Hinkley faces closure over missing safety system

somerset | the environment | press release Saturday May 10, 2008 17:12 by Jim Duffy - Stop Hinkley stophinkley at aol dot com 07968 974805

Hinkley Point B has been warned by the nuclear regulator that it faces being shut down this year if it does not fit a last resort shut-down system at an estimated cost of over £100 million.

Campaigners are calling for a public inquiry, astonished that the system was never fitted as this leaves the ageing and corroded reactor vulnerable with only two lines of defence.

Advance Gas-cooled reactors (AGRs) are designed with three safety systems: the control rods and articulated control rods descend into the reactor core when it is 'tripped' and shut down the nuclear reaction. If that fails, as in the case of misaligned channels, now possible with severe corrosion and cracks, then nitrogen gas is injected into the reactor. This temporary response depends on the reactor pressure for success. Water could also be used but both would fail in a leaking reactor.

The final line of defence is the 'boron beads' system with boron beads or dust poured into the reactor core, soaking up the neutrons and probably meaning the end of the reactor but at least stopping a runaway scenario.

A European Commission document declares Hinkley possesses the boron beads system, crediting British Energy with furnishing the information. (1)

Jim Duffy spokesman for Stop Hinkley said: "British Energy's mantra is safety is their priority but it's astonishing and criminal that a reactor can be built with this crucial line of defence missing, especially when it's part of the design. Even worse when you consider the 25 percent corrosion the worst parts of the reactor core is experiencing plus the surprise discovery of corroded boiler tubes within the reactor vessel last year. Who can trust an industry like this? Hinkley should shut down now and a public inquiry held into how this alarming situation came about. The European Commission were misled. What cover-ups were involved? Heads should roll."

Jim Duffy
Stop Hinkley 10th May 2008
07968 974805
www.stophinkley.org

(1) Nuclear Safety and the Environment EC publication EUR 20056 EN 2001

Scottish Daily Mail (Scroll down for Hinkley reference)
9/5/08

NUCLEAR STATION FACES SHUTDOWN OVER SFAETY
By Alan Simpson and Mark Howarth

SCOTLAND'S oldest nuclear power station is at the centre of fresh safety fears after it was revealed it may be impossible to shut down its reactors in an emergency.
Nuclear inspectors admit that a vital shut-down mechanism at Hunterston B in Ayrshire is not in place, which raises serious concerns about the plant.
The government inspectors have warned that unless work to rectify the shortcomings has started by autumn, the plant could be ordered to close, leaving Scotland facing a potential energy crisis.
The news is a major blow to West Lothian-based British Energy, which runs the plant, as today (FRI) sees the deadline for takeover bids for the troubled company.
It is estimated the cost of making the shut-down systems safe at Hunterston B and its sister plant, Hinkley Point B in Somerset, could be upwards of £100million and may affect potential bids.
The alarm centres on whether the stations could be completely shut down in the event of a major nuclear emergency.
Officials discovered that a vital mechanism that could quickly halt a potentially devastating chain reaction in the nuclear reactors is missing at both sites.
According to experts, this leaves both plants at risk of being unable to prevent full-scale meltdown in an emergency - with potentially devastating consequences.
Leading independent nuclear consultant John Large said last night: "To discover that a shut-down system is not just on the blink but actually missing is, frankly, astonishing.
"These two stations are the oldest in British Energy's portfolio and, not to put too fine a point on it, they are knackered.
"If Hinkley Point and Hunterston were to go offline tomorrow, that would leave around half Britain's nuclear capacity under repair.
"In the long term, that may leave the UK with an energy gap to fill."
Scotland's two nuclear power stations - Hunterston B and Torness in East Lothian - produce more than 30 per cent of the country's electricity.
Hunterston B's two units alone generate 450 megawatts, which is enough energy for about a million homes.
Hunterston B and Hinkley Point are Advanced Gas-Cooled Reactor stations which opened in 1976 and were due to be decommissioned in 2011.
Last year, British Energy, in which the government has a 35 per cent stake, was granted permission to extend the working lives of Hunterston B and Hinkley Point B in Somerset by five years to 2016.
It was given the go-ahead to head off a potential energy shortage while the Westminster Government builds new nuclear stations.
But the Nuclear Installations Inspectorate (NII) could scupper the life extensions if concerns over whether the reactors could be shut down in the event of an emergency in the near future are not addressed.
In the event of a mishap in a nuclear reactor, the final failsafe system is to fire boron beads into the reactor, which achieves permanent shut-down by mopping up neutrons.
But neither site has the boron beads system and the NII has told the company to bring its entire shut-down system up to scratch.
A spokesman said: "NII has required British Energy to perform a study to establish the reasonable practicability of plant modifications and to implement them as appropriate so as to secure the long-term operation of the graphite cores of the reactors at Hinkley Point B and Hunterston B.
"We work on absolutes. If we're not happy, these things don't operate."
British Energy has confirmed the boron bead systems were not in place but played down safety fears.
A spokesman said: "If we, or our regulators, were concerned with any aspect relating to the safe operation of the plant, we would not be permitted to operate.
"All of our reactors have several systems in place to provide defence in depth to ensure immediate shutdown and, if need be, long-term hold down of the reactor."
"We are happy the work contemplated will be manageable within planned budgets for plant investment which were planned last year."
ends