Sayano-Shushenskaya Hydroelectric Station Disaster

[OVERKILL]

Regarding the spent fuel pool, I would expect that the storage protocol it is/was required practice and if not followed would result in severe penalty from the Nuclear Safety Commission

Now, in one of the cores, which would have had active fuel in them? Yes, it is quite possible for that to be happening there.

 

[Shannow]

You only have a packed spent fuel pool if it's not going into reprocessing.

Should only ever have to be stored until it's reduced in it's activity to the point that it can be reprocessed...and it should/must.


Leaving is sitting in a pool until something happens is ridiculous...

 

[Shannow]

These power station places are points of extremely high energy densities, and when things go wrong, it happens very very quickly.

Forgive me for conversion errors in the following

Take my world, there's 300lb per second of coal going in...same energy input as at least 500lb.sec of seasoned wood. Gets turned into steam at 2600psi, and 1005F (265gal/sec of water goes through that process)...got to get the maximum potential that you can to cascade down through the energy recovery process, then decompress and cool through expansion process to get the maximum energy out the other end...at THAT end, and it scares me, it's 22,000V, and thousands of amps (then it's stepped up to 330,000V).

At any point in that process, you can become toast...release the steam, and it expands 200 times. make it a pencil thin "beam", and it will cut and flay you...become part of a circuit, and you vaporise...release the coal dust and ignite it, and it's the same effect as the MOAB.

Nuclear don't have the issues in combustion massflow, the energy source is so concentrated...the downstream is the same.

Hydros are more potential energy wells, with the wells filled by rainfall, and the power being supplied by gravity and mass (think a sack of sand over an elevated pulley, and the rotation of the pulley making power)...you need major volumes and masses of water falling relatively low pressures (head)…steam we did it with temperature and pressure, hydro here only has 350psi of head, so you have to make up for it with mass-flow, and it's tonnes and tonnes per second.

All of these technologies can lay waste to a site in seconds or minutes if the risks aren't managed, and the fact that there are occasional, albeit spectacular news entries are testament to how well they are designed and managed.

How many of these extremely high energy installations are there around the world, and how many headlines ?

WRT the posted incident, there are designs, and maintenance considerations. Engineering considerations when things aren't going exactly right...not defending anything here.

But this unit was the one left doing all of the grid load/frequency control for the section of the grid that it was connected to...and that's the worst place to be in with respect to managing your plant.

Here's a few other major failures
https://www.slideshare.net/JosephFByrdJr/duvha-55780131

pleasant prairie
https://www.osti.gov/biblio/207824-pleasant-prairie-unit-feedwater-line-failure
This one killed a number of plant operators … lead the industry to find out that chrome bumpers in the scrap steel stream protected us from an unknown failure until the cars of the 50s and 60s weren't there anymore.

I got caught with the transition from group 1 to Group 2 lubes causing varnish and sludge in the machines...in other places, that has lead to servo valve failure and catastrophe.

 

[OVERKILL]

Originally Posted By: Shannow
You only have a packed spent fuel pool if it's not going into reprocessing.

Should only ever have to be stored until it's reduced in it's activity to the point that it can be reprocessed...and it should/must.


Leaving is sitting in a pool until something happens is ridiculous...


Unfortunately as far as I know, only Europe reprocesses their fuel.

There was, years ago, discussion about reprocessing CANDU fuel. The problem was that the methods that work on enriched fuel, don't on our natural uranium fuel because there simply isn't the yield. Instead of a few percentage points we are talking small, small fractions of a percentage of viable fissile material that could be extracted, which made it a non-starter.

There was some development work on using Fluorine for chemical extraction and this showed some significant promise and entirely viable in theory but was never pursued further.

The Advanced CANDU 6 (AFCR) could be, and it would probably be more viable, leveraged here using a MOX to integrate spent fuel components with fresh Uranium, Thorium...etc to achieve further efficiency and extend fuel use. I like to think of this unit as the LDT multi-fuel of the nuclear world because it will run on just about anything with the simplest substitute for a NU fuel bundle being a spent enriched bundle, which is how the Chinese are presently using them. It is unfortunate that there isn't greater adoption of this particular technology, as it could be used to actively reduce spent waste stores.

 

[Ducked]

The Chinese seem to be pretty well placed to dominate export of nuclear power plants in the medium future. I understand they are bringing more online domestically than anybody else, so they have experience and some economy of scale advantages. Big plans in Africa.

People are understandably concerned about the UK buying a Chinese nuke, but its probably a loss-leader/demonstrator for them, so I'd expect them to be on their best behaviour, which isn't always the case.

 

[OVERKILL]

Originally Posted By: Ducked
The Chinese seem to be pretty well placed to dominate export of nuclear power plants in the medium future. I understand they are bringing more online domestically than anybody else, so they have experience and some economy of scale advantages. Big plans in Africa.

People are understandably concerned about the UK buying a Chinese nuke, but its probably a loss-leader/demonstrator for them, so I'd expect them to be on their best behaviour, which isn't always the case.


The Chinese have connected the first EPR and largest Nuclear reactor that I am aware of (by power output) to the grid today, the Taishan NPS, which has two Areva (EU) 1660MWe units in it. Unit one had recently been fuelled, tested, and achieved criticality on the 6th of June.

IIRC, there are a number of EPR's in various phases of construction, many of which commenced their build before these units, but of course China didn't have the regulatory delays that the other countries have experienced