[ RadSafe ] Greenpeace nuclear video

[JGinniver at aol.com]

In a message dated 17/01/2006 10:27:31 GMT Standard Time,  
Fred.Dawson199 at mod.uk writes:

Dr Large  makes some very
good points that are not easily  dismissed.


Hmmm, which points area those?
Slide 11
"Non-stochastic doses are  those delivered in one big lump" 

"It is the total dose that matters  irrespective of time"

Slide 13
"26,453 fuel rods/reactor = 360 tonnes  U"?  
Actual data is 193 Fuel assemblies containing 264 fuel pins (total  50,952  
pins) each Fuel Assembly containing 461.4 kg of Uranium (523.4  kg UO2) 
giving a  
total of approximately 89 tonnes of Uranium in the  Sizewell B reactor.   
Data 
from Nuclear Fact Book, published by  G+B Harwood ISBN 3-7186-0273-3

Slide 24
"Chance cannot apply to  terrorism"
Does this mean that a terrorist will succeed at every step of  the  journey?
They will successfully train to pilot the aircraft (one  terrorist was  
already apprehended attempting to do this)
They will  successfully plan the attack in advance in secret.
They will successfully  evade the security screening at the airport (airport  
screening having  been increased significantly since 9/11)
They will overcome the aircrew  (cabin procedures and security of the  
cockpit 
area having been  increased since 9/11)
They will be able to fly the aircraft with no  intervention from passengers  
or crew. (Once the passengers on Flight  93 were aware that it was likely to 
be 
a  suicide attack they fought  against the terrorists, and while unsuccessful 
in  gaining control of  the aircraft, the terrorists did not complete their  
mission).
They  will successfully guide the aircraft onto the target ensuring that at   
least one of the main engines strikes the target building with maximum   
force).
There are a long chain of events that must be successfully completed  to  
even 
have a change of damaging the sensitive areas of the  plant.

Slide 30
Only 2 of the four truck bombs shown have any  possibility of causing a  
radiological release. The only one with the  real potential is adjacent to 
the  fuel 
building, to achieve this the  terrorists must have managed to take a truck  
full of explosives inside  the inner security barrier.  Security  
arrangements 
have increased  significantly on UK nuclear plants since 9/11, not  least the 
addition  of armed officers from the Civil Nuclear Constabulary.

Slide 36
Even  DR Large can't make up his mind whether the aero engine turbo shaft   
(the only item on an aircraft likely to penetrate significantly into  
concrete,  
is 400 to 500 kg as his notes (below the slide) state 300  kg.  The speed  
stated is 400 knots, I'm not convinced that a  terrorist could make an 
accurate  
attack at this speed.  the  landing speed (required to make an accurate  
approach 
to the runway) is  typically between 200 and 250 knots.

Slide 37
"The calculated impulse  loading is 20x the structural strength of typical  
commercial  structures."  Since when is the pre-stressed concrete  
containment  
building a typical commercial structure.

Slide 38
"(It's) touch  and go whether the protective structure surrounding the  
reactor plant  would survive an aircraft crash"  No assessment has been made  
of the  
loss of energy due to the outer reinforced containment structure  before  the 
major components strike the inner pre-stressed containment  structure that  
varies between 1 and 1.3m thick and contains  approximately 50% more steel  
reinforcement than other commercial PWR  containment buildings.  Even if the  
some of 
the components  managed to penetrate the two reinforced concrete walls,  
would 
they  still have enough energy to penetrate the 6mm thick welded steel  liner 
 
of the containment building?

Slide 45
"Terrorist acts are  intelligently driven and not by chance - the defence in  
depth  stratagem cannot apply".  As I've already mentioned above, in order   
for 
a terrorist attack to succeed a long chain of activities have to  be  
successfully carried out, failure of any one of these will affect  the 
success of  the 
attack. It is not simply a case that any terrorist  attack will succeed and  
defence in depth is probably must likely to  thwart an attack.

Slide 70
This slide shows values for Long Term  Mortality Incidence, Etc -  Mean 
Numbers.
This appears to be a copy  of part of Table 41 from NRPB Report R137.   
Firstly there is a  typographical error in the table, the numbers evacuated 
given  in  
Column 2 (p=E Expected) should be 2.4E+4, not 2.4E+3 as shown.   Secondly  
the 
table in the NRPB report has lower, revised values to  take into account  
factors such as retention of activity in the primary  circuit, removal of  
activity 
from the containment atmosphere,  attenuation in leakage paths from  
containment.  These were not  considered in the original report US Reactor  
safety Study  
WASH-1400.  The revised values were calculated by the CEGB/NNC   and 
Westinghouse based on further studies reviews.

This table is the  worst case table from the report there are 12 differnt  
scenarious from  UK1 (the example used) to UK12.  Dr Large doesn't explain  
why  
this is the most appropriate table to use.

And finally,
Despite  all of the graphs, and all of the dose data, there is nothing in  
this  presentation that shows how a terrorist attack with a large aircraft 
would   
succeed in breaching the reactor containment building and causing  sufficient 
 
damage within the containment building or nearby buildings  to cause a core  
meltdown accident which has been used to produce the  large releases 
necessary  
for his dose/plume data to be valid.   even if one or two (for a large four  
engine aircraft) of the shafts  from the jet engines did penetrate the double 
 
containment and steel  liner, how would they cause sufficient damage within 
the  
containment  building to cause a core meltdown? Alternatively if they struck  
 
another of the key buildings on site, DR Large hasn't demonstrated that  this 
 
would be sufficient to cause a core meltdown  either.

Regards,
Julian

P.S if you actually compare the size of  the aircraft in the Greenpeace  
video 
with the size of the Sizewell A  reactor buildings you will discover that  it 
is nearly twice the size  of the world largest passenger aircraft (Airbus 
A380  
- not yet in  service) and approximately 4 times the size of the medium sized 
  
airliner (e.g. Airbus A320) shown in the film.  I'm sure this was just  an  
oversight on the part of Greenpeace and wasn't designed to increase  the fear 
of  
the audience.