Startup tests immediately found weld problems in the steam generators. Both the endcaps and the tubesheets would tend to break and mix water with sodium. In the first three years of operation, there were eight sodium explosions. For some odd reason, loop No. 4 never came apart. In 1974, after two major leaks and three small ones, it was decided to rebuild all the steam generators except No. 4. By February 1975, three loops had been fixed, and they decided to start up. Seven days later, loop No. 5 disintegrated. The steam generator in loop No. 5 was replaced with one made in Czechoslovakia.
As of December 16, 1991, the BN-350 was no longer in the Soviet Union. It was in the newly formed Republic of Kazakhstan, and it was re-named the Aktau Nuclear Power Plant. It continued to supply 120,000 cubic meters of fresh water for the city of Aktau way past its projected lifetime of 1993. BN-350 fissioned its last nucleus in 1999, due to a lack of funds to buy more fuel.[154]
Before the BN-350 was started up, the Soviet government was building an even larger sodium-cooled fast breeder reactor, the BN-600 in Zarechny, Sverdlovsk Oblast, Russia. It successfully started up in 1980, but a larger Russian sodium-cooled reactor means larger sodium explosions. As of 1997, there had been 27 sodium leaks, 14 of which caused serious fires, and the largest accident released over a ton of sodium. Fortunately, each steam generator is in its own blast-wall-protected cubicle, and any one can be reconstructed by the on-site workers while the reactor is running. That is one way to solve the problem of bad welds. A BN-800 and a BN-1600, still larger breeder reactors of the same type, are currently under construction in Russia.
We move on to France, a country firmly committed to a nuclear economy.
France saw the same writing on the wall that warned others about the limited supply of uranium, and in 1962 started construction of a modest-sized, experimental sodium-cooled fast breeder reactor named Rapsodie, in Cardache. It began operations on January 28, 1967, making 20 megawatts of heat. It ran okay, and in 1970 the core was redesigned and the power was increased to 40 megawatts. Under the stress of the higher output, the reactor vessel developed cracks, and it was reduced to 24 megawatts. By April 1983, the sodium leakage in Rapsodie was too costly to fix, and it was put to sleep. On March 31, 1994, a highly experienced, specialized, 59-year-old CEA engineer was killed in an explosion while cleaning the sodium out of a tank at Rapsodie. Four people were injured.
In February 1968, after Rapsodie had run for a year, ground was broken in Marcoule for a bigger, 563-megawatt sodium-cooled breeder named Phénix. Ownership and construction costs were shared by the French Atomic Energy Commission (CEA) and Electricité de France (EDF), the government-owned electrical utility. It was big and ambitious. The starting core was 22,351 rods of pure plutonium, with 17,360 depleted uranium rods in the breeding blanket and an awesome 285,789 around the periphery for neutron reflection back into the blanket and radiation shielding. Its 250 megawatts of electrical power were connected to the grid on December 13, 1973, two months after the Organization of Petroleum Exporting Countries (OPEC) halted oil deliveries to countries that supported Israel and increased the market price of crude oil by a factor of four. The first sodium leak occurred in September 1974. In March and July there were two more, causing slow spontaneous combustion in pipe insulation.
The engineering innovation of Phénix was a free-standing or “free-flowering” core restraint, allowing it to expand or contract as it wished due to thermal, mechanical, or irradiation effects without bending or breaking anything. It ran perfectly for 16 years, as the spot price for uranium went from $6 per pound in 1973 to $40 per pound in 1976. Running on plutonium seemed a splendid idea. On July 11, 1976, a sodium fire broke out at the intermediate heat exchanger. Another one on October 5, and three more by the end of 1988. In May 1979, the fuel cladding failed, releasing radioactive xenon-135.
On August 6, 1989, something very odd happened to Phénix. A sudden very negative reactivity excursion triggered a scram. The reactor simply quit making neutrons, and the power level fell like a lead brick. The engineers had no idea why. The reactor restarted without a problem, but 18 days later it happened again. This time, the instruments were blamed for both negative excursions, but nothing wrong could be found. The ability to make electrical power dropped to near zero as the incidents continued.[155]
On September 14, 1989, the power again went to zero. The cause was believed to be a gas bubble in the core periphery. The problem was solved with mechanical maintenance, and Phénix was restarted in December. It happened again on September 9, 1990, and the gas-bubble hypothesis went out the window.
For the next 12 years, panels of experts pondered the problem, and the plant was tested, taken apart, put back together, repaired, modified, and refurbished, not generating any power to speak of. No one specific scenario or cause of the strange incidents was identified, but the only thing that made sense, given the speed and extent of the events, was that the core was in motion, moving in different directions as it generated power and disturbing the critical configuration of the reactor as designed. Lesson learned: avoid free-flowering core restraints in future reactor designs. In June 2003, Phénix was restarted and ran at reduced power, 130 megawatts, until final shutdown in 2009.
In 1974, a European fast-neutron reactor consortium, NERSA, was established by France, Germany, and Italy to build the biggest plutonium-fueled breeder reactor in the world. This extraordinary allegiance of countries lasted about a year. Germany spun off and decided to make their own breeder, the SNR-300 in Kalkar, and in the middle of 1976 President Valéry Giscard d’Estaing of France proclaimed that his country would build the Superphénix, a 3-gigawatt sodium-cooled breeder, at Creys-Malville, 45 kilometers east of Lyon. Italy stood still and did not make a sound.
Minister of Industry André Giraud announced to a spellbound crowd at the American Nuclear Society meeting in Washington, D.C., that there would be 540 Superphénix-sized breeder reactors in the world by the year 2000, and 20 of them would be in France. Meanwhile, 20,000 people occupied the building site to protest the thought of another reactor project. On July 31, 1977, the protest got serious, with 50,000 participants, and riot police went in armed with grenades. A local teacher, Vital Michalon, was killed, another protester lost a foot, and a third lost a hand in the battle. Ongoing protest and sabotage made construction work difficult, and on the night of January 18, 1982, militant Swiss eco-pacifists fired five rocket-propelled grenades at the containment building, causing cosmetic damage.[156]
Construction continued under bombardment, and the completed Superphénix went critical on September 7, 1985. It was connected to the grid on January 14, 1986. A series of administrative hurdles and incidents prevented any significant power production until March 8, 1987, when a massive liquid-sodium leak was discovered issuing forth from the refueling rotor tank (storage carousel). The reactor was down until April 1989 as an alternate refueling scheme was designed. The rotor tank was too far down in the guts of the reactor, and there was no way to repair the leak, a crack 24 inches long, without dismantling the entire plant.
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Even a breeder reactor has to buy fuel. If the supply services had been operating as planned, the plant would exchange its spent fuel and breeding material for a fresh load of plutonium and depleted uranium. Plutonium would be extracted chemically from the spent load, and there would be enough extra in the breeding stock to more than pay for the chemical separation and fuel-rod fabrication. The BN-350 started out with an expensive load of 20 % enriched uranium with some mixed uranium-plutonium surplus from the Soviet nuclear weapons being demilitarized. By 1999, the now-obsolete fuel-rods would have to be custom-built.
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Subsequent investigations found that similar incidents had occurred in April 1976 and June 1978. They were explained away as “control rod slippage,” which turned out to be wrong.
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The unnamed group of terrorists obtained a Soviet RPG-7 shoulder-fired rocket launcher and eight rockets (“bonbons”) from the German “Red Army Faction” via the Belgian counterpart