Interesting book on UK nuclear history
An interesting edition of Engineering and Technology 24th April 2010 vol 5 iss 6 (a professional magazine of the IET institute of Engineering and Technology)
Dr Ian Fairlie believes unborn babies are particularly susceptible to so-called spike radioactive emissions that occur at nuclear power plants when their reactors are opened, typically once a year, to replace nuclear fuel. This could explain the cancer increases in under five-year- olds living near German nuclear power stations.
“This temporarily large increase in radionuclide concentration could reach foetuses and embryos,” he explains. “Embryos lay down cells at a rapid rate of knots and foetuses get bigger every day; these cells could have the [radionuclides] in them, which doesn’t go away. By the time the babies are born, they have raised concentrations in them:’ Fairlie now questions whether pregnant women and women of child-bearing age should actually be advised to move away from nuclear facilities. “This is anecdotal and there’s no published data but German women of a child bearing age are already moving away from nuclear power stations,” he adds. “I’ve heard this at conferences, am when I ask if this were true, they [fellow delegates] say ‘yes of course’
From the same magazine
After almost 25 years in the planning and almost £90bn wasted, the United States has abandoned its plans for a high-level nuclear waste storage facility at Yucca Mountain in Nevada. So where does that leave the future for storage of nuclear waste? Sean Davies reports
The nuclear industry would argue that the volume of HLW is small, but to the layman the numbers will seem quite staggering. At present there are some 270,000t of HLW around the globe, stored in storage pools at the reactor sites. Each year another 3,500t is added that burden.
In terms of radioactivity, HLW is the major issue, arising from the use of nuclear reactors to generate electricity. Highly radioactive fission products and transuranic elements are produced from uranium and plutonium during reactor opera- tions, and are contained within the used fuel.
A 2MW “windmill” will cost around £1.5M and give about 600kW average.
£90G would have provided 36GW of averaged power (about 10% of us requirements)
Energy from Uranium
Nuclear power the energy balance
National Grid report:
National grid Sizewell+longannet trip report
Nuclear power stations
5.3 The results for nuclear power stations are unambiguous and, as might be expected from their very low discharges, there is no indication of any effect on the incidence of childhood cancer (see Tables 5.1 and 5.2). For leukaemia and non-Hodgkin lymphomas there were only three sites with marginally higher than expected numbers and ten where the numbers were less than expected. None of these was remotely significant from a statistical point of view. For solid tumours, there were five sites with very slightly raised values and eight sites with lower values. Again, none of these exhibited statistical significance. Moreover, within the 25-km circles there was no evidence of any trend for rates to be higher nearer to the sites. We can, therefore, say quite categorically that there is no evidence from this very large study that living within 25 km of a nuclear generating site within Britain is associated with an increased risk of childhood cancer.
Other nuclear sites
5.4 The situation with the other nuclear sites is more complicated. For leukaemia and non-Hodgkin lymphoma (Table 5.3) there are four sites where there is some evidence of a raised incidence close to the installation, namely Sellafield, Burghfield, Dounreay and Rosyth. Each of these sites has been identified previously as having a possibly increased risk in the vicinity. The most important finding in this new analysis is that none of the other sites in this
group has a significantly increased rate of leukaemia and non-Hodgkin lymphoma. Five of these other sites have registration rates slightly higher than the expected value, whereas six sites have slightly lower rates than this value.
Wind turbine synchronisation:
The are 2 main (only?) types of turbine.
1. Synchronous machines that have to rotate at fixed speeds to create 60/50Hz waveforms to couple into the grid. Once phase synchronous to the grid coupled power is supplied. These machines require gearboxes and the blades in a farm all rotate together.
2. non sychronous generator creating DC (through rectification usually) is coupled into an electronic circuit that creates the required grid synchronous frequency (The turbines by enercon do not contain gearboxes - a useful life extender!):
Even when synchronised in this type the rotor speed is not fixed. It is allowed to rotate at a speed that generates optimum wind power converion.
When the wind speed reaches maximum for rated power then the blades are progressively feathered to maintain this power. At this point all turbines in a farm may appear to have the same rotational speed.
A broken turbine is feathered and brakes are locked to stop rotation
A synchronous type turbine running fast or slow is broken and not grid connected
An electronic grid connection allows a variable rotational rate but still has to be speed limited.
If you read the Enercon info you will see that the electronics actually allows the turbine to do useful (to the grid) work when a grid fault occurs.
UK wind power:
IET document Wind power
Energy sources compared:
A survey of world fuel resources and their impact on the development of wind energy
India Point Leak
Davis Besse leak:
Calendar of Nuclear Accidents