0373_0387

USE OF KCL REFERENCE SAMPLES TO CALIBRATE THE EFFICIENCY OF A GROSS ALPHA/BETA COUNTING SYSTEM MPC 2000

MARIAN ROMEO CǍLIN1, ALEXANDRU ERMINIU DRUKER2

1 Horia Hulubei National Institute of Physics and Nuclear Engineering IFIN-HH, Bucharest-Magurele, POB MG-6, Romania, e-mail: [email protected]

2 National Institute of Metrology, Bucharest

Received November 26, 2009

Several methods were used for the efficiency calibration of a counting system ORTEC PROTEAN MPC-2000-DP by using KCl reference samples (reference sources of naturally radioactive potassium chloride), along with 241Am and 90(Sr-Y) radioactive sources. The operations were part of gross alpha and beta counts in various samples at the IFIN-HH SALMROM Laboratory specializing in the spectroscopic survey of the environment and radioactive materials.

Key words: gross alpha and beta counter, calibration, gross alpha/beta counts.

1. INTRODUCTION

The equipment we used was a low-background gross alpha/beta counter ORTEC PROTEAN, MPC-2000-DP, with the following setup: a ZnS scintillation detector - dual phosphorus detector (zinc sulfide and plastic), model MPC-2000-DP, high voltage supply (for the detector); signal processing modules; preamplifier; amplifier; counter; display module; operation and display control board equipped with LCD display; mechanical sample feeder; PC interface (RS 485/RS 232), special device to download data acquired and processed by the MPC 2000 (PIC Communicator - Protean Instrument Corporation). For calibration sources, we used sets of 241Am alpha punctual sources and 90(Sr-Y) beta punctual sources, as well as alpha and beta calibration sources (reference samples) made at two chemical labs.

2. SCOPE AND METHOD

We used a fixed geometry in metallic sample trays, in the MPC 2000 lead shield, directly facing the detector probe; two counting geometries were used:

Rom. Journ. Phys., Vol. 56, Nos. 3–4, P. 373–387, Bucharest, 2011

Marian Romeo Cǎlin, Alexandru Druker 2 374

• Counting geometry I – counting routine: Gross α - β manual count; tray geometry 8 mm below the probe/detector; and

• Counting geometry I – counting routine: ALFA+BETA SUS manual count; tray geometry 3 mm below the probe/detector.

Reference conditions were as follows: temperature: (20 ± 2)0 C, pressure: 1013.25 hPa, while ambient conditions were: temperature: (22 ± 0.1)0 C, pressure: 1002± 0.2 hPa and humidity: 35%.

The settings of the MPC 2000 measuring system were done in conformity with the following procedures: “The measuring of sample activity with the global alfa/beta MPC 2000 system” and „The efficient calibration of the measuring system of samples with the global alfa/beta MPC 2000 system.”

For the initial calibration and standardization of MPC 2000 system we used radioactive sources of: 241Am si 90(Sr-Y) and reference samples of KCl (Potassium Chloride) prepared in the laboratory in two sets, each containing 7 samples (Set 1 – CPR si Set 2 – DFVM) – ethalon samples of natural radioactive KCl. The weight of the KCl samples was between 0.4 g and 1 g as it can be seen in Table 1, bearing 4 decimals. The ethalon samples were meassured with the MPC 2000 system in 6 intervals of 5 minutes, resulting a total measuring time of 30 minutes. The best set of ethalon samples was choosen having the smallest measuring errors(Set 2 – DFVM, as it can be observed in Table 6). In addition to this, we performed a measurement with the empty tray in the same work procedure, visible on line 15 of Table 1. The data showing the weight of the work samples and their measuring errors are shown in Table 1.

Table1

The weight of refernce KCI samples

No. SAMPLE SAMPLE CODE WEIGHT (g) ERROR

1 sample 1 - CPR KCl 0.4 A - carrier 1 0.4004 ±0.0001 2 sample 2 - CPR KCl 0.5 A - carrier 2 0.5003 ±0.0001 3 sample 3 - CPR KCl 0.6 A - carrier 3 0.6002 ±0.0001 4 sample 4 - CPR KCl 0.7 A - carrier 4 0.7004 ±0.0001 5 sample 5 - CPR KCl 0.8 A - carrier 5 0.8003 ±0.0001 6 sample 6 - CPR KCl 0.9 A - carrier 6 0.9000 ±0.0001 7 sample 7 - CPR KCl 1.0 A - carrier 7 1.0000 ±0.0001 8 sample 1 - DFVM KCl 0.4 B - carrier 8 0.4028 ±0.0001 9 sample 2 - DFVM KCl 0.5 B - carrier 9 0.5028 ±0.0001

10 sample 3 - DFVM KCl 0.6 B - carrier 10 0.6028 ±0.0001 11 sample 4 - DFVM KCl 0.7 B - carrier 11 0.7028 ±0.0001 12 sample 5 - DFVM KCl 0.8 B - carrier 12 0.8028 ±0.0001 13 sample 6 - DFVM KCl 0.9 B - carrier 13 0.9028 ±0.0001 14 sample 7 - DFVM KCl 1.0 B - carrier 14 1.0028 ±0.0001 15 empty tray empty tray - carrier 15 0.0000 ±0.0000

3 A gross alpha/beta counting system MPC 2000 375

1. EXPERIMENTAL RESULTS

The samples were measured, and the characteristic calibration curve of the detector was drawn (Graphs 1 and 2) with the help of the PICPLAT_KCl01 (PICPLAT_KCl_GRAPH) file from the “calibration” folder of the measuring system. The graphs were made with the EXCEL software, according to table 2 (x axis – the power tension of the detector; y axis – registered the events).

Thus we obtained:

Table 2

Counts = f (U)

DP Detector Plateau Data

PIC MPC-2000BDP MPC-2000 BDP Plat

VOLTS (V) COUNTS SLOPE(%/100

volts) 705 1 0 720 8 0 735 22 0 750 58 0 765 138 0 780 317 97.54 795 541 83.09 810 947 71.57 825 1548 62.53 840 2222 55.23 855 3009 49.22 870 4053 44.43 885 5140 40.49 900 6341 36.7 915 7753 33.37 930 8996 31.39 945 10252 29.47 960 12432 28.33 975 14127 27.33 990 16620 25.88 1005 19581 24.62 1020 22276 22.96 1035 25093 20.56 1050 27722 17.65 1065 28698 13.3 1080 29495 8.32

Voltage Range 705 to 1290 volts in 15 volt increments Umber 1 Detector Plateau Data MPC-2000BDP Plat


Table 2 (continued)

1095 29585 4.16 1110 29914 0.37 1125 29587 0.57 1140 29578 1.55 1155 29884 2.98 1170 30138 1.37 1185 30078 0.34 1200 29808 1.44 1215 30126 1.85 1230 30463 1.29 1245 30211 0.04 1260 30077 0.15 1275 30329 0 1290 30439 0

COUNTS

0

5000

10000

15000

20000

25000

30000

35000

700 800 900 1000 1100 1200 1300

Graph 1 Plateau curve in concordance to the tension.

SLOPE

-2

3

8

13

18

23

28

1000 1050 1100 1150 1200 1250 1300

Graph 2 Plateau curve interest zone beta.


The point-like sources of 241Am and 90(Sr-Y) were also measured and then the file of mesuring data was established: PICDATA_KCL01_FINAL “ULTERIOR PROCESSING OF MEASUREMENTS DONE FOR STANDARDIATION/ CALIBRATION” (table 8) from the “calibration” folder of the measuring system. This folder containing the data got by the specialized software PIC Comunicator carries all the characteristic parameters of the system and it was the source of the experimental data used in the standardization report and in the report regarding the validation of the word procedure. The measuring data was studied in conformity with the folder PICDATA_KCL01_FINAL (PICDATA_KCL01, KCL_BETA – Weight of the made ethalon sample-1, sample-2, sample-3: The influence of the sample’s weight – The autoabsorbtion correction and the influence of the operator who is preparing the refence samples. The experimental data obtained in this way are in conformity with the technical data and the specifications of the system and the detection eficiency for the alfa, beta and Spillover factor Xtalk were calculated with the formulas below and are present in Table 3 and 4.

100;CPMCPM FondDPM

β ββ

β

−ε = × for the beta radiation;

100;CPMCPM FondDPM

α αα

α

−ε = × for the alpha radiation;

100;CPMtalk

CPM

CPM FondX

CPM Fondβ β

α α

−= ×

−

For the measuring of the samples and the radiation sources the two methods of work were used: Measuring geometry I

• the measuring rutine Gross α - β manual count; • in the tray geometry, at the level of 8 mm under the detector probe; • conversion to Bq coefficient in conformity to the ISO 7503-1/1998; • without backscattering; • does not include the absorption correction in the samples; • the beta and alpha source with ∅ 22 mm; • measuring time: 30 minutes; For this geometry we obtained the detection efficiencies presented in Table 3.


Table 3

Detection efficiencies in measure I geometrics

SURCE/Radionucleid SI (imp/s)/Bq=

(imp/min)/(dez/min)= (CPM)/(DPM)

Detection efficiences (% )MPC2000

Beta Surce 90(Sr-Y) (max. beta en. 546+2260keV medium beta en. 565,5 keV)

0,89872 ± 0,0138

imp/(β in 2π) 0,44936 ± 0,0069 βε = 44,936 ±

0,69

Alfa Source 241Am (alfa en. 5,39...5,49 MeV;

medium alfa en. 5,4774 MeV)

0,62730 ± 0,0050

imp/(α in 2π) 0,31365 ± 0,0025 αε = 31,365 ±

0,25

Xtalk 0,2559 ± 0,0050 25,59 ± 0,50

Measuring geometry II

• the measuring rutine ALFA+BETA SUS manual count; • in the tray geometry, at the level of 8 mm under the detector probe; • conversion to Bq coefficient in conformity to the ISO 7503-1/1998; • without backscattering; • does not include the absorption correction in the samples; • the beta and alpha source with ∅ 22 mm; • measuring time: 30 minutes. For this geometry we obtained the detection efficiencies presented in Table 4.

Table 4

Detection efficiencies in measure II geometrics

SOURCE/Radionucleid SI (imp/s)/Bq =

(imp/min)/(dez/min)= (CPM)/ (DPM)

Detection efficiences (% )MPC2000

Beta Source 90(Sr-Y) (max.beta en. 546+2260keV medium beta en. 565,5 keV)

0,89872 ± 0,0138

imp/(β în 2π) 0,4853 ± 0,0074 βε = 48,53 ±

0,74

Sources/ KCl reference samples

0,80574 ± 0,0142

imp/(β in 2π) 0.40287± 40,287±0,71

Alfa Source 241Am (alfa en. 5,39...5,49 MeV;

medium alfa en. 5,4774 MeV )

0,7246 ± 0,0058

imp/(α in 2π) 0,3623 ± 0,0029 αε = 36,23 ±

0,29

Xtalk 0,3108 ± 0,006 31,08 ± 0,60


As to the influence of the operator preparing the reference samples, we can state that the reference potassium chloride (KCl) standard sample sets have been prepared by two different operators (Operator 1 – CPR and Operator 2 – DFVM) and their influence in the preparation of the standard samples is shown in Table 6 (standardization file PICDATA_KCL01_FINAL/probe 3).

The relative maximum and minimum errors and beta efficiences in BEFF (%) for every KCl sample have also been calculated, for each of the two operators. The resulting data (experimental results) is shown in the standardization file: PICDATA_KCL01_FINAL/KCL_BETA, and the resulting second degree fitting curve is:

y = 5.4799x2 - 18.064x + 50.044

y = 5.4799x2 – 18.064x + 50.044 Coefficients fitare: 5.4799 -18.064 50.044

The EXCEL file – Weight of realised Standard/Errors for Potassium Chloride (Table 7) was used to facilitate de measuring of the reference KCl standard samples. This file allows the determination of the mass acivity in (Bq/g) of a standard sample, for different inserted masses of KCl, etc.

Observation: The reference for the data is: “Halbwertszeiten und Photonen-Emissionswahrscheinlichkeiten von häufig verwendeten Radionukliden”-2005 eiwerterte und korrigierte Auflage von Ulrich Schötzig und Heinrich Schrader Physikalisch-Technische Bundesanstalt (PTB), Braunschweig [1]. The influence of the sample mass and the autoabsorbtion correction on the measurements is also set out in the EXCEL standardization file: PICDATA_KCL01_FINAL/probe 2. The general medium error (% relative), maximum error (% relative), minimum error (% relative), maximum error for the neglection of the autoabsorbtion correction – for averages and maximum error for the neglection of the autoabsorbtion correction for all points have also been calculated (as shown in Table 6).

MAX ERR [%] -4.316 MIN ERR [%] 4.190


The repetability of the measurements/tests is shown/calculated/demonstrated in the PICDATA_KCL01_FINAL/probe 1 file (on 7 x 2 KCl sample sets), to which was added an empty tray measurement. The AVERAGE, S[n-1], S[n-1] (%), S[AVERAGE], S[AVERAGE] (%), and also the efficiency/efficacy - BEFF to beta radiation (%), BEFF-2S(n-1), BEFF+2S(n-1), BEFF-2S[AVERAGE], BEFF+2S[AVERAGE] and AVERAGE (%) and S[POISSON], were measured and are shown for each measurement/test (Table 8).

The minimum detectable activity (MDA) was determined through repeated measurements and takes the form: MDA= 3 Sfond/Eff; For KCl standard samples and for 241Am si 90(Sr-Y) standard samples, the MDA is: MDA/alfa = 0.0747 Bq and MDA/beta = 0.371 Bq. The resulting MDAs are in concordance with the data in the technical specifications of the system. As for the time range error, the root-mean square error for a singular measurement for the time range is smaller than 0,0001 % (as shown in Table 8).

4. COMPARING THE RESULTS

The validation of the calibrating in efficiency method was accomplished by organizing a comparison attended by the SALMROM (DFVM) and LAS (STDR) laboratories. The unknown radiation standard sources were: 90(Sr-Y) and 241Am, with the characteristics described in the Standard Certificates. The SALMROM tests were done in accordance with the working procedures and the SR EN ISO/CEI 17025: 2005 [2] referential, and the activity values measured by the two laboratories are comparable, with small departures from the conventionally true values. The measured data is shown in Table 5.

Table 5

Results Activity [Bq] Measurement uncertainty

RADIOACTIVE SOURCE/

Characteristics SALMROM LAS SALMROM LAS

Uncertainty[Bq]

1.

Detectable beta activity, „ALFA +

BETA SUS” routine 90(Sr-Y) SEB 7-4673

Source/ MPC 2000 System

7.01x103 6.78 x103 Err (%)= -0.17% 251

2.

Routine detectable alfa activity „ALFA

+ BETA SUS” 241Am SEA 4-1

Source/ MPC 2000 System

1.38x104 1.43 x104 Err (%)=-11.53% 425

Tabl

e 6

The

influ

ence

of t

he o

pera

tor w

hi is

pre

parin

g th

e re

fere

nce

sam

ples

OPE

RA

TO

R 1

= C

PR

OPE

RA

TO

R 2

= D

FVM

O

PER

AT

OR

1=

CPR

O

PER

AT

OR

2 =

DFV

M

BE

FF [%

] B

EFF

[%

] C

UR

VE

FI

T g

r.2

MA

SS

AV

ER

AG

E==

====

== >

RE

L. E

RR

tow

ards

FI

T [%

] R

EL

. ER

R

tow

ards

FI

T [%

]

M

AX

ER

R

[%]

M

IN E

RR

. [%

]

0.40

0 43

.983

43

.074

43

.690

0.

672

-1.4

10

-4.3

16

4.19

0 0.

500

44.1

54

41.6

54

42.3

78

4.19

0 -1

.710

-4

.316

4.

190

0.60

0 39

.399

41

.309

41

.176

-4

.316

0.

323

-4.3

16

4.19

0 0.

700

39.6

38

41.3

30

40.0

80

-1.1

04

3.11

9 -4

.316

4.

190

0.80

0 39

.621

39

.182

39

.097

1.

339

0.21

7 -4

.316

4.

190

0.90

0 36

.876

38

.618

38

.225

-3

.528

1.

029

-4.3

16

4.19

0 1.

000

36.5

60

38.6

26

37.4

60

-2.4

03

3.11

3 -4

.316

4.

190

Tabl

e 7

The

wei

ght o

f the

mad

e et

halo

n/Er

rors

for t

he P

otas

syum

Chl

orid

e

Th

e w

eigh

t of t

he m

ade

etha

lon

ER

RO

R

SUB

STA

NC

E

POT

ASS

YU

M C

HL

OR

IDE

10

g K

Cl /

Sam

ple=

= M

ASU

RE

ME

NT

Yie

ld B

ETA

40

-K

50

g K

Cl /

Sam

ple=

= M

ASS

89.3

3%

FOR

MU

LA==

==>

KC

l

100

g K

Cl /

sam

ple=

=

A

TOM

IC M

ASS

INT

RO

DU

CE

S V

AL

UE

M

ASS

===>

0.

4004

g K

Cl /

Sam

ple=

= 0.

0001

g K

Cl /

SA

MPL

E==

EL

EME

NT

A

B

NR

.de

ATO

MI

ATO

MIC

MA

SS P

ERC

ENT

H

00

Table 7 (continued)

K

39.102 39.0983

139.102

0.52447

QU

AN

TIT

Y K

[ g ] AT

TH

E W

EIG

HT

OF E

TH

AL

ON

SO

UR

CE

Cl

35.453 35.4527

135.453

0.475528

5.24472g

O

00

26.2236

g

M

OLEC

ULA

R M

ASS =

reference A=>

74.555

52.4472

g

D

IFEREN

CE B

ETWEEN

TH

EM=====>

0.00537%

0.21

g

M

OLEC

ULA

R M

ASS =

reference B=>

74.551

A

CT

IVIT

Y K

-40 [ Bq ] A

T T

HE

WE

IGH

T O

F ET

HA

LO

N

SOU

RC

E

162.167

Bq

M

ASS

AC

TIV

ITY

V

AL

UE

E

RR

OR

810.834B

q

K-40

30.92

0.22B

q/g K-nat

1621.67B

q E

RR

OR

0.71%

RE

AD

S VA

LU

E

AC

TIV

ITY

===> 6.49315

Bq

0.74%

RE

FER

EN

CE

:

348.02

DPM

“Halbw

ertszeiten und Photonen-Emissionsw

ahrscheinlichkeiten von häufig verwendeten R

adionukliden”-2005

eiwerterte und korrigierte A

uflage

von U

lrich Schötzig und Heinrich Schrader

Physikalisch-Technische B

undesanstalt (PTB), B

raunschweig.

Tabl

e 8

Furth

er p

roce

ssin

g fo

r sta

ndar

diza

tion/

calib

ratio

n af

ter m

easu

rem

ent

E

RR

OR

A

CT

IVIT

Y

S[PO

ISSO

N]

AV

ER

AG

E =

40.2

8 M

ASS

[g]

ER

R_M

ASS

[g

] A

CT

IVIT

Y

[DPM

] E

RR

_AC

T[%

] B

EFF

[%]

BE

FF_E

RR

_abs

olut

[%

]

Gen

Avg

ER

R[%

rel

ativ

]

[% r

elat

ive]

E

RR

med

gen

[% r

elat

iv]

S[n-

1] =

2.6

1276

5 0.

4004

0.00

01

348.

0201

0.

742%

44

.989

1.87

2 11

.67

AV

ER

AG

E =

====

===

>43

.983

9.17

S[

n-1]

[%]=

6.49

0.

4004

0.00

01

348.

0201

0.

742%

44

.701

1.86

5 10

.96

S[n-

1]==

====

==>

1.15

8944

8

S[A

VE

RA

GE

]=0.

2850

76

0.40

040.

0001

34

8.02

01

0.74

2%

41.8

281.

816

3.82

S[

n-1]

===[

%]=

==>

2.63

S[A

VE

RA

GE

] [%

] =0.

71

0.40

040.

0001

34

8.02

01

0.74

2%

43.6

101.

848

8.25

S[

AV

ER

AG

E]=

====

> 0.

4731

372

0.

4004

0.00

01

348.

0201

0.

742%

44

.587

1.86

6 10

.67

S[A

VE

RA

GE

]=[%

]==>

1.

08

0.40

040.

0001

34

8.02

01

0.74

2%

44.1

841.

856

9.67

1.29

0.

5003

0.00

01

434.

8513

0.

737%

43

.088

1.61

2 6.

95

AV

ER

AG

E =

====

===

>44

.154

9.60

0.

5003

0.00

01

434.

8513

0.

737%

42

.398

1.60

2 5.

24

S[n-

1]==

====

==>

1.29

8728

2

0.50

030.

0001

43

4.85

13

0.73

7%

44.0

541.

627

9.35

S[

n-1]

===[

%]=

==>

2.94

0.

5003

0.00

01

434.

8513

0.

737%

44

.192

1.62

9 9.

69

S[A

VE

RA

GE

]===

==>

0.53

0203

6

0.50

030.

0001

43

4.85

13

0.73

7%

45.4

341.

649

12.7

7 S[

AV

ER

AG

E]=

[%]=

=>

1.20

A

VE

RA

GE

ON

M

ED

=40.

287

0.50

030.

0001

43

4.85

13

0.73

7%

45.7

561.

654

13.5

7

1.18

S[n-

1]=2

.391

073

0.60

020.

0001

52

1.68

25

0.73

4%

38.2

551.

382

-5.0

4 A

VE

RA

GE

===

====

>

39.3

99-2

.21

S[n-

1]=[

%]=

5.94

0.

6002

0.00

01

521.

6825

0.

734%

38

.907

1.38

9 -3

.43

S[n-

1]==

====

==>

0.74

4741

4

S[A

VE

RA

GE

]=0.

6390

41

0.60

020.

0001

52

1.68

25

0.73

4%

39.1

751.

393

-2.7

6 S[

n-1]

===[

%]=

==>

1.89

S[A

VE

RA

GE

][%

]=1.

586

0.60

020.

0001

52

1.68

25

0.73

4%

40.0

571.

408

-0.5

7 S[

AV

ER

AG

E]=

====

> 0.

3040

394

0.

6002

0.00

01

521.

6825

0.

734%

40

.095

1.40

7 -0

.48

S[A

VE

RA

GE

]=[%

]==>

0.

77

0.60

020.

0001

52

1.68

25

0.73

4%

39.9

041.

405

-0.9

5

1.15

0.

7004

0.00

01

608.

7744

0.

731%

40

.306

1.29

4 0.

05

AV

ER

AG

E =

====

== >

39

.638

-1.6

1

0.

7004

0.00

01

608.

7744

0.

731%

39

.156

1.27

7 -2

.81

S[n-

1]==

====

==>

1.31

6850

5

0.70

040.

0001

60

8.77

44

0.73

1%

37.1

851.

249

-7.7

0 S[

n-1]

===[

%]=

==>

3.32

0.

7004

0.00

01

608.

7744

0.

731%

40

.568

1.29

8 0.

70

S[A

VE

RA

GE

]===

==>

0.53

7602

0.

7004

0.00

01

608.

7744

0.

731%

39

.977

1.28

8 -0

.77

S[A

VE

RA

GE

]=[%

]==>

1.

36

0.70

040.

0001

60

8.77

44

0.73

1%

40.6

341.

298

0.86

1.07

Table 8 (continued)

0.8003 0.0001

695.6056 0.729%

39.932

1.198 -0.88

AV

ER

AG

E ======= >

39.621-1.65

0.8003 0.0001

695.6056 0.729%

40.565

1.206 0.69

S[n-1]========> 1.0198493

0.8003

0.0001 695.6056

0.729%

40.220 1.203

-0.17 S[n-1]===[%

]===> 2.57

0.8003

0.0001 695.6056

0.729%

37.661 1.166

-6.52 S[A

VE

RA

GE

]=====> 0.4163517

0.8003

0.0001 695.6056

0.729%

39.616 1.193

-1.67 S[A

VE

RA

GE

]=[%]==>

1.05

0.8003 0.0001

695.6056 0.729%

39.731

1.195 -1.38

1.01

0.9000

0.0001 782.2630

0.728%

36.608 1.080

-9.13 A

VE

RA

GE

======= > 36.876

-8.47

0.9000 0.0001

782.2630 0.728%

35.790

1.069 -11.16

S[n-1]========> 0.8434348

0.9000 0.0001

782.2630 0.728%

37.784

1.096 -6.21

S[n-1]===[%]===>

2.29

0.9000

0.0001 782.2630

0.728%

36.071 1.072

-10.47 S[V

AV

ER

AG

E]=====>

0.3443308

0.9000

0.0001 782.2630

0.728%

37.656 1.095

-6.53 S[A

VE

RA

GE

]=[%]==>

0.93

0.9000

0.0001 782.2630

0.728%

37.349 1.090

-7.29

0.99

1.0000

0.0001 869.1811

0.727%

37.963 1.039

-5.77 A

VE

RA

GE

======= > 36.560

-9.25

1.0000 0.0001

869.1811 0.727%

38.447

1.045 -4.57

S[n-1]========> 1.3157308

1.0000 0.0001

869.1811 0.727%

36.076

1.014 -10.45

S[n-1]===[%]===>

3.60

1.0000

0.0001 869.1811

0.727%

35.708 1.008

-11.37 S[A

VE

RA

GE

]=====> 0.5371449

1.0000 0.0001

869.1811 0.727%

35.225

1.002 -12.57

S[AV

ER

AG

E]=[%

]==> 1.47

1.0000

0.0001 869.1811

0.727%

35.938 1.012

-10.79

0.95

0.4028

0.0001 350.1061

0.742%

39.122 1.764

-2.89 A

VE

RA

GE

======= > 43.074

6.92

0.4028 0.0001

350.1061 0.742%

44.035

1.849 9.30

S[n-1]========> 3.1076325

0.4028 0.0001

350.1061 0.742%

42.778

1.828 6.18

S[n-1]===[%]===>

7.21

0.4028

0.0001 350.1061

0.742%

44.949 1.863

11.57 S[A

VE

RA

GE

]=====> 1.2686857

0.4028 0.0001

350.1061 0.742%

40.094

1.783 -0.48

S[AV

ER

AG

E]=[%

]==> 2.95

0.4028

0.0001 350.1061

0.742%

47.463 1.906

17.81

1.29

0.5028

0.0001 437.0242

0.737%

41.135 1.577

2.10 A

VE

RA

GE

======= > 41.654

3.39

0.5028 0.0001

437.0242 0.737%

41.089

1.576 1.99

S[n-1]========> 0.6742501

0.5028 0.0001

437.0242 0.737%

42.188

1.593 4.72

S[n-1]===[%]===>

1.62

0.5028

0.0001 437.0242

0.737%

41.089 1.576

1.99 S[A

VE

RA

GE

]=====> 0.2752615

0.5028 0.0001

437.0242 0.737%

42.691

1.601 5.97

S[AV

ER

AG

E]=[%

]==> 0.66

0.5028

0.0001 437.0242

0.737%

41.730 1.586

3.58

1.20

Ta

ble

8 (c

ontin

ued)

0.

6028

0.

0001

52

3.94

24

0.73

3%

40.2

66

1.40

8 -0

.05

AV

ER

AG

E =

====

== >

41

.309

2.54

0.60

28

0.00

01

523.

9424

0.

733%

41

.640

1.

428

3.36

S[

n-1]

====

====

> 1.

2590

249

0.60

28

0.00

01

523.

9424

0.

733%

40

.953

1.

418

1.65

S[

n-1]

===[

%]=

==>

3.05

0.

6028

0.

0001

52

3.94

24

0.73

3%

43.0

91

1.45

0 6.

96

S[A

VE

RA

GE

]===

==>

0.51

3994

8

0.

6028

0.

0001

52

3.94

24

0.73

3%

39.6

93

1.39

7 -1

.47

S[A

VE

RA

GE

]=[%

]==>

1.

24

0.

6028

0.

0001

52

3.94

24

0.73

3%

42.2

13

1.43

6 4.

78

1.

12

0.70

28

0.00

01

610.

8605

0.

731%

41

.085

1.

302

1.98

A

VE

RA

GE

===

====

>

41.3

302.

59

0.

7028

0.

0001

61

0.86

05

0.73

1%

40.3

97

1.29

3 0.

27

S[n-

1]==

====

==>

0.98

8259

5

0.

7028

0.

0001

61

0.86

05

0.73

1%

40.0

70

1.28

8 -0

.54

S[n-

1]==

=[%

]===

> 2.

39

0.70

28

0.00

01

610.

8605

0.

731%

42

.362

1.

320

5.15

S[

AV

ER

AG

E]=

====

> 0.

4034

553

0.70

28

0.00

01

610.

8605

0.

731%

42

.427

1.

322

5.31

S[

AV

ER

AG

E]=

[%]=

=>

0.98

0.

7028

0.

0001

61

0.86

05

0.73

1%

41.6

41

1.31

1 3.

36

1.

05

0.80

28

0.00

01

697.

7786

0.

729%

39

.578

1.

190

-1.7

6 A

VE

RA

GE

===

====

>

39.1

82-2

.74

0.

8028

0.

0001

69

7.77

86

0.72

9%

38.2

60

1.17

3 -5

.03

S[n-

1]==

====

==>

0.92

1738

3

0.

8028

0.

0001

69

7.77

86

0.72

9%

40.7

54

1.20

6 1.

16

S[n-

1]==

=[%

]===

> 2.

35

0.80

28

0.00

01

697.

7786

0.

729%

38

.317

1.

173

-4.8

9 S[

AV

ER

AG

E]=

====

> 0.

3762

981

0.80

28

0.00

01

697.

7786

0.

729%

39

.034

1.

183

-3.1

1 S[

AV

ER

AG

E]=

[%]=

=>

0.96

0.

8028

0.

0001

69

7.77

86

0.72

9%

39.1

49

1.18

4 -2

.83

1.

02

0.90

28

0.00

01

784.

6967

0.

728%

36

.673

1.

079

-8.9

7 A

VE

RA

GE

===

====

>

38.6

18-4

.14

0.

9028

0.

0001

78

4.69

67

0.72

8%

39.0

18

1.11

0 -3

.15

S[n-

1]==

====

==>

1.19

4457

5

0.

9028

0.

0001

78

4.69

67

0.72

8%

40.3

94

1.12

9 0.

26

S[n-

1]==

=[%

]===

> 3.

09

0.90

28

0.00

01

784.

6967

0.

728%

38

.610

1.

106

-4.1

6 S[

AV

ER

AG

E]=

====

> 0.

4876

352

0.90

28

0.00

01

784.

6967

0.

728%

38

.431

1.

103

-4.6

1 S[

AV

ER

AG

E]=

[%]=

=>

1.26

0.

9028

0.

0001

78

4.69

67

0.72

8%

38.5

84

1.10

4 -4

.23

0.

97

1.00

28

0.00

01

871.

6148

0.

727%

39

.464

1.

056

-2.0

4 A

VE

RA

GE

===

====

>

38.6

26-4

.12

1.

0028

0.

0001

87

1.61

48

0.72

7%

38.7

75

1.04

7 -3

.75

S[n-

1]==

====

==>

0.61

6856

9

1.

0028

0.

0001

87

1.61

48

0.72

7%

38.0

18

1.03

8 -5

.63

S[n-

1]==

=[%

]===

> 1.

60

1.00

28

0.00

01

871.

6148

0.

727%

37

.788

1.

036

-6.2

0 S[

AV

ER

AG

E]=

====

> 0.

2518

308

1.00

28

0.00

01

871.

6148

0.

727%

38

.890

1.

049

-3.4

7 S[

AV

ER

AG

E]=

[%]=

=>

0.65

1.

0028

0.

0001

87

1.61

48

0.72

7%

38.8

21

1.04

8 -3

.64

0.

93

Table 8 (continued)

0.001 0.0001

0.8692 1.072E-01

210.543-347.111

A

VE

RA

GE

======== > 84.754

0.001 0.0001

0.8692 1.072E-01

387.721384.065

S[n-1]========>

383.49508

0.001

0.0001 0.8692

1.072E-01348.604

-339.493

S[n-1]===[%]===>

452.48

0.001

0.0001 0.8692

1.072E-01663.843

392.190

S[AV

ER

AG

E]=====>

156.56121

0.001

0.0001 0.8692

1.072E-01111.599

399.654

S[AV

ER

AG

E]=[%

]==> 184.72

0.001

0.0001 0.8692

1.072E-01-95.492

-320.892

2.60


5. CONCLUSIONS

The results which were obtained in the SALMROM laboratory from the measuring/ testing/rating and comparison data validate the use of the measuring method, pointing out that the MPC 2000 system is correctly calibrated in efficiency, while observing the processed testing geometries. The system can be used for:

• Measuring radioactive alfa and beta concentrations in a wide range of different samples: solid, liquid, filtres, aerosoles etc.;

• Monitoring radioactive alfa and beta concentrations in the environment, biological and food samples, mineral and geological samples, radioactive waste, materials used in the nuclear industry and its applications;

• Characterization of the content of total alfa and beta radionucleids in different samples and screening for the selection of special samples, etc.

REFERENCES

1. Halbwertszeiten und Photonen-Emissionswahrscheinlichkeiten von häufig verwendeten Radionukliden”-2005 eiwerterte und korrigierte Auflage von Ulrich Schötzig und Heinrich Schrader Physikalisch-Technische Bundesanstalt (PTB), Braunschweig.

2. SR EN ISO/CEI 17025: 2005 – Cerinţe generale pentru competenţa laboratoarelor de încercări şi etalonări.

3. Legea 111/1996 privind desfăşurarea în siguranţă a activităţilor nucleare, republicată, cu modificările şi completările ulterioare.

4. Manualul Calitatii al IFIN-HH, MC-00-00, ediţia în vigoare. 5. Manualul Calitatii al SALMROM, MC-FVM-100, Rev. 1, 2009, ediţia în vigoare. 6. Manualele de operare, documentaţia tehnică – Sistem de masură a radioactivităţii alfa şi beta

globale în fond scăzut model MPC – 2000. 7. Precedures manual, Environmental Measurements Laboratory, HASL - 300, U S Department of

Energy, 1992. 8. Raport de Etalonare al sistemului MPC 2000, nr. 2/2008, Cod: RE-FVM-101B, Nr. 2/2009. 9. IAEA - Update of X Ray and Gamma Ray Decay Data Standards for Detector Calibration and

Other Applications, Volume 1: Recommended Decay Data, High Energy Gamma Ray Standards and Angular Correlation Coefficients, 2007.

10. IAEA - Update of X Ray and Gamma Ray Decay Data Standards for Detector Calibration and Other Applications, Volume 2: Data selection, Assessment and Evaluation Procedures, 2007.

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