On 20 August 1997 at 02:30 tests of the modified turbine controller were being carried out and for this reason three out of six main coolant pumps were switched off. Reloading of the reactor and the turbines occurred as expected. At 02:33 unexpedcted level increase in one of the six steam generators (SG) was observed. The level increase continued though the level interlock actuated properly and operator action was carried out. At 02:37 unit protection on high SG level actuated that caused the trip of both operating turbines and consequently reactor protection actuated. During the reactor protection actuation sticking of one of the 37 control rods was identified in a position about 200-250 cm (25-50 cm from the upper end position). The parameters of the reactor were stabilized. The cause of the SG level increase has not yet been identified. For defining the causes of the control rod sticking elaboration of a programme was started. Cooling down of the reactor was initiated. On 7 August 1997 sticking of the same control rod was identified during starting the reactor after annual outage. That time the sticking was eliminated with repeated operation of the rod. During additional tests of the affected rod the failure did not reoccur, the reactor was restarted. INES rating: Table II (chapter III-2.4.2) was used since initating event occurred (trip of both operating turbines). The frequency of the initiating event is expect (column 1 of the table). The reactor protection system is able to fulfill its safety function in case of sticking of one control rod, requirements set by the Technical Specifications were fulfilled. Therefore row B of the table was used and the basic rating 1/2 was selected. Additional uprating factor was taken into account according to chapter III-5.3. of the INES manual, namely the repetition of the event indicated that the possible lessons have not been learnt. The final rating was selected level 2.
A vast subsea nuclear graveyard planned to hold Britain’s burgeoning piles of radioactive waste is set to become the biggest, longest-lasting and most expensive infrastructure project ever undertaken in the UK. The project [UK's nuclear waste dump] is now predicted to take more than 150yrs to complete with lifetime costs of £66bn in today’s money...The […]
Last year, the Dutch Province of Limburg started an alliance in which, besides the local government, research institutes, small nuclear reactor (SMR) developers, utilities, industrial customers and funders cooperated. With this "Limburg SMR alliance" Limburg tried to lead the way towards an SMR in Limburg. The preferred site for a first SMR would be Chemelot, […]
From the IPFM: During a visit to the Civaux nuclear power plant on 18 March 2024, France's Minister of the Armed Forces unveiled a plan to use the plant to produce tritium for the French nuclear weapons program. Civaux is a civilian power plant that belongs to and is operated by Electricité de France. According […]
An analysis by the Norwegian NGO Bellona of transborder trade operations with the customs code 840130 (irradiated fuel assemblies or fuel elements) show a more than twofold increase of import to EU countries of fresh nuclear fuel in cash terms – from 280 million Euros in 2022 to 686 million Euros in 2023. In physical […]
The French government has said it is "seriously" studying the option of building a plant to convert and enrich reprocessed uranium to cut its reliance on Russia following the invasion of Ukraine. The only plant in the world that currently converts reprocessed uranium for use in nuclear power plants is in Russia. "The option of […]