Calder Hall Sellafield

Decommissioning

Martin AdamHeriot-Watt Edinburgh

2008

History

Located in Cumbria, England Worlds First Commercial Nuclear Power

Station Construction started 1953, completed

1956 Her Majesty the Queen Opened the

Power Station on 17 October 1956 Generated Power Until March 2003 Consisted of 4 Magnox reactors each

capable of 50 Mwe of power each. Produced over 70TWh of electricity in its

operational life.

History

Its early life primary function was to produce weapons grade plutonium

From 1964 it was mainly used for commercial fuels

Although it was not until 1995 when the UK government announced that all production of plutonium for weapons had ceased

Calder Hall Site Mission:

Safely, securely and cost-effectively remove all fuel and buildings from site

To processes, treat and dispose of all waste arise

To remediate the ground, where necessary and make the land available for reuse.

Current plan

Stage 1: Defuelling & Preparations 2003 – 2008

Stage 2: Intermin Decommissioning 2004 – 2011

Stage 3: Care & Maintenance 2011 – 2105

Stage 4: Final Site Clearance 2105 - 2117

Defuelling & Preparations: 2003 - 2008

Remove all spent fuel and transfer it to Sellafeild Fuel Handling Plant

Arrangements must be taken to improve nuclear safety before defuelling can commence

Removal of all fuel elements from the reactor core Despatch of all spent fuel from the station Calder Hall has four reactors, with each reactor holding 1696 fuel

channels holding either five or six fuel elements Therefore the site had approx 40,000 elements to remove This phase also deals with maintenance issues dealing with both

the defuelling process and the ongoing site management.

Intermin Decommissioning: 2004 - 2011

Will begin in parallel with the defuelling process. Reactor 1 and Turbine Hall A, are currently under

a request to become listed buildings. Conservation of remaining 3 reactors into

safehouses to be used during the care & maintenance phase

Hazard reduction activities; Asbestos removal from heat exchangers and from within the turbine halls

Removal of redundant facilities (cooling systems, utilities, generators ext.)

Cooling towers were demolished on 29th of September 2007

All Plant not required for industrial Heritage purpose or C&M removed.

Reactors 2, 3 & 4 heat exchangers dismantled and removed.

Intermin Decommissioning: 2004 - 2011

Intermediate waste arising will be transported to the low level waste repository in sellafield

New construction activities are required Three reactors will require weather proofing

and conversion. This will involve re-cladding the roofs which

will also have to been replaced/refurbished every 30 years during the care and maintenance phase

Modification to existing facilities to maintain services such as water, telecommunication, fire detection and security system

A new electrical ring main will be installed, to allow safe termination of existing services

Before C&M can start all hazards must be immobilised in a safe and secure way

Care & Maintenance: 2011 - 2105

This stage is designed to ensure that minimal human intervention is needed during the 100-year Care and Maintenance Program

Initial phase will last 5 years where the site will remain staffed After this phase, surveillance, safety and security will be of great

importance Safehouses will be routinely maintained, inspected regularly and will

undergo periodic surveys. The Scope will also include inspections following severe weather

conditions to check for any failure of the watertight envelope. Weekly external inspections (e.g. identification of any damage) Monthly ground maintenance on the site Half-yearly external engineering inspections for minor maintenance issues Annual internal engineering inspections for minor maintenance issues External/Internal inspections at 25 year intervals for major maintenance

issues

Final Site Clearance: 2105 -2117

To facilitate this stage a suitable site infrastructure will be installed

A waste management facility (WMF) will be constructed to process the waste arising during this phase

Wastes will be transferred in a controlled manned to the WMF, monitored and sentenced Active waste will be packed in a waste

disposal boxes, transported off site and disposed off

Clean waste will be used of infilling voids or disposed of off site

Reactor 1 and Turbine Hall A are assumed to no longer be listed buildings, therefore will be removed

Final Site Clearance: 2105 -2117

Entry to safehouse will be gained during early phases of clearance to carry out preliminary structural and radiological surveys

In turn a section of each safehouse roof will be removed to allow large items of the plant to be lifted out

Once all active plant and any contamination have been removed from the safehouses they will be demolished and any voids below GWL backfilled

Near the end of the phase all services, structures installed to support the project will be deplanted, demolished and removed.

Cost:

Total overall estimated cost around 1 Billion GBP

Cost Distribution by

Key Phase (£k)

Thank You For Your Attention