Text

Yankee Nuclear Power Station - Submittal of YNPS-FSS-AUX01-00 and YNS-FSS-NSY12-00, the Final Status Survey Reports for Survey Areas AUX-01 and NSY-12, Respectively
	ML070470124
Person / Time
Site:	Yankee Rowe
Issue date:	05/11/2006
From:	Jeffery Lynch; Yankee Atomic Electric Co
To:	; Document Control Desk, NRC/FSME
References
	BYR 2006-037 YNPS-FSS-AUX01-00, YNS-FSS-NSY12-00
	Download: ML070470124 (54)
	v • d • e

11 YANKEE ATOMIC ELECTRIC COMPANY Telephone (413) 424-5261 ANKEE 49 Yankee Road, Rowe, Massachusetts 01367 May1 1, 2006 BYR 2006-037 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 1 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-AUXO1-00 and YNS-FSS-NSY12-00, the Final Status Survey Reports for Survey Areas AUX-01 and NSY-12, Respectively

Dear Madam/Sir:

This letter submits YNPS-FSS-AUX01-00, Final Status Survey Report for AUX-01, and YNPS-FSS-NSY12-00, Final Status Survey Report for NSY-12.. These reports were written in accordance with Section 5 of the YNPS License Termination Plan, "Final Status Survey Plan," and are 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 Alice Carson at (301) 916-3995 or the undersigned at (413)-424-2261.

Sincerely, YANKEE ATOMIC ELECTRIC COMPANY Jose Regulatory Affairs Manager

Enclosure:

YNPS-FSS-AUXO1-00 YNPS-FSS-NSY12-00 (2 hard copies plus CD)

U.S. Nuclear Regulatory Commission BYR 2006-037, Page 2 cc (w/o encl):

cc (w/ encl):

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

S Yankee Nuclear Plant Station Final Status Survey Report For NSY-12 Yankee Atomic Electric Company 0

YANKEE NUCLEAR POWER STATION FINAL STATUS SURVEY REPORT REPORT NO.: YNPS-FSS-NSY-12-00 Prepared by:

Reviewed by:

,~rsMsNir, FSS R adiological Engineer Approved by:

Lý r:

A M arn Erickson-,S Manager Date:

Date:

Report No.: YNPS-FSS-NSY-12-00 Section Table of Contents Page 1.0 EX EC U TIV E SUM M A RY...........................................................................................................................

I 1.1 IDENTIFICATION OF SURVEY A REA AND UNITS........................................................................................ I 1.2 DATES(S) OF SURVEY.................................................................................................................................

1 1.3 N UM BER AND TYPES OF M EASUREM ENTS C OLLECTED......................................................................

I 1.4 SUM M ARY OF SURVEY R ESULTS...............................................................................................................

2 1.5 C ONCLUSIONS............................................................................................................................................

2 2.0 FSS PRO G RA M O V ERV IEW....................................................................................................................

2 2.1 SURVEY PLANNING....................................................................................................................................

2 2.2 SURVEY D ESIGN.........................................................................................................................................

2

.2.3 SURVEY IM PLEM ENTATION....................................................................................................................

...3 2.4 SURVEY DATA A SSESSM ENT......................................................................................................................

3 2.5 QUALITY ASSURANCE AND QUALITY CONTROL MEASURES..............................................................

3 3.0 SU RV EY A R EA IN FO R M A T IO N......................................................................................................

3 3.1 SURVEY A REA D ESCRIPTION.....................................................................................................................

3 3.2 H ISTORY OF SURVEY A REA.......................................................................................................................

4 3.3 D IVISION OF SURVEY A REA INTO SURVEY UNITS............................................................................... 4 3.4 SURVEY UNIT N SY-12-01 D ESCRIPTION.............................................................................................

4 4.0 SU RV EY U N IT IN FO R M A T IO N...............................................................................................................

4 4.1

SUMMARY

OF RADIOLOGICAL DATA SINCE HISTORICAL SITE ASSESSMENT (HSA)........................ 4 4.1.1 Chronology and D escription of Surveys Since H SA.......................................................................

4 4.1.2 Radionuclide Selection and Basis.................................................................................................

4 4.1.3 Scoping & Characterization.................................................................................................................

5 4.2 BASIS FOR C LASSIFICATION......................................................................................................................

5 4.3 R EM EDIAL A CTIONS AND FURTHER INVESTIGATIONS........................................................................

5 4.4 UNIQUE FEATURES OF SURVEY UNIT................................................................................................

5 4.5 A LA RA PRACTICES AND EVALUATIONS.............................................................................................. 6 5.0 SURVEY UNIT FINAL STATUS SURVEY.........................................................................................

6 5.1 SURVEY PLANNING....................................................................................................................................

6 5.1.1 Final Status Survey Plan and Associated D QOs.............................................................................

6 5.1.2 D eviations from the FSS Plan as W ritten in the L TP....................................................................

7 5.1.3 D CGL Selection and Use......................................................................................................................

7 5.1.4 M easurem ents.......................................................................................................................................

7 5.2 SURVEY IM PLEM ENTATION A CTIVITIES...............................................................................................

7 5.3 SURVEILLANCE SURVEYS..........................................................................................................................

8 5.3.1 Periodic Surveillance Surveys.....................................................................................................

8 5.3.2 R esu r v ey s...............................................................................................................................................

8 5.3.3 Investigations........................................................................................................................................

8 5.4 SURVEY R ESULTS.......................................................................................................................................

8 5.5 DATA Q UALITY A SSESSM ENT....................................................................................................................

9 6.0 QUALITY ASSURANCE AND QUALITY CONTROL..................................

10 6.1 INSTRUM ENT Q C C HECKS......................................................................................................................

10 6.2 SPLIT SAM PLES AND R ECOUNTS............................................................................................................. 10 6.3 SELF-ASSESSMENTS............

10 7.0 C O N C LUSIO N............................................................................................................................................

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Report No.: YNPS-FSS-NSY-12-00 Table List of Tables Page TABLE I SURVEY AREA NSY-12 EVENTS/CONDITIONS............................................................................................. 4 TABLE 2 SURVEY AREA NSY-12 DESIGN PARAMETERS..........................................................................................

6 TABLE 3 FSS ACTIVITY

SUMMARY

FOR NSY-12 SURVEY UNITS.............................................................................

8 TABLE 4 SURVEY AREA NSY-12 DIRECT M EASUREMENTS....................................................................................... 9 List of Appendices Appendix A - YNPS-FSSP-NSY-12, "Final Status Survey Planning Worksheet Appendix B - YA-REPT-00-015-04, "Instrument Efficiency Determination for Use in Minimum Detectable Concentration Calculations in Support of the Final Status Survey at Yankee Rowe" Appendix C -ALARA Evaluations NSY-12 List of Attachments Attachment A - Maps and Posting Plots Attachment B - Data Quality Assessment Plots and Curves Attachment C - Instrument QC Records (In the electronic version, every Table of Contents, Figures, Appendices and Attachments, as well as every mention of a Table, Figure, Appendix or Attachment is a hyperlink to the actual location or document.)

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Report No.: YNPS-FSS-NSY-12-00 List of Abbreviations and Acronyms AL ALARA.......

c/d DCGL DCGLEMC............

DCGLw.......

DQO....................

EMC ETD FSS FSSP-GPS H o --

HSA HTD ISOCS LBGR LTP MARSSIM MDA MDC PAB QAPP........

Q C.......................

RCA RPRP..................

RSS SFP VC VCC V...............

VSP YNPS Action Level As Low As Reasonably Achievable Counts per Disintegration Derived Concentration Guideline Level DCGL for small areas of elevated activity DCGL for average concentration over a wide area, used with statistical tests Data Quality Objectives Elevated Measurement Comparison Easy-to-Detect Final Status Survey Final Status Survey Plan Global Positioning System Null Hypothesis Historical Site Assessment Hard-to-Detect In-situ Object Counting System Lower Bound of the Grey Region License Termination Plan Multi-Agency Radiation Survey and Site Investigation Manual Minimum Detectable Activity Minimum Detectable Concentration Primary Auxiliary Building Quality Assurance Project Plan Quality Control Radiological Controlled Area Radiation Protection Reactor Support Structure Spent Fuel Pool Vapor Container Vertical Concrete Cask Visual Sample Plan Yankee Nuclear Power Station iii

Report No.: YNPS-FSS-NSY-12-00 1.0 EXECUTIVE

SUMMARY

A Final Status Survey (FSS) was performed of Survey Area NSY-12 in accordance with Yankee Nuclear Power Station's (YNPS) License Termination Plan (LTP). This FSS was conducted as a structure surface FSS with building occupancy Derived Concentration Guideline Levels (DCGLs) even though the NSY-12 structure will be subsurface at license termination.

This practice conservatively implements LTP criteria that subsurface structure surfaces be evaluated for the presence of contamination.

1.1 Identification of Survey Area and Units NSY-12 Survey Area consists of a single Survey Unit, NSY-12-01, which comprises the base for Tank-I (TK-I) and a subsurface pipe chase that connected the TK-I base to the Auxiliary Boiler Room in the Turbine Building. NSY-12 is bounded entirely by NOL-06. NSY-12 is part of the original plant structure. There is no documentation indicating that NSY-12 is contaminated; however, there is information that indicates that the area around NSY-12 is potentially contaminated. However, 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 NSY-12 is identified as a Class 1 Area.

1.2 Dates(s) of Survey The FSS of the NSY-12 Survey Area was performed between November 16th, 2005, and December 1 4 th, 2005.

1.3 Number and Types of Measurements Collected Final Status Survey Plan (FSSP) was developed for this Survey Unit in accordance with YNPS LTP and FSS procedures using the MARSSIM protocol. The planning and design of the survey plan 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 36 direct measurements were taken, providing data for the non-parametric testing of the Survey Area. In addition to the direct measurements, hand-held survey instrument scans, were performed to provide 100 percent coverage of the Survey Area.

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Report No.: YNPS-FSS-NSY-12-00 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.

Fixed point surveys indicated no measurements exceeded the DCGLw as depicted in Attachment B. Retrospective power curves were generated which demonstrated that adequate power was achieved. Therefore, the null hypothesis (H0 ) (that the Survey Unit exceeds the release criteria) is rejected.

1.5 Conclusions Based upon the evaluation of the data acquired for the FSS, NSY-12 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, including that from groundwater.

IOCFR20 Subpart E ALARA requirements have been met as well as the site release criteria for the administrative level DCGLs that ensure that the Massachusetts Department of Public Health's 10 mrem/yr limit will also 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 peer review for plan development.

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 2

Report No.: YNPS-FSS-NSY-12-00 detection levels. DCGLs are developed relative to the surface/material of the Survey Unit and are used to determine 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 allows for 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 whenever possible, 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 the FSS program 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.

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 Description Survey Area NSY-12 consists of the reinforced concrete pad, pipe trench, and subsurface structures of the base of the Primary Water Storage Tank (TK-1) that 3

Report No.: YNPS-FSS-NSY-12-00 remains after the demolition of the tank and system piping. NSY-12 is located in the RCA yard area entirely within the bounds of NOL-06. The footprint of the area is approximately 330 ft' (31 m').

3.2 History of Survey Area The Primary Water Storage Tank (TK-1) was designated "primary" because of the water grade, not because of any connection with the primary coolant system liquid inventories. This tank fed make-up water to the Auxiliary Boilers and Steam Generators.

There is no documentation indicating that NSY-12 is contaminated; however, there is information that indicates that the area around NSY-12 is potentially contaminated.

Table 1 Surve Area NSY-12 Events/Conditions Date Event/Condition Various Was used as base for TK-T Post-HSA Removal of TK-I Winter 2005 Final Remediation and FSS performed 3.3 Division of Survey Area into Survey Units Survey Area NSY-12 consists of a single Survey Unit, NSY-12-01 3.4 Survey Unit NSY-12-01 Description NSY-12-01 Survey Unit consists of the base for Tank-I (TK-1) and a subsurface pipe chase that connects the TK-I base to the Auxiliary Boiler Room in the Turbine Building. NSY-12-01 is bounded entirely by NOL-06. The footprint area of the unit is approximately 330 ft2 (31 M2).

4.0 SURVEY UNIT INFORMATION 4.1 Summary of Radiological Data Since Historical Site Assessment (HSA) 4.1.1 Chronology and Description of Surveys Since HSA Isolation and control measures were implemented for the FSS.

The condition of NSY-12 Survey Unit at the time of FSS was smooth to heavily remediated steel reinforced concrete.

4.1.2 Radionuclide Selection and Basis During the initial DQO process, Co-60 was identified as the radiological nuclide of concern due to its more restrictive DCGL value when compared 4

Report No.: YNPS-FSS-NSY-12-00 to Cs-137 (sampling of soil adjacent to the concrete indicated a relationship of approximately 80% Co-60 to 20% Cs-137). Adjacent soil characterization and survey data indicate no other LTP-specified radionuclides warrant consideration in the NSY-12 Survey Units.

4.1.3 Scoping & Characterization The radiological characteristics of Survey Unit NSY 12-01 are similar to other concrete structures in the RSS area. Eleven concrete survey units in the RSS area have been found to meet LTP release criteria based on FSS data. The FSS data set from survey unit BRT-O1-01 was used in the planning for NSY 12-01 because it showed the highest variability (0 =

1.6E3 dpm/100cm 2), and a higher variability in data requires the collection of more measurements.

4.2 Basis for Classification 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 NSY-12 is identified as a Class 1 Area.

4.3 Remedial Actions and Further Investigations No further investigations or remediation were required for Survey Area NSY-I 2.

4.4 Unique Features of Survey Unit Survey Unit NSY-12-01 exhibited surface characteristics ranging from smooth surfaces to heavily remediated irregular surfaces. Most of the pits and irregularities increased the source-to-detector distance by approximately 11/4 - 1/22 inch, although some increase it as much as I - 2 inches. These types of irregularities in the concrete surfaces were taken into account through the efficiency factor applied to the measurements collected with the HP-100. Technical report YA-REPT-00-015-04 (Appendix B) provides instrument efficiency factors (ci) for various source-to-detector distances.

The ci value for a source-to-detector distance of 1 inch was selected as a representative efficiency for data collected with the HP-100 from the irregular surfaces because it accounts for the 1/22 inch stand-off and the most common depth of pits and surface irregularities (/4

- 1/22 inch).

In contrast to the irregular surfaces, the vertical walls of the structures are relatively smooth. Table 4.2 of the YA-REPT-00-015-04 (Appendix B) provides instrument efficiency factors (6i) for various source-to-detector distances. Detector efficiencies (HP-I OOC) were applied as follows: smooth surface 0.0603 c/d, irregular surface 0.0373 c/d.

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Report No.: YNPS-FSS-NSY-12-00 4.5 ALARA Practices and Evaluations An, ALARA evaluation was developed for the NSY-12 Survey Area which concluded that additional remediation was not warranted. This evaluation is found in Appendix C.

5.0 SURVEY UNIT FINAL STATUS SURVEY 5.1 Survey Planning 5.1.1 Final Status Survey Plan and Associated DQOs The FSS for NSY-12 Survey Unit 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.

The FSS Plan can be found in Appendix A. 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 Table 2.

Table 2 Survey Area NSY-12 Design Parameters Survey Unit Design Parameter Value Basis NSY-12-01 Area 31 m' Class 1, <1000 m2 Number of Direct Measurements 15 (calculated) ct (Type I) = 0.05,

+ 21 (added) 03 (Type 1I) 0.05 ay: 1600 Total: 36a:10 Relative Shift: 2.1 LBGR:3200 Sample Area 2.1 m 2 Area / Sample #

Sample Grid Spacing, triangular pitch 1.5 m (Area/(0.866*Sample #)) 1/2 (Based on 15 original samples.)

Scan area 31 m2 Class I Area - 100%

Scan Investigation Level

> Background Audible SPA-3 & HP-100 Scan 6

Report No.: YNPS-FSS-NSY-12-00 5.1.2 Deviations from the FSS Plan as Written in the LTP The FSSP design was performed to the criteria of the LTP; therefore, no LTP deviations with potential impact to this Survey Area need to be evaluated.

5.1.3 DCGL Selection and Use It must be noted that for the final evaluation of the NSY-12 Survey Unit and throughout this report, the acceptance criteria of Building Surface LTP-listed DCGL values has been applied. However, given that all of the remaining slab and foundation structure will be at least a few feet subsurface before site grading is complete and will be in such a state at license termination, the LTP, section 5.6.3.1.2, "Exterior Surfaces of Building Foundations," establishes the applicable guidance, as it addresses methods that may be applied to determine if subsurface structure surfaces will be acceptable by meeting LTP-required concrete volumetric DCGLs.

With the established LTP guidance, given that Co-60 and Cs-137 have been found to be the only radionuclides of significance in the area of concern, and conventional hand-held instrument survey criteria techniques being conservatively based on Co-60 beta emissions, performing a Class I survey applying Building Surface DCGLs has led to a very conservative approach in determining the final status of the Survey Unit. However, in applying this approach, in addition to evaluating subsurface conditions, there is no unanswered concern should the question of future subsurface structure occupancy arise.

5.1.4 Measurements Error tolerances and characterization sample population statistics drove the selection of the number of fixed point measurements. Professional judgment was exercised adding additional direct measurements to achieve a tighter sampling grid building conservatism into the sampling design.

The direct measurement grid was developed as a systematic grid with spacing consisting of a triangular pitch pattern with a random starting point. Sample measurement locations are provided in Attachment A 5.2 Survey Implementation Activities Table 3 provides a summary of daily activities performed during the Final Status Survey of Survey Unit NSY-1 2-01.

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Report No.: YNPS-FSS-NSY-12-00 Table 3 FSS Activity Summary for NSY-12 Survey Units Survey Unit Date' Activity NSY-12-01 11-16-05 Performed Sample Quantity Calculations, established DQOs 11-17-05 Performed Job Hazard Analysis, and Unit Classification 11-17-05 Generated FFS Sample Plans 11-22-05 Performed walk-down of Survey Unit, established Isolation and Controls 11-23-05 Initiated Scans, and Direct measurements.

12-14-05 Performed DQA, FSS Complete 5.3 Surveillance Surveys 5.3.1 Periodic Surveillance Surveys Upon completion of the FSS of Survey Area NSY-12, the Survey Area was placed into the program for periodic surveillance surveys on a quarterly basis 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.

5.3.2 Resurveys No resurveys were required for this Survey Unit due to surveillance surveys.

5.3.3 Investigations No additional investigations were required for this Survey Unit due to surveillance surveys.

5.4 Survey Results A total of 36 direct measurements were taken in Survey Unit NSY-12-01. None of the direct measurements used in the statistical analysis of the Survey Unit exceeded the DCGLw. Table 4 includes the direct measurements that were gathered for the Survey Unit in NSY-12.

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Report No.: YNPS-FSS-NSY-12-00 Table 4 Survey Area NSY-12 Direct Measurements Results Results Location Surface (cpm)

(dpm/lOOcm2)

NSY-12-01-001-F-FM Smooth 58 958 NSY-12-01-002-F-FM Smooth 75 1240 NSY-12-01-003-F-FM Smooth 14 228 NSY-12-01-004-F-FM Smooth 82 1356 NSY-12-01-005-F-FM Smooth 50 825 NSY-12-01-006-F-FM Rough 57 1522 NSY-12-01-007-F-FM Smooth 71 1173 NSY-12-01-008-F-FM Smooth 74 1223 NSY-12-01-009-F-FM Smooth 64 1057 NSY-12-01-010-F-FM Smooth 39 643 NSY-12-01-011 -F-FM Rough 50 1334 NSY-12-01-012-F-FM Smooth 43 709 NSY-12-01-013-F-FM Smooth 26 427 NSY-12-01-014-F-FM Smooth 64 1057 NSY-12-01-015-F-FM Smooth 112 1853 NSY-12-01-016-F-FM Smooth 34 560 NSY-12-01-017-F-FM Smooth 81 1339 NSY-12-01-018-F-FM Smooth 27 444 NSY-12-01-019-F-FM Smooth 32 527 NSY-12-01-020-F-FM Smooth 41 676 NSY-12-01-021-F-FM Smooth 36 593 NSY-12-01-022-F-FM Smooth 13 212 NSY-12-01-023-F-FM Rough 106 2835 NSY-12-01-024-F-FM Rough 86 2299 NSY-12-01-025-F-FM Smooth 110 1820 NSY-12-01-026-F-FM Smooth 70 1157 NSY-12-01-027-F-FM Smooth 46 759 NSY-12-01-028-F-FM Smooth 81 1339 NSY-12-01-029-F-FM Smooth 63 1041 NSY-12-01-030-F-FM Smooth 107 1771 NSY-12-01-031-F-FM Smooth 56 925 NSY-12-01-032-F-FM Smooth 103 1704 NSY-12-01-033-F-FM Smooth 66 1091 NSY-12-01-034-F-FM Smooth 39 643 NSY-12-01-035-F-FM Smooth 66 1091 NSY-12-01-036-F-FM Smooth 67 1107 5.5 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.

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Report No.: YNPS-FSS-NSY-12-00 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, "Preparation of Survey Plans"; DP-8853, "Determination of the Number and Locations of FSS Samples and Measurements"; DP-8857, "Statistical Tests";

DP-8865, "Computer Determination of the Number of FSS Samples and Measurements" and DP-8852, "Final Status Survey Quality Assurance Project Plan".

A data review was performed on NSY-12-01 and statistical quantities were calculated. The average concentrations from Table 4 are smaller than the respective characterization data and the standard deviation is higher.

However, the retrospective power curve maintained sufficient power to pass the Survey Unit. The data range for the unit was less than two standard deviations. The frequency plot exhibits a normal Poisson distribution. The scatter plot graphically illustrates that the data varies about the arithmetic mean. The data posting plot does not clearly reveal any systematic spatial trends.

The power curves, scatter plot and frequency plots are found in Attachment B.

6.0 QUALITY ASSURANCE AND QUALITY CONTROL 6.1 Instrument QC Checks Operation of the E-600 w/SPA-3 was in accordance with DP-8535,"Setup and Operation of the Eberline E-600 Digital Survey Instrument," with QC checks preformed in accordance with DP-8504, "Control and Accountability of Radiation Protection Portable Survey Instruments."

Instrument response checks were performed prior to and after use for the E-600 w/SPA-3.

All instrumentation involved with the FSS of NSY-12 satisfied the above criteria for the survey. QC records are found in Attachment C.

6.2 Split Samples and Recounts DP-8864,"Split Sample Assessment for Final Status Survey" deals strictly with soil samples and provides no criteria for direct measurements therefore no measurement comparison were made.

6.3 Self-Assessments No self-assessments were performed during the FSS of NSY-12.

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Report No.: YNPS-FSS-NSY-12-00

7.0 CONCLUSION

The FSS of NSY-12 has been performed in accordance with YNPS LTP and applicable FSS procedures. Evaluation of the direct measurement data has shown that none of the direct measurements exceeded the DCGLw, depicted in Attachment B.

Retrospective power curves were generated and demonstrated that adequate power was achieved.

Therefore, the null hypothesis (Ho) is rejected.

NSY-12 meets the objectives of the Final Status Survey.

Based upon the evaluation of the data acquired for the FSS, NSY-12 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, including that from groundwater. IOCFR20 Subpart E ALARA requirements have been met as well as the site release criteria for the administrative level DCGLs that ensure that the Massachusetts Department of Public Health's 10 mrem/yr limit will also be met.

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Report No.: YNPS-FSS-NSY-12-00 List of Appendices Appendix A - YNPS-FSSP-NSY-12, "Final Status Survey Planning Worksheet Appendix B - YA-REPT-00-015-04, "Instrument Efficiency Determination for Use in Minimum Detectable Concentration Calculations in Support of the Final Status Survey at Yankee Rowe" Appendix C - ALARA Evaluations NSY-12 List of Attachments Attachment A - Maps and Posting Plots Attachment B - Data Quality Assessment Plots and Curves Attachment C - Instrument QC Records (In the electronic version, every Table of Contents, Figures, Appendices and Attachments, as well as every mention of a Table, Figure, Appendix or Attachment is a hyperlink to the actual location or document.)

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Attachments A through C have been provided electronically on the enclosed CD.

Final Status Survey Planning Worksheet Page 1 of 4 GENERAL SECTION Survey Area #:

NSY-12 Survey Unit #:

01 Survey Unit Name:

Tank-I Concrete Base FSSP Number:

YNPS-FSSP-NSY 12-01-00 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.

Ef 1.3 The survey unit has been turned over for final status survey. 21 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.

[z 1.5 Activities conducted within area since turnover for FSS have been reviewed.

Z Based on reviewed information, subsequent walkdown:

Rl 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.

ZI Classification: CLASS 1 WI CLASS 2 El CLASS 3 El DATA QUALITY OBJECTIVES (DQO) 1.0 Statement of problem:

Survey Unit NSY12-01 consists of the base for Tank-1 (TK-1), which is a concrete structure totally surrounded by Survey Unit NOL06-03. The footprint area of the unit is approximately 330 ft2 (31 M2). The data collected under this plan will be used to determine whether or not residual plant-related radioactivity on the exposed concrete surface of Survey Unit NSY12-01 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 Radiological 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:

Survey media: concrete Types of measurements: Fixed-point measurements, beta scans, and supplemental gamma scans.

Radionuclides-of-concern: Co-60 (assumed as radionuclide-of-concern).

For planning purposes, it was assumed that the radiological characteristics of unit NSY12-01 are similar to other concrete structures in the RSS area. Eleven concrete survey units in the RSS area have been found to meet LTP release criteria based on FSS data. The FSS data set from survey unit BRTO1-01 was used in the planning for NSY12-01 because it showed the highest variability (a = 1.6E3 dpm/100cm 2), and a higher variability in data requires the collection of more measurements.

Co-60 was assumed as the radionuclide-of-concem for unit NSY12-01 based on the same reasons given in the FSS plan for BRTO1-01 (YNPS-FSSP-BRTO1-01-00).

Average radiation level: 1.5E3 dpm/100cm2 (the mean value of FSS fixed-point measurements from BRT01-01) 8856.1 YNPS-FSSP-NSY 12-01-00 DPF-Page 1 of 4

Standard deviation (q): 1.6E3 dpm/1 00cm2 (variability observed in FFS data from BRTO 1-01)

DCGLs:

(1) Applicable DCGL_: 6.3E3 dpm/100cm2 (Co-60 assumed)

Note: the DCGLW value corresponds to 8.73 mrem/y.

The concrete surface of the unit NSY12-01 contains pits and irregular surfaces, which will increase the source-to-detector distance for some localized areas under the 100cm 2 window of the detector. Most of the pits and irregularities increase the source-to-detector distance by approximately 1/4 - 1/2/2 inch. These types of irregularities in the concrete surfaces will be taken into account through the efficiency factor applied to the measurements collected with the HP-100. Technical report YA-REPT-00-0 15-04 provides instrument efficiency factors (q) for various source-to-detector distances.

The ei. value for a source-to-detector distance of 1 inch was selected as a representative efficiency for data collected with the HP-100 from the irregular concrete surface of the tank base because it accounts for the /2 inch stand-off and the most common depth of pits and surface irregularities (1/4 - 1/2 inch). The sj value for a distance of 1/22 inch will be applied to HP-100 data collected from smooth concrete surfaces. The efficiency factors provided in. YA-REPT-00-015-04 are used below:

q =* 0.2413 c/e for smooth concrete surfaces (reflects a source to detector distance = '/2 inch), and

= 0.149 c/e for pitted/irregular surfaces (reflects a source to detector distance = 1 inch) a, = 0.25 e/d (consistent with the Co-60 assumption) total efficiency for smooth surface = ei

Fs = 0.2413 c/e. 0.25 e/d = 0.0603 c/d total efficiency for pitted/irregular surfaces = P,

E, = 0.149 c/e - 0.25 e/d = 0.0373 c/d (2) Gross measurement DCGL_ (for HP-100): 6.3E3 dpm/1OOcm 2 for smooth concrete surface: 6.3E3 dpm/100cm 2

0.0603 c/d = 3.8E2 cpm/IOOcm 2 for pitted/irregular surface: 6.3E3 dpm/100cm2

0.0373 c/d = 2.3E2 cpm/1OOcm 2 (3) Applicable DCGLT:Mc for fixed-point measurements: DCGLW

AF = 6.3E3 dpm/1OOcm 2

2.4 = 1.5E4 dpm/lOOcm 2 for smooth concrete surface: 1.5E4 dpm/100cm 2

0.0603 c/d = 9. 1E2 cpm/100cm 2 for pitted/irregular surface: 1.5E4 dpm/100cm2

0.0373 c/d = 5.6E2 cpm/100cm2.

Note: the DCGL and DCGLEMC value refer to above-background radioactivity.

Investigation Level for fixed-point measurement:

for smooth concrete surface: >9.1E2 cpm/100cm 2 above background for pitted/irregular concrete surface: >5.6E2 cpm/100cm 2 above background Investigation Level for HP-100 scan: Reproducible indication above background using the audible feature with headphones Investigation Level for SPA-3 scan: Reproducible indication above background using the audible feature with headphones Scan coverage: Beta scan with HP-100: 100% of the accessible concrete surface area on the vertical walls. Supplemental SPA-3 scans on the irregular surfaces of the vertical walls and cracks in the concrete.

MDCRfor HP-100: The accompanying table provides MDCR values by various background levels. The expected ambient background for the HP-100 range is 200 - 400 cpm.

Note: If the ambient background for the HP-100 exceeds 1000 cpm, notify the FSS Radiological Engineer before proceeding with the survey.

MDCO(DCGLEMc) for HP-1O0 scans: The accompanying table provides MDC(fDCGLEMC) values by various background levels.

QC checks and measurements: QC checks for the survey instruments will be performed in accordance with DP-8534. Pre-and post-use instrument QC checks will be performed.

Define the boundaries of the survey:

Boundary of NSY12-01 is as shown on the attached maps. Map 1 shows the footprint of the survey unit with the fixed-point locations on the top surface. Map 2 is the survey unit footprint with an overlay of the random-start systematic grid. Grid points that fall outside the footprint are measurement locations on the vertical walls. Map 3 shows the locations for the collection of ambient background measurements. The survey will be performed under normal weather conditions.

4.0 Develop a decision rule:

(a) If all the FSS data show that residual levels of plant-related radioactivity are below the DCGLw, reject the null hypothesis (i.e., Survey Unit meets the release criteria).

DPF-8856.1 YNPS-FSSP-NSY12-01-00 Page 2 of 4

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

(c) If the average of the FSS measurements is below the DCGLw, but some individual measurements exceed the DCGLW, then apply a statistical test as the basis for accepting or rejecting the null hypothesis.

(d) If the average of the FSS measurements exceeds the DCGLW, then accept the null hypothesis (i.e., Survey Unit fails to meet the release criteria).

5.0 Specify tolerable limits on decision errors:

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

Probability of type I error: 0.05 Probability of type II error: 0.05 6.0 LBGR: 6.3E3 dpm/100 cm 2 - 2 = 3.2E3 dpmi/100 cm2 7.0 Optimize Design:

Type of statistical test: WRS Test [0 Sign Test []

Basis including background reference location (if WRS test is specified): N/A Number samples (per DP-8853): 15 (Note: this number was increased to 31 to extend the grid to the vertical sides of the survey unit.)

Biased Measurements: None GENERAL INSTRUCTIONS

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

2. Locate and mark the measurement points at the locations shown in the attached map.

(a) If a measurement location is obstructed such that a measurement cannot be collected, select an alternate location in accordance with DP-8856.

3. Collect a series of ambient background measurements in accordance with step B.I.c in DP-8866 with the following variation of step B. I.c.2) using the HP-100 that is to be used to collect the fixed-point measurements:

(a) Cover the detector with a 1/8-inch Lucite (or equivalent) shield and collect 7 one-minute readings with the shielded detector facing down but approximately Im from the edge and approximately Im above the concrete surface at the approximate locations of BG1, BG2, and BG3, as shown on map 3.

(b) Record the background data on the attached Form I (even if the measurement was logged).

4. Collect 31 fixed-point (1-min) measurements in accordance with DP-8534.

(a) Designate the fixed-point measurements on the top surface as NSY-12-01-001-F-FM through NSY-12-01-015-F-FM, corresponding to the grid locations 001 through 015 on map 1.

(b) Designate the fixed-point measurements on the vertical sides (using the distances from edge of survey unit footprint as shown on map 2) as NSY-12-01-016-F-FM through NSY-12-01-03 1-F-FM.

(c) The FSS planning assumed that 5 ft of the base wall was exposed by excavation. If the actual vertical space allows further extension of the grid, continue the grid on the vertical area using the dimensions shown on map 2. Additional measurement will be designated in sequence continuing with NSY-12-01-032-F-FM.

(d) Record each fixed-point measurement "as read" (in units of cpm) on the attached Form 2 (even if the measurement was logged). Record any additional measurement on Form 2, as necessary.

(e) When recording the measurements on Form 2, identify those measurements collected from an irregular concrete surface with an asterisk (*).

5. Perform HP-100 and SPA-3 scans as described in the Specific Instructions.

6 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.

7. The job hazards associated with this survey are addressed in the attached JHA for NSY12-01. Use of fall protection will be addressed in the Yankee Rowe Project Daily Activity Plan and reviewed during the pre-survey briefing.

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

SPECIFIC INSTRUCTIONS

1. Beta scans covering 100% of the accessible vertical wall surface:

DPF-8856.1 YNPS-FSSP-NSY12-01-00 Page 3 of 4

(a) Perform the HP-100 scans by moving the detector at a speed no greater than 2 inches per second, using a 1/2/2 inch standoff.

(b) FSS Technicians will wear headphones while scanning and the survey instrument will be in the rate-meter mode.

Surveyors will listen for upscale readings and respond to readings that exceed the investigation level.

(c) Ensure that the name of the FSS Technician(s) performing the scan and the instrument number(s) are record either on DP-8856.2 or the survey map.

(d) If the HP-100 scan investigation level is exceeded:

(1) confirm that the above background indication is reproducible and cannot be attributed to a nearby source (e.g.,

waste container),

(2) if a nearby source is identified, have it removed or shielded, document the finding on DP-8856.2, and repeat the

scan, (3) if reproducible and not caused by a nearby source, collect a fixed-point measurement at the location of the highest reading observed during the scan, (4) The designation for a fixed-point measurement collected during a first-level investigation will continue in sequence beginning with NSY-12-01-032-F-FM-I. Record all investigation fixed-point measurements "as read" (in units of cpm) on the attached Form 2 (even if the measurement was logged).

(5) clearly mark the location of any fixed-point measurement collected during this level of investigation. If further investigation is required, it will be conducted under a separate survey plan.

(e) The FSS Field Supervisor will record information relevant to the HP-100 scans on DPF-8856.2.

2. Gamma scans on the irregular surfaces of the vertical walls and cracks in the concrete:

(a) Perform SPA-3 scans on the irregular surfaces and over cracks by moving the detector slowly (no greater than 0.25m/s) and keeping it < 3 inches from the surface.

(b) FSS Technicians will wear headphones while scanning with the survey instrument in the rate-meter mode. Surveyors will listen for upscale readings and respond to readings that exceed the SPA-3 investigation level.

(c) If a SPA-3 reading exceeds the investigation level:

(1) confirm that the above-background indication is reproducible and cannot be attributed to a nearby source, (2) if the reading is reproducible and not caused by a nearby source, collect a fixed-point measurement with the HP-100 at the highest reading observed during the scan and clearly mark that location. Designate the investigation fixed-point measurement as described in step 1 (c)(3) above. Record all investigation fixed-point measurements "as read" (in units of cpm) on the attached Form 2 (even if the measurement was logged). If further investigation is required, it will be conducted under a separate survey plan.

(d) The FSS Field Supervisor will record information relevant to the SPA-3 scans on DPF-8856.2.

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

(2) Date/time of commencement of HP-100 measurements QA signature:

(3) Date/time of commencement of SPA-3 measurement 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 Calsyn(yankeerowe.com satisfies this step.

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

Prepared by A,

Date

/I-17-"-

FSS Radiological Engineer Reviewed by M

,1=-'

r, Date,

740, S

oR adioi gine r Approved by

-,w-Date FSS Projedt Manager DPF-8856.1 Page 4 of 4 YNPS-FSSP-NSY12-01-00

MDCR/MDC Table for Survey Unit NSY-07-01

Background

(CDm) scan speed

ý (inis)

MDCR (cr~m) jscan speed MDCR MDC(fDCGL(emc)) I in/s)

(cpm)

I 400 2

151 0.23 1000 2

239 0.37 1500 2

292 0.45 2000 2

337 0.52 detector = HP-1 00 MDC(fDCGL)-MDCR tableNSY12-01

TECHNICAL REPORT TITLE PAGE Copy Instrument Efficiency Determination for Use in Minimum Detectable Concentration Calculations in Support of the Final Status Survey at Yankee Rowe Title YA-REPT-00-015-04 REV. 0 Technical Report Number Approvalr,

(

(Print & Sign N; Preparer:i /

0 ane)

Date:

10-- rl-rnq RAepview Date:

'9 Q7/

Approver (C.nzant Manager):

.,Date:

16j /7/0 q YA-REPT-00-015-04 Rev. 0 Page 1 of 26

//

TABLE OF CONTENTS Page 1.0 Executive Summary:.......................................................................................... 4 2.0

==

Introduction:==

4 3.0 Calibration Sources:.......................

...................... 4 4.0 Efficiency Determination:.............................................

................................. 6 4.1 Alpha and Beta Instrument Efficiency (si):....................................................... 6 4.2 Source to Detector Distance Considerations:...................................................... 7 4.2.1 Methodology............................................................................... 7 4.3 Source (or Surface) Efficiency (Fs) Determination:............................................ 8 5.0 Instrument Conversion Factor (E) (Instrument Efficiency for Scanning):.............................. 9 6.0 Applying Efficiency Corrections Based on the Effects of Field Conditions for Total Efficiency:... 9 7.0 C onclusion:..................................................................................................

10 8.0 R eferences:....................................................................................................

11 Tables Table 3.1 Nuclides and Major Radiations: Approximate Energies....................................... 5 Table 4.1 Instrument Efficiencies (Gi)........................................................................

7 Table 4.2 Source to Detector Distance Effects on Instrument Efficiencies for a- 0 Emitters........... 8 Table 4.3 Source Efficiencies as listed in ISO 1703-1:.................................................... 8 Table 5.1 Energy Response and Efficiency for Photon Emitting Isotopes:............................ 9 Appendix APPENDIX A MicroShield, SPA-3 Soil scan - 28 cm radius lpCi/cm3 Co-60..................... 12 APPENDIX B Microsoft Excel Co-60 Calculation Sheet............................................... 13 APPENDIX C MicroShield, SPA-3 Soil scan - 28 cm radius lpCi/cm3 Nb-94................... 14 APPENDIX D Microsoft Excel Nb-94 Calculation Sheet............................................. 15 YA-REPT-00-015-04 Rev. 0 Page 2 of 26

APPENDIX E APPENDIX F APPENDIX G APPENDIX H APPENDIX I APPENDIX J APPENDIX K APPENDIX L APPENDIX M APPENDIX N APPENDIX 0 MicroShield, SPA-3 Soil scan - 28 cm radius lpCi/cm3 Ag-1 08m................. 16 Microsoft Excel Ag-108m Calculation Sheet............................................. 17 MicroShield, SPA-3 Soil scan - 28 cm radius lpCi/cm3 Sb-125................... 18 Microsoft Excel Sb-125 Calculation Sheet.............................................

19 MicroShield, SPA-3 Soil scan - 28 cm radius lpCi/cm3 Cs-134.................... 20 Microsoft Excel Cs-134 Calculation Sheet.............................................

21 MicroShield, SPA-3 Soil scan-28 cm radius lpCi/cm3 Cs-137.......................

22 Microsoft Excel Cs-137 Calculation Sheet.............................................

23 MicroShield, SPA-3 Soil scan-28 cm radius 1pCi/cmn3 Cs-137.................... 24 Microsoft Excel Cs-137 Calculation Sheet.............................................

25 Calculated Energy Response.............................................................. 26 YA-REPT-00-015-04 Rev. 0 Page 3 of 26

1.0 Executive Summary:

The minimum detectable concentration (MDC) of the field survey instrumentation is an important factor affecting the quality of the final status survey (FSS). The efficiency of an instrument inversely impacts the MDC value. The objective of this report is to determine the instrument and source efficiency values used to calculate MDC. Several factors were considered when determining these efficiencies and are discussed in the body of this report. Instrument efficiencies (8i), and source efficiencies (Q), for alpha beta detection equipment under various field conditions, and instrument conversion factors (Ei), for gamma scanning detectors were determined and the results are provided herein.

2.0

==

Introduction:==

Before performing Final Status Surveys of building surfaces and land areas, the minimum detectable concentration (MDC) must be calculated to establish the instrument sensitivity. Table 5.4 of the License Termination Plan (LTP) [8.6] lists the available instrumentation and nominal detection sensitivities; however for the purposes of this basis document, efficiencies for the 100cm 2 gas proportional and the 2"x2" Nal (TI) detectors will be determined. Efficiencies for the other instrumentation listed in the LTP shall be determined on an as needed basis. The 100 cm2 gas propoi-tional probe will be used to perform surveys (i.e. fixed point measurements). A 2" x2" Nal (TI) detector will be used to perform gamma surveys (i.e., surface scans) of portions of land areas and possibly supplemental structural scans at the Yankee Rowe site. Although surface scans and fixed point measurements can be performed using the same instrumentation, the calculated MDCs will be quite different. MDC is dependent on many factors and may include but is not limited to:

instrument efficiency

" background

" integration time

" surface type

source to detector geometiy

source efficiency A significant factor in determining an instrument MDC is the total efficiency, which is dependent on the instrument efficiency, the source efficiency and the type and energy of the radiation. MDC values are inversely affected by efficiency, as efficiencies increase, MDC values will decrease. Accounting for both the instrument and source components of the total efficiency provides for a more accurate assessment of surface activity.

3.0 Calibration Sources:

For accurate measurement of surface activity it is desirable that the field instrumentation be calibrated with source standards similar to the type and energy of the anticipated contamination. The nuclides listed in Table 3.1 illustrate the nuclides found in soil and building surface area DCGL results that are listed in the LTP.

Instrument response varies with incident radiations and energies; therefore, instrumentation selection for field surveys must be modeled on the expected surface activity. For the purposes of this report, isotopes with max beta energies less than that of C-14 (0.158 MeV) will be considered difficult to detect (reference table 3.1). The detectability of radionuclides with max beta energies less than 0.158 MeV, utilizing gas proportional detectors, will be negligible at typical source to detector distances of approximately 0.5 YA-REPT-00-0 15-04 Rev. 0 Page 4 of 26

inches. The source to detector distance of 1.27 cm (0.5 inches) is the distance to the detector with the attached standoff (DP-8534 "Operation and Source Checks of Proportional Friskers")[8.5]. Table 3. 1 provides a summnary of the LTP radionuclides and their detectability using Radiological Health Handbook

[8.4] data.

Table 3.1 Nuclides and Major Radiations: Approximate Energies (Reference 8.4)

Nuclide a Energy E,.. (MeV)

Average

, Photon Energy (MeV) a Detectable..

13 Detectable y

(MeV)

EP wl Gas w/ Gas Detectable (MeV)

Proportional Proportional w/ Nal 2x2" H-3 0 0.018 0.005 C-14 0.158 0.049 Fe-55 0.23 (0.004%)

bremsstrahlung Co-60 0.314 0.094 1.173 (100%), 1.332 4

(100%)

Ni-63 0.066 0.017 Sr-90 0.544 0.200

'4 2.245 (Y-90) 0.931 Nb-94 0.50 0.156 0.702 (100%), 0.871 (100%)

Tc-99 0.295 0.085 4

Ag-1.65 (Ag-0.624 0.434 (0.45%), 0.511 108m 108)

(Ag-(0.56%)

108) 0.615 (0.18%), 0.632 (1.7%)

Sb-125 0.612 0.084 0.6, 0.25, 0.41, 0.46, 0.68, 0.77, 0.92, 1.10, 1.34 Cs-134 1.453 0.152 0.57 (23%), 0.605 (98%)

0.796 (99%), 1.038 (1.0%)

1.168 (1.9%), 1.365 (3.4%)

Cs-1 37 1.167 0.195 0.662 (85%) Ba-137m X-

/

T rays Eu-152 1.840 0.288 0.122 (37%), 0.245 (8%)

0.344 (27%), 0.779 (14%)

0.965 (15%), 1.087 (12%)

1.113 (14%). 1.408 (22%)

Eu-154 1.850 (10%)

0.228 Eu-155 0.247 0.044 0.087 (32%), 0.105 (20%)

/

Pu-238 5.50 (72%)

0.099 (8E-3%)

5.46(28%)

0.150 (1E-3%)

0.77 (5E-5%)

Pu-239 5.16 (88%)

0.039 (0.007%), 0.052 5.11 (11%)

(0.20%), 0.129 (0.005%)...

Pu-241 4.90 0.021 0.005 0.145 (1.6E-4%)

(0.0019%)

4.85 (0.0003%)

Am-241 5.49 (85%)

0.060 (36%), 0.101 5.44 (13%)

(0.04%)...

Cm-243 6.06 (6%)

0.209 (4%), 0.228 (12%),

q 5.99 (6%)

0.278 (14%)

5.79 (73%)

5.74 (11.5%)

YA-REPT-00-015-04 Rev. 0 Page 5 of 26

NUREG-1507 and ISO 7503-1 provide guidance for selecting calibration sources and their use in determining total efficiency. It is common practice to calibrate instrument efficiency for a single beta energy; however the energy of this reference source should not be significantly greater than the beta energy of the lowest energy to be measured.

Tc-99 (0.295 MeV max) and Th-230 (4.68 MeV at 76% and 4.62 MeV at 24%) have been selected as the beta and alpha calibration standards respectively, because their energies conservatively approximate the beta and alpha energies of the plant specific radionuclides.

4.0 Efficiency Determination:

Typically, using the instrument 47r efficiency exclusively provides a good approximation of surface activity. Using these means for calculating the efficiency often results in an under estimate of activity levels in the field. Applying both the instrument 27c efficiency and the surface efficiency components to determine the total efficiency allows for a more accurate measurement due to consideration of the actual characteristics of the source surfaces. ISO 7503-1 [8.2] recommends that the total surface activity be calculated using:

Rs+B - RB where:

A, is the total surface activity in dpm/cm 2, Rs+B is the gross count rate of the measurement in cpm, RB is the background count rate in cpm, sj is the instrument or detector 27c efficiency E: is the efficiency of the source W is the area of the detector window (cm2) 4.1 Alpha and Beta Instrument Efficiency (qi):

Instrument efficiency (qs) reflects instrument characteristics and counting geometry, such as source construction, activity distribution, source area, particles incident on the detector per unit time and therefore source to detector geometry. Theoretically the maximum value of si is 1.0, assuming all the emissions from the source are 2n and that all emissions from the source are detected. The ISO 7503-1 methodology for determining the instrument efficiency is similar to the historical 4zt approach; however the detector response, in cpm, is divided by the 2z surface emission rate of the calibration source. The instrument efficiency is calculated by dividing the net count rate by the 2zr surface emission rate (q 2,)

(includes absorption in detector window, source detector geometry). The instrument efficiency is expressed in ISO 7503-1 by:

YA-REPT-00-015-04 Rev. 0 Page 6 of 26

Rs.B - RB lEi--

q2r where:

Rs+B is the gross count rate of the measurement in cpm, RB is the background count rate in cpm, q 2n is the 2a surface emission rate in reciprocal seconds Note that both the 27r surface emission rate and the source activity are usually stated on the certification sheet provided by the calibration source manufacturer and certified as National Institute of Standards and Technology (NIST) traceable. Table 4.1 depicts instrument efficiencies that have been determined during calibration using the 27r surface emission rate of the source.

Table 4.1 Instrument Efficiencies (el)

Source Emission Active Area of Effective Area 100 cm2 Gas Proportional Source (cm2) of Detector HP-100 Instrument Efficiency (F)

(Contact)

Tc-99 15.2 100 cm 2 0.4148 Th-230 a

15.2 100 cm2 0.5545 4.2 Source to Detector Distance Considerations:

A major factor affecting instrument efficiency is source to detector distance. Consideration must be given to this distance when selecting accurate instrument efficiency. The distance from the source to the detector shall to be as close as practicable to geometric conditions that exist in the field. A range of source to detector distances has been chosen, taking into account site specific survey conditions. In an effort to minimize the error associated with geometry, instrument efficiencies have been determined for source to detector distances representative of those survey distances expected in the field. The results shown in Table 4.2 illustrate the imposing reduction in detector response with increased distance from the source. Typically this source to detector distance will be 0.5 inches for fixed point measurements and 0.5 inches for scan surveys on flat surfaces, however they may differ for other surfaces. Table 4.2 makes provisions for the selection of source to detector distances for field survey conditions of up to 2 inches. If surface conditions dictate the placement of the detector at distances greater than 2 inches instrument efficiencies will be determined on an as needed basis.

4.2.1 Methodology

The practical application of choosing the proper instrument efficiency may be determined by averaging the surface variation (peaks and valleys narrower than the length of the detector) and adding 0.5 inches, the spacing that should be maintained between the detector and the highest peaks of the surface. Select the source to detector distance from Table 4.2 that best reflects this pre-determined geometry.

YA-REPT-00-015-04 Rev. 0 Page 7 of 26

'r-1-1 A I Source to Detector Distance Effects on Instrument Efficiencies for a-P3 Emitters Source to Detector Instrument Efficiency (C1)

Distance (cm)

Tc-99 Th-230 Distributed Distributed Contact 0.4148 0.5545 1.27 (0.5 in) 0.2413 0.1764 2.54 (1 in) 0.1490 0.0265 5.08 (2 in) 0.0784 0.0002 4.3 Source (or Surface) Efficiency (es) Determination:

Source efficiency (s.), reflects the physical characteristics of the surface and any surface coatings. The source efficiency is the ratio between the number of particles emerging from surface and the total number of particles released within the source. The source efficiency accounts for attenuation and backscatter. s, is nominally 0.5 (no self-absorption/attenuation, no backscatter)-backscatter increases the value, self-absorption decreases the value. Source efficiencies may either be derived experimentally or simply selected from the guidance contained in ISO 7503-1. ISO 7503-1 takes a conservative approach by recommending the use of factors to correct for alpha and beta self-absorption/attenuation when determining surface activity. However, this approach may prove to be too conservative for radionuclides with max beta energies that are marginally lower than 0.400 MeV, such as Co-60 with a P3max of 0.314 MeV. In this situation, it may be more appropriate to determine the source efficiency by considering the energies of other beta emitting radionuclides. Using this approach it is possible to determine weighted average source efficiency. For example, a source efficiency of 0.375 may be calculated based on a 50/50 mix of Co-60 and Cs-137. The source efficiencies for Co-60 and Cs-137 are 0.25 and 0.5 respectively, since the radionuclide fraction for Co-60 and Cs-137 is 50% for each, the weighted average source efficiency for the mix may be calculated in the following manner:

(0.25X0.5)+ (0.5XO.5) = 0.375 Table 4.3 lists guidance on source efficiencies from ISO 7503-1.

Table 4.3 Source Efficiencies as listed in ISO 7503-1

> 0.400 MeVm~a

< 0.400 MeVm*a Beta emitters es= 0.5 es = 0.25 Alpha emitters e, = 0.25 ss = 0.25 It should be noted that source efficiency is not typically addressed for gamma detectors as the value is effectively unity.

YA-REPT-00-0 15-04 Rev. 0 Page 8 of 26

5.0 Instrument Conversion Factor (E) ( Instrument Efficiency for Scanning):

Separate modeling analysis (MicroshieldT) was conducted using the common gamma emitters with a concentration of 1 pCi/g of uniformly distributed contamination throughout the volume. MicroShield is a comprehensive photon/gamma ray shielding and dose assessment program, which is widely used throughout the radiological safety community. An activity concentration of 1 pCi/g for the nuclides was entered as the source term. The radial dimension of the cylindrical source was 28 cm, the depth was 15 cm, and the dose point above the surface was 10 cm with a soil density of 1.6 g/cm 3. The instrument efficiency when scanning, Ei, is the product of the modeled exposure rate (MicroShieldTM) in mRhr' /pCi/g for and the energy response factor in cpm/mR/hr as derived from the energy response curve provided by Eberline Instruments (Appendix 0). Table 5.1 demonstrates the derived efficiencies for the major gamma emitting isotopes listed in Table 3.1.

TABLE 5.1 Energy Response and Efficiency for Photon Emitting Isot pes Isotope Calculations for Ei Ei See appendix A through L (cpm/pCi/g)

Co-60 See Appendix Aand B 379 Nb-94 See Appendix C and D 416 Ag-108m See Appendix E and F 637 Sb-125 See Appendix G and H 210 Cs-134 See Appendix I and J 506 Cs-137 See Appendix.K and L 188 Eu-152 See Appendix M and N 344 When performing gamma scan measurements on soil surfaces the effective source to detector geometry is as close as is reasonably possible (less than 3 inches).

6.0 Applying Efficiency Corrections Based on the Effects of Field Conditions for Total Efficiency:

The total efficiency for any given condition can now be calculated from the product of the instrument efficiency si and the source efficiency -s,.

Stot= 86i X SS The following example illustrates the process of determining total efficiency. For this example we will assume the following:

Surface activity readings need to be made in the Primary Auxiliary Building (PAB) on the concrete wall surfaces using the E-600 and C-100 gas proportional detector.

" Data obtained from characterization results from the PAB indicate the presence of beta emitters with energies greater than 0.400 Mev.

" The source (activity on wall) to detector distance is 1.27 cm (0.5 in detector stand off). To calculate the total efficiency, Stot, refer to Table 4.2 "Source to Detector Distance Effects on Instrument Efficiencies for a- 03 Emitters" to obtain the appropriate si value.

Contamination on all surfaces is distributed relative to the effective detector area.

YA-REPT-00-015-04 Rev. 0 Page 9 of 26

When performing fixed point measurements with gas proportional instrumentation the effective source to detector geometry is representative of the calibrated geometries listed in Table 4.2 "Source to Detector Distance Effects on Instrument Efficiencies for a- 03 Emitters".

Corrections for temperature and pressure are not substantial.

In this example, the value for ai is 0.2413 as depicted in Table 4.2 "Source to Detector Distance Effects on Instrument Efficiencies for a- 03 Emitters". The es value of 0.5 is chosen refer to Table 4.3 "Source Efficiencies as listed in ISO 7503-1". Therefore the total efficiency for this condition becomes stot Fi x

, =0.2413 x 0.5 = 0.121 or 12.1%.

7.0

==

Conclusion:==

Field conditions may significantly influence the usefulness of a survey instrument. When applying the instrument and source efficiencies in MDC calculations, field conditions must be considered. Tables have been constructed to assist in the selection of appropriate instrument and source efficiencies. Table 4.2 "Source to Detector Distance Effects on Instrument Efficiencies for a-03 Emitters" lists instrument efficiencies (ai) at V'arious source to detector distances for alpha and beta emitters. The appropriate 8i value should be applied, accounting for the field condition, i.e. the relation between the detector and the surface to be measured.

Source efficiencies shall be selected from Table 4.3 "Source Efficiencies as listed in ISO 7503-1". This table lists conservative Es values that correct for self-absorption and attenuation of surface activity.

Table 5.1 "Energy Response and Efficiency for Photon Emitting Isotopes" lists Ei values that apply to scanning MDC calculations. The MicroshieldTM model code was used to determine instrument efficiency assuming contamination conditions and detector geometry cited in section 5.6.2.4.4 "MDCs for Gamma Scans of Land Areas" of the License Termination Plan [8.6].

Detector and source conditions equivalent to those modeled herein may directly apply to the results of this report.

YA-REPT-00-015-04 Rev. 0 Page 10 of 26

8.0 References 8.1 NUREG-1507, "Minimum Detectable Concentrations with Typical Radiation Survey Instruments for Various Contaminants and Field Conditions," 1998 8.2 ISO 7503-1, "Evaluation of Surface Contamination - Part I: Beta Emitters and Alpha Emitters," 1988-08-01.

8.3 ISO 8769, "Reference Sources for the Calibration of Surface Contamination Monitors-Beta-emitters (maximum beta energy greater 0.15MeV) and Alpha-emitters," 1988-06-15.

8.4 "Radiological Health Handbook," Revised Edition 1970.

8.5 DP-8534, "Operation and source Checks of Portable Friskers".

8.6 Yankee Nuclear Plant Site License Termination Plan, Rev.0, November 2003.

YA-REPT-00-0 15-04 Rev. 0 Page 11 of 26

APPENDIX A MicroShield v6.02 (6.02-00253)

Page DOS File Run Date Run Time Duration

1

SPA3-EFF-Co-60.ms6 September 10, 2004 8: 56:50 AM.

00:00:00 File Ref Date By Checked Case

Title:

SPA3-EFF-Co-60

==

Description:==

SPA-3 Soil scan - 28 cm radius IpCi/cm3 Co-60 Geometry: 8 - Cylinder Volume - End Shields Height Radius Source Dimensions:

15.0 cm 28.0 cm (5.9 in)

(11.0 in)

Dose Points Y

V A

1 X

0 cm 25 cm 0.0 in 9.8 In Shields Dimension Material 3.69e+04 cm 3 Concrete Air z

0 cm 0.0 in Density 1.6 0.00122 Shield N Source Air Gap Nuclide Co-60 Source Input : Grouping Method - Actual Photon Energies curies becquerels PCi/cm3 3.6945e-008 1.3670e+003 1.00OOe-006 Buildup : The material reference is - Source Integration Parameters Bq/cm3 3.7000e-002 Radial Circumferential Y Direction (axial) 20 10 10 Energy Activity MeV Photons/sec 0.6938 1.1732 1.3325 Totals 2.230e-01 1.367e+03 1.367e+03 2.734e+03 Fluence Rate MeV/cm 2/sec No Buildup 9.055e-06 1.098e-01 1.293e-01 2.391e-g1 Results Fluence Rate MeV/cm 2/sec With Buildup 1.590e-05 1.669e-01 1.904e-01 3.573e-01 Exposure Rate mR/hr No Buildup 1.748e-08 1.962e-04 2.244e-04 4.205e-04 Exposure Rate mR/hr With Buildup 3.070e-08 2.982e-04 3.303e-04 6.286e-04 YA-REPT-00-015-04 Rev. 0 Page 12 of 26

APPENDIX B YA-REPT-00-01 5-04 Rev. 0 Page 13 of 26

APPENDIX C MicroShield v6.02 (6.02-00253)

Page DOS File Run Date Run Time Duration

1

SPA3-EFF-Nb-94.ms6 September 16, 2004 3:22:38 PM 00:00:00 File Ref Date By Checked Case

Title:

SPA3-EFF-Nb-94

==

Description:==

SPA-3 Soil scan - 28 cm radius lpCi/cm3 Nb-94 Geometry: 8 - Cylinder Volume - End Shields Height Radius A

1 Source Dimensions:

15.0 cm 28.0 cm Dose Points V

X.

0 cm 0.0 in Y

25 cm 9.8 in (5.9 In)

(11.0 In) z 0 cm 0.0 in Density 1.6 0.00122 Shields Shield N Source Air Gap Dimension 3.69e+04 cm 3 Material Concrete Air Nuclide Nb-94 Source Input: Grouping Method - Actual Photon Energies curies becquerels PCi/cm3 3.6945e-008 1.3670e+003 1.00OOe-006 Buildup : The material reference is - Source Integration Parameters Bq/cm2 3.7000e-002 Radial Circumferential Y Direction (axial) 20 10 10 Energy Activity MeV Photons/sec 0.0023 0.0174 0.0175 0.0196 0.7026 0.8711 Totals 9.067e-02 4.834e-01 9.260e-01 2.720e-01 1.367e+03 1.367e+03 2.736e+03

.Fluence Rate MeV/cma/sec No Buildup 1.391e-10 8.762e-09 1.719e-08 7.924e-09 5.643e-02 7.464e-02 1.311e-01 Results Fluence Rate MeV/cm 2 /sec With Buildup 1.430e-10 9.129e-09 1.792e-08 8.356e-09 9.872e-02 1.228e-01 2.216e-01 Exposure Rate mR/hr No Buildup 1.86le-10 4.729e-10 9.104e-10 2.925e-10 1.088e-04 1.405e-04 2.493e-04 Exposure Rate mR/hr With Buildup 1.913e-10 4.927e-10 9.491e-10 3.085e-10 1.904e-04 2.312e-04 4.216e-04 YA-REPT-00-015-04 Rev. 0 Page 14 of 26

APPENDIX D YA-REPT-00-015-04 Rev. 0 Page 15 of 26

APPENDIX E MicroShield v6.02 (6.02-00253)

Page DOS File Run Date Run Time Duration

1

SPA3-EFF-Ag-108m.ms6 September 16, 2004 3:30:40 PM 00:00:00 File Ref Date By Checked Case

Title:

SPA3-EFF-Ag-108m

==

Description:==

SPA-3 Soil scan - 28 cm radius lpCi/cm3 Ag-108m Geometry: 8 - Cylinder Volume - End Shields Height Radius Source Dimensions:

15.0 cm 28.0 cm (5.9 in)

(11.0 In)

Dose Points Y

Y A

1 X

0 cm 0.0 in 25 cm 9.8 in z

0 cm 0.0 in x(

Shield N Source Air Gap Shields Dimension Material Density 3.69e+04 cm 3 Concrete

.1.6 Air 0.00122 Nuclide Ag-108m Source Input: Grouping Method - Actual Photon Energies curies becquerels pCi/cm 3 3.6945e-008 1.3670e+003 1.00OOe-006 Buildup : The material reference is - Source Integration Parameters Bq/CM 3 3.7000e-002 Radial Circumferential Y Direction (axial) 20 10 10 Energy MeV 0.0028 0.003 0.021 0.0212 0.022 0.0222 0.0238 0.0249 0.0304 0.0792 0.4339 0.6144 0.7229 Totals Activity Photons/sec 6.580e+01 7.853e+00 2.491e+02 4.727e+02 7.024e+00 1.330e+01 1.501e+02 4.289e+00 2.902e-04 9.687e+01 1.229e+03 1.236e+03 1.237e+03 4.768e+03 Fluence Rate MeV/cm 2/sec No Buildup 1.252e-07 1.568e-08 9.534e-06 1.862e-05 3.202e-07 6.251e-07 9.273e-06 3.145e-07 4.431e-11 2.008e-04 2.705e-02 4.282e-02 5.300e-02 1.231e-01 Results Fluence Rate MeV/cm2/sec With Buildup 1.287e-07 1.612e-08 1.015e-05 1.985e-05 3.434e-07 6.714e-07 1.010e-05 3.464e-07 5.248e-11 4.802e-04 5.514e-02 7.808e-02 9.194e-02 2.257e-01 Exposure Rate mR/hr No Buildup 1.351e-07 1.612e-08 2.824e-07 5.389e-07 8.233e-09 1.568e-08 1.863e-07 5.492e-09 4.230e-13 3.190e-07 5.294e-05 8.347e-05 1.019e-04 2.398e-04 Exposure Rate mR/hr With Buildup 1.388e-07 1.657e-08 3.007e-07 5.744e-07 8.83le-09 1.685e-08 2.029e-07 6.050e-09 5.010e-13 7.629e-07 1.079e-04 1.522e-04 1.768e-04 4.389e-04 YA-REPT-00-015-04 Rev. 0 Page 16 of 26

APPENDIX F YA-REPT-00-015-04 Rev. 0 Page 17 of 26

Page DOS File Run Date Run Time Duration A1

SPA3-EFF-Sb-125.ms6

September 16. 2004

3:34:07 PM 00:00:00 APPENDIX G MicroShield v6.02 (6.02-00253)

File Ref Date By Checked Case

Title:

SPA3-EFF-Sb-125

==

Description:==

SPA-3 Soil scan - 28 cm radius IpCi/cm3 Sb-125 Geometry: 8 - Cylinder Volume - End Shields Height Rodius S.orCe Dimensions:

15.0 cm 28.0 cm (5.9 in)

(11.0 in)

Y A

1 Dose Points X

0cm 0.0 in Shields Dimension 3.69e+04 =3 Y

25 cm 9.8 in z

0cm 0.0 in Shield N Source Air Gap Material Concrete Air Densily 1.6 0.00122 Nuclide Sb-125 curies 3.6945e-008 Source Input :Grouping Method - AutilO Phoion Energies Ileequerels pCi/em, I.3670e+003 I.00DOe-006 8q/cm' 3.7000e.002 Buildup :The materia reference is - Source Integration Parameters Radial Circumferential Y Direction (axial) 20 10 10 Energy MeV 0.0038 0.0272 0,0275 0.031 0.0355 0.117 0.159 0.1726 0.1763 0.2041 0.2081 0.2279 0.321 0.3804 0.408 0.4279 0.4435 0.4634 0.6006 0.6066 0.6359 0.6714 Totals Activity photons/sec 6.762e+0 I 1.748e+02 3.262e+02

1. 132e,+02 5.693e+0 I 3,568e+00 9.53le-0I 2,478e+-00 9.422c+0 1 4.4 1 Oe+00 3.324e+00 1.796e+00 5.70 1lc+00 2,045e+O 1 2.486e+00 4,009e+02

4.

130c+00 1.415ce+02 2,430e+02 6.864e+0I 1,.548e+02 2.478e+0 I 1.91 6e+03 Fluence, Rate MeV~em'/lsec No Buildup 1.708e-07 1.785e-05 3.453e-05 1.857e-05 1.492e-05 1.380"50 5.634e-06 1.634e-05 6.392e-04 3.630e-05 2.805e-05 I.70ge-05 8.474e-05 3.79-7e-04 5.05 It-OS 8.668e-03 9.356e-05 3.395e-03 8.1 74e-03 2.340e-03 5.609e-03 9.640e-04 3.060e-02 Results Fluence Rate MeV/cm/sec With Buildup 1.756e-07 2.020e-05 3.922e-05 2.22 1e-05 1.91 Be-05 3.715e-05 1.499e-05 4.295e-05 1.674e-03 9.230"-05 7.103e-05 4.229e-05 1.899e-04 8.052e-04 1.049e-04 1.774e-02

,.894e-04 6.781e-03 1.501e-02 4.283e-03 1.012e-02 1.710e-03 S.90le-02 Exposure Rate mR/hr No Buildup 1.388e-07 2.376e-07 4.461e-07 1.670e-07 9.090e-08

2. 146e-08 9.416e-09 2.787c-08 1.096e-06 6.435e-08 4.994e-08 3.098e-08 1.620e-07 7.364e-07 9.853e-08 1.695e-"5 1.832e-"7 6.658e-06 1.595e-05 4.564e-06 1.09Ie-05 1.867e-06 6.046e-05 Exposure Rate mR/hr With Buildup 1.427e-07 2.689e-07 5.067e-07 1.997e-07 I. 169e-07 5.778t-08 2.505e-08 7.326e-08 2.870e-06 1.636e-07 1.264e-07 7.670e-08 3.632e-07 1.564e-06 2.047e-07 3.470e-05 3.709c-07 1.330e-05 2.930e-05 8.355e-06 1.967e-05 3.31 le.06 1.158e-04 YA-REPT-00-015-04 Rev. 0 Page 18 of 26

APPENDIX H YA-REPT-00-015-04 Rev. 0 Page 19 of 26

APPENDIX I MicroShield v6.02 (6.02-00253)

Page DOS File Run Date Run Time Duration

1

SPA3-EFF-Cs-134.ms6 September 16, 2004 3:39:09 PM

.00:00:00 Oiie Ref Date By Checked Case

Title:

SPA3-EFF-Cs-134

==

Description:==

SPA-3 Soil scan - 28 cm radius lpCi/cm3 Cs-134 Geometry: 8 - Cylinder Volume - End Shields Source Dimensions:

Height 15.0 cm Radius 28.0 cm (5.9 in)

(11.0 in)

Y Dose Points Y

A

1 X

0 cm 25 cm

0.0 in 9.8 in Shields Dimension Material 3.69e+04 cm 3 Concrete Air z

0 cm 0.0 in Density 1.6 0.00122 Shield N Source Air Gap Nuclide Cs-134 Source Input: Grouping Method - Actual Photon Energies curies becquerels ljCi/cm3 3.6945e-008 1.3670e+003 1.00OOe-006 Buildup : The material reference is - Source Integration Parameters Bq/cm3 3.7000e-002 Radial Circumferential Y Direction (axial) 20 10 10 Energy MeV 0.0045 0.0318 0.0322 0.0364 0.2769 0.4753 0.5632 0.5693 0.6047 0.7958 0.8019 1.0386 1.1679 1.3652 Totals Activity Photons/sec 1.222e+00 2.931e+00 5.407e+00 1.968e+00 4.839e-01 1.996e+01 1.146e+02 2.109e+02 1.334e+03 1.167e+03 1.193e+02 1.367e+01 2.461e+01 4.156e+01 3.058e+03 Fluence Rate MeV/cm 2/sec No Buildup 3.658e-09 5.271e-07 1.014e-06 5.611e-07 5.931e-06 4.950e-04 3.545e-03 6.619e-03 4.529e-02 5.668e-02 5.852e-03 9.377e-04 1.964e-03 4.055e-03 1.254e-01 Results Fluence Rate MeV/cm 2/sec With Buildup 3.760e-09 6.386e-07 1.236e-06 7.32le-07 1.391e-05 9.808e-04 6.648e-03 1.237e-02 8.300e-02 9.564e-02 9.853e-03 1.472e-03 2.990e-03 5.936e-03 2.189e-01 Exposure Rate mR/hr No Buildup 2.507e-09 4.391e-09 8.157e-09 3.188e-09 1.113e-08 9.712e-07 6.940e-06 1.295e-05 8.836e-05 1.079e-04 1.113e-05 1.717e-06 3.514e-06 6,993e-06 2.405e-04 Exposure Rate mR/hr With Buildup 2.577e-09 5.320e-09 9.943e-09 4.160e-09 2.610e-08 1.924e-06 1.302e-05 2.421e-05 1.619e-04 1.820e-04 1.874e-05 2.696e-06 5.349e-06 1.024e-05 4.202e-04 YA-REPT-00-015-04 Rev. 0 Page 20 of 26

APPR."NT)TY I YA-REPT-00-015-04 Rev. 0 Page 21 of 26

APPENDIX K MicroShier' v6.02 (6.02-00253)

Page DOS File Run Date Run Time Duration

1

SPA3-EFF-Cs-137.ms6 September 10, 2004 8:52:18 AM 00:00:00 File Ref Date By Checked Case

Title:

SPA3-EFF-Cs-137

==

Description:==

SPA-3 Soil scan - 28 cm radius lpCi/cm3 Cs-137 and Daughters Geometry: 8 - Cylinder Volume - End Shields Source Dimensions:

Height 15.0 cm Radius 28.0 cm Dose Points Y

V A

1 X

0cm 25cm 0.0 in 9.8 in Shields Dimension Material 3.69e+04 cm 3 Concrete Air (5.9 in)

(11.0 in) z 0 cm 0.0 in Density 1.6 0.00122 Shield N Source Air Gap Nuclide Ba-137m Cs-137 Source Input: Grouping Method - Actual Photon Energies curies becquerels lJCi/cm3 3.4950e-008 1.2932e+003 9.4600e-007 3.6945e-008 1.3670e+003 1.00OOe-006 Buildup : The material reference is - Source Integration Parameters Bq/cms 3.S002e-002 3.7000e-002 Radial Circumferential Y Direction (axial) 20 10 10 Energy Activity MeV Photons/sec 0.0045 0.0318 0.0322 0.0364 0.6616 Totals 1.342e+01 2.677e+01 4.939e+01 1.797e+01 1.164e+03 1.271e+03 Fluence Rate MeV/cmz/sec No Buildup 4.020e-08 4.815e-06 9.260e-06 5.126e-06 4.442e-02 4.444e-02 Results Fluence Rate MeV/cm 2/sec With Buildup 4.133e-08 5.834e-06

1. 129e-05 6.688e-06 7.913e-02 7.915e-02 Exposure Rate mR/hr No Buildup 2.755e-08 4.011e-08 7.452e-08 2.912e-08 8.611e-05 8.628e-05 Exposure Rate mR/hr With Buildup 2.833e-08 4.860e-08 9.084e-08 3.800e-08 1.534e-04 1.536e-04 YA-REPT-00-0 15-04 Rev. 0 Page 22 of 26

APPENDIX L YA-REPT-00-015-04 Rev. 0 Page 23 of 26

Page DOS File Run Date Run Time Duration

1

SPA3-EFF-Eu-152.ms6 October 7, 2004 11:25:11 AM 00:00:00 APPENDIX M MicroShield v6.02 (6.02-00253)

File Ref

!Date By Checked Case

Title:

SPA-3-EFF-Eu-152

==

Description:==

SPA-3 Soil scan - 28cm radius 1 pCI/cm3 Eu-152 Geometry: 8 - Cylinder Volume - End Shields Source Dimensions:

Height 15.0 cm (5.9 In)

Radius 28.0 cm:

(11.0 In) o

~ ~...............

A

1 X

0 cm 0.0 In Y

25 cm 9.8 In z

0 cm 0.0 In x

Shields Shield N Dimension Material Density Source 3.69e+04 cm3 Concrete 1.6 Air Gap Air 0.00122 t

Source Input: Grouping Method - Standard Indices Number of Groups :,25 Lower Energy Cutoff: 0.015 Photons < 0.015 : Included Library. Grove curies becquereis.

iC/cm' 3.6945e-008 1.3670e+003 1.00O0e-006 Nuclide Eu-152 Sq/cmm 3.70OOe-002 Radial Circumferential Y Direction (axial)

Buildup : The material reference is - Source Integration Parameters 20 10 10 Results Fluence Rate Energy Activity MeV/cm2/sec MeV Photons/sec No Buildup 0.015 0.04 0.05 0.1 0.2 0.3 0.4 0.5 0.6 0.8 1.0 1.5 Totals 2.077e+02 8.088e+02 2.022e+02 3.887e+02 1.024e+02 3.696e+02 8.590e+01 7.711e+00 5.797e+01 2.434e+02 5.849e+02 3.171e+02 3.376e+03 2.087e-06 3.131e-04 1.507e-04 1.189e-03 8.207e-04 5.029e-03 1.701e-03 2.043e-04 1.948e-03 1.190e-02 3.820e-02 3.490e-02 9.635e-02 Fluence Rate MeV/cm2/sec With Buildup 2.146e-06 4.33le-04 2.467e-04 3.118e-03 2.097e-03 1.151e-02 3.555e-03 3.984e-04 3.579e-03 2.005e-02 6.058e-02 4.999e-02 1.556e-01 Exposure Rate mR/hr No Buildup 1.790e-07 1.385e-06 4.014e-07 1.819e-06 1.448e-06 9.540e-06 3.314e-06 4.010e-07 3.802e-06 2.263e-05 7.042e-05 5.871e-05 1.740e-04 Exposure Rate mR/hr With Buildup 1.841e-07 1.916e-06 6.572e-07 4.770e-06 3.700e-06 2.184e-05 6.926e-06 7.819e-07 6.985e-06 3.813e-05 1.117e-04 8.41le-05 2.817e-04 YA-REPT-00-015-04 Rev. 0 Page 24 of 26

APPENDIX N YA-REPT-00-015-04 Rev. 0 Page 25 of 26

APPENDIX 0 Calculated Energy Response (Eberline Instruments) 1CPMImR/h 1 OOOOOOOF rII I

r, I

Y -

V -

f-I I

I i flffllfllf.,

E

-4 3-

-6.

~

I I-A I

IN 100000 IV I 1

IIt

-I 1

10000( 0 i00 f000 10000 ENERGY (key)

YA-REPT-00-015-04 Rev. 0 Page 26 of 26

ALARA Analysis Worksheet Survey Area: NSY-12 Survey Unit: 01 A. Estimation of Total Cost (COStT)

1. Cost of performing remediation work (CostR) (assume3-staff crew for I day@average $60 per hour; cost

$1800 for heavy equipment not included)

2. Cost of waste disposal (CostwD) = (2.a) * (2.b)

$ 670

a. estimated waste volume: 1 m3

b. cost of waste disposal: $670/M3

3. Cost of workplace accident (CostAcc)

$3,000,000 person-'

4.2x1 0.8 h-'

(3.a)

$ 3.78

a. time to perform remediation action: 30 person-hours

4. Cost of traffic fatality (CostTF) =

{$3,000,000 - 3.8x10-8 kmn' (2.a) - (4.a)}/(4.b)

$ 34.37

a. total distance traveled per shipment: 4100 km

b. waste volume per shipment: 13.6 m3, if unknown, use 13.6m 3 as a default value

5. Cost of worker dose (CostwDose) = $2,000 per person-rem * (5.a) -(5.b)

$0

a. worker TEDE:

rem/h

b. remediation exposure time person-hour CostT

$ 2508 B. Survey Unit Radiological Information Radionuclide Average Concentration Relative Fractiona Half-Life (y)

Decay Constant" (y! )

1. Co-60

a. 6622 dprm/100cm 2

b. 1

c. 5.271

d. 0.13

2.

a.

b.

c.

d.

3.

a.

b.

c.

d.

4.

a.

b.

c.

d.

5.

a.

b.

c.

d.

6.

a.

b.

c.

d.

7.

a.

b.

c.

d.

8.

a.

b.

c.

d.

Total Concentration:

a Relative fraction = average concentration divided by the total concentration.

b Decay constant = 0.693 divided by half-life.

DPF-8867.1 Page l of3

C. Calculation of ALARA Action Level (AL)

1. Removable fraction for remediation action being evaluated: 1.0

2. Monetary discount rate: 0.03 v'1

3. Number of years over which the collective dose is calculated: 1000 V

4. Population density for the critical group: 0.0004 people/m 2

5. Area being evaluated: 100 m2

6. AL for each radionuclide-of-interest:

a. AL = {CostT/($2000. C.4- 0.025 - C.1-C.5)} {(C.2 + B.l.d)/(1-e-C.2+BI.'d)'C.3} {B.1.b} = 13_56

b. AL

{CostT/($200 0 - C.4 0.025 C. 1 C.5)} {(C.2 + B.2.d)/(1-e"(C2+B.2"d) C.3}

{B.2.b} =

c. AL= {CostT/($ 2 0 0 0" C.4 0.025 C.1 C.5)}

{(C.2 + B.3.d)/(,-e-(C' 2+B.3d)C. 3} {B.3.b} =

d. AL= {CostT/($2000 - C.4A 0.025 C.1 - C.5)} {(C.2 + B.4.d)/(l-e"(c'I+B4..d)'C 3}

{B.4.b} =

e. AL= {CostT/($ 200 0 -C.4.0.025 C.1 -C.5)}

{(C.2 + B.5.d)/(1I-e"(C2+B'5"'d)C.3} {B.5.b} =

f. AL = {CostT/($ 2 0 0 0 C.4A 0.025 C.1

C.5)} - {(C.2 + B.6.d)/(1l-e"-C 2+B.6 'd) C.3}

{B.6.b} =

g. AL = {CostT/($ 2 000 CA' 0.025 C.1 I C.5)}) {(C.2 + B.7.d)/(l1-e"(c 2+B'7"'d)C.3} {B.7.b} =

h. AL

{CostT/($2000 C.4A 0.025 C.1

C.5)}) {(C.2 + B.8.d)/(l-e(C 2+B8d)'C.3} {B.8.b} =

7.............................................................................. Sum of ALs (= ALARA AL) = 1356 D. ALARA Evaluation Radionuclide DCGL DCGL Fractiona

1. Co-60 a 6622 dpm/1OOcm 2

b. (B.l.a)/(D.l.a)= 1.0

2.

a.

b. (B.2.a)/(D.3.a) =

3.

a.

b. (B.3.a)/(D.4.a) =

4.

a.

b. (B.4.a)/(D.5.a) =

5.

a.

b. (B.5.a)/(D.6.a) =

6.

a.

b. (B.7.a)/(D.7.a) =

7.

a.

b. (B.8.a)/(D.8.a) =

8.

a.

b. (B.9.a)/(D.9.a) =

9........................................................................... Sum of D CG L Fractions = 1.0 a DCGL fraction = average residual concentration in survey unit (from Section B) divided by the DCGL.

DPF-8867.1 Page 2 of 3

10. Comparison of the sum of the DCGL fractions (D.9) to ALARA AL (C.7):

Check one:

Sum of the DCGL Fractions < ALARA AL Sum of the DCGL Fractions > ALARA AL

12. Decision Criteria: If the sum of the DCGL fractions < AL, then additional remediation is not cost beneficial. If the sum of the DCGL fractions > AL, then additional remediation is cost beneficial.

Check one:

Additional remediation IS NOT cost beneficial V

Additional remediation IS cost beneficial __

Prepared by Date I/-.-----

6 FSS Radiological Engineer Reviewed by 1

rc( t

-&/

Date

/

7 FSS Project Manager DPF-8867.1 Page 3 of 3

ML070470124

Text

References:

Subject:

Dear Madam/Sir:

Enclosure:

SUMMARY

SUMMARY

SUMMARY

7.0 CONCLUSION

Background

4.2.1 Methodology

Title:

Title:

Title:

Title:

Title:

Title:

Title:

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