r pampin , r bestwick euratom/ukaea fusion association amec-nnc ltd
DESCRIPTION
TW5-TSW-001 monitoring meeting CEN-SCK Mol, June 2006. Study on recycling of fusion activated materials: Identify activation levels, characteristics and decay time requirements of irradiated material (deliverable 3). R Pampin , R Bestwick EURATOM/UKAEA Fusion Association AMEC-NNC Ltd. - PowerPoint PPT PresentationTRANSCRIPT
Study on recycling of fusion activated materials:Study on recycling of fusion activated materials:
Identify activation levels, characteristics and Identify activation levels, characteristics and decay time requirements of irradiated materialdecay time requirements of irradiated material
(deliverable 3)(deliverable 3)
R PampinR Pampin, R Bestwick, R Bestwick
EURATOM/UKAEA Fusion AssociationEURATOM/UKAEA Fusion Association
AMEC-NNC LtdAMEC-NNC Ltd
TW5-TSW-001 monitoring meeting TW5-TSW-001 monitoring meeting CEN-SCK Mol, June 2006CEN-SCK Mol, June 2006
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 2/13
BackgroundBackground
European Fusion Programme strategy for fusion irradiated waste:
Release from regulatory control of mildly activated material, usually lifetime, bulky, outer components: TFC, VV, LTS
Recycle within the nuclear industry (fission/fusion) the rest
PPCS radioactive waste results: all material cleared/recycled within 100 years, but:
Release criteria: out-of-date IAEA clearance levels (1996)
Lack of detail in the models (e.g. outer components)
Inadequate modelling of particular materials (e.g. LiPb)
Recycling criteria based on radiological parameters only, which were imprecise and over-conservative.
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 3/13
BackgroundBackground
PPCS recycling criteria: some sensible for certain waste streams following certain routes (e.g. re-melting of steels); “complex recycling” limit is crucial but:
(a) noticeably over-conservative and
(b) depends on route followed!!
waste categorisation criteria contact dose (mSv/h)
decay heat (W/m3)
CI
Permanent disposal (PDW) > 20 > 10
Complex recycling (CRM) 2 – 20 1 – 10
Simple recycling (SRM):
remote
hands-on
< 2
< 10-2
< 1
< 1
Clearance < 1
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 4/13
BackgroundBackground
IAEA 1996/2004 clearance levels: many changes affect fusion-relevant radionuclides (e.g. 30-fold decrease in Ni-63 level).
-5
-4
-3
-2
-1
0
1
2
3
0 50 100 150 200 250mass number (A)
log
(200
4/1
996
)
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 5/13
Scope and objectivesScope and objectives
To review and update PPCS work using:
Up-to-date international clearance regulations: IAEA 2004
Up-to-date nuclear data: EAF 2005.
Practical recycling criteria: findings of this task.
More accurate modelling methodology (e.g. LiPb flow) and increased level of detail (e.g. TFC materials).
With the aim of:
Determining more realistic amounts and description of waste according to actual processing routes.
Identifying interim decay times required before recycling.
Identifying potential for (a) reduction of waste, and (b) simplification of recycling processes.
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 6/13
Computational tools and modelsComputational tools and models
HERCULES code automates 2D geometry + material modelling of tokamak power plants, coupling:
MCNP neutron transport FISPACT transmutation + EAF libraries
W armour
vessel TF coil
breeder zone
manifold
LT shield
HT shield
Fusion Power Plant internal componentsFusion Power Plant internal components
PPCS-AB HERCULES model.
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 7/13
Computational tools and modelsComputational tools and models
187 165
143
209 121
231
99
253
275 77
297
319 55
341 33
11
vessel TF coilneutron penetration - outboard
100001000001E+061E+071E+081E+091E+101E+111E+121E+131E+141E+151E+161E+171E+181E+191E+20
0 1 2 3 4 5 6
radial distance from PF surface (m)
ne
utr
on
flu
x (n
/m2
s)
(a)(b)(c) (d) (e) (f)
(a) VV front casing 316ss
(b) VV radial plates 316ss
(c) VV rear casing 316ss
(d) TFC front casing 316ss
(e) TFC winding pack 316ss, SC cable, incoloy, epoxy
(f) TFC rear casing 316ss
a b c d e f
PPCS
PPCS
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 8/13
Preliminary resultsPreliminary results
New IAEA levels increased amounts of material to be recycled: OB VV and IB TFC.
Segregation alleviates this.
PM-AB clearance index - outboard
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
1.E+08
0.1 1 10 100 1000time (y)
clea
ranc
e in
dex
TFC 2004
TFC 1996
VV 2004
VV 1996
LTS 2004
LTS 1996
0
5000
10000
15000
20000
25000
30000
TFC OB TFC IB VV OB VV IB total
IAEA 1996
IAEA 2004
IAEA 2004 with segregation
PM-AB clearance index (2004) - inboard
1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
0.1 1 10 100 1000time (y)
clea
ranc
e in
dex
TFC 316ss frontTFC 316ss midTFC 316ss backTFC cableTFC incoloyTFC epoxyaverage
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 9/13
Preliminary resultsPreliminary results
Cooling times of PPCS-AB and PPCS-B individual constituents and materials and average components; in preparation.
PPCS-AB IB TFC 2 mSv/h 0.01 mSv/h
rear case < 1y < 1y
rad plates < 1y 25y
front case 1y 45y
SC strand < 1y 10y
incoloy <1y 35y
epoxy-glass < 1y < 1y
average < 1y 30y
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 10/13
Preliminary resultsPreliminary results
PPCS-AB results (general):
Ex-vessel: most materials, individually or as TFC, VV and LTS, show contact dose rates < 2 mSv/h (earlier OB than IB).
Ex-vessel: many of these show < 0.01 mSv/h after suitable decay time (few years OB, several decades IB).
In-vessel: poloidal variation is negligible.
In-vessel: all Eurofer and LTS neutron shield (WC) show contact dose rates < 2 mSv/h after ~75 years.
In-vessel: LiPb breeder and W armour still exceed 2 mSv/h after 100 years:
Dominant nuclides arise from Pb and W isotopes, hence impurity control not very useful in this case! isotopic separation seems imperative reuse in fusion plant?
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 11/13
PM-AB contact dose rates - outboard
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
0 1 10 100 1000time (y)
cont
act
dose
rat
e (S
v/h)
1 cycle LiPb5 cycles LiPbpure Pb
Preliminary resultsPreliminary results
PPCS-AB results: W and LiPb PPCS specifications contain many impurities: (a) manufacturer limits, (b) detection limits.
PM-AB contact dose rates - outboard
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
0 1 10 100 1000time (y)
cont
act
dose
rat
e (S
v/h)
ppcs w 5 FPY
ppcs w 1 FPY
pure w 5 FPY
Co, Ni, Nb, Mo, Eu, Sm, Gd, Tb, Pt, Ir, Pb, U, Th, Bi, Ag, Cd, Ba, Tl, Co, Nb
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 12/13
Preliminary resultsPreliminary results
PPCS-B results (general):
In-vessel: again, all Eurofer and LTS neutron shield (ZrH) show < 2 mSv/h in ~75 years.
In-vessel: Li4SiO4, Be and W armour, however, do not meet this target Li4SiO4 and Be dose entirely due to impurities:
control of these would meet target
PMB contact dose rates - outboard
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
0 1 10 100 1000time (y)
cont
act
dose
rat
e (S
v/h)
ppcs li4sio4pure li4sio4ppcs bepure be
Co, Ni, Nb, Mo, Eu, Sm, Gd, Tb, Pt, Ir, Pb, U, Th, Bi, Ag,
Cd, Ba, Tl, Co, Nb
TW5-TSW-001 monitoring meeting, CEN-SCK Mol, Belgium, June 2006 13/13
SummarySummary
Upgrading PPCS work on PPCS-AB and PPCS-B radioactive waste analysis using recent regulations, new nuclear data, improved modelling and realistic recycling scenarios.
Assess clearance/recycling potential and interim decay times.
Results:
new IAEA levels increase amount of material to recycle.
PPCS analyses over-conservative: most material suitable for “simple-recycling” after < 75y cooling time.
control of impurities crucial, not only in steels but also for e.g. Be and Li4SiO4: requirements being developed.
Further input: definition of “non-simple” recycling routes and radiological criteria.
Draft report & radiological data available shortly