Spent Fuel At Sizewell B
This is my calculation of the amount of spent fuel at Sizewell B. It is not that accurate (estimate 20% either side) but should give us a rough idea
Electrical Output 
1258 
MW_{e} 
Wikipedia gives 62MW used internally. However this figure gives 67MW since BE state power rating at 1191 
Thermal Efficency 
36.5% 

Thermal Power 
3444 
MW_{th} 
Wikipedia value 
3.44 
GW_{th} 

Total maximum energy per year 
1257 
GWdays 

Load Factor 
87% 
Average over lifetime (wolfram alpha) � does not include 2010 

Total energy actually produced 
1093.64 
GWday 

Electrical Output 
9587.47 
GWhours 
Just a check � this is 9.6TWhours which is reasonable if you include the internal electrical consumption (less than 1% out) 
Burnup 
33 
GWday/TU 
The characteristics of LWR fuel at high burnup and their relevance to AGR spent fuel NNL (10) 10930 Issue 2 
Spent Uranium 
33.14 
T 
Amount of Uranium used every year 
U238 Atomic Mass 
238 

UO2 molecular mass 
270 

Spent Fuel 
37.6 
T UO2 
Amount of UO_{2} used every year 
So the amount of spent fuel is 30 – 45 tonnes per year. Greenpeace estimated 220T in 2002. This calculation would give 225T for 2002.
By 2011 this would give 564T.
By the end of 2035 it would give 1466 tonnes.
Casks
Assuming that they use VSC24 casks
Mass of U per assembly 
461.40 
Kg 
U atomic mass 
238.00 
g 
U02 Molecular Mass 
270.00 
g 
Mass of UO2 per assembly 
523.44 
Kg 
Mass of U per cask (24 per flask) 
12562.49 
Kg per cask 
Mass of U per cask (24 per flask) 
12.56 
TUO_{2} per cask 
This gives a figure of about 117 casks
Email from EDF states that they are planning 146 casks.
Dear Peter
Thank you for your telephone call enquiring about the number of casks and the number of fuel assemblies that will be stored at the end of life in the Dry Fuel Store at Sizewell B power station.
The Dry Fuel Store has the capacity to take 146 casks.
I have made enquiries to determine if there are restrictions in terms of a reply to your question on the number of fuel assemblies – “Under the classification policy for the use, storage and transport of nuclear and other radioactive material issued by the Office for Nuclear Regulation (Civil Nuclear Security), this information is classified and, as this is so, cannot be released to the public”. The law which underpins this guidance is The Nuclear Industries Security Regulations 2003 (as amended) and the Antiterrorism, Crime and Security Act 2001.
Thank you
Niki
Niki Spatchett
Communications & Community liaison officer
Sizewell B Power Station, EDF Energy
Leiston, Suffolk
IP16 4UR