On May 17th, we had the admission just below, then following, the scoop
on power uprating--a common disharmonious practice to boost output.
Natalia
(NaturalNews) The truth has finally come out, as officials from the
Tokyo Electric Power Company (TEPCO) now admit that fuel in Reactor 1 of
the Fukushima Daiichi nuclear complex melted just 16 hours after the
devastating earthquake and tsunami hit the area on March 11, 2011. When
asked why it took more than two months to reveal this critical
information, TEPCO officials claim that a lack of data left the company
unaware of the core's true condition until only recently -- and new
reports indicate that other meltdowns could soon follow.
According to a recent report from /The Mainichi Daily News/ (MDN) in
Japan <http://www.naturalnews.com/Japan.html>, TEPCO officials recently
announced that, based on new data, water levels in the pressure vessel
at Reactor 1 began to drop rapidly within just a few hours after losing
power <http://www.naturalnews.com/power.html> at 3:30 pm on March 11. By
7:30 pm, fuel <http://www.naturalnews.com/fuel.html> was fully exposed,
and by 9 pm, reactor core temperatures reached an astounding 2,800
degrees Celsius, or 5,072 degrees Fahrenheit. And by 6:50 am the next
morning, a full meltdown <http://www.naturalnews.com/meltdown.html>
occurred (http://mdn.mainichi.jp/mdnnews/news...
<http://mdn.mainichi.jp/mdnnews/news/20110516p2a00m0na028000c.html>).
So for all the time that electric power was out in multiple reactors,
causing the cooling systems to fail, and during the months after it was
widely known that water levels were consistently dropping in Reactor 4
due to leaks, TEPCO played the ignorance card, acting as though it had
no idea how serious the situation at the plant actually was. Surely the
company must know, even without access to a detailed analysis, that when
cooling systems fail and fuel rods become fully exposed, a meltdown is
sure to follow -- even regular folks with no background in nuclear
<http://www.naturalnews.com/nuclear.html> technology can put two-and-two
together to figure that one out.
But apparently TEPCO thinks it can keep playing dumb, and that the world
will simply believe whatever it says. This new revelation, however,
proves that the company is greatly underestimating the fallout from the
situation at best, and deliberately hiding the truth at worst. Either
way, the situation is far more dire than we have all been led to believe.
"[TEPCO] could have assumed that when the loss of power made it
impossible to cool down the reactor, it would soon lead to a meltdown of
the core," said Hiroaki Koide, professor of nuclear safety engineering
at Kyoto University, to MDN. "TEPCO's persistent explanation that the
damage to the fuel had been limited turned out to be wrong."
And shortly after the announcement about Reactor 1, /The Telegraph/
reported that two more Fukushima
<http://www.naturalnews.com/Fukushima.html> reactors may soon suffer a
meltdown as well. Efforts to cool fuel in Reactors 2 and 3 have failed,
and experts say that if the reactors cores have not already melted, they
soon will (http://www.telegraph.co.uk/news/wor...
<http://www.telegraph.co.uk/news/worldnews/asia/japan/8517861/Japan-meltdown-feared-at-two-more-Fukushima-reactors.html>).
Learn more:
http://www.naturalnews.com/032437_Fukushima_nuclear_meltdown.html#ixzz1PxAzowNR
U.S. is increasing nuclear power through uprating
Turning up the power is a little-publicized way of getting more
electricity from existing nuclear plants. But scrutiny is likely to
increase in the wake of Japan's nuclear crisis.
April 17, 2011 <http://articles.latimes.com/2011/apr/17>|By Alan Zarembo
and Ben Welsh, Los Angeles Times
The U.S. nuclear industry is turning up the power on old reactors,
spurring quiet debate over the safety of pushing aging equipment beyond
its original specifications.
The little-publicized practice, known as uprating, has expanded the
country's nuclear capacity without the financial risks, public anxiety
and political obstacles that have halted the construction of new plants
for the last 15 years.
The power boosts come from more potent fuel rods in the reactor core
and, sometimes, more highly enriched uranium. As a result, the nuclear
reactions generate more heat, which boils more water into steam to drive
the turbines that make electricity.
Tiny uprates have long been common. But nuclear watchdogs and the U.S.
Nuclear Regulatory Commission's own safety advisory panel have expressed
concern over larger boosts --- some by up to 20% --- that the NRC began
approving in 1998. Twenty of the nation's 104 reactors
<http://spreadsheets.latimes.com/nuclear-uprates/> have undergone these
"extended power uprates."
The safety discussions have largely escaped public attention, but they
could become more prominent as the Japanese nuclear crisis focuses more
scrutiny on U.S. reactors.
In an uprated reactor, more neutrons bombard the core, increasing stress
on its steel shell. Core temperatures are higher, lengthening the time
to cool it during a shutdown. Water and steam flow at higher pressures,
increasing corrosion of pipes, valves and other parts.
"This trend is, in principle, detrimental to the stability
characteristics of the reactor, inasmuch as it increases the probability
of instability events and increases the severity of such events, if they
were to occur," the Advisory Committee on Reactor Safeguards, which is
mandated by Congress to advise the NRC, has warned
<http://documents.latimes.com/background-on-nuclear-uprating/#document/p131/a14451>.
Still, the committee has endorsed uprates, based on assurances that any
increased risk falls within federal safety standards and is countered by
additional safety measures such as plant modifications and more frequent
inspections.
"You can always make a plant safer," said William Shack, a materials
engineer and member of the safety committee. "The question is, when do I
say I've made it safe enough?"
Computer models used to analyze risk suggest that a properly uprated
reactor is no more vulnerable than one operating at its original capacity.
But critics of uprates point out that such analyses may fail to account
for unforeseen accident scenarios.
"It's beyond the wit of mankind to identify all challenges to a nuclear
plant," said John Large, a former researcher for the British atomic
energy agency who runs a consulting company in London specializing in
nuclear safety.
A case in point involved three uprated reactors in Illinois.
In 2002, both reactors at the Quad Cities Nuclear Plant were restarted
after having their capacity boosted by 17.8%. Pipes began to shake, and
cracks formed in a steam separator, which removes moisture from the
steam before it enters the turbines. In one case, a 9-by-6-inch metal
chunk broke off and disappeared.
Similar problems were discovered at the Dresden Nuclear Power Plant,
about 60 miles southwest of Chicago, which had undergone a 17% uprate.
Broken parts were replaced, but the problem continued. Exelon Corp.,
which owns the three plants, and the NRC were mystified.
"The greatest concern is loose parts that you can't find," John Sieber,
a nuclear engineer on the NRC advisory committee, said during a 2004
meeting
<http://documents.latimes.com/background-on-nuclear-uprating/#document/p14/a14453>.
"Are they in the bottom of the reactor vessel? .... Is it floating
around where it can damage internal parts of the core?"
Eventually the problem was uncovered: acoustic waves caused by the
geometry of the steam pipes. The pipes were acting like a musical
instrument. Their geometry was modified to "detune" them.
Plans to boost the power by 14.3% at three reactors in Athens, Ala., and
12.9% at a plant in Monticello, Minn., have been held up, in part, by
NRC concerns over the steam separators.
Nuclear industry officials and regulators say that safety calculations
are conservative and that even the biggest uprates fall far short of the
power loads the reactors could actually handle.
Craig Nesbit, an Exelon spokesman, said that uprates "do not cut into
the safety margins of these plants."
He and other industry officials note that uprates often require
replacing turbines, transformers and other major equipment to
accommodate higher water and steam flows.
But some things do not change, including the suppression pool, which is
designed to soak up heat from the reactor core during some kinds of
accidents, and the heat removal pumps, which deliver water from the pool
into the core to prevent the fuel from melting down.
David Lochbaum, a nuclear engineer with the environmental group Union of
Concerned Scientists, has argued that in some uprated reactors the pool
may be too small and could become so hot that its contents could begin
to vaporize, causing the pumps to lose suction.
But factoring in the pressure buildup "represents a decrease in the
safety margin available to deal with a phenomenon subject to large
uncertainties," the agency's safety advisory committee wrote in a March
18, 2009, letter to the agency
<http://documents.latimes.com/background-on-nuclear-uprating/#document/p122/a14452>.
Forcing regulators to show that the safety system would work without the
pressure buildup would offer an extra layer of protection against
"potential melting of the core," the letter said.
The alternative would be requiring plant modifications so costly that
companies say it would no longer make economic sense to uprate.
For the U.S. nuclear industry, which supplies a fifth of the nation's
electricity, uprating is attractive because it is one of the cheapest
ways to add power to the grid.
The 1979 partial meltdown at Three Mile Island eroded public confidence
in nuclear power. Construction proceeded on many reactors that had
already been approved --- the last one went into operation in 1996 ---
but the industry was forced to look for ways to get more out of existing
plants.
The biggest gains have been achieved by running reactors more
efficiently --- less downtime for fuel changes, for example.
But uprates have played an important role, adding the equivalent output
of nearly five average-sized reactors since 1996. Regulators say they
expect to approve boosts totaling 3 1/2 more reactors over the next four
years.
Exelon, the nation's top nuclear provider, plans to spend $3.65 billion
on power boosts equivalent to one new nuclear reactor over the next
eight years, according to its filings for investors.
"They would come at half the cost of a new plant and with less risk
because of the opportunity to defer expansion if power prices do not
support it," its annual report says.
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