r. pampin euratom/ukaea fusion association
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TW5-TSW-001&002 final meeting Culham Science Centre, October 2006. Study on recycling of fusion activated materials: Identify activation levels and decay time requirements of irradiated material (deliverable 3). R. Pampin EURATOM/UKAEA Fusion Association. Background. - PowerPoint PPT PresentationTRANSCRIPT
Study on recycling of fusion activated materials:Study on recycling of fusion activated materials:
Identify activation levels and decay time Identify activation levels and decay time requirements of irradiated materialrequirements of irradiated material
(deliverable 3)(deliverable 3)
R. PampinR. Pampin
EURATOM/UKAEA Fusion AssociationEURATOM/UKAEA Fusion Association
TW5-TSW-001&002 final meeting TW5-TSW-001&002 final meeting Culham Science Centre, October 2006Culham Science Centre, October 2006
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 2/17
BackgroundBackground
European Fusion Programme strategy for fusion irradiated waste:
Release from regulatory control 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Release criteria: out-of-date IAEA clearance levels (1996).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 final meeting, Culham Science Centre, October 2006 3/17
BackgroundBackground
IAEA 1996/2004 clearance levels: many changes affect fusion-relevant radionuclides (e.g. 30-fold decrease in Ni-63 level).
0
1
2
3
4
5
6
7
8
9
10
11
12
0 50 100 150 200 250mass number (A)
log
(200
4 le
vel)
-5
-4
-3
-2
-1
0
1
2
3
0 50 100 150 200 250mass number (A)
log
(200
4/19
96)
TW5-TSW-002 D1 report on implications, TW5-TSW-001 D3 report on specific effects on PPCS-AB.
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 4/17
BackgroundBackground
PPCS recycling criteria: some sensible for certain waste streams following certain routes (e.g. re-melting of steels); “complex recycling” limit is:
(a) noticeably over-conservative and
(b) uncertain: 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 final meeting, Culham Science Centre, October 2006 5/17
Scope and objectivesScope and objectives
To review and update PPCS work using:
Up-to-date international clearance levels: IAEA 2004.
Up-to-date nuclear data: EAF 2005.
Practical feasibility criteria: findings of this task.
More accurate modelling methodology (e.g. LiPb flow) and increased level of detail (e.g. TFC and breeder materials).
With the aim of:
Determining more realistic amounts and activation features of the material inventory.
Identifying interim decay times required during recycling.
Identifying potential for (a) reduction of waste, and (b) simplification of processes.
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 6/17
Material inventoryMaterial inventory
ID category PPCS model materials phase* 1a ferritic-martensitic steels AB, B RAFM eurofer operation and decommission 1b austenitic steels and alloys AB, B 316ss, incoloy decommission 2a tungsten-rich alloys AB, B armour, divertor plates operation and decommission 2b tungsten carbide AB WC decommission 3 lithium lead AB LiPb operation and decommission 4 ceramics B Be, Li4SiO4 operation and decommission 5 zirconium hydride B ZrH1.7 decommission 6 others AB, B epoxy-glass, SC cable decommission
PPCS-AB waste
0
20000
40000
60000
80000
100000
120000
140000
1a 1b 2a 2b 3 4 5 6 totalmaterial category
tonn
es
PPCS-AB operation
PPCS-AB decommission
PPCS-B waste
0
10000
20000
30000
40000
50000
60000
1a 1b 2a 2b 3 4 5 6 totalmaterial category
ton
ne
s
PPCS-B operation
PPCS-B decommission
PPCS-AB based on the HCLL blanket concept, PPCS-B based on the HCPB blanket concept.
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 7/17
Industry experienceIndustry experience
Distinction between recycling and refurbishment:
Refurbishment: little or no processing, on-site, immediate or early reuse in the fusion plant (e.g. LiPb, ceramics).
Recycling: greater processing, off-site, later reuse in the nuclear industry in general.
Recycling strategies in the industry exist for:
Very low activity: fabrication of simple components.
Very high activity: de-activation and re-fabrication of internals.
Recycling routes envisaged for all PPCS-AB and PPCS-B materials (TW5-TSW-001 B report).
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 8/17
clearance index 1specific activity Bq/kg (b+g) 400 4.0E+04 1.2E+07contact dose rate mSv/h 0.001 0.01 2 20 100 10000 1.0E+07decay heat rate W/m3 1 10 100 2000 10000 ????
IAEA-UK [1], [2], [3] NAW VLLW LLW ILW HLW
SEAFP, PPCS [4] NAW SRM CRM PDW
new proposal [5] NAW HOR shielded-HOR RHR
clearance yes no
handling [5] HOR shielded-HOR? increasing RH demands --------------------------------> hot cell limit
cooling [?] no cooling increasing cooling demands --------------------------> hot cell limit
transport [6] unshielded increasing shielding -------> special transport? transport limit
[1] IAEA Safety Standards Series, RS-G-1.7 (2004)[2] IAEA Safety Series 11-G-1.1 (1995)[3] C. Bayliss, Nuclear Decomissioning and Waste Management, UKAEA-Elsevier[4] M. Zucchetti et al., Fusion Engineering and Design[5] L. Ooms, TW5-TSW-001 D2 report[6] IAEA Safety Standards, TS-R-1 (2005)
Radiological levelsRadiological levels
Use radiological levels to ascertain storage times needed for the activity to decay to levels facilitating recycling processes:
Clearance: C.I.Lower RH needs: contact dose rate.Lower cooling needs: decay heat rate.Easier transport: ?
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 9/17
Computational tools and modelsComputational tools and models
1.E+08
1.E+09
1.E+10
1.E+11
1.E+12
1.E+13
1.E+14
1.E+15
1.E+16
1.E+17
1.E+18
1.E+19
1.E-08 1.E-07 1.E-06 1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02
energy (MeV)
flux
pe
r u
nit
leth
arg
y
TFC (IB)VVLTSHTSBLANKET BACKBLANKET FRONTBLANKET FWARMOUR
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 10/17
Results: clearanceResults: clearance
New IAEA levels increased amounts of material to be recycled: OB VV and IB TFC.
Time scales: few years OB, few decades IB.
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 final meeting, Culham Science Centre, October 2006 11/17
Results: refurbishmentResults: refurbishment
Refurbishment of LiPb is possible and reduces considerably the amount of operational waste (from 124000 to 97000 tonnes).
PPCS-B ceramic breeder and other materials also possible, but much lower impact strategic value?
PPCS-AB waste
0
20000
40000
60000
80000
100000
120000
140000
1a 1b 2a 2b 3 4 5 6 totalmaterial category
tonn
es
PPCS-AB operation
PPCS-AB decommission
PM-AB 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
1.E+02
0.1 1 10 100 1000time (y)
cont
act d
ose
rate
(Sv/
h)
54321
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 12/17
Results: recyclingResults: recycling
PPCS-AB results:
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 needed.
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 13/17
PM-AB 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
1.E+02
1.E+03
1.E+04
0.1 1 10 100 1000time (y)
cont
act d
ose
rate
(Sv/
h)
ppcs W 5 fpy
pure W 5 fpy
PM-AB contact dose rates - outboard
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
0.1 1 10 100 1000time (y)
cont
act d
ose
rate
(Sv/
h) ppcs lipb 30 fpy
pure Pb 30 fpy
Results: recycling - impurities Results: recycling - impurities
W and LiPb PPCS specifications contain many impurities: (a) manufacturer limits, (b) detection limits.
Co, Ni, Nb, Mo, Eu, Sm, Gd, Tb, Pt, Ir, Pb, U, Th, Bi, Ag, Cd, Ba, Tl, Co, Nb
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 14/17
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
1.E+02
1.E+03
0 1 10 100 1000time (y)
cont
act d
ose
rate
(Sv/
h) ppcs li4sio4pure li4sio4ppcs be
Results: recycling - impuritiesResults: recycling - impurities
PPCS-B results:
In-vessel: again, (nearly) 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:
Co, Ni, Nb, Mo, Eu, Sm, Gd, Tb, Pt, Ir, Pb, U, Th, Bi, Ag,
Cd, Ba, Tl, Co, Nb
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 15/17
Results: decay timesResults: decay times
component / constituent / material 104 mSv/h 100 mSv/h 2 mSv/h 0.01 mSv/h CI < 1
OB TFC / case rear / 316ss <1d <1d <1d <1d <1d
OB TFC / radial plates / 316ss <1d <1d <1d <1d <1d
OB TFC / case front / 316ss <1d <1d <1d 2y 45y
OB TFC / epoxy-glass / 316ss <1d <1d <1d <1d <1d
OB TFC / conduits / incoloy <1d <1d <1d <1d <1d
OB TFC / cable / SC strand <1d <1d <1d <1d <1d
OB VV / rear wall / 316ss <1d <1d <1d 10y 45y
OB VV / radial plates / 316ss <1d <1d 5y 50y >1000y
OB VV / front wall / 316ss <1d 25y 58y >1000y >1000y
OB LTS / structure / eurofer 180d 25y 50y >1000y >1000y
OB LTS / neutron shield / WC 10d 15y 55y >1000y >1000y
blanket / manifold / eurofer 15y 45y 80y >1000y >1000y
blanket / BZ / eurofer 10y 35y 70y >1000y >1000y
blanket / BZ / LiPb (5 fpy) 120d 15y 90y >1000y >1000y
blanket / BZ / LiPb (30 fpy) 120d 25y >1000y >1000y >1000y
blanket / FW / eurofer 15y 45y 80y >1000y >1000y
blanket / armour / W 5y 45y 500y >1000y >1000y
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 16/17
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/refurbishment/recycling potential and interim decay times.
Results:
new IAEA levels increase amount of material to recycle;
clearance is achieved within few years (OB) or few decades (IB);
most recycling material below 2 mSv/h after ~75y of decay;
are these acceptable time scales?
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 17/17
SummarySummary
Three key issues to optimise fusion recycling strategy by reducing amount of material, secondary wastes and/or radiological levels:
Segregation of materials
Refurbishment
Impurity control
Further work:
Shielding issues, particularly in PPCS-B
Transport requirements?
New categorisation?
Radioactivity build-up due to (a) impurities and (b) reuse.
www.fourmilab.ch/earthscr/
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 18/17
Fusion materials strategy – open
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 19/17
Fusion materials strategy – closed
TW5-TSW-001 final meeting, Culham Science Centre, October 2006 20/17
clearance index 1specific activity Bq/kg (b+g) 400 4.0E+04 1.2E+07contact dose rate mSv/h 0.001 0.01 2 20 100 10000 1.0E+07decay heat rate W/m3 1 10 100 2000 10000 ????
IAEA-UK [1], [2], [3] NAW VLLW LLW ILW HLW
SEAFP, PPCS [4] NAW SRM CRM PDW
new proposal [5] NAW HOR shielded-HOR RHR
clearance yes no
handling [5] HOR shielded-HOR? increasing RH demands --------------------------------> hot cell limit
cooling [?] no cooling increasing cooling demands --------------------------> hot cell limit
transport [6] unshielded increasing shielding -------> special transport? transport limit
[1] IAEA Safety Standards Series, RS-G-1.7 (2004)[2] IAEA Safety Series 11-G-1.1 (1995)[3] C. Bayliss, Nuclear Decomissioning and Waste Management, UKAEA-Elsevier[4] M. Zucchetti et al., Fusion Engineering and Design[5] L. Ooms, TW5-TSW-001 D2 report[6] IAEA Safety Standards, TS-R-1 (2005)
Fusion materials strategy: radiological levels and classification criteria?
– simple transport RHR – complex transport