The Nuclear Decommissioning Authority

NDA Sites Monthly Performance Update

General Evaluation - Key Elements

• Full sets of Earned Value (EV) data were not available for all SLCs for period 1.  
• Electricity generation for Period 1 2009/10 was in line with expectations.

Year to Date Cost and Schedule Performance
Due to work involved in implementing the new programmes of work for 2009/10 a full sets of Earned Value (EV) data was not available for Period 1.  Actual costs have been received from all SLCs.

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 in line with expectations for Period 1 2009/10.

Programme Items of Interest

Key Elements

• The Low Level Waste Repository (LLWR) successfully hosted "LLW2009".  
• Regulator has no concerns over return to service of Oldbury Reactor 2.  
• Dungeness A completed inactive commissioning on Intermediate Level Waste MiniStores.

"Low Level Waste (LLW) 2009" was successfully hosted by the Low Level Waste Repository (LLWR) on Wednesday, 22 April at the Rheged Centre near Penrith.  Nearly 300 people attended this daylong event, with 33 vendor exhibits.  Numerous presentations from LLWR and NDA were made providing the latest progress on LLW strategy and innovations.

Oldbury received good news this period from the regulators Graphite Assessor who stated he has no concerns over the return to service of Reactor 2 following the trepanning anomaly that was discovered in one of the fast track trepanned samples taken during the outage. The regulator is supportive of the site's current approach and the excellent work done by the Graphite Safety Case Team and site staff on this issue.

All inactive commissioning is complete on the Intermediate Level Waste (ILW) MiniStores at Dungeness A and the site is ready to proceed with active resin transfer as soon as agreement is received from the regulator.  The regulator is carrying out an extended review of the safety case.

Safety and Environment Performance

Safety and Environment - Key Elements

• One INES Level 1 event at Sellafield.  
• Three RIDDOR reportable events at Sellafield (1), Oldbury (1), Wylfa (1).  
• One Environment non-compliances at Oldbury.

Nuclear Safety

One events rated at Level 1 on the International Nuclear Event Scale (INES) has been reported as occurring at NDA sites during the month.  

At Sellafield, loss of cooling to Highly Active Liquor Evaporation and Storage occurred due to plant being incorrectly reconfigured following repair.  Cooling was restored within 2 hours which is within the bounds of the plant safety case.

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 have occurred in the month.  

• At Oldbury an employee crushed their finger when a heavy lead pot moved during monitoring.
• At Wylfa an employee tore a calf muscle while moving a drum on a trolley.
• At Sellafield an employee tripped/slipped when walking resulting in an injured ankle.  

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

One environmental non-compliance has been reported in this period.  

At Oldbury water discharged from the silt lagoon had a higher level of suspended solids than permit limit.  This was due to bad weather re-suspending silt.  

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.