ML13142A214
| ML13142A214 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco, 07200011 |
| Issue date: | 04/18/2013 |
| From: | Ronningen E Sacramento Municipal Utility District (SMUD) |
| To: | Collins E NRC Region 4 |
| References | |
| DPG 13-075 | |
| Download: ML13142A214 (31) | |
Text
Powering forward. Together.
- SMUDy DPG 13-075 April 18,2013 U.S. Nuclear Regulatory Commission Elmo Collins, Region IV Administrator 1600 East Lamar Boulevard Arlington, TX 76011-4511 Docket No. 50-312 Rancho Seco Nuclear Generating Station License No. DPR-54 Docket No. 72-11 Rancho Seco Independent Spent Fuel Storage Installation License No. SNM-2510 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT FOR 2012 Attention: Region IV Administrator In accordance with Rancho Seco Quality Manual, Appendix A, Section 1.5.3, we are submitting the Rancho Seco 2012 Annual Radiological Environmental Operating Report for the period of January 1, 2012 through December 31, 2012.
If you or members of your staff have questions requiring additional information or clarification, please contact me at (916) 732-4817 or by email at einar.ronningen@smud.org.
Sincerely,
/
Einar T. Ronningen Superntendent, Rancho Seco Assets cc:
NRC Document Control Desk William Allen John Hickman RIC Rancho Seco Nuclear Generating Station 114440 Twin Cities Road I Herald, CA 95638-9799 1.209.333.2935 I smud.org
ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT JANUARY - DECEMBER 2012 Rancho Seco Nuclear Station Herald, California 10 CFR Part 50 License Number DPR-54 10 CFR Part 72 License Number SNM-2510
2012 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT TABLE OF CONTENTS LIS T O F FIG U R E S.......................................................................................................................................
3 LIS T O F TA B LE S..........................................................................................................................................
4 I.
EXECUTIVE SUM M ARY...........................................................................................................
5 II.
LAND USE CENSUS...............................................................................................................
6 III.
RADIOLOGICAL IMPACT EVALUATION.................................................................................
6 IV.
PROGRAM ANALYSIS RESULTS
SUMMARY
7 IV-A. ATMOSPHERIC MONITORING.........................................................................................
8 IV-B. W ATER MONITORING....................................................................................................
8 IV-C. DIRECT RADIATION MONITORING...............................................................................
8 V.
R E F E R E N C E S....................................................................................................................................
11 V I. A P P E N D IC E S....................................................................................................................................
12 APPENDIX A: LAND USE CENSUS RESULTS........................................................................
13 APPENDIX B: SAMPLE SITE DESCRIPTIONS AND MAPS...................................................
14 APPENDIX C: QUALITY CONTROL SAMPLE ANALYSIS RESULTS.....................................
19 APPENDIX D: SAMPLE COLLECTION AND ANALYSIS METHODS.......................................
21 APPENDIX E: ENVIRONMENTAL MONITORING PROGRAM DESIGN..................................
22 APPENDIX F: 2012 SAMPLE ANALYSIS RAW DATA TABLES..............................................
29 APPENDIX G: 2012 MISSED SAMPLE REPORT...................................................................
30 Rancho Seco Nuclear Station 2
2012 AREOR
LIST OF FIGURES FIGURE TITLE PAGE FIGURE B-1 FIGURE B-2 RADIOLOGICAL ENVIRONMENTAL SAMPLING LOCATIONS ON AND NEAR THE SITE 16 RADIOLOGICAL ENVIRONMENTAL CONTROL LOCATIONS DISTANT FROM THE SITE-17 Rancho Seco Nuclear Station 3
2012 AREOR
LIST OF TABLES TABLE TITLE PAGE I
ENVIRONMENTAL RADIOLOGICAL MONITORING PROGRAM ANNUAL
SUMMARY
10 B-I RADIOLOGICAL ENVIRONMENTAL MONITORING SITES AND MAP LOCATIONS 18 E-I REPORTING LEVELS FOR RADIOACTIVITY CONCENTRATIONS IN ENVIRONMENTAL SAMPLES 28 F-I 2012 LUXEL BADGE
SUMMARY
(DIRECT RADIATION) 29 Rancho Seco Nuclear Station 4
2012 AREOR
2012 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT I.
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 1, 2012 through December 31, 2012. This program is conducted by Sacramento Municipal Utility District (SMUD) staff 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 [RS01].
The results of the 2012 Radiological Environmental Monitoring Program showed that the operation of Rancho Seco Nuclear Station had no significant radiological impact on the environment.
The facility is currently in a static mode of materials storage. There are two licensed areas at the site: an approximately 1-acre facility licensed under 10 CFR 50 storing Class B and Class C low-level radioactive waste in the Interim Onsite Storage Building (IOSB), and; the approximately 10-acre Independent Spent Fuel Storage Installation (ISFSI) licensed under 10 CFR Part 72 for the storage of used nuclear fuel. Activities to complete the license termination for the Part 50 facility will be completed after a suitable disposal facility becomes available for the stored material.
In accordance with the current site status, the REMP Manual reflects that the only normal remaining pathway to impact a member of the public at the Rancho Seco Nuclear Station is the direct radiation pathway from the ISFSI and IOSB. If repackaging of the stored low-level waste is required prior to shipment for disposal, monitoring for potential release of particulate material in gaseous effluents will be performed. The material is currently in storage packaged and ready for shipment, so any need to remove the material from its packaging is considered unlikely.
However, the procedures and processes for monitoring and analyzing this sample stream have been retained in facility procedures.
During the reporting period, the environs adjacent to RSNS were monitored using Luxel monitoring badges. 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 and review of historical data, ranged from indistinguishable above background levels to slightly elevated levels.
Rancho Seco Nuclear Station 5
2012 AREOR
II.
LAND USE CENSUS With the completion of Phase I of Radiological Decommissioning, the requirement to perform a Land Use Census was removed as a required program from the Rancho Seco Quality Manual (RSQM) in 2008.
II1.
RADIOLOGICAL IMPACT EVALUATION PREDICTED POTENTIAL RADIOLOGICAL IMPACT Gaseous Effluent Exposure Pathways No gaseous effluent releases were conducted in 2012; therefore no dose calculations were performed.
Liquid Effluent Exposure Pathways The onsite liquid effluent pathway and any potential source of liquid effluents were removed during the decommissioning process; therefore there were no liquid effluent releases conducted nor dose calculations performed for 2012.
FUEL CYCLE DOSE EVALUATION REMP Manual section 8.1.4 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 [CFRa].
Consistent with REMP Manual section 5.0, no fuel cycle dose evaluation was required to be performed during 2012 since no REMP measurement exceeded the established reporting levels. Additionally, with no liquid or gaseous effluent releases, effluent dose predictions did not exceed twice the dose guidelines of 10 CFR Part 50, Appendix I [CFRb]. Therefore, Appendix I guidelines for radioactive effluents were not exceeded and determination of an actual dose commitment delivered to a real member of the public was not required.
Analysis of the Luxel measurements taken at the perimeter of the facility (fence boundaries beyond which public access is not normally controlled) indicate that in no case could a real member of the public have received more than 25 mrem during 2012, indicating compliance with 10 CFR 72.104.
Rancho Seco Nuclear Station 6
2012 AREOR
OBSERVED POTENTIAL RADIOLOGICAL IMPACT Gaseous Effluent Exposure Pathways Routine gaseous effluent pathways have been deleted from the ODCM and REMP Manual to reflect site conditions. No gaseous effluents were released in 2012, therefore no dose calculations were performed.
Liquid Effluent Exposure Pathways All liquid effluent pathways have been decommissioned at Rancho Seco. The REMP Manual was revised to delete all liquid exposure pathway sample locations in reflection of current site conditions, therefore no dose calculations were completed for 2012.
Direct Radiation Exposure Pathway Based on Luxel control and indicator locations, and a review of historical data, the RSNS did not contribute a significant component to the recorded direct gamma radiation field. The current year's data shows that there is little measurable direct radiation effect on the environment.
Since RSNS is in a static materials storage condition, and there are minimal detectable direct radiation measurements of the surrounding environment, the conclusion remains that the Station has no significant direct radiation effect on the environment. This is the same conclusion that has been made since the fuel was placed into the ISFSI in 2002.
Luxel badge locations around the ISFSI security fence indicated higher readings, attributed to the fuel stored in the ISFSI, and are within design calculations. This monitoring is outside of the REMP and therefore the results of this monitoring are not included in this report.
IV.
PROGRAM ANALYSIS RESULTS
SUMMARY
This section compiles Program data with corresponding evaluations. Each of the following subsections presents information about each of the principal environmental exposure pathways monitored by the Program:
= Direct Radiation (Section IV-C)
Table 1 is a comprehensive data summary presented in a format considered acceptable by the US Nuclear Regulatory Commission. Information contained in Table 1 was derived from data presented in Appendix F.
Rancho Seco Nuclear Station 7
2012 AREOR
IV-A. ATMOSPHERIC MONITORING DATA EVALUATION The REMP Manual was revised in January 2010 to delete all sample locations except for the Luxel direct radiation monitoring badges. No data was collected.
IV-B. WATER MONITORING DATA EVALUATION The REMP Manual was revised in January 2010 to delete all sample locations except for the Luxel direct radiation monitoring badges. No data was collected.
IV-C. DIRECT RADIATION MONITORING DATA EVALUATION The revision to the REMP Manual conducted in 2010 eliminated some locations where dose monitoring was performed to reflect the current status of the licensed facility as discussed above. During 2010, and again in 2011, the locations eliminated from the REMP continued to be monitored. Beginning in 2012, only the locations requiring monitoring by the REMP are being monitored. Comparisons of historical data on a year-to-year basis have been provided in previous reports. Because the environmental impact is so low, such comparisons will no longer be reported.
In addition to the Control Locations utilized for comparison purposes, Quality Control Luxels are included throughout the process to take into account variables like dose received during shipment. Those Quality Control dosimeters were historically stored within the licensed facility inside of a lead-shielded location for the time the REMP dosimeters were deployed in the field. During shipments, and during onsite storage before and after being deployed to monitor environmental doses, the Quality Control dosimeters are kept with the entire batch of dosimeters. In 2012, the building in which the Quality Control dosimeters were kept was abandoned, and now the QC dosimeters are stored in a heavy steel safe inside the current office structure which is a minimum of 350 meters further away from the licensed areas than the closest REMP monitoring location. This has resulted in the Quality Control dosimeters receiving a slightly higher dose compared to the lead-shielded laboratory storage location.
The measured dose from the Quality Control dosimeters is subtracted from the measured doses from both the monitoring location dosimeters and the control location dosimeters to eliminate transportation and storage dose from the evaluation. In the current configuration, while the total numerical values of the doses in the monitoring and control locations show no change, the net does is now not distinguishable from the QC dosimeter doses, in almost all instances. That change results in this report now indicating that most locations now indicate dose impacts below the minimal reporting value of 1 mrem provided by the dosimeter vendor.
Rancho Seco Nuclear Station 8
2012 AREOR
A comparison review of all Luxel data for the indicator and control locations during 2012 shows that the doses were typically within 1 or 2 mrem of the measured Quality Control dose levels. This confirms that there continues to be no significant observable direct radiation component due to Station operations (i.e., storage or utilization of licensed radioactive material within the restricted area).
The summary data for 2012 direct radiation monitoring is presented in Table 1.
Comprehensive data tables are given in Appendix F, Table F-1.
Rancho Seco Nuclear Station 9
2012 AREOR
TABLE 1 ENVIRONMENTAL RADIOLOGICAL MONITORING PROGRAM ANNUAL
SUMMARY
Name of Facility Rancho Seco Nuclear Station Docket No. DPR-54/ SNM-2510 Location of Facility Sacramento, California (County, State)
Reporting Period January - December 2012 Medium or Type and Lower All Indicator Location with Highest Annual Control locations Number of Pathway Total Limit of Locations Mean Mean (f) a Nonroutine Sampled Number of Detection Mean (f)a Name Mean f) a Range Reported (Unit of Analysis (LLD)
Range Distance Range Measurements Measurement)
Performed
& Direction Direct Radiation Luxel 1 mre/t 4(2/48)
RTL0.5NP 5 (1/4) 4( (08) 0 (mrem/qtr.)
196 (1-2) 0.5 miles 2700 (1-21 1
a Mean and Range based upon detectable measurements only.
locations is indicated in parentheses. (f)
Fraction of detectable measurements at specified Rancho Seco Nuclear Station 10 2012 AREOR
V.
REFERENCES CFRa CFRb NRC79a NRC79b Code of Federal Regulations, "Environmental Radiation Protection Standards for Nuclear Power Operations," Title 40, Part 190.
Code of Federal Regulations, "Domestic Licensing of Production and Utilization Facilities," Title 10, Part 50.
United States Nuclear Regulatory Commission, 1979, "An Acceptable Radiological Environmental Monitoring Program," Branch Technical Position, Revision 1.
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.
United States Nuclear Regulatory Commission, 1979, "Radiological Effluent Technical Specifications for PWRs," NUREG-0472, Revision 2.
United States Nuclear Regulatory Commission, 1980, "Methods for Demonstrating LWR Compliance with the EPA Uranium Fuel Cycle Standard (40 CFR Part 190)," NUREG-0543.
RS-LBD-010, Rancho Seco Quality Control Manual, Appendix A NUREG79 NUREG80a RS01 Rancho Seco Nuclear Station 11 2012 AREOR
VI.
APPENDICES Rancho Seco Nuclear Station 12 2012 AREOR
APPENDIX A: LAND USE CENSUS RESULTS With the revision of the REMP Manual in January 2010, the requirement to complete a Land Use Census has been deleted.
Rancho Seco Nuclear Station 13 2012 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-1 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:
TL Direct Gamma Radiation (Luxel)
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.
Sector Letter Degrees Azimuth Compass Point A
348.75 to 11.25 N
B 11.25 to 33.75 NNE C
33.75 to 56.25 NE D
56.25 to 78.75 ENE E
78.75 to 101.25 E
F 101.25 to 123.75 ESE G
123.75 to 146.25 SE H
146.25 to 168.75 SSE J
168.75 to 191.25 S
K 191.25 to 213.75 SSW L
213.75 to 236.25 SW M
236.25 to 258.75 WSW N
258.75 to 281.25 W
P 281.25 to 303.75 WNW Q
303.75 to 326.25 NW R
326.25 to 348.75 NNW The final letter designation indicates if the location is part of the operational REMP program
("0") or post-operational REMP program ("P").
Rancho Seco Nuclear Station 14 2012 AREOR
Table B-1 Lists each location referencing the 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-1 Figure B-2 Site Location Map:
Shows the locations of the sample locations near the Site.
Distant Locations Map: Control locations away from the site are shown on this map.
Map Key 0
94 Location that requires monitoring per REMP Rancho Seco Nuclear Station 15 2012 AREOR
Figure B-1 Radiological Environmental Sampling Locations on and near the Site Rancho Seco Nuclear Station 16 2012 AREOR
Figure B-2 Radiological Environmental Control Locations Rancho Seco Nuclear Station 17 2012 AREOR
Table B-1 Radiological Environmental Monitoring Sites and Map Locations Sapl Tpe IDCoe las Map Collection Sample Te ID Code Class Location No.
Frequency Description. of Location Miles Sector LUXEL RTL1.7FO CON.
43 Quarterly Well pump fence @ reservoir 1.7 G
LUXEL RTL1.8FO CON.
19 Quarterly Rancho Seco Lake Maintenance Building 1.8 F
LUXEL RTLO.3PO IND.
68 Quarterly West Perimeter Fence, West of IOSB 0.3 P
LUXEL RTLO.3NP IND.
88 Quarterly South ISFSI 100m Fence 0.3 N
LUXEL RTLO.4NP IND.
89 Quarterly Southwest Comer ISFSI 100 m Fence 0.4 N
LUXEL RTLO.5NP IND.
90 Quarterly Northwest ISFSI 100 m Fence 0.5 P
LUXEL RTLO.3QP IND.
91 Quarterly North Perimeter Fence 0.3 Q
LUXEL RTLO.4PP IND.
94 Quarterly North ISFSI 100 m Fence 0.4 P
LUXEL RTLO.2PP IND.
95 Quarterly Well East of IOSB 0.2 P
LUXEL RTLO.2NP IND.
96 Quarterly IOSB Electrical Transformer, SE comer 0.2 P
LUXEL RTLO.3NP IND.
97 Quarterly IOSB west roof access ladder 0.3 P
LUXEL RTLO.2NP IND.
98 Quarterly Switchyard Fence north side 0.2 N
LUXEL RTLO.3NP IND.
99 Quarterly ISFS1 100 meter fence, vehicle access gate 0.3 N
LUXEL RTLO.3NP IND.
100 Quarterly West Perimeter Fence, NW of IOSB 0.3 N
Note: Prior to the 2010 Report, the "Map Location No." used here was different than the "Location Number" used in Table F-1. To prevent confusion, the same numbering system is now used throughout the report.
Rancho Seco Nuclear Station 18 2012 AREOR
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:
Sample collection, Packaging, Shipment and receipt, Measurements of radioactivity, Data evaluation, and Reporting.
These program elements are performed according to approved, written procedures to assure the validity of REMP results.
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, [NRC79b].
INTERLABORATORY COMPARISON PROGRAM With the revision of the REMP Manual to delete all sample locations except for Direct Radiation monitoring locations, no discussion of Interlaboratory Comparison or analysis of laboratory Quality Assurance program is necessary.
RANCHO SECO AUDIT AND SURVEILLANCE RESULTS The Rancho Seco Quality Program requires periodic audits of REMP activities. Contract laboratory performance is evaluated by the Rancho Seco QA Department and an "Approved Vendor List" is created from these audits. Audits are either conducted by Rancho Seco QA staff or by reviewing audits conducted by other facilities (NUPIC audit review). Landauer is currently on the approved suppliers list.
Rancho Seco Nuclear Station 19 2012 AREOR
DIRECT RADIATION (Luxel) COMPARISON PROGRAM 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, 2012. NVLAP certification is considered to satisfy the interlaboratory comparison requirements for the direct radiation measurement devices.
This comparison program satisfies the requirement of the REMP Manual section 6.0.
Rancho Seco Nuclear Station 20 2012 AREOR
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. A brief description of these collection and analysis methods is included in this Appendix.
Sample Media DIRECT RADIATION Collection/Analysis Method Monitoring badges, (Luxels), are located within a two (2) mile radius of the site. The badges within a one (1) 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 21 2012 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 has been revised to reflect the requirements of the ISFSI Technical Specifications for direct radiation monitoring and direct radiation monitoring of the lOS building for the 10 CFR Part 50 License.
During 2012 the program was directed and executed by the Superintendent, Rancho Seco Assets who has primary accountability.
The Program is designed consistent with Title 10, Code of Federal Regulations, Part 50, Appendix I - Section IV, B.2, B.3 and C, and Appendix A, "General Design Criteria for Nuclear Power Plants," Criterion 64. The program also complies with Title 10, 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 of the REMP are 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,
=: Direct radiation from materials storage,
= World-wide weapons testing, and
= Major global nuclear accidents Rancho Seco Nuclear Station 22 2012 AREOR
~
PROGRAM BASIS (Continued)
- 2.
Provide the means to verify the effectiveness of the Rancho Seco Nuclear Station Radiological Effluents Control Program.
- 3.
Provide quantitative measurements in the direct radiation exposure pathway.
- 4.
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 and sampling program was revised during 2010 to delete all sample locations except for the direct radiation pathway. The requirement for a Land Use Census and conducting an ICP for the radioactivity analysis laboratory was also deleted.
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 Each of these parameters is discussed below.
Effluent Release Pathways The principal pathways which may result in human exposure to radiation and radioactive material originating from Station operation are direct radiation from onsite sources. Gaseous and liquid effluents are not currently being discharged or monitored.
Direct Radiation In the direct radiation pathway, potential radiation exposure may occur from radioactive material storage areas, which are contained within the facility perimeters.
Rancho Seco Nuclear Station 23 2012 AREOR
PROGRAM BASIS (Continued)
MONITORING LOCATION SELECTION The required monitoring sites are listed in the REMP Manual, Table 3. This program is supplemented with additional samples to compensate for changes in the radiological environment surrounding Rancho Seco. Indicator sites are placed in areas, which would be most sensitive to the effects of Station operations. If radioactive material is detected above background at any of these indicator sites, observed potential exposure and dose to humans can be estimated to verify the effectiveness of the REMP in monitoring potential exposures or doses.
Control locations provide data that should not be influenced by the operation of Rancho Seco.
These locations are selected based upon distance from the Station. 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 direct radiation sources and other natural phenomena or accidental releases, which may result in human exposure.
The direct radiation pathway is monitored through a network of monitoring badges at sites distributed in sectors centered on the Station. The badges are located primarily at the site around the ISFSI and IOSB. 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 locations to record direct radiation to provide 10 CFR Part 72 license required data for the Interim Spent Fuel Storage Installation (ISFSI), and provide additional monitoring data for the IOSB.
Appendix B contains a detailed description and illustration of the REMP sample and monitoring locations.
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 Direct radiation Rancho Seco Nuclear Station 24 2012 AREOR
PROGRAM BASIS (Continued)
SAMPLE MEDIA 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 14 sites that require monitoring per the REMP, which are within a 2-mile radius of the RSNS. The monitoring badges are placed at the Station Industrial Area Boundary, near the property boundary, at the ISFSI and IOSB, and at control locations located beyond one mile of the Station.
SAMPLE ANALYSIS & DATA HANDLING Data comparisons are made between individual control and indicator sample sites to isolate potential Station influences on the measurement results. Quality Control dosimeters stored in a steel safe during the measurement period, but kept with the dosimeters during shipping and storage measure non-environmental doses and this amount is subtracted from the total measurements at the monitoring and control locations.
The summarized results of the 2012 Radiological Environmental Monitoring Program are presented in Table 1.
Individual (raw data) results are presented in Appendix F, Table F-i.
REGULATORY REPORTING LEVELS Sample analysis data is reviewed and evaluated by the Staff as the results are received. All sample analysis results are reviewed for correct sensitivity and anomalies.
The activity concentration values listed in Table E-1 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.
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-1 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 (1). 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.
Rancho Seco Nuclear Station 25 2012 AREOR
No reports of the types described above were required to be submitted during 2012.
SENSITIVITY 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 priori) for each radionuclide of interest and sample analysis type. Typical controllable sensitivity parameters include:
- => Sample volume or mass
=> Sampling efficiency
= Time from sample collection to measurement
= Instrument detection efficiency for the nuclides (energies) of interest
= Background radiation levels
=> 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 as "LLD's", an acronym for "Lower Limit of Detection". LLD's are specified on an "a priori" 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.
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 has been demonstrated. No specific LLD values for Program measurements are included in this report as no applicable monitoring was performed.
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-counting since 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 priori") 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.
Rancho Seco Nuclear Station 26 2012 AREOR
SENSITIVITY OF THE REMP MEASUREMENT PROCESS (continued)
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.
With the revision of the REMP Manual to delete all exposure pathways except for direct radiation, these sensitivities are no longer applicable to the current monitoring program.
Rancho Seco Nuclear Station 27 2012 AREOR
TABLE E-1 REPORTING LEVELS FOR RADIOACTIVITY CONCENTRATIONS IN ENVIRONMENTAL SAMPLES Airborne Particulate or Analysis Gases (pCilm3)
Cs-134 10 Cs-137 20 Gross Beta 2 a a
Notes:
Gross Beta activity in air of ten times the yearly mean of the control samples is indicated as the level that gamma isotopic analysis should be performed on the individual sample. The value indicated is Site specific.
Rancho Seco Nuclear Station 28 2012 AREOR
APPENDIX F: 2012 SAMPLE ANALYSIS RAW DATA TABLES TABLE F-1 2012 Luxel Summary (Direct Radiation)
Quarterly (mrem)
RS Lake Maint. Bldg RS Lake Well Encl.
43 RTL1.7FO C
1 1
1 1
68 RTL0.3PO Site fence west by ISOB I
1 1
1 1
88 RTLO.3NP ISFSI south fence I
1 1
1 1
89 RTLO.4NP ISFSI south fence I
1 1
1 1
90 RTLO.5NP ISFSI west fence I
1 1
2 1
91 RTLO.3QP Site fence NW comer I
1 1
1*
1 94 RTLO.4PP ISFSI fence north I
1 1
1 1
95 RTLO.2PP IOSB Well I
1 1
1 1
96 RTL0.2NP IOSB Electrical Transformer I
1 1
1 97 RTLO.3NP IOSB Roof Access Ladder I
1 1
1 1
98 RTL0.2NP Switchyard Fence I
1_
1 1
1 1
99 RTL0.3NP 100 Meter Fence I
1 1
1 1
100 RTLO.3NP Access Road NW of IOSB I
I I
1 1
Minimal Reporting Dose is I mrem.
- Value is an average of 2 mrem and the minimal reporting dose I = Indicator Location / C = Control Location M = Missing Data, see Appendix G Rancho Seco Nuclear Station 29 2012 AREOR
APPENDIX G: 2012 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.
Direct Monitorina Pathway (Luxel Badne)
None Rancho Seco Nuclear Station 30 2012 AREOR