Dose reconstruction using solid state luminescence methods and monte-carlo simulations after radiation accidents

(1)

LUMINESCENCE DOSE

RECONSTRUCTION USING BUILDING

MATERIALS

H. Yeter Göksu University of Ankara Institute of Nuclear Science

Ankara/ Turkey

• How does it work ?

• What are the limits ?

• What does it provide ?

(2)

Retrospective luminescence dosimetry in

areas affected by fall-out from the

Semipalatinsk nuclear test site

•Luminescence measurements of bricks collected during the field trip of 1999 and 2000 along the trace of the 1949 fall-out

•International Intercomparison: Including USA and Japan using new bricks collected in 2002 and 2003

•Natural background dose assessment based on depth dose distribution in brick

EU- supported INCO-COPERNICUS Project 1998-2001 GSF- Germany.

Durham - United Kingdom.

Helsinki - Finland. ( sub contract)

MRRC – Obninsk Russia. RRCKZ- Alma Alta Kazakhstan

(3)

Dosimetry problem at populated regions

adjacent to SNTS

Limited quantity of historical data

• exposure rate

• radionuclide concentration

• parameters related to the explosion

Heterogeneity of the fallout, change in source configuration

• decontamination efforts

• decay of short lived isotopes

• distribution and mode of deposition: wet or dry?

Relatively narrow trace of the fall-out of 1949 due to strong wind

What does LDR provide ?

• input to radio- epidemiological studies

• support for decision making for the rehabilitation of contaminated areas

(4)

How does it work with fired

objects?

(5)

When ionising radiation interacts with matter, part of the

energy is deposited in the lattice that may be released

as

light

after

thermal

or

optical

stimulation

0 50 100 150 200 250 300 0 200 400 600 800 1000 T L in te ns ity Temperature (°C) 0 10 20 30 40 0 5000 10000 15000 20000 25000 30000 35000 40000 O S L in te n si ty ( a .u .)

Blue light stimulation time (s)

12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0 16.5 17.0 250 300 350 400 450 500 550600 650700 50 75 100 125 150 175 200 225 TL in te ns ity ( a. u .) Wavel engt h (nm ) Temperatu_{re (°C)}

Thermoluminescence

Optically Stimulated

(6)

Source of luminescence from a brick

Clay matrix

Quartz

D

BG =

Age

(D

r

α

+ D

r

β

+D

r

γ

+D

rc

)

Feldspar

Anthropogenic

sources

Cosmic rays

0.15-0.3 mGy/y

Natural

radionuclides

(U, Th, K)

3-5 mGy/y

Terrestrial photons

1-2 mGy/y

-20 0 20 40 60 80 100 120 140 200 250 300 350 400 450 500 550 600 650 700 750 800 D o se in B ri ck ( m G y) Depth (mm)

(7)

•Determinations of cumulative absorbed

dose in brick,

•Verification of external photon

irradiation (depth-dose profiles)

•Evaluation of cumulative dose due to

artificial radionuclides (i.e. fallout), after subtraction of natural dose: DX =DT - DBG

•Conversion to dose in air at the

reference location, RLDX , or immediate

locality, 25mDX W Sample Location Roof Reference Location m2 m3

(8)

Settlements covered during the field trip of 1999,2000 and 2003

Trace of 1949 fall out

475±110mGy 250±60mGy 230±70 <20 mGy <10 mGy <20 mGy <20 mGy <10 mGy

(9)

9 Settlements Age /D_BG Years/mGy D_T mGy D_X mGy

Dose at Ref. Loc

RL DX (mGy ) Other claims Dolon -Church 95±2 330±20 508±11 462±18 180±42 132±40 475±110 415± 140 1.7-5 Gy 1 Gy , Takada 2002 Akkol-Timber Mosk >70 240±11

240±28 - Not detectible 150 mGy

Kanonerka House 87±2 289±10 401±15 387±10 125±33 140±33 225±60 250±60 150 mGy Bolshaya Vladimiirovka 80±5 260±17

258±10 - Not detectible <20 mGy

Izvestka Lime Kiln 80±4 260±20

265±20 - Not detectible <20 mGy

Kainar Adobe -Chimney >50

210±10

82±4 - Re use of bricks, heated 90 mGy

Rubtsovsk Hause Rubtsovsk Baraks 73±2, 216±16 53±2, 182±17 230±10 170±10

- Not detectible <20 mGy

Laptev Log-Workshop 66±4

210±10

198±10 211±14

- Not detectible 480 mGy; Logachev 1997

Leshoz

Topolonskiy-Mill 90±2_274±11 400±23 127±38 230±70 1.4 Gy; Shoikhet 1998

Kuia Church 98±2 317±13 - Not detectible <40 mGy

(10)

Luminescence measurements of bricks from Dolon’ There is a major dosimetry problem in city Dolon Cummulative dose to population: 4.47 Gy -1.67 Gy ?

EU supported group : dose in air: < 0.5 Gy Takada et al. Dose in air: 1 Gy

4 new samples are distributed to all the laboratories

X X

X

Participating Laboartories

GSF- Göksu H.Y of Institute of Radiation Protection,D

Durham -Bailiff I.K University of Durham, UK.

Helsinki –Högne J. University of Helsinki, Finland.

MRRC – Stapenenko V.of RAMS, Obninsk, Russia HRR -Hoshi M. Hiroshima,Japan

(11)

11

The main radioactive impact on the Dolon’ population: August, 1949

3.2 km

New!

The distance between the axis of the fallout and the Church is estimated to be about 3.2 km judging from the results of Cs-137 soil contamination

School

Small church Large church

(12)

• Each laboratory was provided by cut slices of the same bricks collected at different locations in order to avoid differences in the radionuclides composition and exposure geometry of sampling

• The age of the samples were not provided

International intercomparison organized by Japan

and MRRC of Obninsk to resolve the dosimetry

problems of Dolon

1

2

3

4

5

6

7 U

S

A

Ja

p

a

n

G

E

R

G

B

F

IN

R

U

S

_S

(13)

Summary of the EU- results

Sample DL@10mm mGy *D_BG mGy D_X mGy RL**DX mGy KSD 2(1-3)(3) Old church 540 ± 35(30) 350 ± 10 190 ±36 342-494 KSD 3(1-3) Large church 584 ± 63(33) 390 ± 10 194 ± 65 349-504 KSD 3(3-2) Small church 602 ± 64(50) 380 ± 10 222 ± 65 399-577 KSD 3(4-1) School 531 ± 48(42) 320 ± 10 210 ± 50 378-546

*D_BG was assessed from depth dose distribution of the GSF results

(14)

Further imrovements in modelling:

corner versus middle brick

(15)

Absorbed dose in brick – relative contributions from

ground sources (MC simulations)

Ground uniformly

contaminated with fallout (E=662 keV) to a depth of 1 g cm-2

(16)

Validation of the age of the former

old church

• External gamma: at 10 cm inside the brick, calculated from

in-situ dose rate measurements :

0.98 mGy/year (this includes

gamma contribution from brick + cosmic rays + soil)

• Internal beta from U, Th, K content of brick:

• 2.65

mGy/year

• TL depth dose measurements:

347 ± 7

mGy

Age : 95 years in year 2000→ built in 1905 ± 6

Historical record : 1904 ±2

(17)

The use of depth dose profiles

for the assessment of D

_BG

Assumptions:

• External photon source is mainly due to

ground deposition of

137

Cs

(18)

Akkol: Timmber mosque

Age of Building: > 70 ± ?years Age Dose (BG) : 240±11mGy

Cummulative measured D_L: 240 ± 28mGy Fall-0ut Dose: not detectible

(19)

Kanonerka/ House

Age of Building: 87 ± 2 years

Age Dose (BG) : 289 ±10

Cummulative measured (D

_L)

: 394 ± 15mGy

Fall-0ut Dose at brick (D

_x

): 105 ± 20 mGy

(20)

Bolshaya Vladimirovka

Age of Building: 80 ± 5 years

Age Dose (BG) : 260 ±17mGy

Cummulative measured (D

_L

)= 258 ± 10mGy

(21)

Provided samples at 1 .4 m, 3 m, 17 m

Age of Building: 80 ± 4 years

Age Dose (BG) : 260 ±20

Cummulative measured (D

_L)

: 265 ± 20 mGy

Fall-0ut Dose at brick (D

_x

): not detectible

(22)

Kaynar: Adobe house, Chimney brick

Age of Building:> 50 ± ? years

Age Dose (BG) : 210 ±10mGy

Cummulative measured (D

_L

)=82 ± 4 mGy

(23)

Uglovsky Rayon / Rubtsovsk

Age of building: 73 ± 2 years Age dose (BG) : 216 ±16

Cummulative measured (DL): 230 ± 10 mGy Fall-out dose at brick (Dx): not detectible

(24)

Laptev Log / Workshop

(25)

Laptev-Log Workshop

Age of Building: > 70 ± ?years Age Dose (BG) : 240±11mGy

Cummulative measured D_L: 240 ± 28 Fall-0ut Dose: not detectible

(26)

Leskhoz Topolinskiy/ Mill

400 Loc 82 unetched Loc 82 etched Loc 83 etched d do se in b ric k ( m G y) 1.4 m

provided brick at a height of 1.4 m , 12 m

Age of Building: 90 ± 2 years Age Dose (BG): 274 ±11mGy

Cummulative measured (DL): 400 ± 23mGy Fall-0ut Dose at brick (Dx): 126 ± 25 mGy Dose at ref. location (_RLDx): 230 ±45 mGy

Shoiket et al (1998) 1.4 Gy

(27)

Kuria Church

provided brick at the height of the

(28)

CONCLUSION

• No systematic difference was observed between OSL

and TL measurements.

• Natural background dose

due to age of the sample

obtained from the depth dose profiles were in good

agreement with historical records.

• Fallout dose at Dolon in brick

at 10 mm has a mean

value of

200 ± 50 (13)

mGy

including Japan and USA .

Agreement is also achieved in March with EPR and

numerical calculations.

• The intercomparison measurements were found to be in

good agreement with previous results of fallout dose (

182

(29)

Applications

• Hiroshima/Nagasaki Dosimetry System-DS-86

Ichikawa et al. 1966; Maruyama et al 1985.

• Nevada tests affected areas; Haskell et al. 1980

• Chernobyl affected areas;

Bailiff et al. Health Phy 86s

2004

• Semipalatinsk test site affected populated

settlements;

Bailiff et al. Health Phys, 2004 in print

• Areas contaminated due to plutonium production

facilities along Techa river in southern Urals;

Göksu et

al. Health Phys 82,2002; Bougrow et al . Radiat Prot

Dos, 2002

• Mishandling of radioactive sources (Case study Gera

Prison); Internal Report; Göksu, Paratzke 2000

(30)

C um m ul at iv e do se Geological time Zero setting Natural Radiation U, Th, K

Measured dose in laboratory:

Luminescence dose reconstruction using building material

DBG

Fallout dose Dx

D

L = Dx +DBG

Heat

(31)

D_BG – spatial variations

(macro scale)

Gamma dose due to lithogenic radionuclides in wall W Sample Location Roof m2 m3 Gamma dose due to

anthropogenic radionuclides in ground

(32)

Overview of EU- supported study in

Dolon (1999)

(33)

Semipalatinsk

Dolon’ – Depth-dose profile

10 100 1000

0 20 40 60 80 100 120 140 160

Depth from exposed surface (mm)

A bs or be d D os e (m G y) GSF71-2 TL GSF71-2-3 TL MRRC 71-2- OSL Dur 71-2 OSL

Dur71-2-1 MRRC prep OSL Calc GS (0-30 g/cm2) E=662 keV

(34)

Dolon’

0 20 40 60 80 100 120 140 300 400 500 600 Loc 71/2 h= 1.2 m) Loc 71/3 h= 2.76m) Loc 71/4 inner brick) Loc 71/2-3 Sent by Ian)

A bs or be d do se in q ua rt z (m G y) Depth in brick (mm)

(35)

Corners - important but complex

locations

(36)

Internal bricks are often collected

to assess the age of the building

using luminescence dating techniques

Assessment of natural background dose

(37)

Assessment of D

_BG

from inner brick

160 180 200 220 240 260 280 100 200 300 400 500

Inner brick from former Dolon' church TL at 10 mm TL at 100 mm A bs or be d do se ( m G y) Temperature °C 0 20 40 60 80 100 120 200 300 400 500 D_TL = 347 ± 7 mGy D o se in b ri ck ( m G y) Depth in brick (mm)

(38)

Annual dose and age determination using inner

brick

0.1 1 10 0.00 0.05 0.10 0.15 0.20 Granit Floor h=20 cm h=100 cm D os e r at e ( S v/ h)

External gamma dose rate

Automess DA 6150

Dose rate from brick

1. Thin α-Al2O3:C detectors

placed over sample and

evaluated using TL

2. Thick layer alpha counting

for U, Th

(39)

Summary of the fallout dose in bricks, D

_x,

from intercomparison samples of Dolon’

Sample D_TL @10 mm mGy D_BG mGy D_X mGy KSD 2-1 Old Church 540 ± 35 (30) 350 ± 10 190 ± 25 KSD 1-3 Large Church 585 ± 63 (30) 390 ± 10 194 ± 47 KSD 3-2 Small Church 602 ± 64 (50) 380 ± 10 222 ± 47 KSD 4-1 School 531 ± 48 (42) 320 ± 10 210 ± 32 EU-Field 99 KSD (2-1) KSD (1-3) KSD (3-2) KSD (4-1) 150 200 250 Depth 5-15 mm Depth 10-20 mm D os e in b ric k (m G y)

(40)

KSD-2-1, relative depth dose profile plotted

as a function of (D

_TL

– 390) mGy

D_TL-390mGy

MC for 137_{Cs dist. 1gr/cm}2

(41)

D_TL-300mGy

KSD-2-1, relative depth dose profile plotted

as a function of (DTL –

300 ) mGy

(42)

Sample KSD-2-1, relative depth dose profile

plotted as a function of (D

_TL

–

350 )

mGy

D_TL-350mGy

(43)

Large church, relative depth dose profile

plotted as a function of (DTL –

390)

mGy

D_TL-390mGy

(44)

Large church, relative depth dose profile

plotted as a function of (DTL –

400)

mGy

D_TL-400mGy

(45)

Large church, relative depth dose profile

plotted as a function of (D

_TL

– 300) mGy

D_TL-300mGy

(46)

VALIDATION OF THE AGE OF THE

FORMER OLD CHURCH USING

INNER BRICK

AGE BASED ON HISTORICAL RECORDS 1904 ±2

(47)

Depth-dose distributions, calculated with Monte Carlo

methods, for a brick wall at 1 m height from the ground;

wall is exposed to 662 keV photons from various source

configurations

(48)

Dose in bricks from Dolon´ samples at a height of

1 m on the walls of various buildings

150 200 250 Depth 5-15 mm Depth 10-20 mm D os e in b ric k (m G y) D _x= 204 ± 13(50) mGy

(49)

Variation of D

_TL

measurements with temperature,

for two depths @10 and @100mm

150 200 250 300 350 200 300 400 500 600 700 800 KSD 3 (2-1) 10 mm 100 mm D os e (m G y) Temperature °C 150 200 250 300 350 200 300 400 500 600 700 800 _{Large Church KSD 3(1-3)} 10 mm 100 mm D os e (m G y) Temperature °C 150 200 250 300 350 200 300 400 500 600 700 800 _{Small Church KSD 3(3-2} 10 mm 100 mm D os e (m G y) Temperature °C 150 200 250 300 350 200 300 400 500 600 700 800 _{School KSD 3(4-1)} 10 mm 100 mm D os e (m G y) Temperature °C