Читать книгу Industrial and Medical Nuclear Accidents - Jean-Claude Amiard - Страница 36

Construction of a heavy water reactor at the Lucens site in Switzerland began in 1962 (Figure 2.3). It was constructed completely underground, with the exception of a few storage and operations buildings. At the beginning of 1969, after a period of revision, the Lucens power plant reactor was returned to service. On January 21, 1969, when the power was increasing, the pressure in the primary cooling system dropped sharply. The instruments also reported a significant increase in radioactivity in the facility enclosure and a significant loss of heavy water. This meant that the moderator tank was damaged. An emergency shutdown of the reactor was carried out, and the caverns were isolated from the outside by closing the ventilation ducts. A few hours after the accident, radioactivity in the access tunnel decreased and the reactor continued to be cooled. Measurements taken on the night of the accident itself, and subsequently, showed that the level of radioactivity in the vicinity had hardly changed from a background level. After this incident, the facility was completely dismantled and the caverns decontaminated. The dismantling work, the decontamination, the analyses of the causes of the accident, the various expert reports and the publication of the final report took more than 10 years [CAN 11].

Figure 2.3. Diagram of the Lucens experimental nuclear power plant (adapted from [CAN 11]). For a color version of the figure, see www.iste.co.uk/amiard/industrial.zip