Calder Hall Sellafield

1. Calder Hall Sellafield Decommissioning Martin Adam Heriot-Watt Edinburgh 2008

2. 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.

3. 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

4. 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.

5. 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

6. 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.

7. 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.

8. 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

9. 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

10. 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

11. 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.

12. Cost: • Total overall estimated cost around 1 Billion GBP Cost Distribution by Key Phase (£k)

13. Thank You For Your Attention