• November 26, 2015


A response to our query about safety issues at Heysham nuclear power station and the decision to continue its operation beyond its original safe operating date;


The correspondence is self explanatory as usual the Office for Nuclear Regulation assure all is hunky-dory but the plant is operating on reduced power with one boiler isolated which indicates its hardly in pristine condition.

Disappointingly, as usual that the Manx and indeed Irish governments are not enquiring into this more thoroughly, however both governments from a starting point of opposition to the UK nuclear industry now seem to quietly acquiesce. It’s hard to say if it’s a case of inadequacy or incompetence!

“20th November 2015-11-23

For the attention of Mr J B Moffatt – Director of Information

Dear Mr Moffatt


Thank you for your letter dated 31 October 2015 in which you seek clarification on a number of matters in relation to Heysham I nuclear power station.

The legal framework in which ONR regulates the nuclear industry is based around the Health and Safety at Work etc Act 1974, the Energy Act 2013 and the Nuclear Installations Act 1965. For each nuclear licensed site, the ONR attaches 36 licence conditions which must be met by the licensee.

One of the conditions of the nuclear site licence requires the licensee to have a maintenance schedule, and another condition requires operations to be shutdown periodically, when necessary, to allow maintenance and inspection etc. to be carried out in accordance with the schedule.

In 2014, as part of the periodic shutdown of one of the reactors at Heysham I the potential indication of a crack on a boiler spine of one of the boilers (there are 8 in each reactor), which had been revealed during previous routine maintenance, was investigated and this was subsequently confirmed as a crack. The licensee took the immediate decision to shut-down the other potentially effected reactor units at Heysham I and Hartlepool site as they have similar designed boilers. ONR welcomed the conservative decision taken by the licensee in adopting this approach.

The four Advanced Gas-cooled Reactors at Heysham I and Hartlepool have since been operating at reduced power following their return to service at the beginning of this year. The reactors were only allowed to return to service when ONR was fully satisfied with EDF Energy Nuclear Generation Ltd (NGL)’s safety case that justified continued safe operation of the reactors at reduced temperature. Heysham I Reactor I is also operating with the affected boiler isolated from_service.

The licensee has now introduced a cooling modification to each the boilers with the aim of reducing temperatures around the structural welds of the spine that are of prime concern. The cooling modifications are currently being assessed by ONR and we wilt only agree to return of the reactors to full power when we are fully satisfied with the safety justifications provided by the licensee. ONR would need to be satisfied, as part of this safety justification, that the licensee has early indications to ensure that there would not be any catastrophic failure of the spines.

You have raised an issue with respect to wire corrosion at Heysham 1, identified in 2007. 1 assume that you are referring to the tendons and wire-windings that form part of the structure of the concrete pressure vessel of the reactor. There are several hundred of these ‘cables’ within each reactor pressure vessel. These cables are subject to an inspection regime during periodic shutdowns and; where necessary, replacement has been undertaken. ONR is satisfied with the licensee’s regime of inspection and replacement of the reactor pressure vessel cables and that the reactor remains safe to continue operating.

in relation to the operation of the reactors up to 2019, and potentially beyond this date, licensees are required to undertake periodic safety reviews, again to meet a nuclear licence condition, and submit these to the ONR to demonstrate that the plant remains adequately safe for the declared period of operation and that the safety cases are kept up to date.

In summary, ONR is fully satisfied that the continued operations carried out at Heysham 1 remain safe, are in accordance with the limits and conditions given in the safety case that we have assessed; and that any decision to extend the operational service life of the reactors will be subject to us accepting the underpinning safety justifications contained within the extant and future Periodic Safety Reports.

Yours sincerely

Mark Foy

Deputy Chief Inspector & Director ONR Civil Nuclear Reactor Programme”
I am grateful to ONR for there prompt response.
Issued by: The Celtic News



The Celtic League established in 1961 has branches in the six Celtic Countries. It promotes cooperation between the countries and campaigns on a range of political, cultural and environmental matters. It highlights human rights abuse, military activity and socio-economic issues


About Author


0 0 votes
Article Rating
Notify of
Inline Feedbacks
View all comments
The Celtic League
Would love your thoughts, please comment.x