POWER December 2012 - 76

NUCLEAR FUEL
ance. The MFFF will produce upwards of
70,000 pellets each day.
The fuel rods are then assembled in gloveboxes
by arranging the pellets in a long tray
and inserting the pellets into a zirconium alloy
tube (the fuel rod), loaded to an adjusted pellet
column length, pressurized with helium,
welded, and then decontaminated. Each fuel
rod contains approximately 360 pellets. The decontaminated
rods are then removed from the
gloveboxes and placed on racks for inspection.
In the final step, fuel assemblies are
manufactured by inserting the individual
rods into a metallic structure referred to as
the fuel assembly skeleton. A typical MOX
PWR fuel assembly contains 264 fuel rods
in a 17 x 17 array, is 13 feet in length, and
weighs about 1,500 pounds. Each MOX
fuel assembly is subjected to a final inspection
prior to storage and shipment.
The MOX fuel fabrication facility will
have the flexibility to produce fuel for
PWRs and BWRs as well as for the newgeneration
reactors.
Fresh MOX fuel assemblies will be
stored in the assembly storage vault. The
assemblies will be transferred to the shipping
and receiving area and loaded into an
NRC-approved MOX transportation package
and then loaded onto a secure transport
vehicle for shipment to a commercial
nuclear reactor.
Using Recycled Fuel
There are two types of fuel for nuclear
plants: uranium oxide (the most common)
and MOX, a mixture of uranium and plutonium.
Plutonium has more available energy
than uranium-analogous to adding a gallon
or two of premium gasoline to a car's
tank of regular fuel (see sidebar).
In the U.S., there was substantial development
work on MOX fuel technology in
the 1960s and 1970s. That work culminated
in a series of MOX fuel demonstration
programs at five reactors: the San Onofre
and Ginna PWRs and the Dresden, Quad
Cities, and Big Rock Point BWRs. In each
development and deployment of U.S. MOX
fuel technology. A more detailed history of
U.S. attempts at reprocessing and recycling
used fuel can be found in the August 2008
article, " How to Solve the Used Nuclear
Fuel Storage Problem, " available at www
.powermag.com.
Other countries continued their largescale
development and reprocessing of
spent fuel. In the early 1980s, nuclear reactors
in Germany began using substanThere
are two types of fuel for
nuclear plants: uranium oxide
(the most common) and MOX, a
mixture of uranium and plutonium.
program, lead test assemblies were used to
study the performance of MOX fuel rods.
After several operating cycles, the MOX
fuel had performed acceptably and similar
to the co-resident uranium fuel.
The U.S. nuclear industry was poised
to begin large-scale reprocessing of spent
nuclear fuel and associated re-use of the
separated RG plutonium. However, fearing
worldwide nonproliferation consequences
of separating large quantities of plutonium,
the U.S. government decided against reprocessing
spent nuclear fuel and stopped the
tial quantities of reprocessed plutonium
in the form of MOX fuel. Other European
reactors followed in France, Belgium,
and Switzerland. International safeguards
implemented in the MOX fabrication process
have ensured that no proliferation
has occurred from this process for nearly
40 years.
The MELOX facility in France has been
operating since the mid-1990s and produces
nearly all the commercial MOX fuel
assemblies in the world. In fact, MELOX
increased production in April 2007 to keep
2. Pair of processes. The MFFF will house two main process operations: aqueous polishing and the MOX process. Source: Shaw AREVA
MOX Services LLC
Aqueous polishing
PuO2
Dissolution
Ga, Am, U
impurities
Purification
cycle
MOX Process
PuO2
conversion
Polished
PuO2
Powder master
blend & final blend
production
Pellet
production
Rod
production
Fuel rod
assembling
MOX fuel
assemblies
December 2012 | POWER
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