ML22112A232

Annual Radiological Environmental Operating Report 2021

ML22112A232
Person / Time
Site:	Palo Verde
Issue date:	04/22/2022
From:	Gil K Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-08426-KJG/MSC
Download: ML22112A232 (73)

Text

Technical Specification 5.6.2 5 .6.2 Palo Verde Nuclear Generating Station P.O. Box 52034 102-08426-KJG/MSC Phoenix, AZ 85072 Mail Station 7636 April 22, 2022 Tel: (623) 393-2488 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station (PVNGS) Units 1, 2, and 3 Renewed Operating License Nos. NPF-41, NPF-51, and NPF-74 Docket Nos. STN 50-528, STN 50-529, and STN 50-530 Annual Radiological Environmental Operating Report 2021 Enclosed please find the PVNGS Units 1, 2, and 3 Annual Radiological Environmental Operating Report for 2021. Arizona Public Service Company is submitting this report pursuant to the PVNGS Technical Specification Reporting Requirement, Section 5.6.2.

No new commitments are being made to the Nuclear Regulatory Commission (NRC) by this letter.

Should you need further information regarding this submittal, please contact Matthew S. Cox, Licensing Section Leader, at (623) 393-5753.

Sincerely, Digitally signed by Gil, Katherine J(Z05492)

Date: 2022.04.22 05:26:39 -07'00' Katherine J. Gil Director, Nuclear Regulatory Affairs KJG/MSC/mg

Enclosure:

Palo Verde Nuclear Generating Station Annual Radiological Environmental Operating Report 2021 cc: S. A. Morris NRC Region IV Regional Administrator S. P. Lingam NRC NRR Project Manager for PVNGS L. N. Merker NRC Senior Resident Inspector for PVNGS B. Goretzki Arizona Department of Health Services - Bureau of Radiation Controls A member of the STARS Alliance LLC Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek

Enclosure Palo Verde Nuclear Generating Station Annual Radiological Environmental Operating Report 2021

(

Reference:

RCTSAI 1643, Legacy Item No.036843.01)

Digitally signed by Comolli, Comolli, Michelle Michelle (Z09567)

(Z09567) Date: 2022.04.06 19:31:26

-07'00' Prepared by:

Digitally signed by Bungard, Bungard, James James P(Z18012)

P(Z18012) Date: 2022.04.07 09:55:32

-07'00' Reviewed by:

Supervisor, Radiological Engineering Grusecki, Lori Digitally signed by Grusecki, Lori J(Z39643)

J(Z39643) Date: 2022.04.08 Approved by: 14:03:56 -07'00' Manager, Radiation Protection

1. TABLE OF CONTENTS

1. Introduction ............................................................................................................................. 2 1.1 Overview .......................................................................................................................... 2 1.2 Radiation and Radioactivity ............................................................................................. 3

2. Description of the Monitoring Program .................................................................................. 4 2.1 Radiological Environmental Monitoring Program ........................................................... 4 2.2 Radiological Environmental Monitoring Program Changes for 2021 ............................. 4 2.3 REMP Deviations/Abnormal Events Summary ............................................................... 4 2.4 Groundwater Protection ................................................................................................... 5

3. Sample Collection Program .................................................................................................. 11 3.1 Water .............................................................................................................................. 11 3.2 Vegetation ...................................................................................................................... 11 3.3 Milk ................................................................................................................................ 11 3.4 Air................................................................................................................................... 11 3.5 Soil, Sludge, and Sediment ............................................................................................ 11

4. Analytical Procedures ........................................................................................................... 12 4.1 Air Particulate ................................................................................................................ 12 4.1.1 Gross Beta .................................................................................................................... 12 4.1.2 Gamma Spectroscopy .................................................................................................. 12 4.2 Airborne Radioiodine ..................................................................................................... 12 4.2.1 Gamma Spectroscopy .................................................................................................. 12 4.3 Milk ................................................................................................................................ 12 4.3.1 Gamma Spectroscopy .................................................................................................. 12 4.3.2 Radiochemical I-131 Separation .................................................................................. 12 4.4 Vegetation ...................................................................................................................... 12 4.4.1 Gamma Spectroscopy .................................................................................................. 12 4.5 Sludge/Sediment ............................................................................................................ 13 4.5.1 Gamma Spectroscopy .................................................................................................. 13 4.6 Water .............................................................................................................................. 13 4.6.1 Gamma Spectroscopy .................................................................................................. 13 4.6.2 Tritium ......................................................................................................................... 13 4.6.3 Gross Beta .................................................................................................................... 13 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page ii

4.7 Soil ................................................................................................................................. 13 4.7.1 Gamma Spectroscopy .................................................................................................. 13

5. Nuclear Instrumentation........................................................................................................ 14 5.1 Gamma Spectrometer ..................................................................................................... 14 5.2 Liquid Scintillation Spectrometer .................................................................................. 14 5.3 Gas Flow Proportional Counter...................................................................................... 14

6. Isotopic Detection Limits and Reporting Criteria ................................................................. 15 6.1 Lower Limits of Detection ............................................................................................. 15 6.2 Data Reporting Criteria .................................................................................................. 15 6.3 LLD and Reporting Criteria Overview .......................................................................... 15

7. Interlaboratory Comparison Program ................................................................................... 19 7.1 Quality Control Program ................................................................................................ 19 7.2 Intercomparison Results ................................................................................................. 19

8. Data Interpretation and Conclusions ..................................................................................... 21 8.1 Air Particulates ............................................................................................................... 21 8.2 Airborne Radioiodine ..................................................................................................... 21 8.3 Vegetation ...................................................................................................................... 21 8.4 Milk ................................................................................................................................ 22 8.5 Drinking Water ............................................................................................................... 22 8.6 Groundwater ................................................................................................................... 22 8.7 Surface Water ................................................................................................................. 22 8.8 Sludge and Sediment ...................................................................................................... 23 8.8.1 Water Resources Centrifuge Waste Sludge ................................................................. 23 8.8.2 Cooling Tower Sludge ................................................................................................. 23 8.9 Data Trends .................................................................................................................... 23 8.10 Hard-To-Detect Radionuclide Results........................................................................ 23

9. Thermoluminescent Dosimeter (TLD) Results and Data ..................................................... 50

10. Land Use Census................................................................................................................ 55 10.1 Introduction ................................................................................................................ 55 10.2 Census Results ............................................................................................................ 55

11. Summary and Conclusions ................................................................................................ 60

12. References .......................................................................................................................... 65

13. APPENDIX A: ERRATICA .............................................................................................. 66 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page iii

LIST OF TABLES Table 2-1 Sample Collection Locations .......................................................................................... 6 Table 2-2 Sample Collection Schedule ........................................................................................... 7 Table 2-3 Summaries of the REMP Deviations/Abnormal Events ................................................ 8 Table 6-1 ODCM Required Lower Limits of Detection (a priori) ............................................... 17 Table 6-2 ODCM Required Reporting Levels .............................................................................. 18 Table 6-3 Typical MDA Values ................................................................................................... 18 Table 7-1 Interlaboratory Comparison Results ............................................................................. 20 Table 8-1 Particulate Gross Beta in Air 1st-2nd Quarter .............................................................. 24 Table 8-2 Particulate Gross Beta in Air 3rd-4th Quarter .............................................................. 25 Table 8-3 Gamma in Air Filter Composites ................................................................................. 26 Table 8-4 Radioiodine in Air 1st-2nd Quarter .............................................................................. 27 Table 8-5 Radioiodine in Air 3rd-4th Quarter .............................................................................. 28 Table 8-6 Vegetation..................................................................................................................... 29 Table 8-7 Milk .............................................................................................................................. 30 Table 8-8 Drinking Water ............................................................................................................. 31 Table 8-9 Groundwater ................................................................................................................. 33 Table 8-10 Surface Water ............................................................................................................. 34 Table 8-11 Sludge/Sediment ......................................................................................................... 39 Table 8-12 Hard -To-Detect Radionuclide Results ...................................................................... 41 Table 9-1 TLD Site Locations ...................................................................................................... 51 Table 9-2 Environmental TLD Results ......................................................................................... 52 Table 10-1 Land Use Census ........................................................................................................ 56 Table 11-1 Environmental Radiological Monitoring Program Annual Summary........................ 62 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page iv

TABLE OF FIGURES Figure 1-1 Sources of Radiation Exposure in the United States ..................................................... 3 Figure 2-1 REMP Sample Sites- Map (0-10 miles) ........................................................................ 9 Figure 2-2 REMP Sample Sites- Map (10-35 Miles) ................................................................... 10 Figure 8-1 Gross Beta in Air, 1st-2nd Quarter ............................................................................. 42 Figure 8-2 Gross Beta in Air, 3rd-4th Quarter .............................................................................. 43 Figure 8-3 Historical Gross Beta in Air (Weekly System Average) ............................................ 44 Figure 8-4 Historical Gross Beta in Air (Annual Site to Site Comparisons) Compared to Pre-Op

....................................................................................................................................................... 45 Figure 8-5 Gross Beta in Drinking Water ..................................................................................... 46 Figure 8-6 Evaporation Pond Tritium Activity (Pre-Op- 2008) ................................................... 47 Figure 8-7 Evaporation Pond Tritium Activity (2009-2021)........................................................ 48 Figure 8-8 Sedimentation Basin 2 Cs-137 .................................................................................... 49 Figure 9-1 Network Environmental TLD Exposure Rates ........................................................... 53 Figure 9-2 Environmental TLD Comparison: Pre-Operational versus 2021 ................................ 54 Figure 10-1 Historical Comparison of Nearest Resident Dose ..................................................... 57 Figure 10-2 Historical Comparison of Nearest Milk Animal Dose .............................................. 58 Figure 10-3 Historical Comparison of Nearest Garden Dose ....................................................... 59 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page v

ABSTRACT The Radiological Environmental Monitoring Program (REMP) is an ongoing program conducted by Arizona Public Service Company (APS) for the Palo Verde Nuclear Generating Station (PVNGS). Various types of environmental samples are collected near PVNGS and analyzed for plant-related radionuclide concentrations.

During 2021, the following categories of samples were collected by APS:

• Broadleaf vegetation

• Groundwater

• Drinking water

• Surface water

• Airborne particulate and radioiodine

• Goat milk

• Sludge Thermoluminescent dosimeters (TLDs) were used to measure environmental gamma radiation.

The Environmental TLD program is also conducted by APS.

The Arizona Department of Health Services, Bureau of Radiation Control (BRC) performs radiochemistry analyses on various duplicate samples provided to them by APS. Samples analyzed by BRC include onsite samples from the Reservoirs, Evaporation Ponds, and two (2)

Deep Wells. Offsite samples analyzed by BRC include two (2) local resident wells. BRC also performs air sampling at seven (7) offsite locations identical to APS and maintains approximately fifty (50) environmental TLD monitoring locations, eighteen (18) of which are duplicates of APS locations.

A comparison of pre-operational and operational data indicates no changes to environmental radiation levels.

(NOTE: Reference to APS throughout this report refers to PVNGS personnel)

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1. Introduction This report presents the results of the operational Radiological Environmental Monitoring Program conducted by Arizona Public Service Company (APS). The Radiological Environmental Monitoring Program (REMP) was established for the Palo Verde Nuclear Generating Station (PVNGS) by APS in 1979.

This report contains the measurements and findings for 2021. All references are specifically identified in Section 12.

1.1 Overview The Radiological Environmental Monitoring Program ( R E M P ) provides representative measurements of radiation and radioactive materials in exposure pathways. REMP measures radionuclides that lead to the highest potential radiation exposures to members of the public resulting from station operation. This monitoring program implements Title 10 of the Code of Federal Regulations (CFR) Part 50, Appendix I, Section IV.B.2., and thereby supplements the radiological effluent monitoring program by verifying that the measurable concentrations of radioactive materials and levels of radiation are not higher than expected on the basis of the effluent measurements and the modeling of the environmental exposure pathways. Guidance for this monitoring program is provided by the US Nuclear Regulatory Commission (USNRC) in their Radiological Assessment Branch Technical Position on Environmental Monitoring, Revision 1, November 1979 (incorporated into NUREG 1301). Results from the REMP help to evaluate sources of elevated levels of radioactivity in the environment (i.e. atmospheric nuclear detonations or abnormal plant releases).

The Land Use Census ensures that changes in the use of areas at, and beyond the site boundary, are identified and that modifications to the REMP are made if required by the results of this census. This census satisfies the requirements of Section IV.B.3 of Appendix I to 10 CFR Part 50.

The Interlaboratory Comparison Program is provided to ensure that independent checks on the precision and accuracy of the measurements of radioactive material in environmental sample matrices are performed as part of the quality assurance program for environmental monitoring in order to demonstrate that the results are valid for the purposes of 10 CFR 50, Appendix I, Section IV.B.2.

Results of the PVNGS pre-operational environmental monitoring program are presented in Reference 1.

The initial criticality of Unit 1 occurred May 25, 1985. Initial criticality for Units 2 and 3 were April 18, 1986, and October 25, 1987, respectively. PVNGS operational findings (historical) are presented in Reference 2.

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1.2 Radiation and Radioactivity Atoms are the basic building blocks of matter. Unstable atoms emit radiation; material that spontaneously emits radiation is referred to as radioactive. Radioactive material is frequently categorized as either Natural or Man-made Natural sources of radiation exist naturally in the environment and include radon, thoron, cosmic, terrestrial, and internal. The sun and stars are a source of cosmic radiation. Atmospheric conditions, the Earths magnetic field, and differences in elevation can affect the amount, or dose, of cosmic radiation an individual receives. The Earth is a source of terrestrial radiation.

Uranium, thorium, and radium exist naturally in rock and soil. All organic matter contains carbon and potassium, and water contains small amounts of dissolved uranium and thorium. The largest contributor of dose to Americans from natural sources is attributed to radon which is found in air. All people are a source of internal radiation. Potassium-40 and carbon-14 are radioactive nuclides and inside all people from birth, making people a source of exposure.

Man-made sources of radiation include consumer products, nuclear medicine, and medical procedures. There are a number of occupational areas which result in exposure to individuals of varying amounts of radiation such as: radiography, radiology, radiation oncology, power generation, and research laboratories. The Nuclear Regulatory Commission (NRC) requires licensees to monitor exposure to workers and limit occupational exposure to 5,000 millirem per year. Several consumer products contain radioactive material such as: some ceramics, thorium lantern mantles, luminous watches containing tritium, smoke detectors, and tobacco. Other consumer product sources of radiation can come from building and road construction materials, combustible fuels (i.e. gas, coal), and x-ray security systems. The most significant contributor to radiation exposure from man-made sources is medical procedures. Diagnostic x-rays and nuclear medicine procedures, such as those that use iodine-131 or cesium-137, are examples of man-made medical sources.

The average member of the public receives a total annual dose of approximately 620 millirem from ionizing radiation. Approximately half of the exposure is attributed to natural sources, and the other half to manmade sources. Figure 1-1 illustrates the contribution of various sources of radiation and the contribution to exposure in the United States (NCRP Report No.160 (2009)).

Sources of Radiation Exposure in the United States Consumer Products Nuclear Medicine 2% 12%

Industrial/Occupation al 0.1%

Radon and Thoron Medical 37%

Procedures 36%

Cosmic 5%

Internal Terrestrial 5% 3%

Figure 1-1 Sources of Radiation Exposure in the United States PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 3

2. Description of the Monitoring Program APS and vendor organizations performed the pre-operational Radiological Environmental Monitoring Program between 1979 and 1985. APS and vendors continued the program into the operational phase.

2.1 Radiological Environmental Monitoring Program The assessment program consists of routine measurements of environmental gamma radiation and of radionuclide concentrations in media such as air, groundwater, drinking water, surface water, vegetation, milk, sludge, and sediment.

Samples were collected by APS at the monitoring sites shown in Figures 2-1 and 2-2. The specific sample types, sampling locations, and sampling frequencies, as set forth in the PVNGS Offsite Dose Calculation Manual (ODCM), Reference 4, are presented in Tables 2-l, 2-2, and 9-1. Additional onsite sampling (outside the scope of the ODCM) is performed to supplement the REMP. Results are included in this report. Routine sample analyses were performed at the onsite Central Chemistry Laboratory and Operating Unit laboratories. Analyses for hard-to-detect radionuclides were performed by GEL Laboratories LLC.

Environmental gamma radiation measurements were performed by APS using TLDs at fifty (50) locations near PVNGS. The PVNGS Dosimetry Department is accredited by the National Voluntary Laboratory Accreditation Program (NVLAP) to process personnel ionizing radiation dosimeters.

In addition to monitoring environmental media, a Land Use Census is performed annually to identify the nearest milk animals, residents, and gardens. This information is used to evaluate the potential dose to members of the public for those exposure pathways that are indicated.

2.2 Radiological Environmental Monitoring Program Changes for 2021 No changes to the REMP occurred in 2021.

2.3 REMP Deviations/Abnormal Events Summary During calendar year 2021, there were seven (7) deviations/abnormal events with regards to the monitoring program. Additionally, one (1) event that was identified in 2019, and discussed in the 2019 AREOR, was not captured in the 2019 AREOR, Table 2-3, is discussed in greater detail in this report. Refer to Table 2-3 for more detail and corrective actions taken.

There were two (2) events involving Air Sample data. One (1) event involved reduced sampling period due to pump failure. One (1) event involved moisture found inside air sample charcoal cartridges.

One (1) event was due to a high background value that is used for the tritium analysis of Ground and Surface Water samples. The recorded background value was above the procedural QC limit.

Samples could not be recounted, resulting in INFO ONLY data for the Ground and Surface Water, 1st Quarter 2021 sampling period.

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Two (2) events were due to power interruptions to the Multi-Channel Analyzer (MCA). One (1) of these events impacted the ability to meet the required Lower Limit of Detection for I-131; however, a second sample was obtained for the sampling period.

One (1) event was documented due to a procedural exceedance for the Cs-137 action level (30 pCi/L) and exceedance of the ODCM, Table 6-2, action/reporting level of 50 pCi/L from a lined Evaporation Pond sample. Due to the reduced inventory of Evaporation Pond 3A, the pond has two discrete sections of water; the results were 51 pCi/L (+/-10 pCi/L) and 87 pCi/L (+/-12 pCi/L),

with an average activity of 69 pCi/L (+/-11 pCi/L). The samples were taken from a lined pond that is at a near empty inventory and there is no indication of leak to the environment; there is no pathway to drinking water from this source. The event was evaluated under 21-08433-001 and determined to not be plant related; the activity determined to be a result of pre-operation Cs-137 in the soil and sediment around Palo Verde. Further discussion of this evaluation is included in Section 11, Summary and Conclusions.

There were one (1) event involving environmental dosimetry; dosimetry at Site 43 and Site 44 were identified as missing during the 2nd Quarter 2021 TLD change-out. Data for these locations were unavailable for this sampling period.

2.4 Groundwater Protection PVNGS has implemented a groundwater protection initiative developed by the Nuclear Energy Institute (NEI). The implementing guidance of this initiative, NEI 07-07 (Industry Ground Water Protection Initiative - Final Guidance Document, August 2007), and later revised in March of 2019, provides added assurance that groundwater will not be adversely affected by PVNGS operations.

Several monitoring wells have been installed to monitor the subsurface water and shallow aquifer at Units 1, 2, and 3. Many of these wells were previously monitored in accordance with the State of Arizona Aquifer Protection Permit (Area-Wide) No. P-100388 (APP), which provided agreed upon monitoring parameters and reporting thresholds. The APP was revised in 2018, which included the removal of several of the wells from mandated sampling. These wells are now referred to as Legacy Wells and continue to be sampled for data continuity and in support of the Groundwater Protection Initiative. The frequency of sampling of the wells varies and may be done monthly, quarterly, and or annually for chemical and radiological parameters.

Sample results for the shallow aquifer wells are reported in the PVNGS Annual Radioactive Effluent Release Report (ARERR). The APP was revised again in 2021, for non-radiological reasons. The change results in increased sampling frequency of Well 2RAR, from semi-annually to quarterly, for the purposes of trending the naturally occurring Fluoride levels.

Three subsurface samples were obtained, one each from Units 2 and 3 tritium monitoring wells, and one from the shallow aquifer outside of the Unit 1 Radiologically Controlled Area (RCA).

These samples were analyzed for hard-to-detect radionuclides (e.g. C-14, Fe-55, Ni-63, Sr-90) as verification that there are no underground leaks from plant systems that may affect groundwater. All results were <MDA. Refer to Table 8-12 for sample results.

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Table 2-1 Sample Collection Locations SAMPLE SITE # SAMPLE TYPE LOCATION (a) LOCATION DESCRIPTION 4 Air E16 APS Office 6A* Air SSE13 Old US 80 7A Air ESE3 Arlington School 14A Air NNE2 371st Ave. and Buckeye-Salome Rd.

15 Air NE2 NE Site Boundary 17A Air E3 351st Ave.

21 Air S3 S Site Boundary 29 Air W1 W Site Boundary 35 Air NNW8 Tonopah 40 Air N2 Transmission Rd 46 Drinking Water NNW8 Local resident 47 Vegetation N3 Local resident 48 Drinking Water SW1 Local resident 49 Drinking Water N2 Local resident 51 Milk NNE3 Local resident-goats Vegetation NNE3 Local resident 53* Milk NE30 Local resident- goats 54 Milk NNE4 Local resident- goats 55 Drinking Water SW3 Local resident (Supplemental) 57 Groundwater ONSITE Well 27ddc 58 Groundwater ONSITE Well 34abb 58A Groundwater ONSITE Well 27dcb 59 Surface Water ONSITE Evaporation Pond 1 60 Surface Water ONSITE 85 Acre Reservoir 61 Surface Water ONSITE 45 Acre Reservoir 62* Vegetation ENE26 Commercial Farm 63 Surface Water ONSITE Evaporation Pond 2 64 Surface Water ONSITE Evaporation Pond 3 65 Groundwater ONSITE Well 34aab NOTES:

• Designates a control site (a) Distances and direction are from the centerline of Unit 2 containment and rounded to the nearest mile Air sample sites designated with the letter A are sites that have the same site number as a TLD location, but are not in the same location (e.g. site #6 TLD location is different from site

1. 6A air sample location; site #4 TLD location is the same as site #4 air sample location)

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Table 2-2 Sample Collection Schedule SAMPLE AIRBORNE AIRBORNE GROUND DRINKING SURFACE SITE # PARTICULATE MILK RADIOIODINE VEGETATION WATER WATER WATER 4 W W 6A W W 7A W W 14A W W 15 W W 17A W W 21 W W 29 W W 35 W W 40 W W 46 W 47 M/AA 48 W 49 W 51 M/AA M/AA 53 M/AA 54 M/AA 55 W 57 Q 58 Q 59 Q 60 Q 61 Q 62 M/AA 63 Q 64 Q W = WEEKLY M/AA = MONTHLY AS AVAILABLE Q = QUARTERLY PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 7

Table 2-3 Summaries of the REMP Deviations/Abnormal Events Deviation/Abnormal Event Actions Taken The procedural Reporting/Action Level for Cs-137 for Evap Pond 3A,

1. NRC Identified exceedance of collected 4th Quarter 2019 was not reported in Table 2-3 of the 2019 procedural Cs-137 Reporting/ AREOR. This sample did not exceed the ODCM Reporting level of 50 Action level of the 4th Quarter pCi/L; however, the procedural Action Level of 30 pCi/L was exceeded and 2019 Evap Pond 3A sample qualifies as a REMP Deviation/Abnormal Event. The event was discussed was not included in Table 2-3 in Table 8-10 and Section 11 of the 2019 report. This event is further of the 2019 AREOR. discussed in Appendix A of this report. Event documented through CR 21-09933.

The tritium calculations for 1st Qtr 2021 used a background value of 18.8

2. Ground and Surface Water cpm which is above the QC limit of 16.1 cpm. Original samples not tritium results for 1st Qtr 2021, available for recount; tritium values recalculated using the background mean QC above procedural limits. value. Values reported are calculated and are for INFO ONLY. Event Document through CR 21-13878 (Table 8-9 and Table 8-10, Note 1)

APEX software failed to count sample long enough to achieve the desired Lower Limit of Detection (LLD). The software error was discovered once it

3. Milk Sample Site 51 count was too late to re-analyze the samples to achieve the desired LLDs. The Site interruption during analysis 51 I-131 LLD achieved was 1.06 pCi/L. The required LLD per the Offsite resulting in higher MDA than Dose Calculation Manual (ODCM) is 1 pCi/L. Since the ODCM LLD is desired for February 2021 listed with one significant figure, the samples will be considered VALID, sample period.

meeting ODCM requirements, but the event is still noteworthy. Event documented through CR 21-02044 (Table 8-7, Note 1).

Analysis of Site 54 Milk Sample stopped 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after count was initiated.

4. Milk Sample Site 54 count The APEX software typically looks at MDA values and recalculates new interruption during analysis count time if LLDs are not reached within the 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The LLDs were not required second sample achieved at the 6-hour point but the count ended unexpectedly and did not collection to achieve required continue to count to achieve LLDs. A second sample was collected and LLDs for May 2021 sample analyzed to the required LLDs. Event documented through CR 21-06313 period.

(Table 8-7, Note 2).

The 2 TLDs used for monitoring locations 43 and 44 were missing for 2nd

5. TLDs for monitoring locations Quarter, 2021. The MA and LA were calculated using 1st, 3rd, and 4th 43 and 44 were missing for the Quarter Data. BA was calculated using BQ*3. Documented through CR 21-2nd Quarter, 2021.

08001 (Table 9-2, Note 1).

Evaporation Pond 3A composite sample for 2nd Quarter 2021 averaged Cs-137 results of 69 pCi/L +/-11, which exceeds action/reporting level in 74RM-

6. Evaporation Pond 3A exceeds 0EN09 (30 pCi/L) and ODCM 6-2 reporting level (50 pCi/L). Event Action Reporting Level for 2nd evaluated under 21-08433-001 and determined to not be Plant related; result Quarter 2021 sample period. of pre-operational Cs-137 in soil and sediment surrounding Palo Verde. CR 21-14818 for Quarterly Sample Verification (Table 8-10, Note 3). Further discussion in Section 11, Summary and Conclusions.

Pump found inoperable at time of sample change out. Pump replaced.

7. Air Sample Site 40 INVALID Sample volume unknown and conservative values used for analysis; sample due to pump failure for sample is INVALID, and data is for INFO ONLY for Week 26. Event documented period 6/22/2021-6/29/2021.

through CR 21-07886 (Table 8-1 and Table 8-4, Note 1).

Moisture found inside air samples charcoal cartridges. Moisture believed to

8. Moisture found in charcoal be a result of recent heavy rain events. No impact to sample integrity as cartridges during sample documented in Evaluation 15-00990-001; as-found condition of sample change out for sample period media within Technical Performance Specifications for F&J Radioiodine 12/21/2021-12/27/2021. Collection Cartridges containing TEDA Impregnated Charcoal and Silver Samples are VALID. Zeolite Media. Sample VALID. Event documented through CR 21-15290 (Table 8-5, Note 2).

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Figure 2-1 REMP Sample Sites- Map (0-10 miles)

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Figure 2-2 REMP Sample Sites- Map (10-35 Miles)

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3. Sample Collection Program APS Personnel, using PVNGS procedures, collected all samples.

3.1 Water Weekly samples were collected from four (4) residence wells for monthly and quarterly composites. Samples were collected in one-gallon containers (plastic cubitainers) and 500 mL glass bottles. The samples were analyzed for gross beta, gamma-emitting radionuclides, and tritium.

Quarterly grab samples were collected from the 45-acre and 85-acre Reservoirs, a c t i v e Evaporation Ponds 1A/B/C, 2A/B, and 3A/B, and onsite wells 27ddc, 34aab, and 27dcb.

Samples were collected in one-gallon containers (plastic cubitainers) and 500 mL glass bottles.

Samples were analyzed for gamma-emitting radionuclides and tritium.

Treated sewage effluent from the City of Phoenix was sampled as a weekly composite at the onsite Water Resources (WR) and analyzed for gamma- emitting radionuclides. A monthly composite was analyzed for tritium.

3.2 Vegetation Vegetation samples were collected monthly, as available, and were analyzed for gamma-emitting radionuclides.

3.3 Milk Goat milk samples were collected monthly, as available, and were analyzed for gamma-emitting radionuclides, including low level I-131.

3.4 Air Air particulate filters and charcoal cartridges were collected at ten (10) sites on a weekly basis. Particulate filters were analyzed for gross beta. Charcoal cartridges were analyzed for Iodine-131. Particulate filters were composited quarterly, by location, and analyzed for gamma-emitting radionuclides.

3.5 Soil, Sludge, and Sediment Sludge samples were obtained weekly from the WR waste centrifuge (during operational periods) and analyzed for gamma-emitting radionuclides. Cooling tower sludge was analyzed for gamma-emitting radionuclides prior to disposal in the WR sludge landfill.

A soil sample was taken of the Sedimentation Basin 2. This is not a required sample; however, soil samples are taken in this area periodically for historical trending purposes.

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4. Analytical Procedures The procedures described in this report are those used by APS to routinely analyze samples 4.1 Air Particulate 4.1.1 Gross Beta A glass fiber filter sample is placed in a stainless steel planchet and counted for gross beta activity utilizing a low background gas flow proportional counter.

4.1.2 Gamma Spectroscopy The glass fiber filters are counted on a multichannel analyzer equipped with a High-purity Germanium (HPGe) detector. The resulting spectrum is analyzed by a computer for specific radionuclides and verified by trained technicians.

4.2 Airborne Radioiodine 4.2.1 Gamma Spectroscopy The charcoal cartridge is counted on a multichannel analyzer equipped with an HPGe detector. The resulting spectrum is analyzed by a computer for Iodine-131.

4.3 Milk 4.3.1 Gamma Spectroscopy The sample is placed in a plastic marinelli beaker and counted on a multichannel analyzer equipped with an HPGe detector. The resulting spectrum is analyzed by a computer for specific radionuclides and verified by trained technicians.

4.3.2 Radiochemical I-131 Separation Iodine in milk sample is reduced with sodium bisulfite and iodine is absorbed by the anion exchange resin. The iodine is eluted with NaOCl. Iodine is extracted from the sample with carbon tetrachloride. The iodine is back extracted from the organic phase with water containing sodium bisulfate and then precipitated as CuI. The precipitate is mounted in a planchet and counted for gross beta.

4.4 Vegetation 4.4.1 Gamma Spectroscopy The sample is pureed in a food processor, placed in a one-liter plastic marinelli beaker, weighed, and counted on a multichannel analyzer equipped with an HPGe detector. The resulting spectrum is analyzed by a computer for specific radionuclides and verified by trained technicians.

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4.5 Sludge/Sediment 4.5.1 Gamma Spectroscopy The wet/dry sample is placed in a one-liter plastic marinelli beaker, weighed, and counted on a multichannel analyzer equipped with an HPGe detector. The resulting spectrum is analyzed by a computer for specific radionuclides and verified by trained technicians.

4.6 Water 4.6.1 Gamma Spectroscopy The sample is placed in a one-liter plastic marinelli beaker and counted on a multichannel analyzer equipped with a HPGe detector. The resulting spectrum is analyzed by a computer for specific radionuclides and verified by trained technicians.

4.6.2 Tritium The sample is evaluated to determine the appropriate method of preparation prior to counting. If the sample contains suspended solids or is turbid, it may be filtered, distilled, and/or de-ionized, as appropriate. Eight (8) milliliters of sample are mixed with fifteen (15) milliliters of liquid scintillation cocktail. The mixture is dark adapted and counted for tritium activity using a liquid scintillation counting system.

4.6.3 Gross Beta A 200-250 milliliter sample is placed in a beaker. Five (5) milliliters of concentrated nitric (HNO3) acid is added and the sample is evaporated down to approximately twenty (20) milliliters. The remaining sample is transferred to a stainless steel planchet. The sample is heated to dryness and counted for gross beta in a gas flow proportional counter.

4.7 Soil 4.7.1 Gamma Spectroscopy The samples are sieved, placed in a one-liter plastic marinelli beaker, and weighed. The samples are then counted on a multichannel analyzer equipped with an HPGe detector.

The resulting spectrum is analyzed by a computer for specific radionuclides and verified by trained technicians.

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5. Nuclear Instrumentation 5.1 Gamma Spectrometer The Canberra Gamma Spectrometer consists of a Canberra System equipped with HPGe detectors, having resolutions of 1.73 keV and 1.88 keV (as determined by full width half max with an energy of 0.5 keV per channel) and respective efficiencies of 21.5% and 38.4% (as determined by the manufacturer with Co-60). The Canberra System is used for all gamma counting. The system uses Canberra developed software to search, identify, and quantify the peaks of interest.

5.2 Liquid Scintillation Spectrometer A Beckman LS-6500 Liquid Scintillation Counter is used for tritium determinations. The system background averages approximately 12-16 cpm with a counting efficiency of approximately 40% using a quenched standard.

5.3 Gas Flow Proportional Counter The Tennelec S5E is a low background gas flow proportional counter for gross beta analysis.

The system contains an automatic sample changer capable of counting 50 samples in succession. Average beta background count rate is about 1-2 cpm with a beta efficiency of approximately 30% for Cs-137.

PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 14

6. Isotopic Detection Limits and Reporting Criteria 6.1 Lower Limits of Detection The lower limits of detection (LLD) and the method for calculation are specified in the PVNGS ODCM, Reference 4. The ODCM required a priori LLDs are presented in Table 6-1.

6.2 Data Reporting Criteria All results that are greater than the Minimum Detectable Activity (MDA) (a posteriori LLD) are reported as positive activity with its associated 2 counting error. All results that are less than the MDA are reported as less than values at the associated MDA. For example, if the MDA is 12 pCi/liter, the value is reported as <12.

Typical MDA values are presented in Table 6-3.

Occasionally, the PVNGS ODCM a priori LLDs may not be achieved as a result of:

• Background fluctuations

• Unavoidably small sample sizes

• The presence of interfering radionuclides

• Self-absorption corrections

• Decay corrections for short half-life radionuclides

• Other uncontrollable circumstances In these instances, the contributing factors will be noted in the table where the data are presented. A summary of deviations/abnormal events is presented in Table 2-3 Summaries of the REMP Deviations/Abnormal Events and includes a description of any sample results that did not meet a priori LLD requirements.

6.3 LLD and Reporting Criteria Overview Making a reasonable estimate of the limits of detection for a counting procedure or a radiochemical method is usually complicated by the presence of significant background. It must be considered that the background or blank is not a fixed value but that a series of replicates would be normally distributed. The desired net activity is the difference between the gross and background activity distributions. The interpretation of this difference becomes a problem if the two distributions intersect as indicated in the diagram.

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If a sufficient number of replicate analyses are run, it is expected that the results would fall in a normal Gaussian distribution. Standard statistics allow an estimate of the probability of any particular deviation from the mean value. It is common practice to report the mean +/-

one or two standard deviations as the result. In routine analysis, such replication is not carried out, and it is not possible to report a Gaussian standard deviation. With counting procedures, however, it is possible to estimate a Poisson standard deviation directly from the count. Data are commonly reported as the measured value +/- one or two Poisson standard deviations. The reported values are then considered to give some indication of the range in which the true value might be expected to occur.

LLD is the smallest amount of sample activity that will yield a net count for which there is confidence at a predetermined level that activity is present. LLDs are calculated values for individual radionuclides based on a number of different factors including sample size, counting efficiency and background count rate of the instrument, the background and sample counting time, the decay time, and the chemical recovery of the analytical procedures. A minimum detectable activity value (MDA) is the smallest amount of activity that can be detected in an actual sample and uses the values obtained from the instrument and outcome of the analytical process. Therefore, the MDA values may differ from the calculated LLD values if the sample size and chemical recovery, decay values, or the instrument efficiency, background, or count time differed from those used in the LLD calculation.

The factors governing the calculation of the LLD and MDA values are discussed below:

1. Sample Size: The number of observations included in a statistical analysis.

Sample size dictates the amount of information available about a studied subject to make accurate inferences.

2. Counting Efficiency: The fundamental quantity in the measurement of a radioactive substance is the number of disintegrations per unit time. As with most physical measurements in analytical chemistry, an absolute measurement of the disintegration rate is seldom possible, rather it is necessary to compare the sample with one or more standards. The standards determine the counter efficiency that may then be used to convert sample counts per minute (cpm) to disintegrations per minute (dpm).

3. Background Count Rate: Any counter will show a certain counting rate without a sample in position. This background counting rate comes from several sources: 1) natural environmental radiation from the surrounding materials, 2) cosmic radiation, and 3) the natural radioactivity in the counter material itself. The background counting rate will depend on the amounts of these types of radiation and the sensitivity of the counter to the radiation.

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4. Background and Sample Counting Time: The amount of time devoted to the counting of the background depends on the level of activity being measured. In general, with low level samples, this time should be about equal to that devoted to counting a sample.

5. Time Interval between Sample Collection and Counting: Decay measurements are useful in identifying certain short-lived nuclides. The disintegration constant is one of the basic characteristics of a specific radionuclide and is readily determined, if the half-life is sufficiently short.

To ensure the required LLDs are achieved, appropriate decay correction values are used to account for radioactive decay during transit time and sample processing.

Table 6-1 ODCM Required Lower Limits of Detection (a priori)

• If no drinking water pathway exists, a value of 3000 pCi/liter may be used

• • If no drinking water pathway exists, a value of 15 pCi/liter may be used NOTES:

This list does not mean that only these nuclides are to be detected and reported. Other peaks that are measurable and identifiable, together with the above nuclides, shall also be identified and reported.

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Table 6-2 ODCM Required Reporting Levels

• For drinking water samples. This is a 40 CFR 141 value. If no drinking water pathway exists, a value of 30,000 pCi/L may be used.

• • If no drinking water pathway exists, a reporting level of 20 pCi/L may be used.

Table 6-3 Typical MDA Values Water Milk Airborne Particulate Vegetation Analysis/Nuclide (pCi/liter) (pCi/liter) or Gas (pCi/m3) (pCi/kg, wet)

Gross Beta 2.08 0.004 H-3 326 Mn-54 10 Fe-59 20 Co-58 9 Co-60 11 Zn-65 22 Zr-95 16 Nb-95 10 I-131 10a 1 0.04b 49 Cs-134 9 1 0.003b 47 Cs-137 10 1 0.003b 61 Ba-140 33 3 La-140 13 1 NOTES:

a - low level I-131 is not required since there is no drinking water pathway b - Based on 433 m3, the normal weekly sample volume PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 18

7. Interlaboratory Comparison Program 7.1 Quality Control Program APS maintains an extensive QA/QC Program to provide assurance that samples are collected, handled, tracked, and analyzed to specified requirements. This program includes appropriate elements of USNRC Regulatory Guide 4.15, Quality Assurance for Radiological Monitoring Programs (Normal Operations) - Effluent Streams and the Environment, Revision 1. The program includes procedures for sample collection preparation and tracking, sample analysis, equipment calibration and checks, and ongoing participation in an interlaboratory comparison program. Duplicate/replicate samples are analyzed to verify analytical precision and sample methodology. Comprehensive data reviews are performed including trending of data where appropriate.

During 2021, APS analyzed the following sample types under the interlaboratory comparison program:

• Beta/Gamma/ in Air Filter

• I-131 in Air

• Beta in Water

• Gamma in Water

• Tritium in Water

• Gamma in Milk Evaluation 21-00795-001 was conducted to ensure alignment of frequency of Radiochemical Interlaboratory Comparison Program Checks with industry standards. Palo Verde Generating Station had a procedural requirement of semi-annual, NRC Regulatory guide 4.15 requires biennially (every 2 years), and NISP-201 recommends annual blind performance checks. NISP-201 recommends a practical approach to cost effectiveness without sacrificing the promotion of excellence in safe and reliable operation. In 2021, PVNGS adopted an annual blind performance analysis, which aligns PVNGS with the industry standards while still performing the analysis more frequently than the minimum set in the regulatory guidance.

7.2 Intercomparison Results APS participates in a crosscheck program using vendor supplied blind radionuclide samples. Results for the interlaboratory comparison program are presented in Table 7-1 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 19

Table 7-1 Interlaboratory Comparison Results 2021 Eckert & Ziegler Analytics Environmental Cross Check Results Sample Analysis PVNGS 1 sigma Known NRC Nuclide Resolution* Ratio Results Type Type Value Error Value Range E13517 Gamma Ce-141 1.56E+02 1.46E+01 1.51E+02 11 1.03 0.60 - 1.66 Acceptable DET2 Water Co-58 1.60E+02 1.51E+01 1.56E+02 11 1.03 0.60 - 1.66 Acceptable Co-60 1.90E+02 1.16E+01 1.91E+02 16 0.99 0.75 - 1.33 Acceptable Cr-51 3.22E+02 5.23E+01 3.12E+02 6 1.03 0.50 - 2.00 Acceptable Cs-134 1.14E+02 7.51E+00 1.23E+02 15 0.93 0.60 - 1.66 Acceptable Cs-137 1.51E+02 1.41E+01 1.48E+02 11 1.02 0.60 - 1.66 Acceptable Fe-59 1.49E+02 1.26E+01 1.35E+02 12 1.10 0.60 - 1.66 Acceptable Mn-54 1.79E+02 1.64E+01 1.70E+02 11 1.05 0.60 - 1.66 Acceptable Zn-65 2.10E+02 2.05E+01 2.02E+02 10 1.04 0.60 - 1.66 Acceptable E13520 Gamma Ce-141 1.49E+02 1.10E+01 1.47E+02 14 1.01 0.60 - 1.66 Acceptable DET3 Filter Co-58 1.55E+02 1.57E+01 1.51E+02 10 1.03 0.60 - 1.66 Acceptable Co-60 1.88E+02 1.14E+01 1.86E+02 16 1.01 0.75 - 1.33 Acceptable Cr-51 2.98E+02 3.31E+01 3.03E+02 9 0.98 0.60 - 1.66 Acceptable Cs-134 8.64E+01 5.31E+00 1.20E+02 16 0.72 0.75 - 1.33 Not Acceptable 2 Cs-137 1.46E+02 1.83E+01 1.44E+02 8 1.01 0.60 - 1.66 Acceptable Fe-59 1.54E+02 1.19E+01 1.31E+02 13 1.18 0.60 - 1.66 Acceptable Mn-54 1.77E+02 2.04E+01 1.65E+02 9 1.07 0.60 - 1.66 Acceptable Zn-65 2.27E+02 2.17E+01 1.97E+02 10 1.15 0.60 - 1.66 Acceptable E13519 I-131 I-131 8.89E+01 1.04E+01 9.06E+01 9 0.98 0.60 - 1.66 Acceptable DET2 Cartridge E13519 I-131 I-131 8.27E+01 1.04E+01 9.06E+01 8 0.91 0.60 - 1.66 Acceptable DET3 Cartridge Gross Beta E13518 g beta 8.12E+01 2.08E+00 8.31E+01 39 0.98 0.75 - 1.33 Acceptable Air E13521 Gamma I-131 4.05E+01 5.24E+00 4.02E+01 8 1.01 0.60 - 1.66 Acceptable DET 2 Milk Ce-141 2.37E+01 3.34E+00 2.11E+01 7 1.12 0.50 - 2.00 Acceptable Co-58 2.22E+01 2.46E+00 2.17E+01 9 1.02 0.60 - 1.66 Acceptable Co-60 2.83E+01 1.96E+00 2.67E+01 14 1.06 0.60 - 1.66 Acceptable Cr-51 4.60E+01 7.17E+00 4.36E+01 6 1.06 0.50 - 2.00 Acceptable Cs-134 1.66E+01 1.05E+00 1.72E+01 16 0.97 0.75 - 1.33 Acceptable Cs-137 2.19E+01 2.32E+00 2.06E+01 9 1.06 0.60 - 1.66 Acceptable Fe-59 2.03E+01 2.57E+00 1.88E+01 8 1.08 0.60 - 1.66 Acceptable Mn-54 2.54E+01 2.60E+00 2.37E+01 10 1.07 0.60 - 1.66 Acceptable Zn-65 2.08E+01 3.05E+00 2.83E+01 7 0.73 0.50 - 2.00 Acceptable E13521 Gamma I-131 4.15E+01 1.12E+01 4.02E+01 4 1.03 0.50 - 2.00 Acceptable DET 3 Milk Ce-141 2.52E+01 5.44E+00 2.11E+01 5 1.19 0.50 - 2.00 Acceptable Co-58 2.39E+01 3.76E+00 2.17E+01 6 1.10 0.50 - 2.00 Acceptable Co-60 2.81E+01 2.67E+00 2.67E+01 11 1.05 0.60 - 1.66 Acceptable Cr-51 6.05E+01 2.67E+01 4.36E+01 2 1.39 0.40 - 2.50 Acceptable Cs-134 1.73E+01 1.53E+00 1.72E+01 11 1.01 0.60 - 1.66 Acceptable Cs-137 2.31E+01 3.08E+00 2.06E+01 8 1.12 0.60 - 1.66 Acceptable Fe-59 1.97E+01 4.34E+00 1.88E+01 5 1.05 0.50 - 2.00 Acceptable Mn-54 2.54E+01 4.64E+00 2.37E+01 5 1.07 0.50 - 2.00 Acceptable Zn-65 3.03E+01 6.30E+00 2.83E+01 5 1.07 0.50 - 2.00 Acceptable Gross Beta E13522 g beta 3.06E+02 4.04E+00 2.79E+02 76 1.10 0.80 - 1.25 Acceptable Water E13523 H-3 Water H-3 1.08E+04 3.52E+02 1.17E+04 31 0.92 0.75 - 1.33 Acceptable

• calculated from PVNGS value/1 sigma error value NRC Acceptance Criteria 1 Resolution Ratio

<4 0.4-2.5 4-7 0.5-2.0 8-15 0.6-1.66 16-50 0.75-1.33 51-200 0.80-1.25

>200 0.85-1.18 1

From CY-NISP-201, Rev1, Attachment E 2

An interlaboratory cross check sample for 2021 (air filter, source #21-023) analyzed on Central Laboratory gamma spectroscopy detector #3 failed to meet procedural acceptance criteria for Cs-134. The failure is due to coincidence summing and is applicable only to this detector/geometry configuration. The analyzed value was 86.4 microcuries/filter with a known value of 120 microcuries/filter. A new detector is planned to be installed during 2022 to fix the coincidence summing. CR 22-03166, 20-08012 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 20

8. Data Interpretation and Conclusions Associated with the analytical process are potential random and systematic errors. Systematic errors can be caused by instrument malfunctions, incomplete precipitation, back scattering, and self-absorption.

Efforts are made to minimize both systematic and random errors in the data reported. Systematic errors are minimized by performing reviews throughout the analysis. For example, instruments are checked routinely with radioactive sources, and recovery and self-absorption factors based on individual sample analyses are incorporated into the calculation equations where necessary. Random errors are reduced by comparing all data to historical data for the same site and performing comparisons between analytical results when available. In addition, when data appears to not match historical results, analyses may be rerun on a separate aliquot of the sample to verify the presence of the activity. The acceptance of data is dependent upon the results of quality control samples and is part of the data review process for all analytical results.

The "plus or minus value" reported with each analytical result represents the counting error associated with the result and gives the 95% confidence (2) interval around the data.

Most samples contain radioactivity associated with natural background/cosmic radioactivity (e.g. K-40, Th-234, Be-7). Gross beta results for drinking water and air are due to natural background. Gamma-emitting radionuclides, which can be attributed to natural background sources, are not indicated in this report.

Results and interpretation of the data for samples analyzed during 2021 are presented in the following sections.

8.1 Air Particulates Weekly gross beta results, in quarterly format, are presented in Table 8-1 and Table 8-2. Gross beta activity at indicator locations ranged from 0.014 to 0.065 pCi/m3. Mean quarterly activity is normally calculated using weekly activity over a thirteen (13) week period. Also presented in the tables are the weekly mean values of all the sites as well as the percent relative standard deviation (RSD %) for the data.

Table 8-3 displays the results of gamma spectroscopy on the quarterly composites of the weekly samples.

No plant-related activity was identified 8.2 Airborne Radioiodine Table 8-4 and Table 8-5 present the quarterly radioiodine results. Radioiodine was not observed in any samples.

8.3 Vegetation Table 8-6 presents gamma isotopic data for the vegetation samples. No gamma-emitting radionuclides were observed in any of the samples.

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8.4 Milk Table 8-7 presents gamma isotopic data for the goat milk samples. No gamma-emitting radionuclides were observed in any of the samples.

8.5 Drinking Water Samples were analyzed for gross beta, tritium, and gamma-emitting radionuclides. Results of these analyses are presented in Table 8-8. No tritium or gamma-emitting radionuclides were detected in any samples. Gross beta activity ranged from less than detectable to a high of 7.44 pCi/liter. The gross beta activity is attributable to natural (background) radioactive materials.

8.6 Groundwater Groundwater samples were analyzed from three onsite wells (regional aquifer) for tritium and gamma-emitting radionuclides. Results obtained from the analysis of the samples are presented in Table 8-9.

No tritium or gamma-emitting radionuclides were observed in any of the samples.

8.7 Surface Water Surface water samples from the Reservoirs and Evaporation Ponds were analyzed for tritium and gamma-emitting radionuclides. The two Reservoirs contain processed sewage water from the City of Phoenix and are approximately 45 and 85 acres in size. The three Evaporation Ponds receive mostly circulating water from main turbine condenser cooling and are about 200-250 acres each.

Sample results are presented in Table 8-10. I-131 is sometimes observed in reservoirs and Evaporation Ponds, which is the result of radiopharmaceutical I-131 in the Phoenix sewage effluent and is not attributable to plant effluents. However, I-131 was not observed in these surface water samples during 2021.

Tritium was routinely observed in the Evaporation Ponds. The highest concentration was 1029 pCi/liter.

Tritium was not detected in the Reservoirs. The tritium identified in the Evaporation Ponds has been attributed to permitted plant gaseous effluent releases and secondary plant liquid discharges (e.g.

condensate overboard discharge, secondary side steam generator drains, secondary plant sumps, demineralizer regeneration waste). The tritium concentrations were compared to historical values and are considered typical for the Evaporation Ponds.

Low levels of Cs-137 have been detected in Evaporation Pond 3A. Evaporation Pond 3A is in the process of being drained for liner repairs. The water inventory is very low, such that the turbidity of the water samples has visibly increased. Evaporation Pond 3A has not received any influent from the plant since 2016, and the low levels of Cs-137 were not detectable until the water inventory in the pond was low, such that sampling tools also came into contact with the salt and/or sediment during sampling and the general turbidity of the water was visibly higher. The low levels of Cs-137 are consistent with background levels seen in preoperational sediment analysis and are attributed sediment intrusion from the surrounding area.

The Cs-137 levels found in the Evaporation Pond 3A samples were evaluated and documented with Evaluation 21-08433-001. Further discussion is included in Section 11, Summary and Conclusion, of this report.

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8.8 Sludge and Sediment 8.8.1 Water Resources Centrifuge Waste Sludge Sludge samples were obtained from the Water Resources (WR) centrifuge and analyzed by gamma spectroscopy. I-131 activity in the sludge is consistent with historical values and, as previously discussed, is due to radiopharmaceuticals in the WR Influent. The concentration of I-131 ranged from no detectable to 863 pCi/kg.

Results for WR centrifuge waste sludge can be found in Table 8-11.

8.8.2 Cooling Tower Sludge Sludge/sediment originating from the Unit 1 and Unit 3 Cooling Towers and Circulating Water canals was disposed of in the WR sludge landfill during 2021. Sample results can be found in Table 8-11.

8.9 Data Trends Figure 8-1 through Figure 8-8 present data in graphical format. Historical data are displayed for comparison where practical.

8.10 Hard-To-Detect Radionuclide Results Table 8-12 shows the results of the three subsurface samples obtained from 3 tritium monitoring points.

These samples were analyzed for hard-to-detect radionuclides (e.g. C-14, Fe-55, Ni-63, Sr-90) and all results were <MDA. These results indicate that no leaks from plant systems have affected groundwater.

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Table 8-1 Particulate Gross Beta in Air 1st-2nd Quarter PARTICULATE GROSS BETA IN AIR 1st QUARTER ODCM required samples denoted by

• units are pCi/m3 (control)

START STOP Site Site Site Site Site Site Site Site Site Site RSD Week # DATE DATE 4 6A* 7A 14A* 15* 17A 21 29* 35 40* Mean (%) Note 1 28-Dec-20 5-Jan-21 0.035 0.035 0.036 0.028 0.033 0.034 0.032 0.032 0.028 0.029 0.032 9.4 2 5-Jan-21 12-Jan-21 0.048 0.049 0.042 0.041 0.040 0.043 0.040 0.042 0.038 0.036 0.042 9.4 3 12-Jan-21 19-Jan-21 0.042 0.040 0.038 0.035 0.041 0.042 0.039 0.036 0.031 0.033 0.038 10.5 4 19-Jan-21 26-Jan-21 0.021 0.020 0.020 0.019 0.021 0.020 0.020 0.022 0.020 0.020 0.020 4.0 5 26-Jan-21 2-Feb-21 0.020 0.022 0.022 0.019 0.021 0.020 0.018 0.018 0.017 0.018 0.019 9.2 6 2-Feb-21 9-Feb-21 0.029 0.028 0.026 0.023 0.026 0.022 0.024 0.025 0.022 0.024 0.025 8.6 7 9-Feb-21 16-Feb-21 0.025 0.026 0.027 0.023 0.024 0.022 0.022 0.021 0.022 0.017 0.023 12.7 8 16-Feb-21 23-Feb-21 0.016 0.017 0.015 0.015 0.015 0.015 0.016 0.016 0.015 0.015 0.015 3.7 9 23-Feb-21 2-Mar-21 0.025 0.026 0.023 0.022 0.026 0.023 0.023 0.021 0.022 0.022 0.023 7.2 10 2-Mar-21 9-Mar-21 0.029 0.037 0.030 0.032 0.033 0.034 0.031 0.031 0.030 0.032 0.032 7.0 11 9-Mar-21 16-Mar-21 0.014 0.015 0.014 0.016 0.016 0.015 0.016 0.014 0.014 0.014 0.015 6.0 12 16-Mar-21 23-Mar-21 0.022 0.021 0.021 0.021 0.019 0.020 0.022 0.020 0.020 0.020 0.021 5.1 13 23-Mar-21 30-Mar-21 0.021 0.022 0.021 0.018 0.022 0.020 0.021 0.021 0.020 0.018 0.020 6.7 Mean 0.027 0.027 0.026 0.024 0.026 0.025 0.025 0.025 0.023 0.023 0.025 6.0 PARTICULATE GROSS BETA IN AIR 2nd QUARTER ODCM required samples denoted by

• units are pCi/m3 (control)

START STOP Site Site Site Site Site Site Site Site Site Site RSD Week # DATE DATE 4 6A* 7A 14A* 15* 17A 21 29* 35 40* Mean (%) Note 14 30-Mar-21 6-Apr-21 0.035 0.035 0.035 0.027 0.030 0.033 0.035 0.033 0.033 0.032 0.033 8.2 15 6-Apr-21 13-Apr-21 0.025 0.026 0.026 0.027 0.028 0.028 0.024 0.024 0.026 0.025 0.026 5.5 16 13-Apr-21 20-Apr-21 0.038 0.036 0.032 0.033 0.034 0.038 0.032 0.034 0.032 0.031 0.034 7.2 17 20-Apr-21 27-Apr-21 0.027 0.029 0.028 0.023 0.030 0.029 0.027 0.029 0.027 0.026 0.027 7.4 18 27-Apr-21 4-May-21 0.022 0.024 0.023 0.022 0.022 0.021 0.021 0.022 0.023 0.020 0.022 5.7 19 4-May-21 11-May-21 0.031 0.028 0.028 0.029 0.030 0.033 0.031 0.029 0.030 0.028 0.030 5.0 20 11-May-21 18-May-21 0.035 0.033 0.036 0.032 0.033 0.034 0.033 0.031 0.034 0.031 0.033 4.6 21 18-May-21 25-May-21 0.026 0.024 0.024 0.025 0.025 0.027 0.024 0.025 0.025 0.021 0.025 6.3 22 25-May-21 1-Jun-21 0.028 0.027 0.028 0.029 0.030 0.029 0.026 0.027 0.029 0.027 0.028 4.3 23 1-Jun-21 8-Jun-21 0.031 0.030 0.030 0.028 0.029 0.029 0.029 0.029 0.028 0.026 0.029 4.3 24 8-Jun-21 15-Jun-21 0.029 0.034 0.030 0.028 0.028 0.030 0.031 0.031 0.028 0.028 0.030 6.0 25 15-Jun-21 22-Jun-21 0.036 0.035 0.035 0.035 0.033 0.035 0.032 0.034 0.034 0.036 0.034 3.9 26 22-Jun-21 29-Jun-21 0.036 0.034 0.030 0.036 0.033 0.036 0.031 0.036 0.037 0.023 0.034 6.9 1 Mean 0.031 0.030 0.030 0.029 0.029 0.031 0.029 0.029 0.030 0.028 0.030 3.3 NOTE 1: Site 40 Pump failed and actual run time is unknown. Conservative time used for analysis. Data is for INFO ONLY. CR 21-07886 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 24

Table 8-2 Particulate Gross Beta in Air 3rd-4th Quarter PARTICULATE GROSS BETA IN AIR 3rd QUARTER ODCM required samples denoted by

• units are pCi/m3 (control)

START STOP Site Site Site Site Site Site Site Site Site Site RSD Week # DATE DATE 4 6A* 7A 14A* 15* 17A 21 29* 35 40* Mean (%) Note 27 29-Jul-21 6-Jul-21 0.027 0.028 0.026 0.027 0.025 0.029 0.025 0.026 0.028 0.026 0.027 5.5 28 6-Jul-21 13-Jul-21 0.035 0.031 0.033 0.032 0.031 0.034 0.031 0.032 0.034 0.030 0.032 5.2 29 13-Jul-21 20-Jul-21 0.029 0.029 0.029 0.030 0.026 0.033 0.030 0.030 0.032 0.029 0.030 6.3 30 20-Jul-21 27-Jul-21 0.032 0.033 0.033 0.031 0.027 0.032 0.031 0.033 0.034 0.031 0.032 6.3 31 27-Jul-21 3-Aug-21 0.032 0.028 0.030 0.031 0.032 0.032 0.029 0.028 0.028 0.028 0.030 5.7 32 3-Aug-21 10-Aug-21 0.033 0.033 0.031 0.032 0.032 0.033 0.031 0.032 0.034 0.032 0.032 3.0 33 10-Aug-21 17-Aug-21 0.019 0.017 0.018 0.019 0.020 0.018 0.018 0.019 0.020 0.017 0.018 5.7 34 17-Aug-21 24-Aug-21 0.035 0.035 0.033 0.032 0.029 0.030 0.030 0.032 0.034 0.027 0.032 8.0 35 24-Aug-21 31-Aug-21 0.023 0.038 0.033 0.032 0.029 0.035 0.030 0.029 0.030 0.026 0.030 14.2 36 31-Aug-21 7-Sep-21 0.034 0.023 0.032 0.028 0.024 0.030 0.021 0.026 0.022 0.023 0.026 17.2 37 7-Sep-21 14-Sep-21 0.036 0.036 0.037 0.039 0.037 0.039 0.040 0.038 0.038 0.038 0.038 4.1 38 14-Sep-21 21-Sep-21 0.046 0.039 0.042 0.044 0.038 0.044 0.039 0.040 0.044 0.044 0.042 6.5 39 21-Sep-21 28-Sep-21 0.027 0.028 0.026 0.026 0.027 0.030 0.026 0.031 0.027 0.031 0.028 7.2 Mean 0.031 0.031 0.031 0.031 0.029 0.032 0.029 0.030 0.031 0.029 0.031 3.6 PARTICULATE GROSS BETA IN AIR 4th QUARTER ODCM required samples denoted by

• units are pCi/m3 (control)

START STOP Site Site Site Site Site Site Site Site Site Site RSD Week # DATE DATE 4 6A* 7A 14A* 15* 17A 21 29* 35 40* Mean (%) Note 40 28-Sep-21 5-Oct-21 0.033 0.032 0.032 0.033 0.027 0.030 0.030 0.031 0.032 0.032 0.031 5.9 41 5-Oct-21 12-Oct-21 0.026 0.027 0.025 0.025 0.025 0.025 0.025 0.027 0.024 0.022 0.025 5.3 42 12-Oct-21 19-Oct-21 0.031 0.031 0.024 0.030 0.024 0.031 0.029 0.028 0.030 0.030 0.029 9.1 43 19-Oct-21 26-Oct-21 0.033 0.034 0.031 0.032 0.030 0.032 0.035 0.030 0.034 0.029 0.032 5.9 44 26-Oct-21 2-Nov-21 0.027 0.029 0.026 0.025 0.020 0.026 0.027 0.026 0.025 0.026 0.026 8.6 45 2-Nov-21 8-Nov-21 0.049 0.056 0.046 0.043 0.043 0.048 0.047 0.039 0.042 0.041 0.045 10.7 46 8-Nov-21 16-Nov-21 0.040 0.036 0.028 0.035 0.030 0.035 0.031 0.029 0.027 0.033 0.032 12.3 47 16-Nov-21 22-Nov-21 0.059 0.068 0.057 0.056 0.053 0.063 0.065 0.059 0.060 0.055 0.060 8.1 48 22-Nov-21 30-Nov-21 0.059 0.058 0.056 0.054 0.043 0.053 0.051 0.051 0.050 0.052 0.053 8.7 49 30-Nov-21 7-Dec-21 0.064 0.064 0.056 0.040 0.051 0.057 0.060 0.055 0.053 0.047 0.055 13.6 50 7-Dec-21 14-Dec-21 0.045 0.048 0.048 0.044 0.040 0.044 0.042 0.044 0.043 0.043 0.044 6.0 51 14-Dec-21 21-Dec-21 0.026 0.025 0.027 0.020 0.023 0.025 0.025 0.024 0.024 0.020 0.024 9.8 52 21-Dec-21 27-Dec-21 0.041 0.038 0.039 0.038 0.037 0.040 0.039 0.038 0.037 0.035 0.038 4.4 Mean 0.041 0.042 0.038 0.037 0.034 0.039 0.039 0.037 0.037 0.036 0.038 6.3 Annual Average 0.03239 0.03261 0.03106 0.03005 0.02967 0.03191 0.03053 0.03036 0.03017 0.02883 0.0308 7.2648 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 25

Table 8-3 Gamma in Air Filter Composites GAMMA IN AIR FILTER COMPOSITES ODCM required samples denoted by

• units are pCi/m3 (control)

QUARTER Site Site Site Site Site Site Site Site Site Site ENDPOINT NUCLIDE 4 6A* 7A 14A* 15* 17A 21 29* 35 40* Note Cs-134 <0.0007 <0.0007 <0.0020 <0.0030 <0.0024 <0.0054 <0.0018 <0.0011 <0.0013 <0.0023 30-Mar-21 Cs-137 <0.0023 <0.0024 <0.0066 <0.0029 <0.0009 <0.0057 <0.0023 <0.0009 <0.0017 <0.0029 Cs-134 <0.0028 <0.0007 <0.0037 <0.0007 <0.0029 <0.0021 <0.0019 <0.0007 <0.0007 <0.0008 29-Jun-20 Cs-137 <0.0009 <0.0024 <0.0058 <0.0009 <0.0040 <0.0017 <0.0029 <0.0009 <0.0023 <0.0026 Cs-134 <0.0028 <0.0010 <0.0007 <0.0024 <0.0024 <0.0019 <0.0007 <0.0023 <0.0011 <0.0023 28-Sep-21 Cs-137 <0.0031 <0.0023 <0.0030 <0.0034 <0.0024 <0.0038 <0.0024 <0.0008 <0.0024 <0.0034 Cs-134 <0.0025 <0.0031 <0.0007 <0.0019 <0.0024 <0.0024 <0.0029 <0.0024 <0.0020 <0.0028 27-Dec-21 Cs-137 <0.0009 <0.0034 <0.0025 <0.0039 <0.0024 <0.0043 <0.0024 <0.0038 <0.0009 <0.0045 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 26

Table 8-4 Radioiodine in Air 1st-2nd Quarter RADIOIODINE IN AIR 1st QUARTER ODCM required samples denoted by

• units are pCi/m3 (control)

START STOP Site Site Site Site Site Site Site Site Site Site Week # DATE DATE 4 6A* 7A 14A* 15* 17A 21 29* 35 40* Note 1 28-Dec-20 5-Jan-21 <0.033 <0.028 <0.032 <0.023 <0.032 <0.026 <0.041 <0.031 <0.006 <0.041 2 5-Jan-21 12-Jan-21 <0.025 <0.035 <0.039 <0.017 <0.021 <0.028 <0.024 <0.033 <0.025 <0.033 3 12-Jan-21 19-Jan-21 <0.018 <0.006 <0.007 <0.022 <0.018 <0.028 <0.007 <0.036 <0.022 <0.030 4 19-Jan-21 26-Jan-21 <0.031 <0.007 <0.038 <0.024 <0.049 <0.027 <0.063 <0.028 <0.023 <0.028 5 26-Jan-21 2-Feb-21 <0.029 <0.023 <0.023 <0.024 <0.026 <0.028 <0.032 <0.030 <0.027 <0.043 6 2-Feb-21 9-Feb-21 <0.027 <0.030 <0.029 <0.022 <0.036 <0.020 <0.028 <0.021 <0.022 <0.017 7 9-Feb-21 16-Feb-21 <0.033 <0.039 <0.021 <0.035 <0.027 <0.022 <0.030 <0.022 <0.024 <0.025 8 16-Feb-21 23-Feb-21 <0.017 <0.022 <0.026 <0.036 <0.026 <0.017 <0.017 <0.025 <0.006 <0.028 9 23-Feb-21 2-Mar-21 <0.030 <0.024 <0.027 <0.026 <0.036 <0.032 <0.030 <0.018 <0.030 <0.029 10 2-Mar-21 9-Mar-21 <0.031 <0.037 <0.035 <0.025 <0.052 <0.026 <0.065 <0.018 <0.028 <0.022 11 9-Mar-21 16-Mar-21 <0.017 <0.023 <0.049 <0.027 <0.050 <0.022 <0.033 <0.021 <0.021 <0.043 12 16-Mar-21 23-Mar-21 <0.051 <0.036 <0.032 <0.045 <0.028 <0.044 <0.033 <0.035 <0.022 <0.017 13 23-Mar-21 30-Mar-21 <0.022 <0.026 <0.031 <0.025 <0.031 <0.033 <0.030 <0.032 <0.028 <0.034 RADIOIODINE IN AIR 2nd QUARTER ODCM required samples denoted by

• units are pCi/m3 (control)

Week # DATE DATE 4 6A* 7A 14A* 15* 17A 21 29* 35 40* Note 14 30-Mar-21 6-Apr-21 <0.053 <0.047 <0.031 <0.046 <0.018 <0.013 <0.029 <0.035 <0.030 <0.022 15 6-Apr-21 13-Apr-21 <0.018 <0.035 <0.024 <0.058 <0.034 <0.063 <0.017 <0.028 <0.022 <0.025 16 13-Apr-21 20-Apr-21 <0.022 <0.024 <0.034 <0.034 <0.044 <0.038 <0.057 <0.028 <0.024 <0.025 17 20-Apr-21 27-Apr-21 <0.023 <0.018 <0.037 <0.029 <0.054 <0.019 <0.037 <0.035 <0.018 <0.030 18 27-Apr-21 4-May-21 <0.017 <0.035 <0.058 <0.017 <0.045 <0.035 <0.052 <0.022 <0.025 <0.022 19 4-May-21 11-May-21 <0.030 <0.013 <0.044 <0.022 <0.035 <0.029 <0.021 <0.036 <0.023 <0.022 20 11-May-21 18-May-21 <0.017 <0.044 <0.028 <0.045 <0.029 <0.052 <0.034 <0.022 <0.026 <0.025 21 18-May-21 25-May-21 <0.039 <0.022 <0.060 <0.018 <0.048 <0.024 <0.066 <0.018 <0.023 <0.066 22 25-May-21 1-Jun-21 <0.024 <0.037 <0.007 <0.037 <0.033 <0.055 <0.041 <0.007 <0.028 <0.040 23 1-Jun-21 8-Jun-21 <0.029 <0.034 <0.044 <0.006 <0.051 <0.026 <0.044 <0.006 <0.017 <0.025 24 8-Jun-21 15-Jun-21 <0.023 <0.045 <0.036 <0.022 <0.013 <0.027 <0.028 <0.053 <0.029 <0.017 25 15-Jun-21 22-Jun-21 <0.026 <0.025 <0.025 <0.024 <0.017 <0.028 <0.033 <0.017 <0.026 <0.006 26 22-Jun-21 29-Jun-21 <0.034 <0.029 <0.038 <0.023 <0.014 <0.019 <0.047 <0.019 <0.024 <0.051 1 NOTE 1: Site 40 Pump failed and actual run time is unknown. Conservative time used for analysis. Data is for INFO ONLY. CR 21-07886 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 27

Table 8-5 Radioiodine in Air 3rd-4th Quarter RADIOIODINE IN AIR 3rd QUARTER ODCM required samples denoted by *

(control) required LLD <0.070 START STOP Site Site Site Site Site Site Site Site Site Site Week # DATE DATE 4 6A* 7A 14A* 15* 17A 21 29* 35 40* Note 27 29-Jun-21 6-Jul-21 <0.028 <0.007 <0.062 <0.035 <0.037 <0.024 <0.037 <0.030 <0.030 <0.038 28 6-Jul-21 13-Jul-21 <0.006 <0.037 <0.036 <0.006 <0.045 <0.033 <0.035 <0.022 <0.026 <0.026 29 13-Jul-21 20-Jul-21 <0.022 <0.027 <0.007 <0.032 <0.033 <0.007 <0.023 <0.018 <0.030 <0.023 30 20-Jul-21 27-Jul-21 <0.035 <0.025 <0.025 <0.029 <0.029 <0.025 <0.029 <0.020 <0.037 <0.035 31 27-Jul-21 3-Aug-21 <0.018 <0.023 <0.023 <0.023 <0.023 <0.018 <0.030 <0.023 <0.035 <0.018 32 3-Aug-21 10-Aug-21 <0.019 <0.031 <0.018 <0.024 <0.027 <0.019 <0.043 <0.028 <0.031 <0.031 33 10-Aug-21 17-Aug-21 <0.026 <0.027 <0.029 <0.030 <0.027 <0.017 <0.018 <0.022 <0.018 <0.018 34 17-Aug-21 24-Aug-21 <0.023 <0.023 <0.018 <0.036 <0.027 <0.023 <0.023 <0.023 <0.024 <0.022 35 24-Aug-21 31-Aug-21 <0.018 <0.036 <0.031 <0.023 <0.026 <0.027 <0.030 <0.026 <0.033 <0.018 36 31-Aug-21 7-Sep-21 <0.018 <0.027 <0.033 <0.007 <0.037 <0.029 <0.030 <0.007 <0.023 <0.026 37 7-Sep-21 14-Sep-21 <0.027 <0.034 <0.017 <0.026 <0.021 <0.018 <0.034 <0.021 <0.022 <0.006 38 14-Sep-21 21-Sep-21 <0.006 <0.021 <0.034 <0.017 <0.021 <0.021 <0.021 <0.016 <0.032 <0.021 39 21-Sep-21 28-Sep-21 <0.027 <0.027 <0.023 <0.018 <0.026 <0.023 <0.007 <0.027 <0.041 <0.007 RADIOIODINE IN AIR 4th QUARTER ODCM required samples denoted by

• units are pCi/m3 (control) required LLD <0.070 START STOP Site Site Site Site Site Site Site Site Site Site Week # DATE DATE 4 6A* 7A 14A* 15* 17A 21 29* 35 40* Note 40 28-Sep-21 5-Oct-21 <0.025 <0.031 <0.025 <0.031 <0.017 <0.025 <0.025 <0.025 <0.017 <0.025 41 5-Oct-21 12-Oct-21 <0.023 <0.027 <0.030 <0.022 <0.023 <0.026 <0.027 <0.029 <0.027 <0.023 42 12-Oct-21 19-Oct-21 <0.026 <0.028 <0.022 <0.017 <0.030 <0.028 <0.029 <0.025 <0.039 <0.022 43 19-Oct-21 26-Oct-21 <0.031 <0.030 <0.027 <0.019 <0.024 <0.019 <0.034 <0.036 <0.034 <0.028 44 26-Oct-21 2-Nov-21 <0.039 <0.022 <0.029 <0.026 <0.022 <0.029 <0.025 <0.017 <0.021 <0.025 45 2-Nov-21 8-Nov-21 <0.027 <0.022 <0.022 <0.028 <0.027 <0.021 <0.039 <0.037 <0.008 <0.041 46 8-Nov-21 16-Nov-21 <0.016 <0.029 <0.029 <0.021 <0.006 <0.021 <0.037 <0.006 <0.025 <0.034 47 16-Nov-21 22-Nov-21 <0.027 <0.040 <0.043 <0.022 <0.028 <0.039 <0.048 <0.008 <0.036 <0.022 48 22-Nov-21 30-Nov-21 <0.016 <0.031 <0.023 <0.016 <0.025 <0.016 <0.029 <0.028 <0.029 <0.023 49 30-Nov-21 7-Dec-21 <0.018 <0.036 <0.038 <0.028 <0.025 <0.029 <0.032 <0.017 <0.022 <0.022 50 7-Dec-21 14-Dec-21 <0.038 <0.027 <0.029 <0.025 <0.030 <0.025 <0.025 <0.028 <0.028 <0.022 51 14-Dec-21 21-Dec-21 <0.029 <0.029 <0.035 <0.017 <0.022 <0.028 <0.036 <0.027 <0.033 <0.030 52 21-Dec-21 27-Dec-21 <0.037 <0.030 <0.038 <0.023 <0.029 <0.033 <0.029 <0.022 <0.041 <0.023 2 Note 2: Mositure found in Air Sample charcoal cartirages. Water intrusion was previously evalauated under Eval 15-00990-001, and found to be within the Technical Performance Specifications. Samples are VALID. CR 21-15290 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 28

Table 8-6 Vegetation VEGETATION ODCM required samples denoted by

• units are pCi/kg, wet

<60 <60 <80 DATE LOCATION TYPE COLLECTED I-131 Cs-134 Cs-137 Note January- NO SAMPLE AVAILABLE LOCAL February- NO SAMPLE AVAILABLE RESIDENCE Lettuce 18-Mar-21 <44 <33 <50 (Site #47)* Lettuce 22-Apr-21 <48 <47 <41 Rhubarb 20-May-21 <56 <34 <67 June- NO SAMPLE AVAILABLE July- NO SAMPLE AVAILABLE August- NO SAMPLE AVAILABLE September- NO SAMPLE AVAILABLE October- NO SAMPLE AVAILABLE November- NO SAMPLE AVAILABLE December- NO SAMPLE AVAILABLE Spinach 21-Jan-21 <50 <51 <76 Lettuce 21-Jan-21 <39 <50 <71 Spring Mix 19-Feb-21 <50 <45 <63 Spinach 19-Feb-21 <39 <35 <43 Arugula 19-Feb-21 <44 <44 <63 Spinach 19-Mar-21 <39 <37 <42 COMMERCIAL Romaine 19-Mar-21 <44 <43 <71 FARM Red Leaf 19-Mar-21 <43 <42 <52 (Site #62)* Red Romaine 21-Apr-21 <46 <46 <52 Green Tango 21-Apr-21 <35 <39 <60 Arugula 21-Apr-21 <51 <41 <46 May- NO SAMPLE AVAILABLE June- NO SAMPLE AVAIABLE July- NO SAMPLE AVAILABLE August- NO SAMPLE AVAILABLE September- NO SAMPLE AVAILABLE Spinach 15-Oct-21 <42 <41 <44 Baby Tatsoi 19-Nov-21 <37 <57 <64 Lettuce 19-Nov-21 <58 <44 <47 Romaine 19-Nov-21 <51 <28 <52 Kale 10-Dec-21 <59 <49 <37 Pak Choi 10-Dec-21 <32 <52 <76 Baby Green Leaf 10-Dec-21 <43 <16 <38 Collard Greens 21-Jan-21 <42 <43 <80 Lettuce 18-Feb-21 <31 <52 <38 Lettuce 18-Mar-21 <56 <50 <65 Lettuce 22-Apr-21 <49 <32 <39 Swiss Chard 20-May-21 <51 <49 <42 LOCAL Lettuce 17-Jun-21 <39 <48 <67 RESIDENCE Swiss Chard 15-Jul-21 <47 <53 <63 (Site #51)

Collard Greens 19-Aug-21 <51 <47 <45 September- NO SAMPLE AVAILABLE October- NO SAMPLE AVAILABLE November- NO SAMPLE AVAILABLE December- NO SAMPLE AVAILABLE PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 29

Table 8-7 Milk MILK ODCM required samples denoted by

• units are pCi/liter SAMPLE DATE LOCATION COLLECTED I-131 Cs-134 Cs-137 Ba-140 La-140 Note 21-Jan-21 <1 <0.8 <0.9 <3 <1 Local Resident 18-Feb-21 <1 <0.9 <1 <3 <1 1 Goats 18-Mar-21 <1 <0.9 <1 <4 <1 (Site #51)* 22-Apr-21 <1 <0.9 <1 <3 <1 20-May-21 <0.9 <0.7 <1 <3 <1 17-Jun-21 <1 <0.8 <9 <3 <1 15-Jul-21 <0.9 <0.8 <0.9 <3 <1 19-Aug-21 <0.9 <0.7 <0.9 <3 <1 16-Sep-21 <0.9 <0.7 <1 <3 <1 15-Oct-21 <0.9 <0.7 <1 <3 <1 18-Nov-21 <0.9 <0.7 <1 <3 <1 16-Dec-21 <0.9 <0.7 <1 <3 <1

• • NO SAMPLE AVAILABLE- BABY GOATS**

25-Feb-21 <1 <0.8 <1 <3 <1 25-Mar-21 <1 <0.8 <1 <3 <1 Local Resident 29-Apr-21 <1 <0.8 <1 <3 <1 Goats 27-May-21 <0.7 <0.5 <0.6 <2 <1 (Site #53)* 25-Jun-21 <0.9 <0.7 <1 <3 <1 22-Jul-21 <0.9 <0.8 <0.9 <3 <1 27-Aug-21 <0.9 <0.7 <1 <3 <1 23-Sep-21 <0.9 <0.8 <0.9 <3 <1 22-Oct-21 <0.9 <0.8 <0.9 <3 <1 19-Nov-21 <0.9 <0.7 <0.9 <3 <1

• • NO SAMPLE AVAILABLE**

15-Jan-21 <1 <0.8 <1 <3 <1 Local Resident 04-Feb-21 <1 <0.9 <1 <3 <1 Goats 11-Mar-21 <1 <0.8 <0.9 <3 <2 (Site #54)* 15-Apr-21 <1 <0.8 <1 <3 <1 20-May-21 <0.9 <0.8 <0.9 <3 <1 2 10-Jun-21 <0.9 <0.7 <0.9 <3 <1 08-Jul-21 <0.9 <0.8 <0.9 <3 <1 12-Aug-21 <0.9 <0.7 <0.9 <3 <1 09-Sep-21 <0.9 <0.7 <0.9 <3 <1 08-Oct-21 <0.9 <0.7 <1 <3 <1 05-Nov-21 <1 <0.8 <0.9 <3 <1 09-Dec-21 <0.9 <0.7 <1 <3 <1 Note 1: Power interruption resulted in higher than usual I-131 MDA for Site 51. MDA achieved 1.06 pCi/L; ODCM requirement is 1 pCi/L. Sample valid. CR 21-02044 Note 2: Power interrupted during initial sample analysis, preventing analysis from reaching required LLDs.

Additional sample was collected and analysis achieved required LLDs. Results of second sample are reported in this table. CR 21-06313 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 30

Table 8-8 Drinking Water DRINKING WATER ODCM required samples denoted by

• units are pCi/liter SAMPLE MONTH Qtrly LOCATION ENDPOINT Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 Tritium Gross Beta Note 26-Jan-21 <10 <9 <15 <10 <23 <9 <20 <8 <9 <11 <29 <10 <3.17 23-Feb-21 <8 <9 <18 <10 <23 <12 <16 <10 <8 <9 <33 <13 <2.96 30-Mar-21 <13 <14 <25 <12 <29 <12 <24 <11 <11 <12 <44 <15 <345 4.22+/-1.80 27-Apr-21 <8 <9 <20 <11 <20 <11 <17 <7 <9 <11 <29 <12 <2.81 LOCAL 25-May-21 <10 <12 <22 <13 <22 <12 <22 <11 <11 <16 <43 <10 3.20+/-1.83 RESIDENCE 29-Jun-21 <11 <14 <25 <10 <25 <13 <18 <11 <10 <13 <39 <15 <346 <2.79 (Site #48)

• 27-Jul-21 <10 <9 <15 <11 <26 <10 <18 <7 <11 <11 <32 <8 <2.77 31-Aug-21 <9 <8 <20 <11 <19 <11 <20 <9 <9 <9 <28 <14 <2.92 28-Sep-21 <13 <10 <15 <6 <24 <8 <19 <9 <9 <8 <24 <15 <340 <2.80 26-Oct-21 <9 <10 <16 <9 <23 <12 <19 <9 <8 <10 <27 <13 <3.49 30-Nov-21 <10 <9 <16 <9 <20 <9 <16 <9 <9 <10 <28 <9 <2.96 27-Dec-21 <13 <10 <15 <10 <25 <11 <14 <9 <7 <10 <32 <12 <344 <2.93 26-Jan-21 <7 <6 <14 <6 <14 <7 <13 <7 <6 <7 <23 <12 <2.95 23-Feb-21 <8 <10 <18 <8 <22 <11 <18 <9 <9 <9 <36 <14 <2.79 30-Mar-21 <9 <9 <14 <8 <20 <9 <18 <9 <8 <10 <29 <13 <342 7.44+/-1.82 27-Apr-21 <10 <9 <13 <10 <20 <10 <17 <8 <9 <10 <27 <13 3.99+/-1.71 LOCAL 25-May-21 <9 <10 <18 <8 <20 <12 <16 <8 <8 <10 <28 <12 3.56+/-1.74 RESIDENCE 29-Jun-21 <10 <9 <21 <7 <16 <10 <18 <9 <8 <11 <29 <11 <335 4.06+/-1.71 (Site #55) 27-Jul-21 <9 <9 <14 <10 <17 <9 <16 <9 <8 <8 <27 <10 5.04+/-1.73 31-Aug-21 <10 <9 <13 <10 <18 <9 <18 <7 <7 <9 <31 <14 <2.84 28-Sep-21 <12 <9 <16 <11 <24 <10 <14 <9 <7 <11 <30 <11 <339 3.43+/-1.73 26-Oct-21 <10 <11 <19 <11 <21 <10 <16 <9 <8 <9 <39 <10 <3.31 30-Nov-21 <11 <8 <23 <6 <19 <8 <14 <8 <8 <7 <32 <13 <2.82 27-Dec-21 <9 <9 <19 <9 <20 <10 <15 <8 <7 <11 <35 <13 <341 4.15+/-1.78 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 31

Table 8-8 Drinking Water (Continued)

DRINKING WATER ODCM required samples denoted by

• units are pCi/liter SAMPLE MONTH Qtrly LOCATION ENDPOINT Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 Tritium Gross Beta Note 26-Jan-21 <8 <7 <16 <8 <16 <8 <13 <8 <6 <9 <24 <15 <2.90 1 23-Feb-21 <9 <8 <17 <8 <20 <9 <17 <8 <8 <11 <28 <15 <2.75 30-Mar-21 <10 <9 <18 <9 <17 <12 <13 <7 <8 <8 <28 <11 <339 3.09+/-1.65 27-Apr-21 <10 <9 <17 <6 <30 <13 <19 <8 <9 <12 <34 <10 3.94+/-1.69 25-May-21 <13 <12 <23 <10 <20 <10 <18 <10 <10 <12 <33 <15 <2.77 LOCAL 29-Jun-21 <11 <11 <19 <12 <21 <13 <19 <9 <10 <13 <30 <14 <323 <2.53 RESIDENCE 27-Jul-21 <10 <10 <20 <12 <23 <10 <17 <8 <8 <10 <33 <12 2.99+/-1.64 (Site #46)

• 31-Aug-21 <9 <8 <16 <8 <20 <10 <13 <8 <7 <8 <30 <14 <2.82 28-Sep-21 <9 <9 <19 <9 <18 <11 <15 <7 <8 <10 <32 <15 <339 <2.70 26-Oct-21 <8 <9 <17 <9 <14 <11 <17 <8 <8 <11 <28 <9 <3.27 30-Nov-21 <10 <10 <16 <10 <20 <10 <17 <9 <9 <11 <29 <11 <2.78 27-Dec-21 <12 <11 <23 <8 <19 <10 <15 <10 <8 <10 <35 <14 <342 3.82+/-1.75 26-Jan-21 <6 <6 <14 <7 <15 <7 <11 <6 <6 <8 <23 <13 <2.83 23-Feb-21 <9 <9 <21 <10 <25 <9 <13 <10 <8 <9 <26 <11 <2.68 30-Mar-21 <12 <10 <15 <15 <28 <14 <21 <11 <13 <15 <42 <8 <345 <2.51 27-Apr-21 <9 <11 <21 <8 <17 <9 <16 <8 <8 <11 <25 <14 <2.57 25-May-21 <11 <9 <17 <10 <20 <10 <17 <9 <10 <12 <29 <14 <2.63 LOCAL 29-Jun-21 <10 <11 <17 <8 <24 <10 <18 <11 <8 <10 <34 <14 <340 3.42+/-1.67 RESIDENCE 27-Jul-21 <9 <7 <20 <10 <23 <8 <16 <9 <8 <12 <29 <11 <2.50 (Site #49)

• 31-Aug-21 <9 <8 <20 <8 <22 <11 <17 <8 <9 <10 <32 <9 <2.73 28-Sep-21 <12 <10 <16 <10 <17 <11 <14 <9 <7 <8 <28 <11 <320 <2.62 26-Oct-21 <10 <8 <20 <10 <21 <13 <18 <10 <8 <10 <27 <13 <3.18 30-Nov-21 <11 <10 <22 <8 <28 <11 <19 <8 <8 <9 <34 <15 <2.72 27-Dec-21 <11 <9 <21 <10 <19 <11 <15 <10 <9 <9 <32 <15 <339 <2.66 Note 1: Duplicate sample taken. Original duplicate did not meet La-140 LLD and was recounted. Recount met LLD requirements. Reported results are average of original sample results and duplicate recount results.

PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 32

Table 8-9 Groundwater GROUNDWATER ODCM required samples denoted by

• units are pCi/liter SAMPLE DATE LOCATION COLLECTED Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 Tritium Notes 26-Feb-21 <7 <6 <14 <7 <16 <8 <11 <7 <5 <6 <23 <12 <330 1 WELL 27ddc 27-Apr-21 <11 <12 <21 <10 <23 <12 <20 <10 <10 <12 <38 <14 <342 (Site #57)* 27-Jul-21 <7 <8 <13 <6 <15 <8 <12 <7 <6 <8 <25 <13 <340 26-Oct-21 <11 <10 <18 <11 <26 <14 <21 <9 <9 <12 <31 <12 <326 26-Jan-21 <9 <10 <16 <9 <22 <11 <16 <9 <8 <10 <38 <11 <343 1 Well 34aab 27-Apr-21 <9 <12 <20 <10 <30 <12 <17 <10 <8 <12 <36 <9 <337 (Site #65)* 27-Jul-21 <7 <8 <14 <7 <19 <9 <13 <7 <6 <8 <23 <14 <343 26-Oct-21 <9 <8 <15 <8 <18 <9 <14 <7 <5 <7 <25 <15 <322 26-Jan-21 <8 <7 <15 <7 <16 <8 <12 <7 <6 <8 <23 <13 <344 1 Well 27dcb 27-Apr-21 <9 <10 <17 <11 <27 <12 <18 <8 <9 <11 <27 <15 <334 (Site #58A) 27-Jul-21 <13 <12 <20 <10 <26 <12 <18 <10 <8 <10 <30 <15 <342 26-Oct-21 <8 <10 <22 <12 <25 <12 <17 <10 <8 <8 <33 <15 <329 WELL 34abb

• • No Sample. Well Out of Service**

(Site #58)*

Note 1: A background for tritium analysis was identified as being above than the procedurally QC limit of 16.1 cpm. Original samples unavailable for reanalysis; tritium values calculated using background mean value. Reported values are for information only. CR 21-13878 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 33

Table 8-10 Surface Water SURFACE WATER ODCM required samples denoted by

• units are pCi/liter SAMPLE DATE LOCATION COLLECTED Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 Tritium Notes 26-Jan-21 <8 <10 <22 <10 <21 <11 <15 <10 <8 <11 <29 <13 <340 1 45 ACRE 27-Apr-21 <9 <8 <19 <10 <23 <8 <16 <8 <8 <12 <26 <10 <337 RESERVOIR 27-Jul-21 <8 <8 <14 <7 <15 <7 <13 <7 <6 <9 <17 <13 <342 (Site #61)

• 26-Oct-21 <9 <9 <17 <12 <21 <11 <19 <10 <9 <8 <35 <14 <332 26-Jan-21 <10 <9 <21 <7 <22 <11 <15 <9 <7 <10 <32 <11 <340 1 85 ACRE 27-Apr-21 <15 <11 <24 <12 <29 <11 <20 <9 <11 <14 <32 <10 <338 RESERVOIR 27-Jul-21 <8 <9 <18 <11 <16 <10 <14 <10 <8 <8 <34 <15 <342 (Site #60)

• 26-Oct-21 <11 <9 <18 <9 <17 <10 <17 <10 <8 <12 <28 <7 <327 26-Jan-21 <9 <11 <19 <11 <25 <9 <16 <10 <8 <10 <28 <8 961+/-206 1 EVAP POND 1 (Site #59) *CELL 27-Apr-21 <13 <12 <28 <15 <25 <12 <17 <9 <10 <16 <38 <14 1029+/-218 NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE 1A 26-Oct-21 <8 <8 <19 <9 <21 <9 <14 <8 <7 <12 <29 <10 876+/-213 NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE CELL 1B NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE 26-Oct-21 <12 <9 <22 <12 <20 <11 <20 <10 <8 <9 <31 <13 992+/-204 26-Jan-21 <11 <10 <21 <12 <29 <9 <19 <9 <9 <10 <33 <11 543+/-199 1 NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE CELL 1C NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE 26-Oct-21 <10 <11 <22 <12 <27 <11 <18 <8 <8 <11 <27 <14 897+/-208 26-Jan-21 <12 <11 <17 <14 <26 <10 <15 <9 <7 <10 <31 <9 521+/-195 1 EVAP POND 2 27-Apr-21 <12 <10 <19 <14 <25 <12 <18 <9 <8 <10 <31 <11 1025+/-217 (Site #63) *CELL 27-Jul-21 <10 <9 <19 <10 <20 <11 <17 <8 <8 <11 <28 <8 719+/-214 2A NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE CELL 2B 27-Jul-21 <10 <10 <19 <12 <25 <10 <19 <9 <9 <9 <26 <11 688+/-214 26-Oct-21 <10 <8 <17 <13 <19 <11 <19 <9 <9 <12 <35 <11 786+/-208 26-Jan-21 <12 <11 <25 <12 <30 <12 <20 <10 <12 <13 <36 <11 529+/-199 1, 2 NO SAMPLE REQUIRED CELL 2C NO SAMPLE REQUIRED NO SAMPLE REQUIRED NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE EVAP POND 3 (Site #64) *CELL 29-Jun-21 <10 <10 <26 <11 <30 <10 <17 <7 <7 69+/-11 <27 <4 <346 3,4 NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE 3A NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE CELL 3B NO SAMPLE REQUIRED- NO INFLUENT SINCE LAST SAMPLE 26-Oct-21 <10 <9 <23 <11 <23 <10 <19 <10 <10 <12 <33 <11 846+/-199 Note 1: Background for tritium analysis above the procedurally QC limit of 16.1 cpm. Original samples unavailable for reanalysis; tritium values calculated using background mean value. Reported values are for information only. CR 21-13878 Note 2: Cell 2C is not a required sampling location. Cell 2C is a lined sludge collection point and does not receive influent directly from the plant.

Note 3: Original sample taken 6/24/ 2021 was not composite. Resample 6/29/2021 to include East and West side; results averaged. Cs-137 exceeds action/reporting level in 74RM-0EN09 (20 pCi/L) and ODCM 6-2 reporting level (50 pCi/L). Event evaluated under 21-08433-001 and determined to not be Plant related; result of pre-operational Cs-137 in the soil and sediment surrounding Palo Verde. CR 21-14818 for Quarterly Sample Verification Note 4: Pond is in the process of being drained; bodies of water are separated into East and West small bodies of water. Sample of each side taken. Reported values are average of the two samples.

PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 34

Table 8-10 Surface Water (Continued)

SURFACE WATER ODCM required samples denoted by

• units are pCi/liter SAMPLE DATE LOCATION COLLECTED Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 Tritium Notes 5-Jan-21 <10 <8 <14 <7 <19 <11 <15 <10 <7 <10 <38 <10 12-Jan-21 <9 <9 <16 <8 <25 <10 <17 <11 <8 <9 <28 <10 19-Jan-21 <11 <11 <22 <8 <23 <10 <15 <13 <8 <10 <28 <10 26-Jan-21 <11 <9 <20 <10 <19 <9 <13 <11 <9 <11 <31 <10 <363 1 2-Feb-21 <10 <11 <20 <9 <19 <8 <14 8+/-8 <8 <11 <30 <12 9-Feb-21 <11 <9 <19 <12 <21 <9 <14 <12 <6 <10 <34 <10 16-Feb-21 <11 <10 <16 <10 <23 <8 <18 <13 <9 <9 <30 <11 23-Feb-21 <9 <11 <19 <8 <21 <10 <14 21+/-9 <7 <9 <31 <13 <353 2-Mar-21 <9 <11 <15 <9 <26 <9 <15 8+/-9 <8 <9 <30 <10 9-Mar-21 <10 <11 <16 <11 <20 <11 <16 23+/-10 <8 <10 <22 <8 16-Mar-21 <8 <9 <18 <11 <17 <9 <15 <11 <9 <9 <30 <13 23-Mar-21 <9 <7 <16 <12 <27 <8 <20 15+/-9 <8 <12 <32 <12 30-Mar-21 <8 <7 <21 <8 <20 <9 <16 <11 <9 <10 <34 <3 <363 WRF 6-Apr-21 <9 <8 <15 <9 <17 <12 <15 <10 <9 <7 <33 <13 INFLUENT 13-Apr-21 <9 <9 <21 <8 <19 <10 <16 15+/-9 <13 <9 <28 <10 20-Apr-21 **Water Resources Outage- No Sample Available**

27-Apr-21 <10 <11 <17 <10 <23 <11 <16 <11 <9 <9 <33 <11 <357 4-May-21 <10 <9 <17 <8 <20 <9 <16 <10 <7 <11 <28 <6 11-May-21 <13 <8 <19 <8 <26 <10 <18 20+/-9 <9 <10 <34 <8 18-May-21 <11 <9 <12 <7 <17 <11 <17 8+/-8 <7 <10 <33 <8 25-May-21 <11 <8 <19 <11 <20 <9 <18 <12 <9 <9 <30 <9 <356 1-Jun-21 <9 <9 <19 <10 <21 <9 <12 <11 <6 <10 <29 <7 8-Jun-21 <10 <8 <19 <11 <21 <10 <16 <8 <9 <7 <30 <9 15-Jun-21 <11 <8 <20 <7 <17 <10 <18 <11 <9 <10 <29 <13 22-Jun-21 <10 <9 <18 <9 <25 <12 <18 12+/-7 <6 <8 <26 <3 29-Jun-21 <14 <14 <25 <12 <28 <15 <25 <10 <10 <16 <39 <15 <346 Note 1: A background for tritium analysis was identified as being above than the procedurally QC limit of 16.1 cpm. Original samples unavailable for reanalysis; tritium values calculated using background mean value. Reported values are for information only. CR 21-13878 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 35

Table 8-10 Surface Water (Continued)

SURFACE WATER ODCM required samples denoted by

• units are pCi/liter SAMPLE DATE LOCATION COLLECTED Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 Tritium Note 6-Jul-21 <9 <10 <14 <14 <17 <11 <18 <10 <9 <9 <33 <9 13-Jul-21 <10 <10 <20 <4 <22 <8 <18 <8 <8 <10 <31 <9 20-Jul-21 <11 <9 <19 <6 <19 <9 <16 <9 <7 <9 <33 <13 27-Jul-21 <10 <9 <22 <2 <17 <9 <15 <10 <8 <7 <32 <10 <350 3-Aug-21 <9 <9 <16 <9 <24 <10 <15 11+/-8 <11 <8 <27 <11 10-Aug-21 <11 <10 <20 <9 <22 <6 <16 <12 <8 <9 <33 <12 17-Aug-21 <9 <10 <20 <9 <20 <10 <15 <11 <8 <10 <32 <10 24-Aug-21 <9 <9 <17 <9 <21 <8 <17 <10 <8 <11 <25 <8 31-Aug-21 <10 <8 <19 <7 <20 <10 <19 13+/-9 <8 <9 <28 <13 <355 7-Sep-21 <8 <9 <13 <8 <21 <10 <16 <10 <7 <7 <27 <9 14-Sep-21 <9 <9 <14 <6 <20 <10 <13 14+/-9 <8 <7 <29 <9 21-Sep-21 <9 <8 <16 <10 <21 <9 <17 <10 <7 <8 <27 <10 28-Sep-21 <9 <10 <14 <12 <19 <10 <16 <11 <8 <9 <29 <3 <361 5-Oct-21 <9 <9 <13 <11 <17 <12 <17 <11 <8 <9 <29 <12 WRF 12-Oct-21 <10 <12 <19 <10 <20 <9 <18 6+/-6 <9 <7 <29 <12 <351 INFLUENT 19-Oct-21 **Water Resources Outage- No Sample Available**

26-Oct-21 **Water Resources Outage- No Sample Available**

2-Nov-21 <8 <8 <17 <9 <20 <12 <16 14+/-9 <8 <<8 <31 <10 9-Nov-21 <8 <10 <14 <7 <23 <12 <17 <11 <8 <10 <28 <7 16-Nov-21 <9 <10 <19 <10 <24 <10 <19 <9 <8 <10 <31 <11 23-Nov-21 <10 <9 <17 <7 <24 <10 <17 <10 <8 <10 <31 <10 30-Nov-21 <10 <5 <21 <11 <23 <10 <17 <9 <8 <7 <31 <11 <354 7-Dec-21 <10 <9 <25 <10 <20 <10 <18 <10 <8 <7 <29 <13 14-Dec-21 <8 <10 <20 <8 <19 <11 <17 <9 <7 <8 <23 <13 21-Dec-21 <9 <12 <21 <7 <22 <10 <17 <10 <8 <9 <34 <11 28-Dec-21 <9 <9 <20 <9 <20 <10 <17 <9 <8 <8 <31 <13 <358 Note 1: A background for tritium analysis was identified as being above the procedurally QC limit of 16.1 cpm. Original samples unavailable for reanalysis; tritium values calculated using background mean value. Reported values are for information only. CR 21-13878 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 36

Table 8-10 Surface Water (Continued)

SURFACE WATER ODCM required samples denoted by

• units are pCi/liter SAMPLE DATE LOCATION COLLECTED Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 Tritium Note 5-Jan-21 **EMPTY**

12-Jan-21 **EMPTY**

19-Jan-21 **EMPTY**

26-Jan-21 <11 <13 <25 <12 <19 <11 <19 <10 <11 <15 <35 <10 <348 1 2-Feb-21 **EMPTY**

9-Feb-21 **EMPTY**

16-Feb-21 **EMPTY**

23-Feb-21 **EMPTY**

2-Mar-21 **EMPTY**

9-Mar-21 **EMPTY**

16-Mar-21 **EMPTY**

23-Mar-21 **EMPTY**

30-Mar-21 **EMPTY**

SEDIMENTATION 6-Apr-21 **EMPTY**

BASIN #2 13-Apr-21 **EMPTY**

20-Apr-21 **EMPTY**

27-Apr-21 **EMPTY**

4-May-21 **EMPTY**

11-May-21 **EMPTY**

18-May-21 **EMPTY**

25-May-21 **EMPTY**

1-Jun-21 **EMPTY**

8-Jun-21 **EMPTY**

15-Jun-21 **EMPTY**

22-Jun-21 **EMPTY**

29-Jun-21 **EMPTY**

Note 1: A background for tritium analysis was identified as being above than the procedurally QC limit of 16.1 cpm. Original samples unavailable for reanalysis; tritium values calculated using background mean value. Reported values are for information only. CR 21-13878 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 37

Table 8-10 Surface Water (Continued)

ODCM required samples denoted by

• units are pCi/liter SAMPLE DATE LOCATION COLLECTED Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 Tritium Note 6-Jul-21 **EMPTY**

13-Jul-21 **EMPTY**

20-Jul-21 **EMPTY**

27-Jul-21 <8 <9 <21 <9 <23 <9 <14 <8 <7 <10 <26 <9 <395 3-Aug-21 **EMPTY**

10-Aug-21 **EMPTY**

17-Aug-21 <9 <9 <15 <12 <12 <10 <15 <10 <8 <8 <24 <12 <387 24-Aug-21 **EMPTY**

31-Aug-21 **EMPTY**

7-Sep-21 **EMPTY**

14-Sep-21 **EMPTY**

21-Sep-21 **EMPTY**

SEDIMENTATION 28-Sep-21 <7 <9 <21 <7 <18 <10 <17 <9 <8 <9 <30 <11 <380 BASIN #2 5-Oct-21 **EMPTY**

12-Oct-21 **EMPTY**

19-Oct-21 **EMPTY**

26-Oct-21 **EMPTY**

2-Nov-21 **EMPTY**

9-Nov-21 **EMPTY**

16-Nov-21 **EMPTY**

23-Nov-21 **EMPTY**

30-Nov-21 **EMPTY**

7-Dec-21 **EMPTY**

14-Dec-21 **EMPTY**

21-Dec-21 **EMPTY**

27-Dec-21 <10 <9 <17 <10 <20 <11 <17 <8 <7 <12 <32 <13 <359 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 38

Table 8-11 Sludge/Sediment ODCM required samples denoted by

• units are pCi/kg, wet SAMPLE DATE LOCATION COLLECTED I-131 Cs-134 Cs-137 In-111 Notes 5-Jan-21 469+/-145 <81 <79 12-Jan-21 364+/-137 <96 <155 19-Jan-21 226+/-144 <43 <126 26-Jan-21 <122 <150 2-Feb-21 409+/-142 <93 <133 9-Feb-21 466+/-138 <109 <134 16-Feb-21 531+/-145 <69 <85 23-Feb-21 668+/-183 <65 <101 2-Mar-21 428+/-136 <133 <117 9-Mar-21 370+/-144 <34 <80 16-Mar-21 362+/-125 <81 <160 23-Mar-21 <114 <128 WRF 30-Mar-21 489+/-152 <81 <100 CENTRIFUGE 6-Apr-21 377+/-159 <114 <162 WASTE SLUDGE 13-Apr-21 226+/-108 <72 <112 20-Apr-21 **Water Resources Outage- No Sample Available**

27-Apr-21 **Water Resources Outage- No Sample Available**

4-May-21 **Water Resources Outage- No Sample Available**

11-May-21 317+/-144 <60 <141 18-May-21 692+/-197 <115 <36 25-May-21 378+/-147 <106 <89 1-Jun-21 308+/-112 <92 <126 8-Jun-21 <103 <113 15-Jun-21 566+/-158 <91 <146 22-Jun-21 389+/-134 <105 <99 29-Jun-21 276+/-171 <119 <54 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 39

Table 8-11 Sludge/Sediment (Continued)

ODCM required samples denoted by

• units are pCi/kg, wet SAMPLE DATE LOCATION COLLECTED I-131 Cs-134 Cs-137 In-111 Notes 6-Jul-21 217+/-114 <77 <110 13-Jul-21 349+/-181 <136 <169 20-Jul-21 289+/-87 <70 <87 27-Jul-21 <90 <128 3-Aug-21 369+/-142 <93 <99 10-Aug-21 509+/-155 <118 <156 17-Aug-21 479+/-140 <78 <95 24-Aug-21 507+/-127 <94 <101 31-Aug-21 613+/-157 <112 <113 7-Sep-21 863+/-237 <113 <179 14-Sep-21 406+/-138 <33 <113 21-Sep-21 370+/-122 <66 <30 WRF 28-Sep-21 <122 <106 CENTRIFUGE 5-Oct-21 259+/-139 <134 <151 WASTE SLUDGE 12-Oct-21 208+/-109 <33 <99 19-Oct-21 **Water Resources Outage- No Sample Available**

26-Oct-21 <135 <136 2-Nov-21 **Water Resources Outage- No Sample Available**

9-Nov-21 772+/-179 <90 <128 16-Nov-21 563+/-163 <26 <109 23-Nov-21 527+/-144 <25 <106 30-Nov-21 365+/-169 <117 <129 7-Dec-21 <97 <102 14-Dec-21 <107 <102 21-Dec-21 383+/-145 <115 <166 28-Dec-21 363+/-139 <134 <170 ODCM required samples denoted by

• units are pCi/kg, wet SAMPLE DATE <150 <180 LOCATION COLLECTED I-131 Cs-134 Cs-137 In-111 Notes Sedimentation 21-Jul-21 <24 <39 Basin #2 Soil PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 40

Table 8-11 Sludge/Sediment (Continued)

Cooling Tower Sludge Unit Cycle Approximate Volume Isotope Activity Range (pCi/g) Sample Type (yd3)

All principal gamma-U1R22 547 <MDA Towers/Canal Sludge emitters All principal gamma-U3R22 546 <MDA Towers/Canal Sludge emitters Table 8-12 Hard -To-Detect Radionuclide Results Hard-To-Detect Radionuclide (pCi/Liter)

Sample Location Well number Sample Date C-14 Fe-55 Ni-63 Sr-90 Unit 1 (outside RCA) APP-12 11/03/2021 <157 <145 <4.26 <0.972 Unit 2 (inside RCA) H0A 11/13/2021 <159 <131 <3.17 <1.39 Unit 3 (inside RCA) H11 11/13/2021 <160 <136 <2.98 <1.26 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 41

Figure 8-1 Gross Beta in Air, 1st-2nd Quarter PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 42

Figure 8-2 Gross Beta in Air, 3rd-4th Quarter PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 43

Figure 8-3 Historical Gross Beta in Air (Weekly System Average)

PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 44

Figure 8-4 Historical Gross Beta in Air (Annual Site to Site Comparisons) Compared to Pre-Op Note: 7A is not included due to the location change since pre-operational period. The elevated 2011 annual average values are attributed to the Fukushima-Daiichi release.

PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 45

Figure 8-5 Gross Beta in Drinking Water Notes: MDA values are plotted as activity (i.e. <2.3 is plotted as 2.3)

The action level is 30 pCi/liter PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 46

Figure 8-6 Evaporation Pond Tritium Activity (Pre-Op- 2008)

Note: Zero values represent no sample taken for sampling period, per procedural guidance or lack of sample material.

PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 47

Figure 8-7 Evaporation Pond Tritium Activity (2009-2021)

Note: Zero values represent no sample taken for sampling period, per procedural guidance or lack of sample material.

PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 48

Figure 8-8 Sedimentation Basin 2 Cs-137 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 49

9. Thermoluminescent Dosimeter (TLD) Results and Data The environmental TLD used at PVNGS is the Panasonic Model 812 Dosimeter. The Model 812 is a multi-element dosimeter combining two elements of lithium borate and two elements of calcium sulfate under various filters.

TLDs were placed in fifty locations from one to thirty-five miles from the PVNGS. TLD locations are shown in Figure 2-1 and Figure 2-2 and are described in Table 9-1. TLD results for 2021 are presented in Table 9-2. Definitions for Table 9-2 are as follows:

MDDQ: Minimum differential dose, quarterly, 3 times 90th percentile sQ determined from analysis (mRem).

MDDA: Minimum differential dose, annual, 3 times 90th percentile sA determined from analysis (mRem).

BQ: Quarterly baseline (mRem) (average of previous 5 years)

MQ: Locations 91-day standard quarter normalized dose (mRem per standard quarter)

LQ: Quarterly investigation level dose (mRem)

BA: Baseline background dose (mRem) (annual)

MA: Annual monitoring data - MA determined by normalizing available quarterly data to 4 full quarters LA: Annual investigation level dose (mRem)

ND: Non-Detectable The baseline is calculated as the average of the previous 5-year measurements. The minimum differential dose (MDD) is calculated as 3 times the 90th percentile standard deviation of the data from the previous 5 years; quarterly MDD is calculated using the quarterly data and annual MDD is calculated using the annual summation of the quarterly data. Investigation level is calculated by the difference of the data measurement and the baseline; results less than, or equal to the MDD are Non-Detectable (ND) and any result exceeding the MDD meets the threshold for the investigation level.

Locations exceeding the investigation level will be evaluated for cause and impact to the public and environment.

Historical environmental gamma radiation results for 1985 through 2021 are presented in graphical form on Figure 9-1 (excluding transit control TLD #45). Figure 9-2 depicts the environmental TLD results from 2021 as compared to the pre-operational TLD results (excluding sites #41 and #43, as they were deleted and later assigned to a new location, and #46-50, as they had no pre-op TLD at the location for comparison). The site-to-site comparisons indicate a direct correlation with respect to pre-operational results. It is indicated that the offsite dose, as measured by TLDs, has not changed since Palo Verde became operational.

PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 50

Table 9-1 TLD Site Locations (Distance and direction are relative to Unit 2 in miles)

• Site #6 and site #44 are the control locations.

• • Site #45 is the transit control TLD (stored in lead pig).

PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 51

Table 9-2 Environmental TLD Results 2021 Annual Environmental TLD Monitoring Report Palo Verde 2021 MDDQ: 5 mrem Palo Verde 2021 MDD A: 10 mrem Location Quarterly (mrem) Annual (mrem)

Location Description NOTE BQ MQQ1 MQQ2 MQQ3 MQ Q4 LQQ1 LQQ2 LQQ3 LQ Q4 BA MA LA 1 APS Western Division Office, Goodyear 24.8 24.9 26.6 26.3 25.3 ND ND ND ND 99.1 103.1 ND 2 Scott-Libby School, Perryville and Perryville Roads 22.0 22.9 22.3 18.9 23.4 ND ND ND ND 88.0 87.4 ND 3 Liberty School, 19800 West Highway 85 23.9 24.5 21.7 22.2 25.2 ND ND ND ND 95.4 93.5 ND 4 APS Buckeye Office, 615 North 4th Street, Buckeye 24.4 25.3 24.8 24.5 25.9 ND ND ND ND 97.7 100.6 ND 5 Palo Verde School, 291st Ave and Old US 80 20.1 20.0 19.4 21.3 20.8 ND ND ND ND 80.5 81.5 ND 6 APS Gila Bend Substation, Service Road west of town off I-8 26.6 25.5 24.2 24.8 26.3 ND ND ND ND 106.5 100.7 ND 7 Northeast corner of Old US 80 and Arlington School Road 25.8 25.9 25.0 24.7 28.7 ND ND ND ND 103.2 104.4 ND 8 Southern Pacific Pipeline Road, 1.4 miles SW of 355th Ave 24.3 25.4 22.7 21.3 25.8 ND ND ND ND 97.2 95.1 ND 9 Southern Pacific Pipeline Road, 2.5 miles SW of 355th Ave 28.2 30.0 27.8 22.7 31.6 ND ND ND ND 112.7 112.2 ND 10 Southeast corner of 355th Ave and Elliot Road 24.2 25.7 23.7 21.6 26.2 ND ND ND ND 96.7 97.3 ND 11 Northwest corner of 339th Ave and Dobbins Road 25.2 24.6 25.0 22.3 27.1 ND ND ND ND 100.6 98.9 ND 12 Northeast corner of 339th Ave and Buckeye-Salome Road 23.7 27.9 21.9 23.0 25.8 ND ND ND ND 94.9 98.6 ND 13 North site boundary 25.6 25.9 25.0 21.3 27.4 ND ND ND ND 102.3 99.6 ND 14 North Northeast site boundary 25.3 26.3 25.2 21.5 27.3 ND ND ND ND 101.2 100.3 ND 15 Northeast site boundary, on WRF access road 23.8 27.2 27.3 21.7 24.8 ND ND ND ND 95.1 101.0 ND 16 East Northeast site boundary 23.5 26.3 23.0 22.4 25.2 ND ND ND ND 94.0 96.9 ND 17 East site boundary 25.0 26.2 21.7 22.7 26.5 ND ND ND ND 100.2 97.1 ND 18 East Southeast site boundary 23.3 24.8 21.4 20.5 25.1 ND ND ND ND 93.3 91.7 ND 19 Southeast site boundary 25.2 26.9 22.4 22.7 27.3 ND ND ND ND 100.7 99.2 ND 20 South Southeast site boundary 24.4 26.1 23.3 21.3 27.9 ND ND ND ND 97.7 98.5 ND 21 South site boundary 25.9 30.3 22.7 23.7 28.6 ND ND ND ND 103.7 105.3 ND 22 South Southwest site boundary 26.2 28.9 22.1 23.0 29.0 ND ND ND ND 104.6 103.0 ND 23 23.3 25.4 20.5 22.4 24.6 ND ND ND ND 93.1 2 miles north of Elliot Road, 3 miles west of Wintersburg Road 92.8 ND 24 Elliot Road, 2 miles west of Wintersburg at Desert Farms 22.5 24.8 20.3 19.5 24.3 ND ND ND ND 89.8 88.9 ND 25 Elliot Road, 3.5 miles west of Wintersburg at cattle guard 23.5 24.1 21.4 22.2 25.5 ND ND ND ND 94.1 93.2 ND 26 Duke Power Plant on entry gate 27.9 30.1 26.6 26.3 28.7 ND ND ND ND 111.4 111.6 ND 27 Southwest site boundary 27.1 30.3 24.8 25.0 28.2 ND ND ND ND 108.5 108.3 ND 28 West Southwest site boundary 25.8 27.9 24.7 24.7 27.6 ND ND ND ND 103.2 104.8 ND 29 West site boundary 24.1 26.5 21.2 23.8 27.2 ND ND ND ND 96.6 98.6 ND 30 West Northwest site boundary 26.0 27.9 22.8 24.0 28.1 ND ND ND ND 103.8 102.8 ND 31 Northwest site boundary 23.3 28.0 21.6 20.0 26.7 ND ND ND ND 93.3 96.3 ND 32 North Northwest site boundary 25.3 28.5 24.5 21.3 25.6 ND ND ND ND 101.3 100.0 ND 33 Buckeye Road, 0.5 miles west of 359th Ave 26.0 28.4 25.1 21.9 28.7 ND ND ND ND 104.2 104.2 ND 34 Southeast corner of 395th Ave and Van Buren Road 28.3 30.1 25.6 24.2 30.4 ND ND ND ND 113.1 110.4 ND 35 Palo Verde Inn Fire Station, 40901 W. Osborn Road, Tonopah 31.5 33.9 27.0 28.0 34.0 ND ND ND ND 126.1 122.8 ND 36 Southwest corner of Wintersburg and Van Buren Road 25.9 28.9 24.0 22.9 26.4 ND ND ND ND 103.7 102.3 ND 37 Southeast corner of 363rd Ave and Van Buren Road 24.0 25.9 22.3 20.5 25.9 ND ND ND ND 95.9 94.6 ND 38 27.8 30.6 23.6 25.2 29.7 ND ND ND ND 111.1 109.2 ND 355th Ave, 0.2 miles south of Buckeye Road on east side of rd.

39 343rd Ave, 0.5 miles south of Lower Buckeye Road 24.2 26.4 23.9 22.0 25.9 ND ND ND ND 96.7 98.2 ND 40 Wintersburg, Transmission Road at telephone pole 25.0 26.3 23.8 22.2 27.4 ND ND ND ND 100.1 99.7 ND 41 New Arlington School 26.7 26.1 26.5 22.3 28.7 ND ND ND ND 106.8 103.7 ND 42 Ruth Fisher School, Indian School Road and Wintersburg Road 26.8 27.2 25.1 23.0 27.8 ND ND ND ND 107.4 103.1 ND 43 Winters Well Elementary School 27.6 30.2

• 22.5 29.4 ND

• ND ND 82.8 82.0 ND 1 44 El Mirage, 12315 NW Grand Ave. inside rental center 23.8 27.9

• 24.5 27.7 ND

• ND ND 71.4 80.1 ND 1 45 Palo Verde Central Chemistry Lab, Bldg. E, lead pig 5.2 6.6 6.2 5.5 7.5 ND ND ND ND 21.0 25.9 ND 46 Litchfield Park School, Litchfield & Sagebrush Roads 23.9 24.0 23.8 22.9 24.8 ND ND ND ND 95.7 95.4 ND 47 Littleton School, 115th Ave and Highway 85, Cashion 23.7 23.9 23.4 19.9 24.7 ND ND ND ND 94.9 91.9 ND 48 24.0 24.2 22.6 22.3 24.2 ND ND ND ND 96.0 Jackrabbit Trail S. of I-10, W side of road, S of rental center 93.2 ND 49 Palo Verde Road, 0.25 miles south of I-10 22.6 25.8 21.7 21.1 23.4 ND ND ND ND 90.5 92.0 ND 50 Olinski Road, 2 miles south of Buckeye-Salome Road 19.5 21.9 19.2 17.6 20.9 ND ND ND ND 78.0 79.5 ND NOTE 1:

• The 2 TLDs used for monitoring locations 43 and 44 were missing for 2nd Quarter, 2021. The M A and LA were calculated using 1st, 3rd, and 4th Quarter Data. BA was calculated using BQ*3. Documented with CR 21-08001.

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Figure 9-1 Network Environmental TLD Exposure Rates PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 53

Figure 9-2 Environmental TLD Comparison: Pre-Operational versus 2021 Environmental TLD Comparison: Pre-Operational Versus 2021 35 Control TLD 30 25 20 Control TLD 15 TLD exposure (mrem/std qtr) 10 Pre-op (1984-1985) 2021 Average Transit Control TLD 5

Baseline 0

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 42 45 TLD Number The following TLDs are not included on this graph:

TLD #41 monitoring location was deleted in June, 2000 due to school closing (this TLD was replaced at a new school in 2004)

TLD #43 monitoring location was deleted in 1994 due to school closing (this TLD was placed at a new school in 2007)

TLDs #46-50 are not included since they were not included in the pre-op monitoring program.

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10. Land Use Census 10.1 Introduction In accordance with the PVNGS ODCM, Section 6.2, the field portion of the annual Land Use Census was performed by June 2021.

Observations were made in each of the 16 meteorological sectors to determine the nearest milking animals, residences, and food gardens of greater than 500 square feet that contain broadleaf vegetation.

This census was completed by driving the roads and speaking with residents.

The results of the Land Use Census are presented in Table 10-1 and discussed below. The directions and distances listed are in sectors and miles from the Unit 2 containment.

10.2 Census Results The 2021 Land Use Census results identified new potential Radiological Effluent Release Report dose receptor locations. Each location was evaluated. The changes identified, and the evaluation results, are described below.

Nearest Resident There were three (3) changes in nearest resident status from the previous year. Dose calculations indicated the highest dose to be 0.396 mrem.

Milk Animal There were seven (7) c h a n g e s in milk animal status from the previous year. There were five (5) of the locations that were identified in the census which had the potential for having a dose greater than 20% than that of our current sampling location with the lowest dose potential. The locations were visited by the REMP manager to evaluate program participation potential. As of December 2021, three of the locations had no milk animals. One of the locations potentially had milk animals; however, the animals were obscured by shelter and the property had a guard dog and No Trespassing signs that prevented further investigation or contact with owner. One of the properties was identified as having milk animals; an introduction letter was left with the owner so they can contact the REMP manager if they are interested in joining the program. Dose calculations indicated the highest dose to be 0.647 mrem.

Vegetable Gardens There were four (4) changes in the nearest gardens identified from the previous year. One (1) of the locations that was identified in the census which had the potential for having a dose greater than 20% than that of our current sampling location with the lowest dose potential. The location was visited by the REMP manager to evaluate program participation potential. As of December 2021, the garden is not suitable as a donor location; while it meets the size requirement, the garden has gone fallow and has no visible preparation for the growing season. The resident was not available for in-person contact; however, an introduction letter was sent so that the owner can contact the REMP manager if they are interested in joining the program. Dose calculations indicated the highest dose to be 0.247 mrem.

See Table 10-1 for a summary of the specific results and Table 2-1 for current sample locations. Figure 10-1 through Figure 10-3 provide graphs depicting historical calculated doses for nearest residents, nearest milk receptor, and nearest garden receptor locations in each sector.

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Differences in calculated doses are the result of many variables, including:

• Changes in receptor locations from year to year (proximity to the power plant)

• Changes in local meteorology (wind direction, wind speed, precipitation, and temperature)

• Concurrent meteorology at the time of effluent releases

• Exposure pathways Table 10-1 Land Use Census (Distance and direction are relative to Unit 2 in miles)

Nearest Milk Nearest Nearest Calculated Dose Change from Sector Animal Resident Garden (mrem) 2020 (Cow/Goat)

Resident 3.80E-2 Garden N 1.55 2.16 2.09 Garden 1.79E-1 Milk Milk 2.09E-1 Resident 7.80E-2 Milk NNE 1.52 NONE 3.05 Milk 1.43E-1 Resident 1.09E-1 Resident NE 2.37 NONE 3.08 Milk 4.39E-1 Milk Resident 1.26E-1 Milk ENE 1.91 4.84 2.12 Garden 2.47E-1 Milk 6.47E-1 Resident 9.34E-2 Garden E 2.81 NONE 3.49 Milk 3.61E-1 Resident 9.84E-2 Resident ESE 3.03 NONE 3.37 Milk 5.00E-1 Garden Milk Resident 1.22E-1 Milk SE 3.39 NONE 3.92 Milk 5.84E-1 SSE NONE NONE NONE NA S NONE NONE NONE NA SSW NONE NONE NONE NA SW 1.48 NONE NONE Resident 1.06E-1 Resident 3.96E-1 Resident WSW 1.08 NONE 1.08 Milk 3.96E-1 Resident 5.54E-2 Garden W 0.79 NONE NONE WNW NONE NONE NONE NA Resident 3.56E-2 Milk NW 0.92 NONE 3.42 Milk 5.47E-2 Resident 3.36E-2 NNW 1.31 4.34 3.87 Garden 4.79E-2 Milk 6.38E-2 Comments: Dose calculations were performed using GASPAR code and 2020 meteorological data and source term. Dose reported for each location is the total for all three PVNGS Units and is the highest individual critical organ dose identified.

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Historical Comparison of Nearest Resident Dose 6.00E-01 5.00E-01 2021 2020 4.00E-01 2019 2018 2017 3.00E-01 2016 mRem/year 2015 2.00E-01 2014 2013 2012 1.00E-01 0.00E+00 N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Sector Figure 10-1 Historical Comparison of Nearest Resident Dose Historical annual average most prevalent wind direction is from the SW; the next highest is from the N. This contributes to the higher doses assigned to residents in the S sector. The 2017 Land Use Census identified potential garden pathway for the nearest resident in the NE Sector and the 2019 and 2020 Land Use Census identified a potential milk pathway for the nearest resident in the ENE sector; dose is reflective of the assumption of direct radiation and ingestion pathway.

Historical annual average least prevalent wind direction is from the SE; the second least prevalent is from the ESE. This contributes to the lower doses assigned to the residents in the WNW, NW, and NNW sectors.

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Historical Comparison of Nearest Milk Animal Dose 1.20E+00 2021 1.00E+00 2020 2019 8.00E-01 2018 2017 6.00E-01 2016 mRem/year 2015 4.00E-01 2014 2013 2.00E-01 2012 0.00E+00 N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Sector Figure 10-2 Historical Comparison of Nearest Milk Animal Dose Milk animals include goats and/or cows. No milk samples have indicated any plant-related radionuclides. Additionally, milk animals in the desert environment are normally fed stored feed and are not on pasture. The calculated doses are conservative due to the inclusion of pastured feed as part of the calculation.

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Historical Comparison of Nearest Garden 9.00E-01 2021 8.00E-01 2020 7.00E-01 2019 2018 6.00E-01 2017 5.00E-01 2016 mRem/year 2015 4.00E-01 2014 3.00E-01 2013 2012 2.00E-01 1.00E-01 0.00E+00 N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Sector Figure 10-3 Historical Comparison of Nearest Garden Dose Gardens have been sporadically identified from year to year. Gardening is not prevalent in the desert environment.

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11. Summary and Conclusions Summary The conclusions are based on a review of the radioassay results and environmental gamma radiation measurements for the 2021 calendar year. Where possible, the data were compared to pre-operational sample data.

All sample results for 2021 are presented in Table 8-1 through Table 8-12 and do not include observations of naturally occurring radionuclides, with the exception of gross beta in air and gross beta in drinking water. Table 11-1 summarizes the ODCM required samples and is in the format required by the NRC BTP on Environmental Monitoring.

I-131 identified in the evaporation ponds, Water Resources influent, Water Resources centrifuge sludge, and reservoirs is the result of offsite sources and appears in the effluent sewage from Phoenix. The levels of I-131 detected in these locations are consistent with levels identified in previous years.

Cs-137 was detected in the primary and secondary samples of the Evaporation Pond 3A sample. The averaged sample result was 69 pCi/L +/- 11 pCi/L. The required lower limit of detection for Cs-137 in water is 18 pCi/L; the ODCM action level for Cs-137 in water is 50 pCi/L. This event was thoroughly evaluated and documented with Evaluation 21-08443-001. The following is a summary of the conclusion:

Evap Pond 3A is in the process of being drained for repairs. The pond is secured from public access and the water is contained in the Evap Pond. There is no leak to the environment and does not pose a pathway for public consumption.

The source of inputs to the pond were evaluated. The volume of water with the detectable activity was of negligible quantity (approximately 1.5E+6 gallons of released water) when compared to a single ponds capacity (approximately 1.0E+9). Assuming the entire water contribution was deposited into Evap Pond 3A, that volume represents 0.15% of the total pond capacity; however, evidence indicates that little, to none, of this activity was released to Evap Pond 3A from plant operations. There is no indication of Plant related Cs-137 from airborne effluent in the REMP data.

Several data points exist for detectable Cs-137 in the pre-operational studies and monitoring of the 2011 Fukushima Daiichi release. The permeability of the area soil, as well as cesiums affinity to bind to sediment, leads to highest concentrations of cesium being identified in the top 2 inches of undisturbed soil. This activity can therefore be redistributed via high wind events. Given the data that demonstrates a lack of source material from Plant related effluent, there is no indication that the Cs-137 concentration identified in the Evap Pond 3A is Plant related.

Salt sampling from Evap Pond 3A have yielded no detectable Cs-137 activity. Given the propensity for cesium to stay bound to sediment once binding has occurred, and the probability for cesium to precipitate out if introduced as liquid influent, the lack of activity found in any of the salt samples is further indication that the Cs-137 is not Plant related. A pocket of water was also found while conducting salt sampling that was isolated from the surface water. The water would have been from early operation of Evap Pond 3A and it had no detectable Cs-137. This is further indication that the activity found is the result of sediment being blown into the pond from the surrounding environment.

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Multiple sources have indicated there are detectable levels of Non-Plant related Cs-137 in the soil and sediment surrounding Palo Verde. When reviewing liquid influent into the pond and potential airborne sources from the Plant, as well as the review of salt sample taken from within the pond, there is no credible mechanism to attribute the elevated Cs-137 to the operation of Palo Verde.

Tritium concentrations identified in surface water onsite have been attributed to PVNGS permitted gaseous effluent releases and secondary plant releases. These concentrations are consistent with historical values.

Environmental radiation levels are consistent with measurements reported in previous Pre-operational and Operational Radiological Environmental annual reports, References 1 and 2.

Conclusion There was no measurable radiological impact on the environment in 2021 resulting from the operation of PVNGS.

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Table 11-1 Environmental Radiological Monitoring Program Annual Summary TABLE 11.1 ENVIRONMENTAL RADIOLOGICAL MONITORING PROGRAM ANNUAL

SUMMARY

Palo Verde Nuclear Generating Station Docket Nos. STN 50-528/529/530 Maricopa County, Arizona Calendar Year 2021 Medium or Type and Total Lower All Location with Highest Control Number of Pathway Number of Limit of Indicator Annual Mean Locations Nonroutine Sampled Analyses Detection Locations Reported (Unit of Performed (LLD) Measurements Measurement) (from Table Mean (f)a Name Mean Mean (f)a 6.1) Range (f)a Range Distance and Range Direction Direct TLD - 198 NA 24.9 Site #35 30.7 (4/4) 26.7 (7/8) 0 Radiation (187/188)

(mrem/std. 17.6 - 34.0 8 miles 27.0 - 34.0 24.2 - 27.9 qtr.) 330q Air Gross Beta - 520 0.01 0.031 Site # 4 0.032 0.033 (52/52) 0 Particulates (468/468) (52/52)

(pCi/m3) 0.014 - 16 miles 0.014 - 0.015 - 0.068 0.065 92º 0.064 Gamma Spec Composite - 40 Cs-134 0.05 <LLD NA <LLD <LLD 0 (quarterly)

<LLD NA <LLD <LLD Cs-137 0.06 <LLD NA <LLD <LLD 0 (quarterly)

<LLD NA <LLD <LLD Air Gamma Spec. -

Radioiodine 520 (pCi/m3) I-131 0.07 <LLD NA <LLD <LLD 0 Broadleaf Gamma Spec. - 25 Vegetation I-131 60 <LLD NA <LLD <LLD 0 (pCi/Kg-wet) Cs-134 60 <LLD NA <LLD <LLD 0 Cs-137 80 <LLD NA <LLD <LLD 0 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 62

Groundwater H 12 2000 <LLD NA <LLD NA 0 (pCi/liter)

Gamma Spec. - 12 Mn-54 15 <LLD NA <LLD NA 0 Fe-59 30 <LLD NA <LLD NA 0 Co-58 15 <LLD NA <LLD NA 0 Co-60 15 <LLD NA <LLD NA 0 Zn-65 30 <LLD NA <LLD NA 0 Zr-95 30 <LLD NA <LLD NA 0 Nb-95 15 <LLD NA <LLD NA 0 I-131 15 <LLD NA <LLD NA 0 Cs-134 15 <LLD NA <LLD NA 0 Cs-137 18 <LLD NA <LLD NA 0 Ba-140 60 <LLD NA <LLD NA 0 Gross Beta - 48 4 3.18 (48/48) Site #55 3.87 (12/12) NA 0 2.50 - 7.44 3 miles 2.79 -7.44 214q H 16 2000 <LLD NA <LLD NA 0 Gamma Spec. - 48 Drinking Mn-54 15 <LLD NA <LLD NA 0 Water Fe-59 30 <LLD NA <LLD NA 0 (pCi/liter)

Co-58 15 <LLD NA <LLD NA 0 Co-60 15 <LLD NA <LLD NA 0 Zn-65 30 <LLD NA <LLD NA 0 Zr-95 30 <LLD NA <LLD NA 0 Nb-95 15 <LLD NA <LLD NA 0 I-131 15 <LLD NA <LLD NA 0 Cs-134 15 <LLD NA <LLD NA 0 Cs-137 18 <LLD NA <LLD NA 0 Ba-140 60 <LLD NA <LLD NA 0 La-140 15 <LLD NA <LLD NA 0 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 63

Milk Gamma Spec. - 34 (pCi/liter)

I-131 1 <LLD NA <LLD <LLD 0

<LLD NA <LLD <LLD Cs-134 15 <LLD NA <LLD <LLD 0

<LLD NA <LLD <LLD Cs-137 18 <LLD NA <LLD <LLD 0

<LLD NA <LLD <LLD Ba-140 60 <LLD NA <LLD <LLD 0 La-140 15 <LLD NA <LLD <LLD 0 Surface Water Gamma Spec. - 22 (pCi/liter) Mn-54 15 <LLD NA <LLD NA 0 Fe-59 30 <LLD NA <LLD NA 0 Co-58 15 <LLD NA <LLD NA 0 Co-60 15 <LLD NA <LLD NA 0 Zn-65 30 <LLD NA <LLD NA 0 Zr-95 30 <LLD NA <LLD NA 0 Nb-95 15 <LLD NA <LLD NA 0 I-131 15 <LLD NA <LLD NA 0 Cs-134 15 <LLD NA <LLD NA 0 Cs-137 18 69(1/18) Site #64 69 (2/2) NA 1 69-69 Onsite 190º 51 - 87 Ba-140 60 <LLD NA <LLD NA 0 La-140 15 <LLD NA <LLD NA 0 H 25 3000 873 (9/22) Site #59 955 (3/3) NA 0 688-1029 Onsite 190q 876-1029 (a) Mean and range based upon detectable measurements only. Fraction of detectable measurements at specified locations is indicated in parentheses. (f)

NOTE: Miscellaneous samples that are not listed on Tables 2.1 and 9.1 (not ODCM required) are not included on this table.

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12. References

1. Pre-Operational Radiological Monitoring Program, Summary Report 1979-1985

2. 1985-2020 Annual Radiological Environmental Operating Reports, Palo Verde Nuclear Generating Station

3. Palo Verde Nuclear Generating Station Technical Specifications and Technical Reference Manual

4. Offsite Dose Calculation Manual, Revision 29, PVNGS Units 1, 2, and 3

5. Regulatory Guide 4.1, Programs for Monitoring Radioactivity in the Environs of Nuclear Power Plants

6. Regulatory Guide 4.8, Environmental Technical Specifications for Nuclear Power Plants

7. NRC Radiological Assessment Branch Technical Position on Environmental Monitoring, Revision 1, November 1979 (Incorporated into NUREG-1301)

8. "Sources of Radiation." NRC: Sources of Radiation. Nuclear Regulatory Commission, 20 March.

2020. Web. 22 Feb. 2022.

9. "NCRP Report No. 160: Ionizing Radiation Exposure of the Population of the United States."

Journal of Radiological Protection J. Radiol. Prot. 29.3 (2009): 465. Web.

10. NEI 07-07, Nuclear Energy Institute, Industry Groundw ater Protection Initiative - Final Guidance Document, Rev. 1, March 2019 PVNGS ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT- 2021 Page 65

13. APPENDIX A: ERRATICA An abnormal event, occurring in 2019, was not included in Table 2-3 of the 2019 AREOR. The 4th Quarter 2019 Evap Pond 3A sample exceeded the procedural Action/Reporting Levels for Radioactivity Concentrations in Environmental Samples found in Appendix B of 74RM-0EN09, Quarterly Radiological Environmental Sample Analysis Verification. This sample did not exceed the ODCM Reporting level of 50 pCi/L; however, the procedural Action Level of 30 pCi/L was exceeded and qualifies as a REMP Deviation/Abnormal Event. The data was included in the 2019 AREOR, Table 8-10, and discussed in Section 11, Summary and Conclusions. This event should have also been included in Table 2-3, Summaries of the REMP Deviations/Abnormal Events.

As stated in the Summary and Conclusions section of the 2019 AREOR, Cs-137 was detected in one Evaporation Pond 3A sample. The sample result was 41 pCi/L +/- 9 pCi/L. The required lower limit of detection for Cs-137 in water is 18 pCi/L; the action level for Cs-137 in water is 50 pCi/L. Evaporation Pond 3A has not received any influent during 2019 and is being drained to another evaporation pond to make repairs to the top liner. The water inventory in Evaporation Pond 3A is low, such that sediment that has collected in the pond was unavoidably collected in the sample. Cs-137 is known to bind to sediment, and the levels detected in the water sample is consistent with what was found in the preoperational soils in the surrounding area as a result of atmospheric bomb testing.

The failure to report in Table 2-3 of the 2019 AREOR is documented with CR 21-09933.

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