Transcript A European Perspective on the Use of Eichrom Resins

A European Perspective on the
Use of Eichrom Resins
Dr Jon Martin
BNFL
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BNFL UK Sites
Hunterston A
Chapelcross
Wylfa
Maentwrog
Trawsfynydd
Hinkley Point A
Calder Hall
Sellafield
Risley HQ
Berkeley
Oldbury
Sizewell A
Bradwell
Littlebrook
Dungeness A
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An Overview (1992-1998)

Background

Initial use in emergency response planning.

Application to simple matrices.

A difficult problem - resolved with Ln.Resin.

Application to environmental matrices.

Accreditation for plant-support methods.

The broader picture.
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CRL Lab Overview
Central
Radiochemical
Laboratory
Environment
Liquid & Gaseous
Effluent
Magnox
AGR
Low Level Waste
Waste
Characterisation
Lab.
Decommissioning
Lab.
Intermediate
Level Waste
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Extraction Chromatography Application to Emergency Methods
“The aftermath of an accident is not a time to begin the
development of novel procedures”. N. Green, NRPB
• EEC Intervention Levels:
Material
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Limiting Activity Concentration
Sr-89/Sr-90
Pu-239, Am241, Cm-242/4
Dairy produce &
liquid foods (Bq/kg)
125
20
Others with t1/2 >10
days
(excl. H-3 / C-14
1000
Solid & Liquid
Foods (Bq/kg)
750
80
1250
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Sequential Emergency Procedure
Add radionuclide
spikes
Microwave digest
Anion exchange
column
Electrodeposit or
coppt Pu
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Sr, Am, Cm not
retained
Sr.Resin
Am, Cm fraction to
TRU.Resin
Sr-89/90
determination
Coppt Am / Cm
source
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Rapid Sr-89 / 90 Procedure
Elute from Sr.Resin in 8ml water
Cerenkov count (15min)
Sr-85 yield determination
Add Ultima Gold XR
Liquid scint. count
Calculation of Sr-89 & Sr-90 - Correction for Y-90
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Limitations
Merits

Sample size.

Large excess of Am-241 over
Screening of 80 samples &
Am-243 yield tracer.
analysis of 6.

Uranium breakthrough in Pu



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Batch size dominated by
Addresses required limits of
detection and accuracy.
spectrum.

<24 hour turnaround, incl.

Introduced the benefits of
microwave digestion.
extraction
Sampling uncertainty.
chromatography…
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Summary of routine
methodology…1
Analysis Classical separation Extraction
Comments
chromatography
Tritium
Distillation
C-14
Wet / dry oxidation
S-35
Wet oxidation and
chemical isolation and /
or cation exchange
C1-36
Chemical isolation
Ca-45
Chemical isolation
Mn-54
Chemical isolation
Fe-55
Solvent extraction
Ni-63
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Tritium.Resin investigated but
clean-up not sufficient for Magnox
effluent.
Sr.Resin + classical
chemistry
RE.Resin investigated
but little Mn-54 clean-up
Ni.Resin
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Summary of routine
methodology…2
Analysis
Classical
separation
Sr-90 / Sr89
Tc-99
I-129
Extraction
chromatography
Comments
Sr.Resin
Excepting large volume milk
samples
Low requirement
TEVA.Resin
Solvent extraction
ABEC.Resin
Pm-147
Sm-151
Pb-210
Ln.Resin
Po-210
Distillation or direct Sr.Resin
auto deposition
Extraction chromatography not
normally necessary
Sr.Resin
Ra-226
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Uranium /
Thorium
U/TEVA.Resin /
TEVA Resin
Transuranics
TEVA / TRU.
Resins
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Pm-147 / Sm-151
Analysis...Why?
Pm-147

Sm-151
High abundance in fresh fission
product mixtures.



Increasing importance in decayed
fission product mixtures.
Pure soft -active radionuclides.
Radiotoxicity comparable to that of carbon-14.
What yield tracer?
No suitable isotopic yield tracer.
 No naturally occuring isotope.

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No suitable isotopic yield tracer.
 Gravimetric yield determination
possible.

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Assessment of ‘Low Abundance’
Isotopes' compliance with de
minimis Criteria for Disposal
Radionuclide
Se-79
Y-91
Zr-93
Nb-93m
Tc-99
Pd-107
Sn-126
I-129
Cs-135
Sm-151
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Maximum Theorectical
Activity per Consignment
0.0075
10300
0.0047
0.029
0.37
0.002
0.28
0.00069
0.019
6.3
de minimis
13
13
13
13
13
13
13
0.05
13
13
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Pm-147 / Sm-151
Analysis...Interferences
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Eu-154 [8.59y, /g, 580 keV]........1.9
Eu-155 [4.85y, /g, 160 keV]........2.6
Sm-151 [88.7y, , 76 keV].....................0.31
Pm-147 [2.6y, , 225 keV].............................79
Pr-144 [285d, g, 2.996 keV]
Ce-144 [285d, , 318 keV]..........................................................23
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Abundance rel. to Cs-137 (%)
@ 5GWd/T, 4 years decayed
Ho-166m [1200y, ]
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Pm-147 Analysis...Yield tracers
Gd-148, a [3.27 MeV]
Natural Samarium
...natural a
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Natural Neodymium
...natural a
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Promethium147 by Eichrom’s Ln.Resin

Ln.Resin - not to be confused
with RE.Resin (of course!)

HDEPH:
bis(2-ethylhexyl)
phosphoric acid supported on
Amberchrom CG-71 at a
40%w/w loading.

Original work by Horwitz &
Bloomquist, J. Inorg. Nucl.
Chem. 17, 425 (1975).
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Pm-147 / Sm-151
Analysis...Gd-148 yield tracer
1.0
0.9
0.15 M nitric acid
0.25 M nitric acid
0.4 M nitric acid
Normalised count rate (Arb)
0.8
Eu
0.7
Am
Gd
0.6
0.5
Pm
0.4
0.3
0.2
0.1
0.0
0
10
20
30
40
50
60
70
Volume (cm 3)
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Pm-147 / Sm-151
Analysis...Natural Sm yield tracer
Normalised count rate / Sm concentration (Arb)
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
0
50
100
150
200
250
300
Volume (cm 3)
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Summary of Pm-147 / Sm –
151 Results
Sample
description
Pm-147 Result
Sm-151 Result
Ratio
FMDT liquid effluent
annual bulk (15/06/97)
698 + 49
mean of 4 results
9.28 + 2.83
75 + 24
AETP sludge
dissolution liquor – A
2.40 + 0.20
1.92 + 0.22
1.25 + 0.18
AETP sludge
dissolution liquor – B
1.35 + 0.15
0.949 + 0.099
1.42 + 0.22
ILW resin sample
(Lewatit DN)
18.3 + 1.4
13.0 + 1.0
1.41 + 0.15
LLW QC spiked
solution
(-2.8 + 10.8)%
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Benefits

Approximate 60% cost reduction per analysis through time savings
and larger batches.

Fully validated, accredited methods with comprehensive uncertainty
budgets.

Methods proven at national and international intercomparison
exercises.
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Environmental / Bioassay Matrices Overcoming the Interferences

Sr-90 in fish, urine, faecal ash.
3g Sr.Resin in column.

Pu / Am in soils.
 Anion exchange pre-clean-up.

Preliminary work on preconcentration of transuranics on
Diphonix, followed by Fenton’s
Reagent destruction of organics - see
work by Bill Burnett, FSU.
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Application of Eichrom technology
to other BNFL processes

Support to reprocessing: product quality and accountancy.

Tc-99 analysis - TEVA - various matrices.

Environmental monitoring programmes.
Application of Eichrom technology in
Europe
Mature processes which are broadly used in a wide range of applications.
PROCORAD - laboratories from >20 countries. Many used Eichrom
extractants.
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