ARN
Nuclear Regulatory Authority
Spent Fuel Management of NPPs
in Argentina
D.E. Alvarez and H.M. Lee Gonzales
International Conference on Management of Spent Fuel from Nuclear Power Reactors
31 May - 4 June 2010, Vienna Austria
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Spent Fuel Management of
NPPs in Argentina
Uses and applications of nuclear energy have begun in
Argentina in 1950, the year that the National Atomic Energy
Commission (CNEA) has been created
Wide variety of activities were performed in the nuclear field
Management of spent fuel and radioactive waste
Applying the legal and regulatory provisions in force
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Spent Fuel Management of
NPPs in Argentina
- National Congress Act Nº 24804 (1997)
to regulate the Nuclear Activity
Nuclear Regulatory Authority –ARN- (1997)
to regulate and supervise
the nuclear activity
- National Congress Act Nº 25018 (1998)
to determine the Radioactive Waste
Management Regime (Nat. Radioact.
Waste Management Prog. - CNEA -)
- Joint Convention on the Safety of Spent Fuel Management and on
the Safety of Radioactive Waste Management (2001)
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Spent Fuel Management of
NPPs in Argentina
Argentine Government
Nuclear Regulatory Authority
(ARN)
Ministry of Federal Planning,
Public Invest & Services
Secretary of Energy
National Atomic Energy Commission
(CNEA)
Nucleoeléctrica Argentina S. A.
(NA-SA)
NPPs
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Spent Fuel Management of
NPPs in Argentina
Government of Argentina exercises state ownership of special
radioactive fission material contained in spent fuels from any
origin: NPPs and experimental, research and/or production
reactors
According to the Strategic Plan, the decision to reuse fissile
material contained in spent fuel will be adopted before 2030
Meanwhile, the spent fuel generated by the NPP in Argentina is
being stored in interim storages (Primary Responsible NA-SA)
At decommissioning time, an appropriate transfer of Responsible
Entity will be needed and before that a decommissioning license
should be required by CNEA
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Spent Fuel Management of
NPPs in Argentina
EMBALSE NPP
PHWR - 648 MW
700 km from Buenos Aires
BUENOS
AIRES
ATUCHA I NPP
PHWR - 357 MW
112 km from Buenos Aires
ATUCHA II NPP under construction
PHWR - 692 MW
112 km from Buenos Aires
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Spent Fuel Management of
NPPs in Argentina
Atucha I NPP
CNA I is a PHWR (357 MWe) of
German origin which is in
operation since 1974
Former times: natural uranium
fuel (0.71%)
Between 1995 and 2000: fresh
fuel gradually modified from
natural to slightly enriched
uranium (0.85 % nominal)
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Spent Fuel Management of
NPPs in Argentina
Burnup
[MWd / tU]
Refueling
Natural uranium
~ 6.000
~ 1.29/day
SEU (0.85%)
~ 11.300
~ 0.72/day
Fuel element composed by 36 bars (+ 1),
active length of 5323 mm. Each bar
contains 442 UO2 pellets cladding in a
zircaloy-4 alloy tube with an external
diameter of 13.82 mm and 0.5 mm thick.
Fuel assembly (153.5 Kg of U) is very
slender, total length of 6028.5 mm,
external diameter of 107.8 mm and a
weight of approx. 200 kg. Total number of
fuel elements in the reactor core is 252
Atucha I NPP
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Spent Fuel Management of
NPPs in Argentina
Spent fuel is stored temporarily under water
hanging vertically in stainless steel racks
Atucha I NPP
two Pool Buildings
maneuvering pool
+
two decay pools
completed full
3240 FE
maneuvering pool
+
four decay pools
initial capacity: 6944 FE positions
compact arrangement:
storing capacity of 8304 FE
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Spent Fuel Management of
NPPs in Argentina
Atucha I NPP
With a load factor of 85%, the arrangement will satisfy the
storage demand up to 2015. But the end of the design of life of
the Plant would be reached in 2017: it will be required to arrange
a minimum of 620 free positions inside of the spent fuel facility
+
A decision about life extension or decommissioning
should be taken in the near future
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Spent Fuel Management of
NPPs in Argentina
Atucha I NPP
Implementation of a dry storage seems to be the best solution
to cover necessities to create additional capacity for:
• Storing the spent fuel (extension of life) or
• To transfer all the spent fuel out of the NPP in the case
of decommission
A simplified conceptual design of a dry storage is under
development: underground vertical silos placed in a new
building annexed to one of the Pool Buildings
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Spent Fuel Management of
NPPs in Argentina
Atucha II NPP
CNA II is a PHWR similar to CNA I. Start operation in 2011. Spent fuel will
be storaged under water untill a dry storage alternative will be defined
Pool Building
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Spent Fuel Management of
NPPs in Argentina
Embalse NPP
CNE reactor is a typical
CANDU 6 (648 MWe) on
load PHWR that is in
operation in Argentina
since 1984
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Spent Fuel Management of
NPPs in Argentina
Embalse NPP
Fuel bundles are composed by
37 bars of 495.3 mm length.
Each bar, containing 38 UO2
pellets (natural uranium), is
cladding in a zircaloy-4 alloy
tube. Fuel assembly has an
external diameter of 102.74 mm
and 22 Kg of UO2
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Spent Fuel Management of
NPPs in Argentina
Embalse NPP
“Calandria”
has
380
horizontal pressure tubes
/channels with a capacity of
4560 fuel bundles (12 per
channel)
Refueling frequency at full
power is 15.2 fuel bundles
per day, maximum burn up
7800 MWd/tU
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Spent Fuel Management of
NPPs in Argentina
Embalse NPP
Leaving the core, the spent fuel
bundles are transfered underwater to
the reception bay (capacity: 4800
bundles).
They
are
disposed
horizontally on trays of a double array
of 12 bundles each one which are
transfered to the storage bay and
stocked in piles (capacity for 45144
spent fuel bundles, it means 10 years
at maximum power)
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Spent Fuel Management of
NPPs in Argentina
Embalse NPP
A dry storage alternative was
implemented in 1993 to cope with
the spent fuel storage demand up
to the end of the operative life of
CNE. Spent fuel bundles remain
at least 6 years in the wet storage
for
thermal
cooling
and
radioactive decay after being
transfer to the dry storage:
concrete “canisters” arranged in
a yard at the power station site.
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Spent Fuel Management of
NPPs in Argentina
Embalse NPP
Each full loaded canister contains 9 steel sealed
piled baskets, each one with 60 bundles
Canisters are 6.3 m high vertical cylinders and
approx. 3 m external diameter. Cooled by natural
convection, were designed to support some
accidental events as earthquakes, floods,
tornadoes and the risk of explosions
No especial activities of maintenance are
necessary when the canisters are filled and
sealed. At present, there are 152 full loaded silos
from 216
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Spent Fuel Management of
NPPs in Argentina
Embalse NPP
Canisters yard is inside a double
fence which surrounded the NPP
for security protection
CNE was designed with a 30
years nominal life (load factor of
80%). Due load factor = 88% in
the last 10 years, the plant design
life will be reached in 2011. Life
extension project is under
development
The modular design of the dry storage allows to be enlarged, with no
fulfillment of special requirements
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Spent Fuel Management of
NPPs in Argentina
Conclusions
A decision about the fuel cycle back-end strategy will be taken before
2030. It is important to mention that, recently, the National Supreme
Court has been issued on a cause related with a possible entry to the
Country of the spent fuel from an Australian reactor constructed by
an Argentine enterprise, based on the fact that spent fuel is not
radioactive waste
Meanwhile, the spent fuel in each Nuclear Plant is temporarily storage
on site. In Atucha I, the spent fuel is being storage in pools but a dry
storage design is under development. Embalse counts with a dry
storage since 1993; the spent fuel, after certain period of time kept in
wet storage, is transferred to dry storage silos. Enlargement of the
spent fuel interim storage capacity at CNE is made easily through the
construction of new modules of dry storage silos
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Spent Fuel Management of
NPPs in Argentina
Conclusions (cont.)
The management of the spent fuel, during the operation life of the
Nuclear Power Plants, is a responsibility of the operator (NA-SA)
and at the time of decommissioning the responsibility will be of the
Responsible Organization (CNEA). A reasonable time before that
moment both Entities must come to make the appropriate transfer
agreements as well as CNEA should start the decommissioning
license procedure
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Spent Fuel Management of
NPPs in Argentina
THANK YOU FOR
YOUR ATTENTION
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