PBS Forum

Is this the book by Arthington Worsley?

Quote from: David Pilling on July 21, 2023, 01:42:53 PMYep, our hopes depend on you.

LLLOL - I retire in 4 months.

It is no secret that RR is extending one if its Derby sites, but that is to enable them to fill certain orders from Australia. Where it is proposed to build any SMR, I have no idea, but the current plan is that they would be installed on existing nuclear power plant sites - an "odd" decision in many ways.

I have no idea on relative sizes, but Russia does have mobile nuclear plants (I believe that there is more than one) for civilian use, or at least not part of any defence installation. They are (each) on some kind of gigantic barge/pontoon, so far as I am aware.

There would be many problems associated with moving a working SMR via anything but sea, but size/weight alone would be a major one. The pressure vessels are large and very thick and each plant uses more than one. Dismantling anything after start-up, to move it disassembled, would not be an option.
RR talk about 10 acre sites, but I suspect that a lot of this would be security measures - any building would be a "long" way from the perimeter. The claim is, though, that the "modular" part of the name refers to the fact that all parts could be transported as per shipping containers, albeit rather a large number. In all probability, the vessels will be built to something like maximum dimensions for a shipping container.

I do not work for/with the SMR team.

Quote from: Bern on June 12, 2023, 08:39:42 AM

Quote from: David Pilling on June 11, 2023, 06:42:18 PMeven if Putin's army is forced from Ukraine what is left may not be usable.

It appears that both Ukraine and Russia are using land mines in this conflict.  These will be a danger to people and livestock for years after the war is over.  Demining will be a huge undertaking without assurance of complete success.

The danger is far greater from deeply seated munitions that have not detonated. The great majority of mines have been laid in agricultural land and the Ukrainian farmers have teamed with Heath Robinson to demine lots of that already.
Cluster munitions are another problem - they are meant to detonate on landing - the ones that don't are the problem. The US reckons it has very few duds, but boith parties have been using them, even before the US sent any to Ukraine.

Quote from: David Pilling on June 12, 2023, 05:21:15 AMA lot of hope is focused on small nuclear power plants, the type of thing they put in submarines or aircraft carriers - quicker to build in a factory - and you could move them around depending on what the energy policy of the day happens to be.

Dream on. They are absolutely not even remotely portable outside of a vast sub' or ship.
Nor are they "quick" to build, except in comparison to a conventional nuclear power plant.
I work for RR 

I usually use the Quick Reply box.

It is no huge problem, but mighty confusing, especially the first time.

I wonder where this reply will go    

The problem with plastic is that it has no intrinsic strength - apply a modest one-sided force over protracted periods and it warps/creeps.
For reliable long term use, it would need to be fibre-reinforced.

In Europe you also have the hassle that there is nothing that is generally available as a wood treatment that actually lasts. Wood treatments here are now cypermethrin and not much else. Creosote is atill available, but you need a permit/licence.

All of the raised sand plunges that I have ever seen have been "boxes" of sand, on legs - just like a standard greenhouse bench, sort of. I have never made note of construction as I have never contemplated building or buying one.

Just forming a raised bed on the ground would have lots of problems, not least, plants rooting through, outside of the pot. You also could not really control the moisture content of the sand.

I don't know what is available here on the PBS site, but if you can't find anything, there are many, many pic's of Iain Young's raised/plunge and other beds over on SRGC and Iain himself is more than helpful. The same probably applies to the AGS as sand plunges are very very popular amongst alpine ethusiasts.

Looking at off-the-shelf options here in the UK, they are basically small, so that the wieght isn't great when full.

Making timber ones shouldn't be so bad, except that the base would need to be very thick and very well-supported. The sand should mostly be dry, and certainly never be really wet.

For the second time, a reply that I have posted has been added to another thread entirely....

Weird.

I have never built, or contemplated building, a raised sand bed.

Bear in mind (forgive pun), that one cubic yard of sand (which could include your pots if you use high mineral composts) weighs a ton and a quarter when dry and around one and half when damp.
3 foot wide bed, 9 inches deep, 12 feet long, that is one cubic yard. (9 inches isn't very deep for a sand plunge.)

Not only must the bed itself take that weight, but any frame underneath, and any footings/foundations for that frame has to, too.

I can't speak for the US, but flowering size S.m. are freely available at very modest cost in Europe via endless outlets. (Over here, I would not pay more than ~$5 per bulb, although many sellers expect a lot more.)
They are probably field-grown, and certainly from the S hemisphere as they grow well enough but take 2-3 years to sync' properly with N hemisphere seasons.
They are so cheap that I can't imagine that anyone would contemplate producing them within Europe on a commercial scale - they just could not compete.

Quote from: Uli on June 26, 2023, 10:48:13 AMthe thing the English call ,,summer"

That does not stop many growers in the UK from really baking some greenhouse plants.

Most nice summer days here reach low to mid 20'sC (70-80F), and most summers produce at least some days well above that, but unless any greenhouse is either shaded (not the best option), or has more vents and doors than fixed glass, or forced ventilation, 30-35-40+C (85-105+F) is normal in a greenhouse on a sunny day from late spring into autumn (and yes, we have plenty of those during most summers).
Plenty of UK greenhouses get hotter as their owners have totally inadequate ventilation installed.

Quote from: MarcR on June 24, 2023, 03:59:46 PMCrinum like to be moist but not wet all year. 

It depends on the species/hybrid and minimum winter temperature.

Ignoring natans and thaianum, my Crinums are all under glass (actually bulbispermum and boophanoides are on a cold, west-facing kitchen window sill) and although x powellii and macowanii can take several degrees of frost, I keep all of them except variable dry for the winter (greenhouse minimum is around 6C), and would not risk things otherwise.
Some SA Crinums are native to areas with very dry, dry seasons, some are baked into something akin to concrete while dormant. During their active growing season, some are semi- or fully aquatic, although the vleilelies are supposed to flower perfectly well if just kept well-watered rather than submerged, with a dry season.

Quote from: David Pilling on June 23, 2023, 10:30:21 AMFor example if you can manipulate temperatures you could generate two (or more growing seasons) per year.

It is generally (always?) temperature cycles controlling active growing periods, although the warm/cool periods usually need specific minimum lengths to flick the clock over - peonia seeds are a very good example which can be artificially taken through two cycles in one year.

For flowering, it is generally (always?) photo-period, or ratio of dark to light, that triggers things - pointsettias are a very good example.

There are also some plants that grow unlinked to phoo-period or temperature, but grow so long as conditions allow - one comes to mind - some Crinums, which grow so long as there is enough moisture - uncommon in nature, but not so in cultivation. But, they will need a short-long day cycle, and wet-dry, to trigger flowering.

Contact Dr Christian - he is pretty anal about plant ID's and may well help.

Many amaryllid seeds are notorious for germinating within almost no time of maturing - seeds will send out a root before falling in some cases - so-called ephemeral seeds.

I bought a pack of Crinum asiatica seeds back last year and got around 80% germination within a very few weeks with just 2-3 showing nothing. Around 3 weeks ago, the pots were transferred to the greenhouse from the indoor propagator and today two more seeds have a root.

It depends on the plant - many will go dormant as the day lengthens and temperatures rise, and they will rot if kept watered.

Many bulbs depend on dormancy to trigger flowering once mature.