View
221
Download
1
Category
Preview:
Citation preview
Back End – Spent Nuclear Fuel
Management in Germany
S. Geupel, K. Hummelsheim, W. Mester
Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH,
Germany
IAEA TM on Lessons Learned in Spent Fuel Management,
Vienna, 8 – 10 July 2014
German policy for spent fuel management
Concept and current status of spent fuel storage in Germany
Recycling of Plutonium and Uranium from reprocessing
Interdependencies with the disposal concept
2
Outline of the presentation
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
Dry storage before direct disposal in deep geological formations
Two centralised facilities for dry storage commissioned in the 1980s
(Gorleben, Ahaus)
Transportation of spent fuel from power reactors to foreign reprocessing
plants (La Hague, Sellafield) is prohibited since July 2005 (revision of
the Atomic Energy Act in 2002)
On-site dry storage facilities built at all NPP sites with existing spent fuel
inventories (except Obrigheim) since 2002
3
The German policy for spent fuel management
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
Dry spent fuel storage facilities in Germany
4
12 On-site storage facilities
in operation
(since 2002 – 2007)
1 On-site storage facility
applied for (2005)
3 Central storage facilities
in operation
(since 1992, 1995, 1999)
1 Local storage facility
at research center
in operation (since 1993)
License
expires
after
40 years
License
expired
since
July 2013
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014 4
5
German concept for dry storage
Accident-safe dual purpose metal casks for storage
and transport with
two independent sealed barrier lids
permanent monitoring for leak-tightness
vacuum dried and helium filled cask interior
type B(U) certification
Casks emplaced in a storage building for additional
radiation shielding and weather protection
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
Operating licenses for centralised and on-site storage facilities are
generally limited to a period of 40 years, starting with the
emplacement of the first cask
Limitation relies on administrative reasons (anticipated startup of
a disposal facility for spent fuel and heat-generating waste), not on
the technical lifetime of the casks or the storage building
Pending site selection process for a disposal facility increases the
probability that an extension of the licensed storage period beyond
40 years will be needed
Stored casks have to be transportable at any time during storage
Design approval certificates for transport of casks are valid only for
periods of 3, 5 or 10 years
Aspects of licensing
6 IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
16 Licenses for dry spent fuel storage facilities
1000 transport and storage casks with B(U) type approval emplaced
~ 650 to 700 casks for spent fuel are additionally needed
16 different cask types approved for spent fuel from power reactors,
research reactors and vitrified HAW from reprocessing
Cumulated amount of spent fuel generated until decommissioning of
all German NPPs (end of 2022): approximately 17,200 t HM, of which
Current status of spent fuel storage in Germany
7
~ 10,500 t HM are to be disposed of in a repository
~ 6,250 t HM were reprocessed, producing ~ 1,900 t heat-generating
waste to be disposed of in a repository
~ 350 t HM were disposed of via other pathways
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
8
8 NPPs were permanently shut down in 2011, awaiting
decommissioning and dismantling
Irradiated fuel has to be unloaded from the core and stored
Demand of 190 casks shortly for shutdown NPPs
Loading of 40 casks per year
Maximum enrichment of UO2 fuel between 4.0 and 4.7 % U-235
Several fuel elements irradiated only 11 to 300 full load days
Cask approval for special cases
Consequences in Germany from Fukushima accident
Some cask licenses require a minimum of burnup to ensure sub-criticality
Damaged fuel is not allowed in casks (due to corrosion, H2 generation)
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
German spent fuel for reprocessing
shipped to
9
37 t Pu-fiss
286 casks HAW + MAW
Urep
Spent fuel shipped for
reprocessing until 2005
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
Recycling of Plutonium as Mixed Oxide (MOX) fuel
10
Plutonium recycling as MOX carried out since 1966
Licensed in 12 German NPPs (light water reactors), actually used
in 5 operating NPPs
In the past also applied in German prototype reactors
Burning ~ 28% of Plutonium by use of MOX fuel
All Plutonium from reprocessing will be recycled until 2016,
currently 96% reached
Approximately 37 t fissile Plutonium in 2700 MOX fuel elements
recycled
Limited number of positions in dual purpose casks for spent MOX
fuel elements available
Cask approval with more MOX positions
Recycling of Plutonium as Mixed Oxide (MOX) fuel
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
11
Beside Plutonium, also Uranium is partly recycled
ERU fuel is used in 3 operating NPP (1800 fuel elements)
Enrichment up to 4.6% U-235
Burnup up to 60 GWd / tHM
No distinction is made between UO2 and ERU for spent fuel storage
in casks
Recycling of Enriched Reprocessed Uranium (ERU)
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
12
Stress test for German spent fuel storage facilities
after Fukushima accident (1)
The German Nuclear Waste Management Commission (ESK) was
asked by advisory request by the Federal Ministry of Environment,
Nature Conservation and Nuclear Safety (BMU) to carry out a stress
test for all 4 centralised and 12 on-site storage facilities for spent fuel
The stress test should assess the robustness of spent fuel storage
facilities regarding beyond design basis accidents
Security measures are not addressed by the stress test
Assessment of the stress test was performed by the ESK with
technical support by external experts
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
13
Load cases that have been assessed:
Results of the stress test were published by the ESK in March 2013
http://www.entsorgungskommission.de/englisch/downloads/eskstress
testteil114032013revenhp.pdf
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
1 Earthquakes
2 Flooding
3 Heavy rain
4 Other weather-related events
5 Loss of electrical power
6 Internal fires
7 External fires
8 Aircraft crashes
9 Blast waves
Stress test for German spent fuel storage facilities
after Fukushima accident (2)
14
The analyses and assessments carried out by the ESK have shown
that the storage facilities for spent fuel and heat-generating waste
comply with the highest stress levels and reach the highest degree
of protection for almost all load cases
The design of the transport and storage casks ensures compliance
with the general protection goals during storage and also ensures
that even in case of beyond design basis accidents, no major
disaster control measures are required
For none of the facilities considered in the stress test, a failure of
components or measures due to the postulated beyond design load
cases that may lead to a sudden rise of the radiological effects
outside the facility is to be feared
No deficiencies in the design requirements of the facilities have
become apparent in the stress test
Results of the stress test
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
15
Milestones from storage to disposal
Exploration of Gorleben salt dome suspended
Preliminary safety analysis of the Gorleben site finished
Approval of the Site Selection Act by the German Parliament
Commission ‘Disposal of high active waste’ will prepare basic
principles for decision making with regard to
safety requirements, methodology for safety assessment
general and host-rock specific selection and exclusion criteria
participation of the public
Aboveground exploration of up to 5 sites
Underground exploration of up to 2 sites
Final decision for a repository site
Licensing procedure for the construction, operation and closure
of the repository
Commissioning of the repository
End of 2012
March 2013
July 2013
Mid of 2014 –
Mid of 2016
2016 – 2023
2024 – 2031
End of 2031
2032 – ???
???
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
16
Site Selection Act for a repository for spent fuel
and heat-generating radioactive waste
Main objective: Selection of a disposal site until 2031
Key provisions:
New site selection procedure starting with a blank map of Germany without
any site proposals
Site selection based on scientific criteria and the highest safety standards
No premature decisions by excluding individual sites
Fundamental decisions to be taken by the German Parliament
Transparency and public participation in all phases of the stepwise
procedure in order to reach a decision based on broad consensus
Projected costs until finishing the site selection procedure:
ca. 2 Billion Euros (to be paid by the waste producers)
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
Key issues being relevant for
the site selection process will be
evaluated by the Commission
‘Disposal of high active waste’
Drift emplacement
of spent fuel in
thick-walled casks
(POLLUX or CASTOR)
Borehole emplacement
of spent fuel in canisters
(BSK 3)
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
German disposal concepts for spent fuel
pursued as reference and alternative concepts for the disposal of spent fuel in a salt formation
until commencement of the Site Selection Act in 2013
17
18
German container concepts for spent fuel disposal
POLLUX
self-shielding, thick-walled
POLLUX cask
Reference Concept Alternative Concepts
On-site storage in
Conditioning after
intermediate storage
Reloading
Transfer to disposal
Emplacement in
Current status
non-shielding
BSK 3 canister
CASTOR V/19 casks (PWR fuel)
CASTOR V/52 casks (BWR fuel)
BSK 3
Drift Borehole
Transfer cask
Disassembling of
spent fuel assemblies
Aboveground testing finished in
2000, basis for repository layout
Aboveground testing
finished in 2009
DIREGT
Borehole
CASTOR V/19
CASTOR V/52
Whole spent fuel
assemblies
Feasibility studies
ongoing
IAEA TM on Lessons Learned in Spent Fuel Management, Vienna, 8-10 July 2014
TM on Lessons Learned in Spent Fuel Management, IAEA 8-10 July 2014 19
Potentially suitable host rock formations
for a geologic repository in Germany
Exploration mine Gorleben
Recommended