Trident refit and refuelling
Trident is a nuclear powered submarine. The propulsion unit (that powers
the submarine) is a marine Pressurised Water Reactor (PWR). The fuel is
highly enriched natural uranium fuel plates built into modules and inserted
into the reactor. This revolutionary design allows the reactor to last
for ten years without servicing; this US technology puts it well ahead
of the competition.
After ten years, after which the submarines will go for a total refit.
Of the Trident series, HMS Vanguard is currently undergoing the
completion stages of its refit and HMS Vengeance, Victorious
and Vigilant are due to undergo refit in the next 8-10 years.
What happens during a refit?
The submarines are docked at Devonport for a 2 year refit, where the
entire ship is stripped out and refurbished,. Refuelling takes place after
a six month cooling down delay.
About half way through the entire process, a hole is cut in the hull of
the submarine, and highly irradiated (highly radioactive) fuel is removed
and taken by rail to the BNFL plant in Sellafield, Cumbria. During this
first refit operation, Vanguard has been fitted with an advanced design
reactor with the new core H, which will provide sufficient fuel for the
submarine's life, ending costly refuelling.
What's the damage?
Environmental
Tritium is a radioactive element created in the core and coolant system
of the submarines whilst on operational service.
Once docked at Devonport, tritium is discharged from the reactor into
the River Tamar. Tritium contamination of the River Tamar and the surrounding
marine environment is one of the most damaging results of the submarine
refits.
There are also gaseous discharges from the dockside treatment plant which
will eventually drift across the city of Plymouth, contaminating the city.
Science is now only slowly beginning to realise how harmful tritium is.
Financial
A report from the National Audit office released on 29 November 2002 highlighted
increases in costs relating to the rebuilding of docks for the refitting
of the vessels. The initial estimate of £576 million rose to £933
million. The report also pointed out that key facilities crucial to the
Vanguard refit were not completed in time which will result in
an incomplete refit for the first submarine.
Who's involved in the process?
Devonport Management Ltd (DML) are the operators of Devonport Dockyards
in Plymouth, a city with a population of over 270,000.
In 1959, the US transferred basic reactor technology and manufacturing
expertise from Westinghouse (a US company who are now owned by BNFL) to
Rolls Royce. Rolls Royce Associates (RRA) was subsequently formed in 1959,
with the associates being Vickers, Foster Wheeler & Babcock and Wilcox.
RRA are the owners and operators of Marine Power Operations Ltd at Derby,
where reactors cores and fuels for nuclear powered submarines are designed
and manufactured.
Local protest
A large local protest movement has started in the Plymouth and South
West, comprising of environmentalists, peace groups and other concerned
individuals all opposed to the refit taking place in their community.
Locals are gearing themselves up to opposing the expected announcement
from the MOD that Plymouth will be the site chosen for the on land storage
site for decommissioned nuclear submarines.
Up to twenty seven reactor compartments from the redundant subs will end
up in land storage for up to sixty years. The navy is due to make the
announcement within the next two years.
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