Characterisation of the Thule Pu-U particles · DTU Nutech, Technical University of Denmark Add...

Characterisation of the Thule Pu-U particles Per Roos

DTU Nutech

Center for Nuclear Technologies

Technical University of Denmark (Risø Campus)

• Radiation physics

• Radiation dosimetry

• Radiopharmaceuticals

• Radioecology/environmental radioactivity

• Tracer studies

• Radiochemistry

• Nuclear instruments

• Industrial applications of nuclear methods

• Staff of 80 in 3 research programmes and a mechanical workshop

o Radiation Physics

o Biomedical Tracers - Hevesy Laboratory

o Radioecology and Tracer Studies

[Formerly known as Risø National Laboratory]

DTU Nutech, Technical University of Denmark

Add Presentation Title in Footer via ”Insert”; ”Header & Footer”

Investigations of man-made radioactivity in the Danish environment from 1957

3



Radioactivity in Air at Risø

4

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1955 1965 1975 1985 1995 2005 2015

CO

NC

ENTR

ATI

ON

(µ

Bq

/m3)

YEAR

Sr-90

Cs-137

Fukushima, 2011

Chernobyl, 1986

Atmospheric nuclear weapons tests 1945-1980

Radionuclides from Fukushima in air in Denmark



Precipitation

6

Precipitation is collected at Risø and 10 other locations in Denmark and analysed for content of Sr-90 and Cs-137



10° E 13° E12° E11° E

56° N

55° N

Kattegat-413

Langeland bælt

Femern bælt

Gedser odde

Øresund, N, A

Øresund, N, B

Hesselø Kullen

Kattegat SW

Asnæs rev

Halskov rev

Øresund, S

Møen

Sea water and plants



Caesium-137 in fish/cod

0.01

0.1

1

10

100

1960 1970 1980 1990 2000 2010

Ko

ncen

trati

on

(B

q/

kg

fris

k v

æg

t)

År

Færøerne

Grønland

Nordsøen

Kattegat

Østersøen



Radioactive contamination in Denmark

9

• Poster in building 204 shows concentrations of strontium-90 and caesium-137 in air, precipitation, milk and grass at Risø and in Denmark since the 1950’s.



Ore heaps at Risø with crushing house in background

Sample 238Pu 239Pu 240Pu 241Pu 242Pu 241Am 243,244Cm 238Pu/239+240Pu 242Pu/239+240Pu 239Pu/240Pu 241Am/241Pu 243,244Cm/241Am

1A 341 233 228 6898 0.48 809 63 0.741 1.040-3 1.02 0.117 0.078

1B 11670 4937 4899 136500 11.5 17910 2657 1.19 1.170-3 1.01 0.131 0.148

2 96314 20458 34986 1194000 89.8 158000 23670 1.74 1.620-3 0.585 0.132 0.150

3 17955 3626 6787 233700 16.5 318400 4556 1.72 1.590-3 0.534 0.136 0.143

4 79 23 37 1108 0.068 145 11 1.32 1.140-3 0.619 0.131 0.079

5 48 98 56 1017 0.074 107 6.9 0.310 0.480-3 1.76 0.105 0.064

6 4,6 1.6 2.0 82 0.006 7.6 1.2 1.27 1.640-3 0.842 0.092 0.157


1A 341 233 228 6898 0.48 809 63 0.741 1.040-3 1.02 0.117 0.078

1B 11670 4937 4899 136500 11.5 17910 2657 1.19 1.170-3 1.01 0.131 0.148

2 96314 20458 34986 1194000 89.8 158000 23670 1.74 1.620-3 0.585 0.132 0.150

3 17955 3626 6787 233700 16.5 318400 4556 1.72 1.590-3 0.534 0.136 0.143

4 79 23 37 1108 0.068 145 11 1.32 1.140-3 0.619 0.131 0.079

5 48 98 56 1017 0.074 107 6.9 0.310 0.480-3 1.76 0.105 0.064

6 4,6 1.6 2.0 82 0.006 7.6 1.2 1.27 1.640-3 0.842 0.092 0.157


1A 341 233 228 6898 0.48 809 63 0.741 1.040-3 1.02 0.117 0.078

1B 11670 4937 4899 136500 11.5 17910 2657 1.19 1.170-3 1.01 0.131 0.148

2 96314 20458 34986 1194000 89.8 158000 23670 1.74 1.620-3 0.585 0.132 0.150

3 17955 3626 6787 233700 16.5 318400 4556 1.72 1.590-3 0.534 0.136 0.143

4 79 23 37 1108 0.068 145 11 1.32 1.140-3 0.619 0.131 0.079

5 48 98 56 1017 0.074 107 6.9 0.310 0.480-3 1.76 0.105 0.064

6 4,6 1.6 2.0 82 0.006 7.6 1.2 1.27 1.640-3 0.842 0.092 0.157

Decommissioning work

Analytical capacity in-house:

• C:a 20+10 gamma (Ge) detectors (including one anti-compton well detector).

• One low-energy HPGe for characteristic x-ray analysis.

• 30 Gas-flow anticoincidence shielded GM-counters.

• Quantulus 1220 + PerkinElmer TriCarb LSC.

• 32 solid state (PIPS) alpha detectors.

• Q-ICP-MS & ICP-OES

Neighbours toys:

• SEM/EDX (10+ systems)

• TEM.

• FIB.

• TOF-SIMS (IonTOF 4).

• Micro-RAMAN

• Etc……

Analytical Methods

Radionuclides

Chemical

Analyses LSC

Total Beta

Counting

Gamma

Spec

Alpha

Spec ICPMS AMS 3H X X 90Sr X X X 99Tc X X X 129I X X 137Cs X X 210Pb X 210Po X X 226Ra X X X 230Th X X 232Th X X X 234U X X X 238U X X X 237Np X X X 239Pu X X 240Pu X X 239+240Pu X X X 241Am X X X

Other gamma

emitters X

Analytical Methods in decommissioning work

Radionuclides

Chemical

Analyses LSC

Total Beta

Counting

Gamma

Spec

Alpha

Spec ICPMS AMS 55Fe X X 63Ni X X 14C X X 41Ca X X 36Cl X X

Operation Crested Ice

• Plane wreckage and weapons

components sent to US.

• Contaminated ice/snow stored

temporarily in 25000 Gallon tanks

at Tank Farm before sending to

US.

• Radioecological follow-up

Previous investigations

•Marine expeditions:

•1968, 1970, 1974, 1979, 1984, 1991, 1997, 2003

•Sediment, water, animals and sea plants.

•Terrestrial sampling (Including lakes):

1968 (Crested Ice). Pu on snow at Narssarssuk, Saunders Island and Wolstenholme identified.

1968 (WC Hanson). Investigations around Kap Atholl. Weapons Pu identified.

1997 (Eriksson & Holm). Soil & lake sediments north & east of TAB. No sign of weapons Pu.

2003 (Thule-2003 exp). Soil sampling at Narssarssuk (main focus on marine programme)

2006 Sampling at Nassarssuk and south of Green Valley.

2007+2008 Sampling at Nassarssuk, Thule Air Base, Moriusaq village, Saunders Island.

Mapping and screening 2007+2008

Grønnedal

Narssarssuk

Moriusaq

Thule Air Base

Saunders Island

Wolstenholme Island

Soil sampling

Summary of soil deposition at investigated sites

Particles – characterization methodology

• Isolation technique.

• Radioisotope content via gamma and x-ray spectrometry (large particles)

• Radioisotope content via ICP-MS (small particles)

• Visual appearance via optical microscopy.

• Morphology & element composition via SEM/EDX.

• Mechanical and chemical stability in the environment and in the body.

• Additional techniques (TOF-SIMS, XPS etc)

Region with ”strong” lines from Pu-239, 240, 241 & U-235

129.3 keV Pu-239

144 keV U-235

163 keV U-235

160 keV Pu-240 208 keV Pu-241 (U-237)

186 keV U-235

129.3 keV : 0.0063% [Pu-239]

160.3 keV : 0.000402% [Pu-240]

208 keV : 0.000502% [Pu-241 (U-237)]

375 & 414 keV Pu-239 lines….

375 keV 414 keV

375 keV 0.00155%

414 keV 0.00147%

Gamma lines used for elemental/isotopic composition of particles

241Am 238Pu 239Pu 240Pu 235U

[keV] [keV] [keV] [keV] [keV]

26.34 2.400% 43.48 0.03958% 38.66 0.0105% 45.24 0.0450% 143.8 10.96%

33.20 0.126% 99.85 0.00736% 51.62 0.0271% 104.2 0.0072% 163.3 5.08%

43.42 0.073% 56.83 0.0010% 160.3 0.0004% 185.7 57.20%

59.54 35.940% 129.3 0.0063% 205.3 5.01%

123.0 0.0010% 203.6 0.00057%

125.3 0.0041% 332.8 0.00049%

345.0 0.00056%

375.1 0.00155%

”1%” HPGe & 5kBq Pu-239 Thule particle (230 ksec)

Canberra GL0055P.

50mm2 active area, 5mm thick.

FWHM 122keV: 0.47 keV

FWHM 5.9 keV: 0.13 keV


38.66 keV Pu-239

43.5 keV Pu-238

45.2 keV Pu-240

51.6 keV Pu-239

Ge Kα escape 59.4 keV Am-241


Lα Lβ Lγ

Lζ

Complexity of the Lx-peak groups (here Lβ in a Thule particle)

Thule particle on Si(Li)-detector

Plasma Trace 2

Sector field ICP-MS

Thermo X-series II

Quadrupole ICP-MS

Risø ICP-MS instruments

Atom% Atom% Atom%

REFERENCE VALUES U-238 U-235 U-234 n(235)/n(238) n(234)/n(235)

NBL U112-A 99,2746 0,72017 0,0052458 0,007254324 0,007284113

0

0.00002

0.00004

0.00006

0.00008

0.0001

0 2 4 6 8 10 12

UH

/U

Measurement No

UH/U ratio vs time 12/9-2013

Important point:

UH/U may depend on cone & plasma

conditions. The UH/U value closest in time

to the sample of interest may be most accurate.

UH/U decrease with time in the set above.

This means UH/U=6.14E-5

Elemental & isotopic Pu-U composition of Thule particles

Sample 1C 7200-7700 s sputtering (10 points summed)

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

233 234 235 236 237 238 239 240 241 242 243

Mass (amu)

No

rma

lize

d in

ten

sit

y (

%)

Sample 1A 0-50 s sputtering (10 points summed)

0

20

40

60

80

100

233 234 235 236 237 238 239 240 241 242 243Mass (amu)

No

rmali

zed

in

ten

sit

y (

%)

TOF-SIMS

1

3

2

Sample K

235/238

1 4.71

2 4.69

3 4.68

4 4.73

5 4.78

6 4.62

7 4.77

8 4.70

9 4.61

10 4.71

Ave 4.70

StDev 0.06

Sample 1

Position 1 Position 2 Position 3

235/238 235/238 235/238

A 121 111

B 122 114 109

C 121 115 109

Ave 121.3 114.5 109.7

StDev 0.6 0.7 1.2

100

105

110

115

120

125

Position 1 Position 2 Position 3

Int.(2

35U

) / In

t.(2

38U

)

Homogeneous 235U/238U ratios in particles or not?

SEM/EDX

Thank you for your attention !

Characterisation of the Thule Pu-U particles · DTU Nutech, Technical University of Denmark Add...

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