.01E+02 SE 52 562731002 11/17/2021 Tl-208 5.38E+02 5.01E+01 4.75E+01 SE 52 562731002 11/17/2021 Zn-65 4.03E+01 3.46E+01 1.18E+02 U SE 52 562731002 11/17/2021 Zr-95 7.06E+01 3.43E+01 1.20E+02 U SE 57 545146003 5/11/2021 Ac-228 4.71E+02 1.25E+02 1.99E+02 SE 57 545146003 5/11/2021 Ag-108m -5.53E+00 1.20E+01 4.07E+01 U SE 57 545146003 5/11/2021 Ag-110m -7.15E+00 2.10E+01 6.61E+01 U SE 57 545146003 5/11/2021 Ba-140 -1.15E+02 8.82E+01 2.51E+02 U SE 57 545146003 5/11/2021 Be-7 1.71E+02 1.28E+02 4.71E+02 U SE 57 545146003 5/11/2021 Bi-214 2.81E+02 6.19E+01 9.38E+01 SE 57 545146003 5/11/2021 Ce-141 1.32E+00 4.55E+01 7.78E+01 U SE 57 545146003 5/11/2021 Ce-144 2.40E+01 8.54E+01 3.03E+02 U SE 57 545146003 5/11/2021 Co-57 -9.25E+00 1.06E+01 3.47E+01 U SE 57 545146003 5/11/2021 Co-58 2.32E+00 1.62E+01 5.61E+01 U SE 57 545146003 5/11/2021 Co-60 -2.84E+01 1.84E+01 4.51E+01 U SE 57 545146003 5/11/2021 Cr-51 -1.36E+02 1.36E+02 4.48E+02 U SE 57 545146003 5/11/2021 Cs-134 2.61E+01 1.81E+01 6.50E+01 U SE 57 545146003 5/11/2021 Cs-137 -9.89E+00 1.45E+01 4.51E+01 U SE 57 545146003 5/11/2021 Fe-59 4.06E+01 4.07E+01 1.49E+02 U SE 57 545146003 5/11/2021 I-131 3.26E+01 4.02E+01 1.49E+02 U SE 57 545146003 5/11/2021 K-40 2.38E+04 1.58E+03 4.05E+02 SE 57 545146003 5/11/2021 La-140 -1.13E+01 3.13E+01 9.69E+01 U SE 57 545146003 5/11/2021 Mn-54 -1.57E+01 1.67E+01 4.87E+01 U SE 57 545146003 5/11/2021 Nb-95 -2.26E+01 1.96E+01 5.62E+01 U SE 57 545146003 5/11/2021 Pb-212 4.31E+02 6.67E+01 7.70E+01 SE 57 545146003 5/11/2021 Pb-214 3.09E+02 7.05E+01 1.08E+02 SE 57 545146003 5/11/2021 Ra-226 2.81E+02 6.19E+01 9.38E+01 SE 57 545146003 5/11/2021 Ru-103 9.35E+00 1.53E+01 5.54E+01 U SE 57 545146003 5/11/2021 Ru-106 -1.15E+01 1.28E+02 4.34E+02 U SE 57 545146003 5/11/2021 Sb-124 3.64E+01 2.89E+01 1.16E+02 U SE 57 545146003 5/11/2021 Sb-125 6.71E+00 3.56E+01 1.27E+02 U SE 57 545146003 5/11/2021 Se-75 1.26E+01 1.86E+01 6.74E+01 U SE 57 545146003 5/11/2021 Th-228 4.31E+02 6.67E+01 7.70E+01 SE 57 545146003 5/11/2021 Th-230 2.81E+02 6.19E+01 9.38E+01 SE 57 545146003 5/11/2021 Tl-208 9.07E+01 3.69E+01 4.90E+01 SE 57 545146003 5/11/2021 Zn-65 -1.98E+01 4.97E+01 1.44E+02 U SE 57 545146003 5/11/2021 Zr-95 5.79E+01 4.05E+01 1.43E+02 U

-204-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

SE 57 562730003 11/15/2021 Ac-228 0.00E+00 1.45E+02 2.25E+02 U SE 57 562730003 11/15/2021 Ag-108m 1.50E+00 5.64E+00 2.03E+01 U SE 57 562730003 11/15/2021 Ag-110m -7.49E+00 1.27E+01 4.21E+01 U SE 57 562730003 11/15/2021 Ba-140 8.53E+01 5.84E+01 2.07E+02 U SE 57 562730003 11/15/2021 Be-7 4.60E+01 7.39E+01 2.54E+02 U SE 57 562730003 11/15/2021 Bi-214 2.68E+02 4.50E+01 4.47E+01 SE 57 562730003 11/15/2021 Ce-141 -1.22E+01 1.26E+01 3.65E+01 U SE 57 562730003 11/15/2021 Ce-144 0.00E+00 6.85E+01 1.20E+02 U SE 57 562730003 11/15/2021 Co-57 6.52E+00 4.58E+00 1.70E+01 U SE 57 562730003 11/15/2021 Co-58 -4.97E+00 8.88E+00 2.58E+01 U SE 57 562730003 11/15/2021 Co-60 -1.32E+01 1.22E+01 2.87E+01 U SE 57 562730003 11/15/2021 Cr-51 1.90E+01 7.61E+01 2.83E+02 U SE 57 562730003 11/15/2021 Cs-134 3.56E+01 2.08E+01 3.92E+01 U SE 57 562730003 11/15/2021 Cs-137 -8.96E+00 1.01E+01 3.14E+01 U SE 57 562730003 11/15/2021 Fe-59 7.79E-01 2.28E+01 7.69E+01 U SE 57 562730003 11/15/2021 I-131 5.32E-01 2.12E+01 7.73E+01 U SE 57 562730003 11/15/2021 K-40 1.23E+04 7.80E+02 3.46E+02 SE 57 562730003 11/15/2021 La-140 -5.82E+00 1.48E+01 4.67E+01 U SE 57 562730003 11/15/2021 Mn-54 -6.30E+00 8.01E+00 2.62E+01 U SE 57 562730003 11/15/2021 Nb-95 -1.50E+00 1.05E+01 3.23E+01 U SE 57 562730003 11/15/2021 Pb-212 3.30E+02 3.14E+01 3.90E+01 SE 57 562730003 11/15/2021 Pb-214 2.08E+02 4.69E+01 5.35E+01 SE 57 562730003 11/15/2021 Ra-226 2.68E+02 4.50E+01 4.47E+01 SE 57 562730003 11/15/2021 Ru-103 -1.14E+01 9.28E+00 2.90E+01 U SE 57 562730003 11/15/2021 Ru-106 5.60E+01 7.03E+01 2.46E+02 U SE 57 562730003 11/15/2021 Sb-124 -1.84E+01 2.11E+01 6.17E+01 U SE 57 562730003 11/15/2021 Sb-125 -1.62E+01 1.76E+01 5.82E+01 U SE 57 562730003 11/15/2021 Se-75 -2.42E+00 1.08E+01 3.29E+01 U SE 57 562730003 11/15/2021 Th-228 3.30E+02 3.14E+01 3.90E+01 SE 57 562730003 11/15/2021 Th-230 2.68E+02 4.50E+01 4.47E+01 SE 57 562730003 11/15/2021 Tl-208 9.89E+01 2.09E+01 2.41E+01 SE 57 562730003 11/15/2021 Zn-65 -4.45E+01 2.96E+01 6.99E+01 U SE 57 562730003 11/15/2021 Zr-95 1.10E+01 1.66E+01 6.03E+01 U

-205-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TF 02 547919004 6/16/2021 Ac-228 1.60E+01 1.46E+01 3.89E+01 U TF 02 547919004 6/16/2021 Ag-108m -7.09E-01 1.77E+00 5.82E+00 U TF 02 547919004 6/16/2021 Ag-110m 4.93E+00 2.92E+00 1.01E+01 U TF 02 547919004 6/16/2021 Ba-140 1.48E+00 1.01E+01 3.39E+01 U TF 02 547919004 6/16/2021 Be-7 2.25E+01 1.90E+01 6.54E+01 U TF 02 547919004 6/16/2021 Ce-141 4.45E+00 3.70E+00 1.21E+01 U TF 02 547919004 6/16/2021 Ce-144 2.58E+00 1.32E+01 4.34E+01 U TF 02 547919004 6/16/2021 Co-57 1.29E+00 1.62E+00 5.39E+00 U TF 02 547919004 6/16/2021 Co-58 1.02E-01 1.98E+00 6.46E+00 U TF 02 547919004 6/16/2021 Co-60 -1.95E+00 2.35E+00 7.06E+00 U TF 02 547919004 6/16/2021 Cr-51 2.87E+01 2.13E+01 6.78E+01 U TF 02 547919004 6/16/2021 Cs-134 4.31E+00 2.49E+00 8.51E+00 U TF 02 547919004 6/16/2021 Cs-137 2.34E+00 2.28E+00 7.83E+00 U TF 02 547919004 6/16/2021 Fe-59 2.28E+00 4.81E+00 1.59E+01 U TF 02 547919004 6/16/2021 I-131 -8.08E-01 2.97E+00 8.93E+00 U TF 02 547919004 6/16/2021 K-40 1.36E+03 1.20E+02 6.92E+01 TF 02 547919004 6/16/2021 La-140 -4.78E+00 3.49E+00 8.63E+00 U TF 02 547919004 6/16/2021 Mn-54 1.08E-04 1.98E+00 6.43E+00 U TF 02 547919004 6/16/2021 Nb-95 -6.38E-01 2.10E+00 6.66E+00 U TF 02 547919004 6/16/2021 Ru-103 8.13E-01 2.01E+00 6.88E+00 U TF 02 547919004 6/16/2021 Ru-106 2.54E+00 1.90E+01 6.36E+01 U TF 02 547919004 6/16/2021 Sb-124 -1.15E-01 5.06E+00 1.67E+01 U TF 02 547919004 6/16/2021 Sb-125 -1.88E+00 5.26E+00 1.74E+01 U TF 02 547919004 6/16/2021 Se-75 1.23E+00 2.79E+00 8.93E+00 U TF 02 547919004 6/16/2021 Th-228 1.32E+00 6.90E+00 1.16E+01 U TF 02 547919004 6/16/2021 Zn-65 -7.28E+00 6.45E+00 1.61E+01 U TF 02 547919004 6/16/2021 Zr-95 -6.37E+00 4.91E+00 1.14E+01 U TF 02 549905004 7/14/2021 Ac-228 -1.12E+01 1.32E+01 3.66E+01 U TF 02 549905004 7/14/2021 Ag-108m -4.31E-01 1.83E+00 5.98E+00 U TF 02 549905004 7/14/2021 Ag-110m 4.01E+00 3.12E+00 1.08E+01 U TF 02 549905004 7/14/2021 Ba-140 -1.45E-01 9.81E+00 3.22E+01 U TF 02 549905004 7/14/2021 Be-7 5.46E+01 4.92E+01 8.12E+01 U TF 02 549905004 7/14/2021 Ce-141 -5.26E-01 3.15E+00 1.02E+01 U TF 02 549905004 7/14/2021 Ce-144 -4.52E-01 1.19E+01 3.87E+01 U TF 02 549905004 7/14/2021 Co-57 -1.52E+00 1.84E+00 5.43E+00 U TF 02 549905004 7/14/2021 Co-58 -8.12E+00 3.72E+00 7.23E+00 U TF 02 549905004 7/14/2021 Co-60 7.27E-01 2.86E+00 9.67E+00 U TF 02 549905004 7/14/2021 Cr-51 3.02E+00 2.14E+01 6.67E+01 U TF 02 549905004 7/14/2021 Cs-134 5.67E+00 3.14E+00 1.09E+01 U TF 02 549905004 7/14/2021 Cs-137 6.03E+00 2.94E+00 1.01E+01 U TF 02 549905004 7/14/2021 Fe-59 -3.99E+00 5.71E+00 1.72E+01 U TF 02 549905004 7/14/2021 I-131 6.03E+00 4.07E+00 1.41E+01 U TF 02 549905004 7/14/2021 K-40 5.83E+02 9.22E+01 8.45E+01 TF 02 549905004 7/14/2021 La-140 -7.48E+00 4.60E+00 8.65E+00 U TF 02 549905004 7/14/2021 Mn-54 2.29E+00 2.74E+00 9.28E+00 U TF 02 549905004 7/14/2021 Nb-95 -5.70E-01 2.77E+00 8.65E+00 U TF 02 549905004 7/14/2021 Ru-103 -1.21E+00 2.54E+00 8.04E+00 U TF 02 549905004 7/14/2021 Ru-106 -2.60E+01 2.44E+01 6.87E+01 U TF 02 549905004 7/14/2021 Sb-124 -1.84E+00 8.37E+00 2.59E+01 U TF 02 549905004 7/14/2021 Sb-125 -1.44E+00 6.09E+00 2.00E+01 U

-206-

Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TF 02 549905004 7/14/2021 Se-75 -3.61E+00 3.00E+00 8.06E+00 U TF 02 549905004 7/14/2021 Th-228 -2.43E+00 4.78E+00 1.48E+01 U TF 02 549905004 7/14/2021 Zn-65 6.06E+00 6.17E+00 2.04E+01 U TF 02 549905004 7/14/2021 Zr-95 3.77E+00 4.99E+00 1.62E+01 U TF 02 552744004 8/10/2021 Ac-228 -8.85E+00 1.46E+01 5.11E+01 U TF 02 552744004 8/10/2021 Ag-108m 4.82E+00 2.82E+00 9.86E+00 U TF 02 552744004 8/10/2021 Ag-110m -2.16E+00 3.52E+00 1.05E+01 U TF 02 552744004 8/10/2021 Ba-140 -3.21E+00 1.17E+01 3.65E+01 U TF 02 552744004 8/10/2021 Be-7 0.00E+00 4.54E+01 6.74E+01 U TF 02 552744004 8/10/2021 Ce-141 -1.60E+00 4.27E+00 1.33E+01 U TF 02 552744004 8/10/2021 Ce-144 1.32E-01 1.74E+01 5.60E+01 U TF 02 552744004 8/10/2021 Co-57 3.38E-01 2.15E+00 7.03E+00 U TF 02 552744004 8/10/2021 Co-58 -4.52E+00 3.10E+00 7.78E+00 U TF 02 552744004 8/10/2021 Co-60 1.11E+00 2.56E+00 8.98E+00 U TF 02 552744004 8/10/2021 Cr-51 -6.27E+00 2.39E+01 7.88E+01 U TF 02 552744004 8/10/2021 Cs-134 2.33E+00 3.41E+00 1.18E+01 U TF 02 552744004 8/10/2021 Cs-137 1.49E+00 2.66E+00 9.07E+00 U TF 02 552744004 8/10/2021 Fe-59 9.15E-01 7.34E+00 2.44E+01 U TF 02 552744004 8/10/2021 I-131 2.24E-01 4.15E+00 1.25E+01 U TF 02 552744004 8/10/2021 K-40 6.60E+02 1.05E+02 1.52E+02 TF 02 552744004 8/10/2021 La-140 -1.01E+01 5.89E+00 1.16E+01 U TF 02 552744004 8/10/2021 Mn-54 -3.20E+00 2.78E+00 7.50E+00 U TF 02 552744004 8/10/2021 Nb-95 3.96E-01 2.53E+00 8.72E+00 U TF 02 552744004 8/10/2021 Ru-103 1.84E+00 2.89E+00 9.94E+00 U TF 02 552744004 8/10/2021 Ru-106 -7.13E+00 2.42E+01 7.41E+01 U TF 02 552744004 8/10/2021 Sb-124 2.36E-01 5.65E+00 1.90E+01 U TF 02 552744004 8/10/2021 Sb-125 -1.24E+00 7.62E+00 2.37E+01 U TF 02 552744004 8/10/2021 Se-75 -1.56E+00 3.33E+00 1.09E+01 U TF 02 552744004 8/10/2021 Th-228 -8.93E+00 6.51E+00 1.99E+01 U TF 02 552744004 8/10/2021 Zn-65 -1.17E-01 6.54E+00 2.14E+01 U TF 02 552744004 8/10/2021 Zr-95 -8.27E+00 5.77E+00 1.51E+01 U TF 03 547919005 6/16/2021 Ac-228 2.86E+01 1.77E+01 4.25E+01 U TF 03 547919005 6/16/2021 Ag-108m -2.56E+00 1.78E+00 4.90E+00 U TF 03 547919005 6/16/2021 Ag-110m -2.42E+00 3.74E+00 1.10E+01 U TF 03 547919005 6/16/2021 Ba-140 -5.76E+00 9.41E+00 2.89E+01 U TF 03 547919005 6/16/2021 Be-7 4.73E+01 2.37E+01 7.90E+01 U TF 03 547919005 6/16/2021 Ce-141 -1.43E-02 2.96E+00 9.50E+00 U TF 03 547919005 6/16/2021 Ce-144 9.22E+00 1.11E+01 3.69E+01 U TF 03 547919005 6/16/2021 Co-57 1.45E+00 1.59E+00 5.26E+00 U TF 03 547919005 6/16/2021 Co-58 1.93E-01 1.94E+00 6.30E+00 U TF 03 547919005 6/16/2021 Co-60 1.79E+00 2.90E+00 1.02E+01 U TF 03 547919005 6/16/2021 Cr-51 -1.24E+01 1.82E+01 5.86E+01 U TF 03 547919005 6/16/2021 Cs-134 -5.25E-01 2.57E+00 8.08E+00 U TF 03 547919005 6/16/2021 Cs-137 -1.46E+00 2.15E+00 6.03E+00 U TF 03 547919005 6/16/2021 Fe-59 -1.36E+01 6.46E+00 1.44E+01 U TF 03 547919005 6/16/2021 I-131 2.08E-01 3.16E+00 1.07E+01 U TF 03 547919005 6/16/2021 K-40 1.60E+03 1.32E+02 7.37E+01 TF 03 547919005 6/16/2021 La-140 3.54E+00 3.57E+00 1.32E+01 U TF 03 547919005 6/16/2021 Mn-54 5.33E+00 3.89E+00 6.34E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TF 03 547919005 6/16/2021 Nb-95 -1.08E+00 2.12E+00 6.40E+00 U TF 03 547919005 6/16/2021 Ru-103 -3.75E+00 2.19E+00 5.56E+00 U TF 03 547919005 6/16/2021 Ru-106 -8.84E+00 1.80E+01 5.56E+01 U TF 03 547919005 6/16/2021 Sb-124 -1.12E+00 4.18E+00 1.28E+01 U TF 03 547919005 6/16/2021 Sb-125 -7.43E+00 6.68E+00 1.73E+01 U TF 03 547919005 6/16/2021 Se-75 -3.83E-01 2.32E+00 7.90E+00 U TF 03 547919005 6/16/2021 Th-228 6.85E+00 1.19E+01 2.04E+01 U TF 03 547919005 6/16/2021 Zn-65 -1.52E+00 5.13E+00 1.67E+01 U TF 03 547919005 6/16/2021 Zr-95 2.91E+00 4.49E+00 1.52E+01 U TF 03 549905005 7/14/2021 Ac-228 2.17E+01 1.30E+01 4.53E+01 U TF 03 549905005 7/14/2021 Ag-108m -3.57E+00 2.29E+00 5.99E+00 U TF 03 549905005 7/14/2021 Ag-110m -3.97E+00 3.82E+00 1.13E+01 U TF 03 549905005 7/14/2021 Ba-140 2.46E+01 1.32E+01 4.44E+01 U TF 03 549905005 7/14/2021 Be-7 5.18E+01 2.97E+01 7.55E+01 U TF 03 549905005 7/14/2021 Ce-141 -1.26E+01 6.09E+00 1.29E+01 U TF 03 549905005 7/14/2021 Ce-144 6.37E+00 1.51E+01 5.16E+01 U TF 03 549905005 7/14/2021 Co-57 6.99E-02 1.85E+00 6.27E+00 U TF 03 549905005 7/14/2021 Co-58 -1.73E+00 2.48E+00 7.71E+00 U TF 03 549905005 7/14/2021 Co-60 2.11E+00 3.49E+00 1.09E+01 U TF 03 549905005 7/14/2021 Cr-51 3.69E+00 2.31E+01 7.65E+01 U TF 03 549905005 7/14/2021 Cs-134 9.39E+00 6.94E+00 1.28E+01 U TF 03 549905005 7/14/2021 Cs-137 4.16E+00 3.28E+00 1.10E+01 U TF 03 549905005 7/14/2021 Fe-59 -6.15E+00 7.62E+00 1.96E+01 U TF 03 549905005 7/14/2021 I-131 8.10E+00 5.97E+00 1.22E+01 U TF 03 549905005 7/14/2021 K-40 2.42E+03 1.89E+02 1.12E+02 TF 03 549905005 7/14/2021 La-140 2.43E+00 4.95E+00 1.70E+01 U TF 03 549905005 7/14/2021 Mn-54 -1.71E-01 2.82E+00 9.47E+00 U TF 03 549905005 7/14/2021 Nb-95 5.85E+00 6.58E+00 8.36E+00 U TF 03 549905005 7/14/2021 Ru-103 -9.84E-01 3.27E+00 9.26E+00 U TF 03 549905005 7/14/2021 Ru-106 -1.80E-02 2.50E+01 7.98E+01 U TF 03 549905005 7/14/2021 Sb-124 2.51E+00 7.26E+00 2.45E+01 U TF 03 549905005 7/14/2021 Sb-125 7.31E+00 7.06E+00 2.38E+01 U TF 03 549905005 7/14/2021 Se-75 5.25E-01 2.98E+00 9.94E+00 U TF 03 549905005 7/14/2021 Th-228 2.87E-01 9.07E+00 1.76E+01 U TF 03 549905005 7/14/2021 Zn-65 -3.83E+00 6.38E+00 1.98E+01 U TF 03 549905005 7/14/2021 Zr-95 2.24E+00 4.89E+00 1.60E+01 U TF 03 552744005 8/10/2021 Ac-228 -1.64E+01 1.58E+01 4.49E+01 U TF 03 552744005 8/10/2021 Ag-108m -3.74E-01 2.42E+00 7.84E+00 U TF 03 552744005 8/10/2021 Ag-110m -2.54E+00 5.18E+00 1.44E+01 U TF 03 552744005 8/10/2021 Ba-140 2.64E+01 1.52E+01 5.18E+01 U TF 03 552744005 8/10/2021 Be-7 -4.51E+01 2.71E+01 7.01E+01 U TF 03 552744005 8/10/2021 Ce-141 -2.52E+00 3.78E+00 1.02E+01 U TF 03 552744005 8/10/2021 Ce-144 2.15E+01 1.32E+01 4.22E+01 U TF 03 552744005 8/10/2021 Co-57 2.79E-01 1.69E+00 5.36E+00 U TF 03 552744005 8/10/2021 Co-58 5.21E-01 3.07E+00 1.05E+01 U TF 03 552744005 8/10/2021 Co-60 -7.66E-01 3.73E+00 1.19E+01 U TF 03 552744005 8/10/2021 Cr-51 -2.74E+00 2.37E+01 7.85E+01 U TF 03 552744005 8/10/2021 Cs-134 -1.39E-01 3.23E+00 1.09E+01 U TF 03 552744005 8/10/2021 Cs-137 8.54E-01 3.00E+00 9.83E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TF 03 552744005 8/10/2021 Fe-59 4.38E+00 7.46E+00 2.59E+01 U TF 03 552744005 8/10/2021 I-131 5.96E+00 4.34E+00 1.49E+01 U TF 03 552744005 8/10/2021 K-40 1.70E+03 1.55E+02 8.54E+01 TF 03 552744005 8/10/2021 La-140 1.62E+00 6.96E+00 2.31E+01 U TF 03 552744005 8/10/2021 Mn-54 -4.11E+00 3.45E+00 1.01E+01 U TF 03 552744005 8/10/2021 Nb-95 -1.13E+00 3.18E+00 1.05E+01 U TF 03 552744005 8/10/2021 Ru-103 6.71E-01 2.88E+00 9.53E+00 U TF 03 552744005 8/10/2021 Ru-106 5.56E+01 3.19E+01 1.07E+02 U TF 03 552744005 8/10/2021 Sb-124 -8.20E+00 8.06E+00 2.02E+01 U TF 03 552744005 8/10/2021 Sb-125 -1.26E+00 7.10E+00 2.30E+01 U TF 03 552744005 8/10/2021 Se-75 1.49E+00 3.09E+00 1.06E+01 U TF 03 552744005 8/10/2021 Th-228 2.45E+00 6.37E+00 1.70E+01 U TF 03 552744005 8/10/2021 Zn-65 5.10E+00 8.16E+00 2.83E+01 U TF 03 552744005 8/10/2021 Zr-95 -3.72E+00 6.11E+00 1.80E+01 U TF 06 547919006 6/16/2021 Ac-228 -1.19E+01 1.75E+01 5.99E+01 U TF 06 547919006 6/16/2021 Ag-108m -6.62E-01 2.94E+00 9.28E+00 U TF 06 547919006 6/16/2021 Ag-110m 3.73E+00 5.22E+00 1.87E+01 U TF 06 547919006 6/16/2021 Ba-140 -1.48E+01 1.69E+01 4.69E+01 U TF 06 547919006 6/16/2021 Be-7 8.97E+01 3.92E+01 1.32E+02 U TF 06 547919006 6/16/2021 Ce-141 -4.58E+00 5.83E+00 1.62E+01 U TF 06 547919006 6/16/2021 Ce-144 -4.21E+01 2.16E+01 5.55E+01 U TF 06 547919006 6/16/2021 Co-57 4.30E-02 2.42E+00 8.20E+00 U TF 06 547919006 6/16/2021 Co-58 3.40E+00 2.89E+00 1.10E+01 U TF 06 547919006 6/16/2021 Co-60 1.36E+00 1.39E+00 6.32E+00 U TF 06 547919006 6/16/2021 Cr-51 -1.97E+01 3.32E+01 1.03E+02 U TF 06 547919006 6/16/2021 Cs-134 7.94E+00 4.29E+00 1.59E+01 U TF 06 547919006 6/16/2021 Cs-137 -3.77E+00 3.76E+00 9.83E+00 U TF 06 547919006 6/16/2021 Fe-59 3.21E+00 8.13E+00 2.83E+01 U TF 06 547919006 6/16/2021 I-131 -4.88E+00 6.06E+00 1.79E+01 U TF 06 547919006 6/16/2021 K-40 2.04E+03 2.07E+02 9.15E+01 TF 06 547919006 6/16/2021 La-140 3.05E+00 4.53E+00 1.71E+01 U TF 06 547919006 6/16/2021 Mn-54 5.12E-01 3.65E+00 1.25E+01 U TF 06 547919006 6/16/2021 Nb-95 3.49E+00 4.21E+00 1.39E+01 U TF 06 547919006 6/16/2021 Ru-103 1.88E+00 2.97E+00 1.03E+01 U TF 06 547919006 6/16/2021 Ru-106 -1.76E+01 3.35E+01 9.89E+01 U TF 06 547919006 6/16/2021 Sb-124 6.08E+00 9.21E+00 3.34E+01 U TF 06 547919006 6/16/2021 Sb-125 1.02E+01 9.22E+00 3.22E+01 U TF 06 547919006 6/16/2021 Se-75 -2.26E+00 4.69E+00 1.49E+01 U TF 06 547919006 6/16/2021 Th-228 -1.74E+00 6.41E+00 1.97E+01 U TF 06 547919006 6/16/2021 Zn-65 -1.36E+01 1.04E+01 2.02E+01 U TF 06 547919006 6/16/2021 Zr-95 -3.32E+00 5.14E+00 1.55E+01 U TF 06 552744006 8/10/2021 Ac-228 -1.18E+01 1.85E+01 6.02E+01 U TF 06 552744006 8/10/2021 Ag-108m -2.38E+00 2.85E+00 8.86E+00 U TF 06 552744006 8/10/2021 Ag-110m 6.25E-01 4.11E+00 1.35E+01 U TF 06 552744006 8/10/2021 Ba-140 2.27E+01 1.58E+01 5.68E+01 U TF 06 552744006 8/10/2021 Be-7 -2.47E+00 2.66E+01 8.93E+01 U TF 06 552744006 8/10/2021 Ce-141 -2.32E+00 4.99E+00 1.60E+01 U TF 06 552744006 8/10/2021 Ce-144 -3.75E+00 1.75E+01 5.74E+01 U TF 06 552744006 8/10/2021 Co-57 2.35E+00 2.22E+00 7.57E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TF 06 552744006 8/10/2021 Co-58 -1.15E+00 4.17E+00 1.31E+01 U TF 06 552744006 8/10/2021 Co-60 6.45E-01 3.92E+00 1.34E+01 U TF 06 552744006 8/10/2021 Cr-51 3.22E+01 2.80E+01 9.32E+01 U TF 06 552744006 8/10/2021 Cs-134 2.70E+00 3.66E+00 1.28E+01 U TF 06 552744006 8/10/2021 Cs-137 1.51E+00 2.64E+00 9.30E+00 U TF 06 552744006 8/10/2021 Fe-59 5.47E+00 7.45E+00 2.50E+01 U TF 06 552744006 8/10/2021 I-131 2.14E+00 5.53E+00 1.77E+01 U TF 06 552744006 8/10/2021 K-40 7.32E+02 1.10E+02 1.18E+02 TF 06 552744006 8/10/2021 La-140 -9.00E+00 5.68E+00 9.39E+00 U TF 06 552744006 8/10/2021 Mn-54 -6.22E+00 3.70E+00 5.36E+00 U TF 06 552744006 8/10/2021 Nb-95 5.10E-01 4.05E+00 1.34E+01 U TF 06 552744006 8/10/2021 Ru-103 5.18E+00 4.42E+00 8.99E+00 U TF 06 552744006 8/10/2021 Ru-106 2.87E+00 1.97E+01 6.67E+01 U TF 06 552744006 8/10/2021 Sb-124 6.80E+00 7.14E+00 2.79E+01 U TF 06 552744006 8/10/2021 Sb-125 -9.05E+00 8.27E+00 2.47E+01 U TF 06 552744006 8/10/2021 Se-75 7.63E-02 3.84E+00 1.23E+01 U TF 06 552744006 8/10/2021 Th-228 2.45E+00 7.72E+00 1.95E+01 U TF 06 552744006 8/10/2021 Zn-65 -4.26E+00 7.78E+00 2.43E+01 U TF 06 552744006 8/10/2021 Zr-95 -3.38E+00 5.92E+00 1.77E+01 U TF 06 549905006 7/14/2021 Ac-228 0.00E+00 2.60E+01 4.19E+01 U TF 06 549905006 7/14/2021 Ag-108m 3.71E+00 2.45E+00 8.08E+00 U TF 06 549905006 7/14/2021 Ag-110m 8.34E+00 4.87E+00 1.67E+01 U TF 06 549905006 7/14/2021 Ba-140 3.80E+00 1.30E+01 4.39E+01 U TF 06 549905006 7/14/2021 Be-7 1.95E+02 3.96E+01 5.93E+01 TF 06 549905006 7/14/2021 Ce-141 -2.59E+00 3.40E+00 1.03E+01 U TF 06 549905006 7/14/2021 Ce-144 -1.11E+00 1.25E+01 4.03E+01 U TF 06 549905006 7/14/2021 Co-57 1.53E+00 2.31E+00 5.27E+00 U TF 06 549905006 7/14/2021 Co-58 0.00E+00 2.73E+00 7.87E+00 U TF 06 549905006 7/14/2021 Co-60 4.12E+00 4.22E+00 1.47E+01 U TF 06 549905006 7/14/2021 Cr-51 -1.93E+01 2.25E+01 6.83E+01 U TF 06 549905006 7/14/2021 Cs-134 4.82E+00 3.18E+00 1.04E+01 U TF 06 549905006 7/14/2021 Cs-137 -3.63E-01 2.95E+00 9.48E+00 U TF 06 549905006 7/14/2021 Fe-59 5.75E+00 6.70E+00 2.30E+01 U TF 06 549905006 7/14/2021 I-131 1.62E+00 4.01E+00 1.33E+01 U TF 06 549905006 7/14/2021 K-40 3.04E+03 2.18E+02 7.75E+01 TF 06 549905006 7/14/2021 La-140 4.99E+00 3.73E+00 1.41E+01 U TF 06 549905006 7/14/2021 Mn-54 -4.50E+00 3.00E+00 8.13E+00 U TF 06 549905006 7/14/2021 Nb-95 -1.14E+00 2.80E+00 9.11E+00 U TF 06 549905006 7/14/2021 Ru-103 4.95E-01 2.55E+00 7.69E+00 U TF 06 549905006 7/14/2021 Ru-106 -1.26E+01 2.54E+01 7.94E+01 U TF 06 549905006 7/14/2021 Sb-124 -1.31E+00 5.62E+00 1.81E+01 U TF 06 549905006 7/14/2021 Sb-125 5.47E+00 6.92E+00 2.28E+01 U TF 06 549905006 7/14/2021 Se-75 3.80E+00 3.23E+00 1.01E+01 U TF 06 549905006 7/14/2021 Th-228 7.34E+00 8.28E+00 1.61E+01 U TF 06 549905006 7/14/2021 Zn-65 -3.54E+00 7.30E+00 2.24E+01 U TF 06 549905006 7/14/2021 Zr-95 1.91E+00 4.67E+00 1.62E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TG 08 545422001 5/19/2021 Ac-228 6.25E+00 1.73E+01 5.44E+01 U TG 08 545422001 5/19/2021 Ag-108m -3.66E+00 2.73E+00 8.07E+00 U TG 08 545422001 5/19/2021 Ag-110m 2.40E+00 4.74E+00 1.64E+01 U TG 08 545422001 5/19/2021 Ba-140 1.09E+01 1.87E+01 5.77E+01 U TG 08 545422001 5/19/2021 Be-7 3.56E+02 6.95E+01 8.71E+01 TG 08 545422001 5/19/2021 Ce-141 -2.92E+00 6.58E+00 1.59E+01 U TG 08 545422001 5/19/2021 Ce-144 4.00E+01 1.88E+01 5.74E+01 U TG 08 545422001 5/19/2021 Co-57 -1.02E+00 2.16E+00 6.90E+00 U TG 08 545422001 5/19/2021 Co-58 -1.24E+00 3.72E+00 1.15E+01 U TG 08 545422001 5/19/2021 Co-60 -4.94E+00 4.80E+00 1.21E+01 U TG 08 545422001 5/19/2021 Cr-51 -4.38E+01 3.47E+01 8.34E+01 U TG 08 545422001 5/19/2021 Cs-134 -1.91E+00 5.49E+00 1.38E+01 U TG 08 545422001 5/19/2021 Cs-137 -2.64E+00 4.65E+00 1.29E+01 U TG 08 545422001 5/19/2021 Fe-59 -7.04E+00 1.08E+01 2.63E+01 U TG 08 545422001 5/19/2021 I-131 2.32E+00 5.27E+00 1.80E+01 U TG 08 545422001 5/19/2021 K-40 5.03E+03 3.05E+02 9.96E+01 TG 08 545422001 5/19/2021 La-140 -2.29E+00 4.81E+00 1.45E+01 U TG 08 545422001 5/19/2021 Mn-54 2.39E+00 3.39E+00 1.11E+01 U TG 08 545422001 5/19/2021 Nb-95 3.33E+00 3.56E+00 1.18E+01 U TG 08 545422001 5/19/2021 Ru-103 1.08E+00 3.08E+00 1.03E+01 U TG 08 545422001 5/19/2021 Ru-106 -3.87E+01 3.07E+01 8.78E+01 U TG 08 545422001 5/19/2021 Sb-124 3.94E+00 5.64E+00 1.98E+01 U TG 08 545422001 5/19/2021 Sb-125 -1.81E+00 7.71E+00 2.55E+01 U TG 08 545422001 5/19/2021 Se-75 7.51E-01 3.85E+00 1.21E+01 U TG 08 545422001 5/19/2021 Th-228 6.14E+00 9.49E+00 2.17E+01 U TG 08 545422001 5/19/2021 Zn-65 8.31E+00 8.40E+00 2.89E+01 U TG 08 545422001 5/19/2021 Zr-95 4.09E+00 6.65E+00 2.19E+01 U TG 08 547919001 6/16/2021 Ac-228 -3.39E+00 3.17E+01 1.04E+02 U TG 08 547919001 6/16/2021 Ag-108m -1.79E+00 4.64E+00 1.34E+01 U TG 08 547919001 6/16/2021 Ag-110m -6.51E+00 7.54E+00 2.35E+01 U TG 08 547919001 6/16/2021 Ba-140 3.38E+00 2.50E+01 8.28E+01 U TG 08 547919001 6/16/2021 Be-7 3.35E+02 1.02E+02 1.49E+02 TG 08 547919001 6/16/2021 Ce-141 -6.47E+00 8.07E+00 2.48E+01 U TG 08 547919001 6/16/2021 Ce-144 3.16E+01 2.80E+01 9.20E+01 U TG 08 547919001 6/16/2021 Co-57 7.10E+00 3.77E+00 1.20E+01 U TG 08 547919001 6/16/2021 Co-58 1.02E+01 6.03E+00 2.01E+01 U TG 08 547919001 6/16/2021 Co-60 -2.40E+00 5.74E+00 1.79E+01 U TG 08 547919001 6/16/2021 Cr-51 -2.57E+01 4.45E+01 1.47E+02 U TG 08 547919001 6/16/2021 Cs-134 2.05E+00 5.76E+00 1.88E+01 U TG 08 547919001 6/16/2021 Cs-137 0.00E+00 1.22E+01 1.34E+01 U TG 08 547919001 6/16/2021 Fe-59 -3.11E+00 1.27E+01 4.15E+01 U TG 08 547919001 6/16/2021 I-131 -4.39E+00 9.49E+00 3.13E+01 U TG 08 547919001 6/16/2021 K-40 4.20E+03 3.24E+02 1.92E+02 TG 08 547919001 6/16/2021 La-140 -4.26E+00 8.77E+00 2.63E+01 U TG 08 547919001 6/16/2021 Mn-54 6.46E-02 5.08E+00 1.62E+01 U TG 08 547919001 6/16/2021 Nb-95 -3.53E+00 5.54E+00 1.66E+01 U TG 08 547919001 6/16/2021 Ru-103 1.83E+00 5.37E+00 1.81E+01 U TG 08 547919001 6/16/2021 Ru-106 -1.05E+01 4.94E+01 1.58E+02 U TG 08 547919001 6/16/2021 Sb-124 -3.46E+00 1.40E+01 4.33E+01 U TG 08 547919001 6/16/2021 Sb-125 4.79E+00 1.40E+01 4.75E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TG 08 547919001 6/16/2021 Se-75 4.84E+00 6.49E+00 2.07E+01 U TG 08 547919001 6/16/2021 Th-228 3.63E+01 2.01E+01 3.76E+01 U TG 08 547919001 6/16/2021 Zn-65 -9.19E+00 1.62E+01 4.45E+01 U TG 08 547919001 6/16/2021 Zr-95 5.47E+00 9.16E+00 3.05E+01 U TG 08 549905001 7/14/2021 Ac-228 8.17E+01 5.11E+01 1.37E+02 U TG 08 549905001 7/14/2021 Ag-108m 1.80E+00 4.66E+00 1.63E+01 U TG 08 549905001 7/14/2021 Ag-110m -7.87E+00 9.38E+00 2.72E+01 U TG 08 549905001 7/14/2021 Ba-140 2.92E+01 2.73E+01 9.02E+01 U TG 08 549905001 7/14/2021 Be-7 2.24E+03 1.94E+02 1.50E+02 TG 08 549905001 7/14/2021 Ce-141 -7.40E+00 7.94E+00 2.41E+01 U TG 08 549905001 7/14/2021 Ce-144 -1.24E+01 3.09E+01 9.13E+01 U TG 08 549905001 7/14/2021 Co-57 5.98E+00 4.43E+00 1.49E+01 U TG 08 549905001 7/14/2021 Co-58 5.51E+00 6.31E+00 2.20E+01 U TG 08 549905001 7/14/2021 Co-60 8.13E+00 5.92E+00 2.26E+01 U TG 08 549905001 7/14/2021 Cr-51 1.04E+02 6.07E+01 1.97E+02 U TG 08 549905001 7/14/2021 Cs-134 -8.54E+00 7.14E+00 1.95E+01 U TG 08 549905001 7/14/2021 Cs-137 7.07E+00 6.12E+00 2.16E+01 U TG 08 549905001 7/14/2021 Fe-59 -6.31E+00 1.15E+01 3.32E+01 U TG 08 549905001 7/14/2021 I-131 -1.78E+01 1.07E+01 2.60E+01 U TG 08 549905001 7/14/2021 K-40 2.17E+03 2.46E+02 2.31E+02 TG 08 549905001 7/14/2021 La-140 -3.21E+00 9.79E+00 3.09E+01 U TG 08 549905001 7/14/2021 Mn-54 -1.12E-01 6.25E+00 2.04E+01 U TG 08 549905001 7/14/2021 Nb-95 -3.88E+00 6.63E+00 1.92E+01 U TG 08 549905001 7/14/2021 Ru-103 -1.27E+00 5.46E+00 1.81E+01 U TG 08 549905001 7/14/2021 Ru-106 1.21E+02 9.12E+01 1.27E+02 U TG 08 549905001 7/14/2021 Sb-124 1.63E+01 1.52E+01 5.68E+01 U TG 08 549905001 7/14/2021 Sb-125 -1.78E+01 1.71E+01 4.77E+01 U TG 08 549905001 7/14/2021 Se-75 2.74E+00 6.72E+00 2.19E+01 U TG 08 549905001 7/14/2021 Th-228 1.86E+01 1.57E+01 2.98E+01 U TG 08 549905001 7/14/2021 Zn-65 1.08E+01 1.25E+01 4.37E+01 U TG 08 549905001 7/14/2021 Zr-95 -1.17E+00 9.11E+00 2.62E+01 U TG 08 552744001 8/10/2021 Ac-228 -9.70E+00 3.68E+01 1.31E+02 U TG 08 552744001 8/10/2021 Ag-108m 1.50E+00 6.05E+00 1.95E+01 U TG 08 552744001 8/10/2021 Ag-110m 5.22E+00 1.04E+01 3.51E+01 U TG 08 552744001 8/10/2021 Ba-140 3.11E+00 3.64E+01 1.09E+02 U TG 08 552744001 8/10/2021 Be-7 9.78E+02 1.43E+02 1.64E+02 TG 08 552744001 8/10/2021 Ce-141 6.92E+00 1.02E+01 3.47E+01 U TG 08 552744001 8/10/2021 Ce-144 -1.38E+01 3.82E+01 1.26E+02 U TG 08 552744001 8/10/2021 Co-57 -5.49E+00 5.10E+00 1.60E+01 U TG 08 552744001 8/10/2021 Co-58 -2.48E+00 6.72E+00 2.13E+01 U TG 08 552744001 8/10/2021 Co-60 -2.55E+00 7.03E+00 2.25E+01 U TG 08 552744001 8/10/2021 Cr-51 -3.50E+01 6.20E+01 1.92E+02 U TG 08 552744001 8/10/2021 Cs-134 -2.48E+00 8.26E+00 2.64E+01 U TG 08 552744001 8/10/2021 Cs-137 -6.57E+00 7.63E+00 2.33E+01 U TG 08 552744001 8/10/2021 Fe-59 -1.24E+00 1.48E+01 4.70E+01 U TG 08 552744001 8/10/2021 I-131 -8.79E+00 1.14E+01 3.42E+01 U TG 08 552744001 8/10/2021 K-40 5.83E+03 4.88E+02 2.25E+02 TG 08 552744001 8/10/2021 La-140 -1.63E+01 1.22E+01 3.14E+01 U TG 08 552744001 8/10/2021 Mn-54 5.40E-01 6.80E+00 2.24E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TG 08 552744001 8/10/2021 Nb-95 -5.04E+00 7.25E+00 2.23E+01 U TG 08 552744001 8/10/2021 Ru-103 -1.40E-01 6.14E+00 2.07E+01 U TG 08 552744001 8/10/2021 Ru-106 -7.56E+01 7.03E+01 2.11E+02 U TG 08 552744001 8/10/2021 Sb-124 -6.80E+00 1.13E+01 3.21E+01 U TG 08 552744001 8/10/2021 Sb-125 5.16E+01 2.18E+01 6.78E+01 U TG 08 552744001 8/10/2021 Se-75 -1.39E+01 9.53E+00 2.70E+01 U TG 08 552744001 8/10/2021 Th-228 8.76E-01 2.06E+01 4.69E+01 U TG 08 552744001 8/10/2021 Zn-65 7.13E+00 2.44E+01 6.54E+01 U TG 08 552744001 8/10/2021 Zr-95 8.97E+00 1.18E+01 4.06E+01 U TG 08 555715001 9/8/2021 Ac-228 3.42E+01 5.94E+01 1.46E+02 U TG 08 555715001 9/8/2021 Ag-108m -3.94E+00 7.43E+00 2.35E+01 U TG 08 555715001 9/8/2021 Ag-110m 4.04E+00 1.14E+01 3.90E+01 U TG 08 555715001 9/8/2021 Ba-140 -5.61E+01 4.71E+01 1.34E+02 U TG 08 555715001 9/8/2021 Be-7 1.72E+03 2.14E+02 2.57E+02 TG 08 555715001 9/8/2021 Ce-141 -1.85E+01 1.53E+01 3.91E+01 U TG 08 555715001 9/8/2021 Ce-144 6.15E+01 5.01E+01 1.63E+02 U TG 08 555715001 9/8/2021 Co-57 6.82E-02 5.64E+00 1.83E+01 U TG 08 555715001 9/8/2021 Co-58 3.51E+00 1.03E+01 3.15E+01 U TG 08 555715001 9/8/2021 Co-60 1.49E+01 1.09E+01 3.79E+01 U TG 08 555715001 9/8/2021 Cr-51 -5.13E+01 7.37E+01 2.36E+02 U TG 08 555715001 9/8/2021 Cs-134 2.41E+01 1.57E+01 3.45E+01 U TG 08 555715001 9/8/2021 Cs-137 2.67E+01 1.14E+01 3.62E+01 U TG 08 555715001 9/8/2021 Fe-59 -1.41E+00 2.09E+01 6.79E+01 U TG 08 555715001 9/8/2021 I-131 -3.23E+01 1.69E+01 4.48E+01 U TG 08 555715001 9/8/2021 K-40 4.37E+03 3.88E+02 2.29E+02 TG 08 555715001 9/8/2021 La-140 -7.25E+00 1.47E+01 4.62E+01 U TG 08 555715001 9/8/2021 Mn-54 3.41E-02 7.16E+00 2.12E+01 U TG 08 555715001 9/8/2021 Nb-95 -8.99E+00 1.13E+01 2.94E+01 U TG 08 555715001 9/8/2021 Ru-103 4.88E+00 9.15E+00 3.05E+01 U TG 08 555715001 9/8/2021 Ru-106 -4.69E+01 7.92E+01 2.39E+02 U TG 08 555715001 9/8/2021 Sb-124 2.44E+01 1.63E+01 6.29E+01 U TG 08 555715001 9/8/2021 Sb-125 -3.19E+00 2.18E+01 7.13E+01 U TG 08 555715001 9/8/2021 Se-75 8.01E+00 1.03E+01 3.57E+01 U TG 08 555715001 9/8/2021 Th-228 1.87E+01 2.09E+01 5.77E+01 U TG 08 555715001 9/8/2021 Zn-65 -2.19E+01 2.17E+01 6.28E+01 U TG 08 555715001 9/8/2021 Zr-95 1.30E+01 1.49E+01 5.24E+01 U TG 09 545422002 5/19/2021 Ac-228 -1.18E+01 1.82E+01 5.40E+01 U TG 09 545422002 5/19/2021 Ag-108m -2.75E+00 3.11E+00 9.57E+00 U TG 09 545422002 5/19/2021 Ag-110m -1.40E+00 5.52E+00 1.81E+01 U TG 09 545422002 5/19/2021 Ba-140 -1.34E+01 1.73E+01 5.24E+01 U TG 09 545422002 5/19/2021 Be-7 3.87E+02 5.55E+01 9.85E+01 TG 09 545422002 5/19/2021 Ce-141 2.03E+00 5.67E+00 1.83E+01 U TG 09 545422002 5/19/2021 Ce-144 7.83E+00 2.12E+01 6.86E+01 U TG 09 545422002 5/19/2021 Co-57 -1.35E+00 2.67E+00 8.43E+00 U TG 09 545422002 5/19/2021 Co-58 3.30E-02 3.29E+00 1.11E+01 U TG 09 545422002 5/19/2021 Co-60 -5.74E+00 4.72E+00 1.30E+01 U TG 09 545422002 5/19/2021 Cr-51 -3.63E+01 3.18E+01 9.82E+01 U TG 09 545422002 5/19/2021 Cs-134 -5.04E+00 4.23E+00 1.21E+01 U TG 09 545422002 5/19/2021 Cs-137 2.06E+00 4.32E+00 1.40E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TG 09 545422002 5/19/2021 Fe-59 -1.25E+01 1.02E+01 2.95E+01 U TG 09 545422002 5/19/2021 I-131 1.62E+01 1.06E+01 2.00E+01 U TG 09 545422002 5/19/2021 K-40 4.97E+03 3.04E+02 1.01E+02 TG 09 545422002 5/19/2021 La-140 -5.14E+00 5.41E+00 1.57E+01 U TG 09 545422002 5/19/2021 Mn-54 -1.28E+00 3.58E+00 1.17E+01 U TG 09 545422002 5/19/2021 Nb-95 -8.65E-01 3.53E+00 1.17E+01 U TG 09 545422002 5/19/2021 Ru-103 1.57E+00 3.66E+00 1.21E+01 U TG 09 545422002 5/19/2021 Ru-106 5.18E+01 3.39E+01 1.11E+02 U TG 09 545422002 5/19/2021 Sb-124 -8.68E+00 9.49E+00 2.80E+01 U TG 09 545422002 5/19/2021 Sb-125 -4.92E+00 9.82E+00 3.14E+01 U TG 09 545422002 5/19/2021 Se-75 1.19E+01 6.39E+00 1.56E+01 U TG 09 545422002 5/19/2021 Th-228 -9.07E+00 8.43E+00 2.39E+01 U TG 09 545422002 5/19/2021 Zn-65 -4.45E+00 8.91E+00 2.79E+01 U TG 09 545422002 5/19/2021 Zr-95 1.27E+01 9.18E+00 2.52E+01 U TG 09 547919002 6/16/2021 Ac-228 2.13E+01 2.30E+01 7.36E+01 U TG 09 547919002 6/16/2021 Ag-108m -8.46E+00 4.37E+00 1.14E+01 U TG 09 547919002 6/16/2021 Ag-110m -9.70E+00 7.49E+00 1.81E+01 U TG 09 547919002 6/16/2021 Ba-140 4.53E+01 2.26E+01 7.40E+01 U TG 09 547919002 6/16/2021 Be-7 7.38E+02 8.57E+01 1.22E+02 TG 09 547919002 6/16/2021 Ce-141 -6.88E+00 8.05E+00 2.19E+01 U TG 09 547919002 6/16/2021 Ce-144 -3.94E+00 2.38E+01 7.60E+01 U TG 09 547919002 6/16/2021 Co-57 2.80E+00 2.96E+00 9.71E+00 U TG 09 547919002 6/16/2021 Co-58 -7.36E+00 4.89E+00 1.39E+01 U TG 09 547919002 6/16/2021 Co-60 4.99E+00 4.74E+00 1.64E+01 U TG 09 547919002 6/16/2021 Cr-51 1.96E+01 3.93E+01 1.34E+02 U TG 09 547919002 6/16/2021 Cs-134 -5.40E-01 5.52E+00 1.70E+01 U TG 09 547919002 6/16/2021 Cs-137 3.30E+00 4.45E+00 1.47E+01 U TG 09 547919002 6/16/2021 Fe-59 -3.57E-02 8.92E+00 2.92E+01 U TG 09 547919002 6/16/2021 I-131 4.28E+00 7.20E+00 2.22E+01 U TG 09 547919002 6/16/2021 K-40 4.33E+03 2.96E+02 1.44E+02 TG 09 547919002 6/16/2021 La-140 4.65E+00 7.08E+00 2.50E+01 U TG 09 547919002 6/16/2021 Mn-54 2.67E+00 4.31E+00 1.49E+01 U TG 09 547919002 6/16/2021 Nb-95 7.25E+00 4.71E+00 1.63E+01 U TG 09 547919002 6/16/2021 Ru-103 -6.51E+00 4.44E+00 1.22E+01 U TG 09 547919002 6/16/2021 Ru-106 4.54E+01 4.18E+01 1.39E+02 U TG 09 547919002 6/16/2021 Sb-124 -6.31E+00 9.91E+00 3.00E+01 U TG 09 547919002 6/16/2021 Sb-125 -1.15E+01 1.14E+01 3.45E+01 U TG 09 547919002 6/16/2021 Se-75 -2.53E+00 5.46E+00 1.82E+01 U TG 09 547919002 6/16/2021 Th-228 -1.01E+01 9.06E+00 2.76E+01 U TG 09 547919002 6/16/2021 Zn-65 -1.41E+01 1.20E+01 3.45E+01 U TG 09 547919002 6/16/2021 Zr-95 -1.04E+01 9.10E+00 2.32E+01 U TG 09 549905002 7/14/2021 Ac-228 -2.08E+01 2.47E+01 7.66E+01 U TG 09 549905002 7/14/2021 Ag-108m -5.31E+00 4.19E+00 1.21E+01 U TG 09 549905002 7/14/2021 Ag-110m 4.01E+00 6.74E+00 2.30E+01 U TG 09 549905002 7/14/2021 Ba-140 -7.87E-01 2.36E+01 7.82E+01 U TG 09 549905002 7/14/2021 Be-7 1.35E+03 1.29E+02 1.21E+02 TG 09 549905002 7/14/2021 Ce-141 -1.02E+01 8.91E+00 2.41E+01 U TG 09 549905002 7/14/2021 Ce-144 -2.79E+01 2.89E+01 8.57E+01 U TG 09 549905002 7/14/2021 Co-57 1.85E-01 3.35E+00 1.09E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TG 09 549905002 7/14/2021 Co-58 1.60E+00 3.67E+00 1.26E+01 U TG 09 549905002 7/14/2021 Co-60 3.04E+00 4.95E+00 1.78E+01 U TG 09 549905002 7/14/2021 Cr-51 2.47E+01 4.00E+01 1.41E+02 U TG 09 549905002 7/14/2021 Cs-134 1.35E+01 9.26E+00 1.72E+01 U TG 09 549905002 7/14/2021 Cs-137 -3.73E+00 5.35E+00 1.62E+01 U TG 09 549905002 7/14/2021 Fe-59 1.48E+00 9.72E+00 3.15E+01 U TG 09 549905002 7/14/2021 I-131 -1.12E+01 9.29E+00 2.62E+01 U TG 09 549905002 7/14/2021 K-40 2.44E+03 2.41E+02 1.66E+02 TG 09 549905002 7/14/2021 La-140 1.70E+00 8.78E+00 2.99E+01 U TG 09 549905002 7/14/2021 Mn-54 2.39E+00 4.29E+00 1.47E+01 U TG 09 549905002 7/14/2021 Nb-95 -4.04E+00 5.11E+00 1.49E+01 U TG 09 549905002 7/14/2021 Ru-103 -5.65E+00 4.98E+00 1.45E+01 U TG 09 549905002 7/14/2021 Ru-106 -7.03E+01 5.42E+01 1.26E+02 U TG 09 549905002 7/14/2021 Sb-124 1.20E+01 1.09E+01 4.15E+01 U TG 09 549905002 7/14/2021 Sb-125 9.34E+00 1.16E+01 4.06E+01 U TG 09 549905002 7/14/2021 Se-75 -6.86E+00 6.90E+00 1.95E+01 U TG 09 549905002 7/14/2021 Th-228 -1.59E+01 1.09E+01 3.19E+01 U TG 09 549905002 7/14/2021 Zn-65 -2.65E+00 1.27E+01 3.87E+01 U TG 09 549905002 7/14/2021 Zr-95 2.29E+00 8.30E+00 2.52E+01 U TG 09 552744002 8/10/2021 Ac-228 4.03E+01 3.58E+01 1.17E+02 U TG 09 552744002 8/10/2021 Ag-108m -6.02E+00 6.22E+00 1.61E+01 U TG 09 552744002 8/10/2021 Ag-110m -6.30E+00 8.05E+00 2.40E+01 U TG 09 552744002 8/10/2021 Ba-140 1.54E+01 3.29E+01 1.00E+02 U TG 09 552744002 8/10/2021 Be-7 7.05E+02 1.17E+02 1.63E+02 TG 09 552744002 8/10/2021 Ce-141 4.24E+00 8.93E+00 2.88E+01 U TG 09 552744002 8/10/2021 Ce-144 1.03E+01 3.13E+01 1.01E+02 U TG 09 552744002 8/10/2021 Co-57 2.38E+00 4.27E+00 1.40E+01 U TG 09 552744002 8/10/2021 Co-58 9.78E+00 6.43E+00 2.23E+01 U TG 09 552744002 8/10/2021 Co-60 6.70E+00 8.27E+00 2.89E+01 U TG 09 552744002 8/10/2021 Cr-51 9.31E-01 5.37E+01 1.68E+02 U TG 09 552744002 8/10/2021 Cs-134 1.02E+01 7.48E+00 2.58E+01 U TG 09 552744002 8/10/2021 Cs-137 -1.25E+01 7.23E+00 1.94E+01 U TG 09 552744002 8/10/2021 Fe-59 -9.43E-01 1.28E+01 4.09E+01 U TG 09 552744002 8/10/2021 I-131 5.95E+00 9.53E+00 3.21E+01 U TG 09 552744002 8/10/2021 K-40 4.38E+03 3.52E+02 1.71E+02 TG 09 552744002 8/10/2021 La-140 -2.06E+01 1.55E+01 3.26E+01 U TG 09 552744002 8/10/2021 Mn-54 -3.80E+00 6.39E+00 1.99E+01 U TG 09 552744002 8/10/2021 Nb-95 -6.69E+00 7.32E+00 2.08E+01 U TG 09 552744002 8/10/2021 Ru-103 2.85E+00 6.42E+00 2.11E+01 U TG 09 552744002 8/10/2021 Ru-106 -9.90E+01 5.77E+01 1.56E+02 U TG 09 552744002 8/10/2021 Sb-124 8.60E+00 1.27E+01 4.51E+01 U TG 09 552744002 8/10/2021 Sb-125 -6.76E+00 1.80E+01 5.72E+01 U TG 09 552744002 8/10/2021 Se-75 -1.33E+00 7.29E+00 2.44E+01 U TG 09 552744002 8/10/2021 Th-228 0.00E+00 2.46E+01 4.25E+01 U TG 09 552744002 8/10/2021 Zn-65 5.19E+00 1.87E+01 5.20E+01 U TG 09 552744002 8/10/2021 Zr-95 -9.11E+00 1.24E+01 3.85E+01 U TG 09 555715002 9/8/2021 Ac-228 4.67E+01 3.13E+01 1.08E+02 U TG 09 555715002 9/8/2021 Ag-108m -3.07E+00 6.86E+00 2.02E+01 U TG 09 555715002 9/8/2021 Ag-110m 1.15E+01 1.05E+01 3.65E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TG 09 555715002 9/8/2021 Ba-140 1.04E+01 3.04E+01 9.98E+01 U TG 09 555715002 9/8/2021 Be-7 9.31E+02 1.32E+02 1.68E+02 TG 09 555715002 9/8/2021 Ce-141 2.29E+00 9.20E+00 2.67E+01 U TG 09 555715002 9/8/2021 Ce-144 2.12E+01 3.14E+01 1.00E+02 U TG 09 555715002 9/8/2021 Co-57 1.90E+00 3.87E+00 1.24E+01 U TG 09 555715002 9/8/2021 Co-58 2.02E+01 8.77E+00 2.92E+01 U TG 09 555715002 9/8/2021 Co-60 5.13E+00 7.17E+00 2.48E+01 U TG 09 555715002 9/8/2021 Cr-51 2.22E+01 4.90E+01 1.66E+02 U TG 09 555715002 9/8/2021 Cs-134 1.08E+01 9.18E+00 3.18E+01 U TG 09 555715002 9/8/2021 Cs-137 -3.44E+00 7.83E+00 2.58E+01 U TG 09 555715002 9/8/2021 Fe-59 3.23E+01 1.73E+01 5.96E+01 U TG 09 555715002 9/8/2021 I-131 7.27E+00 1.05E+01 3.54E+01 U TG 09 555715002 9/8/2021 K-40 6.06E+03 4.54E+02 2.91E+02 TG 09 555715002 9/8/2021 La-140 1.69E+01 9.75E+00 3.76E+01 U TG 09 555715002 9/8/2021 Mn-54 7.84E+00 7.41E+00 2.58E+01 U TG 09 555715002 9/8/2021 Nb-95 8.98E+00 7.89E+00 2.75E+01 U TG 09 555715002 9/8/2021 Ru-103 1.84E+00 5.82E+00 1.92E+01 U TG 09 555715002 9/8/2021 Ru-106 1.24E+02 7.60E+01 2.31E+02 U TG 09 555715002 9/8/2021 Sb-124 6.28E+00 1.68E+01 5.87E+01 U TG 09 555715002 9/8/2021 Sb-125 6.54E+00 1.67E+01 5.56E+01 U TG 09 555715002 9/8/2021 Se-75 9.44E+00 7.17E+00 2.43E+01 U TG 09 555715002 9/8/2021 Th-228 1.62E+01 1.87E+01 4.11E+01 U TG 09 555715002 9/8/2021 Zn-65 1.50E+01 1.82E+01 6.24E+01 U TG 09 555715002 9/8/2021 Zr-95 -6.45E+00 1.19E+01 3.81E+01 U TG 10 545422003 5/19/2021 Ac-228 2.92E+01 2.95E+01 6.27E+01 U TG 10 545422003 5/19/2021 Ag-108m 1.50E+00 2.82E+00 9.48E+00 U TG 10 545422003 5/19/2021 Ag-110m -1.90E+00 4.67E+00 1.53E+01 U TG 10 545422003 5/19/2021 Ba-140 1.41E+01 1.70E+01 5.69E+01 U TG 10 545422003 5/19/2021 Be-7 4.16E+02 6.98E+01 9.32E+01 TG 10 545422003 5/19/2021 Ce-141 1.24E+01 9.91E+00 1.59E+01 U TG 10 545422003 5/19/2021 Ce-144 2.43E+00 2.03E+01 6.38E+01 U TG 10 545422003 5/19/2021 Co-57 -5.32E-01 2.60E+00 8.06E+00 U TG 10 545422003 5/19/2021 Co-58 -4.62E-01 3.82E+00 1.20E+01 U TG 10 545422003 5/19/2021 Co-60 2.75E+00 4.69E+00 1.60E+01 U TG 10 545422003 5/19/2021 Cr-51 -5.14E+00 2.93E+01 9.72E+01 U TG 10 545422003 5/19/2021 Cs-134 -9.88E-01 3.99E+00 1.24E+01 U TG 10 545422003 5/19/2021 Cs-137 4.77E-01 3.50E+00 1.13E+01 U TG 10 545422003 5/19/2021 Fe-59 9.31E-01 8.33E+00 2.80E+01 U TG 10 545422003 5/19/2021 I-131 -5.84E+00 6.25E+00 1.94E+01 U TG 10 545422003 5/19/2021 K-40 4.51E+03 3.03E+02 1.37E+02 TG 10 545422003 5/19/2021 La-140 1.12E+01 6.36E+00 2.26E+01 U TG 10 545422003 5/19/2021 Mn-54 3.77E+00 3.77E+00 1.32E+01 U TG 10 545422003 5/19/2021 Nb-95 -7.20E+00 5.23E+00 1.36E+01 U TG 10 545422003 5/19/2021 Ru-103 -4.46E+00 3.54E+00 1.02E+01 U TG 10 545422003 5/19/2021 Ru-106 2.97E+00 3.43E+01 1.11E+02 U TG 10 545422003 5/19/2021 Sb-124 1.71E+01 1.07E+01 3.51E+01 U TG 10 545422003 5/19/2021 Sb-125 3.44E-01 8.90E+00 2.94E+01 U TG 10 545422003 5/19/2021 Se-75 -6.26E+00 4.09E+00 1.20E+01 U TG 10 545422003 5/19/2021 Th-228 1.10E+01 1.02E+01 2.34E+01 U TG 10 545422003 5/19/2021 Zn-65 -7.54E+00 1.13E+01 3.37E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TG 10 545422003 5/19/2021 Zr-95 2.03E+00 7.11E+00 2.30E+01 U TG 10 547919003 6/16/2021 Ac-228 3.92E+01 2.67E+01 7.07E+01 U TG 10 547919003 6/16/2021 Ag-108m -6.49E+00 4.16E+00 1.14E+01 U TG 10 547919003 6/16/2021 Ag-110m 6.28E+00 5.96E+00 2.04E+01 U TG 10 547919003 6/16/2021 Ba-140 1.07E+01 2.35E+01 7.63E+01 U TG 10 547919003 6/16/2021 Be-7 9.36E+02 9.85E+01 1.23E+02 TG 10 547919003 6/16/2021 Ce-141 -3.78E+00 7.03E+00 2.17E+01 U TG 10 547919003 6/16/2021 Ce-144 -1.50E+01 2.48E+01 7.66E+01 U TG 10 547919003 6/16/2021 Co-57 -1.26E+00 3.15E+00 9.93E+00 U TG 10 547919003 6/16/2021 Co-58 4.38E+00 5.15E+00 1.75E+01 U TG 10 547919003 6/16/2021 Co-60 -4.02E-01 6.10E+00 2.03E+01 U TG 10 547919003 6/16/2021 Cr-51 1.05E+01 4.04E+01 1.36E+02 U TG 10 547919003 6/16/2021 Cs-134 3.21E+00 5.93E+00 2.00E+01 U TG 10 547919003 6/16/2021 Cs-137 0.00E+00 6.28E+00 1.52E+01 U TG 10 547919003 6/16/2021 Fe-59 -3.96E+00 9.88E+00 3.05E+01 U TG 10 547919003 6/16/2021 I-131 6.83E+00 7.93E+00 2.66E+01 U TG 10 547919003 6/16/2021 K-40 2.94E+03 2.47E+02 1.61E+02 TG 10 547919003 6/16/2021 La-140 -3.25E+00 8.26E+00 2.59E+01 U TG 10 547919003 6/16/2021 Mn-54 -3.46E+00 4.50E+00 1.38E+01 U TG 10 547919003 6/16/2021 Nb-95 -2.63E+00 5.73E+00 1.60E+01 U TG 10 547919003 6/16/2021 Ru-103 -3.39E+00 4.46E+00 1.34E+01 U TG 10 547919003 6/16/2021 Ru-106 -3.49E-01 4.33E+01 1.46E+02 U TG 10 547919003 6/16/2021 Sb-124 -3.45E+00 1.05E+01 3.28E+01 U TG 10 547919003 6/16/2021 Sb-125 -6.03E+00 1.19E+01 3.74E+01 U TG 10 547919003 6/16/2021 Se-75 3.95E+00 5.77E+00 1.97E+01 U TG 10 547919003 6/16/2021 Th-228 1.94E+01 1.51E+01 3.05E+01 U TG 10 547919003 6/16/2021 Zn-65 -3.36E+00 1.23E+01 3.31E+01 U TG 10 547919003 6/16/2021 Zr-95 -6.53E+00 8.48E+00 2.64E+01 U TG 10 549905003 7/14/2021 Ac-228 -6.08E+01 5.71E+01 1.46E+02 U TG 10 549905003 7/14/2021 Ag-108m 1.69E-01 8.88E+00 2.84E+01 U TG 10 549905003 7/14/2021 Ag-110m -1.64E+00 1.34E+01 4.32E+01 U TG 10 549905003 7/14/2021 Ba-140 -1.83E+01 3.50E+01 1.12E+02 U TG 10 549905003 7/14/2021 Be-7 2.26E+03 2.66E+02 2.25E+02 TG 10 549905003 7/14/2021 Ce-141 6.27E+00 1.40E+01 4.39E+01 U TG 10 549905003 7/14/2021 Ce-144 -5.90E+01 5.12E+01 1.59E+02 U TG 10 549905003 7/14/2021 Co-57 1.43E+01 7.22E+00 2.41E+01 U TG 10 549905003 7/14/2021 Co-58 9.20E+00 1.01E+01 3.53E+01 U TG 10 549905003 7/14/2021 Co-60 4.45E+00 1.25E+01 4.31E+01 U TG 10 549905003 7/14/2021 Cr-51 6.88E+00 8.86E+01 2.60E+02 U TG 10 549905003 7/14/2021 Cs-134 -1.18E+01 1.26E+01 3.52E+01 U TG 10 549905003 7/14/2021 Cs-137 2.25E+01 1.14E+01 3.93E+01 U TG 10 549905003 7/14/2021 Fe-59 -3.83E+01 2.42E+01 5.73E+01 U TG 10 549905003 7/14/2021 I-131 -6.69E+00 1.54E+01 4.82E+01 U TG 10 549905003 7/14/2021 K-40 2.09E+03 2.92E+02 2.76E+02 TG 10 549905003 7/14/2021 La-140 -4.21E+00 1.63E+01 5.16E+01 U TG 10 549905003 7/14/2021 Mn-54 2.53E+01 1.09E+01 3.75E+01 U TG 10 549905003 7/14/2021 Nb-95 5.49E+00 1.07E+01 3.64E+01 U TG 10 549905003 7/14/2021 Ru-103 -4.84E+00 9.48E+00 2.85E+01 U TG 10 549905003 7/14/2021 Ru-106 -9.87E+01 8.07E+01 2.30E+02 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TG 10 549905003 7/14/2021 Sb-124 2.15E+01 1.97E+01 7.50E+01 U TG 10 549905003 7/14/2021 Sb-125 1.40E+01 2.45E+01 8.13E+01 U TG 10 549905003 7/14/2021 Se-75 5.75E+00 1.14E+01 3.83E+01 U TG 10 549905003 7/14/2021 Th-228 -2.79E+01 2.05E+01 6.17E+01 U TG 10 549905003 7/14/2021 Zn-65 6.24E+00 2.59E+01 8.50E+01 U TG 10 549905003 7/14/2021 Zr-95 -3.75E+00 1.69E+01 5.46E+01 U TG 10 552744003 8/10/2021 Ac-228 1.69E+01 3.91E+01 1.41E+02 U TG 10 552744003 8/10/2021 Ag-108m 2.73E+00 5.91E+00 2.01E+01 U TG 10 552744003 8/10/2021 Ag-110m 5.47E-01 8.82E+00 3.01E+01 U TG 10 552744003 8/10/2021 Ba-140 1.34E+00 3.85E+01 1.26E+02 U TG 10 552744003 8/10/2021 Be-7 1.26E+03 1.70E+02 2.14E+02 TG 10 552744003 8/10/2021 Ce-141 -1.49E+01 1.30E+01 3.69E+01 U TG 10 552744003 8/10/2021 Ce-144 1.18E+01 4.36E+01 1.39E+02 U TG 10 552744003 8/10/2021 Co-57 -3.95E+00 5.54E+00 1.65E+01 U TG 10 552744003 8/10/2021 Co-58 6.55E+00 8.31E+00 2.80E+01 U TG 10 552744003 8/10/2021 Co-60 3.39E+00 9.74E+00 3.32E+01 U TG 10 552744003 8/10/2021 Cr-51 5.73E+01 6.59E+01 2.27E+02 U TG 10 552744003 8/10/2021 Cs-134 -6.85E+00 9.10E+00 2.62E+01 U TG 10 552744003 8/10/2021 Cs-137 1.80E+00 9.02E+00 2.95E+01 U TG 10 552744003 8/10/2021 Fe-59 -2.22E+01 2.02E+01 5.88E+01 U TG 10 552744003 8/10/2021 I-131 -8.38E+00 1.19E+01 3.73E+01 U TG 10 552744003 8/10/2021 K-40 6.05E+03 5.38E+02 3.14E+02 TG 10 552744003 8/10/2021 La-140 9.39E+00 1.09E+01 3.96E+01 U TG 10 552744003 8/10/2021 Mn-54 2.55E+00 8.29E+00 2.70E+01 U TG 10 552744003 8/10/2021 Nb-95 -1.23E+01 9.37E+00 2.56E+01 U TG 10 552744003 8/10/2021 Ru-103 -1.51E+01 7.31E+00 1.59E+01 U TG 10 552744003 8/10/2021 Ru-106 -1.40E+02 8.04E+01 1.92E+02 U TG 10 552744003 8/10/2021 Sb-124 4.87E+00 1.29E+01 4.53E+01 U TG 10 552744003 8/10/2021 Sb-125 -1.92E+00 1.78E+01 5.82E+01 U TG 10 552744003 8/10/2021 Se-75 1.19E+01 9.63E+00 3.32E+01 U TG 10 552744003 8/10/2021 Th-228 2.11E+01 2.21E+01 5.45E+01 U TG 10 552744003 8/10/2021 Zn-65 4.58E+01 2.54E+01 5.47E+01 U TG 10 552744003 8/10/2021 Zr-95 1.02E+01 1.30E+01 4.42E+01 U TG 10 555715003 9/8/2021 Ac-228 6.91E+00 6.08E+01 1.25E+02 U TG 10 555715003 9/8/2021 Ag-108m -4.24E+00 6.02E+00 1.81E+01 U TG 10 555715003 9/8/2021 Ag-110m -3.00E+00 1.01E+01 3.06E+01 U TG 10 555715003 9/8/2021 Ba-140 3.02E+01 3.13E+01 1.08E+02 U TG 10 555715003 9/8/2021 Be-7 1.28E+03 1.48E+02 1.51E+02 TG 10 555715003 9/8/2021 Ce-141 7.63E+00 9.76E+00 3.29E+01 U TG 10 555715003 9/8/2021 Ce-144 -1.71E+01 3.31E+01 1.09E+02 U TG 10 555715003 9/8/2021 Co-57 1.02E+00 4.21E+00 1.43E+01 U TG 10 555715003 9/8/2021 Co-58 -1.95E+00 5.82E+00 1.85E+01 U TG 10 555715003 9/8/2021 Co-60 5.84E+00 7.66E+00 2.67E+01 U TG 10 555715003 9/8/2021 Cr-51 -3.63E+01 6.77E+01 1.84E+02 U TG 10 555715003 9/8/2021 Cs-134 -1.02E+00 7.79E+00 2.54E+01 U TG 10 555715003 9/8/2021 Cs-137 1.42E+00 6.46E+00 2.17E+01 U TG 10 555715003 9/8/2021 Fe-59 -1.33E+01 1.57E+01 4.03E+01 U TG 10 555715003 9/8/2021 I-131 -8.29E-02 1.00E+01 3.20E+01 U TG 10 555715003 9/8/2021 K-40 5.32E+03 3.82E+02 1.68E+02

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/kg) (pCi/kg) (pCi/kg)

TG 10 555715003 9/8/2021 La-140 9.84E-01 9.83E+00 3.28E+01 U TG 10 555715003 9/8/2021 Mn-54 -4.42E+00 7.61E+00 2.04E+01 U TG 10 555715003 9/8/2021 Nb-95 1.41E+01 7.63E+00 2.53E+01 U TG 10 555715003 9/8/2021 Ru-103 -6.21E+00 5.70E+00 1.75E+01 U TG 10 555715003 9/8/2021 Ru-106 -2.40E+01 5.38E+01 1.74E+02 U TG 10 555715003 9/8/2021 Sb-124 -1.37E+01 1.11E+01 2.68E+01 U TG 10 555715003 9/8/2021 Sb-125 -1.75E+01 1.83E+01 5.36E+01 U TG 10 555715003 9/8/2021 Se-75 9.49E+00 8.68E+00 2.60E+01 U TG 10 555715003 9/8/2021 Th-228 1.78E+01 2.22E+01 4.15E+01 U TG 10 555715003 9/8/2021 Zn-65 1.20E-01 1.50E+01 4.81E+01 U TG 10 555715003 9/8/2021 Zr-95 -2.71E+00 1.07E+01 3.44E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

TM 15 532371001 1/13/2021 Ac-228 0.00E+00 5.46E+00 8.66E+00 U TM 15 532371001 1/13/2021 Ag-108m 5.01E-01 4.61E-01 1.55E+00 U TM 15 532371001 1/13/2021 Ag-110m 9.67E-01 1.26E+00 2.41E+00 U TM 15 532371001 1/13/2021 Ba-140 -5.12E-01 2.41E+00 7.99E+00 U TM 15 532371001 1/13/2021 Be-7 -2.12E+00 6.58E+00 1.46E+01 U TM 15 532371001 1/13/2021 Bi-214 2.85E-01 2.13E+00 3.29E+00 U TM 15 532371001 1/13/2021 Ce-141 1.09E+00 1.05E+00 3.07E+00 U TM 15 532371001 1/13/2021 Ce-144 -3.80E+00 3.93E+00 1.21E+01 U TM 15 532371001 1/13/2021 Co-57 5.62E-01 5.09E-01 1.62E+00 U TM 15 532371001 1/13/2021 Co-58 4.46E-01 5.73E-01 1.70E+00 U TM 15 532371001 1/13/2021 Co-60 3.44E-01 5.56E-01 1.91E+00 U TM 15 532371001 1/13/2021 Cr-51 -3.58E+00 4.80E+00 1.59E+01 U TM 15 532371001 1/13/2021 Cs-134 7.07E-01 6.10E-01 1.99E+00 U TM 15 532371001 1/13/2021 Cs-137 3.30E+00 1.03E+00 1.81E+00 M TM 15 532371001 1/13/2021 Fe-59 -1.41E-01 1.24E+00 3.96E+00 U TM 15 532371001 1/13/2021 I-131 4.22E-01 2.65E-01 8.68E-01 U TM 15 532371001 1/13/2021 K-40 1.92E+03 9.68E+01 1.35E+01 TM 15 532371001 1/13/2021 La-140 4.22E-02 6.93E-01 2.33E+00 U TM 15 532371001 1/13/2021 Mn-54 -1.54E-01 5.42E-01 1.74E+00 U TM 15 532371001 1/13/2021 Nb-95 6.73E-01 5.69E-01 1.86E+00 U TM 15 532371001 1/13/2021 Pb-212 -2.11E+00 1.74E+00 3.74E+00 U TM 15 532371001 1/13/2021 Pb-214 4.10E-01 1.75E+00 4.23E+00 U TM 15 532371001 1/13/2021 Ru-103 -6.88E-01 5.19E-01 1.59E+00 U TM 15 532371001 1/13/2021 Ru-106 2.03E-02 4.73E+00 1.57E+01 U TM 15 532371001 1/13/2021 Sb-124 -9.18E-01 9.06E-01 2.70E+00 U TM 15 532371001 1/13/2021 Sb-125 1.93E-01 1.32E+00 4.47E+00 U TM 15 532371001 1/13/2021 Se-75 -3.63E-01 7.52E-01 2.30E+00 U TM 15 532371001 1/13/2021 Th-228 -2.11E+00 1.74E+00 3.74E+00 U TM 15 532371001 1/13/2021 Zn-65 -3.33E-01 1.41E+00 4.46E+00 U TM 15 532371001 1/13/2021 Zr-95 -7.49E-01 9.69E-01 3.04E+00 U TM 15 537616001 3/10/2021 Ac-228 5.43E+00 6.92E+00 8.45E+00 U TM 15 537616001 3/10/2021 Ag-108m 2.78E-01 4.77E-01 1.62E+00 U TM 15 537616001 3/10/2021 Ag-110m -5.41E-01 8.12E-01 2.53E+00 U TM 15 537616001 3/10/2021 Ba-140 -7.35E+00 3.28E+00 8.54E+00 U TM 15 537616001 3/10/2021 Be-7 -7.66E+00 4.92E+00 1.46E+01 U TM 15 537616001 3/10/2021 Bi-214 9.82E-01 2.88E+00 3.67E+00 U TM 15 537616001 3/10/2021 Ce-141 1.04E+00 1.11E+00 3.53E+00 U TM 15 537616001 3/10/2021 Ce-144 6.05E-02 4.23E+00 1.36E+01 U TM 15 537616001 3/10/2021 Co-57 -3.16E-01 7.17E-01 1.79E+00 U TM 15 537616001 3/10/2021 Co-58 0.00E+00 8.82E-01 1.93E+00 U TM 15 537616001 3/10/2021 Co-60 8.46E-01 6.39E-01 2.18E+00 U TM 15 537616001 3/10/2021 Cr-51 -2.41E+00 5.19E+00 1.75E+01 U TM 15 537616001 3/10/2021 Cs-134 2.17E-01 6.24E-01 2.06E+00 U TM 15 537616001 3/10/2021 Cs-137 2.61E+00 1.04E+00 1.77E+00 M TM 15 537616001 3/10/2021 Fe-59 1.20E+00 1.44E+00 4.68E+00 U TM 15 537616001 3/10/2021 I-131 2.16E-01 1.86E-01 6.13E-01 U TM 15 537616001 3/10/2021 K-40 1.88E+03 9.60E+01 1.78E+01 TM 15 537616001 3/10/2021 La-140 2.03E-01 8.14E-01 2.76E+00 U TM 15 537616001 3/10/2021 Mn-54 3.07E-01 5.44E-01 1.79E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

TM 15 537616001 3/10/2021 Nb-95 -1.12E+00 6.56E-01 1.83E+00 U TM 15 537616001 3/10/2021 Pb-212 1.30E+00 2.09E+00 4.32E+00 U TM 15 537616001 3/10/2021 Pb-214 2.03E+00 2.51E+00 4.86E+00 U TM 15 537616001 3/10/2021 Ru-103 -3.02E-01 6.66E-01 1.96E+00 U TM 15 537616001 3/10/2021 Ru-106 3.14E-01 4.94E+00 1.64E+01 U TM 15 537616001 3/10/2021 Sb-124 -4.07E-02 1.08E+00 3.60E+00 U TM 15 537616001 3/10/2021 Sb-125 -1.67E+00 1.53E+00 4.85E+00 U TM 15 537616001 3/10/2021 Se-75 9.11E-01 8.65E-01 2.69E+00 U TM 15 537616001 3/10/2021 Th-228 1.30E+00 2.09E+00 4.32E+00 U TM 15 537616001 3/10/2021 Zn-65 4.38E-02 1.52E+00 4.85E+00 U TM 15 537616001 3/10/2021 Zr-95 1.11E+00 1.08E+00 3.55E+00 U TM 15 540357001 4/7/2021 Ac-228 -4.30E+00 3.07E+00 6.08E+00 U TM 15 540357001 4/7/2021 Ag-108m -3.61E-01 3.61E-01 1.15E+00 U TM 15 540357001 4/7/2021 Ag-110m -4.43E-01 6.61E-01 2.05E+00 U TM 15 540357001 4/7/2021 Ba-140 -2.46E-01 2.03E+00 6.71E+00 U TM 15 540357001 4/7/2021 Be-7 5.98E+00 3.69E+00 1.20E+01 U TM 15 540357001 4/7/2021 Bi-214 2.18E+00 1.89E+00 3.00E+00 U TM 15 540357001 4/7/2021 Ce-141 1.08E+00 1.54E+00 2.39E+00 U TM 15 540357001 4/7/2021 Ce-144 -8.22E-01 2.88E+00 9.23E+00 U TM 15 540357001 4/7/2021 Co-57 9.21E-02 3.75E-01 1.22E+00 U TM 15 540357001 4/7/2021 Co-58 -1.60E-01 4.83E-01 1.54E+00 U TM 15 540357001 4/7/2021 Co-60 -8.74E-01 5.18E-01 1.47E+00 U TM 15 540357001 4/7/2021 Cr-51 7.80E+00 4.05E+00 1.29E+01 U TM 15 540357001 4/7/2021 Cs-134 9.75E-01 5.07E-01 1.59E+00 U TM 15 540357001 4/7/2021 Cs-137 7.54E-01 5.02E-01 1.62E+00 U TM 15 540357001 4/7/2021 Fe-59 3.69E-01 1.05E+00 3.37E+00 U TM 15 540357001 4/7/2021 I-131 8.96E-02 1.68E-01 5.70E-01 U TM 15 540357001 4/7/2021 K-40 1.49E+03 7.32E+01 1.37E+01 TM 15 540357001 4/7/2021 La-140 -2.72E-01 5.98E-01 1.92E+00 U TM 15 540357001 4/7/2021 Mn-54 8.24E-01 4.95E-01 1.57E+00 U TM 15 540357001 4/7/2021 Nb-95 2.20E-01 4.50E-01 1.48E+00 U TM 15 540357001 4/7/2021 Pb-212 1.38E-01 1.92E+00 2.50E+00 U TM 15 540357001 4/7/2021 Pb-214 -1.60E-01 1.50E+00 3.38E+00 U TM 15 540357001 4/7/2021 Ru-103 -1.85E-01 4.61E-01 1.52E+00 U TM 15 540357001 4/7/2021 Ru-106 1.88E+00 3.68E+00 1.23E+01 U TM 15 540357001 4/7/2021 Sb-124 -4.95E-01 7.26E-01 2.23E+00 U TM 15 540357001 4/7/2021 Sb-125 -3.17E-01 1.07E+00 3.57E+00 U TM 15 540357001 4/7/2021 Se-75 -1.57E-01 5.87E-01 1.82E+00 U TM 15 540357001 4/7/2021 Th-228 1.38E-01 1.92E+00 2.50E+00 U TM 15 540357001 4/7/2021 Zn-65 -2.22E-02 1.07E+00 3.64E+00 U TM 15 540357001 4/7/2021 Zr-95 8.73E-03 8.06E-01 2.63E+00 U TM 15 541847001 4/21/2021 Ac-228 -6.83E+00 5.23E+00 9.63E+00 U TM 15 541847001 4/21/2021 Ag-108m -7.15E-02 5.10E-01 1.72E+00 U TM 15 541847001 4/21/2021 Ag-110m -1.41E+00 9.59E-01 2.70E+00 U TM 15 541847001 4/21/2021 Ba-140 2.45E+00 2.87E+00 9.69E+00 U TM 15 541847001 4/21/2021 Be-7 2.41E+00 5.15E+00 1.75E+01 U TM 15 541847001 4/21/2021 Bi-214 -2.58E+00 2.37E+00 4.73E+00 U TM 15 541847001 4/21/2021 Ce-141 1.87E+00 1.90E+00 3.48E+00 U TM 15 541847001 4/21/2021 Ce-144 2.64E+00 4.33E+00 1.42E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

TM 15 541847001 4/21/2021 Co-57 1.32E-01 5.65E-01 1.86E+00 U TM 15 541847001 4/21/2021 Co-58 -3.41E-02 6.40E-01 2.07E+00 U TM 15 541847001 4/21/2021 Co-60 1.35E+00 8.46E-01 2.82E+00 U TM 15 541847001 4/21/2021 Cr-51 1.36E+01 6.81E+00 1.99E+01 U TM 15 541847001 4/21/2021 Cs-134 2.26E-02 7.01E-01 2.28E+00 U TM 15 541847001 4/21/2021 Cs-137 1.73E+00 1.22E+00 2.21E+00 U TM 15 541847001 4/21/2021 Fe-59 -1.57E+00 1.62E+00 4.77E+00 U TM 15 541847001 4/21/2021 I-131 -1.04E-01 1.36E-01 4.49E-01 U TM 15 541847001 4/21/2021 K-40 1.57E+03 8.92E+01 2.05E+01 TM 15 541847001 4/21/2021 La-140 3.16E-01 8.09E-01 2.75E+00 U TM 15 541847001 4/21/2021 Mn-54 -4.80E-01 6.21E-01 1.91E+00 U TM 15 541847001 4/21/2021 Nb-95 1.09E+00 6.68E-01 2.16E+00 U TM 15 541847001 4/21/2021 Pb-212 1.49E+00 2.75E+00 3.82E+00 U TM 15 541847001 4/21/2021 Pb-214 -8.30E-01 2.04E+00 5.08E+00 U TM 15 541847001 4/21/2021 Ru-103 -6.53E-01 6.36E-01 2.00E+00 U TM 15 541847001 4/21/2021 Ru-106 -5.33E+00 5.43E+00 1.68E+01 U TM 15 541847001 4/21/2021 Sb-124 1.56E+00 1.30E+00 4.48E+00 U TM 15 541847001 4/21/2021 Sb-125 -1.46E+00 1.69E+00 5.49E+00 U TM 15 541847001 4/21/2021 Se-75 8.62E-01 9.34E-01 2.94E+00 U TM 15 541847001 4/21/2021 Th-228 1.49E+00 2.75E+00 3.82E+00 U TM 15 541847001 4/21/2021 Zn-65 -1.04E+00 1.63E+00 4.94E+00 U TM 15 541847001 4/21/2021 Zr-95 -3.18E+00 1.35E+00 3.24E+00 U TM 15 544028001 5/5/2021 Ac-228 0.00E+00 4.60E+00 6.20E+00 U TM 15 544028001 5/5/2021 Ag-108m -4.14E-01 3.48E-01 1.09E+00 U TM 15 544028001 5/5/2021 Ag-110m -6.24E-02 5.84E-01 1.85E+00 U TM 15 544028001 5/5/2021 Ba-140 4.03E-01 2.85E+00 8.47E+00 U TM 15 544028001 5/5/2021 Be-7 3.82E+00 3.55E+00 1.17E+01 U TM 15 544028001 5/5/2021 Bi-214 4.48E+00 1.93E+00 2.58E+00 UI TM 15 544028001 5/5/2021 Ce-141 -1.68E+00 9.03E-01 2.54E+00 U TM 15 544028001 5/5/2021 Ce-144 -7.35E-01 2.67E+00 8.59E+00 U TM 15 544028001 5/5/2021 Co-57 -1.93E-01 3.47E-01 1.11E+00 U TM 15 544028001 5/5/2021 Co-58 -3.95E-01 4.32E-01 1.31E+00 U TM 15 544028001 5/5/2021 Co-60 -2.67E-01 4.69E-01 1.51E+00 U TM 15 544028001 5/5/2021 Cr-51 -1.04E+00 4.03E+00 1.37E+01 U TM 15 544028001 5/5/2021 Cs-134 6.77E-01 4.55E-01 1.44E+00 U TM 15 544028001 5/5/2021 Cs-137 0.00E+00 6.73E-01 1.37E+00 U TM 15 544028001 5/5/2021 Fe-59 -6.05E-01 1.14E+00 3.28E+00 U TM 15 544028001 5/5/2021 I-131 1.74E-01 1.87E-01 5.47E-01 U TM 15 544028001 5/5/2021 K-40 1.61E+03 9.16E+01 1.19E+01 TM 15 544028001 5/5/2021 La-140 -6.11E-01 7.76E-01 2.39E+00 U TM 15 544028001 5/5/2021 Mn-54 -3.15E-02 4.13E-01 1.32E+00 U TM 15 544028001 5/5/2021 Nb-95 0.00E+00 7.91E-01 1.40E+00 U TM 15 544028001 5/5/2021 Pb-212 1.41E+00 1.59E+00 2.92E+00 U TM 15 544028001 5/5/2021 Pb-214 2.45E+00 2.34E+00 3.36E+00 U TM 15 544028001 5/5/2021 Ru-103 1.94E-01 4.96E-01 1.49E+00 U TM 15 544028001 5/5/2021 Ru-106 -5.01E+00 4.15E+00 1.11E+01 U TM 15 544028001 5/5/2021 Sb-124 -1.80E-01 8.72E-01 2.80E+00 U TM 15 544028001 5/5/2021 Sb-125 -5.69E-01 1.06E+00 3.48E+00 U TM 15 544028001 5/5/2021 Se-75 -7.66E-02 5.74E-01 1.78E+00 U TM 15 544028001 5/5/2021 Th-228 1.41E+00 1.59E+00 2.92E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

TM 15 544028001 5/5/2021 Zn-65 1.07E+00 1.06E+00 3.54E+00 U TM 15 544028001 5/5/2021 Zr-95 -6.22E-01 7.62E-01 2.35E+00 U TM 15 545456001 5/19/2021 Ac-228 -1.90E+00 3.72E+00 8.53E+00 U TM 15 545456001 5/19/2021 Ag-108m 1.56E-01 4.73E-01 1.54E+00 U TM 15 545456001 5/19/2021 Ag-110m -2.60E-01 7.60E-01 2.52E+00 U TM 15 545456001 5/19/2021 Ba-140 -2.90E+00 4.27E+00 1.32E+01 U TM 15 545456001 5/19/2021 Be-7 -2.49E+00 5.94E+00 1.67E+01 U TM 15 545456001 5/19/2021 Bi-214 9.05E-02 1.80E+00 4.29E+00 U TM 15 545456001 5/19/2021 Ce-141 -8.56E-01 1.13E+00 3.69E+00 U TM 15 545456001 5/19/2021 Ce-144 -4.18E+00 3.74E+00 1.20E+01 U TM 15 545456001 5/19/2021 Co-57 3.20E-01 5.09E-01 1.72E+00 U TM 15 545456001 5/19/2021 Co-58 -4.03E-02 6.90E-01 2.05E+00 U TM 15 545456001 5/19/2021 Co-60 4.82E-01 6.50E-01 2.17E+00 U TM 15 545456001 5/19/2021 Cr-51 6.07E-01 6.16E+00 2.03E+01 U TM 15 545456001 5/19/2021 Cs-134 -5.43E-01 6.25E-01 2.01E+00 U TM 15 545456001 5/19/2021 Cs-137 1.47E+00 8.43E-01 2.04E+00 U TM 15 545456001 5/19/2021 Fe-59 4.97E-01 1.51E+00 5.05E+00 U TM 15 545456001 5/19/2021 I-131 5.31E-01 2.98E-01 9.46E-01 U TM 15 545456001 5/19/2021 K-40 1.53E+03 7.46E+01 1.84E+01 TM 15 545456001 5/19/2021 La-140 8.94E-01 1.43E+00 4.23E+00 U TM 15 545456001 5/19/2021 Mn-54 -1.60E-01 5.47E-01 1.83E+00 U TM 15 545456001 5/19/2021 Nb-95 -8.22E-02 6.04E-01 2.04E+00 U TM 15 545456001 5/19/2021 Pb-212 8.52E-01 2.02E+00 3.78E+00 U TM 15 545456001 5/19/2021 Pb-214 9.93E-01 1.91E+00 4.53E+00 U TM 15 545456001 5/19/2021 Ru-103 -1.24E-01 6.66E-01 2.13E+00 U TM 15 545456001 5/19/2021 Ru-106 -7.91E+00 5.63E+00 1.61E+01 U TM 15 545456001 5/19/2021 Sb-124 -6.20E-01 1.22E+00 3.78E+00 U TM 15 545456001 5/19/2021 Sb-125 -4.52E-01 1.40E+00 4.49E+00 U TM 15 545456001 5/19/2021 Se-75 -7.06E-01 7.80E-01 2.48E+00 U TM 15 545456001 5/19/2021 Th-228 8.52E-01 2.02E+00 3.78E+00 U TM 15 545456001 5/19/2021 Zn-65 -1.54E+00 1.52E+00 4.74E+00 U TM 15 545456001 5/19/2021 Zr-95 8.41E-01 1.09E+00 3.70E+00 U TM 15 546358001 6/2/2021 Ac-228 -4.34E+00 5.22E+00 1.38E+01 U TM 15 546358001 6/2/2021 Ag-108m 4.79E-02 5.99E-01 2.04E+00 U TM 15 546358001 6/2/2021 Ag-110m 1.59E+00 1.14E+00 3.71E+00 U TM 15 546358001 6/2/2021 Ba-140 -3.30E-01 3.60E+00 1.20E+01 U TM 15 546358001 6/2/2021 Be-7 1.84E+00 5.77E+00 1.97E+01 U TM 15 546358001 6/2/2021 Bi-214 5.22E+00 3.81E+00 5.24E+00 U TM 15 546358001 6/2/2021 Ce-141 -4.86E-01 1.24E+00 4.06E+00 U TM 15 546358001 6/2/2021 Ce-144 0.00E+00 7.53E+00 1.45E+01 U TM 15 546358001 6/2/2021 Co-57 4.18E-01 6.02E-01 2.01E+00 U TM 15 546358001 6/2/2021 Co-58 9.38E-01 8.31E-01 2.74E+00 U TM 15 546358001 6/2/2021 Co-60 -2.73E+00 2.65E+00 2.80E+00 U TM 15 546358001 6/2/2021 Cr-51 -2.23E+01 1.08E+01 2.05E+01 U TM 15 546358001 6/2/2021 Cs-134 7.66E-02 8.27E-01 2.70E+00 U TM 15 546358001 6/2/2021 Cs-137 1.38E+00 1.53E+00 2.60E+00 U TM 15 546358001 6/2/2021 Fe-59 0.00E+00 4.33E+00 6.48E+00 U TM 15 546358001 6/2/2021 I-131 -2.14E-02 2.11E-01 5.98E-01 U TM 15 546358001 6/2/2021 K-40 1.61E+03 8.85E+01 2.43E+01

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

TM 15 546358001 6/2/2021 La-140 -8.07E-02 1.23E+00 4.03E+00 U TM 15 546358001 6/2/2021 Mn-54 4.87E-02 8.04E-01 2.61E+00 U TM 15 546358001 6/2/2021 Nb-95 4.37E-01 8.39E-01 2.77E+00 U TM 15 546358001 6/2/2021 Pb-212 2.69E+00 2.73E+00 5.34E+00 U TM 15 546358001 6/2/2021 Pb-214 4.17E+00 4.20E+00 6.60E+00 U TM 15 546358001 6/2/2021 Ru-103 1.08E-01 8.14E-01 2.75E+00 U TM 15 546358001 6/2/2021 Ru-106 2.65E+00 6.65E+00 2.23E+01 U TM 15 546358001 6/2/2021 Sb-124 -9.65E-02 1.72E+00 5.58E+00 U TM 15 546358001 6/2/2021 Sb-125 -8.82E-01 1.85E+00 6.17E+00 U TM 15 546358001 6/2/2021 Se-75 -2.84E-02 9.69E-01 3.08E+00 U TM 15 546358001 6/2/2021 Th-228 2.69E+00 2.73E+00 5.34E+00 U TM 15 546358001 6/2/2021 Zn-65 -1.96E+00 2.06E+00 6.56E+00 U TM 15 546358001 6/2/2021 Zr-95 -1.69E+00 1.48E+00 4.41E+00 U TM 15 547916001 6/16/2021 Ac-228 3.09E+00 2.08E+00 6.73E+00 U TM 15 547916001 6/16/2021 Ag-108m -4.40E-01 3.73E-01 1.19E+00 U TM 15 547916001 6/16/2021 Ag-110m 3.11E-01 6.49E-01 2.15E+00 U TM 15 547916001 6/16/2021 Ba-140 -8.93E+00 4.71E+00 1.06E+01 U TM 15 547916001 6/16/2021 Be-7 1.79E-01 3.76E+00 1.28E+01 U TM 15 547916001 6/16/2021 Bi-214 0.00E+00 2.43E+00 3.60E+00 U TM 15 547916001 6/16/2021 Ce-141 -3.66E-01 9.33E-01 2.78E+00 U TM 15 547916001 6/16/2021 Ce-144 2.44E-01 2.92E+00 9.60E+00 U TM 15 547916001 6/16/2021 Co-57 6.32E-01 4.21E-01 1.24E+00 U TM 15 547916001 6/16/2021 Co-58 1.83E-01 5.05E-01 1.68E+00 U TM 15 547916001 6/16/2021 Co-60 2.72E-01 5.51E-01 1.78E+00 U TM 15 547916001 6/16/2021 Cr-51 3.82E-01 5.07E+00 1.60E+01 U TM 15 547916001 6/16/2021 Cs-134 6.23E-01 4.82E-01 1.60E+00 U TM 15 547916001 6/16/2021 Cs-137 3.89E-01 4.36E-01 1.47E+00 U TM 15 547916001 6/16/2021 Fe-59 -9.19E-01 1.26E+00 3.89E+00 U TM 15 547916001 6/16/2021 I-131 -1.25E-02 2.42E-01 8.21E-01 U TM 15 547916001 6/16/2021 K-40 1.68E+03 8.11E+01 1.51E+01 TM 15 547916001 6/16/2021 La-140 -3.22E-01 8.84E-01 2.90E+00 U TM 15 547916001 6/16/2021 Mn-54 -7.62E-01 5.02E-01 1.45E+00 U TM 15 547916001 6/16/2021 Nb-95 -1.97E-01 5.19E-01 1.69E+00 U TM 15 547916001 6/16/2021 Pb-212 0.00E+00 1.48E+00 2.48E+00 U TM 15 547916001 6/16/2021 Pb-214 1.18E-01 1.66E+00 3.46E+00 U TM 15 547916001 6/16/2021 Ru-103 1.83E-01 5.35E-01 1.65E+00 U TM 15 547916001 6/16/2021 Ru-106 -1.01E+00 3.91E+00 1.30E+01 U TM 15 547916001 6/16/2021 Sb-124 -3.38E-01 1.05E+00 3.31E+00 U TM 15 547916001 6/16/2021 Sb-125 -8.98E-01 1.20E+00 3.54E+00 U TM 15 547916001 6/16/2021 Se-75 -8.20E-01 6.31E-01 1.84E+00 U TM 15 547916001 6/16/2021 Th-228 0.00E+00 1.48E+00 2.48E+00 U TM 15 547916001 6/16/2021 Zn-65 1.01E+00 1.23E+00 3.99E+00 U TM 15 547916001 6/16/2021 Zr-95 3.82E-01 8.67E-01 2.90E+00 U TM 15 550014001 7/14/2021 Ac-228 4.01E+00 4.86E+00 7.92E+00 U TM 15 550014001 7/14/2021 Ag-108m 1.02E+00 5.98E-01 1.92E+00 U TM 15 550014001 7/14/2021 Ag-110m 1.05E+00 9.43E-01 3.04E+00 U TM 15 550014001 7/14/2021 Ba-140 4.83E-01 4.19E+00 1.40E+01 U TM 15 550014001 7/14/2021 Be-7 3.44E+00 5.60E+00 1.88E+01 U TM 15 550014001 7/14/2021 Bi-214 3.40E+00 3.76E+00 4.23E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

TM 15 550014001 7/14/2021 Ce-141 2.84E+00 2.75E+00 3.81E+00 U TM 15 550014001 7/14/2021 Ce-144 -9.79E-01 4.08E+00 1.32E+01 U TM 15 550014001 7/14/2021 Co-57 -9.49E-01 5.88E-01 1.72E+00 U TM 15 550014001 7/14/2021 Co-58 -6.66E-01 7.35E-01 2.24E+00 U TM 15 550014001 7/14/2021 Co-60 -7.95E-01 6.74E-01 2.04E+00 U TM 15 550014001 7/14/2021 Cr-51 4.53E+00 6.50E+00 2.23E+01 U TM 15 550014001 7/14/2021 Cs-134 6.29E-02 7.08E-01 2.29E+00 U TM 15 550014001 7/14/2021 Cs-137 7.15E-01 1.33E+00 2.29E+00 U TM 15 550014001 7/14/2021 Fe-59 -5.01E-01 1.45E+00 4.82E+00 U TM 15 550014001 7/14/2021 I-131 2.23E-01 3.99E-01 1.32E+00 UDL TM 15 550014001 7/14/2021 K-40 1.63E+03 9.26E+01 1.91E+01 TM 15 550014001 7/14/2021 La-140 -2.99E-01 1.23E+00 3.99E+00 U TM 15 550014001 7/14/2021 Mn-54 1.05E+00 8.34E-01 2.19E+00 U TM 15 550014001 7/14/2021 Nb-95 -2.32E-01 6.97E-01 2.22E+00 U TM 15 550014001 7/14/2021 Pb-212 -1.57E-01 1.70E+00 4.10E+00 U TM 15 550014001 7/14/2021 Pb-214 -3.50E+00 2.61E+00 4.86E+00 U TM 15 550014001 7/14/2021 Ru-103 -4.40E-01 7.25E-01 2.36E+00 U TM 15 550014001 7/14/2021 Ru-106 -4.89E+00 6.13E+00 1.93E+01 U TM 15 550014001 7/14/2021 Sb-124 1.70E+00 1.79E+00 4.01E+00 U TM 15 550014001 7/14/2021 Sb-125 -1.55E+00 1.67E+00 5.34E+00 U TM 15 550014001 7/14/2021 Se-75 2.01E-01 8.66E-01 2.72E+00 U TM 15 550014001 7/14/2021 Th-228 -1.57E-01 1.70E+00 4.10E+00 U TM 15 550014001 7/14/2021 Zn-65 4.94E-01 1.67E+00 5.06E+00 U TM 15 550014001 7/14/2021 Zr-95 -1.67E+00 1.94E+00 3.95E+00 U TM 15 551095001 7/28/2021 Ac-228 7.10E+00 4.89E+00 7.97E+00 U TM 15 551095001 7/28/2021 Ag-108m -2.07E-01 4.52E-01 1.41E+00 U TM 15 551095001 7/28/2021 Ag-110m 1.05E-01 7.09E-01 2.32E+00 U TM 15 551095001 7/28/2021 Ba-140 2.03E+00 2.77E+00 9.34E+00 U TM 15 551095001 7/28/2021 Be-7 -4.96E+00 4.76E+00 1.33E+01 U TM 15 551095001 7/28/2021 Bi-214 0.00E+00 2.93E+00 3.24E+00 U TM 15 551095001 7/28/2021 Ce-141 -1.57E+00 1.35E+00 3.14E+00 U TM 15 551095001 7/28/2021 Ce-144 1.23E-01 3.22E+00 1.08E+01 U TM 15 551095001 7/28/2021 Co-57 2.03E-01 4.18E-01 1.41E+00 U TM 15 551095001 7/28/2021 Co-58 4.19E-02 5.54E-01 1.82E+00 U TM 15 551095001 7/28/2021 Co-60 -4.34E-01 5.99E-01 1.92E+00 U TM 15 551095001 7/28/2021 Cr-51 -5.05E+00 5.77E+00 1.59E+01 U TM 15 551095001 7/28/2021 Cs-134 -1.53E+00 8.99E-01 1.93E+00 U TM 15 551095001 7/28/2021 Cs-137 1.35E+00 6.48E-01 1.99E+00 U TM 15 551095001 7/28/2021 Fe-59 -8.26E-01 1.49E+00 4.03E+00 U TM 15 551095001 7/28/2021 I-131 9.88E-03 1.87E-01 6.18E-01 U TM 15 551095001 7/28/2021 K-40 1.77E+03 9.26E+01 1.46E+01 TM 15 551095001 7/28/2021 La-140 -9.94E-01 7.83E-01 2.28E+00 U TM 15 551095001 7/28/2021 Mn-54 2.24E-01 5.77E-01 1.77E+00 U TM 15 551095001 7/28/2021 Nb-95 -9.76E-01 8.68E-01 1.74E+00 U TM 15 551095001 7/28/2021 Pb-212 3.27E+00 2.09E+00 3.50E+00 U TM 15 551095001 7/28/2021 Pb-214 4.54E-02 2.68E+00 3.94E+00 U TM 15 551095001 7/28/2021 Ru-103 8.98E-03 5.18E-01 1.75E+00 U TM 15 551095001 7/28/2021 Ru-106 4.32E-01 4.24E+00 1.42E+01 U TM 15 551095001 7/28/2021 Sb-124 -5.34E-01 1.23E+00 3.36E+00 U TM 15 551095001 7/28/2021 Sb-125 7.62E-01 1.34E+00 4.29E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

TM 15 551095001 7/28/2021 Se-75 -1.05E+00 8.40E-01 2.27E+00 U TM 15 551095001 7/28/2021 Th-228 3.27E+00 2.09E+00 3.50E+00 U TM 15 551095001 7/28/2021 Zn-65 -2.04E+00 1.48E+00 4.28E+00 U TM 15 551095001 7/28/2021 Zr-95 4.34E-01 9.13E-01 3.03E+00 U TM 15 552751001 8/11/2021 Ac-228 2.66E-01 5.59E+00 9.90E+00 U TM 15 552751001 8/11/2021 Ag-108m 9.06E-01 5.47E-01 1.74E+00 U TM 15 552751001 8/11/2021 Ag-110m 1.44E+00 1.17E+00 2.86E+00 U TM 15 552751001 8/11/2021 Ba-140 -5.12E-01 2.75E+00 8.88E+00 U TM 15 552751001 8/11/2021 Be-7 2.73E+00 5.44E+00 1.61E+01 U TM 15 552751001 8/11/2021 Bi-214 3.57E+00 3.46E+00 3.97E+00 U TM 15 552751001 8/11/2021 Ce-141 -6.18E-01 1.18E+00 3.53E+00 U TM 15 552751001 8/11/2021 Ce-144 -1.92E+00 4.07E+00 1.36E+01 U TM 15 552751001 8/11/2021 Co-57 -6.21E-01 5.65E-01 1.82E+00 U TM 15 552751001 8/11/2021 Co-58 3.55E-01 6.30E-01 2.04E+00 U TM 15 552751001 8/11/2021 Co-60 -4.94E-01 7.26E-01 2.34E+00 U TM 15 552751001 8/11/2021 Cr-51 1.39E+01 6.72E+00 1.87E+01 U TM 15 552751001 8/11/2021 Cs-134 -2.47E+00 1.17E+00 2.19E+00 U TM 15 552751001 8/11/2021 Cs-137 0.00E+00 1.27E+00 2.05E+00 U TM 15 552751001 8/11/2021 Fe-59 4.16E-01 1.46E+00 4.99E+00 U TM 15 552751001 8/11/2021 I-131 1.48E-01 1.32E-01 4.48E-01 U TM 15 552751001 8/11/2021 K-40 1.68E+03 9.57E+01 2.13E+01 TM 15 552751001 8/11/2021 La-140 -8.97E-01 9.00E-01 2.73E+00 U TM 15 552751001 8/11/2021 Mn-54 -5.91E-01 6.62E-01 2.00E+00 U TM 15 552751001 8/11/2021 Nb-95 1.94E-01 6.54E-01 2.11E+00 U TM 15 552751001 8/11/2021 Pb-212 1.03E-02 2.69E+00 4.45E+00 U TM 15 552751001 8/11/2021 Pb-214 3.86E+00 1.64E+00 4.81E+00 U TM 15 552751001 8/11/2021 Ru-103 -1.04E+00 7.43E-01 1.93E+00 U TM 15 552751001 8/11/2021 Ru-106 4.78E+00 5.31E+00 1.73E+01 U TM 15 552751001 8/11/2021 Sb-124 1.57E+00 1.30E+00 4.48E+00 U TM 15 552751001 8/11/2021 Sb-125 1.39E+00 1.59E+00 5.24E+00 U TM 15 552751001 8/11/2021 Se-75 -3.71E-01 7.96E-01 2.61E+00 U TM 15 552751001 8/11/2021 Th-228 1.03E-02 2.69E+00 4.45E+00 U TM 15 552751001 8/11/2021 Zn-65 1.16E+00 1.64E+00 4.99E+00 U TM 15 552751001 8/11/2021 Zr-95 -5.16E-01 1.07E+00 3.34E+00 U TM 15 554148001 8/25/2021 Ac-228 1.66E+00 4.59E+00 9.59E+00 U TM 15 554148001 8/25/2021 Ag-108m -1.50E-01 4.83E-01 1.57E+00 U TM 15 554148001 8/25/2021 Ag-110m -1.11E+00 9.84E-01 2.89E+00 U TM 15 554148001 8/25/2021 Ba-140 6.66E+00 3.86E+00 1.11E+01 U TM 15 554148001 8/25/2021 Be-7 -1.34E+00 5.12E+00 1.66E+01 U TM 15 554148001 8/25/2021 Bi-214 3.42E+00 2.76E+00 3.74E+00 U TM 15 554148001 8/25/2021 Ce-141 2.40E-01 1.28E+00 3.92E+00 U TM 15 554148001 8/25/2021 Ce-144 2.01E+00 4.24E+00 1.44E+01 U TM 15 554148001 8/25/2021 Co-57 -1.53E-01 5.49E-01 1.85E+00 U TM 15 554148001 8/25/2021 Co-58 -3.09E-01 6.47E-01 2.02E+00 U TM 15 554148001 8/25/2021 Co-60 1.85E+00 8.20E-01 2.58E+00 U TM 15 554148001 8/25/2021 Cr-51 6.25E-01 6.13E+00 2.04E+01 U TM 15 554148001 8/25/2021 Cs-134 2.40E-01 6.97E-01 2.25E+00 U TM 15 554148001 8/25/2021 Cs-137 0.00E+00 8.62E-01 1.88E+00 U TM 15 554148001 8/25/2021 Fe-59 1.89E-01 1.55E+00 5.28E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

TM 15 554148001 8/25/2021 I-131 -3.93E-01 3.53E-01 7.25E-01 U TM 15 554148001 8/25/2021 K-40 1.72E+03 9.72E+01 1.86E+01 TM 15 554148001 8/25/2021 La-140 1.62E+00 1.12E+00 3.81E+00 U TM 15 554148001 8/25/2021 Mn-54 -8.92E-01 6.74E-01 1.94E+00 U TM 15 554148001 8/25/2021 Nb-95 5.94E-01 6.81E-01 2.20E+00 U TM 15 554148001 8/25/2021 Pb-212 5.16E-01 2.70E+00 4.45E+00 U TM 15 554148001 8/25/2021 Pb-214 1.18E+00 3.20E+00 4.96E+00 U TM 15 554148001 8/25/2021 Ru-103 4.22E-01 6.86E-01 2.03E+00 U TM 15 554148001 8/25/2021 Ru-106 -7.75E+00 5.79E+00 1.60E+01 U TM 15 554148001 8/25/2021 Sb-124 -2.01E+00 1.51E+00 4.33E+00 U TM 15 554148001 8/25/2021 Sb-125 -3.87E-01 1.61E+00 5.24E+00 U TM 15 554148001 8/25/2021 Se-75 6.33E-01 8.42E-01 2.81E+00 U TM 15 554148001 8/25/2021 Th-228 5.16E-01 2.70E+00 4.45E+00 U TM 15 554148001 8/25/2021 Zn-65 3.00E+00 2.01E+00 4.77E+00 U TM 15 554148001 8/25/2021 Zr-95 -7.43E-01 1.22E+00 3.78E+00 U TM 15 555713001 9/8/2021 Ac-228 1.13E+01 5.83E+00 1.18E+01 U TM 15 555713001 9/8/2021 Ag-108m 5.25E-01 5.76E-01 1.82E+00 U TM 15 555713001 9/8/2021 Ag-110m -8.94E-01 1.02E+00 3.25E+00 U TM 15 555713001 9/8/2021 Ba-140 4.95E+00 4.19E+00 1.35E+01 U TM 15 555713001 9/8/2021 Be-7 8.30E+00 6.24E+00 2.01E+01 U TM 15 555713001 9/8/2021 Bi-214 3.10E+00 3.13E+00 5.61E+00 U TM 15 555713001 9/8/2021 Ce-141 1.24E+00 1.91E+00 3.09E+00 U TM 15 555713001 9/8/2021 Ce-144 1.01E+00 3.71E+00 1.17E+01 U TM 15 555713001 9/8/2021 Co-57 5.04E-01 4.77E-01 1.49E+00 U TM 15 555713001 9/8/2021 Co-58 -1.67E+00 8.36E-01 2.31E+00 U TM 15 555713001 9/8/2021 Co-60 -7.11E-01 8.84E-01 2.74E+00 U TM 15 555713001 9/8/2021 Cr-51 5.07E+00 6.17E+00 2.06E+01 U TM 15 555713001 9/8/2021 Cs-134 5.60E-01 8.60E-01 2.63E+00 U TM 15 555713001 9/8/2021 Cs-137 1.95E+00 1.43E+00 2.57E+00 U TM 15 555713001 9/8/2021 Fe-59 1.38E-01 2.04E+00 6.78E+00 U TM 15 555713001 9/8/2021 I-131 -4.09E-02 2.25E-01 7.17E-01 U TM 15 555713001 9/8/2021 K-40 1.60E+03 8.43E+01 2.44E+01 TM 15 555713001 9/8/2021 La-140 4.30E-01 1.30E+00 4.15E+00 U TM 15 555713001 9/8/2021 Mn-54 -8.84E-01 1.06E+00 2.51E+00 U TM 15 555713001 9/8/2021 Nb-95 9.65E-01 7.74E-01 2.62E+00 U TM 15 555713001 9/8/2021 Pb-212 7.55E-01 2.25E+00 3.44E+00 U TM 15 555713001 9/8/2021 Pb-214 0.00E+00 4.17E+00 5.42E+00 U TM 15 555713001 9/8/2021 Ru-103 -1.61E+00 8.32E-01 2.26E+00 U TM 15 555713001 9/8/2021 Ru-106 2.29E+00 6.25E+00 2.03E+01 U TM 15 555713001 9/8/2021 Sb-124 -5.42E-01 2.03E+00 5.53E+00 U TM 15 555713001 9/8/2021 Sb-125 -1.13E+00 1.72E+00 5.48E+00 U TM 15 555713001 9/8/2021 Se-75 -4.66E-01 7.84E-01 2.59E+00 U TM 15 555713001 9/8/2021 Th-228 7.55E-01 2.25E+00 3.44E+00 U TM 15 555713001 9/8/2021 Zn-65 -4.66E+00 2.22E+00 5.89E+00 U TM 15 555713001 9/8/2021 Zr-95 1.11E+00 1.44E+00 4.63E+00 U TM 15 556849001 9/22/2021 Ac-228 4.91E+00 4.22E+00 1.01E+01 U TM 15 556849001 9/22/2021 Ag-108m -3.52E-01 5.66E-01 1.74E+00 U TM 15 556849001 9/22/2021 Ag-110m 5.07E-01 9.04E-01 3.03E+00 U TM 15 556849001 9/22/2021 Ba-140 1.21E-01 2.94E+00 9.78E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

TM 15 556849001 9/22/2021 Be-7 -2.21E+00 4.93E+00 1.63E+01 U TM 15 556849001 9/22/2021 Bi-214 -4.21E+00 2.48E+00 5.03E+00 U TM 15 556849001 9/22/2021 Ce-141 -1.02E+00 9.90E-01 3.03E+00 U TM 15 556849001 9/22/2021 Ce-144 5.21E+00 3.81E+00 1.21E+01 U TM 15 556849001 9/22/2021 Co-57 2.26E-01 4.78E-01 1.57E+00 U TM 15 556849001 9/22/2021 Co-58 -5.22E-01 7.00E-01 2.26E+00 U TM 15 556849001 9/22/2021 Co-60 -2.71E-01 7.47E-01 2.43E+00 U TM 15 556849001 9/22/2021 Cr-51 -1.65E+00 5.10E+00 1.66E+01 U TM 15 556849001 9/22/2021 Cs-134 5.48E-01 7.28E-01 2.47E+00 U TM 15 556849001 9/22/2021 Cs-137 0.00E+00 8.72E-01 2.18E+00 U TM 15 556849001 9/22/2021 Fe-59 1.35E+00 1.96E+00 5.57E+00 U TM 15 556849001 9/22/2021 I-131 -3.69E-01 3.05E-01 9.09E-01 U TM 15 556849001 9/22/2021 K-40 1.47E+03 7.42E+01 2.05E+01 TM 15 556849001 9/22/2021 La-140 -7.48E-01 9.86E-01 3.01E+00 U TM 15 556849001 9/22/2021 Mn-54 3.26E-01 6.65E-01 2.24E+00 U TM 15 556849001 9/22/2021 Nb-95 -2.18E-01 6.81E-01 2.27E+00 U TM 15 556849001 9/22/2021 Pb-212 -7.31E-01 1.41E+00 3.74E+00 U TM 15 556849001 9/22/2021 Pb-214 4.70E+00 3.26E+00 4.85E+00 U TM 15 556849001 9/22/2021 Ru-103 -6.33E-02 6.54E-01 2.19E+00 U TM 15 556849001 9/22/2021 Ru-106 -9.51E+00 6.39E+00 1.86E+01 U TM 15 556849001 9/22/2021 Sb-124 -2.11E+00 1.60E+00 4.72E+00 U TM 15 556849001 9/22/2021 Sb-125 2.46E-01 1.68E+00 5.33E+00 U TM 15 556849001 9/22/2021 Se-75 -1.05E-01 7.21E-01 2.41E+00 U TM 15 556849001 9/22/2021 Th-228 -7.31E-01 1.41E+00 3.74E+00 U TM 15 556849001 9/22/2021 Zn-65 -2.18E+00 1.89E+00 5.65E+00 U TM 15 556849001 9/22/2021 Zr-95 -1.22E+00 1.17E+00 3.72E+00 U TM 15 558374001 10/6/2021 Ac-228 -8.33E+00 4.26E+00 9.21E+00 U TM 15 558374001 10/6/2021 Ag-108m -5.68E-01 5.68E-01 1.53E+00 U TM 15 558374001 10/6/2021 Ag-110m -2.78E-02 1.33E+00 2.95E+00 U TM 15 558374001 10/6/2021 Ba-140 -2.93E+00 3.15E+00 9.47E+00 U TM 15 558374001 10/6/2021 Be-7 5.89E+00 5.34E+00 1.72E+01 U TM 15 558374001 10/6/2021 Bi-214 -2.48E+00 1.81E+00 4.81E+00 U TM 15 558374001 10/6/2021 Ce-141 9.41E-01 1.10E+00 3.22E+00 U TM 15 558374001 10/6/2021 Ce-144 -6.35E+00 3.95E+00 1.13E+01 U TM 15 558374001 10/6/2021 Co-57 -7.65E-03 4.92E-01 1.58E+00 U TM 15 558374001 10/6/2021 Co-58 1.29E+00 7.57E-01 2.18E+00 U TM 15 558374001 10/6/2021 Co-60 -1.37E-01 6.54E-01 2.16E+00 U TM 15 558374001 10/6/2021 Cr-51 -6.21E+00 5.51E+00 1.72E+01 U TM 15 558374001 10/6/2021 Cs-134 1.33E+00 7.22E-01 2.30E+00 U TM 15 558374001 10/6/2021 Cs-137 1.79E+00 1.02E+00 2.01E+00 U TM 15 558374001 10/6/2021 Fe-59 2.19E-02 1.62E+00 5.21E+00 U TM 15 558374001 10/6/2021 I-131 0.00E+00 2.48E-01 5.41E-01 U TM 15 558374001 10/6/2021 K-40 1.80E+03 9.56E+01 2.00E+01 TM 15 558374001 10/6/2021 La-140 9.47E-01 9.65E-01 3.24E+00 U TM 15 558374001 10/6/2021 Mn-54 7.50E-01 7.06E-01 2.08E+00 U TM 15 558374001 10/6/2021 Nb-95 -5.96E-01 9.24E-01 2.12E+00 U TM 15 558374001 10/6/2021 Pb-212 2.52E+00 2.35E+00 4.10E+00 U TM 15 558374001 10/6/2021 Pb-214 5.18E-01 3.20E+00 4.53E+00 U TM 15 558374001 10/6/2021 Ru-103 -1.39E+00 7.16E-01 1.91E+00 U TM 15 558374001 10/6/2021 Ru-106 -8.88E+00 5.58E+00 1.66E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

TM 15 558374001 10/6/2021 Sb-124 -2.10E+00 1.32E+00 3.51E+00 U TM 15 558374001 10/6/2021 Sb-125 2.96E-01 1.56E+00 5.10E+00 U TM 15 558374001 10/6/2021 Se-75 0.00E+00 1.60E+00 2.60E+00 U TM 15 558374001 10/6/2021 Th-228 2.52E+00 2.35E+00 4.10E+00 U TM 15 558374001 10/6/2021 Zn-65 -2.08E+00 1.69E+00 4.96E+00 U TM 15 558374001 10/6/2021 Zr-95 -1.64E+00 1.15E+00 3.40E+00 U TM 15 561297001 11/2/2021 Ac-228 -5.71E+00 4.72E+00 9.80E+00 U TM 15 561297001 11/2/2021 Ag-108m -8.04E-02 5.49E-01 1.75E+00 U TM 15 561297001 11/2/2021 Ag-110m 6.58E-01 8.82E-01 2.92E+00 U TM 15 561297001 11/2/2021 Ba-140 1.35E+00 3.57E+00 1.22E+01 U TM 15 561297001 11/2/2021 Be-7 8.36E+00 7.39E+00 1.82E+01 U TM 15 561297001 11/2/2021 Bi-214 2.31E+00 2.39E+00 3.99E+00 U TM 15 561297001 11/2/2021 Ce-141 -1.90E+00 1.20E+00 3.68E+00 U TM 15 561297001 11/2/2021 Ce-144 1.20E+00 3.93E+00 1.34E+01 U TM 15 561297001 11/2/2021 Co-57 -1.60E-01 5.25E-01 1.78E+00 U TM 15 561297001 11/2/2021 Co-58 8.59E-01 6.82E-01 2.24E+00 U TM 15 561297001 11/2/2021 Co-60 -1.15E-01 7.09E-01 2.37E+00 U TM 15 561297001 11/2/2021 Cr-51 -3.32E+00 6.29E+00 2.01E+01 U TM 15 561297001 11/2/2021 Cs-134 8.47E-01 7.59E-01 2.50E+00 U TM 15 561297001 11/2/2021 Cs-137 0.00E+00 9.94E-01 2.20E+00 U TM 15 561297001 11/2/2021 Fe-59 -1.38E+00 1.62E+00 4.98E+00 U TM 15 561297001 11/2/2021 I-131 -2.55E-02 2.30E-01 6.87E-01 U TM 15 561297001 11/2/2021 K-40 1.96E+03 1.01E+02 2.00E+01 TM 15 561297001 11/2/2021 La-140 -1.20E+00 1.10E+00 3.32E+00 U TM 15 561297001 11/2/2021 Mn-54 -2.65E-01 6.34E-01 2.05E+00 U TM 15 561297001 11/2/2021 Nb-95 1.04E+00 7.21E-01 2.34E+00 U TM 15 561297001 11/2/2021 Pb-212 -1.28E+00 1.79E+00 4.46E+00 U TM 15 561297001 11/2/2021 Pb-214 2.64E+00 2.49E+00 4.88E+00 U TM 15 561297001 11/2/2021 Ru-103 -1.29E+00 9.49E-01 2.32E+00 U TM 15 561297001 11/2/2021 Ru-106 9.92E-01 5.27E+00 1.78E+01 U TM 15 561297001 11/2/2021 Sb-124 -1.22E+00 1.37E+00 4.16E+00 U TM 15 561297001 11/2/2021 Sb-125 -8.74E-01 1.70E+00 5.33E+00 U TM 15 561297001 11/2/2021 Se-75 3.37E-01 8.35E-01 2.76E+00 U TM 15 561297001 11/2/2021 Th-228 -1.28E+00 1.79E+00 4.46E+00 U TM 15 561297001 11/2/2021 Zn-65 -2.82E+00 1.75E+00 4.93E+00 U TM 15 561297001 11/2/2021 Zr-95 -7.17E-01 1.23E+00 3.45E+00 U TM 15 563892001 12/1/2021 Ac-228 -4.98E+00 4.76E+00 1.01E+01 U TM 15 563892001 12/1/2021 Ag-108m -4.61E-02 5.42E-01 1.78E+00 U TM 15 563892001 12/1/2021 Ag-110m -4.13E-01 1.06E+00 2.92E+00 U TM 15 563892001 12/1/2021 Ba-140 -2.77E-01 4.47E+00 1.45E+01 U TM 15 563892001 12/1/2021 Be-7 6.01E+00 5.75E+00 1.88E+01 U TM 15 563892001 12/1/2021 Bi-214 4.77E-01 2.74E+00 4.07E+00 U TM 15 563892001 12/1/2021 Ce-141 4.90E-01 2.54E+00 3.85E+00 U TM 15 563892001 12/1/2021 Ce-144 -1.61E+00 4.39E+00 1.48E+01 U TM 15 563892001 12/1/2021 Co-57 5.12E-01 5.77E-01 1.94E+00 U TM 15 563892001 12/1/2021 Co-58 5.54E-01 7.31E-01 2.37E+00 U TM 15 563892001 12/1/2021 Co-60 7.09E-01 7.67E-01 2.61E+00 U TM 15 563892001 12/1/2021 Cr-51 -6.35E+00 7.28E+00 2.32E+01 U TM 15 563892001 12/1/2021 Cs-134 -5.00E-01 9.54E-01 2.25E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

TM 15 563892001 12/1/2021 Cs-137 4.68E+00 1.08E+00 1.99E+00 M TM 15 563892001 12/1/2021 Fe-59 5.83E-01 1.75E+00 5.98E+00 U TM 15 563892001 12/1/2021 I-131 -7.07E-02 1.46E-01 4.79E-01 U TM 15 563892001 12/1/2021 K-40 1.87E+03 1.05E+02 2.06E+01 TM 15 563892001 12/1/2021 La-140 3.28E-01 1.43E+00 4.25E+00 U TM 15 563892001 12/1/2021 Mn-54 -6.66E-01 7.64E-01 2.03E+00 U TM 15 563892001 12/1/2021 Nb-95 -2.07E+00 1.12E+00 2.28E+00 U TM 15 563892001 12/1/2021 Pb-212 8.12E-01 2.17E+00 3.65E+00 U TM 15 563892001 12/1/2021 Pb-214 0.00E+00 3.38E+00 5.19E+00 U TM 15 563892001 12/1/2021 Ru-103 -1.15E+00 7.90E-01 2.32E+00 U TM 15 563892001 12/1/2021 Ru-106 4.71E+00 5.46E+00 1.78E+01 U TM 15 563892001 12/1/2021 Sb-124 -5.55E-01 1.28E+00 3.94E+00 U TM 15 563892001 12/1/2021 Sb-125 -2.50E-01 1.65E+00 5.38E+00 U TM 15 563892001 12/1/2021 Se-75 -4.30E-01 9.33E-01 2.74E+00 U TM 15 563892001 12/1/2021 Th-228 8.12E-01 2.17E+00 3.65E+00 U TM 15 563892001 12/1/2021 Zn-65 2.53E+00 1.69E+00 5.62E+00 U TM 15 563892001 12/1/2021 Zr-95 -1.38E+00 1.32E+00 3.94E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WG 01 537618001 3/10/2021 Ac-228 -6.53E+00 3.89E+00 8.27E+00 U WG 01 537618001 3/10/2021 Ag-108m -6.91E-01 7.93E-01 1.84E+00 U WG 01 537618001 3/10/2021 Ag-110m 4.73E-01 8.52E-01 2.77E+00 U WG 01 537618001 3/10/2021 Ba-140 -1.29E+00 3.07E+00 9.98E+00 U WG 01 537618001 3/10/2021 Be-7 -4.05E+00 4.92E+00 1.57E+01 U WG 01 537618001 3/10/2021 BETA 5.23E+00 1.38E+00 3.48E+00 WG 01 537618001 3/10/2021 Bi-214 8.50E+00 2.60E+00 3.74E+00 X(1)

WG 01 537618001 3/10/2021 Ce-141 -1.31E+00 1.13E+00 3.42E+00 U WG 01 537618001 3/10/2021 Ce-144 -2.92E+00 3.93E+00 1.24E+01 U WG 01 537618001 3/10/2021 Co-57 2.34E-01 4.89E-01 1.60E+00 U WG 01 537618001 3/10/2021 Co-58 2.85E-01 5.81E-01 1.90E+00 U WG 01 537618001 3/10/2021 Co-60 -3.85E-01 5.31E-01 1.65E+00 U WG 01 537618001 3/10/2021 Cr-51 5.70E+00 5.83E+00 1.99E+01 U WG 01 537618001 3/10/2021 Cs-134 -7.78E-01 7.18E-01 2.13E+00 U WG 01 537618001 3/10/2021 Cs-137 -3.25E-01 6.12E-01 1.94E+00 U WG 01 537618001 3/10/2021 Fe-59 -5.41E-01 1.16E+00 3.80E+00 U WG 01 537618001 3/10/2021 H-3 -2.89E+01 8.17E+01 2.77E+02 U WG 01 537618001 3/10/2021 I-131 -5.99E-01 1.10E+00 3.64E+00 U WG 01 537618001 3/10/2021 K-40 0.00E+00 1.64E+01 1.70E+01 U WG 01 537618001 3/10/2021 La-140 -3.05E-01 1.03E+00 3.31E+00 U WG 01 537618001 3/10/2021 Mn-54 1.30E+00 6.98E-01 2.19E+00 U WG 01 537618001 3/10/2021 Nb-95 -2.50E-01 5.80E-01 1.83E+00 U WG 01 537618001 3/10/2021 Pb-212 1.84E+00 2.12E+00 3.65E+00 U WG 01 537618001 3/10/2021 Pb-214 7.43E+00 3.27E+00 4.33E+00 X(1)

WG 01 537618001 3/10/2021 Ru-103 2.26E-02 6.77E-01 2.02E+00 U WG 01 537618001 3/10/2021 Ru-106 -2.80E+00 5.86E+00 1.66E+01 U WG 01 537618001 3/10/2021 Sb-124 -6.78E-01 1.82E+00 4.63E+00 U WG 01 537618001 3/10/2021 Sb-125 1.54E+00 1.60E+00 5.41E+00 U WG 01 537618001 3/10/2021 Se-75 5.41E-01 8.41E-01 2.65E+00 U WG 01 537618001 3/10/2021 Th-228 1.84E+00 2.12E+00 3.65E+00 U WG 01 537618001 3/10/2021 Zn-65 8.25E-01 1.35E+00 4.12E+00 U WG 01 537618001 3/10/2021 Zr-95 -1.65E+00 1.15E+00 3.24E+00 U WG 01 546353001 6/2/2021 Ac-228 0.00E+00 5.67E+00 7.33E+00 U WG 01 546353001 6/2/2021 Ag-108m -8.85E-01 7.62E-01 1.61E+00 U WG 01 546353001 6/2/2021 Ag-110m 3.82E-01 6.49E-01 2.10E+00 U WG 01 546353001 6/2/2021 Ba-140 1.99E+00 2.36E+00 7.86E+00 U WG 01 546353001 6/2/2021 Be-7 6.22E+00 4.25E+00 1.39E+01 U WG 01 546353001 6/2/2021 BETA 5.92E+00 1.40E+00 3.29E+00 WG 01 546353001 6/2/2021 Bi-214 1.11E+01 2.48E+00 2.86E+00 X(1)

WG 01 546353001 6/2/2021 Ce-141 0.00E+00 1.69E+00 2.60E+00 U WG 01 546353001 6/2/2021 Ce-144 5.10E+00 3.40E+00 1.06E+01 U WG 01 546353001 6/2/2021 Co-57 1.91E-01 4.35E-01 1.42E+00 U WG 01 546353001 6/2/2021 Co-58 6.49E-02 5.84E-01 1.68E+00 U WG 01 546353001 6/2/2021 Co-60 -1.00E+00 5.45E-01 1.47E+00 U WG 01 546353001 6/2/2021 Cr-51 1.15E+00 4.59E+00 1.57E+01 U WG 01 546353001 6/2/2021 Cs-134 3.35E-01 5.48E-01 1.79E+00 U WG 01 546353001 6/2/2021 Cs-137 6.26E-01 5.11E-01 1.67E+00 U WG 01 546353001 6/2/2021 Fe-59 -1.29E+00 8.99E-01 2.65E+00 U WG 01 546353001 6/2/2021 H-3 1.91E+02 1.16E+02 2.98E+02 U WG 01 546353001 6/2/2021 I-131 7.90E-01 9.07E-01 3.07E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WG 01 546353001 6/2/2021 K-40 2.39E+00 1.10E+01 1.52E+01 U WG 01 546353001 6/2/2021 La-140 -1.68E+00 8.92E-01 2.30E+00 U WG 01 546353001 6/2/2021 Mn-54 -2.88E-01 4.95E-01 1.54E+00 U WG 01 546353001 6/2/2021 Nb-95 -7.95E-01 5.50E-01 1.58E+00 U WG 01 546353001 6/2/2021 Pb-212 -5.36E+00 2.24E+00 3.21E+00 U WG 01 546353001 6/2/2021 Pb-214 0.00E+00 2.45E+00 4.97E+00 U WG 01 546353001 6/2/2021 Ru-103 9.19E-02 4.95E-01 1.66E+00 U WG 01 546353001 6/2/2021 Ru-106 -1.41E+00 3.99E+00 1.29E+01 U WG 01 546353001 6/2/2021 Sb-124 -5.70E-01 9.67E-01 2.99E+00 U WG 01 546353001 6/2/2021 Sb-125 -1.38E+00 1.26E+00 3.99E+00 U WG 01 546353001 6/2/2021 Se-75 -6.92E-01 6.94E-01 2.05E+00 U WG 01 546353001 6/2/2021 Th-228 -5.36E+00 2.24E+00 3.21E+00 U WG 01 546353001 6/2/2021 Zn-65 -6.13E-01 1.06E+00 3.02E+00 U WG 01 546353001 6/2/2021 Zr-95 6.60E-02 8.85E-01 2.87E+00 U WG 01 555714001 9/9/2021 Ac-228 3.11E-01 3.93E+00 7.69E+00 U WG 01 555714001 9/9/2021 Ag-108m 1.80E-01 4.24E-01 1.42E+00 U WG 01 555714001 9/9/2021 Ag-110m 1.62E-01 6.15E-01 2.10E+00 U WG 01 555714001 9/9/2021 Ba-140 -2.96E+00 3.23E+00 9.93E+00 U WG 01 555714001 9/9/2021 Be-7 -7.53E+00 4.57E+00 1.30E+01 U WG 01 555714001 9/9/2021 BETA 1.41E+01 2.03E+00 3.54E+00 WG 01 555714001 9/9/2021 Bi-214 3.27E+00 2.32E+00 4.37E+00 U WG 01 555714001 9/9/2021 Ce-141 -2.93E+00 1.50E+00 2.94E+00 U WG 01 555714001 9/9/2021 Ce-144 -1.32E-01 3.21E+00 1.03E+01 U WG 01 555714001 9/9/2021 Co-57 -9.74E-02 4.29E-01 1.38E+00 U WG 01 555714001 9/9/2021 Co-58 1.69E-02 5.36E-01 1.61E+00 U WG 01 555714001 9/9/2021 Co-60 3.11E-01 5.33E-01 1.78E+00 U WG 01 555714001 9/9/2021 Cr-51 3.00E+00 5.13E+00 1.74E+01 U WG 01 555714001 9/9/2021 Cs-134 2.73E-02 5.06E-01 1.72E+00 U WG 01 555714001 9/9/2021 Cs-137 6.60E-01 5.76E-01 1.86E+00 U WG 01 555714001 9/9/2021 Fe-59 3.06E-01 1.14E+00 3.82E+00 U WG 01 555714001 9/9/2021 H-3 -5.16E+01 1.46E+02 4.88E+02 U WG 01 555714001 9/9/2021 I-131 -9.78E-01 1.34E+00 4.33E+00 U WG 01 555714001 9/9/2021 K-40 1.41E+01 1.33E+01 1.83E+01 U WG 01 555714001 9/9/2021 La-140 -1.84E+00 1.36E+00 3.05E+00 U WG 01 555714001 9/9/2021 Mn-54 -2.10E+00 9.75E-01 1.61E+00 U WG 01 555714001 9/9/2021 Nb-95 -1.89E-01 5.83E-01 1.82E+00 U WG 01 555714001 9/9/2021 Pb-212 -1.49E-01 1.62E+00 3.52E+00 U WG 01 555714001 9/9/2021 Pb-214 0.00E+00 2.56E+00 4.50E+00 U WG 01 555714001 9/9/2021 Ru-103 -1.18E+00 6.07E-01 1.63E+00 U WG 01 555714001 9/9/2021 Ru-106 7.16E+00 4.98E+00 1.60E+01 U WG 01 555714001 9/9/2021 Sb-124 -1.17E+00 1.32E+00 4.11E+00 U WG 01 555714001 9/9/2021 Sb-125 3.61E-01 2.52E+00 4.53E+00 U WG 01 555714001 9/9/2021 Se-75 2.47E-01 6.55E-01 2.25E+00 U WG 01 555714001 9/9/2021 Th-228 -1.49E-01 1.62E+00 3.52E+00 U WG 01 555714001 9/9/2021 Zn-65 1.39E+00 1.11E+00 3.73E+00 U WG 01 555714001 9/9/2021 Zr-95 1.57E+00 1.09E+00 3.48E+00 U WG 01 563876001 12/1/2021 Ac-228 1.48E-01 3.38E+00 4.82E+00 U WG 01 563876001 12/1/2021 Ag-108m -8.93E-02 2.88E-01 9.71E-01 U WG 01 563876001 12/1/2021 Ag-110m -3.15E-01 4.47E-01 1.39E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WG 01 563876001 12/1/2021 Ba-140 2.17E+00 4.45E+00 8.98E+00 U WG 01 563876001 12/1/2021 Be-7 -6.35E+00 5.52E+00 9.96E+00 U WG 01 563876001 12/1/2021 BETA 3.40E+00 1.30E+00 3.54E+00 U WG 01 563876001 12/1/2021 Bi-214 0.00E+00 1.81E+00 2.03E+00 U WG 01 563876001 12/1/2021 Ce-141 -1.70E+00 7.92E-01 2.14E+00 U WG 01 563876001 12/1/2021 Ce-144 2.32E+00 2.24E+00 7.26E+00 U WG 01 563876001 12/1/2021 Co-57 2.03E-01 2.78E-01 9.12E-01 U WG 01 563876001 12/1/2021 Co-58 -2.56E-01 3.68E-01 1.16E+00 U WG 01 563876001 12/1/2021 Co-60 -1.23E-01 3.27E-01 1.09E+00 U WG 01 563876001 12/1/2021 Cr-51 -2.27E+00 3.95E+00 1.21E+01 U WG 01 563876001 12/1/2021 Cs-134 1.78E-01 3.62E-01 1.20E+00 U WG 01 563876001 12/1/2021 Cs-137 -2.36E-01 3.42E-01 1.10E+00 U WG 01 563876001 12/1/2021 Fe-59 -5.10E-01 8.51E-01 2.31E+00 U WG 01 563876001 12/1/2021 H-3 2.45E+02 1.57E+02 4.72E+02 U WG 01 563876001 12/1/2021 I-131 -3.09E+00 1.44E+00 3.59E+00 U WG 01 563876001 12/1/2021 K-40 7.09E-01 1.06E+01 1.03E+01 U WG 01 563876001 12/1/2021 La-140 -5.18E-01 8.49E-01 2.73E+00 U WG 01 563876001 12/1/2021 Mn-54 6.28E-02 3.34E-01 1.10E+00 U WG 01 563876001 12/1/2021 Nb-95 2.52E-01 3.77E-01 1.26E+00 U WG 01 563876001 12/1/2021 Pb-212 -4.89E-01 1.16E+00 3.15E+00 U WG 01 563876001 12/1/2021 Pb-214 0.00E+00 1.87E+00 2.35E+00 U WG 01 563876001 12/1/2021 Ru-103 8.41E-02 4.11E-01 1.26E+00 U WG 01 563876001 12/1/2021 Ru-106 3.88E+00 3.08E+00 1.02E+01 U WG 01 563876001 12/1/2021 Sb-124 -6.40E-01 8.07E-01 2.52E+00 U WG 01 563876001 12/1/2021 Sb-125 -1.16E+00 8.44E-01 2.63E+00 U WG 01 563876001 12/1/2021 Se-75 6.01E-01 4.86E-01 1.52E+00 U WG 01 563876001 12/1/2021 Th-228 -4.89E-01 1.16E+00 3.15E+00 U WG 01 563876001 12/1/2021 Zn-65 5.77E-01 7.32E-01 2.17E+00 U WG 01 563876001 12/1/2021 Zr-95 6.78E-01 6.29E-01 2.09E+00 U WG 13 537618002 3/10/2021 Ac-228 6.30E+00 4.92E+00 9.04E+00 U WG 13 537618002 3/10/2021 Ag-108m -1.16E-01 5.22E-01 1.75E+00 U WG 13 537618002 3/10/2021 Ag-110m 2.27E-01 9.52E-01 2.78E+00 U WG 13 537618002 3/10/2021 Ba-140 -9.38E+00 4.60E+00 9.57E+00 U WG 13 537618002 3/10/2021 Be-7 3.38E+00 5.41E+00 1.84E+01 U WG 13 537618002 3/10/2021 BETA 1.73E+00 1.12E+00 3.36E+00 U WG 13 537618002 3/10/2021 Bi-214 2.77E+01 3.92E+00 3.65E+00 X(1)

WG 13 537618002 3/10/2021 Ce-141 -1.19E+00 1.30E+00 4.03E+00 U WG 13 537618002 3/10/2021 Ce-144 -4.07E+00 4.75E+00 1.49E+01 U WG 13 537618002 3/10/2021 Co-57 -3.38E-02 6.08E-01 1.99E+00 U WG 13 537618002 3/10/2021 Co-58 5.51E-01 6.87E-01 2.07E+00 U WG 13 537618002 3/10/2021 Co-60 2.09E+00 8.37E-01 2.66E+00 U WG 13 537618002 3/10/2021 Cr-51 -2.91E+00 6.75E+00 2.06E+01 U WG 13 537618002 3/10/2021 Cs-134 -2.15E-01 6.99E-01 2.23E+00 U WG 13 537618002 3/10/2021 Cs-137 -2.85E-01 6.32E-01 2.03E+00 U WG 13 537618002 3/10/2021 Fe-59 5.09E-01 1.36E+00 4.41E+00 U WG 13 537618002 3/10/2021 H-3 6.88E+01 9.06E+01 2.80E+02 U WG 13 537618002 3/10/2021 I-131 2.03E+00 1.25E+00 4.14E+00 U WG 13 537618002 3/10/2021 K-40 0.00E+00 1.98E+01 1.89E+01 U WG 13 537618002 3/10/2021 La-140 -5.04E-01 1.13E+00 3.63E+00 U WG 13 537618002 3/10/2021 Mn-54 -1.43E-01 6.23E-01 1.99E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WG 13 537618002 3/10/2021 Nb-95 -4.43E-01 7.00E-01 2.19E+00 U WG 13 537618002 3/10/2021 Pb-212 5.57E+00 2.46E+00 3.95E+00 X(1)

WG 13 537618002 3/10/2021 Pb-214 2.07E+01 3.64E+00 4.50E+00 X(1)

WG 13 537618002 3/10/2021 Ru-103 2.89E-01 6.19E-01 2.10E+00 U WG 13 537618002 3/10/2021 Ru-106 -3.79E+00 5.20E+00 1.64E+01 U WG 13 537618002 3/10/2021 Sb-124 1.42E+00 1.44E+00 4.98E+00 U WG 13 537618002 3/10/2021 Sb-125 -7.71E-01 1.69E+00 5.60E+00 U WG 13 537618002 3/10/2021 Se-75 -5.01E-01 9.25E-01 2.84E+00 U WG 13 537618002 3/10/2021 Th-228 5.57E+00 2.46E+00 3.95E+00 X(1)

WG 13 537618002 3/10/2021 Zn-65 1.72E+00 1.39E+00 4.20E+00 U WG 13 537618002 3/10/2021 Zr-95 -2.16E+00 1.16E+00 3.00E+00 U WG 13 546353002 6/2/2021 Ac-228 2.16E+00 4.83E+00 7.97E+00 U WG 13 546353002 6/2/2021 Ag-108m 4.21E-01 4.63E-01 1.49E+00 U WG 13 546353002 6/2/2021 Ag-110m -5.62E-01 6.97E-01 2.16E+00 U WG 13 546353002 6/2/2021 Ba-140 2.24E+00 2.62E+00 8.93E+00 U WG 13 546353002 6/2/2021 Be-7 7.21E+00 4.90E+00 1.54E+01 U WG 13 546353002 6/2/2021 BETA 2.87E+00 1.14E+00 3.08E+00 U WG 13 546353002 6/2/2021 Bi-214 2.27E+01 3.01E+00 3.65E+00 X(1)

WG 13 546353002 6/2/2021 Ce-141 1.73E+00 1.11E+00 3.28E+00 U WG 13 546353002 6/2/2021 Ce-144 -2.70E+00 3.52E+00 1.17E+01 U WG 13 546353002 6/2/2021 Co-57 -1.15E-01 4.97E-01 1.53E+00 U WG 13 546353002 6/2/2021 Co-58 1.53E-01 5.41E-01 1.80E+00 U WG 13 546353002 6/2/2021 Co-60 1.88E+00 1.04E+00 2.00E+00 U WG 13 546353002 6/2/2021 Cr-51 -5.81E-02 5.19E+00 1.69E+01 U WG 13 546353002 6/2/2021 Cs-134 -1.91E-01 5.16E-01 1.67E+00 U WG 13 546353002 6/2/2021 Cs-137 -4.71E-01 5.49E-01 1.75E+00 U WG 13 546353002 6/2/2021 Fe-59 -2.06E+00 1.86E+00 3.65E+00 U WG 13 546353002 6/2/2021 H-3 2.14E+02 1.15E+02 2.86E+02 U WG 13 546353002 6/2/2021 I-131 -9.82E-01 1.03E+00 3.17E+00 U WG 13 546353002 6/2/2021 K-40 -1.04E+01 9.30E+00 2.49E+01 U WG 13 546353002 6/2/2021 La-140 6.12E-01 1.03E+00 3.46E+00 U WG 13 546353002 6/2/2021 Mn-54 -6.96E-01 5.28E-01 1.56E+00 U WG 13 546353002 6/2/2021 Nb-95 -1.30E-01 8.22E-01 2.13E+00 U WG 13 546353002 6/2/2021 Pb-212 0.00E+00 2.10E+00 3.16E+00 U WG 13 546353002 6/2/2021 Pb-214 2.28E+01 3.40E+00 3.75E+00 X(1)

WG 13 546353002 6/2/2021 Ru-103 -5.01E-01 5.80E-01 1.75E+00 U WG 13 546353002 6/2/2021 Ru-106 -2.83E+00 4.41E+00 1.43E+01 U WG 13 546353002 6/2/2021 Sb-124 1.68E+00 1.29E+00 4.27E+00 U WG 13 546353002 6/2/2021 Sb-125 -6.21E-01 1.54E+00 4.29E+00 U WG 13 546353002 6/2/2021 Se-75 -4.32E-01 6.92E-01 2.23E+00 U WG 13 546353002 6/2/2021 Th-228 0.00E+00 2.10E+00 3.16E+00 U WG 13 546353002 6/2/2021 Zn-65 7.75E-01 1.15E+00 3.34E+00 U WG 13 546353002 6/2/2021 Zr-95 2.44E+00 1.08E+00 3.33E+00 U WG 13 555714002 9/9/2021 Ac-228 2.53E+00 4.71E+00 8.46E+00 U WG 13 555714002 9/9/2021 Ag-108m -3.28E-02 4.60E-01 1.48E+00 U WG 13 555714002 9/9/2021 Ag-110m -8.18E-02 6.75E-01 2.21E+00 U WG 13 555714002 9/9/2021 Ba-140 -4.95E+00 3.70E+00 1.06E+01 U WG 13 555714002 9/9/2021 Be-7 -2.70E-01 4.65E+00 1.49E+01 U WG 13 555714002 9/9/2021 BETA 1.72E+01 2.25E+00 3.09E+00

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WG 13 555714002 9/9/2021 Bi-214 0.00E+00 2.62E+00 4.42E+00 U WG 13 555714002 9/9/2021 Ce-141 9.09E-01 1.19E+00 3.43E+00 U WG 13 555714002 9/9/2021 Ce-144 -3.12E+00 3.69E+00 1.11E+01 U WG 13 555714002 9/9/2021 Co-57 2.50E-01 4.72E-01 1.49E+00 U WG 13 555714002 9/9/2021 Co-58 6.69E-01 5.52E-01 1.84E+00 U WG 13 555714002 9/9/2021 Co-60 -5.90E-01 5.06E-01 1.52E+00 U WG 13 555714002 9/9/2021 Cr-51 -6.90E+00 5.71E+00 1.75E+01 U WG 13 555714002 9/9/2021 Cs-134 1.04E+00 6.16E-01 2.01E+00 U WG 13 555714002 9/9/2021 Cs-137 1.41E-01 4.89E-01 1.66E+00 U WG 13 555714002 9/9/2021 Fe-59 -4.12E-01 1.18E+00 3.74E+00 U WG 13 555714002 9/9/2021 H-3 1.63E+02 1.59E+02 4.90E+02 U WG 13 555714002 9/9/2021 I-131 7.63E-01 1.51E+00 4.96E+00 U WG 13 555714002 9/9/2021 K-40 0.00E+00 1.49E+01 1.70E+01 U WG 13 555714002 9/9/2021 La-140 1.03E+00 1.17E+00 3.97E+00 U WG 13 555714002 9/9/2021 Mn-54 1.10E+00 7.90E-01 1.54E+00 U WG 13 555714002 9/9/2021 Nb-95 -1.60E+00 1.04E+00 1.80E+00 U WG 13 555714002 9/9/2021 Pb-212 -5.73E+00 2.50E+00 4.10E+00 U WG 13 555714002 9/9/2021 Pb-214 -6.87E-01 1.98E+00 4.14E+00 U WG 13 555714002 9/9/2021 Ru-103 -1.15E+00 6.65E-01 1.82E+00 U WG 13 555714002 9/9/2021 Ru-106 -7.90E+00 4.76E+00 1.39E+01 U WG 13 555714002 9/9/2021 Sb-124 -2.73E+00 1.80E+00 4.13E+00 U WG 13 555714002 9/9/2021 Sb-125 -2.15E+00 1.55E+00 4.52E+00 U WG 13 555714002 9/9/2021 Se-75 -5.48E-01 7.02E-01 2.26E+00 U WG 13 555714002 9/9/2021 Th-228 -5.73E+00 2.50E+00 4.10E+00 U WG 13 555714002 9/9/2021 Zn-65 -3.57E-01 1.23E+00 3.40E+00 U WG 13 555714002 9/9/2021 Zr-95 -1.27E+00 9.95E-01 3.00E+00 U WG 13 563876002 12/1/2021 Ac-228 -1.06E+00 3.81E+00 6.11E+00 U WG 13 563876002 12/1/2021 Ag-108m -4.17E-02 3.61E-01 1.17E+00 U WG 13 563876002 12/1/2021 Ag-110m -2.91E-01 5.84E-01 1.92E+00 U WG 13 563876002 12/1/2021 Ba-140 2.77E+00 3.29E+00 1.06E+01 U WG 13 563876002 12/1/2021 Be-7 -2.36E+00 4.19E+00 1.32E+01 U WG 13 563876002 12/1/2021 BETA 2.55E+00 1.15E+00 3.22E+00 U WG 13 563876002 12/1/2021 Bi-214 2.35E+00 2.32E+00 2.65E+00 U WG 13 563876002 12/1/2021 Ce-141 -1.02E+00 9.22E-01 2.96E+00 U WG 13 563876002 12/1/2021 Ce-144 6.86E+00 3.69E+00 9.26E+00 U WG 13 563876002 12/1/2021 Co-57 -3.80E-01 3.82E-01 1.24E+00 U WG 13 563876002 12/1/2021 Co-58 -3.37E-01 4.64E-01 1.51E+00 U WG 13 563876002 12/1/2021 Co-60 4.96E-01 6.36E-01 1.53E+00 U WG 13 563876002 12/1/2021 Cr-51 1.10E+01 8.65E+00 1.57E+01 U WG 13 563876002 12/1/2021 Cs-134 -2.34E-01 4.46E-01 1.47E+00 U WG 13 563876002 12/1/2021 Cs-137 3.77E-01 4.51E-01 1.45E+00 U WG 13 563876002 12/1/2021 Fe-59 5.42E-01 9.58E-01 3.22E+00 U WG 13 563876002 12/1/2021 H-3 -4.18E+01 1.45E+02 4.84E+02 U WG 13 563876002 12/1/2021 I-131 -1.16E+00 1.57E+00 4.95E+00 U WG 13 563876002 12/1/2021 K-40 0.00E+00 1.23E+01 1.37E+01 U WG 13 563876002 12/1/2021 La-140 -1.34E+00 1.18E+00 3.46E+00 U WG 13 563876002 12/1/2021 Mn-54 3.78E-01 4.22E-01 1.43E+00 U WG 13 563876002 12/1/2021 Nb-95 9.41E-01 5.68E-01 1.46E+00 U WG 13 563876002 12/1/2021 Pb-212 -1.82E+00 1.63E+00 2.96E+00 U WG 13 563876002 12/1/2021 Pb-214 -3.37E+00 1.91E+00 3.42E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WG 13 563876002 12/1/2021 Ru-103 -1.41E-01 5.30E-01 1.69E+00 U WG 13 563876002 12/1/2021 Ru-106 5.71E-02 3.88E+00 1.24E+01 U WG 13 563876002 12/1/2021 Sb-124 8.40E-01 1.20E+00 3.97E+00 U WG 13 563876002 12/1/2021 Sb-125 -9.75E-01 1.17E+00 3.66E+00 U WG 13 563876002 12/1/2021 Se-75 4.17E-01 5.95E-01 1.97E+00 U WG 13 563876002 12/1/2021 Th-228 -1.82E+00 1.63E+00 2.96E+00 U WG 13 563876002 12/1/2021 Zn-65 5.17E-01 1.00E+00 2.98E+00 U WG 13 563876002 12/1/2021 Zr-95 5.37E-01 8.00E-01 2.73E+00 U WG 14 537618003 3/10/2021 Ac-228 3.43E+00 2.34E+00 7.66E+00 U WG 14 537618003 3/10/2021 Ag-108m 3.96E-01 5.38E-01 1.85E+00 U WG 14 537618003 3/10/2021 Ag-110m -1.28E-01 8.12E-01 2.64E+00 U WG 14 537618003 3/10/2021 Ba-140 -1.02E+00 2.74E+00 9.09E+00 U WG 14 537618003 3/10/2021 Be-7 -9.20E+00 5.17E+00 1.50E+01 U WG 14 537618003 3/10/2021 BETA 2.64E+00 1.19E+00 3.42E+00 U WG 14 537618003 3/10/2021 Bi-214 1.68E+02 8.78E+00 3.67E+00 X(1)

WG 14 537618003 3/10/2021 Ce-141 -6.02E+00 2.05E+00 3.64E+00 U WG 14 537618003 3/10/2021 Ce-144 -5.51E+00 4.41E+00 1.35E+01 U WG 14 537618003 3/10/2021 Co-57 -4.59E-01 5.56E-01 1.77E+00 U WG 14 537618003 3/10/2021 Co-58 1.44E+00 9.34E-01 1.71E+00 U WG 14 537618003 3/10/2021 Co-60 1.46E-01 6.27E-01 2.02E+00 U WG 14 537618003 3/10/2021 Cr-51 -1.75E+00 7.37E+00 1.90E+01 U WG 14 537618003 3/10/2021 Cs-134 7.81E-01 6.20E-01 2.06E+00 U WG 14 537618003 3/10/2021 Cs-137 1.21E+00 6.43E-01 1.92E+00 U WG 14 537618003 3/10/2021 Fe-59 -1.76E+00 1.22E+00 3.37E+00 U WG 14 537618003 3/10/2021 H-3 1.07E+02 9.10E+01 2.71E+02 U WG 14 537618003 3/10/2021 I-131 -4.43E-01 1.13E+00 3.47E+00 U WG 14 537618003 3/10/2021 K-40 9.12E+00 1.34E+01 1.70E+01 U WG 14 537618003 3/10/2021 La-140 -2.31E+00 1.20E+00 3.20E+00 U WG 14 537618003 3/10/2021 Mn-54 -1.05E+00 6.97E-01 1.74E+00 U WG 14 537618003 3/10/2021 Nb-95 7.10E-01 6.48E-01 1.97E+00 U WG 14 537618003 3/10/2021 Pb-212 2.50E+00 2.03E+00 3.55E+00 U WG 14 537618003 3/10/2021 Pb-214 1.66E+02 8.57E+00 4.50E+00 X(1)

WG 14 537618003 3/10/2021 Ru-103 6.68E-02 5.98E-01 2.04E+00 U WG 14 537618003 3/10/2021 Ru-106 1.09E+01 5.53E+00 1.65E+01 U WG 14 537618003 3/10/2021 Sb-124 -4.28E-02 1.27E+00 4.24E+00 U WG 14 537618003 3/10/2021 Sb-125 1.55E+00 1.53E+00 5.21E+00 U WG 14 537618003 3/10/2021 Se-75 2.59E-01 8.06E-01 2.57E+00 U WG 14 537618003 3/10/2021 Th-228 2.50E+00 2.03E+00 3.55E+00 U WG 14 537618003 3/10/2021 Zn-65 9.48E-01 1.26E+00 3.76E+00 U WG 14 537618003 3/10/2021 Zr-95 1.56E-01 1.05E+00 3.50E+00 U WG 14 546353003 6/2/2021 Ac-228 -5.41E+00 3.72E+00 7.75E+00 U WG 14 546353003 6/2/2021 Ag-108m 4.07E-01 4.11E-01 1.37E+00 U WG 14 546353003 6/2/2021 Ag-110m 5.32E-01 6.45E-01 2.21E+00 U WG 14 546353003 6/2/2021 Ba-140 -7.63E-01 2.44E+00 7.91E+00 U WG 14 546353003 6/2/2021 Be-7 -1.94E+00 4.07E+00 1.32E+01 U WG 14 546353003 6/2/2021 BETA 3.65E+00 1.12E+00 2.75E+00 M WG 14 546353003 6/2/2021 Bi-214 5.22E+01 3.59E+00 2.82E+00 X(1)

WG 14 546353003 6/2/2021 Ce-141 0.00E+00 1.78E+00 2.72E+00 U WG 14 546353003 6/2/2021 Ce-144 1.20E+00 3.19E+00 1.04E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WG 14 546353003 6/2/2021 Co-57 5.23E-02 4.10E-01 1.34E+00 U WG 14 546353003 6/2/2021 Co-58 -4.26E-01 4.65E-01 1.38E+00 U WG 14 546353003 6/2/2021 Co-60 3.28E-01 4.81E-01 1.61E+00 U WG 14 546353003 6/2/2021 Cr-51 -7.04E+00 4.60E+00 1.41E+01 U WG 14 546353003 6/2/2021 Cs-134 5.88E-01 5.12E-01 1.65E+00 U WG 14 546353003 6/2/2021 Cs-137 1.35E+00 9.84E-01 1.37E+00 U WG 14 546353003 6/2/2021 Fe-59 1.78E+00 1.06E+00 3.46E+00 U WG 14 546353003 6/2/2021 H-3 -4.44E+00 8.18E+01 2.71E+02 U WG 14 546353003 6/2/2021 I-131 1.22E+00 9.48E-01 3.15E+00 U WG 14 546353003 6/2/2021 K-40 -1.41E+01 1.06E+01 2.32E+01 U WG 14 546353003 6/2/2021 La-140 2.26E-02 9.09E-01 2.94E+00 U WG 14 546353003 6/2/2021 Mn-54 1.12E-01 4.54E-01 1.45E+00 U WG 14 546353003 6/2/2021 Nb-95 -5.22E-01 7.97E-01 1.69E+00 U WG 14 546353003 6/2/2021 Pb-212 2.66E+00 1.58E+00 2.92E+00 U WG 14 546353003 6/2/2021 Pb-214 5.09E+01 3.70E+00 3.34E+00 X(1)

WG 14 546353003 6/2/2021 Ru-103 -8.54E-02 5.48E-01 1.61E+00 U WG 14 546353003 6/2/2021 Ru-106 7.26E+00 4.34E+00 1.38E+01 U WG 14 546353003 6/2/2021 Sb-124 1.73E-01 1.20E+00 3.90E+00 U WG 14 546353003 6/2/2021 Sb-125 6.53E-01 1.23E+00 4.15E+00 U WG 14 546353003 6/2/2021 Se-75 1.11E+00 7.20E-01 2.18E+00 U WG 14 546353003 6/2/2021 Th-228 2.66E+00 1.58E+00 2.92E+00 U WG 14 546353003 6/2/2021 Zn-65 -1.12E+00 1.05E+00 2.77E+00 U WG 14 546353003 6/2/2021 Zr-95 -1.82E-01 1.33E+00 2.72E+00 U WG 14 555714003 9/9/2021 Ac-228 2.98E+00 3.94E+00 7.77E+00 U WG 14 555714003 9/9/2021 Ag-108m -2.77E-01 4.50E-01 1.44E+00 U WG 14 555714003 9/9/2021 Ag-110m -3.86E-01 6.75E-01 2.19E+00 U WG 14 555714003 9/9/2021 Ba-140 -2.87E-01 3.31E+00 1.07E+01 U WG 14 555714003 9/9/2021 Be-7 -1.19E-01 4.82E+00 1.57E+01 U WG 14 555714003 9/9/2021 BETA 3.05E+00 9.12E-01 2.08E+00 M WG 14 555714003 9/9/2021 Bi-214 7.40E+01 4.21E+00 3.23E+00 X(1)

WG 14 555714003 9/9/2021 Ce-141 7.39E-01 1.15E+00 3.39E+00 U WG 14 555714003 9/9/2021 Ce-144 2.76E+00 3.72E+00 1.19E+01 U WG 14 555714003 9/9/2021 Co-57 3.60E-02 4.73E-01 1.53E+00 U WG 14 555714003 9/9/2021 Co-58 -1.64E-01 5.28E-01 1.75E+00 U WG 14 555714003 9/9/2021 Co-60 4.42E-01 5.66E-01 1.86E+00 U WG 14 555714003 9/9/2021 Cr-51 1.36E+00 5.43E+00 1.83E+01 U WG 14 555714003 9/9/2021 Cs-134 3.47E-01 5.25E-01 1.79E+00 U WG 14 555714003 9/9/2021 Cs-137 -7.06E-01 5.54E-01 1.60E+00 U WG 14 555714003 9/9/2021 Fe-59 2.18E-02 1.08E+00 3.53E+00 U WG 14 555714003 9/9/2021 H-3 3.04E+02 1.69E+02 4.95E+02 U WG 14 555714003 9/9/2021 I-131 -3.60E+00 1.64E+00 4.40E+00 U WG 14 555714003 9/9/2021 K-40 -7.84E+00 1.10E+01 2.48E+01 U WG 14 555714003 9/9/2021 La-140 -2.64E-01 1.12E+00 3.71E+00 U WG 14 555714003 9/9/2021 Mn-54 -8.41E-01 5.23E-01 1.53E+00 U WG 14 555714003 9/9/2021 Nb-95 1.72E+00 7.90E-01 1.80E+00 U WG 14 555714003 9/9/2021 Pb-212 -2.30E+00 1.68E+00 3.55E+00 U WG 14 555714003 9/9/2021 Pb-214 7.52E+01 5.22E+00 3.65E+00 X(1)

WG 14 555714003 9/9/2021 Ru-103 -6.91E-01 6.46E-01 1.98E+00 U WG 14 555714003 9/9/2021 Ru-106 -4.68E+00 5.11E+00 1.36E+01 U WG 14 555714003 9/9/2021 Sb-124 -6.46E-01 1.25E+00 4.01E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WG 14 555714003 9/9/2021 Sb-125 1.14E+00 1.34E+00 4.44E+00 U WG 14 555714003 9/9/2021 Se-75 -9.04E-01 1.14E+00 2.28E+00 U WG 14 555714003 9/9/2021 Th-228 -2.30E+00 1.68E+00 3.55E+00 U WG 14 555714003 9/9/2021 Zn-65 1.06E+00 1.10E+00 3.25E+00 U WG 14 555714003 9/9/2021 Zr-95 0.00E+00 2.53E+00 3.24E+00 U WG 14 563876003 12/1/2021 Ac-228 -2.79E+00 3.39E+00 6.16E+00 U WG 14 563876003 12/1/2021 Ag-108m -1.54E-01 3.30E-01 1.09E+00 U WG 14 563876003 12/1/2021 Ag-110m -1.33E-01 5.76E-01 1.82E+00 U WG 14 563876003 12/1/2021 Ba-140 -2.20E+00 3.23E+00 1.03E+01 U WG 14 563876003 12/1/2021 Be-7 1.76E+00 3.63E+00 1.22E+01 U WG 14 563876003 12/1/2021 BETA 2.10E+00 1.06E+00 2.95E+00 U WG 14 563876003 12/1/2021 Bi-214 2.76E+01 2.78E+00 2.54E+00 X(1)

WG 14 563876003 12/1/2021 Ce-141 2.03E-01 8.02E-01 2.38E+00 U WG 14 563876003 12/1/2021 Ce-144 -1.32E+00 2.60E+00 7.59E+00 U WG 14 563876003 12/1/2021 Co-57 1.40E-01 3.00E-01 9.70E-01 U WG 14 563876003 12/1/2021 Co-58 2.14E-01 4.74E-01 1.54E+00 U WG 14 563876003 12/1/2021 Co-60 1.64E+00 7.84E-01 1.66E+00 U WG 14 563876003 12/1/2021 Cr-51 -1.83E+00 4.39E+00 1.48E+01 U WG 14 563876003 12/1/2021 Cs-134 4.65E-01 4.60E-01 1.49E+00 U WG 14 563876003 12/1/2021 Cs-137 2.19E-01 4.78E-01 1.41E+00 U WG 14 563876003 12/1/2021 Fe-59 -8.24E-02 9.57E-01 3.21E+00 U WG 14 563876003 12/1/2021 H-3 2.59E+02 1.66E+02 4.98E+02 U WG 14 563876003 12/1/2021 I-131 -2.93E+00 1.63E+00 4.79E+00 U WG 14 563876003 12/1/2021 K-40 -9.98E+00 9.75E+00 1.87E+01 U WG 14 563876003 12/1/2021 La-140 7.47E-01 1.15E+00 3.85E+00 U WG 14 563876003 12/1/2021 Mn-54 -3.71E-01 4.40E-01 1.34E+00 U WG 14 563876003 12/1/2021 Nb-95 1.15E+00 6.15E-01 1.72E+00 U WG 14 563876003 12/1/2021 Pb-212 3.20E+00 1.58E+00 2.03E+00 X(1)

WG 14 563876003 12/1/2021 Pb-214 2.70E+01 2.82E+00 5.44E+00 X(1)

WG 14 563876003 12/1/2021 Ru-103 -4.34E-01 5.29E-01 1.50E+00 U WG 14 563876003 12/1/2021 Ru-106 -3.46E+00 3.84E+00 1.19E+01 U WG 14 563876003 12/1/2021 Sb-124 1.03E+00 1.16E+00 3.85E+00 U WG 14 563876003 12/1/2021 Sb-125 -1.89E+00 1.11E+00 3.25E+00 U WG 14 563876003 12/1/2021 Se-75 5.14E-01 6.16E-01 1.70E+00 U WG 14 563876003 12/1/2021 Th-228 3.20E+00 1.58E+00 2.03E+00 X(1)

WG 14 563876003 12/1/2021 Zn-65 2.88E-01 9.53E-01 2.87E+00 U WG 14 563876003 12/1/2021 Zr-95 -1.42E+00 8.42E-01 2.32E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 01 532364001 1/12/2021 Ac-228 -1.30E+00 3.51E+00 7.50E+00 U WS 01 532364001 1/12/2021 Ag-108m -5.37E-01 4.25E-01 1.33E+00 U WS 01 532364001 1/12/2021 Ag-110m 8.68E-01 6.99E-01 2.31E+00 U WS 01 532364001 1/12/2021 Ba-140 7.80E-01 2.22E+00 7.57E+00 U WS 01 532364001 1/12/2021 Be-7 6.16E-01 3.91E+00 1.33E+01 U WS 01 532364001 1/12/2021 Bi-214 0.00E+00 2.45E+00 2.99E+00 U WS 01 532364001 1/12/2021 Ce-141 1.55E+00 1.19E+00 2.50E+00 U WS 01 532364001 1/12/2021 Ce-144 -2.40E+00 3.07E+00 9.79E+00 U WS 01 532364001 1/12/2021 Co-57 -2.55E-01 4.04E-01 1.31E+00 U WS 01 532364001 1/12/2021 Co-58 -1.40E-01 4.91E-01 1.58E+00 U WS 01 532364001 1/12/2021 Co-60 -1.08E-02 5.63E-01 1.90E+00 U WS 01 532364001 1/12/2021 Cr-51 -3.17E+00 4.53E+00 1.37E+01 U WS 01 532364001 1/12/2021 Cs-134 -2.02E-01 5.33E-01 1.71E+00 U WS 01 532364001 1/12/2021 Cs-137 2.35E-01 4.90E-01 1.65E+00 U WS 01 532364001 1/12/2021 Fe-59 2.56E+00 1.48E+00 3.64E+00 U WS 01 532364001 1/12/2021 I-131 -8.66E-01 9.97E-01 2.95E+00 U WS 01 532364001 1/12/2021 K-40 3.09E+02 2.53E+01 1.71E+01 WS 01 532364001 1/12/2021 La-140 9.36E-01 1.38E+00 2.53E+00 U WS 01 532364001 1/12/2021 Mn-54 1.15E+00 8.28E-01 1.59E+00 U WS 01 532364001 1/12/2021 Nb-95 3.56E-01 4.56E-01 1.53E+00 U WS 01 532364001 1/12/2021 Pb-212 -1.24E+00 1.90E+00 3.60E+00 U WS 01 532364001 1/12/2021 Pb-214 1.69E+00 2.18E+00 4.31E+00 U WS 01 532364001 1/12/2021 Ru-103 -8.33E-02 4.53E-01 1.52E+00 U WS 01 532364001 1/12/2021 Ru-106 -1.91E+00 4.24E+00 1.38E+01 U WS 01 532364001 1/12/2021 Sb-124 -5.71E-01 1.76E+00 4.13E+00 U WS 01 532364001 1/12/2021 Sb-125 1.93E+00 1.36E+00 4.57E+00 U WS 01 532364001 1/12/2021 Se-75 1.23E+00 8.21E-01 2.11E+00 U WS 01 532364001 1/12/2021 Th-228 -1.24E+00 1.90E+00 3.60E+00 U WS 01 532364001 1/12/2021 Zn-65 1.35E+00 1.19E+00 3.74E+00 U WS 01 532364001 1/12/2021 Zr-95 -4.38E-01 8.61E-01 2.74E+00 U WS 01 535172001 2/10/2021 Ac-228 1.67E+00 3.79E+00 9.60E+00 U WS 01 535172001 2/10/2021 Ag-108m -7.46E-02 5.78E-01 1.84E+00 U WS 01 535172001 2/10/2021 Ag-110m -1.24E-01 8.18E-01 2.72E+00 U WS 01 535172001 2/10/2021 Ba-140 2.46E+00 3.54E+00 1.14E+01 U WS 01 535172001 2/10/2021 Be-7 -4.01E+00 5.56E+00 1.70E+01 U WS 01 535172001 2/10/2021 Bi-214 0.00E+00 2.79E+00 5.01E+00 U WS 01 535172001 2/10/2021 Ce-141 6.75E-01 1.29E+00 3.85E+00 U WS 01 535172001 2/10/2021 Ce-144 1.70E+00 4.30E+00 1.43E+01 U WS 01 535172001 2/10/2021 Co-57 4.33E-01 5.94E-01 1.97E+00 U WS 01 535172001 2/10/2021 Co-58 -7.26E-01 6.50E-01 2.00E+00 U WS 01 535172001 2/10/2021 Co-60 -3.14E-01 6.66E-01 2.12E+00 U WS 01 535172001 2/10/2021 Cr-51 -4.99E-01 5.68E+00 1.83E+01 U WS 01 535172001 2/10/2021 Cs-134 -3.95E-01 7.84E-01 2.24E+00 U WS 01 535172001 2/10/2021 Cs-137 4.22E-01 6.17E-01 2.12E+00 U WS 01 535172001 2/10/2021 Fe-59 -4.02E-01 1.76E+00 4.54E+00 U WS 01 535172001 2/10/2021 I-131 0.00E+00 1.97E+00 3.49E+00 U WS 01 535172001 2/10/2021 K-40 3.29E+02 2.53E+01 1.85E+01 WS 01 535172001 2/10/2021 La-140 1.34E-02 9.55E-01 3.11E+00 U WS 01 535172001 2/10/2021 Mn-54 -2.06E-01 6.39E-01 2.11E+00 U WS 01 535172001 2/10/2021 Nb-95 1.08E+00 6.71E-01 2.24E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 01 535172001 2/10/2021 Pb-212 8.37E-02 1.70E+00 4.31E+00 U WS 01 535172001 2/10/2021 Pb-214 4.73E+00 2.94E+00 5.33E+00 U WS 01 535172001 2/10/2021 Ru-103 -2.70E-01 6.64E-01 2.07E+00 U WS 01 535172001 2/10/2021 Ru-106 5.29E+00 5.69E+00 1.95E+01 U WS 01 535172001 2/10/2021 Sb-124 -1.80E+00 1.56E+00 4.42E+00 U WS 01 535172001 2/10/2021 Sb-125 -2.39E-01 1.77E+00 5.64E+00 U WS 01 535172001 2/10/2021 Se-75 -1.57E-01 8.55E-01 2.77E+00 U WS 01 535172001 2/10/2021 Th-228 8.37E-02 1.70E+00 4.31E+00 U WS 01 535172001 2/10/2021 Zn-65 -2.21E+00 1.43E+00 4.02E+00 U WS 01 535172001 2/10/2021 Zr-95 -9.14E-01 1.83E+00 4.12E+00 U WS 01 538500001 3/17/2021 Ac-228 2.39E+00 4.32E+00 7.31E+00 U WS 01 538500001 3/17/2021 Ag-108m -1.59E-01 3.82E-01 1.26E+00 U WS 01 538500001 3/17/2021 Ag-110m 5.10E-02 6.05E-01 2.06E+00 U WS 01 538500001 3/17/2021 Ba-140 4.37E+00 3.00E+00 7.28E+00 U WS 01 538500001 3/17/2021 Be-7 -4.53E+00 3.98E+00 1.23E+01 U WS 01 538500001 3/17/2021 Bi-214 -2.73E+00 1.91E+00 3.63E+00 U WS 01 538500001 3/17/2021 Ce-141 -1.75E+00 8.74E-01 2.39E+00 U WS 01 538500001 3/17/2021 Ce-144 -6.65E-01 2.85E+00 9.23E+00 U WS 01 538500001 3/17/2021 Co-57 -5.32E-01 4.02E-01 1.22E+00 U WS 01 538500001 3/17/2021 Co-58 -7.29E-01 5.97E-01 1.40E+00 U WS 01 538500001 3/17/2021 Co-60 -6.67E-01 5.06E-01 1.47E+00 U WS 01 538500001 3/17/2021 Cr-51 -2.99E+00 3.80E+00 1.25E+01 U WS 01 538500001 3/17/2021 Cs-134 1.83E+00 6.99E-01 1.84E+00 U WS 01 538500001 3/17/2021 Cs-137 -5.99E-01 8.84E-01 2.05E+00 U WS 01 538500001 3/17/2021 Fe-59 4.16E-01 9.91E-01 3.34E+00 U WS 01 538500001 3/17/2021 I-131 -1.60E+00 8.02E-01 2.26E+00 U WS 01 538500001 3/17/2021 K-40 3.38E+02 2.51E+01 1.51E+01 WS 01 538500001 3/17/2021 La-140 -6.05E-01 7.67E-01 2.32E+00 U WS 01 538500001 3/17/2021 Mn-54 1.14E-01 4.76E-01 1.36E+00 U WS 01 538500001 3/17/2021 Nb-95 -4.84E-01 6.82E-01 1.64E+00 U WS 01 538500001 3/17/2021 Pb-212 9.35E-01 1.86E+00 2.58E+00 U WS 01 538500001 3/17/2021 Pb-214 4.78E-01 1.52E+00 3.83E+00 U WS 01 538500001 3/17/2021 Ru-103 -1.49E-02 4.92E-01 1.45E+00 U WS 01 538500001 3/17/2021 Ru-106 6.89E+00 4.03E+00 1.28E+01 U WS 01 538500001 3/17/2021 Sb-124 3.10E+00 1.99E+00 3.84E+00 U WS 01 538500001 3/17/2021 Sb-125 1.80E-01 1.13E+00 3.80E+00 U WS 01 538500001 3/17/2021 Se-75 6.82E-01 6.37E-01 1.98E+00 U WS 01 538500001 3/17/2021 Th-228 9.35E-01 1.86E+00 2.58E+00 U WS 01 538500001 3/17/2021 Zn-65 2.53E+00 1.19E+00 3.73E+00 U WS 01 538500001 3/17/2021 Zr-95 2.01E-01 7.81E-01 2.52E+00 U WS 01 543399001 3/17/2021 H-3 -1.34E+02 1.42E+02 4.92E+02 U WS 01 541846001 4/19/2021 Ac-228 -2.56E+00 3.65E+00 7.68E+00 U WS 01 541846001 4/19/2021 Ag-108m -2.97E-01 4.53E-01 1.46E+00 U WS 01 541846001 4/19/2021 Ag-110m -4.56E-01 6.68E-01 2.02E+00 U WS 01 541846001 4/19/2021 Ba-140 3.37E+00 2.93E+00 8.81E+00 U WS 01 541846001 4/19/2021 Be-7 5.16E+00 4.61E+00 1.53E+01 U WS 01 541846001 4/19/2021 Bi-214 -1.95E+00 2.20E+00 4.34E+00 U WS 01 541846001 4/19/2021 Ce-141 -2.74E+00 1.77E+00 3.06E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 01 541846001 4/19/2021 Ce-144 -2.20E+00 3.74E+00 1.16E+01 U WS 01 541846001 4/19/2021 Co-57 1.54E-01 4.75E-01 1.52E+00 U WS 01 541846001 4/19/2021 Co-58 -1.39E-01 4.97E-01 1.57E+00 U WS 01 541846001 4/19/2021 Co-60 -5.22E-01 5.04E-01 1.52E+00 U WS 01 541846001 4/19/2021 Cr-51 -7.80E+00 5.57E+00 1.63E+01 U WS 01 541846001 4/19/2021 Cs-134 9.97E-02 5.60E-01 1.81E+00 U WS 01 541846001 4/19/2021 Cs-137 1.20E-04 5.12E-01 1.66E+00 U WS 01 541846001 4/19/2021 Fe-59 -4.02E-01 1.17E+00 3.39E+00 U WS 01 541846001 4/19/2021 I-131 3.08E+00 1.21E+00 3.56E+00 U WS 01 541846001 4/19/2021 K-40 3.60E+02 2.85E+01 1.58E+01 WS 01 541846001 4/19/2021 La-140 -1.14E+00 9.92E-01 2.89E+00 U WS 01 541846001 4/19/2021 Mn-54 2.50E-01 5.01E-01 1.63E+00 U WS 01 541846001 4/19/2021 Nb-95 -3.05E-01 8.56E-01 1.71E+00 U WS 01 541846001 4/19/2021 Pb-212 8.15E-01 2.24E+00 3.16E+00 U WS 01 541846001 4/19/2021 Pb-214 2.50E+00 3.10E+00 4.32E+00 U WS 01 541846001 4/19/2021 Ru-103 1.67E-01 5.44E-01 1.81E+00 U WS 01 541846001 4/19/2021 Ru-106 7.38E+00 5.36E+00 1.58E+01 U WS 01 541846001 4/19/2021 Sb-124 -2.03E-01 1.30E+00 4.21E+00 U WS 01 541846001 4/19/2021 Sb-125 1.11E+00 1.33E+00 4.47E+00 U WS 01 541846001 4/19/2021 Se-75 7.64E-01 6.93E-01 2.34E+00 U WS 01 541846001 4/19/2021 Th-228 8.15E-01 2.24E+00 3.16E+00 U WS 01 541846001 4/19/2021 Zn-65 -3.75E-01 1.03E+00 3.39E+00 U WS 01 541846001 4/19/2021 Zr-95 -1.28E+00 9.22E-01 2.60E+00 U WS 01 544777001 5/11/2021 Ac-228 -6.27E-01 3.40E+00 7.93E+00 U WS 01 544777001 5/11/2021 Ag-108m -1.14E-01 4.57E-01 1.45E+00 U WS 01 544777001 5/11/2021 Ag-110m -2.56E-01 6.90E-01 2.24E+00 U WS 01 544777001 5/11/2021 Ba-140 1.02E+00 2.92E+00 9.37E+00 U WS 01 544777001 5/11/2021 Be-7 1.23E+01 6.20E+00 1.43E+01 U WS 01 544777001 5/11/2021 Bi-214 -4.96E-01 1.94E+00 4.38E+00 U WS 01 544777001 5/11/2021 Ce-141 -1.94E-01 1.04E+00 3.14E+00 U WS 01 544777001 5/11/2021 Ce-144 1.96E+00 3.57E+00 1.22E+01 U WS 01 544777001 5/11/2021 Co-57 1.26E+00 6.88E-01 1.50E+00 U WS 01 544777001 5/11/2021 Co-58 1.11E-01 5.03E-01 1.69E+00 U WS 01 544777001 5/11/2021 Co-60 -5.84E-02 5.68E-01 1.81E+00 U WS 01 544777001 5/11/2021 Cr-51 -1.87E+00 5.44E+00 1.67E+01 U WS 01 544777001 5/11/2021 Cs-134 -1.01E+00 6.17E-01 1.76E+00 U WS 01 544777001 5/11/2021 Cs-137 -1.44E+00 7.82E-01 1.69E+00 U WS 01 544777001 5/11/2021 Fe-59 1.63E-01 1.08E+00 3.53E+00 U WS 01 544777001 5/11/2021 I-131 3.17E-02 1.05E+00 3.40E+00 U WS 01 544777001 5/11/2021 K-40 3.32E+02 2.50E+01 1.70E+01 WS 01 544777001 5/11/2021 La-140 -5.22E-01 8.96E-01 2.87E+00 U WS 01 544777001 5/11/2021 Mn-54 7.85E-01 4.71E-01 1.73E+00 U WS 01 544777001 5/11/2021 Nb-95 2.51E-01 5.12E-01 1.73E+00 U WS 01 544777001 5/11/2021 Pb-212 -1.50E+00 1.48E+00 3.67E+00 U WS 01 544777001 5/11/2021 Pb-214 -1.27E+00 1.91E+00 4.28E+00 U WS 01 544777001 5/11/2021 Ru-103 -1.13E+00 6.55E-01 1.78E+00 U WS 01 544777001 5/11/2021 Ru-106 2.51E+00 4.75E+00 1.62E+01 U WS 01 544777001 5/11/2021 Sb-124 1.66E+00 1.27E+00 4.38E+00 U WS 01 544777001 5/11/2021 Sb-125 -1.26E+00 1.93E+00 4.70E+00 U WS 01 544777001 5/11/2021 Se-75 8.47E-02 7.67E-01 2.54E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 01 544777001 5/11/2021 Th-228 -1.50E+00 1.48E+00 3.67E+00 U WS 01 544777001 5/11/2021 Zn-65 1.86E-01 1.09E+00 3.56E+00 U WS 01 544777001 5/11/2021 Zr-95 -1.51E+00 9.95E-01 2.90E+00 U WS 01 548321001 6/15/2021 Ac-228 -5.30E+00 3.73E+00 7.11E+00 U WS 01 548321001 6/15/2021 Ag-108m 3.67E-01 4.03E-01 1.35E+00 U WS 01 548321001 6/15/2021 Ag-110m 8.17E-01 6.79E-01 2.19E+00 U WS 01 548321001 6/15/2021 Ba-140 -4.67E-01 3.75E+00 1.23E+01 U WS 01 548321001 6/15/2021 Be-7 -1.58E+00 4.63E+00 1.35E+01 U WS 01 548321001 6/15/2021 Bi-214 1.63E+00 2.44E+00 3.88E+00 U WS 01 548321001 6/15/2021 Ce-141 2.38E+00 1.30E+00 3.61E+00 U WS 01 548321001 6/15/2021 Ce-144 4.48E+00 3.63E+00 1.13E+01 U WS 01 548321001 6/15/2021 Co-57 -4.92E-01 4.46E-01 1.34E+00 U WS 01 548321001 6/15/2021 Co-58 1.51E-01 5.27E-01 1.62E+00 U WS 01 548321001 6/15/2021 Co-60 -1.65E-01 4.34E-01 1.41E+00 U WS 01 548321001 6/15/2021 Cr-51 9.50E-01 4.97E+00 1.69E+01 U WS 01 548321001 6/15/2021 Cs-134 4.55E-01 4.66E-01 1.52E+00 U WS 01 548321001 6/15/2021 Cs-137 -2.99E-01 4.53E-01 1.42E+00 U WS 01 548321001 6/15/2021 Fe-59 -8.01E-01 1.33E+00 3.79E+00 U WS 01 548321001 6/15/2021 I-131 -7.31E-01 1.77E+00 5.86E+00 U WS 01 548321001 6/15/2021 K-40 3.20E+02 2.65E+01 1.47E+01 WS 01 548321001 6/15/2021 La-140 -1.86E-02 1.26E+00 4.11E+00 U WS 01 548321001 6/15/2021 Mn-54 2.87E-01 4.86E-01 1.58E+00 U WS 01 548321001 6/15/2021 Nb-95 7.53E-01 1.24E+00 1.61E+00 U WS 01 548321001 6/15/2021 Pb-212 2.06E-01 1.87E+00 3.68E+00 U WS 01 548321001 6/15/2021 Pb-214 2.64E+00 2.12E+00 3.74E+00 U WS 01 548321001 6/15/2021 Ru-103 -4.46E-01 5.46E-01 1.72E+00 U WS 01 548321001 6/15/2021 Ru-106 -6.23E+00 4.42E+00 1.28E+01 U WS 01 548321001 6/15/2021 Sb-124 3.62E-01 1.23E+00 4.09E+00 U WS 01 548321001 6/15/2021 Sb-125 3.04E-01 1.20E+00 4.01E+00 U WS 01 548321001 6/15/2021 Se-75 4.70E-01 6.63E-01 2.26E+00 U WS 01 548321001 6/15/2021 Th-228 2.06E-01 1.87E+00 3.68E+00 U WS 01 548321001 6/15/2021 Zn-65 -4.93E-01 1.08E+00 3.54E+00 U WS 01 548321001 6/15/2021 Zr-95 1.49E+00 9.11E-01 2.92E+00 U WS 01 552141001 6/15/2021 H-3 -2.84E+02 1.76E+02 6.19E+02 U WS 01 550012001 7/13/2021 Ac-228 -2.59E+00 2.99E+00 7.52E+00 U WS 01 550012001 7/13/2021 Ag-108m 1.49E-01 4.13E-01 1.42E+00 U WS 01 550012001 7/13/2021 Ag-110m -3.94E-02 7.13E-01 2.06E+00 U WS 01 550012001 7/13/2021 Ba-140 -3.48E-01 2.44E+00 8.16E+00 U WS 01 550012001 7/13/2021 Be-7 2.04E+00 3.99E+00 1.37E+01 U WS 01 550012001 7/13/2021 Bi-214 2.94E+00 2.21E+00 4.03E+00 U WS 01 550012001 7/13/2021 Ce-141 -9.19E-01 9.00E-01 2.81E+00 U WS 01 550012001 7/13/2021 Ce-144 -4.40E-01 3.26E+00 1.08E+01 U WS 01 550012001 7/13/2021 Co-57 -5.62E-01 4.35E-01 1.33E+00 U WS 01 550012001 7/13/2021 Co-58 -3.78E-01 4.96E-01 1.53E+00 U WS 01 550012001 7/13/2021 Co-60 0.00E+00 6.11E-01 1.48E+00 U WS 01 550012001 7/13/2021 Cr-51 -1.02E+01 5.46E+00 1.42E+01 U WS 01 550012001 7/13/2021 Cs-134 3.33E-01 5.06E-01 1.70E+00 U WS 01 550012001 7/13/2021 Cs-137 3.00E-01 5.12E-01 1.73E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 01 550012001 7/13/2021 Fe-59 -1.13E+00 1.17E+00 3.40E+00 U WS 01 550012001 7/13/2021 I-131 -6.65E-01 9.00E-01 2.67E+00 U WS 01 550012001 7/13/2021 K-40 3.36E+02 2.72E+01 1.66E+01 WS 01 550012001 7/13/2021 La-140 -1.08E+00 8.64E-01 2.47E+00 U WS 01 550012001 7/13/2021 Mn-54 4.01E-01 5.59E-01 1.69E+00 U WS 01 550012001 7/13/2021 Nb-95 1.21E-01 4.72E-01 1.57E+00 U WS 01 550012001 7/13/2021 Pb-212 1.26E+00 1.61E+00 3.69E+00 U WS 01 550012001 7/13/2021 Pb-214 -1.94E+00 1.73E+00 3.67E+00 U WS 01 550012001 7/13/2021 Ru-103 -5.41E-01 5.56E-01 1.57E+00 U WS 01 550012001 7/13/2021 Ru-106 9.47E+00 5.02E+00 1.63E+01 U WS 01 550012001 7/13/2021 Sb-124 -1.55E+00 1.21E+00 3.38E+00 U WS 01 550012001 7/13/2021 Sb-125 -1.38E+00 1.97E+00 4.22E+00 U WS 01 550012001 7/13/2021 Se-75 -5.90E-01 7.08E-01 2.15E+00 U WS 01 550012001 7/13/2021 Th-228 1.26E+00 1.61E+00 3.69E+00 U WS 01 550012001 7/13/2021 Zn-65 8.45E-01 1.18E+00 3.88E+00 U WS 01 550012001 7/13/2021 Zr-95 -7.23E-01 9.13E-01 2.83E+00 U WS 01 552735001 8/10/2021 Ac-228 -4.26E+00 4.57E+00 7.50E+00 U WS 01 552735001 8/10/2021 Ag-108m -1.83E-01 4.30E-01 1.39E+00 U WS 01 552735001 8/10/2021 Ag-110m 9.69E-02 6.48E-01 2.08E+00 U WS 01 552735001 8/10/2021 Ba-140 -2.61E+00 2.85E+00 8.82E+00 U WS 01 552735001 8/10/2021 Be-7 -3.75E-02 4.18E+00 1.37E+01 U WS 01 552735001 8/10/2021 Bi-214 -2.15E+00 1.96E+00 3.43E+00 U WS 01 552735001 8/10/2021 Ce-141 6.15E-02 1.27E+00 3.09E+00 U WS 01 552735001 8/10/2021 Ce-144 8.88E-01 3.25E+00 1.10E+01 U WS 01 552735001 8/10/2021 Co-57 -1.08E-01 4.33E-01 1.46E+00 U WS 01 552735001 8/10/2021 Co-58 -2.97E-01 4.97E-01 1.54E+00 U WS 01 552735001 8/10/2021 Co-60 -2.43E-01 5.09E-01 1.67E+00 U WS 01 552735001 8/10/2021 Cr-51 8.42E+00 5.18E+00 1.64E+01 U WS 01 552735001 8/10/2021 Cs-134 -2.12E+00 1.03E+00 1.67E+00 U WS 01 552735001 8/10/2021 Cs-137 2.44E-01 8.05E-01 1.67E+00 U WS 01 552735001 8/10/2021 Fe-59 -2.88E-01 1.11E+00 3.28E+00 U WS 01 552735001 8/10/2021 I-131 -1.13E+00 1.13E+00 3.55E+00 U WS 01 552735001 8/10/2021 K-40 2.84E+02 2.43E+01 1.59E+01 WS 01 552735001 8/10/2021 La-140 -2.43E-01 9.82E-01 3.22E+00 U WS 01 552735001 8/10/2021 Mn-54 -1.33E-01 4.77E-01 1.50E+00 U WS 01 552735001 8/10/2021 Nb-95 -1.07E-01 4.93E-01 1.57E+00 U WS 01 552735001 8/10/2021 Pb-212 -1.45E+00 1.90E+00 3.41E+00 U WS 01 552735001 8/10/2021 Pb-214 3.13E+00 1.31E+00 3.79E+00 U WS 01 552735001 8/10/2021 Ru-103 -8.27E-01 5.45E-01 1.59E+00 U WS 01 552735001 8/10/2021 Ru-106 -2.15E-01 4.13E+00 1.34E+01 U WS 01 552735001 8/10/2021 Sb-124 -1.22E+00 1.09E+00 3.23E+00 U WS 01 552735001 8/10/2021 Sb-125 -1.56E+00 1.28E+00 3.88E+00 U WS 01 552735001 8/10/2021 Se-75 4.86E-01 6.27E-01 2.09E+00 U WS 01 552735001 8/10/2021 Th-228 -1.45E+00 1.90E+00 3.41E+00 U WS 01 552735001 8/10/2021 Zn-65 -1.36E+00 1.08E+00 3.21E+00 U WS 01 552735001 8/10/2021 Zr-95 2.87E-01 8.98E-01 2.91E+00 U WS 01 556375001 9/13/2021 Ac-228 4.85E+00 4.41E+00 6.11E+00 U WS 01 556375001 9/13/2021 Ag-108m -3.64E-01 5.43E-01 1.48E+00 U WS 01 556375001 9/13/2021 Ag-110m 3.10E-02 7.04E-01 2.31E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 01 556375001 9/13/2021 Ba-140 -5.50E+00 3.38E+00 1.01E+01 U WS 01 556375001 9/13/2021 Be-7 3.71E+00 4.91E+00 1.57E+01 U WS 01 556375001 9/13/2021 Bi-214 0.00E+00 2.47E+00 3.37E+00 U WS 01 556375001 9/13/2021 Ce-141 3.18E-01 1.08E+00 3.31E+00 U WS 01 556375001 9/13/2021 Ce-144 2.98E-01 3.44E+00 1.18E+01 U WS 01 556375001 9/13/2021 Co-57 2.00E-01 4.73E-01 1.62E+00 U WS 01 556375001 9/13/2021 Co-58 -4.19E-01 5.66E-01 1.79E+00 U WS 01 556375001 9/13/2021 Co-60 3.57E-01 5.86E-01 1.99E+00 U WS 01 556375001 9/13/2021 Cr-51 5.08E+00 5.56E+00 1.81E+01 U WS 01 556375001 9/13/2021 Cs-134 4.52E-01 5.88E-01 1.96E+00 U WS 01 556375001 9/13/2021 Cs-137 8.07E-01 5.59E-01 1.85E+00 U WS 01 556375001 9/13/2021 Fe-59 -1.48E+00 1.33E+00 3.94E+00 U WS 01 556375001 9/13/2021 I-131 2.44E-01 1.29E+00 4.19E+00 U WS 01 556375001 9/13/2021 K-40 3.33E+02 2.83E+01 1.60E+01 WS 01 556375001 9/13/2021 La-140 1.05E+00 1.11E+00 3.76E+00 U WS 01 556375001 9/13/2021 Mn-54 -2.05E-01 5.14E-01 1.66E+00 U WS 01 556375001 9/13/2021 Nb-95 1.44E+00 6.59E-01 2.03E+00 U WS 01 556375001 9/13/2021 Pb-212 1.92E+00 2.17E+00 4.06E+00 U WS 01 556375001 9/13/2021 Pb-214 0.00E+00 2.62E+00 4.54E+00 U WS 01 556375001 9/13/2021 Ru-103 -2.11E-01 6.23E-01 1.95E+00 U WS 01 556375001 9/13/2021 Ru-106 8.55E+00 5.31E+00 1.73E+01 U WS 01 556375001 9/13/2021 Sb-124 2.13E-01 1.28E+00 4.25E+00 U WS 01 556375001 9/13/2021 Sb-125 -1.72E+00 1.50E+00 4.46E+00 U WS 01 556375001 9/13/2021 Se-75 1.29E+00 9.03E-01 2.33E+00 U WS 01 556375001 9/13/2021 Th-228 1.92E+00 2.17E+00 4.06E+00 U WS 01 556375001 9/13/2021 Zn-65 -5.58E-01 1.41E+00 3.83E+00 U WS 01 556375001 9/13/2021 Zr-95 2.69E-01 9.60E-01 3.21E+00 U WS 01 560827001 9/13/2021 H-3 -5.02E+01 2.28E+02 7.61E+02 U WS 01 558886001 10/12/2021 Ac-228 -3.72E+00 3.69E+00 9.08E+00 U WS 01 558886001 10/12/2021 Ag-108m -2.39E-01 5.54E-01 1.81E+00 U WS 01 558886001 10/12/2021 Ag-110m -9.61E-01 9.76E-01 2.83E+00 U WS 01 558886001 10/12/2021 Ba-140 1.14E+00 2.88E+00 9.67E+00 U WS 01 558886001 10/12/2021 Be-7 -1.23E+01 6.14E+00 1.62E+01 U WS 01 558886001 10/12/2021 Bi-214 2.50E+00 3.56E+00 4.86E+00 U WS 01 558886001 10/12/2021 Ce-141 -3.15E+00 1.31E+00 3.21E+00 U WS 01 558886001 10/12/2021 Ce-144 5.90E-01 3.81E+00 1.23E+01 U WS 01 558886001 10/12/2021 Co-57 -8.90E-01 5.97E-01 1.52E+00 U WS 01 558886001 10/12/2021 Co-58 8.81E-03 5.91E-01 1.90E+00 U WS 01 558886001 10/12/2021 Co-60 -2.64E-01 8.39E-01 2.37E+00 U WS 01 558886001 10/12/2021 Cr-51 3.15E+00 5.49E+00 1.89E+01 U WS 01 558886001 10/12/2021 Cs-134 1.23E+00 7.83E-01 2.57E+00 U WS 01 558886001 10/12/2021 Cs-137 3.27E-01 7.44E-01 2.46E+00 U WS 01 558886001 10/12/2021 Fe-59 -2.54E+00 1.57E+00 4.41E+00 U WS 01 558886001 10/12/2021 I-131 -2.82E-01 1.05E+00 3.52E+00 U WS 01 558886001 10/12/2021 K-40 3.43E+02 2.96E+01 2.48E+01 WS 01 558886001 10/12/2021 La-140 -3.62E-01 1.17E+00 3.71E+00 U WS 01 558886001 10/12/2021 Mn-54 7.81E-01 7.03E-01 2.32E+00 U WS 01 558886001 10/12/2021 Nb-95 2.90E-01 7.28E-01 2.39E+00 U WS 01 558886001 10/12/2021 Pb-212 2.90E+00 2.27E+00 3.58E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 01 558886001 10/12/2021 Pb-214 3.26E+00 2.98E+00 5.92E+00 U WS 01 558886001 10/12/2021 Ru-103 -5.21E-01 6.90E-01 2.18E+00 U WS 01 558886001 10/12/2021 Ru-106 1.95E+00 5.28E+00 1.75E+01 U WS 01 558886001 10/12/2021 Sb-124 -1.72E+00 1.62E+00 4.54E+00 U WS 01 558886001 10/12/2021 Sb-125 -1.09E+00 1.78E+00 5.76E+00 U WS 01 558886001 10/12/2021 Se-75 7.29E-01 7.73E-01 2.66E+00 U WS 01 558886001 10/12/2021 Th-228 2.90E+00 2.27E+00 3.58E+00 U WS 01 558886001 10/12/2021 Zn-65 2.34E+00 1.74E+00 5.42E+00 U WS 01 558886001 10/12/2021 Zr-95 4.01E-01 1.30E+00 4.24E+00 U WS 01 563415001 11/17/2021 Ac-228 -4.93E+00 3.48E+00 7.16E+00 U WS 01 563415001 11/17/2021 Ag-108m 8.20E-01 9.91E-01 1.66E+00 U WS 01 563415001 11/17/2021 Ag-110m -7.60E-01 7.69E-01 2.29E+00 U WS 01 563415001 11/17/2021 Ba-140 -8.68E-01 4.05E+00 1.33E+01 U WS 01 563415001 11/17/2021 Be-7 8.47E+00 5.61E+00 1.75E+01 U WS 01 563415001 11/17/2021 Bi-214 4.73E-01 2.43E+00 3.19E+00 U WS 01 563415001 11/17/2021 Ce-141 4.44E-01 1.17E+00 3.50E+00 U WS 01 563415001 11/17/2021 Ce-144 -2.83E+00 3.40E+00 1.07E+01 U WS 01 563415001 11/17/2021 Co-57 3.40E-01 4.76E-01 1.44E+00 U WS 01 563415001 11/17/2021 Co-58 -5.50E-01 6.16E-01 1.64E+00 U WS 01 563415001 11/17/2021 Co-60 9.22E-01 5.97E-01 1.80E+00 U WS 01 563415001 11/17/2021 Cr-51 1.65E+00 5.93E+00 2.04E+01 U WS 01 563415001 11/17/2021 Cs-134 8.78E-01 5.99E-01 1.91E+00 U WS 01 563415001 11/17/2021 Cs-137 5.31E-01 5.27E-01 1.73E+00 U WS 01 563415001 11/17/2021 Fe-59 2.03E-01 1.09E+00 3.70E+00 U WS 01 563415001 11/17/2021 I-131 2.21E-01 2.02E+00 6.86E+00 U WS 01 563415001 11/17/2021 K-40 3.46E+02 2.64E+01 1.65E+01 WS 01 563415001 11/17/2021 La-140 1.70E+00 1.33E+00 4.47E+00 U WS 01 563415001 11/17/2021 Mn-54 -3.34E-01 5.21E-01 1.61E+00 U WS 01 563415001 11/17/2021 Nb-95 -3.75E+00 1.41E+00 1.82E+00 U WS 01 563415001 11/17/2021 Pb-212 -1.45E+00 1.58E+00 3.54E+00 U WS 01 563415001 11/17/2021 Pb-214 3.09E+00 2.83E+00 4.28E+00 U WS 01 563415001 11/17/2021 Ru-103 -1.20E+00 6.80E-01 1.96E+00 U WS 01 563415001 11/17/2021 Ru-106 7.95E+00 4.51E+00 1.43E+01 U WS 01 563415001 11/17/2021 Sb-124 1.62E+00 1.31E+00 4.40E+00 U WS 01 563415001 11/17/2021 Sb-125 -1.22E+00 1.34E+00 4.29E+00 U WS 01 563415001 11/17/2021 Se-75 -5.92E-01 7.92E-01 2.40E+00 U WS 01 563415001 11/17/2021 Th-228 -1.45E+00 1.58E+00 3.54E+00 U WS 01 563415001 11/17/2021 Zn-65 -6.38E-01 1.19E+00 3.41E+00 U WS 01 563415001 11/17/2021 Zr-95 -1.42E-01 9.78E-01 3.14E+00 U WS 01 565202001 12/8/2021 Ac-228 -4.19E+00 4.79E+00 7.47E+00 U WS 01 565202001 12/8/2021 Ag-108m 1.18E-01 4.11E-01 1.34E+00 U WS 01 565202001 12/8/2021 Ag-110m -4.49E-01 6.68E-01 2.13E+00 U WS 01 565202001 12/8/2021 Ba-140 0.00E+00 8.17E+00 1.62E+01 UI WS 01 565202001 12/8/2021 Be-7 5.79E+00 4.82E+00 1.54E+01 U WS 01 565202001 12/8/2021 Bi-214 -3.24E+00 1.86E+00 3.45E+00 U WS 01 565202001 12/8/2021 Ce-141 0.00E+00 2.32E+00 3.41E+00 U WS 01 565202001 12/8/2021 Ce-144 3.91E+00 3.30E+00 1.01E+01 U WS 01 565202001 12/8/2021 Co-57 -2.91E-01 4.36E-01 1.34E+00 U WS 01 565202001 12/8/2021 Co-58 -5.14E-01 5.18E-01 1.61E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 01 565202001 12/8/2021 Co-60 2.90E-01 4.99E-01 1.70E+00 U WS 01 565202001 12/8/2021 Cr-51 -8.86E+00 1.15E+01 2.06E+01 U WS 01 565202001 12/8/2021 Cs-134 -3.48E-01 5.12E-01 1.64E+00 U WS 01 565202001 12/8/2021 Cs-137 -3.84E-02 4.46E-01 1.50E+00 U WS 01 565202001 12/8/2021 Fe-59 1.39E+00 1.30E+00 4.23E+00 U WS 01 565202001 12/8/2021 I-131 3.63E+00 2.92E+00 9.39E+00 U WS 01 565202001 12/8/2021 K-40 3.36E+02 2.40E+01 1.53E+01 WS 01 565202001 12/8/2021 La-140 -4.68E-01 1.67E+00 5.46E+00 U WS 01 565202001 12/8/2021 Mn-54 1.36E-01 4.50E-01 1.50E+00 U WS 01 565202001 12/8/2021 Nb-95 3.68E-01 5.51E-01 1.85E+00 U WS 01 565202001 12/8/2021 Pb-212 3.02E+00 2.14E+00 3.61E+00 U WS 01 565202001 12/8/2021 Pb-214 3.17E-01 2.20E+00 3.43E+00 U WS 01 565202001 12/8/2021 Ru-103 6.92E-03 6.86E-01 1.95E+00 U WS 01 565202001 12/8/2021 Ru-106 -1.80E+00 4.03E+00 1.34E+01 U WS 01 565202001 12/8/2021 Sb-124 -4.49E-01 1.56E+00 4.36E+00 U WS 01 565202001 12/8/2021 Sb-125 1.18E+00 1.21E+00 3.91E+00 U WS 01 565202001 12/8/2021 Se-75 -1.69E-01 6.34E-01 2.10E+00 U WS 01 565202001 12/8/2021 Th-228 3.02E+00 2.14E+00 3.61E+00 U WS 01 565202001 12/8/2021 Zn-65 1.15E+00 1.52E+00 3.69E+00 U WS 01 565202001 12/8/2021 Zr-95 -2.38E-02 8.94E-01 2.98E+00 U WS 01 568410001 12/8/2021 H-3 -1.10E+02 1.87E+02 6.33E+02 U WS 10 544777004 5/13/2021 Ac-228 1.46E+00 5.81E+00 1.17E+01 U WS 10 544777004 5/13/2021 Ag-108m -4.76E-01 5.79E-01 1.79E+00 U WS 10 544777004 5/13/2021 Ag-110m 5.54E-01 1.21E+00 2.98E+00 U WS 10 544777004 5/13/2021 Ba-140 2.39E+00 3.17E+00 1.04E+01 U WS 10 544777004 5/13/2021 Be-7 -1.50E+01 8.50E+00 1.80E+01 U WS 10 544777004 5/13/2021 Bi-214 7.33E-01 3.11E+00 4.24E+00 U WS 10 544777004 5/13/2021 Ce-141 -2.98E+00 1.54E+00 3.06E+00 U WS 10 544777004 5/13/2021 Ce-144 7.56E-01 3.61E+00 1.14E+01 U WS 10 544777004 5/13/2021 Co-57 5.93E-01 5.07E-01 1.58E+00 U WS 10 544777004 5/13/2021 Co-58 -1.01E-01 7.63E-01 2.23E+00 U WS 10 544777004 5/13/2021 Co-60 -1.02E-01 7.24E-01 2.31E+00 U WS 10 544777004 5/13/2021 Cr-51 -2.12E+00 5.46E+00 1.78E+01 U WS 10 544777004 5/13/2021 Cs-134 5.63E-01 1.27E+00 2.57E+00 U WS 10 544777004 5/13/2021 Cs-137 -4.04E-01 7.79E-01 2.25E+00 U WS 10 544777004 5/13/2021 Fe-59 1.97E+00 1.52E+00 5.11E+00 U WS 10 544777004 5/13/2021 I-131 4.36E-01 9.92E-01 3.30E+00 U WS 10 544777004 5/13/2021 K-40 1.91E+02 2.14E+01 2.55E+01 WS 10 544777004 5/13/2021 La-140 -8.33E-01 1.13E+00 3.54E+00 U WS 10 544777004 5/13/2021 Mn-54 -9.52E-02 6.41E-01 2.13E+00 U WS 10 544777004 5/13/2021 Nb-95 1.73E+00 8.61E-01 2.78E+00 U WS 10 544777004 5/13/2021 Pb-212 2.75E+00 2.34E+00 4.41E+00 U WS 10 544777004 5/13/2021 Pb-214 3.29E+00 3.26E+00 5.39E+00 U WS 10 544777004 5/13/2021 Ru-103 2.69E-01 6.64E-01 2.17E+00 U WS 10 544777004 5/13/2021 Ru-106 1.96E+00 6.59E+00 2.12E+01 U WS 10 544777004 5/13/2021 Sb-124 8.74E-01 1.60E+00 4.95E+00 U WS 10 544777004 5/13/2021 Sb-125 -5.38E-01 1.79E+00 5.75E+00 U WS 10 544777004 5/13/2021 Se-75 8.77E-01 7.85E-01 2.63E+00 U WS 10 544777004 5/13/2021 Th-228 2.75E+00 2.34E+00 4.41E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 10 544777004 5/13/2021 Zn-65 -1.04E+00 1.62E+00 5.04E+00 U WS 10 544777004 5/13/2021 Zr-95 -1.11E+00 1.21E+00 3.81E+00 U WS 10 563415004 11/15/2021 Ac-228 0.00E+00 4.84E+00 7.88E+00 U WS 10 563415004 11/15/2021 Ag-108m 4.42E-01 4.07E-01 1.35E+00 U WS 10 563415004 11/15/2021 Ag-110m 5.99E-01 7.22E-01 2.20E+00 U WS 10 563415004 11/15/2021 Ba-140 -1.86E+01 8.72E+00 1.39E+01 U WS 10 563415004 11/15/2021 Be-7 1.16E+00 4.64E+00 1.54E+01 U WS 10 563415004 11/15/2021 Bi-214 1.13E+00 2.59E+00 3.22E+00 U WS 10 563415004 11/15/2021 Ce-141 2.10E+00 1.20E+00 2.60E+00 U WS 10 563415004 11/15/2021 Ce-144 2.74E+00 2.61E+00 8.29E+00 U WS 10 563415004 11/15/2021 Co-57 4.98E-01 3.65E-01 1.06E+00 U WS 10 563415004 11/15/2021 Co-58 -1.29E-01 5.15E-01 1.73E+00 U WS 10 563415004 11/15/2021 Co-60 -5.23E-01 5.39E-01 1.63E+00 U WS 10 563415004 11/15/2021 Cr-51 -9.51E+00 5.61E+00 1.67E+01 U WS 10 563415004 11/15/2021 Cs-134 1.10E-01 5.44E-01 1.74E+00 U WS 10 563415004 11/15/2021 Cs-137 6.80E-01 5.63E-01 1.81E+00 U WS 10 563415004 11/15/2021 Fe-59 -4.20E-01 1.23E+00 4.00E+00 U WS 10 563415004 11/15/2021 I-131 -6.82E+00 3.63E+00 6.58E+00 U WS 10 563415004 11/15/2021 K-40 1.10E+02 1.75E+01 1.62E+01 WS 10 563415004 11/15/2021 La-140 -3.24E-01 1.42E+00 4.48E+00 U WS 10 563415004 11/15/2021 Mn-54 -1.38E+00 1.18E+00 1.60E+00 U WS 10 563415004 11/15/2021 Nb-95 6.35E-01 6.02E-01 1.93E+00 U WS 10 563415004 11/15/2021 Pb-212 9.73E-01 1.82E+00 2.38E+00 U WS 10 563415004 11/15/2021 Pb-214 2.21E+00 2.47E+00 3.72E+00 U WS 10 563415004 11/15/2021 Ru-103 -2.98E-01 5.75E-01 1.85E+00 U WS 10 563415004 11/15/2021 Ru-106 3.82E+00 4.51E+00 1.47E+01 U WS 10 563415004 11/15/2021 Sb-124 1.99E+00 1.34E+00 4.43E+00 U WS 10 563415004 11/15/2021 Sb-125 5.03E-01 1.22E+00 4.06E+00 U WS 10 563415004 11/15/2021 Se-75 -1.29E-02 5.18E-01 1.77E+00 U WS 10 563415004 11/15/2021 Th-228 9.73E-01 1.82E+00 2.38E+00 U WS 10 563415004 11/15/2021 Zn-65 -2.21E-01 1.21E+00 3.48E+00 U WS 10 563415004 11/15/2021 Zr-95 -5.24E-01 1.06E+00 3.27E+00 U WS 51 532364002 1/11/2021 Ac-228 2.62E+00 3.54E+00 4.91E+00 U WS 51 532364002 1/11/2021 Ag-108m 7.42E-01 6.90E-01 1.20E+00 U WS 51 532364002 1/11/2021 Ag-110m -7.24E-01 6.35E-01 1.83E+00 U WS 51 532364002 1/11/2021 Ba-140 -1.40E+00 2.29E+00 7.33E+00 U WS 51 532364002 1/11/2021 Be-7 4.63E-01 3.87E+00 1.30E+01 U WS 51 532364002 1/11/2021 Bi-214 -1.72E+00 1.60E+00 3.60E+00 U WS 51 532364002 1/11/2021 Ce-141 -3.88E-01 8.58E-01 2.73E+00 U WS 51 532364002 1/11/2021 Ce-144 1.72E+00 3.09E+00 1.01E+01 U WS 51 532364002 1/11/2021 Co-57 -4.33E-01 4.03E-01 1.24E+00 U WS 51 532364002 1/11/2021 Co-58 2.72E-03 4.32E-01 1.39E+00 U WS 51 532364002 1/11/2021 Co-60 -2.91E-01 5.07E-01 1.40E+00 U WS 51 532364002 1/11/2021 Cr-51 -5.43E-01 4.08E+00 1.39E+01 U WS 51 532364002 1/11/2021 Cs-134 2.38E-01 4.84E-01 1.58E+00 U WS 51 532364002 1/11/2021 Cs-137 -3.44E-01 6.66E-01 1.54E+00 U WS 51 532364002 1/11/2021 Fe-59 -1.21E+00 9.99E-01 3.05E+00 U WS 51 532364002 1/11/2021 I-131 -5.31E-01 9.04E-01 2.99E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 51 532364002 1/11/2021 K-40 3.47E+02 2.63E+01 1.36E+01 WS 51 532364002 1/11/2021 La-140 -7.67E-01 7.33E-01 2.13E+00 U WS 51 532364002 1/11/2021 Mn-54 1.19E-03 7.12E-01 1.40E+00 U WS 51 532364002 1/11/2021 Nb-95 -1.69E-01 4.80E-01 1.52E+00 U WS 51 532364002 1/11/2021 Pb-212 3.40E-01 1.41E+00 3.37E+00 U WS 51 532364002 1/11/2021 Pb-214 -1.09E+00 1.58E+00 3.58E+00 U WS 51 532364002 1/11/2021 Ru-103 -9.61E-01 5.32E-01 1.50E+00 U WS 51 532364002 1/11/2021 Ru-106 4.54E+00 4.34E+00 1.43E+01 U WS 51 532364002 1/11/2021 Sb-124 3.91E-01 1.06E+00 3.54E+00 U WS 51 532364002 1/11/2021 Sb-125 -2.10E+00 1.22E+00 3.30E+00 U WS 51 532364002 1/11/2021 Se-75 3.66E-01 6.49E-01 2.04E+00 U WS 51 532364002 1/11/2021 Th-228 3.40E-01 1.41E+00 3.37E+00 U WS 51 532364002 1/11/2021 Zn-65 2.63E+00 1.26E+00 3.73E+00 U WS 51 532364002 1/11/2021 Zr-95 -6.13E-01 8.24E-01 2.53E+00 U WS 51 535172002 2/10/2021 Ac-228 6.12E+00 5.10E+00 8.17E+00 U WS 51 535172002 2/10/2021 Ag-108m 4.95E-02 4.59E-01 1.57E+00 U WS 51 535172002 2/10/2021 Ag-110m -1.90E-01 7.65E-01 2.45E+00 U WS 51 535172002 2/10/2021 Ba-140 9.29E-01 2.53E+00 8.63E+00 U WS 51 535172002 2/10/2021 Be-7 -2.22E-01 4.25E+00 1.44E+01 U WS 51 535172002 2/10/2021 Bi-214 3.39E+00 2.89E+00 4.40E+00 U WS 51 535172002 2/10/2021 Ce-141 0.00E+00 1.05E+00 2.32E+00 U WS 51 535172002 2/10/2021 Ce-144 -2.11E+00 4.69E+00 1.16E+01 U WS 51 535172002 2/10/2021 Co-57 -4.22E-01 4.54E-01 1.44E+00 U WS 51 535172002 2/10/2021 Co-58 -6.48E-01 5.04E-01 1.44E+00 U WS 51 535172002 2/10/2021 Co-60 -3.49E-02 5.12E-01 1.72E+00 U WS 51 535172002 2/10/2021 Cr-51 -1.74E+00 5.12E+00 1.58E+01 U WS 51 535172002 2/10/2021 Cs-134 -4.49E-01 5.80E-01 1.79E+00 U WS 51 535172002 2/10/2021 Cs-137 3.26E-01 5.60E-01 1.89E+00 U WS 51 535172002 2/10/2021 Fe-59 4.26E-01 1.21E+00 3.92E+00 U WS 51 535172002 2/10/2021 I-131 -1.32E-01 1.04E+00 2.95E+00 U WS 51 535172002 2/10/2021 K-40 3.30E+02 2.73E+01 1.81E+01 WS 51 535172002 2/10/2021 La-140 -2.74E+00 1.66E+00 2.83E+00 U WS 51 535172002 2/10/2021 Mn-54 6.94E-02 5.78E-01 1.90E+00 U WS 51 535172002 2/10/2021 Nb-95 -1.87E-01 8.12E-01 1.90E+00 U WS 51 535172002 2/10/2021 Pb-212 1.20E+00 2.26E+00 3.79E+00 U WS 51 535172002 2/10/2021 Pb-214 2.12E+00 2.15E+00 4.42E+00 U WS 51 535172002 2/10/2021 Ru-103 -2.48E-02 4.92E-01 1.66E+00 U WS 51 535172002 2/10/2021 Ru-106 3.26E+00 4.93E+00 1.67E+01 U WS 51 535172002 2/10/2021 Sb-124 -1.11E-01 1.23E+00 4.06E+00 U WS 51 535172002 2/10/2021 Sb-125 -7.05E-01 1.31E+00 4.34E+00 U WS 51 535172002 2/10/2021 Se-75 2.18E+00 1.18E+00 2.22E+00 U WS 51 535172002 2/10/2021 Th-228 1.20E+00 2.26E+00 3.79E+00 U WS 51 535172002 2/10/2021 Zn-65 -2.74E+00 1.45E+00 3.59E+00 U WS 51 535172002 2/10/2021 Zr-95 -1.00E-01 9.18E-01 3.00E+00 U WS 51 538500002 3/18/2021 Ac-228 -1.19E+00 3.63E+00 7.99E+00 U WS 51 538500002 3/18/2021 Ag-108m -3.92E-01 4.68E-01 1.43E+00 U WS 51 538500002 3/18/2021 Ag-110m -4.88E-01 6.85E-01 2.20E+00 U WS 51 538500002 3/18/2021 Ba-140 -1.09E+00 2.53E+00 7.90E+00 U WS 51 538500002 3/18/2021 Be-7 -2.51E-02 4.50E+00 1.44E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 51 538500002 3/18/2021 Bi-214 2.87E+00 2.11E+00 3.28E+00 U WS 51 538500002 3/18/2021 Ce-141 8.16E-01 1.04E+00 3.08E+00 U WS 51 538500002 3/18/2021 Ce-144 3.40E+00 4.42E+00 1.20E+01 U WS 51 538500002 3/18/2021 Co-57 -1.74E-01 4.79E-01 1.57E+00 U WS 51 538500002 3/18/2021 Co-58 -2.06E-01 5.41E-01 1.79E+00 U WS 51 538500002 3/18/2021 Co-60 2.59E-01 5.28E-01 1.77E+00 U WS 51 538500002 3/18/2021 Cr-51 1.41E-02 4.71E+00 1.53E+01 U WS 51 538500002 3/18/2021 Cs-134 2.49E-01 5.46E-01 1.86E+00 U WS 51 538500002 3/18/2021 Cs-137 -2.49E-01 5.51E-01 1.83E+00 U WS 51 538500002 3/18/2021 Fe-59 -3.23E-01 1.02E+00 3.34E+00 U WS 51 538500002 3/18/2021 I-131 1.66E-01 8.19E-01 2.65E+00 U WS 51 538500002 3/18/2021 K-40 3.11E+02 2.30E+01 1.82E+01 WS 51 538500002 3/18/2021 La-140 -1.73E-01 9.14E-01 2.56E+00 U WS 51 538500002 3/18/2021 Mn-54 4.78E-01 7.54E-01 1.72E+00 U WS 51 538500002 3/18/2021 Nb-95 -4.21E-01 8.08E-01 1.78E+00 U WS 51 538500002 3/18/2021 Pb-212 2.74E+00 2.70E+00 2.90E+00 U WS 51 538500002 3/18/2021 Pb-214 -8.13E-01 1.89E+00 4.17E+00 U WS 51 538500002 3/18/2021 Ru-103 -4.64E-01 5.59E-01 1.70E+00 U WS 51 538500002 3/18/2021 Ru-106 6.44E+00 4.75E+00 1.59E+01 U WS 51 538500002 3/18/2021 Sb-124 1.29E+00 1.25E+00 4.17E+00 U WS 51 538500002 3/18/2021 Sb-125 -2.37E+00 1.52E+00 4.31E+00 U WS 51 538500002 3/18/2021 Se-75 1.13E+00 8.34E-01 2.39E+00 U WS 51 538500002 3/18/2021 Th-228 2.74E+00 2.70E+00 2.90E+00 U WS 51 538500002 3/18/2021 Zn-65 -8.84E-01 1.21E+00 3.84E+00 U WS 51 538500002 3/18/2021 Zr-95 -8.33E-01 9.20E-01 2.93E+00 U WS 51 543399002 3/18/2021 H-3 -7.45E+00 1.55E+02 5.10E+02 U WS 51 541846002 4/21/2021 Ac-228 -4.13E+00 4.19E+00 8.99E+00 U WS 51 541846002 4/21/2021 Ag-108m 4.72E-01 5.63E-01 1.80E+00 U WS 51 541846002 4/21/2021 Ag-110m -2.15E+00 1.01E+00 2.60E+00 U WS 51 541846002 4/21/2021 Ba-140 -3.86E-01 2.76E+00 9.14E+00 U WS 51 541846002 4/21/2021 Be-7 4.06E-02 5.27E+00 1.78E+01 U WS 51 541846002 4/21/2021 Bi-214 -1.25E+00 2.20E+00 5.04E+00 U WS 51 541846002 4/21/2021 Ce-141 -1.19E+00 9.79E-01 2.93E+00 U WS 51 541846002 4/21/2021 Ce-144 -3.67E+00 3.64E+00 1.12E+01 U WS 51 541846002 4/21/2021 Co-57 6.76E-03 4.63E-01 1.52E+00 U WS 51 541846002 4/21/2021 Co-58 2.41E-01 6.20E-01 2.00E+00 U WS 51 541846002 4/21/2021 Co-60 -1.40E+00 8.16E-01 2.23E+00 U WS 51 541846002 4/21/2021 Cr-51 1.03E+01 6.02E+00 1.90E+01 U WS 51 541846002 4/21/2021 Cs-134 5.34E-02 6.85E-01 2.25E+00 U WS 51 541846002 4/21/2021 Cs-137 7.92E-02 7.19E-01 2.34E+00 U WS 51 541846002 4/21/2021 Fe-59 1.54E+00 1.41E+00 4.66E+00 U WS 51 541846002 4/21/2021 I-131 -1.13E+00 1.07E+00 3.24E+00 U WS 51 541846002 4/21/2021 K-40 3.02E+02 2.78E+01 2.37E+01 WS 51 541846002 4/21/2021 La-140 4.64E-01 1.12E+00 3.70E+00 U WS 51 541846002 4/21/2021 Mn-54 -1.31E-01 6.39E-01 2.12E+00 U WS 51 541846002 4/21/2021 Nb-95 -3.11E-01 6.18E-01 2.03E+00 U WS 51 541846002 4/21/2021 Pb-212 -2.07E+00 1.62E+00 4.26E+00 U WS 51 541846002 4/21/2021 Pb-214 1.73E+00 2.74E+00 4.90E+00 U WS 51 541846002 4/21/2021 Ru-103 -7.20E-01 6.98E-01 1.90E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 51 541846002 4/21/2021 Ru-106 -6.97E+00 5.53E+00 1.63E+01 U WS 51 541846002 4/21/2021 Sb-124 -6.44E-01 1.64E+00 5.33E+00 U WS 51 541846002 4/21/2021 Sb-125 -3.49E-01 1.86E+00 5.18E+00 U WS 51 541846002 4/21/2021 Se-75 -6.94E-01 7.66E-01 2.45E+00 U WS 51 541846002 4/21/2021 Th-228 -2.07E+00 1.62E+00 4.26E+00 U WS 51 541846002 4/21/2021 Zn-65 3.31E-01 2.69E+00 5.04E+00 U WS 51 541846002 4/21/2021 Zr-95 1.64E-01 1.03E+00 3.51E+00 U WS 51 544777002 5/11/2021 Ac-228 -2.41E+00 3.13E+00 6.20E+00 U WS 51 544777002 5/11/2021 Ag-108m 1.81E-01 3.91E-01 1.35E+00 U WS 51 544777002 5/11/2021 Ag-110m -2.67E-02 6.44E-01 2.10E+00 U WS 51 544777002 5/11/2021 Ba-140 -1.03E+00 3.15E+00 8.49E+00 U WS 51 544777002 5/11/2021 Be-7 -3.78E+00 3.62E+00 1.14E+01 U WS 51 544777002 5/11/2021 Bi-214 9.86E-02 2.30E+00 3.94E+00 U WS 51 544777002 5/11/2021 Ce-141 1.95E-01 8.19E-01 2.69E+00 U WS 51 544777002 5/11/2021 Ce-144 -5.13E-01 3.00E+00 9.78E+00 U WS 51 544777002 5/11/2021 Co-57 2.86E-01 3.82E-01 1.26E+00 U WS 51 544777002 5/11/2021 Co-58 4.11E-01 4.75E-01 1.60E+00 U WS 51 544777002 5/11/2021 Co-60 4.75E-02 4.98E-01 1.59E+00 U WS 51 544777002 5/11/2021 Cr-51 -1.26E+00 4.52E+00 1.40E+01 U WS 51 544777002 5/11/2021 Cs-134 -3.00E-01 8.06E-01 1.72E+00 U WS 51 544777002 5/11/2021 Cs-137 -1.12E-01 4.52E-01 1.49E+00 U WS 51 544777002 5/11/2021 Fe-59 -2.01E-01 1.09E+00 3.49E+00 U WS 51 544777002 5/11/2021 I-131 -6.43E-01 8.97E-01 2.67E+00 U WS 51 544777002 5/11/2021 K-40 3.02E+02 2.53E+01 1.41E+01 WS 51 544777002 5/11/2021 La-140 1.49E-01 8.87E-01 3.02E+00 U WS 51 544777002 5/11/2021 Mn-54 -1.31E-01 4.74E-01 1.53E+00 U WS 51 544777002 5/11/2021 Nb-95 -1.32E-01 4.50E-01 1.46E+00 U WS 51 544777002 5/11/2021 Pb-212 0.00E+00 1.74E+00 2.79E+00 U WS 51 544777002 5/11/2021 Pb-214 3.36E-01 2.12E+00 4.00E+00 U WS 51 544777002 5/11/2021 Ru-103 -3.33E-01 5.28E-01 1.54E+00 U WS 51 544777002 5/11/2021 Ru-106 -7.55E-01 4.00E+00 1.33E+01 U WS 51 544777002 5/11/2021 Sb-124 -1.79E+00 1.14E+00 3.03E+00 U WS 51 544777002 5/11/2021 Sb-125 1.08E+00 1.14E+00 3.94E+00 U WS 51 544777002 5/11/2021 Se-75 9.49E-01 6.57E-01 2.06E+00 U WS 51 544777002 5/11/2021 Th-228 0.00E+00 1.74E+00 2.79E+00 U WS 51 544777002 5/11/2021 Zn-65 2.29E-01 1.02E+00 3.33E+00 U WS 51 544777002 5/11/2021 Zr-95 1.28E-01 8.42E-01 2.81E+00 U WS 51 548321002 6/14/2021 Ac-228 1.01E+01 3.87E+00 1.14E+01 U WS 51 548321002 6/14/2021 Ag-108m -4.23E-01 5.84E-01 1.92E+00 U WS 51 548321002 6/14/2021 Ag-110m 2.48E-01 1.06E+00 3.46E+00 U WS 51 548321002 6/14/2021 Ba-140 8.89E+00 6.12E+00 2.04E+01 UDL WS 51 548321002 6/14/2021 Be-7 1.70E+01 1.01E+01 2.10E+01 U WS 51 548321002 6/14/2021 Bi-214 -5.43E+00 3.33E+00 6.15E+00 U WS 51 548321002 6/14/2021 Ce-141 -6.92E+00 2.79E+00 4.62E+00 U WS 51 548321002 6/14/2021 Ce-144 6.67E+00 4.52E+00 1.45E+01 U WS 51 548321002 6/14/2021 Co-57 1.47E-01 5.51E-01 1.84E+00 U WS 51 548321002 6/14/2021 Co-58 8.61E-01 7.41E-01 2.47E+00 U WS 51 548321002 6/14/2021 Co-60 -8.98E-02 7.11E-01 2.36E+00 U WS 51 548321002 6/14/2021 Cr-51 1.02E+01 8.16E+00 2.56E+01 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 51 548321002 6/14/2021 Cs-134 7.91E-01 8.06E-01 2.67E+00 U WS 51 548321002 6/14/2021 Cs-137 4.03E-01 7.45E-01 2.49E+00 U WS 51 548321002 6/14/2021 Fe-59 1.20E+00 2.22E+00 5.37E+00 U WS 51 548321002 6/14/2021 I-131 1.79E+00 3.21E+00 9.32E+00 U WS 51 548321002 6/14/2021 K-40 3.28E+02 2.62E+01 2.18E+01 WS 51 548321002 6/14/2021 La-140 -9.31E-01 2.36E+00 7.51E+00 U WS 51 548321002 6/14/2021 Mn-54 7.03E-02 6.91E-01 2.25E+00 U WS 51 548321002 6/14/2021 Nb-95 -6.03E-01 8.15E-01 2.52E+00 U WS 51 548321002 6/14/2021 Pb-212 -1.92E+00 2.13E+00 4.79E+00 U WS 51 548321002 6/14/2021 Pb-214 4.61E+00 3.51E+00 6.20E+00 U WS 51 548321002 6/14/2021 Ru-103 2.36E-03 8.67E-01 2.63E+00 U WS 51 548321002 6/14/2021 Ru-106 4.94E-01 6.45E+00 1.92E+01 U WS 51 548321002 6/14/2021 Sb-124 1.10E+00 2.14E+00 6.73E+00 U WS 51 548321002 6/14/2021 Sb-125 1.28E+00 1.74E+00 5.99E+00 U WS 51 548321002 6/14/2021 Se-75 1.15E+00 1.47E+00 3.13E+00 U WS 51 548321002 6/14/2021 Th-228 -1.92E+00 2.13E+00 4.79E+00 U WS 51 548321002 6/14/2021 Zn-65 7.51E-01 1.51E+00 4.89E+00 U WS 51 548321002 6/14/2021 Zr-95 -2.81E+00 1.51E+00 3.94E+00 U WS 51 552141002 6/14/2021 H-3 -1.87E+01 1.42E+02 4.72E+02 U WS 51 550012002 7/14/2021 Ac-228 -3.34E-02 4.01E+00 8.52E+00 U WS 51 550012002 7/14/2021 Ag-108m 7.75E-01 4.90E-01 1.58E+00 U WS 51 550012002 7/14/2021 Ag-110m -2.36E-01 7.08E-01 2.32E+00 U WS 51 550012002 7/14/2021 Ba-140 3.43E-01 2.39E+00 7.79E+00 U WS 51 550012002 7/14/2021 Be-7 4.65E+00 4.70E+00 1.55E+01 U WS 51 550012002 7/14/2021 Bi-214 -3.77E+00 2.27E+00 4.24E+00 U WS 51 550012002 7/14/2021 Ce-141 2.09E+00 1.77E+00 3.13E+00 U WS 51 550012002 7/14/2021 Ce-144 -9.47E-01 3.56E+00 1.14E+01 U WS 51 550012002 7/14/2021 Co-57 -9.35E-01 5.01E-01 1.39E+00 U WS 51 550012002 7/14/2021 Co-58 3.07E-01 5.30E-01 1.61E+00 U WS 51 550012002 7/14/2021 Co-60 7.05E-01 6.07E-01 2.01E+00 U WS 51 550012002 7/14/2021 Cr-51 7.98E+00 5.14E+00 1.67E+01 U WS 51 550012002 7/14/2021 Cs-134 4.02E-01 5.30E-01 1.82E+00 U WS 51 550012002 7/14/2021 Cs-137 1.71E-01 5.59E-01 1.80E+00 U WS 51 550012002 7/14/2021 Fe-59 -2.04E+00 1.25E+00 3.43E+00 U WS 51 550012002 7/14/2021 I-131 -3.09E-01 8.19E-01 2.69E+00 U WS 51 550012002 7/14/2021 K-40 2.21E+02 2.04E+01 1.98E+01 WS 51 550012002 7/14/2021 La-140 -1.47E+00 9.27E-01 2.58E+00 U WS 51 550012002 7/14/2021 Mn-54 -1.01E+00 5.63E-01 1.57E+00 U WS 51 550012002 7/14/2021 Nb-95 -2.59E-01 5.04E-01 1.65E+00 U WS 51 550012002 7/14/2021 Pb-212 -2.60E+00 1.72E+00 3.78E+00 U WS 51 550012002 7/14/2021 Pb-214 2.36E+00 1.86E+00 3.94E+00 U WS 51 550012002 7/14/2021 Ru-103 -1.48E+00 8.09E-01 1.61E+00 U WS 51 550012002 7/14/2021 Ru-106 -9.23E-01 4.70E+00 1.49E+01 U WS 51 550012002 7/14/2021 Sb-124 2.76E+00 1.47E+00 4.94E+00 U WS 51 550012002 7/14/2021 Sb-125 -1.15E+00 1.42E+00 4.47E+00 U WS 51 550012002 7/14/2021 Se-75 2.75E-01 6.70E-01 2.30E+00 U WS 51 550012002 7/14/2021 Th-228 -2.60E+00 1.72E+00 3.78E+00 U WS 51 550012002 7/14/2021 Zn-65 1.23E+00 1.47E+00 4.09E+00 U WS 51 550012002 7/14/2021 Zr-95 -6.51E-01 9.87E-01 3.21E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 51 552735002 8/9/2021 Ac-228 -2.69E+00 4.63E+00 6.51E+00 U WS 51 552735002 8/9/2021 Ag-108m 1.34E-02 4.10E-01 1.38E+00 U WS 51 552735002 8/9/2021 Ag-110m -3.44E-01 6.16E-01 1.91E+00 U WS 51 552735002 8/9/2021 Ba-140 -2.33E-01 2.99E+00 9.89E+00 U WS 51 552735002 8/9/2021 Be-7 -4.09E+00 4.27E+00 1.36E+01 U WS 51 552735002 8/9/2021 Bi-214 1.10E+00 2.12E+00 3.21E+00 U WS 51 552735002 8/9/2021 Ce-141 -6.48E+00 2.34E+00 3.09E+00 U WS 51 552735002 8/9/2021 Ce-144 7.01E-01 3.29E+00 1.07E+01 U WS 51 552735002 8/9/2021 Co-57 6.15E-01 4.88E-01 1.44E+00 U WS 51 552735002 8/9/2021 Co-58 -4.22E-01 4.78E-01 1.45E+00 U WS 51 552735002 8/9/2021 Co-60 -4.23E-01 4.68E-01 1.46E+00 U WS 51 552735002 8/9/2021 Cr-51 3.48E+00 5.10E+00 1.75E+01 U WS 51 552735002 8/9/2021 Cs-134 5.83E-01 7.57E-01 1.79E+00 U WS 51 552735002 8/9/2021 Cs-137 7.95E-01 5.04E-01 1.62E+00 U WS 51 552735002 8/9/2021 Fe-59 -4.19E-01 1.03E+00 3.41E+00 U WS 51 552735002 8/9/2021 I-131 -7.87E-01 1.20E+00 3.96E+00 U WS 51 552735002 8/9/2021 K-40 2.92E+02 2.36E+01 1.51E+01 WS 51 552735002 8/9/2021 La-140 -7.13E-01 1.08E+00 3.39E+00 U WS 51 552735002 8/9/2021 Mn-54 -4.08E-02 4.64E-01 1.49E+00 U WS 51 552735002 8/9/2021 Nb-95 -1.02E+00 9.05E-01 1.65E+00 U WS 51 552735002 8/9/2021 Pb-212 -2.07E-01 1.76E+00 3.50E+00 U WS 51 552735002 8/9/2021 Pb-214 -3.08E+00 1.97E+00 3.79E+00 U WS 51 552735002 8/9/2021 Ru-103 -2.23E-01 7.07E-01 1.64E+00 U WS 51 552735002 8/9/2021 Ru-106 -8.92E-01 4.21E+00 1.37E+01 U WS 51 552735002 8/9/2021 Sb-124 -3.08E+00 1.38E+00 3.26E+00 U WS 51 552735002 8/9/2021 Sb-125 -6.28E-01 1.20E+00 3.94E+00 U WS 51 552735002 8/9/2021 Se-75 -4.73E-01 7.05E-01 2.14E+00 U WS 51 552735002 8/9/2021 Th-228 -2.07E-01 1.76E+00 3.50E+00 U WS 51 552735002 8/9/2021 Zn-65 -4.92E-01 1.09E+00 3.16E+00 U WS 51 552735002 8/9/2021 Zr-95 1.21E+00 9.29E-01 3.01E+00 U WS 51 556375002 9/15/2021 Ac-228 2.42E+00 4.57E+00 7.49E+00 U WS 51 556375002 9/15/2021 Ag-108m -1.30E+00 7.74E-01 1.50E+00 U WS 51 556375002 9/15/2021 Ag-110m 3.69E-01 7.06E-01 2.28E+00 U WS 51 556375002 9/15/2021 Ba-140 1.87E+00 2.71E+00 9.02E+00 U WS 51 556375002 9/15/2021 Be-7 -1.31E+00 3.96E+00 1.31E+01 U WS 51 556375002 9/15/2021 Bi-214 3.35E+00 1.98E+00 3.73E+00 U WS 51 556375002 9/15/2021 Ce-141 1.71E+00 1.77E+00 2.68E+00 U WS 51 556375002 9/15/2021 Ce-144 7.86E-01 3.24E+00 1.06E+01 U WS 51 556375002 9/15/2021 Co-57 1.76E-01 4.24E-01 1.39E+00 U WS 51 556375002 9/15/2021 Co-58 -4.40E-01 5.57E-01 1.71E+00 U WS 51 556375002 9/15/2021 Co-60 -1.33E+00 9.47E-01 1.50E+00 U WS 51 556375002 9/15/2021 Cr-51 -5.79E+00 4.75E+00 1.52E+01 U WS 51 556375002 9/15/2021 Cs-134 -2.31E-01 5.26E-01 1.65E+00 U WS 51 556375002 9/15/2021 Cs-137 5.72E-01 4.96E-01 1.62E+00 U WS 51 556375002 9/15/2021 Fe-59 -2.83E-01 9.23E-01 3.07E+00 U WS 51 556375002 9/15/2021 I-131 -4.45E-01 9.78E-01 3.27E+00 U WS 51 556375002 9/15/2021 K-40 3.55E+02 2.59E+01 1.49E+01 WS 51 556375002 9/15/2021 La-140 -3.63E-01 8.64E-01 2.75E+00 U WS 51 556375002 9/15/2021 Mn-54 -3.90E-01 5.05E-01 1.54E+00 U WS 51 556375002 9/15/2021 Nb-95 9.84E-02 8.68E-01 1.78E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 51 556375002 9/15/2021 Pb-212 0.00E+00 2.92E+00 3.50E+00 U WS 51 556375002 9/15/2021 Pb-214 2.15E-01 1.68E+00 4.04E+00 U WS 51 556375002 9/15/2021 Ru-103 -1.89E-01 5.78E-01 1.70E+00 U WS 51 556375002 9/15/2021 Ru-106 -4.36E-01 4.16E+00 1.36E+01 U WS 51 556375002 9/15/2021 Sb-124 -6.04E-02 9.81E-01 3.18E+00 U WS 51 556375002 9/15/2021 Sb-125 2.40E-01 1.30E+00 4.39E+00 U WS 51 556375002 9/15/2021 Se-75 -6.57E-01 7.35E-01 2.20E+00 U WS 51 556375002 9/15/2021 Th-228 0.00E+00 2.92E+00 3.50E+00 U WS 51 556375002 9/15/2021 Zn-65 -2.34E-01 1.02E+00 3.40E+00 U WS 51 556375002 9/15/2021 Zr-95 -4.77E-01 9.06E-01 2.85E+00 U WS 51 560827002 9/15/2021 H-3 -1.91E+02 2.22E+02 7.69E+02 U WS 51 558886002 10/12/2021 Ac-228 3.58E+00 4.79E+00 6.57E+00 U WS 51 558886002 10/12/2021 Ag-108m 2.78E-01 5.00E-01 1.70E+00 U WS 51 558886002 10/12/2021 Ag-110m -1.53E+00 8.37E-01 2.08E+00 U WS 51 558886002 10/12/2021 Ba-140 -2.42E-03 2.83E+00 9.40E+00 U WS 51 558886002 10/12/2021 Be-7 9.26E+00 5.95E+00 1.49E+01 U WS 51 558886002 10/12/2021 Bi-214 8.53E+00 2.78E+00 3.48E+00 X(1)

WS 51 558886002 10/12/2021 Ce-141 -1.16E+00 1.03E+00 3.07E+00 U WS 51 558886002 10/12/2021 Ce-144 1.38E+00 3.70E+00 1.20E+01 U WS 51 558886002 10/12/2021 Co-57 -5.22E-01 4.76E-01 1.44E+00 U WS 51 558886002 10/12/2021 Co-58 -4.37E-01 6.89E-01 2.01E+00 U WS 51 558886002 10/12/2021 Co-60 -5.59E-01 6.80E-01 2.11E+00 U WS 51 558886002 10/12/2021 Cr-51 5.02E+00 5.01E+00 1.72E+01 U WS 51 558886002 10/12/2021 Cs-134 7.43E-01 6.24E-01 2.08E+00 U WS 51 558886002 10/12/2021 Cs-137 5.33E-01 5.81E-01 1.95E+00 U WS 51 558886002 10/12/2021 Fe-59 -2.03E+00 1.65E+00 4.01E+00 U WS 51 558886002 10/12/2021 I-131 -9.38E-01 9.20E-01 2.90E+00 U WS 51 558886002 10/12/2021 K-40 3.02E+02 2.37E+01 1.36E+01 WS 51 558886002 10/12/2021 La-140 9.02E-01 1.02E+00 3.17E+00 U WS 51 558886002 10/12/2021 Mn-54 7.63E-01 5.51E-01 1.83E+00 U WS 51 558886002 10/12/2021 Nb-95 -4.53E-01 6.29E-01 1.93E+00 U WS 51 558886002 10/12/2021 Pb-212 6.71E-01 2.20E+00 3.41E+00 U WS 51 558886002 10/12/2021 Pb-214 -1.73E+00 2.03E+00 4.76E+00 U WS 51 558886002 10/12/2021 Ru-103 -2.21E-01 6.02E-01 1.75E+00 U WS 51 558886002 10/12/2021 Ru-106 6.55E-01 5.10E+00 1.68E+01 U WS 51 558886002 10/12/2021 Sb-124 2.05E+00 1.07E+00 3.87E+00 U WS 51 558886002 10/12/2021 Sb-125 -1.71E+00 1.35E+00 4.05E+00 U WS 51 558886002 10/12/2021 Se-75 1.86E-01 7.54E-01 2.37E+00 U WS 51 558886002 10/12/2021 Th-228 6.71E-01 2.20E+00 3.41E+00 U WS 51 558886002 10/12/2021 Zn-65 -1.33E-02 1.27E+00 3.79E+00 U WS 51 558886002 10/12/2021 Zr-95 8.12E-01 9.14E-01 3.07E+00 U WS 51 563415002 11/17/2021 Ac-228 -1.30E+00 3.16E+00 6.93E+00 U WS 51 563415002 11/17/2021 Ag-108m 5.61E-02 3.91E-01 1.30E+00 U WS 51 563415002 11/17/2021 Ag-110m -1.13E+00 6.97E-01 2.02E+00 U WS 51 563415002 11/17/2021 Ba-140 4.28E+00 4.11E+00 1.35E+01 U WS 51 563415002 11/17/2021 Be-7 2.75E+00 4.30E+00 1.43E+01 U WS 51 563415002 11/17/2021 Bi-214 3.69E+00 2.34E+00 4.05E+00 U WS 51 563415002 11/17/2021 Ce-141 -5.68E+00 2.03E+00 3.07E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 51 563415002 11/17/2021 Ce-144 2.21E+00 3.18E+00 1.04E+01 U WS 51 563415002 11/17/2021 Co-57 -2.09E-02 4.29E-01 1.40E+00 U WS 51 563415002 11/17/2021 Co-58 9.56E-01 5.83E-01 1.93E+00 U WS 51 563415002 11/17/2021 Co-60 -5.97E-01 6.93E-01 1.62E+00 U WS 51 563415002 11/17/2021 Cr-51 2.43E+00 5.43E+00 1.85E+01 U WS 51 563415002 11/17/2021 Cs-134 7.44E-01 5.54E-01 1.69E+00 U WS 51 563415002 11/17/2021 Cs-137 2.01E-01 4.78E-01 1.55E+00 U WS 51 563415002 11/17/2021 Fe-59 -1.51E+00 1.51E+00 3.98E+00 U WS 51 563415002 11/17/2021 I-131 -3.00E-02 1.81E+00 6.07E+00 U WS 51 563415002 11/17/2021 K-40 3.16E+02 2.39E+01 1.65E+01 WS 51 563415002 11/17/2021 La-140 -1.18E+00 1.35E+00 4.23E+00 U WS 51 563415002 11/17/2021 Mn-54 -4.21E-01 4.72E-01 1.51E+00 U WS 51 563415002 11/17/2021 Nb-95 6.22E-01 5.66E-01 1.93E+00 U WS 51 563415002 11/17/2021 Pb-212 1.57E+00 1.90E+00 3.63E+00 U WS 51 563415002 11/17/2021 Pb-214 -1.28E+00 2.02E+00 3.81E+00 U WS 51 563415002 11/17/2021 Ru-103 -1.90E+00 7.14E-01 1.62E+00 U WS 51 563415002 11/17/2021 Ru-106 -1.72E+00 4.32E+00 1.37E+01 U WS 51 563415002 11/17/2021 Sb-124 -2.19E+00 1.74E+00 4.10E+00 U WS 51 563415002 11/17/2021 Sb-125 -1.38E-01 1.14E+00 3.78E+00 U WS 51 563415002 11/17/2021 Se-75 4.62E-01 6.28E-01 2.16E+00 U WS 51 563415002 11/17/2021 Th-228 1.57E+00 1.90E+00 3.63E+00 U WS 51 563415002 11/17/2021 Zn-65 1.47E+00 1.20E+00 3.98E+00 U WS 51 563415002 11/17/2021 Zr-95 -3.06E+00 1.71E+00 2.91E+00 U WS 51 565202002 12/9/2021 Ac-228 1.85E+00 4.41E+00 9.41E+00 U WS 51 565202002 12/9/2021 Ag-108m 1.92E-01 4.75E-01 1.56E+00 U WS 51 565202002 12/9/2021 Ag-110m -5.94E-01 8.15E-01 2.64E+00 U WS 51 565202002 12/9/2021 Ba-140 3.30E+00 5.51E+00 1.79E+01 UDL WS 51 565202002 12/9/2021 Be-7 -1.29E-01 5.78E+00 1.88E+01 U WS 51 565202002 12/9/2021 Bi-214 8.44E-01 3.19E+00 4.55E+00 U WS 51 565202002 12/9/2021 Ce-141 -2.91E+00 1.78E+00 3.29E+00 U WS 51 565202002 12/9/2021 Ce-144 -4.35E+00 3.22E+00 9.18E+00 U WS 51 565202002 12/9/2021 Co-57 1.45E-02 4.98E-01 1.21E+00 U WS 51 565202002 12/9/2021 Co-58 2.22E-01 6.35E-01 2.17E+00 U WS 51 565202002 12/9/2021 Co-60 1.66E+00 8.25E-01 2.36E+00 U WS 51 565202002 12/9/2021 Cr-51 -1.08E+01 7.09E+00 2.12E+01 U WS 51 565202002 12/9/2021 Cs-134 1.14E+00 6.53E-01 2.14E+00 U WS 51 565202002 12/9/2021 Cs-137 1.30E+00 6.78E-01 2.07E+00 U WS 51 565202002 12/9/2021 Fe-59 3.37E+00 3.82E+00 5.34E+00 U WS 51 565202002 12/9/2021 I-131 -1.29E+00 2.79E+00 9.03E+00 U WS 51 565202002 12/9/2021 K-40 3.64E+02 2.59E+01 1.75E+01 WS 51 565202002 12/9/2021 La-140 -3.96E+00 2.56E+00 5.93E+00 U WS 51 565202002 12/9/2021 Mn-54 -9.02E-01 6.11E-01 1.84E+00 U WS 51 565202002 12/9/2021 Nb-95 3.52E-01 6.81E-01 2.33E+00 U WS 51 565202002 12/9/2021 Pb-212 -3.65E+00 2.03E+00 3.59E+00 U WS 51 565202002 12/9/2021 Pb-214 0.00E+00 3.01E+00 4.32E+00 U WS 51 565202002 12/9/2021 Ru-103 -4.77E-01 7.11E-01 2.23E+00 U WS 51 565202002 12/9/2021 Ru-106 5.29E+00 5.54E+00 1.78E+01 U WS 51 565202002 12/9/2021 Sb-124 1.80E+00 1.73E+00 5.72E+00 U WS 51 565202002 12/9/2021 Sb-125 1.08E+00 1.45E+00 4.74E+00 U WS 51 565202002 12/9/2021 Se-75 -1.57E+00 7.71E-01 2.17E+00 U

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Seabrook REMP Summary of 2021 Data SAMPLE END CONC STD.DEV. MDC FLAGS TYPE STATION LSN DATE NUCLIDE (pCi/L) (pCi/ L) (pCi/ L)

WS 51 565202002 12/9/2021 Th-228 -3.65E+00 2.03E+00 3.59E+00 U WS 51 565202002 12/9/2021 Zn-65 -6.10E-01 1.36E+00 4.40E+00 U WS 51 565202002 12/9/2021 Zr-95 1.69E-01 1.16E+00 3.95E+00 U WS 51 568410002 12/9/2021 H-3 -3.80E+02 1.71E+02 6.22E+02 U FLAGS A blank Flag field indicates that the measured activity is considered positive as it is greater than the MDC and has no other qualifiers noted.

U: Target isotope was analyzed for but not detected above the MDC and LLD.

UI: Uncertain identification for gamma spectroscopy.

X: Lab-specific qualifier:

(1) False positive due to the presence of radon gas in the water.

M: Reported result is less than the LLD and greater than the MDC.

DL: Measured MDC is greater than the LLD.

DL*: Near miss of MDC being within round-off difference of being greater than the LLD.

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SBK-L-22043, 2021 Annual Radiological Environmental Operating Report

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SBK-L-22043, 2021 Annual Radiological Environmental Operating Report

Text

SUMMARY

1.0 INTRODUCTION

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SUMMARY

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