The UK's Office for Nuclear Regulation (ONR) today published a list of events reported to the authority over 14 years and has concluded that "the total number has increased over recent years, but the number of those that are of nuclear safety significance has not".
The most significant nuclear safety event in the period covered by the report - between 1 April 2001 and 31 March 2015 - occurred about 10 years ago, with one event rated above the lowest level of significance on the International Nuclear Event Scale (INES) having occurred since 2009.
"The increase in the rate of reporting of events to ONR is attributable to an increase in the very minor events, in the absence of an increase in more significant safety events, is consistent with a maturing and positive safety reporting culture, which is important in achieving and maintaining the highest standards of safety," the ONR said.
In 2012, the regulator introduced improvements to its event reporting and recording arrangements, particularly in relation to the consistency of information recorded, and the extent and consistency of event categorisation. This was intended to facilitate more meaningful reporting and analysis of the data in the future, it said, "to better inform continuous improvement by 'dutyholders' and ONR's future regulatory focus". The regulator's activities have expanded in the period under review to areas other than nuclear safety and security, including conventional health and safety, radioactive materials and transport safety.
"To date, whilst three years of data has been collected under the improved arrangements, this is judged insufficient to support meaningful detailed trend analysis. However, the ability to conduct more detailed analysis of the data will develop as the post 2012 data set increases over time," the ONR said. "Notwithstanding this, the data does suggest a small number of high level conclusions."
The first of these conclusions is that there has been an increase, over recent years, in the rate of reporting of events of no or very low nuclear safety significance, "which is consistent with a positive, proactive and developing safety culture," it said.
Secondly, of the 3866 events reported to the ONR during the period covered by the report, the nuclear safety significance of 3857 (more than 99.7%) was very low (rated at or below level 1 - an anomaly - provided by the seven level INES).
Eight events, only one of which has occurred since 2009, were rated at the next significance level of the scale (INES level 2 - an incident). One event - that took place about a decade ago - was of sufficient significance to merit an INES level 3 rating (a serious incident). None of the more significant events reported had any detrimental effect on public safety or the environment, the ONR said.
The ONR said it "considers all events reported to it, whether minor or otherwise, as being of potential importance in providing opportunities for dutyholders to make improvements to safety arrangements". As a consequence, it "expects dutyholders to review all events in order to identify and deliver safety improvements". For its part, the ONR regulates and oversees the "delivery of necessary improvements in a manner that is proportionate to the nature of the event".
The ONR said it intends to publish future reports of events reported to it, and "to continue to review the nature of information reported in order to increase its transparency and usefulness further".
"This publication of the list of events reported to ONR between April 2001 and March 2015 represents a significant step in ONR's ongoing commitment to openness, transparency, and accountability to those that it serves (workers and the public), and is an important element of ONR's commitment to fostering a climate of trust, respect and confidence amongst its stakeholders," it said.
"The data presented in this report is that held by ONR, although it is recognised that, for historic reasons, the capacity and suitability of the data to accommodate detailed trend, thematic or detailed statistical analysis is restricted. Consequently, whilst the data provides a useful overview of what has been reported to and recorded by ONR during the period covered by this report, its detailed analysis has not been attempted in this report," it said.
Following the ONR's publication of its report, EDF Energy said that the vast majority of events reported relating to the utility are "very minor and have no impact on safety".
EDF Energy has owned and managed all of the UK's eight currently operating reactor sites since January 2009, when its French parent company Electricité de France acquired them from British Energy. The 15 reactor units have a combined capacity approaching 9000 MWe.
"EDF Energy believes that its level of reporting reflects a healthy culture of openness and a commitment to improvement. The number of events with safety implications has fallen since EDF Energy took over the running of the stations in 2009. This is the result of our increasing investment, and a focus on safety and operational performance," the company said.
EDF Energy has voluntarily reported all reportable events since 2011 in its monthly station community newsletters published on the company's website. All nuclear reportable events affecting EDF Energy's nuclear power stations since 2001 are published there.
"As part of our reporting arrangements we inform the ONR of incidents and events that happen on our sites, of these the vast majority were rated at INES Level 1 or below. There have not been any events rated greater than INES 1 within EDF Energy for more than five years. None of these events have had an impact on public safety or the environment," it said.
Initially created on 1 April 2011 as a non-statutory agency of the Health and Safety Executive (HSE), the ONR was formed from the merger of the HSE's Nuclear Directorate (the Nuclear Installations Inspectorate, the Office for Civil Nuclear Security and the UK Safeguards Office) and from 1 June 2011, the Department for Transport's Radioactive Materials Transport Team. The ONR formally launched as an independent statutory corporation on 1 April 2014.
Researched and written
by World Nuclear News