ML13127A066

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Yankee Nuclear Power Station, Independent Spent Fuel Storage Installation, Enclosure 1 to BYR 2013-017, Annual Radiological Environmental Operating Report January - December 2012
ML13127A066
Person / Time
Site: Yankee Rowe
Issue date: 03/31/2013
From:
Radiological Safety & Control Services
To:
Office of Nuclear Material Safety and Safeguards, Yankee Atomic Electric Co
References
BYR 2013-017
Download: ML13127A066 (28)


Text

BYR 2013-017 ENCLOSURE I YANKEE NUCLEAR POWER STATION INDEPENDENT SPENT FUEL STORAGE INSTALLATION ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT JANUARY - DECEMBER 2012 April 2013

YANKEE NUCLEAR POWER STATION INDEPENDENT SPENT FUEL STORAGE INSTALLATION License No. DPR-3 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT January - December 2012 RSCS Radiatoon Safety & Control Seroies March 2013 Prepared by:

Radiological Safety & Control Services 91 Portsmouth Avenue Stratham, NH 03885-2468

EXECUTIVE

SUMMARY

Yankee Nuclear Power Station was permanently shutdown in 1991. 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 Yankee Nuclear Power Station (YNPS) Independent Spent Fuel Storage Installation (ISFSI) located in Rowe, MA was continued for the period January through December 2012 in compliance with the YNPS Off-Site Dose Calculation Manual (ODCM).

No changes were made to the ODCM during 2012. 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 six locations in the vicinity of the ISFSI and one control location 7.6 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 2012 also show that operating the YNPS 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.

YNPS 2012 Annual REO Report Page 2 of 27

TABLE OF CONTENTS Section Title Page

1.0 INTRODUCTION

................................................................................ 6 2.0 GENERAL ISFSI AND SITE INFORMATION .................................... 7 3.0 PROGRA M DESIGN ......................................................................... 7 3.1 MONITO RING Z ONES ......................................................................................... 8 3.2 PATHWAYS MONITORED .................................................................................... 8

3.3 DESCRIPTION

OF MONITORING PROGRAM ............................................................. 8 4.0 RADIOLOGICAL DATA

SUMMARY

TABLES ................................. 14 5.0 ANALYSIS OF ENVIRONMENTAL RESULTS ............................... 26 5.1 SAMPLING PROGRAM DEVIATIONS ................................................................... 26 5.2 DIRECT RADIATION PATHWAY ........................................................................ 26

6.0 REFERENCES

................................................................................ 27 YNPS 2012 Annual REO Report Page 3 of 27

LIST OF TABLES Table Title Page 3.1 Radiological Environmental Monitoring Program ........................ 9 3.2 Radiological Environmental Monitoring Locations ................... 10 4.1 TLD Measurements by Half-Year ........................ 15 4.2 Exposure Rates from TLD Measurements ................................... 16 4.3 TLD Data Sum m ary ....................................................................... 17 4.4 Direct Dose from ISFSI Operations ............................................. 18 YNPS 2012 Annual REO Report Page 4 of 27

LIST OF FIGURES Figure Title Page 3.1 Onsite Direct Radiation Monitoring Locations ............................ 11 3.2 Direct Radiation Monitoring Locations (Within 1 mile) .............. 12 3.3 Offsite Control Location ............................................................... 13 4.1 Exposure Rate Trend at GM-2 ....................................................... 19 4.2 Exposure Rate Trend at GM-6 ....................................................... 20 4.3 Exposure Rate Trend at GM-15 .................................................... 21 4.4 Exposure Rate Trend at GM-16 .................................................... 22 4.5 Exposure Rate Trend at GM-17 .................................................... 23 4.6 Exposure Rate Trend at GM-21 .................................................... 24 4.7 Exposure Rate Trend at Control Location GM-27 ....................... 25 YNPS 2012 Annual REO Report Page 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 the Independent Spent Fuel Storage Installation in Rowe, Massachusetts during the calendar year. It is submitted annually in compliance with the Offsite Dose Calculation Manual (ODCM). The remainder of this report is organized as follows:

Section 2: Provides a brief description of the Yankee site and its environs.

Section 3: Provides a description of the overall REMP design. Included is a summary of the ODCM requirements for REMP sampling, tables listing TLD monitoring locations with compass sectors and distances from the plant, 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), TLD data converted to exposure rates (pR per hour) 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 calendar year 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 YNPS 2012 Annual REO Report Page 6 of 27

2.0 GENERAL ISFSI AND SITE INFORMATION The Yankee Nuclear Power Station site is located on over 1800 acres in a predominantly rural area of northwestern Massachusetts, three-quarters of a mile south 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, reaching elevations of 2100 feet.

The Deerfield River is used extensively for hydroelectric power generation both upstream and downstream of YNPS. The Sherman Dam, immediately adjacent to the site, operates as a hydroelectric generating station. Sherman Pond, the impoundment behind this dam, had been used as a source of cooling water for the former power plant.

The former nuclear power plant was voluntarily shut down on October 1, 1991 after 31 years of operation. The site was involved in the process of decommissioning over the years which involved the disassembly and removal of the plant components and structures and was completed in 2006. This process took place in strict conformance with USNRC regulations. Oversight of the site closure 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 DESIGN The Radiological Environmental Monitoring Program (REMP) for the Yankee Nuclear Power Station 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 through 3.3 of this report.

YNPS 2012 Annual REO Report Page 7 of 27

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.

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 2012 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 semi-annual basis.

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 YNPS ISFSI Radiological Environmental Monitoring Program.

YNPS 2012 Annual REO Report Page 8 of 27

Table 3.1 Radiological Environmental Monitoring Program Exposure Collection Analysis Pathway Pathway Number of Routine and/or Numbler of auine Collection Analysis Analysis Sample Sample Sampling Frequency Type Frequency Media Locations Mode Direct Total Locations: 7 Continuous Semi- Gamma Each TLD Radiation (6 around annual dose (TLD) perimeter of the site and 1 offsite control location)

YNPS 2012 Annual REO Report Page 9 of 27

Table 3.2 Radiological Environmental Monitoring Locations Distance Direction Station Code Station Description Zone From ISFSl From ISFSI (km)

GM-27 Number Nine Road (O)* 2 7.60 ENE GM-02 Observation Stand (O)** 1 0.50 NW GM-06 Readsboro Road Barrier (O)** 1 1.30 N GM-15 Onsite Perimeter (I)** 1 0.24 NW GM-16 Onsite Perimeter (I)** 1 0.22 NNW GM-17 Onsite Perimeter (I)** 1 0.13 NNE GM-21 Onsite Perimeter (l)** 1 0.17 WSW

  • 2 = Control TLD; 1 = Indicator TLD
    • I = Inner Ring TLD; 0 = Outer Ring TLD YNPS 2012 Annual REO Report Page 10 of 27

Figure 3.1 Onsite Direct Radiation Monitoring Locations YNPS 2012 Annual REO Report Page 11 of 27

Figure 3.2 Direct Radiation Monitoring Locations (Within 1 mile)

YNPS 2012 Annual REO Report Page 12 of 27

Figure 3.3 Offsite Control Location YNPS 2012 Annual REO Report Page 13 of 27

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 direct measurements presented in Table 4.1 are converted to exposure rates in the following manner:

o The total TLD exposure time is determined from the anneal and read dates.

o The total deployment time is determined from the placement and retrieval dates.

o The non-deployment time is converted to exposure and subtracted from the TLD reading presented in Table 4.1.

o The resulting net exposure (deployment exposure) is divided by the deployment time in hours to calculate the exposure rate in pR per hour.

o The calculated exposure rates are presented in Table 4.2.

The summarized exposure rate results, shown in Table 4.3, are presented in a format similar to that prescribed in the NRC's Radiological Assessment Branch Technical Position on Environmental Monitoring (Reference 1).

Table 4.4 presents the estimated direct dose from ISFSI operations as determined by TLD data shown in Table 4.1.

YNPS 2012 Annual REO Report Page 14 of 27

Table 4.1 TLD Measurements by Half-Year (mR)

Station ID Location 1st Half-Year 2nd Half-Year GM-02 Observation Stand 36 49 GM-06 Readsboro Road Barrier 38 62 GM-I5 On-site perimeter 48 55 GM-16 On-site perimeter 44 63 GM-17 On-site perimeter 44 58 GM-21 On-site perimeter 44 55 GM-27 Control 36 46 GM-27a Control Backup 35 49 YNPS 2012 Annual REO Report Page 15 of 27

Table 4.2 Exposure Rates from TLD Measurements (pR per hour)

Station ID Direction 1st Half-Year 2nd Half-Year Annual Ave GM-02 NW 6.2 7.8 7.0 GM-06 N 6.7 10.7 8.7 GM-15 NW 9.0 9.1 9.1 GM-16 NNW 8.0 11.0 9.5 GM-17 NNE 8.0 9.8 8.9 GM-21 WSW 8.0 9.1 8.6 GM-27 Control 6.1 7.4 6.8 YNPS 2012 Annual REO Report Page 16 of 27

Table 4.3 TLD Data Summary (pR per hour)

Inner Ring TLDs Control TLDs Station With Highest Mean Mean Mean Station # Mean (Range) (Range) (Range)

(No. Measurements)* (No. Measurements)* (No. Measurements)*

8.6 6.8 GM-16 9.5 (6.2-11.0) (6.1 -7.4) (8.0-11.0)

(12) (4) (2)

  • Each "measurement" is based on semi-annual readings YNPS 2012 Annual REO Report Page 17 of 27

Table 4.4 Direct Dose from ISFSI Operations (mrem) 1st Half-Year 2nd Half-Year Net TLD Calculated Net TLD Calculated Annual Station ID Result Dose Result Dose Dose GM-02 0.50 0.03 1.50 0.09 0.11 GM-06 2.50 0.14 14.50 0.83 0.97 GM-15 12.50 0.71 7.50 0.43 1.14 GM-16 8.50 0.48 15.50 0.88 1.37 GM-17 8.50 0.48 10.50 0.60 1.08 GM-21 8.50 0.48 7.50 0.43 0.91 Max Dose => 1.37 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 second half-years YNPS 2012 Annual REO Report Page 18 of 27

Figure 4.1 FIxnonurA RatA TrAnd at (M-2 1US4J i,,ýý11111ýý1111l

'9

- Result, Discrimination Level O  ! Ikl 1*6^ flA IIA*d,^d

.ýauIjwu N~ame LO UaUrI~~ 01CHWOUIL 2 SIlarna E-rror uscrimiJIioLUI Level GM-02-001 03/31/2003 4.2E+000 pR/h t 6.OOE-001 2.5E+000 GM-02-002 06/30/2003 6.9E+000 pR/h t 1.OOE+000 2.5E+000 GM-02-003 09/3012003 6.7E+000 pR/h t 8.OOE-001 2.5E+000 GM-02-004 12/31/2003 6.9E+000 MJR/h t 8.OOE-001 2.5E+000 GM-02-005 03/31/2004 6.OE+000 MR/h t

  • 6.OOE-001 2.5E+000 GM-02-006 06/30/2004 7.3E+000 pR/h t 1.60E+000 2.5E+000 GM-02-007 09/30/2004 7.OE+000 pR/h t 8.OOE-001 2.5E+000 GM-02-008 12/31/2004 6.8E+000 pR/h t 8.OOE-001 2.5E+000 GM-02-009 03/31/2005 5.5E+000 pR/h t 6.OOE-001 2.5E+000 GM-02-01 0 06/30/2005 7.3E+000 pR/h t
  • 6.COE-001 2.5E+000 GM-02-01 1 09/30/2005 6.7E+000 pR/h t
  • 1.OOE+000 2.5E+000 GM-02-012 12/31/2005 6.9E+000 pR/h t 6.0OE-001 2.5E+000 GM-02-01 3 03/31/2006 6.9E+000 pR/h t 1.40E+000 2.5E+000 GM-02-014 12/31/2006 6.9E+000 pR/h t 1.OOE+000 2.5E+000 GM-02-015 06/30/2007 7.OE+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-02-016 12/31/2007 7.6E+000 pR/h t 8.OOE-001 2.5E+000 GM-02-01 7 06/30/2008 7.4E+000 MR/h t
  • 8.OOE-001 2.5E+000 GM-02-018 12/31/2008 7.5E+000 MR/h t
  • 8.OOE-001 2.5E+000 GM-02-019 06/30/2009 6.9E+000 MR/h t
  • 6.OOE-001 2.5E+000 GM-02-020 12131/2009 6.1E+000 pR/h t 6.OOE-001 2.5E+000 GM-02-022 12/31/2010 6.2E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-02-023 06/30/2011 8.3E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-02-024 12/31/2011 6.OE÷000 pR/h t
  • 6.OOE-001 2.5E+000 GM-02-025 06/30/2012 6.2E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-02-026 12/31/2012 7.8E+000 pR/h t
  • 8.OOE-001 2.5E+000 Results marked with
  • are greater than 2 Sigma Error.

t t Results m *rn'ea V",Iýý ulz7-nnual er tha ki-*eu iminat ion Level Npor Page 19 of 27

a Figure 4.2 Exposure Rate Trend at GM-6 IAM4 to4o"=

-1 Result - Discrimination Level rnmnla Mdama rlata f~nlltaa, IOa, .1 Sam r I- N-m- n.f. IýMl-+.A 0 .1+ IQ; a - C- M-A - ;. ý; - I- I GM-06-001 03/31/2003 4.7E+000 pR/h t

  • 6.00E-001 2.5E+000 GM-06-002 06/30/2003 7.6E+000 pR/h t
  • 6.00E-001 2.5E+000 GM-06-003 09/30/2003 7.3E+000 pR/h t
  • 8.00E-001 2.5E+000 GM-06-004 12/31/2003 7.3E+000 pR/h t
  • 1.00E+000 2.5E+000 GM-06-005 03/31/2004 5.8E+000 pR/h t
  • 6.00E-001 2.5E+000 GM-06-006 06/30/2004 7.7E+000 pR/h t
  • 1.20E+000 2.5E+000 GM-06-007 09/30/2004 7.8E+000 pR/h t
  • 6.00E-001 2.5E+000 GM-06-008 12/31/2004 7.6E+000 pR/h t
  • 8.00E-001 2.5E+000 GM-06-009 03/31/2005 5.7E+000 pR/h t
  • 8.00E-001 2.5E+000 GM-06-010 06/30/2005 7.5E+000 pR/h t
  • 6.00E-001 2.5E+000 GM-06-01 1 09/30/2005 7.4E+000 pR/h t
  • 8.00E-001 2.5E+000 GM-06-012 12/31/2005 7.2E+000 pR/h t
  • 1.00E+000 2.5E+000 GM-06-013 03/31/2006 7.2E+O00 jJR/h t
  • 1.00E+000 2.5E+000 GM-06-014 12/31/2006 7.7E+000 pR/h t
  • 8.00E-001 2.5E+000 GM-06-015 06/30/2007 7.6E+000 MR/h t
  • 4.00E-001 2.5E+000 GM-06-016 12/31/2007 9.OE+000 MR/h t
  • 8.00E-001 2.5E+000 GM-06-017 06/30/2008 6.7E+000 MR/h t
  • 600E-001 2.5E+000 GM-06-018 12/31/2008 8.2E+000 pR/h t
  • 8.00E-001 2.5E+000 GM-06-019 06/30/2009 6.5E+000 MR/h t
  • 6.00E-001 2.5E+000 GM-06-020 12/31/2009 7.OE+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-06-021 06/30/2010 7.4E+000 PR/h t
  • 8.00E-001 2.5E+000 GM-06-022 12/31/2010 8.4E+000 MR/h t
  • 8.00E-001 2.5E+000 GM-06-023 06/30/2011 8.5E+000 MR/h t
  • 8.00E-001 2.5E+000 GM-06-024 12/31/2011 7.6E+000 MR/h t
  • 8.00E-001 2.5E+000 GM-06-025 06/30/2012 6.7E+000 pR/h t
  • 6.00E-001 2.5E+000 GM-06-026 12/31/2012 1.1E+001 MR/h t* 1.00E+000 2.5E+000 Results marked with
  • are greater than 2 Sigma Error.

i~: ~nrnn Results mq ieathmination Level Y *1*u~-Anar epo* Page 20 of 27 I

Figure 4.3 Exposure Rate Trend at GM-1 5 A

900"M

'9

'9 4e

- Result - Discrimination Level Q.nm~ 1ýKnIa rng. t'mi-ht-Ae r 0-.I+ ,JM m-i I= -,~ r%;-;-; +;n .~ I - Il M a . -

GM-15-001 03/31/2003 6.2E+000 PR/h t* 8.OOE-001 2.5E+000 GM-15-002 06/30/2003 8.7E+000 pRIh t* 8.OOE-001 2.5E+000 GM-15-003 09/30/2003 7.8E+000 WtR/h

  • 1.OOE+000 2.5E+000 GM-15-004 12/31/2003 8.OE+000 pR/h t* 1.OOE+000 2.5E+000 GM-15-005 03/31/2004 6.5E+000 phRh t* 6.OOE-001 2.5E+000 GM-15-006 06/30/2004 7.3E+000 pRMh t* 1.20E+000 25E+000 GM-15-007 09/30/2004 7.9E+000 pR/h t* 8.OOE-001 2.5E+000 GM-15-008 12/3112004 8.3E+000 pR/h t* 6.OOE-001 2.5E+000 GM15-009 03/31/2005 7.3E+000 pR/h t
  • 1.60E+000 2.5E+000 GM-15-010 06/30/2005 7.6E+000 pR/h t* 4.OOE-001 2.5E+000 GM-15-011 09/30/2005 8.3E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-1 5-012 12/31/2005 8.IE+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-15-013 03/31/2006 8.OE+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-15-014 12/31/2006 9.1E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-15-015 06/30/2007 1.OE+001 pR/h t
  • 6.00E-001 2.5E+000 GM-15-016 12/31/2007 1.OE+001 pR/h t
  • 1.OOE+000 2.5E+000 GM-15-017 06/30/2008 8.1 E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-15-018 12/31/2008 9.6E+000 pR/h t
  • 1.OOE+000 25E+000 GM-15-019 06/30/2009 1.1E+001 pR/h t
  • 1.20E+000 2.5E+000 GM-15-020 12/31/2009 8.8E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-15-021 06/30/2010 8.8E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-15-022 12/31/2010 9.6E+000 MR/h t
  • 1 OOE+000 2.5E+000 GM- 15-023 06/30/2011 1.1E+001 pR/h t
  • 1.OOE+000 2.5E+000 GM-I15-024 12/31/2011 9.OE+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-15-025 06/30/2012 9.OE+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-1 5-026 12/31/2012 9.1 E+000 pR/h t
  • 1.OOE+000 2.5E+000 Results marked with
  • are greater than 2 Sigma Error.

Results m A"*'ýM h ater thanthe grz-nnual m<*-u,imin epor tion Level Page 21 of 27

Figure 4.4 Exoosure Rate Trend at GM-16 2O401+=

- Result - Discrimination Level tRninla klein rnet. t~ll.,4.,4 ~l. 9 ~inne Frrnr flierrivninetinn I nun!

Sam le Name Date Collected Result 2 Si ma Error Discrimination Level GM-16-001 03/31/2003 7.2E+000 pR/h t

  • 1.OOE+000 25E+000 GM- 16-002 06/30/2003 1.OE+001 pR/h t
  • 6.OOE-001 2,5E+000 GM- 16-003 09/30/2003 7.OE+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-16-004 12/31/2003 7.3E+000 JR/h t
  • 8.OOE-001 2.5E+000 GM-16-005 03/31/2004 5.9E+000 jR/h t
  • 8.OOE-001 2.5E+000 GM-16-006 06130/2004 6.1E+000 pR/h t
  • 1.60E+000 2.5E+000 GM-16-007 09/30/2004 7.1E+000 JR/h t
  • 1.OOE+000 2.5E+000 GM-16-008 12/31/2004 7.OE+000 JR/h t
  • 6.OOE-001 2.5E+000 GM-16-009 03/3112005 5.9E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-16-010 06/30/2005 6.3E+000 pR/h t
  • 4.OOE-001 2.5E+000 GM-16-011 09/30/2005 8.5E+000 jR/h t
  • 8.OOE-001 2.5E+000 GM-16-012 12/31/2005 8.OE+000 iRJh t
  • 1.OOE+000 2.5E+000 GM-16-013 03/31/2006 7.9E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-16-014 12/31/2006 8.IE+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-16-015 06/30/2007 8.2E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-16-016 12/31/2007 9.2E+000 pR/h t
  • 1.OOE+000 2.5E+000 GM-16-017 06/30/2008 7.9E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-16-018 12/31/2008 9.3E+000 MR/h t
  • 1.OOE+000 2.5E+000 GM-16-019 06130/2009 7.4E+000 MR/h t
  • 8.OOE-001 2.5E+000 GM-16-020 12/31/2009 5.2E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-16-021 06/30/2010 7.7E+000 MR/h t
  • 8.OOE-001 2.5E+000 GM-16-022 12/31/2010 8.2E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-16-023 06/30/2011 9.9E+000 pR/h t
  • 1.OOE+000 2.5E+000 GM-16-024 12/31/2011 9.4E+000 pR/h t
  • 1.OOE+000 2.5E+000 GM-16-025 06/30/2012 8.OE+000 MR/h t
  • 8.OOE-001 2.5E+000 GM-16-026 12/31/2012 1.1E+001 pR/h t
  • 1.OOE+000 2.5E+000 Results marked with
  • are greater than 2 Sigma Error.

Results mtthamj YIttýM gu~-nnnualR m,.

ination Level I-(tuIeo Page 22 of 27

Figure 4.5 Exposure Rate Trend at GM-17 2Q~406II

- Result - Discrimination Level I Q.- 1. Mft- r%ý*. f% H 6-4 Dn. .It I Qi -a =-,* n'i-ri-mlnftinn 1 -1 K ki GM-17-001 03/31/2003 6.1E+000 pR/h t

  • 6OOE-001 2.5E+000 GM- 17-002 06/30/2003 9.0E+000 pR/h t
  • 8OOE-001 2.5E+000 GM-17-003 09/30/2003 8.9E+000 PR/h t
  • 8.00E-001 2.5E+000 GM-17-004 12/31/2003 8.9E+000 PR/h t
  • 1.40E+000 2.5E+000 GM-17-005 03/31/2004 6.8E+000 JR/h t
  • 6.OOE-001 2.5E+'000 GM-17-006 06/30/2004 7.7E+000 pR/h t* 1.40E+000 2.5E+000 GM-17-007 09/30/2004 8.6E+000 pR/h t
  • 1.20E+000 2.5E+000 GM-17-008 12/31/2004 8.7E+000 pR/h t
  • 8.00E-001 2.5E+000 GM-17-009 03/31/2005 6.9E+O00 pWh t
  • 1.20E+000 2.5E+000 GM-17-010 06/30/2005 7.7E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-17-011 09/30/2005 8.OE+000 pJ/h t
  • 8.OOE-001 2.5E+000 GM-17-012 12/31/2005 8.3E+000 pR/h t* 8.OOE-001 2.5E+000 GM-17-013 03/31/2006 8.1E+000 pR/h t* 8.OOE-001 2.5E+000 GM-17-014 12/31/2006 7.9E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-17-015 06/30/2007 8.5E+000 pR/h t* 1.20E+000 2.5E+000 GM-17-016 12/31/2007 9.OE+000 pR/h t* 8.OOE-001 2.5E+000 GM-17-017 06/30/2008 8.8E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-17-018 12/31/2008 9.8E+000 pR/h t
  • 1.OOE+000 2.5E+000 GM-17-019 06/30/2009 6.9E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-17-020 12/31/2009 8.8E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-17-021 06/30/2010 8.3E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-17-022 12/31/2010 1.OE+001 pR/h t
  • 1.OOE+000 2.5E+000 GM-17-023 06/30/2011 9.7E+000 pR/h t
  • 1.OOE+000 2.5E+000 GM-17-024 12/31/2011 9.2E+000 pR/h t
  • 1.OOE+000 2.5E+000 GM-17-025 06/30/2012 8.0E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-17-026 12/31/2012 9.8E+000 pR/h t
  • I.OOE+000 2.5E+000 Results marked with
  • are greater than 2 Sigma Error.

Results m Av~ln-' n geter Auiz ttha nnuatl-NW:U .i~mintion epon Level Page 23 of 27

Figure 4.6 Exposure Rate Trend at GM-21 IADOW too"=00 wme

-* Result - Discrimination Level Samnia llama I*c. .*i ')~inma ~.*.n, fli..,ininaui,~n I Sam le Name Date Collected Result 2 Si m- Error Di-primi-C- 1 .1 GM-21-001 03/31/2003 6.OE+000 MR/h t

  • 8.OOE-001 2.5E+000 GM-21-002 06/30/2003 8.7E+000 MR/h t
  • 1.OOE+000 2.5E+000 GM-21-003 09/30/2003 8.OE+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-21-004 12/31/2003 8.SE+000 pMh t* 1.20E+000 2.5E+000 GM-21-005 03/31/2004 6.4E+000 pMR/h t
  • 6.OOE-001 2.5E+000 GM-21-006 06/30/2004 7.3E+000 pR/h t
  • 1.20E+000 2.5E+000 GM-21-007 09/30/2004 7.8E+000 pMRt* 6.OOE-001 2.5E+.000 GM-21-008 12/31/2004 8.4E+000 MR/h t
  • 1.OOE+000 2.5E+000 GM-21-009 03/31/2005 6.5E+000 MR/h t
  • 6.OOE-001 2.5E+000 GM-21-010 06/30/2005 7.3E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-21-011 09/30/2005 7.9E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-21-012 12/31/2005 7.9E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-21-013 03/31/2006 7.9E+000 pR/h t
  • 1.40E+000 2.5E+000 GM-21-014 12131/2006 8.OE+000 pMRh t
  • 8.OOE-001 2.5E+000 GM-21-015 06/30/2007 8.3E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-21-016 12/31/2007 9.4E+000 pR/h t
  • 1.O0E+000 2.5E+000 GM-21-017 06/30/2008 7.6E+000 MR/h t
  • 8.OOE-001 2.5E+000 GM-21-018 12/31/2008 7.8E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-21-019 06/30/2009 7.6E+000 MR/h t
  • 8.OOE-001 2.5E+000 GM-21-020 12/31/2009 8.6E+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-21-021 06/30/2010 7.9E+000 pR/h t
  • 8OOE-001 2.5E+000 GM-21-022 12/31/2010 8.9E+000 pR/h t
  • 8OOE-001 2.5E+000 GM-21-023 06/3012011 8.8E+000 pMRh t
  • 8.OOE-001 2.5E+000 GM-21-024 12/31/2011 7.BE+000 pR/h t
  • 8.OOE-001 2.5E+000 GM-21-025 06/30/2012 8.OE+000 MR/h t
  • 8.OOE-001 2.5E+000 GM-21-026 12/31/2012 9.1E+000 pR/h t
  • 1.OOE+000 2,5E+000 Results marked with
  • are greater than 2 Sigma Error.

Results ma atsrJp9r_,erth)a i=U-Yl~l*zu~z-nnua t~bqsrmination ePon Level Page 24 of 27

Figure 4.7 Exnosure Rate Trend at Control Location GM-27 7OD"Ma Ik

?AD"=44 GAON=

- Result oiscrimination Level D

r% 0 f% 11-+-A 0-. .1+ -3 0; C M  ;  ; ý6; 1 1

~C**~MIC ,.a,,Ic L.a.. ~ n.cMt S onj,.,a ~I ~.hi LS*Ct.* ,I,,,Iaq.n.n, Law.,

GM-27-001 03/31/2003 4.2E+000 pR/h t

  • 4.OOE-001 2.5E+000 GM-27-002 06/30/2003 6.OE+O00 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-003 09/30/2003 6.1E+000 iRlh t
  • 6.OOE-001 2.5E+000 GM-27-004 12/31/2003 6.1E+000 R/h t* 8.OOE-001 2.5E+000 GM-27-005 03/31/2004 4.8E+000 jR/h t
  • 4.OOE-001 2.5E+000 GM-27-006 06/30/2004 5.1E+000 lR/h t* 1.20E+000 2.5E+000 GM-27-007 09/3012004 6.5E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-008 12/31/2004 6.3E+000 pR/h t
  • 4.OOE-001 2.5E+000 GM-27-009 03/31/2005 5.OE+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-01 0 06/30/2005 6.4E+000 JR/h t
  • 4.OOE-001 2.5E+000 GM-27-01 1 09/30/2005 5.8E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-012 12/31/2005 6.2E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-013 03/31/2006 6.3E+000 PR/h t
  • 1.OOE+000 2.5E+000 GM-27-014 12/31/2006 6.3E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-015 06/30/2007 6.3E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-016 12/31/2007 6.5E+000 pR/h t
  • 6OOE-001 2.5E+000 GM-27-017 06/30/2008 5.8E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-018 12/31/2008 6.6E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-019 06/3012009 6.2E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-020 12/31/2009 6.1E+000 JR/h t* 6.OOE-001 2.5E+000 GM-27-021 06/30/2010 6.7E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-022 12/31/2010 6.4E+000 jR/h t
  • 6.OOE-001 2.5E+000 GM-27-023 06/30/2011 6.9E+000 pR/h t
  • 6.OOE-001 2.5E+000 GM-27-024 12/31/2011 5.8E+000 MR/h t
  • 6.OOE-001 2.5E+000 GM-27-025 06/30/2012 6.1 E+000 jR/h t* 6.OOE-001 2.5E+000 GM-27-026 12/31/2012 7.4E+000 jR/h t
  • 8.OOE-001 2.5E+.000 Results marked with
  • are greater than 2 Sigma Error.

Results mafgp f Pbgea tha=rtVNJý.

YIII:*zuz-nnual i- iminaton Level epon Page 25 of 27

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.

No deviations of the sampling requirements occurred during this monitoring period.

5.2 Direct Radiation Pathway 5.2.1 Exposure Rates Direct radiation is continuously measured at 6 indicator locations surrounding the YNPS ISFSI, along with 1 control location at Number Nine Road using thermoluminescent dosimeters (TLDs). These dosimeters are collected semi-annually for readout at the NVLAP certified dosimetry services vendor.

Review of the data in Tables 4.2 and 4.3 shows that all indicator locations were slightly elevated in comparison to the control location exposure rates. Figures 4.1 through 4.7 provide exposure rate trends of the monitoring locations since 2003. Review of Figures 4.1 through 4.7 shows no significant difference in exposure rates over time at either the indicator or control locations. The data listed under each of the trend graphs show values for the result errors and discrimination levels. Note that these values are estimated and are shown only for information.

5.2.2 Direct Doses from ISFSI Operations The ODCM specifies that a cumulative dose estimate from direct radiation is required 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 be present adjacent to the site for recreational activities throughout the year. The ODCM states that direct exposure above background can be estimated by subtracting the average TLD value of the control station from the indicator YNPS 2012 Annual REO Report Page 26 of 27

location measurements. As in previous years, the 2012 dose estimate assumes a 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 /> are used in both the first and second half-years. The most likely location for exposure to a member of the public from the ISFSI is in Sherman Reservoir for boating and fishing; however, the time estimates are conservatively applied to all monitoring locations.

Table 4.4 presents the results of the dose calculations. The highest calculated dose is at Station ID number GM-16. The maximum calculated annual dose at this location is 1.37 mrem. This value is only 6 percent of the 25 mrem per year limit. This represents a conservative dose estimate because a member of the public would normally be situated further away in the reservoir.

6.0 REFERENCES

1. USNRC Radiological Assessment Branch Technical Position, "An Acceptable Radiological Environmental Monitoring Program," Revision 1, November 1979.
2. Yankee Nuclear Power Station Off-site Dose Calculation Manual, Revision 21.
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".

YNPS 2012 Annual REO Report Page 27 of 27