Problems at Hunterston B

Post by **adam2** » Fri Mar 08, 2019 8:24 am

Doubts have been raised about the continued operation of Hunterston B.

The current maintenance outage for inspection of the graphite core has revealed a number of cracks in the graphite bricks.

Some cracks are to be expected and a limited number are acceptable, but the arguments are regarding how many cracks are acceptable.

Cracking of the graphite is undoubtedly a limiting factor in the safe working life of the reactor, it remains to be seen if this is the end for this reactor or not.
I suspect that it will be allowed to run for another year or two, but not for much longer.

Under normal steady state operating conditions the cracks are of little consequence. The risk is that an earthquake could distort the core, prevent the insertion of the control rods and potentially prevent a controlled shutdown.

https://www.bbc.co.uk/news/uk-scotland-47485321

Post by **adam2** » Tue Mar 19, 2019 11:29 am

One reactor at Hunterston B was due to re start at the end of this month, but this has now been put back to the end of JUNE !

The other reactor is still listed as being expected to re start at the end of April, it remains to be seen if this be achieved.

Post by **adam2** » Sat Apr 27, 2019 9:29 am

The restarting of one of the Hunterston reactors has been delayed from April 30 until May 14.

Post by **adam2** » Wed May 08, 2019 4:21 pm

adam2 wrote:The restarting of one of the Hunterston reactors has been delayed from April 30 until May 14.

Now further delayed until May 30.
The other reactor is still due to re-start on June 30.

Post by **kenneal - lagger** » Thu May 09, 2019 3:26 pm

Judging from the lack of response, Adam, no one is at all surprised about there being massive problems with ancient nuclear equipment. We're just waiting for the same to happen throughout the nuclear industry over the next few years and for the massive cost of decommissioning which the taxpayer, of course, will be expected to fund but which we will not hear about for quite a few years yet.

Post by **adam2** » Thu May 23, 2019 9:39 am

Re-starting delayed AGAIN.
The reactor that was due to restart on May 30 has now been put back to June 24.
The other reactor that was due to restart on June 30 has now been put back to July 31.

Post by **adam2** » Fri Jun 21, 2019 4:11 pm

And yet again.
Restarting of one reactor has been put back from June 24 until July 22.
Restarting of the other reactor has been put back from July 31 until October 1st.

Post by **kenneal - lagger** » Fri Jun 21, 2019 4:24 pm

adam2 wrote:And yet again.
Restarting of one reactor has been put back from June 24 until July 22.
Restarting of the other reactor has been put back from July 31 until October 1st.

Not a problem. Carry on until you decide that it can't be restarted at all.

Post by **adam2** » Tue Jul 23, 2019 1:40 pm

latest delay.
The restarting of the reactor that was due on July 22 has now been delayed until August 5.

Post by **adam2** » Fri Aug 09, 2019 2:09 pm

Well what a surprise ! Reactor number 4* at Hunterston was due to re start on August 5, this has now been again delayed until August 30.

Reactor number 3* at Hunterston is still allegedly on target to re start on October 1st.

*These numbers are allocated nationally, not per power station. There are two reactors at Hunterston B, number 3 and number 4.

Little John · Post by **Little John** » Fri Aug 09, 2019 2:22 pm

Nuclear reactors rely heavily on the entire edifice of hydrocarbon powered civilizational infrastructure, both directly and indirectly.

As contradictory to conventional wisdom as it may sound, I believe that as we are pushed, inexorably, off our industrial perch, we need to withdraw from nuclear simultaneously. To the extent we do not, is the extent to which the probability of several more Chernobyl-type incidents occurring somewhere down the line rises.

Post by **clv101** » Wed Aug 21, 2019 10:20 am

Unit 4 has now been approved to restart, apparently they are planning to let it become as cracked as unit 3. As far as I can tell the risk of significant structural failure is pretty much impossible to have high confidence in.

Post by **adam2** » Wed Aug 28, 2019 1:38 pm

clv101 wrote:Unit 4 has now been approved to restart, apparently they are planning to let it become as cracked as unit 3. As far as I can tell the risk of significant structural failure is pretty much impossible to have high confidence in.

Indeed, reactor 4 is now actually running, only at part load but a fairly gradual increase in power is the norm.

I wonder if the other reactor at Hunterston B will ever re start ?

Post by **adam2** » Thu Sep 05, 2019 2:10 pm

As above, one reactor at Hunterston B is now running, though only at part load as yet.
Reactor 3 is now not expected to re-start until mid January 2020, a significant delay over the previous forecast of October 1.

The lack of reactor 3 for at least part of the approaching winter is of slight concern. It represents about 1% of peak demand, not hugely significant in itself but possibly significant as it will be in addition to other planned outages and inevitable breakdowns.

Post by **adam2** » Wed Dec 11, 2019 2:41 pm

Reactor 3 that was due to re start in mid January, is now not expected to re start until February 28, a delay of another 6 weeks.

Reactor 4 at Hunterston that was eventually re started a few months ago after a prolonged core inspection outage is now reducing load prior to another outage for inspection of the graphite core.
A second core inspection outage after such a short interval certainly suggests that TPTB have concerns about the continued safe operation of this reactor.
Forecast restarting of reactor 4 is now March 13.

It seems almost certain that both reactors at Hunterston will be out of use during the coldest part of the winter, a loss of about 1Gw or about 2% of peak winter demand.
Not hugely significant in itself, National grid do allow for outages like this, but it could be interesting if combined with other failures.