During rated power operation, an automatic reactor shutdown occurred due to signal of "Neutron Flux High". As a result of investigation, it was estimated that since fastening of the rotation preventing pin had been insufficient, which had been attached at the connecting part of between a valve poppet and a valve stem in one of the 8 main steam isolation valves (MSIVs). This pin was damaged by vibration caused from steam flow and detached pilot- and main poppets plugged the main steam line causing increased reactor pressure which resulted in "Neutron Flux High". There was no release of radioactive materials outside the reactor facility. Also there was no unplanned occupational exposure of employees working under radiation. BASIS FOR RATING: The occurrence probability of detachment of poppet from a main steam isolation valve is considered being the same as inadvertent closure of an MSIV due to malfunction. Then a real initiator of expected frequency can be assumed for this event. Thus rating of this event by INES resulted in a level-0 using the defence-in-depth criterion. DIFFICULTIES IN RATING: Definition of occurrence frequency of an initiator like such a new event was rather difficult.
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 […]