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 Power Stations’ Site Stakeholder Group (SSG) and covers activities associated with the regulation of safety at Dungeness A Nuclear Power Station. These reports are distributed quarterly and are also available on the HSE’s web site. Site Inspectors of HM Nuclear Installations Inspectorate attend SSG meetings and will respond to questions raised there by members of the SSG. Any other person wishing to inquire about matters covered by this report may contact the HSE’s Nuclear Directorate Information Centre on 0151 951 4103.
http://www.hse.gov.uk/nuclear/llc/index.htm
The Nuclear Installations Inspectorate (NII) Site Inspector visited Dungeness A during the quarter. The Chief Inspector and the HSE Director of Communications also visited site on 26 October; inspections were made on the following days: -
24 – 27 October 2005
14 – 17 November 2005
Compliance Inspections: Routine i nspections are undertaken for the purpose of monitoring compliance with (i) the conditions attached by HSE to the nuclear site licences, and (ii) other relevant provisions of the Health and Safety at Work etc Act 1974, including the Ionising Radiations Regulations 1999. In this period routine inspections covered:
Unplanned Reactor Shutdowns: In a two-week period beginning on 30 October 2005 there were three unplanned reactor shutdowns; two on R2 and the other on R1. The causes of these shutdowns were rooted in unrelated plant failures and on two occasions the operators took a prudent decision to manually shutdown the reactor. The third event involved a failure of an electrical contactor, which cut power to a group of control rods, which in turn fell into the core in fail-safe fashion and shut the reactor down. During these shutdowns safe operating limits and conditions were complied with. The licensee’s investigation and recovery from these events has been monitored and judged to be satisfactory. However the licensee has been asked by NII to consider any reasonably practicable enhancements it can make to its monitoring arrangements to detect plant ageing for the final year of generation.
Incidents: On 31 October 2005 control room staff were alerted to smoke being generated in a room containing safety related electrical equipment. No fire was found and the cubicle from which the smoke was emanating was electrically isolated. The subsequent investigation revealed that the failure of a small transformer had caused the smoke detector to alarm. During the event Kent Fire Brigade were alerted and attended site as a precaution. NII investigated this event and has concurred with the licensee that this was an isolated failure not indicative of a type fault. Nevertheless the action placed by NII in paragraph 3 above is directed at attempted early detection of failure of some of the plant and equipment, which is of original design.
As part of its regulation under nuclear site licences NII issues regulatory documents, collectively termed Licence Instruments (LI). One was issued for Dungeness A during the quarter: -
LI No 506 – Agreement to extend the normal 2 year operating period of R1 by 5 months to the end of December 2006 (Issued on 22 December 2005).
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.
HM Nuclear Installations Inspectorate
Health and Safety Executive
St Peter’s House
Bootle
Merseyside
L20 3LZ
Licence Instruments are formal documents issued under the licence conditions and arrangements, including Consents, Approvals, Directions, Specifications, Notifications, Agreements and Acknowledgements.