POWER August 2015 - 8

More Nuclear Plants
Deemed Unprofitable in
Sweden, Germany
E.ON in late June announced that it wants
to shutter its Oskarshamn 2 reactor (Figure
1) in southeastern Sweden because it
is unprofitable. The announcement is the
latest in a string of early nuclear plant retirements
from around the world.
The German company wants to shutter
the 1974-built reactor instead of installing
upgrades to comply with new cooling requirements
and extend the 40-year lifetime
of the 638-MW plant. It also said the reactor
suffers technical problems. " In E.ON's view,
the economic prerequisites for investments
to run Oskarshamn 2 beyond 2020 do not
exist, and . . . the prerequisites do not exist
either for the measures that would be required
to continue operations until 2020, "
E.ON Sweden said in a statement.
E.ON owns 55% of plant operator OKG.
Finland's Fortum owns the remainder. OKG
in June applied for an environmental court
ruling in preparation for the future decommissioning
of the 1972-built Oskarshamn
1. The 1985-built, 1,400-MW, Oskarshamn
3 reactor is expected to continue operations.
However, Fortum said in a statement
that it would prefer the continued operation
of the two older Oskarshamn units.
" Contrary to EON's view, we believe that
it is possible to continue production from
Oskarshamn units 1 and 2 until the end of
their planned operational lifetimes, " said
Fortum's executive vice president for nuclear
and thermal power, Tiina Tuomela. Fortum
said that recent modernization investments
in the reactor had been carried out with a
target to continue production until the end
of the unit's lifetime and with increased capacity.
" Considering the investments made,
1. Early retirement. The 638-MW Oskarshamn
2 nuclear reactor, built in 1974, is at
risk of early closure because it is unprofitable,
says part-owner E.ON. The reactor could become
one of a growing number of units that
have suffered a similar fate. Courtesy: OKG
as well as our strong expertise as a nuclear
operator and a global service provider, we
see that there are other measures [that
could be] taken to ensure safe and reliable
production at Oskarshamn 2 till the end of
its planned lifetime, " Tuomela said.
Industry experts expect OKG to make a
formal decision on the reactor's fate later
this year.
E.ON's announcement comes as Sweden
contemplates the role of its 10 reactors
and three nuclear plants in its future power
mix. Social Democrat Prime Minister Stefan
Löfven had said that nuclear, which generated
about 40% of the country's power in
2013, remains necessary, but he has also
pledged to expand renewable energy in the
country. Last December, meanwhile, Sweden
decided to nearly double fees paid by
utilities into the country's nuclear waste
fund over the 2015-2017 period. The move
increased taxes on nuclear power from
US$0.29/kWh in 2014 to $0.49/kWh.
E.ON, which in April announced it would
spin off all its nuclear assets owing to Germany's
energy transition, in late June also said
it would retire the 1.3-GW Grafenrheinfeld
nuclear power plant half a year ahead of its
final decommissioning date because it is not
profitable. Running the 33-year-old reactor
would only make sense if it could be operated
for a longer period of time and without
a nuclear tax costing about $89 million to
refuel the plant, E.ON said. Grafenrheinfeld
is the first of nine remaining German reactors
that will retire per the country's nuclear
phase-out. The next closures will occur by
the end of 2017 and 2019.
E.ON isn't alone. Earlier this year, Swedish
state-owned Vattenfall said it would
shutter two reactors at its 1975-built Ringhals
plant in southwestern Sweden seven
years early due to declining profitability
and increased costs.
In the U.S., reactors at five plants were
shuttered or slated for shutdown in 2013
owing to low demand, depressed wholesale
prices, cheap gas, high costs of operation,
or ill-fated repair projects: Dominion Resource's
Kewaunee nuclear plant in Wisconsin,
Duke Energy's Crystal River plant
in Florida, Southern California Edison's
San Onofre Nuclear Generating Station,
and Entergy's Vermont Yankee plant. Several
more are flailing financially, including
Exelon's New York Ginna facility and its Illinois
Clinton facility; Entergy's Massachusetts
Pilgrim facility; and FirstEnergy's Ohio
Davis-Besse facility.
8
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Vattenfall Gets Siemens'
First Virtually Oil-Free
Steam Turbine
Steam turbine technology took a leap in
June as Siemens revealed a 10-MW prototype
that uses magnetic force to suspend
a rotor weighing several tons. The innovation
means that instead of needing hundreds
of liters of oil for the bearings, the
first-of-its-kind steam turbine only needs
about three liters of oil (for the valve actuators
that control the steam supply).
And by eliminating the entire oil management
system, it also removes the need for
oil tanks, lines, pumps, disposal systems,
and safety precautions against fires and
environmental damage.
The SST-600 (Figure 2), as it is dubbed
by Siemens, was developed in cooperation
with the University of Zittau/Görlitz.
The turbine with magnetic bearings has
since seen a successful trial run at Vattenfall's
lignite-fired 3-GW Jänschwalde
steam power plant in the German state of
Brandenburg. It has run reliably in regular
full-load operation as one of a dozen
10-MW drive turbines for the power plant's
feedwater pumps since February 2015, at
speeds of between 3,600 and 5,700 rpm,
under main steam temperatures of up to
535C and pressure of 36 bar. This June,
Siemens officially handed the model SST600
steam turbine to Vattenfall.
Siemens noted that active magnetic
bearings that suspend rotating components
with electromagnets are currently
used in other machines such as compressors
and electric motors. They have never
been used in steam turbines, however,
because of high operational temperatures
that often exceed 500C. To overcome this
hurdle, Siemens developed a patented air
2. Magical magnets. Siemens and the
University of Zittau/Görlitz in June handed
over the first SST-600 steam turbine, a model
that uses magnetic bearings and only needs
about three liters of oil (for the valve actuators).
Courtesy: Siemens
POWER | August 2015
http://www.powermag.com
POWER August 2015

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