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Spent Fuel Management:
Current Situation in Germany
Konrad Linnemann
Uwe Herbrich
Frank Wille
Holger Völzke
BAM Federal Institute for Material Research and Testing
IAEA Technical Meeting
“Lessons Learned in Spent Fuel Management”
IAEA Headquarter
Vienna, Austria
08.-10.07.2014
Outline
� Spent fuel situation in Germany
o Phase out decision
o Estimated amount of spent fuel assemblies
o Dual purpose casks
o Extended storage periods
� Spent fuel issues for transport and storage
o Protection goals and requirements
o Fuel rod behavior and assumptions in
− Criticality safety analysis
− Containment assessment
o High burn-up fuel
o Experimental testing
� R & D
� Conclusions
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 2
Spent fuel situation in Germany
Phase out decision in 2011
Until 2011: 17 NPPs (11 PWR + 6 BWR)
Since 2011: 9 NPPs (7 PWR + 2 BWR)
2022: Shut-down of last NPP
Accumulated spent fuel until 31.12.2012:
8,000 Mg HM (+ 6,700 Mg HAW) 53,100 fuel assemblies
Additional:
2,500 Mg HM 6,900 fuel assemblies
Total at 31.12.2022:
10,500 Mg HM (+ 6,700 Mg HAW) 60,000 fuel assemblies
1,000 dual purpose casks in use
5001600 additional dual purpose casks needed
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 3
Spent fuel situation in Germany
Dry storage concept for spent fuel
� According to Recommendations of German
Waste Management Commission in 2013
� Accident safe dual purpose transport and
storage casks
� Double barrier lid system
� Barrier system permanently monitored
� Valid Type B(U) approval required at
storage placement
o Permanent transportability
� Storage license limited up to 40 years
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 4
© GNS
Spent fuel situation in Germany
Perspectives
Expiration of some interim storage licenses:
Jülich 30.06.2013 !
Gorleben: 31.12.2034
12 on-site storage facilities: 2042/43
Timeline based on Site Selection Law for Disposal:
Extended storage period will be required!
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 5
2016
Site selection
procedure
2023
Site selection for
underground
exploration
2031
Final site
selection
Licensing procedure and
repository construction15 1 20 years
≈ 2050Operation phase
≈ 30 years
(50 casks per year)
2034 2042/2043
Expiration of
interim storage
licenses
At least 40 years
extended interim
storage
≈ 2080
(After only 20 years, transport in preparation)
Spent fuel situation in Germany
Dual-purpose casks
� GNS CASTOR
� AREVA TN International
� Storage and transport of high burn-up fuel
possible (up to 65 GWd/tU)
� What are the spent fuel issues assessed
by BAM?
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 6
© GNS
Spent fuel issues for storage licensing
Protection goals
� Confinement of radioactive material
� Stable removal of decay heat
� Maintenance of subcriticality
� Avoidance of unnecessary radiation exposure
Requirements for spent fuel
� Fuel assembly without defects or encapsulation of defective fuel
� Prevent systematic cladding failure
o Limitation of cladding tube corrosion
o Compliance of valid stress/strain
(according to Recommendations of German Waste Management Commission in 2013)
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 7
Spent fuel issues for transport licensing
Regulatory transport conditions (IAEA test scenarios)
� Routine conditions of transport
o Regular transport
o No incidents
� Normal and accident conditions of
transport
o Impact loads of drop tests
o Thermal load of fire test
o Examples:
− 0.3 m drop onto unyielding target
− 9 m free drop onto unyielding target
+ 1 m puncture drop
+ 30 minutes fire at 800 °C
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 8
Spent fuel issues for transport licensing
Interface for criticality safety analysis
� Influence on criticality safety(accident conditions of transport)
o Deformation of fuel assembly
(distances between fuel rods)
o Fuel rod breakage
� evaluation of critical mass of fissile material in cavity
� Limited data
� simplified enveloping approach necessary
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 9
Spent fuel issues for transport licensing
Interface for criticality safety analysis (cont’d)
� Assessment by BAM based on:
o Deformation state � fracture points
of fuel assembly
o Amount of released fissile material
per fuel assembly
� Total amount of released fuel in cavity
� Input for criticality safety analysis
(BfS, Federal Office for Radiation Protection)
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 10
Source: Papaioannou et al:
Jahrestagung Kerntechnik,
12-14 Mai (2009)
Spent fuel issues for transport licensing
Activity release calculation
� Maximum loss of radioactive contents
specified in transport regulations (SSR-6)
� Fuel rod failure and activity release (normal and accident conditions of transport)
� Cladding breaches lead to:
o Activity release into cask cavity (gas, volatiles, fine fuel particles)
o Increase of cask internal pressure
� Assumption of Failure rates
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 11
Fuel rod section
release of:
- fission gas
- volatiles
- fine fuel
particles
fuel
pellets
cladding
cladding
breaches
plenum
Spent fuel issues for transport licensing
Activity release calculation (cont’d)
� Failure rates of fuel rods
o Normal conditions of transport (e.g. 0.3 m drop)
− 3 % for burn-up ≤ 55 GWd/tU (based on NUREG/CR-6487 report)
− 100 % for burn-up ≤ 65 GWd/tU
o Accident conditions of transport (e.g. 9 m drop)
− 100 % for all burn-up (based on NUREG/CR-6487 report)
� Amount of released fissile products in cavity
� Containment analysis based on standard leakage rate
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 12
R & D
� Long-term performance tests for extended storage at BAM
o Metal seal relaxation and creep
o Leakage rate measurement concerning:
− Elastomer auxiliary seal degradation
− Helium contamination
o Degradation of polymer components for neutron shielding
� Investigation of spent fuel assemblies in cooperation with:
o Sandia National Labs (Albuquerque, USA)
o Institute for Transuranium Elements (Karlsruhe, Germany)
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 13
Conclusions
� Phase-out decision and complete restart of repository siting
procedure in Germany
o Storage period of more than 40 years will be expected
� Dual purpose casks in Germany
o Valid Type B(U) approval required at storage placement
� Spent fuel issues for transport and storage
o General storage requirements
o Criticality safety analysis
o Containment assessment
o Limited data of fuel behavior
� R&D
BAM 3.3 Linnemann IAEA Technical Meeting 08.-10.07.2014 14
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