Framatome has delivered three replacement steam generators for unit 3 of the Cruas-Meysse NPP in France. The generators, which are each 21 metres long weighing 329 tonnes, were delivered from the Framatome plant in Saint-Marcel in Saône-et-Loire to the plant by waterway and road. CFT (Compagnie Fluviale de Transport) transported them via the Saône and Rhône rivers while SCALES was responsible for the road transportation. This involved a two-day journey including 280 km by barge and 3 km by road. Replacement operations will take place during the summer and is expected to take around 100 days and to involve some 1,000 professionals.
The replacement of the steam generators is part of the fourth 10-year review by the nuclear safety authority, ASN (Autorité de Sûreté Nucléaire). In November, ASN agreed to give EDF more time to complete safety upgrades at its 32 900 MWe nuclear power reactors in operation at the Blayais, Bugey, Chinon, Cruas-Meysse, Dampierre, Gravelines, Saint-Laurent and Tricastin NPPs. These include France’s oldest nuclear units, which began operation between 1977 and 1988. Every 10 years. France’s reactors are reviewed by ASN, first undergoing an initial generic review phase, which covers subjects common to all 900 MWe reactors. This is followed by a 'specific' review phase, which relates to each reactor individually.
The replacement of steam generators Cruas-Meysse 3 will be the 31st such operation in the French nuclear park and the third for Cruas-Meysse. Similar replacements were undertaken for unit 4 in 2014 and for unit 1 in 2017 the power plant. Replacement at unit 2 is planned for 2027.
EDF said the new steam generators will be installed in place of those which will be dismantled after 40 years of use. After they are welded to the hydraulic circuits of the power plant, a very long phase of tests will follow. The old generators will be removed from the reactor building and stored at a special facility on site. EDF explained that the steam generators comprise thousands of tubes, which over time can get dirty and clogged reducing the efficiency of the heat exchange. Their replacement of improves performance by providing a 13% additional heat exchange surface due to the number of tubes being increased from 3460 to 4460.
Cruas-Meysse 3 will be shut down in August 2024 for the ASN review which will include a thorough inspection of the facilities to ensure its compliance with international safety standards. It will be the first unit at the plant to undergo a fourth 10-year review. It will be key to obtaining ASN approval for a further 10 years of operation.
Image: One of the three steam generators delivered to Cruas-Meysse (courtesy of EDF)
