ZS-2019-0037, Independent Spent Fuel Storage Installation - Annual Radiological Groundwater Protection Program Report, 1 January Through 31 December 2018

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Independent Spent Fuel Storage Installation - Annual Radiological Groundwater Protection Program Report, 1 January Through 31 December 2018
ML19129A131
Person / Time
Site: Zion, 07201031  File:ZionSolutions icon.png
Issue date: 05/06/2019
From:
Teledyne Brown Engineering Environmental Services, ZionSolutions
To:
Office of Nuclear Material Safety and Safeguards
References
ZS-2019-0037
Download: ML19129A131 (51)
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Text

Docket No: 50-295 50-304 72-1037 ZION NUCLEAR POWER STATION Annual Radiological Groundwater Protection Program Report 1 January through 31 December 2018

. Prepared By Teledyne Brown Engineering Environmental Services

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Zion Nuclear Power Station Zion, IL 60099 May 2019 2018 Zion GWPPR

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Table Of Contents I. Summary and Conclusions ............................. :.................................... :........................... 1 II. Introduction ..................................................................................................................... 3 A. Objectives of the RGPP ................................................. '. ..................................... 3 B. Implementation of the Objectives ........................................................................ 3 C. Program Description ................................... :........................................................ 4 D. Characteristics of Tritium (H-3) ........................................................................... 5 Ill. Program Description ...................................................................................................... 6 A. Sample Analysis .................................................................................................. 6 B. Data Interpretation ................................................................._. ............................. 6 C. Background Analysis ........................................................................................... 7

1. Background Concentrations of Tritium ..................................................... 8 .

IV. Results and Discussion ...................................................... :........................................ : 11 A. Missed Samples .......................................................................... :..................... 11 B. Groundwater and Surface Water Results .......................................................... 11 C. Drinking Water Well Survey .............................................................................. 13 D. Summary of Results - Inter-laboratory Comparison Program .......................... 13 E. Leaks, Spills, and Releases ..............................*...................... ,......................... 13 F. Trends ................................................................................................................ 13 G. Investigations .................................................................................................... 13 H. Actions Taken .................................................................................................... 14 2018 Zion GWPPR

Appendices Appendix A Zion Well Locations Tables Table A-1 Radiological Groundwater Protection Program - Sampling Locations

-- and Distance, Zion Nuclear Power Station, 2018 Figures Figure A-1 Radiological Groundwater Protection Program Groundwater and Surface Water Locations of the Zion Nuclear Power Station, 2018 Appendix 8 Data Tables Tables Table 8-1.1 Concentrations of Tritium, Strontium, Gross Alpha and Gross Beta in Groundwater Samples Collected in the Vicinity of Zion Nuclear Power Station, 2018 Table 8-1.2 Concentrations of Gamma Emitters in Groundwater Samples Collected in the Vicinity of Zion Nuclear Power Station, 2018 Table 8-1.3 Concentrations of lron-55 and Nickel-63 in Groundwater Samples Collected in the Vicinity of Zion Nuclear Power Station, 2018 Table 8-11.1 Concentrations of Tritium, Strontium, Gross Alpha and Gross Beta in Surface Water Samples Collected in the Vicinity of Zion Nuclear Power Station, 2018 Table 8-11.2 Concentrations of Gamma Emitters in Surface Water Samples Collected in the Vicinity of Zion Nuclear Power Station, 2018 Table 8-11.3 Concentrations of lron-55 and Nickel-63 in Surface Water Samples Collected in the Vicinity of Zion Nuclear Power Station, 2018 ii 2018 Zion GWPPR

I. Summary and Conclusions In 2006, Exelon instituted a comprehensive program to evaluate the impact of station operations on groundwater and surface water in the vicinity of Zion Nuclear Power Station. This report covers both groundwater and surface water samples, collected from the environment, on station property in 2018. During that time period, 491 analyses were performed on 46 samples from 11 locations. Phase 1 of the monitoring was part of a comprehensive study initiated by Exelon to determine whether groundwater or surface water at and in the vicinity of Zion Nuclear Power Station had been adversely impacted by any releases of radionuclides. Phase 1 was conducted by Conestoga Rovers and-Associates (CRA) and the conclusions were made available to state and federal regulators as well as the public in station specific reports.

Phase 2 of the RGPP was conducted by ZionSolutions (Exelon was responsible for the program up to 8/31/2010; ZionSolutions became the licensee on 9/1/2010, thus assuming responsibility for the RGPP) personnel to initiate follow up of Phase 1 and begin long-term monitoring at groundwater and surface water locations selected during Phase 1. All analytical results from Phase 2 monitoring are reported herein.

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

Naturally-occurring Potassium-40 (K-40) was detected in 1 surface water and 2 groundwater samples. No other gamma-emitting radionuclides were detected at concentrations greater than their respective Lower Limits of Detection (LLDs) as specified in the Offsite Dose Calculation Manual (ODCM) in any of the groundwater or surface water samples. Strontium-90 was not detected in any of the samples analyzed in 2018.

Tritium was not detected in any surface water samples analyzed in 2018.

Tritium was detected in 7 groundwater samples. This first appearance of tritium in groundwater at Zion Station since the NRG Part 50 license was transferred to Zion Solutions and is reviewed and discussed in Section G of this report, Investigations.

Gross Alpha and Gross Beta analyses in the dissolved and suspended fractions were performed on 1 surface water and 10 groundwater locations during all four quarters of sampling in 2018. Gross Alpha (dissolved) and Gross Alpha (suspended) were not detected at any of the locations. Gross Beta (dissolved) was detected in all 46 samples. The surface water concentrations ranged from 1.9 to 2.2 pCi/L. The groundwater concentrations ranged from 2.9 to 16.3 2018 Zion GWPPR

pCi/L. Gross Beta (suspended) was not detected in any of the surface or groundwater locations.

lron-55 (Fe-55), Nickel-59 (Ni-59), and Nickel-63 (Ni-63) analyses were performed in 2018 on 46 samples from 10 groundwater and 1 surface water location. All results were less than their respective LLDs.

2018 Zion GWPPR

II. Introduction The Zion Nuclear Power Station (ZNPS), consisting of two 1,100 MWt pressurized water reactors was owned and operated by Exelon Corporation, is located in Zion, Illinois adjacent to Lake Michigan. Unit No. 1 went critical in December 1973. Unit No. 2 went critical in September 1974. The plant permanently ceased operation in January of 1998 and has been permanently defueled. The site is located in northeast Illinois on the western shore of Lake Michigan, approximately 50 miles north of Chicago, Illinois, and is currently in the final stages of decommissioning, where all structures have been demolished and the station is in the last stages of Final Status Survey (FSS) and working with the Nuclear Regulatory Commission to terminate the Station's 10 CFR Part 50 license.

This report covers those analyses performed by Teledyne Brown Engineering

  • (TBE) and Environmental Inc. (Midwest Labs) on samples collected in 2018.

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

1. Identify suitable locations to monitor and evaluate potential impacts from station operations before significant radiological impact to the environment and potential drinking ,water sources.
2. Understand the local hydrogeologic regime in the vicinity of the station and maintain up-to-date knowledge of flow patterns on the surface and shallow subsurface.
3. Perform routine water sampling and radiological analysis of water .

from selected locations.*

4. Report new leaks, spills, or other events with potential radiological significance to stakeholders in a timely manner.
5. Regularly assess analytical results to identify adverse trends.
6. Take necessary corrective actions to protect groundwater resources.
7. The RGPP supports implementation of License Termination Plan (LTP) requirements for groundwater characterization and ultimately groundwater compliance under the LTP for site release.

B. Implementation of the Objectives The objectives identified have been implemented at Zion Nuclear Power 2018 Zion GWPPR

Station as discussed below:

1. Exelon and its consultant identified locations as described in the Phase 1 study. Phase 1 studies were conducted by Conestoga Rovers and Associates (CRA) and the results and conclusions were made available to state and federal regulators as well as the public in station specific reports.
2. The Zion Nuclear Power Station reports describe the local hydrogeologic regime. Periodically, the flow patterns on the surface and shallow subsurface are updated based on ongoing measurements. The 5-year hydrogeological report was conducted in 2016.
3. Zion Nuclear Power Station will continue to perform routine sampling and radiological analysis of water from selected locations.
4. Zion Nuclear Power Station has continued using established procedures to identify and report new leaks, spills, or other detections with potential radiological significance in a timely manner.
5. Zion Nuclear Power Station staff and consulting hydrogeologist assess analytical results on an ongoing basis to identify adverse trends.

C. Program Description

1. Sample Collection Sample locations can be found in Table A-1 and Figure A-1, Appendix A.

Groundwater and Surface Water Samples of water are collected, managed, transported and analyzed in accordance with approved procedures following EPA methods. Groundwater samples were collected by Environmental Inc. (Midwest Labs). Sample locations, sample collection frequencies and analytical frequencies are controlled in accordance with approved station procedures. Contractor and/or station personnel are trained in the collection, preservation management, and shipment of samples, as well as in documentation of sampling events. Analytical laboratories are subject to internal quality assurance programs, industry cross-2018 Zion GWPPR

check programs, as well as nuclear industry audits. Station personnel review and evaluate all analytical data deliverables as data are received.

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

D. Characteristics of Tritium (H-3)

Tritium (chemical symbol H-3) is a radioactive isotope of hydrogen. The most common form of tritium is tritium oxide, which is also called "tritiated water". The chemical properties of tritium are essentially those of ordinary hydrogen ..

Tritiated water behaves the same,as ordinary water in both the environment and the body. Tritium can be taken into the body by drinking water, breathing air, eating food, or absorption through skin.

Once tritium enters the body, it disperses quickly and is uniformly distributed throughout the body. Tritium is excreted primarily through urine with a clearance rate characterized by an effective biological half-life of about 14 days. Within one month or so after ingestion, essentially all tritium is cleared. Organically bound tritium (tritium that is incorporated in organic compounds) can remain in the body for a longer period.

Tritium is produced naturally in the upper atmosphere when cosmic rays strike air molecules. Tritium is also produced during nuclear weapons explosions, as a by-product in reactors producing electricity, and in special production reactors, where the isotopes lithium-7 and/or boron-10 are activated by neutron flux, resulting in the production of tritium. Like normal water, tritiated water is colorless and odorless. Tritiated water behaves chemically and physically like non-tritiated water in the subsurface, and therefore tritiated water will travel at the same velocity as the average groundwater velocity.

Tritium has a half-life of approximately 12.3 years. It decays spontaneously to Helium-3 (He-3). This radioactive decay releases a beta particle (low-energy electron). The radioactive decay of tritium is the source of the health risk from exposure to tritium. Tritium is one of the least dangerous radionuclides because it emits very weak radiation and leaves the body relatively quickly. Since tritium is almost always found as water, it goes directly into soft tissues and organs. The associated dose to these tissues is generally uniform and is dependent on the water content of the specific tissue.

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Ill. Program Description A. Sample Analysis This section describes the general analytical methodologies used by TSE to analyze the environmental samples for radioactivity for the Zion Nuclear Power Station RGPP in 2018. In order to achieve the stated objectives, the current program includes the following analyses:

1. Concentrations of gamma emitters in groundwater and surface water
2. Concentrations of strontium in groundwater and surface water
3. Concentrations of tritium in groundwater and surface water
4. Concentration of gross alpha and gross beta in groundwater and surface water
5. Concentrations of lron-55 in groundwater and surface water
6. Concentrations of Nickel-59 and Nickel-63 in groundwater and surface water
8. Data Interpretation The radiological data collected prior to Zion Nuclear Power Station becoming operational were used as a baseline with which these operational data were compared. For the purpose of this report, Zion Nuclear Power Station was considered operational at initial criticality ..

Several factors were important in the interpretation of the data:

1. Lower Limit of Detection and Minimum Detectable Concentration The lower limit of detection (LLD) is specified by federal regulation as a minimum sensitivity value that must be achieved routinely by the analytical parameter.
2. Laboratory Measurements Uncertainty The estimated uncertainty in measurement of tritium in environmental samples is frequently on the order of 50% of the measurement value.

Statistically, the exact value of a measurement is expressed as a range with a stated level of confidence. The convention is to 2018 Zion GWPPR

report results with a 95% level of confidence. The uncertainty comes from calibration standard stated accuracy, sample volume or weight measurements, sampling uncertainty and other factors.

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

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

C. Background Analysis A pre-operational Radiological Environmental Monitoring Program (pre-operational REMP) was conducted to establish background radioactivity levels prior to operation of the Station. The environmental media sampled and analyzed during the pre-operational REMP were atmospheric radiation, fall-out, domestic water, surface water, marine life, and foodstuffs. The results of the monitoring were detailed in the report entitled, Environmental Radiological Monitoring for Zion Nuclear Power Station, Commonwealth Edison Company, Annual Report 1973, issued May 1974.

The pre-operational REMP contained analytical results from samples collected from the surface water and groundwater.

Tritium levels in Lake Michigan water were studied in the vicinity of Zion Station throughout 1970. The concentration of tritium in the surface water samples from the Lake at Zion ranged from approximately 311 +/-

20 pCi/L to 374 +/- 34 pCi/L and averaged 340 pCi/L. There was no statistical difference in average tritium concentrations among the stations (eight stations from Kenosha to Waukegan).

Prior to 1998, surface water samples were collected at the following six locations along Lake Michigan:

  • Kenosha, Wisconsin (intake located 10 miles north of the station)
  • Lake County Public Water District (intake located 1.1 miles north of the Station)
  • Waukegan, Illinois (intake located 6 miles south of the Station)
  • North Chicago, Illinois (intake located 10 miles south of the Station)
  • Great Lakes NTS (intake located 13 miles south of the Station)
  • Lake Forest, Illinois (intake located 16.5 miles south of the Station)

After 1998, surface water samples were collected at the following four 2018 Zion GWPPR

locations along Lake Michigan:

  • Kenosha, Wisconsin (intake located 10 miles north of the station)
  • Lake County Public Water District (intake located 1.1 miles north of the Station)
  • Waukegan, Illinois (intake located 6 miles south of the Station)
  • Lake Forest, Illinois (intake located 16.5 miles south of the Station)

Lake Michigan surface water data are collected as part of the REMP.

Tritium concentrations in surface water samples from Lake Michigan taken between 1973 and 2018 have ranged from non-detect to 660 pCi/L.

Groundwater was collected from one off-site well on a quarterly basis.

Gamma isotopic, lron-:55, Nickel-59, Nickel-63, Strontium-90 and tritium analyses were performed on all samples. Fe-55, Ni-59, Ni-63, Sr-90, tritium and gamma emitters were below their respective LLDs.

1. Background Concentrations of Tritium .

The purpose of the following discussion is to summarize background measurements of tritium in various media performed by others. Additional detail may be found by consulting references (CRA 2006).

a. Tritium Production Tritium is created in the environment from naturally-occurring processes both cosmic and subterranean, as well as from anthropogenic (i.e., man-made) sources. In the upper atmosphere, "Cosmogenic" tritium is produced from the bombardment of stable nuclides and combines with oxygen to form tritiated water, which will then enter the hydrologic cycle.

Below ground, "lithogenic" tritium is produced by the bombardment of natural lithium present in crystalline rocks by neutrons produced by the radioactive decay of naturally abundant uranium and thorium. Lithogenic production of tritium is usually negligible compared to other sources due to the limited abundance of lithium in rock. The lithogenic tritium is introduced directly to groundwater.

A major anthropogenic source of tritium and Sr-90 comes from the former atmospheric testing of thermonuclear

  • weapons. Levels of tritium in precipitation increased significantly during the 1950s and early 1960s, and later with additional testing, resulting in the release of significant 2018 Zion GWPPR

amounts of tritium to the atmosphere. The Canadian heavy water nuclear power reactors, other commercial power

. reactors, nuclear research and weapons production continue to influence tritium concentrations in the environment.

b. Precipitation Data Precipitation samples are routinely collected at stations around the world for the analysis of tritium and other radionuclides. Two publicly available databases that provide tritium concentrations in precipitation are Global Network of Isotopes in Precipitation (GNIP) and USEPA's RadNet database. GNIP provides tritium precipitation concentration data for samples collected worldwide from 1960 to 2018.

RadNet provides tritium precipitation concentration data for samples collected at stations throughout the U.S. from 1960 up to and including 2018. Based on GNIP data for sample stations located in the U.S. Midwest, tritium concentrations peaked around 1963. This peak, which approached 10,000 pCi/Lfor some stations, coincided with the atmospheric testing of thermonuclear weapons. Tritium concentrations in surface water showed a sharp decline up until 1975 followed by a gradual decline since that time. Tritium concentrations in Midwest precipitation have typically been below 100 pCi/L since around 1980. Tritium concentrations in wells may still be above the 200 pCi/L detection limit from the external causes described above. Water from previous years and decades is naturally captured in groundwater, so some well water sources today are affected by the surface water from the 1960s that were elevated in tritium.

c. Surface Water Data Tritium concentrations are routinely measured in large surface water bodies, including Lake Michigan and the Mississippi River. Illinois surface water data were typically less than 100 pCi/L.

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

According to USE PA, this corresponds to a +/- 70 to 100 pCi/L 95% confidence bound on each given measurement.

Therefore, the typical background data provided may be subject to measurement uncertainty of approximately +/- 70 to 100 pCi/L.

2018 Zion GWPPR

The radio-analytical laboratory is counting tritium results to an Exelon specified LLD of 200 pCi/L. Typically, the lowest positive measurement will be reported within a range of 40 to 240 pCi/L or 140 +/- 100 pCi/L. Clearly, these sample resuits

  • cannot be distingu'ished as different from background at this concentration.

2018 Zion GWPPR

IV. Results and Discussion A. Missed Samples There were no missed samples in 2018.

B. Groundwater and Surface Water Results Groundwater and Surface Water Samples were collected from on-site wells throughout the year in accordance with the station radiological groundwater protection program.

Analytical results and anomalies are discussed below:

Tritium Samples from all locations were analyzed for tritium activity (Table B-1.1, Appendix B) (Table B-11.1, Appendix B). Tritium was not detected in any surface water samples analyzed. Tritium was detected in 7 groundwater samples. The concentrations ranged from 208 - 507 pCi/L. Zion Nuclear Power Station does not have any off-site wells. This was the first time tritium had been detected at levels greater than the a posteri MDAs since the NRG license was transferred from Exelon to Zion Solutions in September, 2010. A level 2 Condition Report was written, and an investigation was conducted to identify the source of the tritium.

As part of the condition report process, and investigation review was conducted to identify the reason for the sudden appearance of tritium in the well furthest from all the demolition activity, specify corrective actions, and communicate lessons learned. The results of the investigation may be found in Section G. of this report, Investigations.

Strontium Sr-90 was not detected in any of the samples analyzed in 2018.

lron-55 was not detected in any of the samples analyzed in 2018.

Nickel Nickel-59 and Nickel-63 were not detected in any of the samples analyzed in 2018.

2018 Zion GWPPR

Gross Alpha and Gross Beta (Dissolved and Suspended)

Gross Alpha and Gross Beta analyses in the dissolved and suspended fractions were performed on 1 surface water and 11 groundwater locations during all four quarters of sampling in 2018. Gross Alpha (dissolved) and Gross Alpha (suspended) were not detected at any of the locations. Gross Beta (dissolved) was detected in all 46 samples.

The surface water concentrations ranged from 1.9 to 2.2 pCi/L. The groundwater concentrations ranged from 2.9 to 16.3 pCi/L. Gross Beta (suspended) was not detected in any of the surface or groundwater locations.

Gamma Emitters Naturally-occurring K-40 was detected in 3 of 46 samples analyzed. The concentrations ranged from 56 to 91 pCi/L. All other gamma-emitting radionuclides were not detected in either groundwater or surface water samples analyzed (Table B-1.2, Appendix B) (Table 8-11.1, Appendix B).

Other Naturally-occurring and Non-plant-Related Isotopes Gross beta activity, present in the environment, may be detected from the following sources: Beryllium-? (Be-7), Potasium-40 (K-40) and the decay products of naturally-occurring uranium and thorium (radon daughters), for example. There are also non-Zion plant-related, manmade sources such as Cesium-137 (Cs-137) and Stronium-90 (Sr-

90) (sources: above ground testing of nuclear weapons, commercial plant accidents such as Chernobyl and Fukashima). Tritium, which is man-made in fission reactors, but also occurs naturally, is created in the upper atmosphere when cosmic radiations interact with nitrogen .atoms, and reaches the ground by precipitation. Although a beta (electron) emitter, tritium is.not detected by gross beta analysis due to the weak energy of the beta particle emitted, and the nature of gross beta analysis.

It is, however, measured accurately at very low levels using liquid scintillation analysis.

Normally, gross beta is used as a screening tool and when elevated levels are identified, further investigative analysis follows. The Zion GWPP program requires completing these additional analysis for Cs-137, Sr-90, H-3, and other beta, gamma and alpha emitters specifically, in addition to analyzing for gross beta and regardless of gross beta levels, as it is not unusual to see spikes in natural gross beta due to a sudden release of radon or other natural radionuclides from soil or well/surface water, or washout from a heavy rain event.

2018 Zion GWPPR

C. Drinking Water Well Survey A drinking water well survey was conducted during the summer 2006 by CRA (CRA 2006) around the Zion Nuclear* Power Station.

D. Summary of Results - Inter-Laboratory Comparison Program Inter-Laboratory Comparison Program results for TBE are presented in theAREOR.

E. Leaks, Spills, and Releases There were no leaks, spills or non-permitted releases in 2018.

F. Trends There are no previously identified plumes; therefore, there are no trends.

G. Investigations With detectable tritium appea~ing in Well 08S with the first quarter round of GW sampling on 2/18/18, an investigation was launched to identify the

.source and path of the contaminant at trace, but detectable levels. The presence of tritium at this well location was unexpected as it was furthest from the former protected area and wells sampled within the former protected area continued to provide tritium results less than MDA.

Following resampling and reanalysis, a Condition Report was written (CR-2018- 0166) and issued, and an Issue Review (IR-2018-0590) conducted to provide a summary of the cause, develop and assign actions to prevent recurrence and permit closure of the condition report.

In summary, the results of the investigation were as follows: early in the third quarter of 2017, two dewatering wells were established on the west side of the Fuel Handling Building footprint to minimize ground water in-leakage to the Auxiliary Building. Minimizing ground water intrusion to the Auxiliary Building was necessary to permit performance of radiation surveys of the basement structure(s) in support of Final Status Survey, remediation efforts and general worker safety. The groundwater pumped from the dewatering wells was pumped to silt pillows located on the west side of the containment structures near storm drains supporting the Switchyard. (See Appendix A, Figure A-2)

Storm drains within the radiologically controlled area simply drain to ground and would not have alleviated the in leakage, so directing ground water from the area surrounding the Auxiliary Building to the Switchyard storm drains would facilitate efforts to keep the Aux Building basement 2018 Zion GWPPR

free of groundwater, and permit completion of demolition, remediation

  • and surv~ys.

Water pumped out was sampled and analyzed for gamm~ emitters, but not tritium when dewatering wells were put into service. When water pumped from the dewatering wells was analyzed for tritium at an MDA that was at NEI 07-07 recommended sensitivities for groundwater monitoring, trace levels oftritium were identified just above MDA in May 2018 in water pumped to pillows.

At the time, the destination of storm water flowing through the Switchyard storm drains was not clearly understood. A dye test was performed and identified the endpoint at a drainage ditch located 50 feet from well OBS (see F,igure 1) It is hypothesized that tritium in the Auxiliary Building basement concrete leached from the structure into accumulated rainwater that intermingled with groundwater surrounding this structure, and made to well OBS via the Switchyard storm drain system*

The ground water travel rate estimated by Conestoga Rover, Inc. for Zion station ranged from 50 to 100 feet per year which meant travel time from the drainage ditch to well OBS would be between six (6) and twelve

( 12) months. The initial detection of tritium appeared seven (7) months after the dewatering wells were put in service. The pump out of groundwater continued over a four to six month period, which is approximately the same duration tritium was identified at levels just above the MDA at well OBS before returning to previous <MDA levels, where it remains. For a complete description of the investigation and results, the reader is referred to IR 2018 0590, issued 11/5/2018.

H Actions Taken

1. Compensatory Actions There have been no station events requiring compensatory actions at the Zion Nuclear Power Station.
2. Installation of Monitoring Wells No new wells were required to be installed.
3. Actions to Recover/Reverse Plumes There have been no station events requiring actions to recover/reverse any plumes.

2018 Zion GWPPR

APPENDIX A ZION WELL LOCATIONS 2018 Zion GWPPR

TABLEA-1: Sampling Locations and Distance for the Radiological Groundwater Protection Program, Zion Station, 2018 Site Site Type Temporary/Permanent Distance MW-ZN-01S Monitoring Well Permanent On-Site MW-ZN-02S Monitoring Well Permanent On-Site MW-ZN-03S Monitoring Well Permanent On-Site MW-ZN-04S Monitoring Well Permanent On-Site MW-ZN-05S Monitoring Well Permanent On-Site MW-ZN-06S Monitoring Well Permanent On-Site MW-;!'.N-07S Monitoring Well Permanent On-Site MW-ZN-OBS Monitoring Well Permanent On-Site MW-ZN-10S Monitoring Well Permanent On-Site MW-ZN-11S Monitoring Well Permanent On-Site SW-ZN-01 Surface Water Lake Michigan On-Site A-1 2018 Zion GWPPR

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  • Surfaee Wat pie- Loeatlon e JLocatlon Figure A-1 Radiological Ground Water Protection Program Groundwater and Surface Water Locations of the Zion Station , 2018 A-2 2018 Zion GWPPR

Surface Water and Grot.1ndwater Sample Local ions

  • Surface Water Sample Loci!llon
  • VEIi location Figure A-2 Radiological Ground Water Protection Program Tritium Investigation of Well 08S , 2018 A-3 2018 Zion GWPPR

APPENDIX B DATA TABLES 2018 Zion GWPPR

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TABLE B-1.1 Concentrations of Tritium, Strontium, Gross Alpha and Gross Beta in Groundwater Samples Collected in the Vicinity of Zion Nuclear Power Station, 2018_

Results in Units of pCi/liter +/- 2 Sigma COLLECTION SITE DATE H-3 Sr-90 Gr-A (Dis) Gr-A (Sus) Gr-B (Dis) Gr-8 (Sus)

MW-ZN-01S 02/18/18 < 193 < 0.6 < 1.3 < 0.4 10.8 +/- 1.3 < 1.6 MW-ZN-01S 05/04/18 < 176 < 0.7 < 2.0 < 0.4 14.0 +/- 1.8 < 1.9 MW-ZN-01S 08/03/18 < 194 < 0.8 < 1.8 < 0.7 12.4 +/- 1.4 < 1.4 MW-ZN-01S 12/13/18 < 184 < 0.8 < 1.6 < 0.7 13.6 +/- 1.5 < 1.5 MW-ZN-02S 03/11/18 < 191 < 0.6 < 1.4 < 0.4 16.3 +/- 1.5 < 1.6 MW-ZN-02S 05/04/18 < 180 < 0.8 < 1.9 < 0.4 15.4 +/- 1.7 < 1.9 MW-ZN-02S 08/03/18 < 193 < 0.5 < 1.5 < 0.7 9.7 +/- 1.1 < 1.4 MW-ZN-02S 10/28/18 < 196 < 0.8 < 0.9 < 0.8 7.5 +/- 1.0 < 1.9 MW-ZN-03S r 03/04/18 < 189 < 0.7 .< 1.3 < 0.4 6.2 +/- 1.1 < 1.6 MW-ZN-03S 05/05/18 < 178 < 0.8 < 2.4 < 0.4 10.0 +/- 1.7 < 1.9 MW-ZN-03S 08/03/18 < 193 < 0.6 < 2.0 < 0.7 10.1 +/- 1.4 < 1.4 MW-ZN-03S 10/28/18 < 196 < 0.5 < 2.7 < 0.8 9.4 +/- 2.1 < 1.9 MW-ZN-04S 03/04/18 < 172 < 0.7 < 1.5 < 0.4 10.7 +/- 1.5 < 1.6 MW-ZN-04S 05/05/18 < 182 < 1.0 < 1.7 < 0.3 11.8 +/- 1.5 < 1.5 MW-ZN-04S 08/04/18 < 194 < 0:1 .< 2.0 < 0.7 13.2 +/- 1.6 < 1.4 MW-ZN-04S 10/27/18 < 196 < 0.5 < 2.4 < 0.8 10.7 +/- 2.2 < 1.9 MW-ZN-05S 03/04/18 < 173 < 0.7 < 1.3 < 0.4 2.9 +/- 1.1 < 1.6 MW-ZN-05S 05/05/18 < 181 < 0.8 < 1.5 < 0.3 3.1 +/- 1.1 < 1.5 MW-ZN-05S 08/04/18 < 193 < 0.5 < 1.6 < 0.7 3.7 +/- 1.0 < 1.4 MW-ZN-05S 2ND 08/11/18 < 189 MW-ZN-05S 10/27/18 < 194 < 0.6 < 0.5 < 0.8 3.1 +/- 1.0 < 1.9 MW-ZN-06S 03/11/18 < 173 <"0.9 < 1.5 < 0.4 5.0 +/- 1.3 < 1.6 MW-ZN-06S 05/05/18 < 181 < 0.7 < 1.8 < 0.3 4.7 +/- 1.2 < 1.5 MW-ZN-06S 08/04/18 < 189 < 0.7 < 1.9 < 0.7 5.8 +/- 1.3 < 1.5 MW-ZN-06S 10/27/18 < 197 < 0.9 < 1.1 < 0.8 4.1 +/- 1.1 < 1.9 MW-ZN-07S 03/11/18 < 171 < 0.5 < 1.8 < 0.5 4.3 +/- 1.3 < 1.6 MW-ZN-07S 05/05/18 < 178 < 0.8 < 2.3 < 0.3 3.6 +/- 1.3 < 1.5 MW-ZN-07S 08/10/18 < 194 < 0.4 < 1.1 < 1.2 2.2 +/- 0.7 < 3.1 MW-ZN-07S 10/27/18 < 196 < 0.6 < 1.2 < 0.7 3.3 +/- 1.1 < 1.9 MW-ZN-OBS 02/18/18 242 +/- 122 < 0.5 < 1.4 < 0.5 3.7 +/- 1.1 < 1.6 MW-ZN-OBS Recount 02/18/.18 233 +/- 117 MW-ZN-OBS Reanalysis 1 02/18/18 308 +/- 122 MW-ZN-OBS Reanalysis 2 02/18/18 240 +/- 126 MW-ZN-OBS 03/04/18 262 +/- 120 < 0.8 < 1.4 < 0.5 3.5 +/- 1.1 < 1.6 MW-ZN-OBS Recount 03/04/18 206 +/- 116 MW-ZN-OBS Reanalysis 03/04/18 307 +/- 124 MW-ZN-OBS 04/25/18 330 +/- 127 MW-ZN-OBS Reanalysis 1 04/25/18 308 +/- 126 MW-ZN-OBS Reanalysis 2 04/25/18 357 +/- 127 MW-ZN-OBS 04/25/18 416 +/- 132 MW-ZN-OBS Reanalysis 1 04/25/18 381 +/- 128 MW-ZN-OBS Reanalysis 2 04/25/18 373 +/- 129 MW-ZN-OBS 05/04/18 507 +/- 144 < 0.8 < 1.6 < 0.6 4.0 +/- 1.3 < 1.3 MW-ZN-OBS 05/06/18 260 +/- 133 < 0.8 < 1.4 < 0.6 3.0 +/- 1.2 < 1.3 MW-ZN-OBS 08/03/18 < 200 < 0.5 < 1.1 < 1.2 4.6 +/- 0.8 < 3.1 MW-ZN-OBS 10/26/18 . 208 +/- 131 < 0.5 < 2.5 < 0.6 9.3 +/- 1.6 < 1.8 MW-ZN-OBS Recount 10/26/18 < 193 MW-ZN-10S 02/18/18 < 172 < 0.5 < 0.9 < 0.5 8.3 +/- 1.2 < 1.6 MW-ZN-10S 05/04/18 < 181 < 0.7 < 1.7 < 0.3 11.1 +/- 1.5 < 1.5 MW-ZN-10S 08/04/18 < 199 < 0.6' < 0.9 < 0.4 7.0 +/- 1.2 < 1.6 MW-ZN-10S 10/28/18 < 199 < 0.8 < 1.0 < 0.6 6.8 +/- 1.2 < 1.8 MW-ZN-11S 02/18/18 < 175 < 0.7 < 1.0 < 0.5 5.0 +/- 1.1 < 1.6 MW-ZN-11S 05/04/18 < 181 < 0.7 < 1.6 < 0.3 5.2 +/- 1.2 < 1.5 MW-ZN-11S 08/03/18 < 194 < 0.5 < 1.5 < 0.4 6.6 +/- 1.3 < 1.6 MW-ZN-11S 10/26/18 < 195 < 0.6 < 1.0 < 0.6 4.6 +/- 1.1 < 1.8 B-1 2018 Zion GWPPR

TABLE 8-1.2 Concentrations of Gamma-Emitters in. Groundwater Sam pies Collected in the Vicinity of Zion Nuclear Station, 2018 Results in Units of pCi/liter +/- 2 Sigma COLLECTION SITE DATE K-40 Co-60 Nb-94 Sb-125 Cs-134 Cs-137 MW-ZN-01S 02/18/18 < 86 <.4 <5 < 15 <6 <5 MW-ZN-01S 05/04/18 < 19 < 1 < 1 <3 < 1 < 1 MW-ZN-01S 08/03/18 < 77 < 6 <5 < 14 <6 <5 MW-ZN-01S 12/13/18 < 45 <5 <5 < 15 <6 < 5 MW-ZN-02S 03/11/18 < 104 <7 <7 < 13 <5 <7 MW-ZN-02S 05/04/18 < 25 < 1 < 1 <3 < 1 < 1 MW-ZN-02S 08/03/18 < 99 <6 <6 < 15 <6 <6 MW-ZN-02S 10/28/18 56 +/- 33 <2 < 2 <6 <2 < 2 MW-ZN-03S 03/04/18 < 95 <4 <5 < 12 <5 <4 MW-ZN-03S 05/05/18 < 23 < 2 < 1 <4 < 1 < 1 MW-ZN-03S 08/03/18 < 38 <5 <5 < 14 <5 <5 MW-ZN-03S 10/28/18 < 15 < 2 < 1 <4 < 2 <2 MW-ZN-04S 03/04/18 91 +/- 56 <6 <6 < 15 <6 <6 MW-ZN-04S 05/05/18 < 36 <2 < 2 <5 < 2 < 2 MW-ZN-04S 08/04/18 < 103 <7 <7 < 14 <7 <5 MW-ZN-04S 10/27/18 < 32 <2 < 2 <5 <2 < 2 MW-ZN-05S 03/04/18 < 85 < 7 <4 < 14 <5 < 5 MW-ZN-05S 05/05/18 < 27 < 2 < 1 <4 < 2 <2 MW-ZN-05S 08/04/18 < 107 <5 <6 < 13 <6 <5 MW-ZN-05S 10/27/18 < 16 < 2 < 2 <5 < 2 <2 MW-ZN-06S 03/11/18 < 115 < 5 <4 < 15 <6 <5 MW-ZN-06S 05/05/18 < 29 < 1 < 1 <3 < 1 ' < 1 MW-ZN-06S 08/04/18 < 88 <5 <5 < 12 < 5 <4 MW-ZN-06S 10/27/18 < 48 <4 <4 < 14 <6 < 5 MW-ZN-07S 03/11/18 < 50 < 6 < 5 < 14 <6 <6 MW-ZN-07S 05/05/18 < 27 < 1 < 1 <4 < 2 < 1 MW-ZN-07S 08/10/18 < 52 <6 <5 < 14 <5 <5 MW-ZN-07S 10/27/18 < 34 <4 <3 < 10 <4 <4 MW-ZN-OBS 02/18/18 < 126 <6 <5 < 14 <6 <5 MW-ZN-OBS 03/04/18 < 18 <5 <5 < 15 <6 <5 MW-ZN-OBS 05/04/18 < 58 < 3 <5 < 15 <6 <6 MW-ZN-OBS 05/06/18 < 55 < 5 <6 < 15 <6 <6 MW-ZN-OBS 08/03/18 < 104 <5 < 5 < 13 <6 <5 MW-ZN-OBS 10/26/18 < 82 <4 <4 < 14 <5 <4 MW-ZN-10S 02/18/18 < 93 <5 < 5 < 13 <5 <6 MW-ZN-10S 05/04/18 '-< 10 < 1 < 1 <4 < 1 < 1 MW-ZN-10S 08/04/18 < 38 <5 <5 < 14 < 5 <5 MW-ZN-10S 10/28/18 < 42 <5 <5 < 14 < 5 <5 MW-ZN-11S 02/18/18 < 68 <4 <5 < 15 < 6 <6 MW-ZN-11S 05/04/18 < 23 < 2 < 1 <4 <2 < 1 MW-ZN-11S 08/03/18 < 84 < 5 <5 < 13 <6 <6 MW-ZN-11S 10/26/18 < 74 < 5 <3 < 10 <4 <4 8-2 2018 Zion GWPPR

TABLE 8-1.3 Concentrations of lron-55, Nickel-59, and Nickel-63 in Groundwater Samples Collected in the Vicinity of Zion Nuclea*r Station, 2018 Results in Units of pCi/liter +/- 2 Sigma COLLECTION SITE DATE Fe-55 Ni-59 Ni-63 MW-ZN-01S 02/18/18 < 55 < 65 < 4.9 05/04/18 < 108 < 72 < 4.4 08/03/18 < 98 < 111 < 4.6 12/13/18 < 47 < 142 < 4.3 MW-ZN-02S 03/11/18 < 42 < 59 < 4.5 05/04/18 < 123 < 42 < 4.7 08/03/18 < 158 < 143 < 4.3 10/28/18 < 190 < 78 < 4.2 MW-ZN-03S 03/04/18 < 172 < 90 < 4.8 05/05/18 < 141 < 71 < 4.7 08/03/18 < 185 < 162 < 5.0 10/28/18 < 184 < 187 < 4.5 MW-ZN-04S 03/04/18 < 140 < 63 < 4.8 05/05/18 < 186 < 52 < 4.8 08/04/18 < 186 < 181 < 4.6 10/27/18 < 148 < 75 < 4.5 MW-ZN-05S 03/04/18 < 63 < 72 < 4.8 05/05/18 < 137 < 107 < 5.0 08/04/18 < 184 < 133 < 4.7 10/27/18 < 185 < 148 < 4.4 MW-ZN-06S 03/11/18 < 56 < 87 < 4.8 05/05/18 < 139 < 104 < 5.0 08/04/18 < 176 < 146 < 4.9 10/27/18 < 196 < 91 < 4.8 MW-ZN-07S 03/11/18 < 56 < 33 < 5.0 05/05/18 < 129 < 85 < 2.6 08/10/18 < 47 < 97 < 4.7 10/27/18 < 184 < 127 < 4.9 MW-ZN-OBS 02/18/18 < 89 < 69 < 4.9 03/04/18 < 95 < 55 < 4.3 05/04/18 < 195 < 156 < 4.8 05/06/18 < 195 < 150 < 4.2 08/03/18 < 126 < 193 < 4.9 10/26/18 < 90 < 193 < 4.6 MW-ZN-10S 02/18/18 < 97 < 93 < 4.7 05/04/18 < 99 < 113 < 4.0 08/04/18 < 89 < 98 < 4.9 10/28/18 < 177 < 109 < 4.4 MW-ZN-11S 02/18/18 < 83 < 97 < 4.9 05/04/18 < 156 < 84 < 4.1 08/03/18 < 59 < 185 < 5.0 10/26/18 < 59 < 186 < 4.4 8-3 2018 Zion GWPPR

TABLE 8-11.1 Concentrations of Tritium, Strontium, Gross Alpha and Gross Beta in Surface Water Samples Collected in the Vicinity of Zion Nuclear Power Station, 2018 Results in Units of pCi/liter +/- 2 Sigma COLLECTION SITE DATE H-3 Sr-90 Gr-A (Dis) Gr-A (Sus) Gr-8 (Dis) Gr-8 (Sus)

SW-ZN-01 03/04/18 < 171 < 0.5 < 0.7 < 0.5 2.0 +/- 0.7 < 1.6 SW-ZN-01 05/05/18 < 181 < 0.7 < 1.1 < 0.3 1.9 +/- 0.7 < 1.5 SW-ZN-01 08/03/18 < 196 < 0.5 < 1.1 < 0.4 1.9 +/- 0.8 < 1.6 SW-ZN-01 10/28/18 < 192 < 0.6 < 0.8 < 0.7 2.2 +/- 0.9 < 1.9 8-4 2018 Zion GWPPR

TABLE B-11.2 Concentrations of Gamma-Emitters in Surface Water Samples Collected in the Vicinity of Zion Nuclear Station, 2018 Results in Units of pCi/liter +/- 2 Sigma COLLECTION SITE DATE K-40 Co-60 Nb-94 Sb-125 Cs-134 Cs-137 SW-ZN-01 03/04/18 < 40 < 6 <4 < 15 .< 6 < 5 SW-ZN-01 05/05/18 < 83 < 5 <5 < 14 < 4 < 5 SW-ZN-01 08/03/18 85 +/- 53 < 6 <5 < 13 < 6 < 5 SW-ZN-01 10/28/18 < 22 < 5 < 5 < 13 < 5 < 5 B-5 2018 Zion GWPPR

TABLE B-11.3 Concentrations of lron-55, Nickel-59, and Nickel-63 in Surface Water Samples Collected in the Vicinity of Zion Nuclear Station, 2018 Results in Units of pCi/Liter +/- 2 Sigma COLLECTION SITE DATE Fe-55 Ni-59 Ni-63 SW-ZN-01 03/04/18 < 84 < 91 < 4.6 SW-ZN-01 05/05/18 < 133 < 54 < 3.7 SW-ZN-01 08/03/18 < 187 < 114 < 4.1 SW-ZN-01 10/28/18 < 94 < 73 < 4.9 B-6 2018 Zion GWPPR

APPENDIX F ERRATA DATA 2018 Zion GWPPR

Intentionally left blank 2018 Zion GWPPR

APPENDIX F ERRATA DATA 2018 Zion GWPPR

2016 AREOR ERRATA Corrections to pages in this report follow and are indicated by change bars. The entire page is.included and may be inserted as a direct replacement for the original page. These corrections to the 2016 AREOR close out the action items identiied in ES-ZION-2018-0150.

Page A-1 (directly below) Change reflects 2 controls and 2 indicator samples. TLD data on page A-3 reflected Z-13 control values only in the original report and did not require revision. Tables C-Vl.1 to C-Vl.3 did require revision and follow in this Errata section.

TABLE A-1 RADIOLOGICAL ENVIRONMEIIITAL MONITORING PROGRAM ANNUAL

SUMMARY

FOR THE ZION NUCLEAR POWER STATION, 2016 Name of Facility: ZION NUCLEAR POWER STATION DOCKET NUMBER: 50-295 & 50-304 Location of Facility: ZION.IL REPORTING PERIOD: 2016 INDICATOR COITTROL MEDIUM OR REQUIRED LOCATIONS LOCAT!Oll{S) LOCATION WITH HIGHEST ANNUAL MEAN (M) NUMBER PA1HWAY SAMPLED TYPES OF NUMBER OF LOWER LIMIT MEAN(M) MEAN(M) MEAN(M) STATION# NONROUl

{UNITOF ANALYSIS ANALYSIS OF DETECTION (F) (F) (Fl NAME REPORTI MEASUREMENT} PERFORMED PERFORMED (LLD) RANGE RANGE RANGE DISTANGE AND DIRECTION MEASUREM PUBLIC WATER GR-B 48 4 3 3 3.1 Z-15 INDICATOR 0

{PCVLITER} (17124) (16124) (8112) LAKE COUNTY WATER WORKS Z.2-3.8 21-4.7 2.3-3.8 1.4 MILES NNW OF SITE H-3 16 200 <LLD <LLD 0 GAMMA 48 MN-54 15 <LLD <LLD 0 C0-58 15 <LLD <LLD 0 FE-59 30 <LLD <LLD 0 C0-60 15 <LLD <LLD ZN-65 30 <LLD <LLD 0 NB-95 15 <LLD <LLD 0 ZR-95 15 <LLD <LLD 0 CS-134 15 <LLD <LLD 0 CS-137 18 <LLD <LLD 0 BA-140 NA <LLD <LLD 0 LA-140 NA <LLD <LLD 0 FISH GAMMA 2 (PCVKGWET) MN-54 130 <LLD NA 0 C0-58 130 <LLD NA 0 FE-59 260 <LLD NA 0 C0-60 130 <LLD NA 0 ZN-65 260 <LLD NA 0 NB-95 NA <LLD NA 0 ZR-95 NA <LLD NA 0 CS-134 100 <LLD NA 0 CS-137 100 <LLD NA 0 BA-140 NA <LLD NA 0 LA-140 NA <LLD NA 0

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

A-1 2018 Zion GWPPR

The 2016 AREOR change below adds Z-112 as a special interest TLD inadvertently omitted in the original report -

and an editorial correction.

129, Z-130, Z-131 Special Interest: Z-113, Z-114, Z-115, Z-112 Outer Ring: Z-209, Z-211, Z-212, Z-213, Z-214, Z-215, Z-216 Control: Z-13 The specific TLD locations were determined by the following criteria:

1. The presence of relatively dense population;
2. Site meteorological data taking into account distance and elevation for each of the sixteen-22 1/2 degree sectors around the site, where estimated annual dose from ZNPS, if any, would be most significant;
3. On hills free from local obstructions and within sight of the vents (where practical);
4. And near the closest dwelling to the vents in the prevailing downwind direction.

Two TLDs were placed at each location approximately four to eight feet above ground level. The TLDs were exchanged quarterly and sent to Mirion Technologies for analysis.

B. Sample Analysis This section describes the general analytical methodologies used by TBE and Environmental Inc. (Midwest Labs) to analyze the environmental samples for radioactivity for the ZNPS REMP in 2016. The analytical procedures used by the laboratories are listed in Table B-2.

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

1. Concentrations of beta emitters in public water and air particulates
2. Concentrations of gamma emitters in public water, air particulates, fish, and sediment
3. Concentrations of tritium in public water
4. Ambient gamma radiation levels at various site environs 4

2018 Zion GWPPR

In the 2016 AREOR, the number of positive gross beta results and sample locations is corrected below.

IV. Results and Discussion A. Aquatic Environment

1. Public Water Samples were taken weekly and composited monthly at four locations {Z-14, Z-15, Z-16 and Z-18). The following analyses were performed.

Gross Beta Samples from all locations were analyzed for concentrations of gross beta {Table C-1.1, Appendix C). Gross beta was detected in 33 of 48 samples. The values ranged from 2.1 pCi/1 to 4.7 pCi/1.

Concentrations detected were consistent with those detected in previous years (Figures C-1 and C-2, Appendix C).

Tritium Quarterly composites of weekly collections were analyzed for tritium activity (Table C-1.2, Appendix C). No tritium was detected and the LLD was met (Figures C-3 and C-4, Appendix C).

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

2. Fish Fish samples comprised of white sucker, northern pike, common carp, brown trout, lake trout, and burbot were collected at two locations (Z-26 and Z-27) semiannually. The following analysis was performed:*

Gamma Spectrometry The edible portion of fish samples from both locations was analyzed for gamma-emitting nuclides (Table C-11.1, Appendix C).

No nuclides were detected and all required LLDs were met.

3. Sediment Aquatic sediment samples were collected at one location {Z-25) semiannually. The following analysis was performed:

7 2018 Zion GWPPR

. In the 2016 AREOR, the description of TLD types (indicator and control) and location was clarified.

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

D. Ambient Gamma Radiation Ambient gamma radiation levels were measured using thermoluminescent dosimeters. Sixty-four TLDs were posted at 29 indicator locations around the site, and one control location 1O miles northwest (NW) of the site. Results of TLD measurements are listed in Tables C-Vl.1 to C-Vl.3, Appendix C.

Most TLD measurements were below 25 mR/quarter, with a range of 13 mR/quarter to 50 mR/quarter.

E. Land Use Survey A Land Use Census conducted during August 2016 around the Zion Nuclear Power Station (ZNPS) was performed by Zion Station Personnel for ZS to comply with Chapter 3 of the Zion Offsite Dose Calculation Manual. The purpose of the survey was to document the nearest resident, milk producing animal and garden of greater than 500 ft2 in each of the sixteen 22 % degree sectors around the site. The results of this survey are summarized below:

Distance in Miles from ZS Sector Residence Garden Milk Farm Miles Miles Miles N 2.5 3.4 >10 NNE NE ENE E

ESE SE SSE s

SSW 1.9 >10 >10 SW 1.1 4.8 >10 WSW 1.0 3.0 >10 w 1.1 2.9 >10 WNW 1.0 2.7 >10 NW 1.0 3.2 >10 NNW 1.3 3.5 >10 9

2018 Zion GWPPR

The change below reflects a corrected Occupancy Factor in Appendix E, Effluents Section.

SUMMARY

Gaseous, liquid and solid waste effluents for the period contributed to only a small fraction of the Station Technical Specification limits. Calculations of environmental concentrations based on effluent and historical meteorological data for the period indicate that consumption by the public of radionuclides attributable to the Zion Station does not exceed regulatory limits. Radiation exposure from direct radiation from the ISFS I and containerized waste at the site boundary represented the critical pathway for the period with a maximum individual total body dose estimated to be 1.49E+01 mrem for the year, where a factor to analyze exposure based on habits of the real individual of 3.33-01 was applied at the maximally exposed receptor. The assessment of radiation doses is performed in accordance with the Zion Station Offsite Dose Calculation Manual (ODCM). The results of analysis confirm that the station is operating in compliance with 10 CFR 50 Appendix I, 10 CFR 20, 10 CFR 72 and 40 CFR 190.

2 2018 Zion GWPPR

The next series of corrected pages reflecnranscription-and rounding errors in tables sulitma-ritihgthe TLD results. Additionally, updated direct dose data resulting from a lower background with the removal of TLD data for Z-14 control TLDs which are not identified in the ODCM, revision 11 and cannot be included. The net result is that background dose dropped an average of 0.55 mrem per quarter and total direct dose increased by the same amount.

Table C-Vl.1 Quarterly TLD Results for Zion Nuclear Power Station, 2016 Results in Units of Milli-Roentgen/Quarter+/- 2 Standard Deviations STATION MEAN CODE +/-2S.D_ JAN - MAR APR-JUN JUL- SEP OCT-DEC Table C-Vl.1 Quarterly TLD Results for Zion Nuclear Power Station, 2016 Results in Units of Milli-Roentgen/Quarter+/- 2 Standard Deviations STATION MEAN CODE +2S.D_ JAN - MAR APR-JUN JUL- SEP OCT-DEC Z-01 29 +/- 11 36 30 26 23 I Z-02 17 +/- 4 18 18 17 14 I Z-03 Z-13 18 18

+/-

+/-

4 4

18 18

. 20 19 18 20 15 16 I

I Z-101 17 +/- 5 18 20 16 14 Z-102 19 +/- 4 21 19 19 16 Z-103 17 +/- 3 18 18 17 15 Z-104 17 +/- 2 17 17 17 15 Z-105 18 +/- 4 20 19 18 15 Z-106 18 +/- 5 20 20 17 15 Z-107 18 +/- 3 19 18 17 16 Z-108 21 +/- 3 22 21 20 19 Z-109 33 +/- 23 48 35 29 20 Z-112 19 +/- 4 19 21 19 16 Z-113 17 +/- 4 17 18 18 14 Z-114 18 +/- 4 17 19 19 15 Z-115 18 +/- 3 19 19 19 16 Z-121 17 +/- 4 17 19 17 14 Z-124 18 +/- 4 18 19 19 15 Z-125 19 +/- 2 20 19 20 18 Z-129 17 +/- 4 17 19 15 15 Z-130 21 +/- 5 22 22 21 17 Z-131 42 +/- 19 48 50 41 29 Z-209 18 +/- 3 18 18 19 16 Z-211 22 +/- 5 24 20 23 19 Z-212 23 +/- 6 23 25 25 19 Z-213 24 +/- 5 25 24 25 20 Z-214 21 +/- 3 22 21 21 18 Z-215 23 +/- 5 23 23 25 19 Z-216 19 +/- 3 19 20 19 16 C-10 2018 Zion GWPPR

Table C-Vl.2. MEAN QUARTERLY TLD RESULTS FOR INNER RING, OUTER RING, SPECIAL INTEREST, AND CONTROL STATIONS FOR ZION NUCLEAR POWER STATION, 2016 Results in Units of Milli-Roentgen/Quarter+/- 2 Standard Deviations of the Station Data COLLECTION INNER RING OUTER RING SPECIAL CONTROL PERIOD +/-2S.D. INTEREST 3AN-MAA 23 +/- 20 22 +/- 5 18 +/- 2 18 +/- 2 APR-JUN 22 +/- 16 22 +/- 5 19 +/- 3 19 +/- 2 JUL-SEP 20 +/- 12 22 +/- 6 19 +/- 1 20 +/- 2 OCT-DEC 17 +/- 8 18 +/- 3 15 +/- 2 16 +/- 2 Table C-Vl.3

SUMMARY

OF THE AMBIENT DOSIMETRY PROGRAM FOR ZION NUCLEAR POWER STATION, 2016 RESULTS IN UNITS OF MILLI-ROENTGEN/QUARTER SAMPLES PERIOD PERIOD PERIOD MEAN LOCATION ANALVZED MINIMUM MAXIMUM +/-2S.D.

INNER RING 162 14 50 20 +/- 15 OUTER RING 63 16 25 21 +/- 5 SPECIAL INTEREST 36 14 21 18 +/- 4 CONTROL 54 15 21 18 +/- 4 INNER RING STATIONS - Z-01, Z-02, Z-03, Z-101, Z-102, Z-103, Z-104, Z-105, Z-106, Z-107, Z-108, Z-109, Z-121, Z-124, Z-125, Z-129, 2130, Z-131 SPECIAL INTEREST STATIONS - Z-112, Z-113, Z-114, Z-115 OUTER RING STATIONS-Z-209, Z-211, Z-212, Z-213, Z-214, Z-215, Z-216 CONTROL STATION- Z-13 C-11 2018 Zion GWPPR

Table 3.3-1 Maximum Dose Resulting from Direct Radiation,_

Zion Station 2016 Maximally Exposed Sector: J (25 mrem/year limit)

Unit Qtr 1 (mrem) Qtr 2(mrem) Qtr 3 (mi*em) Qtr4 (mrem) 2016 (mrem)-

Unit 1 2.06E+OO 1.19E+OO 6.85E-01 7.96E-01 4.73E+OO Unit 2 2.06E+OO 1.19E+OO 6.85E-01 7.96E-01 4.73E+OO ISFSI- 2.06E+OO 1.19E+OO 6.85E-01 7.96E-01 4.73E+OO Gamma ISFSI- 6.0?E-01 2.89E-01 2.86E-01 O.OOE+OO 1.18E+OO Neutron Sum: 6.79E+OO 3.86E+OO 2.34E+OO 2.39E+OO 1.54E+01 Maximally exposed switch yard: Switch yard South ( l 00 mrem/year limit)

Switchvard Qtr 1 (mrem) Qtr 2 (mrem) Qtr3 (mrem) Qtr4(mrem) 2016 (mrem)

Gamma 2.47E+01 2.97E+01 2.48E+01 1.17E+01 9.09E+01 Neutron 2.40E+OO 2.40E+OO 3.50E+OO O.OOE+OO 8.30E+OO Sum: 2.71 E+01 3.21 E+01 2.83E+01 1.17E+01 9.92E+01 E-1.9 .

2018 Zion GWPPR

Table 3.4-1 ZION STATION 2016 Unit 1 10 CFR 20 Compliance Assessment

1. 10 CFR 20.1301 (a) (1) Compliance Total Effective Dose Equivalent (TEDE) 4.75E+OO mrem/year

% of the limit 4.75E+OO %

2. Compliance Summary 10 CFR 20 1st Otr. 2nd Otr. 3rd Otr. 4th Otr  % of Limit TEDE* 2.07E+OO 1. 19E+OO 6.89E-01 7.98E-01 4.75E+OO%
  • TEDE includes dose from external direct radiation (4.73 mrem) and internal dose from inhalation and ingestion of air, foodstuffs and water containing licensed material. Total body dose from internal exposure (liquid and gaseous) includes 1.92E-02 mrem in the TEDE dose above ..

E-1.10 2018 Zion GWPPR

Table 3.4-1 (continued)

ZION STATION 2016 Unit 2 10 CFR 20 Compliance Assessment

t. 10 CFR 20.1301 (a) (1) Compliance Total Effective Dose Equivalent 4.75E+OO mrem/year 10 CFR 20.1301 (a) (1) limit 100 mrem/year

% of the limit 4.75E+OO %

2. Compliance Summary 10 CFR 20 1st Qtr. 2nd Otr. 3rd Qtr. 4th Qtr  % of Limit TEDE* 2.07E+OO 1.19E+OO 6.89E-01 7.98E-01 4.75E+OO%
  • TEDE includes dose from external direct radiation {4.73 mrem) and internal dose from inhalation and ingestion of air, foodstuffs and water containing licensed material. Total body dose from internal exposure (liquid and gaseous) includes 1.92E-02 mrem in the TEDE dose above.

E-1.11 2018 Zion GWPPR

Table 3.4-1 (continued)

ZION STATION 2016 Switchyard 10 CFR 20 Compliance Assessment

1. 10 CFR 20.1301 (a) (1) Compliance Total Effective Dose Equivalent 9.92E+01 mrem/year 10 CFR 20.1301 (a) (1) limit 100 mrem/year

% of the limit 9.92E+01%

2. Compliance Summary 10 CFR 20 1st Qtr. 2nd Otr. 3rd Qtr. 4th Qtr  % of Limit TEDE* 2. 71 E+01 3.21 E+01 2.83E+01 1.17E+01 9.92E+01 %

NOTE: Qtr 1,2,3 Harshaw TLD100 represents 30% gamma over-response. Qtr 4 TLD changed to Panasonic TLD 814 which does not over-respond when in presence of neutrons I

  • TEDE includes dose from external direct radiation (99.2 mrem) and internal dose from inhalation and ingestion of air, foodstuffs and water containing licensed material. Total body dose from internal exposure (liquid and gaseous) includes 1.92E-02 mrem. Normally on-site internal dose is not evaluated unless there is a known uptake. Internal dose calculated for Units 1 and 2 was added here for consistency, but is measured for the nearest off site resident .or hypothetical resident at site boundary (whichever is higher).

E-1.12 2018 Zion GWPPR

Table 3.4-1 (continued}

ZION STATION 2016 ISFSI 10 CFR 72.104 Compliance Assessment

1. 10 CFR 72.104 (a) (2) Compliance Total Effective Dose Equivalent 5.91 E+OO mrem/year 10 CFR 72.104 (a) limit 25 mrem/year

% of the limit 2.36E+01%

2. Compliance Summary 10 CFR 20 1st Qtr. 2nd Qtr. 3rd Qtr
  • 4th Qtr  % of Limit TEDE* 2.67E+OO 1.48E+OO 9.71 E-01 7.96E-01 2.36E+01%
  • TEDE for ISFSI includes only external direct radiation exposure. There is no licensed material released to the atmosphere or surface/groundwater from the ISFSI that could be inhaled or ingested by a member of the public.

E-1.13 2018 Zion GWPPR

This last correction for the 2016 AREOR is corrects a typographical error for Unit 2 Organ close.

Table 3.5-1 Doses Resulting from Airborne Releases The following are the maximum annual calculated cumulative offsite doses resulting from Zion Station airborne releases.

Unit 1:

Dose Maximum Value Sector Affected Qamma air llJ O.OOE+OO mrad beta air tcJ O.OOE+OO mrad whole body l~J 1.48E-02 mrem East skin t4 J O.OOE+OO mrad East*

organ l5 > (infant liver) 5.1 OE-02 mrem East

\ Unit 2:

Dose Maximum Value Sector Affected gamma air (1) O.OOE+OO mrad beta air (2) O.OOE+OO mrad whole body (3) 1.48E-02 mrem East skin (4) O.OOE+OO mrad East organ (5) (infant liver) 5.1 OE-02 mrem East All values based on historical values of atmospheric dispersion coefficients and XOQDOQ values reflecting the time period from Jan. 1, 2009 to Dec. 31 2014.

Meteorological Tower was removed March 2015.

Data recovery: 98.71 %

(1) Gamma Air Dose - GASPAR II, NUREG-0597 (2) Beta Air Dose - GASPAR II, NUREG-0597 (3) Whole Body Dose - GASPAR II, NUREG-0597 (4) Skin Dose - GASPAR 11, NUREG-0597 (5) Inhalation and Food Pathways Dose - GASPAR II, NUREG-0597 E-1.13 2018 Zion GWPPR

The Appendix G Groundwater Report correction below is editorial (1st correction) and reports the correcc

  • number of positive Potassium 40 results in groundwater (S versus 2) for this naturally occurring radionuclide.

I. Summary and Conclusions In 2006, Exelon instituted a comprehensive program to evaluate the impact of station operations on groundwater and surface water in the vicinity of Zion Nuclear Power Station. This report covers both groundwater and surface water samples, collected from the environment, on station property in 2016. During that time period, 501 analyses were performed on 51 samples from 12 locations.

Phase 1 of the monitoring was part of a comprehensive study initiated by Exelon to determine whether groundwater or surface water at and in the vicinity of Zion Nuclear Power Station had been adversely impacted by any releases of radionuclides. Phase 1 was conducted by Conestoga Rovers and Associates (CRA) and the conclusions were made available to state and federal regulators as well as the public in station specific reports.

Phase 2 of the RGPP was conducted by ZionSolutions (Exelon was responsible for the program up to 8/31/201 o; Zion Solutions became the licensee on 9/1/201 O, thus assuming responsibility for the RGPP) personnel to initiate follow up of Phase 1 and begin long-term monitoring at groundwater and surface water locations selected during Phase 1. All analytical results from Phase 2 monitoring are reported herein.

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

Naturally-occurring Potassium -40 (K-40) was detected in 5 groundwater samples. No other gamma-emitting radionuclides were detected at concentrations greater than their respective Lower Limits of Detection (LLDs) as specified in the Offsite Dose Calculation Manual (ODCM) in any of the groundwater or surface water samples. Strontium-90 was not detected in any of the samples analyzed in 2016.

Tritium was not detected in any groundwater or surface water samples analyzed in 2016. In the case of tritium, Zion Solutions specified that its laboratories achieve a lower limit of detection 1O times lower than that required by federal regulation.

Gross Alpha and Gross Beta analyses in the dissolved and suspended fractions were performed on groundwater samples during all four quarters of sampling in 2016. Gross Alpha (dissolved) and Gross Alpha (suspended) was not detected at any of the locations. Gross Beta (dissolved) was detected in all 44 samples.

2018 Zion GWPPR

In the 2016 GWPP report, found in Appendix G, a duplicate paragraph was deleted directly below as it was redundant to that on the previous page in the original report (page 10) and had not been updated with 2016 data. As a clarification in the second paragraph, of the 6 positive K-40 results, 5 were in groundwater and one was in surface water, as is discussed in a later section.

The concentration range of the isotopes can be found in Appendix B, Table B-1.1 and Table B-11.1.

Gamma Emitters Naturally-occurring K-40 was detected in 6 of 48 samples analyzed. The concentrations ranged from 37 to 162 pCi/l. All other gamma-emitting radionuclides were not detected in either groundwater or surface water samples analyzed (Table B-1.2, Appendix B) (Table B-11.1, Appendix B).

Other Naturally-occurring Isotopes Gross Beta activity present in the environment may be detected from the following sources: Beryllium-? (Be-7) and tritium (H-3) produced in the upper atmosphere when galactic rays strike nitrogen atoms, which then may reach the ground during precipitation. Gross Beta may also be detected from Cesium-137 (Cs-137) from past atomic bomb testing as it is still detectable in the environment. K-40 is a naturally-occurring radioactive isotope that occurs as a percentage of all stable isotopes of potassium.

Gross alpha can occur as naturally-occurring uranium in soil undergoes decay to form radon gases and in this decay chain, many isotopes of alpha-emitting radionuclides are present.

B. Drinking Water Well Survey A drinking water well survey was conducted during the summer 2006 by CRA (CRA 2006) around the Zion Nuclear Power Station.

C. Summary of Results - Inter-Laboratory Comparison Program Inter-Laboratory Comparison Program results for TBE and Environmental Inc. (Midwest Labs) are presented in the AREOR.

2018 Zion GWPPR

2017 AREOR ERRATA New TLD trending graphs were added to the 2017 AREOR. The y-axis title on the bottom graphs for these graphs on pages C-18 and C-19 erroneously listed these as annual doses. They were in fact average quarterly doses, and this measure was selected to be in line with the industry standard for TLD trending graphs using quarterly data. The corrected graphs, Figures C.7 and C.8, may be found on the following 2 pages. (Self-identified - this errata completes corrective action for ES-ZION-Cr-2018-2019 - Note 5 from QA audit A-18-001).

2018 Zion GWPPR

FIGURE C-7 Z PS I NER RING TLD'S POTENTIALLY IMPACTED BY ISFSI 2017 40_00 35..00 QI 30.00 t:

llt

, 25.00 a

l 20.00 E

§ 15.00 E

10..00 5.00 0.00 QTR2 QTR3 Z control a Z--01 a Z-109 Z-131 2013 - 2017 60.00

... 50.00 llt

~

E 40.00 f

=

E 2: 30.00 QI t:

llt

I O' 20.00 i

I 10.00 0 .00 2013 2014 2015 z-u - control

  • z-01 a z-100 Z-131 2016 I

2017 C-18 2017 Zien AREOR 2018 Zion GWPPR

FIGURE C-7 ZNPS INNER RING TLD'S POTENTIALLY IMPACTED BY ISFSI 2017 40.00 35.00 CII 30.00 t:

Ill

I 25.00 a...

QI Q. 20.00 E

I!!

15.00 e

10.00 5 .00 0.00 QJRl QJR2 QTR3 QJR4 z.-B - control

  • Nil
  • Z.-109 Z-131 2013- 2017 60.00

... 50.00 tll

~

~ 40.00 e

z-

... 30.00 CII t:

tll

I r:, 20.00 i

~ 10.00 0 .00 2013 2014 Z-13

  • Ctlalrol 2015 a z.--01 a z-109 Z-B1 2016 II 2017 C-1 8 2017 Zian EOR 2018 Zion GWPPR
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