Health and Safety
Executive / Commission
Nuclear
LLC reports
This report is issued as part of the Health and Safety Executive's commitment to make information about inspection and regulatory activities relating to the above site available to the public. It is for distribution to members of the Dungeness Site Stakeholder Group (SSG) and covers activities associated with the regulation of safety at Dungeness B Power Station. These reports are distributed quarterly. Site Inspectors of HM Nuclear Installations Inspectorate (part of the Health and Safety Executive's Nuclear Directorate) attend LCLC meetings and will be happy to respond there to questions raised by members of the LCLC. Any person wishing to inquire about matters covered by this report should contact the HSE, Nuclear Directorate Information Centre on 0151 951 4103.
This report will be placed on the HSE website at www.hse.gov.uk/nuclear/llc/index.htm under “Local Liaison Committee Reports”.
Nuclear Directorate1.1 The Nuclear Installations Inspectorate (NII) Site Inspector visited Dungeness B on the following dates during the quarter covered by this report:
1.2 Other NII inspectors with specialist technical expertise also visited Dungeness B and other British Energy establishments during the period to support the Site Inspector by performing inspections on specific aspects of the Licensee’s arrangements and nuclear safety case.
1.3 On 18 – 19 October the station was visited by NII’s Superintending Inspector with responsibility for overseeing the regulation of nuclear safety at Dungeness B and a number of other nuclear power stations.
1.4 Dungeness B was also visited by Dr M W Weightman, NII’s Chief Inspector of Nuclear Installations, and Mr C Douglas, HSE’s Director of Communications.
Routine planned inspections are carried out throughout the year and enable NII to judge whether a Licensee is complying with the conditions attached to the Nuclear Site Licence, the Ionising Radiations Regulations, and other relevant statutory provisions on a sampling basis. In this period routine inspections were largely associated with the statutory periodic shutdown of Reactor 22.
2.1 Reactor 22 Periodic Shutdown
The Reactor 22 periodic shutdown formally concluded in early December. This followed a start-up meeting held on 19 October, at which progress to complete outage related work was reviewed and a list of actions required prior to start-up was agreed. Completion of these actions was confirmed before the Licensee sought NII’s permission to start-up Reactor 22. The only significant emergent issue concerned the discovery of minor cracking in drain lines near parts of the reactor pressure circuits (see 3.2.below). Inspections of outage-related areas were conducted on 18 October and 10 November, and NII’s Consent to re-start Reactor 22 was granted on 14 November. The Reactor was eventually returned to service, following a number of minor plant issues, on 5 December.
2.2 Joint Inspection with the Environment Agency
A joint inspection was carried out with inspectors from the Environment Agency on 6 November. Topics included environmental aspects of maintenance, records, training, system health monitoring, liquid effluent management and internal audits. Findings were generally satisfactory, although some areas for improvement were identified.
As part of their planned inspection site inspectors examine safety-related events that have occurred and the Licensee’s response to them. Generally the Licensee’s internal system for following up events is robust and the appropriate actions are implemented. More noteworthy events followed up during the period include the following:
3.1 Defective Fuel Elements
As previously mentioned, in the Spring of 2005 we became concerned that 9 fuel elements with very small defects were known to be present in the two operating reactors. Whilst recognising the low probability that any one defect would develop into a significant failure, we pressed for early removal of the defective fuel elements. The Licensee subsequently committed to a programme under which all elements known to be defective should be removed from the reactors by April 2006. This is a key focus for the station and, by the end of the year, only 3 of the defective elements remained in the reactors.
3.2 Cracks in Drain Lines
During the outage of Unit 22, the Licensee identified small cracks in drain lines near parts of the reactor pressure circuits. Subsequent analysis by the Licensee found that the cracks were not as deep as at first thought. Following detailed specialist assessment, NII concluded the Licensee had provided acceptable safety cases for the continued operation of Reactors 21 and 22 until further inspections are carried out during their next scheduled statutory outages.
Under Health and Safety legislation the Site Inspector, or other HSE Inspectors, may issue formal notices to secure improvements to safety. No such notices were issued during the reporting period.
The Inspectorate has powers under the Licence to issue Consents, Approvals and Directions. In addition the Inspectorate uses Licence Instruments to issue Specifications and Agreements under the conditions of the Licence. These are all called Licence Instruments. In accordance with formal regulatory procedure, NII issued the following Licence Instrument to Dungeness B under Site Licence No. 61 during the reporting period: