ML070470110

Submittal of Yankee Nuclear Power Station Final Status Survey Report for Survey Area NOL-01

ML070470110
Person / Time
Site:	Yankee Rowe
Issue date:	03/30/2006
From:	Carson A Yankee Atomic Electric Co
To:	Document Control Desk, NRC/FSME
References
BYR 2006-027, YNPS-FSS-NOL01-00
Download: ML070470110 (132)

Text

YANKEE ATOMIC ELECTRIC COMPANY 49 Yankee Road, Rowe, Massachusetts 01367 YANKEE March 30, 2006 BYR 2006-027 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-001

References:

(a) License No. DPR-3 (Docket No. 50-29)

(b) BYR 2004-133, Submittal of Revision I to the Yankee Nuclear Power Station's License Termination Plan (c) Yankee Nuclear Power Station - Issuance of Amendment 158 Re: License Termination Plan

Subject:

Submittal of YNPS-FSS-NOLO1-00, Final Status Survey Report for Survey Area NOL-01

Dear Madam/Sir:

This letter submits YNPS-FSS-NOL01-00, Final Status Survey Report for NOL-01.

YNPS-FSS-NOLO1-00 was written in accordance with Section 5 of the YNPS License Termination Plan, "Final Status Survey Plan," and is consistent with the guidance provided in the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM).

We trust that this information is satisfactory; however if you should have any questions or require any additional information, please contact me at (301) 916-3995.

Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY Alice C. Carson Licensing Manager

Enclosure:

YNPS-FSS-NOLO1-00 (2 hard copies plus CD)

Ja! ý&'l

BYR 2006-013 Page 2 cc (w/o end): S. Collins, NRC Region I Administrator Marie Miller, Chief, Decommissioning Branch, NRC Region I J. Kottan, Region I D. Everhart, Region I J. Hickman, NRC Project Manager D. Howland, Regional Engineer, MA DEP R. Walker, Director, MA DPH M. Whalen, MA DPH M. Rosenstein, US Environmental Protection Agency, Region 1 W. Perlman, Executive Committee Chair, FRCOG T.W. Hutcheson, Chair, Franklin Regional Planning Board L. Dunlavy, Executive Director, FRCOG P. Sloan, Directory of Planning & Development, FRCOG D. Katz, CAN Jonathan Block, CAN

Yankee Nuclear Plant Station Final Status Survey Report For NOL-01 Yankee Atomic Electric Company

Report No.: YNPS-FSS-NOLOI-00 YANKEE NUCLEAR POWER STATION FINAL STATUS SURVEY REPORT REPORT NO.: YNPS-FSS-NOLOI-00 Prepared by: ex Date: :3/: /_9

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Martin 6rickson, FKS Radiological Engineer Reviewed by ( ANA, .. Date: lot(

Chris Messier, F, Radiological Engineer Date:

Approved by:

Dann Smith, FSS Manager

Report No.: YNPS-FSS-NOLOI-00 Table of Contents Section Page 1.0 Executive Summary 1 1.1 Identification of Survey Area and Units ----------------------------------------------- 1 1.2 D a te (s) o f S urv e y s ------------------------------------------------------------- 1 1.3 Number and Types of Measurements Collected ------------------------------------------ 1 1.4 Summary of Survey Results ------------------------------------------------------- 2 1.5 -Conclusions------------------------------------------------------ 2 2.0 FSS Program O verview ..................................................................................................... 2 2.1 Survey Planning --------------------------------------------------------------- 2 2.2 Survey Design ...........................................................------------------------------------------------------ 3 2.3 Survey Implementation ---------------------------------------------------------- 3 2.4 Survey Data Assessment --------------------------------------------------------- 3 2.5 Quality Assurance and Quality Control Measures ---------------------------------------- 4 3.0 Survey Area Information ---------------------------------------------------------- 4 3.1 Survey Area Description and HSA Information ------------------------------------------ 4 3 .2 H is tory o f Su rv e y Are a .................................................................................................... 4 3.3 Division ofN OL-01 into Survey Units ........................................................................... 5 3.4 Survey Unit Description ---------------------------------------------------------- 5 4.0 Individual Survey Unit Information --------------------------------------------------- 6 4 .1 S u rve y Un it N O L -0 1-0 1 ---------------------------------------------------------- 6 4.1.1 Summary of Radiological Data Since HSA -------------------------------------------------------------- 6 4.1.1.1 Chronology and Description of Surveys Since HSA ---------------------------------- 6 4.1.1.2 Radionuclide Selection and Basis 6 4.1.1.3 Summary of Scoping/Characterization Survey Data ---------------------------------- 7 4.1.2 Basis for Classification 8 4.1.3 Remedial Actions and Further Investigations ----------------------------------------- 8 4.1.4 Unique features of Survey Unit -------------------------------------------------- 8 4.1.5 ALARA Practices and Evaluations 8 4.2 Survey Unit NOL-01-02 ---------------------------------------------------------- 8 ii

Report No.: YNPS-FSS-NOL0I-00 4.2.1 Summary of Radiological Data Since HSA .............................................................. 8 4.2.1.1 Chronology and Description of Surveys Since HSA ---------------------------------- 8 4.2.1.2 Radionuclide Selection and Basis 9 4.2.1.3 Summary of Scoping/Characterization Survey Data ---------------------------------- 9 4.2.2 Basis for Classification 10 4.2.3 Remedial Actions and Further Investigations ........................................................... 10 4.2.4 U nique features of Survey U nit --------------------------------------------------- 10 4.2.5 ALARA Practices and Evaluations 10 4.3 Survey U nit N O L-01-03 ................................................................................................ 10 4.3.1 Summary of Radiological Data Since HSA --------------------------.--------------- 10 4.3.1.1 Chronology and Description of Surveys Since HSA --------------------------------- 10 4.3.1.2 Radionuclide Selection and Basis 11 4.3.1.3 Summary of Scoping/Characterization Survey Data ........................................... 11 4.3.2 Basis for Classification 11 4.3.3 Remedial Actions and Further Investigations ----------------------------------------- 11 4.3.4 Unique features of Survey Unit --------------------------------------- ---....................................... 12 4.3.5 ALARA Practices and Evaluations 12 4.4 Survey Unit NOL-01-04 ....................................................---------------------------------------------- 12 4.4.1 Summary of Radiological Data Since HSA ------------------------------------------ 12 4.4.1.1 Chronology and Description of Surveys Since HSA ---------------------------------- 12 4.4.1.2 Radionuclide Selection and Basis 12 4.4.1.3 Summary of Scoping/Characterization Survey Data ---------------------------------- 13 4.4.2 Basis for Classification 13 4.4.3 Remedial Actions and Further Investigations ----------------------------------------- 13 4.4.4 Unique features of Survey Unit -------------------------------------------------- 13 4.4.5 ALARA Practices and Evaluations 14 4.4.6 Final Status Survey --.------------....................................----------------------------------------------- 14 5 .1 Su rv e y U n it N O L -0 1-0 1 ---------------------------------------------------------- 14 5.1.1 Final Status Survey Plan and Associated DQOs --------------------------------------- 14 5.1.2 Deviations from the FSS Plan as Written in the LTP 15 5.1.3 DCGL Selection and Use 16 5.1.4 Measurements 16 iii

Report No.: YNPS-FSS-NOL01-00 5.1.5 Survey Implem entation A ctivities ------------------------------------------------- 17 5.1.6 Surveillance Surveys ................................................................................................. 19 5.1.6.1 Periodic Surveillance Surveys ............................................................................. 19 5.1.6.2 R esurveys ............................................................................................................ 19 5.1.6.3 Investigations....................................................................................................... 19 5.1.7 Survey R esults ........................................................................................................... 19 5.1.8 D ata Quality A ssessm ent ........................................................................................... 21 5.2 Survey Unit N OL-01-02 .................................................................................................. 22 5.2.1 Final Status Survey Plan and Associated DQOs ....................................................... 22 5.2.2 Deviations from the FSS Plan as Written in the LTP 23 5.2.3 DCGL Selection and Use .......................................... 25 5.2.4 Measurements .................................................. 25 5.2.5 Survey Implem entation Activities 27 27...............................

5.2.6 Surveillance Surveys ................................................................................................. 28 5.2.6.1 Periodic Surveillance Surveys ............................................................................. 28 5.2.6.2 R esurveys ............................................................................................................ 28 5.2.6.3 Investigations ...................................................................................................... 29 5.2.7 Survey R esults ........................................................................................................... 29 5.2.8 D ata Quality A ssessm ent ........................................................................................... 32 5.3 Survey Unit N OL-01-03 .................................................................................................. 34 5.3.1 Final Status Survey Plan and Associated DQOs......................... 34 5.3.2 Deviations from the FSS Plan as Written in the LTP ........... 35 5.3.3 DCGL Selection and Use 36 5.3.4 Measurements .................................................. 36 5.3.5 Survey Im plem entation Activities ------------------------------------------------ 38 5.3.6 Surveillance Surveys ............................................ 40 5.3.6.1 Periodic Surveillance Surveys ................................... 40 5.3.6.2 R esurveys ............................................................................................................ 40 5.3.6.3 Investigations .............................................. 41 5.3.7 Survey R esults ........................................................................................................... 41 5.3.8 Data Quality A ssessm ent ........................................................................................... 44 5.4 Survey U nit N O L-01-04 .................................................................................................. 45 iv

Report No.: YNPS-FSS-NOL01-00 5.4.1 Final Status Survey Plan and Associated DQOs --------------------------------------- 45 5.4.2 Deviations from the FSS Plan as Written in the LTP 46 5.4.3 DCGL Selection and Use 47 5.4.4 Measurements ------------------------------------------------- 48 5.4.5 Survey Implementation Activities ------------------------------------------------- 49 5.4.6 Surveillance Surveys --------------------------------------------------------- 50 5.4.6.1 Periodic Surveillance Surveys ------------------------------------------------- - ---------- 50 5.4.6.2 Resurveys -------------------------------------------------- 50 5.4.6.3 Investigations ----------------------------------------------------------- 50 5 .4 .7 50 S u rve y Re su l t s .. .......... ............................................................ .............................I......

5.4.8 Data Quality Assessment ------------------------------------------------------ 53 6.0 Quality Assurance and Quality Control ------------------------------------------------- 55 6.1 Instrum ent Q C Checks .................................................................................................... 55 6.2 Split Samples and Recounts ------------------------------------------- 55 6.3 Self-Assessments 55 7.0 Conclusion ------------------------------------------------------- 56

Report No.: YNPS-FSS-NOLOI-O0 Table of Contents (Continued)

List of Tables Table Page Table 1 - Survey Area N OL-0l Events .................................................................................... 4 Table 2 - Survey Area NOL-0l Surveys .................................................................................... 7 Table 3 - Survey Units NOL-01-02 and NOL-01-03 Surveys .................................................... 9 Table 4 - Survey Unit NOL-01-04 Surveys -------------------------------------------------- 13 Table 5 - Survey Unit NOL-01-01 Design Parameters ------------------------------------------ I 14 Table 6 - DCGLs and MDCs for Survey Unit NOL-01-01 for all LTP Radionuclides ------- 15 Table 7 - Sample Measurement Locations with GPS Coordinates ----------------------------------- 17 Table 8 -FSS Activity Summary for Survey Unit NOL-01-01 ------------------------------------- 18 Table 9 - Summary of Sample Results for Survey Unit NOL-01-01 ............. ...--------------------

20 Table 10 - Summary of Investigation Samples in Survey Unit NOL-01-01 ----------------------------- 21 Table 11 - Survey Unit NOL-01-02 Design Parameters ------------------------------------------------------ 23 Table 12 - DCGLs and MDCs for Survey Unit NOL-01-02 for all LTP Radionuclides ------------ 24 Table 13 - Sample Measurement Locations with GPS Coordinates .------.........................----------- 26 Table 14 - FSS Activity Summary for Survey Unit NOL-01-02 .............................................. 27 Table 15 - Summary of Sample Results for Survey Unit NOL-0 1-02 --------------------------------- 30 Table 16 - Summary of ISOCS Scan Results for Survey Unit NOL-01-02 ----------------------------- 31 Table 17 - Summary of Investigation Point #017 in Survey --------------------------

Unit NOL-01 32 Table 18 - Survey Unit NOL-0 1-03 Design Parameters ............................................................. 34 Table 19 - DCGLs and MDCs for Survey Unit NOL-01-03 for all LTP Radionuclides ------------ 35 Table 20 - Sample Measurement Locations with GPS Coordinates . 37 Table 21 - FSS Activity Summary for Survey Unit NOL-01-03..------------------------------------ 38 Table 22 - Samples in Response to ORISE Sampling-------------------------------------------- 39 Table 23 - Post-Remediation Sampling of Location NOL-0 1-03-036-F-I ------------------------------ 40 Table 24 - Summary of Sample Results for Survey Unit NOL-01-03 --------------------------------- 41 Table 25 - Summary of ISOCS Scan Results for Survey Unit NOL-01-03 ----------------------------- 42 Table 26 - Summary of Investigation Point #012 in Survey Unit NOL-01-03 ------------- 44 Table 27 - Survey Unit NOL-01-04 Design Parameters ------------------------------------------ 46 Table 28 - DCGLs and MDCs for Survey Unit NOL-01-04 for all LTP Radionuclides ----------- 47 vi

Report No.: YNPS-FSS-NOL0 1-00 Table 29 - Sample Measurement Locations with GPS Coordinates ---------------------------------- 48 Table 30 - FSS Activity Summary for Survey Unit NOL-01-03 ................................................ 49 Table 31 - Summary of Sample Results for Survey Unit NOL-0 1-03 ........................................ 51 Table 32 - Summary of ISOCS Scan Results for Survey Unit NOL-01-03 ............................... 52 List of Figures Figure Page Figure 1 - Map of Survey Units Relative to Structures ------------------------------------------- 57 Figure 2 -Site M ap....................................................................................................................... 58 Figure 3 - Map of Survey Units Relative to Survey Area .......................................................... 59 List of Attachments Attachment A - ISOCS Results Attachment B - Data Quality Assessment Plots and Curves Attachment C - Instrument QC Records List of Appendices Appendix A - YA-REPT-00-003-05, "Generic ALARA Review for FinalStatus Survey of Soil at YNPS "

Appendix B - FSSP YNPS-FSSP-NOLO 1-02-03, "FinalStatus Survey Planning Worksheets, Survey Area NOL-01, Units 1 through 4" Appendix C -YA-REPT-00-018-05, "Use of In-situ Gamma Spectrum Analysis to Perform Elevated Measurement Comparison in Support of Final Status Surveys" vii

Report No.: YNPS-FSS-NOL01-00 List of Abbreviations and Acronyms ALARA --------------- As Low As Reasonably Achievable DCGL-------- Derived Concentration Guideline Level DCGLEMC ------------ DCGL for small areas of elevated activity DCGLw ................ DCGL for average concentration over a wide area, used with statistical tests DQO ---------- Data Quality Objectives DPH ...................... Massachusetts Department of Public Health EMC Elevated Measurement Comparison ETD Easy-to-Detect FSS Final Status Survey FSSP Final Status Survey Plan GPS Global Positioning System H o ------

.---------- .... Null Hypothesis HSA Historical Site Assessment HTD Hard-to-Detect ISOCS In-situ Object Counting System LBGR Lower Bound of the Grey Region LTP License Termination Plan MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual MDA Minimum Detectable Activity MDC Minimum Detectable Concentration PAB Primary Auxiliary Building Q AP P ------------------- Quality Assurance Project Plan QC ----------------------- Quality Control RCA Radiological Controlled Area RP Radiation Protection RSS Reactor Support Structure SFP Spent Fuel Pool VC Vapor Container YNPS Yankee Nuclear Power Station viii

Report No.: YNPS-FSS-NOL0I-00 1.0 EXECUTIVE

SUMMARY

1.1 Identification of Survey Area and Units A Final Status Survey (FSS) was performed of Survey Area NOL-01 in accordance with Yankee Nuclear Power Station's (YNPS) License Termination Plan (LTP).

NOL-0 1 is described in the LTP as the Eastern Lower RCA Yard. Decommissioning of the area resulted in the complete excavation of the land area and the encompassed structures. As a result, the boundaries of NOL-01 include the areas discussed below.

NOL-01 consists of the designated open land areas and is the site of the former Spent Fuel Pool (SFP-01), Ion Exchange Pit (NSY-02), Vapor Container (VC) Elevator Foundation (NSY-09), the North and South Decontamination Pads and Fuel Transfer Enclosure (NSY-01). All structures have been demolished and removed from the survey area resulting in an open land FSS area survey. Figure 1 illustrates the relationship of the former structures to Survey Area NOL-0 1.

NOL-0 1 is located within the Radiologically Controlled Area (RCA), as delineated in years 2004-2005, and is classified as a MARSSIM Class I area. The survey area encompasses a land area of approximately 2,183 square meters and has been subdivided into four distinct Survey Units.

1.2 Dates(s) of Survey The FSS of the NOL-01 survey units was performed during the following time periods:

NOL-01-01 - August 24 to September 8, 2005 NOL-01-02 - August 1 to 23, 2005 NOL-01-03 - August 1 to 23, 2005 NOL-01-04 - November 17 to November 29, 2005 1.3 Number and Types of Measurements Collected Final Status Survey Plans (FSSPs) were developed for each survey unit in accordance with YNPS LTP and FSS procedures utilizing the MARSSIM protocol.

The planning and design of the survey plans employed the Data Quality Objective (DQO) process, ensuring that the type, quantity and quality of data gathered was appropriate for the decision-making process and that the resultant decisions were technically sound and defensible. A total of 62 fixed-point soil samples were collected, providing data for the non-parametric testing of the survey area. In addition to the fixed-point samples, a total of 354 In-Situ Object Counting System (ISOCS) scans, supplemented by hand-held survey instrument scans, were performed to provide 100% coverage of the survey area. Eleven (11) biased soil samples and I

Report No.: YNPS-FSS-NOLOI-00 103 investigative soil samples were collected in areas of concern identified as elevated by scan surveys.

1.4 Summary of Survey Results Following the survey, the data were reviewed against the survey design to confirm completeness and consistency, to verify that the results were valid, to ensure that the survey plan objectives were met and to verify survey unit classification. The boundaries of areas of elevated activity were determined based upon the results of a 100% surface scan, and the average activity within each area was compared to the fractional elevated measurement comparison ( DCGLEMC) or the elevated area was remediated. The fractional sum of the DCGLEMC was also calculated for each survey unit and determined to be less than 1 by the unity rule. No significant anomalies were observed in the graphical representation of the data collected as depicted in Attachment B. Retrospective power curves were generated that demonstrated that adequate power was achieved. An evaluation of the fixed-point sample data shows that: (1) none of the LTP radionuclide values exceeded the DCGLw and (2) the sum-of-fractions for those nuclides is less than 1, per the unity rule for each of the survey units. Therefore, the null hypothesis (Ho) (that is, that the survey unit exceeds the release criteria) is rejected.

1.5 Conclusions Based upon the evaluation of the data acquired for the FSS, NOL-01 meets the release requirements set forth in the YNPS LTP. The Total Effective Dose Equivalent (TEDE) to the average member of the critical group does not exceed 25 mrem/yr, and 10CFR20 Subpart E ALARA requirements have been met. This survey unit was evaluated against the site release criteria administrative level DCGLs that ensure that the 10 mrem/yr limit of the Massachusetts Department of Public Health (DPH) will be met.

2.0 FSS PROGRAM OVERVIEW 2.1 Survey Planning The YNPS FSS Program employs a strategic planning approach for conducting final status surveys with the ultimate objective to demonstrate compliance with the DCGLs, in accordance with the YNPS LTP. The DQO process is used as a planning technique to ensure that the type, quantity, and quality of data gathered is appropriate for the decision-making process and that the resultant decisions are technically sound and defensible. Other key planning measures are the review of historical data for the survey unit and the use of a team for plan development.

2

Report No.: YNPS-FSS-NOLOI-00 2.2 Survey Design In designing the FSS, the questions to be answered are: "Does the residual radioactivity, if present in the survey unit, exceed the LTP release criteria?" and "Is the potential dose from this radioactivity ALARA?" In order to answer these questions, the radionuclides present in the survey units must be identified, and the survey units classified. Survey units are classified with respect to the potential for contamination: the greater the potential for contamination, the more stringent the classification and the more rigorous the survey.

The survey design additionally includes the number, type and locations of fixed measurements/samples (as well as any judgmental assessments required), scanning requirements, and instrumentation selection with the required sensitivities or detection levels. DCGLs are developed relative to the surface/material of the survey unit and guide the minimum sensitivity required for the survey. Determining the acceptable decision error rates, the lower bound of the gray region (LBGR),

statistical test selection and the calculation of the standard deviation and relative shift allow the development of a prospective power curve plotting the probability of the survey unit passing FSS.

2.3 Survey Implementation Once the planning and development has been completed, the implementation phase of the FSS program begins. Upon completion of remediation and final characterization activities, a final walk down of the survey unit is performed. If the unit is determined to be acceptable (i.e. physical condition of the unit is suitable for FSS), it is turned over to the FSS team, and FSS isolation and control measures are established. After the survey unit isolation and controls are in place, grid points are identified for the fixed measurements/samples, using Global Positioning System (GPS) coordinates consistent with the Massachusetts State Plane System, and the area scan grid is identified. Data is collected and any required investigations are performed.

2.4 Survey Data Assessment The final stage of FSS involves assessment of the data collected to ensure the validity of the results, to demonstrate achievement of the survey plan objectives, and to validate survey unit classification. During this phase, the DQOs and survey design are reviewed for consistency between DQO output, sampling design and other data collection documents. A preliminary data review is conducted to include:

checking for problems or anomalies, calculation of statistical quantities and preparation of graphical representations for data comparison. Statistical tests are performed, if required, and the assumptions for the tests are verified. Conclusions are then drawn from the data, and any deficiencies or recommendations for improvement are documented.

3

Report No.: YNPS-FSS-NOL01-00 2.5 Quality Assurance and Quality Control Measures YNPS FSS activities are implemented and performed under approved procedures, and the YNPS Quality Assurance Project Plan (QAPP) assures plans, procedures and instructions have been followed during the course of FSS, as well as providing guidance for implementing quality control measures specified in the YNPS LTP.

3.0 SURVEY AREA INFORMATION 3.1 Survey Area Descriptions and Historical Site Assessment (HSA) Information Survey Area NOL-01 consists of land area containing approximately 2183 square meters of surface area. Since the beginning of plant operations, the area designated as NOL-01 has been posted and controlled as an RCA. Figure 2 depicts the boundaries of NOL-01 in relation to the site map. The LTP assumed that the Spent Fuel Pool and Fuel Transfer Chute system (SFP-01), VC elevator and stairway access (NSY-09), Fuel Transfer Enclosure and Vertical Concrete Cask transporter pad (NSY-01) and the Ion Exchanger Pit (NSY-02) structures, located within and adjacent to NOL-01, were to undergo FSS and remain onsite. However, subsequent management decisions resulted in the complete demolition and removal of these structures and the soil surface area of the former structures was incorporated into NOL-O1.

3.2 History of Survey Area NOL-01 is adjacent to the original Radiation Protection (RP) Control Point that was the normal access to the upper RCA, thus causing the potential for contamination migration from routine personnel and material traffic into and out of the RCA. In addition, unplanned operational events and activities led to the contamination of NOL-01, as listed in Table 1.

Table 1 Survey Area NOL-01 Events Date Event September 18, 1963 Shield Tank Cavity Shield Water Spill October 8, 1963 De-watering Pump Packing Leakage October 3, 1964 Leakage from Ion Exchanger Pit September 27, 1966 Spent Fuel Pit Water Spill November 1, 1966 Hose Failure (Fuel Chute Pump-back System draining in progress)

July 16, 1975 Yard Area Contamination May 15, 1981 Contamination of Yard during Reactor Head Removal 4

Report No.: YNPS-FSS-NOL0 1-00 February 17 & 18, 19941 LLeakage from Frozen Fuel Chute De-watering Line February 23, 1994 Leakage from Frozen NST Telltale Lines 3.3 Division of NOL-01 into Survey Units NOL-01 is subdivided into four distinct survey units: NOL-01-01, NOL-01-02, NOL-01-03 and NOL-01-04. Figure 3 depicts the survey units relative to the survey area.

3.4 Survey Unit Description NOL-01-01 NOL-01-01 consists of an open land area inside the Reactor Support Structure (RSS) footprint. NOL-01-01 extends south from the common boundary with Survey Unit NOL-06-01 (to the north) terminating at the face of the foundation of the former Primary Auxiliary Building (PAB), Survey Areas AUX-01 and AUX-02. A line tangent to the RSS support ring forms the eastern boundary. Survey Unit BRT-01 forms the western boundary. Originally, NOL-01-01 comprised a larger surface area; however, a portion of NOL-01-01 was transferred to NOL-01-02 and NOL 03 due to the SFP excavation. The resultant total area of NOL-01-01 is approximately 178 in 2 .

NOL-01-02 Survey Unit NOL-01-02 is the previous site of the northern portion of the SFP and some surrounding land areas adjacent to the former RSS. Original demolition plans called for the SFP floor, foundations, and sub-grade structures to remain in place after demolition; however, most sub-surface structures were subsequently removed as part of the deconstruction process. Survey Unit NOL-01-02 is bounded by NOL-01-04 on the north, NOL-02-01 on the east, NOL-01-03 on the south, and NOL 01 on the west. NOL-01-02 has a total area of approximately 469 in 2.

NOL-01-03 Survey Unit NOL-01-03 is the previous site of the southern portion of the SFP, Ion Exchange (IX) Pit and Elevator Shaft and some surrounding land areas adjacent to the former RSS. The IX Pit was used for housing the reactor water cleanup ion exchangers and a portion of the structure was originally planned to remain after demolition. Subsequent management decisions resulted in the IX Pit structure and Elevator Shaft being demolished. Survey Unit NOL-01-03 is bounded by NOL 02 on the north, NOL-02-01 on the east, AUX-0 1 on the south, and NOL-0 1-01 on the west. NOL-01-03 has a total area of approximately 655 in2 .

5

Report No.: YNPS-FSS-NOLO 1-00 NOL-01-04 Survey Unit NOL-01-04 consists of the excavated open land area in the section of the eastern lower RCA yard that abuts the Turbine Building and Service Building foundations and is referred to as the "alley way." Originally the Fuel Transfer Enclosure, Rad Lab Sump, North and South Decon Rooms and the Fuel Oil Transfer House structures were contained within the survey unit but have since been demolished and removed. The unit shares its west boundary with survey unit NOL-0 1-01, its south boundary with survey units NO-L01-02 and NOL-02-01, and its east boundary with survey area OOL-12. The NOL-01-04 footprint is approximately 881 2

4.0 INDIVIDUAL SURVEY UNIT INFORMATION 4.1. Survey Unit NOL-01-01 4.1.1 Summary of Radiological Data Since HSA 4.1.1.1 Chronology and Description of Surveys Since HSA A remediation/characterization effort was performed in Survey Unit NOL-01-01 from August 3 to 11, 2005, during which time 100 % of the unit was scanned using a SPA-3 (sodium iodide hand-held survey instrument) and remediation was performed as necessary. In addition to the scans, a total of 83 soil samples were taken. Of the 83 samples taken, 12 samples represented the "as left" condition of the survey unit at the time of turnover and were used to determine the statistical values for the DQOs (see Table 2).

Upon completion of the characterization effort, isolation and control measures were implemented for the FSS including ground and storm water controls. NOL-01-01 boundaries were marked with Survey Unit NOL-06-01 (to the north) terminating at the face of the foundation of the former PAB, Survey Areas AUX-01 and AUX-02 to the south. A line tangent to the RSS support ring formed the eastern boundary. Survey Unit BRT-0 1 formed the western boundary. The condition of NOL-01-01 at the time of FSS was an open land area consisting of soil and small rocks.

4.1.1.2 Radionuclide Selection and Basis A large amount of the soil area in the RSS footprint was remediated for both radiological (elevated concentrations of Cs-137 and Co-60) and environmental (PCB-contamination) reasons. Characterization 6

Report No.: YNPS-FSS-NOLOI-00 data (post-remediation soil samples) from areas NOL-01 and NOL-06 were used in the FSS planning for unit NOL-01-01. Cesium-137 and Co-60 were the only easy-to-detect (ETD) plant-related radionuclides identified in the characterization (post-remediation) surface soil samples. The average Cs-137 concentration was 0.17 pCi/g and the average Co-60 concentration was 0.064 pCi/g, and thus both average values were below the respective 10-mrem/yr DCGLs. The average Cs-137 concentration represented approximately 73% of the identified plant-related activity and the average Co-60 concentration represented approximately 27%.

One pre-remediation soil sample was sent to an offsite laboratory for analyses of HTD nuclides. Several HTD radionuclides (i.e., C-14, Ni-63, and Sr-90) were identified in that sample at levels greater than the critical level but less than MDA. Post-remediation soil samples identified Cs-137 and Co-60 at concentrations that were acceptable for area turnover (i.e., concentrations below the respective DCGL values), but the post-remediation soil samples were not analyzed for HTD nuclides.

4.1.1.3 Summary of Scoping/Characterization Survey Data Table 2 summarizes scoping, characterization, and remedial action surveys for Survey Area NOL-01-01.

Table 2 Summary of Results for Survey Unit NOL-01-01 Characterization Data Parameter Remediad/Chatacterization 08/03/05-08/11/05 Number of samples Collected 12 Co 60 : Mean Concentration 0.06 pCi/g Standard Deviation 0.11 pCi/g 37 CS1  : Mean Concentration 0.17 pCi/g Standard Deviation 0.19 pCi/g 7

Report No.: YNPS-FSS-NOLO0 -00 4.1.2 Basis for Classification Based upon the historical use and radiological conditions associated with Survey Unit NOL-01-01, the unit was designated as MARSSIM Class 1.

After review of data and information obtained during the course of demolition and interviews with personnel, it was determined that NOL-0 1-01 would remain a Class 1 unit.

4.1.3 Remedial Actions and Further Investigations Survey Unit NOL-01-01 has passed FSS; therefore, no investigations into the reason for failure or potential impact are warranted.

4.1.4 Unique Features of Survey Unit There are no unusually unique features in NOL-01-01 4.1.5 ALARA Practices and Evaluations The generic ALARA evaluation for soils, as documented in Technical Report YA-REPT-00-003-05, "Generic ALARA Review for Final Status Survey of Soil at YNPS," (provided in Appendix A) concludes that no further remediation of soil below the 8.73 merm DCGL is warranted.

4.2. Survey Unit NOL-01-02 4.2.1 Summary of Radiological Data Since HSA 4.2.1.1 Chronology and Description of Surveys Since HSA During the period of June 27 to July 25, 2005, an extensive remediation/characterization effort was performed within the SFP excavation, which included Survey Units NOL-01-02 and NOL 03. During this time, 100% of the excavation was scanned using a SPA-3 and remediation was performed as necessary. In addition to the scans, a total of 135 soil samples were taken. Of the 135 samples taken, 16 samples represented the "as left" condition of the survey unit at the time of turnover and were used to determine the statistical values for the DQOs (see Table 3).

Upon completion of the characterization effort, isolation and control measures were implemented for the FSS of the SFP excavation including ground and storm water controls. NOL-01-02 boundaries were marked with adjacent Survey Units BRT-01-01, NOL-01-03, NOL-01-04, and NOL-02-01 determining the western, southern, northern and eastern boundaries respectively. The condition of 8

Report No.: YNPS-FSS-NOL0I-00 NOL-01-02 at the time of FSS was an open excavation consisting of soil and small rocks sloping downward from the east and west directions.

4.2.1.2 Radionuclide Selection and Basis During the initial DQO process, Co 60, Cs 13 7 and Ag'°8m were identified as the radiological nuclides of concern due to their presence in the characterization sample results. Tritium was added to the list of radionuclides of concern due to its presence in a nearby groundwater plume identified by well monitoring. The remaining LTP-required radionuclides were ruled out of the initial DQO process because of their absence in the characterization results.

Since multiple radionuclides were assumed to be present in the survey area, the unity rule (i.e. sum-of-fractions) is employed to show compliance with the release criteria.

4.2.1.3 Summary of Scoping/Characterization Survey Data Table 3 summarizes scoping, characterization, and remedial action surveys for Survey Units NOL-01-02 and NOL-01-03.

Table 3 Survey Units NOL-01-02 and NOL-01-03 Surveys

~Remedial , scoping Characterization Par~meter ~ 09/28/92- 05/21/93- ~ 07/16/05-10/27/92 111798: . 07/23/,05 Number of samples Collected 19 56 16 Co 60 : Mean Concentration 0.94 pCi/g 0.77 pCi/g 0.05 pCi/g Standard Deviation 1.23 pCi/g 0.56 pCi/g 0.07 pCi/g Minimum Concentration 0.05 pCi/g 0.06 pCi/g -0.02 pCilg Maximum Concentration 3.87 pCi/g 1.77 pCi/g 0.24 pCi/g 37 Cs1 : Mean Concentration 10.31 pCi/g 0.53 pCi/g 0.19 pCi/g Standard Deviation 32.86 pCi/g 0.58 pCi/g 0.23 pCi/g Minimum Concentration 0.07 pCi/g 0.05 pCi/g 0.002 pCi/g Maximum Concentration 160 pCi/g 1.80 pCi/g 0.62 pCi/g 9

Report No.: YNPS-FSS-NOL0 1-00 4.2.2 Basis for Classification Based upon the historical use and radiological conditions associated with Survey Unit NOL-01-02, the unit was designated as MARSSIM Class 1.

After review of data and information obtained during the course of demolition and interviews with personnel, it was determined that NOL-0 1-02 would remain a Class 1 unit.

4.2.3 Remedial Actions and Further Investigations Survey Unit NOL-01-02 has passed FSS; therefore, no investigations into the reason for failure or potential impact are warranted.

4.2.4 Unique Features of Survey Unit A unique feature associated with NOL-01-02 is a depression in the central portion of the survey unit, which was the location of the former Spent Fuel Follower Tube.

4.2.5 ALARA Practices and Evaluations Soil remediation activities were performed in NOL-01 during the construction of the security shield wall around the SFP in 1992 (see Table 2 for related data). Additional remediation was performed in conjunction with the characterization effort to lower the levels of residual activity ALARA (i.e. reduction of activity levels below the DCGLw).

The generic ALARA evaluation for soils, as documented in Technical Report YA-REPT-00-003-05, "Generic ALARA Review for Final Status Survey of Soil at YNPS," (provided in Appendix A) concludes that no further remediation of soil below the 8.73 mrem DCGL is warranted.

4.3. Survey Unit NOL-01-03 4.3.1 Summary of Radiological Data Since HSA 4.3.1.1 Chronology and Description of Surveys Since HSA During the period of June 27 to July 25, 2005, an extensive remediation/characterization effort was performed within the SFP excavation, which included Survey Units NOL-0 1-02 and NOL-0 1-

03. During this time, 100% of the excavation was scanned using a SPA-3 (sodium iodide hand-held survey instrument) and remediation was performed as necessary. In addition to the scans, a total of 135 10

Rcport No.: YNPS-FSS-NOLOI-00 soil samples were taken. Of the 135 samples taken, 16 samples represented the "as left" condition of the survey unit at the time of turnover and were used to determine the statistical values for the DQOs (see Table 3).

Upon completion of the characterization effort, isolation and control measures were implemented for the FSS of the SFP excavation including ground and storm water controls. NOL-01-03 boundaries were marked with adjacent Survey Units AUX-01-01, NOL-01-01, NOL-01-02, andNOL-02-01, delineating the southern, western, northern and eastern boundaries respectively. The condition of NOL-01-03 at the time of FSS was an open excavation consisting of soil and small rocks sloping downward from the south, east and west directions.

4.3.1.2 Radionuclide Selection and Basis During the initial DQO process, Co 60 , Cs1137 and Ag008~Mwere identified as the radiological nuclides of concern due to their presence in the characterization sample results. The remaining LTP-required radionuclides were ruled out of the initial DQO process because of their absence in the characterization results.

Since multiple radionuclides were assumed to be present in the survey area, the unity rule (i.e. sum-of-fractions) is employed to show compliance with the release criteria.

4.3.1.3 Summary of Scoping/Characterization Survey Data Table 3 summarizes scoping, characterization, and remedial action surveys for Survey Unit NOL-01-03.

4.3.2 Basis for Classification Based upon the historical use and radiological conditions associated with Survey Unit NOL-01-03, the unit was designated as MARSSIM Class 1.

After review of data and information obtained during the course of demolition and interviews with personnel, it was determined that NOL 03 would remain a Class 1 unit.

4.3.3 Remedial Actions and Further Investigations Survey Unit NOL-01-03 has passed FSS; therefore, no investigations into the reason for failure or potential impact are warranted.

11

Report No.: YNPS-FSS-NOLOI-00 4.3.4 Unique Features of Survey Unit There are no unusually unique features for this survey unit.

4.3.5 ALARA Practices and Evaluations The generic ALARA evaluation for soils, as documented in Technical Report YA-REPT-00-003-05, "Generic ALARA Review for Final Status Survey of Soil at YNPS," (provided in Appendix A) concludes that no further remediation of soil below the 8.73 mrem DCGL is warranted.

4.4. Survey Unit NOL-01-04 4.4.1 Summary of Radiological Data Since HSA 4.4.1.1 Chronology and Description of Surveys Since HSA Upon completion of the characterization effort, isolation and control measures were implemented for the FSS of the SFP excavation including ground and storm water controls. NOL-01-04 boundaries were marked with the Turbine and Service Building pads on its north, survey unit NOL-01-01 on the west, its south boundary with survey units NOL-01-02 and NOL-02-01, and its east boundary with survey area OOL-12. The condition of NOL-01-04 at the time of FSS was an open excavation consisting of soil and small rocks sloping downward from the north, east and west directions.

4.4.1.2 Radionuclide Selection and Basis The FSS planning for NOL-01-04 used onsite gamma analysis results for 11 post-remediation soil samples collected from unit NOL-01-04. Co-60 and Cs-137 were the only plant-related gamma-emitting radionuclides identified in the samples, although not consistently at concentrations that were greater than the MDCs for the analyses. The mean soil concentrations of Co-60 and Cs-137 were 0.08 pCi/g +/- 0.092 pCi/g and 0.03 pCi/g +/- 0.024 pCi/g, respectively. The Co-60 and Cs-137 concentrations were all well below the respective DCGL (the Co-60 concentrations ranged from

<MDA to 0.27pCi/g and the Cs-137 concentrations ranged from

<MDA to 0.073 pCi/g).

The presence of all LTP-required radionuclides (gamma-emitters, HTD beta-emitters, and TRUs) in the soil was evaluated under the survey plan. The YNPS Chemistry Department analyzed each FSS soil sample for all LTP-listed gamma-emitting nuclides, except Cm-243/244. In addition, 4 FSS soil samples were sent to an 12

Report No.: YNPS-FSS-NOLO1-00 independent laboratory for analyses of gamma-emitters, HTD beta-emitting radionuclides, and alpha-emitting radionuclides, including Cm-243/244.

4.4.1.3 Summary of Scoping/Characterization Survey Data Table 4 summarizes scoping, characterization, and remedial action surveys for Survey Unit NOL-01-04.

Table 4 Survey Unit NOL-01-04 Surveys

,Characterization,

,Paramefer Number of samples Collected 11 Co 60 : Mean Concentration 0.08 pCi/g Standard Deviation 0.09 pCi/g Minimum Concentration -0.00 pCi/g Maximum Concentration 0.27 pCi/g Cs' 37: Mean Concentration 0.03 pCi/g Standard Deviation 0.02 pCi/g Minimum Concentration 0.00 pCi/g Maximum Concentration 0.07 pCi/g 4.4.2 Basis for Classification Based upon the historical use and radiological conditions NOL-01-04 was designated as MARSSIM Class 1. Based upon reviews of data and information obtained during the course of demolition and interviews with personnel, it was determined that NOL-0 1-04 would remain a Class 1 unit.

4.4.3 Remedial Actions and Further Investigations Survey Unit NOL-01-04 has passed FSS; therefore, no investigations into the reason for failure or potential impact are warranted.

4.4.4 Unique Features of Survey Unit A unique feature associated with NOL-0 1-04 was a depression in the south central portion of the survey unit, which was a portion of the former Spent Fuel Follower Tube location. There were two smaller depressions in the northeast section of the unit along with an exposed wellhead.

13

Report No.: YNPS-FSS-NOLO0 -00 4.4.5 ALARA Practices and Evaluations The generic ALARA evaluation for soils, as documented in Technical Report YA-REPT-00-003-05, "Generic ALARA Review for Final Status Survey of Soil at YNPS," (provided in Appendix A) concludes that no further remediation of soil below the 8.73 mrem DCGL is warranted.

5.0 FINAL STATUS SURVEY 5.1. Survey Unit NOL-01-01 5.1.1 Final Status Survey Plan and Associated DQOs The FSS for NOL-01-01 (YNPS-FSSP-NOLOl-01-01) was planned and developed in accordance with the LTP using the DQO process. Form DPF-8856.1, found in YNPS Procedure 8856, "Preparation of Survey Plans," was used to provide guidance and consistency during development of the FSS Plan and can be found in Appendix B. The DQO process allows for systematic planning and is specifically designed to address problems that require a decision to be made in a complex survey design and in turn provides alternative actions. The DQO process was used to develop an integrated survey plan providing the survey unit identification, sample size, selected analytical techniques, survey instrumentation, and scan coverage. The Sign Test was specified for non-parametric statistical testing for this survey unit, if required. The design parameters developed are presented in the Table 5.

Table 5 Survey Unit NOL-01-01 Design Parameters Survey Unit Design Parameter. Basi Area 178 m' Class 1, <2,000 m2 Number of Direct 15 Based on a LBGR of 0.5 Measurements (unity rule), sigma of 0.1 and an adjusted relative shift of 2 cc=pB= 0.05 Sample Area 11.9 m 2 178 m 2 / 15 = 11.9 m 2 Sample Grid Spacing 3.7 m (178/(0.866* 15)) 1/2 with a triangular pitch 14

Report No.: YNPS-FSS-NOLOI-00 Su-eUni Design Parameter3/4 Basis Scan area 178 m2 Class 1 Area- 100%

Scan Investigation Level No audible indication > Based on a Bkgd. With a SPA-3 J(DCGLEMC)< 1 5.1.2 Deviations from the FSS Plan as Written in the LTP The null hypothesis (H.) is stated and tested in the negative form: "Residual licensed radioactive materials in Survey Unit NOL-0 1-01 exceeds the release criterion." This null hypothesis is designed to protect the health of the public as well as to demonstrate compliance with the requirements set forth in the Yankee Rowe LTP. The tolerable limits established for this survey plan set the probability of Type I errors (a) at 0.05 and the probability of Type II errors (03) at 0.05. Investigation levels for the fixed measurements were set at:

(a) >DCGLEMc for either Cs-137 or Co-60, or (b) a sum of DCGLEMC fractions >1.0, or (c) >DCGL for either Cs-137 or Co-60 and greater than 3 times the standard deviation of the mean as defined in the LTP The desired Minimum Detectable Concentration (MDC) for fixed measurements was set at 10% of the DCGLw for each applicable radionuclide; however, if it was impracticable to achieve those values, the MDCs were permissible to be as high as 50% of the DCGLw. All MDCs for the surveys ofNOL-01-01 were met in accordance with YNPS LTP. DCGL values and the associated MDC values can be found in Table 6.

Table 6 DCGLs and MDCs for Survey Area NOL-01-01 for All LTP Radionuclides Nuclide K DCGLw (pCiigY H-3 1.3E+02 6.4E+01 C-14 1.9E+00 9.7E-01 Fe-55 1.OE+04 5.1E+03 2

Co-60 1.4E+00 7.OE-01 Ni-63 2.8E+02 1.4E+02 Sr-90 6.OE-01 3.OE-01 2Nb-94 2.5E+00 1.3E+00 15

Report No.: YNPS-FSS-NOLOI-00

.GLW (pCilg):: Required~

MDC (50% of the, DCGLw) a04, Tc-99 5.OE+00 2.5E+00 2

Ag-108m 2.5E+00 1.3E+00 2

Sb-125 1.1E+01 5.6E+00 2

Cs-134 1.7E+00 8.7E-01 2

Cs-137 3.OE+00 1.5E+00 2

Eu-152 3.6E+00 1.8E+00 2

Eu-154 3.3E+00 1.7E+00 2

Eu-155 1.4E+02 6.9E+01 Pu-238 1.2E+01 5.8E+00 Pu-239, 240 1.1E+01 5.3E+00 Pu-241 3.4E+02 1.7E+02 Am-241 1.OE+01 5.1E+00 Cm-243, 244 1.LE+01 5.6E+00 1Based on 8.73 mrem/yr (TEDE) 2 Gamma emitting nuclides The FSSP design was performed to the criteria of the LTP; therefore, no subsequent LTP deviations with potential impact to this survey unit need to be evaluated.

5.1.3 DCGL Selection and Use The LTP DCGLs for soil were calculated using the resident farmer scenario.

For the resident farmer scenario, the average member of the critical group is the resident farmer who lives on the site, grows all of his/her diet onsite and drinks water from a groundwater source onsite. The residual radioactive material was assumed to be in the top 2.89 m soil layer, available for use in residential and light farming activities-. The LTP DCGLs were performed using RESRAD Version 6.21 analyses and based upon a resulting dose of 25 mrem/yr.

The DCGLs in NOL-01-01 Survey Plan were derived by scaling the LTP DCGLs to 8.73 mrem/yr. The use of the 8.73 mrem/yr value was necessitated by the DPH site release criteria of 10 mrem/yr subtracting the maximum dose contribution for subsurface partial structures (0.5 mrem/yr) and the maximum dose contribution from groundwater (0.77 mrem/yr). The resulting scaled DCGL values and associated MDCs are in Table 6.

5.1.4 Measurements The sample design required that 15 surface soil samples be used for the Sign Test based on the probability of error tolerance (a and P3), LBGR and 16

Report No.: YNPS-FSS-NOLOI-00 relative shift value found in Table 5. Two additional samples were added for the statistical test to increase the power of the survey. Two of the samples, in the sample set, were split and analyzed for LTP hard-to-detect HTD radionuclides in addition to the easy-to-detect ETD radionuclides. Two samples were designated as "recount" samples, thus satisfying the QC requirements of the QAPP.

The fixed-point sampling grid was developed as a systematic grid with spacing consisting of a triangular pitch pattern with a random starting point.

With the aid of a GPS and AutoCAD-generated survey unit map, the systematic random start grid was developed utilizing Visual Sample Plan software. Sample measurement locations are provided with the GPS coordinates in Table 7.

Table 7 Sample Measurement Locations with GPS Coordinates

]Designation 24.Northi4ng' Ea0i96.86 NOL-01-01-002-F 272451.2417 3093602.861 NOL-0 1-01-002-F 272467.2394 3093602.861 NOL-01-01-003-F 272443.2429 3093589.006 NOL-0 1-01-004-F 272459.2406 3093589.006 NOL-01-01-005-F 272475.2382 3093589.006 NOL-01-01-006-F 272491.2359 3093589.006 NOL-01-01-007-F 272435.2441 3093575.152 NOL-01-01-008-F 272451.2417 3093575.152 NOL-01-01-009-F 272467.2394 3093575.152 NOL-01-01-010-F 272483.237 3093575.152 NOL-01-01-011-F 272499.2347 3093575.152 NOL-01-01-012-F 272411.2476 3093561.298 NOL-01-01-013-F 272427.2453 3093561.298 NOL-01-01-014-F 272443.2429 3093561.298 NOL-01-01-015-F 272459.2406 3093561.298 5.1.5 Survey Implementation Activities Table 8 provides a summary of daily activities performed during the Final Status Survey of NOL-01-01.

17

Report No.: YNPS-FSS-NOL0 1-00 Table 8 FSS Activity Summary for Survey Unit NOL-01-01 Date P ~Activity ~

August 24, 2005 Performed walk-down of NOL-01-01 Established Isolation and Controls August 25, 2005 Scanned 100% of NOL-01-01 with SPA-3 August 26, 2005 Commenced Investigative scans. GPS of fixed-point sample locations. Completed sampling of fixed-point and biased samples.

August 30, 2005 Commenced investigative sampling regimen September 8, 2005 Performed successful remediation at investigative sample location NOL-01-027-F-I. FSS completed.

Remedial actions performed during the FSS of NOL-01-01 include the removal of soil at investigative location NOL-0 1-01-027-F-I.

The apparent cause of the area having the potential to contain undesirable quantities of residual radioactivity during FSS was that the turnover surveys, though designed similarly to FSS, were performed with hand-held scanning instrumentation.

In recognizing a more consistent, less human error-prone survey methodology in fixed-rig ISOCS surveys, the FSS Program implemented ISOCS final status surveys to as large an extent as radiologically and ergonomically practical. This practice led to a condition in which FSS sensitivities would likely result in more investigations and occasional elevated measurements that went undetected during hand-held instrument turnover surveys.

To mitigate this condition, Yankee management incorporated a Remediation Group into the RP organization during the fourth quarter of 2005. The Remediation Group uses FSS-quality instruments and ISOCS, as well as FSS-trained and experienced personnel, to guide remediation and conduct turnover surveys. Additionally, the group establishes administrative survey acceptance criteria at 50 percent of FSS investigation criteria, providing an increased level of assurance that FSS DCGLs will be met during FSS.

Initial efforts were somewhat hampered by limited FSS-quality ISOCS and crane support, but funding and resources have been aligned to provide the project with six FSS-quality ISOCS with adequate crane support for the duration of remaining remediation work.

18

Report No.: YNPS-FSS-NOLO1-00 5.1.6 Surveillance Surveys 5.1.6.1 Periodic Surveillance Surveys Survey Unit NOL-01-01 is subject to periodic surveillance surveys in accordance with YNPS procedure DP-8860, "Area Surveillance Following Final Status Survey." These surveys provide assurance that areas with successful FSS remain unchanged until license termination.

5.1.6.2 Resurveys No resurveys were required in NOL-01-01 5.1.6.3 Investigations No investigation survey was warranted.

5.1.7 Survey Results The onsite laboratory analyzed the 17 fixed-point soil samples collected from NOL-01-01. All samples were analyzed by gamma spectroscopy with sensitivity sufficient to achieve the MDCs in Table 6 for gamma-emitting nuclides. One sample (NOL-01-01-005-F-S) exceeded the DCGLw for C-14.

The sample point adjacent to NOL-01-01-005-F-S (NOL-01-01-006-F-S) indicated a C-14 concentration less than DCGLw, therefore, for conservatism; the AF for the elevated area was determined from the area outlined in the FSSP (Table 5). The concentration of C-14 in the elevated area was less than DCGLEMc and the sum-of-fractions were less than one (unity). The sign test was used on the data set as outlined in the FSSP and the survey unit passed FSS. Table 9 includes the gamma spectroscopy results as well as the offsite HTD analysis for radionuclides positively identified.

Two biased samples were taken. NOL-01-01-018-F-B and NOL-01-01-019-F-B soil samples were taken by the southeast section of the RSS ring foundation. These samples were counted onsite using the gamma spectroscopy system then shipped, without drying, to General Engineering Laboratories in Charleston, SC, for analysis of both ETD radionuclides and tritium. The results of these biased samples are included in Table 9.

19

Report No.: YNPS-FSS-NOLOI-00 Table 9 Summary of Sample Results for Survey Unit NOL-01-01 o o) S 37 Ag 10M C 14Pu23/20Tc 99Am'41 H3 f Sample Number~ ICi!,, (lL Ci/g !Cig Ci/g pCi!g ;P Ci! Ci!g PCi! -DCGL*>

FSS-NOL-01-01-001-F 1.2E-02 9.6E-03 0.27 0.09 0.16 FSS-NOL-01-01-002-F 1.1 E-02 5.OE-02 0.02 FSS-NOL-01-01-003-F 2.8E-02 1.4E-01 0.05 FSS-NOL-01-01-004-F -3.4E-03 9.6E-02 0.03 FSS-NOL-01-01-005-F 6.8E-02 1.4E-01 4.86 4.96 FSS-NOL-01-01-006-F 4.OE-02 3.3E-01 0.26 0.37 FSS-NOL-01-01-007-F 4.1 E-02 9.3E-02 0.03 FSS-NOL-01-01-008-F 3.9E-02 9.7E-02 0.03 FSS-NOL-01-01-009-F 1.7E-02 6.4E-02 0.02 FSS-NOL-01-01-010-F 1.8E-01 -1.1E-02 0.18 1.0E-02 -3.1.E-04 0.00 FSS-NOL-01-01-011-F 1 .O-02-3.1-04<MDA)

FSS-OL-0-01-12-F0.00 FSS-NOL-01-01-012-F -1.8E-03 5.OE-03 (<MDA)

F1 0.00

(<MDA)

-2.6E-03 -1.5E-03 FSS-NOL-01-01-014-F -2.6E-03 -1.1E-03 6.89 0.05 FSS-OLTT1-01-015-F 0.00

-2.7E-03 -2.8E-04 (<MDA) 0.00 FSS-NOL-01-01-01 6-F 1.1 E-02 -6.5E-03 (<MDA) 0.00 FSS-NOL-01-01-017-F -2.6E-03 1.1 E-02 (<MDA)

FSS-NOL-01-01-018- 0.00 F-B 0.OE+00 1.6E-01 0.644 (<MDA)

FSS-NOL-01-01-019- 0.00 F-B 2.1E-02 2.5E-02 (<MDA) mean 2.6E-02 6.OE-02 Standard deviation 4.6E-02 8.8E-02

• DCGL fraction, Unity Rule applied 20

Report No.: YNPS-FSS-NOLO1-00 Table 10 Summary of Investigation Samples in Survey Unit NOL-OI-O1 Sample Number ' C.o", 'pCijg '%f-DCGL' ~Cs'-'- Pýig -DG NOL-01-01-020-F-I 9.7E-03 0.0069 -9.9E-03 -0.0033 NOL-01-01-021-F-I 8.1 E-02 0.0577 3.9E+00 1.29372 NOL-01-01-022-F-I 2.6E-02 0.0188 1.2E-01 0.0414 NOL-01-01-023-F-I 9.3E-03 0.0066 4.1E-02 0.0138 NOL-01-01-024-F-I 8.8E-03 0.0063 9.5E-02 0.0315 NOL-01-01-025-F-I 2.7E-02 0.0193 6.6E-02 0.0219 NOL-01-01-026-F-I 1.8E-02 0.0129 -1.1E-02 -0.0038 NOL-01-01-027-F-I 6.7E+00 4.82063 3.OE+00 0.98813 NOL-01-01-028-F-I -2.3E-04 -0.0002 -4.1 E-03 -0.0014 NOL-01-01-029-F-I 4.1E-03 0.0029 2.2E-02 0.0073 NOL-01-01-030-F-I 1.9E-02 0.0135 2.9E-02 0.0097 NOL-01-01-031-F-I -3.2E-03 -0.0023 5.7E-03 0.0019 NOL-01-01-032-F-I 1.3E-02 0.0094 4.1E-03 0.0014 NOL-01-01-033-F-I -1.3E-03 -0.0009 2.7E-03 0.0009 NOL-01-01-034-F-I -5.2E-05 0.0000 6.7E-02 0.0223 NOL-01-01-035-F-I 1.7E-02 0.0124 1.8E-02 0.0061 NOL-01-01-036-F-I 9.3E-03 0.0066 -1.2E-02 -0.0040 NOL-01-01-037-F-I 7.6E-03 0.0054 -1.2E-02 -0.0039 NOL-01-01-038-F-I 5.8E-03 0.0041 -9.3E-03 -0.0031 NOL-01-01-039-F-I -5.2E-03 -0.0037 -7.6E-03 -0.0025 NOL-01-01-040-F-I -4.OE-03 -0.0028 -2.4E-03 -0.0008 NOL-01-01-041-F-I -3.1 E-03 -0.0022 4.6E-04 0.0002 NOL-01-01-042-F-I 4.1E-03 0.0029 2.3E-02 0.0078 NOL-01-01-043-F-I -3.OE-03 -0.0022 1.4E-02 0.0047 NOL-01-01-044-F-I 1.2E-03 0.0008 5.4E-03 0.0018 NOL-01-01-045-F-I -5.7E-04 -0.0004 2.3E-02 0.0076 NOL-01-01-046-F-I 1.4E-02 0.0099 2.6E-02 0.0085 NOL-01-01-047-F-I 2.9E-01 0.2102 5.7E-01 0.1911 NOL-01-01-048-F-I 1.2E+00 0.8877 1.1 E+00 0.3549 NOL-01-01-049-F-I 3.6E-02 0.0256 1.2E-01 0.0407 NOL-01-01-050-F-I 1.7E+00 1.2026 1.9E+00 0.6346

'DCGL fraction, Unity Rule DCGL of"l" applied 2 > DCGLw but < DCGLEMC 3 Location remediated (047, 048 and 049 are the post-remedial samples) 5.1.8 Data Quality Assessment The Data Quality Assessment phase is the part of the FSS where survey design and data are reviewed for completeness and consistency, ensuring the 21

Report No.: YNPS-FSS-NOLOI-00 validity of the results, verifying that the survey plan objectives were met, and validating the classification of the survey unit.

The sample design and the data acquired were reviewed and found to be in accordance with applicable YNPS procedures DP-8861, "DataQuality Assessment"; DP-8856, "Preparationof Survey Plans";DP-8853, "Determinationof the Number and Locations of FSS Samples and Measurements"; DP-8857, "Statistical Tests"; DP-8865, "Computer Determinationof the Number of FSS Samples and Measurements"; and the QAPP.

A preliminary data review was performed and statistical quantities were calculated. The average concentrations and standard deviations of Co-60 and Cs- 137 from Table 9 are smaller than the respective characterization data from Table 2. The retrospective power curve maintained sufficient power to pass the survey unit. The data range data for both the Cs-137 and Co-60 are within three standard deviations of the mean average value. Frequency plots for both Co-60 and Cs-137 show that the data is skewed slightly negative.

The scatter plots generated for survey unit NOL-01-01 graphically illustrate that the data for Co-60 and Cs-137 shows a normal variance about their respective mean. The data posting plots for both radionuclides do not clearly reveal any systematic spatial trends. Review of the quantile plots for NOL-01-01 indicates some asymmetry in the lower quartiles.

Review of the data in Table 9 illustrates that one of the C-14 sample data points is above the DCGLw, therefore requiring a statistical test (sign test) of the data.

Copies of the power curves, quantile plots, scatter plots and posting plots are found in Attachment B.

The actual level of residual activity was lower than the estimated level (i.e.,

values derived from characterization data) used for the survey design. The survey demonstrated sufficient power to indicate that the survey unit null hypothesis should be rejected.

5.2. Survey Unit NOL-01-02 5.2.1 Final Status Survey Plan and Associated DQOs The FSS for NOL-01-02 (YNPS-FSSP-NOLO1-02-03) was planned and developed in accordance with the LTP using the DQO process. Form DPF-8856.1, found in YNPS Procedure 8856, "Preparation of Survey Plans," was used to provide guidance and consistency during development of the FSS Plan and can be found in Appendix B. The DQO process allows for systematic planning and is specifically designed to address problems that 22

Report No.: YNPS-FSS-NOLO 1-00 require a decision to be made in a complex survey design and in turn provides alternative actions. The DQO process was used to develop an integrated survey plan providing the survey unit identification, sample size, selected analytical techniques, survey instrumentation, and scan coverage.

The Sign Test was specified for non-parametric statistical testing for this survey unit, if required. The design parameters developed are presented in the Table 11.

Table 11 Survey Unit NOL-01-02 Design Parameters

~SuI-eNUnit I~Designi Rarameter1 Basis Area 469 m 2 Class 1, <2,000 m 2 Number of Direct 15 Based on a LBGR of 0.5 Measurements (unity rule), sigma' of 0.12 and an adjusted relative shift of 2 c=13= 0.05 Sample Area 31.3 m 2 469 m 2 / 15 = 31.3 m 2 Sample Grid Spacing 6m (469/(0.866* 15)) 1/2 with a triangular pitch Scan Grid Area ISOCS scans at 2 meters 2.6 m on center Scan area 469 m 2 Class 1 Area- 100%

Scan Investigation Level 0.87 pCi/g Co60 Surrogated to Ni63 , Sr 90 4.00 pCi/g Cs' 37 and H3 (based on the 10 1.3 pCi/g Ag 1Sm mrem/yr criteria)*

60 37 Initially Co , Cs' and Aglosm Investigation levels were surrogated to account for HTD radionuclides (i.e. Ni 63 , Sr 9° and H3) expected to be present in the survey unit. Subsequent off-site analysis of samples; however, has indicated that these HTD nuclides are not present in detectable levels.

5.2.2 Deviations from the FSS Plan as Written in the LTP The null hypothesis (Ho) is stated and tested in the negative form: "Residual licensed radioactive materials in Survey Unit NOL-01-02 exceeds the release criterion." This null hypothesis is designed to protect the health of the public as well as to demonstrate compliance with the requirements set forth in the Yankee Rowe LTP. The tolerable limits established for this survey plan set the probability of Type I errors (a) at 0.05 and the 23

Report No.: YNPS-FSS-NOLOI-00 probability of Type II errors (03) at 0.05. Investigation levels for the fixed measurements were set at >DCGLw and greater than 3 times the standard deviation from the mean or >DCGLEMC. The desired MDC for fixed measurements was set at 10% of the DCGLw for each applicable radionuclide; however, if it was impracticable to achieve those values, the MDCs were permissible to be as high as 50% of the DCGLw. All MDCs for the surveys of NOL-01-02 were met in accordance with YNPS LTP. DCGL values and the associated MDC values can be found in Table 12.

Table 12 DCGLs and MDCs for Survey Area NOL-01-02 for All LTP Radionuclides Nuld DCGL,7 (p(-ilg4) 'Required ,

.MDC (50*0/o of the /

DCGLw) pCi/g H-3 1.3E+02 6.4E+01 C-14 1.9E+00 9.7E-01 Fe-55 L.OE+04 5.lE+03 2Co-60 1.4E+00 7.OE-01 Ni-63 2.8E+02 1.4E+02 2

Sr-90 6.OE-01 3.OE-01 Nb-94 2.5E+00 1.3E+00 Tc-99 5.OE+00 2.5E+00 2

Ag-108m, 2.5E+00 1.3E+00 2Sb-125 L.lE+01 5.6E+00 2

Cs-134 1.7E+00 8.7E-01 2

Cs-137 3.OE+00 1.5E+00 2

Eu-152 3.6E+00 1.8E+00 2

Eu-154 3.3E+00 1.7E+00 2

Eu-155 1.4E+02 6.9E+01 Pu-238 1.2E+01 5.8E+00 Pu-239, 240 L.lE+01 5.3E+00 Pu-241 3.4E+02 1.7E+02 Am-241 1.OE+01 5.1E+00 Cm-243, 244 L.1E+01 5.6E+00 Based on 8.73 mrem/yr (TEDE)

Gamma emitting nuclides (or ETD radionuclides)

The FSSP design was performed to the criteria of the LTP; therefore, no subsequent LTP deviations with potential impact to this survey unit need to be evaluated.

24

Report No.: YNPS-FSS-NOL01-00 5.2.3 DCGL Selection and Use The LTP DCGLs for soil were calculated using the resident farmer scenario.

For the resident farmer scenario, the average member of the critical group is the resident farmer who lives on the site, grows all of his/her diet onsite and drinks water from a groundwater source onsite. The residual radioactive material was assumed to be in the top 2.89 m soil layer, available for use in residential and light farming activities. The LTP DCGLs were performed using RESRAD Version 6.21 analyses and based upon a resulting dose of 25 mrem/yr.

The DCGLs in NOL-01-02 Survey Plan were derived by scaling the LTP DCGLs to 8.73 mrem!yr. The 8.73 mrem/yr value was necessitated by the DPH site release criteria of 10 mrem/yr subtracting the maximum dose contribution for subsurface partial structures (0.5 mrem/yr) and the maximum dose contribution from groundwater (0.77 mrem/yr). The resulting scaled DCGL values and associated MDCs are in Table 12.

5.2.4 Measurements The sample design required that 15 surface soil samples be used for the Sign Test based on the probability of error tolerance (a and P3), LBGR and relative shift value found in Table 11. Two of the samples were split and analyzed for LTP HTD radionuclides in addition to the ETD radionuclides.

Two samples were designated as "recount" samples, thus satisfying the QC requirements of the QAPP. Based upon sample analysis results from NOL-01-03, the survey unit adjacent to NOL-01-02, containing small amounts of HTD nuclides, all of the samples from NOL-01-02 and NOL 03 were analyzed for HTD radionuclides.

The fixed-point sampling grid was developed as a systematic grid with spacing consisting of a triangular pitch pattern with a random starting point.

With the aid of a GPS and AutoCAD-generated survey unit map, the systematic random start grid was developed utilizing Visual Sample Plan software. Sample measurement locations are provided with the GPS coordinates in Table 13.

25

Report No.: YNPS-FSS-NOL0 1-00 Table 13 Sample Measurement Locations with GPS Coordinates Designation 2 4Northing 3Eas0ing NOL-01-02-001-F 272451.2417 3093602.861 NOL-01-02-002-F 272467.2394 3093602.861 NOL-01-02-003-F 272443.2429 3093589.006 NOL-01-02-004-F 272459.2406 3093589.006 NOL-01-02-005-F 272475.2382 3093589.006 NOL-01-02-006-F 272491.2359 3093589.006 NOL-01-02-007-F 272435.2441 3093575.152 NOL-01-02-008-F 272451.2417 3093575.152 NOL-01-02-009-F 272467.2394 3093575.152 NOL-01-02-010-F 272483.237 3093575.152 NOL-01-02-011-F 272499.2347 3093575.152 NOL-01-02-012-F 272411.2476 3093561.298 NOL-01-02-013-F 272427.2453 3093561.298 NOL-01-02-014-F 272443.2429 3093561.298 NOL-01-02-015-F 272459.2406 3093561.298 A total of 65 ISOCS scans were performed in NOL-01-02 providing 100%

coverage of the survey unit. The ISOCS scan grid used a 2.6-m point-to-point grid with no perimeter points farther than 1.3 m from the survey unit boundary. The ISOCS scan grid did not require a random start. ISOCS scans were performed at a height of 2 m from the surface positioned perpendicular to the scan point using a 90-degree collimator. The adjusted investigation levels, referenced in Table 3, (surrogated for HTD radionuclides) for the ISOCS were derived by multiplying the DCGLEMC (DCGLw

• AF for a 1 M2 elevated area) by the ratio of MDCs obtained from the 12.6 m2 field of view relative to the MDC obtained for a 1 m 2 area at the edge of the 12.6 m 2 field of view, as this leads to a conservative model. The values developed for the 1 m2 elevated area at the edge of the field of view used for the ISOCS scan investigative levels are sensitive enough to detect the elevated comparison values for the 31.3 m 2 area (from Table 11). MDC values for the Portable ISOCS scans were set at the DCGLEMC for the individual radionuclides. The technical basis for the use of the ISOCS is documented in Technical Report YA-REPT-00-018-05, "Use ofIn-situ Gamma Spectrum Analysis to Perform Elevated Measurement Comparison in Support of FinalStatus Surveys" (Appendix C).

26

Report No.: YNPS-FSS-NOLOI-O0 5.2.5 Survey Implementation Activities Table 14 provides a summary of daily activities performed during the Final Status Survey of NOL-01-02.

Table 14 FSS Activity Summary for Survey Unit NOL-01-02 Date A'cti-,ity July 30, 2005 Performed walk-down of NOL-0 1-02 Established Isolation and Controls August 1, 2005 Started gridding of Survey Unit. Commenced ISOCS scans August 2, 2005 Continued ISOCS scans. Layout of fixed-point grid (GPS).

Collected soil samples August 3, 2005 Completed ISOCS scans August 6, 2005 Initiated investigations in elevated scan survey points 004,006, 010,011,012 and 017. Found a small piece of concrete in 004, 006, 010,011, and 012. Removed concrete and drew soil samples and rescanned. Sampled and performed scans in elevated scan area 017.

August 8, 2005 Rescan elevated scan area 017. Drew soil samples to determine boundary of elevated scan area 017.

August 9, 2005 Continued rescans of elevated scan area 017 August 10, 2005 Drew soil samples to determine bounds of elevated scan area 017 August 11, 2005 Expanded boundary of elevated area 017. Drew soil samples for boundary identification August 12, 2005 Boundary for elevated scan area 017 established. Drew four random selected soil samples for average activity in the elevated area.

August 15, 2005 Performed Scans and soil sampling in Unit due to heavy rains to assess possible impact August 17, 2005 Performed Resurvey in Unit due to heavy rains possible impact August 23, 2005 FSS Completed 27

Report No.: YNPS-FSS-NOL0 1-00 Remedial actions implemented during the FSS include the removal of the piece of concrete in scan areas 004, 006, 010, 011 and 012. The removal of the concrete eliminated the source of the elevated scan readings as confirmed by the subsequent soil sampling and ISOCS scans.

While surveying NOL-01-02 and NOL-01-03, ORISE communicated that a number of elevated measurements were detected during their confirmatory surveying and requested sample preparation and onsite analysis support.

Yankee provided this support and, thus, acquired firsthand knowledge and documentation of the ORISE sample results. ORISE reported that, with the exception of a rock that exhibited elevated gamma radiation believed to be attributable to naturally occurring radioactive materials, each case of elevated activity was due to discrete particles within the soil sample. Each area of the ORISE-detected elevated measurements was investigated applying the LTP, FSS procedures and FSS Plan criteria as applicable to Yankee-detected elevated measurements. This included the locations that did not contain sufficient radioactivity to warrant an elevated measurement comparison evaluation. In all but one location, the initial investigation samples indicated that DCGLw was met ( see section 5.3.5).

5.2.6 Surveillance Surveys 5.2.6.1 Periodic Surveillance Surveys Survey Unit NOL-01-02 is subject to periodic surveillance surveys in accordance with YNPS procedure DP-8860, "Area Surveillance Following Final Status Survey." These surveys provide assurance that areas with successful FSS remain unchanged until license termination.

5.2.6.2 Resurveys A heavy rain event, after the FSS of NOL-01-02 and prior to backfill, necessitated a resurvey of the survey unit to assess the potential impact to the FSS. An area surveillance plan (ASP) was developed (YNPS-ASP-NOLO1-02-01) to include biased soil samples and judgmental ISOCS scans. The samples and scans concentrated in the locations in which the FSS was most likely to have been impacted by the rain event. The ASP acceptance criterion was that no single survey point exceeds two standard deviations from the mean of the FSS for the survey unit. Data assessment of the resurvey concluded that no single data point exceeded the acceptance criteria; therefore, no investigation survey was warranted.

28

Rcport No.: YNPS-FSS-NOLOI-00 5.2.6.3 Investigations No investigation survey was warranted.

5.2.7 Survey Results The onsite laboratory analyzed the 15 fixed-point soil samples collected from NOL-01-02. All samples were analyzed by gamma spectroscopy with sensitivity sufficient to achieve the MDCs in Table 12 for gamma-emitting nuclides. No samples greater than the DCGLw for the radionuclides present were identified, and the sum-of-fractions were all less than 1 (unity rule).

Therefore no statistical test was necessary. Table 15 includes the gamma spectroscopy results for the only radionuclides positively identified during onsite analysis.

Three biased samples were taken. NOL-01-02-016-F-B soil sample was taken in a temporary well used to pump water out of the SFP excavation.

This sample was counted onsite using the gamma spectroscopy system. The other 2 biased samples were taken in the approximate location of a known groundwater tritium plume. These samples were shipped, without drying, to General Engineering Laboratories in Charleston, SC, for analysis of both ETD and HTD radionuclides. The results of these biased samples are included in Table 15.

29

Report No.: YNPS-FSS-NOLOI-00 Table 15 Summary of Sample Results for Survey Unit NOL-01-02

. . Y*CO .6T Cs 1-i17 Ag1AR108 C.14 *P12 3 9/ 24 0 9. .... Sr 9 ' *A

.sample Number: " Cpi/"g Ci/g pCLg_ pCi/g " .pCi.g PO

.. g...

' P' "*Cigf g

FSS-NOL-01-02-001-F 0.04 0.369 0.15 FSS-NOL-01-02-002-F 0.043 0.306 0.05** 0.14 FSS-NOL-01-02-003-F 0.277 0.368 0.32 FSS-NOL-01-02-004-F -0.0002 0.033 0.01 FSS-NOL-01-02-005-F -0.001 0.136 0.04 FSS-NOL-01-02-006-F 0.008 0.126 0.05 FSS-NOL-01-02-007-F 0.164 0.401 0.25 FSS-NOL-01-02-008-F 0.251 0.564 0.04** 0.37 FSS-NOL-01-02-009-F 0.098 1.934 0.71 FSS-NOL-01-02-010-F -0.0002 0.015 0.00 0.007 0.035 0.02

,FSS-NOL-01-02-011-F 0.02

- FSS-NOL-01-02-01 1-F + 0.007 0.035 4 4 4 4 4 4. 4.

'F SS-NOL-01-02-012-F 0.122 0.342 0.20 FSS-NOL-01-02-013-F 0.362 0.556 0.44 FSS-NOL-01-02-014-F 0.142 0.127 0.201 0.22 FSS-NOL-01-02-015-F 0.008 0.225 0.08 FSS-NOL-01-02-016-F- 0.374 0.555 0.45 B

FSS-NOL-01-02-017-F- 0.000 0.064 0.132** 0.243** 0.109** 0.15 B

FSS-NOL-01-02-018-F- 0.201 0.395 0.187** 0.016** 0.34 B

0.434 Stdev 0.127 0 '434 Mean 0.118 0.364

• DCGL fraction, Unity Rule applied

• • Identified below the MDC value Sixty-five ISOCS scans were performed and the results compared to the respective Action Levels. A summary of the ISOCS scans is provided in Table 16.

30

Report No.: YNPS-FSS-NOLOI-O0 Table 16 Summary of ISOCS Scan Results for Survey Unit NOL-01-02 Sample

-01I0L,-G Title f S .ample Title f (DCG EMCl)

NOL-01-02-001-F-G 0.73 NOL-0 1-02-034-F-G 0.05 NOL-01-02-002-F-G 0.44 NOL-01-02-035-F-G 0.44 NOL-Ol 003-F-G 0.72 NOL-01-02-036-F-G 0.06 0.54*

NOL-01-02-064-F-G-I NOL-01-02-037-F-G 0.09 NOL-01-02-005-F-G 0.95 NOL-01-02-038-F:G 0.13 NOL-01-02-065-F-G-I 0.52* NOL-01-02-039-F-G 0.66 NOL-01-02-007-F-G 0.79 NOL-01-02-040-F-G 0.45"**

NOL-01-02-008-F-G 0.59 NOL-01-02-041-F-G 0.07**

NOL-0 1-02-009-F-G 0.74 NOL-01-02-042-F-G 0.81 NOL-01-02-066-F-G-I 0.57* NOL-01-02-043-F-G 0.80 NOL-01-02-067-F-G-I 0.63* NOL-01-02-044-F-G 0.48 NOL-01-02-068-F-G-I 0.38 NOL-01-02-045-F-G 0.06 NOL-01-02-014-F-G 0.31 NOL-01-02-046-F-G 0.04 NOL-01-02-015-F-G 0.09 NOL-01-02-047-F-G 0.05 NOL-01-02-016-F-G 0.04 NOL-01-02-048-F-G 0.06 NOL-01-02-017-F-G See Table 17 NOL-0 1-02-049-F-G 0.06 NOL-01-02-018-F-G 0.81 NOL-01-02-050-F-G 0.10 NOL-01-02-019-F-G 0.00 NOL-01-02-051-F-G 0.23 NOL-01-02-020-F-G 0.60 NOL-01-02-052-F-G 0.25 NOL-01-02-021-F-G 0.61 NOL-01-02-053-F-G 0.38 NOL-01-02-022-F-G 0.55 NOL-01-02-054-F-G 0.15 NOL-01-02-023-F-G 0.30 NOL-01-02-055-F-G 0.27 NOL-01-02-024-F-G 0.89 NOL-01-02-056-F-G 0.05 NOL-01-02-025-F-G 0.54 NOL-01-02-057-F-G 0.15 NOL-01-02-026-F-G 0.53 NOL-01-02-058-F-G 0.64 NOL-01-02-027-F-G 0.06 NOL-01-02-059-F-G 0.57 NOL-01-02-028-F-G 0.24 NOL-0 1-02-060-F-G 0.04 NOL-01-02-029-F-G 0.56 NOL-0 1-02-061 -F-G 0.30 NOL-01-02-030-F-G 0.29 NOL-0 1-02-062-F-G 0.06 NOL-01-02-031-F-G 0.59 NOL-01-02-063-F-G 0.43 NOL-01-02-032-F-G 0.65 NOL-0 1-02-064-F-G 0.54 NOL-01-02-033-F-G 0.00 NOL-01-02-065-F-G 0.52

• Investigations performed at these scan areas (004, 006, 010, 011, 012). Post remedial scan resulted in f(DCGLEMC) < 1 as shown with the "as left" scan results.

A 20% correction was applied to these ISOCS results to account for increased density due to moisture content in the soil.

Copies of the ISOCS reports are found in Attachment A.

An investigation was performed at scan location 017. Through the use of ISOCS scans and perimeter soil samples (gamma-specific boundary soil 31

Report No.: YNPS-FSS-NOL0I -00 samples identified in Table 17), the boundaries of the elevated area were established at 2-m by 2.3-m. Four randomly selected soil sample locations were chosen by multiplying the length and the width of the area by random numbers taken from Table 1.6 of MARSSIM. The results of the analysis of the random samples were then averaged to give the average elevated concentration within the elevated area and a fractional DCGLEMC was performed for the survey unit. The following calculation and table demonstrate the elevated measurement comparison.

Average elevated area concentration (C-eevoed): 0.25 pCi/g Co60 ; 0.84 pCi/g C 1 37 DCGLw: 1.4 pCi/g Co 60 ; 3.0 pCi/g Cs 2

Area factor for 6m : CO60= 3.2; CS137 = 6.6 37 Mean of NOL-01-02 (f): 0.10 pCi/g Co6; 0.369 pCi/g CS1 Note: The non-elevated area Mean is identical to the Mean of the Survey Unit.

,5 Celevated -- t5

<1 DCGLW (AreaFactor)x DCGLW 0.10 0.25-0.10 0 0 .369 0.84-.369

+____ 0.10 CO6 3.0 + (6.6)xx3.0 - 0.15 Cs 137 1.4 (3.2)xl.4 Table 17 Summary of Investigation Point #017 in Survey Unit NOL-01-02

,,S4mpjeNumber CO~ p"iI? Cs3 Ci/g ý KAjW iig <f-DCL.

NOL-01-02-017-F-G 1.13 NOL-01-02-032-F-I' 0.439 1.382 ND 3 0.774 NOL-01-02-033-F-I 0.573 1.614 ND3 0.947 NOL-01-02-034-F-I1 0.053 0.366 ND 3 0.16 NOL-01-02-035-F-11 0.082 0.266 ND3 0.15 NOL-01-02-036-F-I' 0.001 0.23 ND 3 0.08 NOL-01-02-038-F-I' 0.662 1.328 ND 3 0.92 NOL-01-02-039-F-1 1 0.548 1.034 ND3 0.74 NOL-01-02-050-F-I1 0.624 0.493 ND 3 0.61 NOL-01-02-045-F-I 0.005 0.04 ND3 N/A 4 NOL-01-02-046-F-I 0.523 0.993 ND3 N/A 4 NOL-01-02-047-F-I 0.442 2.294 ND 3 N/A 4 NOL-01-02-048-F-I 0.045 0.044 ND 3 N/A 4 Soil samples determining the boundaries of the elevated area (2 meters by 2.3 meters) 2 DCGL fraction, Unity Rule DCGL of"I" applied 3

Radionuclide Not Detected 4

f-DCGL data Not Applicable (N/A) for the average concentration determination 5.2.8 Data Quality Assessment 32

Report No.: YNPS-FSS-NOLOI-00 The Data Quality Assessment phase is the part of the FSS where survey design and data are reviewed for completeness and consistency, ensuring the validity of the results, verifying that the survey plan objectives were met, and validating the classification of the survey unit.

The sample design and the data acquired were reviewed and found to be in accordance with applicable YNPS procedures DP-8861, "Data Quality Assessment"; DP-8856, "Preparationof Survey Plans"; DP-8853, "Determinationof the Number and Locations of FSS Samples and Measurements"; DP-8857, "Statistical Tests"; DP-8865, "Computer Determinationof the Number of FSS Samples and Measurements"; and the QAPP.

A preliminary data review was performed and statistical quantities were calculated. The average concentrations and standard deviations of Co-60 and Cs-137 from Table 15 are larger than the respective characterization data from Table 11. However, the retrospective power curve maintained sufficient power to pass the survey unit. The concentration data for Cs-137 indicated that one sample (FSS-NOL-01-02-009-F) was statistically higher than the remaining samples. However, this value (1.9 pCi/g) was less than the DCGLw (3 pCi/g). This data point skewed the average Cs-137 concentration value high. Without this value, the range of data would have been slightly over one standard deviation. The data range for Co-60 was approximately three standard deviations. Frequency plots for both Co-60 and Cs-137 show that the data is skewed negative with the Co-60 being skewed more so than the Cs-137. The scatter plots generated for NOL-01-02 graphically illustrate that the data for Co-60 and Cs-137 vary about their respective mean, with the exception of the higher Cs-137 sample result discussed above. The data posting plots for both radionuclides do not clearly reveal any systematic spatial trends. Review of the quantile plots for NOL-0 1-02 indicates some asymmetry about the mean and illustrates the elevated Cs-137 result. There were no especially unusual features in the quantile plot for Co-60.

Review of the data in Table 15 illustrates that all of the sample data for the soil concentrations of all plant-related LTP nuclides are below the DCGLw and the sum-of-fractions for these nuclides are less than unity. Therefore no statistical test is required.

Copies of the power curves, quantile plots, scatter plots and posting plots are found in Attachment B.

The actual level of residual activity was higher than the estimated level (i.e.,

values derived from characterization data) used for the survey design; however, the survey demonstrated sufficient power to indicate that the survey 33

Report No.: YNPS-FSS-NOLO1-00 unit null hypothesis should be rejected. One elevated area existed in survey unit NOL-0 1-02 and upon assessment, it was determined that f(DCGLEMC) for the survey unit was less than unity. The area investigated where a small piece of concrete existed was successfully remediated by removing the piece of concrete and the area was resurveyed. No other remedial actions were required in NOL-01-02.

5.3. Survey Unit NOL-01-03 5.3.1 Status Survey Plan and Associated DQOs The FSS for NOL-01-02 (YNPS-FSSP-NOL01-02-03) was planned and developed in accordance with the LTP using the DQO process. Form DPF-8856.1, found in YNPS Procedure 8856, "Preparation of Survey Plans," was used to provide guidance and consistency during development of the FSS Plan and can be found in Appendix B. The DQO process allows for systematic planning and is specifically designed to address problems that require a decision to be made in a complex survey design and in turn provides alternative actions. The DQO process was used to develop an integrated survey plan providing the survey unit identification, sample size, selected analytical techniques, survey instrumentation, and scan coverage.

The Sign Test was specified for non-parametric statistical testing for this survey unit, if required. The design parameters developed are presented in the Table 18.

Table 18 Survey Unit NOL-01-03 Design Parameters Su rNeN, Umtin -, Design Parameter B..sis Area 655 m2 Class 1, <2,000 m 2 Number of Direct 15 Based on a LBGR of 0.5 Measurements (unity rule), sigma' of 0.12 and an adjusted relative shift of 2 a=13= 0.05 Sample Area 43.7 m2 655 m2 / 15 = 43.7 m2 Sample Grid Spacing 7.1 m (655/0.866* 15) '

with a triangular pitch Scan Grid Area ISOCS scans at 2 meters 2.6 m on center Scan area 469 m2 Class 1 Area- 100%

34

Report No.: YNPS-FSS-NOLO 1-00 5.3.2 Deviations from the FSS Plan as Written in the LTP The null hypothesis (Ho) is stated and tested in the negative form: "Residual licensed radioactive materials in Survey Unit NOL-01-02 exceeds the release criterion." This null hypothesis is designed to protect the health of the public as well as to demonstrate compliance with the requirements set forth in the Yankee Rowe LTP. The tolerable limits established for this survey plan set the probability of Type I errors (a) at 0.05 and the probability of Type II errors (P3)at 0.05. Investigation levels for the fixed measurements were set at >DCGLw and greater than 3 times the standard deviation and at >DCGLEMC. The desired MDC for fixed measurements was set at 10% of the DCGLw for each applicable radionuclide; however, if it was impracticable to achieve those values, the MDCs were permissible to be as high as 50% of the DCGLw. All MDCs for the surveys of NOL-01-02 were met in accordance with YNPS LTP. DCGL values and the associated MDC values can be found in Table 19.

Table 19 DCGLs and MDCs for Survey Area NOL-01-03 for All LTP Radionuclides H-3 1.3E+02 6.4E+01 C-14 1.9E+00 9.7E-01 Fe-55 2Co-60 1.OE+04 5. 1E+03 1.4E+00 7.OE-01 Ni-63 2.8E+02 1.4E+02 Sr-90 6.OE-01 3.OE-01 2

Nb-94 2.5E+00 1.3E+00 Tc-99 5.OE+00 2.5E+00 2Ag-108m 2.5E+00 1.3E+00 2Sb-125 1.LE+01 5.6E+00 2Cs-134 1.7E+00 8.7E-01 2Cs 137 3.OE+00 1.5E+00 2Eu-152 3.6E+00 1.8E+00 35

Report No.: YNPS-FSS-NOLOI-00 NulieDCGLNN r~uc~ue4MDC (pCig RqrdK (50%' of the DCGLwN))Cpiýg 2

Eu-154 3.3E+00 1.7E+00 2Eu-155 1.4E+02 6.9E+01 Pu-238 1.2E+01 5.8E+00 Pu-239, 240 1.1E+01 5.3E+00 Pu-241 3.4E+02 1.7E+02 Am-241 1.OE+01 5.1E+00 Cm-243, 244 1.1E+01 5.6E+00 1Based on 8.73 mrem/yr (TEDE) 2 Gamma emitting nuclides (or ETD radionuclides)

The FSSP design was performed to the criteria of the LTP; therefore, no subsequent LTP deviations with potential impact to this survey unit need to be evaluated.

5.3.3 DCGL Selection and Use The LTP DCGLs for soil were calculated using the resident farmer scenario.

For the resident farmer scenario, the average member of the critical group is the resident farmer who lives on the site, grows all of his/her diet onsite and drinks water from a groundwater source onsite. The residual radioactive material was assumed to be in the top 2.89 m soil layer, available for use in residential and light farming activities. The LTP DCGLs were performed using RESRAD Version 6.21 analyses and based upon a resulting dose of 25 mrem/yr.

The DCGLs in NOL-01-03 Survey Plan were derived by scaling the LTP DCGLs to 8.73 mrem/yr. The 8.73 mrem/yr value was necessitated by the DPH site release criteria of 10 mrem/yr subtracting the maximum dose contribution for subsurface partial structures (0.5 mrem/yr) and the maximum dose contribution from groundwater (0.77 mrem/yr). The resulting scaled DCGL values and associated MDCs are in Table 19.

5.3.4 Measurements The sample design required that 15 surface soil samples be used for the Sign Test based on the probability of error tolerance (c and PB), LBGR and relative shift value found in Table 18. Two of the samples were split and analyzed for LTP HTD radionuclides in addition to the ETD radionuclides.

Two samples were designated as "recount" samples, thus satisfying the QC requirements of the QAPP. Based upon sample analysis results from NOL-0 1-03 containing small amounts of HTD nuclides, all of the samples from NOL-01-02 and NOL-01-03 were analyzed for HTD radionuclides.

36

Report No.: YNPS-FSS-NOLOI -00 The fixed-point sampling grid was developed as a systematic grid with spacing consisting of a triangular pitch pattern with a random starting point.

With the aid of a GPS and AutoCAD-generated survey unit map, the systematic random start grid was developed utilizing Visual Sample Plan.

Sample measurement locations are provided with the GPS coordinates in Table 20.

Table 20 Sample Measurement Locations with GPS Coordinates Designation N272Northing 429.E8.ting NOL-01-03-001-F 272429.8162 3093548.4972 NOL-01-03-002-F 272446.5794 3093548.4972 NOL-01-03-003-F 272463.3425 3093548.4972 NOL-01-03-004-F 272480.1057 3093548.4972 NOL-01-03-005-F 272421.4346 3093533.9799 NOL-01-03-006-F 272438.1978 3093533.9799 NOL-01-03-007-F 272454.9610 3093533.9799 NOL-01-03-008-F 272471.7241 3093533.9799 NOL-01-03-009-F 272488.4873 3093533.9799 NOL-01-03-010-F 272429.8162 3093519.4625 NOL-01-03-011-F 272446.5794 3093519.4625 NOL-01-03-012-F 272463.3425 3093519.4625 NOL-01-03-013-F 272480.1057 3093519.4625 NOL-01-03-014-F 272438.1978 3093504.9452 NOL-01-03-015-F 272454.9610 3093504.9452 A total of 68 ISOCS scans were performed in NOL-01-03 providing 100%

coverage of the survey unit. The ISOCS scan grid used a 2.6-m point-to-point grid with no perimeter points farther than 1.3 m from the survey unit boundary. The ISOCS scan grid did not require a random start. ISOCS scans were performed at a height of 2 m from the surface positioned perpendicular to the scan point using a 90-degree collimator. The adjusted investigation levels, referenced in Table 18, (surrogated for HTD radionuclides) for the ISOCS were derived by multiplying the DCGLEMC (DCGLw

• AF for a 1 m2 elevated area) by the ratio of MDCs obtained from the 12.6 M 2 field of view relative to the MDC obtained for a 1 in 2 area at the edge of the 12.6 m2 field of view, as this leads to a conservative model. The values developed for the 1 m 2 elevated area at the edge of the field of view used for the ISOCS scan investigative levels are sensitive enough to detect 37

Report No.: YNPS-FSS-NOLOI-00 the elevated comparison values for the 43.7 m2 area (from Table 3). MDC values for the Portable ISOCS scans were set at the DCGLEMC for the individual radionuclides. The technical basis for the use of the ISOCS is documented in Technical Report YA-REPT-00-018-05, "Use ofln-situ Gamma Spectrum Analysis to Perform Elevated Measurement Comparison in Support of FinalStatus Surveys" (Appendix C).

5.3.5 Survey Implementation Activities Table 21 provides a summary of daily activities performed during the Final Status Survey ofNOL-01-03.

Table 21 FSS Activity Summary for Survey Unit NOL-01-03 DJate 1/4 > Activity August 17, 2005 Performed walk-down of NOL-01-02 Established Isolation and Controls August 4, 2005 Started gridding of Survey Unit. Commenced ISOCS scans.

Layout of fixed-point grid (GPS). Collected soil samples August 12, 2005 Performing investigations at NOL-01-03-12-F-G. Bounding the elevated area and determining the average concentration in the area.

August 17, 2005 Performed resurvey after rain storm August 19, 2005 Initiated investigations at scan location NOL-01-03-041-F-G.

Performed remediation at this location.

August 23, 2005 Performed post-remedial scans and sampling. FSS complete.

38

Report No.: YNPS-FSS-NOL0 1-00 While surveying NOL-01-02 and NOL-01-03, ORISE communicated that a number of elevated measurements were detected during their confirmatory surveying and they requested sample preparation and onsite analysis support. Yankee provided this support and, thus, acquired firsthand knowledge and documentation of the ORISE sample results. ORISE reported that, with the exception of a rock that exhibited elevated gamma radiation believed to be attributable to naturally occurring radioactive materials, each case of elevated activity was due to discrete particles within the soil sample. Each area of the ORISE-detected elevated measurements was investigated applying the LTP, FSS procedures and FSS Plan criteria as applicable to Yankee-detected elevated measurements. This included the locations that did not contain sufficient radioactivity to warrant an elevated measurement comparison evaluation. In all but one location, the initial investigation samples indicated that DCGLW was met. One sample NOL-01-03-036 indicated that, while radioactivity levels could have passed the elevated measurement comparison to 10CFR20.1402 criteria, further remediation was necessary to meet the lower DCGLs established by the Massachusetts criteria.

Remedial actions included the removal of soils around scan location NOL-01 041-F-G corresponding to sample location NOL-01-03-036. The removal of the soils eliminated the source of the elevated scan readings as confirmed by the subsequent soil sampling and ISOCS scans. This remediation was accomplished per Section 5.5.3.3 of the LTP. ORISE sampling results and corresponding YNPS results for NOL-01-03 are provided in Table 22.

Table 22 Samples in Response to ORISE Sampling_

ORISE Sample Number Date Co-60 (pCi!

Cs-137 (pCi/g) SOF

[ .........

NPS SampleNumber (j:i o6 Date ____(__i/g)_

/.......____

Cs-137

(_ _ Spg 1672S0001 8/10/05 8.75 1.84 6.86 NOL-01-03-049-F-1 8/24/05 0.18 0.53 0.31 1672S0002 8/10/05 0.01 347 115.67 NOL-01-03-035-F-I 8/17/05 0.00 0.27 0.09 1672S0003 8/10/05 14.02 0.54 10.19 NOL-01-03-036-F-I 8/16/05 4.47 0.91 3.502 In response to ORISE sampling Yankee pulled samples at the ORISE sample locations.

2 Yankee sample NOL-01-03-036 indicated a DCGL sum-of-fractions in excess of unity. Subsequent sampling determined that additional remediation was required in that location. Post-remedial sampling results indicated that the source of the elevated readings was removed and are summarized in Table 23, below.

39

Report No.: YNPS-FSS-NOLOI-00 Table 23 Post-Remediation Sampling of Location NOL-01-03-036-F-I Co-60 Cs-137 YNPS Sample Number Date [ (pCi/g) (pCi/g) SOF NOL-01-03-054-F-I 8/23/05 -0.008 0.021 0.00 NOL-01-03-055-F-I 8/24/05 0.006 0.001 0.00 NOL-01-03-056-F-I 8/23/05 0.378 0.685 0.50 NOL-01-03-057-F-I 8/23/05 -0.0001 -0.0005 0.00 NOL-01-03-058-F-I 8/23/05 0.139 0.426 0.24 5.3.6 Surveillance Surveys 5.3.6.1 Periodic Surveillance Surveys Survey Unit NOL-01-03 is subject to periodic surveillance surveys in accordance with YNPS procedure DP-8860, "Area Surveillance Following Final Status Survey." These surveys provide assurance that areas with successful FSS remain unchanged until license termination.

5.3.6.2 Resurveys A heavy rain event, after the FSS of NOL-01-03 and prior to backfill, necessitated a resurvey of the survey unit to assess the potential impact to the FSS. An area surveillance plan (ASP) was developed (YNPS-ASP-NOLOl-03-01) to include biased soil samples and judgmental ISOCS scans. The samples and scans concentrated in the locations in which the FSS was most likely to have been impacted by the rain event. The ASP acceptance criterion was that no single survey point exceeds two standard deviations from the mean of the FSS for the survey unit. Data assessment of the resurvey concluded that no single data point exceeded the acceptance criteria; therefore, no investigation survey was warranted.

40

Report No.: YNPS-FSS-NOLOI -00 5.3.6.3 Investigations No investigation survey was warranted.

5.3.7 Survey Results The onsite laboratory analyzed the fifteen (15) fixed-point soil samples collected from NOL-01-03. All samples were analyzed by gamma spectroscopy with sensitivity sufficient to achieve the MDCs in Table 19 for gamma-emitting nuclides. No samples greater than the DCGLw for the radionuclides present were identified, and the sum-of-fractions were all less than 1 (unity rule). Therefore no statistical test was necessary. Table 24 includes the gamma spectroscopy results for the only radionuclides positively identified during onsite analysis.

Two biased samples were taken in temporary wells used to pump water out of the SFP excavation. The results of the biased samples are included in Table 24.

Table 24 Summary of Sample Results for Survey Unit NOL-01-03 c060' Cs137 01 4 P~U239/240 P21 rt

~Sample NumiberI P6ii pci/g pCilg Pci/g pCIilg 'PCi/g f,-'CGL*I FSS-NOL-01-03-001-F 0.07 0.39 0.18 FSS-NOL-01-03-002-F 0.09 0.50 0.23 FSS-NOL-01-03-003-F 0.07 0.28 0.16 FSS-NOL-01-03-004-F -0.01 0.22 0.07 FSS-NOL-01-03-005-F 0.04 0.09 0.06 FSS-NOL-01-03-006-F 0.49 1.48 0.84 FSS-NOL-01-03-007-F 0.00 0.00 0.00 FSS-NOL-01-03-008-F 0.03 1.18 0.50 FSS-NOL-01-03-009-F 0.00 0.13 0.04 FSS-NOL-01-03-010-F 0.03 0.02 0.03 FSS-NOL-01-03-011-F 0.01 0.01 0.29 0.19 21.9 0.24 FSS-NOL-01-03-012-F 0.02 -0.01 0.01 FSS-NOL-01-03-013-F 0.08 0.02 0.06 FSS-NOL-01-03-014-F 0.03 -0.01 0.47 10.3 0.04 0.37 41

Report No.: YNPS-FSS-NOLOI-00 60 37 4 2 3 91 2 4 0 24 90 Co Cs1 C0 Pu Pu ' Sr Sample Number pCi/g pCi/g PCi/g pCilg pCi/g pCi/g f-DCGL*

FSS-NOL-01-03-015-F 0.03 0.01 0.02 FSS-NOL-01-03-016-F-B 0.06 0.19 0.10 FSS-NOL-01-03-017-F-B 0.26 0.48 0.35 Stdev 0.12 0.45 Mean 0.064 0.287

• DCGL fraction, Unity Rule applied Sixty-five ISOCS scans were performed and the results compared to the respective Action Levels. A summary of the ISOCS scans is provided in Table 25.

Table 25 Summary of ISOCS Scan Results for Survey Unit NOL-01-03

• Sample Title fAJJCGL4MC)Y Saniie-Tile;

... (DCGLEMc)

NOL-01-03-001-F-G 0.05 NOL-01-03-034-F-G 0.65 NOL-01-03-002-F-G 0.04 NOL-01-03-035-F-G 0.24 NOL-01-03-003-F-G 0.06 NOL-01-03-036-F-G 0.23 NOL-01-03-004-F-G 0.21 NOL-01-03-037-F-G 0.08 NOL-01-03-005-F-G 0.15 NOL-01-03-038-F-G 0.12 NOL-01-03-006-F-G 0.06 NOL-01-03-039-F-G 0.47 NOL-01-03-007-F-G 0.30 NOL-01-03-040-F-G 0.00 NOL-01-03-008-F-G 0.60 NOL-01-03-099-R-G 0.06 NOL-01-03-009-F-G 0.95 NOL-01-03-042-F-G 0.82 NOL-01-03-010-F-G 0.50 NOL-01-03-043-F-G 0.30 NOL-01-03-011-F-G 0.91 NOL-01-03-044-F-G 0.07 NOL-01-03-013-F-G 0.57 NOL-01-03-045-F-G 0.13 NOL-01-03-014-F-G 0.57 NOL-01-03-046-F-G 0.20 NOL-01-03-015-F-G 0.74 NOL-01-03-047-F-G 0.59 NOL-01-03-016-F-G 0.52 NOL-01-03-048-F-G 0.42 NOL-01-03-017-F-G 0.04 NOL-01-03-049-F-G 0.00 NOL-01-03-018-F-G 0.31 NOL-01-03-050-F-G 0.00 NOL-01-03-019-F-G 0.64 NOL-01-03-051 -F-G 0.00 NOL-01-03-020-F-G 0.84 NOL-01-03-052-F-G 0.00 NOL-01-03-021-F-G 0.64 NOL-01-03-053-F-G 0.04 NOL-01-03-022-F-G 0.27 NOL-01-03-054-F-G 0.02 NOL-01-03-023-F-G 0.06 NOL-01-03-055-F-G 0.65 NOL-01-03-024-F-G 0.09 NOL-01-03-056-F-G 0.00 NOL-01-03-025-F-G 0.11 NOL-01-03-057-F-G 0.00 NOL-01-03-026-F-G 0.65 NOL-01-03-058-F-G 0.00 NOL-01-03-027-F-G 0.56 NOL-01-03-059-F-G 0.00 42

Report No.: YNPS-FSS-NOLOI-00

.. ;$amilleTitl* (DCGLEMc) Samle'Titll;e:'

• 5 (D*CGL'cy NOL-01-03-028-F-G 0.46 NOL-01-03-060-F-G 0.00 NOL-01-03-029-F-G 0.26 NOL-01-03-061-F-G 0.00 NOL-01-03-030-F-G 0.37 NOL-01-03-062-F-G 0.00 NOL-01-03-031-F-G 0.00 NOL-01-03-063-F-G 0.00 NOL-01-03-032-F-G 0.50 NOL-01-03-064-F-G 0.00 NOL-01-03-033-F-G 0.00 NOL-01-03-065-F-G 0.00

• • Scan result represents post-remedial (i.e. "as left") condition Copies of the ISOCS reports are found in Attachment A.

An investigation was performed at scan location NOL-01-03-012-F-G.

Through the use of ISOCS scans and perimeter soil samples (gamma-specific boundary soil samples identified in Table 26), the boundaries of the elevated area were established at 2-m by 2-m. Four randomly selected soil sample locations were chosen by multiplying the length and the width of the area by random numbers taken from Table 1.6 of MARS SIM. The results of the

'analysis of the random samples were then averaged to give the average elevated concentration within the elevated area and a fractional DCGLEMC was performed for the survey unit. The following calculation and table demonstrate the elevated measurement comparison:

Average elevated area concentration (Ce,,,ad): 4.3 pCi/g Co-60 1.79 Cs-137 DCGLw: 1.4 pCi/g 3 pCi/g Area factor for 4m 2 Co-60: 4.1 Co-60 8.5 Cs-137 Mean of NOL-01-03 (.5): 0.064 pCi/g Co-60 .287pCi/g Cs-137 Note: The non-elevated area Mean is identical to the Mean of the Survey Unit.

S +

Celevated

, .,- (

DCGLw (AreaFactor)xDCGLW 0.064 00-+ 4.3 - 0.064 0.287 1.79-0.287

= 0.78 Co-60 =0.15 Cs-137 3 + (8.5)x3 1.4 (4.1)xl.4 43

Report No.: YNPS-FSS-NOLOI-00 Table 26 Summary of Investigation Point #012 in Survey Unit NOL-01-03 Sam~ple Numb&W4Celg r~c~ 6 7 C' pig g f-DCGII-NOL-01-02-028-F-Il' 0.06 0.06 ND3 0.06 NOL-01-02-029-F-I1 0.01 0.02 ND 3 0.01 NOL-01-02-030-F-I' -0.02 0.04 ND3 0.01 NOL-01-02-032-F-I' 0.439 1.382 ND 3 0.774 NOL-01-02-033-F-I' 0.573 1.614 ND3 0.947 NOL-01-02-034-F-I' 0.053 0.366 ND 3 0.16 NOL-01-03-037-F-I 0.052 1.82 ND3 N/A 4 NOL-01-03-038-F-I 15.15 0.96 ND 3 N/A 4 NOL-01-03-039-F-I 1.862 4.12 ND3 N/A4 NOL-01-03-040-F-I 0.049 0.27 ND3 N/A 4 Soil samples determining the boundaries of the elevated area (2 meters by 2 meters) 2 DCGL fraction, Unity Rule DCGL of"I" 3 applied Radionuclide Not Detected 4

f-DCGL data Not Applicable (N/A) for the average concentration determination 5.3.8 Data Quality Assessment The Data Quality Assessment phase is the part of the FSS where survey design and data are reviewed for completeness and consistency, ensuring the validity of the results, verifying that the survey plan objectives were met, and validating the classification of the survey unit.

The sample design and the data acquired were reviewed and found to be in accordance with applicable YNPS procedures DP-8861, "Data Quality Assessment"; DP-8856, "Preparationof Survey Plans"; DP-8853, "Determinationof the Number and Locations of FSS Samples and Measurements"; DP-8857, "Statistical Tests"; DP-8865, "Computer Determinationof the Number of FSS Samples and Measurements"; and the QAPP.

A preliminary data review was performed and statistical quantities were calculated. The average concentrations and standard deviations of Co-60 and Cs-137 from Table 24 are larger than the respective characterization data from Table 18. However, the retrospective power curve maintained sufficient power to pass the survey unit. The concentration data for Co-60 indicated that one sample (NOL-01-03-006-F) was higher than the remaining samples. However, this value (0.49 pCi/g) was less than the DCGLW (1.4 pCi/g). This data point skewed the average Co-60 concentration value slightly high. Without this value, the range of data would have been within one standard deviation. The concentration data for Cs-137 indicated that two samples (NOL-01-03-006-F and NOL-01-03-008-F) were higher than the remaining samples, however, less than the DCGLw. As with Co-60, without these data points the data set would have been within one standard deviation.

44

Report No.: YNPS-FSS-NOLOI-00 Frequency plots for both Co-60 and Cs-137 show a normal data set. The scatter plots generated for NOL-01-03 graphically illustrate that the data for Co-60 and Cs-137 vary about their respective mean, with the exception of the higher Co-60 and Cs-137 sample results discussed above. The data posting plots for both radionuclides do not clearly reveal any systematic spatial trends. Review of the quantile plots for NOL-01-03 indicates some asymmetry in the lower quartiles for both of the radionuclides being more prominent with Cs-137 and illustrates the elevated Co-60 and Cs-137 results.

Review of the data in Table 24 illustrates that all of the sample data for the soil concentrations of all plant-related LTP nuclides are below the DCGLw and the sum-of-fractions for these nuclides are less than unity. Therefore no statistical test is required.

Copies of the power curves, quantile plots, scatter plots and posting plots are found in Attachment B.

The actual level of residual activity was higher than the estimated level (i.e.,

values derived from characterization data) used for the survey design; however, the survey demonstrated sufficient power to indicate that the survey unit null hypothesis should be rejected. One elevated area existed in NOL-01-03 and upon assessment, it was determined that f(DCGLEMC) for the survey unit was less than unity. One area was remediated by removing soils and subsequent scans and sampling indicated a successful remediation. No other remedial actions were required in NOL-01-03.

5.4. Survey Unit NOL-01-04 5.4.1 Status Survey Plan and Associated DQOs The FSS for NOL-01-04 (YNPS-FSSP-NOLO1-04-00) was planned and developed in accordance with the LTP using the DQO process. Form DPF-8856.1, found in YNPS Procedure 8856, "Preparation of Survey Plans," was used to provide guidance and consistency during development of the FSS Plan and can be found in Appendix B. The DQO process allows for systematic planning and is specifically designed to address problems that require a decision to be made in a complex survey design and in turn provides alternative actions. The DQO process was used to develop an integrated survey plan providing the survey unit identification, sample size, selected analytical techniques, survey instrumentation, and scan coverage.

The Sign Test was specified for non-parametric statistical testing for this survey unit, if required. The design parameters developed are presented in the Table 27.

45

Report No.: YNPS-FSS-NOL01 -00 Table 27 Survey Unit NOL-01-04 Design Parameters SirveyrUdni-t" Design Parameter Basis "

Area 881 m2 Class 1, <2,000 m2 Number of Direct 15 Based on a LBGR of 0.5 Measurements (unity rule), sigma' of 0.177 and a relative shift of 2.8 c=p=3= 0.05 Sample Area 58.7 m2 881 m2 / 15 = 31.3 m2 Sample Grid Spacing 8.2 m (881/(0.866* 15)) 1/2 with a triangular pitch Scan Grid Area ISOCS scans at 2 meters 2.6 m on center Scan area 881 m2 Class 1 Area - 100%

Scan Investigation Level 1.0 pCi/g Co 60 (based on the 8.73 4.3pCi/g Cs1 37 mrem/yr criteria) 5.4.2 Deviations from the FSS Plan as Written in the LTP The null hypothesis (Ho) is stated and tested in the negative form: "Residual licensed radioactive materials in Survey Unit NOL-01-04 exceeds the release criterion." This null hypothesis is designed to protect the health of the public as well as to demonstrate compliance with the requirements set forth in the Yankee Rowe LTP. The tolerable limits established for this survey plan set the probability of Type I errors (a) at 0.05 and the probability of Type II errors (P3)at 0.05. Investigation levels for the fixed measurements were set at>DCGLw and greater than 3 times the standard deviation or >DCGLEMC. The desired MDC for fixed measurements was set at 10% of the DCGLw for each applicable radionuclide; however, if it was impracticable to achieve those values, the MDCs were permissible to be as high as 50% of the DCGLw. All MDCs for the surveys of NOL-01-04 were met in accordance with YNPS LTP. DCGL values and the associated MDC values can be found in Table 28.

46

Report No.: YNPS-FSS-NOL0I-00 Table 28 DCGLs and MDCs for Survey Area NOL-01-04 for All LTP Radionuclides

~

Nuclide ~ ~pi/)Wuired ReGw Nuclde ~<CGLW(p~lg)MDC (50% of the DCGL,),Ocilg H-3 1.3E+02 6.4E+01 C-14 1.9E+00 9.7E-01 Fe-55 1.OE+04 5.1E+03 2Co-60 1.4E+00 7.OE-01 Ni-63 2.8E+02 1.4E+02 Sr-90 6.OE-01 3.OE-01 2Nb-94 2.5E+00 1.3E+00 Tc-99 5.OE+00 2.5E+00 2

A9-108m 2.5E+00 1.3E+00 2Sb-125 1.LE+01 5.6E+00 2Cs-134 1.7E+00 8.7E-01 2

Cs-137 3.OE+00 1.5E+00 2

Eu-152 .3.6E+00 1.8E+00 2

Eu-154 3.3E+00 1.7E+00 2

Eu-155 1.4E+02 6.9E+01 Pu-238 1.2E+01 5.8E+00 Pu-239, 240 L.1E+01 5.3E+00 Pu-241 3.4E+02 1.7E+02 Am-241 L.OE+01 5.1E+00 Cm-243, 244 L.1E+01 5.6E+00

'Based on 8.73 mrem/yr (TEDE) 2 Gamma emitting nuclides (or ETD radionuclides)

The FSSP design was performed to the criteria of the LTP; therefore, no subsequent LTP deviations with potential impact to this survey unit need to be evaluated.

5.4.3 DCGL Selection and Use The LTP DCGLs for soil were calculated using the resident farmer scenario.

For the resident farmer scenario, the average member of the critical group is the resident farmer who lives on the site, grows all of his/her diet onsite and drinks water from a groundwater source onsite. The residual radioactive material was assumed to be in the top 2.89 m soil layer, available for use in residential and light farming activities. The LTP DCGLs were performed using RESRAD-Version 6.21 analyses and based upon a resulting dose of 25 mrem/yr.

47

Report No.: YNPS-FSS-NOL0 1-00 The DCGLs in NOL-01-04 Survey Plan were derived by scaling the LTP DCGLs to 8.73 mrem/yr. The 8.73 mrem/yr value was necessitated by the DPH site release criteria of 10 mrem/yr subtracting the maximum dose contribution for subsurface partial structures (0.5 mrem/yr) and the maximum dose contribution from groundwater (0.77 mrem/yr). The resulting scaled DCGL values and associated MDCs are in Table 28.

5.4.4 Measurements The sample design required that 15 surface soil samples be used for the Sign Test based on the probability of error tolerance (ax and 3), LBGR and relative shift value found in Table 27. Four of the samples were split and analyzed for LTP HTD radionuclides in addition to the ETD radionuclides.

Three biased samples were drawn and analyzed for both HTD and ETD radionuclides. Two samples were designated as "recount" samples, thus satisfying the QC requirements of the QAPP.

The fixed-point sampling grid was developed as a systematic grid with spacing consisting of a triangular pitch pattern with a random starting point.

With the aid of a GPS and AutoCAD-generated survey unit map, the systematic random start grid was developed utilizing Visual Sample Plan.

Sample measurement locations are provided with the GPS coordinates in Table 29.

Table 29 Sample Measurement Locations with GPS Coordinates Designation*i Northinge!:, asting*

NOL-01-04-001 272496.7351 3093680.7947 NOL-01-04-002 272522.0591 3093680.7947 NOL-01-04-003 272458.7490 3093658.8634 NOL-01-04-004 272484.0731 3093658.8634 NOL-01-04-005 272509.3971 3093658.8634 NOL-0 1-04-006 272395.4389 3093636.9322 NOL-0 1-04-007 272420.7630 3093636.9322 NOL-01-04-008 272446.0870 3093636.9322 NOL-01-04-009 272471.4110 3093636.9322 NOL-01-04-010 272408.1010 3093615.0009 NOL-01-04-011 272433.4250 3093615.0009 NOL-01-04-012 272458.7490 3093615.0009 NOL-01-04-013 272395.4389 3093593.0697 NOL-01-04-014 272420.7630 3093593.0697 48

Report No.: YNPS-FSS-NOLOI-00 D gnation Northing ,;Easting NOL-01-04-015 272408.1010 3093571.1384 A total of 167 ISOCS scans were performed in NOL-01-04 providing 100%

coverage of the survey unit. The ISOCS scan grid used a 2.6-m point-to-point grid with no perimeter points farther than 1.3 m from the survey unit boundary. The ISOCS scan grid did not require a random start. ISOCS scans were performed at a height of 2 m from the surface positioned perpendicular to the scan point using a 90-degree collimator. The adjusted investigation levels, referenced in Table 27, for the ISOCS were derived by multiplying the DCGLEMC (DCGLw

• AF for a 1 m2 elevated area) by the ratio of MDCs obtained from the 12.6 m 2 field of view relative to the MDC obtained for a 1 m2 area at the edge of the 12.6 m 2 field of view, as this leads to a conservative model. The values developed for the 1 m 2 elevated area at the edge of the field of view used for the ISOCS scan investigative levels are sensitive enough to detect the elevated comparison values for the 58.7 m2 area (from Table 27). MDC values for the Portable ISOCS scans were set at the DCGLEMC for the individual radionuclides. The technical basis for the use of the ISOCS is documented in Technical Report YA-REPT-00-018-05, "Use of In-situ Gamma Spectrum Analysis to Perform Elevated Measurement Comparisonin Support of FinalStatus Surveys" (Appendix B).

5.4.5 Survey Implementation Activities Table 30 provides a summary of daily activities performed during the Final Status Survey of NOL-01-04.

Table 30 FSS Activity Summary for Survey Unit NOL-01-04

• Ž Datei~ PK " Activity November 17, 2005 Performed walk-down of NOL-01-02 Established Isolation and Controls November 18, 2005 Started gridding of Survey Unit. Commenced ISOCS scans November 22, 2005 Continued ISOCS scans. Layout of fixed-point grid (GPS).

November 29, 2005 Completed ISOCS scans. Completed soil sampling. FSS complete December 2, 2005 Initiated Area Surveillance Plan in response to water and mud intrusion after a heavy rainstorm. Performed biased scans and soil sampling.

49

Report No.: YNPS-FSS-NOL0I-00 While performing surveys in NOL-01-04 ORISE communicated that an elevated measurement was detected during their confirmatory surveying and they requested sample preparation and onsite analysis support. Yankee provided this support and, thus, acquired firsthand knowledge and documentation of the ORISE sample results.

On site separation of the ORISE sample determined that the source of the elevated activity was due to a discrete particle within the soil sample. The area of the ORISE-detected elevated measurement was investigated by scanning with no scan readings above background remaining at the ORISE sample site.

5.4.6 Surveillance Surveys 5.4.6.1 Periodic Surveillance Surveys Survey Unit NOL-01-04 is subject to periodic surveillance surveys in accordance with YNPS procedure DP-8860, "Area Surveillance Following Final Status Survey." These surveys provide assurance that areas with successful FSS remain unchanged until license termination.

5.4.6.2 Resurveys A heavy rain event, after the FSS of NOL-01-04 and prior to backfill, necessitated a resurvey of the survey unit to assess the potential impact to the FSS. An area surveillance plan (ASP) was developed (YNPS-ASP-NOLO 1-04-00) to include biased soil samples and judgmental ISOCS scans. The samples and scans concentrated in the locations in which the FSS was most likely to have been impacted by the rain event. ISOCS scans taken in the eastern section of the potentially impacted area were adjusted by 20% to account for the increased density due to the increased moisture content of the soil. The ASP acceptance criterion was that no single survey point exceeds two standard deviations from the mean of the FSS for the survey unit. Data assessment of the resurvey concluded that no single data point exceeded the acceptance criteria; therefore, no investigation survey was warranted.

5.4.6.3 Investigations No investigation survey was warranted.

5.4.7 Survey Results 50

Report No.: YNPS-FSS-NOLOI-00 The onsite laboratory analyzed the 15 fixed-point soil samples collected from NOL-01-04. All samples were analyzed by gamma spectroscopy with sensitivity sufficient to achieve the MDCs in Table 28 for gamma-emitting nuclides. No samples greater than the DCGLw for the radionuclides present were identified, and the sum-of-fractions were all less than 1 (unity rule).

Therefore no statistical test was necessary. Table 7 includes the gamma spectroscopy results for the only radionuclides positively identified during onsite analysis.

Three biased samples were taken. These samples were shipped, without drying, to General Engineering Laboratories in Charleston, SC, for analysis of both ETD and HTD radionuclides. The results of these biased samples are included in Table 31.

Table 31 Summary of Sample Results for Survey Unit NOL-01-04 Ag .Pu . I .... ... .. Am*p' I ySample Number CoigpC POi/ "pi/g' PO/g~ pCi/gJ Ip~ig pGi/g f-DCGL.*

FSS-NOL-0 1-02-001 -F 3.09E-02 -1.56E-03 0.022 FSS-NOL-01-02-002-F -1.50E-02 2.47E-02 -0.002 FSS-NOL-01-02-003-F 8.49E-02 2.91 E-02 0.070 FSS-NOL-01-02-004-F 1.11 E-02 2.33E-02 0.016 FSS-NOL-01-02-005-F -2.46E-02 1.20E-02 -0.014 FSS-NOL-01-02-006-F 7.26E-02 -1.94E-02 0.045 FSS-NOL-01-02-007-F 9.91E-01 1.30E-01 0.751 FSS-NOL-01-02-008-F 2.96E-02 5.71 E-02 0.040 FSS-NOL-01-02-009-F 9.11 E-02 8.55E-02 0.094 FSS-NOL-01-02-010-F 3.61E-02 2.69E-02 0.035 FSS-NOL-01-02-011-F 2.20E-01 5.92E-02 0.177 FSS-NOL-01-02-012-F 3.32E-02 2.59E-02 0.032 FSS-NOL-01-02-013-F 1.19E-02 5.OOE-02 0.025 FSS-NOL-01-02-014-F 2.32E-03 1.22E-02 0.006 FSS-NOL-01-02-015-F 7.71E-03 9.63E-02 0.038 FSS-NOL-0 1-02-135-F- 0.06 B -2.44E-03 1.67E-01 FSS-NOL-0 1-02-136-F- 0.02 B 1.60E-02 1.71E-02 FSS-NOL-01-02-137-F- 0.10 B 6.22E-02 1.73E-01 Stdev 0.25 0.04 51

Report No.: YNPS-FSS-NOL0 1-00 Mean 0.11 0.04 1

• DCGL fraction, Unity Rule applied One hundred and sixty seven ISOCS scans were performed and the results compared to the respective Action Levels. A summary of the ISOCS scans is provided in Table 32.

Table 32 Summary of ISOCS Scan Results for Survey Unit NOL-01-04

. Samip! Titile f'~J.JLM). Sample Title -,f (DCGLEMC,), Sample Title f (DCGLfN)'

NOL-01-04-009-R- G 0.06 NOL-01-04-039-F- G 0.00 NOL-01-04-071-F-G 0.00 NOL-01-04-010-R- G 0.35 NOL-01-04-040-F- G 0.18 NOL-01-04-072-F-G 0.00 NOL-01-04-011 -R- G 0.00 NOL-01-04-041-F- G 0.16 NOL-01-04-073-F-G 0.00 NOL-01-04-012-R- G 0.00 NOL-01-04-042-F- G 0.26 NOL-01-04-074-F-G 0.13 NOL-01-04-013-R- G 0.30 NOL-01-04-043-F- G 0.17 NOL-01-04-075-F-G 0.00 NOL-01-04-014-R- G 0.00 NOL-01-04-044-F- G 0.00 NOL-01-04-076-F-G 0.00 NOL-01-04-016-F- G 0.36* NOL-01-04-045-F- G 0.38 NOL-01-04-077-F-G 0.00 NOL-01-04-017-F- G 0.10 NOL-01-04-046-F- G 0.00 NOL-01-04-078-F-G 0.00 NOL-01-04-019-F- G 0.00 NOL-01-04-047-F- G 0.00 NOL-01-04-079-F-G 0.02 NOL-01-04-020-F- G 0.24 NOL-01-04-048-F- G 0.00 NOL-01-04-080-F-G 0.00 NOL-01-04-021-F- G 0.00" NOL-01-04-049-F- G 0.16 NOL-01-04-081-F-G 0.00 NOL-01-04-021-F- G 0.18 NOL-01-04-050-F- G 0.17 NOL-01-04-082-F-G 0.00 NOL-01-04-022-F- G 0.00 NOL-01-04-051-F- G 0.00 NOL-01-04-083-F-G 0.00 NOL-01-04-023-F- G 0.00 NOL-01-04-052-F- G 0.00 NOL-01-04-084-F-G 0.12 NOL-01-04-024-F- G 0.00 NOL-01-04-053-F- G 0.03 NOL-01-04-085-F-G 0.00 NOL-01-04-025-F- G 0.00 NOL-01-04-054-F- G 0.03 NOL-01-04-086-F-G 0.02 NOL-01-04-026-F- G 0.00" NOL-01-04-055-F- G 0.00 NOL-01-04-087-F-G 0.00 NOL-01-04-026-F- G 0.00 NOL-01-04-056-F- G 0.16 NOL-01-04-088-F-G 0.30 NOL-01-04-027-F- G 0.00 NOL-01-04-057-F- G 0.18 NOL-01-04-089-F-G 0.00 NOL-01-04-028-F- G 0.00 NOL-01-04-058-F- G 0.03 NOL-01-04-090-F-G 0.00 NOL-01-04-029-F- G 0.00 NOL-01-04-059-F- G 0.00 NOL-01-04-091-F-G 0.00 NOL-01-04-030-F- G 0.00 NOL-01-04-060-F- G 0.00 NOL-01-04-092-F-G 0.00 NOL-01-04-031-F- G 0.00 NOL-01-04-061-F- G 0.00 NOL-01-04-093-F-G 0.00 NOL-01-04-031-F- G 0.00* NOL-01-04-062-F- G 0.15 NOL-01-04-094-F-G 0.00 NOL-01-04-032-F- G 0.14 NOL-01-04-063-F- G 0.00 NOL-01-04-094-F-G 0.00 NOL-01-04-032-F- G 0.19 NOL-01-04-064-F- G 0.00 NOL-01-04-095-F-G 0.00 NOL-01-04-033-F- G 0.41 NOL-01-04-065-F- G 0.00 NOL-01-04-096-F-G 0.00 NOL-01-04-034-F- G 0.14 NOL-01-04-066-F- G 0.00 NOL-01-04-097-F-G 0.00 NOL-01-04-035-F- G 0.12 NOL-01-04-067-F- G 0.18 NOL-01-04-098-F-G 0.00 52

Report No.: YNPS-FSS-NOLOI-00 Sample Title T ,(DCGLEiiC) - ampeftftieý_ f (_DCGLEmc Sample Title) f

!DCGLENie),

NOL-01-04-036-F- G 0.00 NOL-01-04-068-F- G 0.00 NOL-01-04-099-F-G 0.21 NOL-01-04-037-F- G 0.45* NOL-01-04-069-F- G 0.20 NOL-01-04-100-F-G 0.02 NOL-01-04-038-F- G 0.31 NOL-01-04-070-F- G 0.00 NOL-01-04-101-F-G 0.00 NOL-01-04-102-F-G 0.04 NOL-01-04-147-F-G 0.02 NOL-01-04-176-F-G 0.19 NOL-01-04-1 03-F-G 0.00 NOL-01-04-148-F-G 0.00 NOL-01-04-177-F-G 0.00 NOL-01-04-104-F-G 0.03. NOL-01-04-149-F-G 0.00 NOL-01-04-178-F-G 0.00 NOL-01-04-1 05-F-G 0.00 NOL-01-04-150-F-G 0.03 NOL-01-04-179-F-G 0.00 NOL-01-04-106-F-G 0.00 NOL-01-04-151-F-G 0.08 NOL-01-04-1 80-F-G 0.00 NOL-01-04-107-F-G 0.00 NOL-01-04-152-F-G 0.00 NOL-01-04-181-F-G 0.00 NOL-01-04-108-F-G 0.00 NOL-01-04-153-F-G 0.00 NOL-01-04-109-F-G 0.00 NOL-01-04-153-F-G 0.00 NOL-01-04-110-F-G 0.00 NOL-01-04-154-F-G 0.11 NOL-01-04-111-F-G 0.00 NOL-01-04-154-F-G 0.00 NOL-01-04-112-F-G 0.00 NOL-01-04-155-F-G 0.00 NOL-01-04-113-F-G 0.00 NOL-01-04-156-F-G 0.30 NOL-01-04-114-F-G 0.00 NOL-01-04-157-F-G 0.00 NOL-01-04-115-F-G 0.00 NOL-01-04-158-F-G 0.00 NOL-01-04-116-F-G 0.00 NOL-01-04-159-F-G 0.00 NOL-01-04-117-F-G 0.00 NOL-01-04-160-F-G 0.24 NOL-01-04-118-F-G 0.00 NOL-01-04-161-F-G 0.24 NOL-01-04-119-F-G 0.00 NOL-01-04-162-F-G 0.03 NOL-01-04-120-F-G 0.00 NOL-01-04-163-F-G 0.00 NOL-01-04-121-F-G 0.00 NOL-01-04-164-F-G 0.00 NOL-01-04-123-F-G 0.00 NOL-01-04-165-F-G 0.00 NOL-01-04-125-F-G 0.00 NOL-01-04-166-F-G 0.21 NOL-01-04-127-F-G 0.00 NOL-01-04-167-F-G 0.03 NOL-01-04-138-F-G 0.12 NOL-01-04-168-F-G 0.02 NOL-01-04-139-F-G 0.00 NOL-01-04-169-F-G 0.16 NOL-01-04-140-F-G 0.00 NOL-01-04-170-F-G 0.04 NOL-01-04-141-F-G 0.00 NOL-01-04-171-F-G 0.00 NOL-01-04-142-F-G 0.13 NOL-01-04-172-F-G 0.00 NOL-01-04-143-F-G 0.00 NOL-01-04-172-F-G 0.00 NOL-01-04-144-F-G 0.28 NOL-01-04-173-F-G 0.00 NOL-01-04-145-F-G 0.32 NOL-01-04-174-F-G 0.00 NOL-01-04-146-F-G 0.37 NOL-01-04-175-F-G 0.12 ISOCS results adjusted 20% to account for increased density due to moisture content of the soil.

Copies of the ISOCS reports are found in Attachment C.

5.4.8 Data Quality Assessment 53

Report No.: YNPS-FSS-NOLO1-00 The Data Quality Assessment phase is the part of the FSS where survey design and data are reviewed for completeness and consistency, ensuring the validity of the results, verifying that the survey plan objectives were met, and validating the classification of the survey unit.

The sample design and the data acquired were reviewed and found to be in accordance with applicable YNPS procedures DP-8861, "Data Quality Assessment"; DP-8856, "Preparationof Survey Plans"; DP-8853, "Determinationof the Number and Locations of FSS Samples and Measurements"; DP-8857, "Statistical Tests"; DP-8865, "Computer Determinationof the Number of FSS Samples and Measurements"; and the QAPP.

A preliminary data review was performed and statistical quantities were calculated. The average concentrations and standard deviations of Co-60 and Cs- 137 from Table 31 are larger than the respective characterization data from Table 4. However, the retrospective power curve maintained sufficient power to pass the survey unit. The concentration data for Co-60 indicated that one sample (FSS-NOL-01-04-007-F) was statistically higher than the remaining samples; however, this value (0.99 pCi/g) was less than the DCGLw. This data point skewed the average Co-60 concentration value slightly high. Without this value, the range of data would have been within one standard deviation of the mean. The data range for Cs-137 was approximately three standard deviations of the mean. Frequency plots for both Co-60 and Cs- 137 demonstrate a normal data distribution with the Co-60 being skewed high. The scatter plots generated for NOL-01-04 graphically illustrate that the data for Co-60 and Cs-137 vary about their respective Mean, with the exception of the higher Co-60 sample result discussed above. The data posting plots for both radionuclides do not clearly reveal any systematic spatial trends. Review of the quantile plots for NOL-0 1-04 indicates some asymmetry in the lower quartiles and illustrates the elevated Co-60 result.

Review of the data in Table 31 illustrates that all of the sample data for the soil concentrations of all plant-related LTP nuclides are below the DCGLw and the sum-of-fractions for these nuclides are less than unity. Therefore no statistical test is required.

Copies of the power curves, quantile plots, scatter plots and posting plots are found in Attachment B.

The actual level of residual activity was higher than the estimated level (i.e.,

values derived from characterization data) used for the survey design; however, the survey demonstrated sufficient power to indicate that the survey unit null hypothesis should be rejected.

54

Report No.: YNPS-FSS-NOLO1-00 6.0 QUALITY ASSURANCE AND QUALITY CONTROL 6.1 Instrument QC Checks Operation of the portable ISOCS was in accordance with DP-8871,"Operationof the CanberraPortableISOCS System," with QC checks performed in accordance with DP-8869,"In-situ (ISOCS) Gamma Spectrum Assay System Calibration Procedure"and DP-8871, "Operationof the CanberraPortableISOCS System."

Operation of the E-600 w/SPA-3 was in accordance with DP-8535,"Setup and Operationof the EberlineE-600 DigitalSurvey Instrument," with QC checks preformed in accordance with DP-8540, "Operation and Source Checks of Portable Friskers." Instrument response checks were performed prior to and after use for the E-600 w/SPA-3 and once per shift for the Portable ISOCS. Any flags (i.e.

anomalies in the QC results) encountered during the ISOCS QC Source Count were corrected/resolved prior to surveying. All instrumentation involved with the FSS of NOL-01 satisfied the above criteria for the survey. QC records are found in Attachment E.

6.2. Split Samples and Recounts Samples NOL-02-03-005-F-S and NOL-02-03-010-F-S were designated as split samples and sent for full analysis by the offsite laboratory for all LTP radionuclides.

The results of the offsite analyses were compared with the onsite results in accordance with DP-8864, "Split Sample Assessment for FinalStatus Survey." Two recount samples (NOL-01-02-007-F and NOL-01-02-012-F) were counted twice on site and the results compared in accordance with DP-8864,"SplitSample Assessment for FinalStatus Survey." Split sample locations and recount samples were selected randomly using the Microsofto Excel "RANDBETWEEN" function. There was acceptable agreement between field-split results as well as the recounts. The sample analysis vendor maintains QA/QC plans as part of normal operation. Onsite gamma spectroscopy analysis is performed in accordance with MARLAP protocol. DP-9600, "Chemistry Laboratory Quality Control Program," and DP-96 10, "Preparation of Quality Control Charts," govern the QA/QC.

6.3. Self-Assessments No self-assessments were performed during the FSS of NOL-01.

55

Report No.: YNPS-FSS-NOLO I-O0

7.0 CONCLUSION

The FSS of NOL-01 has been performed in accordance with YNPS LTP and applicable FSS procedures. Evaluation of the fixed-point sample data has shown that none of the LTP radionuclide values exceeded the DCGLw and the sum-of-fractions for those nuclides is less than unity. Therefore, the null hypothesis (Ho) is rejected. One (this could be more with the inclusion of other survey units) elevated area was identified and bounded. The fractional sum of DCGLEMc is less than unity. No large anomalies were observed in the graphical representation of the data collected. The retrospective power curve generated shows adequate power was achieved.

NOL-01 meets the objectives of the Final Status Survey.

Based upon the evaluation of the data acquired for the FSS, NOL-01 meets the release requirements set forth in YNPS LTP. The TEDE to members of the critical group does not exceed 25 mrem/yr, including that from groundwater and the requirement of 10CFR20 Subpart E for ALARA has been met.

56

Report No.: YNPS-FSS-NOL01-00 Figure 1 Map of Survey Units Relative to Structures 57

Report No.: YNPS-FSS-NOLOI-00 Figure 2 Site Map 1~.

S 1=, i Yankee Atomic Power Company (l.20 Figure: I I - -1.111 -ý I survey unit Survey Pro$-~s (.y .f

Report No.: YNPS-FSS-NOLO1-00 Figure 3 Map of Survey Units Relative to Survey Area 59

Report No.: YNPS-FSS-NOLOI-00 Attachment A ISOCS Results NOL-01-02 NOL-01-03 NOL-01-04

Attachment A has been provided on the enclosed CD.

Report No.: YNPS-FSS-NOLO1-00 Attachment B Data Quality Assessment Plots and Curves NOL-01-01 NOL-01-02 NOL-01-03 NOL-01-04

Attachment B has been provided on the enclosed CD.

Report No.: YNPS-FSS-NOLOI-00 Appendix A YA-REPT-00-003-05 Generic ALARA Review for Final Status Survey of Soil at YNPS

Report No.: YNPS-FSS-NOLOI-O0 TECHNICAL REPORT TITLE PACE G ene~ric AILARA Review fI'm Final StattisSun'ev o~f S4iI at YNPS Tititl YA-REPT-OOWfHI3-O5 Technical Report Number Appi o-vals (Print K&Sian Name)

Preparer: J, Hummer signoature on file Date: 1/1810!f5 Reviewer: J. liss~ot sim~ature onl rile ~5 lDatc: 1l /0 Approver (Copenizant klanagcr): 1), (C. .Smithi sienatlire on rile Date: I/ tt/OS

Report No.: YNPS-FSS-NOLOI-00 TABLE OF CONTENTS Title Page ..............

Table of' Contens .......... ...................... ...... ........... .................. 2 Exccut veSuctimm.. .... .... . . ........................

. .................. .............. 3 Introduction i-ým. . . . . ................. .......................... ..................... 3 D iscussion -...... . . . . . . . . . .. . . . . . . . ................. . .. ........................... 3 Calculation .............................................................

Conclusions ................................... .......................... 6 IRel'cr:e , s ....... ............... ............................... ......... ........................ 6 Altadcm*dl I ............................................................ 7 YA-REPT-00-003-05 Papge 2 of'7

Report No.: YNPS-FSS-NOLOI-O0 Executive Summuary In addition to the requirement to limit the dose from residual, plant-related radioactivity in soil to nienibers of the critical group to 25 mreni in any ,'ear, the License Temination Plan (LUP) requires an evaluation demonstrating that these levels are as low as reasonably achievable (ALARA). If compliance with the ALARA criterion cannot be demonstrated, remediation otf the soil is required, even though this would further reduce the otherwise acceptablc exposure to the critical group to levels below those required. *Ibis report is intended to provide a generic ALARA review to bound the condition.s under which no further remediation is necessary tbr soils. Calculations were perforrncd using 1LT'P equations and conservative asstmuptions. Tlhe conclusion is that it is not cost-beneficial to remediate soil in which the levels of residual, plant-related radioactivity are below LTP release criteria.

The State of Massachusetts requirement limits dose to 10 ntrem/year, Reniediation below this level would be even less practical.

Introduction Section 4.3.1 oflthe L.,TPI I states that a generic AI.ARA evaluation for soils will be developed to detennine if the clean-up of soils beyond the l)CUILos will be cost-beneficial for YNPS. Appendix 4A of the LTP 11] provides an equation and default values for this calculation. This process will be followed, assuming that the soil is at the DCGI.L mad using conservative estimates oflcosts, distances and other inputs that the worksheet requires. The equation will calculate an action level (AL) that represents the ratio otconcentration to the DCGL that would be cost-benelicial to remediate. Iftthat ratio is greater than 1, remediation is not cost-beneficial.

'Ibis calculation is meant to apply to areas of any XIARSSIM class and any size. In a Class I area, where values of residual contamination may exceed the DCGLw in limited areas, the meanuconcentration may never exceed the lCGI.w. Since it is assumcd that the entire volume ofsoil removed is at DCGIlw, the assumed mean will be at I)CUILw. Therefore, the assumed case will be bounding.

I)iscussion T[he total cost (Cost-r) will be calculated using LITP equation B-2 (friom Appendix 4, section 4,A. 1.1 of the LTP[t1]):

COSIT = COSIR +/- COtWrD + CoStAC'C CSt + CoSIwD,1 +/-- COStpDgc

'lhese terms are defined and their values calculated as follows:

Cost of perfurrming remnediation work ((CustR):

6 Initially it will be assumed that the job is big enough to require earthmoving equipment. At a minimumL this would be either an excavator or a loader amd truck.

Ibis turns out niot to be a constraint, as explained later.

0 To come tip with a conservative scenario, the cost oflremediating one square meter from a larger project is calculated. Any smaller job by, itself. would have planning and administration costs that would be dominant. Factor, contributing to CostR are identitied in Atachmeme 1. The initial estimate for Costit is based on a job to YA-REPT-00-003-05 Page 3 of"7

Report No.: YNPS-FSS-NOLOI-00 rcticdiatc 2000 square meteris of soil, but to make it comparable to the other costs.

thai value is adjusted to reflect the cost of I square meter.

• 1he adjusted value oftCOsMR is $7.32 to remcdiate I square meter of soil.

• Rounding down to the dollar. Costit = $7 Note: The value of CostR calculated above bounds the cost of a smaller excavation, e.g.,

one that doesn't require eanrhmoving equipment. For example. two workers who take an hour to dig up some soil and bring it hack in wheelharrow, with no work order or other fonial planning. would cost the project about $100 in labor costs (:Lssuming the cost to the project is $50/hr), So. the constraint that this only applies to jobs big enough to require carthmoving equipment can be removed, Cost of waste disposal (Costwo):

" As above. it will be assumed that one square meter of surtice soil is to be remediated. Surface soil is considered to be the top 15 cm. The estimated waste volume will therefbre be 15 cm timcs the area of I 12 This comes to 0. 15 m.,

• 'the current cost of waste disposal for radiologically contaminated soil is $19 per cubic toot [2]. This includes burial tbes and shipping.

" Since 1 fW3equals .0283 m3 .. this comes to $100S70 to dispose of the assumed voltmle.

" RotwLding down to the dollar,. Costta')o SI00 Cost ofrworkplace accident (CostAcO):

• Costcc = (S3.000,000)x(4.2E-Shq)x('T'imc to perfonn rcmediation) ... (Equation 4A UI,,T[I 11)

" S3,000,000 is the monetary value of a fiaality equivalent to $2000 per person-rem.

" 4.2E-8 is the workplace fiatality rate, in fatalitics per hour worked.

" For a I square meter excavation, this would not be more than a Iw person-hours, (Assume Time = 2 hr)

• (S3,000,000) x (4.2E-8ih) x (2 h) = S0.25

" Rounding down to the dollar, COSIAt(- $0 Cost of traflic fatality (Costor):

" CostTF (S3=000,000)x(3= 1.-8.knt)x(Volume)x(listattee)/(Volutneshiprntnt).

(Etquation 4A-5, L,'PjI I].)

" Round trip distance from YNPS to Memphis. 'IN: 2550 kimshipment ... (from Yahoo Maps)

• Waste volume per shipment: 13.6 nmt /shpmt ... (default in LIT I l, section 4.A. 1.1 and consistent with YNSI) shipping agent's 131 figure of 500 IV or 14 in3 )

• (S3.000.000)x(3.8E-&ikn)x(0. 15 m 3 )(2550 km/shpmt)/(13.6 mný/shpmt) 1$3.21

• Rounding down to the dollar, Costlz = S3 YA-REPT-00-003-05 Pipge 4 of 7

Report No.: YNPS-FSS-NOLOI-00 Cost of worker dose (Costwvo*):

• Costwt,* -. (S2OOO/person-rern)x(Worker dose rate)x(Time) ... (Equation 4A-6.

LTPII]).

• Dose rates would be insignificant. (Assume dose rate . 0. mrem/h , E-4 remin)

• ($2000vperson-rem) x (I E-4 rem/h) x (2 h) :f S0.40

• Rounding down to the dollar, Costw0 ,, SO Cost of Dose to the Public (Costpm.):

• Costop is assumed to be no more than the Costwo.

" Assumed Costpn), r- = $0 Total CostT:

" COSiT - COSIR + CONIWD , COStAC + CoStF + CostlwD 0 .ia Costp4Dost

" Costr$Sll0 Calculation ALARA Action Level (ALt,):

Cone Cos. r+ .

AL = $2000x~. PD 0.025xFxA - (LTP [1], Equation 4A.1) where:

• Cost-, has been calculated above

• S2000 is the monetary value of'one person-rem (Section 4A. 1. I.TI 1P])

" F = removahle fraction = ... (most conservative possible)

• 0.025 is the annual dose in rem to an average member of critical group from residual radioactivity (TIhis is the LTP[1I limit, state of Massachusmtts limit is 0.0t10. which would make the remediation less practical.)

" r = monetary discount rate = 0.03?y .° (Table 4A-1, LITP I ])

• N = Number ofycars over which the collective dose is calculated 1000 y ...

(Table 4A-1, LTIP I 11)

" P) = Population density for the critical group = 0,0004 pcoplelmn ... (Table 4A-LI LTP [I])

" A -= Area being evaluated ., I u i

• Most conservative nuelide of concern is that with the longest half-lit, eTC-99, with a half-lilf of 2.13E5 years (Table 2-6, LtTPI 1) and a decay constant 0() of 3254E-6 y-1 (Note: With the values for other variables used for this calculation, the I-e...

term equals I for any value of).. 'Iaerefore, the smallest AL which is the most conservative, will occur when X. in the top of the equation, is smallest.)

Applying these values to the equation:

YA-REPT-00-003-05 Page 5 ot'7

Report No.: YNPS-FSS-NOLO0-00 SIl S= 0.03 +3254E- 6 S2000 x0.004 x 0.025 S I x1 s 1- e .°QO:254 *561 AL = 165 If Tc-99 were at DCGL:

SSum olf DCGI. Fractions = I Since AL is greater than the Sum of I)CGI.. Fractions. remediation is not cost-beneficial. In fact, remediation would noi be cost-beneficial unless the Concentration of any LTP nuclide in soil were at least 165 limes the DCGL.

Conclusions Based upon the results o" this AIARA evaluation, it is not cost-benef'icial to remediate soil in which the levels of'residual,. plant-relaied radioactivity are below LTP release criteria, References

1. YNPS License Termination Plan

2. Interview with Rod Dee, Contracts Administralor. 1113105.

3. Interview with Don Maffei, YNSP Shipping Agent, 1/11105.

YA-REIPT-00-003-05 Page 6 otf7

Report No.: YNPS-FSS-NOLOI-00 ATTACHMENT I Cost estimate for remediation work (Coste)

Assume larger project, to dilute fixed costs: 2000 Mi. removing the top 15 cm of soil hr Rate (ihr)j T . Cost2...

Conest Planner. Rd engineer Isu§ýpteivi n/ma aem~ent iResurvev IAdditional ofst nlss2smls I5

-i'

$200 0,

$50,00, S25W000

$200:00, I S2,440.00 1Acld- tiuwoFn n-e si a s(15:1sampLeý)___

10 S250...

fI---O! S1500.00 1 S2.500.00.

!.H.P covýe!rage. .................... .....

.................. $14.640 ,00 '

Tfo-t a"l'f'or 2-0,00 inm TS5(T5 T $7.32L YA-REPT-00-003-05 Page 7 of 7

Report No.: YNPS-FSS-NOLOI-00 Appendix B YNPS-FSSP-NOL01-01-01 through YNIPS-FSSP-NOL01-04-00 Final Status Planning Worksheet NOL-01-01 NOL-01-02 NOL-01-03 NOL-01-04

Final Status Survey Planning Worksheet Page I of 5 GENERAL SECTION Survey Area #: NOL-01 Survey Unit #: 01 Survey Unit Name: RSS Footprint Within The East Lower RCA Yard FSSP Number: YNPS-FSSP-NOLO 1-01-01 (Rev. 1 changes are in bold font)

PREPARATION FOR FSS ACTIVITIES Check marks in the boxes below signify affirmative responses and completion of the action.

1.1 Files have been established for survey unit FSS records. l]

1.2 ALARA review has been completed for the survey unit. Z (YA-REPT-00-003-05) 1.3 The survey unit has been turned over for final status survey. Z 1.4 An initial DP-8854 walkdown has been performed and a copy of the completed Survey Unit Walkdown Evaluation is in the survey area file. El 1.5 Activities conducted within area since turnover for FSS have been reviewed. 21 Based on reviewed information, subsequent walkdown: El not warranted El warranted If warranted, subsequent walkdown has been performed and documented per DP-8854. El OR The basis has been provided to and accepted by the FSS Project Manager for not performing a subsequent walkdown. El 1.6 A final classification has been performed. El Classification: CLASS 1 El CLASS 2 El CLASS 3 El DATA QUALITY OBJECTIVES (DQO) 1.0 Statement of problem:

NOLOI-01 consists of a soil area falling inside the RSS footprint within Survey Area NOL-01. The soil area in NOLOI-01 extends south from the common boundary with Survey Unit NOL06-01 (to the north), ending at the face of the foundation of the PAB (Survey Areas AUX-01 and AUX-02). The east boundary is formed with the SFP excavation and the remaining Survey Area NOL-01. Survey Unit NOL06-01 forms the west boundary. Portions of the RSS ring and mat foundations are present in, but are not part of, Survey2 Unit NOL01-01.

2 The total area (soil plus concrete structures) falling within the unit's boundaries is approximately 7,254 ft (674 Mi). However, excluding the concrete ring and mat foundations,. the remaining area is significantly smaller at approximately 1,919 ft2 (178 M2 ). Only the soil area is considered under this survey plan. The concrete structures are not included in Survey Unit NOL01-01 and will be surveyed under separate survey plans. The data collected under this plan will be used to determine whether or not residual plant-related radioactivity in soil of Survey Unit NOLO 1-01 meet LTP release criteria.

The planning team for this effort consists of the FSS Project Manager, FSS Radiological Engineer, FSS Field Supervisor, and FSS Technicians. The FSS Rad. Engineer will make primary decisions with the concurrence of the FSS Project Manager.

2.0 Identify the decision:

Does residual plant-related radioactivity, if present in the survey unit, exceed LTP release criteria? Alternative actions that may be implemented in this effort are investigations and remediation followed by re-surveying.

3.0 Identify the inputs to the decision:

Sample media: soil Types of measurements: soil samples and gamma scans.

Radionuclide-of-concern: Cs-137 and Co-60 A large amount of the soil area in the RSS footprint was remediated for both radiological (elevated concentrations of Cs-137 and Co-60) and environmental (PCB-contamination) reasons. Characterization data (post-remediation soil samples) from areas NOL-01 and NOL-06 were used in the FSS planning for unit NOL01-01. Cesium-137 and Co-60 were the only easy-to-detect plant-related radionuclides identified in the characterization (post-remediation) surface soil samples. The average Cs-137 concentration was 0.17 pCi/g and the average Co-60 concentration was 0.064 pCi/g, both average values were below the DPF-8 856.1 YNPS-FSSP-NOLO 1-01-01 Page 1 of 5

respective 10-mrem/y DCGLs. The average Cs-137 concentration represented approximately 73% of the identified plant-related activity and the average Co-60 concentration represented approximately 27%.

One pre-remediation soil sample was sent to an offsite laboratory for analyses of HTD nuclides. Several HTD radionuclides (i.e., C-14, Ni-63, and Sr-90) were identified in that sample. Post-remediation soil samples identified Cs-137 and Co-60 at concentrations that were acceptable for area turnover (i.e., concentrations below the respective DCGL values), but the post-remediation soil samples were not analyzed for HTD nuclides.

The presence all LTP-listed radionuclides (gamma-emitters, HTD beta-emitters, and TRUs) in the soil will be evaluated under this survey plan. The YNPS Chemistry Dept. will analyze each soil sample for all LTP-listed gamma-emitting nuclides, and at least 5, which is more than the minimum requirement of 5% of the FSS soil samples, will be sent to an independent laboratory for analyses of gamma-emitters and HTD radionuclides.

Applicable DCGL: The DCGLs applied under this survey plan correspond to annual doses of 8.73 mrem/y (the 10-mrem/y DCGL adjusted for the dose contributions from sub-surface concrete structures and tritium in ground water).

DCGL DCGL DCGL Nuclide (pCi/g) Nuclide (pCi/g) Nuclide (pCi/g)

Co-60 1.4E+0 Eu- 152 3.5E+0 Sr-90 5.9E-1 Nb-94 2.5E+0 Eu- 154 3.3E+0 Tc-99 4.8E+0 Agl08m 2.5E+0 Eu-155 1.4E+2 Pu-238 1.1E+l1 Sb125 1.IE+l H-3 1.3E+2 Pu-239/240 L.0E+1 Cs- 134 l.7E+0 C-14 l.9E+0 Pu-241 3.4E+2 Cs-137 3.OE+0 Fe-55 1.0E+4 Am-241 1.0E+I Ni-63 2.8E+2 Cm-243/244 I .lE+l Average concentration:Cs-137 = 0.17 pCi/g and Co-60 = 0.064 pCi/g Standarddeviation (a): Cs-137 = 0.19 pCi/g and Co-60 = 0.11 pCi/g Weighted sum a = 0.1 pCi/g DCGLEMc: Cs- 137 = 11.1 pCi/g (based on AF =3.7), Co-60 = 2.5 pCi/g (based on AF = 1.8)

If needed, DCGLEMC values for other LTP-nuclides will be calculated using AF values associated with 25 m2 .

InvestigationLevelfor soil samples: (a) >DCGLEMC for either Cs- 137 or Co-60, or (b) a sum of DCGLEMc fractions >1.0, or (c) >DCGL for either Cs-I137 or Co-60 and a statistical outlier as defined in the LTP Note: the same criteria will be applied to any other LTP-listed if identified in the FSS soil samples.

Investigation Level for scan: >background indication using an audible signal with headphones Radionuclidesfor analysis: All LTP-listed nuclides with the focus on Cs-137 and Co-60.

MDCs for gamma analysis of soil samples:

Nuclide Target MDC Nuclide Target MDC Nuclide Target MDC (pCi/g) (pCi/g) (pCi/g)

Co-60 1.4E- 1 Sb125 1.1E+0 Eu-152 3.5E-1 Nb-94 2.5E- I Cs-b134 1.7E- Eu-154 3.3E-1 Ag 108m 2.5E- I Cs-137 3.6E- I Eu-155 1.4E+l Note: If a target MDC value cannot be achieved in analysis, then a value no greater than 5X the listed value must be achieved in the analysis.

MDCs for analyses of HTD nuclides:

Nuclide Target MDC Nuclide Target MDC Nuclide Target MDC (pCi/g) (pCi/g) (pCi/g)

H-3 1.3E+l Sr-90 5.9E-2 Pu-241 3.4E+ 1 C- 14 1.9E- I Tc-99 4.8E-1 Am-241 1.OE+0 Fe-55 1.OE+3 Pu-238 1.1E+0 Cm-243/244 1.1E+0 Ni-63 2.8E+ I Pu-239/240 1.OE+0 I I Note: If a target MDC value cannot be achieved in analysis, then a value no greater than 5X the listed value must be achieved in the analysis.

Scan coverage: SPA-3 scans will be performed for 100% of the total surface of the soil area in the survey unit. The expected DPF-8856.1 YNPS-FSSP-NOLO1-01-01 Page 2 of 5

ambient background is 15,000 - 20,000 cpm.

MDCR for SPA-3: The accompanying table provides MDCR values by various background levels.

MDC(fDCGLEMc )for SPA-3 scans: The accompanying table also provides MDC values by various background levels.

QC checks and measurements: QC checks for the SPA-3 will be performed in accordance with DP-8540. Four QC split samples will be collected, and QC recounts for 2 soil samples will be performed by the YNPS Chemistry Lab.

4.0 Define the boundaries of the survey:

Boundaries of NOLO 1-01 are as shown on the attached map. The survey will be performed under normal weather conditions and in daylight hours (allowing adequate daylight time for ingress and egress).

5.0 Develop a decision rule:

(a) If all the sample data show that the soil concentrations of all plant-related nuclides are below the DCGL and the sum of the DCGL fractions for identified nuclides is <1, reject the null hypothesis (i.e., Survey Unit meets the release criteria).

(b) If the investigation level is exceeded, then perform an investigation survey.

(c) If the average concentrations of all LTP-listed radionuclides are below the DCGL, or if the sum of the fractions for identified LTP-listed radionuclides <1, but some individual measurements exceed the DCGL, then apply a statistical test as the basis for accepting or rejecting the null hypothesis.

(d) If the average concentration of any LTP-listed nuclide exceeds the DCGL or the sum of the fractions exceeds one, then accept the null hypothesis (i.e., Survey Unit fails to meet the release criteria).

6.0 Specify tolerable limits on decision errors:

Null hypothesis: Residual plant-related radioactivity in Survey Unit NOLO 1-01 exceeds the release criteria.

Probabilityof type I error:0.05 Probabilityof type II error:0.05 LBGR: 0.5 7.0 Optimize Design:

Type of statistical test: WRS Test El Sign Test 21 Basis including background reference location (if WRS test is specified): N/A Number samples (perDP-8853): 15. Refer to the completed DPF-8853.2 in the survey package file.

Note: The number of samples will be increased by 2 (bringing the total of systematic samples to 17), which increases the statistical power for the data set.

Biased samples: 2 from soil by the SE section of the ring foundation for H-3 evaluation.

GENERAL INSTRUCTIONS

1. The FSS Field Supervisor is responsible for contacting the QA Department regarding the FSS activities identified as QA notification points.

2. Standing water must be removed prior to the collection of any FSS measurement in that area.

3. Mark the sampling points at the coordinates provided with the attached map. If a measurement location is obstructed such that a sample cannot be collected, select an alternate location in accordance with DP-8856.

4. Collect 17 systematic (grid) soil samples and 2 biased soil samples in accordance with DP-8120, using sampling equipment as stated in DP-8120. Five of the 17 grid soil samples will be QC split samples. Soil sample designations are as follows:

(a) Grid soil sample designations: NOL-01-01-001-F through NOL-01-01-017-F corresponding to FSS samples collected at locations 001 through 017.

(b) 5 QC split sample designations: NOL-01-01-005-F-S, NOL-01-006-F-S, NOL-01-01-008-F-S, NOL-01-01-012-F-S, and NOL-01-017-F-S collected at sample locations 005, 006, 008, 012, and 017, respectively. The results will be compared in accordance with DP-8864.

(c) Biased soil sample designations: NOL-01-01-018-F-B and NOL-01-01-019-F-B.

DPF-8 *856.1 YNPS-FSSP-NOLO1-01 -01 Page 3 of 5

Note: Samples NOL-01-01-005-F-S, NOL-01-006-F-S, NOL-01-01-008-F-S, NOL-01-01-012-F-S, and NOL-01-017-F-S are to be sent to the off-site laboratory as collected from the field (i.e., without drying) for analyses of gamma-emitters, HTD beta-emitters (including H-3), and TRUs. Samples NOL-01-01-018-F-B and NOL-01-01-019-F-B also are to be sent to the off-site laboratory as collected from the field (i.e., without drying) for analyses of gamma-emitters and H-3. YNPS chemistry will count these 7 samples in the "wet" condition prior to shipment to the offsite laboratory.

Note: Soil samples NOL-01-01-007-F and NOL-01-01-013-F are QC recounts (to be performed by the YNPS Chemistry Lab) and the results will be compared in accordance with DP-8864. The designations for the recount analyses are NOL-01-01-007-F-RC and NOL-0 1-01-01 3-F-RC, respectively.

5. All soil samples will be received and prepared in accordance with DP-8813.

6. Chain of Custody form is to be used in accordance with DP-8123 for the soil samples sent to an off-site laboratory. The required MDCs for the analyses performed by the off-site laboratory will be communicated to the Lab via the Chain-of-Custody form or an attachment to the form.

7. Scanning will cover 100% of the survey unit. The FSS Field Supervisor will record information relevant to the SPA-3 scans on DPF-8856.2.

8. Survey instrument: Operation of the E-600 w/SPA-3 will be in accordance with DP-8535, with QC checks performed in accordance with DP-8540. The instrument response checks shall be performed before issue and after use.

9. The job hazards associated with this survey are addressed in the accompanying JHA for NOL-06-01.

10. All personnel participating in this survey shall be trained in accordance with DP-8868.

SPECIFIC INSTRUCTIONS

1. SPA-3 scans are to be performed by moving the detector at a speed no greater than 0.25 m/s, keeping the probe at a distance of less than 3 inches from the ground surface, and following a serpentine pattern that includes at least 3 passes across each square meter. When scanning and walking, a slow pace (i.e., 1 step per second) shall be used. FSS Technicians will wear headphones while scanning and the survey instrument will be in the rate-meter mode. Surveyors will listen for upscale readings, to which they will respond by slowing down or stopping the probe to distinguish between random fluctuations in the background and greater than background readings. A location where detectable-above-background scan measurement is found will be investigated. Note: The FSS Field Supervisor shall monitor and time scan speeds for at least 50% of scanned areas to ensure that the scan speed of 0.25 m/s is maintained.

A first level investigation may be done with the SPA-3/E-600 to determine if an observed elevated scan measurement is reproducible and if it is due to a rock/boulder or to an outside source of radiation (e.g., the ISFSI or a nearby waste). If it can be demonstrated that the cause of the elevated scan reading is a rock/boulder or an outside source, record that finding on form DPF-8856.2. If it is demonstrated that the rocks and boulders do not account for an above background SPA-3 measurement, a soil sample will be collected at the point of the highest SPA-3 reading in the scanned area. Flag the location of an investigation sample. Detailed descriptions of investigation actions are to be recorded on form DPF-8856.2 and the location of the elevated scan measurement and sample are to be indicated on the survey map. If investigation samples are collected, the designations will continue in sequence beginning with NOL-01-01-020-F-I.

2 If a cluster of greater-than-background indications are found in a small, localized area (e.g., within a 1mi area):

2

1. Measure a 1-m square that surrounds the cluster (a fabricated 1m frame may be used instead of measuring).

2

2. Repeat the scan to find the highest reading within the 1M , and collect a soil sample at that point.

3. Designate the soil sample as described above.

2. YNPS Chemistry will dry and analyze all soil samples for gamma-emitting radionuclides, except samples NOL-01-01-005-F-S, NOL-01-006-F-S, NOL-01-01-008-F-S, NOL-01-01-012-F-S, NOL-01-017-F-S, NOL-01-01-018-F-B, NOL-01-01-019-F-B. YNPS chemistry will count these 7 samples in the "wet" condition prior to shipment to the offsite laboratory. If the results of the gamma analyses identify radionuclides at concentrations greater than the investigation level, an investigation survey will be conducted under a separate plan.

3. Soil samples NOL-01-01-005-F-S, NOL-01-006-F-S, NOL-01-01-008-F-S, NOL-01-01-012-F-S, and NOL-01-017-F-S will be sent to the off-site laboratory. These samples will be analyzed for H-3, gamma-emitting nuclides, HTD beta-emitting nuclides, and TRUs. Ensure that the lid to the I-liter marinelli container for each sample is secured to prevent loss of moisture during shipping. If the results of the offsite laboratory's analyses identify radionuclides at concentrations greater than the investigation level, an investigation survey will be conducted under a separate plan.

4. Soil samples NOL-01-01-018-F-B and NOL-01-019-F-B also will be sent to the off-site laboratory. These samples will be analyzed for H-3 and gamma-emitting nuclides. Ensure that the lid to the 1-liter marinelli container for each sample is secured to prevent loss of moisture during shipping. If the results of the offsite laboratory's analyses identify radionuclides at concentrations greater than the investigation level, an investigation survey will be conducted under a separate plan.

DPF-8 856.1 YNPS-FSSP-NOLO 1-01-01 Page 4 of 5

5. On-site and off-site analyses of the FSS samples shall achieve the required MDC values stated in Section 3 of this plan.

The MDCs will be communicated to the laboratory using an attachment to the Chain-of-Custody form.

NOTIFICATION POINTS QA notification* point(s) (y/n) y (1) Date/time of initial pre-survey briefing OA signature:

(2) Date/time of commencement of soil sampling OA signature:

(3) Date/time of initial scan measurement QA signature:

E-mail notification to Trudeau@vankee.com with a copy to Calsyn@vankee.com satisfies this step.

FSI point(s) (y/n) n Specify:

Prepared by_ Date FSS Radiological Engineer Reviewed by_ Date FSS Radiological Engineer Approved by_ Date FSS Project Manager DPF-8856.1 YNPS-FSSP-NOLO1-01-01 Page 5 of 5

Final Status Survey Planning Worksheet Page -1 of 10 GENERAL SECTION Survey Area #: NOL-0l Survey Unit #: 02 Survey Unit Name: Spent Fuel Pit Excavation Northwest FSSP Number: YNPS-FSSP-NOL01-02-03 Revisions are in Bold PREPARATION FOR FSS ACTIVITIES Check marks in the boxes below signify affirmative responses and completion of the action.

1.1 Files have been established for survey unit FSS records. 0 1.2 ALARA review has been completed for the survey unit. [ See YA-REPT-00-003-05 1.3 The survey unit has been turned over for final status survey.

1.4 An initial DP-8854 walkdown has been performed and a copy of the completed Survey Unit Walkdown Evaluation is in the survey area file. 0 1.5 Activities conducted within area since turnover for FSS have been reviewed. D Based on reviewed information, subsequent walkdown: Z not warranted El warranted Note: Based upon Rad Engineer walkdown at the Final Turnover If warranted, subsequent walkdown has been performed and documented per DP-8854. ED OR The basis has been provided to and accepted by the FSS Project Manager for not performing a subsequent walkdown. []

1.6 A final classification has been performed. Z Classification: CLASS 1 Z CLASS 2 E] CLASS 3 E]

DATA QUALITY OBJECTIVES (DQO) 1.0 State the problem:

Survey Area NOL-01-02 is the previous site of the Spent Fuel Pool Pit and some surrounding land areas towards the former Reactor Support Structure.The Spent Fuel Pool Pit was designed for the transfer of new fuel into the reactor, and transfer/storage of spent fuel out of the reactor.

Original demolition plans called for the SFP floor, foundations, and sub-grade structures to remain in place after demolition, however, it has since been determined that most sub-surface structures will be removed as part of the deconstruction process, which was accomplished in this area. The soils located around and under NOL-01-02 include backfill, overburden, and glacio-lacustrine till. Permeability to groundwater flow is varied with the till being the most impermeable and the backfill being the least impermeable. Geoprobe soil samples taken from around the SFP have shown amounts in excess of the DCGL values for Co-60, Cs-137 and Ag-108m and subject soil was removed during excavation. Demolition activities have since been completed in NOL-01 -02.

. DPF-8856.1 YNPS-FSSP-NOLO1-02-03 C

Post excavation remediation and a Characterization Survey have been performed in NOL 02. Characterization sampling indicates levels of Co-60 less than 0.6 pCi/gm and Cs-137 levels less than 1.5 pCi/gm. Initial scans were performed using SPA-3 and ISOCS with remediation carried out at locations that indicated elevated levels of radioactivity.

Based upon the radiological condition of this survey area identified in the operating history, and as a result of the decommissioning activities performed to date, survey area NOL-01-02 is identified as a Class 1 Area.

The problem, therefore, is to ascertain that the accumulation of licensed radioactive materials, existing in Survey Unit NOL-01-02, meets the release criterion.

The planning team for this effort consists of the FSS Project Manager, FSS Radiological Engineer, Radiation Protection Manager, FSS Field Supervisor, and FSS Technicians. The FSS Radiological Engineer will make primary decisions with the concurrence of the FSS Project Manager.

2.0 Identify the decision:

The decision to be made can be stated "Does residual plant-related radioactivity, if present in the survey unit, exceed the release criteria?"

Alternative actions that may be employed are investigation, remediation and re-survey.

3.0 Identify the inputs to the decision:

Inputs to the decision include information that will be required to resolve the decision. The information will address such topics as:

• Survey techniques and analytical methodologies selected to generate the required analytical data

" Types and number of samples required to demonstrate compliance with the release criterion

• Identification of the radionuclides-of-concern and their corresponding DCGLs The various aspects of the data such as quality and data sensitivity ensure accurate information is utilized in the testing of the hypothesis.

Sample media: soil Types of measurements: soil samples and 100% scans.

60 137, A 8m Radionuclides-of-concern: Co , Cs 'AG O'and H'3 2 YNPS-FSSP-NOLO1 03 DPF-8856.1 1 DPF-8856. 2 YNPS-FSSP-NOLOI-02-03

Table 1 8.73 mrem/yr DCGL Radionuclide Soil (pCi/gm)

H3 130 Co 60 1.4 Nb94 2.5 Agl0 8m 2.5 Sb125 11 CS1 34 1.7 Cs' 37 3.0 Eu' 52 3.5 Eu15 4 3.3 Eu' 55 140 C' 4 1.9 55 Fe 1.0E04 Ni63 280 9

Sr o 0.6 Tc 99 4.8 Pu2 38 11 P236 Pu239,240 10 4

PuZ 1 340 24 Am 1 10 24 3 Cm , 244 11 SPA-3Scan MDCR and MDC(fDCGLEMc): See Attachment 2 SPA-3 DCGLEMc: 6.9 pCi/gm SurrogateDCGLs (ISOCS): Co-60 (1.2 pCi/gm) Cs-137 (2.8 pCi/gm) Agl08m (2.1 pCi/gm)

DCGLEMc (surrogated): Co-60 13 pCi/gm Cs-137 (61 pCi/gm) Ag-108m (19 pCi/gm)

Note: Surrogates were developed based upon the nuclide mix in sample SFP-GP-12-01 Radionuclidesfor analysis: All LTP nuclides with the focus on Co 60 , CS1 37 , Ag-108m ISOCS Nuclide Library: Library will include the gamma emitters listed in Table 2 Investigation Level for soil samples: Investigation Level for soil samples will be at the DCGL for all nuclides specified in the LTP.

Adjusted investigation Level for ISOCS Measurements:

3 YNPS-FSSP-NOLO1-02-03 0 DPF-8856.1

• Co-60 (0.87 pCi/gm)

• Cs-137 (4.0 pCi/gm)

• Ag-108m (1.3 pCi/gm)

• Cs-134 (1.80 pCi/gm)

Note: The DCGLEMc for the SPA-3 was developed using area factors for a 43.7m2 area (the area in the systematic grid). The adjusted investigation levels for the ISOCS were derived by multiplying the DCGLEMC (DCGLw

• AF for a 1 m2 elevated area) by the ratio of MDAs obtained from the 12.6 m 2 field of view relative to the MDA obtained for a lm 2 area at the edge of the 12.6 m2 field of view as this leads to a conservative model. Cs-134 was not surrogated due to its absence in the characterization samples. The values developed for the lm 2 elevated area at the edge of the field of view used for the ISOCS scan investigative levels are sensitive enough to detect the elevated comparison values for the 43.7m 2 area.

Investigation Level for SPA-3/E-600: Audible increases above background that are reproducible MDCsfor gamma analysis of soil samples:

Table 2 MDCs for gamma emitters Nuclide 10-50% DCGLw (pCi/gm Co-60 0.14-0.70 Nb-94 0.25-1.2 Ag-108m 0.25-1.2 Sb-125 1.1-5.5 Cs-134 0.17-0.86 Cs-137 0.30-1.5 Eu-152 0.35-1.8 Eu-154 0.33-1.7 Eu-155 14-70 The desired MDCs in the laboratory analysis of FSS soil samples should be the 10% values. If it is impractical to achieve those, the 50% DCGLw values must be achieved in the laboratory analysis of the FSS soil samples. ISOCS measurements will meet the 10-50% DCGLEMC values for the LTP gamma emitting nuclides.

MD Cs for HTD nuclides: In addition to the MDC values listed above, the following MDC values will also be transmitted to the outside laboratory via the chain-of-custody form accompanying the FSS soil samples:

DPF-8856.1 4 YNPS-FSSP-NOLO1 -()2-03

Table 3 MDCs for Hard-to-Detect nuclides "Nuclide ' 10-50%,DCGLw (pCi/gmn) l>

H-3 13-65 C-14 0.19-0.95 Fe-55 1E03-5E03 Ni-63 28-140 Sr-90 0.06-0.29 Tc-99 0.48-2.4 Pu-238 1.1-5.7 Pu-239,240 1.0-5.2 Pu-241 34-170 Am-241 1.0-5.2 Cm-243, 244 1.1-5.5 Survey coverage: Scan measurements, or ISOCS, will provide a 100% coverage of the survey area QC checks and measurements: QC checks for the Portable ISOCS will be in accordance with DP-8869 and DP-8871. Two samples will be chosen as QC split samples and will be analyzed by an off-site laboratory for all LTP nuclides. Additionally, two samples will be analyzed twice in-house by gamma spectroscopy and the results compared.

4.0 Define the boundaries of the survey:

Survey Unit NOL-01-02 is located within the RCA and is bounded by NOL-01 on the north, NOL-02-03 on the east, AUX-01 on the south, and NOL-01 on the west.

Surveying of NOL-0 1-02 will be performed during daylight hours when weather conditions will not adversely affect the data acquisition.

5.0 Develop a decision rule:

Null hypothesis: The null hypothesis (Ho), as required by MARSSIM, is stated and tested in the negative form: "Residual licensed radioactive materials in Survey Unit 02 exceeds the release criterion. The null hypothesis, as stated in this manner, is designed to protect the health of the public as well as to demonstrate compliance with the requirements set forth in the Yankee Rowe License Termination Plan. In general, hypothesis testing will result in the following assessments:

DPF-8 856.1 5 YNPS-FSSP-NOLOI-02-03

a. If all of the sample data show that the soil concentrations of all plant-related LTP nuclides are below the DCGLs and the sum of fractions for these nuclides are less than unity, reject the null hypothesis (i.e. NOL-01-02 meets the release criteria).

b. If the investigation levels are exceeded, then perform an investigation survey.

c. If the average concentration is below the DCGL, but individual measurements exceed the DCGL then apply a statistical test to either accept or reject the null hypothesis.

d. If the average concentration of any individual nuclide exceeds the DCGL or if the sum of fractions exceeds unity, then accept the null hypothesis (i.e. NOL-01-02 does not meet the release criteria).

6.0 Specify tolerable limits on decision errors:

Probabilityof type I (a) error: 0.05 Probabilityof type H (fl) error: 0.05 LBGR: 0.5 7.0 Optimize Design:

Type of statistical test: WRS Test L] Sign Test Z Basis includingbackgroundreference location (if WRS test is specified): N/A Number of samples: 15 Random Selected Split Samples: Two samples will be split samples Hard-to-Detectanalyses: Two samples sent for off-site analysis will be analyzed for all LTP hard-to-detect radionuclides referenced in this survey plan Sample Recounts: Two samples will be recounted on-site Biased Samples: 3 biased samples will be taken. One sample taken in the well will be gamma spec counted on-site and the two samples taken in the tritium plume will be gamma spec counted on-site and then sent off-site for tritium analysis.

GENERAL INSTRUCTIONS

1. Notify QA of date and time of the pre-survey briefing, commencement of soil sampling and any other scheduled activities subject to QA notification that are currently known.

2. Soil samples will be collected in accordance with DP-8120 in one-liter marinelli beakers.

Extraneous materials (e.g. vegetation, debris, rocks, etc.) will be removed prior to placing the soil into the marinellis.

. DPF-8856.1 6 YNPS-FSSP-NOLO1-02-03

2. Collect the unbiased soil samples at 15 systematic locations with a random start point.

. 3. Soil sample

a. FSS soildesignation:

samples: NOL-01-02-001-F through NOL-01-02-015-F.

b. Samples NOL-02-03-005-F-S, NOL-02-03-010-F-S will be designated as split samples sent for full analysis by the off-site laboratory for all LTP nuclides.

c. Biased samples will be collected in the following sample sites:

• NOL-01-02-016-F-B will be taken in the well indicated on Attachment 2.

" NOL-01-02-017-F-B and NOL-01-02-018-F-B will be taken in the approximate location of the tritium plume indicated on Attachment 2. NOL-01-02-017-F-B and NOL-01 018-F-B will be counted onsite for gamma analysis then will be sent off site for tritium analysis.

d. The off-site gamma spec. results will be compared with the on-site results in accordance with DP-8864.

Two recount samples: NOL-01-02-007-F and NOL-01-02-012-F will be counted twice on site and the results compared in accordance with DP-8864.

4. All soil samples will be received and prepared in accordance with DP-8813.

5. Chain-of-Custody form will be used in accordance with DP-8123 for all the split samples.

6. The sampling locations will be identified using GPS. In cases where the location cannot be determined directly using GPS, an offset will be used to describe the distance and bearing from a known GPS location. Each location will be marked by a flag, either prior to or at the time of the sampling. The FSS Radiological Engineer or FSS Field Supervisor will guide the FSS

• Technician to the sample locations.

7. Verify that QA has been notified of the date and time of the commencement of the first ISOCS measurements.

8. Survey instrument: Operation of the Portable ISOCS will be in accordance with DP-8871, with QC checks performed in accordance with DP-8869 and DP-8871. Operation of the E-600 w/SPA-3 will be in accordance with DP-8535, with QC checks preformed in accordance with DP-8540. Instrument response checks shall be performed prior to and after use for the E-600 w/SPA-3 and once per shift for the Portable ISOCS. Any flags encountered during the ISOCS QC Source Count must be corrected/resolved prior to surveying. If anomalies cannot be corrected or resolved, contact the Cognizant FSS Engineer for assistance.

9. The job hazards associated with the FSS in Survey Unit 02 are addressed in the accompanying JHA for NOL-01-02.

10. All personnel participating in this survey shall be trained in accordance with DP-8868.

SPECIFIC INSTRUCTIONS

1. ISOCS measurements will be performed in accordance with DP-8871 "Operation of the Canberra Portable ISOCS".

Grid NOL-01-02 for 100% scan coverage by placing markers 3 meters on center in rows no more than 3 meters apart with every other row shifted 11/22 meters off axis from the adjacent row

. DPF-8856. 1 7 YNPS-FSSP-NOL01-02-03

forming a triangular scan grid pattern or place parallel rows of markers forming a square pattern at a maximum distance of 2.6 meters apart. Continue marking the survey unit until there are no markers greater than 1.3 meters from the boundary of NOL-0 1-02 (add additional scan points closer than 3 meters apart as necessary). Using the 900 collimator, position the ISOCS detector directly at each marker 2 meters from the surface to be scanned. Angle the detector as necessary perpendicular to the scan surface and perform an analysis in accordance with DP-8871 employing a preset count time sufficient to meet the MDAs referenced in this survey plan Review the report and verify that the MDAs have been met for the nuclides. Identify radionuclides representing licensed radioactive material and compare their concentration to their respective DCGLEMC value. Record the ISOCS measurement location on the survey map using the appropriate FSS numbering protocol (e.g. NOL-01 xxx (sequential number)-F-G).

Note: Only radionuclides associated with licensed material (i.e. nuclides listed in the LTP) will be assessed through the use of the unity rule. Nuclides associated with natural background radiation will not be included in the assessment.

The unity rule is represented by the following expression:

C1 ++. C2 Cn <_1

<1 DCGLW DCGLW DCGLW Where:

C = concentration DCGLw = DCGLw value for each individual radionuclide (1,2.. .n)

Formula in accordance with LTP Section 5.7.4 Equation 5-27

2. If an analysis of a survey area is equal to or greater than unity then an investigation of that area shall be performed as follows:

a. Further subdivide the survey area into equal sub-areas.

b. Place a marker in the center of each sub-area.

c. Lower the ISOCS detector to approximately 1 meter above the surface and center directly above the marker.

d. Perform an analysis of that sub-area in accordance with DP-8871. -

e. Repeat the analysis sequence for each of the sub-areas within the survey area.

f. In lieu of using ISOCS for first level investigations, SPA-3 scanning may be used for first level investigations.

3. If SPA-3 scanning is utilized for initial scans (i.e. ISOCS scanning is inaccessible, etc.) FSS Technicians will perform scans by moving the SPA-3 detector at a speed 0.25 m/s, keeping the probe within approximately three inches of the ground surface, and following a serpentine pattern that includes at least three passes across each square meter. The FSS Field Supervisor will time and monitor a minimum of 50% of these scans. When scanning and walking, a slow pace (i.e., 1 step per second) shall be used. Scanning will be performed in the rate-meter mode with the audible feature on. Surveyors will listen for upscale readings, to which they will respond by slowing down or stopping the probe to distinguish between random fluctuations in the background and greater than background readings. Location(s) where detectable-above-background scan readings are found will be investigated.

. DPF-8856.1 8 YNPS-FSSP-NOL01-02-03

4. If ISOCS is used for investigations, and a sub-area is determined to contain radiologically elevated areas, then scan the sub-area with a SPA-3 to identify and determine the boundaries of the elevated area. SPA-3 investigative scanning is performed similar in manner as described in step 3 with the exception of the scan speed (move detector 2 to 3 inches per second) and the detector need not be moved in a serpentine pattern.

Note: Background levels for the SPA-3 should range between 10000 and 20000 cpm. If the background levels exceed 24000 cpm, contact a Radiological Engineer prior to commencing/continuing the scan with the SPA-3.

Note: Standing water may shield gamma contamination. Standing water should be removed from the excavation prior to scanning.

5. Once the elevated area, requiring an investigation, has been identified and bounded, locate the point of the highest SPA-3 reading within the bounded area and collect a one-liter soil sample for analysis. If a soil sample is collected during the first level investigation, the sample designation will consist of the next sequential measurement location code plus the letter "I" (for investigation). For example, if a soil sample is collected during a first level investigation at measurement location 019, it will be designated NOL-01-02-019-F-I. If the investigation calls for more than one sample, sequentially number the investigation samples (e.g. NOL-0 1-02-020-F-I). A gamma analysis will be performed on all investigative soil samples. If it can be demonstrated that the presence of rocks and boulders is the cause of an increased count rate during a SPA-3 scan, record that finding form DPF-8856.2 and no soil sample is required. The responsible FSS Radiological Engineer will evaluate analysis of any investigation samples for the LTP suite of nuclides.

Detailed descriptions of investigative actions will be recorded on form DPF-8856.2 and the location of the investigation analyses along with the sample designation will be recorded on the survey map. The location description must provide sufficient detail (i.e.) to allow revisiting the spot at a later time.

All sample analysis will achieve the MDC values stated in he DQO section of this plan.

NOTIFICATION POINTS QA notification point(s) (y/n) y* QA Signature/Date:

(1) Date/time of initial pre-survey briefing /

(2) Date/time of commencement of soil sampling /

(3) Date/time of first scan measurement (4) Date/time of daily pre-survey briefing I

• Email notification to trudeau@yankee.com with a copy to calsyn@yankee.com satisfies this step FSI point(s) (y/n) _ n FSS Radiological Engineer Signature/Date:

(1) /

(2) /

Prepared by Date DPF-8856.1 9 YNPS-FSSP-NOLO1-I 02-03

FSS Radiological Engineer Reviewed by Date FSS Radiological Engineer Approved by Date FSS Project Manager 10 YNPS-FSSP-NOLO1-02-03 0 DPF-8856.1

Final Status Survey Planning Worksheet Page -1 of 9_

GENERAL SECTION Survey Area #: NOL-01 Survey Unit #: 03 Survey Unit Name: Spent Fuel Pit Excavation Southwest FSSP Number: YNPS-FSSP-NOL0 1-03-01 Note: changes notated in bold type PREPARATION FOR FSS ACTIVITIES Check marks in the boxes below signify affirmative responses and completion of the action.

1.1 Files have been established for survey unit FSS records. 0 1.2 ALARA review has been completed for the survey unit. [ See YA-REPT-00-003-05 1.3 The survey unit has been turned over for final status survey.

1.4 An initial DP-8854 walkdown has been performed and a copy of the completed Survey Unit Walkdown Evaluation is in the survey area file. H 1.5 Activities conducted within area since turnover for FSS have been reviewed. [

Based on reviewed information, subsequent walkdown: N not warranted El warranted Note: Based upon Rad Engineer walkdown at the Final Turnover If warranted, subsequent walkdown has been performed and documented per DP-8854. E]

OR The basis has been provided to and accepted by the FSS Project Manager for not performing a subsequent walkdown. D]

1.6 A final classification has been performed. [

Classification: CLASS 1 N CLASS 2 [: CLASS 3 ED DATA QUALITY OBJECTIVES (DQO) 1.0 State the problem:

Survey Area NOL-01-03 is the previous site of the Spent Fuel Pool Pit, IX Pit and Elevator Shaft and some surrounding land areas towards the former Reactor Support Structure. The Spent Fuel Pool Pit was designed for the transfer of new fuel into the reactor, and transfer/storage of spent fuel out of the reactor. The IX Pit was used for housing the Reactor Water cleanup ion exchangers. During plant operation known leaks were discovered in the SFP and IX Pit. Original demolition plans called for the SFP floor, foundations, and sub-grade structures as well as a portion of the IX Pit to remain in place after demolition, however, it has since been determined that most sub-surface structures will be removed as part of the deconstruction process, which was accomplished in this area. The soils located around and under NOL-01-03 include backfill, overburden, and glacio-lacustrine till. Permeability to groundwater flow is varied with the till being the most impermeable and the backfill being the least impermeable. Geoprobe soil samples taken from around the SFP and IX Pit have shown

. amounts in excess of the DCGL values for Co-60, Cs-137 and Ag-108m and the subject soil DPF-8856.1 1 YNPS-FSSP-NOLO1-03-01

was removed during excavation. Demolition activities have since been completed in NOL 03.

Post excavation remediation and a Characterization Survey have been performed in NOL 03. Characterization sampling indicates levels of Co-60 less than 0.6 pCi/gm and Cs-137 levels less than 1.5 pCi/gm. Initial scans were performed using SPA-3 and ISOCS with remediation carried out at locations that indicated elevated levels of radioactivity.

Based upon the radiological condition of this survey area identified in the operating history, and as a result of the decommissioning activities performed to date, survey area NOL-01-03 is identified as a Class 1 Area.

The problem, therefore, is to determine whether the accumulation of licensed radioactive materials generated during plant operation, existing in Survey Unit NOL-01-03, meets the release criterion.

The planning team for this effort consists of the FSS Project Manager, FSS Radiological Engineer, Radiation Protection Manager, FSS Field Supervisor, and FSS Technicians. The FSS Radiological Engineer will make primary decisions with the concurrence of the FSS Project Manager.

2.0 Identify the decision:

The decision to be made can be stated "Does residual plant-related radioactivity, if present in the survey unit, exceed the release criteria?"

Alternative actions that may be employed are investigation, remediation and re-survey.

3.0 Identify the inputs to the decision:

Inputs to the decision include information that will be required to resolve the decision. The information will address such topics as:

" Survey techniques and analytical methodologies selected to generate the required analytical data

" Types and number of samples required to demonstrate compliance with the release criterion

" Identification of the radionuclides-of-concern and their corresponding DCGLs The various aspects of the data such as quality and data sensitivity ensure accurate information is utilized in the testing of the hypothesis.

Sample media: soil Types of measurements: soil samples and 100% scans 60 37 0 Radionuclides-of-concern:Co , Cs1 , Ag' °m and H3 DPF-8856.1 2 YNPS-FSSP-NOLO1-03-01

Table 1 8.73 mrem/yr DCGL Radionuclide Soil (pCi/gm)

H3 130 Co 60 1.4 Nb 94 2.5 Ag108m 2.5 Sb' 25 11 Cs1 34 1.7 Cs13 7 3.0 Eu' 52 3.5 Eu' 54 3.3 Eu' 55 140 4

C1 1.9 55 Fe 1.OE+04 Ni 63 280 Sr90) 0.6 TC 99 4.8 Pu 238 11 pu239, 240 10 PU241 340 24 Am 1 10 243 Cm , 244 11 SPA-3Scan MDCR and MDC(fDCGLEMc): See Attachment 1 SPA-3 DCGLEMc: 6.94 pCi/gm Surrogate DCGLs (ISOCS): Co-60 (1.2 pCi/gm) Cs-137 (2.8 pCi/gm) Agl08m (2.1 pCi/gm)

DCGLEMc (surrogated): Co-60 13 pCi/gm Cs-137 (61 pCi/gm) Ag-108m (19 pCi/gm)

Note: Surrogates were developed based upon the nuclide mix in sample SFP-GP-12-01 60 37 Radionuclidesfor analysis: All LTP nuclides with the focus on Co , CS1 and Agl°8m ISOCS Nuclide Library: Library will include the gamma emitters listed in Table 2 Investigation Level for soil samples: Investigation Level for soil samples will be at the 3 YNPS-FSSP-NOLO1-03-01 0 DPF-8856.1

DCGLw for all nuclides specified in the LTP.

Adjusted investigation Level (DCGLEMc)for ISOCS Measurements:

• Co-60 (0.87 pCi/gm)

• Cs-137 (4.0 pCi/gm)

• Ag-108m (1.3 pCi/gm)

• Cs-134 (1.80 pCi/gm)

Note: The DCGLEMc for the SPA-3 was developed using area factors for a 43.7m 2 area (the area in the systematic grid). The adjusted investigation levels for the ISOCS were derived by multiplying the DCGLEMC (DCGLw

• AF for a lm2 elevated area) by the ratio of MDAs obtained from the 12.6 m 2 field of view relative to the MDA obtained for a lm 2 area at the edge of the 12.6 m2 field of view as this leads to a conservative model. Cs-134 was not surrogated due to its absence in the characterization samples. The values developed for the Im2 elevated area at the edge of the field of view used for the ISOCS scan investigative levels are sensitive enough to detect the elevated comparison values for the 43.7m2 area.

Investigation Level for SPA-3/E-600: Audible increases above background that are reproducible MDCsfor gamma analysis of soil samples:

Table 2 MDCs for gamma emitters Nuclide 10-50% DCGLw (pCi/gm Co-60 0.14-0.70 Nb-94 0.25-1.2 Ag-108m 0.25-1.2 Sb-125 1.10-5.50 Cs-134 0.17-0.86 Cs-137 0.30-1.5 Eu-152 0.35-1.8 Eu-154 0.33-1.7 Eu-155 14-70 The desired MDCs in the laboratory analysis of FSS soil samples should be the 10% values. If it is impractical to achieve those, the 50% DCGLw values must be achieved in the laboratory analysis of the FSS soil samples. ISOCS measurements will meet the 10-50% DCGLEMC values for the LTP gamma emitting nuclides.

4 YNPS-FSSP-NOL01 01 0 DPF-8856.1

MDCsfor HTD nuclides: In addition to the MDC values listed above, the following MDC values will also be transmitted to the outside laboratory via the chain-of-custody form accompanying the FSS soil samples:

Table 3 MDCs for Hard-to-Detect nuclides Nuclide 10-50% DCGLw (pCi/g&)

H-3 13-64 C-14 0.19-0.95 Fe-55 1E03-5E03 Ni-63 28-140 Sr-90 0.06-0.29 Tc-99 0.48-2.4 Pu-238 1.1-5.7 Pu-239,240 1.0-5.2 Pu-241 34-170 Am-241 1.0-5.2 Cm-243, 244 1.1-5.5 Survey coverage: Scan measurements, or ISOCS (the primary method of scans), will provide a 100% coverage of the survey area QC checks and measurements: QC checks for the Portable ISOCS will be in accordance with DP-8869 and DP-8871. Two samples will be chosen as QC split samples and will be analyzed by an off-site laboratory for all LTP nuclides. Additionally, two samples will be analyzed twice in-house by gamma spectroscopy and the results compared.

4.0 Define the boundaries of the survey:

Survey Unit NOL-01-03 is located within the RCA and is bounded by NOL-01-02 on the north, NOL-02-03 on the east, AUX-01 on the south, and NOL-01 on the west.

Surveying of NOL-0 1-03 will be performed during daylight hours when weather conditions will not adversely affect the data acquisition.

5.0 Develop a decision rule:

5 YNPS-FSSP-NOLO1-03-01 0 DPF-8856.1

Null hypothesis: The null hypothesis (Ho), as required by MARSSIM, is stated and tested in the negative form: "Residual licensed radioactive materials in Survey Unit 03 exceeds the release criterion. The null hypothesis, as stated in this manner, is designed to protect the health of the public as well as to demonstrate compliance with the requirements set forth in the Yankee Rowe License Termination Plan. In general, hypothesis testing will result in the following assessments:

a. If all of the sample data show that the soil concentrations of all plant-related LTP nuclides are below the DCGLs and the sum of fractions for these nuclides are less than unity, reject the null hypothesis (i.e. NOL-01-03 meets the release criteria).

b. If the action levels are exceeded, then perform an investigation survey.

c. If the average concentration is below the DCGL, but individual measurements exceed the DCGL then apply a statistical test to either accept or reject the null hypothesis.

d. If the average concentration of any individual nuclide exceeds the DCGL or if the sum of fractions exceeds unity, then accept the null hypothesis (i.e. NOL-01-03 does not meet the release criteria).

6.0 Specify tolerable limits on decision errors:

Probabilityof type I (a) error: 0.05 Probabilityof type H (fl) error: 0.05 LBGR: 0.5 7.0 Optimize Design:

Type of statistical test: WRS Test E] Sign Test Z Basis including backgroundreference location (if WRS test is specified): N/A Number of samples: 15 Random Selected Split Samples: Two samples will be split samples Hard-to-Detectanalyses: Two samples sent for off-site analysis will be analyzed for all LTP hard-to-detect radionuclides referenced in this survey plan Sample Recounts: Two samples will be recounted on-site Biased Samples: 2 biased samples will be taken, one in each well, and will be gamma spec.

counted on-site GENERAL INSTRUCTIONS

. DPF-8856.1 6 YNPS-FSSP-NOL( )1-03-01

1. Notify QA of date and time of the pre-survey briefing, commencement of soil sampling and any other scheduled activities subject to QA notification that are currently known.

2. Soil samples will be collected in accordance with DP-8120 in one-liter marinelli beakers.

Extraneous materials (e.g. vegetation, debris, rocks, etc.) will be removed prior to placing the soil into the marinellis.

2. Collect the unbiased soil samples at 15 systematic locations with a random start point.

3. Soil sample designation:

a. FSS soil samples: NOL-01-03-001-F through NOL-01-03-015-F.

b. Samples NOL-02-03-0011-F-S, NOL-02-03-014-F-S will be designated as split samples sent for full analysis by the off-site laboratory for all LTP nuclides.

c. Biased samples will be collected in the following sample sites:

• NOL-01-03-016-F-B and NOL-01-03-17-F-B will be taken in the wells indicated on Attachment 2.

d. The off-site gamma spec. results will be compared with the on-site results in accordance with DP-8864.

Two recount samples: NOL-01-03-002-F and NOL-01-03-008-F will be counted twice on site and the results compared in accordance with DP-8864.

4. All soil samples will be received and prepared in accordance with DP-8813.

5. Chain-of-Custody form will be used in accordance with DP-8123 for all the split samples.

6. The sampling locations will be identified using GPS. In cases where the location cannot be determined directly using GPS, an offset will be used to describe the distance and bearing from a known GPS location, Each location will be marked by a flag, either prior to or at the time of the sampling. The FSS Radiological Engineer or FSS Field Supervisor will guide the FSS Technician to the sample locations.

7. Verify that QA has been notified of the date and time of the commencement of the first ISOCS measurements.

8. Survey instrument: Operation of the Portable ISOCS will be in accordance with DP-8871, with QC checks performed in accordance with DP-8869 and DP-8871. Operation of the E-600 w/SPA-3 will be in accordance with DP-8535, with QC checks preformed in accordance with DP-8540. Instrument response checks shall be performed prior to and after use for the E-600 w/SPA-3 and once per shift for the Portable ISOCS. Any flags encountered during the ISOCS QC Source Count must be corrected/resolved prior to surveying. If anomalies cannot be corrected or resolved, contact the Cognizant FSS Engineer for assistance.

9. The job hazards associated with the FSS in Survey Unit 03 are addressed in the accompanying JHA for NOL-01-03.

10. All personnel participating in this survey shall be trained in accordance with DP-8868.

SPECIFIC INSTRUCTIONS

1. ISOCS measurements will be performed in accordance with DP-8871 "Operation of the DPF-8856.1 7 YNPS-FSSP-NOL01-03-01

Canberra Portable ISOCS".

Grid NOL-01-03 for 100% scan coverage by placing markers 3 meters on center in rows no more than 3 meters apart with every other row shifted 11/22 meters off axis from the adjacent row forming a triangular scan grid pattern or place parallel rows of markers forming a square pattern at a maximum distance of 2.6 meters apart. Continue marking the survey unit until there are no markers greater than 1.3 meters from the boundary of NOL-01-03 (add additional scan points closer than 3 meters apart as necessary). Using the 900 collimator, position the ISOCS detector directly at each marker 2 meters from the surface to be scanned. Angle the detector as necessary perpendicular to the scan surface and perform an analysis in accordance with DP-8871 employing a preset count time sufficient to meet the MDAs referenced in this survey plan. At the completion of the analysis review the report and verify that the MDAs have been met for the nuclides. Identify radionuclides representing licensed radioactive material and compare their concentration to their respective DCGLEMc value. Record the ISOCS measurement location on the survey map using the appropriate FSS numbering protocol (e.g. NOL-01 xxx(sequential number)-F-G).

Note: Only radionuclides associated with licensed material (i.e. nuclides listed in the LTP) will be assessed through the use of the unity rule. Nuclides associated with natural background radiation will not be included in the assessment.

2. If an analysis of a survey area is equal to or greater than the investigation level then an investigation of that area shall be performed as follows:

a. Further subdivide the survey area into equal sub-areas.

b. Place a marker in the center of each sub-area.

c. Lower the ISOCS detector to approximately 1 meter above the surface and center directly above the marker.

d. Perform an analysis of that sub-area in accordance with DP-8871.

e. Repeat the analysis sequence for each of the sub-areas within the survey area.

f. In lieu of using ISOCS for first level investigations, SPA-3 scanning may be used for first level investigations.

3. If SPA-3 scanning is utilized for initial scans (i.e. ISOCS scanning is inaccessible, etc.) FSS Technicians will perform scans by moving the SPA-3 detector at a speed 0.25 m/s, keeping the probe within approximately three inches of the ground surface, and following a serpentine pattern that includes at least three passes across each square meter. The FSS Field Supervisor will time and monitor a minimum of 50% of these scans. When scanning and walking, a slow pace (i.e., 1 step per second) shall be used. Scanning will be performed in the rate-meter mode with the audible feature on. Using the headsets, surveyors will listen for upscale readings, to which they will respond by slowing down or stopping the probe to distinguish between random fluctuations in the background and greater than background readings. Location(s) where detectable-above-background scan readings are found will be investigated.

4. If ISOCS is used for investigations, and a sub-area is determined to contain radiologically elevated areas, then scan the sub-area with a SPA-3 to identify and determine the boundaries of the elevated area. SPA-3 investigative scanning is performed similar in manner as described in step 3 with the exception of the scan speed (move detector 2 to 3 inches per second) and the detector need not be moved in a serpentine pattern.

DPF-8856.1 8 YNPS-FSSP-NOL01-03-01

Note: Background levels for the SPA-3 should range between 10000 and 20000 cpm. If the background levels exceed 24000 cpm, contact a Radiological Engineer prior to commencing/continuing the scan with the SPA-3.

Note: Standing water may shield gamma contamination. Standing water should be removed from the excavation prior to scanning.

5 Once the elevated area, requiring an investigation, has been identified and bounded, locate the point of the highest SPA-3 reading within the bounded area and collect a one-liter soil sample for analysis. If a soil sample is collected during the first level investigation, the sample designation will consist of the next sequential measurement location code plus the letter "I" (for investigation). For example, if a soil sample is collected during a first level investigation it will be designated NOL-01-02-018-F-I. If the investigation calls for more than one sample, sequentially number the investigation samples (e.g. NOL-01-02-019-F-I). A gamma analysis will be performed on all investigative soil samples. If it can be demonstrated that the presence of rocks and boulders is the cause of an increased count rate during a SPA-3 scan, record that finding form DPF-8856.2 and no soil sample is required. The responsible FSS Radiological Engineer will evaluate analysis of any investigation samples for the LTP suite of nuclides.

Detailed descriptions of investigative actions will be recorded on form DPF-8856.2 and the location of the investigation analyses along with the sample designation will be recorded on the survey map. The location description must provide sufficient detail (i.e.) to allow revisiting the spot at a later time.

All sample analysis will achieve the MDC values stated in the DQO section of this plan.

NOTIFICATION POINTS QA notification point(s) (y/n) y* QA Signature/Date:

(1) Date/time of initial pre-survey briefing /

(2)Date/time of commencement of soil sampling /

(3)Date/time of first scan measurement /

(4) Date/time of daily pre-survey briefing /

• Email notification to trudeau@yankee.com with a copy to calsyn@yankee.com satisfies this step FSI point(s) (y/n) _ n FSS Radiological Engineer Signature/Date:

(1). I (2) /

Prepared by Date FSS Radiological Engineer Reviewed by Date FSS Radiological Engineer Approved by Date FSS Project Manager DPF-8856.1 9 YNPS-FSSP-NOL01-03-01

Final Status Survey Planning Worksheet Page I of 5 GENERAL SECTION Survey Area #: NOL-01 Survey Unit #: 04 Survey Unit Name: Eastern Lower RCA Yard - The "Alley Way" FSSP Number: YNPS-FSSP-NOLO1-04-00 PREPARATION FOR FSS ACTIVITIES Check marks in the boxes below signify affirmative responses and completion of the action.

1.1 Files have been established for survey unit FSS records.  !]

1.2 ALARA review has been completed for the survey unit. [71 (YA-REPT-00-003-05) 1.3 The survey unit has been turned over for final status survey. []

1.4 An initial DP-8854 walkdown has been performed and a copy of the completed Survey Unit Walkdown Evaluation is in the survey area file. Wl 1.5 Activities conducted within area since turnover for FSS have been reviewed. l]

Based on reviewed information, subsequent walkdown: M] not warranted El warranted If warranted, subsequent walkdown has been performed and documented per DP-8854. El OR The basis has been provided to and accepted by the FSS Project Manager for not performing a subsequent walkdown. El 1.6 A final classification has been performed. 2 Classification: CLASS 1 l] CLASS 2 El CLASS 3 E]

DATA QUALITY OBJECTIVES (DQO) 1.0 Statement of problem:

Survey Unit NOLO1-04 consists of the excavated open land area in the section of the eastern lower RCA yard that abuts the Turbine Building and Service Building foundations. It is referred to as the "alley way." The unit shares its west boundary with survey unit NOL01-01, its south boundary with survey units NOL01-02 and NOL02-01, and its east boundary with survey area OOL-12. The NOL01-04 footprint is approximately 9,483 ft2 (881 M2). The data collected under this plan will be used to determine whether or not residual plant-related radioactivity in soil of Survey Unit NOLOI-04 meets the LTP release criteria.

The planning team for this effort consists of the FSS Project Manager, FSS Radiological Engineer, FSS Field Supervisor, and FSS Technicians. The FSS Rad. Engineer will make primary decisions with the concurrence of the FSS Project Manager.

2.0 Identify the decision:

Does residual plant-related radioactivity, if present in the survey unit, exceed LTP release criteria? Alternative actions that may be implemented in this effort are investigations and remediation followed by re-surveying.

3.0 Identify the inputs to the decision:

Sample media: soil Types of measurements: soil samples, ISOCS assays, and gamma scans.

Radionuclide-of-concern: Cs-137 and Co-60 FSS planning used onsite gamma analysis results for 11 post-remediation soil samples collected from unit NOLO1-04. Co-60 and Cs-137 were the only plant-related gamma-emitting radionuclides identified in the samples, although not consistently at concentrations that were greater than the MDCs for the analyses. The mean soil concentrations of Co-60 and Cs-137 were 0.08 pCi/g +/- 0.092 pCi/g and 0.03 pCi/g +/- 0.024 pCi/g, respectively. The Co-60 and Cs-137 concentrations were all well below the respective DCGL (the Co-60 concentrations ranged from <MDA to 0.27pCi/g and the Cs-137 concentrations ranged from <MDA pCi/g to 0.073 pCi/g).

The presence of all LTP-listed radionuclides (gamma-emitters, HTD beta-emitters, and TRUs) in the soil will be evaluated under this survey plan. The YNPS Chemistry Dept. will analyze each FSS soil sample for all LTP-listed gamma-emitting nuclides, except Cm-243/244. In addition, 4 FSS soil samples will be sent to an independent laboratory for analyses of DPF- 8856.1 YNPS-FSSP-NOLOI-04-00 Page 1 of 5

gamma-emitters, HTD beta-emitting radionuclides, and alpha-emitting radionuclides, which will include Cm-243/244.

Applicable DCGL: The DCGLs applied under this survey plan correspond to annual doses of 8.73 mrem/y (the 10-mrem/y DCGL adjusted for the dose contributions from sub-surface concrete structures and tritium in ground water).

DCGL DCGL DCGL (pCi/g)

Nuclide (pCi/g) Nuclide (pCi/g) Nuclide Co-60 1.4E+0 Eu-152 3.5E+0 Sr-90 5.9E-1 Nb-94 2.5E+0 Eu- 154 3.3E+0 Tc-99 4.8E+0 AglO8m 2.5E+0 Eu- 155 1.4E+2 Pu-238 l.lE+1 Sb125 1.IE+1 H-3 1.3E+2 Pu-239/240 1.OE+1 Cs-134 1.7E+0 C-14 1.9E+0 Pu-241 3.4E+2 Cs-137 3.0E+0 Fe-55 L.OE+4 Am-241 1.OE+l Ni-63 2.8E+2 Cm-243/244 1.11E+1 Average concentration: Cs-137 = 0.03 pCi/g and Co-60 = 0.08 pCi/g Standarddeviation (a): Cs-137 = 0.024 pCi/g and Co-60 = 0.092 pCi/g Weighted sum a = 0.066 pCi/g DCGLL-Mc: Cs- 137 = 8.7 pCi/g (based on AF = 2.9), Co-60 = 2.0 pCi/g (based on AF = 1.4)

Investigation Level for soil samples: (a) >DCGLEMc for either Cs-137 or Co-60, or (b) a sum of DCGLEMC fractions >1.0, or (c) >DCGL for either Cs-137 or Co-60 and a statistical outlier as defined in the LTP Note: the same criteria will be applied to any other LTP-listed if identified in the FSS soil samples.

ISOCS assays coverage: 100% of the surface area, ensured by overlapping field-of-views Investigation Level for ISOCS assays: 1.0 pCi/g Co-60, 4.3 pC/g Cs- 137, or a sum of their fractions >1.0.

Note: The investigation levels for the ISOCS assays were derived by multiplying the DCGLEMc 2 associated with a lm 2 area by2 2 and 3.14m for side assays) to the MDC for a lm the ratio of the MDC for the full field of view (12.6m for overhead assays area at the edge of the full field of view. Additional details regarding the investigation levels for ISOCS assays can be found in YA-REPT-00-018-05. The investigation levels developed in this manner are sensitive enough to detect the Co-60 and Cs-137 DCGLEMc values based on the grid area (2.0 pCi/g and 8.7 pCi/g, respectively).

MDCs forISOCS measurements:

MDC MDC MDC Nuclide (pCi/g) Nuclide (pCi/g) Nuclide, (pCi/g)

Co-60 2.OE-1 Sb-125 1.3E+0 Eu-152 4.2E- 1 Nb-94 3.OE-1 Cs-134 3.6E-1 Eu-154 4.3E-1 Ag-108m 3.OE-1 Cs-137 8.7E-1 Eu-155 1.7E+1 2

Note: The MDCs listed in the above table are 10% of the DCGLEMC values (based on nuclide-specific AF value for 75 m from LTP, Appendix 6Q). If the MDC values in the above table cannot be achieved in a reasonable count time, then an MDC no greater than 5X the table value must be achieved.

Scan coverage: SPA-3 scans will be performed only for the surface soil within the field-of-view of an ISOCS assay that 2

exceeds the investigation criteria. The SPA-3 scan will cover 100% of the total field-of-view area (12.6m ).

InvestigationLevelfor SPA-3 scan: >background indication using an audible signal with headphones Radionuclidesfor analysis: All LTP-listed nuclides with the focus on Cs-137 and Co-60.

MDCs for gamma analysis of soil samples:

Target MDC Target MDC Target MDC Nuclide (pCi/g) Nuclide (pCi/g) Nuclide (pCi/g)

Co-60 1.4E- 1 Sb125 1.1E+0 Eu- 152 3.5E-1 Nb-94 2.5E- I Cs- 134 1.7E-1 Eu- 154 3.3E-1 AglO8m 2.5E-1 Cs-137 3.OE-1 Eu-155 1.4E+1 Am-241 1.OE+0 Note: If a target MDC value cannot be achieved in analysis, then a value no greater than 5X the listed value must be achieved in the analysis. II DPF-:8856.1 YNPS-FSSP-NOLO1-04-00 Page 2 of 5

MDCsfor analyses of HTD nuclides:

Target MDC Target MDC Target MDC Nuclide (pCi/g) Nuclide (pCi/g) Nuclide (pCi/g)

H-3 1.3E+l Sr-90 5.9E-2 Pu-241 3.4E+1 C- 14 1.9E- I Tc-99 4.8E-1 Am-241 1.OE+O Fe-55 L.OE+3 Pu-238 1.1E+O Cm-243/244 1.1E+O Ni-63 2.8E+l Pu-239/240 l.OE+O Note: If a target MDC value cannot be achieved in analysis, then a value no greater than 5X the listed value must be achieved in the analysis.

OC checks and measurements: QC checks for the SPA-3 will be performed in accordance with DP-8540. Four QC split samples will be collected, and QC recounts for 2 soil samples will be performed by the YNPS Chemistry Lab. QC checks for the ISOCS will be in accordance with DP-8869 and DP-8871.

4.0 Define the boundaries of the survey:

Boundaries of NOL01-04 are as shown on the attached maps. Map 1 identifies the locations of FSS soil samples. Map 2 shows the planned coverage of ISOCS assays for the horizontal surface. Map 3 shows the planned coverage of ISOCS assays for the sloping walls of the main excavation. The survey will be performed under weather conditions that permit surveying.

5.0 Develop a decision rule:

(a) If all the sample data show that the soil concentrations of all plant-related nuclides are below the DCGL and the sum of the DCGL fractions for identified nuclides is <1, reject the null hypothesis (i.e., Survey Unit meets the release criteria).

(b) If the investigation level is exceeded, then perform an investigation survey.

(c) If the average concentration of the radionuclide-of-concern is below the DCGL, or if the sum of the fractions for identified radionuclides-of-concern <1, but some measurements exceed the DCGL, then apply a statistical test as the basis for accepting or rejecting the null hypothesis.

(d) If the average concentration of any LTP-listed nuclide exceeds the DCGL or the sum of the fractions exceeds one, then accept the null hypothesis (i.e., Survey Unit fails to meet the release criteria).

6.0 Specify tolerable limits on decision errors:

Null hypothesis: Residual plant-related radioactivity in Survey Unit NOLOI-04 exceeds the release criteria.

Probabilityof type I error:0.05 Probabilityof type HIerror:0.05 LBGR: 0.5 7.0 Optimize Design:

Type of statistical test: WRS Test El Sign Test I]

Basis including background reference location (if WRS test is specified): N/A Number samples (perDP-8853): 15.

Biased samples: Three GENERAL INSTRUCTIONS

1. The FSS Field Supervisor is responsible for contacting the QA Department regarding the FSS activities identified as QA notification points.

2. Standing water must be removed prior to the collection of any FSS measurement in that area. Do not perform this survey if there is a solid snow cover; FSS activities will be performed under a revised plan.

3. Mark the sampling points at the coordinates provided with the attached map. If a measurement location is obstructed such that a sample cannot be collected, select an alternate location in accordance with DP-8856.

4. Collect 18 soil samples in accordance with DP-8120, using sampling equipment as stated in DP-8120. Four of the 18 soil samples will be QC split samples. Soil sample designations are as follows:

(a) Grid soil sample designations: NOL-01-04-001-F through NOL-01-04-015-F corresponding to FSS samples collected at locations 001 through 015 (refer to map 1).

(b) Biased soil sample designation: NOL-01-04-135-F-B through NOL-01-04-137-F-B, corresponding to the FSS DPF-:8856.1 YNPS-FSSP-NOLO1-04-00 Page 3 of 5

sample collected at location 135 through 137 (refer to map 1).

(c) 4 QC split sample designations: NOL-01-04-001-F-S, NOL-01-04-002-F-S, NOL-01-04-005-F-S, and NOL-01 014-F-S, collected at sample locations 001, 002, 005, and 014, respectively. The results will be compared in accordance with DP-8864.

Note: Samples NOL-01-04-001-F-S, NOL-01-04-002-F-S, NOL-01-04-003-F-S, and NOL-01-04-014-F-S will be sent to the off-site laboratory as collected from the field (i.e., without drying). YNPS Chemistry will count these 4 soil samples in the "wet' condition prior to shipment to the offsite laboratory, where they will be analyzed for gamma-emitters, HTD beta-emitters (including H-3), and TRUs.

Note: Soil samples NOL-01-04-006-F and NOL-01-04-011 -F are QC recounts (to be performed by the YNPS Chemistry Lab) and the results will be compared in accordance with DP-8864. The designations for the recount analyses are NOL-01-04-006-F-RC and NOL-01-04-011 -F-RC, respectively.

5. Collect 119 (or more, as determined necessary in the field) ISOCS measurements in accordance with DP-8871. In all assays, use the 900 collimator and a preset count time ensuring that the MDC values listed in DQO 3.0 are met.

(a) The location (center-point) for 87 ISOCS assays for the horizontal surface area will be identified by GPS coordinates and marked (refer to map 2). If the field-of-view of an ISOCS assay includes a large amount of miscellaneous concrete structure present in the unit, record that observation on DP-8856.2.

(b) The location of the ISOCS assays on the excavation slopes must be identified through measurement, such as with a tape measure or "calibrated" rope. (refer to map 3). Note: The number of ISOCS assays shown in map 3 was based on an estimated area for walls of the main excavation in unit NOL01-04. The actual number of assays required to assure 100% coverage of the surface area may be more (or fewer) than indicated in map 3.

(c) Position the ISOCS at 2m directly above (and perpendicular to) the assay center point (the center of the field of view for the ISOCS assay), angling the detector as necessary to keep it perpendicular to the area being surveyed. Each ISOCS assay has been assigned a measurement code, which appears at the center of the fields of view shown in maps 2 and 3. Designate the assays as NOL-01-04-016-F-G through NOL-01-04-134-F-G, as shown by maps 2 and 3.

Note: If additional ISOCS assays are necessary to assure 100% coverage of the survey unit, designate them in continuing sequence from the last number assigned to an ISOCS measurement. Record detailed information about any additional ISOCS assay on DPF-8856.2.

Note: If the results of an ISOCS assay exceed an investigation level, investigate the area within the field-of-view area for that ISOCS assay as directed in Specific Instructions 1.

6. All soil samples will be received and prepared in accordance with DP-8813.

7. Chain of Custody form will be used in accordance with DP-8123 for all soil samples sent to an off-site laboratory. The required MDCs for the analyses performed by the off-site laboratory will be communicated to the Lab via the Chain-of-Custody form or an attachment to that form.

8. Survey instrument: Operation of the E-600 will be in accordance with DP-8534. Pre- and post-use QC checks for survey instruments are to be performed.

9. ISOCS: Operation of the ISOCS will be in accordance with DP-8871, with QC checks performed once per shift in accordance with DP-8869 and DP-8871. Any flag encountered during the ISOCS QC source count must be corrected/resolved prior to surveying. If an anomaly cannot be corrected or resolved, contact the cognizant FSS Engineer for assistance.

10. The job hazards associated with this survey, particularly accessing the sloping walls of the excavation, are addressed in the JHA for NOLO1-04 and also will be addressed in the Yankee Rowe Project Daily Activity Plan and discussed at the pre-survey briefing.

11. All personnel participating in this survey shall be trained in accordance with DP-8868.

SPECIFIC INSTRUCTIONS

1. If the results of a 2-m ISOCS assay exceed an investigation level, perform a first level investigation as follows:

a) Collect 9 additional ISOCS assays in accordance with DP-8871 (use the 900 collimator and a preset count time ensuring that the MDC values listed in DQO 3.0 are met). Use Figure 1 as a reference for positioning the detector.

(1) Position the ISOCS at lm directly above (and perpendicular to) the center point of the ISOCS assay that exceeded the investigation level, angling the detector as necessary to keep it perpendicular to the area being surveyed.

Designate this ISOCS assay as NOL-01-04-xxx-F-G-I, where "xxx" continues from the last ISOCS assay.

(2) Measure a distance of 1.25 meters from the center point of the ISOCS assay that exceeded the investigation level.

Position the ISOCS at 1m directly above (and perpendicular to) that point, angling the detector as necessary to keep it perpendicular to the area being surveyed. Before collecting the ISOCS measurement, ensure that the position of the detector agrees with Figure 1. Designate this ISOCS assay as NOL-01-04-xxx-F-G-I, where "xxx" continues from the last ISOCS assay.

DPF-:8856.1 YNPS-FSSP-NOLO1-04-00 Page 4 of 5

(3) In the clockwise direction, measure a distance of 1.25 meters from the center point (of the ISOCS assay that exceeded the investigation level) that also forms a 450 angle to the previous ISOCS measurement location. Position the ISOCS at Im directly above (and perpendicular to) that point, angling the detector as necessary to keep it perpendicular to the area being surveyed. Before collecting the ISOCS measurement, ensure that the position of the detector agrees with Figure 1. Designate this ISOCS assay as NOL-01-04-xxx-F-G-I, where "xxx" continues from the last ISOCS assay.

b) Review the ISOCS results to identify the location of elevated activity.

c) Perform a SPA-3 scan of the area (3.1m 2) within the field-of-view of the 1-meter ISOCS identifying the highest amount of plant-related activity. If the results for other I-meter ISOCS (i.e., adjacent, overlapping assays) results are within 25%

of the highest identified activity, perform SPA-3 scans in the fields-of-view for those ISOCS measurement also.

2. If a SPA-3 scan is performed in response to exceeding an ISOCS assay investigation level:

" The FSS Field Supervisor should monitor and time scan speeds for at least 50% of scanned areas to ensure that the scan speed of 0.25 m/s is maintained, and record that action on DPF-8856.2,

• Ensure that the name of the FSS Technician performing the scan, the instrument serial numbers, and scan path are recorded on the survey map or on DPF-8856.2.

a) SPA-3 scans are to be performed by moving the detector at a speed no greater than 0.25 m/s, keeping the probe at a distance of less than 3 inches from the ground surface, and following a serpentine pattern that includes at least 3 passes across each square meter. When scanning and walking, a slow pace (i.e., 1 step per second) shall be used. FSS Technicians will wear headphones while scanning and the survey instrument will be in the rate-meter mode. Surveyors will listen for upscale readings, to which they will respond by slowing down or stopping the probe to distinguish between random fluctuations in the background and greater than background readings. Location(s) with the 3.1 m 2 field-of-view of the ISOCS measurement will be marked, and a soil sample will be collected at the location of the highest SPA-3 reading.

b) Detailed descriptions of investigation actions will be recorded on form DPF-8856.2 and the location of the investigation soil sample will be recorded on the survey map. If investigation samples are collected, the designations will continue in sequence as NOL-01-04-xxx-F-I, where "xxx" continues from the last number assigned to an FSS measurement.

2. Soil samples NOL-01-04-005-F-S, NOL-01-04-007-F-S, NOL-01-04-008-F-S, NOL-01-04-012-F-S, and NOL-01-04-135-F-B through NOL-01-04-137-F-B are to be sent to the off-site laboratory. These samples will be analyzed for H-3, gamma-emitting nuclides, HTD beta-emitting nuclides, and TRUs. Ensure that the lid to the 1-liter marinelli container for each sample is secured to prevent loss of moisture during shipping. If the results of the offsite laboratory's analyses identify radionuclides at concentrations greater than the investigation level, an investigation survey will be conducted under a separate plan.

4. On-site and off-site analyses of the FSS samples shall achieve the required MDC values stated in Section 3 of this plan.

The MDCs will be communicated to the laboratory using an attachment to the Chain-of-Custody form.

5. Remove the trash left in the well-head stand area when conducting FSS activities in that area.

6. Remove minor pieces of concrete from the unit during FSS activities.

NOTIFICATION POINTS QA notification* point(s) (y/n) _y (1) Date/time of initial pre-survey briefing QA signature:

(2) Date/time of commencement of soil sampling QA signature:

(3) Date/time of commencement of ISOCS measurements QA signature:

(4) Time(s) of daily pre-shift briefing QA signature:

(for each shift that the FSS is performed)

• Voice mail notification or E-mail notification to Trudeau@yankeerowe.com with a copy to Marchi@cyapco.com satisfies this step.

FSI point(s) (y/n) n Specify:

Prepared by_ Date FSS Radiological Engineer Reviewed by_ Date FSS Radiological Engineer Approved by_ Date DPF-:8856.1 YNPS-FSSP-NOLO1-04-00 Page 5 of 5

Report No.: YNPS-FSS-NOLOI-O0 Appendix C YA-REPT-00-018-05 Use of In-Situ Gamma Spectrum Analysis to Perform Elevated Measurement Comparison in Support of Final Status Surveys

Report No.: YNPS-FSS-NOLOI-00 Use Of In-Situ Gmnma Spectrum Analysis To Perform Elevated Measurement Comparisons In Support O1" Final Status Surveys YA-REPT-00-018-05 Approvals (Print & Sign Name)

Preparer: Greg Astrauekas!Signature on file Date: 10/10/05 PreTarer: Gtordon Madison, CH1P!/Signature on file Date: 10/11405 Reviewer: Jim Hummer, CHP/Signature on file Date: 10118:05 Approver (FSS Manager):

Dann Smith, ClIP/Signature on file Date: 11/4/05 Rev. 0

Report No.: YNPS-FSS-NOLOI-00 YA-R EPT-O0-01 8-05 Re,. 0 T'edcnical Report YA-REPI'-O0-OI 8-05, Rev. 0 Use Of ln-Silu Gaumma Spectrum Analysis To Performt Elevated Measurement Comparisons In Support Of Final Status Surveys TABLE OF CONTENTS 1.0 Report .................................................. 2 1.. I Inroduction-....... ........ .......................... ... 2 1.2 Discussion ................ ................................ 2 1.2,1 Detector Description ............................................ 2 1.2.2 Traditional Approach..-................. .......................3 1.23 Innovative Appruach .......... ......................... 4 1.2.4 Investigalion Ievel ................. .................. 4 1.2.5 Detector Sensitivity .........-- ........ ........................ 8 1.2.6 Area Covetag........................ ............... 8

.1.2.7 Moisture Content in the Soil Matrix ....... .......................... 9 1.2.8 I)iscrcuk P irtieles in the Soil M.rix . . .............. ...... 10 1.2,9 Procedures and Guidance Documents ...................... 10 1.2.10 Environmental Background ............ ............. 11 1.2.11 Quality Control ....................................... . 1 1.2,12 Data Collection ................................... 12 1.2.13 Efficiency Calibration ............................. ........ 13 1.2,14 D)ata Managcment ................................... 13 1.3 ConclusionsRcco ndations..................... .................- 14 1.4 References ............................................... 14 Altachments Attachment 1. ISOCS Detector System Photos........................................5......A Attachment 2, Field-Of-View Characterization....................................... 16 Attachment 3, Typical Grid Pattern For In-Situ Gamma Spectroscopy ................ 18

-I-

Report No.: YNPS-FSS-NOLO1-00 YA-R EPT-00-018-05 Rev. 0 1.0 REPORT

1. I Introduction Tl7he ISOCS In-Situ Gamma Spectrum detector system manufactured by Canberra Industries is being employed to perforn elevated measurement comparison (EMC) surveys in support of the Final Status Surveys at Yankee Atomic's Yankee Rowe facility. 'this system uses an II Pe detector and specialized efliciency calibration software designed to perform in-situ gamma-spectroscopy assays. Thie ISOCS system will primarily be employed to evaluate survey units for elevated measurement comparisons. 'lie ISOCS system can obtain a static measurcment at a tixed distance from a pre-determined location. Count times can be tailored to achieve required detection scnsitivities. ;arma spectroscopy readily distinguishes background activity from plant-related licensed radioactivity, This at.rihUIC is particularly beneficial where natural radioactivity introduces significant investigation survey etTorts. Additionally, background subtraction or collimation can be employed where background influences are problematic due to the presence of stored spent. fuel (ISFSl),

This technical report is intended to outline the technical approach associated with the use ofIISOCS for implementing a MARSSIM-based Final Status Survey with respect to scanning surveys fbr elevated measurement comparisons fbr both open land areas and building stuacr.s. While the examples and discussions in this report primarily address open land areas, the sane approach and methodology will he applied when deriving investigation levels, grid spacing ,ad measurement spacing for evaluating building surfaces.

Validation of the ISOCS software is beyond the scope of this technical report.

Canberra Industries has pcrtbricd extensive testing and validation on both the MCNP-based detector characterization process and the ISOCS calibration algorithms associated with the calibration software. The fill MCNNP method has been shown to be accurate to within 5% typically. ISOCS results have been compared to both full MCNP and to 119 dill~rent radioactive calibration sources. In general. ISOCS is accurate to within 4-5% at high cnergi,ýs and 7-11% at 1 standard deviation for low energies. Additionally, the ISOCS teclnology has been previously qualified in Yankee Atomic Technical Report YA-RElPT-00-022-04, "Use Of Gamma Spectrum Analysis 1l Evaluate Bulk Materials For Compliance With License Tennination Criteria."

1.2 Discussion 1.2,1 Detector Description Two ISOCS-characterized IHPic detectors tuanufactured by Canberra Industries have been procured. Each detct2or is a reverse-electrode t?Hc, Report No.: YNPS-FSS-NOLOI-00 Y A-REPTI-O 1.-05 Rev. 0 detector rated at 50% efficiency (relative to a Nal detector). Resolution for these detectors is 2.2 keV @ 1332 keV. As the project progresses, other ISOCS detevtors (e.g. standard electrode coaxial). if available. may bc used to increase productivity. The key element regarding the use of other types of ISOCS*' detectors is that speeific efficiency calibrations will be developed to account f'or each detcctor's unliquC characteristics.

The HPGc detector is mounted onl a bracket designed to hold the detector I cryostat assembly and associated collimators. 'his bracket may bc mountcd in a wheeled cart or in a cage-like frame. Both the wheeled cart and frame permit the detector to be oriented (pointed) over a full range from a horizontal to vertical position. [he friame's design allows the detector to be suspended above the ground. Photographs of the firame-mounted system are presented in Attachment 1. During evaluations of Class I areas f'or clevated radioactivity. the detector will generally be, outfitted with the 90-degree collimator. Suspending the detector at 2 meters above the target surface yields a nominal field-oi-view of' 12.6 m'.

Tlhie InSpector (MCA) unit that drives the signal chain and the laptop computer that runs t(le acquisition software (Genie-2000) are mounted either it0 the frame or on thewheeled calr. These components are battery powered.

Back-up power supplies (inverter or UPS) are available to support the duty cycle. A wireless network has been installed at the site so that the laptop computers used to run the systems can be completely controlled from any workstation at tile thcilily. 'this configuration also enables the saving of data files directly to a centralized file server. Radio communication will be used to coordinate system operation.

1.2,2 TFraditional Approach With respect to Class I Survey Units, small areas of elevated activity are evaluatcd via tihe perfornance of scan surveys. 1lt size of the potential area of elevated activity alects the DCGLIw1c and is typically determined by that area bounded by the grid points used for fixed measurements. 'Ibis area in turn dictates the area factor(s) used for deriving the associated 1CG1,.,\sc.

These scan surveys. are traditionally conducted with hand-held field insmuments that have a detection sensitivity sufficiently low to identify areas of localized activity above the DCGI.stc. Occasionally, the detection sensitivity ofthese instruments is greater than the DCGLI.mc. In order to increase tihe DCGLF,**1 to the point where hand-held instrutmentation can be reasonably employed, the survey design is augmented to require additional fixed-point measurements. 'The effect of these additional measurement points is to lighten the fixed measurement grid spacing, thus reducing the area applied to deriving Ihe I)CGLntc and increasing the detection sensitivity criteria.

N Report No.: YNPS-FSS-NOLO1-00 YA-R EP'fI-00-01 8-05 Rev. 0 Background influences (Front the ISFSI) and natural ter-estrial sources F'urther impact the sensitivity of these instrumints. To address these impacts. the fixed-point grid spacing would again need to be reduced (requiring even more samples) in order to increase the DCCGl.,astc to the point where hand-held instrumentation can be used. Generally, the collection of additional fixed measurements (i.e. samples) increases project costs.

Survey designs for Class 2 and Class 3 survey units arn not driven by the elevated measurement compaison becausc areas of clevated activity are not expected. In Class 2 areas, any indication of activily above the IXCGItw requires Further investigation. Similarly, in Class 3 areas, any.positive indication of licensed radioactivity also requi res frther in vest igation.

Becamec the D)CGtr,a.,tc is not applicable to Class 2 or Class 3 areas, adjustments lo grid spacing do not occur. However, the increased field-of-view associated with the in-situ gamma spectroscopy system improves the efficiency of the survey's implementation.

1.2.3 Innovative Approach In-situ assays allow fixed-point grid spacing to be uncoupled fr'om the derivation of applicable investigation levels. In contrast to the traditional approach where the DCGI-eofc (based on grid size) determines both investigation levels and detection sensitivities, the use of this technology provides two independent dynamics as fbllows:

" Detection sensitivity is determined by tihe DCGLI,,m< associated wi [h the (optinsal) fixed-point grid spacing.

" Investigation levels are based on the detector's field-of-view and adjusted for ilte smallest area of concerni (i.e. I ml).

1.2.4 lnvesli,*tion Level Development of the investigation (action) levels applied to in-situ assay results is a departure from tte traditional approach For implementing a MARSSIM survey. Examples are provided lor both open land areas (i.e. soil) and for building surlaces, however lhe approach for both is identical.

To support the use of in-situ spctroscopy to evaluate areas ofelevated activity the l-lPGe detector's field-of-view was characterized. Attachment 2 presents data from tlic field-of-view characterization for a detector configured with a 90-degree collimator positioned 2 meters from the target surface.

Alternate configurations will be evaluated in a similar manner before being employed. As exhibited in Atlachmcnt 2, when the detector is positioned at 2 meters above the target suriace the field-of-view has a radius of at least 2.3 Report No.: YNPS-FSS-NOL01-00 YA-R E IlT-O0-0 18-05 Rev. 0 meters. This value was rounded down to 2.0 meters for implementation purposes, introducing a conservative bias (approximately 9%) in reported results. The example provided in this technical report assumes a 2-meter source-to-detector distance, yielding a nominal field-of-view surface area of 12.6 rnA Oca*sionally, alternate source-to-detector distances (using the 90-degree collimator) may be employed, particularly in a characterization or investigation capacity, In such cases, the detector's field-of-view will be calculated by setting the radius equal to the source-to-detector distance, thereby maintaining the conservative attribute previously described, If alternative collimator conftgurations are used to perform elevated nmcasurement comparisols, then specific evaluations will be documented in the 1bm1 of a technical evaluation or similar. Associated investigation levels will be derived using the same approach and methodology outlined below in this section.

After the delector's field-of-view is deternined, ain appropriate investigation level is developed to account for a potential one-meter square area of elevated activity. DCGLjE.mc values for a one-square meter area are presented in Table 1.

T.ABLE 1, SOIL DCGLr-mc FOR I m-"

Soil Soil DCLUle DCG Lw DCGLw \AreaFactor for I m-"

(pCiieg) (p1Ci/a) tor I M, (p< hg)

(NOTE ) (NOTE 1) 1NCTM 3) (NOTE 4" Co-6o 3M 1,4 11 15

..... .... ....... . . 7 ....... ....

{.......

..... ,[........................

(.S-134 4.7 1.7 16 82 Cs-137 8.2 3T 22 66

\oOr, I I.PTb: -

NOII- Audljatd1o8, a nl~)r NOIT. 3- LIP Apimud',i 6Q N(YTE d - Soil t)C t..I4*. kdj~~ 1o5,73 amRctaynr) ar I a'parY-The al)CGUlC \;values listed in Table I do not account l'or a source positioned at the edge of'the field-of-view. "lleretore. the IM21ICiL4,.k1C values are adjusted via a correction factor. To develop this correction factor, a spectrutm free of plant-related radioactivity was analyzed using two different efficiency calibrations (i.e. geometries). The first scenario assumes radioactivity uniformly distributed over the delectors 12.6 nil field-of-view.

"The second scenario assumes radioactivity localized over a 1 mr' situated at the edge ofethe detector's field-of-view. The resultant MDC values were compared to characterize the difference in detection efficiencies between the 2

two scenarios. As expected, the condition with localized (1 n1 ) radioactivily at the edge of the detector's field-of-view yielded higher MDC values. The ratio between the reported IMDC values for the two scenarios is used as a correction factor, This correction factor is referred to as the oflset geomnetry Report No.: YNPS-FSS-NOLOI-00 YA-R EPT-00-01 8-05 Rev. 0 adjwstment fIactor. Ilhe investigation levels for soils presented in Table 2 were calculated as follows:

Nuclide Investigation Level (pCi!g) ý (DCGL 1 1x,*,) ' CF Where: l)C(.L+1 C = (I)CGI.w or D)CGI.s 1t 5 )

• AFkI ni and CF = Mean oftsel geometry adjustment factor TAI3.E '2,SOl, INV]t;S'I'IGA'tION t '. 1, DERIVATION S..

MIX. D(GL~c U**:

pICi/g NU)C pCifg RATIO Icr I mr pCi/g (NOTE 1 a0 NOTE 2) (INOTE 3) (NOTE 5) (NOTE 6)

(,k,>-o -0.i21 1S6 i 0.0651 1 1Jo

• -10?n I O.IS4 -22 w.52 2-3-.

Cs-034 i o.189 229U .51 137 1.. .... ....... 55 I.7. . i 4.3 Otfset Geometr- Adjustment Factor 0.065.4 N(OE I - A m oddtivIty &IOUJ dovr 2.icodif-vi 12,6 N(Mf"2 - Efriciarcy ,alibrution didxcdor a I or arej Oilaall d. Ihc odot of'die du elor's riltd-l-r-oicsi, 'hix nriiod aw,.xiha all adivil(y k~strbcdwiciiiithe I r NOT'l 3 - ltati-i (12.6 I ifii MI 2 I Mr MIX,),

NOTE 41- 'fli iocii .aloo of (the olios I i* pitild iii Ith offT-Ngooriilry adjuslillol [t~ol.

NOTE 5 . DC(Lh,.c valute o r I ni (firomTable 1)

NOEi tnvoalinoo~ levets utriv~i by *loyn ofrht otll~e gouliry aid-omnatofaoor (og. (.)6533)io l*tr DCGLt- fbrorI fpria fortudi rad,imuiidi.

With respect to huilding surfaces, the development of the investigation level is identical to that for soil surfaces. "IThe one-meter square DCGLEmc for building surfli*cs are prcenled in Table 3.

TABLE 3. BUILDING SURFZACE DC C FOR 1 mc Ilkdg I)(X(l..w 3dg IXIGI,,w Area !Iactor ForI M-(dl*pui1650) (CIlPIl Ouemo) For I M! (dIlmcuAr01 15NThI'1 (NOYfli2) (NO.T 3) 5N(0Ti41 C,.-GO I lO.( 6,301 7,3 1 4f6.()l0 Os ,[3 2-9.Wl 1o(, 7.4 74,M) 1 NOTE I -

NOTE ? -

LTP TabledIX 6-1 A@uorleIo 3.73 n~mcn,)t 63 0 22f0r) 7.6 167,00(1 N~oTE3 - 1,TIPApptnft 6S NO'lI 4 - Ilihldo i)f-i l.t' (ililjilegl Iii 8.84 .1 R3 c II)I fI" a I "I' "area Using the same approach described for soils, a correction factor to account for efficiency differences due to geometry considerations is developed the one-etner square DCGzLp,. ISOCS cflicicncy calibrations for activity distributed over the detector's field-of-view and tbr activity within one-square meter located at the edge of the detector's field-of-view were developed. The MDC values tor these two geometrics were compared to characterize the difference 3

in detewtion efficiencies. As expected, the condition with localized (I ni )

Report No.: YNPS-FSS-NOLOI-00 YA-R EPT-00-018-05 Rev. 0 radioactivity at the edge of the detector's field-of-view yielded higher M1C values. The ratio between the reported MDC values for the two scenarios is used as the offset geometry adjustment factor. The MDC values, the associated ratios, and the derived investigation level for building surfaces are presented in Table 4.

TABLE 4, BUILDING SURFACE INVESTIGATION LEVEL DERIVATION

- BUILDI~NG SURFACE 12.6 in I M- Li)XL`,C 2VVESTIGATION MDC MIDX For I rni LEVEL oc)} 7_ I ('*Ot T R itt)( dpm I*,v:*uO ....... tIU "-

tEO~hI*\Oh 2~(V)TF3~, NOTE 3 0

I 'o-60 715 1 400 0,, 446,00 WO'0 A..I-Otim 8i39 l 0,0 (106-b 62,60 :*,0605 Cs- 134 900 14*20) 0J0634 74.-M) 4.700 C2s-137 1 922 --- 14.600 t0,063) 167.000 1060 Ofrvt Geoiurtr-yjktij'-itnwat I' wtr, 0,0636 I'0TE4)

NOTH I - kAml ac~dtivity diri~l-iltd over th 13611, hldo,6c v J(XI 2 - fliency calibrts-aa ~aErtAd fort~ I niý a~reaýiniaitd fdI1.ti mthe cd- ruc hdctataor', acitd-or.

viewv,'The model t ll ativitay is &itttubtacdw~ihittttte I r iau-ts NO'TE3 - .i~oi-ttM6ml MDUX I inz MDCI NOTE4i-flit itm, vulijeoftII,erawi ic 2plticdx,*ill. OcIi fuontyaji~iiittdor.

NOTFI3 )UIS vtic forwtifukI IIc, mi'l-ab 5I NOflI r0 uvc i ii~ui t i eoMiei"iis ,1c ,eoir dsiei tdr15dv3lt i Mcti-rqlcr nitem DC0tiw, In summary, effective investigalion levels for both open land areas (ie. soils) and for building surfaces can be derived and applied to in-situ gamnia spectroscopy results. Note the MD)C values associated with the detector's field-of-view were well below the derived investigation levels, The investigation levels presented in Table 2 and Tlable 4 do not address the use of surrogate DCGLs. Use of'surrogaue DCGLs will be addressed in Final Status Survey Plans, particularly where it is necessary to evaluate non-gamma emitting radionudlides on building surfaces. When surrogate DCGLs are employed, investigation levels will be developed on a case-by-case basis using the approach outlined in this document. Similarly, the offset geometry adjustment factor presented in Table 2 and Table 4 will vary for different geometries. Although unlikely, if dillerent geometries are employed, this value will be determiined on a case-by-case basis using the methodology reflected in Table 2 and will be docunrented in the applicable Final Status Survey Plan.

For both open land areas and for building surfaces, when an investigation level is encountered, investigatory protocols will be initiated to evaluate the presence of elevated activity and bound the region as necessary. Such evaluations may include both hand-held field instrumentation as well as the in-situ HPGe detector system. After investigation activities are completed, Report No.: YNPS-FSS-NOLO1-00 YA-R EPT-00-018*-05 Rev. 0 subsequent (follow--up) scanning evaluations will most likely be conducted using the in-situ gamma spectroscopy system.

1.2.5 Detector Sensitivity For Class 1 scan surveys, the minimum detectable concentration is governed by the DCGI.-,I't associated with the grid area used to locate fixed-point measurements. The system's count time cal be controlled to achieve the required detection sensitivity. 'Flhcrt*orc, the grid spacing for the fixed-point measurements can be optimized thus eliminating uneccssary increasws to the number of fixed-point measurements while ensuring that elevated areas between fixed measurement locations cmalbe identified and evaluated.

Based on preliminary work, it has been determined that a count time of 900 seconds will yield an acceptable sensitivity for many areas on the site, This count lime provides M DC values well below the investigation levels presented in Table 2 and Table 4. Count times will be adjusted as necessary as survey unit-specific investigation levels are derived or where background conditions warrant to ensure that detection sensitivities are below the applicable investigation level. Since each assay report includes a report of the MDC values achieved during the assay, this iniformation is considered technical supporl that required MDC values were met, 1.2.6 Area Coverage Based on the nominal 12.6 mý field-of-view, a 3-meter spacing between each survey point will result in well over 100% of the survey unit to he evaluated for elevated activity. This spacing convention typically employs a grid pattern that is completely independent from the grid used t) locate fixed-point measurements. An example ol'the grid pattern and spacing is presented in Attachment 3.

Alternate spacing conventions may be applied on a case-by-case basis. For instance, spacing may be decreased when problematic topographies ttre encountered. Note that decreased grid spacing in this context is not. associated to tlte fixed-point measurements. Occasionally it may be necessary to position tile detector at one meter or less from the target surface to evaluate unusual (e.g. curved) surfaces or to assist in bounding aireas of elevated activity, In cases where it may be desirable to increase the field-of-view via collimator or souree-to-detector distances, grid-spacing conventions (and applicable investigation levels) will be determined using the approach described in titis document.

Report No.: YNPS-FSS-NOLOI-00 YA-R EPT-00-0 18-05 Rev. 0 1.2,7 Moisture Content in tihe Soil Matrix In-situ gamma spectroscopy of open land areas is indherently subject to various environmental variables not present in laboratory analyses. Most notably is the impact that water saturation has on assay results. h'Iis impact has two components. First, the total activity result For the assay is assigned over a larger, possibly non-radioactive mass introduced by the presence of water.

Secondly, water introduces a self-absorption factor.

'1Thc increase in sample mass due to (he presence of water is addressed by the application of a massimetric efficiency developed by Canberra Industries.

Mkassimetric elf*ciceny units arv defined as Jcounts per secondl/[gannmas per second per gram of samplel. Mathematically, this is the product of traditional efficiency and the mass of the sample. When the efficiency is expressed this way, the efficiency asymptotically approaches a constant value as the sample becomes very large (e.g. infinite), tinder these conditions changes in sample size, including ma-ss variations from excess moisture, have little impact on the counting efficiency. However, the massimetric efficiency does not completely address attenuation characteristics associated with water in the soil matrix.

To evatluate (he extent of self-absorption, (traditional) counting efficiencies were compared for two densities. Bascd on empirical data associated with the moniloring wells, typical nominally diy in-situ soil is assigned a density of.

1.7 glee. A density of 2.08 glee. obtained from a technical referenice publication by 'lThomals J. Glover, represents saturated soil. A density of 2.08 gcc accounts for a possible water content of 20%. A summary of this comparison is presented in Table 5.

-rAB ti;s5, COUtNTINNG FF~EG OPRs:

fLtfmci'.ncses iDeviation due to densitv keV 1.7 . .. 2c1 c increas, (excess moiture) 43 4 ~ 33F,6 2.7E 661,65 .9E-6 141E-6 -17.i%

1173.22 2,5 1"6 l-,......

131249 2. E-6 LI -6 In cases when the soil is observed to contain more than "typical" amounts of water, potential under-reporting can be addressed in one of two manners. Onhe way is to adjust the investigation level down by 20%. 'lie second way is to reduce the sample mass by 20%. Either approach achieves the same objeclive: to introduce a conservative mechanism for triggering the investigation level where the presence o(f water may inhibit etinting efficiency. The specific nmechanism to be applied will be prescribed in implementing procedures.

Report No.: YNPS-FSS-NOLOI-00 YA-REPT-00-018-05 Rev. 0

'Ithe presence of standing water (or ice or snow) on the surface of the soil being assayed will be accounted lor in customized elliciency calibrations applied during data analysis activities.

12.8 Discrete particles in the Soil Matrix Discrete particles are not specitically addressed in the license Tertnination Plan. Howcver, an evaluation was perforned assuming all the activity in the detector's field-of-view, to a depth of 15 cm, was situated in a discrete point-sourcc configuration. A concentration of 1,0 pCiig (Co-60), corresponding to the investigation level presented in Tahle 2, correlates to a discrete point-source ot'approximately 3.2 .uCi. AIis activity value is considered as the discrete particle of concern. Since the presence of any discrete particles will most likely bc accompanied by distributed activity, the investigation level may provide an opporlunity to detect discrete particles below 3.2 pCi, Discrete particles exceeding this magnitude would readily be detected during characterization or investigation surveys. The MDCs associated with hand-held field instruments used for scan surveys are capable of detecting very small areas of elevated radioactivity that could be present in the tbnn of' discrete point sources. The minittum delectable particle activity fbr these scanning instruments and methods correspond to a small fraction of the TEDE limit provided in 10CFR2( subpart E. Note that the MDC values presented in Table 2 ar. significantly lower than those published in 'fable 5-4 of the License Temina tion Plan.

When (lie investigation level in a Class I area is observed, subsequent investigation surveys will be performed to include the use of hand-held detectors. T'h dtlection sensitivities of instruments used for these surve,,ys havse been previously addressed in the LIT. Furtlernnore, discrete point sources do not contribute to the uniformly distributed activity of the survey unit. It is not expected that such sources at this magnitude svtould impact t survey unit's ability to satisfy' the applicable acceptance criteria.

Noting that Class 2 or Class 3 area survey designs do not employ elevated measurement comparisons,. associated investigation levels ate based on positive indications of licensed radioactivity above the DCGLW, or above background. Because such areas are minimally impacted or disturbed.

potential discrete particles would most likely be situated near the soil surface where detection efficiencics arc highest.

1.2,9 Procedures And Guidance Documents General use of the portable ISOCS system is administrated by departmental implementing procedures that address the calibration and operation activities as well as analysis of the data. These procedures are listed as follows:

Report No.: YNPS-FSS-NOLOI-00 YA-R EPIT-O0-O 18-05 Rev. 0

• DP-8869, In-Situ (ISOCS) Gamma Spectrum Assay System Calibration Procedure."

• DP-8971, '*Op*r*tion Of The Canberra Portable ISOCS Assay System."

" DP-8872. "ISOCS Post Acquisition Processing And Data Review."

Where the portable ISOCSO system is used for Final Status Surveys, the applicable FSS Plan will address detector and collimator configurations, applicable (surrogated) investigation levels, MDC requirements, and appropriate Data Quality Objectives, as applicable.

1 A secondary application of tho portable 1S(X2S ' system is to assay surfaces or bulk materials ior characterization or unconditional release evaluations. Use of the portable ISOCS'*system for miscellaneous evaluations will be administrated under a specific guidance document (e.g. Sample Plan, etc.).

Operating parameters such as physical configuration, efficiency calibrations.

countlimes, and MI)Cs will be applied so as to meet ithe criteria in the associated controlling docuuments. Such docuncints will also address any tntiique technical issues associated wiith the application and may provide guidance beyond that of procedure. \P-0052, "Radiation Protection Release of Materials, Eqtuipment and Vehicles,"

,1.2. 10 Environmental Kack-erounts If background subtraction is used, an appropriate background spcectrui will be collected and saved. Count times for environmental backgrotnds shotld exceed the count time associated with the assay. In areas where the background radioactivity is particularly problematic (e.g. ISFSI), the background will he characterized to the point of identifying gradient(s) such that background subtractions arc either appropriate or conservative.

D)ocumentation regarding the collection and application of environmental backgrounds will be provided as a component of the final survey plan.

1.2.11 Quality Control Quality Control (QC) activities for the ISOCS system ensure that the energy calibration is valid and detecior resolution is within specifications. A QC file will be set tip for each detector system to track centroid position, FWIM, and activity. Quality Control cotnts will be performed on a shiftly basis prior to the system's use to verify that the system's energy calibration is valid. The Na-22 has a 1274.5 keV photon which will be the primary mechanism used Ibr performance monitoring. If the energy calibration is tbund to be out of an acceptable tolerance (e.g. greater than +/-4 channels), then the amplifier gain may be adjusted and a follow-up QC count performed. If the detector's resolution is found to be above the lhetorv specification. then an evaluation Report No.: YNPS-FSS-NOLO1-00 Y A-R EPT-O0-0 18-05 Rev. 0 will be performed to determine if the detector should be removed from service and/or if the data is impacted. Evaluations associated with QC counts shall be documented. Stuch documentation may be limited to a remark directly on the applicable QC report or in a logbook if the resolution does not render the system out ot' service. Otherwise the evaluation should be separately documentcd (e.g. Condition Report, etc.) so i-s to address the impact of any assay results obtained since the last acceptable (" surveillance.

Where it is determined that background subtraction is necessary, a baseline QC background will be deternined specific to that area or region. When background subtraction is required, a QC background surveillance will be perlornied before a set of measurements are made to vei the applicability of the background to be subtracted. Due to the prevailing variability otithe background levels across the site, the nature and extent of such surveillances will be on a case-by-case basis and should be addressed in the documnentation associated wilh the applicable survey plan(s).

In addition to the routine QC counts, each assay report is routinely reviewed with respect to K-40 to provide indications where amplifier drift impacts nuclide identification routines. TDhis review precludes the necessity for specific (i.e. required) alter-shill QC surveillances. It also minimizes investigations of previously collected data should the system fail a before-use (X surveillance on the next day of use.

1.2.12 I)ata Collection Data collection to support FSS activities will be administered by a specilie Survey Plan. Survey Plans may include an index oftneasurement locations with associated spectrum filenamcs to ensure that all the required measurements are made and results appropriately managed. Personnel specifically trained to operate the system will perfonn data collection activilies.

Data collection activities will address environmental conditions that may impact soil moisture content, Logs, shall be maintained so as to provide a mechanism to annotate such conditions to ensure that efiiciency calibration files address the in-situ condition(s). In extreme cases (e.g. standing water, etc.) specific conditions will be addressed to enstire that analysis results reflect the conditions. As previously discussed with respect to water, when unique environmental conditions exist that may impact analysis restlts, conservative compensatory' factors will be applied to the analysis of the data.

Report No.: YNPS-FSS-NOLOI-00 YA-R EPT00-018-05 Rev. 0 1,213 Efficiency Calibration The central feature of the portable ISOCS technology is to support in-situ gamma spectroscopy via the application ofimathematically derived el'ficiency calibrations, l)ue to the nature of the environment and smaWaces being evaluated (assayed), input parameters for the ISOCS efficiency calibrations will be reviewed on a case-by-case basis to ensure the applicability of the resultant efficiency. Material densities applied to efficiency calibrations will be documented, In practice, a single efficiency calibration file may be applied to the majority oflihe miea.surcements.

'The gcomctry most generally employed will be a circular plane assuming unilomily distributed activity. Efficicncy calibrations will address a depth of 15 cm for soil and a depth up to 5 cm tbr concrete surfaces to account for activity embedded in cracks, etc, Other geometries (e.g. exponential circular plane, rectangular plane. etc.) will be applied if warranted by the physical attributes of the area or surface being evaluated. Efficiency calibrations are developed by radiological engineers who have received training with respect to the ISOCS'sofiware. Efficiency calibrations will be documented in accordance with procedure DP-8869, lIn-Situ (ISOCS) Gamma Spectrum Assay System Calibration Procedure."

1.2.14 Data Management Data management will be implementcd in various stages as follows:

• An index or log will be mainnained to account for each location where evaluations for elevated activity arc pcrforned. Raw spectrum files will be written directly or copied to a central file server.

Data Analysis - After the spectrwn is collected and analy*zed, a quialified Radiological Engineer will review the results. The data review process includes application of appropriate background, nuclide libraries, and efficiency calibrations. Dama reviews also verify assay results with respect to the applicable investigation levels and the MWCs achieved. Data reviews may include monitoring systemn performance tailizing K-40. When lhe data analysis is compleled, the analyzed data file will be archived to a unique directory located on a central file server.

• Data Reporting - The results of data files whose reviews have been completed and are deemed to be acceptable may be uploaded to a central database for subsequent reporting and statistical analysis.

. 13-

Report No.: YNPS-FSS-NOLOI-00 YA-R EPT-00-018-05 Rev. 0 0 Data Archiving - Roulinely (daily) the centralized file server(s) where the raw and analyzed data tiles are maintained will be backed up to tape.

1.3 ConclutsionsiReconunendajions The in-situ gamma spectroscopy system is a cost-effeclive tecluhology well-suited to replace traditional scanning survey techniques to evaluate areas for elevated radioactivity. The static manner in which this system is operated eliminates many variables and limitations inherent to hand-held deteclors moving over a surface. This system provides a demonstrably lower detection sensitivity than those offered by hanid-held field instnrnens. Thisnattribute qualities this system as an altemative technology in lieu of hand-held Nal field instruments in areas where background radiation levels would prohibit the use of such detectors to evaluate ror elevated gross activity. The MDC to whiich this system will be operated satisfies (or exceeds) criteria applied to traditional scan surveys using hand-held field instruments.

Effective investigation levels for both open land areas (i.e. soils) and for building surfaces can be derived and applied to in-situ gamma speetroscopy results. Where surrogate DCGLs are employed, investigation levels will developed on a case-by-case basis using the approach outlined in this document.

The manner in which investigation levels are derived employs several conservative decisions and assumptions; Additionally, adequate spacing applied to scanning survey locations yields an overlap in surface coverage providing .100-percent coverage of Class I areas and redundant opportunities in a significant portion of the survey area to detect localized elevated activity.

1.4 References 1, YNPS License Termination Plan. Revision 1

2. Multi-Agency Radiation Survey And Site Investigation Manual (MARSSIM)

Revision 1. 2000

3. Canberra User's Manual Model S573 ISOCS Calibration Software, 2002

4. Decommissioning Health Physics - A Handbook for MAR.SSIM Users, E.W.

Abelquist, 2001 5, Canberra's Genic 2000 V3.0 Operations Manual. 2004

6. ln-Situ (ISOCS) Gannna Spectrum Assay System Calibration Procedure DP-8869, Revision 0

7. Operation of the Canberra Portable ISOCS Assay System D1P-8871 Revision 0

8. Tlechnical Ref., by Ibomas Ji.Glover.

Report No.: YNPS-FSS-NOLO1-00 YA-REPT-00-018-05 Rev. 0 Attachment 1 Portable ISOCS Detector System Photos Report No.: YNPS-FSS-NOLO1-00 YA-REPT-00-018-05 Rev. 0 Attachment 2 Field-Of-View Characterization Generally, the HPGe detector will be outfiuted with a 90-degree collimator situated at2 meters perpendicular to the surface being evaluated. Note that characterizing the detector's field-of-view could he perlfrmed without a source by comparing ISOCS-generated efficiencies for various geometries. If a different collimator configuration is to be employed, a similar field-of-view characterization will be performed.

To qualify the field-of-view for this configuration, a series of measurements were made at various oNf-ses relative to the center of Ihe reference plane. The source used ri" Ihese measurements was a 1.2 g.Ci Co-60 point-source with a physical size of approximately I cmi3 . Each spectrum was analy-zed as a point source both with and without background subtract. It was observed that the delcctor responded quite well to the point source.

Figure I presents the results with background subtraction applied. Note that there is a good correlation with the expected nominal activity and that outside the 2-meter radius of the '"vorking" field-of-view (i.e. at 90 inches) some detector response occurs. This validates that the correct attenuation factors are applied to the algorithms used to compute the etffcienc* calibration.

11G UREt 1 POtNT SOURCE TEST (back-gound subtracted)

UHi-n- -

S 2 r.flh]o 0 18 48 60 66 72 ad-78 84 90 Offset (inches)

Figure 2 shows the effect of plant-derived materials present in the reference background, which indicates an increasing over-respose the flurter the point soturce is moved off center. Detector response outside the assumed (i.e. 2-meter) field-of-view would yield conservative results.

Normally, source term adjacent to the survey units should be reduced to eliminate background interference.

Report No.: YNPS-FSS-NOLO1-00 YA-R EPT-00-0]I -05 Rev. 0 JIG URr 2 POIN SOMMTESTIS u 0 18 48 60 65 72 78 84 90 Oifset (inchecs)

Report No.: YNPS-FSS-NOLOI-00 YA-REPT-00-018-05 Rev. 0 Attachment 3 Typical Grid Pattern For In-Situ Gamma Spectroscopy K -

N Typical Scan Grid Pattern (For 2rn scan height using 90' collimator.)

'=Scan Area Footprint 35 -

=Scan Point Location