The latest quarterly report statement from the UK HSE Chief Inspector of Nuclear Installations has been received by the Celtic League. The report logs two issues in relation to the Sellafield nuclear plant:
“Sellafield – Calder Hall
On the 24 August 2010 an incident occurred when one of two gas analysers serving Magnox Swarf Storage Silo Compartment No.7, was found to be disconnected from its sample pipe, and the other analyser was out of service. As a result no analysis of the air space in Compartment No. 7 to detect hydrogen content was carried out for a period of 6 days. There was no release of radioactivity, no personal injury and no requirement for the equipment to have operated.
The safety case requires two diverse hydrogen analysers per compartment to provide the means of measuring hydrogen concentration in the extract flow from the compartments. It is also required that one analyser must be in service before the second one may be taken out of service.
Sellafield Ltd (SL) launched an immediate Board of Inquiry into the circumstances preceding and during the incident. HSE carried out a separate investigation in to the event during September 2010. Subsequent consideration of the incident, and application of the HSE Enforcement Management Model, resulted in HSE serving an Improvement Notice under Section 2 of the Health and
Safety at Work Act 1974. SL has responded positively to the incident and has developed an improvement programme to address its Board of Inquiry findings and the requirements of the Improvement Notice.
HSE is monitoring SL’s performance in responding to the learning opportunities from the incident, and implementation of its improvement programme. This incident has been rated at Level 1, an anomaly, on the 7 level International Nuclear and Radiological Event Scale (INES).
Sellafield – Calder Hall
Sellafield Ltd (SL) is pursuing a programme of work to identify and record areas of local radiological contamination adjacent to ventilation ductwork and pipework in the Magnox Reprocessing Plant. The analysis of samples taken in support of this work identified an area of ground that is contaminated with plutonium bearing liquors. The area of contaminated ground is relatively small and is located within a controlled area (known as the “Separation Area”) – towards the centre of the licensed site. No emergency response was necessary, although access to the immediate area is being controlled. No workers are reported to have been affected.
SL has made an estimate of the amount of radioactive material present at the location based on sample results. The estimate indicates the event is reportable to HSE, in accordance with the Ionising Radiation Regulations 1999. However, the confirmed figure will not be known until the contaminated material has been removed and examined.
HSE has followed up this event and is content with SL’s response to date. However, in conjunction with the Environment Agency, our inspectors will continue to monitor the licensee’s response to ensure the area is appropriately remediated and, workers and the environment are protected.
SL identified this contamination during a programme of work to improve knowledge f legacy contamination on the site, and in response to past events (including an event which occurred in January 2009 which was investigated by HSE and Environment Agency). The HSE welcomes the commitment by SL to resolve shortfalls in contamination control, which are attributed to previous incidents on the site.
This incident has been provisionally rated at Level 1 on INES, which is an anomaly on the 7 level scale.”
Though both instances recorded are minor the issues do point to the need for constant monitoring in relation to the troubled plants operations.
The ground contamination issue also reminds the Celtic League that the UK authorities were less than positive in their response to our request for information about the monitoring of stormwater outfalls from the plant which we believe poses a significant risk of contaminant exiting the environs of theSellafield complex (see links below):
J B Moffatt (Mr)
Director of Information