ML20105D178

Beta Dosimetry Rept

ML20105D178
Person / Time
Site:	Surry, 05000000
Issue date:	08/12/1983
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML20105C697	List: ML20105C946 ML20105D058 ML20105D110 ML20105D144 ML20105D178 ML20105D243
References
FOIA-84-574 CAL-280-83-01, CAL-280-83-1, CAL-281-83-01, CAL-281-83-1, NUDOCS 8502090612
Download: ML20105D178 (37)

Text

• - - - - - - . _ . _ -

}

e o y..

I o

A e

VIRGINIA ELECTRIC AND POWER COMPANY d j

9 BETA DOSIMETRY REPORT s s

cp BY:

1 CORPORATE HEALTH PHYSICS AUGUST 12, 1983 , ,

v 1

a e

i i

i i

i I

Dkh9ff12840809 MAYBEkR84-574 ppg -l

.._ l

's;

L ,-

1 TABLE OF CONTENTS

~

! PAGE INTRODUCTION 1 EQUIPMENT 2 PROCEDURE 2 RESULTS 4 RECOMMENDATIONS AND CONCLUSION 5 i

1 - FIGURES 7 - 11 TABLES 12 - 14 APPENDIX I APPENDIX II i

REFERENCES i

i BIBLIOGRAPHY i

4 1

i

)

2 4

e i

y . . - . - , , _ , - - . _ . , _ __

.g, 1

INTRODUCTION On April 11, 1983, Virginia Electric and Power Company (Vepco) received a l Confirmation of Action Letter (CAL-280/83-01 and CAL-281/83-01) from the l Nuclear Regulatory Commission (NRC) pertaining to the Surry Power Station. ~ ,

Item Number 3 stated, "By July 5, 1983, complete an evaluation to resolve the discrepancy between beta radiation dose measurements made with portable survey instruments and measurements made with thermoluminescent dosimeters. Until this evaluation is completed, retain detailed survey records to provide sufficient information to adjust thermoluminescent dosimetry results, should such adjustment become necessary. Also, until the above evaluation is completed, control personnel exposure to beta radiation based on dose rate i measurements made with portable survey instruments".

In order to resolve this item, Vepco developed the following action plan:

1. Empirically identify the beta spectral components;

2. Determine the response of the beta survey instrumentation _(Eberline Model R02A) to the identified spectra and determine a correction factor for l this instrumentation;

3. Assess the beta dose to the lens of the eye as it relates to whole body ,

dose;

4. Determine if a beta source similar to the identified station beta spectra is available;

5. Review the thermoluminescent dosimetry (TLD) beta dose algorithms with respect to the identified station spectra in order to determine . if a correction factor is required;

6. Expose TLD's to a beta slab source at known distances and dose rates to determine a TLD correction factor;

7. Compare the TLD dose algorithm for Strontium / Yttrium-90 to the correction factor determined using the beta slab source.

NOTE: Items 1-3 will be addressed in this report. The remaining items will be addressed in a subsequent report.

]

l 1

Implementation of the action plan was initiated by acquiring swipes from.

Surry's Unit Number 2 primary system components. A Feather's analysis (Ch67) was performed on each swipe to determine the beta transmission. This procedure was then duplicated using swipes acquired from Unit Number 1.

The data was then analyzed using a method developed by T. Baltakmens (Ba77), ,

as discussed in Appendix II, to determine an effective average and maximum l beta energy. From this data an arithmetic average beta energy was calculated to determine which beta emitting standard would best approximate the beta energies characteristic of Surry Power Station.

9

. . 4 '

EQUIPMENT The equipment used to perform the Feather's analysis was an Eberline Model HP-210T thin window (1.4 - 2.0 mg/cm*) Gieger Muller (GM) probe, high voltage power supply set for 900 Volts DC, two Eberline Model SH-4A sample holders, and an amplifier-scaler to count the pulses from the probe. The aluminum absorber set used was an Atomic Accessories. Inc. Absorber Set, Model AB-23, Serial Number #7688. This set has 24 aluminum absorbers (3.0 - 1604.2 mg/cm 2) and five lead absorbers (978.1 - 7190.8 mg/cm 2). The sample holders and HP-210T detector were assembled as illustrated in Figure 1. The detector and sample holder assembly were placed inside a shield constructed of lead bricks whose walls were two to four inches in thickness in order to minimize the background contribution to the data. In order to ensure that there were no shifts in the data an electronic stability check was performed using a strontium / yttrium-90 calibration source each day prior to taking data.

PROCEDURE Prior to any beta analysis each swipe was counted on the GeLi system at the station to determine the isotopic ratios of the nuclides present. The results of these GeLi scans are summarized in Table 1. Examination of Table 1 indl-cates that c_esium and cobalt are the primary beta emitting nuclides found at Surry Power Station. The beta counting apparatus was arranged as illustrateT in Figure 2. With an empty stainless steel planchet in place, background counts were taken. Stainless steel planchets were also used for counting the swipes and calibration sources. The counting interval for the initial count, with an empty absorber ring placed above the source, was chosen to obtain at least 10,000 counts. Subsequent counts with absorbers in place were taken to obtain a minimum of 1000 counts. Tables of the data for both swipes and known sources are included as Appendix I. The gross count rates were then corrected for detector dead-time using the following equation:

i Corrected Count Rate = (C) [1.0/(1.0 - CT))

C = Gross Count Rate in CPS

-6 T = Resolution Time (50. x 10 see for HP210T) l l

l The data was then corrected for the photon contribution. Due to the short  !

range of beta particles, the count rate through 1604.2 ag/cm 2of aluminum was I assumed to be due entirely to photons. Therefore, the count rate due to photons with 0.0 thickness of aluminum can be calculated by using the following equation:

I(6) = I(1604.2) exp (p,/p

• X) l l

l

. :g -

, i where: l 1(1604.2) =

The photon count rate through 1604.2 mg/cm2 of aluminum.

I(0) =

The count rate due to photons with 0 mg/cm2 of aluminum.

p*/p =

Mass attenuation coefficient for the photons in aluminum (cma jg),

2 X = 1604.2 mg/cm of aluminum converted to g/cm2 ,

All other values of I(x), where x is some thickness of aluminum absorber, may be calculated using the following equation:

I(x) = I(6) exp (-y,/p * (x) mg/cm2 )

The mass attenuation coefficient, p /p, was taken from NSRDS - NBS29 Photon Cross Sections, Attenuation Coeffic[ents, and Energy Absorption Coefficients from 10 kev to 100 GeV for the cobalt-60 and cesium-137 calibration sources.

For the swipe data and strontium / yttrium-90 calibration source the mass attenuation coefficient was calculated either using the data taken through the lead attenuators or2 determined by analyzing the photon attenuation between 1200 and 1600 mg/cm of aluminum and assuming that no betas can penetrate that l thickness. In order to have a beta contribution to the count rate through 2

l 1200 mg/cm of aluminum, the beta must have an energy greater than 2.5 MeV.

Isotopic analysis of the swipes did not indicate the presence of any isotopes that emit betas 8 above 2.5 MeV. The photon count rate data between 1200 and 1600 mg/cm was least-squares fitted in order to calculate the mass attenuation coefficient using the equation:

i Y = a exp (bx) where:

Y = The count rate.

a = Constant b =

The mass attenuation coefficient cm8 /ag.  !

, x = Aluminum thickness in ag/cas ,

i

The least-squares fitted value of b was then used to calculate the photon count rate for each thickness of aluminum attenuator. The same correction for i

dead-time was applied'to the calculated photon count rate prior to subtraction from the gross count rate.

Subtraction of the photon contribution results in a count rate due only to the  !

beta flux. Figure 3 illustrates the " Beta Transmission versus Attenuator  ;

, Thickness". Transsission is defined as the beta count rate through the i attenuator thickness divided by the beta count rate with no attenuation. Note t i

that almost all of the curves have reached zero by 300 mg/cm2 .

l l

i

'o '

-L-The method used to determine the endpoint and average beta energy assuces that beta absorption is an exponential process and that it is possible to calculate a mass absorption coef ficient to describe the beta absorption with distance.

A beta mass absorption coefficient was calculated for each of the 10 samples using the following equation.  !

2 p,/p(cm /mg) = 0.693 -

x (eg/cm ) 3 where:

2 u,/p(cm /mg) = Beta mass absorption coefficient x = The thickness of aluminum that reduces the beta response by 50% (i.e., the first half-value thickness).

The y /p value was then used to calculate the endpoint and average beta energy using,the power function relationship between beta mass absorption coefficient developed by Mr. Baltakmens (Ba77).

Beta Endpoint Energy: E, = 6.47 n~*

Average Beta Energy: E,y, = 2.90 n -0.745 where:

n = The beta mass absorption coefficient.

These beta endpoint and average energy values were then averaged to obtain a representative beta energy value for Surry Power Station.

RESULTS j

Figure 3 illustrates that in spite of the varying nuclide distribution, the shift in the beta attenuation spectra is small. Some of the attenuation curves diverge from the classical shape of a beta attenuation range curve.

This deviation below 10% transmission is probably due to the bremsstrahlung

' contributions, photon buildup and scattering, and beta range straggling for which corrections were unable to be made or were inadequate. Therefore, the

! method outlined by T. Baltaksens (Ba77) was used to determine beta maximum and beta average energies. Mr. Baltaksens' assumption of a power function l relationship between the apparent beta mass absorption coefficient and the beta endpoint energy is supported by previous experimental work as reported by Evans (Ev67), Hine (HiS6), and Fitzgerald (F167).

l The apparent beta mass absorption coefficient was calculated from the

( thickness of aluminum that was required to reduce by 50% the incident flux of

beta reaching the detector. The half-value criteria was taken as a compromise

! between attempting to minimize the error due to bremsstrahlung and range

straggling and wanting to include as much of the attenuation curve as possible

3 .

d 4

in the measurement. The results of this analysis are in Table 2. In co= piling Table 2 five smears from each unit were used to determine the average beta maximum energy that would be characteristic of Surry Power Station. Note that the Unit I and Unit 2 smears represent mixtures of 1 l nuclides that were decayed for different periods of time. Unit 2 smears had decayed approximately 1 week prior to beta counting, whereas Unit 1 smears were allowed to decay about 4 weeks prior to beta counting in order to see how

! much shif t in beta spectra would occur. Also note that the shift in the average beta maximum energy is approximately 100 kev. The resulting beta i

maximum average value for the week-old fission products is 0.631 MeV and 0.526 MeV for the four-week-old fission products.

Beta spectra from three calibration sources, cobalt-60, cesium-137, and strontium / yttrium-90, were also analyzed concurrently with the swipe spectra to verify the experimental results. Beta E and E vere calculated and compared to the published reference values. " The cafc* lated values and the reference values taken from Baltakmens paper are listed in Table 3. The

calculated and reference values from the experiment agree to within 12%.

j Possible differences between the experimental and reference values for the cesium-137 and the strontium / yttrium-90 may be due to interference between the high and low energy betas emitted in the decay scheme of these nuclides.

i 1

From the determination of the E and E characteristic of " fresh" (one week old) and " aged"-(four weeks IO*d) fiss[o'n* products at Surry Power Station, j it was determined that thallium-204 would be the most appropriate calibration 4 source. Mr. Bryce Rich's paper on " Applied Beta Dosimetry" presented at the 1982 Health Physics Society Meeting (rib 2), depicted a comparison between

! measured and theoretical beta spectra for a thallium-204 point source (Figure 1

4). The figure illustrates that at 20 cm from the source the measured E and E are very close to Surry's calculated E and E for "freIP l fissioY* products. The comparison is made only inh the M esh" fission j products since most of the situations in which workers are exposed to large j doses of beta radiation during an outage occur within the first weeks of the

! unit's shutdown. At 20 cm from a thallium-204 source the Eberline Model R02A portable ionization chamber will only register 55% (see Figure 5) of the total beta dose. This under-response indicates that the beta correction factor 8

should be 1/0.55 or 1.82. This is much less than the correction factor of 4 presently in use at Surry Power Station.

}

i i

RECOMMENDATIONS AND CONCLUSION 4

l Vepco has empirically identified the beta spectral components as beig j primarily isotopes of cobalt and cesium. From the analysis of the collected .y j data a beta spectral distribution with a maximum beta energy of 0.63_1 MeV was determined to be representative of Surry's spectra.

j i

j The data analysis discussed in the previous section indicates that the current j practice of using a beta correction factor of 4 for the Eberline R02A .

l instruments is overly conservative. It is recommended, based upon the j experimental results, that a beta correction factor of 2 be used for all Eberline R02A measurements. Although the experimental results show that the i correction factor is actually 1.82, a correction factor of 2 is recommended i for ease of use. The use of this correction factor will result in a conservative estimate of the beta dose rates, which should be sufficient to correct for shifts in the beta spectra due to decay.

]

l u__ . _ . _ _ _ ~ _ . _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _.- ._ - - _ - _ - -

o. .

t Fore !;RC-5, Current Occupational External Radiation Exposure, states that lens of the eye dose is measured at 300 mg/cm8 . Therefore, in order for the betas to contribute to the lens of the eye dose they must have a range greater than 300 mg/cm2 . The " maximum" or extrapolated range of 631 kev betas is approximately 225 mg/cm*. Comparing this range to the lens of the eye mass density thickness of 300 mg/cm 2 indicates that there is no beta contribution to the lens of the eye dose. The dose to the lens of the eye is solely a ,

function of the photon component of the radiation field.

FIGURE 1 Eberline Model HP210 Probe 1

%{

}

, Y '

Attenuator Drawer Eberline Sample ,

Holder SH-4A e g

l .

~

t Swipe Drawer l

l

r .

1 I

i l

1 l

i High Voltage Amplifter a j Descriminst Scaler -

Power Supply 4

m w

a

.1 e

1 u

i 1

4 4

HP-210 Probe 1

j t

l Equipment Configuration o,

.i 8 i

i

~

BETA TRANSMISSION VS ATTENUATOR THICKNESS .

Surry Power Stat'on Un its 16 2 Swipe Data .

1.00a 0,80-

'N c s

.? 0.60- N O

5

\ e

! $ 'N A c Nm, m

[ 0.40-

' " \ ,,\

'sN 0.20-s

\

s.

0. 00 , ,

- ; 7m: ,

1E+02 30 1E403 1E+98 1E+01 Attenuator thickness (mg/cmV F 2) i l

l FIGURE 4 6 , , , , , , ,

5 - / , ,,..,ge--Eq)N = 267 5

~

b / \

g 4 g -

_e ---- Theoretical ,

5 Measured at 10 cm from source f 3

- ~

-.- Measured at 20 cm from source i \

}2 -

E = 249

\

\

1 ~ /g-

.g,%. E ,m 822 eb Eo= 725

~

/  %. E 0 ' ' ' ' ' ' ' 'o=176 O 100 200 300 400 500 600 700 800 Energy (kev) mEL.J.is21 Comparison of measured-to-theoretical beta spectra for 204TL 1

. From Rich (Ri82) p. 20 1

l t

i a

f

11 -

FIGURE 5 1.1 4 +

+ +} +

1.0 -

+ sos , soy

't g R9 -

or 5 08 -

4 0$c

=

• E k 0.7

. O

• z C g[

• \ ,;

+ 2047 j"* as . ,*

-I 0,5 -

04 - 8%

0 2 4 6 8 to 12 14 16 18 20 22 N 26 20 30 32 34 DISTANCE lanl 50URCE TO CENTE R Of IONIZATION CHAMBE R

. TYPICAL BETA RESPONSE OF 'MODELS RO-2 AND RO-2A From Eberline Instrument Corporation Product and j j Services Catalogue, July 1979, (Santa Fe, New Mexico).

i 4

'i 1

a

TABLE 1 ISOTOPIC ANALYSIS OF SURRY SMEAR DATA

SUMMARY

OF DATA Range of Average Unit 1 Smears Percent Composition Composition Co-58 0.2 - 44.5% 14.1%

Co-60 1.4 - 35.4% 13.2%

Mn-54 0.2 - 6.5% 1.8%

Cs-134 1.4 - 38.4% 26.7%

Cs-137 1.7 - 66.3% 41.9%

Cr-51 Only 1 Smear -

Fe-59 Only 1 Smear -

Range of Average Unit 2 Smears Percent Composition Composition co-58 11.9 - 32.9% 24.7%

Co-60 2.7 - 31.6% 15.1%

Mn-54 0.7 - 2.9% 1.7%

I-131 2.3 - 69.8% 19.0%

I-133 Only 1 Smear -

Cs-134 7.9 - 21.4% 16.3%

Cs-137 7.2 - 29.4% 21.0%

9 i

1 l

l

\ .-

TABLE 2 Half Value Beta Attenuation (MeV)

Sample i Thickness (mg/cm2 ) Coefficient (cm 8/g) max (MeV) E, Unit 1 1 10.56 65.6 0.407 0.128 2 18.39 37.7 0.587 0.194 3 16.77 41.3 0.553 0.181 4 15.38 45.1 0.522 0.178 5 17.0S 40.7 0.559 0.183 Unit 2 1 14.99 46.2 0.513 0.167 2 18.73 37.0 0.595 0.197 3 24.46 28.3 0.709 0.240 4 24.46 28.3 0.709 0.240 5 20.40 -34.0 0.629 0.210 l

I

. o TABLE 3

' Calibration Source Calculated Values Reference Values E E E E max ave max ave Sr/Y-90 2.044 0.791 Y-90 2.27 0.936 Sr-90 0.546 0.196 Co-60 0.281 0.084 0.319 0.095 Cs-137 0.604 0.200 Sg 1.18 0.390 6 0.514 0.170 2

I

%9 I

l

=

i

. ~ . _ . . _ , _ , _ _ . , _... .. .

0 e e )

l APPENDIX I SWIPE AND SOURCE DATA l

1 1

i i

I

CONTAINMENT UNIT 1 RHR Ft.AT PUMP CASINC SWlPE TIME OROSS CPM DEADTIME BACMROUNO PHOTON SETA RAY AL ASSORSER CROSS COUNTRATE TNICKNESS CTS (MIN) CORRECTED CORRECTED (CPM) ,

(CPM) (CPM) (CPM)

MG/CM2 '

829056 829056 2681988 2681880 21516.0 2660364 0.0 1 763816 1 763816 2101359 2101251 21511.7 2079739 3.0 667276 1503088 1502980 21506.2 1481474 6.8 667276 1 605266 605266 1221251 1221143 21496.3 1199646 13.7 1 20.4 512071 1 512071 893239 893131 21486.6 871645 34.6 375186 1 375186 545848 545740 21466.2 524274 1

82.7 154826 1 154826 177761 177653 21397.1 156256 110.4 105316 1 105316 115448 115340 21357.4 93983 135.8 70155 1 70155 74511 74403 21321.1 53082 171.5 48421 1 48421 50457 50349 21270.2 29079

, 221.8 32686 1 32686 33601 33493 21198.6 12295 277.5 26421 1 26421 27016 26908 21119.7 5788 342.0 25716 1 25716 26279 26171 21028.6 5143 425.7 23331 1 23331 23794 23686 20911.0 2775 491.5 22441 1 22441 22869 22761 20819.0 1942 547.7 22553 1 22553 22985 22877 20740.8 2136 619.5 21656 1 21656 22054 21946 20641.2 1305 687.3 21591 1 21591 21987 21879 20547.7 1331 857.9 20433 1 20433 20787 20679 20314.1 365 1220.5 19526 1 19526 19849 19741 19826.6 0 1604.2 19323 1 19323 19639 19531 19323.4 208 I

-e

@ F1

• -* tb u

CONTAINMENT UNIT 1 A CUSICAL FLOOR DRAIO SWlPE O .

71ME GROSS CPM DEADTIME BACMROUNO PHOTON BETA RAY Al. ASSORSER Cross COUNTRATE d

THICKNESS CTS (MIN) CORRECTED CORRECTED ( CPM )

• (CPM) (CPM) (CPM)

MG/CM2 .

' O.0 71042 1 71042 75512.5 75405.5 1157.00 74248.5 62026 65406.8 65299.8 1156.72 64143.0

3.0 62026 1 6.8 50033 1 50033 52209.8 52102.8 1156.36 50946.5 13.7 42363 1 42363 43913.2 43806.2 1155.72 42650.5 34919 35965.6 35858.6 1155.09 34703.5 20.4 34919 1 34.6 22856 1 22856 23299.8 23192.8 1153.77 22039.0 8861 8926.9 8819.9 1149.29 7670.6 82.7 8861 1 110.4 5956 1 5956 5985.7 5878.7 1146.71 4732.0 135.8 4026 1 4026 4039.6 3932.6 1144.36 2788.2

- 171.5 2841 1 2841 2847.7 2740.7 1141.06 1599.7 221.8 1753 1 1753 1755.6 1648.6 1136.42 512.1 277.5 1383 1 1383 1384.6 1277.6 1131.32 146.3 I

342.0 1571 1 1571 1573.1 1466.1 1125.43 340.6 425.7 1301 1 1301 1302.4 1195.4 1117.83 77.6 491.5 1231 1 1231 1232.3 1125.3 1111.90 13.4 547.7 1273 1 1273 1274.4' 1167.4 1106.85 60.5 I 687.3 1193 1 1193 1194.2 1087.2 1094.42 0.0 1 960.3 1141 1 1141 1142.1 1035.1 1070.52 0.0 1220.5- 1113 1 1113 1114.0 1007.0 1048.22 0.0

< 1604.2 1016 1 1016 1016.9 909.9 1016.1s 0.0 4

s x

H v _ _ _ - _ . - _ _ _ _ _ _ _ _ . _ _ . _ . _ . _ . _ . _

1 I, CONTAINME%T UNIT 1 CU61 CAL SWlPE #1 .

CROSS TIME OROSS CPM DEADTIME SACNROUNO PHOTON SETA RAY **

AL ASSORSER COUNTRATE 7 NICENESS CTS (MIN) CORRECTED CORRECTED (C PM )

(CPM) (CPM) { CPM)

MG/CM2 .

0.0 657051 1 657051 1452183 1452080 8630.00 1443450 3.0 603066 1 603066 1212327' 1212224 8628.37 1203596 6.8 521722 1 521722 923023 922920 8626.32 91429t4 4

474109 474109 783769 783666 8622.58 775043 13.7 1 20.4 403191 1 403191 607209 607106 8618.95 598487 34.6 292111 1 292111 386097 385994 8611.27 377383 111851 123348 123245 8585.30 114660 82.7 111851 1 110.4 73983 1 73983 78844 78741 8570.37 70171 135.8 45401 1 45401 47186 47083 8556.71 38527 26733 26733 27342 27239 8537.55 18702 l 171.5 1 221.8 14171 1 14171 14340 14237 8510.63 5727 277.5 9710 1 9710 9789 9686 8480.91 1205 342.0 8986 1 8986 9054 8951 8446.62 504 425.7 8656 1 8656 8719 8616 8402.34 214 547.7 8733 1 8733 8797 8694 8338.21 356 687.3 8506 1 8506 8567 8464 8265.43 198 960.3 8413 1 8413 8472 8369 8124.93 244 8156 8156 8212 8109 7993.25 116 1220.5 1 1604.2 7803 1 7803 7854 7751 7802.94 0 i

00 T em H

l l

l

CONTA1HNENT Utili 1 CU81 CAL SWIPE #2

• AL. A890R8ER CROSS TIME GROSS CPM DEADTIME 8ACNROUND PHOTON SETA RAY **

THICNNESS CTS (MIN) CORRECTED CORRECTED (CPM) COUNTRATE -

MG/CM2 (CPM) (CPM) (CPM) 0.0 547731 1 547731 1007678 1007575 7254.00 1000321 3.0 500561 1 500561 858793 858690 7252.61 851437 l 6.8 427960 1 427960 665188 665085 7250.84 657834 13.7 385436 1 385436 567817 567714 7247.64 560466 20.4 324406 1 324406 444598 444495 7244.54 437250 34.6 230833 1 230833 285612 285709 7237.95 278471 82.7 87623 1 87623 94525 94422 7215.71 87206 110.4 56353 1 56353 59130 59027 7202.93 51824 135.8 35971 1 35971 37083 36980 7191.23 29788 171.5 21856 1 21856 22261 22158 7174.82 14984 221.8 11561 1 11561 11673 11570 7151.76 4419 277.5 8001 1 8001 8055 7952 7126.31 825

-342.0 7823 1 7823 7874 7771 7096.95 674 425.7 7681 1 76R1 7730 7627 7059.03 568 491.5 7491 1 7491 7538 7435 7029.37 406 547.7 7491 1 7491 7538 7435 7004.13 431 687.3 7560 1 7560 7608 7505 6941.83 563 960.3 6673 1 6673 6710 6607 6821.60 0 1220.5 6616 1 6616 6653 6550 6708.94 0 1604.2 6546 1 6546 6582 6479 6546.20 0 l

m>

EY a p

. -g x

l 3-4

CONTAINMEIIT UNIT 1 CU81 cat. SMEAR #3 .

AL ASSOASER GROSS TIME OROSS CPM DEADTIME BACKROUND PHOTON SETA RAY ,,

CORRECTED CORRECTED (CPM ) COUNTRATE -

TMICENESS CTS (MIN)

MG/ CME ( C PM) (CPM) (CPM) .

0.0 1079116 1 1079116 10712246 10712139 38059.0 10674000 3.0 1014957 1 1014957 6581975 6581868 38051.9 6543816 6.8 914856 1 914856 3850080 3849973 38043.0 3811930 13.7 849056 1 849056 2903219 2903112 38026.7 2865085 20.4 752273 1 752273 2016246 2016139 38011.0 1978128 34.6 508381 1 508381 882071 881964 37977.6 843987 82.7 304336 -1 304336 407746 407639 37864.7 369774 110.4 234330 1 234330 291193- 291086 37799.8 253286 135.8 179566 1 179566 211164 211057 37740.4 173317 171.5 141371 1

~

141371 160250 160143 37657.1 122486 221.8 111375 1 111375 122770 122663 37540.0 R5123 277.5 92266 1 92266 99951 99844 37410.8 62433 342.0 82713 1 82713 88836 88729 37261.8 51467 425.7 68749 1 68749 72927 72820 37069.2 35751 491.5 61122 1 61122 64402 64295 36918.5 27377 547.7 57316 1 57316 60191 60084 36790.3 23294 619.5 52210 1 52210 54585 54478 36627.2 17851 687.3 49921 1 49921 52088 51981 36473.8 15507 857.9 42481 1 42481 44040 43933 36090.6 7842 960.3 38363 1 38363 39630 39523 35862.6 3660 1084.5 37435 1 37435 38640 38533 35587.9 2945 1220.5 36503 1 .36503 37648 37541 35289.6 2252 3

1372.8 35466 1 35466 36546 36439 34958.5 1481 1491.7 34433 1 34433 35450 35343 34702.1 641 1604.2 34461 1 34461 35480 35373 34461.3 912 ffN V1 (n

x H

CONTAINMECT IMllT 2 REClRC SPRAY VALVE SWIPE A4. ASSORSER CROSS TIME GROSS CPM DEADTIME 8ACNROUNO PHOTON SETA RAY **'

CORRECTED CORRECTED (CPM) COUNTRATE .

THICNNESS CTS (MIN)

M0/CM2 (CPM) (CPM) (CPM) 0.0 20000 1.09 18348.6 18633.5 18594.8 394.650 18200.1 3.0 20000 1.26 15873.0 16085.8 16047.0 394.566 15652.5 6.8 20000 1.56 12820.5 12959.0 12920.2 394.459 12525.8 13.7 20000 1.82 10989.0 11090.6 11051.8 394.266 10657.6 20.4 20000 2.24 8928.6 8995.5 8956.8 394.078 8562.7 34.6 10000 1.66 6024.1 6054.5 6015.7 393.680 5622.1 55.0 10000 2.43 4115.2 4129.4 4090.6 393.110 3697.5 82.7 10000 3.69 2710.0 2716.2 2677.4 392.336 2285.1 110.4 10000 5.04 1984.1 1987.4 1948.7 391.564 1557.1 135.8 4000 2.60 1538.5 1540.4 1501.7 390.858 1110.8 171.5 4000 3.48 1149.4 1150.5 1111.8 389.867 721.9 221.8 4000 4.77 838.6 839.2 800.4 388.475 411.9 277.5 2000 3.05 655.7 656.1 617.3 386.940 230.4 342.0 2000 3.59 557.1 557.4 518.6 385.169 133.4 425.7 2000 4.48 446.4 446.6 407.8 382.884 25.0 619.5 2000 5.22 383.1 383.3 344.5 377.644 0.0 960.3 1000 2.76 362.3 362.4 323.7 368.604 0.0 1604.2 2000 5.68 352.1 352.2 313.5 352.109 0.0 l

% ??

n6 M

1

.. .. ._. - .- _ ~ . - _ .-.

l CONTAIISIEllT UtilT 2 SEAL TABLE SWIPE AL * - rR CROSS TIME GIIOSS CPM DEADTipIE BACNROUNO PHOTON SETA RAY CTS CORRECTED CORRECTED (CPM) COUMTRATE TNICKNESS (MIN) ,

DIG /CM2 (CPM) (CPM) (CPM) 0.0 10000 0.57 17543.9 17804.2 17767.6 443.880 17323.7 3.0 10000 0.67 14925.4 15113.4 15076.8 443.785 14633.0 6.8 10000 0.88 11363.6 11472.3 11435.7 443.665 10992.0 I

13.7 10000 1.05 9523.8 9600.0 9563.4 443.448 9120.0 16.7 10000 1.18 8474.6 8534.9 8498.3 443.353 8054.9 20.4 10000 1.36 7352.9 7398.3 7361.7 443.237 6918.4 i

34.6 10000 2.21 4524.9 4542.0 4505.4 442.789 4062.6 55.0 10000 3.47 2881.8 2888.8 2852.2 44?.148 P410.0 82.7 10000 5.53 1808.3 1811.0 1774.4 441.278 1333.2 f

i 110.4 4000 2.98 1342.3 1343.8 1307.2 440.409 866.8

? 135.8 4000 4.14 966.2 967.0 930.4 439.615 490.7 2

171.5 4000 5.17 773.7 774.2 737.6 438.500 299.1 1

j 221.8 2000 3.21 623.1 623.4 586.8 436.935 149.8 277.5 2000 3.69 542.0 542.3 505.7 435.208 70.4 i 342.0 2000 3.77 530.5 530.7 494.1 433.?17 60.9 425.7 2000 4.08 490.2 490.4 453.8 430.646 23.2 619.5 2000 4.36 458.7 458.9 422.3 424.753 0.0 960.3 2000 4.73 422.8 423.0 386.4 414.585 0.0 1604.2 2000 5.05 396.0 396.2 359.6 396.032 0.0 l.

N

, m M

CONTAlHMECT UNIT 2 A CUSICAL HOT LE3 ROOT VALVE SWIPE GROSS TIME OROSS CPM DEADTIME SACNROUND PHOTON SETA RAY AL ASSORSER THICNNESS CTS (MIN) CORRECTED CORRECTED (CPM) COUNTRATE .- "

(CPM) (CPM) { CPM)

MG/CM2

• 0.0 40000 1.34 29850.7 30612.2 30569.6 457.470 30112.2 3,0 40000 1.53 26143.8 26's26.1 26683.5 457.372 26226.1 1.82 21978.0 22388.1 22345.5 457.249 21888.2 6.8 40000 13.7 40000 2.03 19704.4 20033.4 19990.8 457.025 19533.8 20.4 20000 1.21 16528.9 16759.8 16717.2 456.807 16260.4 34.6 20000 1.62 12345.7 12474.0 12431.4 456.346 11975.1 82.7 20000 3,25 6153.8 6185.6 6143.0 454.788 5688.2 110.4 10000 2.11 4739.3 4758.1 4715.5 453.893 4261.6 135.8 10000 2.79 3584.2 3595.0 3552.4 453.074 3099.3 171.5 10000 3.67 2724.8 2731.0 2688.4 451.926 2236.5 221.8 10000 4.91 2036.7 2040.1 1997.5 450.312 1547.2 J

277.5 4000 3.06 1307.2 1308.6 1266.0 448.532 817.5 342.0 4000 3.99 1002.5 1003.3 960.7 446.480 514.3 425.7 4000 6.08 657.9 658.3 615.7 443.831 171.8 j

491.5 2000 3.67 542.0 542.3 499.7 441.760 57.9 547.7 2000 4.16 480.8 481.0 438.4 439.998 0.0 619.5 2000 4.48 446.4 446.6 404.0 437.757 0.0 687.3 2000 4.55 439.6 439.7 397.1 435.652 0.0 1604.2 2000 4.90 408.2 408.3 365.7 408.157 0.0 4

k 2D i: A w6

CONTAINMENT UNIT 2 A CUBICAL DRAIN SWIPE GROSS TIME 0000S$ CPM DEADTIME BACKROUND PHOTON BETA RAY AL ASSORSER COUNTRATE ..

TNICENESS CTS (MIN) CORRECTE0 CORRECTED (CPM)

• i (CPM) (CPM) (CPM)

MG/CM2

• 0.0 40000 0.20 200000 240000 239954 3163.84 236790 l

40000 0.22 181818 214286 214239 3163.17 211076 3.0 l' 176424 3162.31 173262 6.8 40000 0.26 153846 176471 40000 142857 162162 162116 3160.76 158955 13.7 0.28 40000 117647 130435 130388 3159.25 127229 20.4 0.34 34.6 40000 0.44 90909 98361 98314 3156.07 95158 82.7 40000 0.90 44444 46154 46107 3145.29 42962 110.4 40000 1.18 33898 34884 34837 3139.10 31698 40000 1.58 25316 25862 25816 3133.44 22682

.135.8 171.5 40000 2.12 18868 19169 19123 3125.50 15997 221.8 20000 1.44 13889 14052 14005 3114.34 10891 277.5 20000 2.19 9132 9202 9156 3102.03 6054 342.0 10000 1.48 6757 6795 6749 3087.84 3661 10000 2.20 4545 4563 4516 3069.51 1447 425.7 491.5 10000 2.65 3774 3785. 3739 3055.19 684 547.7 10000 2.93 3413 3423- 3376 3043.00 333 619.5 10000 2.95 3390 3399 3353 3027.51 326 687.3 10000 3.26 3067 3075 3029 3012.95 16 857.9 10000 3.30 3030 3038 2992 2976.62 15 960.3 10000 3.34 2994 3002 2955 2955.03 0 1004.5 10000 3.42 2924 , 2931 2885 2929.05 0 I

1220.5 10000 3.39 2950 2957 2911 2900.86 10 1372.8 10000 3.33 3003 3011 2964 2869.62 95

, 1491.7 10000 3.65 2740 2746 2700 2845.47 0 4

1604.2 10000 3.54 2825 2832 2785 2822.80 0 2D l

%M A

2 U

i

- - _ . - - - - - , - - . __ -a.i.. s--,-%. .-- e. ...u._ ia. - - - . =--.4-L- hm"b. ,-L- +.i+a --k - A - - 4- GL 1 - - -

i C001TA11SIENT UNIT 2 C CUSICAL FLOOR SWIPE AL A380RSER CROSS TIME OROSS CPM DEADTIIGE BACNROUNO PHOTON SETA ftAY CORRECTED CORRECTED (CPM) COUNTRATE . . ,

TMICRIeESS CTS (MIN) (CPM) peg /CM2 (CPM) (CPM) i 0.0 20000 1.30 15384.6 15584.4 15550.8 271.130 15279.7 3.0 20000 1.48 13513.5 13667.4 13633.8 271.072 13362.8 l 6.8 20000 1.84 10869.6 10968.9 10935.3 270.999 10664.3 13.7 10000 1.03 9708.7 9787.9 9754.3 270.866 9483.5 20.4 10000 1.25 8000.0 8053.7 8020.1 270.737 7749.4 34.6 10000 1.86 5376.3 5400.5 5366.9 270.464 5096.5 -

55.0 10000 2.83 3533.6 3544.0 3510.4 270.072 3240.3 82.7 10000 4.41 2267.6 2271.9 2238.3 269.540 1968.7 i 110.4 4000 2.53 1581.0 1583.1 1549.5 269.010 1280.5 1

135.8 4000 3.42 1169.6 1170.7 1137.1 268.525 868.6 171.5 4000 4.77 838.6 839.2 805.6 267.844 537.7 221.8 2000 3.39 590.0 590.3 556.7 266.888 289.8 1

l 277.5 2000 4.37 457.7 457.8 424.2 265.833 158.4 i 342.0 1000 2.49 401.6 401.7 368.1 264.617 103.5 425.7 1000 2.99 334.4 334.5 300.9 263.047 37.9 1

491.5 1000 3.24 308.6 308.7 275.1 261.819 13.3 547.7 2000 6.36 314.5 314.5' 280.9 260.775 20.2 160ds.2 2000 7.26 275.5 275.5 241.9 241.904 0.0 1

t

• 1$ I

%' i 0

cu w

i I

CESIUM 137 SOURCE DATA AL A890RSER GROSS TIME CROSS CPM DEA 0 TIME SACNROUNO PHOTON SETA RAY

• 7MICNNESS CTS (MIN) CORRECTED CORRECTID (CPM) COUNTRATE .

MG/CM2 (CPM) ( C PM ) (CPM)

~

0.0 134663 1.00 134663 151685 151659 837.000 150822 3.0 117949 1.00 117949 130806 130780 836.821 129943 6.8 96745 1.00 96745 105229 105?o2 836.595 10.4366 9.8 86747 1.00 86747 93507 93480 836.417 92644 13.7 84095 1.00 84095 90432 90406 836.185 89570 16.7 76743 1.00 76743 81986 81960 836.007 81124 20.4 68862 1.00 68862 73054 73028 835.787 72192 34.6 46737 1.00 46737 48631 48605 834.943 47770 55.0 28961 1.00 28961 29677 29651 833.733 28817 82.7 16799 1.00 16799 17038 17011 832.093 16179 110.4 11109 1.00 11109 11213 11187 830.456 10356 135.8 10000 1.46 6849 6889 6862 8P8.957 6033 171.5 10000 2.55 3922 3934 3908 826.856 3081 1

191.9 4000 1.58 2532 2537 2511 875.657 1685 221.8 10000 5.83 1715 1718 1691 8?3.904 868 277.5 4000 4.22 948 949 922 820.648 102 342.0 2000 2.19 913 914 888 816.893 71 425.7 2000 2.27 881 882 855 812.046 43 491.5 2000 2.41 830 830 804 808.?56 0 547.7 2000 2.31 866 866 840 805.032 35 960.0 2000 2.38 840 841 815 781.776 33 1604.2 10000 12.94 773 773 747 746.776 0 5N 9:'"

APPENDIX I Page 12 w

>.= . m e- - e n . N . N N m e o m - a e e . .

i i a:

it~E 4., A i@ a a. ,i- a @i .iN ; i 5

<=u Nd N.a- -in 3' a 8,'

_ e > N -

. m. @ ,e N - - .

N e ,- - m. e. N. E m. -

N w 8_ N

.O 9 , N N - - -

e m @ . e , .

E C a. N. m.

a. -

e- . N - . . . ~ .. m :

. m. a. . #. C. . e. ... .

e.

• I N N @ @ @ c e a m O N 3 O @ C m e C -

OA N N P= N N N N >= ,= > @ @ @ c e a m - a. m N.

ZQ N N N N N N N N N N N fw N N N N N N - - O

&w N N N N N N N N N N N N N N N N N N N N N

.O Ew

>=. @ @ . . . - @ . .

e @

,=. e. ,=. a.

N . M.,. o e , N#. .

. . . . M. N. N. . O.

Bu=r EWL e m m M >= . . e e ,

@ m e N .

e C . - N

- N

• EO e # # # e e e.s S. . @ m. @ e m m M N N -

fg=, gN - gM e

N N - -

N m N @ m M N N N N N N N N N wm

< g-= . .. .. . . . N. .

P- . . . ... . .

. N. N.

. M.

8 cS.Ee o

<=_ , ~

"R.m, 3,@- 2@N2., Nf R

2

- NE

@ m S

• N . N M

8 2e 5, ,8 m3 2 5 3 *I N N N N N N N N N M N -

W @ # N N N - e-W 8Q "

w C

e SE* . . . . . . . . @ . N , ,. m . N . N . N N, . 89i ,.A4iJa4 , arm

. m 4 >: A ,: i .-i.M ,e: im ei @ 4 .:

.o.

i M. N m @

m N .

- e . m - .-

@ - N N N - -

tR = .N,

1. , m o n N -

N N N N N N N N WE 888888825EE2R*53: ; RSR c5  : ; ; ; ; ; ;;;a.aaaa;;;;;;i

8. -

U 8 8. " *e 2'2 M . ,

• = # . m

• N -

N 8e O

IE R &

EII 2 3 6 1 @ g N N N N.

c e- - - o= e= e= - o= e- e-l M g . . . . P. N S S @ . P* 4 . . . af% . ,* M e N ED ms i N i Y- k i b b e='

la

• S 22 m 8 -- m M 2NR,K3E. .

' u.

-E . - e 1 1

i i

l l

STR0llTIUM/YTTO1UM-90 SOURCE DATA AL ASSORSER CROSS TIME CROSS CPM DEADTIME BACNROUNO PHOTOM SETA RAY ,

THICENESS CTS (MIN) CORRECTED CORRECTED (CPM) COUNTRATE MG/CM2 (CPM) (C PM ) 4(CPM) 0.0 105375 1.00 105375 115519 115473 540.900 114932 3.0 102617 1.00 102617 112213 112166 540.785 111625 1

6.8 97730 1.00 97730 106395 106348 540.639 105808 9.8 97358 1.00 97358 105954 105908 540.523 105367 13.7 94366 1.00 94366 102420 102374 540.373 101833 i 20.4 90062 1.00 90062 97370 97323 540.116 96783 26.8 85576 1.00 85576 92147 92101 539.870 91561 34.6 81892 1.00 81892 87890 87843 539.571 87304 55.0 73194 1.00 73194 77948 77902 538.789 77363 82.7 64920 1.00 64920 66633 68587 537.729 68049 110.4 58051 1.00 58051 61002 60956 536.671 60419 135.8 50928 1.00 50928 53185 53139 535.703 52603 171.5 43728 1.00 43728 45382 45335 534.345 44801 221.8' 35953 1.00 35953 37063, 37017 532.437 36485 277.5 26948 1.00 26948 27567 27521 530.333 26990 342.0 20390 1.00 20390 20742 20696 527.906 20168 376.6 16449 1.00 16449 16678 16631 526.609 16104 425.7 12312 1.00 12312 12440 12393 524.774 11868 491.5 7283 1.00 7263 7327 7281 522.324 6759 547.7 10000 1.66 6024 6054 6008 520.241 5488 619.5 10000 2.82 3546 3557 3510 517.592 2993 j 687.3 10000 4.22 2370 2374 2328 515.103 1813 857.9 4000 4.60 870 870 824 508.893 315 960.3 2000 3.15 635 635 589 505.201 84 l 1984.5 2000 3.59 557 557 511 500.760 10 g'u>y 1220.5 2000 3.61 554 554 508 495.941 12 ,h 1604.2 10000 20.72 483 483 436 482.594 0 E

1 e e

• O e APPENDIX II 4

BACKGROUND INFORMATION 2

e

. APPENDIX II Page 1 BACKGROUND INFORMATION

! The objective of the data analysis was to determine the " range" and the maximum and average energy of the beta particles emitted from the sources.

Since electrons are thought to lose energy more or less continuously as they pass through matter, if given the electron's maximum energy, it should be possible to calculate a definite range. This range is known as the mean range and is denoted in Figure 1 of this Appendix as R,. However, the energy loss 2 by an electron is only continuous to a first approximation. In fact there are statistical fluctuations causing the distribution of energy loss to be Gaus-sian. Therefore, the range distribution would also be Gaussian as illustrated i

by the shape of the curve in Figure 1. The " extrapolated" range (R is the

,i distance that is most often referred to in the literature and in thI)s report as the " absolute" or " maximum" range of a beta particle. " Range straggling" is the term used to describe the difference between R and the tail of the range curve and is the direct result of this Caussion ralge distribution. The fraction of betas involved in straggling will vary as a function of R, and the atomic number of the material the beta passes through. A more complete mathematical treatment of range straggling can be found in Kase (K78).

For single nuclides Feather's analysis is a useful method of determining beta particle range and maximum energy. This method compares the attenuation of the sample in aluminum to the attenuation of a known standard. However, the l

choice of an appropriate standard is difficult since both radionuclides need

to have similar beta spectral distribution (i.e., both must be either allowed j or forbidden transitions). In nuclear power stations the radionuclide j mixtures consist of nuclides which decay by either allowed or forbidden transitions, which makes the application of Feather's method inappropriate for the determination of maximum energy or range of the beta particles. However, Feather's method of recording the beta count rate through a series of aluminum attenuators was performed to generate a series of transmission curves. These curves were used to document the similarity of the beta spectra at the station regardless of the differences in radionuclide composition ratios.

An alternate method of determining the maximum energy or range of a beta particle takes advantage of the fact that to a first approximation beta absorption is exponential. Therefore, an apparent beta mass absorption coefficient can be determined as discussed in the body of the report. From this mass absorption coefficient a maximum beta energy can be calculated using j

the power function relationship between the maximum beta energy and ~ the l apparent mass absorption coefficient.

! g. = 6 where:

= The maximum beta energy.

E, k&a = Constants.

n = The apparent mass absorption coefficient.

APPENDIX II ,

, '. . Pcge 2 '

l 4

Baltakmens (Ba77) has experimentally calculated values for the constants k and a utilizing data from 21 beta emitting radionuclides including cesium-137, cobalt-60, iodine-131, strontium-90, yttrium-90, and strontium-89. His least

squares "best fit" to the data results in the following equations

E m

= 6.47n -0.661

-0.745 E,y, = 2.90n

where:

1 E = The maximum beta energy (MeV).

E,y, = The average beta energy (MeV).

i n = The apparent mass absorption coefficient (cas fg),

i i However, these equations for absorption in aluminum will yield slightly different results from the theoretial values calculated using Loevinger's

emperical equation for the apparent mass absorption coefficient (v) for tissue as a function of beta energy.

1 18.6 IInve/I,y,))

v= [2 I (Em - 0.036)I'37 i

where:

4 j E, = The maximum beta energy.

l (E,,,/E*,,) = The forbidden spectra correction factor, generally considered to be approximately 1. .

v = Loevingers apparent absorption coefficient.

For a beta energy of 631 kev, v has a value of 37.88 ca s/g which corresponds to i the 34.76 ca8 /g absorbtion coefficient calculated from Surry Unit 2 data. If i the Z/A correction factor taken from Morgan (Mo73) for tissue and aluminum is l applied to the experimental value there would be agreement to within 6%, which denotes " good" agreement.

i .

1 i

i 1

- ~ . , , . _ _ . ~ _ _ _ . - . . . _ . _ . . . _ , _ . _ . _ . - - _ _ - , , _ , . _ . , _ , _ . . , _ , , _ _ . _ _ _ _ _ . . , _ , _ _ _ _ _ , _ _ , _ . . . _ _ , _ _

APPE!; DIX II Page 3 FIGURE 1 1

N I

2 -

1 1

i1 Distance Ro Re l l

From Kase (K78) page 65 l

l I

REFERENCES (Ba77) Baltakmens, T., " Accuracy of Absorption Methods in the Identification of Beta Emitters". Nuclear Instruments and Methods, 1977 Vol. 142, pp. 535-538.

(Ch67) Chase, G.D., Rabinowitz, J.L., " Principles of Radioisotope Methodology" (Minneapolio, Minn.: Burgess Publishing Co.), pp.

208-215, 1962.

(Mo73) Morgan, K.E., Turner, J.E., " Principles of Radiation Protection" (New York: R.E. Krieger Publishing Co.), 1973, p. 254.

4 (R182) Rich, B.L., " Applied Beta Dosimetry", Presented at the Health Physics Society Meeting June 1982. EGG-SD-5916.

l 1

1

. . .o * *

• BIBLIOGRAPHY (Ba82) Baker, K.R., " Personnel Protection From Beta Particles", pp.97-131 Presented at the INPO Radiological Protection Seminar, ,

April 5, 1982.

(Ba Dy82) Baker, K.R., Dyer, N.C., " Personnel Protection From Beta Particles". OEN-04 of the Radiological Experience Notebook, 1982, Institute of Nuclear Power Operations Atlanta, Ga.

(Ba77) Baltakmens. T., " Accuracy of Absorption Methods in the Identification of Beta Emitters". Nuclear Instruments and Hethods, 1977, Vol. 142, pp. 535-538.

(Br78) Brodsky, A.B., " CRC Handbook of Radiation Measurement and Protection". (New York: CRC Press), p. 418, 1978.

(Ch) Chabot, G.E., Kahn. D.E., Skrable, K.W., " Preparation and Characterization of Large Area Thick Plastic Sources Containing

, Uniform Distributions of Beta Emitting Radionuclides", University of Lowell, Unpublished.

l (Ch67) Chase, G.D., Rabinowitz, J.L., " Principles of Radioisotope Methodology" (Minneapolis, Minn.: Burgess Publishing Co.), pp.

208-215, 1962.

(Co-83) Coleman, R.L., Hudson, C.G., and Plato. P.A., " Depth - Dose Curves for Sr-90, Natural Uranium, and Depleted Uranium in Mylar". Health Physics Vol. 44, No. 4 (April), pp. 395-402, 1983.

(Da) Darois, E.L., "The Use of Large Energy Spatial Equlibrium Beta Plaques as Calibration Sources for Personnel Dosimetry and Survey Meters". Yankee Atomic Electric Company, Unpublished.

(Ev67) Evans, R.D., "The ATOMIC NUCLEUS", (New York: McGraw-Hill).

Eleventh Printing - 1967.

(F167) Fitzgerald, J.J., et.al., " Mathematical Theory of Radiation Dosimetry", Chapter 2 and 8. (New York: Gordan 4 Breach), 1967.

(Ha82) Hankins, D.E., " Evaluation of Beta Energy ( max) and Spectral Type Using Survey Instruments". UCRL-88275 Lawrence Livermore National Laboratory, 1982. ,

)

, ,, e ao *

(HiS6) Hine, G.J., Brownell, G.L., " Radiation Dosimetry", (New York:

Academic Press), 1956.

(K78) Kase, K.R., Nelson, W.R., " Concepts of Radiation Dosimetry",

Chapter 3, (New York: Pergamon Press), 1978.

(Mo73) Morgan, K.Z. , Turner, J.E. , " Principles of Radiation Protection" (New York: R.E. Krieger Publishing Co.),1973, p. 254.

k (rib 2) Rich, B.L., " Applied Beta Dosimetry", Presented at the Health Physics Society Meeting June 1982. EGG-SD-5916.

T l

l (Wa81) Walker. E., Jacobs, R., " Evaluation of Portable Survey i Instruments for TMI-2 Containment Entry". Presented at the 1981 Health Physics Society Meeting.

I 1

i l

T

.