Design Superphénix

1 design

1.1 background
1.2 earlier work , phénix
1.3 superphénix

design
background

france had considered problem of plutonium production after end of world war ii. @ time, conventional solution problem use graphite moderated air or water cooled reactor fueled natural uranium. such designs have little economic value in terms of power production, simple solutions problem of breeding plutonium fuel, can separated original uranium fuel chemical processing.

however, had long been known solution breeder reactor design replace graphite liquid sodium metal. graphite used moderator, slowing neutrons released in nuclear reactions speed makes other uranium atoms sensitive them. however, if 1 replaces natural uranium fuel 1 sensitive fast neutrons, typically highly enriched uranium or plutonium, reaction can run without use of moderator.

while design eliminates need moderator, core still needs cooled. ideally coolant both highly efficient, allowing core size reduced, being largely transparent neutrons. studied example of such material liquid sodium, although salts , other metals have been used.

this not reduces size of reactor, fast neutrons single reaction capable of causing several breeding reactions. surrounding core additional fertile material such natural uranium, or nuclear waste other reactors, breeding reaction take place in larger volume , in otherwise useless materials. section known blanket. such design has quality generates more fuel consumes, long breeding ratio greater 1.

such design has 3 major advantages on conventional military designs; entire reaction cycle occurs faster breeds new fuel @ faster rate, can use wider variety of breeding materials because not used fuel well, , generates ample amounts of heat, can used efficiently produce power. downside has fueled sort of enriched fuel, although fissile material being bred in blanket can used.

earlier work , phénix

plans french fast reactor date far 1958 s rapsodie, , followed in 1964 larger design power output of 1 gwe. construction of rapsodie facility started in 1962 , went critical on 28 january 1967. did not have power producing systems, 22 mw of thermal output (mwth) translate perhaps 9 mw of electrical output (mwe). experiments on core configurations carried out in masurca facility starting in 1966, , design of larger power-producing facility underway.

during 1960s, interest in nuclear power reaching crescendo. france, little uranium supply of own, large scale generation subject supply constraints, given nuclear power experiencing boom in construction suggested available supply limited on worldwide basis. in france s plans, breeders serve twin purposes of producing fuel conventional light water reactor fleet, producing fuel waste fuel reactors, thereby reducing amount of nuclear waste have dispose of. small number of breeders, estimated around 20, required fuel fleet of 200 light water reactors.

france began construction of phénix demonstration plant in november 1968, year after rapsodie went critical. fueled 931 kg of highly enriched plutonium, around 77% pu-239. fuel load capable of running 90 days maximum, in practice ran 2 month periods. due design, refueling required reactor shut down. result, had low capacity factor (cf), on order of 65%. prototype plant, high cf not design goal, although practical design have improve this. phénix demonstrated breeding ratio of 1.16, meaning produced 16% more fuel consumed, while producing 233 mwe in normal operation.

phénix ran without problems through 1970s , 80s, in 1990s began demonstrate number of unexplained behaviours, including large power transients. had serious safety implications, , reactor repeatedly shut down, spending of period 1991 1994 being studied while offline. long offline period required recertified, plant underwent significant refurbishment between 1994 , 2002. rectified in june 2003, @ reduced power of 130 mwe.

superphénix

a cut-away model of superphenix containment. national atomic museum, united state

in 1971 , 1972, france, germany , italy signed agreements joint construction of full-scale breeders, 1 in france , 1 in germany. 1973 oil crisis made issue of fuel security of significant importance. part of messmer plan, france began plan future in vast majority of electrical power come nuclear sources. new priority given follow-on breeder design goal of continual operation, high cf, , economic operation stand-alone reactor. became superphénix design.

a public enquiry carried out on excessively short period 9 october 8 november 1974. led immediate opposition. in november, group of 80 physicists lyon physics institute wrote open letter risks of breeder technology, , in february 1975, 400 scientists signed name expanded letter. on other side of argument, andre giraud, head of french nuclear commission (cea), stated should carry on buildout, warning delays have catastrophic consequences on uranium savings expected. in spite of opposition, superphénix construction pushed ahead in 1976, although not made official until next year, when initial construction underway.