ML081330692

Annual Radiological Groundwater Protection Program Report for 2007

ML081330692
Person / Time
Site:	Clinton
Issue date:	04/30/2008
From:	Teledyne Brown Engineering Environmental Services
To:	Office of Nuclear Reactor Regulation
References
FOIA/PA-2010-0209
Download: ML081330692 (20)

Text

Docket No: 50-461 CLINTON POWER STATION Annual Radiological Groundwater Protection Program Report 1 January Through 31 December 2007 Prepared By Teledyne Brown Engineering Environmental Services Amer., M An Exelon Company Clinton Power Station Clinton, IL 61727 April 2008

Table Of Contents I. S um m ary and Conclusions . ... ................................................................................... 1 II. Intro d uctio n ............................................................................................. . . . . . ..... 3 A . O bjectives of the RG PP ................................................................................. 3 B. Im plem entation of the Objectives ................................................................... 3 C. Program Description ....................................... 4 D . Characteristics of Tritium (H-3) ..................................................................... 5 Ill. P rog ram D escriptio n ................................................................................................ . .. 5 A . Sam ple A nalysis ......................................................................................... ... . 5 B. Data Interpretation ............... .. .................................................. 6 C . B ackground Analysis.............................................................

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1. Background Concentrations of Tritium ................................................ 7 IV. Results and Discussion.... ........ .. * .. . ... ............................ 99 A. Groundwater Results ....................................... 9 I

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Appendices Appendix A Location Designation of the Annual Radiological Groundwater Protection Program Report (ARGPPR)

Tables Table A-1: Radiological Groundwater Protection Program - Sampling Locations, Clinton Power Station, 2007 Figures Security-Related Information: Maps of the Clinton Power Station have been withheld from public disclosure under 10CFR2.390 and N.J.S.A.

47:1A-1.1 Appendix B Data Tables of the Annual Radiological Groundwater Protection.

Program Report (ARGPPR)

Tables Table B-1.1 Concentrations of Tritium in Groundwater Samples Collected in the Vicinity of Clinton Power Station, 2007.

Table B-1.2 Concentrations of Gamma Emitters in Groundwater Samples Collected in the Vicinity of Clinton Power Station, 2007.

Table B-11.1 Concentrations of Tritium in Surface Water Samples Collected in the Vicinity of Clinton Power Station, 2007.

Table B-11.2 Concentrations of Gamma Emitters in Surface Water Samples Collected in the Vicinity of Clinton Power Station, 2007.

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I Summary and Conclusions In 2006, Exelon instituted a comprehensive program to evaluate the impact of R station operations on groundwater and surface water in the vicinity of Clinton Power Station. This evaluation involved numerous station personnel and contractor support personnel. This report covers groundwater and surface water samples, collected outside of the Licensee required Off-Site Dose Calculation Manual (ODCM) requirements, both on and off station property in 2007. During that time period, 92 analyses were performed on 69 samples from 23 locations.

The monitoring was conducted in two phases.

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

Gamma-emitting radionuclides associated with licensed plant operations were not detected at concentrations greater than their respective Lower Limits of Detection (LLDs) as specified in NUREG-1 302 in any of the groundwater or

£ surface water samples. In the case of tritium, Exelon specified that the independent laboratory achieve a lower limit of detection 10 times lower than that I required by the United States Environmental Protection Agency (USEPA) regulation.

Strontium-89/90 was not evaluated in 2007.

Tritium was not detected in any of the groundwater or surface water samples at I concentrations greater than the United States Environmental Protection Agency (USEPA) drinking water standard (and the Nuclear Regulatory Commission Reporting Limit) of 20,000 pCi/L. Background levels of tritium were detected at concentrations greater than the self-imposed LLD of 200 pCi/L in 3 of 69 I

groundwater monitoring locations. The tritium concentrations ranged from 634 +

131 pCi/L to 704 +/- 157 pCi/L.

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Intentionally left blank Introduction The Clinton Power Station (CPS), consisting of one approximately 1140 MW gross electrical power output boiling water reactor is located in Harp Township, DeWitt County, Illinois. CPS is owned and operated by AmerGen Energy Company and became operational in 1987. Unit No. 1 went critical on 15 February 1987. The site encloses approximately 13,730 acres. This includes the 4,895 acre, man-made cooling lake and about 452 acres of property not owned by AmerGen. The plant is situated on approximately 150 acres. The cooling water discharge flume - which discharges to the eastern arm of the lake

- occupies an additional 130 acres. Although the nuclear reactor, supporting equipment and associated electrical generation and distribution equipment lie in Harp Township, portions of the aforementioned 13,730 acre plot reside within Wilson, Rutledge, DeWitt, Creek, Nixon and Santa Anna Townships.

This report covers. those analyses performed by Teledyne Brown Engineering (TBE) and Environmental Inc. (Midwest Labs) on samples collected in 2006.

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

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

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

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

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

5. Regularly assess analytical results to identify adverse trends. I

6. Take necessary corrective actions to protect groundwater resources.

B. Implementation of the Objectives The objectives identified have been implemented at Clinton Power Station I as discussed below:

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• 1. Exelon and its consultant identified locations as described in the Phase 1 study. Phase 1 studies were conducted by Connestoga Rovers and Associates (CRA) and the results and conclusions were made available to state and federal regulators- as well as the public on an Exelon web site in station specific reports..

http7Hlwww-exeloncorp.com/ourcompanies/powergen/nuclearlTritiu m.htm

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

3. Clinton Power Station will continue to perform routine sampling and radiological analysis of water from selected locations.

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

5. Clinton Power Station staff and consulting hydrogeologist assess analytical results on an ongoing basis to identify adverse trends.

C. Program Description.

1. Sample Collection

.'Samp0le"locations can be found in Table A-1 and Figures A-1 and

'A-2, Appendix A.,

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

Analytical laboratories are subject to internal quality assurance programs, inter-laboratory cross-check programs, as well as nuclear industry audits. Station personnel review and evaluate all analytical data deliverables after initial review by the contractor.

Analytical data results are reviewed by both station personnel and U

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 U 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 I 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 to produce tritium. Like, normal water, t.ritiated water is colorless and odorless. Tritiated water behaves chemically and physically like non-tritiated water in the subsurface, and therefore tritiated water will travel at the same velocity as the average groundwater velocity.

Tritium has a half-life of approximately 12.3 years, It decays spontaneously to helium-3 (3He). This radioactive decay releases a beta particle (low-energy electron). The radioactive decay of tritium is the source of the health risk from exposure to tritium. Tritium is one of the least dangerous radionuclides because it emits very weak beta 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.

I Ill. Program Description A. Sample Analysis This section describes the general analytical methodologies used by TBE and EIML to analyze the environmental samples for radioactivity for the 3 I

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Clinton Power Station RGPP in 2007.

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.

B. Data Interpretation The radiological data collected prior to Clinton Power Station becoming operational were used as a baseline with which these operational data were compared. For the purpose of this report, Clinton 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 report results with a 95% level of confidence. The uncertainty comes from calibration standards, sample Volume*or weight measurements, sampling uncertainty and other factors. Exelon 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.

Exelon 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.

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

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

For groundwater and surface water 13 nuclides, Be-7, K-40, Mn-54, Co-58, Fe-59, Co-60, Zn-65, Nb-95, Zr-95, Cs-134, I

Cs-137, Ba-140 and La-140 were reported.

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, milk, and vegetation. Theresults of the monitoring were detailed in the report entitled, Environmental Radioiogical Monitoring for Clinton Power Nuclear Power Station, Illinois Power:Company, AnnUal Report 1987, May 1988.

The pre-operationalIREMP contained analytical results from samples "collected'fromthe surface Water'. and groundwater.

1. Background Concentrations of Tritium:

The purpose of the following discussion is to summarize background measurements of tritium in various media performed by I

• ,~~others: ' .

a. Tritium Production ' I Tritium is created in theienvironment 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.

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A major anthropogenic source gftritium and strontium-90 comes from the former atmospheric testing of thermonuclear weapons. Levels of tritium in precipitation increased significantly during the 1950s and early 1960s, and later with additional testing, resulting in the release of significant amounts of tritium to the atmosphere. The Canadian heavy water nuclear power reactors, other commercial power reactors, nuclear research and weapons production continue to influence tritium concentrations in the environment.

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 world.wide from 1960 to 2006.

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

-surface water showed a.sharp decline up until 1975, followed by a gradual decline since that time. Tritium concentrations in Midwest precipitation have typically been below 100 pCi/L since around 1980. Tritium concentrations in wells may still be above the 200 pCi/L detection limit from the external causes described above.

c. Surface Water Data Tritium concentrations are routinely measured in Clinton Lake. Illinois surface water data were typically less than 100 pCi/L.

According to the USEPA, surface water data typically has an uncertainty +/- 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.

I 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- I 240 pCi/L or 140 +/- 100 pCi/L. Clearly, these sample results cannot be distinguished as different from background at this concentration.

IV. Results and Discussionn A. Groundwater Results Groundwater Baseline samples were collected from on and off-site wells during two (2) Phases at the station. Analytical results and anomalies are I

discussed below.

Samples from 23locations were analyz~ed for tritium activity (Tablei B-1.1 Appendix B). "Tritium values ranged from below the Exelon imposed LLD of 200 pico-curies per liter to 704 pCi/I.

Strontium Strontium-90 was not evaluated in 2007. I Gamma Emitters Naturally occurring Beryllium-7 was not detected in 2007.

Additionally, naturally occurring Potassium-40 was detected in three of 22 samples. The concentrations ranged from 58 pCi/liter to 118I pCi/liter. No other gamma emitting nuclides were detected. (Table B-1.2, Appendix B).

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APPENDIX A LOCATION DESIGNATION OF THE ANNUAL RADIOLOGICAL GROUNDWATER PROTECTION PROGRAM REPORT(ARGPPR)-

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TABLE A-I: Radiological Groundwater Protection Program - Sampling Locations, Clinton Power Station, 2007 Site Site Type I B-3 Monitoring Well MW-1 Monitoring WellI MW-CL-121 Monitoring Well MW-CL-131 Monitoring Well MW-CL-13S Monitoring Well MW-CL-14S Monitoring Well MW-CL-151 Monitoring Well MW-CL-15S Monitoring Well MW-CL-16S Monitoring Well MW-CL-17S Monitoring Well MW-CL-181 Monitoring Well MW-CL-18S Monitoring Well MW-CL-19S Monitoring Well MW-CL-2 Monitoring Well MW-CL-20S Monitoring Well MW-CL-21S Monitoring Well MW-CL-22S Monitoring Well SW-CL-1 Surface Water SW-CL-2 Surface Water SW-CL-4 Surface Water SW-CL-5 Surface Water SW-CL-6 Surface Water SW-CL-7 SW-CL-7 Surface Water Surface Water I I

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APPENDIX B DATA TABLES OF THE ANNUAL RADIOLOGICAL GROUNDWATER PROTECTION PROGRAM REPORT (ARGPPR)

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TABLE B-I.1 CONCENTRATIONS OF TRITIUM IN GROUNDWATER SAMPLES COLLECTED IN THE VICINITY OF CLINTON POWER STATION, 2007 I RESULTS IN UNITS OF PCI/LITER +/-2 SIGMA COLLECTION I

SITE DATE H-3 I

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B-3 04/24/07 B-3 07/24/07 166 B-3 11/02/07 185 MW-I MW-i MW-i 04/24/07 07/24/07 11/02/07 165 171 186 I

MW-CL-121 04/25/07 173 MW-CL-121 MW-CL-121 MW-CL-131 07/23/07 11/01/07 04/25/07 171 187 166 I

MW-CL-1 31 MW-CL-131 MW-CL-13S 07/24/07 11/02/07 04/25/07 173 187 167 I

I MW-CL-1 3S 07/24/07 171 MW-CL-13S 11/02/07 191 MW-CL-14S 04/25/07 176 + 113 MW-CL-14S 07/23/07 174 MW-CL-14S MW-CL-151 MW-CL-1 51 11/01/07 04/24/07 07/24/07 189 172 172 I

MW-CL-151 MW-CL-15S MW-CL-1 5S 11/02/07 04/24/07 07/24/07 183 168 170 I

MW-CL-15S 11/02/07 190 MW-CL-16S MW-CL-16S MW-CL-16S 04/25/07 07/23/07 11/01/07 170 170 190 I

MW-CL-17S MW-CL-1 7S MW-CL-17S 04/25/07 07/23/07 11/01/07 168 173 189 I

MW-CL-181 04/25/07 164 MW-CL-1 81 MW-CL-181 MW-CL-18S 07/23/07 11/01/07 04/25/07 171 184 169 I

MW-CL-1 8S MW-CL-18S MW-CL-19S 07/23/07 11/01/07 04/25/07 170 197 170 I

I MW-CL-19S 07/23/07 171 MW-CL-19S 11/01/07 191 MW-CL-2 04/24/07 171 MW-CL-2 07/24/07 168 MW-CL-2 11/02/07 186 I

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TABLE B-I.1 CONCENTRATIONS OF TRITIUM IN GROUNDWATER*SAMPLES COLLECTED IN THE VICINITY OF CLINTON POWERtSF-TATION, 2007 RESULTS IN UNITS OF PCI/LITER +/- 2SIGMA COLLECTION SITE DATE H-3 MW-CL-20S 04/24/07 167 MW-CL-20S 07/24/07 173 MW-CL-20S 11/02/07 194 MW-CL-21 S 04/25/07 634 +/- 131 MW-CL-21 S 07/24/07 662 +/- 134 MW-CL-21 S 11/02/07 704 +/- 157 MW-CL-22S 04/25/07 166 MW-CL-22S 07/23/07 162 MW-CL-22S 11/01/07 191 B-2

TABLE B-1.2 CONCENTRATIONS OF GAMMA EMITTERS IN GROUNDWATER SAMPLES COLLECTED IN THE VICINITY OF CLINTON POWER STATION, 2007 RESULTS IN UNITS OF PCI/LITER + SIGMA STC COLLECTION Be-7 K-40 Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 PERIOD B-3 11/02/07 < 26 < 22 < 3 < 3 < 7 <3 < 5 <3 < 6 < 2 < 3 < 30 - <10 MW-i 11/02/07 < 34 < 62 < 3 <4 < 8 <4 < 6 < 4 < 7 < 3 <4 < 39 k 14 MW-CL-2 1111/2/7 (1)

MW-CL-121 11/01/07 < 31 < 62 < 3 < 4 < 8 < 3 < 6 < 4 < 7 < 3 < 3 < 35 < 14 MW-CL-131 11/02/07 < 38 < 35 < 3 < 4 < 9 < 3 < 7 < 4 < 7 < 3 < 4 < 38 < 13 MW-CL-13S 11/02/07 <20 114 _ 22 < 2 < 2 < 5 < 2 <4 < 2 <4 < 2 < 2 < 26 < 8 MW-CL-14S 11/01/07 < 21 < 41 < 2 < 2 < 6 < 2 < 4 < 3 < 4 < 2 < 2 < 26 < 9 MW-CL-151 11/02/07 < 20 < 43 < 2 < 3 < 6 < 2 < 5 < 3 < 4 < 2 < 2 < 26 < 9 MW-CL-15S 11/02/07 < 20 < 37 < 2 < 2 < 5 < 2 < 4 < 3 < 4 < 2 < 2 < 26 < 8 MW-CL-16S 11/01/07 < 21 < 17 < 2 < 2 < 5 < 2 < 4 < 3 < 4 < 2 < 2 < 26 < 8 MW-CL-17S 11/01/07 < 26 < 43 < 2 < 3 < 7 < 2 < 5 < 3 < 5 < 2 < 2 < 31 < 11 MW-CL-181 11/01/07 < 24 < 37 < 2 < 3 < 7 < 2 < 4 < 3 < 5 < 2 < 2 < 32 < 12 MW-CL-18S 11/01/07 < 31 < 51 < 3 < 3 < 8 < 3 <6 < 4 < 7 < 3 < 3 < 46 < 14 MW-CL-19S 11/01/07 < 28 < 47 < 3 < 3 < 7 < 3 < 5 < 3 < 5 < 2 < 3 < 40 < 14 MW-CL-20S 11/02/07 < 35 < 59 < 3 < 4 < 9 < 3 < 6 < 4 < 7 < 3 < 3 < 48 < 15 MW-CL-21S 11/02/07 < 26 < 46 < 2 < 3 < 7 < 2 < 5 < 3 < 5 < 2 < 2 < 35 < 12 MW-CL-22S 11/01/07 < 22 < 34 < 2 < 3 < 6 < 2 < 4 < 3 < 4 < 2 < 2 < 33 < 12 (1) WELL RAN DRY. ONLY ENOUGH WATER COLLECTED FOR H-3 ANALYSIS

m. m- m - - m m

= m - m m= m - m

TABLE B-II.1 CONCENTRATIONS OF TRITIUM IN SURFACE WATER SAMPLES COLLECTED IN THE VICINITY OF CLINTON POWER STATION, 2007 CO ....

RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA COLLECTION SITE DATE H-3

=---- _--j CPS LAKE 06/07/07 < 153 SW-CL-1 04/25/07 < 159 SW-CL-1 07/23/07 < 160 SW-CL-1 10/31/07 < 193 SW-CL-2 04/24/07 < 166 SW-CL-2 07/23/07

• 161 SW-CL-2 10/31/07 < 192 SW-CL-4 04/24/07 < 160 SW-CL-4 07/23/07 < 161 SW-CL-4 10/31/07 < 194 SW-CL-5 04/24/07 < 166 SW-CL-5 07/23/07 < 162 SW-CL-5 10/31/07 < 191 SW-CL-6 04/24/07 < 165 SW-CL-6 07/23/07 < 166 SW-CL-6 10/31/07 < 193 SW-CL-7 04/24/07 < 164 SW-CL-7 07/23/07 < 162 SW-CL-7 10/31/07

• 196 B]-4

TABLE B-1I.2 CONCENTRATIONS OF GAMMA EMITTERS IN SURFACE WATER SAMPLES COLLECTED INTHE VICINITY OF CLINTON POWER STATION, 2007 RESULTS IN UNITS OF PCI/LITER +/- SIGMA STC COLLECTION Be-7 K-40 Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 PERIOD SW-CL-1 10/31/07 < 23 < 36 <2 <2 <6 <2 <4 <2 <5 <2 <2 <33 <11 SW-CL-2 10/31/07 < 30 118 +/- 33 <3 <3 <8 <3 <5 <3 <6 <2 <3 <49 <15 SW-CL-4 10/31/07 < 30 <46 <2 <3 <7 <3 <5 <3 <5 <2 <2 <47 < 14 SW-CL-5 10/31/07 < 30 58 +/- 37 < 3 <3 <7 <2 <5 <3 <5 <2 <2 < 45 < 14 SW-CL-6 10/31/07 < 29 <23 <3 <3 <7 <3 <6 <3 <5 <2 <3 < 45 < 15 SW-CL-7 10/31/07 < 29 < 24 <3 <3 <7 <2 <5 <3 <6 <2 <2 < 41 < 14 tz 0m m m =m m - - - = - - m m m n m