ML062350205

Sacramento Municipal Utility District (Smud), Rancho Seco Nuclear Station, 2005 Annual Radiological Environmental Operating Report

ML062350205
Person / Time
Site:	Rancho Seco, 07200011
Issue date:	04/18/2006
From:	Redeker S Sacramento Municipal Utility District (SMUD)
To:	NRC Region 4
References
MPC&D 06-047
Download: ML062350205 (75)

Text

MlClBAL UTILITY DJSTRICT The Pawer To Do I%lEBle.'L

- I_ I_ _ -- --

--l_-.l. -

P.O. Box 15830, Snci-anzento, CA 95852-1830; 1-885-742-SMUD (7G53)

MPC&D 06-047 A p r i l 18, 2006 U.S. Nuclear Regulatory Commission Region IV Administrator 61 1 Ryan Plaza Drive, Suite 400 Arlington, Texas 7601 1-8064 Docket 50-3 12 Rancho Seco Nuclear Station License DPR-54 2005 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT Attention: Region IV Administrator In accordance with Rancho Seco Quality Manual Appendix A, Section 1.5.3, the District submits the enclosed Rancho Seco Annual Radiological Environmental Operating Report for the period January 1, 2005 through December 3 1: 2005.

You or members of your staff requiring additional information or clarification may contact Steve Nicolls at (916) 732-4850.

Sincerely, 9

Steve J. Redeker Manager, Plant Closure and Decommissioning Enclosure cc: Document Control Desk, NRC, Washington DC J. Hiclunan, NRC, Washington DC R. Hall. NRC. Roclcville hlD RANCHO SECO NUCLEAR PLANT 14440 Twin Cities Road, Herald, CA 95638-9799; (209) 333-2935

4 005 2005 AN b RADIOL GAL ENVIRONMENTAL QPERAT REPORT TABLE OF CONTENTS TABLE OF CONTENTS ......................................................................................... ........................................

. ii LIST OF FIGURES .......................................................................:.........,.,.,........................ .............................

111 LIST OF TABLES ......................................................................................................................................... .iv I. EXECUTIVE

SUMMARY

............................................................. ............................. 1 ..........:.......................1 II. LAND USE CENSUS ................................................................................................................................. 2 Ill. RADIOLOGICAL IMPACT EVALUATION ................................................................................................. 2 PREDICTED POTENTIAL RADIOLOGICAL IMPACT ...................................................................... 2 FUEL CYCLE DOSE EVALUATION ................................................................................................. 3 OBSERVED POTENTIAL RADIOLOGICAL IMPACT ....................................................................... 3 IV. PROGRAM ANALYSIS RESULTS

SUMMARY

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

'IV-A. ATMOSPHERIC MONITORING'............................................................................................ 6 IV-B. DIRECT RADIATION MONITORING...........................................................................  ;.........7 IV-C. TERRESTRIAL MONITORING ....................... ;....................................................................... 7 IV-D. AQUATIC LIFE MONITORING .............................................................................................. 8 IV-E. WATER MONITORING.......................................................................................................... 8 V. REFERENCt=S r .

.................................................................................................................................... 15 VI. APPENDICES ...................................................................................................................................... 17 2003/ 2004 LAND USE CENSU,S RESULTS ............................................................................... A-I SAMPLE SITE DESCRIPTIONS AND MAPS ................................................................................ B-I QUALITY CONTROL SAMPLE ANALYSIS RESULTS ................................................................. C-I SAMPLE COLLECTION AND ANALYSIS METHODS .................................................................. D-I ENVIRONMENTAL MONITORING PROGRAM DESIGN ............................... .............................. E-I 2005 SAMPLE ANALYSIS RAW DATA TABLES ...............................................................................

2005 MISSED SAMPLE REPORT......;...........................,.......~........,.,..........................................G-I Rancho Seco Nuclear Station ii 2005 AREOR

LIST OF FIGURES FIGURE . TITLE PAGE FIGURE B-I RADIOLOGICAL ENVIRONMENTAL SAMPLING LOCATIONS ON AND NEAR FIGURE B-2 FIGURE B-3 FIGURE B-4 Rancho Seco Nuclear Station 2005 AREOR

LIST OF TABLES TABLE TITLE PAGE 1 2005 LIQUID EFFLUENT PATHWAY POTENTIAL DOSE COMPARISON 5 2 ENVIRONMENTAL RADIOLOGICAL MONITORING PROGRAM ANNUAL

SUMMARY

10 B- I RADIOLOGICAL ENVIRONMENTAL MONITORING SITES AND MAP LOCATIONS B-7 c-I 2005 INTERLABORAT0RY COMPARI SON PROGRAM c-4 E-I REPORTING LEVELS FOR RADIOACTIVITY CONCENTRATIONS IN ENVl RONMENTAL SAMPLES E-I 0 E-2 MAXIMUM (REQUIRED) LLD VALUES FOR ENVIRONMENTAL SAMPLES E-I 1 F-I 2005 WEEKLY AIR SAMPLE

SUMMARY

F-2 F-2 2005 LUXEL BADGE

SUMMARY

(DIRECT RADIATION) F-4 F-3 2005 GARDEN VEGETABLES F-5 F-4 2005 SEDIMENT F-5 F-5 2005 FISH F-6 F-6 2005 WELL WATER F-6

. F-7 2005 RUNOFF WATER F-7 F-8 2005 SURFACE WATER F-8 F-9 2005 DRINKING WATER F-I 0 Rancho Seco Nuclear Station iv 2005 AREOR

2005 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT

1. EXECUTIVE

SUMMARY

This report contains results from the Radiological Environmental Monitoring Program (REMP) for the Rancho Seco Nuclear Station (RSNS) compiled for the period January I 2005 through December 31, 2005. The Radiation Protection/ Chemistry Group at RSNS conducts this program in accordance with the REMP manual. This report is compiled and submitted in accordance with the Rancho Seco Quality Manual, Appendix A, Section 1.5.2.3 [RSOZ].

The results of the 2005 Radiological Environmental Monitoring Program showed that the operation of Rancho Seco Nuclear Station had no significant radiological impact on the environment.

Currently, the Plant is permanently shutdown and undergoing Decommissioning. Fuel transfer to the Independent Spent Fuel Storage Installation (ISFSI) was completed on August 21 2002.

During the reporting period, the atmospheric, terrestrial and aquatic environs adjacent to RSNS were monitored. The sample measurements showed that the levels of radioactivity in the sampled media were consistent with previous years evaluations. All detected nuclides (greater than minimum detected activity) were below the required Nuclear Regulatory commission (NRC) reporting levels. All Lower Limits of Detection (LLD) were at or lower than the maximum required by the NRC.

Doses resulting from ambient exposure.to terrestrial and atmospheric direct radiation sources were measured through the placement and retrieval of Luxel monitoring badges. Direct radiation measurements attributable to Station operations, based on control and indicator locations,wereidistinguishable above backgroun-d levels. Two m-0-niforing badge locations, placed in an area near the effluents discharge stream are being used to evaluate the higher than average soil activity. This activity is a result of historic monitored liquid effluent releases during Station operation. One monitoring badge location in this area is indicating dose higher than the indicator average. The dose at this location does not exceed the regulatory limits of 10 CFR Part 20. Onsite Luxel badge locations near the ISFSI access road show higher readings, attributed to the ISFSI, and are within design calculations.

Isotopic identifications were consistent with known releases of radioactive material fromthe Station to the atmospheric and aquatic environments. As expected, fish and sediment samples obtained from the environment of the No Name and Clay Creeks contributed the majority of positive isotopic identifications. Cesium-I 37 and Cobalt-60 are the predominant nuclides identified in the aquatic environment.

Rancho Seco Nuclear Station 1 2005 AREOR

11. LAND USE CENSUS The 2004 Land Use Census was conducted in accordance with the Rancho Seco Quality Manual [RS02] Section 1.4.3.2 and the Radiological Environmental Monitoring Program (REMP) manual section 4.0.This evaluation is in accordance with the requirements of IO CFR Part 50,Appendix I, section IV.B.3.The land use census is performed on a biennial schedule and was petformed during 20031 2004 and then completed in 2005. See Appendix A for results from this Land Use Census. The next land use census will be conducted during 20051 2006 and completed in 2007.

111. RADIOLOGICAL IMPACT EVALUATION PREDICTED POTENTIAL RADIOLOGICAL IMPACT Gaseous Effluent Exposure Pathwavs The maximum calculated annual organ dose commitment due to gaseous releases of tritium and particulate isotopes was 6.61 E -02 mRem (as calculated using the Rancho Seco Offsite Dose Calculation Manual (ODCM)). This calculated organ dose commitment was 0.441% of the associated Rancho Seco Quality Manual (RSQM) [RS02] limit (10CFR50, Appendix i guideline).

Noble g a s e s were not,released in 2005 and therefore no dose calculations for noble g a s e s were necessary.

Liquid Effluent Exposure Pathwavs During -2005, 3.33-E+06 liters of wastewater were _released into_"NoName" Creek from the two-onsite Retention Basins. This volume of wastewater was dispersed into 2.07 E+lO liters of dilution water. The estimated error associated with determining these volumes were 5% and 20%, respectively.

The Liquid source term resulted in a calculated annual child total body dose commitment of 0.0234mRem and a calculated child bone dose commitment of 0.0910mRem (as calculated using the ODCM). These calculated dose commitments were 0.778% and 0.910%,

respectively, of the associated 10 CFR Part 50, Appendix I guidelines. The quarterly dose commitments reflect the age group@) that could have received the highest annual dose commitment from the liquid source term.

This information is summarized in Table 1.

Rancho Seco Nuclear 'Station 2 2005 AREOR

Ill. RADIOLOGICAL IMPACT EVALUATION (Continued)

FUEL CYCLE DOSE EVALUATION REMP Manual section 8.14 requires each Annual Radiological Environmental Operating Report (AREOR) to include information related to REMP manual section 5.0; Fuel Cycle Dose.

The Fuel Cycle Dose Specification limits the dose or dose commitment to any real member of the public to 25 mRem to the total body or any organ, except the thyroid which is limited to 75 mRem. This specification implements requirements promulgated by the United States Environmental Protection Agency [CFRd].

Consistent with REMP manual section 5.0, no fuel cycle dose evaluation was required to b e performed during 2005 since no REMP measurement exceeded the established reporting levels. Additionally, the Station effluent dose predictions did not exceed twice the dose guidelines of 10 CFR Part 50, Appendix I [CFRc]. The station operated within the Appendix I guidelines envelope for radioactive effluents (a condition supported by Program measurements); therefore, determination of an actual dose commitment delivered to a real member of the public was not required.

OBSERVED POTENTIAL RADIOLOGICAL IMPACT Gaseous Effluent Exposure Pathwavs The calculated gaseous effluent dose commitment of 6.61 E -02 mRem [RSOI] is based on tritium and particulate activity. Cesium 137 particulate activity was released during the first quarter of 2005. The observed dose commitment dose calculation, if completed, using the gross beta data (which is primarily due to naturally occurring.radioisotopes) would not provide a n accurate-correlationwith t h e predicted tritium-and paFtiGulate activity dose calculations.

Also, none of the REMP quarterly air filter composite gamma isotopic analysis results for the airborne pathway indicated the presence of nuclides of Station origin. Therefore, no dose comparison was completed.

Direct Radiation Exposure Pathway Based on Luxel control and indicator locations measurement results obtained during 2005, the Station proper did not contribute an observable component to the recorded direct gamma radiation field. This Luxel data supports the Gaseous Effluent Exposure Pathway conclusions and supports the conclusion that the Plant has no direct radiation effect on the environment.

Luxel monitoring badges placed near the effluent stream was used to evaluate the dose from this area. Dose levels at these locations are higher than the mean of the control and indicator locations reported. This above average dose is due to elevated soil activity due to historic liquid effluent releases. Luxel badge locations around the ISFSI outside fence (required by the ISFSl License) show higher readings, attributed to the fuel stored in the ISFSI, and are within design calculations.

Rancho Seco Nuclear Station 3 2005 AREOR

111. RADIOLOGICALIMPACTEVALUATION (Continued)

OBSERVED POTENTIAL RADIOLOGICALIMPACT Liquid Effluent Exposure Pathwavs To evaluate the impact on the environment from the liquid effluent pathway, dose calculations were performed and compared with the annual dose commitment calculations reported in the January -December 2005 Rancho Seco Annual Radioactive Effluent Release Report [RSOI].

The observed results presented in Table I were obtained using the Cs-I 37 activity reported for the fish samples from 2005 (Appendix F, Table F-5), default consumption quantities for fish (ODCM), and nuclide-specific dose factors [NRC77].

As in past reports, the observed potential dose commitments listed in Table 1 are subject to uncertainty, principally due to the assumption that the observed radioactivity was due to 2005 Station operations only and was not affected by radioactivity introduced into the environment prior to 2005. A major portion of the activity identified by Program measurements in 2005 is attributable to historical releases documented in previous annual reports. Additionally, the observed dose commitment calculations are based on conservative default consumption factors for fish.

The 2004 Land Use Census indicates the liquid/ fish and liquid/ irrigated vegetation pathways are potential exposure pathways. The fish pathway dose commitment calculation uses conservative default fish consumption factors instead of using actual Land Use Census data. Also, the dose commitment calculation uses fish sample analysis data derived from fish samples collected from the plant effluent stream in 2005. Vegetation sample analysis results indicated no radioactivity attributable to station operation in 2005 via the liquid/

irrigated vegetation pathway; therefore, no dose commitment calculations were performed for this pathway.

Rancho Seco Nuclear Station 4 2005 AREOR

Ill. RADIOLOGICAL IMPACT EVALUATION (Contin u ed) 0BSERVED POTENTIAL RAD10LOG I CAL IMPACT TABLE I 2005 Liquid Effluent Pathway Potential Dose Comparison PREDICTED DOSE OBSERVED DOSE PERCENT OF THE 10 CFR COMMITMENT (a) COMMITMENT (b) (c) PART 50 APPENDIX I (mRem) (mRem) DOSE LIMITS 0.0234 0.045 1.50 %

(Adult total body for 2"d quarter, (Adult Total Body) Total Body Child total body for 4'h quarter) (3 mRem guideline) 0.0910 0.072 0.72 %

(Child bone for 2ndand 4th (Teen Liver) Organ qua tte r) (10 mRem guideline)

(b) Calculated using Gs-137 activity for fish samples (Appendix F, Table F-5).

(c) The'observed dose commitments for doses reflect the age group that could have received the highest annual dose commitment from the liquid source term Rancho Seco Nuclear Station 5 2005 AREOR

IV. PROGRAM ANALYSIS RESULTS

SUMMARY

This section compiles Program data with corresponding evaluations. Each of the following five subsections presents information about each of the principal environmental exposure pathways monitored by the Program:

z Atmospheric (Section IV-A) q Direct Radiation (Section IV-B) z Terrestrial (Section IV-C) 3 Aquatic Life (Section IV-D) 3' Water (Section IV-E)

Each of these sections contains a data evaluation subsection, which provides a summary of the data collected.

Table 2 is a comprehensive, all-media data summary presented in a format considered acceptable by the US Nuclear Regulatory Commission. Information contained in Table 2 was derived from data presented in Appendix F.

iV-A. ATMOS PHE WI C MON1TORING DATA EVALUATION No radionuclides attributable to the operation of Rancho Seco were observed in gamma spectrometry analyses,of the quarterly composites of the particulate filters.

Therefore, since all data was reported as being below the associated minimum detectable activity (MDA) for the nuclides of interest, no table is presented for the composite air filter data. The data indicates that there was no measurable contribution to the airborne radioactivity inventory that could reasonably be attributable to Station ope'rations.

The results of the gross beta analyses of the particulate samples are given in Appendix F, Table F-I.

Rancho Seco Nuclear Station 6 2005 AREOR

IV-B. DIRECT RADIATION MONITORING DATA EVALUATION A comparison review of all Luxel data for the indicator ancI control locations during 2005 showed that there was no observable direct radiation component due to Station operations (i.e. , storage or utilization of licensed radioactive material within the restricted area.)

Two Luxel locations are being used to evaluate the dose in areas next to the effluent stream.

The data from these locations indicates doses are within regulatory4mits of 10 CFR Part 20.

Luxel badge locations on the outside fence of the ISFSl show higher readings, but this is expected due to the spent fuel storage in the ISFSI. The results are within the design criteria and no license or regulatory limits were exceeded, The summary data for 2005 direct radiation monitoring is presented in Table 2.

Comprehensive data tables are given in Appendix F, Table F-2.

IV-e. TERRESTRIAL MONITORING DATA EVALUATION Garden Vegetation - Six (6) garden vegetation samples were collected and analyzed for nuclides of interest during 2005. No gamma emitting isotopes were found in any of the samples analyzed. A site boundary irrigated garden has been utilized as a conservative method for evaluating the liquid effluent pathway. This method meets the requirement of the Land Use Census for monitoring gardens. This site boundary garden is used for the-Land Use Census.

The summary data for 2005 terrestrial monitoring is presented in Table 2. Comprehensive data tables are given in the following Appendix F table:

3 F-3 (Garden Vegetables)

Rancho Seco Nuclear Station 7 2005 AREOR

IV-D. AQUATIC LIFE MONITORING DATA EVALUATION Sediment - Twelve (12) samples of sediment were collected from the onsite discharge canal during 2005. Gamma spectrometry analysis of these samples indicated the presence of Cs-I37 (12 samples, 36.8 to 243 pCi/kg, 131 pCi/kg mean), and Co-60 (IO samples, 18.4 to 87.6 pCi/kg, 53.6 pCi/kg mean).

T h e presence of nuclides of interest in sediments is attributed to historical permitted liquid effluent discharges .

Fish -Three (3) fish samples were collected during 2005 and analyzed for nuclides of interest by gamma spectrometry. Samples were collected in the effluent creek. Gamma spectrometry analysis of these samples indicated the presence of Cs-I37 (1 sample, 30.1 pCi/kg).

T h e summary data for the aquatic life-monitoring program is shown in Table 2.

Comprehensive data tables are given in the following Appendix F Tables:

F-4 Sediment r=> F-5 Fish IV-E. WATER MONITORING DATA EVALUATION Well Water - Eight (8) well water samples were collected at indicator and control locations around the site during 2005. Tritium and gamma spectrometry analysis of the samples indicated results less than LLD. Gross beta activity levels for all samples were within regulatory limits.

Runoff Water - Thirty (30) runoff water samples were collected at the site boundary during 2005. Tritium and gamma spectrometry analysis of the samples indicated results less than LLD.

Surface Water - Five locations (3 indicator and 2 control) were included in the surface water-monitoring Program. Composite samplers located at the,Plant intake (Folsom South Canal) and effluent discharge provide monthly composite samples. During 2005, 64 samples were collected and analyzed for nuclides of interest. Tritium and gamma spectrometry analysis of the samples indicated results less than LLD Rancho Seco Nuclear Station 8 2005 AREOR

IV-E. WATER MONITORING DATA EVALUATION (continued)

Drinking Water -Water supplied from two site wells is distributed in a potable w ter supply system for Station personnel consumption and use. On a monthly frequency, samples were collected and analyzed for nuclides of interest. A sample from the Rancho Seco Reservoir Well is collected as a control location. No gamma emitting isotopes were found present in the 36 samples collected in 2005. Gross Beta analysis showed activity within regulatory limits.

The summary data for the water-monitoring program is shown in Table 2. Comprehensive data tables are given in the following Appendix F Tables:

3 F-4 Sediment 3 F-6 Well Water

' F-7 Runoff Water 3 F-8 Surface Water 3 F-9 Drinking Water Rancho Seco Nuclear Station 9 2005 AREOR

TABLE 2 ENVIRONMENTAL RADIOLOGICAL MONITORING PROGRAM ANNUAL

SUMMARY

(NRC Format)

Rancho Seco Nuclear Station 10 2005 AREOR

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V. REFERENCES I CFRa Code of Federal Regulations, 2005, "National Primary Drinking Water Regulations," Title 40, Part 141.

CFRb Code of Federal Regulations, 2005, "Standards for.Protection Against Radiation," Title I O , Part 20.

CFRc Code of Federal Regulations, 2005, "Domestic Licensing of Production and Utilization Facilities," Title I O , Part 50.

CFRd Code of Federal Regulations, 2005, "Environmental .Radiation Protection Standards for Nuclear Power Operations," Title 40, Part 190.

CFRe Code of Federal Regulations,2005, "Licensing Requirements for the Independent Storage of Spent Nuclear Fuel, High Level Radioactive Waste, and Reactor-Related Greater than Class C Waste," Title 10, Part 72.

NRC74 United States Nuclear Regulatory.Comrnission, 1974, "Permanently Defueled Technical Specifications for the Rancho Seco Nuclear Station," Appendix A to Facility License No. DPR-54 (as amended).

NRC 00 United States Nuclear Regulatory Commission, 2000, Rancho Seco Nuclear Generating Station, "License for Independent Storage of Spent Nuclear Fuel and High Level Radioactive Waste," SNM-2510. (as amended)

NRCii United States Nuclear Regulatory Commission, 1977, "Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with I O CFR Part 50, Appendix I," Regulatory Guide 1.log, Revision 1.

NRC79a United States Nuclear Regulatory Commission, 1979, "An Acceptable Radiological Environmental Mo'nitoring Program," Branch Technical Position, Revision 1.

NRC79b United States Nuclear Regulatory Commission, 1979, "Quality Assurance for Radiological Monitoring Programs (Normal Operations) -

Effluent Streams and the Environment," Regulatory Guide 4.15, Revision 1.

NRC92 United States Nuclear Regulatory Commission, "Air Sampling in the Workplace", Regulatory Guide 8.25, June 1992 NUREG79 United States Nuclear Regulatory Commission, 1979, ;'Radiological Effluent Technical Specifications for PWRs," NUREG-0472, Revision 2.

Rancho Seco Nuclear Station 15 2005 AREOR

v. REFERENCES (continued)

NUREG80a United States Nuclear Regulatoiy Commission, 1980, "Methods for Demonstrating LWR Compliance with the EPA Uranium Fuel Cycle Standard (40 CFR Part 190)," NUREG-0543.

RSOl Rancho Seco Nuclear Station, 2005, ."Annual Radioactive Effluent Release Report, January -December 2005," Sacramento Municipal Utility District report.

RS02 . Rancho Seco Quality Control Manual, Appendix A Rancho Seco Nuclear Station 16 2005 AREOR

VI. APPENDICES Rancho Seco Nuclear Station 17 2005 AREOR

APPENDIX A 2003/2004LAND US CENSUS RESULTS In compliance with the Rancho Seco Quality Manual [RS02] and the REMP Manual, section 4.0, "Land Use Census", a land use census was completed on March 16, 2005. The method of conducting the primary survey was to use an aerial survey that was conducted during June 2004. Evaluating the aerial photographs continues to provide an accurate method of determining locations and distances of the nearest residences. The aerial photos also provided a method to identify any changes in the agricultural, commercial, residential, or industrial use of the land surrounding the site. The use of conservative dose factors for the purpose of projected dose calculations still requires that we evaluate the use of the area surrounding the site. The information that is presented is to verify this assumption and validate the process.

The land use census covered an area bounded by each of the sixteen meteorological sectors out to a two-mile radius from the Reactor Building.

The 20031 2004 Land Use Census did not identify any changes in the use of the unrestricted areas that would require modifications in the Radiological Environmental Monitoring Program for evaluating doses to individuals from principal pathways of exposure. This evaluation and determination are in accordance with the requirements of 10 CFR Part 50, Appendix I , section IV.B.3.

The Land Use Census is completed on a biennial schedule. Aerial surveys will be conducted during 2006 and the Gal,t Irrigation report covering 2005 and 2006 will be requested during the last quarter of 2005 and 2006 (respectively). This information will b e used to complete the 2005/ 2006 census, which is scheduled io be completed during the first quarter of 2007.

Rancho Seco Nuclear Station A- I 2005 AREOR

A. RESIDENT EXPOSURE PATHWAY

SUMMARY

Inhalation, Ground Plane and Water Consumption The 20031 2004 census determined that seven of the 16 radial sectors have residences that are within the 2-mile (3219 meters) Land Use Census radius. The closest residence in each of the seven sectors is identified below:

It is expected that all seven residences use well water for consumption and other domestic purposes.

Rancho Seco Nuclear Station A-2 2005 AREOR

B. DEPOSITION EXPOSURE PATHWAY

SUMMARY

Beef Consurn p ti on Based on conservative dose calculation parameters in use, the following is a summary for the 2003/ 2004 land use census of the potential deposition exposure pathways at the .

locations listed below:

F I I . I I Sector Distance Consumption Comment (meters) Pathway A 433 Beef Unrestricted Area Boundary I I I I

I B I

1'430 1 Beef I Unrestricted Area Boundary I C 531 . Beef Unrestricted Area Boundary D 451 Beef Unrestricted Area Boundary E 483 . Beef Unrestricted Area Boundary F 499 Beef Unrestricted Area Boundary G 579 Beef Unrestricted Area Boundary

- H I98 . Beef Unrestricted Area Boundary F J I 195 1 Beef 1 Unrestricted Area Boundarv I K 195 Beef Unrestricted Area Boundary L 286 Beef I Unrestricted Area Boundary I M 404 Beef Unrestricted Area Boundary N 514 Beef Unrestricted Area Boundary P 708 Beef Unrestricted Area Boundary Q 579 Beef . Unrestricted Area Boundary R 448 Beef Unrestricted Area Boundary Due to the revision of the ODCM, which eliminated the gaseous effluent pathway (August 26, 2002), the Deposition Exposure Pathway is not considered a credible evaluation with current plant canditions. Land Use Census use of this evaluation will be considered for revision in future surveillances.

Rancho Seco Nuclear Station A-3 2005 AREOR

C. IRRIGATED CROP EXPOSURE PATHWAY

SUMMARY

Laguna Creek Gait Irrigation District The Gait Irrigation District's 2003 Crop'Report stated 2651.4 acre-feet of Laguna Creek water was diverted for irrigation purposes during the 2003. crop production season. Crops irrigated were Oats, Corn, Clover, Pasture, Sudan, and Alfalfa over a total of 1021 acres.

The Gait Irrigation District's 2004 Crop Report stated 3019.499 acre-feet of Laguna Creek water was diverted for irrigation purposes during the 2002 crop production season. Crops irrigated were Oats, Corn, Clover, Pasture, Sudan, and Alfalfa over a total of 1021 acres.

Rossini Farming Company In addition to the above, SMUD has contracted with Rossini Farming Co., the owners of the

'vineyards adjacent to Rancho Seco Station, to supply irrigation water from Clay Creek on an as needed basis.

The following information was reported by the SMUD Water and Power Group, which monitors the usage. For the years of 2003 and 2004 it was reported that >500 Acre-feet of water was used from the effluent creek for irrigating purposes for the vineyards.

Rancho Seco Nuclear Station A-4 2005 AREOR

D. OTHER EXPOSURE PATHWAYS The 2003/2004 Land Use Census confirmed previous knowledge that the Clay/ Laguna Creeks are utilized by the general public for aquatic life consumption purposes. Based on direct observation cattle consume water from the Clay, Hadselville, and Laguna Creeks.

Past census evaluations have been unsuccessful in determining the usage/ occupancy factors for this consumption. Therefore, insufficient data existed to justify ODCM usage factor modification.

E. REMP EVALUATION An objective of the 2003/ 2004 Land Use Census was to compare census and current REMP Manual locations to ensure consistency exists between monitoring activities and actual land utilization. The following discussion is a summary of the comparison evaluation for each of the four exposure pathways..

Resident Exposure Pathway Luxel dosimetry and air particulate sampling and analysis monitor the inhalation and ground plane exposure pathways, the principal components of the Resident Exposure Pathway, directly and indirectly. Well water was monitored at three locations.

' Since the existing REMP was more conservative with respect to Resident Exposure Pathway monitoring, no changes were required.

Deposition Exposure Pathwav The Deposition Exposure Pathway is monitored directly within the Station Site Boundary through garden vegetation sampling and analysis. The potential for a deposition pathway has been evaluated by the ODCM and REMP programs and found to have little potential for the current plant status. Since the current REMP was representative and conservative with respect to Deposition Exposure Pathway monitoring, no changes were required.

lrriqated Crop Exposure Pathwav The REMP was effective in monitoring the identified irrigated crop.exposure pathways. This conclusion was because the REMP included irrigated vegetation sampling.

REMP surface water surveillance activities monitor irrigation water radiological quality.

Current ODCM calculations are conservative since dilution effects are not included when predicting potential dose delivered .through downstream pathways.

Rancho Seco .Nuclear Station A-5 2005 AREOR

E. REMP EVALUATION (continued)

Other Exposure Pathways Existing aquatic life, surface water and sediment sampling analysis practices are effective in monitoring potential observable effects associated with recreational activities occurring at the Clay Creek, Hadselville Creek, Laguna Creek, Folsom South Canal and Rancho Seco Lake.

With respect to availability and quantity of food sources, the other identified consumption activities were considered inconsequential for pathway monitoring purposes.

No REMP changes were required to monitor other exposure pathways.

F. ODCM EVALUATION Based on 2003/2004 Land Use Census findings, the following 'potential exposure pathways exist at the indicated locations:

LIQUlD EFFLUENT Exposure Pathway Location Comment Freshwater Fish Clay Creek Recreation beyond the Site Boundary Swimming Clay Creek Recreation beyond the Site Boundary Shoreline Deposits Clay Creek Recreation beyond the Site Boundary Irrigated vegetation Clay Creek Commercial vineyards and potential residences beyond the site boundary Irrigated forage Clay Creek Cattle grazing beyond the Site Boundary Drinking Water Clay Creek .Cattle drinking water beyond the Site Boundary Rancho Seco Nuclear Station A-6 2005 AREOR

F. ODCM EVALUATION (continued)

Specifying the Laguna Creek location also provides additional conservatism since the beneficial effects of downstream dilution are not considered when specifying effluent release restrictions.

As required by the 2003/ 2004 Land Use Census the above information for exposure pathways and locations was submitted for incorporation in the ODCM.

Rancho Seco Nuclear Station A-7 ,2005 AREOR

APPENDIX B SAMPLE SITE DESCRIPTIONS AND MAPS This appendix provides descriptive information about the sampling locations and maps of all the locations for the Radiological Environmental Monitoring Program sites.

Table B-I provides information on sample type, identification codes, and map location references. The sample identification code is an alphanumeric string beginning with the prefix R (for Rancho Seco Nuclear Station) followed by two letters to identify the sample media:

AS Air MS Mud and Silt RW Runoff Water FS Fish SW Surface Water LV Garden Vegetable DW Drinking Water TL Direct Gamma Radiation (Luxel)

WW Well Water The numeric designations, which follow the letter designations, indicate the straight-line distance (in miles) from the center of the Reactor Building to the monitoring site.

The next letter designates the sector in which the monitoring location is located. The letters A through R are used for sector designators. The letters I and 0 are not used to prevent confusion with the numbers one and zero in the ID codes.

Rancho Seco Nuclear Station 6--l 2005 AREOR

SAMPLE SITE DESCRlPTlONS AND MAPS (Continued)

The final letter designation indicates if the location is part of the operational REMP program

("0")or post-operational REMP program ("P").

Table B-I Lists each location referencing t h e sample type and the location ID code to the map site number on one of the four Radiological Environmental Monitoring Site Maps included in this Appendix.

Figure B-I Site Location Map: Shows the locations of the sample locations on and/or near the Site (including Storm Drain locations).

Figure 6-2 IMile Radius map: Sampling locations within one mile of the Reactor Building centerline are shown. on this map.

Figure B-3 5 Mile Radius map: Sampling locations between one and five miles from the Reactor Building centerline are shown on this map.

Figure B-4 25 Mile Radius map: Sampling locations between five to 25 miles from the Reactor Building centerline are shown on this map.

Rancho Seco Nuclear Station B-2 2005 AREOR

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Figure B-2 Radiological Environrnentai Sampling Locations within Imile from the Reactor Building Rancho Seco Nuclear Station B-4 2005 AREOR

I Figure B-3 Radiological Environmental Sampling Locations from 1 to 5 miles from the Reactor Building Rancho Seco Nuclear Station B-5 2005 AREOR

Figure B-4 Radiological Environmental Sampling Locations 5 to 25 miles from the Reactor Building Rancho Seco Nuclear Station B-6 2005 AREOR

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APPENDIX C QUALITY CONTROL SAMPLE ANALYSIS RESULTS QUALITY ASSURANCE AND CONTROL Implementation of the Radiological Environmental Monitoring Program (REMP) consists of a number of discrete steps including:

3 Sample collection, 3 Packaging, 3 Shipment and receipt, 3 Measurements of radioactivity, 3 Data evaluation, and 3 Reporting.

These program elements are performed according to approved, written procedures to assure the validity of REMP results. This section discusses the internal quality control measurements made by the analysis laboratory, Eberline Services, and the results of their participation in the lnterlaboratory Comparison Program implemented by the National Institute of Standards Testing (NIST). The Interlaboratory Comparison Program and the analysis laboratories Quality Assurance Programs provide information on the validity (accuracy and precision) of the REMP implementation steps listed above.

Because REMP measurement validity is-important for evaluating protection of the health and safety of the public, RSNS has established an Environmental Quality Assurance Program (EQAP) for radiological environmental measurements. The Environmental QA Program implements the guidance provided in Regulatory Guide 4.15, (NRC79a).

INTERLABORATORY COMPARISON PROGRAM Eberline Services participates in the lnterlaboratory Comparison Program (ICP) sponsored by the DOE. The ICP is a radiological analysis quality control program implemented by NIST and provided by vendor laboratories. Eberline Services participates in an ICP provided by Department of Energy (DOE) and Environmental Resources Associates (ERA), Participation in an ICP is a requirement of the Rancho Seco Quality Manual (RS02), section 1.4.3.2. It provides for an independent check of the proficiency of the laboratory. It also provides information on the precision and accuracy of measurements of radioactive material in REMP samples by Eberline Services. The extent of Eberline Services participation in this program includes all of the environmental radioactivity determinations that are related to the analyses required by the REMP manual.

Rancho Seco Nuclear Station c-1 2005 AREOR

INTERLABORATORY COMPARISON PROGRAM (Continued)

The lntercomparison Program consists of sample media spiked with known quantities of specific radioactive materials at levels normally found in environmental samples. Most ,

samples require long counting times to determine if any activity is present, and the results may have large deviations from the mean. When the samples are distributed, there is an implied precision requirement given in terms of the analysis requested to be performed. After the labs provide the results of their analyses, the DOE and ERA laboratories provides a statistical summary of all the results by the participating laboratory. This report includes the acceptance control limits, the mean of all laboratories and the standard deviation of the results by all labs, among other statistics.

If the results of a determination by Eberline Services in the ICP is outside the specified control limits or do not pass the outliers test, Eberline Services must investigate and, if a problem is identified, take corrective action to prevent problem recurrence.

During 2005, Eberline Services analyzed 55 ICP sample analysis related to the current REMP program. One analysis foi Gross Beia in Water was outside the control limits. Eberline initiated a Corrective Action Report (CAR) and results of the investigation were acceptable.

See Note on Table C-I, The Eberline Services measurement results are presented in Table C-I along with the acceptable values for each test.

iNTWLABOM-i-ORY QUALITY ASSUWANCE PRQGMM Eberline Services by contract also operate an lntralaboratory Comparison Program (Quality Assurance Program) to maintain an acceptable quality.level on a routine basis.

As part of their Quality Assurance Program; the laboratory performs background counts, an analysis of spiked samples, and duplicate samp1e.count.s for every ten Rancho Seco REMP samples analyzed. These quality control procedures are performed for all analyses except gamma spectrometry,.forwhich weekly energy and efficiency checks are performed.

Personnel not directly involved with the analysis prepare the spiked and duplicate samples.

Spiked samples, a s well a s the radioactive sources used for the gamma spectrometer checks, are traceable to the National Institute for Standards and Technology (NET).

Rancho Seco Nuclear Station c-2 2005 AREOR

RANCHO SECO AUDIT AND SURVEILLANCE RESULTS The Rancho Seco Quality Program requires periodic audits of REMP activities, including Eberline Services. Contract laboratory performance is evaluated by the Rancho Seco QA Department.

CONCLUSIONS The.lntralaboratory and Interlaboratory results provided by.Eberline Services indicate that Eberline Services performance was acceptable.

DIRECT RADIATION (Luxel) COMPARISON PROGRAM The monitoring badge vendor, Landauer participates in a comparison program provided by the Idaho NationalEnvironmental Laboratory (INEL). INEL did not conduct this comparison program in 2005; therefore no results from that program are available for this report. Landauer also maintains NVLAP certification with NIST. A review of Landauer's NVLAP certification results indicates that Landauer has satisfactorily completed all of the required tests for the types of environmental radiation monitored at RSNS and is certified through December 31 ,

2006.

This comparison program satisfies the requirement of the REMP manual section 6.0.

Rancho Seco Nuclear Station c-3 2005 AREOR

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APPENDIX D SAMPLE COLLECTION AND ANALYSIS METHODS For each of the sample media collected, the method of collection is documented in Rancho Seco Nuclear Station procedures. Detailed analysis methods are documented in procedures controlled by the contract laboratory, Eberline Services:. A brief description of these collection and analysis methods is included in this Appendix.

Sample Media C oI lect i onlAn a l y s is Method An .air sampler continuously moves air through a filter paper designed to capture particulates by filter paper impaction. The air samplers are equipped with an elapsed time meter and flow gauge, which are used to calculate the volume of air that has passed through the filter paper.

The filter paper is exchanged weekly. At least one day is allowed to elapse between sample collection and counting to reduce the interference of naturally occurring radon and thorium daughters on the sample analysis. The filter paper is assayed for gross beta radioactivity by placing the filter on a stainless steel planchet and counted with an internal g a s flow proportional counter.

The individual particulate filter papers are saved over a calendar quarter and the composite collection is assayed for gamma isotopic radioactivity by gamma spectroscopy.

DIRECT RADlAT10N Monitoring badges, (Luxels), are located within a ten ( I O ) mile radius of the site. The badges within a five (5) mile radius are considered indicator badges. Two (2) badges are placed at each monitoring location to assure adequate data recovery and to improve measurement statistics. The badge field exposure cycle is approximately ninety (90) days. At the end of the field exposure cycle, the badges are exchanged and returned to the contract laboratory for processing.

Rancho Seco Nuclear Station D-I 2005 AREOR

Sample Media CollectionlAnalysis Method SEDIMENT Samples of sediment are collected from the top three inches of the sampled material. Sediment samples are obtained approximately two feet from the shoreline. Each sample is assayed directly for gamma isotopic radioactivity by gamma spectroscopy.

GARDEN PRODUCE Samples of vegetables are collected semi-annually from a garden, which is maintained'at the Station Site Boundary. Control location samples are collected from a local commercial vendor. The vegetables are assayed directly for gamma isotopic radioactivity by gamma spectroscopy.

FISH Fish are collected semi-annually from the Clay Creek system. The dissected (edible) portion of each sample is assayed directly for gamma isotopic radioactivity by gamma spectroscopy, WATER I-liter grab samples of water from locations in the liquid effluent pathway and groundwater are collected as follows:

0 Surface water and Drinking water are collected monthly Runoff water is collected biweekly - - - - - -

-0 Wen wafer%$coIlectedquarierly -

At two locations, samples are obtained to provide a monthly composite

. sample. All samples are assayed for tritium by liquid scintillation counting and for gamma isotopic radioactivity by gamma spectroscopy.

Drinking and Well water samples are analyzed for Gross Beta activity.

Rancho Seco Nuclear Station D-2 2005 AREOR

APPENDIX E ENVIRONMENTAL MONITORING PROGRAM DESIGN PROGRAM BASIS The Sacramento Municipal Utility District conducts a continuous Radiological Environmental Monitoring Program (REMP) at the Rancho Seco Nuclear Station to assess the impact of Station operation on the surrounding environment. The current Post-Operational REMP is a continuation of a similar program initiated prior to and during operation of the Station. Samples of the surrounding environment are collected on a routine basis and analyzed to determine the amount of radiation and radioactive materials present in the exposure pathways.

During 2005 the program was directed and executed by the Radiation Protection/ Chemistry Superintendent. Decommissioning Chemistry/ Radiation Protection Technicians perform sample collection. The Radiological Health Supervisor performs data review and Program maintenance/ oversight. The Program is operated with primary accountability and cognizance of the Manager, Plant Closure and Decommissioning.

The Program is designed consistent with Title 10, Code of Federal Regulations, Part 50, Appendix I - Section IV; 6.2, B.3 and C, and Appendix A, "General Design Criteria for Nuclear Power Plants," Criterion 64. The program also complies with Title I O , Code of Federal Regulations, Part 20, "Standards for Protection Against Radiation," Section 1302. These federal requirements are cited in the Rancho Seco Quality Manual, Appendix A, and the REMP manual. REMP requirements are implemented through the review, approval and routine use of several documents, namely the REMP Manual, Offsite Dose Calculation Manual, Surveillance Procedures and Health Physics Implementing Procedures.

The programmatic elements oftheREMPare-based-on regulatory requirements-and associated guidelines. The objectives of the Program are to:

1. Provide the technological basis and the instruction for monitoring the environs for radioactivity sources. The radioactive sources, which contribute to detectable radioactivity in the local environs, are comprised of:

= Naturally occurring background, a Releases during normal operations, 3 World-wide weapons testing, and 3 Major global nuclear accidents Rancho Seco Nuclear Station E-I 2005 AREOR

PROGRAM BASIS (Continued)

2. Provide the means to verify the effectiveness of the.Rancho Seco Nuclear Station Radiological Effluents Control Program.

3. Meet the minimum detectable limits for radioisotopes in environmental samples.

4. Provide quantitative measurements in the gaseous (airborne particulate), liquid, and direct radiation exposure pathways for radionuclides.

5. Provide indications of the largest potential radiation exposure for individuals as a result of radionuclides in the principal exposure pathways.

The Program is developed and conducted using recognized standards and practices NRC79a, NRC79b, NUREG79, and NUREG80a.

REMP CHANGES The REMP manual was not revised during 2005. Administratively controlled sampling was modified as follows:

Soil, Rainwater, and Algae sampling was discontinued.

e Garden samples from the local vineyards were discontinued.

0 The back-up Control air sample location at the Rancho Seco Lake Well Enclosure was discontinued.

0 2 Luxel badge locations were discontinued.

3 of the 5 sediment sample locations were discontinued - - - .- .- - - .- .

i 7 wellwater sample IocationsweTe-disZontTrGued-These modifications were made as part of the REMP program downsizing of the Decommissioning Project and were reviewed by Plant Management prior to implementation.

EXPOSURE PATHWAYS The fundamental parameters, which have been defined prior to monitoring the environs, are:

1. Identification of the effluent release pathways

2. Identification of the human exposure pathways

3. Identification of the land use parameters-bythe population within a two-mile radius of the plant site.

Each of these three parameters is discussed below.

Rancho Seco Nuclear Station E-2 2005 AREOR

EXPOSURE PATHWAYS Effluent Release Pathways There are two principal pathways, which may result in human exposure to radiation and radioactive material originating from Station operation:

1. Liquid effluents and

2. Direct radiation from these effluents and onsite sources.

Liquid Effluents In the liquid exposure pathway, humans can ingest radioactive materials in surface waters directly or indirectly through the consumption of aquatic foods such as fish and shellfish.

Humans can consume vegetation, which is irrigated with Clay Creek water, which may contain radioactive material. Another exposure pathway from liquid effluents results from the consumption of animal products such a s meat and milk from animals, which have fed upon irrigated vegetation and/ or consumed Clay Creek water.

Direct Radiation In the direct radiation pathway, potential radiation exposure may occur from radioactive material storage areas, which are contained within the site boundary. People can potentially be exposed to direct radiation from ground deposition of particulates deposited on the ground from liquid effluents. With the off-loading of spent fuel to the ISFSI, the ISFSI has become part of the direct radiation-pathway. . -- --- . -- -- - - - - . - -

Rancho Seco Nuclear Station E-3 2005 AREOR

LAND USE CENSUS On a biennial basis, a land use census is conducted within a two-mile radius to identify any changes in the human exposure pathways. The Land Use Census is used to determine the changes needed for REMP monitoring activities. The results of the land use census conducted during 20031 2004 are presented in Appendix A of this Report. The next scheduled land use census will be conducted in 20051 2006 and reported in the 2006 AREOR. From data obtained from the Land Use Census, exposure pathways are analyzed through a systematic process, which identifies a sample medium, or organism that is found to potentially contribute to an individual's radiation exposure. Usage and bioaccumulation factors (NRC77) are then specified which represent the magnitude of radioactive material transfer through the food chain to a receptor. The analysis of the effluent and exposure pathways enables monitoring sites to be identified as "indicator" (for sites at which the potential effects of Station effluents would be readily detected) or "control" (for those sites which are not expected to be influenced by Station operation). The analysis results of samples obtained at indicator and control sites are routinely compared to identify potential exposures above background levels, The REMP maintains the monitoring sites required by the REMP manual, Table 6. This program is supplemented with additional samples to compensate for changes in the radiological environment surrounding Rancho Seco. The California Department of Health Services also selected some of the monitoring sites a s part of their monitoring programs.

Indicator sites ars placed in areas, which would be most sensitive to the effscfs of Station effluents such as downwind, or downstream areas near the Station. If radioactive material is detected above background at any of these indicator sites, observed potential exposure and dose-to-humans can-beestimated to verify-the effectiveness of the Offsite Do3e Calculalion Manual in predicting potential exposures or doses. It is important to hote that the detection of radioactive material in indicator samples does not necessarily mean that its presence can be attributed to Rancho Seco operations. Moreover, especially with liquid effluentpathway samples, the detection of radioactive material is difficult to interpret since it is unknown when the material was deposited. In many instances, the observed radioactive material could correctly be ascribed to historical (pre-2005)depositions.

Control locations provide data that should notbe influenced by the operation of Rancho Seco.

These locations are selected based upon distance from the Station in the upwind or upstream direction of the effluent release pathways. Samples obtained from control locations should, upon analysis, reveal information about the presence and distribution of naturally occurring and man-made radioactive materials. Data from these locations are used to aid in the discrimination between the effects of Rancho Seco releases and other natural phenomena or accidental releases, which may result in human exposure.

Rancho Seco Nuclear Station E-4 2005 AREOR

MONITORING LOCATION SELECTION (Continued)

Liquid radioactive effluents are discharged in batches from two onsite Retention Basins into "No Name" Creek located southwest of the Station. Dilution water, obtained from the Folsom South Canal, is discharged into "No Name" Creek to give reasonable assurance of compliance with the 10CFR50, Appendix I dose guidelines. "No Name" Creek flows southerly into the Clay Creek. Without this dilution water flow, the Clay Creek would be in a dry state for most of the year.

Beyond the Site Boundary at a point north of Highway 104, the Clay Creek empties into the Hadselville Creek. Hadselville Creek then empties into the Laguna Creek at a point west of North Clay Station Road near the Folsom South Canal. Finally, Laguna Creek flows into the Cosumnes River at a point located approximately 20 straight-line miles west of Rancho Seco.

Since this stream system is the only routine release pathway for liquid radioactive and non-radioactive effluents from the Station, the liquid exposure pathway indicator sites are located along these creeks and nearby land.

The direct radiation pathway is monitored principally through a nebvork of monitoring badges at sites distributed in sectors centered on the Station. The badges are located prjmarily at the site, residential, and recreational areas around the Rancho Seco location. This design provides the capability to easily detect Station-induced direct radiation contributions to the observed terrestrial and cosmic direct radiation background.

Some badges have been sited in special locations to record direct radiation resulting from known depositions of radioactive material and to provide IO CFR Part 72 license required data for the Interim Spent Fuel Storage Installation (ISFSI).

Appendix B contains a detailed description and illustration of the REMP sample and monitoring locations.

Rancho Seco Nuclear Station E-5 2005 AREOR

SAMPLE MEDIA Samples are collected from predetermined monitoring sites at a specified frequency. The sample media chosen is a function of the type of monitoring desired and coincides with one of the following exposure pathways:

o . Atmospheric 0 Direct radiation 0 Terrestrial 0 Aquatic life 0 Water Atmospheric monitoring is accomplished by filtering a volume of air using a mechanical air pump to collect particulates with a particulate filter paper. Three air sampler locations are used to coilect weekly air samples. One location (Meteorological Tower) is a control location and the remaining two locations are indicator locations on the plant site.

Direct radiation monitoring is achieved by placing monitoring badges at aboveground sites.

The monitoring badges respond to, and record the amount of, gamma radiation exposure. The source of this gamma radiation exposure is varied and includes potential Station effluents, naturally occurring terrestrial, and cosmogonic radionuclides. The monitoring badges are also influenced by seasonal and global (fallout) radiation sources.

-There are-33-siteq which are monitored within 3-10-mile radius-of-the Station. The-monitoring badges are placed at the Station Industrial Area Boundary, near the property boundary, locations of interest such as nearby residences, and at control locations located beyond five miles of the Station.

Terrestrial monitoring is accomplished by obtaining sam.ples of sediment and garden vegetation to measure the quantity of radioactive material deposited from liquid effluents.

There are two mud and silt (sediment) and 2 garden vegetation locations.

Aquatic monitoring includes the szmpling of fish. There are four fish sample locations.

Rancho Seco Nuclear Station E-6 2005AREOR .

SAMPLE MEDIA (Continued)

Water monitoring includes samples of surface, runoff, drinking, and well sources from locations in the liquid effluent pathway and from area wells. The six surface water sampling locations monitor site supply water (Folsom South Canal), runoff water and water discharged from the Station. Drinking water is sampled from two groundwater wells and three drinking water taps.

SAMPLE ANALYSIS 8t DATA HANDLING The laboratory, which provides radio-analyticalservices for the Program, is Eberline Services located in Richmond, California. Sample analysis results submitted by Eberline Services are reviewed for accuracy and completeness and then entered into a computerized database for evaluation.

Data comparisons are made between individual control and indicator sample sites' to isolate potentiai Station influences on the measurement results.

The summarized results of the 2005 Radiological Environmental Monitoring Program are presented in Table 2.

Individual (raw data) results are presented in Appendix F, Tables F-I through F-9.

REGULATORY REPORTING LEVELS . . . . ...

Sample analysis .data is reviewed'and evaluated by the Radiological Health Supervisor as the results are received. All sample analysis results are reviewed for correct sensitivity and a,nomalies.

The activity concentration values listed in Tab1e.E-I are the environmental Fuel Cycle Dose quantities that, if exceeded, require a Special Report to be submitted to the USNRC. In accordance with the REMP Manual (Section 5, Fuel Cycle Dose), the Special Report must include an evaluation of any release conditions, environmental factors or other aspects, which caused the reporting limits to be exceeded.

Rancho Seco Nuclear Station E-7 2005 AREOR

REGULATORY RE PORT1NG LEVELS (Continued)

In addition to the Fuel Cycle Dose reporting requirements, a Special Report is required to be submitted to the USNRC when more than one of the radionuclides in Table E-I are detected in the sampling medium and the summed ratio of detected activity concentration to the respective Reporting Level concentration is greater than, or equal to, unity (I). When radionuclides other than those listed in Table E-1 are detected which are a result of Station effluents, a Special Report is required to be submitted if the potential annual dose commitment exceeds the 10 CFR 50, Appendix I guidelines.

No reports of the types described above were required to be submitted during 2005, SENSlTlVlN OF THE REMP MEASUREMENT PROCESS

.All Program measurements must be performed at a sensitivity, which meets USNRC requirements. This sensitivity is determined "before the fact" (a prior/] for each .radionuclide of interest and sample analysis type. Typical controllable sensitivity parameters include:

3 Sample volume or mass 3 Sampling efficiency 3 Time from sample collection to measurement 3 Instrument detection efficiency for the nuclides (energies) of interest 3 Background radiation levels

=3 Chemical recovery factors By adjusting and controlling each of these parameters to maximize measurement process efficiency, a maximum sensitivity level (activity concentration) can be specified for each nuclide of interest and analysis type while maintaining an economic measurement process. The maximum sensitivities in the REMP are specified by the USNRC in the REMP Manual approved for Rancho Seco. These sensitivities are referred to a s "LLD's", an acronym for "Lower Limit of Detection". LLD's are specified on an "a prior/' basis and apply to routine measurement process capabilities when no other interfering radioactivity is present. The word "routine" is emphasized since occasional circumstances, such as limited sample mass, elevated levels of background radiation and interfering nuclides can contribute to sensitivity degradation.

Such occurrences are normally noted and reported during the conduct.of REMP activities.

Rancho S e c o Nuclear Station E-8 ' 2005AREOR

SENSITIVITY OF THE REMP MEASUREMENT PROCESS (Continu ed)

Meeting the LLD requirements is a quality control function shared by both REMP and the analytical laboratory personnel. Once the laboratory establishes values for the controllable parameters for each analysis type, sample chain of custody controls ensure that these parameters are upheld. If all parameters are upheld, then compliance with the LLD requirements h a s been demonstrated. The specific LLD values for Program measurements are included in Table E-2.

Since most of the samples analyzed result in the detection decision "activity not identified", a Minimum Detectable Activity (MDA) concentration value is calculated and reported. This value can be thought of as the LLD-at-the-time-of-countingsince it is calculated using an equation, which is similar to the one, used to establish LLD parameters. The biggest difference is that actual (not " a prior?) parameters are used, including interference from natural radioactive material in the sample. It is important to note that MDA's are reported only for those measurements where the "activity not identified" decision has already been made.

MDA values are used primarily to identify changes in the measurement process and to convey more information' about the measurement itself. Without the use of the MDA concept, most Program measurements would be reported simply as "<LLD". With MDA used, Program measurements are reported as xxx where "xxx"is the calculated MDA concentration.

'I< 'I Rancho Seco Nuclear Station E-9 2005 AREOR

TABLE E-I REPORTING LEVELS FOR RADIOACTIVITY CONCENTRATIONS IN ENVIRONMENTAL SAMPLES Water Airborne Fish Food (pCi/L) Particulate or (pCi/kg, wet) Products Analysis G a s e s (pCi/m3) (pCilkg, wet)

H-3 20000a Mn-54 1000 30000 CO-60 300 10000 Zn-65 300 20000 cs-I34 30 1000 cs-I 37 50 20 2000 2000 Gross Beta 40 2c a

Notes.: For drinking water samples, this is a 40 CFR Part 141 value h

U Gross Beta activity in water of ten times the yearly mean of the control samples is indicated as t h e level that gamma isotopic analysis shouldbe pe-rformsdon_the .

individuatsample(NRCETa]: Gamma kotopk analysis 0%each water sample is required by the REMP and therefore this requirement does not apply.

c Gross Beta activity is air of ten times the yearly mean of the control samples is indicated as thelevel that gamma isotopic analysis should be performed on the individual sample. The value indicated is Site specific.

Rancho Seco Nuclear Station E-1 0 2005 AREOR

TABLE E-2 MAXIMUM (REQUIRED)LLD VALUES FOR ENVIRONMENTALSAMPLES~'

(N RC79A)

Airborne Analysis Water Particulate or G a s e s (d) (PCiU. . (pCi,m3)

I I I(

H-3 Mn-54 I .

2000 (1000, b, 15 1 3 130 I I '

I CO-60 ' 15 130 I50e Zn-65 30 260 130 I

60 I

150 I

130 60 150 Notes:

(a) Analysis requirements are those recommended in the BTP [NRC79A] and RETS-[N!JREG79], . . . - - - . . . - _ _ - _ _ _

(b) LLD for water samples utilized for human consumption only [NUREG79].

(c) Other peaks, which are measurable and identifiable, together with the nuclides in Table E-2, shall be identified and reported.

(d) Composite analysis LLD is Shown; individual sample LLD is 0.05 pCi/m3(Site-specific value).

(e) LLD for Mud and Silt (20-60 is not required by RETS [NUREG79]. This value is consistent with the.RETS required value for Cs-I 34 and Cs-137.

Rancho Seco Nuclear Station E-I 1 ' 2005AREOR

APPENDIX F 2005 SAMPLE ANALYSIS RAW DATA TABLES Rancho Seco Nuclear Station F-I 2005 AREOR

. TABLE F-I 2005 WEEKLY AIR SAMPLE

SUMMARY

Gross Beta Activity in Air Particulates (pci/rn3) 5/10/2005 0.009 0.001 0.008 0.001 0.009 0.001 5/16/2005 0.011 0,001 0.011 0.001 0.012 0.001 Rancho Seco Nuclear Station F-2 2005 AREOR

TABLE F-1 2005 WEEKLY AIR SAMPLE

SUMMARY

(Contin ued)

Gross Beta Activity in Air Particulates

. (pci/rn3)

Rancho Seco Nuclear Station F-3 2005 AREOR

Table F-2 2005 Luxel Summary (Direct Radiation)

Quarterly (mRem)

I = Indicator Location / C = Control Location Rancho Seco Nuclear Station F-4 2005 AREOR

Table F-3 2005 Garden Vegetables Semi-annual (pCi/kg, wet)

RLVO.6MO I 1/27/2005 140.7 1e9.99 j1<26.9 4 2 . 0 143.5__

RLVl8.OKO I 1/27/2005 k6.97 ac7.01 /<I 9.8 . ~ 7 . 6 6 1.14.67 -

RLVO.6MO 1 7/25/2005  !<3.52 9~3.35

- 1 1~9.36 [<3.62 1<7.93 1

1 iRLVl8.OKO I -

7/25/2005 \<4.59 [<4.56 142.6__I b5.12.- \<3.44 1RLVO.6MO 11/10/2005 k2.27 k2.31 <6.72 k2.66 k1.95 Table F-4 2005 SEDIMENT Quarterly (pCi/kg)

IRMSO.6MOQ I 10/25/2005 14.62 154.3 144.1 )<6.86 I 135 I Rancho Seco Nuclear Station F-5 2005 AREOR

TABLE F-5 2005 FISH Semi-Annual (pCi/kg, wet)

IRFSO.GMOI1) I 5/13/2005 k6.93 k7.56 k18.2k8.07 I 30.1 I IRFSO.GMO(1) I 10/24/2005 (<20.0 1<21.2 1<52.6 1<32.5 I <20.0 I Note: (l)=Predator Species TABLE F-6 2005 WELL WATER Quarterly (pCi/L)

Rancho Seco Nuclear Station F-6 2005 AREOR

TABLE F-7 2005 RUNOFF WATER Biweekly (pCi/L)

Rancho Seco Nuclear Station F-7 2005 AREOR

TABLE F-8 2005 SURFACE WATER Monthly Grab I Monthly Composite (pCi/L)

IRSW1.3FO 1 6/27/2005 (<314 1 4 0 . 6 ( 4 1 . 7 1<22.8 1 4 2 . 7 1~10.2 I

. . Rancho S.eco Nuclear Station F-8 2005 AREOR

TABLE F-8 (Continued) 2005 SURFACE WATER Monthly Grab1 Monthly Composite .

(pCilL)

Rancho Seco Nuclear Station ' F-9 2005 AREOR

TABLE F-9 2005 Drinking Water Monthly (pCilL)

Rancho Seco Nuclear Station F-I 0 2005 AREOR

APPENDIX G 2005 MISSED SAMPLE REPORT In accordance with the requirements REMP manual section 3.1, the following samples are being reported as not being collected for the reasons indicated. Corrective action as required by the REMP manual is as indicated.

Air Sampler (Airborne Pathwav)

RAS0.7E0, Rancho Seco Meteorological Tower (control)/- On February 16, 2005, during routine change out, the air sampler was found not running due to a storm related power outage. Air sampler run time was 2898.8 minutes and the volume did meet the minimum required.

M§0.70, Rancho Seco Meteorological Tower (control)/- On April 12, 2005, during routine change out, the air sampler was found not running due to a storm related power outage. Air sampler run time was 6968 minutes and the volume did meet the minimum required.

RAS0.3M0, Plant Effluent (indicator) /RASO.l CO, PAP/ Security Bldg. (indicator) - On April 19, 2005, during routine change out both air samplers were found not running due to an unscheduled Site power outage which occurred on April 13, 2005. The total sample time for these two locations was reduced by 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 52 minutes. The minimum sample volume was achieved.

RASO.7E0, Rancho Seco Meteorological Tower (control)/- On September 20, 2005, during routine change-out, the alrsampler wasfound not rummg duetcra-pwer outage. Air sampler run time was 6241.9 minutes and the volume did meet the minimum required.

RAS0.7E0, Rancho Seco Meteorological Tower (control)/- On December 20, 2005, during routine change out, the air sampler was found not running due to a storm related power outage. Air sampler run time was 7078.4 minutes and the volume did meet the minimum required.

RAS0.7E0, Rancho Seco Meteorological Tower (control)/- On December 27, 2005, during routine change out, the air sampler was found not running due to a storm related power outage. Air sampler run time was 10088.7 minutes and the volume did meet the minimum required.

Rancho Seco Nuclear Station G-I 2005 AREOR

APPENDIXG .

2005 MISSED SAMPLE REPORT JContinuedl Water monitoring .

RRWO.6MO Site Boundary (Indicator) On August 2, 2005 at 1400 the analysis lab (Eberline) reported by telecon that the runoff water sample collected on July 25, 2005 at 1120 had been damaged during shipment. The one liter cubitainer, which is used for the gamma analysis, was damaged and the sample was lost for this container. The glass container for the tritium was intact. Direction was given to use the tritium container for both analyses. Results received for this sample were received and all were acceptable.

Direct Monitoring Pathway (Luxel Badge))

RTL8.2KO Elliott Cemetery (Control) -The first quarter 2005 badges were shipped to Landauer for processing and it was reported that one of the two badges from this location was lost in transit. Chain of custody showed that all badges were shipped and the badge from this location did not arrive at the vendor for processing. Data for this location for the first quarter 2005 will be from the remaining badge.

RTL3.7NO Folsom South Canal, Back Entrance (Indicator) -The second quarter 2005 badges were shipped to Landauer for processing and it was reported that one of the two badges from this location was lost in transit. Chain'of custody showed that all badges were shipped and the badge from this location did not arrive at the vkridor fctr processing. Data for this location for the second quarter 2005 will be from the remaining .badge Rancho Seco Nuclear Station G-2 2005 AREOR