ML15132A084
| ML15132A084 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 04/28/2015 |
| From: | Radiation Safety & Control Services |
| To: | Document Control Desk, Office of Nuclear Material Safety and Safeguards |
| Shared Package | |
| ML15132A076 | List: |
| References | |
| BYR 2015-018 | |
| Download: ML15132A084 (27) | |
Text
YANKEE NUCLEAR POWER STATIONINDEPENDENT SPENT FUEL STORAGE INSTALLATION License Nos. DPR-3 and SFGL-13ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORTJanuary -December 2014RSCSR~awrt~.
Safety & CmW SormJApril 2015Prepared by:Radiation Safety & Control Services91 Portsmouth AvenueStratham, NH 03885-2468 EXECUTIVE SUMMARYYankee Nuclear Power Station was permanently shutdown in 1991. All fuel has beentransferred into dry storage casks and placed at the Independent Spent Fuel StorageInstallation.
The Radiological Environmental Monitoring Program (REMP) for theYankee Nuclear Power Station (YNPS) Independent Spent Fuel Storage Installation (ISFSI) located in Rowe, MA was continued for the period January through December2014 in compliance with the YNPS Offsite Dose Calculation Manual (ODCM).By design, there are no liquid or gaseous effluents associated with the operation of theISFSI. Therefore, the ODCM only requires monitoring of direct exposure from thefacility.
TLDs were used to measure direct gamma exposure at six locations in thevicinity of the ISFSI and one control location 7.6 kilometers away. The results of thesemeasurements showed no significant change in exposure rates and potential doses tomembers of the public during the monitoring period. The results of the monitoring performed in 2014 also show that operating the YNPS ISFSI results in only a smallfraction of the 40 CFR Part 190 and 10 CFR Part 72.104 direct radiation dose limit of 25mrem/year to members of the public.YNPS 2014 Annual REO ReportPage 2 of 27 TABLE OF CONTENTSSection Title Page
1.0 INTRODUCTION
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62.0 GENERAL ISFSI AND SITE INFORMATION
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73.0 PROGRAM DESIGN ..................................................................................
73.1 MONITORING ZONES ..........................................................................................
83.2 PATHWAYS MONITORED
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83.3 DESCRIPTION OF MONITORING PROGRAM ........................................................
84.0 RADIOLOGICAL DATA SUMMARY TABLES .........................................
155.0 ANALYSIS OF ENVIRONMENTAL RESULTS ........................................
265.1 SAMPLING PROGRAM DEVIATIONS
...................................................................
265.2 DIRECT RADIATION PATHWAY ........................................................................
2
66.0 REFERENCES
........................................................................................
27YNPS 2014 Annual REO ReportPage 3 of 27 LIST OF TABLESTable Title Pace3.1 Radiological Environmental Monitoring Program ................................
93.2 Radiological Environmental Monitoring Locations
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104.1 TLD Measurements by Half-Year
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164.2 TLD Data Sum m ary ................................................................................
174.3 Direct Dose from ISFSI Operations
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18YNPS 2014 Annual REO ReportPage 4 of 27 LIST OF FIGURESFigure Title Paqe3.1 All Radiation Monitoring Locations
.......................................................
113.2 Onsite Direct Radiation Monitoring Locations
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123.3 Direct Radiation Monitoring Locations (Within I mile) ......................
133.4 Offsite Control Location
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144.1 Annual Dose Trend at GM-02 ...............................................................
204.2 Annual Dose Trend at GM-06 ...............................................................
214.3 Annual Dose Trend at GM-15 ................................................................
224.4 Annual Dose Trend at GM-16 ................................................................
234.5 Annual Dose Trend at GM-17 ...............................................................
244.6 Annual Dose Trend at GM-21 ...............................................................
25YNPS 2014 Annual REO ReportPage 5 of 27
1.0 INTRODUCTION
This report summarizes the findings of the Radiological Environmental Monitoring Program (REMP) conducted by Yankee in the vicinity of theIndependent Spent Fuel Storage Installation in Rowe, Massachusetts during thecalendar year. It is submitted annually in compliance with the Offsite DoseCalculation Manual (ODCM). The remainder of this report is organized asfollows:Section 2:Section 3:Section 4:Section 5:Section 6:Provides a brief description of the Yankee site and its environs.
Provides a description of the overall REMP design. Included is asummary of the ODCM requirements for REMP sampling, tableslisting TLD monitoring locations with compass sectors anddistances from the ISFSI, and maps showing the location of eachof the TLD monitoring locations.
Provides a complete set of TLD data showing measured results(mR) and calculated doses (mrem per year). This section alsoprovides the summarized TLD data in the format specified by theNRC Branch Technical Position on Environmental Monitoring (Reference 1).Provides the results of the calendar year monitoring program.
Theperformance of the program in meeting ODCM requirements isdiscussed, and the data acquired during the year is analyzed.
References YNPS 2014 Annual REO ReportPage 6 of 27 2.0 GENERAL ISFSI AND SITE INFORMATION The Yankee Nuclear Power Station site is located on over 1800 acres in apredominantly rural area of northwestern Massachusetts, three-quarters of a milesouth of the Vermont border. The site resides in the town of Rowe,Massachusetts, approximately 9 air miles east-northeast of North Adams,Massachusetts.
The surrounding area is heavily forested and lightly populated.
Hills bounding the river valley rise 500 to 1000 feet above the site, reachingelevations of 2100 feet.The Deerfield River is used extensively for hydroelectric power generation bothupstream and downstream of YNPS. The Sherman Dam, immediately adjacentto the site, operates as a hydroelectric generating station.
Sherman Pond, theimpoundment behind this dam, had been used as a source of cooling water forthe former power plant.The former nuclear power plant was voluntarily shut down on October 1, 1991after 31 years of operation.
The site was involved in the process ofdecommissioning over the years which involved the disassembly and removal ofthe plant components and structures and was completed in 2006. This processtook place in strict conformance with USNRC regulations.
Oversight of the siteclosure process also took place from the U.S. Environmental Protection Agency,the Massachusetts Department of Environmental Protection, and Massachusetts Department of Public Health.3.0 PROGRAM DESIGNThe Radiological Environmental Monitoring Program (REMP) for the YankeeNuclear Power Station ISFSI was designed to provide assurance to regulatory agencies and the public that the station's environmental impact is known andwithin anticipated limits. The direct dose limit for members of the public fromoperation of the ISFSI is 25 mrem per year (References 3 and 4).The detailed sampling requirements of the REMP are given in the ODCM. Thesampling requirements specified in the ODCM are summarized in Table 3.1 ofthis report. Details of the monitored locations are shown in Table 3.2, as well asFigures 3.1 through 3.4 of this report.YNPS 2014 Annual REO ReportPage 7 of 27 3.1 Monitoring ZonesThe REMP is designed to allow comparison of levels of radioactivity in samplesfrom the area possibly influenced by the ISFSI to levels found in areas notinfluenced by the ISFSI. The first area is called "indicator stations".
The secondarea is called "control stations".
The distinction between the two is based onrelative direction from the facility and distance.
Analysis of survey data from thetwo zones aids in determining if there is a significant difference between the twoareas. It can also help in differentiating between radioactivity or radiation due toreleases and that due to other fluctuations in the environment, such as seasonalvariations in the natural background.
3.2 Pathways Monitored Based on the design of the ISFSI, only the direct radiation exposure pathway ismonitored by the REMP. This pathway is monitored by the collection ofthermoluminescent dosimeters (TLDs) which are described in more detail below.3.3 Description of Monitoring Program3.3.1 Direct Radiation Direct gamma radiation exposure was continuously monitored during 2014 withthe use of thermoluminescent dosimeters (TLDs). At each monitoring
- location, these TLDs are sealed in plastic bags and attached to an object such as a tree,fence or utility pole. The TLDs are posted and retrieved on a semi-annual basis.All TLDs are provided and processed by a National Voluntary Laboratory Accreditation Program (NVLAP) certified vendor. The TLDs are placed at variouslocations around the Independent Spent Fuel Storage Installation (ISFSI).
Table3.2 lists the Station ID Codes, distances and direction of the TLDs from theISFSI.3.3.2 Special Monitoring Special samples can be taken that are not required in the ODCM. The samplelocations do not appear in Table 3.1 or 3.2 of this report. For this monitoring period, no special samples were collected as part of the YNPS ISFSIRadiological Environmental Monitoring Program.YNPS 2014 Annual REO ReportPage 8 of 27 Table 3.1Radiological Environmental Monitoring ProgramExposure Collection AnalysisPathwayand/or Number of Routine Collection Analysis AnalysisSample Sample Sampling Frequency Type Frequency Media Locations ModeDirect Total Locations:
7 Continuous Semi- Gamma Semi-Radiation (6 around annual dose annual(TLD) perimeter of thesite and 1 offsitecontrol location)
YNPS 2014 Annual REO ReportPage 9 of 27 Table 3.2Radiological Environmental Monitoring Locations Distance Direction Station Code Station Description Zone* From ISFSI From eSFSi(km)GM-15 Onsite Perimeter (I)** 1 0.24 NWGM-16 Onsite Perimeter (I)** 1 0.22 NNWGM-17 Onsite Perimeter (I)** 1 0.13 NNEGM-21 Onsite Perimeter (I)** 1 0.17 WSWGM-02 Observation Stand (O)** 1 0.50 NWGM-06 Tunnel Road Readsboro 1 1.30 NTown Line (O)**GM-27 Number Nine Road (O)* 2 7.60 ENE*2 = Control TLD;1 = Indicator TLD**I = Inner Ring TLD; 0 = Outer Ring TLDYNPS 2014 Annual REO ReportPage 10 of 27 Figure 3.1All Radiation Monitoring Locations F ~ ~ --I ~ ______s~I~1~
YNPS 2014 Annual REO ReportPage 11 of 27 Figure 3.2Onsite Direct Radiation Monitoring Locations MWFS 3NC M~ SWG&hZamCOLkwwsdAa'ea C OvmnurCoi~edAau Prepared1Dae:
BRP 0512813Checked~ate:
MGV 08128113 a iITILD Locatlous IYNPS 2014 Annual REO ReportPage 12 of 27 Figure 3.3Direct Radiation Monitoring Locations (Within 1 mile)YNPS 2014 Annual REO ReportPage 13 of 27 Figure 3.4Offsite Control LocationYNPS 2014 Annual REO ReportPage 14 of 27 4.0 RADIOLOGICAL DATA SUMMARY TABLESThis section summarizes the analytical results of the environmental samples,which were collected during the monitoring period.Data from direct radiation measurements made by TLDs are presented inTable 4.1.The summarized TLD measurements, shown in Table 4.2, are presented in a format similar to that prescribed in the NRC's Radiological Assessment Branch Technical Position on Environmental Monitoring (Reference 1).Table 4.3 presents the estimated direct dose from ISFSI operations asdetermined by TLD data shown in Table 4.1.YNPS 2014 Annual REO ReportPage 15 of 27 Table 4.1 TLD Measurements by Half-Year (mR)Station ID Location Ist Half-Year 2nd Half-Year GM-02 Observation Stand 48 37GM-06 Tunnel Road Readsboro 49 42Town LineGM-15 On-site perimeter 58 51GM-16 On-site perimeter 51 46GM-1 7 On-site perimeter 45 43GM-21 On-site perimeter 45 43GM-27 Control 36 38GM-27a Control Backup 45 37Note: the TLD at location GM-16 was not present for retrieval at the end of theyear. The value listed is the average of the year 2013 measurements.
YNPS 2014 Annual REO ReportPage 16 of 27 Table 4.2 TLD Data Summary(mR)Indicator TLDs Control TLDs Station With Highest MeanMean Mean Station # Mean(Range) (Range) (Range)(No. Measurements)*
(No. Measurements)*
(No. Measurements)*
46 39 GM-15 55(37- 58) (36 -45) (51 -58)(11) (4) (2)Note: the TLD at location GM-1 6 was not present for retrieval at the end of theyear. The values listed in the Indicator TLDs column include the 2013 averageGM-1 6 value substituted for the missing measurement.
- Each "measurement" is based on semi-annual readingsYNPS 2014 Annual REO ReportPage 17 of 27 Table 4.3 Direct Dose from ISFSI Operations (mrem)1st Half-Year 2nd Half-Year Net TLD Calculated Net TLD Calculated AnnualStation ID Result Dose Result Dose DoseGM-02 7.50 0.43 0.00 0.00 0.43GM-06 8.50 0.48 4.50 0.26 0.74GM-15 17.50 1.00 13.50 0.77 1.77GM-16 10.50 0.60 8.00* 0.46 1.06GM-17 4.50 0.26 5.50 0.31 0.57GM-21 4.50 0.26 5.50 0.31 0.57Max Dose => 1.77Note: the TLD at location GM-1 6 was not present for retrieval at the end of theyear. The value shown in the Net TLD result column in the 2nd Half-Year wasbased upon the average of the year 2013 measurements.
Note: Doses based on a 250 hour0.00289 days <br />0.0694 hours <br />4.133598e-4 weeks <br />9.5125e-5 months <br /> occupancy in both of the first and secondhalf-years.
YNPS 2014 Annual REO ReportPage 18 of 27 Radiological Environmental Monitoring Program TrendingA series of graphs of REMP TLD data have been developed and are provided fortrending purposes.
The trending is developed for each of the indicator locations basedon the annual historical doses. The trending is provided for the "real members of thepublic" based on the guidance provided in the ODCM. The analysis of the trends andassociated data shows very small annual doses with minor fluctuations in the data. Theanalysis and trending of the REMP TLD data in this report has changed from theprevious years. Previously, the net TLD results were converted to exposure rates,summarized and then plotted for trending purposes.
Starting with this report, only theuncorrected TLD results will be summarized and the annual doses, calculated for "realmembers of the public" based upon guidance in the ODCM, will be plotted for trending.
YNPS 2014 Annual REO ReportPage 19 of 27 Figure 4.1 Annual Dose Trend at GM-02GM-0230.0025.0020.00E 15.00E 10.005.000.00-4-GM-020.44 0.63 0.17 0.00 0.43 0.11 0.37 0.432007 2008 2009 2010 2011 2012 2013 2014YearAnnual Doses (mrem/yr)
Location 1 2007 2008 2009 2010 1 2011 2012 1 2013 2014I GM-02 1 0.44 0.63 0.17 1 0.00 1 0.43 1 0.11 1 0.37 1 0.43YNPS 2014 Annual REO ReportPage 20 of 27 Figure 4.2 Annual Dose Trend at GM-06GM-0630.0025.00 m, 20.0015.00--*GM-061 0.00 -U i5.00 0.63 0.29 0.71 0.88 .97 0.740.00 6 -dt- ---2007 2008 2009 2010 2011 2012 2013 2014YearAnnual Doses (mrem/yr)
Location 2007 2008 2009 2010 2011 2012 2013 2014GM-06 0.92 0.63 0.29 0.71 0.88 0.97 0.54 0.74YNPS 2014 Annual REO ReportPage 21 of 27 Figure 4.3 Annual Dose Trend at GM-15GM-1530.00125.00 20.00 i15.0010.00 -_5.00 1 1.880.00--*-'GM-15--W-limit1.4 1.34 1.14 1.51 1.772007 2008 2009 2010 2011Year2012 2013 2014Annual Doses (mrem/yr)
Location 2007 2008 2009 2010 2011 2012 2013 2014GM-15 1.79 1.31 1.88 1.34 1.74 1.14 1.51 1.77YNPS 2014 Annual REO ReportPage 22 of 27 Figure 4.4 Annual Dose Trend at GM-16GM-1630.0025.0020.00E 15.00ElE 10.005.000.00-4-GM-16U- -limit-.4 1t0.29 0.71 U.66 L.UO_I2007 2008 2009 2010 2011 2012 2013 2014YearAnnual Doses (mrem/yr)
I Location 1 2007 1 2008 2009 2010 2011 1 2012 1 2013 20147I GM-16 1 1.13 1 1.20 0.29 1 0.71 1 1.68 1 1.37 1 0.88 1 1.06 1YNPS 2014 Annual REO ReportPage 23 of 27 Figure 4.5 Annual Dose Trend at GM-17GM-1730.0025.0020.00E 15.0010.005.000.00--$--GM-17-U-limit1.14 1.54 0.86 1.54 1.57 L.uo 1.34 0.572007 2008 2009 2010 2011Year2012 2013 2014Annual Doses (mrem/yr)
Location 2007 2008 2009 2010 2011 2012 2013 2014GM-17 1.14 1.54 0.86 1.34 1.57 1.08 1.34 0.57YNPS 2014 Annual REO ReportPage 24 of 27 Figure 4.6 Annual Dose Trend at GM-21GM-2130.0025.0020.0015.0010.005.000.001 -- m -m n n n -_i ---GM-21-- limit7 1.20 0.74 0.97 0.94 1.00 0.91 1.40 0.572007 20082012 2013 20142009 2010 2011yearAnnual Doses (mrem/yr)
Location 2007 2008 2009 2010 2011 2012 2013 2014GM-21 1.20 0.74 0.97 0.94 1.00 0.91 1.40 0.57YNPS 2014 Annual REO ReportPage 25 of 27 5.0 ANALYSIS OF ENVIRONMENTAL RESULTS5.1 Sampling Program Deviations A sampling program deviation is defined as samples that are unobtainable dueto hazardous conditions or to malfunction of sampling equipment.
Suchdeviations do not compromise the program's effectiveness and in fact areconsidered insignificant with respect to what is normally anticipated for thisRadiological Environmental Monitoring Program.There were two deviations in the sampling program in 2014.1. The TLD at location GM-1 6 was not present for retrieval at the end of theyear due to the tree it was mounted on was taken down by a beaver. Theaverage of the year 2013 GM-1 6 readings were used as the value for thesecond half of 2014.2. The incorrect TLD model was deployed at YNPS in 2014. At the time ofthe second quarter TLD change-out at the Connecticut Yankee and MaineYankee ISFSI sites, it was discovered that the wrong type TLD (modelBT36) was deployed instead of the requested TLD (model BT17). Themodel BT36 was'also deployed at YNPS in 2014. A condition report wasinitiated and parallel testing at those two sites was initiated for theremainder of 2014. The results of the parallel testing concluded that thevariation between the BT17 and BT36 TLD readings is insignificant andconsistent with the variations observed in the past BT1 7 TLD readings.
5.2 Direct Radiation Pathway5.2.1 Annual Dose TrendsDirect radiation is continuously measured at 6 indicator locations surrounding theYNPS ISFSI, along with 1 control location at Number Nine Road usingthermoluminescent dosimeters (TLDs). These dosimeters are collected semi-annually for readout at the NVLAP certified dosimetry services vendor.Review of Figures 4.1 through 4.6 shows no significant difference in annualdoses over time at the indicator locations and their relation to the 25 mrem/yrlimit.YNPS 2014 Annual REO ReportPage 26 of 27 5.2.2 Direct Doses from ISFSI Operations The ODCM specifies that a cumulative dose estimate from direct radiation isrequired to be determined semi-annually.
This dose estimate is the potential dose to any real member of the public that could use portions of the site or bepresent adjacent to the site for recreational activities throughout the year. TheODCM states that direct exposure above background can be estimated bysubtracting the average TLD value of the control station from the indicator location measurements.
As in previous years, the 2014 dose estimate assumesa total of 500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> occupancy for the dose calculation; of which 250 hours0.00289 days <br />0.0694 hours <br />4.133598e-4 weeks <br />9.5125e-5 months <br /> areused in both the first and second half-years.
The most likely location forexposure to a member of the public from the ISFSI is in Sherman Reservoir forboating and fishing;
- however, the time estimates are conservatively applied to allmonitoring locations.
Table 4.3 presents the results of the dose calculations.
The highest calculated dose is at Station ID number GM-15. The maximum calculated annual dose atthis location is 1.77 mrem. This value is only 7 percent of the 25 mrem per yearlimit. This represents a conservative dose estimate because a member of thepublic would normally be situated further away in the reservoir.
6.0 REFERENCES
- 1. USNRC Radiological Assessment Branch Technical
- Position, "AnAcceptable Radiological Environmental Monitoring Program,"
Revision 1,November 1979.2. Yankee Nuclear Power Station Offsite Dose Calculation Manual, Revision22.3. 40 CFR Part 190, "Environmental Radiation Protection Standards for NuclearPower Operation".
- 4. 10 CFR Part 72.104, "Criteria for Radioactive Materials in Effluents andDirect Radiation from an ISFSI or MRS".YNPS 2014 Annual REO ReportPage 27 of 27