Nuclear
 
Energia nucleara este prima optiune la care se gândesc oamenii când e vorba de alternative

Despre optiunile nucleare

 

http://www.eia.doe.gov/oiaf/aeo/electricity.html

Aceasta adresa este a site-ului guvernamental "Energy Information Administration" un fel de Ministerul informatiilor energetice si apartine de DoE - "Department of Energy" adica ministerul energiei SUA. Traducere libera - Departamentul de analiza statistica al Ministerului Energiei.

Despre optiuniile nucleare la capitolul "productie electicitate":

1Capacitatea centralelor nucleare va creste modest.

2 Nici o centrala nucleara noua nu va devenii operationala intre 2002 si 2025, deoarece termocentralele pe  carbune si gaz natural sint mai rentabile economic.

 

Lucrurile sint simple aici. Nu va faceti prea multe sperante. Pe scurt combustibilul primordial, uraniu natural (U238) este greu de gasit. Se poate extrage din mai multe locuri, inclusiv din apa marii, dar data fiind concentratia infima nu este o solutie reala.

 

Foarte pe scurt exista doua metode importante:

Reactoarele de ardere ( apa usoara, apa grea, gaz, etc)

Reactoarele regeneratoare ( in stadiul de cercetare "avansata" de 55 de ani).

Nuclear fission. There are two isotopes of uranium, uranium-235 and uranium-238. Only uranium-235 is fissionable, and it is only .7 percent of all uranium. The 99.3 percent which is uranium-238 is not fissionable, but uranium-235 can be used to produce a new element from uranium-238, plutonium-239, which is fissionable. Although uranium in both forms is a finite resource, converting uranium-238 to plutonium-239 (a process called "breeding") could possibly extend our use of uranium for power by perhaps 100 times (Meyers, 1983).

The end product of nuclear fission is electricity. How to use electricity to efficiently replace oil (gasoline, diesel, kerosene) in the more than 700 million vehicles worldwide has not yet been satisfactorily solved. There are severe limitations of the storage batteries involved. For example, a gallon of gasoline weighing about 8 pounds has the same energy as one ton of conventional lead-acid storage batteries. Fifteen gallons of gasoline in a car's tank are the energy equal of 15 tons of storage batteries. Even if much improved storage batteries were devised, they cannot compete with gasoline or diesel fuel in energy density. Also, storage batteries become almost useless in very cold weather, storage capacity is limited, and batteries need to be replaced after a few years use at large cost. There is no battery pack which can effectively move heavy farm machinery over miles of farm fields    Where oil is used for electric power production, nuclear fission can replace oil as a fuel. However, in the U.S. now only about 2 percent of electric power is generated from oil.

Fapt este ca arderea atomilor fisionabili (reactoarele de ardere) face din energia nucleara o solutie de scurta durata. ("Energy in a finite world" IIASA,  Wolf Hafele - Cambridge 1981) Uraniul natural este mai putin abundent pe planeta decât petrolul daca e sa comparam echivalent energetic. Iar un reactor nuclear foloseste doar 3-4 % din combustibil, restul se arunca. In principiu un reactor regenerator ar trebuii sa foloseasca "gunoiul" reactoarelor obisnuite si sa-l transforme inapoi in combustibil utilizabil.

Discutiile despre reactoarele nucleare regeneratoare (fastbreeders), minunea minunilor pentru fizicieni, le voi pasa in pagina de texte si linkuri in engleza, pur si simplu pentru ca sint lungi, complexe si contradictorii. E foarte mult de tradus.

Ce trebuie sa stiti e ca FBR-urile  (fast breeder - reactor regenerabil) costa enorm, mai multe miliarde, in cazul Frantei peste 10 miliarde - s-au aruncat la un proiect monstruos, si pâna in prezent din motive tehnologice sau nu, NU functioneaza.

Va prezint succint tabelul cu cele care au fost inchise si va rog sa-l comparati cu cele 3(trei) care mai functioneaza.

 

Super Reactoare regenerabile
Japonia a fost ultima tara cu planuri serioase de construire a unui FBR (fast breeder - reactor regenerabil).
Reactorul regenerabil prototip Monju a fost inchis dupa un incendiu in decembrie 1995 si doarme de atunci. Programul nuclear japonez este in criza si Monju este simbolul. Takagi, directorul CNIC , centrul de informatii nucleare, spune ca reactoarele Superphoenix (FBR) nu au nici o viabilitate comerciala si au fost pastrate peste tot in lume din diverse motive politice si de marketing.
Exemplul Frantei e poate cel mai graitor si poate cel mai trist.
 
Situatia FBR in lume
Exceptând Phoenixul francez care doarme de mai multi ani, nu mai exista FBR-uri in Europa.
India  si Rusia au inca planuri pentru reactoare regenerabile dar nu in urmatoarele doua decenii.
Exceptând reactoarele mici pentru teste, mai exista 3 reactoare regenerabile inca in functie in lume.
Lista cu reactoare regenerabile inchise, dintre care unele nu au functionat niciodata, e mult mai lunga (mai jos)
 
FBR-uri in functie
Tara
Nume
Putere (MW)
Functioneaza din
India
FBTR
14
1991
Kazachstan
BN-350
150
1973
Russia
Bjelojarsk 3
600
1981
France *
Phenix
250
1974
Japan *
Monju
300
1995
* Situatie neclara: Nu functioneza, nu a fost totusi inchis
FBR-uri inchise. Unele nu au functionat niciodata.
Deschis
Inchis
Nume
Tara
Putere (Mw)
1949
1952
Clementine
USA
0.025 th
1956
1957
BR-2
RUSSIA
0.1 th
1954
1959
BR-5
RUSSIA
5-10 th
1951
1963
EBR-1
USA
0.2 e
1961
1965
Lampre
USA
1 th
1966
1972
Fermi-1
USA
66
1969
1972
Sefor
USA
20 th
1962
1977
DFR
UK
15/60 th
1975
1994
PFR
UK
270
1967
1982
Rapsodie
FRANCE
40 th
niciodata
1983
Clinch River
USA
280
1988
1988
PEC
ITALY
120 th
1977
1988
KNK II
BRD
20/100 th
niciodata
1991
Kalkar
BRD
346

1965

1995

EBR 2

USA

20

1985

1997

Superphenix

FRANCE

1240

Sursa:The MOX Myth, WISE NC www.antenna.nl/wise/475/4708.html, 11 April 1997 ; Reuter, 20 June 1997

 

Despre Fuziunea nucleara si Fuziunea la rece

Nu va pot spune decit ca aceste "vise" nu au parasit laboratoarele nici pentru 3 minute. Ambele tehnologii sunt in stadiul de cercetare fundamentala. Si pot ramâne in stadiul asta 50 sau 100 de ani. Daca vi se pare prea mult va rog sa recititi despre promisiunile stiintei in Sinopsis

Despre nuclear in general, va rog sa vizitati acest site superb http://www.kiddofspeed.com/chapter1.html  Cernobil. Este facut de o fata care a calatorit acolo pe motocicleta sa.  Pentru cei cu legatura pe dial-up, site-ul nu este recomantat. Contine aproape exclusiv poze. Ultima pagina contine o poza cu o sculptura care a fost in centrul orasului si a fost mutata dupa accident in interiorul fostei centrale atomice. Sculptura il reprezinta pe Prometeu furând focul de la zei ca sa-l dea oamenilor.

 

The World Energy Commission says that a shortage of uranium limits the expansion of conventional nuclear energy. By 2035, all American nuclear plants will have been decommissioned and represent an energy-production loss equivalent to about 9 million barrels of oil per day. Moreover, America, Germany, and France have all dropped their fast-breeder reactor programs!

Links

Overall, uranium is relatively scarce in the earth's crust, at about 4 parts per million on average. Therefore, a significant expansion of nuclear power -- even the five-fold expansion widely canvassed before the incidents at Three Mile Island and (much more disturbing) at Chernobyl -- would out-run readily accessible supplies. These supplies include both deposits previously exploited but mothballed due to lack of current demand, and known high concentration pockets that could be opened up quite quickly. Therefore, the expansion of nuclear would highlight the need to bring rapidly back on course the development of fast-breeder reactors and pursue fusion technology." p. 90, ENERGY FOR TOMORROW'S WORLD; World Energy Council, 1993

 


 


This kind of huge and ruinously project (the name itself has something 
Freudian in it) is an expression of the blindness and megalomania of 
our arrogant technocratic elites. That blind faith in technology, that 
irrational hunger for power, that firm belief that mankind can shape 
its environment to satisfy its needs whatever the cost, IS JUST MENTAL 
ILLNESS.

That is not science, this is madness. Science without conscience will 
be our downfall.



So I conclude this kind of technology does not scale. If not, explain 
why France abdandonned its breeder reactor projects, the country where 
nuclear megalomania has reached its zenith. Why it has just magically 
extended the lifetime of its old nuclear plants from 30 to 40 years. 
Because it's awfully expensive - construction, maintenance, demolition, 
ore mining, uranium extraction, waste reprocessing (requires itself 3-4 
reactors full time), required infrastructures (all oil dependent); 
costs are beyond reason. Because it's energetically inefficient when 
all costs and constraints are taken into account - at least 50% of the 
global energy feeds the entropy. Because we still dont' know how to 
demolish those monsters and how long it will take, because we still 
don't know what to do with the all the waste we have accumulated so 
far.

Because it's an economic and energetic nonsense. Because nuclear energy 
was just an excuse for the military to develop their toys. If civil 
nuclear technology couldn't have been used to produce plutonium, it 
would never have existed. End of story. The rest is bullshit. Even 
French former CEA (commissariat a l'énergie atomique) researchers admit 
it.

 

http://multinationalmonitor.org/hyper/issues/1992/04/mm0492_08.html

 

Extracte:
-----------------------------
Breeding Disaster

The fastbreeder has been stopped for nearly two years (1992)following
a series of accidents...

Superphoenix is not just a single nuclear plant; it is also the trump
card in the French nuclear establishment's international strategy and
a key element in the industry's plans to perpetuate itself. With
Superphoenix, the French are front-runners in the field of
fastbreeders (which theoretically "breed" more fuel than they use),
and fastbreeders are the nuclear industry's only hope of prolonging
world uranium resources for more than one or two generations. (All
pro-nuclear scenarios, such as U.S. President George Bush's recent
plan, call for a shift to fastbreeders toward the middle of the next
century.)... France's state power company, Elecricité de France
(EDF), is defending Superphoenix, despite its record-breaking history
of breakdowns - it has operated at full power for less than six
months of its six-year existence - and its great cost - the bill is
over $9 billion for a site that is still not finished or in working
condition. Including fuel reprocessing costs would push the bill even
higher.

It does not appear likely that Superphoenix will win the necessary
approvals. The DSIN has stated that, before authorizing a startup for
Superphoenix, it wants to understand the mysterious and potentially
dangerous variations in reactivity that have been plaguing Phoenix
(Superphoenix's predecessor) for the past two years.

Superphoenix - stillbirth of a fastbreeder

 The two French fastbreeders, Phoenix and Superphoenix, were named
for the mythical bird, perpetually reborn from its own ashes, because
theoretically fastbreeders prepare their own fuel. Functioning on
plutonium, they can at the same time transmute non-fissile uranium
238 into plutonium - thereby enormously multiplying the world's (and
particularly France's) modest nuclear fuel reserves. When President
Carter stopped the U.S. program, the French saw a chance to be the
frontrunner in a strategic race. Fastbreeders are also an abundant
source of military-grade plutonium, which is highly valued by a
French military that hopes to become the nucleus of a European
nuclear strike force. The technicians' alchemical dream thus blended
with state ambitions to blind the authorities to the incredible costs
and risks of the plutonium fuel cycle.

 Economically, the Superphoenix has been a major disaster. The
reactor itself has already cost $9 billion, six times its initial
price tag, and it is not finished or in working condition. EDF claims
that the reactor will eventually produce electricity for only about
twice the cost of standard PWRs, but it admits now that commercial
models won't be viable until the middle of the next century.

Even that price estimate is misleading, however, since it does not
take into account the costs of the whole fuel cycle, in particular
reprocessing. Economist Dominique Finon of the University of Grenoble
conducted an extensive independent analysis of the plutonium fuel
cycle. He concluded that reprocessing costs roughly 10 times more
than stocking used fuel without reprocessing. In fact, Finon says
that "it would probably cost less to extract uranium from seawater"
than it does to reprocess it.

The dangers of fastbreeders are so great that many otherwise pro-
nuclear physicists oppose them. Superphoenix houses more than 6 tons
of plutonium, a human- made element that is perhaps the most toxic
substance in existence. It loses only half of its radioactivity in
24,000 years, and inhaling as little as a millionth of a gram can
cause cancer. CRIIRAD has already detected traces of plutonium from
the reactor in the Rhone River. Fastbreeder reactors are also the
only reactors in which there can actually be an atomic explosion. An
study conducted by Professor Jochen Benecke of Berlin University
concluded that "it is impossible to affirm scientifically that the
quantity of energy released would be less than the resistance of the
confinement." He concludes that "a brutal rupture of the confinement,
having as a consequence a catastrophic liberation of radioactivity,
cannot be excluded."

 These dangers are inherent in Superphoenix's design, and were known
before construction started. The actual experience with Superphoenix
has added a long list of breakdowns to the list of dangers, and
demonstrated that the reality of fastbreeding is considerably less
elegant than the idea. An incredible series of "impossible" accidents
have occurred, two of which had been allotted an official probability
of occurring "not more than once in 10,000 to 100,000 years." The
accidents included: sodium leakage and destruction of the fuel
transfer and storage drum (leaving the reactor incapable of
evacuating or storing damaged fuel rods); the fall of a crane
weighing several tons on the dome of the reactor; a sodium leak in
the secondary circuit; cracks in the reactor vessel; and collapse of
the roof (under a heavy load of snow!) onto one of the turbo-
alternators, cutting off the plant from the electricity grid.

 Understandably, the DSIN safety authorities have become unusually
and publicly critical. Last summer, after the belated discovery of
the problem in the secondary circuit, the DSIN director
stated, "There is a question as to the operator's control of the
reactor." DSIN is demanding that three problems be resolved before it
will authorize a new startup.

Going Global
THE FASTBREEDER LOBBY is in trouble, facing difficulties throughout
the world. Germany's Kalkar is abandoned. The British prototype at
Dounreay may not be re-funded after 1994. It was shut down in June
1991 and repair is proving very expensive. The Scottish nuclear
industry has abandoned reprocessing as too expensive. In Japan, the
Monju prototype, scheduled to start operation at the end of the year,
has run into problems with the primary and secondary coolant
circuits, and has difficulty producing fuel pellets that meet safety
standards. (Substandard pellets can swell and crack fuel cladding,
leading to radioactive leakage.)

 Among the DSIN's demands is an explanation for why the Phoenix
reactor has experienced sudden drops in reactivity. They were first
attributed to a bubble of argon leaked into the reactor core, leading
the CEA itself to admit that "a nuclear excursion [a euphemism for an
explosion] ... is theoretically possible." It contended, however,
that "the bubble would have had to be much more voluminous" for an
explosion to have occurred. The incidents occurred again, however,
just a few months after argon filters were changed on Phoenix and
Superphoenix. The new hypothesis (deformation of the fuel rods)
remains unproven, but also has serious safety implications. Yet EDF's
Tanguy dismisses their importance. "The incidents didn't occur on
Superphoenix," he says, "and I don't see why they would."