ML12130A267

Annual Environmental and Annual Radiological Environmental Operating Reports - Chapter 6 Through End

ML12130A267
Person / Time
Site:	South Texas
Issue date:	04/30/2012
From:	South Texas
To:	Office of Nuclear Reactor Regulation
References
Download: ML12130A267 (42)

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9-~ Tirn e tp RadiologicalEnvironmental OperatingReport PROGRAM DESCRIPTION The South Texas Project initiated a comprehensive pre-operational Radiological Environmental Monitoring Program in July 1985. That program terminated on March 7, 1988, when the operational program was implemented. The pre-operational monitoring program data forms the baseline against which operational changes are measured.

Analysis of the environmental pathways requires that samples be taken from water, air, and land environments. These samples are obtained to evaluate potential radiation exposure to people.

Sample types are based on established pathways and experience gained at other nuclear facilities.

Sample locations were determined after considering site meteorology, site hydrology, local demography, and land use. Sampling locations are further evaluated and modified according to field and analysis experience. Table I at the end of this section lists the required sampling locations and frequency of collection. Additional discretionary samples were also collected.

Sampling locations consist of indicator and control stations. Indicator stations are locations on or off the site that may be influenced by plant discharges during plant operation. Control stations are located beyond the measurable influence of the South Texas Project. Although most samples analyzed are accompanied by a control sample, it should be noted that this practice is not always possible or meaningful with all sample types. Fluctuations in the concentration of radionuclides and direct radiation exposure at indicator stations are evaluated in relation to historical data and against the control stations. Indicator stations are compared with characteristics identified during the pre-operational program to monitor for radiological effects from plant operation.

Two sample identification methods are used in the program. Figures 6-1 and 6-2 are maps that identify permanent sample stations. Descriptions of sample stations shown on Figure 6-1 and 6-2 are found in Table 2. Table 2 also includes supplemental sampling locations and media types that may be used for additional information. Figure 6-3 illustrates zones that may be used instead of permanent, numbered sample stations.

Photo By: Mike LeMay 6-2 STP Nuclear Operating Company

2011 EnvironmentalReport RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM DESIGNATED SAMPLE LOCATION MAP N=124,241 & NýýE NN , -

NW N WNW ENE WSW ESE weww SW1 7*ý' SE Figure 6-1 C l h I. I,,,-

a -,,-.*

r n a l

• n n*-;, 6 -3 I I'ULI t Vo I'.JIa~l lyj '.AJ I iO y

OperatingReport RadiologicalEnvironmental MAP ENVIRONMENTAL LOCATION RADIOLOGICAL SAMPLE ONSITE 6-2 Figure Operating Company STP Nuclear 6-4

2011 Environmental Report RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ZONE LOCATION MAP I

The zone station is determined in the following manner:

• The first character of the station number "Z" to identify it as a zone station.

• The second character is the direction coordinate number 1-8.

• The third character is the distance from the site number 1-6.

Figure 6-3 6-5 STP Nuclear Operating Company

RadiologicalEnvironmental OperatingReport ANALYSIS OF RESULTS AND TRENDS Environmental samples from areas surrounding the South Texas Project continue to indicate no radiological effects from plant operation. Analytical values from offsite indicator sample stations continue to trend with the control stations. Measurements from onsite indicator samples continued to increase or decrease within their expected values.

Average quarterly air particulate sample beta activity from three onsite indicator stations and a single control station have been compared historically from 2001 through 2011 (see Figure 6-4). The average of the onsite indicators trends closely with the offsite control values. The comparison illustrates that plant operations are not having an impact on air particulate activity even at the Sensitive Indicator Stations (#1, #15, and #16). These stations are located near the site boundary downwind from the plant, based on the prevailing wind direction. The beta activity measured in the air particulate samples is from natural radioactive material. Gamma analysis is performed on quarterly composites of the air particulate samples to determine if any activity is from the South Texas Project. The gamma analyses revealed no radioactivity from the South Texas Project. However, effects from the radiological event at the Fukushima Daiichi nuclear power station in Japan following the earthquake and tsunami on March 11, 2011 were noticed throughout the North American continent. The Fukushima results are discussed in a later section.

Historical Comparison of Average Quarterly Beta Activity from Indicator and Control Air Samples 2001 - 2011 S 0.035

• t6 * ',.,0.030

• ~0.025 3 0.020 0.015 0.010 oo.o 0.005 0.000

- Station #001, #015 & #016 Average of Onsite Indicators Station #037 Offsite Control Figure 6-4 6-6 STP Nuclear Operating Company

2011 EnvironmentalReport Direct gamma radiation is monitored in the environment by thermoluminescent dosimeters located at 40 sites. The natural direct gamma radiation varies according to location because of differences in the natural radioactive materials in the soil, soil moisture content, and other factors. Figure 6-5 compares the amount of direct gamma radiation measured at the plant since the fourth quarter of 2001 for three different types of stations. The Control Stations, Stations #23 and #37, are greater than 10 miles from the site in the minimal wind direction. The least frequent direction into which the wind blew in 2011 was the ENE sector. The prevailing wind direction is into the NNW sector. The Sensitive Indicator Stations are one mile NW, NNW, and N from the power plants on FM 521 at Stations # 15, # 16 and #1 respectively. The Indicator Stations are the remainder of the required stations. The values plotted are the averages for all of the stations according to type. Thermoluminescent Dosimeter Station # 9 saw an increase in direct radiation two times higher than the normal quarterly average of 14 milliroentgen. Station # 9 is located on site 0.25 miles south of the units on the reservoir embankment facing the temporary storage building just outside Unit 2 which housed the old reactor vessel heads. Direct radiation values returned to normal following removal of the old reactor vessel heads from site. The average of the Control Stations is higher than the other stations because station #23 is in an area that has a slightly higher natural background radiation. The trends of Figure 6-5 clearly show that the power plants are not adding to the direct radiation in the offsite environment.

Environmental Dosimeter Comparisons 22 Averge of Indicator Stations Average of Control Stations - Sensitive Indicator Stations 20 18

, 16 14 S 12 I0 Results by Quarter Figure 6-5 STP Nuclear Operating Company 6-7

RadiologicalEnvironmental OperatingReport Bottom sediment samples are taken from the Main Cooling Reservoir each year. Figure 6-6 shows the positive results from the plant-produced radioactive material Cobalt-60. The Cobalt-60 inventory in the reservoir has decreased since 1992 because of radioactive decay and equipment installed to reduce radioactive effluents. Although the total activity of Cobalt-60 has decreased over time, there is an inventory of Cobalt-60 still in the reservoir as seen at Stations # 215 and # 216. In 2011, Cobalt-60 was identified in four of six samples. Figure 6-7 demonstrates the calculated decline in the total amount of Cobalt-60 in the reservoir.

Cesium- 137 was measured in five of six bottom sediment samples from Stations #215 and #216 in the Main Cooling Reservoir and one of two shoreline sediment samples taken at station # 227.

The highest measurement in 2011 was 119 pCi/kg at Station # 215. The activity measured at station # 216 was 52 pCi/kg. Cesium-137 is often found in environmental media including soil and sediment from residual radioactive material from nuclear weapons testing fallout. Soil and sediment samples taken in 1986 and 1987 prior to operation of STP contained Cesium- 137 from weapons testing fallout. The pre-operational average Cesium- 137 concentration was 118 pCi/kg when it was detected in soil and sediment samples but the highest sample measured 383 pCi/kg.

The 119 pCi/kg measured at Station # 215 and the 22 pCi/kg at Station # 227 are consistent with these pre-operational concentrations reduced by 25 years of radioactive decay.

Tritium has been monitored in the shallow aquifer since 1997 on the south side of the Main Cooling Reservoir. Models used when licensing the site predicted tritium in the shallow aquifer.

These models were validated with additional studies for the proposed Units 3 & 4. A site conceptual model developed in 2008 to implement the Nuclear Energy Institute's Groundwater Protection Initiative also validated the original predictions of the site hydrology study.

Photo By: Steve Antonio 6-8 STP Nuclear Operating Company

2011 EnvironmentalReport Historical Compar ison of Cobalt-58 & Cobalt-60 in Main Coo ling Reservoir Sediment 2001 -2011 350 U Station #215 : Cobalt-f0 300 Plant Discharge 2 Station #216 : Cobalt-60 2 Blowdown Structure 250

.*200 The inventory of Co-60 has been calculated and is shown in Figure 6-7.

. 150

. 100 50 2001 2003 2005 2007 2009 2011 Figure 6-6 Calculated Cumul itive Curies of Cobalt-60 in the Main Cooling Reservoir 2.0T 1.5 6,, 1.0-U Cobalt-60 0.5 0.0-ASSUMPTIONS:

1. Radioactive decay is the on1ly mechanism for removal from the Main Cooling Reservoir.

2. The initial time for calculatirng the remaining radioactivity is July 1 of the year released.

Figure 6-7 STP Nuclear Operating Company 6-9

RadiologicalEnvironmental OperatingReport Tritium is a radioactive isotope of hydrogen and is produced during plant operation. Tritium produced in the reactors is a part of the water molecule. Wastewater is treated to remove impurities before release, but tritium cannot be removed because it is chemically part of the water molecule. Some of the tritium is released into the atmosphere, and the remainder is released into the Main Cooling Reservoir. The tritium escapes from the Main Cooling Reservoir by evaporation, movement into the shallow aquifer, and by percolation from the relief wells which are a part of the reservoir embankment's stabilization system. Figure 6-8 shows the amount of tritium released to the Main Cooling Reservoir each year and the amount present during the last quarter of each year.

The concentration of tritium in the Main Cooling Reservoir was relatively stable in 2011. The amount of tritium measured in the Main Cooling Reservoir was consistent with the amount released. The amount of rainfall and river makeup normally influences the concentration of tritium in the Main Cooling Reservoir and the shallow aquifer surrounding it. The effect of reduced rainfall in the area due to drought conditions in 2011 resulted in higher concentrations of tritium in surface waters across the site. Tritium enters the sloughs and ditches of the site as runoff from the relief wells that surround the reservoir. In 2011, tritium levels remained low in the relief wells as shown in Figure 6-9.

Historical Comparison of Tritium Added to and Remaining in the Main Cooling Reservoir 2001 -2011 3500 3000 +

2500 4I E

"* 2000

.* 1500 1000 0°°t 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 U

0 Tritium Released to the Main Cooling Reservoir M Tritium Measured in the Main Cooling Reservoir Figure 6-8 6-10 STP Nuclear Operating Company

2011 EnvironmentalReport The tritium concentration in eight surface water sample points from 2001 through 2011 is shown in Figure 6-10. The specific sample point locations can be found in Table 2. Tritium levels in the onsite sloughs and ditches vary due to the concentration in the reservoir and the amount of rainfall received. The average tritium concentration in the relief wells, sloughs, and ditches is less than the reservoir because the water is diluted as it migrates through the reservoir relief well system. In 2011, four required and nine non-required surface water samples tested positive for tritium. Tritium activity was one and a half times higher than the nine month average for the surface water at station # 213 due to limited rainfall. All test results were below the United States Environmental Protection Agency drinking water limit of 20,000 pCi/kg. Rainwater was collected and analyzed during 2011 to determine if the tritium from the reservoir precipitated in the local area. Tritium was not measured in any of the rainwater samples.

Tritium was identified in the shallow (ten to thirty feet deep) aquifer test wells at Station #235, approximately seventy-five yards south of the reservoir embankment base during 1999. Starting in 2000, samples were collected from the shallow aquifer well at Station #251 southeast of the Main Cooling Reservoir. The tritium results from these two shallow aquifer wells are shown in Figure 6-11. In 2011, the concentration of the well at Station #235 was higher than average but consistent with values over the past three years. Tritium concentrations have remained near the Historical Comparison of Tritium Activity in Reservoir Relief Wells 2001 - 2011 30,000 picoCuries per Kilogram - Nuclear Regulatory Commision Reporting Level S30000 S25000 2 20000 20,000 picoCuries per Kilogram - Environmental Protection Agency Drinking Water Limit 15000

= 10000 0

2001 2003 2005 2007 2009 2011 El Main Cooling Reservoir Relief Well (onsite) #701 Figure 6-9 STP Nuclear Operating Company 6-11

RadiologicalEnvironmental OperatingReport concentrations found in the relief wells. Wells at Stations #258 and #259 on the west side of the site boundary have been sampled since 2006. Wells at Stations #270 and #271 were installed during the last quarter of 2008. The sample results are shown in Figure 6-12. Tritium levels were generally stable in 2011 with a peak of 1,980 pCi/kg and remained below the United States Environmental Protection Agency drinking water limit (20,000 pCi/kg). The well at Station

1. 271, located adjacent to site property on a county road easement directly west of the Main Cooling Reservoir, indicated a concentration in 2011 of 653 pCi/kg which is slightly above the detection limit. This is the second year that a positive measurement has been detected at this shallow monitoring well location. A windmill-powered ground water well, sample station # 267, first indicated tritium activity slightly above detection limits at 544 pCi/kg in 2011. This ground water sample station is the most distant location from the Main Cooling Reservoir that tritium has been detected.

The drinking water onsite is pumped from deep aquifer wells and is tested quarterly to verify tritium is not present. The South Texas Project uses no water from the reservoir, shallow aquifers or other surface water for drinking. If the water with the highest tritium concentration that leaves the site (Little Robbins Slough) was used for drinking, the maximum dose to an individual would be about one millirem in a year. This dose is insignificant compared to approximately 620 mrem the public receives a year from natural radioactivity in the environment and the radiation received from medical procedures (reference National Council on Radiation Protection Report No. 160).

Other samples are collected and analyzed in addition to those required by our licensing documents or internal procedures. These samples are collected to give additional assurance that the public and the environment are protected from any adverse effects from the plant. These samples include pasture grass, sediment samples, rain water, shallow aquifer well water, water from various ditches and sloughs onsite, and air samples near communities or other areas of interest. The results of these analyses indicate that plant related radioactive material released to the environment during plant operation has no health impact.

Photo By: Bernadette White 6-12 STP Nuclear Operating Company

2011 EnvironmentalReport Historical Comparison of Tritium Activity in Surface Water 2001-2011 30.000 picoCuries er Kilo ram - Nuclear Re ulato rrCommisionRe orin Level 30000 20,000 picoCuries per Kilogram - Environmental Protection Agency Drinking Water Limit 25000 20000

.* 15000 10000 5000 0

2001 2003 2005 2007 2009 2011 U River Sample Upstream of Plant (Offsite) #Q02 U River Sample Downstream of Plant (Offsite) #QO0 EWest Branch of River (Onsite) #213 N Little Robbins Slough (Onsite) #212

• East Branch of Little Robbins Slough (Onsite) #211 Ditch NE of Main Cooling Reservoir (Onsite) #229 o Main Cooling Reservoir Blowdown (Onsite) #237 03Main Cooling Reservoir (Onsite) #216 Figure 6-10 Historical Comparison of Tritium Activity in Shallow Aquifer Ground Water 2001 - 2011 30,000 picoC*aois per Kilogram Nuclear Regulary Commision Reporting Level j 30000 25000 0 picoCuries per Kilogram - En, ironmental Protection Agency Drinking Water Limit S 2110000 15000 0 10000 S 5000 0

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 nTest Well B-3 directly south from MCR (onsite) #235 ETest Well B-4 Upper Aquifer (onsite) #251 Figure 6-11 STP Nuclear Operating Company 6-13

RadiologicalEnvironmental OperatingReport Tritium Activity in Shallow Ground Water West of the Main Cooling Reservoir 2006 - 2011 5000 450W-40001 3250

00. . . . . . .. . .. . . .. . .

• o2000 2500-

"*1000-1 500-0 QWr. Qtr. Qtr. Qtr. Qtr. Qtr. Qtr. Qtr. Qtr. Qtr. Qtr. Qtr' Qtr. Qtr. Qtr. Qtr. Qtr. Qtr. Qtr. Qtr. Qtr. Qtr. Qtr.

06 06 06 07 07 07 07 08 08 08 08 09 09 09 09 10 10 ,0 10 11 11 11 11 Figure 6-12 Photo By: Sherrie Deen 6-14 STP Nuclear Operating Company

2011 EnvironmentalReport LAND USE CENSUS The Annual Land Use Census is performed to determine if any changes have occurred in the location of residents and the use of the land within five miles of the South Texas Project generating units. The information is used to determine whether any changes are needed in the Radiological Environmental Monitoring Program. The census is performed by contacting area residents and local government agencies that provide the information. In addition, a survey is performed to verify the nearest residents within five miles of the South Texas Project generating units in each of 16 sectors. The results of the survey indicated no changes for 2011. The eleven sectors that have residents within five miles and the distance to the nearest residence in each sector are listed below.

SECTOR DISTANCE (MILES) LOCATION ENE 4.5 CR 232 (Ryman Rd)

ESE 3.5 Selkirk Island SE 3.5 Selkirk Island SW 4.5 CR 386 (Corporon Rd)

SSW 4.5 CR 391 (Robbins Slough Rd.)

WSW 2.5 FM 521 W 4.5 FM 1095 WNW 4.5 CR 356 (Ashby-Buckeye Road)

NW 4.5 CR 354 (Mondrik Road)

NNW 3.0 Runnells Ranch - FM 1468 N 3.0 Runnells Ranch - FM 1468 The following items of interest were noted during the census:

• Colorado River water from below the Bay City Dam has not been used to irrigate crops.

• There were no identified commercial vegetable farms located within the five mile zone.

• No commercial dairy operates within Matagorda County and there is no source of milk within the five mile zone.

Two commercial fish farms cqntinue to operate. One is two miles west of the plant near FM 521, and the second is between four to five miles southwest of the plant located in the area north of Robbins Slough Road and east of South Citrus Road. The water supply, deep aquifer wells and Lower Colorado River Authority irrigation water, for the ponds is not affected by the operations of the South Texas Project generating units.

Broadleaf vegetation sampling is performed at the site boundary in the three most frequent downwind sectors and at a control location in lieu of a garden census. The broadleaf vegetation samples taken satisfy the milk collection requirement when milk samples are not available.

STP Nuclear Operating Company 6-15

RadiologicalEnvironmental OperatingReport QUALITY ASSURANCE Quality assurance encompasses planned and systematic actions to ensure that an item or facility will perform satisfactorily. Reviews, surveillance, and audits have determined that the programs, procedures and personnel are adequate and perform satisfactorily.

Quality audits and independent technical reviews help to determine areas that need attention and re-evaluation. Areas that need attention are addressed in accordance with the station's Corrective Action Program.

The measurement capabilities of the Radiological Laboratory are demonstrated by participating in an inter-laboratory measurement assurance program as well as duplicate and split sample analyses. A total of approximately 10% of the analyses performed are quality control samples consisting of inter-laboratory measurement assurance program samples, duplicate samples, and split samples.

The inter-laboratory measurement assurance program provides samples that are similar in matrix and size to those measured by the Radiological Environmental Monitoring Program. This 2011 Radiological Laboratory Quality Assurance Program Performance 0-5% Difference 10-15% Difference 5-10% Difference 78 Total Analyses Figure 6-13 6-16 STP Nuclear Operating Company

2011 EnvironmentalReport program assures that equipment calibrations and sample preparation methods accurately measure radioactive material in samples. Figure 6-13 summarizes the results of the inter-laboratory comparison programs.

Duplicate sampling of the environment allows the STP Nuclear Operating Company to estimate the repeatability of the sample collection, preparation, and analysis process. Splitting samples allows estimation of the precision and bias trends of the method of analysis without the added variables introduced by sampling. Generally, two samples split from the same original sample material should agree better than two separate samples collected in the same area and time period. Figure 6-14 shows the fraction of duplicate and split sample pairs that agreed with less than a 0.5% chance that any disagreement was due to chance alone.

Figure 6-14 depicts how results agreed for the 114 samples with detected radioactive material found in 258 duplicate or split samples collected from the same location in 2011. Historically, duplicate/split samples agreed 95% of the time. In 2011,91.5% of the samples were in agreement at the 99.5% confidence interval. New-style air monitoring equipment tested in 2011 may have reduced air alpha measurement agreement from the historical average.

2011 DUPLICATE & SPLIT SAMPLE AGREEMENT Air Alpha Variances, 4.9%

Air Beta Variances, 1.2%

Tritium Variances, 0.0%

S All Other Variances, 2.4%

Acceptable, 91.5%

Figure 6-14 STP Nuclear Operating Company 6-17

RadiologicalEnvironmentalOperatingReport PROGRAM DEVIATIONS In addition to measurement accuracy, radiochemical measurements must meet sensitivity requirements at the Lower Level of Detection for environmental samples. Deviations from the sampling program or sensitivity requirements must be acknowledged and explained in this report.

During 2011 the following samples were not collected or were unacceptable for analysis:

" Twenty six out of thirty-six required broadleaf vegetation samples were not collected from January through December due to seasonal unavailability, extreme drought conditions, and destruction from wild hogs. Electric fencing has been installed to help prevent future destruction from wild hogs.

" One (Station # 266) out of twenty ground water samples was not collected due to drought conditions.

The minimum Radiological Environmental Monitoring Program is presented in Table 1. The table is organized by exposure pathway. Specific requirements such as location, sampling method, collection frequency, and analyses are given for each pathway.

NEI GROUNDWATER PROTECTION INITIATIVE Nuclear industry events involving tritium prompted the station to sample groundwater in the shallow aquifer near the nuclear plants in 2005. Some samples indicated the presence of tritium, but all were at concentrations below the Environmental Protection Agency drinking water limit of 20,000 pCi/kg.

In 2007, the Nuclear Energy Institute established a standard for monitoring and reporting radioactive isotopes in groundwater titled "NEI Groundwater Protection Initiative", NEI 07-07.

The station implemented the recommendations of this industry standard and has broadened the groundwater monitoring program to include samples collected near the nuclear plants. Some of the positive results of this broadened monitoring program. likely reflect tritium associated with the Main Cooling Reservoir.

Wells near the nuclear plants Sample 2011 Measurements Historical High are sampled semiannually, Station (pCi/liter) (pCi/liter) annually or once every five 801 780 1152 years depending on the concentration of tritium 807 1300 15300 anticipated and the location 808 990 2858 of the wells. The following 809 315 less than 300 table contains the 2011 results 811 995 274 along with the historical high 815 275 321 prior to 2011 for each station 816 378 971 since sampling began in 2006 and their locations are shown 821 549 386 in Figure 6-15. 836 991 3324 6-18 STP Nuclear Operating Company

2011 Environmental Report Two wells sampled quarterly (807 and 808) are adjacent to where a pipe was broken and repaired several years ago. The tritium concentration at these two wells continued to decrease in 2011 as it has for the last four years. Well 809 became positive recently and the source of that tritium is also likely to be related to the previously referenced pipe break and subsequent repair. Well #836 has always been positive but has been decreasing from its peak concentration several years ago.

All the other wells sampled in 2011 that had detectable tritium are influenced by groundwater originating in the Main Cooling Reservoir. Their concentrations remain in the range of groundwater tritium concentrations associated with the Main Cooling Reservoir. All the 2011 measurements of tritium in groundwater are a small fraction of the United States Environmental Protection Agency drinking water limit (20,000 pCi/liter).

Following the transport of a reactor head package to a temporary radiologically controlled area in 2011, a heavy rain storm soaked the package. Following the storm, water was noticed leaking from the head packaging to the ground. The soil and gravel were removed to remediate the areas affected. No ground water remediation was required. Information regarding the leaking rainwater and subsequent response was documented in the station's Correction Action Program.

The evaluation identified no release via a credible pathway, no radioactive material was released offsite, and there was no impact to the drinking water or the health and safety of the public.

STP PROTECTED AREA GROUND WATER MONITORING WELLS N

S 04-03-2012 Legend

• WELLS Figure 6-15 STP Nuclear Operating Company 6-19

RadiologicalEnvironmental OperatingReport FUKUSHIMA DAIICHI On March 11, 2011, a large earthquake followed by a tsunami inundated the Fukushima Daiichi nuclear power station in Japan. This radiological event released radioactive material into the atmosphere. During March and April of 2011 airborne radioactive material was detected at South Texas Project air sample stations, including the control station located greater than 10 miles from the South Texas Project. Numerous other North American nuclear power stations also measured similar concentrations of radioactive material during these two months following the incident at Fukushima Daiichi.

Air particulate and air iodine samples were obtained as part of our normal continuous air samples which are collected and counted on a weekly routine. The air sample stations measured low levels of Iodine- 131 and Cesium- 137 from March 22 to April 19, 2011. The highest Iodine- 131 weekly air sample concentration was 0.1 pCi/m 3 and was measured at three different locations

(#15, #18, and #35) on March 29, 2011. All air sample stations measured Iodine- 131 during this period of time.

Additional daily air samples were also measured for informational purposes as part of a United States Environmental Protection Agency study in response to the Japanese nuclear event at Fukushima. The highest daily measurement at STP for Iodine- 131 was 0.27 pCi/m 3 detected on March 24, 2011.

Air samples that indicated Iodine- 131 or Cesium- 137 are attributed to the Fukushima Daiichi event and not to operations at the South Texas Project. The low levels of airborne radioactive material posed no health risk to the residents near the South Texas Project, but the Fukushima Daiichi event did allow the station to demonstrate the capability to detect ultra-low concentrations of airborne radioactive material originating as far away as Japan.

Photo By: Jodie Jankauskas 6-20 STP Nuclear Operating Company

2011 EnvironmentalReport TABLE 1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM EXPOSURE: DIRECT RADIATION 40 TOTAL SAMPLING STATIONS Sample Media, Number, Approximate Location and Distance of Routine Sampling Sampling and Analysis Minimum Sample Stations from Containment. Mode Collection Type Analysis Frequency Frequency Exposure Media: TLD 16- Located in all 16 meteorological sectors, 0.2* to 4 miles. Continuously Quarterly Gamma dose Quarterly 16- Located in all 16 meteorological sectors, 2 to 7 miles.

6- Located inspecial interest areas (e.g. school, population centers), within 14 miles.

2- Control stations located in areas of minimal wind direction (WSW,ENE), 10-16 miles.

• The inner ring of stations in the southern sectors are located within I mile because of the main cooling reservoir EXPOSURE: AIRBORNE 5 TOTAL SAMPLING STATIONS Sample Media, Number, Approximate Location, and Distance of Routine Sampling Nominal Analysis Minimum Sample Stations from Containment. Mode Collection Type Analysis Frequency Frequency Charcoal and Particulate Filters 3- Located at the exclusion zone, N, NNW, NW Sectors, I mile. Continuous sampler Weekly or more Radioiodine Weekly operations frequently if Canister:

I-Located in Bay City, 14 miles. required by dust 1-131 loading I- Control Station, located in a minimal wind direction (WSW), 10 Particulate miles. Sampler:

Gross Beta Following filter Activity change Gamma- Quarterly Isotopic of composite (by location)

STP Nuclear Operating Company 6-21

RadiologicalEnvironmental OperatingReport TABLE 1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM (Continue)

EXPOSURE: WATERBORNE 13 TOTAL SAMPLING STATIONS Sample Media, Number And Approximate Location of Sample Routine Sampling Nominal Analysis Minimum Stations Mode Collection Type Analysis Frequency Frequency Surface I- Located in MCR at the MCR blowdown structure. Composite sample Monthly Gamma- Monthly over a I month Isotopic I-Located above the site on the Colorado River not influenced by period (grab if not plant discharge (control). available) Tritium Quarterly Composite

_- Located downstream from blow down entrance into the Colorado River.

Ground 5- Located in wells used to monitor tritium migration in the shallow Grab Quarterly Gamma- Quarterly aquifer. Isotopic &

Tritium EXPOSURE: WATERBORNE (CONTINUED)

Sample Media, Number And Approximate Location of Sample Routine Sampling Nominal Analysis Minimum Stations Mode Collection Type Analysis Frequency Frequency Drinking Water 1- Located on site.

• Grab Monthly Gross Beta & Monthly Gamma-

- Located at a control station. Isotopic Tritium Quarterly Composites Sediment Grab Semiannually Gamma- Semiannually Isotopic I - Located above the site on the Colorado River, not influenced by plant discharge.

I_-Located downstream from blowdown entrance into the Colorado River.

I1-Located in MCR.

No municipal water systems are affected by STP. This sample taken from deep aquifer supplying drinking water to employees while at work.

6-22 STP Nuclear Operating Company

2011 Environmental Report TABLE 1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM (Continue)

EXPOSURE: INGESTION 7 TOTAL SAMPLING STATIONS Sample Media, Number And Approximate Location of Sample Routine Sampling Nominal Analysis Minimum Stations Mode Collection Type Analysis Frequency Frequency Milk Grab Semi-monthly Gamma- Semi-monthly when animals are Isotopic when animals are on pasture; And Low Level on pasture; monthly at other 1-131 monthly at other times, times.

Broadleaf Vegetation**

2- Located at the exclusion zone, N, NW, or NNW sectors. Grab Monthly during As collected growing season Gamma-I- Located in a minimal wind direction. (When available) Isotopic

• Limited source of sample in vicinity of the South Texas Project. (Attempts will be made to obtain samples when available.)

• • Three different kinds of broadleaf vegetation are to be collected over the growing season, not each collection period.

EXPOSURE: INGESTION (continued)

Sample Media, Number And Approximate Location of Sample Routine Sampling Nominal Analysis Minimum Stations Mode Collection Type Analysis Frequency Frequency Fish and Invertebrates (edible portions) 1- Representing commercially or recreational important species Grab Sample semi- Gamma- As collected in vicinity of STP that maybe influenced by plant operation. Isotopic on annually edible portions 1- Same or analogous species in area not influenced by STP.

1- Same or analogous species in the MCR.

Gamma-Agricultural Products Grab Isotopic As collected Analysis in

• edible portion Domestic Meat At time of harvest Gamma-1- Represents domestic stock fed on crops grown exclusively within Grab Isotopic As collected 10 miles of the plant.

Annually No sample stations have been identified in the vicinity of the site. Presently no agricultural land is irrigated by water into which liquid plant wastes will be discharged. Agricultural products will be considered if these conditions change.

STP Nuclear Operating Company 6-23

RadiologicalEnvironmental OperatingReport TABLE 2 SAMPLE MEDIA AND LOCATION DESCRIPTIONS Al AIRBORNE RADIOIODINE L6 COLLARD GREENS AP AIRBORNE PARTICULATE L7 MUSTARD GREENS BI RESIDENT DABBLER DUCK MI BEEF MEAT B2 RESIDENT DIVER DUCK M2 POULTRY MEAT B3 MIGRATORY DABBLER DUCK M3 WILD SWINE B4 MIGRATORY DIVER DUCK M4 DOMESTIC SWINE B5 GOOSE M5 EGGS B6 DOVE M6 GAME DEER B7 QUAIL M7 ALLIGATOR B8 PIGEON M8 RABBIT CC CRUSTACEAN CRAB OY OYSTER CS CRUSTACEAN SHRIMP SO SOIL DR DIRECT RADIATION Si SEDIMENT - SHORELINE Fl FISH - PISCIVOROUS S2 SEDIMENT - BOTTOM F2 FISH - CRUSTACEAN & INSECT VB ANY COMBINATION OF FEEDERS BROADLEAF SAMPLES (LI thru L7)

F3 FISH - PLANKTIVORES & DETRITUS VP PASTURE GRASS FEEDERS Li BANANA LEAVES WD DRINKING WATER L2 CANA LEAVES WG GROUND WATER L4 TURNIP GREENS WR RAIN WATER L5 CABBAGE WS SURFACE WATER WW RELIEF WELL WATER 6-24 STP Nuclear Operating Company

2011 Environmental Report TABLE 2 SAMPLE MEDIA AND LOCATION DESCRIPTIONS MEDIA CODE STATION VECTOR LOCATION DESCRIPTION CODE (Approximate)

DRAI AP VB VP SO 001 1 mileN FM521 DR 002 1 mile NNE FM 521 DR 003 1 mile NE FM 521 DR 004 1 mile ENE FM 521 DR 005 1 mile E FM 521 DR Al AP SO 006 3.5 miles ESE Site near Reservoir Makeup Pumping Facility DR 007 3.5 miles SE MCR Dike DR 008 0.25 mile SSE MCR Dike DR 009 0.25 mile S MCR Dike DR 010 0.25 mile SSW MCR Dike DR 011 0.5 mile SW MCR Dike DR 012 1.5 mile WSW MCR Dike DR 013 1.5 mile W FM 521 DR 014 1.5 mile WNW FM 521 DR AI AP VB SO VP 015 1 mile NW FM521 DR AI AP VB SO VP 016 1 mile NNW FM 521 DR 017 6.5 miles N Buckeye --FM 1468 DR Al AP SO 018 5.5 miles NNE OXEA Corp. - FM 3057 DR 019 5.5 miles NE FM 2668 MCR-STP Main Cooling Reservoir STP- South Texas Project Media codes typed in bold satisfy collection requirement described in Table 1.

• - Control Station STP Nuclear Operating Company 6-25

RadiologicalEnvironmental OperatingReport TABLE 2 SAMPLE MEDIA AND LOCATION DESCRIPTIONS MEIACOESTATION VECTOR MEDIA CODE CODE (Appro (Approximate) ) LOCATION DESCRIPTION DR 020 5 miles ENE FM 2668 & FM 2078 DR 021 5 miles E FM 521 & FM 2668 DR 022 7 miles E Lyondell Chemical Plant DR 023

• 16 miles ENE Intersection of FM 521 and FM 2540 DR 024 4 miles SSE MCR Dike DR 025 4 miles S MCR Dike DR 026 4 miles SSW MCR Dike DR 027 2.5 miles SW MCR Dike DR 028 5 miles WSW FM 1095 & Ellis Road DR SO 029 4.5 miles W FM 1095 DR 030 6 miles WNW Tres Palacios Oaks, FM 2853 DR 031 5.5 miles NW Wilson Creek Road DR 032 3.5 miles NNW FM 1468 DR AI AP SO 033 14 miles NNE Microwave Tower at end of Kilowatt Road in Bay Ct City DR 034 7.5 miles ENE Wadsworth Water Supply Pump Station DR Al AP SO 035 8.5 miles SSE Matagorda DR 036 9 miles WSW College Port DR Al AP VB VP SO 037* 10 miles WSW Palacios AEP Substation DR 038 10.5 miles NW AEP Substation on TX 71 near Blessing MCR-STP Main Cooling Reservoir STP- South Texas Project Media codes typed in bold satisfy collection requirement described in Table 1.

• Control Station 6-26 STP Nuclear Operating Company

2011 EnvironmentalReport TABLE 2 SAMPLE MEDIA AND LOCATION DESCRIPTIONS MEDIA CODE STATION VECTOR LOCATION DESCRIPTION CODE (Approximate)

DR Al AP SO 039 9 miles NW TX 35 under High Voltage Power lines near Tidehaven High School DR 040 4.5 miles SW Citrus Grove DR 041 2.0 miles ESE MCR Dike DR 042 8.5 miles NW FM 459 at Tidehaven Intermediate School DR 043 4.5 miles SE Site boundary at blowdown outlet WG 205 4.0 miles SE Piezometer Well #446A, 40' deep WG 206 4.0 miles SE Piezometer Well #446, 78' deep WS 209 2 miles ESE Kelly Lake WD 210 On Site Approved drinking water supply from STP WS Sl 211 3.5 miles S Site, E. Branch Little Robbins Slough WS S1 212 4 miles S Little Robbins Slough WS S1 213 4 miles SE West Branch Colorado River F (1,2, or 3) CC 214 2.5 miles SE MCR at Makeup Water Discharge S2 215 0.5 mile SW MCR at Circulating Water Discharge WS S2 216 3.5 miles SSE MCR at blowdown structure WS S(1 or 2) F(1,2 OR 3) 217 7-9 miles SSE Region 1 (mouth of the Colorado River to marker 1)

F (1, 2, or 3) CC CS OY 222 >10 miles West Matagorda Bay West bank of Colorado River downstream of STP across WS S(1 or 2) 227 5-6 miles SE from channel marker #22 WD 228* 14 miles NNE Le Tulle Park public water supply Drainage ditch north of the reservoir that empties into WS S1 229 2.3 miles ESE Colorado River upstream of the reservoir makeup pumping facility Colorado River at point where drainage ditch (#229)

S( or 2) 230 3.5 miles ESEinto it MCR-STP Main Cooling Reservoir STP- South Texas Project Media codes typed in bold satisfy collection requirement described in Table 1.

• Control Station STP Nuclear Operating Company 6-27

RadiologicalEnvironmental Operating Report TABLE 2 SAMPLE MEDIA AND LOCATION DESCRIPTIONS MEDIA CODE STATION VECTOR LOCATION DESCRIPTION CODE (Approximate)

S(1 or 2) WS 233 4.5 miles SE Colorado canlepisit River wheret MCR blowdown discharge channel empties into it.

WG 235 3.8 miles S Well B-3 directly south from MCR B8 236 N/A STP Protected Area WS 237 3.7 miles SSE Blowdown discharge channel from MCR S(1 or 2) WS 242* >10 miles N Colorado River where it intersects Highway 35 WS 243* >10 miles N Colorado River upstream of Bay City Dam at the Lower Colorado River Authority pumping station WG 245 4.5 miles SSE Water well approximately 60' deep located on private property about 0.5 miles south of MCR WS 247 <1 mile E Essential Cooling Pond F(1,2, or 3) 249* N/A Control sample purchased from a local retailer so 250 0.75 miles NW Sewage sludge land farming area WG 251 4.0 miles SSE Test Well B-4, upper aquifer WG 255 4.2 miles SE Piezometer Well # 415 110' deep WG 256 2.8 miles ESE Piezometer Well # 417 100' deep Piezometer Well # 421-02, 80' deep WG 257 3.9 miles SSW 1.1 miles down STP Road from Well # 258 approximately 20' inside east fence (site boundary)

Piezometer Well # 435-01, 1.5 miles down STP WG 258 2.9 miles SW Road from HWY 521 along east fence (site boundary)

Piezometer Well # 435-02, 1.5 miles down STP WG 259 2.9 miles SW Road from HWY 521 20' east of fence (site boundary)

WG 260 3.7 miles S Piezometer Well # 437, 74' deep WG 263 3.2 miles ESE Piezometer Well # 447, 104! deep MCR-STP Main Cooling Reservoir STP- South Texas Project Media codes typed in bold satisfy collection requirement described in Table 1.

• Control Station 6-28 STP Nuclear Operating Company

2011 EnvironmentalReport TABLE 2 SAMPLE MEDIA AND LOCATION DESCRIPTIONS MEDIA CODE STATION VECTOR LOCATION DESCRIPTION CODE (Approximate)

WG 264 3.2 miles ESE Piezometer Well # 447A , 46' deep WG 266 0.68 miles NW Piezometer Well # 602A, 40' deep WG 267 2.7 miles ESE Windmill north of Heavy Haul Road WG 268 3.0 miles SE Windmill west of MCR Windmill south of STP owner contolled area on WG 269 4.2 miles SSE piaeln private land WG 270 2.9 miles SW Monitoring Well # MW-0805L, depth 49' WG 271 2.9 miles SW Monitoring Well # MW-0805U, depth 33' F(l, 2, or 3) CC S2 301-356 S STP Main Cooling Reservoir WW 701 4 miles S MCR Relief Well # 440 WS Q01 N/A Quarterly composite of station #227 and/or alternate

1. 233 SQ02 N/A Quarterly composite of station #243 and/or alternate WS QN/A#242 MCR-STP Main Cooling Reservoir STP- South Texas Project Media codes typed in bold satisfy collection requirement described in Table 1.

• Control Station Photo By: Mark Scheuerman STP Nuclear Operating Company 6-29

RadiologicalEnvironmental OperatingReport 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

A summary of all required samples is given in Table 3. The table has been formatted to resemble a United States Nuclear Regulatory Commission industry standard. Modifications have been made for the sole purpose of reading ease. Only positive values are given in this table.

Media type is printed at the top left of each table, and the units of measurement are printed at the top right. The first column lists the type of radioactivity or specific radionuclide for which each sample was analyzed. The second column gives the total number of analyses performed and the total number of non-routine analyses for each indicated nuclide. A non-routine measurement is a sample whose measured activity is greater than the reporting levels for Radioactivity Concentrations in Environmental Samples. The "LOWER LIMIT OF DETECTION" column lists the normal measurement sensitivities achieved. The sensitivities were better than required by the Nuclear Regulatory Commission.

A set of statistical parameters is listed for each radionuclide in the remaining columns. The parameters contain information from the indicator locations, the location having the highest annual mean, and information from the control stations. Some sample types do not have control stations. When this is the case, "no samples" is listed in the control location column. For each of these groups of data, the following is calculated:

• The mean positive values.

" The number of positive measurements / the total number of analyses.

" The lowest and highest values for the analysis.

The data placed in the table are from the samples listed in Table

1. Additional thermoluminescent dosimeters were utilized each quarter for quality control purposes. The minimum samples required by Table 1 were supplemented in 2011 by 15 direct radiation measurements, eight surface water samples for gamma analysis, one additional ground water samples, two drinking water samples, four rain water samples, and four sediment shoreline samples.

Fish and crustacean samples vary in number according to availability but Photo BY: Kim Danielski also exceeded the minimum number required by Table 1.

6-30 STP Nuclear Operating Company

2011 EnvironmentalReport TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Direct Radiation Units: MilliRoentgen/Standard Quarter ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN t LOCATION MEAN t MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Gamma 175/0 --- 1.4E+01 ( 167/ 167) 0.25 miles S 2.0E+01 ( 4 / 4) 1.5E+01 ( 8 / 8) 1 I.IE+01 - 2.9E+01 ) (#009) (I.4E+0I - 2.9E+01) ( 1.3E+01 - 1.8E+01 )

t Number of positive measurements / total measurements at specified locations.

TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Airborne Particulate & Radioiodine Units: PicoCuries per Cubic Meter ANALYSIS TOTAL ANALYSES LOWER INDI)CATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN t LOCATION MEAN t MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Gross Beta 260/0 I.4E-03 212E-02 ( 208 / 208 ) 1 mile NNW 2.2E-02 ( 52 / 52 ) 2.2E-02 ( 52 / 52 1

( 7.5E 4.1 E-02 ) (#016) ( 8.7E 4.OE-02) ( 9.2E 4.OE-02 )

Iodine-131 260/0 I.4E-02 4.5E-02 ( 15/ 2081 1 mileNNW 5.1E-02( 4/ 52) 4.2E-02( 4/ 52)

(4.7E 1.1E-O0 ) (#016) ( 8,2E 9.9E-02) ( 5.6E 9.3E-02 )

Cesium-134 20/0 5.3E-04 --- ( 0/ 16) --- --- --- ( 0/ 4)

Cesium-137 20/0 5.1E-04 1.6E-04( 1/ 16) 14milesNNE 1.6E-04( 1/ 4) --- ( 0/ 4)

,6E 1.6E-04)

.( (#033) ( ,6E 1.6E-04 I Manganese-54 20/0 5.7E-04 --- 0/ 16) --- --- --- ( 0/ 4)

Iron-59 20/0 2.5E-03 --- 0/ 16) --- ( 0/ 4)

Cobalt-58 20/0 8.6E-04 --- I 0/ 16) --- --- --- ( 0/ 4)

Cobalt-60 20/0 5.5E-04 --- )(0/ 16) ... --- ... 0/ 4)

Zinc-65 20/0 I.4E-03 --- ( 0/ 16) --- -- --- ( 0/ 4)

Zirconium-95 20/0 1.6E-03 --- 0/ 16) ---.... ( 0/ 4)

Niobium-95 20/0 9.3E-04 --- ( 0/ 16) --- --- --- 0/ 4)

Lanthanum-140 20/0 1.2E-02 --- 0/ 16) ....--- --- 0/ 4)

Barium- 140 t Number of positive measurements / total measurements at specified locations.

Photo By: Krist' Moss STP Nuclear Operating Company 6-31

RadiologicalEnvironmental OperatingReport TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Surface Water Units: PicoCuries per Kilogram ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN t LOCATION MEAN t MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Hydrogen-3 12/0 1.9E+02 +1.4E+04( 4/ 8) 3milesSSE +1.4E+04( 4/ 4) --- ( 0/ 4)

(+1.3E+04 - +1.5E+04) (#216) (+1.3E+04 - +1.5E+04)

Iodine-131 44/0 5.6E+00 --- ( 0/ 30) --.--- --- ( 0/ 14)

Cesium-134 44/0 1.9E+00 --- ( 0/ 30) --.--- --- ( 0/ 14)

Cesium-137 44/0 2.E1E+00 --- ( 0/ 30) --- ( 0/ 14)

Manganese-54 44/0 2.0E+00 --- ( 0/ 30) ---.--- --- 0/ 14)

Iron-59 44/0 4.9E+00 --- ( 0/ 30) ---.... ( 0/ 14)

Cobalt-58 44/0 2.1E+00 --- ( 0/ 30) --- --- -( 0/ 14)

Cobalt-60 44/0 2.E1-E+00 --- ( 0/ 30) --- ( 0/ 14)

Zinc-65 44/0 4.5E+00 --- ( 0/ 30) --- ( 0/ 14)

Zirconium-95 44/0 3.8E+00 --- ( 0 / 30) ---... ( 0/ 14)

Niobium-95 44/0 2.2E1+00 --- ( 0/ 30) --- ( 0/ 14)

Lanthanum-140 44/0 5.1E+00 --- ( 0/ 30) --- ( 0/ 14)

Barium-140 t Number of positive measurements / total measurements at specified locations.

TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Ground Water (On site test well) Units: PicoCuries per Kilogram ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN t LOCATION MEAN t MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Hydrogen-3 21/0 1.7E+02 3.9E+03 ( 14 / 21) 4.0 miles SSE 6.OE+03 ( 5 / 5) no samples 1.4E+03 - 6.2E+03) (#251) (5.7E+03 - 6.2E+03 Iodine-131 21/0 3.3-E+00 --- ( 0/ 21) --- --- no samples Cesium-134 21/0 2.8E+00 --- ( 0 / 21 ) --- --- no samples Cesium-137 21/0 2.8E+00 --- ( 0 / 21 ) --- --- no samples Manganese-54 21/0 2.6E+00 --- ( 0 / 21 ) --- --- no samples Iron-59 21/0 5.3E+00 --- ( 0/ 21 ) --- --- no samples Cobalt-58 21/0 2.6E+00 --- ( 0/ 21) --- --- no samples Cobalt-60 21/0 2.7E+00 --- ( 0 / 21) --- --- no samples Zinc-65 21/0 7.OE+00 --- ( 0 / 21) --- --- no samples Zirconium-95 21/0 4.5E+00 --- ( 0 / 21) --- --- no samples Niobium-95 21/0 2.8E+00- --- ( 0 / 21) ...... no samples Lanthanum-140 21/0 3.9E+00 --- ( 0 / 21) --.--- no samples Barium- 140 1 t Number of positive measurements / total measurements at specified locations.

6-32 STP Nuclear Operating Company

2011 EnvironmentalReport TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Drinking Water Units: PicoCuries per Kilogram ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN t LOCATION MEAN f MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Gross Beta 26/0 9.5E-0I 2.OE+00 ( 13 / 13 ) 14 miles NNE 6.2E+00 ( 13 / 13) 6.2E+00 ( 13 / 13)

( 1.7E 4.0E+00) (#228) (5.9E I.0E+01 ) (5.9E I.OE+01 )

Hydrogen-3 8/0 2.8E+02 --- ( 0/ 4) --- --- --- ( 0/ 4)

Iodine-131 26/0 3.9E+00 --- ( 0/ 13) --.--- --- ( 0/ 13)

Cesium-134 26/0 2.7E+00 --- ( 0/ 13) --- ( 0/ 13)

Cesium-137 26/0 2.7E+00 --- ( 0/ 13) --.--- --- ( 0/ 13)

Manganese-54 26/0 2.5E+00 --- ( 0/ 13) --- --- --- ( 0/ 13)

Iron-59 26/0 5.5E+00 --- ( 0/ 13) --.--- --- ( 0/ 13)

Cobalt-58 26/0 2.7E+00 --- ( 0/ 13) --- -- ( 0/ 13)

Cobalt-60 26/0 2.7E+00 --- ( 0/ 13) --- --- - ( 0/ 13)

Zinc-65 26/0 6.7E+00 --- ( 0/ 13) --- --- - ( 0/ 13)

Zirconium-95 26/0 4.5E+00 --- ( 0/ 13) --.--- --- ( 0/ 13)

Niobium-95 26/0 2.8E+00 --- ( 0/ 13) --.--- --- ( 0/ 13)

Lanthanum-140 26/0 4.4E+00 --- ( 0/ 13) --.--- --- ( 0/ 13)

Barium- 140 I I I I t Number of positive measurements / total measurements at specified locations.

TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Rain Water Units: PicoCuries per Kilogram ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN t LOCATION MEAN t MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Hydrogen-3 4/0 2.9E+02 --- ( 0 / 4) --- -- no samples Iodine-131 4/0 6.8E+00 --- ( 0 / 4) --- -- no samples Cesium-134 4/0 2.3E+00 --- ( 0 / 4) --- --- no samples Cesium-137 4/0 2.3E+00 --- ( 0 / 4) --- --- no samples Manganese-54 4/0 2.2E+00 --- ( 0 / 4) --- --- no samples Iron-59 4/0 5.5E+00 --- ( 0 / 4) --- --- no samples Cobalt-58 4/0 2.4E1+00 --- ( 0 / 4) --- --- no samples Cobalt-60 4/0 2.4E+00 --- ( 0 / 4) ... --- no samples Zinc-65 4/0 5.1-E+00 --- ( 0 / 4) --- --- no samples Zirconium-95 4/0 4.3E+00 --- ( 0 / 4) --- --- no samples Niobium-95 4/0 2.4E+00 --- ( 0 / 4) --- --- no samples Lanthanum-140 4/0 6.0E+00 --- ( 0 / 4) --- --- no samples Barium-140 I I I I t Number of positive measurements / total measurements at specified locations.

STP Nuclear Operating Company 6-33

RadiologicalEnvironmentalOperatingReport TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Sediment-Shoreline Units: PicoCuries per Kilogram dry weight ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN f LOCATION MEAN t MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Cesium-134 4/0 2.3E+01 --- ( 0/ 2) --- --- --- ( 0/ 2)

Cesium-137 4/0 1.8E+01 2.2E+01 ( 1/ 2) 6 miles SE 2.2E+01 ( 1/ 2) --- ( 0/ 2)

(2.2E+01 - 2.2E+01 ) (#227) (2.2E+01 - 2.2E+01 )

Manganese-54 4/0 2.2E+-0I --- ( 0/ 2) --- --- --- ( 0/ 2)

Iron-59 4/0 8.5E+01 --- ( 0/ 2) --.--- --- ( 0/ 2)

Cobalt-58 4/0 3.0E+01 --- ( 0/ 2) --.--- --- ( 0/ 2)

Cobalt-60 4/0 2.2E+01 --- ( 0/ 2) --.--- --- ( 0/ 2)

Zinc-65 4/0 .6.7E+0I --- ( 0/ 2) ---.--- --- 0/ 2)

Zirconium-95 4/0 5.9E+0I --- ( 0/ 2) --.--- --- ( 0/ 2)

Niobium-95 4/0 3.6E+01 --- ( 0/ 2) --- --- --- ( 0/ 2)

Lanthanum-140 4/0 3.2E+02 --- ( 0/ 2) ....---. ( 0/ 2)

Barium-140 I t Number of positive measurements / total measurements at specified locations.

TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Sediment-Bottom Units: PicoCuries per Kilogram dry weight ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN t LOCATION MEAN t MEAN f MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Cesium-134 6/0 2.9E+01 --- ( 0 / 6) --- -- no samples Cesium-137 6/0 4.7E+00 8.3EE+i0I ( 5 / 6) 1 mile SW LIEE+02 ( 3 / 3) no samples (2.9E+01 - 1.5E+02) (#215) (6.5E+01 - 1.5E+02)

Manganese-54 6/0 2.6E+01 --- ( 0 / 6) --.--- no samples lron-59 6/0 9.OE+01 --- ( 0/ 6) --- --- no samples Cobalt-58 6/0 3.2E+01 --- ( 0 / 6) --- --- no samples Cobalt-60 6/0 8.1E+00 1.2E+02 ( 4 / 6) 1 mile SW 2.2E+02 ( 2 / 3) no samples

(_1.4E+0I - 2.3E+02) (#215) (2.1 E+02 - 2.3E+02)

Zinc-65 6/0 8.4E+01 ( 0 / 6) --- --- no samples Zirconium-95 6/0 6.4E+0I --- ( 0 / 6) --- --- no samples Niobium-95 6/0 4.OE+01 --- ( 0 / 6) .... no samples Lanthanum-140 6/0 2.3E+02 --- ( 0/ 6) --- --- no samples Barium-140 "1 ]Nrlnnter nf nocutive nmena~rem~ent* / total m~etcurem~ent* utsnecifted Inentinnuc t N. u .. be. . ....... ............................ ........... ... sp ....... ..........

6-34 STP Nuclear Operating Company

2011 Environmental Report TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Banana Leaves Units: PicoCuries per Kilogram wet weight ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN t LOCATION MEAN I MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Iodine-131 8/0 2.OE+01 --- ( 0/ 4) --- --- - ( 0/ 4)

Cesium-134 8/0 3.1E+00 --- ( 0/ 4) --- --- --- ( 0/ 4)

Cesium-137 8/0 3.5E+00 -- ( 0/ 4) --- ( 0/ 4)

Manganese-54 8/0 3.8E1+00 --- ( 0/ 4) --- --- --- ( 0 / 4)

Iron-59 8/0 1.5E+01 --- ( 0/ 4) --- --- --- ( 0/ 4)

Cobalt-58 8/0 4.4E+00 --- ( 0/ 4) --- --- --- 0/ 4)

Cobalt-60 8/0 4.8E+00 --- ( 0/ 4) --- --- --- ( 0/ 4)

Zinc-65 8/0 1.3E+01 --- ( 0/ 4) ---.... ( 0/ 4)

Zirconium-95 8/0 7.8E+00 --- ( 0/ 4) --- --- --- ( 0/ 4)

Niobium-95 8/0 4.4E+00 --- ( 0/ 4) ---.--- --- 0/ 4)

Lanthanum-140 8/0 9.9E+00 --- ( 0/ 4) ....... ( 0/ 4)

Barium-140 I t Number of positive measurements / total measurements at specified locations.

Photo By: Nancy Kubecka STP Nuclear Operating Company 6-35

RadiologicalEnvironmental OperatingReport TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Collard Greens Units: PicoCuries per Kilogram wet weight ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL-LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN t LOCATION MEAN t MEAN f MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Iodine-131 2/0 2.OE+01 --- ( 0 / 2) --- no samples Cesium-134 2/0 1.9E+00 --- ( 0 / 2) --- -- no samples Cesium-137 2/0 2.4E+00 --- ( 0 / 2)_ --- --- no samples Manganese-54 2/0 2.5E+00 --- ( 0 / 2) --- -- no samples Iron-59 2/0 1.IE+01 --- ( 0/ 2) --- -- no samples Cobalt-58 2/0 3.1 E+00 --- ( 0 / 2) --- --- no samples Cobalt-60 2/0 3.2E+00 --- ( 0 / 2) --- --- no samples Zinc-65 2/0 8.4E+00 --- ( 0 / 2) --- --- no samples Zirconium-95 2/0 5.5E+00 --- ( 0 / 2) ... --- no samples Niobium-95 2/0 3.1 E+00 --- ( 0/ 2) --- --- no samples Lanthanum-140 2/0 7.8E+00 --- ( 0 / 2) ...--- no samples Barium-140 t Number of positive measurements / total measurements at specified locations.

TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Fish - Piscivorous Units: PicoCuries per Kilogram wet weight ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN t LOCATION MEAN t MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Cesium-134 4/0 3.6E+01 --- ( 0/ 2) --- --- --- ( 0/ 2)

Cesium-137 4/0 3.8E+01 --- ( 0/ 2) --- --- --- ( 0/ 2)

Manganese-54 4/0 3.7E+01 --- ( 0/ 2) --- --- --- ( 0/ 2)

Iron-59 4/0 9.3E+01 --- ( 0/ 2) --- --- --- ( 0/ 2)

Cobalt-58 4/0 3.8E+01 --- ( 0/ 2) --- --- --- ( 0/ 2)

Cobalt-60 4/0 4.OE+01 --- ( 0/ 2) --- --- --- ( 0/ 2)

Zinc-65 4/0 8.9E+01 --- ( 0/ 2) --- --- --- ( 0/ 2)

Zirconium-95 4/0 7.0E+01 --- ( 0/ 2) --- --- --- ( 0/ 2)

Niobium-95 4/0 4.0E+01 --- ( 0/ 2) --- --- --- ( 0/ 2)

Lanthanum-140 4/0 1.IE+02 --- ( 0/ 2) --- --- --- ( 0/ 2)

Barium- 140 psimeumnttleuenatpiilcis t Number of positive measurements / total measurements at specified locations.

6-36 STP Nuclear Operating Company

2011 EnvironmentalReport TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Me1,di~um Fish - rnietncean &r Insert Feeders IUnits- PicoCu~ries n~er Kilnoram wet weioht M edium:... i.... C.. .... ............ sect .F...ers........ P u r -e..... Kio rm wet..... wei---

ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUT[NE LIMIT OF MEAN t LOCATION MEAN t MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Cesium-134 7/0 3.6E+01 --- ( 0 / 7) --- --- no samples Cesium-137 7/0 3.7E+01 --- ( 0 / 7) --- --- no samples Manganese-54 7/0 3.4E+01 --- ( 0 / 7 ) --- --- no samples Iron-59 7/0 8.3E+01 --- ( 0/ 7) --- --- no samples Cobalt-58 7/0 3.5E+01 --- ( 0/ 7 ) --- --- no samples Cobalt-60 7/0 4.OE+01 --- ( 0 / 7 ) --- --- no samples Zinc-65 7/0 8.5E+01 --- ( 0/ 71 --- --- no samples Zirconium-95 7/0 6+3E+01 --- ( 0 / 71 --- --- no samples Niobium-95 7/0 3.6E+01 --- ( 0/ 7) --- --- no samples Lanthanum-140 7/0 8.IE+01 --- ( 0/ 7) --- --- no samples Barium- 140

+ Number of positive measurements / total measurements at specified locations.

Photo By: Kristy Moss STP Nuclear Operating Company 6-37

RadiologicalEnvironmental OperatingReport TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Crustacean Shrimp Units: PicoCuries per Kilogram wet weight ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN t LOCATION MEAN f MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Cesium-134 4/0 3.4E+01 --- ( 0/ 2) --- -( 0/ 2)

Cesium-137 4/0 3.5E+01 --- ( 0/ 2) --- -- ( 0/ 2)

Manganese-54 4/0 3.2E+01 --- ( 0/ 2) ---.--- -- ( 0/ 2)

Iron-59 4/0 7.7E+01 --- ( 0/ 2) --.--- --- ( 0/ 2)

Cobalt-58 4/0 3.3E+01 --- ( 0/ 2) --- --- - ( 0/ 2)

Cobalt-60 4/0 3.4E+01 --- ( 0/ 2) ---.... ( 0/ 2)

Zinc-65 4/0 7.6E+01 --- ( 0/ 2) ---.--- -- ( 0/ 2)

Zirconium-95 4/0 6.IE+01 --- ( 0/ 2) ---.--- -- ( 0/ 2)

Niobium-95 4/0 3.5E+01 --- ( 0/ 2) ...--- - ( 0/ 2)

Lanthanum-140 4/0 L.OE+02 --- ( 0/ 2) ---.... ( 0/ 2)

Barium- 140 t Number of positive measurements / total measurements at specified locations.

TABLE 3 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANALYSIS

SUMMARY

Medium: Beef Meat Units: PicoCuries per Kilogram wet weight ANALYSIS TOTAL ANALYSES LOWER INDICATOR LOCATIONS LOCATION WITH HIGHEST ANNUAL MEAN CONTROL LOCATIONS TYPE /NONROUTINE LIMIT OF MEAN f LOCATION MEAN f MEAN t MEASUREMENTS DETECTION RANGE INFORMATION RANGE RANGE Cesium-134 2/0 3.IE+01 --- ( 0 / 2) --- -- no samples Cesium-137 2/0 3.3EE+i0I --- ( 0 / 2) --- --- no samples Manganese-54 2/0 3.1E1+01 --- ( 0/ 2) --- -- no samples Iron-59 2/0 9.1E+-0I --- ( 0/ 2) --.--- no samples Cobalt-58 2/0 3.9E1+01 --- ( 0/ 2) --- -- no samples Cobalt-60 2/0 3.4E+01 --- ( 0 / 2) --- --- no samples Zinc-65 2/0 7.8E+01 --- ( 0 / 2) --- --- no samples Zirconium-95 2/0 7.0E+01 --- ( 0 / 2) --- -- no samples Niobium-95 2/0 3.9E+01 - ( 0 / 2) --- --- no samples Lanthanum-140 2/0 1.7E+02 --- ( 0/ 2) ---... no samples Barium- 140 t Number of positive measurements / total measurements at specified locations.

6-38 STP Nuclear Operating Company

2011 Environmental Report Photo By: Kristy Moss STP Nuclear Operating Company 6-39

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