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 Hinkley Point Site Stakeholder Group and covers activities associated with the regulation of safety at Hinkley Point B Power Station. These reports are distributed quarterly and are also available on the HSE’s web site. Site Inspectors of HM Nuclear Installations Inspectorate normally attend Site Stakeholder Group meetings and will respond to any questions raised there or subsequently by members of the Site Stakeholder Group. Any other person wishing to inquire about matters covered by this report should contact the HSE, Nuclear Safety Directorate Information Centre on 0151-951-4103.
This report will be placed on the HSE website at: http://www.hse.gov.uk/nuclear/llc/index.htm
Routine inspections continued in accordance with the NII annual plan. The HMNII Site Inspector made the following planned visits during the period:
In addition, separate visits by 4 HMNII Specialist and Project Inspectors took place during this period to examine the safety case presented in the Hinkley Point B Periodic Safety Review for electrical systems, fuel route and to monitor progress with implementing identified safety improvements. A visit by 2 HMNII Specialist Inspectors took place to review plans for the planned statutory shutdown of Reactor 3. A team of 6 HMNII Inspectors visited Hinkley Point B over 3 days in July 2006 to review compliance with Licence Condition 26 (Operating Rules). Finally, an HSE Inspector seconded to HMNII visited Hinkley Point B to conduct a benchmark inspection of arrangements for industrial safety.
Routine and reactive inspections have continued throughout the period to confirm that the site is operating in compliance with the conditions attached to the Nuclear Site Licence. These included inspections of Licence Conditions 7, 11, 15, 23, 25, 26, 28, 30, 32 and 34. In general the arrangements on site were found to be satisfactory. In areas where opportunities for improvement were identified, remedial work has been agreed with station management, with the intention of achieving improvements to current station arrangements in those areas.
A meeting to discuss plans for the periodic shutdown of Hinkley Point B Reactor 3 was held on 6th July 2006. Proposals for work to be undertaken during the shutdown were generally found to be acceptable. Proposals for inspection of the graphite core and boiler tubes were of particular significance and NII agreed that the proposed inspection programmes were adequate. Outstanding work to replace certain sections of cast iron pipework, which can only be done during a Reactor 3 shutdown, will also be completed. A number of improvements were identified in the Hinkley Point B process for developing periodic shutdown proposals and the need for company wide guidance.
HMNII attended the Emergency Planning Consultative Committee on 7th September 2006 at which off-site emergency arrangement were discussed.
The management and recording of some events that occurred on the station during the period were inspected. Most of these were relatively minor and those of concern to the HMNII Site Inspector were discussed with the appropriate company staff. HMNII was generally satisfied with the actions taken.
During the period of this report there has been one unplanned manual trip of Reactor 3 due to a black control rod falling into the core. There have also been 2 automatic trips of Reactor 4; one due to overcooling caused by excess feedwater to the boilers and a second due to loss of supply to station transformer 4 during washing of the 275KVA substation by National Grid. The reactor safety systems functioned correctly during all of these events.
A site incident was declared on 11th September 2006 following the release of 3 tonnes of clean CO2 from a safety relief valve. There was one minor injury and no radiological consequences. There have been a number of similar releases of CO2 over the past 18 months and Hinkley point B has implemented a programme to improve plant reliability that HMNII will continue to monitor.
Recent inspection results from Hunterston B Reactor 3, which is of a similar design to Hinkley Point B, showed a larger number of boiler tube defects than were expected. These findings have increased the probability of a boiler tube leak. As a consequence, British Energy has decided that it would be prudent to bring forward the Hinkley Point B Reactor 3 statutory outage boiler inspection programme. NII will closely monitor the findings from these inspections to ensure that the safety case for Hinkley Point B Reactors 3 and 4 remain acceptable.
Under Health and Safety legislation the Site Inspector, or other HSE Inspectors, may issue formal notices to secure improvements to safety. A Prohibition Notice was issued on 5th September 2006 concerning the means of access to the main chargehall crane and requiring improvements to prevent falls from height.
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. The following Licence Instruments were issued during the quarter:
HM Nuclear Installations Inspectorate
Redgrave Court, Merton Road, Bootle, Merseyside L20 7HS