EDF Energy, the owner of British Energy, the nuclear business responsible for generating 10% of the UK’s energy recently announced that they needed to shut down four of its 15 UK reactors.
EDF found that “unexpected cracking” had occurred in the boiler spine of the Heysham-1 reactor. This spine is a central forged metal tube that supports the weight of the boiler tubes around them and its failure could lead to water entering the reactor vessel. Serious stuff indeed.
In response both reactors at Heysham 1 and a further two at Hartlepool were shut down in a precautionary measure. EDF have initially forecast that the reactors will be shut for two months, however some expect this to be significantly longer.
The Office for Nuclear Regulation (ONR) said:
“The shut downs [of the four reactors] will allow [EDF Energy] to undertake accelerated inspections of all of the boilers in each of the reactors, which are a similar design, and to fit equipment that will enable monitoring of the condition of the boiler spines.”
The ONR added that the reactors would only be allowed to reopen once EDF Energy had proved beyond doubt that the problems had been fully resolved and they had produced “an acceptable safety case”.
Regardless of the length of time that the reactors will be offline the scale of the lost capacity is already significant with first estimates suggesting that EDF will produce 4.5% less electricity than forecast and will thereby shorten the UKs peak winter capacity (the level of surplus electricity expected to be available to deal with any sudden spike in demand).
Already spare power capacity was forecast to fall to less than 2% by winter 2015-16 however the EDF Energy shut down is now expected to bring this fragile balance forward to the coming winter.
To make matters worse, coal fired power station Ferrybridge incapacitated because of a fire means the market is faced with unplanned losses of 3 GW of electricity generation capacity.
National Grid declined to be drawn on the risks in advance of its official winter outlook report due in October by saying:
“Demand is low at this time of year, and a lot of wind power is being generated right now.
“At the moment we are in the consultation stage for our Winter Outlook report for 2014/15.
“Any changes to capacity will be fed into this report and we will continue to keep the situation under close review”
Whilst Ofgem said hopefully:
“While no system can ever give a 100% guarantee, [we] can be confident that National Grid has the right levers to help keep the lights on.”
However in June, pre dating the latest capacity shut downs, Ofgem’s own outlook report estimated peak demand for the coming winter, assuming average weather conditions, would have a supply margin of just 5-10%.
This margin is now forecast to shrink to just 2.5GW bringing margins in line with the estimated 2-5% forecast for winter 2015/16.
If a more severe winter is experienced an even higher high risks of blackouts could be seen.
Addressing the risks, Jonathan Brearley a former DECC Director and a key architect of the government’s electricity market reform said:
“National Grid and Ofgem need to face this challenge to secure supply for this winter, especially ahead of a general election. A lot of ministers will be telling them the same thing.
“This is exactly the kind of problem that the capacity market was designed to address but the current decline in supply margins was always going to be a risk as we make the transition to EMR”
With the full impact of EMR (Electricity Market Reform) some way off, the on-going shut down and mothballing of plant and stasis in new generation investment as the CMA investigation runs its course, these latest shutdowns and a less benign winter than 2013/14 could see blackouts return to a thoroughly unprepared system.
No wonder the authorities are playing down the risk, the reality is simply too much to bear.