ML043640178

Maine Yankee Final Status Survey Release Record FA-2600 LSA Test Pit Survey Unit 1

ML043640178
Person / Time
Site:	Maine Yankee
Issue date:	12/22/2004
From:	Donna Anderson, Cooper W J, Pillsbury G, Tozzie R J Maine Yankee Atomic Power Co
To:	NRC/FSME
References
MN-04-060, RA-04-118 FA-2600-01, Rev 0
Download: ML043640178 (25)

Text

MAINE YANKEE FINAL STATUS SURVEY RELEASE RECORD FA-2600 LSA TEST PIT SURVEY UNIT I Prepared By: Date: jFSS Engieler -Signature Printed Name Reviewed By: Date: -lot HESj is S ignature 4 Printed Name Reviewed By: *d.c Lh Date: ia Iwa M o4 Independent Review -Signature Pnted Namet Approved By: __ Date: SI' FSS, MOP- Signature Printed Name Approved By: 0/ /t , Date:z8/c5 FSS., M\OP -Signature Printed Name Revision 0 MAINE YANKEE FINAL STATUS SURVEY RELEASE RECORD FA-2600 LSA TEST PIT SURVEY UNIT I A. SURVEY UNIT DESCRIPTION Survey Unit I is located in Survey Area FA2600, the LSA Test Pit. The survey unit consists of concrete and rock/ledge surfaces within the LSA Test Pit. The pit was located inside the LSA rad waste packaging building under a cover in the building floor. The LSA Building floor slab footprint will be surveyed with FR 0111 Yard West Excavations.

The pit was used during inspections of the Containment Building concrete.

It is located near grid coordinates 407,650 N and 623,700 E using the Maine State Coordinate System (West Zone) NAD 1927.The LSA Test Pit is shown in relation to other major site structures in map FA 2600-1 SITE.All maps referenced in this release record are provided in Attachment I unless otherwise noted. The survey unit is approximately 54 m.B. SURVEY UNIT DESIGN INFORMATION The area was designated a Class I land survey per the LTP (Table 5-I B, A2600, LSA Bldg.Slab). Minor remediation of the concrete surfaces in the Test Pit (dewatering, removing flowable solids) was performed prior to the Final Status Survey. In addition, cross bracing between the test pit walls was also removed prior to final surveys. The former locations of these braces are shown on the maps. Since the survey unit was already Class 1, no reassessment of classification was required.The survey unit design parameters are shown in Table 1. Given an adjusted relative shift of 3, it was determined that 14 direct measurements were required for the Sign Test; however, the number of samples was increased because one additional sample point fell within the area when the locations were laid out. Fifteen direct measurements were actually performed.

Measurement locations were determined using a fixed grid with a randomly determined start point and are illustrated on the maps FA 2600-IDP and FA 2600-Old through FA 2600-Of.Once the direct measurement readings were completed, removable contamination samples were obtained at each measurement location.The survey was also designed to include 56 scan grids for flat surfaces, each of approximately I m 2 area (see maps FA 2600-Ola through FA 2600-Olc).

Instrument scan setpoints were conservatively set below the DCGLEMC, as shown in Table 2-2 (Attachment 2). In addition, there were four junctures scanned as shown on map FA 2600-01g.To accommodate measurement geometry requirements for surfaces of non-uniform smoothness, the SHP-360 probe was used to augment the 43-68 scan survey. First, a 43-68 scan was performed on all surfaces, including those that were unlikely to meet geometry requirements for that model of probe. Then a repeat scan, using the SHP-360, was performed on areas with surface irregularities that required a smaller probe size. Ninety-degree surface junctures (wall-wall) were scanned using the 43-68 probe with a reduced efficiency.

FA-2600-01, Revision 0 Page 2 of 25 Background values were established, for each particular instrument probe application based on ambient background values in the survey unit and previously established material backgrounds.

These background values, listed in Table 1, were used to establish net activity for direct measurements, scan alarm setpoints, and to confirm the scan MDCs used were appropriate.

The instruments used in this survey are listed by model and serial number in Attachment 2 (Table 2-1). Scan MDCs are also listed in Attachment 2 (Table 2-2) and are compared to the DCGL, the investigation level, and the DCGLENMc.

As shown in this table, the scan MDC is less than the scan investigation level in all cases, thus providing high confidence (95% or higher) that an elevated area would be detected in the scanning process. Further, since the investigation level at the alarm setpoint was always less than the design DCGLENIC, no EMC sample size adjustment was necessary.

TABLE 1 SURVEY UNIT DESIGN PARAMETERS Survey Unit J Design Criteria l Basis Area 54 m'Based on an adjusted LBGR of NumberofDirect 15,162 dpm/I00 cm 2 , sigma' of M 14 946 dpm/O00 cm 2 , and a relative IMeasurements Required shift of 3.0.Type I = Type II = 0.05 Sample Area 3.86 m' 54 m' / 14 samples'Sample Grid Spacing 1.96 m (3.86)'-Scan Grid Area I m.Area Factor 13 50 m 1/3.86 m' (Reference 3)Scan Survey Area 54 ml Class I -100%Background 7;43-68 Direct and Scan 3,346 dpm/100 cm 2 Ambient and Material (flat surfaces)43-68 Scans 6,257 dpm/100 cm2 Ambient and Material SHP-360 Scans 9,211 dpm/100 cm 2 Ambient and material (surface irregularities)

_Scan Investigation Level <DCGLemc See Table 2-2 (Attachment 2)DCGL 18,000 dpm/100 cm" LTP, Rev. 3 Design DCGLEMC 234,000 dpm/100 cm 2 Area Factor x DCGL 2 Design sigma is based on test pit remediation survey data.This survey unit was initially designed for N=14 samples. Tle N=I 4 design led to a survey unit map with 15 locations on the systematic grid. The Area Factor used reflects the design grid size.FA-2600-01, Revision 0 Page 3 of 25 C. SURVEY RESULTS Fifteen direct measurements were made in Survey Unit 1. All direct measurements were less than the DCGL. The resulting data are presented in Table 2 below. One grid, the floor of the pit including the wall/floor junctures, was wet, and although the floor wvas surveyed with the 43-68 probe, was too wet for full confidence in the scan result. A concrete volumetric sample was therefore collected from this single grid.No verified alarms were received during the surface scans. Therefore, no investigations were required.TABLE 2 DIRECT MEASUREMENTS Gross Activt Net Activity pLocation cl c (Table I Background Subtracted) dpm/ IO00cm Jdpm!100 cm 2 FA2600-01-COO]

2576 -769 FA2600-01-C002 2766 -580 FA2600-01 -C003 2674 -672 FA2600-01-COO4 2979 -366 FA2600-0 1-COO5 2955 -391 FA2600-0I-C006 3028 -317 FA2600-01-C007 2839 -507 FA2600-0 1-COO8 2485 -861 FA2600-01 -COO9 2900 -446 FA2600-O1-CO1O 2967 -379 FA2600-01-COI 1 2851 -495 FA2600-01-CO12 3297 -49 FA2600-01-C013 2686 -659 FA2600-01-C014 2973 -372 FA2600-01-C015 3114 -232 Mean 2873 -473 Median 2900 -446 Standard Deviation.

211 211 Sample Range 2485 to 3297 -861 to -49 D. SURVEY UNIT INVESTIGATIONS PERFORMED AND RESULTS No investigations were required as there were no verified scan alarms.FA-2600-OI, Revision 0 Page 4 of 25 E. SURVEY UNIT DATA ASSESSMENT An analysis of the direct sample measurement results, including the mean, median, standard deviation, and sample result range, are provided in Table 2. Without subtracting background, all direct measurement results were below the DCGL. The maximum direct sample result with background subtracted was less than the initial background and was equivalent to -49 dpm/l 00 cm 2.When adjusted for background, the mean residual contamination level is -473 dpm/l 00 cm 2.This is equivalent to an annual dose of 0.0 mrem.There were no verified alarms, and therefore there were no investigations and no Elevated Measurement Comparison test was required.The single volumetric sample collected of the concrete from the bottom of the Test Pit indicated positive Co-60 and Cs-1 37, at a total activity of about 310 dpm/l 00 cm 2 or less than 2% of the DCGL.F. ADDITIONAL DATA EVALUATION Attachment 4 provides additional data evaluation associated with Survey Unit I, including relevant statistical information.

Based on survey unit direct measurement data, this attachment provides the Sign Test Summary, Quantile Plot, Histogram, and Retrospective Power Curve.1. The Sign Test Summary provides an overall summary of design input (Table I) and resulting calculated values used to determine the required number (N) of direct measurements (per LTP Section 5.4.2). The Sign Test Summary is a separate statistical analysis that also calculates the mean, median, and standard deviation of the direct measurements.

The Sign Test Summary table calculated the total standard deviation by propagating the individual standard deviation values used in the subtracted background survey design (using the square root of the sum of the squares method). Therefore, median, mean, and standard deviation values listed in the Sign Test Summary table are slightly different from those listed in Table 2. These differences, however, are minor and have no impact on the statistical analysis or conclusions.

The critical value and the result of the Sign Test are provided in the Sign Test Summary table, as well as a listing of the key release criteria.

As is shown in the table, all of the key release criteria were clearly satisfied for the FSS of this survey unit.2. The Quantile Plot was generated from direct measurement data listed in Table 2 and indicates general symmetry about the median. The data set and plot are consistent with expectations for a Class I survey unit. There is no reason to conclude that the data set represents other than random variations in a Class I concrete surface survey unit. It also should be noted that the maximum net activity (-49 dpm/lOO cm 2 at location CO 12) is well below the DCGL of 18,000 dpm/l 00 cm .FA-2600-01, Revision 0 Page 5 of 25

3. A Histogram Plot was also developed based on the direct measurement values. This plot shows that the direct data were essentially a normal distribution.

4. A Retrospective Power Curve was constructed, based on FSS results. The curve shows that this survey unit having a mean residual activity at a small fraction of the DCGL, has a high probability

("power")

of meeting the release criteria.

Thus, it can be concluded that the direct measurement data support rejection of the null hypothesis, providing high confidence that the survey unit satisfied the release criteria and that the data quality objectives were met.As mentioned in Section B, removable contamination samples were obtained at each (direct)measurement location.

In that this survey unit involved a foundation area and not a standing building, the removable contamination measurements were not applicable to release decisions for the survey unit. However, the samples were obtained and evaluated, indicating alpha activity less than the MDA values (i.e., < 3.2 dpm/l 00 cm2). Fourteen of the fifteen beta activity counts were also less than the MDA values (i.e., < 3.7 dpm/l 00 cm 2). One beta removable contamination sample had a positive result at about 0.04% of the DCGL of 6.8 dpm/l 00 cm 2.The removable contamination sampling effort indicated that the majority of activity is fixed.As shown in Table 2, all of the net activities reported are less than zero. This is a consequence of small variations in background that occur dependent on instrumentation, and variable impact of radon progeny. Because all of the direct and scan measurements are well below the DCGL, this has no consequence on the survey unit results or conclusion.

G. CHANGES IN INITIAL SURVEY UNIT ASSUMPTIONS ON EXTENT OF RESIDUAL ACTIVITY The survey was designed as a Class I area; the FSS results were consistent with that classification.

The direct measurement sample standard deviation was less than the design sigma. Thus, a sufficient number of sample measurements were taken.H. LTP CHANGES SUBSEQUENT TO SURVEY UNIT FSS The FSS of Survey Unit 1 was designed and performed using the criteria of the approved LTP (Revision 3 Addenda).

No subsequent LTP changes have any impact on the design, conduct, or assessment of the final status survey of Survey Unit 1.I. CONCLUSION The FSS of this survey unit was designed based on the LTP designation as a Class I area.The survey design parameters are presented in Table 1. The required number of direct measurements was determined for the Sign Test in accordance with the LTP. As presented in Table 2, all beta direct measurements were less than the DCGL of 18,000 dpm/100 cm 2.A Sign Test Summary analysis demonstrated that the Sign Test criteria were satisfied.

The direct measurement sigma was determined to be less than that used for design, thus indicating that a sufficient number of samples was taken.FA-2600-01, Revision 0 Page 6 of 25 The Retrospective Power Curve shown in Attachment 4 confirmed that sufficient samples were taken to support rejection of the null hypothesis, providing high confidence that the survey unit satisfied the release criteria and the data quality objectives were met. Attachment 4 also revealed that direct measurement data represented essentially a normal distribution, with variance consistent with expectations for a Class I survey unit.The scan survey design for this survey unit was developed in accordance with the LTP with significant aspects of the design discussed in Section B and Table 1. Scanning resulted in a no verified alarms (Section C). Since there were no alarms, the survey unit wvas determined to satisfy the elevated measurement comparison unity rule per LTP methodology.

In addition, while not part of the release decision criteria, removable contamination sampling confirmed that the majority of remaining activity in this foundation survey unit wvas fixed.It is concluded that FA2600 Survey Unit 1 meets the release criteria of I 0CFR20.1402 and the State of Maine enhanced criteria.J. REFERENCES

1. Maine Yankee License Termination Plan, Revision 3, October 15, 2002 2. Maine Yankee letter to the NRC, MN-02-061, dated November 26,2002 3. NRC letter to Maine Yankee, dated February 28, 2003 4. Maine Yankee letter to the NRC, MN-03-049, dated September 11,2003 FA-2600-01, Revision 0 Page 7 of 25 Attachment I Survey Unit Maps FA-2600-01, Revision 0 Page 8 of 25 I. -I.-U, LL 9.CL co Q/)4-cc:E-9(e C..)E 0 C S*_.0 0 a'(A 0 0'4 0 0 0 0 0 0"'4 0%0 co 0 0 0 0 0 0 4 0%D 0 0 0 0'0 (A 0 0 4 0 0 0 0 0 0 0 ,cm C.4).)0:3 0..-J 4)E co z co 9)>1)a)2::n w'>, (n(1 2 M C,)C iL U_>0 E H.C 16 C)0.N 4)..a)n.4;0.>5 2>5 4)Di-623,. 000 E-623, 500 E-623, 728 E-624, 000 E 440 CT-624, 500 E-625..000 E-625, 500 E-626, 000 E Note: Grid based on Maine State Coordinate System (West Zone) NAD 1927 SURVEY AREA, FA 2600 NorthWest Coordinate of LSAB at -407,670N-623,728E Maine Yankee IMap ID #: FA 2600-1 DP Decommissioning Team Maine Yankee Decomnnissioning Project Survey Form IRevised:

3-17-04 Survey Type: 0 Characterization E Tumover N Final Status Survey I Survey Area Name: Low Source Activity Building LSAB: Survey Unit 1 Direct Points Reference Map 5m 0,0 5m 009 osI 0061Y /E Io IL 00 0087/, PI ev W [l_1 U I' I'U FA-2600-01, Revision 0 Page 10 of 25 Surface Area Total for SU 1 -54 sq-rn Maine Yankee I Map ID#: FA2600-1a Decommissioning Team Maine Yankee Decommissioning Project Survey Rormn Revised: 3-10-04_Survey Type: 0 Characterization 0 Turnover X Final Status Survey Survey Area Name: Low Source Activity Building Test Pit LSAB: Survey Unit 1 LSAB Test Pit Section A-A Concrete Wall Survey Scans C001 -C019 Top of Cover Plate.ADZ A....A.4 -As' ',z.- ------------------- ---- ------- LSAB WW EL212k-1 ---- I I .cool C002 C003-ja -, U .CW7 I COM C005 -9 g I COM I coo I col C018/-I:i.CO19 EI-I* Containment

/Foundation Mat.Section A-A FA-2600-0l, Revision 0 Page I I of 25 Surface Area Sec A-A -17.3 sq-m Surface Area Total for SU I -54 sq-n Scan Grids are approx. 1mx 1m Maine Yankee Map ID #: FA 2600-1b Decommissioning Team Maine Yankee Deconmnissioning Project Survey Form Revised: 3-10-04-Survey Type: U Characterization E Turnover R- Final Status Survey Survey Area Name: Low Source Activity Building Test Pit LSAB: Survey Unit 1 LSAB Test Pit Section B-B Concrete Wall Survey Scans C020 -C038 Top of Cover Plate , LSAB Slab El. 21' ..... -. -..... --FC029 I....... ..... 5 q C021 C020-LK-C025 C026_C2 I C02* aft..U,..oU, a-.CDU,* b U,-a 6 b Containment Foundation Mat 'L _FA-2600-01, Revision 0 Page 12 of 25 Section B-B Scan Grids are approx. 1mx Im Surface Area Sec B-B -17.3 sq-m Surface Area Total for SU 1 -54 sq-m Maine Yankee ~Map ID #: FA 2600-1 c Decommissioning Team IMaine Yankee Decomnmissioning Project Survey Formn IRevised:

3-10-04 Survey Type: E Characterization O Turnover X Final Status Survey iSurvey Area Name: Low Source Activity Building Test Pit LSAB: Survey Unit 1 LSAB Test Pit Sections C-C, D-D Ledge/Concrete Wall& Top of Foundation Mat Surface Survey Scans C039 -C056 Top of Cover Plate C039 Top of Cover Plate C04 7 C040 I[Bottom of Concrete Footing C048] C049 I I co50 I-C041 C0U4.C051]I C043 I C044 T f n o Top of Foundation Mat I -Top of Foundation Mat Xf C052 LJ C053 C045 I C046 Section D-C I I C054 I.-COSS5-1 Section C-C FA-2600-O1, Revision 0 Page 13 of 25 Surface Area Sec. C-C -9.2 sq-m Surface Area Sec. D-D -9.2 sq-m Surface Area at Bottom -1 sq-m Total Surface Area for SU 1 -54 sq-m Scan Grids are approx. Imx 1m Maine Yankee Map ID #: FA2600-01d Decommissioning Team Maine Yankee Decommissioning Project Survey Fornm Revised: 3-17-04 Survey Type: 0 Characterization El Tumover X Final Status Survey I Survey Area Name: Low Source Activity Building Test Pit LSAB: Survey Unit 1 LSAB Test Pit Section A-A Concrete Wall Direct Points C005 -C009.4...0..I.....42£.D 4.O.=, A. ..4 ..4 A. A_..A..0.6m f 007 9 O-L2.Om 9 I 2.Om 2.Om -L 4 :. :, Containment

' Foundation Mat.l a 4 .. ,.I Section A-A FA-2600-01, Revision 0 Page 14 of 25 Surface Area Sec A-A- 17.3 sq-n Surface Area Total for SU 1 -54 sq-rn Maine Yankee Map ID#: FA2600-01e Decommissioning Team I Maine Yankee Decommissioning Project Survey Forn Revised: 3-17-04 I Survey Type: E Characterization l Turnover NI Final Status Survey FSurvey Area Name: Low Source Activity Building Test Pit LSAB: Survey Unit 1 LSAB Test Pit Section B-B Concrete Wall Direct Points C010 -C015 1.0m I 2.0m* &.0'*0-I-.I-..=&.5 .5 2.Om 2.Om.\Containment Foundation Mat Is, I '*. 'FA-2600-01, Revision 0 Page 15 of 25 Section B-B Surface Area Sec B-B -17.3 sq-m'Surface Area Total for SU 1 -54 sq-n Maine Yankee Map ID #: FA2600-1Of Decommissioning Team Maine Yankee Decommissioning Project Survey Forn Revised: 3-17-04 Survey Type: 0 Characterzation El Turnover LK Final Status Survey I Survey Area Name: Low Source Activity Building Test Pit LSAB: Survey Unit 1 LSAB Test Pit Sections C-C, D-D Ledge/Concrete Wall& Top of Foundation Mat Surface Direct Points C001 -C004 Top of Cover Plate C=E. ......Bottom of Concrete Footing I I I I I I I I I I Top of Foundation Mat Section D-D FA-2600-01, Revision 0 Page 16 of 25 Section C-C Surface Area Sec. C-C -92 sq-m Surface Area Sec. D-D -9.2 sq-m Surface Area at Bottom -I sq-m Total Surface Area for SU 1 -54 sq-m Maine Yan~ee map ID) ;: t-Ape)Ut Decommissioning Team MAline Yankee Decomnissioning Project survej Form IRevised:

3-23-04 Survey Type: O Characterization E Turnover I Final Status Survey I Survey Area Name: Low Source Activity Building LSAB: Survey Unit 1 LSAB Test Pit Juncture Map Cl:-1o Test Pit RCA Building Containment u B Fuel Building FA-2600-01, Revision 0 Page 17 of 25 Attachment 2 Survey Unit Instrumentation FA-2600-01, Revision 0 Page 18 of 25 TABLE 2-1 INSTRUMENT INFORMATION E-600 S/N Probe S/N (type)2619 149069 (43-68)2619 149071 (43-68)2619 149074 (43-68)2489 148396 (43-68)2619 459 (SHP-360)2619 465 (SHP-360)2489 463 (SHP-360)HPGe Detectors (Laboratory Analysis)j Detector No. l MDC (dpm/1 00cm 2)DET2 1 75 TABLE 2-2 INSTRUMENT SCAN MDC, DCGL, INVESTIGATION LEVEL, AND DESIGN DCGLEMC 43-8 4168Slip-360 Detector a43-68 l43-68 Surface Flat Junctures J Irregularities Scan M 2C 1,832 4,330 10,484 (dpm/lO00 cm2) LTP Table 5-6 (Note I) LTP Table 5-6 DCGL (dp/L00 cm 2) 18,000 18,000 18,000 Investigation Level 21,337 24,257 109,649 (Alarm setpoint)

(- DCGL plus bacDCGL plus ( 47% Design (dpm/100 cm 2) background) (Note 2) DCGLEIC)Design DCGLMc (dpm/100 cm ) 234,000 234,000 234,000 (from Release Record Table 1)NOTE: 1. Separate scan MDC developed for the 43-68 vhen applied to juncture geometry by adjusting the LTP Table 5-6 value for the change in efficiency.

2. 43-68 Juncture surveys were performed with an alarm setpoint of 3,495 cpm. All data was evaluated with the lower investigation levels in this table (1,834 cpm).FA-2600-01, Revision 0 Page 19 of 25 Attachment 3 Investigation Table (No Investigations Required)FA-2600-01, Revision 0 Page 20 of 25

-.. I Attachment 4-Statistical Data FA-2600-01, Revision 0 Page 21 of 25 Survey Package FA2600 Unit I Surface Sign Test Summary ,,e',;R-',-.^i,.'-'.:'Evaluation

'lrot uValues C- -..'-.omriiints' Survey Package: FA2600 LSA Building Test Pit Survey Unit: 01 Evaluator:

WJC DCGLW: 18,000 DCGL,: 234,000 LBGR: 15,162 adjusted Sigma: 946 post-remediation data 3/15/04 Type I error: 0.05 Type II error: 0.05 Total Instrument Efficiency:

13.0%Detector Area (cm 2): 126 Concrete Choosing 'N/A' sets material Material Type: Unpainted background to "0" Zr,,: 1.645 Z1.0: 1.645 Sign p: 0.998651 Calculated Relative Shift: '3.0 Relative Shift Used: 3.0 Uses 3.0 if Relative Shift >3 N-Value: 1_1 N-Value+20%:

1 4 Number of Samples: 15 Median: -449 Mean: -476 Net Static Data Standard Deviation:

211 Total Standard Deviation:

457 Sum of samples and all background Maximum: -52..i- 'Test. t ; a ft l Comments 'Adjusted N Value: 15 St Value: 15 Critical Value: .11.-z ;.'1/2-X,.,2.ita atis ctlodlrr'f

.. -,'-im Sufficient samples collected

Pass Maximum value <DCGL.,: Pass Median value <DCGL,~: Pass Mean value <DCGL,: Pass Maximum value <DCGL.,,,:

Pass Total Standard Deviation

<=Sigma: .-Pass Sign test results: , 'Pass The survey unit passes all conditions:

Pass Survey Unit Passes FA2600-SU I SurfaceSign.xls FA-2600-01, Revision 0 Page 22 of 25 12119104 11:39AM FA-2600 SU-1 Quantile Plot F 0x vF 0 6,-C>To Ooft E 0 0 IT" E 0.._-a0* n u-0-100-200-300-400-500-600-700-800-900-1000_ ... .... ..... .... .......... .. ... ............. .........

..... ... .......................

... ......._ .... ....... .... ... ...... ... .. ...... .......__ _ ....... ... .. ..__ ..............

.. .... _. ._...... ..... .._ ..... ... __ ._ .... .. .. .. .... .... .... .......+ -... _ _. ... ... .._ ... ........ ... ....* Activity (dpm/100 cm2)-Median (dpm/100 cm2)-I ---- -_______________

__________________________-I 0 25 50 Percent 75 100 One-Sample T-Test Report Page/Date/Time 2 12/14104 4:09:24 PM Database Variable C2 Plots Section Histogram of FA-2600, SU-i C,.a E.0 E z FA-2600-01, Revision 0 Page 24 of 25 One-Sample T-Test Power Analysis Page/Date/Time 2 12/14/04 4:10:41 PM Chart Section L..a)0 0L Retrospective Power Curve ,1.0*___.0.48----

---0.6--.-. -.\--0.4- -----0.2 - X-,-5d00 0 5d00 iokoo 15600 Survey Unit Mean (dpm/100 cm2)20600 FA-2600-01, Revision 0 Page 25 of 25