Actinide L-line ED-XRF and HKED Spectra Processing

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Submitted on 26 Feb 2020

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Actinide L-line ED-XRF and HKED Spectra Processing

E. Esbelin, V. Boyer-Deslys, A. Beres, C. Rivier

To cite this version:

E. Esbelin, V. Boyer-Deslys, A. Beres, C. Rivier. Actinide L-line ED-XRF and HKED Spectra Pro-cessing. 5th ATALANTE Conference on Nuclear Chemistry for Sustainable Fuel Cycles, Jun 2016, Montpellier, France. �hal-02441895�

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E. ESBELIN, V. BOYER-DESLYS, A. BERES, C. RIVIER

CEA, Nuclear Energy Division, RadioChemistry & Processes Department,

Analysis and Materials Metrology Laboratory, BP 17171, 30207 Bagnols sur Cèze Cedex, France

ACTINIDE L-LINE ED-XRF AND HKED SPECTRA PROCESSING

Analytical Schielded Line - CBA

L-LINE ED-XRF

HYBRID K-EDGE

DENSITOMETER

(HKED)

E_U,edge E_Pu,edge

Spectra processing (CEA software)

Elements analyzed: focus on U and Pu for our use Absorption (K-edge) :

Concentration range: • >10 g/L (LQ)

• Best accuracy>50 g/L (uncertainty <2%) Counting time: 800 s/sample

 No experimental calibration: theoritical model  Matrix effects : low sensitivity

Schematic Data Processing

Conclusion

Examples

X-ray Fluorescence (ED-XRF): Concentration range:

• >0.1 g/L (LQ)

Counting time: 800 s/sample

 Relative calibration (hybrid mode: coupled with K-edge)

 Absolute calibration (autonomous mode)

Work in progress about autonomous mode of ED-XRF for improvement of results accuracy.

Processing (CEA software)

13 14 15 16 17 0,0 0,2 0,4 0,6 0,8 1,0 theoritical calculus from measurements F energy (keV)

Estimation of the monochromator transfer function

Schematic Data Processing

Monochromator range

Examples

Passive spectrum of the sample XRF Spectrum of

the sample

Dissolution of residues from spent fuel dissolution in presence of AgO

K-rays of Ag

Analytical Technique _(mg/L)U _(mg/L)Pu

L-Line XRF without correction 33.3 18.7

L-Line XRF with matrix effects correction 102.8 57.8

ID-TIMS (reference values) 109.2 59.8 Matrix effects (attenuation) because of high content of

AgO (~90 g/L) – have to be taken into account by spectrum processing

Analyzed elements : U, Pu, Np, Am, Sr, Zr, Br, Rb, Y/Cm, Pb Concentration ranges:

• 0.5 mg/L (LD)  5 g/L (uncertainty 10%) • 5 g/L  20 g/L (qualitative mode)

Counting time: 800 s/sample

 Calibration : numerous standards required

Conclusion

Matrix effects correction:

- Sample analysis in organic medium by simulating matrix composition and application of the

correction (aqueous calibration used)

- Continuous feedback: comparaison with other analytical techniques results (large diversity of analyzed matrix)

K-edge (CEA) ID-TIMS (IAEA – OSL, Japan) Relative deviation K-edge/ID-TIMS

U (g/L) Pu (g/L) U (g/L) Pu (g/L) U Pu 284.5 163.0 283.62 163.56 0.31% -0.36% 61.0 35.2 60.89 35.11 0.15% 0.37% 143.7 82.5 142.18 81.99 1.06% 0.62% 179.7 103.5 180.01 103.58 -0.20% -0.09% 212.5 104.4 212.38 104.30 0.03% 0.05% 167.5 81.6 167.57 82.22 -0.04% -0.71% K -EDGE HKED

Standards (±2%) Experimental Relative deviation U (g/L) Pu (g/L) U/Pu (g/g) U by K-edge _(g/L) Pu by Hybrid _{XRF (g/L)} U Pu

22.8 4.58 5 23.2 4.61 1.6% 0.7% 75.1 5.01 15 75.6 5.02 0.7% 0.2% 150.0 1.50 100 149.3 1.47 0.5% 1.3% 20.0 0.11 181.6 19.6 0.11 -1.0% 0.0% 50.4 0.23 219.1 50.3 0.22 0.2% -4.3% 302.6 0.50 605.2 298.8 0.50 0.2% 0.0% 249.1 2.45 101.7 252.6* 2.52* 1.4% 2.9%

* Unsuitable blank spectrum

Deconvolution from « fingerprint » of monoelementary spectra Matrix effects correction Results Fluorescence spectrum Processing Sample medium description if different from calibration medium XCOM database Calibration array Fluorescence spectra of standards Passive spectrum (optional) Sample CEA Software Calibration process

Device special feature: graphite monochromator

 Available free or commercial software is unsuitable

 CEA software development with new approach for the matrix effects correction (~ Lachance-Traill)

More details in E. Esbelin, X-RAY Spectrometry 43, 198–208 (2014)

Smoothed spectrum in blue Fitted curve in red

Difference in green

Raw XRF spectrum of sample

Raw K-edge spectrum of sample

Example of automatic baseline definition and the peak search and integration

U

Pu

- Algorithms: automatic peaks find and integrate + automatic baseline

determination

- Improvement of law for relative calibration

- Fundamental parameters and Monte Carlo currently under study

Based on H. Ottmar and M. Collins’ works + possibility of manual edge determinations

 very useful for wide U/Pu range

Movable delimiting points

Example of multi-edge processing for height edge estimation

CEA Processing Software XRF module

CEA Processing Software K-edge module U and/or Pu result(s) Relative Calibration f(U,Pu)=g(SU,SPu) Pu or U result semi-empirical

calibration with matrix correction (Lachance-Traill type)

U and Pu results Other approaches under

study:

Fundamental Parameters, Monte-Carlo Sample fluorescence

spectrum

Sample absorption spectum and

X-ray tube intensity

Results: U, Pu + Am, Np, Cm ... Choice of a reference element U or Pu Theoretical model Determination of edge height(s) XCOM database Physical parameters of device: thickness of sample Blank sample absorption spectum

and

X-ray tube intensity Voltage setting of X-ray tube : 150 kV

Hybrid mode Peak areas SU and SPu Individual mode Spectrum processing Spectrum processing

Fluorescence spectra of mixed standards (U,Pu)

Calibration processes

Work in progress

Two

NON DESTRUCTIVE ANALYSIS

devices designed for high activity liquid samples

The analysis laboratory in the CEA Atalante facility at Marcoule (France) performs numerous R&D

studies carried out in glove-boxes or in hot cells. The samples are measured in liquid phase,

aqueous or organic.

The concentration of the main actinides of interest (U, Np, Pu, Am and Cm) are determined by XRF

in a hot cell using a device built specifically for these actinides analyses via their L-line X-ray

between 13 and 15 keV.

For sample with U and/or Pu in high concentrations, the hybrid K-edge densitometer is used.

New software were developed for these devices.

Minimization of χ2 =

𝜉=𝑒_𝑎

𝑒_b _I_mod,ξ _{C − I}_exp,ξ 2

σ_ξ2

I_exp,ξ : net intensity

σ_ξ2 : variance of the measured intensity

New a pp ro a c hes 𝛼 induced particule Internal conversion 𝑒𝑠𝑐𝑎𝑝𝑒 𝑝𝑒𝑎𝑘 𝑜𝑓 𝛾 𝑖𝑛 26.3 𝑘𝑒𝑉 𝛾 Am Origin : Internal conversion

Example of passive spectrum of 241_{Am standard (1 g/L)} X Photon L K M L K M X Photon L K M Auger Electron Primary Fluorescence L K M L K M Secondary Fluorescence w_f + w_a=1 Scattering Coherent Incoherent Other photons X photons Photoelectric Effect

Absorption

10 100 1 10 100 1000 17.2 keV 20.9 keV 21.8 keV L III LI L II L-edge [µ /  ] Total cm 2 g -1 Energy (keV) U K-edge 115.6 keV