What is this part from my dad's work at a nuclear research establishment?

[marcosmatt]

TL;DR Summary

Trying to identify my avatar. It was my Dad's from his days working a nuclear research establishment

Does anyone know what this is. It became my dad's coffee mug mat for as long as I can remember and it is something I have of his now he has gone. Its was a part of something from his work at a nuclear research establishment. Any help would be appreciated.

 

[jedishrfu]

Is it radioactive?

 

[marcosmatt]

Is it radioactive?

No I don't believe it was ever used.

 

[DaveC426913]

Jesus. The manhole cover from the Pascal B test finally came back down.

 

[DaveC426913]

That is the work of a drill press, a determined mind and a lot of time.

Every one of those holes is drilled out by at least eight applications of a smaller drill bit:

It's exacting work - holes from different parts of the piece match very closely*.
*flipping the image and layering them shows how close

Assuming this was made before computer-controlled milling machines, I am not sure if it were done by (a very steady) hand, or if this is the limit of precision drilling back then.

At first I thought it might have been a slug for a practice exercise. But it also seems to have had the raw edges filed down. Which suggests it served a purpose beyond simply making it.

@marcosmatt: Am I right about the edges being filed down, or is that just a trick of the oblique light source?

I think it's a one-off part intended to replace a factory-part that couldn't be obtained.

None of which shed any light on what purpose, exactly it might have served.

 

[DaveC426913]

Further: it kind of resembles a drain grill. But regular drain grills are designed to withstand a lot of weight placed on them, and they are designed for low/infrequent water flow, so you get more metal than hole, thus:

But the OP object seems to be quite streamlined (more hole than metal). A lot of effort went into making this thing cause as little drag as possible. Even to the point of fragility - it's not going to support much weight.

This suggests to me it's intended for a protected area where there is high fluid flow. Such as inside a coolant pipe or some such.I wonder if it originally had standard holes (which would provide the preset pattern of holes) and someone felt it was causing too much drag, so they pulled it out and milled it down to the bare minimum.

Odd though that the attachment holes are in the body of the grill, rather than around the perimeter.

 

[DaveC426913]

And I haven't even touched on the conductive properties of the metal. Perhaps it's merely a heat sink with lots of surface area.

@marcosmatt : can you tell what it's made of?

 

[marcosmatt]

I think it maybe stainless but not 100% on that. Some edges are filled down will attach pic to show.
It's very impressive engineering considering it was made in the 1970s best guess.
I was told what it was when I was very young and have a vague memory of it being something to do with a cooling system for nuclear rods. But maybe very wrong however what I do notice is that the raised / thicker sections of wall perfectly support a rod. This would support the idea of coolant being able to pass rods inserted into it.
I could be miles of course here though.

 

[marcosmatt]

Pic showing raised and filed edges

 

[marcosmatt]

This one shows what I mean about the support faces. The curved face of each of those raised sections makes a perfect circle. Exactly the same size on every hole.

 

[Vanadium 50]

Does it have to be a "thing"? Could it be a model of a thing?

 

[DaveC426913]

This one shows what I mean about the support faces. The curved face of each of those raised sections makes a perfect circle. Exactly the same size on every hole.

That's because they were either
- the original holes of the device, or
- they were drilled out after-market by a large bit.
Then someone came with a smaller bit to shave the vanes down to minimum.

 

[DaveC426913]

Still, a quick Google suggests: nuclear fuel rods are

- about 1cm in diameter, and
- arranged into bundles about 10cm in diameter.



https://www.britannica.com/technology/nuclear-reactor/Coolant-system

 

[DaveC426913]

Interesting pattern of holes. It's hexagonal:
(360°), 60°, 30°, 20°, 15° per hole.
1, 6, 12, 18, 24 holes per ring.

Not quite the same as the drain grill in post 6. This is perfectly geometrical.

Like this:

But this has only 4 concentric rings (1,6,12 and 18). No 5th ring of 24.Finding some interesting thumbnails:

For the life of me, I cannot find a bundle that has 5 concentric rings like the OP's object.

 

[berkeman]

Paging some of our nuclear specialists: @Astronuc @anorlunda @Alex A @gmax137

 

[anorlunda]

I think DaveC is on the right track with a fuel pin spacer grid. However, the one in the OP looks far too crude for a production reactor. On the other hand, research reactors might use one-off parts hand-made in the machine shop. If the material was zirconium, that would be a strong hint.

What are the dimensions of the object in the OP?

Finding some interesting thumbnails:

 

[Astronuc]

Summary: Trying to identify my avatar. It was my Dad's from his days working a nuclear research establishment

Does anyone know what this is. It became my dad's coffee mug mat for as long as I can remember and it is something I have of his now he has gone. Its was a part of something from his work at a nuclear research establishment. Any help would be appreciated.

It looks like a grid for a 61 fuel element CANDU (CANDU 6) assembly. I've not seen the details before. The end fitting are usually more open, and the fuel rod cladding would have spacer tabs brazed on the surface to act as spacing elements. The end fitting material would line up with the fuel rods. I'm wondering if it is a prototype.

It could be a 304 or 316 stainless steel.

If not CANDU, it could be an AGR (or perhaps Magnox) spacer grid. It's been a while since I've looked at AGR components, and details are hard to find in the public domain.

 

[marcosmatt]

I think DaveC is on the right track with a fuel pin spacer grid. However, the one in the OP looks far too crude for a production reactor. On the other hand, research reactors might use one-off parts hand-made in the machine shop. If the material was zirconium, that would be a strong hint.

What are the dimensions of the object in the OP?View attachment 304583

Hi

I would fully expect it to be a research / prototype piece as that was his side of things rather than being involved in running a reactor.
Have taken pic with ruler to show dimensions. It's approx 13cm round. Seems to be 12mm ish for hole. Where I put the drill bit.

 

[marcosmatt]

Hi

I would fully expect it to be a research / prototype piece as that was his side of things rather than being involved in running a reactor.
Have taken pic with ruler to show dimensions. It's approx 13cm round. Seems to be 12mm ish for hole. Where I put the drill bit.

I also have no idea how to tell if it is zirconium

 

[Orodruin]

I also have no idea how to tell if it is zirconium

Well, for starters it would have a density of 6.5 g/cm^3, which should be easily testable by a fairly precise kitchen scale.

 

[DaveC426913]

Well, for starters it would have a density of 6.5 g/cm^3, which should be easily testable by a fairly precise kitchen scale.

... and a water-filled container to measure its volume...

 

[marcosmatt]

Well, for starters it would have a density of 6.5 g/cm^3, which should be easily testable by a fairly precise kitchen scale.

That's creating lot of fun and mess in our kitchen. It weighs 216grams. Trying to work out volume using std kitchen equipment is proving a lot harder. Water everywhere

 

[Orodruin]

That's creating lot of fun and mess in our kitchen. It weighs 216grams. Trying to work out volume using std kitchen equipment is proving a lot harder. Water everywhere

Fill container to the brim and weigh it. Put container in kitchen sink and drop object into it. Fish out object. Weigh container. Water is 1 g/cm^3.

 

[Orodruin]

Also, pray that it is not made of potassium ...

... on the other hand ... if it is it probably should not be used as a coffee mug mat or put inside a nuclear reactor ...

 

[marcosmatt]

Tried that with a saucepan and tray as only things it would fit into. On our scales that came up with a weight change if 19 to 20g so 19 to 20ml. That leaves us with a density of 10.8 to 11.3g/cm^3. Kind of rules out zirconium. Good thing is all the old coffee has now washed off it looks lot better

 

[Orodruin]

It is also not potassium

 

[marcosmatt]

So didn't believe earlier result so made something to measure better. This brings me to 29g and a density of 7.4g/cm^3. That I believe is around the stainless steel mark. Few pics for entertainment value

 

[Astronuc]

300 series stainless steel should be around 8 g/cm³, give or take. It would be slightly greater density if contained Mo or Nb, and the British used something similar to a Type 347, but much greater Ni content, e.g., 20Cr/25Ni/0.7Mn/0.5Nb, which would be more like 8.2-8.3 g/cm³.

I have a colleague who tentatively identified the component as an AGR brace, as opposed to spacer grid. He will check his drawings.

 

[DaveC426913]

So didn't believe earlier result so made something to measure better. This brings me to 29g

29g? Last measurement was 216g.

That I believe is around the stainless steel mark.

So, non-magnetic?

 

[Orodruin]

So didn't believe earlier result so made something to measure better. This brings me to 29g and a density of 7.4g/cm^3. That I believe is around the stainless steel mark. Few pics for entertainment value

The best kind of experiment is that which can be performed in a home kitchen. Bonus points if it is edible.

In my book at least two illustrations are based on photos I took in my kitchen.

 

[Orodruin]

29g? Last measurement was 216g.

The displaced water, not the object itself.

 

[marcosmatt]

29g? Last measurement was 216g.So, non-magnetic?

29g of water so 29ml

 

[marcosmatt]

300 series stainless steel should be around 8 g/cm³, give or take. It would be slightly greater density if contained Mo or Nb, and the British used something similar to a Type 347, but much greater Ni content, e.g., 20Cr/25Ni/0.7Mn/0.5Nb, which would be more like 8.2-8.3 g/cm³.

I have a colleague who tentatively identified the component as an AGR brace, as opposed to spacer grid. He will check his drawings.

Awesome thanks for that. So next Q will be what is an AGR brace... off to Google

 

[Astronuc]

Awesome thanks for that. So next Q will be what is an AGR brace... off to Google

What is AGR Fuel?​

AGR fuel is a type of oxide fuel made from uranium dioxide powder. An AGR fuel element is made up of uranium oxide pellets stacked inside stainless steel tubes, which are grouped together in a graphite sleeve to form a fuel assembly. Thirty-six stainless steel tubes, each containing 64 pellets, make up an assembly. The steel tubes are held by a machined brace – a recent innovation that improves fuel performance and nuclear safety.

https://info.westinghousenuclear.com/blog/the-art-of-innovation-westinghouse-agr-fuel

BNFL bought Westinghouse, then sold it to Toshiba, which then got mired in the bankruptcy of Westinghouse over the fiasco of US AP1000 projects. Westinghouse Electric Co. is now owned by a Canadian private equity group, Brookfield Business Partners.

https://www.nytimes.com/2017/03/29/business/westinghouse-toshiba-nuclear-bankruptcy.html
https://world-nuclear-news.org/Articles/Westinghouse-sale-to-Brookfield-completed

https://en.wikipedia.org/wiki/British_Nuclear_Fuels_Ltd - a complicated history.

Westinghouse operates what was BNFL's Springfield plant.
https://www.westinghousenuclear.com/uknuclear/

 

[gmax137]

Late to the party, so nothing really to add. Other than "Safety Third" -- if it IS zirconium, don't go drilling or machining it. Zirconium fires are no joke and I'm betting you don't have a Class D extinguisher in the kitchen.

Fun facts: zirconium is used in reactor structures (eg, grids) due to its very low neutron cross section. Other uses included the "brillo" in old flashbulbs and the flash powder used by earlier photogs.