ML050330404

to Calculation 004-04(MY), Exploranium GR-130 Minimum Detectable Concentration (MDC) of Cs-137 and Co-60 in Surface Soil.

ML050330404
Person / Time
Site:	Maine Yankee
Issue date:	01/17/2005
From:	Cooper W, Henries W, Randall D Maine Yankee Atomic Power Co
To:	NRC/FSME
References
004-04(MY), Rev 0
Download: ML050330404 (29)

Text

Proc. No. I Rev. No. I Page 9 of I ATTACHMENT A CALC NO. 004-04(MY)

MAINE YANKEE CALCULATION REV. NO. 0 l PAGE I OF k- 29 (Zt fcherap)

I ENGINEERING COVER SHIEET TECH. FILENO. 17.12 p0, i-TITLE: Exploranium GR-130 Minimum Detectable Concentration (MDC) ofCS-137 and Co-60 in Surface Soil SOURCE DOCUMENT: LTP. Rev. 3 ID NO. N/A (i.e. EDCR, TE, PROC, WO, SDCM, SPEC)

PLANT SYSTEM: N/A SYSTEM CODE: N/A SAFETY PLANT COMPONENT: N/A l.D. NO. N/A CLASS N/A TYPE OF CALC: 0 Stress O Thermal O Hydraulic O Capacity X Other Radiological-FSS DISCIPLINE: O Electrical O l & C O Mechan'ical O Civil X Other Rad Enttineering-FSS PURPOSE AND METHODOLOGY: To develop a means to utilize the quantitative potential of the GR-130 to investigate scan alarms to determine whether the alarm is related to plant derived activity in surface soils (to a depth of 15cm). In order to do this, the MDC for a variety of counting intervals must be determined. This calculation documents the soil MDC associated with the site's most significant gamma-emitting isotopes (Cs- 137 and Co-60).

successful SOURCES OF DATA:

Experiments of 09-04-04 and 10-06-04 (Att. I)

SOURCES OF FORMULAE AND

REFERENCES:

1. GR-130 miniSPEC User Manual ReV 14 January 30, 2001

2. Maine Yankee DI-164 Operation of the Exploranium GR- 130.

3. G. F. Knoll, Radiation Detection and Measurement, Second Edition, Wiley, New York (1989)

4. NUREG-1507, USNRC, December 1997

5. D.C. Kocher, Radioactive Decay Data Tables, ORNL, US Department of Energy, 1981.

Preliminary 0 Final Calc X Supersedes Calc NoRev. No. 0 Other Calculations Requiring Revision none Prepared by: D. B. Randall, Jr. Date: 12-29-04 Reviewed by: _______ Date: / _______5 Senior Engineer (or above): A/, i/gkJcie S Date: ih 3:'

The attached calculation shall include (as a minimum): (I) appropriate design input values, (2) assumptions, with justifications, (3) computations with explanatory text, figures and tables, and (4) summary of results and conclusions.

Calc. No. 004-04 (MY)

Rev. 0 Page 2 of 29 9

! piZ Executive Summary l- X7 -

The Exploranium GR-130 MiniSPEC (GR-130) is a portable, battery powered, hand held instrument with an internal 4.5 cubic inch NaI(TI) gamma scintillator probe. It uses a 256-channel pulse height analyzer that provides nuclide identification capabilities from a limited nuclide identification suite. The detector can be used to evaluate Cesium-137 and Co-60 concentrations in soil media.

Testing was performed to determine the Minimum Detectable Concentration (MDC) of Cs-137 and Co-60 in surface soil. These MDCs were calculated for spectra collected in 10, 20 and 30-minute count intervals by downloading the data, and evaluating it using an Excel spreadsheet (Attachment 1).

Inputs

1. Experiment data of 09-04-04, and subsequent analyses to support the CS-1 37 soil MDC (Attachment 1)

2. Experiment data of 10-06-04 and subsequent analyses to develop the Co-60 in soil MDC (Attachment 1)

3. Source Certificates (Attachment 2)

4. DI-164, Rev B Assumptions

1. The MDCs determined apply to downloaded data that has been reviewed by an analyst. This should be done in accordance with the method described on page 16 of Attachment 1. (The instrument based quantitative analysis output may be adequate, but the associated algorithms are not documented in the user's manual, and the output was not sufficiently tested by this exercise to be considered reliable for the purposes of this calculation.)

2. Background spectra (channel by channel) will not be subtracted when data is analyzed. (The instruments amplifier has exhibited some drift over typical count intervals, making background subtraction inappropriate').

3. Surface soil is defined as the top 15 cm of the soil media being measured.

4. The barrel geometry as described on the source certificate, (Attachment 2) is appropriately representative of contaminated soils. (Smaller surface area geometries would have higher MDCs)

It is considered inappropriate to subtract one spectrum from another directly. However, the subtracting of a background result from a sample result may be appropriate, based on professional judgment.

Caic. No. 004-04 (MY)

Rev. 0 Page 3 of79?

5. The GR-l 30 will be used in the horizontal position (display facing up), with the P/4 internal probe located above the center on the area being analyzed. rs Computation The Cs-137 MDC was determined by direct measurement from a homogenous, NIST traceable soil standard. The MDC for Co-60 was then estimated, based on the Cesium MDCs. This was done by comparing the relative gamma efficiencies for both cobalt and cesium NIST traceable button sources counted separately for 20 minutes in identical geometries. Additional computational details are provided below.

CS-137 MDC determination Testing was performed to determine the Minimum Detectable Concentration of Cs-1 37 in soil for downloaded spectra collected in 10, 20 and 30-minute count intervals. The data was then evaluated to determine the instrument's MDC by downloading the data, and performing an evaluation using an Excel spreadsheet (Attachment 1, pp. 4-15). The review of this calculation has verified the accuracy of the spreadsheet analyses.

GR-1 30 spectra were collected first on a blank. This wvas done for 600, 1200 and 1800 second count intervals. These blank counts were used to determine whether any ambient background Cs'137 could be detected. No activity was detected in the blanks. (Had any been detected, it would have been accounted for as necessary.) The soil source was also counted for 600, 1200 and 1800 second counts using an identical geometry. The source used was a NIST traceable homogenized soil source in a volumetric geometry with a nominal specific activity of 3.0 pCi/g Cs-137 (the source certificate is included in ). The detector was placed with its center of detection over the source center, oriented such that it sat on the horizontal with the display facing up.

Table I is a summary of the source activity calculation Table 1 Cs-137 Soil Source Information Source No. 62994-60 Activity (dps) 6.1 47E+03 Sand Weight 56.95 kg Calculated Activity (pCi/g) 2.92 60dpni lpCi I _____

=6.147Eo3(dps)x x l x I 1kg dps. 2.22dpm 56.95kg 1,OOOg Assay Date 01-29-02 Experiment date 09-04-04 Activity on Experiment date (pCi/g) 2.75 A = A40e' , Where AO = initial activity, X= (In(2)/T1 n2), Tl,= 30.17y (Ref 5) t = elapsed time =2.6y

Calc. No. 004-04 (MY)

Rev. 0 Page 4 of w Analysis The background data (Att. 1) was reviewed to determine whether detectable levels of ambient Cs-137 background were present at the test location. No discemable Cs-137 peaks were present in background counts as observed by the GR-130 analyses, or by the analyst's review of the downloaded data.

The GR-130 screen output results indicated that Cs-137 was present in each of the runs conducted with the source present. This was also the case for the analyzed data. The Cs-137 soil MDC was determined by subtracting the Compton continuum from the 662 keV photopeak, in accordance with the method described in Knoll (Reference 3). Photo-peak Regions Of Interest (ROI) are determined by the analyst, as is indicated by the hatch marks on the spreadsheet data of Att.l. As stipulated in the Assumptions, the MDC result cited is valid only for situations where the data is downloaded, and evaluated by a trained analyst, since the algorithm used by the GR-1 30 is not known. However, GR-1 30 screen results do compare wvell with the analyses performed and are presented for informational purposes. The experimental results are summarized in Table 2. The supporting data is located in Att. 1.

, Table 2 CS-137 MDC Experimental Results Spectrum. # 16 17 18 Count Time (s) 600 1200 1800 Calculated values (from analyses of downloaded data)

Cs-137R01 Gross (counts) 2,192 5,102 7119

.s-137 BKGD/Ch (counts/channel) 143 299 414 s-137 Bkg. Integral (counts) 1,573 3887 4968 Cs-1 37 Net counts 619 1215 2151 Full Width at Half the Maximum (FWHM)

(channels, estimated) 5.5 5.5 8.0 Efficiency (counts/pCi/g) 225 442 782 Efficiency (cpm/pC/g) 22.509 22.091 26.073 Cs-137 MDC (pCilg) (Ref 4) 3 + 4.65Vrbackground(counts)

MDC = .

EffIcencqcounts I pCi / g) 0.833 0.663 0.423 Reported Results (from GR-130 instrument screen output)

Cs-137 Gross (counts) N/A N/A N/A Cs-137 BKGD/Ch (counts/channel) N/A N/A N/A Cs-137 Bkg. Integral (counts) NIA N/A NIA Cs-137 detected (Yes/No) Yes Yes Yes Cs-137 Net counts 675 1,467 2,376

,FWHM (GR-130) 5.2 6.0 5.7 Efficiency (counts/pCi/g) 245.5 533.5 864.0

Calc. No. 004-04 (MY)

Rev. 0 Page 5 ofWX2 'P -

1-n7 - OX Efficiency (cpm/pCi/g) 24.55 26.7 28.8 ime weighted average Efficiency (cpmlpCi/g)

EJQtgot _ Ef

-3600 *600+Eff,2 *1200+EffA8O*1800 24.15 s-137 MDC (pCi/g) N/A N/A N/A Variance (Calculated vs. GR-130) = (Eff.-GR-130eff)124.15 Efficiency Variance (Calculated vs. GR-130) l-8.45% l -19.08% l -11.29%

Co-60 MDC Determnination Ideally, a homogeneous Co-60 soil source would be used to determine the instrument's MDC, as was done for Cs-137. Since such a source was unavailable the Cobalt MDC was conservatively estimated. First, the ratio of Cobalt-60 efficiency to Cesium-1 37 efficiency for a point source was determined. This ratio was then multiplied by the Cs-137 soil MDC to determine the Co-60 MDC.

The method described is conservative since the lower energy (662 keV) Cs-137 direct2 gammas are more attenuated when homogeneously mixed into a soil matrix than the higher energy (1173 and 1332 keV) emissions for Co-60.

To determine the point source efficiency ratio, two NIST traceable button sources of I jtCi nominal activity wvere selected and counted in a uniform geometry, with the source centered at 12 inches from the face of the detector. Source information is included in Table 3. The analysis results determining the Co-60 MDC are included as Table 4. The 1332 keV cobalt line was selected for analysis due to the fact that unlike the 1173 line (the only alternative), its background is less affected by the scattered photons from more energetic emissions originating from the source itself.

A background run was performed prior to doing the individual source counts. No discernable source related photo-peaks were present in background counts as observed by the GR-130 analyses, or by an analyst's review of the downloaded data.

2In this context, direct gamma means those gammas that emanate out of the soil matrix, with no interactions with matter within the source matrix.

Caic. No. 004-04 (MY)

Rev. 0 Page 6 of 24§ or: I t7-nS Table 3 Cs-137 and Cobalt-60 button Source Information Isotope Cs-l 37 Co-60 Half life (years) (Ref.5) 30.17 5.271 Source No. 93CS2502228 59436A-60 Activity (pCi) 0.923 1.036 Geometry Button Button Assay Date 08-12-1993 04-06-2000 Experiment date 10-06-2004 10-06-2004 Activity on Experiment date (,uCi) 0.713 0.573 A = Ae-A' Gamma Yield (Ref.5) 85 % 100 %

4 Pi Gamma emission rate (gps) 2.24E4 2.12E4 Table 4 Cs-137 and Cobalt-60 button Source Information Spectrum# 20 (Att.1, pp.4-14) 21 (Att.1, pp.4-14)

Count Time (s) 1200 1200 Isotope Cs-1 37 Co-60 Calculated values (from analyses of downloaded data)

Gross (counts) in peak ROI 8906 3456 BKGD/Ch (counts/channel) in ROI 137.00 65.00 Bkg. Integral (counts) in ROI 2466 1235 Net counts 6440 2221 FWHM (channels, estimated) E 1__

Efficiency (net counts/gps)

= (net counts/ 4pi emmison rate) 0.288 0.10_

Efficiency Ratio (Co-60 countslgps per Cs-137 counts/gps) 0.364 Co-60 Estimated Efficiency CPM/pCVg (0.364 x Efficiencycs) 8.84 Estimated Co-60 MDC (pCilg)

[MDCcobaft = MDCct,,um x Efficiency Ratio (0.364)]

Count time 600s 1,200 s l 1,800 s Co-60 MDC (pCilg) 2.29 1.82 1.16

Caic. No. 004-04 (MY)

Rev. 0 Page 7 ofo9S~

Conclusion l A P i 7, The GR-130's MDC for cesium-137 and cobalt-60 in soil have been established as shown by the values listed in Tables 2 and 4. The GR-130 can easily detect CS-137 activity at or below the soil DCGls (typically 2.39 pCi/g). The MDC values for Co-60 are typically greater than the DCGLs (typically 0.86 pCi/g) for the nominal count times used. Where quantitative assessment is required, it is recommended that the data be downloaded as to permit analytical evaluation. Calibration factors may be determined from the efficiency values provided.

References

1. GR-130 miniSPEC user manual -REV 14 (January 30,2001).

2. DI-164 Operation of the Exploranium GR-130.

3. G. F. Knoll, Radiation Detection and Measurement, Second Edition, Wiley, New York (1989), p. 323.

4. NUREG-1507 "Minimum Detectable Concentrations with Typical Radiation Survey Instruments for Various Contaminants and Field Conditions",

Washington, D.C., Nuclear Regulatory Commission. December 1997.

5. D.C. Kocher, Radioactive Decay Data Tables, Office of Scientific and Technical Information, Oak Ridge National Laboratory, US Department of Energy, 1981.

Calc. No. 004-04 (MY)

Rev. 0 Page 8 of,2, -

Index Page Executive Summary. 2 Inputs 2 Assumptions 2 Computation 3 Cs-137 MDC determination 3 Analysis 4 Co-60 MDC determination 5 Conclusion 6 References 7 Index 8 Attachments Att 1. 17 pages Att 2. 4 pages Total Pages 29

004-04 (MY)

Caic. No.

Calc. No. 004-04 (MY)

Rev. 0 pAge-'

pL I, -I-)- 57 pllftChc { or i7 Attachment 1 Experimental Data & Equations

U4,14 A10, LId - V ( ;J1 7 GR-130 Data Page

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- I IInstrument Im nenstr tS /N Cal Due Detector Detector SIN Cal Due GR-130 9955 1 N/A N/A N/A A' _ _ _ _ _ _ _ _ _ _

STABILIZATION BACKGROUND Time OK? Peak Ch FWHM % Gain Count Peak Peak Peak

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Count Time Peak Peak Peak Survey Location (min) keV ID keV ID keV ID Comments s'P c.W eJ / 152Il4: ,v.r l. I I I I k2 93 ,f 2.Z 16v 9 5.j/3V ~

Comments Techfile 19.20.8.3

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Survey Date: /0 - I - 0 ' Survey Team Time: /4': y' 3 I9o5a Oec Au'V / ViC JO t%4,/

Instrument Instrument S/N Cal Due Detector Detector SIN Cal Due GR-130 9955 /P N/A N/A NIA STABILIZATION BACKGROUND TimeTieOK? OPeak Ch FWHM % Gain Count CutlP, Pep$ Peak ekl Peak lPa (YIN) PTime e ID key I ke ID V

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Time/*PeakPakek _ Peak llPeak l Survey Location l keV ID keV ID keV ID Comments S 71- t'(e-C 1ss < h Izoo I___II_ _ T_ _u S~______

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_ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ C Oc - (p Comments Probably Techfile 19.20.8.3

GR-130 Download Data Page I of 10

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A B C D E F G H I J Cs-137 Cs-137 Cs-137 Co-60 Co-60 button test 1 MDC MDC MDC MDC MDC Cs-137 MDC Cs-137 MDC Cs-137 MDC BKG 2 Spectrum Number 16 17 18 20 21 13 14 15 19 600s CS- 1200s CS- 1800s CS- CS-137 Co-60 Background Background Background 3 Spectrum Channel 137 137 137 button button (info only) (info only) (info only) (Info only) 4 Time (s) 600 1200 1800 1200 1200 600 1200 1800 1200 5 1 9 18 27 18 18 9 18 27 18 6 2 23 52 75 36 36 25 46 63 20 7 3 504 1014 1557 734 702 439 950 1401 500 8 4 655 1280 1902 1230 910 553 1122 1701 714 9 5 776 1600 2424 1810 1254 703 1426 2112 920 10 6 828 1638 2454 1384 1276 768 1518 2196 850 11 7 897 1796 2622 .1424 1404 792 1582 2439 1018 12 8 1058 1992 2937 1676 1688 917 1910 2868 1326 13 9 1320 2478 3600 2100 2012 -1118 2296 3450 1656 14 10 1618 3088 4578 2544 2530 1398 2942 4530 2066 15 11 1952 3932 5754 2950 2922 1793 3698 5562 2484 16 12 2562 4818 7329 3404 3382 2109 4438 6885 2804 17 13 2911 5682 8568 3730 3620 2542 5310 8007 3270 18 14 2860 5726 8628 3822 3744 2612 5376 8052 3384 19 15 2955 5752 8721 3864 3752 2612 5310 7953 3360 20 16 2887 5856 8661 3804 3888 2742 5312 7920 3472 Il 21 17 2853 5604 8418 3612 3728 2544 5276 7680 3214 22 18 2894 5638 8478 3578 3614 2561 5162 7776 3298 23 19 2745 5536 8460 3458 3642 2465 5076 7800 3168 24 20 2866 5472 8289 3568 3436 2537 5048 7413 3102 25 21 2782 5438 8244 3422 3468 2534 4968 7380 2938 26 22 2695 5496 8076 3172 3418 2488 4802 7371 2878 27 23 2562 5214 7626 3028 3192 2325 4732 6876 2748 28 24 2520 4904 7599 3058 3120 2312 4536 6720 2596 29 25 2406 4990 7185 2888 2994 2140 4488 6312 2448 30 26 2244 4642 6921 2722 2784 2118 4068 6219 2336 31 27 2156 4452 6573 2604 2704 2037 3948 6009 2154 32 28 2042 4264 6291 2496 2528 1914 3870 5580 2004

GR-130 Download Data Page 2 of 10

.' -4. A B C D E F G H I J Cs-137 Cs-137 Cs-137 Co-60 Co-60 button test 1 MDC MDC MDC MDC MDC Cs-137 MDC Cs-137 MDC Cs-137 MDC BKG 2 Spectrum Number 16 17 18 20 21 13 14 15 19 If, 1.2 600s CS- 1200s CS- 1800s CS- CS-137 Co-60 Background Background Background S- c 3 Spectrum Channel 137 137 137 button button (info only) (info only) (info only) (Info only) 33 29 2003 4036 6042 2396 2354 1844 3528 5289 1926 34 30 1896 3962 5835 2356 2304 1668 3454 5196 1844 35 31 1831 3758 5634 2342 2254 1700 3284 4998 1808 36 32 1800 3682 5496 2176 2070 1555 3208 4752 1622 37 33 1712 3470 5262 2020 2092 1548 3052 4593 1538 38 34 1663 3302 4974 2018 1978 1421 2948 4395 - 1476 39 35 1604 3236 4650 1908 1866 -1430 2772 4122 1322 40 36 1533 3124 4560 1698 1896 1405 2658 4056 1312 41 37 1375 2812 4314 1616 1862 1266 2490 3846 1304 42 38 1432 2842 4230 1604 1830 1245 2406 3768 1206 43 39 1492 2790 4275 1516 1756 1259 2554 3762 1218 44 40 1413 2870 4323 1488 1684 1276 2504 3768 1166 45 41 1366 2826 4134 .1402 1528 1217 2346 3717 1050 46 42 1264 2616 3753 1244 1478 1146 2214 3315 950 47 43 1043 2308 3240 1258 1320 1002 1922 2817 874 48 44 964 2004 2994 1180 1240 904 1670 2550 860 49 45 908 1832 2748 1036 1196 803 1596 2292 784 50 46 853 1694 2607 990 1144 781 1476 2187 726 51 47 906 1628 2463 970 1070 693 1442 2079 684 52 48 756 1632 2436 894 1072 700 1402 2046 650 53 49 779 1598 2256 884 964 668 1376 2007 630 54 50 746 1464 2190 860 910 682 1246 1941 620 55 51 708 1466 2091 812 858 601 1216 1755 524 56 52 691 1362 2070 780 906 609 1132 1638 516 57 53 628 1240 1896 760 834 550 1056 1533 550 58 54 585 1226 1875 714 800 512 1022 1548 476 59 55 583 1196 1686 696 756 439 1018 1524 484 60 56 599 1176 1713 764 704 476 1008 1524 454 61 57 614 1130 1737 674 694 526 1018 1506 418

GR-130 Download Data Page 3 of 10 A B C D E F G H I J Cs-1 37 Cs-1 37 Cs-1 37 Co-60 Co-60 button test 1 MDC MDC MDC MDC MDC Cs-137 MDC Cs-137 MDC Cs-137 MDC BKG 2 Spectrum Number 16 17 18 20 21 13 14 15 19 600s CS- 1200s CS- 1800s CS- CS-137 Co-60 Background Background Background 3 Spectrum Channel 137 137 137 button button (info only) (info only) (info only) (Info only) 62 58 550 1194 1662 648 746 495 962 1464 428 63 59 565 1074 1638 660 684 507 958 1317 376 64 60 516 1116 1611 570 622 467 880 1413 386 65 61 488 1000 1464 564 626 442 864 1218 338 66 62 479 874 1356 582 600 442 748 1134 336 67 63 409 848 1284 544 576 350 656 1011 318 68 64 391 816 1206 534 548 336 650 912 294 69 65 379 716 1131 480 530 319 614 936 278 70 66 378 718 1104 516 526 293 580 864 276 71 . 67 320 .728 . 999 462 . -514 334 580 879 260 72 - 68 339 650 987 500 502 269 570 819 262 73 69 301 670 939 460 462 271 494 780 250 74 70 298 592 882 432 456 255 534 753 210 75 71 325 598 870 470 444 230 500 750 228 76 72 294 622 837 438 462 218 466 702 226 77 73 274 588 870 426 404 226 428 690 210 78 74 280 612 822 432 448 240 442 657 218 79 75 271 510 789 400 420 214 456 618 228 80 76 280 490 744 400 420 204 438 696 224 81 77 274 528 753 332 450 214 430 648 198 82 78 262 518 738 322 450 229 412 618 202 83 79 248 480 714 328 404 198 420 621 196 84 80 221 480 639 304 384 162 372 585 196 . I -.

85 81 240 458 690 312 410 175 414 591 182 .I':  :-

86 82 227 446 681 304 398 187 380 624 180 - -,, ,

(.3 87 83 201 498 744 258 362 199 430 603 192 88 84 240 450 726 256 396 183 396 624 168 89 85 220 392 723 228 340 202 420 609 164 90 86 230 458 705 242 376 219 400 588 190 -#4

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GR-130 Download Data Page 4 of 10 A B C D E F G H J Cs-137 Cs-137 Cs-137 Co-60 Co-60 button test I MDC MDC MDC MDC MDC Cs-137 MDC Cs-137 MDC Cs-137 MDC BKG 2 Spectrum Number 16 17 18 20 21 13 14 15 19 600s CS- 1200s CS- 1800s CS- CS-137 Co-60 Background Background Background 3 Spectrum Channel 137 137 137 button button (info only) (info only) (info only) (Info only) 91 87 214 440 657 218 366 180 390 513 178 92 88 181 440 633 228 340 223 380 561 182 93 89 189 410 582 224 376 159 352 477 170 94 90 185 356 561 174 322 156 314 459 132 95 91 166 356 525 188 288 142 340 483 162 96 92 171 330 492 194 302 134 320 438 164 97 93 192 348 513 168 350 172 322 411 154 98 94 167 334 528 198 296_ 148 320 495 128

99. 95 186 376 537 190 308 150 326 468 108 100 96 178 392 570 '194 326 164 340 516 126 101 97 197 412 582 184 284 164 354 546 124 102 98 204 388 597 176 318 195 316 615 1 28 103 99 213 398 678 218 330 172 370 561 136 104. 100 2181 412 609 202 296 201 356 510 152 105 282 156 380 516 130 106 107 10:

108 10o 109 10!

110 101 ill 10' 112 10 113 10!

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114 11' -.- -

-'b . ( s 115 11 116 - t: t 11 ,

., t 117 111 118 11 -I 119 11 244 o -.1 ..

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GR-130 Download Data Page 5 of 10 A B C D E F G H I J Cs-137 Cs-137 Cs-137 Co-60 Co-60 button test 1 _ MDC MDC MDC MDC MDC Cs-137 MDC Cs-137 MDC Cs-137 MDC BKG 2 Spectrum Number 16 17 18 20 21 13 14 15 19 600s CS- 1200s CS- 1800s CS- CS-137 Co-60 Background Background Background 3 Spectrum Channel 137 137 137 button button (info only) (info only) (info only) (Info only) 120 116\ 272 \ 7Z \\\ \\\\ \\

121 117 102 . '4. 26 9 7\\\ S \8$

122 118 103 218 264 \ 226 78 182 237 }7 123 119 97 178 282\ ' 234 106 182 237 \\ \ 6 124 120 107 168 264 84 252 75 172 240 84 125 121 89 178 261 92 232 76 144 237 74 126 122 76 162 210 66 272 69 136 255 80 127 123 93 156 246 76 232 67 164 216 76 128 124 76 144 210 66 252 74 142 198 70 129. 125 65 148 234 80 238 84 126 222 76 130 126 70 110 192 68 220 67 146 207, 92 131 127 68 162 225 78 232 75 104 216 70 132 128 73 150 198 64 252 76 140 219 72 133 129 66 136 231 58 232 73 134 201 82 134 130 77 142 207 66 262 66 144 204 76 135 131 74 122 192 56 260 81 154 195 70 136 132 77 122 192 76 268 74 118 - 201 76 137 133 65 122 180 66 258 57 132 183 56 138 134 51 132 189 46 268 67 122 201 64 139 135 61 116 171 66 228 60 114 174 70 140 136 60 118 171 68 264 50 104 168 70 141 137 50 126 174 64 250 50 140 189 50 142 138 55 108 186 66 272 59 108 165 56 143 139 62 102 177 60 236 61 102 144 48 :ts -, r 144 140 53 106 183 58 258 56 112 138 64 M. x,~._

145 141 61 130 171 72 262 59 96 159 56 146 142 61 108 183 60 244 45 98 .156 62 I' 147 143 55 142 189 54 228 60 116 156 50 148 144 57 112 210 68 242 61 124 165 58

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GR-130 Download Data Page 6 of 10 A B C D E F G H I J Cs-137 Cs-137 Cs-137 Co-60 Co-60 button test 1 MDC MDC MDC MDC MDC Cs-137 MDC Cs-137 MDC Cs-137 MDC BKG 2 Spectrum Number 16 17 18 20 21 13 14 15 19 600s CS- 1200s CS- 1800s CS- CS-137 Co-60 Background Background Background 3 Spectrum Channel 137 137 137 button button (info only) (info only) (info only) (Info only) 149 145 47 104 150 54 240 63 124 201 56 150 146 50 124 195 66 262 55 118 174 64 151 147 59 126 198 70 258 81 138 171 64 152 148 69 136 186 44 272 60 128 195 44 153 149 72 120 192 70 258 63 134 168 -70 154 150 56 130 210 82 238 70 116 186 66 155_ 151 58 136 222 56 268 91 146 162 64 156 152 69 138 195 62 216 62 142 195 60 157 153 56 128 .183 60 252 54 122 198 54 158E 154 76 - 148 162 - 70 250 . 69 132 168 46 159 155 73 120 186 64 2221 68 130 192 44 160 156 55 144 177 60 208 54 128 186 60 161 157 63 140 159 44 188 57 134 186 60 162 158 43 104 183 46 198 57 112 168 52 163 159 55 116 192 62 216 76 114 168 64 164 . 160 54 114 198 52 202 58 96 162 48 1651 161 50 124 168 60 192 54 122 159 50 166 162 49 106 156 42 182 49 88 141 50 167 163 40 108 144 54 1781 45 116 147 44 168 164 35 74 138 56 160 54 84 111 46 169 165 40 98 144 44 178 37 78 105 60 170 166 38 92 111 36 190 46 80 93 46 171 167 32 66 93 48 178 42 76 105 40 172 168 34 84 117 50 142 38 74 117 32 'OC-.'

173 169 35 82 96 46 162 37 70 102 44 174 170 30 72 96 44 164 44 68 93 54 175 171 32 60 105 40 146 30 76 108 36 176 172 36 64 105 42 146 28 54 102 32 177 173 31 68 102 30 160 30 66 84 44

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GR-130 Download Data Page 7 of 10 A B C D E F G H I J Cs-I 37 Cs-i 37 Cs-i 37 Co-60 Co-60 button test 1 MDC MDC MDC MDC MDC Cs-137 MDC Cs-137 MDC Cs-137 MDC BKG 2 Spectrum Number 16 17 18 20 - 21 13 14 15 19 600s CS- 1200s CS- 1800s CS- CS-137 Co-60 Background Background Background 3 Spectrum Channel 137 137 137 button button (info only) (info only) (info only) (Info only) 178 174 41 60 99 44 138 44 70 111 36 179 175 30 80 105 42 164 34 66 108 40 18C 176 37 64 117 46 144 33 60 90 38 181 177 39 74 114 40 142 36 80 123 38 182 178 36 74 87 36 106 24 80 108 44 183 179 37 66 105 42 116 27 68 93 40 184 180 42 60 117 50 128 33 64 114 40 185 181 32 68 132 40 126 37 82 108 50 186 182 28 84 .120 40 144 22 70 96 44 187 .183 42 72 129 46 140 37 80 102 40 188. 184 ;40 82 126 36 176 48 82 108 44 1895 185 30 70 99 46 208 40 62 105 38 190 186 31 70 99 48 2701 26 70 99 44 191 187 27 66 105 46 280 32 82 111 36 192 188 39 60 102 44 316 26 68 93 46 193 189 35 56 96 52 350 40 70 84 38 194 190 33 54 93 40 382 40 58 81 40 195 191 33 62 117 38 384 34 52 66 30 196 192 26 62 93 32 350 26 56 78 38 197 193 31 66 84 36 308 28 44 87 36 198 194 18 56 87 50 306 25 48 81 38 199 195 23 68 90 36 252 25 50 78 44 200 196 20 64 84 44 238 33 54 66 36 201 197 29 46 78 36 162 17 46 72 30 202 198 29 64 72 26 168 29 60 84 40 ", 'N Z ..

203 199 18 50 81 32 106 23 44 72 24 204 200 34 60 96 26 92 30 70 81 24 205 201 25 56 81 -24 74 19 60 90 32 -- k .

206 202 28 70 87 36 62 31 56 60 26 i'.

GR-130 Download Data Page 8 of 10 A B C D E F G H I J Cs-137 Cs-137 Cs-137 Co-60 Co-60 button test 1 . MDC MDC MDC MDC MDC Cs-137 MDC Cs-137 MDC Cs-137 MDC BKG 2 Spectrum Number 16 17 18 20 21 13 14 15 19 600s CS- 1200s CS- 1800s CS- CS-137 Co-60 Background Background Background 3 Spectrum Channel 137 137 137 button button (info only) (info only) (info only) (Info only) 207 203 27 48 78 32 66 29 44 78 32 208 204 29 56 57 26 48 34 50 63 30 209 .ns 277 56 84 R1 41 A

, All vv 81 v, 9r 210 206 33 50 75 3C 29 54 81 211 207 26 56 78 2_ 17 42 84 212 208 17 54 81 2C 25 46 72 213 209 19 38 84 1ii 23 56 78 2 14 210 29 56 69 1iE 31 36 63 215 211 22 48 84 _ ___ 22 42 54 216 212 23 36 63 24 29 44 54 F217 213 22 36 54 _ E 1_ 14 50 57 218 214 19 44 72 1E 20 40 48 219 215 12 44 66 1Ei 20 44 51 220 216 16 30 33 _ 1 18 32 69 221 217 12 40 78 2_ 18 34 42 222 218 21 40 51 _ 1 22 40 36 223 219 15 28 60 ill 14 38 48 224 220 16 40 51 2_ 20 30 48 225 221 20 28 42 1z 17 32 57 226 222 16 42 48 IE 13 40 54 227 223 12 381 721 14i 20 , 32 48 228 2241 18 30 601 2, 15 38 57 229 225 29 401 57 15 32 69 230 2261 221 441 661 221 22 44 63 231 227 18 . 46 63 . I 1'. _ I 38 2321 2281 271 6 721 44 48 22 36 233 229 32 48 66 44 441 16 32

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234j 2301 311 501 75 46 52 16 50 96 2351 2311 301 50j 841 46 60 19 601 84 7- -. ',

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GR-130 Download Data Page 9 of 10 A B C D E F G H IJ Cs-i 37 Cs-i 37 Cs-137 Co-60 Co-60 button test 1 MDC MDC MDC MDC MDC Cs-137 MDC Cs-137 MDC Cs-137 MDC BKG 2 Spectrum Number 16 17 18 20 21 13 14 15 19 600s CS- 1200s CS- 1800s CS- CS-137 Co-60 Background Background Background 3 Spectrum Channel 137 137 137 button button (info only) (info only) (info only) (Info only) 236 232 27 68 108 50 56 21 50 84 56 237 233 29 60 90 70 60 21 52 108 70 238 234 43 62 111 70 54 25 60 105 64 239 235 47 62 87 60 50 29 70 114 84 240 236 39 62 102 52 60 33 76 102 '54 241 237 31 74 87 48 56 39 64 93 54 242 238 23 70 108 46 56 33 66 81 64 243 239 36 70 84 32 40 41 54 81 54 244 240 32 74 105 26 48 23 58 84 34 245 241 19 50 60 30 36 26 54 60 42 246- 242 22 54 66 26 26 35 40 57 28 247 243 17 40 63 24 20 29 44 54 40 248 244 19 40 57 18 20 17 40 48 18 249 245 16 38 54 16 22 19 30 45 22 250 246 17 20 42 12 26 15 22 45 20 251 - 247 13 24 - 36 8 8 16 30 39 18 2521 248 9 30 45 8 16 15 24 45 18 25 249 23 24 42 14 12 11 24 48 18 254 250 16 28 51 14 4 18 24 33 14 255 251 9 30 45 16 16 16 30 45 12 256 252 15 28 45 10 6 16 40 30 10 257 253 0 0 0 0 0 0 0 0 0 258 254 0 0 0 0 0 0 0 0 0 259 Sum (counts, whole spectra) 109098 218826 326328 141182 159442 97151 193998 289695 106682 260 Spec.# 16 17 -- _18 20_ 21 13 14 15 19 261 ROI Gross (counts) 2192 5102 7119 8906 3456 NIA N/A N/A N/A '-r-, i 262 ROI BKGD/Ch (counts/channel) 143.00 299.00 414.00 137.00 65.00 N/A N/A N/A NIA 263 ROI Bkgd Integral (counts) 1573 3887 4968 2466 1235 N/A N/A N/A N/A 264 ,tlM 619 1W41215 5 s-b L.i% 222I W6440 N/A N /A N/A N/A

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GR-130 Download Data Page 10 of 10 A B C 0 E F G H I J Cs-137 Cs-137 Co-60 Co-60 button test 1 Cs-137 MDC MDC MDC MDC MDC Cs-137 MDC Cs-137 MDC Cs-137 MDC BKG 2 Spectrum Number 16 17 18 20 21 13 14 15 19 1200s CS 1800s CS- CS-137 Co-60 Background Background Background 3 Spectrum Channel 600s CS-137 137 137 button button (info only) (info only) (info only) (Info only) 265 Cesium MDC Calculations . ___

266 Efficiency (countslpCi/g) 225 442 782 _ __

267 Efficiency (cpm/pCi/g) 22.509 22.091 26.073 24.1515 .

268 Cs-137 MDC (pCi/g) - 0.833 0.663 0.423 - -  :

269 Cobalt MDC Calculations _

270 Spec.# 20 21 .-

Souce Activity for 662 or 1332 271 line In (gps)-- 2.24E+04 2.12E+04.. ..

272 Efficiency Counts/gps 0.288 0.105 . ".r- r .  :,;

j ':

Efficiency ratio, § (Co.-.

273 60 gps/ Cs-137 gps) 0.364 Estimated Co-60 MDC 274 (pCilg)(10,20&30 ml) 2.29 1.82 1.16 .

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GR-130 Download Data Page 1 of 2 A B C I Cs-137 MDC Cs-137 MDC 2 Spectrum Number 16 17 3 Spectrum Channel 600s CS-137 1200s CS-137 260 Spec. # 16 17 261 ROI Gross (counts) =SUM(B110:B120) =SUM(C109:C121) 262 ROI BKGD/Ch (counts/channel) =(B109+B121)/2 =(Cl08+C122)/2 263 ROI Bkgd Integral (counts) =B262*COUNT(Bl 10:B1 20) =C262*COUNT(C109:C121) 265 Cesium MDC Calculations 266 Efficiency (counts/pCi/g) =B264/2.75 =C264/2.75 267 Efficiency (cpm/pCi/g) =60*B266/B4 =60*C266/C4 268 Cs-137 MDC (pCi/g) =((3+(4.65*(SQRT(B263))))/B266) =((3+(4.65*(SQRT(C263))))/C266) 269 Cobalt MDC Calculations 270 Spec. # 20 21 271 Souce Activity for 662 or 1332 line in (gps) 22400 21200 272 Efficiency Counts/gps =E264/B271 =F264/C271 273 Efficiency ratio (Co-60 gps/ Cs-137 gps) =C272/B272 274 Estimated Co-60 MDC (pCi/g)(10,20&30 min) =B268/$B$273 =C2681$B$273

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GR-130 Download Data Page 2of 2 D E F I Cs-137 MDC Co-60 MDC Co-60 MDC 2 18 20 21 3 1800s CS-137 CS-137 button Co-60 button 260 18 20 21 261 =SUM(D110:D121) =SUM(E106:E123) =SUM(F210:F228) 262 =(D109+D122)/2 =(E105+E124)/2 =(F209+F229)/2 263 =D262*COUNT(D110:D121) =E262*(1 8) =F262*(1 9) 264 -(D26.1'D263)- ________________

265 266 =D264/2.75 267 =60*D266/D4 =(1 *B267+2*C267+3*D267)/6 268 =((3+(4.65*(SQRT(D263))))/D266) 269.,

27C 271 2721.

273 274 =D268/$B$273

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.mii Pe-y c / ,Ci T 17 No contrnou, I?%

Peakt area - C, i2A 1

I_l Channel no.

(a)

With continuum Counts per B channel Peak area - 'SC, - 1-A) '4( C (C,) 2 i=A

• qua1 indi.

I Channel no.

(b)

• eviouslv Figure 10-26 Methods of obtaining peak areas from multichannel spectra.

l iodide.

in Figs.

If the peak were a simple isolated one without any superimposed continuum, as ion, but shown in Fig.10-26a, its area could be determined by simple integration between the I poorer limits shown. When the spectrum is recorded in a multichannel analyzer, the equivalent If BGO.

process is a simple addition of the content of each channel between the indicated limits. If

) crystal a continuum is also present, as in Fig.10-26b, some additional unwanted counts are nergies. included in this process and must be subtracted. Some shape must therefore be assumed Section for the continuum within the region under the peak, and a number of fitting procedures of and for varying degrees of complexity can be applied. A linear interpolation between the continuum values on either side of the peak is the easiest approach and will give sufficient accuracy for many purposes.

At times, closely spaced or overlapping peaks do not allow the straightforward i peaks summation method to be applied. More complex methods must then be used to separate normal the individual contributions of each of the closely lying peaks. These methods normally l many involve fitting an analytic shape to that portion of the peak which can be clearly resolved, ways a and assuming that the remainder of the peak is described by the fitted function. A i peak. Gaussian curve fitted to the points that lie within one standard deviation on either side of

C 5lI c ,>':, '>I'1,4 - !, / . If Kfv 0 STATISTICAL INTERPRETATIONS OF MDCs I Table 3.1 MIDC Results for Data Obtained From Gas Proportional Detector Using Various AMDC Expressions ab MDC ResultC AI)C ExpressionaX (dpm/100 cm2 ) Reference

+ . 210 NCRP58 l2.71 + 4.65 F lEPA 1980 l2.71 + 4.65 GB204 Currie 1968 2.71 + 3.29 a8 146 Currie 1968 3 + 211 Brodsky & Gallaghar l ~~3 + 4.65 rB91 1991 d

3 + 3.29 Rbtg (1 + A)

( n 211 Strom& Stansbury 1992 l ~~~~(Efficienciy)(tg)--. .. l aThe data used in each MDC expression were obtained from a 43-68 gas proportional detector and SrY-90 source.

Average background counts (B) of 354 in I minute, standard deviation of 18, probe area correction for 126-cm 2 detector, and detector efficiency of 0.34 count per disintegration were obtained.

tEach MDC expression is written using symbols that may be different from the ones that were presented in their respective references. However, the meaning of each has been preserved.

'Each MDC result was presented in terms of dpm/i 00 cm2 to facilitate comparison of the different MDC expressions.

Tiis involved correcting the MDC expression for probe area and detector efficiency.

dThe terms R^, t. and th refer to the background counting rate, gross count time, and background counting time, respectively. Using to equal to tf,(I minute), resulted in the same expression as that of Brodsky and Gallaghar (1991).

DECEMBER 1997 . 3-7 NuREG- I 507

Calc. No. 004-04 (MY)

Rev. 0 2e. 7

/PageX24 All 2-. p. fr/oT PA'-/ ,.

Attachment 2 Source Certificates

R &'~. oo -oyr 1380 Seaboard Industrial Blvd.

ANALYTICS A'. ,/ .,t;A 'l Atlanta. Georgia 30318 .USA.

Phone (404) 352-8677 Fax (404) 352-2837 Cl RT11i FCATE1 OF CALIB3RY010N Standard Radionticlidc Source 62994-60 Cs-137 Sand in Short Steel Drum Filled to Top This standard radionuclide source was prepared gravimetrically from a calibrated master solution. The master solution was calibrated in an ionization chamber that was calibrated by the National Physical Laboratory, Teddington, U.K., and is directly traceable to national standards.

Radionuclide purity and calibration were checked using a germanium gamma spectrometer system. The nuclear decay rate and assay date for this source are given below.

ANALYTICS maintains traceability to the National Institute of Standards and Technology through Measurements Assurance Programs as described in USNRC Reg. Guide 4.15, Revision 1 ISOTOPE: Cs-137 ACTIVITY (dps):

2.,gtS;,

6.147 E3 HALF-LIFE: 3.007 El years CALIBRATION DATE: January 29, 2002 12:00 EST TOTAL UNCERTAINTY*: 5.0%

SYSTEMATIC: 4.7%

RANDOM: 0.3%

• 99% confidence level.

Impurities: y-impurities <0.1%

39 L / 56.95 kg of sand.

P 0 NUMBER 02-00007, Item SOURCE PREPARED BY: _ __ ___ _____ _

Is. D. CurI~e, Radiochemist Q A APPROVED: i./ i; e l m > za- -a-

Ce1c. /aV. 004-$4q (712Y)

Riev op >.~

w-R.O#,

I,__________ PA UlJJU INC.

Radiation standards and check sources Ref.'POP 2810 Slier Lane, Santa Fe, NM 87501 (505)473-9538 FAX(505)473-5805 Certificate of Calibrationi ",

(Gamma Source)

The Cesium 137 gamma ray emission rate was compared with NIST referenced source 4200B-134 The comparison was completed using a Sodium Iodide or GeLi gamma detector.

The activity of the source or1 08-12-93 1200 EST was 0.923uCi -

The uncertainty of the measurement and the activity of the source is _10.%/o which is the sum of the uncertainty of the NIST standard and the random error of counting at the 99.0% confidence interval.

Serial NO. 93CS2502228 Cover Active Diameter(or/area)_ .. X if Mounting Material Plastic Total D' eter(or/lrea)_ 1lo Thickness 1/8" Calibration Manager Aichael A. Ortiz

).A. Manager Cr

-. 'harles L. Gonzales The source was leak tested and was found to have oc..005uC 1 Iu removeable activity.

GCO07-93

Co/e No. Q04- Qq Revr f ANAIYTICS 1380 Seaboard Industrial Blvd.

Atlanta. Georgia 30318 U SA.

PITis- / 7-"` Phone (404) 352-8677 Fax (404) 352-2837 CERTIFICATE OF CALIBRATION Standard Radionuclidc Source 59436A-60 Co-60 I Inch x 1/4 Inch Button Source

-.4 IQSI P1% This standard radionuclide source was prepared using an aliquot measured gravimetrically from a calibrated master liquid radionuclide solution source. The master source was calibrated in an ion chamber that was calibrated by the National Physical Laboratory, Teddington, U.K., and is directly traceable to national standards.

Radionuclide purity and calibration were checked using a germanium gamma spectrometer system. The nuclear decay rate and assay date for this source are given below.

ANALYTICS maintains traceability to the National Institute of Standards and Technology through Measurements Assurance Programs as described in USNRC Reg. Guide 4.15, Revision 1.

ISOTOPE: Co-6O ACTIVITY (dps): -- 3.835 E4 HALF-LIFE: 5.2714 years CALIBRATION DATE: April 6, 2000 12:00 EST TOTAL UNCERTAINTY*: 4.8%

SYSTEMATIC: 4.5%

RANDOM: 0.3%

• 99% Confidence Level Impurities: y-impurities <0.1%

P 0 NUMBER 08196-RP-00-0011 -742 REV. 1, Item 1 SOURCE PREPARED BY: I (

Q A APPROVED: . AG UAQ Y6 (a -3 4_10rc b. 1> . 1> I X