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 Heysham Power Stations’ Local Community Liaison Council (LCLC) and covers activities associated with the regulation of safety at Heysham 1 & 2 Nuclear Power Stations. These reports are distributed quarterly and are also available on the HSE’s web site at http://www.hse.gov.uk/nuclear/llc/index.htm. Site Inspectors of HM Nuclear Installations Inspectorate attend LCLC meetings and will respond to questions raised there by members of the LCLC. Any other person wishing to inquire about matters covered by this report may contact the HSE’s Nuclear Directorate on 0151-951-3484/3290 .
1. The Nuclear Installations Inspectorate (NII) Site Inspectors and other inspectors, including the Chief Inspector, visited Heysham during the quarter; inspections were made on the following days:
| Heysham 1 | Heysham 2 | |
|---|---|---|
| 21 & 27 | July 2006 | 4, 5, 25, 26 & 27 |
| 5, 6, 7, 14 & 27 | Sept 2006 | 15, 19, 20, 21, 28 & 29 |
Routine inspections are undertaken for the purpose of monitoring compliance with (i) the conditions attached by HSE to the nuclear site licence, and (ii) other relevant provisions of the Health and Safety at Work etc Act 1974, including the Ionising Radiations Regulations 1999. This includes monitoring licensee’s actions in relation to station events, plant operations, site projects, plant modifications, safety case changes and other matters which may affect safety. In this period routine inspections of both stations covered:
In general the arrangements made and implemented by the stations in response to licence condition requirements were generally deemed to be adequate in the areas inspected. Where improvements were considered necessary, satisfactory commitments to address the issues were made by station and the site inspectors will inspect progress during future visits. Other aspects of particular significance of a routine nature are summarised below.
NII and Station held the annual safety review meeting on 5 July 2006 to review the station’s last period of operation, discuss plans for the period ahead and to progress any outstanding safety issues. Prior to the meeting the NII team inspected various parts of the plant, in general areas inspected were considered adequate. During the meeting station gave commitments to making enhancements in certain areas with a view to improving its performance. These commitments were subsequently confirmed in a letter from NII to the Station Director.
NII site inspectors consider non-routine matters and events that have occurred on the site and examine the Licensee’s response to them. Licensees are required to have arrangements to respond to such matters and NII inspectors judge the adequacy of their response in taking appropriate remedial action and implementing necessary improvements. Matters of particular note considered during the current period include the following.
The Site Inspector has followed up two events during the reporting period.
The station reported that on 30 June, during an unplanned trip of reactor 1, operators incorrectly interpreted an operating rule governing the availability of emergency boiler feed pumps (EBFPs). Although the physical configuration of the plant complied with the intent of the operating rule, the operators recognised that they were unable to complete the required verification checks in a timely manner. The subsequent root cause investigation attributed the incident to:
The Site Inspector noted that the investigation included a comprehensive Corrective Action Programme with agreed deadlines that addresses the principal causes of the incident. Furthermore, NII has held discussions with station on its proposals to remove the ambiguity from the operating rule.
On 11 July the station reported that a normally open valve in the pipework supplying a sub circuit of the fixed jet fire system protecting a nuclear safety system was found in the closed position. The station has investigated the incident and concluded that the station had failed to adequately control the configuration of a safety related item. The incident was aggravated by a design feature of the valve, which obsures the position of the valve spindle. The station has completed safety briefs to all operating personnel and modfied the valve spindle.
The site inspector is content with the station's response to the above events.
NII continues to liaise closely with station on the results of inspections of the prestressed concrete boiler closure units (BCUs). Radiographic examinations are indicating that all prestressing components are intact with no evidence of gross disruption or corrosion. Recent radiograph examination of R2's BCUs indicate additional wire tails at several locations. A Safety Case has considered the significance of these additional wires and concluded that they are an artifact of construction. The NII asked station to seek the advice of its Nuclear Safety Committee on the examination results before R2 returned to service in September.
An incident occurred on 25 August 06 when information was wrongly inputted to the control desk and this led to a temperature rise in a single fuel channel. The temperature rise was arrested by an installed safety interlock. Reactor operating limits or conditions were not challenged during the incident. BE is investigating the circumstances surrounding the event; the aim being to recommend corrective actions to reduce the likelihood of a recurrence. In the interim BE has introduced additional regular peer checking of certain operations in the control room, including the one that led to this incident. NII will continue to monitor the actions emerging from BE’s investigations.
NII issued an improvement notice (IN) in relation to Station’s failure to adequately maintain dampers required as part of the safety case for preventing fires challenging the integrity of nuclear safety fire barriers. There are some 266 such dampers in ventilation ducting at the station and the maintenance regime was not aligned to recognised standards or manufacturers’ recommendations. The IN formalises regulatory requirements to make improvements in this area. The Station has until August 2007 to comply with the IN.
As part of its regulation under nuclear site licences NII issues regulatory documents, collectively termed Licence Instruments (LI) [ 1 ]. 6 were issued in total for both stations during the quarter: -
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.
1 Licence Instruments are formal documents issued under the licence conditions and arrangements, including Consents, Approvals, Directions, Specifications, Notifications, Agreements and Acknowledgements.
HM Nuclear Installations Inspectorate
Health and Safety Executive
Redgrave Court
Merton Road
Bootle
Merseyside
L20 7HS