On Tuesday, 2 August 2016 19:00:50 UTC+1, T i m wrote:
On Tue, 02 Aug 2016 14:11:19 +0100, "Dave Plowman (News)"
wrote:

In article ,
T i m wrote:
However, there really isn't anything to understand is there.

Solar panels only work when there is light on them. At night there is
no light so there is no power. ZERO.

Wind turbines only work when the wing is blowing over them (and even
then only over a fairly small range of speeds). So, when the wind
isn't blowing there is NO POWER.

And conventional power stations only work when there is fuel for them.
Remember the 3 day week?

How does that lack of availability compare with nighttime or windless
days OOI Dave? ;-)

So, I wonder where Harry (and his kind) think the power is going to
come from when it's dark and when the wind isn't blowing?

Well, the wind may not be blowing round your way. But may well be
elsewhere. As with the sun shining.

Sue, if we cover the globe with sufficient 'green' power and connect
it to a worldwide grid then you could be right. Not sure how the UK
leaving Europe will help that, well, less we also have superconductors
that will span the Atlantic etc. ;-)

In rather the same way as the amount of power you consume at home isn't
the same at all times. You probably only use a tiny amount when asleep,
for example.

Quite. Luckily that's also when the sun isn't shining (here).

I really can't see what the problem is having a variety of types of power
generation. They all have both pros and cons.

Of course, however, if *any* of these alternatives are never a net
energy pollution benefit then should they exist in the first place?

How would you market a machine that gave an output 750W and that took
the equivalent of 1000W to make it work?

Now, I'm not saying that we should be looking for or use *real* energy
efficient replacements, just most of what we have so far aren't it.

Like, if harry with his big place and cash to splash on covering his
roof in solar collectors, can't live 'off grid' (even ignoring the
cost or the ecology) then how could anyone in the UK not living like a
caveman ever expect to not rely on the current range of reliable
energy sources (with the current alternatives available).

Cheers, T i m

I could live off grid if it became neccesary.
But I choose not to because of minor inconveniences.

On 03/08/16 10:30, Chris Hogg wrote:
On Wed, 3 Aug 2016 01:20:14 -0700 (PDT), harry
wrote:

On Tuesday, 2 August 2016 19:00:50 UTC+1, T i m wrote:
Like, if harry with his big place and cash to splash on covering his
roof in solar collectors, can't live 'off grid' (even ignoring the
cost or the ecology) then how could anyone in the UK not living like a
caveman ever expect to not rely on the current range of reliable
energy sources (with the current alternatives available).

Cheers, T i m

I could live off grid if it became neccesary.
But I choose not to because of minor inconveniences.

Those minor inconveniences being having to use candles and wear
several layers of woolly jumpers in the winter evenings, of course.

Bearing in mind your electric car has a sizeable battery in it, and
also that the likes of Tesla and Nissan are now promoting batteries
for storing electricity in the home, either charged off the grid
overnight or from PV's on sunny days, why don't you use your car
battery in a similar fashion? All you'd need is a suitable converter
to plug into.

There speaks a man who Cant Do Sums.

20 million households.

Each one with a 50Kwh electric car battery.
UK winter consumption 50GW

so about 20 hours and all the car batteries are flat.

And no one is going anywhere, and the lights are all out.



--
"What do you think about Gay Marriage?"
"I don't."
"Don't what?"
"Think about Gay Marriage."

"Chris Hogg" wrote in message
...
On Wed, 3 Aug 2016 01:20:14 -0700 (PDT), harry
wrote:

On Tuesday, 2 August 2016 19:00:50 UTC+1, T i m wrote:
Like, if harry with his big place and cash to splash on covering his
roof in solar collectors, can't live 'off grid' (even ignoring the
cost or the ecology) then how could anyone in the UK not living like a
caveman ever expect to not rely on the current range of reliable
energy sources (with the current alternatives available).

Cheers, T i m

I could live off grid if it became neccesary.
But I choose not to because of minor inconveniences.

Those minor inconveniences being having to use candles and wear
several layers of woolly jumpers in the winter evenings, of course.

Nope, he could run lights off the car and he has always said that
his place is insanely insulated and that he does scrounge wood from
fallen trees etc so that would be fine for the winter evening heating.

Bearing in mind your electric car has a sizeable battery in it, and
also that the likes of Tesla and Nissan are now promoting batteries
for storing electricity in the home, either charged off the grid
overnight or from PV's on sunny days, why don't you use your car
battery in a similar fashion? All you'd need is a suitable converter
to plug into.

Don't even need that if the lights are done properly.

In article ,
Chris Hogg wrote:
That was when the NUM decided there should be an end to coal mining
in the UK.

And most of our fuel now comes from abroad, so totally secure. You
think?

All the more reason to push forward with fracking ASAP.

Very true. Would it happen close to where you live?

--
*Never miss a good chance to shut up.*

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Chris Hogg wrote:
Bearing in mind your electric car has a sizeable battery in it, and
also that the likes of Tesla and Nissan are now promoting batteries
for storing electricity in the home, either charged off the grid
overnight or from PV's on sunny days, why don't you use your car
battery in a similar fashion? All you'd need is a suitable converter
to plug into.

You make it sound so very simple. ;-)

--
*Before they invented drawing boards, what did they go back to?

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 3 Aug 2016 01:20:14 -0700 (PDT), harry
wrote:

snip

Like, if harry with his big place and cash to splash on covering his
roof in solar collectors, can't live 'off grid' (even ignoring the
cost or the ecology) then how could anyone in the UK not living like a
caveman ever expect to not rely on the current range of reliable
energy sources (with the current alternatives available).


I could live off grid if it became neccesary.
But I choose not to because of minor inconveniences.

Quite, like not having *any* power overnight and reduced power on
overcast days and the winter you mean?

And assuming we can't buy our energy in (so no imported gas, coal or
uranium), how well would you be able to heat your house in the winter
from your panels alone because your area was the one they turned off
during the power rationing?

How much help do you think your private use, electricity consumer
subsidised energy supply is re justifying a real / reliable UK base
load generation?

I can see you at the meeting now ... "Well, solar can easily meet 10%
of the UK's energy needs on a hot Sunday afternoon (when most of the
factories are closed)" ... assuming more of don't fit aircon units and
drive electric cars that is ...

So, play fair, give up the FIT payments and then you won't be labeled
a parasite for not having to suffer those little 'inconveniences'
because the rest of us are paying more all year for *you* to keep your
lights and heating on at night and in the winter.

Cheers, T i m

In article ,
T i m wrote:
I can see you at the meeting now ... "Well, solar can easily meet 10%
of the UK's energy needs on a hot Sunday afternoon (when most of the
factories are closed)"

And Hinkley was said to be able to meet 7% of the demand. When and if it
ever gets built and actually works, of course.

Surely having a variety of means of generation isn't a bad thing?

--
*DOES THE LITTLE MERMAID WEAR AN ALGEBRA?

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 03 Aug 2016 13:26:34 +0100, "Dave Plowman (News)"
wrote:

In article ,
T i m wrote:
I can see you at the meeting now ... "Well, solar can easily meet 10%
of the UK's energy needs on a hot Sunday afternoon (when most of the
factories are closed)"

And Hinkley was said to be able to meet 7% of the demand. When and if it
ever gets built and actually works, of course.

Surely having a variety of means of generation isn't a bad thing?

Yes, as long as I'm not having to pay any individuals for the
privilege of supplying and using the energy themselves and as long as
it is environmentally justifiable.

Like I said, who is going to pay you say £10 per kWh for you to
generate electricity in your shed by burning old car tyres. The tyres
are there, you have the generator, we need the electricity, what's not
to like?

And don't call me Shirley. ;-)

Cheers, T i m

In article ,
T i m wrote:
And Hinkley was said to be able to meet 7% of the demand. When and if it
ever gets built and actually works, of course.

Surely having a variety of means of generation isn't a bad thing?

Yes, as long as I'm not having to pay any individuals for the
privilege of supplying and using the energy themselves and as long as
it is environmentally justifiable.

And Hinkley with a guaranteed price at roughly twice the going rate fits
in just how?

--
*Why is it that most nudists are people you don't want to see naked?*

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 03 Aug 2016 16:48:26 +0100, "Dave Plowman (News)"
wrote:

In article ,
T i m wrote:
And Hinkley was said to be able to meet 7% of the demand. When and if it
ever gets built and actually works, of course.

Surely having a variety of means of generation isn't a bad thing?

Yes, as long as I'm not having to pay any individuals for the
privilege of supplying and using the energy themselves and as long as
it is environmentally justifiable.

And Hinkley with a guaranteed price at roughly twice the going rate fits
in just how?

Well, 1) it will provide power 24/7 (even when it's dark) and whilst
it doesn't pretend to be 'green', it could well be greener than many
of the so called 'green' alternatives.

So, I'm not against solar or wind farms or you burning tyres in your
shed-genny, I'm against anything that favours a tiny minority
financially at the cost to other electricity users and especially
those solutions that are supposed to be green but may never actually
repay their energy investment (or cover their carbon footprint).

How can anyone justify a supposedly 'green' energy solution that
consumes more energy than it can ever yield?

Now, cut the solar is green bs, take away the FIT thefts, get local
storage to match the full capacity of the (PV) generation (and the
batteries / hydro dams / compressed air tanks may be no more polluting
than many of the alternatives) and yes, it may be that many would then
be willing to consider it as a realistic energy solution (and no more
or less dirty than the rest).

Cheers, T i m

On Wed, 03 Aug 2016 17:07:32 +0100, Chris Hogg wrote:

On Wed, 03 Aug 2016 16:48:26 +0100, "Dave Plowman (News)"
wrote:

In article ,
T i m wrote:
And Hinkley was said to be able to meet 7% of the demand. When and if it
ever gets built and actually works, of course.

Surely having a variety of means of generation isn't a bad thing?

Yes, as long as I'm not having to pay any individuals for the
privilege of supplying and using the energy themselves and as long as
it is environmentally justifiable.

And Hinkley with a guaranteed price at roughly twice the going rate fits
in just how?

Below the guaranteed price for renewables, whether wind or solar,
that's how. http://tinyurl.com/h4qlrwk or see my post earlier in this
thread.

And that's how we came to be (supposedly) leaving the EU. How can
anyone put up an argument if they don't have (or don't want to hear /
know) the actual facts? ;-)

I know Dave is just asking the 'why not' question but the answer is
not a direct / easy one.

If I choose to use a solar panel on a camping holiday to charge some
batteries (to use at night when the solar panels aren't working) I do
so because it's convenient, fairly cheap and if the sun doesn't shine,
I can often pay for power hookup. I don't do so because of some bogus
'green' cause or expect anyone else to subsidise it for me. I also
know that if the sun doesn't shine I can use the alternatives but what
if everyone used solar panels? Why would the campsites bother to run
power to the poles (when they in turn are having to pay to do that)?

Cheers, T i m

En el artículo ,
newshound escribió:

http://www.ingenia.org.uk/Content/in...e5/Flewitt.pdf

Unnerving.

A circumferential crack half the thickness of the steel, with a length
of 4.5m, on the boiler of Sizewell A reactor 2. And they think it's
been there since it was built.

I know this is the boiler, not the reactor pressure vessel, but still...

--
(\_/)
(='.'=) systemd: the Linux version of Windows 10
(")_(")

On Wed, 03 Aug 2016 16:48:26 +0100, Dave Plowman (News) wrote:

In article ,
T i m wrote:
And Hinkley was said to be able to meet 7% of the demand. When and if
it ever gets built and actually works, of course.

Surely having a variety of means of generation isn't a bad thing?

Yes, as long as I'm not having to pay any individuals for the privilege
of supplying and using the energy themselves and as long as it is
environmentally justifiable.

And Hinkley with a guaranteed price at roughly twice the going rate fits
in just how?

It fits in rather cheaper than offshore wind.



--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

On Wednesday, 3 August 2016 11:08:25 UTC+1, Dave Plowman (News) wrote:
In article ,
Chris Hogg wrote:
That was when the NUM decided there should be an end to coal mining
in the UK.

And most of our fuel now comes from abroad, so totally secure. You
think?

All the more reason to push forward with fracking ASAP.

Very true. Would it happen close to where you live?

It's possible.
However I'm not worried. I used to live in a coal mining area.
Much worse than fracking.

On Wednesday, 3 August 2016 10:49:03 UTC+1, The Natural Philosopher wrote:
On 03/08/16 10:30, Chris Hogg wrote:
On Wed, 3 Aug 2016 01:20:14 -0700 (PDT), harry
wrote:

On Tuesday, 2 August 2016 19:00:50 UTC+1, T i m wrote:
Like, if harry with his big place and cash to splash on covering his
roof in solar collectors, can't live 'off grid' (even ignoring the
cost or the ecology) then how could anyone in the UK not living like a
caveman ever expect to not rely on the current range of reliable
energy sources (with the current alternatives available).

Cheers, T i m

I could live off grid if it became neccesary.
But I choose not to because of minor inconveniences.

Those minor inconveniences being having to use candles and wear
several layers of woolly jumpers in the winter evenings, of course.

Bearing in mind your electric car has a sizeable battery in it, and
also that the likes of Tesla and Nissan are now promoting batteries
for storing electricity in the home, either charged off the grid
overnight or from PV's on sunny days, why don't you use your car
battery in a similar fashion? All you'd need is a suitable converter
to plug into.

There speaks a man who Cant Do Sums.

20 million households.

Each one with a 50Kwh electric car battery.
UK winter consumption 50GW

so about 20 hours and all the car batteries are flat.

And no one is going anywhere, and the lights are all out.

Most electric cars have less than 20Kwh capacity.
My own car is 16Kwh.

En el artículo , Dave Plowman (News)
escribió:

And Hinkley with a guaranteed price at roughly twice the going rate fits
in just how?

It's guaranteed power, unlike wind and solar. That's what thick
greenies like harriet can't get through their thick skulls.

--
(\_/)
(='.'=) systemd: the Linux version of Windows 10
(")_(")

Dave Plowman (News) wrote
T i m wrote

I can see you at the meeting now ... "Well, solar can easily meet 10%
of the UK's energy needs on a hot Sunday afternoon (when most of the
factories are closed)"

And Hinkley was said to be able to meet 7% of the demand.
When and if it ever gets built and actually works, of course.

Clearly more than just the one is needed.

Surely having a variety of means of generation isn't a bad thing?

It is with stuff like wind generators that have to have the power generation
capacity to handle the situation where the wind isnt blowing.

When you have that with nukes, you might as well run them all the time
and not bother with the immense cost of the wind generating systems.

On Wednesday, 3 August 2016 18:36:29 UTC+1, Mike Tomlinson wrote:
En el artÃ*culo , Dave Plowman (News)
escribió:

And Hinkley with a guaranteed price at roughly twice the going rate fits
in just how?

It's guaranteed power, unlike wind and solar. That's what thick
greenies like harriet can't get through their thick skulls.

No it's not.
Not one of these devices has ever worked.
In spite of taking three times the money and time anticipated.
Total white elephant.
Obsolete before it's even started it's been so long in the planning.

http://www.no2nuclearpower.org.uk/ne...l-be-obsolete/

https://www.theguardian.com/commenti...-david-cameron

You're the one with a thick skull.
Living in the past.

On Saturday, July 30, 2016 at 10:07:26 PM UTC+1, bert wrote:

For once I agree with you. Whilst I am very much in favour of nuclear it
does seem a bit foolish to begin building a 3rd example when the first
two are in deep trouble.
We should crack on with known proven designs even if that means another
Sizewell B or three.
--
bert

If the French can't even build a car that doesn't fall to bits or cost a fortune to maintain, why should we even consider trusting them to design and build a nuclear reactor on our soil? I feel uneasy enough having one just accross the Channel! Furthermore, previous big technology projects we've done with the French have typically ended up costing twice as much and taking twice as long as promised. (I'm thinking of Concorde and Chunnel, for example.) I'd like to see a British company being commissioned to harness the tidal power in the Severn Estuary. The silt issue seems a weak excuse for rejecting this option. Is un-silting so difficult?

JD

On 04/08/16 11:17, wrote:
I'd like to see a British company being commissioned to harness the
tidal power in the Severn Estuary. The silt issue seems a weak excuse
for rejecting this option. Is un-silting so difficult?


Oh, so instead of a French company with an impeccable safety record in
an industry that produces stuff that powers most of NW Europe, we should
have a British company do something that will be several times more
expensive, intermittent and with no track record of actually delivering
anything?

Wottastoopid****UR.


--
Ideas are more powerful than guns. We would not let our enemies have
guns, why should we let them have ideas?

Josef Stalin

wrote in message
...
On Saturday, July 30, 2016 at 10:07:26 PM UTC+1, bert wrote:

For once I agree with you. Whilst I am very much in favour of nuclear it
does seem a bit foolish to begin building a 3rd example when the first
two are in deep trouble.
We should crack on with known proven designs even if that means another
Sizewell B or three.

If the French can't even build a car that doesn't fall to bits or cost a
fortune to maintain, why
should we even consider trusting them to design and build a nuclear
reactor on our soil?

Because they have had fewer problems with theirs than the yanks, russians or
japs.

I feel uneasy enough having one just accross the Channel!

More fool you.

Furthermore, previous big technology projects we've done with the French
have
typically ended up costing twice as much and taking twice as long as
promised.

Corse nothing like that has ever happened with anything where the frogs are
not involved, eh ?

(I'm thinking of Concorde and Chunnel, for example.) I'd like to see a
British
company being commissioned to harness the tidal power in the Severn
Estuary.

More fool you.

The silt issue seems a weak excuse for rejecting this option. Is
un-silting so difficult?

Very expensive.

On 8/4/2016 11:17 AM, wrote:
On Saturday, July 30, 2016 at 10:07:26 PM UTC+1, bert wrote:

For once I agree with you. Whilst I am very much in favour of nuclear it
does seem a bit foolish to begin building a 3rd example when the first
two are in deep trouble.
We should crack on with known proven designs even if that means another
Sizewell B or three.
--
bert

If the French can't even build a car that doesn't fall to bits or cost a fortune to maintain, why should we even consider trusting them to design and build a nuclear reactor on our soil? I feel uneasy enough having one just accross the Channel! Furthermore, previous big technology projects we've done with the French have typically ended up costing twice as much and taking twice as long as promised. (I'm thinking of Concorde and Chunnel, for example.) I'd like to see a British company being commissioned to harness the tidal power in the Severn Estuary. The silt issue seems a weak excuse for rejecting this option. Is un-silting so difficult?

JD

What the French got right, at least in the first three phases of their
nuclear expansion after the 70's oil price shock was replication. I
suspect that some of the problems of EPR relate to the hiatus, plus the
political requirement to meld the German "Westinghouse" PWR (Konvoi)
with the French one.

As for the Severn Barrage, the bird lobby will put paid to that. OK it
is not economic, but as you imply neither was the channel tunnel, but
nevertheless once built it is a great infrastructure asset. Barrage
would be good for sailors, as well as providing another crossing for
road and/or rail.

On Thursday, August 4, 2016 at 11:35:59 AM UTC+1, The Natural Philosopher wrote:
On 04/08/16 11:17, wrote:
I'd like to see a British company being commissioned to harness the
tidal power in the Severn Estuary. The silt issue seems a weak excuse
for rejecting this option. Is un-silting so difficult?


Oh, so instead of a French company with an impeccable safety record in
an industry that produces stuff that powers most of NW Europe, we should
have a British company do something that will be several times more
expensive, intermittent and with no track record of actually delivering
anything?

Wottastoopid****UR.


--
Ideas are more powerful than guns. We would not let our enemies have
guns, why should we let them have ideas?

Josef Stalin

I didn't suggest picking a company with no track record of delivering anything. :-)

On 8/3/2016 5:36 PM, Mike Tomlinson wrote:
En el artículo ,
newshound escribió:

http://www.ingenia.org.uk/Content/in...e5/Flewitt.pdf

Unnerving.

A circumferential crack half the thickness of the steel, with a length
of 4.5m, on the boiler of Sizewell A reactor 2. And they think it's
been there since it was built.

I know this is the boiler, not the reactor pressure vessel, but still...

Another "quite interesting" fact is that cracking in this location was
not anticipated. I understant that was detected during a routine
non-destructive testing of other welds on the boiler when the operator
moved the probe over a "clear area", not on his inspection schedule, to
confirm its baseline performance.

While large cracks in "new" vessels sound alarming, this is in part a
measure of the size of the safety factors in designs from that era.
There was much agonising over the Magnox plant part way through the life
about the strength of the bellows units which connected the boilers to
the pressure vessels. After Berkeley was shut down, some bellows were
removed for inspection and testing. I don't recall the exact figures,
but I think they had been proof tested before installation at something
like 20% over the maximum working pressure. One of these (perhaps more
than one) was pressure tested to destruction and my recollection is that
it failed at something like three times the proof test pressure. And
this wasn't a catastrophic failure, it just split and released the pressure.

Another part of the design methodology was the idea of "leak before
break". While you don't really want hot, mildly radioactive carbon
dioxide leaking from a working boiler or reactor, this is what we call a
revealed fault. What you need to avoid at all costs is a brittle
fracture where a vessel comes apart (or a very large hole develops, for
example at a nozzle) essentially instantaneously. That gives you a large
energy release, what the tabloids might term "an explosion". This is bad
enough, but would also compromise cooling of the fuel taking you into
Fukushima territory.

En el artículo ,
newshound escribió:

Another "quite interesting" fact is that cracking in this location was
not anticipated.

Of course, materials science, analysis and computer modelling have come
on in huge leaps and bounds since the 1960s, when these boilers were
built.

As you mention later regarding the bellows units at Berkeley, I suspect
the designers, not having the benefit of full understanding of the
materials used that we would have today, deliberately built in a large
safety margin, as you say he

One of these (perhaps more
than one) was pressure tested to destruction and my recollection is that
it failed at something like three times the proof test pressure

Another part of the design methodology was the idea of "leak before
break". While you don't really want hot, mildly radioactive carbon
dioxide leaking from a working boiler or reactor, this is what we call a
revealed fault.

I understand. A revealed fault allows the source of the leak to be
identified, an explosion leaves little (less?) evidence to go on when
diagnosing the cause.

What you need to avoid at all costs is a brittle
fracture where a vessel comes apart (or a very large hole develops, for
example at a nozzle) essentially instantaneously. That gives you a large
energy release, what the tabloids might term "an explosion".

It's what Elon Musk called a "rapid unscheduled disassembly" when one of
the SpaceX rockets made an unsuccessful landing

This is bad
enough, but would also compromise cooling of the fuel taking you into
Fukushima territory.

I was under the impression the AGRs were fail-safe, is this not the
case?

Thanks for the feedback btw, really interesting reading.

--
(\_/)
(='.'=) systemd: the Linux version of Windows 10
(")_(")

On 04/08/2016 11:17, wrote:
On Saturday, July 30, 2016 at 10:07:26 PM UTC+1, bert wrote:

For once I agree with you. Whilst I am very much in favour of
nuclear it does seem a bit foolish to begin building a 3rd example
when the first two are in deep trouble. We should crack on with
known proven designs even if that means another Sizewell B or
three. -- bert

If the French can't even build a car that doesn't fall to bits or
cost a fortune to maintain, why should we even consider trusting them
to design and build a nuclear reactor on our soil? I feel uneasy
enough having one just accross the Channel! Furthermore, previous big
technology projects we've done with the French have typically ended
up costing twice as much and taking twice as long as promised. (I'm
thinking of Concorde and Chunnel, for example.) I'd like to see a
British company being commissioned to harness the tidal power in the
Severn Estuary. The silt issue seems a weak excuse for rejecting this
option. Is un-silting so difficult?

JD


If un-silting were easy we could dig a big hole in east anglia and
scotland use them for tidal power.

On 04/08/2016 13:10, newshound wrote:


Another part of the design methodology was the idea of "leak before
break". While you don't really want hot, mildly radioactive carbon
dioxide leaking from a working boiler or reactor, this is what we call a
revealed fault. What you need to avoid at all costs is a brittle
fracture where a vessel comes apart (or a very large hole develops, for
example at a nozzle) essentially instantaneously. That gives you a large
energy release, what the tabloids might term "an explosion". This is bad
enough, but would also compromise cooling of the fuel taking you into
Fukushima territory.

Not with an AGR it wouldn't, they would take days to get too hot without
any cooling.

On 8/4/2016 1:21 PM, Mike Tomlinson wrote:


This is bad
enough, but would also compromise cooling of the fuel taking you into
Fukushima territory.

I was under the impression the AGRs were fail-safe, is this not the
case?

I'm not really familiar with this part of the AGR safety case, but they
have several good features compared to Magnox or water reactors.

They are oxide fuel (unlike Magnox) and therefore the fuel won't burn if
it gets hot enough and exposed to air because the gas circuit has
failed. The fuel has stainless steel cladding, rather than the zircalloy
used in water reactors. If it gets hot enough, zircalloy reacts with
water to release hydrogen, which is why Fukushima (also Three Mile
Island) had hydrogen explosions which disrupted the pond buildings.

The AGR power density is much lower than in a water reactor, so they
don't get so hot so quickly if things go tits up. And your cooling does
not drop by such a large factor if the plant depressurises.

Also, concrete pressure vessels can't fail catastrophically like steel
ones, so they don't depressurise anything like so fast, unless one of
the larger closures fails (like the circulator closures, or the boiler
closures at Hartlepool and Heysham 1) but there are a lot of engineered
safeguards against these failing.


Thanks for the feedback btw, really interesting reading.

On 8/4/2016 1:54 PM, dennis@home wrote:
On 04/08/2016 13:10, newshound wrote:


Another part of the design methodology was the idea of "leak before
break". While you don't really want hot, mildly radioactive carbon
dioxide leaking from a working boiler or reactor, this is what we call a
revealed fault. What you need to avoid at all costs is a brittle
fracture where a vessel comes apart (or a very large hole develops, for
example at a nozzle) essentially instantaneously. That gives you a large
energy release, what the tabloids might term "an explosion". This is bad
enough, but would also compromise cooling of the fuel taking you into
Fukushima territory.

Not with an AGR it wouldn't, they would take days to get too hot without
any cooling.

Agreed, but we were talking about steel pressure vessel failures which,
in the UK, means Magnox or Sizewell B.

On Thursday, 4 August 2016 11:17:43 UTC+1, wrote:
On Saturday, July 30, 2016 at 10:07:26 PM UTC+1, bert wrote:

For once I agree with you. Whilst I am very much in favour of nuclear it
does seem a bit foolish to begin building a 3rd example when the first
two are in deep trouble.
We should crack on with known proven designs even if that means another
Sizewell B or three.
--
bert

If the French can't even build a car that doesn't fall to bits or cost a fortune to maintain, why should we even consider trusting them to design and build a nuclear reactor on our soil? I feel uneasy enough having one just accross the Channel! Furthermore, previous big technology projects we've done with the French have typically ended up costing twice as much and taking twice as long as promised. (I'm thinking of Concorde and Chunnel, for example.) I'd like to see a British company being commissioned to harness the tidal power in the Severn Estuary. The silt issue seems a weak excuse for rejecting this option. Is un-silting so difficult?


Yes, actually it is.

On 04/08/16 16:53, newshound wrote:
On 8/4/2016 1:21 PM, Mike Tomlinson wrote:


This is bad
enough, but would also compromise cooling of the fuel taking you into
Fukushima territory.

I was under the impression the AGRs were fail-safe, is this not the
case?

I'm not really familiar with this part of the AGR safety case, but they
have several good features compared to Magnox or water reactors.

They are oxide fuel (unlike Magnox) and therefore the fuel won't burn if
it gets hot enough and exposed to air because the gas circuit has
failed. The fuel has stainless steel cladding, rather than the zircalloy
used in water reactors. If it gets hot enough, zircalloy reacts with
water to release hydrogen, which is why Fukushima (also Three Mile
Island) had hydrogen explosions which disrupted the pond buildings.

The AGR power density is much lower than in a water reactor, so they
don't get so hot so quickly if things go tits up. And your cooling does
not drop by such a large factor if the plant depressurises.

Also, concrete pressure vessels can't fail catastrophically like steel
ones, so they don't depressurise anything like so fast, unless one of
the larger closures fails (like the circulator closures, or the boiler
closures at Hartlepool and Heysham 1) but there are a lot of engineered
safeguards against these failing.


Thanks for the feedback btw, really interesting reading.


Though they are not intended to be passibvely cooled, after SCRAMing
they dont need to be pumped if there is enough feedwater to the boilers.

Very safe design indeed.

--
€œBut what a weak barrier is truth when it stands in the way of an
hypothesis!€�

Mary Wollstonecraft

On Thursday, 4 August 2016 13:10:51 UTC+1, newshound wrote:
On 8/3/2016 5:36 PM, Mike Tomlinson wrote:
En el artÃ*culo ,
newshound escribió:

http://www.ingenia.org.uk/Content/in...e5/Flewitt.pdf

Unnerving.

A circumferential crack half the thickness of the steel, with a length
of 4.5m, on the boiler of Sizewell A reactor 2. And they think it's
been there since it was built.

I know this is the boiler, not the reactor pressure vessel, but still....

Another "quite interesting" fact is that cracking in this location was
not anticipated. I understant that was detected during a routine
non-destructive testing of other welds on the boiler when the operator
moved the probe over a "clear area", not on his inspection schedule, to
confirm its baseline performance.

While large cracks in "new" vessels sound alarming, this is in part a
measure of the size of the safety factors in designs from that era.
There was much agonising over the Magnox plant part way through the life
about the strength of the bellows units which connected the boilers to
the pressure vessels. After Berkeley was shut down, some bellows were
removed for inspection and testing. I don't recall the exact figures,
but I think they had been proof tested before installation at something
like 20% over the maximum working pressure. One of these (perhaps more
than one) was pressure tested to destruction and my recollection is that
it failed at something like three times the proof test pressure. And
this wasn't a catastrophic failure, it just split and released the pressure.

Another part of the design methodology was the idea of "leak before
break". While you don't really want hot, mildly radioactive carbon
dioxide leaking from a working boiler or reactor, this is what we call a
revealed fault. What you need to avoid at all costs is a brittle
fracture where a vessel comes apart (or a very large hole develops, for
example at a nozzle) essentially instantaneously. That gives you a large
energy release, what the tabloids might term "an explosion". This is bad
enough, but would also compromise cooling of the fuel taking you into
Fukushima territory.

Pressure vessels are not tested with a gas.
Any rupture would be catastrophic.
They are tested with water so that any failure is a none event.
Ie not dangerous.

On Thursday, 4 August 2016 13:21:46 UTC+1, Mike Tomlinson wrote:
En el artÃ*culo ,
newshound escribió:

Another "quite interesting" fact is that cracking in this location was
not anticipated.

Of course, materials science, analysis and computer modelling have come
on in huge leaps and bounds since the 1960s, when these boilers were
built.

As you mention later regarding the bellows units at Berkeley, I suspect
the designers, not having the benefit of full understanding of the
materials used that we would have today, deliberately built in a large

Bellows have been used in steam systems for around a hundred years.
They are well understood.

On 8/4/2016 5:02 PM, The Natural Philosopher wrote:
On 04/08/16 16:53, newshound wrote:
On 8/4/2016 1:21 PM, Mike Tomlinson wrote:


This is bad
enough, but would also compromise cooling of the fuel taking you into
Fukushima territory.

I was under the impression the AGRs were fail-safe, is this not the
case?

I'm not really familiar with this part of the AGR safety case, but they
have several good features compared to Magnox or water reactors.

They are oxide fuel (unlike Magnox) and therefore the fuel won't burn if
it gets hot enough and exposed to air because the gas circuit has
failed. The fuel has stainless steel cladding, rather than the zircalloy
used in water reactors. If it gets hot enough, zircalloy reacts with
water to release hydrogen, which is why Fukushima (also Three Mile
Island) had hydrogen explosions which disrupted the pond buildings.

The AGR power density is much lower than in a water reactor, so they
don't get so hot so quickly if things go tits up. And your cooling does
not drop by such a large factor if the plant depressurises.

Also, concrete pressure vessels can't fail catastrophically like steel
ones, so they don't depressurise anything like so fast, unless one of
the larger closures fails (like the circulator closures, or the boiler
closures at Hartlepool and Heysham 1) but there are a lot of engineered
safeguards against these failing.


Thanks for the feedback btw, really interesting reading.


Though they are not intended to be passibvely cooled, after SCRAMing
they dont need to be pumped if there is enough feedwater to the boilers.

Very safe design indeed.

Safe, but complicated and expensive. Not helped by three and a half
different designs (Heysham 2 and Torness are improved versions of
Hinkley Point B and Hunterston B).

I used to be very anti water reactors compared to AGR for just those
reasons. However one thing which Three Mile Island demonstrated was that
in that in spite of being a not particularly robust design PWR
(once-through rather than recirculating boilers which means overheating
happens three times faster than in a Westinghouse / Sizewell B design)
they had a commercial disaster and destroyed their investment by very
poor handling of a relatively minor fault, but the actual release of
activity to the environment was very small, with no practical
consequences to the staff let alone the surrounding population.

On 8/4/2016 5:05 PM, harry wrote:
On Thursday, 4 August 2016 13:10:51 UTC+1, newshound wrote:
On 8/3/2016 5:36 PM, Mike Tomlinson wrote:
En el artÃ*culo ,
newshound escribió:

http://www.ingenia.org.uk/Content/in...e5/Flewitt.pdf

Unnerving.

A circumferential crack half the thickness of the steel, with a length
of 4.5m, on the boiler of Sizewell A reactor 2. And they think it's
been there since it was built.

I know this is the boiler, not the reactor pressure vessel, but still...

Another "quite interesting" fact is that cracking in this location was
not anticipated. I understant that was detected during a routine
non-destructive testing of other welds on the boiler when the operator
moved the probe over a "clear area", not on his inspection schedule, to
confirm its baseline performance.

While large cracks in "new" vessels sound alarming, this is in part a
measure of the size of the safety factors in designs from that era.
There was much agonising over the Magnox plant part way through the life
about the strength of the bellows units which connected the boilers to
the pressure vessels. After Berkeley was shut down, some bellows were
removed for inspection and testing. I don't recall the exact figures,
but I think they had been proof tested before installation at something
like 20% over the maximum working pressure. One of these (perhaps more
than one) was pressure tested to destruction and my recollection is that
it failed at something like three times the proof test pressure. And
this wasn't a catastrophic failure, it just split and released the pressure.

Another part of the design methodology was the idea of "leak before
break". While you don't really want hot, mildly radioactive carbon
dioxide leaking from a working boiler or reactor, this is what we call a
revealed fault. What you need to avoid at all costs is a brittle
fracture where a vessel comes apart (or a very large hole develops, for
example at a nozzle) essentially instantaneously. That gives you a large
energy release, what the tabloids might term "an explosion". This is bad
enough, but would also compromise cooling of the fuel taking you into
Fukushima territory.

Pressure vessels are not tested with a gas.
Any rupture would be catastrophic.
They are tested with water so that any failure is a none event.
Ie not dangerous.

I don't think you understand. By proof testing with water, the *stored
energy* is very much less than with gas, so the bits don't go so far.
But in a proof test you can still have a brittle fracture where the
vessel splits into two bits, or you can just open up a split, releasing
the pressure. The former is particularly bad news if it happens in
service with gas. The latter isn't, provided the structures can resist
the gas forces. And this is what happened in the Berkeley tests. These
showed that they would fail in a relatively benign way at something
around three times the normal working pressure without throwing large
chunks of metal a mile or more. You wouldn't want to be too close to
them if they failed, but you would not be *anyway* because of the local
radiation levels when the reactors were at power.

On 8/4/2016 5:07 PM, harry wrote:
On Thursday, 4 August 2016 13:21:46 UTC+1, Mike Tomlinson wrote:
En el artÃ*culo ,
newshound escribió:

Another "quite interesting" fact is that cracking in this location was
not anticipated.

Of course, materials science, analysis and computer modelling have come
on in huge leaps and bounds since the 1960s, when these boilers were
built.

As you mention later regarding the bellows units at Berkeley, I suspect
the designers, not having the benefit of full understanding of the
materials used that we would have today, deliberately built in a large

Bellows have been used in steam systems for around a hundred years.
They are well understood.

Not at that size and rating. The construction of the Berkeley ones was
in fact quite innovative.

On 04/08/16 22:38, newshound wrote:
You wouldn't want to be too close to them if they failed, but you would
not be *anyway* because of the local radiation levels when the reactors
were at power.

The local radiation levels are trivial in the water circuits of a
working reactor, especially AGR or PWR designs, which use two stage heat
exchangers to cool the cores and heat the water.

Only BWRs have the actual turbine water going through the actual reactor
core.

"Because the water around the core of a reactor is always contaminated
with traces of radionuclides, the turbine must be shielded during normal
operation, and radiological protection must be provided during
maintenance. The increased cost related to operation and maintenance of
a BWR tends to balance the savings due to the simpler design and greater
thermal efficiency of a BWR when compared with a PWR. Most of the
radioactivity in the water is very short-lived (mostly N-16, with a
7-second half-life), so the turbine hall can be entered soon after the
reactor is shut down. "




--
"What do you think about Gay Marriage?"
"I don't."
"Don't what?"
"Think about Gay Marriage."

On Thursday, 4 August 2016 22:38:57 UTC+1, newshound wrote:
On 8/4/2016 5:05 PM, harry wrote:
On Thursday, 4 August 2016 13:10:51 UTC+1, newshound wrote:
On 8/3/2016 5:36 PM, Mike Tomlinson wrote:
En el artÃ*culo ,
newshound escribió:

http://www.ingenia.org.uk/Content/in...e5/Flewitt.pdf

Unnerving.

A circumferential crack half the thickness of the steel, with a length
of 4.5m, on the boiler of Sizewell A reactor 2. And they think it's
been there since it was built.

I know this is the boiler, not the reactor pressure vessel, but still....

Another "quite interesting" fact is that cracking in this location was
not anticipated. I understant that was detected during a routine
non-destructive testing of other welds on the boiler when the operator
moved the probe over a "clear area", not on his inspection schedule, to
confirm its baseline performance.

While large cracks in "new" vessels sound alarming, this is in part a
measure of the size of the safety factors in designs from that era.
There was much agonising over the Magnox plant part way through the life
about the strength of the bellows units which connected the boilers to
the pressure vessels. After Berkeley was shut down, some bellows were
removed for inspection and testing. I don't recall the exact figures,
but I think they had been proof tested before installation at something
like 20% over the maximum working pressure. One of these (perhaps more
than one) was pressure tested to destruction and my recollection is that
it failed at something like three times the proof test pressure. And
this wasn't a catastrophic failure, it just split and released the pressure.

Another part of the design methodology was the idea of "leak before
break". While you don't really want hot, mildly radioactive carbon
dioxide leaking from a working boiler or reactor, this is what we call a
revealed fault. What you need to avoid at all costs is a brittle
fracture where a vessel comes apart (or a very large hole develops, for
example at a nozzle) essentially instantaneously. That gives you a large
energy release, what the tabloids might term "an explosion". This is bad
enough, but would also compromise cooling of the fuel taking you into
Fukushima territory.

Pressure vessels are not tested with a gas.
Any rupture would be catastrophic.
They are tested with water so that any failure is a none event.
Ie not dangerous.

I don't think you understand. By proof testing with water, the *stored
energy* is very much less than with gas, so the bits don't go so far.
But in a proof test you can still have a brittle fracture where the
vessel splits into two bits, or you can just open up a split, releasing
the pressure. The former is particularly bad news if it happens in
service with gas. The latter isn't, provided the structures can resist
the gas forces. And this is what happened in the Berkeley tests. These
showed that they would fail in a relatively benign way at something
around three times the normal working pressure without throwing large
chunks of metal a mile or more. You wouldn't want to be too close to
them if they failed, but you would not be *anyway* because of the local
radiation levels when the reactors were at power.

That's what I said in a tenth of the words.

I was responsible for hydraulic testing of steamb oilers in the past.
A test used for over a hundred years.

Its odd how greenies hate coal and nukes but rely on them to keep their
lights on. I agree that you should and the other greenies have a green
tariff that cuts you off when there isn't enough green energy to go
around to encourage you to understand the problems.


We've got a loopy woman down the road she laps up ALL the green crap and
then some more. Solar and wind good, Nuclear spawn of Satan, but I'd bet
you as much as you like she'd wail if she didn't have the nuke and
coal/gas back up when her sun doesn't shine for her;!..

Silly cow...
--
Tony Sayer

In article , Dave Plowman (News)
scribeth thus
In article ,
T i m wrote:
I can see you at the meeting now ... "Well, solar can easily meet 10%
of the UK's energy needs on a hot Sunday afternoon (when most of the
factories are closed)"

And Hinkley was said to be able to meet 7% of the demand. When and if it
ever gets built and actually works, of course.


Well lets hope it does and as soon as Dave as the other ones won't run
forever they too will need replacement and you could cover the UK with
windy mills and solar but you'd be very hard pressed to match the
reliability of what Nuclear can do...


Surely having a variety of means of generation isn't a bad thing?

;!...
--
Tony Sayer