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 available also from the Internet at http://www.hse.gov.uk/nuclear/index.htm. Site Inspectors of HM Nuclear Installations Inspectorate (NII) normally 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 should contact the HSE’s Nuclear Directorate on 0151-951-3484/3290.
Nuclear Safety Directorate
Health and Safety Executive
Redgrave Court
Merton Road
Bootle
Merseyside
L20 7HS
The Nuclear Installations Inspectorate (NII) Site Inspectors and other inspectors made inspections at Heysham on the following dates during the quarter:
| Heysham 1 | Heysham 2 | |
|---|---|---|
| 19, 24, 25, & 26 | April 2007 | 10, 11, 12, 24, 25 & 26 |
| 8, 9, 22, 23, 24 & 30 | May 2007 | 1, 2, 3, 15, & 16 |
| 6, 7, 12, 21 | June 2007 | 6, 7, 8, 25, 26 & 27 |
Inspections are undertaken at site as part of the process for monitoring compliance with:
the conditions attached by HSE/NII to the nuclear site licence;
the Health and Safety at Work etc Act (HSWA) 1974 and
regulations made under the HSWA for example the Ionising Radiations Regulations 1999 and the Management of Health and Safety at Work Regulations 1999.
This entails monitoring licensee’s actions on the site in relation to incidents, operations, maintenance, projects, modifications, safety case changes and any other matters which may affect safety. The licensee is required to make and implement adequate arrangements under the conditions attached to the licence in order to ensure legal compliance. Inspections seek to judge both the adequacy of these arrangements and their implementation. In this period routine inspections on site covered:
In general the arrangements made and implemented by the stations in response to safety requirements were deemed to be adequate in the areas inspected. However, where improvements were considered necessary, satisfactory commitments to address the issues were made by or are being sought from the licensee, and the site inspectors will monitor progress during future visits. Where necessary, formal regulatory intervention action may be taken to ensure that appropriate remedial measures are implemented to reasonably practicable timescales.
At the beginning of May 2007 Reactor 1 embarked on its triennial periodic shutdown. During this shutdown the Licensee: conducts maintenance activities in accordance with the plant’s Maintenance Schedule; undertakes inspections to support the station safety case and to comply with statutory requirements; implements modifications to enhance safety of the plant; and completes other remedial work requiring a reactor outage. The Site Inspector and NII specialist assessors inspect a sample of these activities, which on this occasion includes an extensive programme of inspections to fulfil commitments set out in the safety case for the boiler closure units. These inspections, and other key documents supplied by the licensee, will inform NII’s response to the station’s request for consent to return R1 to service for a further period of 3 years. Prior to making this decision, NII will attend a Start Up meeting with station management on 11 July.
At the beginning of April 2007 Reactor 8 embarked on its triennial periodic shutdown. During this shutdown, the Licensee conducted maintenance activities in accordance with the plant’s Maintenance Schedule, together with inspections to support the station safety case and to comply with statutory requirements and implemented modifications and other remedial work requiring a reactor outage. This included a large replacement programme of auxiliary cooling pipes using high density poly-ethylene pipe-work. A formal Start- Up meeting was held with Station managers on 15 May where Station presented the findings from its shutdown work to NII. Inspections by specialist NII inspectors did not reveal any significant shortcomings in the arrangements and conduct of outage activities. Following successful completion of all necessary outage work NII granted Consent to BE to start up the reactor on 25 May 2007.
Licensees are required to have arrangements to respond to non-routine matters and events. NII inspectors judge the adequacy of the licensee’s response including actions taken to implement any necessary improvements. Matters of particular note considered during the period include the following:
A review of maintenance schedule for safety related equipment revealed that the station had failed to undertake a test on a gas turbine at the prescribed interval. The station completed the test, which confirmed the equipment to be performing within specification, and immediately reported the incident to NII. The station has categorised this event as Level 1 on the International Nuclear Event Scale (INES), i.e. a safety anomaly having the potential to have only a minor impact on plant safety. The station has initiated a Significant Abnormal Condition Investigation to establish the route cause of the event and propose appropriate corrective action to prevent a recurrence. The Site Inspector is satisfied with the station’s response to this event and continues to monitor progress with the investigation.
On 20 June the station notified NII that the lift of a heavy component at pile cap level failed to comply with the relevant Station Operating Instruction (SOI), which aims to control the movement of such components above sensitive areas of the plant. The error was identified by a vigilant lift co-ordinator, who took immediate action to ensure the lift was completed in accordance with the SOI. The station has initiated a Significant Abnormal Condition Investigation to establish the route cause of the incident and propose corrective actions to prevent a recurrence. The Site Inspector continues to monitor progress with the investigation.
Following the failure of a section of the cast iron Essential Cooling Water pipework in 2003, the station embarked upon a programme to replace the cast iron with pipework fabricated from glass flaked carbon steel. The ECW pipework within the reactor building and turbine hall was replaced in 2004. The station is about to embark upon the last phase of this programme which will see all the remaining cast iron sections external to station buildings replaced during this financial year. The Site Inspector and NII specialist assessors are closely monitoring the progress of this project.
Reactor 2 continues to operate at reduced load due to the higher than expected temperatures indicated by one of several instruments monitoring underdome hot box surface metal temperatures. The station is committed to seeking NII’s agreement before implementing a safety case that would permit the reactor to operate with top dome metal temperatures above the current design limit.
During the reactor 8 periodic shutdown an INES level 1 event was reported to NII. This incident occurred on the reactor pile-cap when a team of BE personnel were engaged in changing seals on a neutron plug reactor assembly. A fault developed on the 3Te hoist normally used to lift the assembly. The operators decided to proceed with the work and perform the lift with the charge hall crane, which was not in compliance with their written instructions. A vigilant reactor operator stopped the work. The Station undertook a thorough investigation into the event and as a result has proposed corrective actions to help prevent a recurrence. NII will monitor the implementation of these corrective actions.
In May towards the end of the periodic shutdown on reactor 8 operators were undertaking reactor start-up checks. During one of these checks they inadvertently turned off a feed-water valve on the running reactor, this led to an automatic shutdown of reactor 7. An investigation into the circumstances surrounding this event is ongoing with a view to determining the root causes and to recommend corrective actions to help prevent a recurrence. NII will review the outcome of the Station’s investigation.
During restart of reactor 7 a few days later a leak was discovered on a feed-water heater pipe and this was temporarily repaired. Station continued to monitor the efficacy of the repair to this pipe and was not entirely satisfied that it had been completely successful. Thus in early June the Station took a prudent decision to manually shutdown reactor 7 for a week, to both cut out and replace the degraded pipe and to refuel the reactor. During the shutdowns no plant operating limits or conditions were exceeded. NII was content with the actions taken.
Under Health and Safety legislation NII Site Inspectors, and other HSE Inspectors, may issue formal documents to ensure compliance with regulatory requirements. Under nuclear site licence conditions NII issues regulatory documents, which either permission an activity or requires some form of action to be taken; these are collectively termed Licence Instruments (LI). In addition inspectors may issue enforcement notices to secure improvements to safety.
Four LI were issued to Heysham during the quarter:
No enforcement notices were issued during the reporting period.