ML15132A292
| ML15132A292 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 12/31/2014 |
| From: | Radiation Safety & Control Services |
| To: | Document Control Desk, Office of Nuclear Material Safety and Safeguards |
| Shared Package | |
| ML15132A276 | List: |
| References | |
| OMY-15-018 | |
| Download: ML15132A292 (29) | |
Text
OMY-15-018 ENCLOSURE 2 MAINE YANKEE INDEPENDENT SPENT FUEL STORAGE INSTALLATION ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT JANUARY - DECEMBER 2014
MAINE YANKEE INDEPENDENT SPENT FUEL STORAGE INSTALLATION License Nos. DPR-36 and SFGL-14 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT January - December 2014 RadiationSafey&Control Services April 2015 Prepared by:
Radiation Safety & Control Services 91 Portsmouth Avenue Stratham, NH 03885-2468
EXECUTIVE
SUMMARY
The Maine Yankee Independent Spent Fuel Storage Installation (ISFSI) has been in operation since 2001. All fuel has been transferred into dry storage casks and placed at the Independent Spent Fuel Storage Installation. The Radiological Environmental Monitoring Program (REMP) for the Maine Yankee ISFSI located in Wiscasset, ME was continued for the period January through December 2014 in compliance with the Maine Yankee Offsite Dose Calculation Manual (ODCM).
By design, there are no liquid or gaseous effluents associated with the operation of the ISFSI. Therefore, the ODCM only requires monitoring of direct exposure from the facility. TLDs were used to measure direct gamma exposure at nine locations in the vicinity of the ISFSI and one control location 5.2 kilometers away. The results of these measurements showed no significant change in exposure rates and potential doses to members of the public during the monitoring period. The results of the monitoring performed in 2014 also show that operating the Maine Yankee ISFSI results in only a small fraction of the 40 CFR Part 190 and 10 CFR Part 72.104 direct radiation dose limit of 25 mrem/year to members of the public.
MY 2014 Annual REO Report Page 2 of 28
TABLE OF CONTENTS Section Title Pacqe
1.0 INTRODUCTION
........................................................................................ 6 2.0 GENERAL ISFSI AND SITE INFORMATION ............................................ 7 3.0 PROGRAM DESIGN ................................................................................. 7 3.1 M O NITO RING Z O NES ........................................................................................... 7 3.2 PATHW AYS M ONITO RED ...................................................................................... 8
3.3 DESCRIPTION
OF MONITORING PROGRAM ........................................................ 8 4.0 RADIOLOGICAL DATA
SUMMARY
TABLES ........................................ 13 5.0 ANALYSIS OF ENVIRONMENTAL RESULTS ....................................... 27 5.1 SAMPLING PROGRAM DEVIATIONS ..................................................................... 27 5.2 DIRECT RADIATION PATHWAY ........................................................................ 27
6.0 REFERENCES
........................................................................................ 28 MY 2014 Annual REO Report Page 3 of 28
LIST OF TABLES Table Title Paqe 3.1 Radiological Environmental Monitoring Program ................................. 9 3.2 Radiological Environmental Monitoring Locations ............................ 10 4.1 TLD Measurements by Quarter ........................................................... 14 4.2 TLD Data Summary ............................................................................... 15 4.3 Direct Dose from ISFSI Operations ..................................................... 16 MY 2014 Annual REO Report Page 4 of 28
LIST OF FIGURES Fiqure Title Paqe 3.1 Radiological Environmental Monitoring Locations (within 0.28 kin) ..... 11 3.2 Direct Radiation Monitoring Locations (outside I kin) ....................... 12 4.1 Annual Dose Trend at TL-I-02 ................................................................ 18 4.2 Annual Dose Trend at TL-1-04 ................................................................. 19 4.3 Annual Dose Trend at TL-1-06 ................................................................ 20 4.4 Annual Dose Trend at TL-1-08 .............................................................. 21 4.5 Annual Dose Trend at TL-1-10 ................................................................ 22 4.6 Annual Dose Trend at TL-1-12 ................................................................ 23 4.7 Annual Dose Trend at TL-1-14 .............................................................. 24 4.8 Annual Dose Trend at TL-1-15 .............................................................. 25 4.9 Annual Dose Trend at TL-1-16 ................................................................ 26 MY 2014 Annual REO Report Page 5 of 28
1.0 INTRODUCTION
This report summarizes the findings of the Radiological Environmental Monitoring Program (REMP) conducted by Maine Yankee in the vicinity of the Independent Spent Fuel Storage Installation in Wiscasset, Maine during the calendar year 2014. It is submitted annually in compliance with Appendix A, of the Offsite Dose Calculation Manual (ODCM). The remainder of this report is organized as follows:
Section 2: Provides a brief description of the Maine Yankee site and its environs.
Section 3: Provides a description of the overall REMP design. Included is a summary of the requirements for REMP sampling, tables listing routine TLD monitoring locations with compass sectors and distances from the ISFSI, and maps showing the location of each of the TLD monitoring locations.
Section 4: Provides a complete set of TLD data showing measured results (mR) and calculated doses (mrem per year). This section also provides the summarized exposure rate data in the format specified by the NRC Branch Technical Position on Environmental Monitoring (Reference 1).
Section 5: Provides the results of the monitoring program. The performance of the program in meeting ODCM requirements is discussed, and the data acquired during the year is analyzed.
Section 6: References MY 2014 Annual REO Report Page 6 of 28
2.0 GENERAL ISFSI AND SITE INFORMATION The Maine Yankee Independent Spent Fuel Storage Installation (ISFSI) is located in the town of Wiscasset, Lincoln County, Maine, approximately six miles northeast of Bath, Maine. The site vicinity is rural and lightly populated.
The ISFSI site is located near Bailey Point, a peninsula bounded to the east by the Back River and to the west by a shallow inlet known as Bailey Cove, both of which are part of the Montsweag Bay-Sheepscot River Estuary. Bailey point is an elongated bedrock ridge with flat or gently rolling topography rising to an average elevation of about 25 feet above sea level.
The Radiological Environmental Monitoring Program (REMP) for the ISFSI began pre-operational measurements in the 4th quarter of 1999, approximately 2 years prior to the initial spent fuel transfer to the ISFSI. The ISFSI REMP has been in continuous operation since this transfer began.
3.0 PROGRAM DESIGN The Radiological Environmental Monitoring Program (REMP) for the Maine Yankee ISFSI was designed to provide assurance to regulatory agencies and the public that the station's environmental impact is known and within anticipated limits. The direct dose limit for members of the public from operation of the ISFSI is 25 mrem per year (References 3 and 4).
The detailed sampling requirements of the REMP are given in the ODCM. The sampling requirements specified in the ODCM are summarized in Table 3.1 of this report. Details of the monitored locations are shown in Table 3.2, as well as Figures 3.1 and 3.2 of this report.
3.1 Monitoring Zones The REMP is designed to allow comparison of levels of radioactivity in samples from the area possibly influenced by the ISFSI to levels found in areas not influenced by the ISFSI. The first area is called "indicator stations". The second area is called "control stations". The distinction between the two is based on relative direction from the facility and distance. Analysis of survey data from the two zones aids in determining if there is a significant difference between the two areas. It can also help in differentiating between radioactivity or radiation due to releases and that due to other fluctuations in the environment, such as seasonal variations in the natural background.
MY 2014 Annual REO Report Page 7 of 28
3.2 Pathways Monitored Based on the design of the ISFSI, only the direct radiation exposure pathway is monitored by the REMP. This pathway is monitored by the collection of thermoluminescent dosimeters (TLDs) which are described in more detail below.
3.3 Description of Monitoring Program 3.3.1 Direct Radiation Direct gamma radiation exposure was continuously monitored during 2014 with the 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 quarterly basis. During the fourth quarter of this year, a change was made to the ODCM to increase the deployment time from quarterly to semi-annually. All TLDs are provided and processed by a National Voluntary Laboratory Accreditation Program (NVLAP) certified vendor. The TLDs are placed at various locations around the Independent Spent Fuel Storage Installation (ISFSI). Table 3.2 lists the Station ID Codes, distances and direction of the TLDs from the ISFSI.
3.3.2 Special Monitoring Special samples can be taken that are not required in the ODCM. The sample locations 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 Maine Yankee ISFSI Radiological Environmental Monitoring Program.
MY 2014 Annual REO Report Page 8 of 28
Table 3.1 Radiological Environmental Monitoring Program Exposure Collection Analysis Pathway and/or Number of Routine Sampler Sample Smper Sample Sampling Sampling Collection Feuny Analysis Tp Analysis rqec Media Locations Mode Frequency Type Frequency Direct Total Locations:10 Continuous Semi- Gamma Semi-Radiation (9 around annual dose annual (TLD) perimeter of the site and 1 offsite control location)
Note: the previous collection and analysis frequency was quarterly. During the fourth quarter of this year a change was made to the ODCM to increase the deployment and analysis time to semi-annual.
MY 2014 Annual REO Report Page 9 of 28
Table 3.2 Radiological Environmental Monitoring Locations Distance Direction Station Station Description Zone* From ISFSI Dron Code (km) From ISFSI TL-1-02 Spent Fuel Storage (l)** 1 < 0.28 N TL-1-04 Spent Fuel Storage (I)** 1 < 0.28 NE TL-1-06 Spent Fuel Storage (I)** 1 < 0.28 E TL-1-08 Spent Fuel Storage (I)** 1 < 0.28 SE TL-1-10 Spent Fuel Storage (I)** 1 < 0.28 S TL-1-12 Spent Fuel Storage (I)** 1 < 0.28 SW TL-1-14 Spent Fuel Storage (I)** 1 < 0.28 W TL-1-15 Spent Fuel Storage (I)** 1 < 0.28 WNW TL-1-16 Spent Fuel Storage (I)** 1 < 0.28 NW TL-O-36 Wiscasset Fire Station (0) 2 5.2 NW
Figure 3.1 Radiological Environmental Monitoring Locations (within 0.28 km)
I MY 2014 Annual REO Report Page 11 of 28
Figure 3.2 Direct Radiation Monitoring Locations (outside 1 km)
MY 2014 Annual REO Report Page 12 of 28
4.0 RADIOLOGICAL DATA
SUMMARY
TABLES This 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 in Table 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 as determined by TLD data shown in Table 4.1.
MY 2014 Annual REO Report Page 13 of 28
Table 4.1 TLD Measurements by Quarter (mR)
Station ID Direction 1 st Qtr 2 nd Qtr 3 rd Qtr 4 th Qtr TL-1-02 N 27 22 23 24 TL-I-04 NE 30 20 23 21 TL-1-06 E 27 28 32 31 TL-1-08 SE 33 25 26 23 TL-1-10 S 33 24 25 27 TL-1-12 SW 36 27 31 27 TL-1-14 W 31 23 29 27 TL-1-15 WNW 36 27 25 26 TL-1-16 NW 33 23 31 29 TL-O-36 Control 30 21 23 25 TL-O-36a Control Backup 33 24 26 25 MY 2014 Annual REO Report Page 14 of 28
Table 4.2 TLD Data Summary (mR)
Indicator TLDs Control TLDs Station With Highest Mean Mean Mean Station # Mean (Range) (Range) (Range)
(No. Measurements)* (No. Measurements)* (No. Measurements)*
27.4 25.9 TL-1-012 30.3 (20- 36) (21 - 33) (27- 36)
(36) (8) (4)
- Each "measurement" is based on quarterly readings MY 2014 Annual REO Report Page 15 of 28
Table 4.3 Direct Dose from ISFSI Operations (mrem)
Q1 Q2 Q3 Q4 Net TLD Calculated Net TLD Calculated Net TLD Calculated Net TLD Calculated Annual Station ID Result Dose Result Dose Result Dose Result Dose Dose TL-1-02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 TL-1-04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 TL-1-06 0.00 0.00 5.50 0.33 7.50 0.44 6.00 0.22 0.99 TL-1-08 1.50 0.02 2.50 0.15 1.50 0.09 0.00 0.00 0.26 TL-1-10 1.50 0.02 1.50 0.09 0.50 0.03 2.00 0.07 0.21 TL-1-12 4.50 0.07 4.50 0.27 6.50 0.39 2.00 0.07 0.80 TL-1-14 0.00 0.00 0.50 0.03 4.50 0.27 2.00 0.07 0.37 TL-1-15 4.50 0.07 4.50 0.27 0.50 0.03 1.00 0.04 0.41 TL-1-16 1.50 0.02 0.50 0.03 6.50 0.39 4.00 0.15 0.59 Max Dose => 0.99 Note: Doses based on a 32.5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> occupancy in the first quarter, a 130 hour0.0015 days <br />0.0361 hours <br />2.149471e-4 weeks <br />4.9465e-5 months <br /> occupancy in both of the second and third quarters. The doses in the fourth quarter are based upon a 81.25 hour2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> occupancy.
MY 2014 Annual REO Report Page 16 of 28
Radiological Environmental Monitoring Program Trending A series of graphs of REMP TLD data have been developed and are provided for trending purposes. The trending is developed for each of the indicator locations based on the annual historical doses. The trending is provided for the "real members of the public" based on the guidance provided in the ODCM. The analysis of the trends and associated data shows very small annual doses with minor fluctuations in the data. The analysis and trending of the REMP TLD data in this report has changed from the previous years. Previously, the net TLD results were converted to exposure rates, summarized and then plotted for trending purposes. Starting with this report, only the uncorrected TLD results will be summarized and the annual doses, calculated for "real members of the public" based upon guidance in the ODCM, will be plotted for trending.
MY 2014 Annual REO Report Page 17 of 28
Figure 4.1 Annual Dose Trend at TL-I-02 TL-1-02 30.00 25.00 . . . .....
20.00 E 15.00
--#TL-I-02 10.00 E
B--limit 5.00 0.17 0.55 0.08 0.30 0.00 0.14 0.07 0.00 0.00 - _
2007 2008 2009 2010 2011 2012 2013 2014 Year Annual Doses (mrem/yr)
Location 2007 1 2008 I 2009 I 2010 1 2011 1 2012 1 2013 I 2014 1 I TL-I-02 1 0.17 1 0.55 1 0.08 1 0.30 o0.00 0.14 0.07 I 0.00 MY 2014 Annual REO Report Page 18 of 28
Figure 4.2 Annual Dose Trend at TL-I-04 TL-I-04 30.00 25.00 -
20.00 E 15.00
,-=,-TL-1-04 E10.00
=.lnlimit 5.0 0.01 0.12 0.10 0.09 0.13 0.06 0.00 0.00 , , - -,
2007 2008 2009 2010 2011 2012 2013 2014 Year Annual Doses (mrem/yr)
Location 2007 2008 1 2009 1 2010 1 2011 1 2012 I 2013 1 2014 I TL-1-04 1 0.01 1 0.12 I 0.10 1 1.45 1 0.09 1 0.13 I 0.06 1 0.00 1 MY 2014 Annual REO Report Page 19 of 28
Figure 4.3 Annual Dose Trend at TL-I-06 TL-I-06 30.00 25.00 ----
20.00 E 15.00
- - ~--0-TL-1-06 E10.00
-,-U-limit 2 4 5.00 1.21 8 0 4--."---6
-1.65 1.74 1.65 1.15 0.99 0.00 ' 111 2007 2008 2009 2010 2011 2012 2013 2014 Year Annual Doses (mrem/yr)
Location I 2007 2008 2009 2010 12011 12012 12013 1 2014 ITL-1-06 I 1.21 1 1.68 1 2.04 1 1.65 1 1.74 1 1.65 1 1.15 1 0.99 1 MY 2014 Annual REO Report Page 20 of 28
Figure 4.4 Annual Dose Trend at TL-1-08 TL-I-08 30.00 25.00 20.00 E 15.00
-,--TL-I-08 E 10.00
limit 5.00 0.35 0.70 0.38 0.70 0.48 0.70 0.04 0.26 0.00 2007 2008 2009 2010 2011 2012 2013 2014 Year Annual Doses (mrem/yr)
I Location 1 2007 I 2008 2009 1 2010 1 2011 1 2012 2013 1 2014 1 TL-I-08 0.35 1 0.70 0.38 0.70 1 0.48 0.70 1 0.04 1 0.26 1 MY 2014 Annual REO Report Page 21 of 28
Figure 4.5 Annual Dose Trend at TL-1-10 TL-I-1O 30.00 25.00 20.00 E 15.00 t TL-1-10 10.00 E
limit 500 0.48 0.49 0.26 0.85 0.53 0.41 0.23 0.21 0.00 F- $ , $ 1* , ,
2007 2008 2009 2010 2011 2012 2013 2014 Year Annual Doses (mrem/yr)
I Location 12007 1 2008 12009 1 2010 1 2011 1 2012 1 2013 1 2014 1 I TL-1-10 1 0.48 1 0.49 1 0.26 1 0.85 1 0.53 1 0.41 I 0.23 I 0.21 1 MY 2014 Annual REO Report Page 22 of 28
Figure 4.6 Annual Dose Trend at TL-1-12 TL-1-12 30.00 25.00oo Z -
20.00 E 15.00 E 10.00 10.00 =@@'=limit 5.00 0.05 0.79 0.10 0.61 0.25 0.41 0.13 0.80 0.00oo . -, * ,
2007 2008 2009 2010 2011 2012 2013 2014 Year Annual Doses (mrem/yr)
Location 2007 1 2008 1 2009 1 2010 1 2011 1 2012 1 2013 1 2014 TL-1-12 1 0.05 1 0.79 I 0.10 1 0.61 0.25 1 0.41 I 0.13 1 0.80 1 MY 2014 Annual REO Report Page 23 of 28
Figure 4.7 Annual Dose Trend at TL-1-14 TL-1-14 30.00 25.00 ----- a-20.00 E 15.00 I-, TL-1-14 E 10.00 5.00 0.30 0.55 0.23 0.40 0.67 0.22 0.28 0.37 0.00 0- ~ # T h ~
- 2007 2008 2009 2010 2011 2012 2013 2014 Year Annual Doses (mrem/yr)
Location 2007 2008 2009 2010 2011 2012 2013 20 TL-1-14 0.30 0.55 0.23 0.40 0.67 0.22 0.28 0.37 MY 2014 Annual REO Report Page 24 of 28
Figure 4.8 Annual Dose Trend at TL-1-15 TL-1-15 30.00 25.00 o . 2 -- --
20.00 E 15.00 E 10.00 10.00 ==m=limit 5.00 0.30 0.67 0.76 0.87 0.57 0.66 0.50 0.41 0.00L -" _
2007 2008 2009 2010 2011 2012 2013 2014 Year Annual Doses (mrem/yr)
Location 1 2007 1 2008 1 2009 2010 1 2011 1 2012 I 2013 1 2014 I TL-1-15 1 0.30 1 0.67 I 0.76 1 0.87 1 0.57 1 0.66 I 0.50 1 0.41 1 MY 2014 Annual REO Report Page 25 of 28
Figure 4.9 Annual Dose Trend at TL-1-16 TL-1-16 30.00 25.00 20.00 E 15.00 E 10.00 5.00 0.44 0.77 0.36 0.89 0.66 0.45 0.34 0.59 0.00 p .
2007 2008 2009 2010 2011 2012 2013 2014 year Annual Doses (mrem/yr)
Location 2007 2008 2009 2010 2011 2012 2013 2014 TL-1-16 0.44 0.77 0.36 0.89 0.66 0.45 0.34 0.59 MY 2014 Annual REO Report Page 26 of 28
5.0 ANALYSIS OF ENVIRONMENTAL RESULTS 5.1 Sampling Program Deviations A sampling program deviation is defined as samples that are unobtainable due to hazardous conditions or to malfunction of sampling equipment. Such deviations do not compromise the program's effectiveness and in fact are considered insignificant with respect to what is normally anticipated for this Radiological Environmental Monitoring Program.
There was one deviation of the sampling program in 2014. The incorrect TLD model was deployed at MY in 2014. At the time of the second quarter TLD change-out at the Connecticut Yankee and Maine Yankee ISFSI sites, it was discovered that the wrong type TLD (model BT36) was deployed instead of the requested TLD (model BT1 7). A condition report was initiated and parallel testing at those two sites was initiated for the remainder of 2014. The results of the parallel testing concluded that the variation between the BT17 and BT36 TLD readings is insignificant and consistent with the variations observed in the past BT17 TLD readings.
5.2 Direct Radiation Pathway 5.2.1 Annual Dose Trends Direct radiation is continuously measured at 9 indicator locations surrounding the Maine Yankee ISFSI, along with 1 control location (Wiscasset Fire Station) using thermoluminescent dosimeters (TLDs). These dosimeters are collected every calendar quarter for readout at the NVLAP certified dosimetry services vendor.
Review of the data in Figures 4.1 through 4.9 shows no significant difference in annual doses over time at the indicator locations and their relation to the 25 mrem/yr limit.
5.2.2 Direct Doses from ISFSI Operations A dose estimate is the potential dose to any real member of the public that could use portions of the site or be present adjacent to the site for recreational activities throughout the year. Direct exposure above background can be estimated by subtracting the average TLD value of the control station from the indicator location measurements. Unlike previous years, the 2014 dose estimate assumes MY 2014 Annual REO Report Page 27 of 28
a total of 373.75 hours8.680556e-4 days <br />0.0208 hours <br />1.240079e-4 weeks <br />2.85375e-5 months <br /> occupancy for the dose calculation; of which 32.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> are used in the first quarter; 130 hours0.0015 days <br />0.0361 hours <br />2.149471e-4 weeks <br />4.9465e-5 months <br /> are used in both the second and third quarters and 81.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> for the fourth quarter. The most likely location for exposure to a member of the public from the ISFSI is along the Back River, Bailey Cove or Montsweag Bay for boating and fishing and the mud flats in the Cove or Bay exposed at low tides which is worked by clam diggers and worm diggers; however, the time estimates are conservatively applied to all monitoring locations.
Table 4.3 presents the results of the dose calculations. The highest calculated dose is at Station ID number TL-I-06. The maximum calculated annual dose at that location is 0.99 mrem. This value is only 4 percent of the 25 mrem per year limit. It is noted that most of the mud flat region in Bailey Cove that is used by the public is situated further away from this Station. As a result, actual exposures from direct radiation would be much less than the maximum calculated value.
6.0 REFERENCES
- 1. USNRC Radiological Assessment Branch Technical Position, "An Acceptable Radiological Environmental Monitoring Program," Revision 1, November 1979.
- 2. Maine Yankee Offsite Dose Calculation Manual, Revision 36.
- 3. 40 CFR Part 190, "Environmental Radiation Protection Standards for Nuclear Power Operation".
- 4. 10 CFR Part 72.104, "Criteria for Radioactive Materials in Effluents and Direct Radiation from an ISFSI or MRS".
MY 2014 Annual REO Report Page 28 of 28