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 on 0151 951 3484/3290.
This report will be placed on the HSE website at http://www.hse.gov.uk/nuclear/llc/index.htm under “Local Liaison Committee Reports”.
Nuclear Directorate
Health and Safety Executive
St Peter’s House
Balliol Road
Bootle
Merseyside
L20 3LZ
The Nuclear Installations Inspectorate (NII) Site Inspector visited Dungeness B on the following dates during the quarter covered by this report:
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. This included specialist fire safety inspector, a team inspection and a visit by the Superintending Inspector.
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. Compliance with the following Licence Conditions was inspected during the period:
In general the station’s arrangements were found to be satisfactory. In those areas where improvements were identified, satisfactory commitments to address the issues were made by the station. Routine aspects of particular significance are summarised below. The inspection of the station’s arrangements made under LC 28: Maintenance were the subject of a team inspection comprising four inspectors.
Reactor 21 shutdown for its three yearly statutory maintenance period on 14 May 2006. NII Inspectors with specialist technical expertise carried out inspections in the following areas:
NII concluded that the arrangements being implemented at Dungeness B were broadly satisfactory. The Superintending Inspector visited site to attend the Start-up Meeting.
An inspection of Dungeness B’s fire safety arrangements was carried out by one of HMNII’s specialist fire inspectors on 03 and 04 July 2006. The inspection identified some areas for improvement and these were discussed and agreed with the station.
Dungeness B and HMNII participated in the Level 2 emergency exercise GANGES on 27 September 2006. A level 2 exercise, as required by Licence Condition 11, is used to test the off-site response following a nuclear emergency at the station.
The Emergency Planning Consultative Committee meeting was attended on 06 July 2006.
A routine meeting was held with the Trades Unions safety representatives on 13 July 2006.
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:
Reactor 21 was coming back to power following a three yearly statutory outage. The reactor had gone critical on ‘coarse’ group control rods and was being taken up to operating power. The reactor was at a nominal temperature of 330 degrees C. A temperature check across the core identified some anomalies and further checks showed anomalies in the core flux distribution. A check of control rod positions showed that ‘trim’ rods C18 and X18 were fully inserted into the core instead of being in the positions expected. The reactor was manually tripped and all post trip cooling functions operated as designed and in a satisfactory manner. A formal investigation was carried out between 22 and 23 August 2006. This investigation concluded that the root causes if this event were procedural non-compliance and human error. HMNII has written to the station expressing its concern at these causes, and will monitor this area closely.
This incident occurred on 19 July 2006. While diving operations were being carried out at Dungeness B out on the isolated B station cooling water intake structure, a diver had to invoke emergency actions. This involved switching from umbilical air to bottled air when the umbilical became entangled with two guide ropes following turbulence from the adjacent Dungeness A cooling water intake structure. The diver cut both guide ropes and was then manually recovered to the dive vessel. This incident was reported to HSE under RIDDOR. A specialist diving inspector from HSE’s Offshore Division commenced an investigation into this incident on 06 September 2006. The investigation remains ongoing.
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: