Nuclear Plant Journal, July-August 2014 NuclearPlantJournal.com
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experienced employees from nuclear
sector suppliers at ENERGUS Convention
Center in West Cumbria, U. K. We were
supported in planning and conducting
the conference by Britain’s Energy
Coast Business Cluster. And we have
a Memorandum of Understanding in
place with engineering firms Costain,
Arup and Pöyry. In addition, we met
with several supply chain representatives
during an event in November 2011 at
the Church House Conference Center
in Westminster, London and we have
a memorandum of understanding with
National Nuclear Laboratory Ltd. (NNL)
and the University of Manchester for
expert technical input to the deployment
of PRISM. We continue to work with
potential UK suppliers for the project
and are committed to the greatest extent
possible to utilizing UK companies and
workers for this effort.
7.
What is the planned timeline for
design, construction and operation of
PRISM in the United Kingdom after
receiving the go-ahead?
While no formal commercial
contract arrangements have been
developed, we estimate the schedule for
the first irradiation of plutonium in a
PRISM reactor to be comparable to other
options. Licensing is always significant
for new nuclear plants because safety is
of the utmost importance, but multiple
reviews including one performed by the
U.S. NRC have concluded that there are
no fundamental impediments to PRISM
licensing. The technology is proven and
PRISM’s simplified reactor design should
speed construction.
PRISM represents a multi-billion
pound investment in the UK, regional
and local economy. This will be a
much needed boost to the UK business
community, particularly as the economy
continues to emerge out of recession.
Based upon preliminary investment plans
and current thinking, it is estimated that
the construction of a PRISM reactor
could create a peak of several thousand
jobs in the local economy, with 900 of
these being permanent operational jobs
at Sellafield. In addition to jobs directly
associated with the project and plant,
further jobs would be created in the local
economy, for example from suppliers to
the plant and in the local retail sector. The
engineering and research work to support
PRISM will undoubtedly have a direct
and significant impact on jobs and skills
in West Cumbria, bolstering the UK’s
nuclear research capability in many areas
pre and post-construction phase.
8.
When was the prototype for PRISM
tested to ensure its operation after
deployment?
The basis of PRISM technology
comes from the 30-year operation of EBR
II from 1964-1994. In addition, PRISM
leveraged the testing and demonstration
done during the Clinch River breeder
reactor program from 1972-1983 as well
as large component testing during the
Advanced Liquid Metal Reactor program
from 1984-1994. Many of these tests were
done at the U.S. Department of Energy’s
Energy Technology Engineering Center
in California.
9.
How
does
PRISM
coolant
temperature compare with ESBWR and
an ABWR under normal conditions and
under accident conditions?
The normal operating temperature for
sodium cooled reactors is about 500° Celsius
whereas the normal operating temperature
for water cooled reactors like the ESBWR
and ABWR is about 300° Celsius. In
addition, PRISM is designed to operate at
much lower pressure than either boiling or
pressurized water reactors.
10.
Describe the safety aspects of
PRISM reactor under a Beyond Design
Basis Event.
Various safety features of the PRISM
design are specifically intended to
prevent a loss of coolant accident. These
safety features make PRISM robust for
coping with beyond design basis events.
For example, PRISM is the only nuclear
facility designed to sit on seismic isolation
bearings. The seismic isolation system
reduces horizontal seismic accelerations
that are transmitted to the reactor module
by a factor of three. Another example
is that the control room, reactor plant
and steam plant are separated and don’t
impact each other. Yet another example
is that PRISM has the ability to remove
decay heat passively without any operator
action.
In the event of a worst-case-scenario
accident, the metallic core is designed to
expand as the temperature rises so that its
density decreases, thereby slowing the
fission reaction. The reactor simply shuts
itself down. PRISM’s very conductive
metal fuel and metal coolant then readily
dissipates excess heat without damaging
any of its components. Passive safety is a
design feature that relies upon the laws of
physics, instead of human, electronic or
mechanical intervention, to mitigate the
risk of an accident.
11.
Describe any other important
features.
The manufacture of PRISM metallic
fuel will incorporate more forgiving
dimensional tolerances than plutonium
oxide fuel. Because PRISM’s fuel can
accommodate a larger relative proportion
of plutonium than other reactor options
being considered by the UK, this is highly
likely to mean lower fuel manufacturing
cost, less fuel handling and less used
fuel to dispose. Plant electrical output is
designed to permit tailoring to operator
needs through the modular addition
of power blocks. This modularity is
expected to allow expansion from one
power block to as many as desired on one
side. Factory fabrication of the modules
is aimed at providing improved quality,
reduced cost and shortened construction
times.
Contact: Jon Allen, GE Hitachi
Nuclear, 3901 Castle Hayne Road,
Wilmington, North Carolina 28401;
telephone: (910) 819-2581, email:
.
PRISM Cutaway Illustration.
