A power excursion, which resulted in a reactor trip on overpower, occurred at the McMaster Nuclear Reactor (MNR) during a refuelling operation. MNR is a pool type research reactor currently operating at 2 MW. Following replacement of a shim safety rod control assembly, the fuel assemblies were being returned to the core. After loading the 5th fuel assembly, the shim safety rods were withdrawn to check that the reactor was not critical. The rods were then driven to the 85% withdrawn position instead of required 40% (safeguard position). On insertion of the 6th fuel assembly a blue glow was seen and the reactor tripped on overpower. The Log N trip had been bypassed to avoid spurious trips while moving irradiated fuel into position for loading into the core and the bypass had not been turned off. The power transient maximum was estimated to be about 300% full power. MNR is analyzing this incident to establish energy output, fuel temperature etc. and will be monitoring fuel behaviour. Procedures related to refuelling are being reviewed and revised. Rating is INES level 2 from Table II - Degradation of defense in depth, with an high/expected initiator (reactor trip due to reactivity excursion) and just adequate safety function availability (Level 2 rather than 3 was chosen on account of the full containment provision and the smaller hazard potential to the public of the pool type reasearch reactor compared to a power reactor).
Location: MCMASTER RESEARCH REACTOR Event date: Tue, 04-01-1994
EPZ, the operator of the Borssele nuclear power plant, has long claimed that it recycles "95 percent" of its nuclear fuel, and that only "5 percent" remains as nuclear waste. Following a complaint by Laka, the Board of Appeals of the Dutch Advertising Authority, ruled yesterday that these are misleading environmental advertisement claims. In its […]
(Nederlandse versie) On Sunday, September 11, the Mikhail Dudin arrives in the port of Rotterdam; a ship carrying Russian uranium. There it will be transferred to trucks that will then transport it across the Netherlands on Monday to Lingen, Germany, where the uranium will be processed into fuel rods. This was announced this morning by […]
(Nederlandse versie) Laka sometimes gets the question that if nuclear power plants in France can be used flexibly, can nuclear power not be used as a intermittent source of electricity, complementing wind and solar? The short answer then is, that if nuclear power plants can be used flexibly, it does not mean that in France […]
New brochure focusing on the uranium enrichment consortium Urenco. The Treaty of Almelo was signed on 4 March 1970 ‒ an agreement between the Netherlands, the United Kingdom and West Germany on setting up a company with the aim of enriching uranium: Urenco. The origin of uranium enrichment is military and until then enrichment was […]
Despite its triumphant press release of the contrary, two years ago, NRG, the operator of the High Flux Reactor in the Netherlands, this week confirmed Laka’s suspicion that NRG is still using weapons-grade highly enriched uranium in its reactor. Therefore, the Netherlands is currently in breach of its agreement with Obama, reached at the Nuclear […]