Investigation into faulty fire detection systems underway at Atomic Weapons Establishment

The government's nuclear safety watchdog, the Office for Nuclear Regulation (ONR), is investigating the adequacy of fire detection systems at the Atomic Weapons Establishment (AWE), where the UK's nuclear weapons are manufactured, following two incidents when alarm systems were discovered to be defective.  The regulator is considering taking enforcement action against AWE following the incidents.

Concerns over fire safety systems at AWE Aldermaston came to light at the beginning of the year, when AWE reported two situations when fire alarms in buildings holding radioactive materials were not working.  In one case, a faulty fire detector was repaired but was found to still not be functioning several days later, raising anxieties that it was not possible to be confident that alarms were operating properly at all times.

Following the discoveries AWE undertook an investigation into the operability and availability of fire detection systems in buildings at Aldermaston to check whether the problems had wider implications across the site.  According to ONR, the review has shown that all detection systems are functional, but further action will be necessary in the medium and long term to ensure that alarm systems are managed properly and effectively by AWE.  

The company has now commenced a remediation programme involving contractors and its own staff to ensure that alarm systems are functioning correctly.  Work is starting in high-hazard areas and includes checks to the configuration and control of systems, training and maintenance procedures, and system documentation.  ONR is currently said to be content that the programme is adequate to address their concerns, and that adequate progress is being made in implementing the programme.

ONR is now considering whether to take enforcement action against AWE for breaching safety regulations and is currently conducting its own investigation into shortfalls in management of the alarm system before deciding what further action is necessary.

Evidence suggests that problems with fire alarm systems at AWE have been experienced over a longer period than the recent past.  Copies of 'Abnormal Event Reports' giving summaries of incidents with the potential to affect nuclear security at AWE, provided to Nuclear Information Service following a request under the Freedom of Information Act, reveal that fire detection systems were found to be “unexpectedly isolated” in buildings at AWE on two occasions in 2011 (documents available to download at the bottom of this article).

Fire is a sensitive issue for AWE following a blaze in an explosives handling facility at AWE Aldermaston in August 2010 in which a member of staff was injured.  Following the incident AWE plc was prosecuted by the Health and Safety Executive and fined £200,000 at Reading Crown Court for breaching safety laws.  Since the 2010 fire a number of low-level incidents have occurred at AWE as a result of alarms being activated by smoke from faulty drive systems for ventilation fans.

Download a copy of the AWE Abnormal Incident reports relating to fire alarm issues in 2011 here:


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