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.
Visits
The Nuclear Installations Inspectorate (NII) site inspectors made visits to Heysham on the following dates during this quarter:
|
Heysham 1 |
Heysham 2 |
|---|---|
| 9, 10, 16, 17, 28, 29 October 2003 | 7, 16, 17, 29, 30 October 2003 |
| 6, 7, 13, 21, 25 November 2003 | 6, 7, 13, 21, 27 November 2003 |
| 8, 16, 17 December 2003 | 17, 18, 22, 29 December 2003 |
Other members of the NII, including specialist inspectors visited the Heysham site during the period, as follows.
The UK, Nuclear Installations Inspectorate (NII) and French, Direction Generale De La Surete Nucleaire Et De La Radioprotection (DGSNR) bilateral steering committee visited Heysham 1 & 2 power stations on 16 October 2003. The steering committee provides a forum for coordinating technical exchange between the UK and French nuclear regulatory bodies. The visit was lead by a Deputy Chief Inspector from each of the regulatory bodies. Committee members toured both stations, and took particular interest in operator dose control, control of radioactive discharges and periodic safety reviews. The visitors expressed satisfaction with the outcome from the visit.
The NII site inspector and specialist inspectors attended site on
a number of occasions during the period in relation to matters
associated with the failure of the ECW seawater cooling pipework. A
team of NII inspectors lead by a superintending inspector witnessed a
level 1 demonstration of the station's emergency arrangements. An
anonymous report made to NII was followed-up with the aid of a
specialist inspector.
Heysham 2
Specialist inspectors inspected station provisions for: process fire safety; general fire precautions; conventional safety; intentions for reactor 8 2004 outage work; implementation of Technical Specifications; follow-up of an anonymous report.
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.
The NII site inspectors attended the Local Community Liaison Council meeting which took place on 7 November 2003. NII's inspection activities for both Heysham 1 & 2 were summarised and further information was provided as necessary in response to members' questions.
Discussions took place during the period regarding the arrangements for notifying the public, within the Detailed Emergency Planning Zone (DEPZ), should there be a nuclear emergency at Heysham. The arrangements are required under the Radiation Emergency Preparedness and Public Information Regulations (REPPIR). Lancashire Constabulary has stated that from 1 January 2004, the Police would withdraw from providing the 'Warn and Inform' function as stated in the Site Emergency Plan and Public Information Calendars for 2003. Lancashire County Council Emergency Planners, Lancashire Constabulary, British Energy, NII Site Inspectors and NII's Emergency Planning Specialists discussed revisions to the on-site emergency arrangements and the Off-Site Emergency Plan, and revised wording for the affected site documents has been agreed. The stations are working to complete the necessary changes to an agreed timescale.
NII is satisfied that the Licensee will perform the 'Warn & Inform' function in the future, and that the site emergency arrangements remain adequate beyond 1 January 2004.
During the period a team of NII inspectors led by one of the
superintending inspectors for AGR reactors observed a demonstration
of the emergency arrangements at Heysham 1. Station demonstration
exercises are carried out annually and are in addition to the
training exercises routinely carried out by each shift. The emergency
exercise scenarios are developed to allow key aspects of the
station's emergency arrangements to be exercised and inspected on
a regular basis.
Following the exercise it was concluded that the station had provided
an adequate demonstration of the emergency arrangements in the areas
considered, and this was confirmed to the station by letter. In line
with expectations for continuous improvement a number of learning
points were identified which will be actioned through the
station's programme of emergency arrangements staff training and
shift exercises planned for 2004.
NII completed an assessment of a category 2 nuclear safety modification proposing a redefinition of the basis of plant maintenance, inspection and testing to a 35 day month rather than a calendar month. The licensees proposal was part of a generic development for all AGR stations and was initially introduced at Heysham 2. The licensees case for the change was made to bring about improvements in the completion of maintenance, testing and inspection activities and alignment with recently introduced work management practices. NII's assessment concluded that an adequate justification had been provided and NII granted Approval, under Licence Condition 28, to a revised Maintenance Schedule 'Preface' allowing implementation of the change.
During the period the NII site inspector observed the Heysham 2 contribution to the Heysham 1 demonstration exercise, and the response was deemed adequate. However, a number of areas for improvement were reported to station, and they are working to address them.
We also respond to non-routine matters arising on site that may affect safety, and in this report include details of the following matters.
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 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.
Following an anonymous report made to NII regarding gas circulator rotor balancing facilities at Heysham, the NII conventional safety specialist visited site to inspect the equipment in question at both stations.
For the Heysham 1 facility the inspector concluded that the rotor balancing equipment fell well short of minimum standards for guarding and protection of the operators. During the inspection we were informed the equipment had been taken out of use for routine maintenance and modification work. As the equipment was not in use we didn't consider it necessary to issue a formal Prohibition or Improvement Notice. Following our inspection the Station Director confirmed in writing to NII that the rotor balancing equipment was and would remain locked out of use until improvements, in line with relevant regulations and codes of practice, have been put in place to provide adequate guarding and protection of operators.
The inspector concluded that for the Heysham 2 facility, the equipment was in a dedicated room, had suitable guarding, was positioned behind protective transparent sheeting and the door to the room was interlocked to prevent access whilst equipment was in use. Therefore the circulator rotor balancing facility was deemed suitable for use and the provisions adequate.
Both reactors at Heysham 1 were shutdown on 28 October 2003 following the failure of a section of cast iron pipework within the Essential Cooling Water (ECW) system, which resulted in some flooding to the turbine hall basement and water ingress to the reactor basement. NII Inspectors attended site on the day of the event to satisfy themselves the plant was and would remain in a safe condition and commenced an initial investigation. Investigations revealed the ECW system had suffered a failure of the cast iron pipework due to a combination of graphitic corrosion and cracking.
The cast iron pipework was known to be degraded due to corrosion by the seawater it carries and was undergoing a phased programme of replacement with glass-coated steel piping at the time of the incident. Extensive inspections since the failure led to decisions by the licensee to bring forward the pipework replacement programme before seeking to make a safety case for return to service, which had to cater both for the cooling needs of safety-related plant and for the consequences of flooding.
The NII site inspector and a team of NII specialists carefully reviewed the licensees recovery process and assessed the adequacy of the licensees safety case to support a return to service of the reactors. NII's agreement to the return to service of the reactors was provided on 14 February 2004.
During work being carried out to return one of the starting/standby boiler feed pumps to service, the main boiler feed pump and the single available starting/standby boiler feed pump tripped and led to a reactor trip. Following the reactor trip the post trip sequencing equipment (PTSE ) signalled the circulator variable frequency drives to start, but only 5 out of 8 drives achieved the target speed. Other equipment required by the PTSE operated as expected, and adequate post trip cooling was established. Whilst the event challenged the station provisions for defence in depth, it remained within the bounds of the station safety case. The event was reported formally to NII, and a Divisional Panel of Inquiry has been carried out by the licensee, with a technical assist team established to support the inquiry panel. The station presented an interim category one safety case to the nuclear safety committee prior to the return to service of reactor 8, which also provided justification for the continued operation of reactor 7. The station inquiry is complete, and actions identified for the short and long term are being addressed. NII is monitoring the situation and is being kept informed of developments and progress. Station proposes to submit a safety case to the NSC, in April 2004, for the longer term.
Station informed NII that a number of inspections required under the above regulations had not been carried out. The site inspector and a specialist inspector visited station and carried out an investigation into the circumstances of the event. During the visit, station confirmed that no inspections of nuclear safety significance had been omitted. Station has since confirmed to NII that they have now reached a position with the competent person, which returns them to compliance with the regulations.
The following regulatory documentation was issued during the quarter:
(i) Licence Instrument Number 62 was issued to Heysham 2 specifying that proposed modification to 'Replace the Heysham 2 Probabilistic Risk Monitor ESSM with ESOP' should not be implemented without the agreement of the Health & Safety Executive.
(ii) Licence Instrument Number 63 was issued to Heysham 2 providing the agreement of the Health & Safety Executive to the modification 'Use of Teresstic 46 to replace Essotron 46, as the Gas Circulator Lubricant at Heysham 2'.
(iii) Approval Number 30 was issued to Heysham 1 granting approval by the Health & Safety Executive to an amendment to the 'Heysham 1 Maintenance Schedule'.
The following regulatory document was issued in February 2004 and has been included within this report for completeness:
(iv) Licence Instrument Number 64 was issued to Heysham 1 providing the agreement of the Health & Safety Executive to the return to service of reactors 1 & 2 as modified by the document 'Heysham 1 Power Station Return of Both Reactor Units to Service following failure of the Essential Cooling Water Supply Main in the Turbine Hall'
Published on the HSE web site 14 April 2004