Sizewell B Reactor Pressure Vessel Integrity — An Update

Readers of News 193 will be aware of our concerns about the integrity of the Sizewell B reactor pressure vessel in the light of weaknesses found in two similar plants in Belgium, namely Doel 3 and Tihange 2. The Belgian safety regulator FANC revealed that, because of irradiation of the vessel bodies, it had ordered an accelerated additional physical irradiation test programme, the results of which will not be known until Autumn 2014, or even later. This led us to ask our Office of Nuclear Regulation: is Sizewell B affected? In reply, the ON R said ‘whilst the Belgian information is noteworthy, the measurements taken at Sizewell B are directly relevant and used by the Licensee to underpin the safety case demonstrating the continued integrity of the RPV’, even though the results of the FANC ordered investigations are not yet published….lt is alarming to read, courtesy of Flanders News BE, 2 1-‘3t August 2014, that ‘small cracks in the Belgian two nuclear reactors are turning out to be a bigger problem than initially thought’ and ‘the company that supplied the walls of the reactor vessels supplied similar material for 22 other nuclear reactors worldwide, including 10 in the United States. Problems could emerge at these sites as well’…. We will follow up this saga as soon as the results of the FANC investigations are published. Meanwhile Doel 3 and Tihange 2 are stood down: possibly they may never be restarted.