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 Heysham Power Station available to the public. It is for distribution to members of the Heysham Local Community Liaison Council and covers activities associated with the regulation of safety at Heysham. These reports are distributed quarterly. Site Inspectors of HM Nuclear Installations Inspectorate attend LCLC meetings and will respond to any questions raised there by members of the LCLC. Any other person wishing to enquire about matters covered by this report should contact the HSE, Nuclear Directorate Information Centre on 0151-951-4103.
This report will be put onto the HSE website at http://www.hse.gov.uk/nuclear/index.htm under ‘Local Liaison Committee reports’.Visits
The Nuclear Installations Inspectorate (NII) site inspectors made visits to Heysham on the following dates during this quarter:
Heysham 1 Heysham 2
6,20,21,26,27 January 2005 12,13,26,27,28,31
17,22,23,24 February 2005 15,16,23,24
4,8,9,24,31 March 2005 1,4,8,9,14,15
Other members of the NII and specialist inspectors visited the Heysham site during the period, as follows.
Heysham 1
The NII Site Inspector and specialist NII Inspectors attended site to carry out routine inspection and to inspect the station's response to events on the site. A team of inspectors, including the site inspector, attended site to observe a level 1 emergency exercise further demonstration.
Heysham 2
The NII site inspector, specialist NII Inspectors and an NII Superintending Inspector attended site to carry out routine inspection and to inspect matters associated with matters arising on the site. A team of inspectors, including the site inspector, attended site to carry out an inspection of station readiness to move from commissioning control of low power refuelling and off load pressurised refuelling to routine operational control.
As part of our routine work we inspect for compliance against the requirements of the Stations’ Nuclear Site Licence Conditions and the arrangements made under them, the Health and Safety at Work Act and other relevant safety legislation. We sample activities on site that may affect safety, and in this report include details of the following matters.
Heysham 1 & 2
Emergency Planning Consultative Committee.
The Heysham 1 NII site inspector attended the Emergency Planning Consultative Committee meeting, which took place on 4 March 2005. The conduct of this meeting ensured an open and effective discussion of issues affecting the site emergency arrangements at Heysham.
Heysham 1
Heysham 1 Level 1 Emergency exercise for 2004– Further Demonstration.
On 9 March a team of NII inspectors observed the Heysham 1 emergency exercise. NII observed that staff responded well to the incident scenario by exercising their duties effectively and with realism. The post exercise debrief provided the opportunity to discuss a number of learning opportunities. The NII team concluded that Heysham 1 had satisfactorily demonstrated its emergency arrangements.
Reactor 2 Periodic Shutdown.
A periodic shutdown (outage) will take place on Heysham 1 Reactor 2 commencing in May 2005. The NII Site Inspector, assisted by specialist assessment inspectors, has examined the proposals for inspecting the core, pressure vessel and electrical systems and agreed a programme of inspections during the shutdown. The NII site inspector and his specialist colleagues will inspect and assess work undertaken during the outage. These inspection and assessment activities will inform NII’s decision on whether the station has made an adequate case for further reactor operation.
Heysham 2
Station contributed to the Level 2 emergency exercise based on an hypothetical event at Heysham 2, and involving participation by the local emergency services, local authorities and the British Energy emergency support organisation. In responding to the requirements of the exercise station was deemed to have complied adequately with the emergency arrangements. They have identified areas for improvement from the exercise, and are currently working to address them.
Routine Operational Control of Low Power and Off-load Pressurised Refuelling (LPR/OPR).
A team of NII inspectors carried out an inspection to assess station readiness to move to routine operational control of LPR/OPR following commissioning of the plant involved. Following the inspection, NII has requested station to provide a programme for completing outstanding work relating to LPR/OPR, prior to making the changes.We respond to non-routine matters arising on site that may affect safety, and in this report include details of the following matters.
Heysham 1 & 2.
Appointment of Single Director at Heysham.
Since 1 February 2005 the Heysham stations have operated with a Plant Manager for each station reporting to a single Director overseeing both stations. This revision to the organizational structure of the stations has complied with the requirements of the arrangements to control such changes.
Hazards Safety Case.
NII's report to the LCLC for the last quarter of 2004 advised station had agreed to enhance protection against the potential consequences of a turbine failure. During this quarter, the station has progressed the first stage construction of an internal hazards wall that will provide a passive barrier to spread of flood and/or fire from the turbine hall basement to the reactor building basement. Station is also commissioning a system that is capable of detecting flooding in the turbine hall basement and initiating a sequence of measures that will arrest further flooding and thus prevent any attendant fire spreading to the reactor building basement. NII specialist assessors have attended station to monitor the construction and installation of these protection measures. Station has provided NII with a commitment to implement further enhancement of passive and active measures for protecting the plant against the consequences of turbine failure.
Implementation of CAP Process.
Heysham 1 implemented the generic BEG Corrective Action Programme on 21 February 2005. This process, which replaced the previous arrangements for reporting and responding to events, is intended to improve station’s approach to focussing on abnormal plant conditions and effecting prompt and permanent corrective actions.
Heysham 2
Visit by NRC staff and NII inspectors.
Three members from the Nuclear Regulatory Commission of the USA, accompanied by two NII inspectors, visited station as part of a short series of visits to UK licensed nuclear sites. They were given a presentation on the station design and made an accompanied inspection of selected areas of the station. They reported that the visit had been very informative and were pleased with the outcome.
Events on Site
As part of our inspection activities at the site we investigate safety related events that occur and follow-up those which are perceived, initially, to have the potential to be more significant, we particularly examine the licensee’s response to such issues and events. From our inspections in this quarter we are satisfied that events which occurred did not represent a significant challenge to the safety case, and response by stations has been in accordance with appropriate arrangements. We summarise our reaction to the selected events as follows.
Heysham 1 & 2
The NII has followed up the following event during this quarter.
BE Generic AGR Fuel Issue.
During January BE suspended movement of all AGR fuel following a report that quality checks during the manufacturing identified fuel that did not conform fully to specification. NII has investigated stations’ response, and have been advised that Heysham 1 & 2 have been provided with a generic interim justification for the continued operation of all BE reactors which may contain fuel potentially not in conformance with its specification. It was also confirmed that the initial safety case would be replaced by station specific justification before further refuelling took place. In the interim stations’ reported that further supplies of fuel from the manufacturer would be suspended until fuel conformance with specification was restored. NII's specialist inspectors are monitoring the response by BE to this event, at this stage they have deemed it to be adequate.
Heysham 1
The NII has followed up the following events during this quarter.
Fuel Assembly Component Discovered in Maintenance Facility.
On 19 January a technician discovered a fuel assembly component in a maintenance facility. Station reported this event to NII after an investigation concluded that the component might have been omitted from a fuel assembly currently in service. The site inspector discussed with station its strategy for locating a rogue assembly. The station advised that none of the fuel assemblies currently in service displayed evidence of abnormal behaviour. It had implemented a search strategy that had identified potential candidate assemblies and gave priority to inspecting those currently in service. Station very quickly established that the component had not been omitted from an in-service assembly and subsequently reported that the component had been omitted from a unit located in a storage location. The site inspector is satisfied with station's response to the discovery of the component and that the search strategy made appropriate use of reactor performance data and station records to locate the rogue assembly.
CO2 Standby Clayton Boiler.
On 21 January routine checking of the CO2 Standby Clayton Boilers revealed that a drain valve had been left open on all three in-service units, thus rendering them unavailable to respond to a fall in reactor coolant pressure. The valves were immediately closed and the boilers declared available. The station commissioned a Significant Abnormal Condition Investigation (SACI) in line with its arrangements for responding to incidents, which revealed that the drain valves had been left open for about 24 hours. The site inspector has expressed concern that the station had not fully recognised the potential safety significance of this event and that its initial response and investigation did not reflect the level of rigour called for by its own arrangements. Station accepted this and elevated the category of the event. The site inspector has since reviewed the station's report of the investigation and has deemed it to be adequate.
Turbine T/A2 Blade failure.
On 30 January Heysham 1 Unit 2 was manually tripped due to high vibration on the main turbine TA2. The vibration was caused by a structural failure of a single blade in a final stage of rotor LP1. The site inspector, assisted by a specialist assessor, has reviewed the stations response to this event and held regular discussions with members of the Panel of Inquiry charged with investigating the case of the failure. The site inspector concluded that station has undertaken a thorough review of the cause of the blade failure and noted that, subject to implementation of its recommendations, the Panel of Inquiry supports the return to service of Unit 2 and also the continued operation of Unit 1. Furthermore, the site inspector is satisfied that the event has not challenged the basis of the existing safety case for the failure of a single LP rotor blade.
Heysham 2
The NII has followed up the following events during this quarter.
Tritium Bearing Liquid found in Tritiated Effluent Tank Cell Sump.
Station reported that tritium bearing liquid has been discovered in the tritiated effluent tank cell sump in the combined active waste building (CAWB), which they believe may have been admitting groundwater. They have investigated this event and have identified recommended corrective actions to improve the current condition of the plant and help reduce the likelihood of a recurrent event. NII and EA attended a meeting at the station to receive a presentation on the station’s response to this event, following which station has been requested to provide further information. This matter is being considered jointly by NII and the Environment Agency, and justification is being sought that station has adequate arrangements to control or contain radioactive material, which may be present in the CAWB sumps.
Incorrectly Programmed Turbine Governor Program Card Leading to an Unplanned Trip of Reactor 8.No regulatory documentation was issued during the quarter: