Rules for transporting nuclear fuel trains through tunnels.

[thenorthern]

Obviously nuclear fuel is regularly moved by train, perfectly safely on the same tracks used by passenger trains.

I was reading however, that a concern that nuclear opponents raised during the 1984 testing was that around the same time there was the Summit Tunnel fire which burned for several days which was much longer than the flasks were rated for. It was pointed out at the time however, that nuclear flasks and petrol would not be allowed to be transported through a tunnel at the same time.

Anyway I was wondering if there are any rules about taking nuclear trains through tunnels and if they are allowed to be moved through tunnels at the same time as passenger or other freight trains. Also in regards the summit tunnel fire it happened in the early hours where there were no passenger trains anyway but are there rules about fuel wagons and passenger trains going through a tunnel at the same time?

 

[Boilinthebag]

The instructions are local rather than national. For example, dangerous goods trains are not permitted to run through the Severn Tunnel at the same time as a passenger train, but that doesn't apply to Pathway just up the line. The issue with a rule for tunnels in general is that tunnels can be very short as well as long and a blanket ban on tunnels would be impractical.

 

[CHAPS2034]

The instructions are local rather than national. For example, dangerous goods trains are not permitted to run through the Severn Tunnel at the same time as a passenger train, but that doesn't apply to Pathway just up the line. The issue with a rule for tunnels in general is that tunnels can be very short as well as long and a blanket ban on tunnels would be impractical.

Isn't Patchway two separate tunnel bores, one for the up and one for the down line?

 

[Dieseldriver]

Isn't Patchway two separate tunnel bores, one for the up and one for the down line?

Yes two completely seperate bores

 

[Boilinthebag]

Rusty route knowledge! Pilning

 

[CHAPS2034]

Rusty route knowledge! Pilning

AFAIK the eastern portal of the Severn Tunnel is at Pilning and the next tunnel going east is Patchway.

 

[zwk500]

AFAIK the eastern portal of the Severn Tunnel is at Pilning and the next tunnel going east is Patchway.

The Eastern Portal of the Severn Tunnel (11m01ch) is a bit west of Pilning (9m43ch), and there is the 89m long Ableton Lane Tunnel Between the Severn Tunnel portal and Pilning station.

Between Patchway and Pilning there are 3 tunnels, all single bore - the New Tunnel on the Up Tunnel, and then the Old and Short Tunnels on the Down Tunnel. Collectively known as the 'Patchway Tunnels'

 

[unlevel42]

I wonder what the rules would be for a location which was on an embankment with tunnels at both ends, the potential of having two boat train expresses at platforms, two trains of chlorine and bromine wagons and two trains carrying nuclear flasks being shunted in and out of the tunnels. I forgot the cinema, a main hospital, three hotels, two main roads and my nains house.
-Bangor

 

[mike57]

I actually suspect that nuclear flasks are less of a problem than some other materials that are transported by rail. The 1984 flask test proved that whilst the contents are dangerous the flask is going to pretty much stand up to any foreseeable accident. Over the years the dangerous cargo rail accidents that come to mind are the Summit tunnel fire here as well as 1989 Helena, USA and a crash in Canada at Lac-Mégantic in 2013. These all involved petrochemicals as far as I am aware.

 

[thenorthern]

I actually suspect that nuclear flasks are less of a problem than some other materials that are transported by rail. The 1984 flask test proved that whilst the contents are dangerous the flask is going to pretty much stand up to any foreseeable accident. Over the years the dangerous cargo rail accidents that come to mind are the Summit tunnel fire here as well as 1989 Helena, USA and a crash in Canada at Lac-Mégantic in 2013. These all involved petrochemicals as far as I am aware.

I think one of the problems is if there is a tunnel fire would the fire burn for longer than the flask is rated for? I the flasks themselves are rated for 30 mins at 800 degrees Celsius. Realistically, they could probably survive much longer. However, the Summit Tunnel fire burnt for 4 days which is much longer than the flasks are rated for. Other tunnel fires such as the Channel Tunnel fire in 2008 burnt for 16 hours although I don't think nuclear fuel is allowed to be transported through the tunnrel.

I know it's a road tunnel but Mont Blanc Tunnel fire burnt for 54 hours in 1999 which is way longer than the flasks are rated for. I have checked the Mont Blanc tunnel regulations. My French is not brilliant but from what I can the transport nuclear fuel in the Mount Blanc tunnel is prohibited. Given how much French energy is from nuclear this is actually quite significant.

 

[mike57]

themselves are rated for 30 mins at 800 degrees Celsius.

I think another factor would be what they contained, spent fuel would I think be more of a concern than fresh fuel. Having seen the flasks I think the 800C for 30 minutes would be very conservative unless there are other aggravating factors, e.g. coupled with mechanical damage. Fires involving petroleum products seem to be the biggest cause of serious accidents.

 

[45Fox]

In his concluding remarks to the accident report concerning the 1984 Summit Tunnel fire the investigating officer made a recommendation that BR should seriously consider not timetabling nuclear flask trains to pass trains of flammable materials in long tunnels, where practicable.

However, he didn't insist on an outright ban on it occurring.

 

[edwin_m]

I know it's a road tunnel but Mont Blanc Tunnel fire burnt for 54 hours in 1999 which is way longer than the flasks are rated for. I have checked the Mont Blanc tunnel regulations. My French is not brilliant but from what I can the transport nuclear fuel in the Mount Blanc tunnel is prohibited. Given how much French energy is from nuclear this is actually quite significant.

I don't know how they deal with the logistics but I assume their nuclear fuel stays within France or goes in and out by sea, with no need for transit through the Alpine tunnels (road or rail).

 

[QueensCurve]

I actually suspect that nuclear flasks are less of a problem than some other materials that are transported by rail. The 1984 flask test proved that whilst the contents are dangerous the flask is going to pretty much stand up to any foreseeable accident. Over the years the dangerous cargo rail accidents that come to mind are the Summit tunnel fire here as well as 1989 Helena, USA and a crash in Canada at Lac-Mégantic in 2013. These all involved petrochemicals as far as I am aware.

The '1984 test' was a publicity stunt subjecting the flask to conditions less severe than in the mandatory testing for a 'Type B transport container' The actual test applicable at the time fas a 9m drop test onto an 'unyielding surface'. As I understand it BR instrumented the rail vehicles to get useful data.

 

[thenorthern]

I did read somewhere that in the 1980s BNFL were flying fuel from Carlisle Airport. Given that a flask weighs 50 tonnes and given that a plane can cause a lot more damage than a train it's no wonder the public were concerned about it.

I don't know how they deal with the logistics but I assume their nuclear fuel stays within France or goes in and out by sea, with no need for transit through the Alpine tunnels (road or rail).

Sort of, Italy decommissioned all of its nuclear power plants in 1990 and a lot of the spent fuel was sent to other countries to be reprocessed most notably France and the United Kingdom.

 

[cf111]

I did read somewhere that in the 1980s BNFL were flying fuel from Carlisle Airport. Given that a flask weighs 50 tonnes and given that a plane can cause a lot more damage than a train it's no wonder the public were concerned about

Dounreay were flying plutonium from Wick airport to the US a few years back. I think it was meant to be a big secret but you couldn't help but notice the large USAF cargo plane and the enormous Police Scotland/Civil Nuclear Constabulary convoy .

 

[GRALISTAIR]

As others have said, I would be more concerned with petrochemicals and other toxic chemicals than nuclear materials.

 

[PartyOperator]

I think another factor would be what they contained, spent fuel would I think be more of a concern than fresh fuel. Having seen the flasks I think the 800C for 30 minutes would be very conservative unless there are other aggravating factors, e.g. coupled with mechanical damage. Fires involving petroleum products seem to be the biggest cause of serious accidents.

Fresh fuel isn’t transported in flasks, it’s barely radioactive. I assume it’s transported by road mostly.

 

[Mile Post 13]

The '1984 test' was a publicity stunt subjecting the flask to conditions less severe than in the mandatory testing for a 'Type B transport container' The actual test applicable at the time fas a 9m drop test onto an 'unyielding surface'. As I understand it BR instrumented the rail vehicles to get useful data.

Publicity stunt it was not. The 1984 test was to respond to negative outputs from pressure groups about the safety of spent nuclear fuel in the event of a derailments towards an oncoming train. The test applied considerably more severe that a 9m drop from a crane !

 

[Spaceship323]

On the M25/A282 at the Dartford tunnel they stop all the traffic in one bore and send all the fuel and hazardous trucks through in convoy - lovely if you're a tanker driver!, no idea on the rails though

 

[QueensCurve]

I did read somewhere that in the 1980s BNFL were flying fuel from Carlisle Airport. Given that a flask weighs 50 tonnes and given that a plane can cause a lot more damage than a train it's no wonder the public were concerned about it.

There is a difference between irradiated (used) fuel and unirradiated fuel. Irradiated fuel is highly radioactive because of the fission products it contains and people must be shield from it since the gamma radiation it emits couid be fatal after even breif exposure. Hence the 47 tonne flasks which provide about 350mm of steel sheilding and are designed to withstand transport accidents.

I don't know much about the flights from carlisle airport but they would have been uniradiated fuel which is much less radioactive. It does contain alpha radioactivity which is highly dangerous if taken into the body. It will still be transported in a container designed to withstand transport accidents but it doesn't require 47 tonnes of steel shielding. The requirements for containers used in air transport were tightened in recent times.

== Doublepost prevention - post automatically merged: 2 Mar 2026 ==

Publicity stunt it was not. The 1984 test was to respond to negative outputs from pressure groups about the safety of spent nuclear fuel in the event of a derailments towards an oncoming train. The test applied considerably more severe that a 9m drop from a crane !

Yes. It was a response to 'negative outputs from pressure groups. It subjected the flask to less onerous conditions than the required testing for Type B containers.