Five nuclear sites with most safety problems named by government watchdog

05 November 2013

The government’s nuclear safety watchdog has named the five UK sites that need the most regulation because of the safety problems they pose.

They are the reprocessing complex at Sellafield in Cumbria, the nuclear bomb factories at Aldermaston and Burghfield in Berkshire, the nuclear submarine base at Devonport in Plymouth and the former fast breeder centre at Dounreay in Caithness.

These sites have been highlighted by the Office for Nuclear Regulation (ONR) in its 2013 annual report out today as requiring an “enhanced level of regulatory attention”. This is because of the radioactive hazards on the sites, the risk of radioactive leaks contaminating the environment around the sites and ONR’s view of operators’ safety performances, the report says.

ONR expects that the extensive nuclear decommissioning programme at Sellafield will need enhanced regulation for “at least five years” because the problems “are not easily or quickly resolved.” It says that the other four sites will need enhanced attention for “around two years”.

This is the first time that ONR has ranked nuclear sites in this way. The remaining 30 nuclear sites across the UK, including power stations, defunct reactors and a radioactive waste dump, require only “a routine level of regulation”, it says.

The ONR report also discloses the “compliance inspection rating” for all nuclear sites over the last three years. In a quarter of all inspections – 1,444 – sites’ performances were judged to be “below standard”, “significantly below standard” or “unacceptable”.

In two thirds of inspections (3,821) sites were rated as “adequate”, with only eight per cent (478) defined as “good”. A mere six inspections praised sites as “exemplar”, all in 2010-11 with none in the last two years (see table below).

Four of the site inspections judged unacceptable were at the former reactor research facility at Harwell in Oxfordshire. These were because a hoist lifting nuclear waste cans fail, and because of deficiencies in training, experience and supervision.

Sellafield was also rated unacceptable in one inspection because a back-up gas turbine to provide power to the site in emergencies was “at imminent risk of failure to operate” because of severe corrosion. “Failure would reduce the availability of nuclear safety significant equipment, and also potentially injure or harm the workforce,” says ONR.

The most serious safety problem at any nuclear site in the last three years occurred at Aldermaston in 2012. The discovery of corrosion in structural steelwork caused the closure of a top secret plant making enriched uranium components for nuclear warheads and fuel for nuclear submarines. 

The total number of site inspections carried out by ONR’s 220 safety inspectors fell by 16% from 2,046 to 1,709 between 2010-11 and 2012-13. According to the ONR report this was partly because of the pressure of work to assess the designs of proposed new nuclear plants.

Office for Nuclear Regulation compliance inspections at all sites

Rating / 2010-11 / 2011-12 / 2012-13 / total

Unacceptable / 1 / 1 / 3 / 5
Significantly below standard / 43 / 38 / 23 / 104
Below standard / 440 / 457 / 438 / 1,335
Adequate / 1,388 / 1,345 / 1,088 / 3,821
Good standard / 168 / 152 / 157 / 478
Exemplar / 6 / 0 / 0 / 6
All inspections / 2,046 / 1,993 / 1,709 / 5,748

source: ONR 2013 annual report