The Nuclear Decommissioning Authority

NDA Sites Monthly Performance Update

General Evaluation - Key Elements

• Programme Performance was in line with expectations at the end of August 2009.  
• Electricity generation for August and Year to Date 2009/10 was above target.

Year to Date Cost and Schedule Performance
At the end of August 2009, the programme delivered work for less than planned cost.  Measured against the year to date budget the programme of work at the end of August was in line with expectations.

Earned Value Performance Management.  Please note: We use Earned Value Performance Management to measure programme performance.  This compares the budgeted cost of work that was scheduled with the budgeted cost of work that was actually performed to determine schedule performance and the budgeted cost of work actually performed with its actual cost to determine cost performance.

Electricity generation at the fleet of Magnox nuclear reactors operated by the NDA was above target for August and Year to Date 2009/10.

Items of Interest

Programme Items of Interest - Key Elements

• Sizewell A begins defuelling

Sizewell A began defuelling on 14 August when the first spent fuel flask since it ceased generating on 31 December 2006 was dispatched to Sellafield.  This is the start of a key phase in the site's decommissioning plan and its eventual completion, planned for 2012, will represent a huge milestone for the site.  The flask dispatch programme will continue for the next three years until all the fuel, which is currently stored safely in Sizewell's twin reactors, has been shipped to Sellafield for processing.

Safety and Environment Performance

Safety and Environment - Key Elements

• One INES event  
• Two RIDDOR events  
• Three environmental non compliances

Nuclear Safety

No events rated at Level 1 on the International Nuclear Event Scale (INES) have been reported as occurring at NDA sites during the month.

Radiological Protection

The sites provide data on average individual dose, maximum individual dose and collective dose. These metrics are measured separately for SLC employees and for contractors. Dose figures are reported by calendar year rather than financial year and the following two graphs show average individual doses and maximum individual doses respectively (ordered by employee dose) for dosimeters worn by workers in calendar year 2008 and processed to date. Average individual doses and maximum individual doses should be compared with (and are all well below) the legal annual limit of 20 mSv.

Dosimetry is the measurement of absorbed dose in matter and tissue resulting from the exposure to ionizing radiations.

Industrial Health and Safety

Three events reportable under RIDDOR occurred in the month.  

• Two RIDDOR events at Sellafield, one back injury and work related illness (chronic arm injury).
• At Harwell, one back injury while installing cables.  

RIDDOR stands for the reporting of injuries diseases and dangerous occurrences regulations 1995.  RIDDOR '95 requires the reporting of work-related accidents, diseases and dangerous occurrences. It applies to all work activities, but not to all incidents.

Environmental Protection

Five environmental non-compliances have been reported this month.  

• At Sellafield one event was reported to the Environment Agency due to loss of refrigeration.
• At Chapelcross a non compliance occurred as a result of pH discharge in breach of limit specified in water use licence.
• At Sizewell a non compliance occurred due to an environmental maintenance schedule anomaly.
• At LLWR a non compliance occurred due to a breach of non radiological discharge consent limit.
• At Springfields a non compliance occurred due to a loss of refrigeration.

An Environmental Non Compliance is a breach of a permit condition set by the Environment Agency or the Scottish Environmental Protection Agency that prevents or controls risk of pollution to the environment.

Please note: We give the actual number of occurrences in each category. Not all sites employ the same number of people and/or undertake the same activities. This must be taken into account before comparisons between sites can be made.