11 thirpa11.irpa.net/pdfs/KL-3appt.pdf · AEA Tech. DoseGuard S10 Aloka PDM112 Automess ADOS Canberra Dosicard Comet APD (Panasonic Ind. Eur.) Dositec L36 Fuji Electric NRY 20001

International Radiation Protection Association11th International Congress

Madrid, Spain - May 23-28, 2004

Keynote Lecture 3aActive Methods & Instruments for Personal Dosimetry

of External Radiation in EuropePresented by Teresa Bolognese-MilsztajnCo-authors: M.Ginjaume and F.Vanhavere

2004 May the 24th IRPA 11 Keynote Lecture 3a 2

Contents

INTRODUCTION Recommendations and legal requirementsCalibrations and Standards

INSTRUMENTS AND METHODSDetectors Calibration and testing Measured quantitiesAPD (Active personal dosemeter) use in workplaces APD problems and advantages for usersIntercomparisons

CONCLUSIONS AND FUTURE NEEDS


Legal requirements in europeancountries

The 96/29 EU directive is widely spread in Europe for external radiation:

Individual monitoring is practiced in most countries for category A workers Individual monitoring systems are delivered by accredited servicesIndividual monitoring record: passive dosemeters are mostly used.Optimisation of doses: APD are considered better tools for day-to-day, job-to-job processing data


The 96/29 European Union directive is based on ICRP recommendations

Directive does not specify type of dosemeters for individual monitoring

butIn several european countries APD are considered better tools for optimisation of ALARA principlebecause of:

Instant direct reading Daily dose recording Data transfer to and from computer network Lower dose sensitivityAlarms


APD USE IN EUROPE

In most EU countries passive dosemeters are obligatory and used for dose recordingIn some countries the legislations do not specify the type of dosemeter to be usedAPDs are mosty required in particularsituations:

Licence conditions in some workplacesObligatory for potential high dose level situationsItinerant workers Obligatory in France together with passives


Calibrations and Standards

Calibration and testing specified by memberstates ISO Standard 17025 is progressively being applied in EuropeIEC Standards for APD are less well known and national calibration and testing are applied Progress still to be done to harmonise standards practices (EURADOS)


IEC 61283 series.

IEC 1283: Radiation Protection Instrumentation – Direct reading personal dose equivalent (rate) monitors – X, gamma and high-energy beta radiation. IEC 61283 (1995)

IEC 1525: Radiation protection instrumentation – X, gamma, high energy beta and neutron radiations – Direct reading personal dose equivalent and/or dose equivalent rate monitors. IEC 1525, 1996

IEC: Radiation Protection Instrumentation. Measurement of Personal Dose Equivalent Hp (10) and Hp (0.07) for X, Gamma and Beta radiation: Direct Reading Personal Dose Equivalent and/or Dose Equivalent Rate Dosemeters. IEC 61526 (1998)

IEC1323

IEC 1323: Radiation Protection Instrumentation – Neutron radiation - Direct reading personal dose equivalent and/or dose equivalent rate monitors IEC-1323 (1995)

IAEA IAEA Safety Series: Safety Guide: Assessment of occupational exposures to external sources of radiation RS-G-1.3, 1999

Table 1 standards relevant for APDs


Detectors

APDs commercially available are based on:Geiger-Müller

Pulse type ion chambers , electrons collected apply a constant electric field, low efficiency

Silicon diodesIonisation process and charge collection ~10 times more

efficient than for GM type detectors Direct ion storage (DIS)

Ionisation chamber combined with MOSFET data storage device ( active and passive device)

(Bubble detectors)Passive device but direct reading


DIS

Figure 1 a Photon sensitive ion chamber Wall Material: Graphite or Teflon

Figure 1b Neutron/photon sensitive ion chamber Wall Material: A-150/PE containing 6Li or 10B


EURADOS consortiumWorking group: Harmonization of individual monitoring in Europe

Report on APD in preparationTo be published in RPD

Status of implementation of direct reading devices in EU countriesAPD catalogue of gamma and betaAPD catalogue for neutronsAPD problems and advantages for users


APDsγ−β from EURADOS catalogue


APD catalogue for gamma and beta measurements

Overview of the main characteristics of some APDs used in Europe. A set of 22 dosemeters produced by 15 manufacturers was selected.

General information: manufacturer and type, year introduced, type of application, type of detector.

Radiological performance: measured quantities, type of radiation measured and energy response, range, angular response.

Physical characteristics: dimensions, weight, battery type and life-timefor typical use.

Environmental performance: electromagnetic fields sensitivity. Mechanical performance: acoustic sensitivity and shock resistance.Dose recording procedure: manual reading, reading equipment,

software.Type test: lab that conducted the type testing, standard followed or

approval.


Table 2: Main Characteristics of a set of 22 photon APD(information provided by manufacturers)

Energy range (keV) APD Reference M in Max % 137Cs

Angular response % 137Cs

W eight (g)

Volume (cm 3)

AEA Tech. DoseGuard S10 60 3000 80 115.0 Aloka PDM 112 40 1000 50 52.2

Automess ADOS 70 3000 0º-45º 20% 190 133.9 Canberra Dosicard 50 2000 15% 0º-90º 25% (Co-60) 65 83.3

Comet APD (P anasonic Ind. Eur.) 20 1600 0º-60º 20% 109 93.5 Dositec L36 60 6200 25% 77 57.1

Fuji E lectric NRY 20001 50 6000 25% 0º-60º 20% 100 85.0 Graetz ED 150 50 2000 160 92.5

M GP DMC 2000S 50 6000 20% IEC 61283 70 70.6 M GP DMC 2000X 20 6000 30% IEC 61283 70 70.6

M GP DM C 2000XB 20 6000 30% IEC 61526 70 70.6 M GP SOR/R 50 6000 IEC 61283 55 37.0

M ini Instruments 6100 30 1000 20% 125 118.8 Polimaster PM 1203 60 1500 25% 90 126.0

Rados D IS-1 15 9000 30% 0º-60º 20% 20 16.2 Rados RAD-51/51T 60 3000 25/35% IEC 61283 90 115.0 Rados RAD-60/62 60 3000 25% IEC 61283 80 115.0

Rados RDD-20/RDR-20 50 1500 30% IEC 61283 24 14.0 Saic PD-2i/PD-3i 55 6000 25% 90 58.8

Saphydose Gam m a 50 1300 30% IEC 61283 165 167.3 Siemens EPD1, EPD2 (M k1) 20 10000 20% IEC 61526 170 162.3

Siemens Mk2 15 7000 20% IEC 61526 95 101.7


1 10 10 0 10 0 0 10 0 0 0

A E A T e c h. D o s e G ua rd S 10A lo ka P D M 112

A ut o me s s A D O SC a nb e r ra D o s ic a rd

C o me t A P D (P a na s o nic Ind . E ur .)D o s it e c L3 6

F uji E le c t r ic N R Y 2 0 0 0 1G ra e t z E D 150

M G P D M C 2 0 0 0 SM G P D M C 2 0 0 0 X

M G P D M C 2 0 0 0 X BM G P S O R / R

M ini Ins t rume nt s 6 10 0P o lima s t e r P M 12 0 3

R a d o s D IS -1R a d o s R A D -51/ 51TR a d o s R A D -6 0 / 6 2

R a d o s R D D -2 0 / R D R -2 0S a ic P D -2 i/ P D -3 i

S a p hyd o s e G a mmaS ie me ns E P D 1, E P D 2 (M k1)

S ie me ns M k2

Ph o to n e n e r g y (k e V )Low er limit( IEC

Low er limit

Upper limit

APD Energy range from constructors

Figure 4.3: Energy range within a +/- 30 % of 137Cs response


New developments

For high doses Detectors based on industrial diamonds

Biological tissues equivalent, resistant to high doses but low detection efficiency compared to siliconSuitable for measurements in radiotherapy

Low doses CCD coupled with Caesium iodine detectors and MOS detectors

Down to µSv region Extremity

Small sensors coupled with pocket size readout unit Few data publishedNo specific standards yet


APDs for neutrons


APD catalogue for neutrons

10-8 10-3 10-1 1010,01

0,1

1

10

100

GSF PTB DOS-2002 Pisa SDD RADOS DIS-N Munich amira

Hp,

m(1

0)/H

p,c(1

0)

En / MeV

Figure 5.2 Response as a function of the energy of APD prototypes

Figure 5.1 Response as a function of the energy for some commercial APDs

10-8 10-3 10-1 1010,01

0,1

1

10

100

SIEMENS EPD-N SIEMENS EPD-N2 ALOKA PDM-313 FUJI ELECTRIC NRNO BTI BD-PND BTI BDT Saphydose-n

Hp,

m(1

0)/H

p,c(1

0)

En / MeV


The Saphydose-n individual electronic dosemeter for neutrons

Poster section 3h35 ID 288



E. C. project November 2002 – April 2005Oral section 3a-347 H. Schuhmacher et. al.

Poster ID 730 V. Lacoste et al., Neutron spectrometry in workplaces of european nuclear industryPoster ID 956 F. Vanhavere, M. Coeck,Improvements of the Neutron Shielding around the VENUS Reactor Facility at the Belgian Nuclear Research Centre Session: 3b. External exposurePoster ID 670 M. Reginatto et al., Dose Equivalent Response Of Neutron Dosemeters Determined Using Unfolding MethodsPoster ID 288 T.Lahaye et al., Individual electronic neutron dosimetry in workplaces of european power plants and fuel processing facilities

EvaluationEvaluation of of Individual DosimetryIndividual Dosimetry ininMixed Neutron Mixed Neutron andand Photon Radiation FieldsPhoton Radiation Fields


IM 2005European workshop on individualmonitoring of ionising radiation

April 11 - 15, 2005Renaissance Penta Hotel

Vienna / Austria

organised by theARC Seibersdorf research GmbH

Health Physics Division

in co-operation withthe European Radiation Dosimetry Group

EURADOS and IAEA


Calibration and testing

ISO 4037 and IEC-61526 standards for γ and βReference radiation quality recommended :

Filtered X -radiation in the range 12 to 300 keV Gamma sources 137Cs(662 keV) and 60Co(1.25 MeV)

Calibration on ISO 4037-3 defined phantoms (table)For neutrons IEC-13233 standard

Reference radiation quality recommended : Thermal Mono-energetic up to 15 MeV

For both : environmental tests :Electromagnetic compatibility, humidity, temperature, drop test, etc...


From EURADOS reportCalibration and testing from users

questionaire

0

1

2

3

4

5

6

7

NPP Fuel Cycle Research Industrial Medical

No periodic calibration

periodic internal radiological test

periodic external calibration


Measured quantities

Ambient Dosemeter

H*

The ambient dose equivalent is an isotropic quantity

The personal dose equivalent is a directional quantity

Hp

Hp (10) = dose equivalent at 10 mm in the body at the location where the personal dosemeter is worn ( chest )


ICRP60 recommends the effective dose E for radiological protection

E is not measurable but can be approximated, for individual monitoring, by the operational quantity Hp(10)

Hp = ∫ ∫ hp(Ε, α) ΦΕ,αdΕ dα

hp(E, α) is defined between 0° and 75°; new coefficients calculations are in progress for higher angles

Hp accurately estimates E only for certain geometries end energy field distributions see fig (5)


Hp/E

FIG 5 Ratio personal dose equivalent Hp to effective dose equivalent as a

function of the energy for photons at AP,ROT and PA field geometry

104 105 106 107

Photon Energy / eV

0

5

10

15

20

25

Rat

io

H*(10)/E(AP)

H*(10)/E(ISO)H*(10)/E(ROT)

10-2 10-1 100 101 102 103 104 105 106 107 108

Energy (eV)

0

1

2

Rat

io

Hp(10,AP) / E(AP)Hp(10,ROT) / E(ROT)Hp(10,ISO) / E(ISO)

FIG 5 Ratio personal dose equivalent Hp to effective dose

equivalent as a function of the energy for neutrons at AP, ROT and PA field

geometry


Accuracy of Hp measurements with personal dosemeters

Dosemeter reading should be tested in workpaces conditions Spectrometric measurement at workplacesTest on phantoms

Difficulties:Workplace field conditions are sometimes difficult to reproduce

Simulated workplaces fieldsIso phantoms represents only average workers, i.e. : workers

morphology is not taken into accountInstrumented antropomorphic phantoms

Hp accuracy in laboratory conditions may be ~10 to 20% (95%CL)

In workplaces:Hp measured/ Hp reference � 1.5for low doses and for neutrons


10-8 10-7 10-6 10-5 10-4 10-3 10-2 10-1 100 1010.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Proton recoil spectrometers Bonner spheres (Average) New MCNP

∆Φ(E

)/∆ln

(E) (

cm-2/ N

DA)

Neutron Energy (MeV)

10-2 10-1 1000.00

0.05

0.10

0.15

0.20

Proton recoil spectrometers Bonner spheres (Average) New MCNP

∆Φ(E

)/∆ln

(E) (

cm-2/ N

DA)


CANEL/T400New geometry

To be published

water lens

depleted Unat

polyethylene

iron

end cap of the accelerator beam line and TiD target water lens

depleted Unat

polyethylene

iron

end cap of the accelerator beam line and TiD target

See Poster ID 730Neutron spectrometry in workplaces

of european nuclear industry

ISO 12789-1, Reference neutron radiations: Characteristics and methods of production of simulated workplace neutron fields (2001)


Neutron fluence energy distribution for different directional intervals from 0o to 50o at theCANEL/T400 calibration area.

10-8 10-7 10-6 10-5 10-4 10-3 10-2 10-1 100

10-3

10-2

10-1

100

Total 20o - 30o

0o - 10o 30o - 40o

10o - 20o 40o - 50o

∆Φ(E

)/∆ln

(E) (

cm-2.N

DA-1

)


Lacoste, V., Gressier, V., Monte-Carlo simulation of the IRSN CANEL/T400 realistic mixed neutron-photon field, RPD (in press) (2004)


APD use in workplaces

APD should be adapted to the workplace field More reliable APD use in power plants

Centralize recordingIndividual use

In hospitalsEnergy range not always adaptedManual recording

In some power plants, systematic comparison with passives performed

Differences between 3 and 8%When > 10% differences are investigated


Photon field measurements in workplaces from ref : [Burgess],

[d’Errico] [Ambrosi]

0.00

0.20

0.40

0.60

0.80

1.00

Photon energy (keV)

Spec

tral

dis

trib

utio

n (d

Hp(

10)/d

E ar

b.un

its) Hospital

TestingHotcellsNuclear power

10 20 40 100 200 400 1000


APD energy response compared with photon spectra in nuclear industry (Janwillem van Dijk)

0.0%

0.1%

0.2%

0.3%

0.4%

0.5%

0.6%

0.7%

0.8%

0.9%

1.0%

Photon energy (keV)

Spec

tral

dis

trib

utio

n (d

Hp(

10)/d

E)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Response (H

p (10)m /Hp (10)true )

SWRPSWROSiemensDISRAD50MGP SOR/TTLD-Arnhem

20 40 100 200 400 100010


APD energy response compared to hot cells spectra

0.0%

0.1%

0.2%

0.3%

0.4%

0.5%

0.6%

0.7%

0.8%

0.9%

1.0%

Photon energy (keV)

Spec

tral

dis

trib

utio

n (d

H p(1

0)/d

E)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Response (H

p (10)m /Hp (10)true )

HZCsHZPmVSQuHZJSiemensDISRAD50MGP SOR/TTLD-Arnhem

Bre

mss

tral

ung

147P

m

10 20 40 100 200 400 1000


Comparison of X-ray spectral distribution in medical sector with some APD response as a

function of the energy

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

Photon energy (keV)

Spec

tral

dis

trib

utio

n (d

H p(1

0)/d

E)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Response (H

p (10)m /Hp (10)true )

AngioCbogHkathEndoSiemensDISEuroSysMGP SOR/TTLD-Arnhem

20 40 100 200 400


Neutron spectra measurements EVIDOS

Bare fuel rodsFuel rods in a rack

10-9 10-8 10-7 10-6 10-5 10-4 10-3 10-2 10-1 100 1010

2

4

6

8

10

12

14

16

18

POINT 1 POINT 2a POINT 2b POINT 3


E ∆

Φ/∆

E (c

m-2.s

-1)

0

10

20

30

40

50

60

70

E ∆Φ

/∆E (cm

-2.s-1)

Poster ID 730 V.Lacoste et al., Neutron spectrometry in workplaces of european nuclear industry


APD problems and advantages for users ( from EURADOS report)

The ideal dosemeter for userscheaper dosemetersbetter environmental characteristicslonger battery lifebetter radiological response:

most end-users make the assumption that present dosemeters measure the radiation quantities adequately

NPP only wish for an electronic neutron dosemeterbetter mechanical characteristics were not

considered a high priority


Intercomparisons

Several national intercomparisons were performedBased on standards

EURADOS-AIEA intercomparison projectObjectives :

Verify performance of the different APD types available on the marketHelp the participating APD suppliers/ Member States in achieving a sufficiently accurate dosimetry Provide guidelines for improvements .

No budget availableIrradiation time foreseen by some EURADOS standard laboratoriesAIEA organiserHope to have devices from constructors >


ISO 4037 and IEC-61526 standards radiation tests

Reproducibility of the readingRepeatability of the readingDose equivalent rate dependenceRelative intrinsic errorResponse as a function of radiation energyResponse as a function of radiation angle of incidenceRetention of readingAccuracy of alarm levelsResponse time


Intercomparisons

FIG 7 Measured [Tex] response as function of energy of some commercial APD


EURADOS-AIEA intercomparison preliminary protocol

Energy responsePhoton

S-Co,S-CS,N-30,N-80,N-300

0.1 mSvper quality

Dose rate response. Photon

S-Cs 10 mSv(at 1Sv/h)

10 µSv(at 1 mSv/h)

Angular responsePhoton

S-CS(Horizontal rotation)

1 mSv(for each angle: 0o, 45o 60o)

Electromagnetic interference

Mobile phone Dose set to lower limit of effective range of

measurement

Mixed field Photons

N-30 + S-CS0o angle

1 mSv

ResponseBeta

To be defined0o

1 mSv



APDs for γ/β as reliable or better than passivesExperience in power plants confirm the advantages of APDs over conventional dosimetry mainly because of alarm featuresand direct reading allowing betteroptimisation of practicesImprovements needed for extremity, lowdoses, high intensity and neutrons



Improvements on effective dose assessmentby:

Angular and energy spectrometry in workplacesChoice of detectors and calibration practicesSimulated workplaces fields calibrations

Type testing and standardHarmonize practices in EuropeStandards for extremity needed

APD use for legal Record?

Documents

11 thirpa11.irpa.net/pdfs/KL-3appt.pdf · AEA Tech. DoseGuard S10 Aloka PDM112 Automess ADOS Canberra Dosicard Comet APD (Panasonic Ind. Eur.) Dositec L36 Fuji Electric NRY 20001