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Fessenheim: radioactive steam generators

Nuclear Monitor Issue: 
Jean-Marie Brom

The French Nuclear Safety Authority (ASN) requests the replacement of the three steam generators at the French Fessenheim-2 reactor. The local anti-nuclear groups, supported by the national umbrella Sortir du Nucleaire, are calling for the definitive shut-down of the reactor.

In May 2009, during a "normal shut-down for refuelling and maintenance operations" of the second reactor at Fessenheim on the French-German border, traces of corrosion were detected on some internal tubes in one steam generator. The same observations were made earlier at the also French Bugey nuclear power plant. Both reactors are of about the same age, from 1977 and 1979 respectively.

The studies undertaken to find out the causes of the corrosion and the search for possible remedies took the rest of the year 2009. In January 2010, the ASN asked Électricité de France (EDF), the owner of the plant, to start a complete survey on the steam generator design and performance. “This will allow an early replacement, before too much damages occur to the steam generators". In other words, EDF has to replace the steam generators which have "serious anomalies". In 2001, the three steam generators of the first Fessenheim reactor have already been replaced. The operation costs were more than 100 million Euros (US$135 million).

Those three old steam generators, with a combined weight of more than 300 tons and highly radioactive, are still stored on the Fessenheim site. Since 1995, EDF adopted a 'standard building project' suitable for storage of contaminated steam generators on all French nuclear sites: a concrete roof and walls from 50 to 80 cm thick. This building can accommodate the three decommissioned steam generators of a unit.

Since the steam generators are part of the primary cooling system, with thousands of small tubes inside through which the primary coolant flows, these pipes have the same kind of contamination that all the other pipes in the primary cooling system have – fission products (which emit beta and gamma radiation) like cobalt-60 and cesium-137, transuranic elements (mostly alpha-emitters) such as plutonium, americium and curium, and corrosion products. Activation products such as tritium and carbon-14 (both beta-emitters with no gamma) are also present. The significance of the transuranic elements is their very long half-lives, measured in centuries or millennia, combined with their very high toxicity. Being alpha emitters, they are harmless inside the steam generator, but once outside in the environment they are very dangerous and remain so for a very long time.

Building new steam generators takes time and installing them takes about half a year, during which no electricity can be produced. The contribution of the second Fessenheim reactor to the total French nuclear electricity production is less than 1%. That is, if the reactor functions well. In the last 3 years it has been plagued by several incidents and has not been productive for more than 60% of the time.

In March 2010, EDF and ASN together decided to postpone the decennial check-up, initially foreseen for this year, to 2012, in order to prepare the replacement of the steam generators. This decision is in fact illegal, the previous authorization for 10 years has been issued in 2001. Even with new steam generators the plant will not be able to run for much more than ten years on. The replacement operation will cost at least 150 millions Euros, and take 6 months, at least. It is highly questionable whether the be-needed investment will be recuperated within the remaining 10 years of operation.

Sources: Press release "Stop transports - halte au nucleaire” / 'Replacement of Two-Blocks Steam Generators', Remi Thevenet, AREVA, 2009, available at: / Email Gordon Edwards, 10 March 2010

Contact: Stop transports – halte au Nucleaire, Jean-Marie Brom, 5 Rue de Mundolsheim, 67300 Schiltigheim, France. Tel: 33 3 8897 9884

Contaminated SGRs from Canada to Sweden.

Canadian Bruce Power's plans to ship 16 old radioactive contaminated steam generators (SGR) through the Great Lakes and over to Sweden where they will be taken apart by Studsvik. The intention is to take the steam generators apart in order to separate the more radioactive components from the less radioactive parts, with the idea that the less radioactive metals can be recycled whereas the more radioactive parts would be repackaged and shipped back to Bruce.

The 100-ton steam generators will be trucked and shipped to Montreal where they will be loaded onto an ocean-going vessel bound for Sweden. It is supposed to happen this year, possibly starting soon.

There is an interesting video available on youtube. It includes some discussion of radiation levels, but the concern is limited to (1) penetrating gamma radiation and (2) surface contamination. The video is called "Radiation Protection" and available at:


Fessenheim-2Sortir du Nucleaire