DIRECTORATE OF ESTATES AND DEVELOPMENT CONTROL OF GAS NETWORK OPERATIONS

Transcription

1 DIRECTORATE OF ESTATES AND DEVELOPMENT CONTROL OF GAS NETWORK OPERATIONS Document Name: HS0010 Author: Paul Richards Issue Number: 6 Number of Pages: 25 Issue Date: 30 May 2015 Approved by: Wilcock Consulting Last revised: 23/02/2018 By - Paul Richards / Phil Winnard Current revision 23/08/2018 By Phil Winnard/Paul Richards

2 REVISION HISTORY SHEET Document Status Checked by Authorised by Issued 17 th March review of documentation and updating drawing information 23 rd February 2018, full review of documentation following Hawthorns decant, Barnes new build and G3 network alterations for Hydeploy project. 8 th August 2018, Inclusion of Hydeploy procedural and material change proposals for HSE review 23 rd August 2018, update of Hydeploy procedures following review of detection techniques Paul Richards Phil Winnard, Wilcock consulting / Paul Richards Paul Richards / Phil Winnard Wilcock consulting Paul Richards Keele Web site updated Issue to Hydeploy team and HSE inspectors for comment 27 th November 2018 Paul Richards / Elizabeth Cameron Keele web site updated 2

3 CONTENTS 1. FOREWORD INTRODUCTION DESCRIPTION OF THE OPERATION GENERAL DESCRIPTION OF PLANT, PREMISES AND LOCATION SITE GENERAL OPERATION AND MAINTENANCE PROCEDURES RISK ASSESSMENT HEALTH AND SAFETY ARRANGEMENTS MONITORING HEALTH AND SAFETY PERFORMANCE COMPETENCE AND TRAINING MANAGEMENT OF CONTRACTORS AUDIT AND REVIEW OF MANAGEMENT SYSTEMS CO-OPERATION WITH OTHER PARTIES GAS ESCAPE AND INVESTIGATIONS CONTENT AND OTHER CHARACTERISTICS OF GAS CONTINUITY OF SUPPLY AND SUPPLY EMERGENCIES OTHER INCIDENTS GLOSSARY OF TERMS APPENDICES... 28

4 1. FOREWORD Purpose This procedure details the operational arrangements to ensure the safety and integrity of the gas network, within the ownership and responsibility of Keele University. Scope These procedures are also designed to give guidance during emergency situations and supply interruptions. 2. INTRODUCTION 2.1 For the purposes of the Gas Safety (Management) Regulations 1996, the Duty holder for the University of Keele gas distribution network is: Professor Trevor McMillan, Vice Chancellor. The registered office of the University of Keele is: Keele University, Keele, ST5 5BG. This Safety Case has been prepared by the University of Keele, as a Licensed Gas Transporter / Supplier within Great Britain, to demonstrate compliance with the Gas Safety (Management) Regulations 1996 (GS(M)R) in the construction, maintenance and operation of the Keele University Gas Distribution Network. It sets out the arrangements for ensuring that the natural gas network, owned by the University of Keele, is operated and maintained safely and that the risk to site occupiers and visitors arising from its operation is as low as reasonably practicable. The document includes a risk assessment and sets out the preventative measures in place to avoid incidents and the protective measures to be implemented in the event of an incident. It contains the essential elements of a gas safety management system. The document makes reference to Keele University standard procedures including the procedures to be followed in the event of a partial or total supply failure and the procedures for reporting and dealing with gas escapes and gas related incidents. All gas supplies to the site are delivered under firm gas contracts, hence there are no issues arising from interruptible gas contracts. 3. DESCRIPTION OF THE OPERATION 3.1 The University of Keele owns and maintains a gas distribution network which conveys natural gas from the outlet of 4 meters (i.e. primary meters located at points across the site) to student and staff houses and flats, places of assembly such as halls of residence, lecture theatres and other commercial buildings. Most of the staff housing and student flats take gas via secondary meters but supplies to the Halls of Residence and some of the other buildings are not metered and hence the gas flows directly into internal pipework and then on to appliances. The primary meters are owned by National Grid plc (CADENT) and gas is delivered to them via the CADENT gas distribution system. It is CADENT s responsibility to maintain adequate meter inlet pressures and gas quality. 1

5 Any new gas distribution infrastructure, extensions or alterations to the gas system are affected in accordance with procedure KU/Gas/11 Gas site works process 4. GENERAL DESCRIPTION OF PLANT, PREMISES AND LOCATION 4.1 The University conveys the gas to consumers from the outlet of the primary meters via 9 km of below ground gas main. The gas mains are connected to the premises via gas service pipes. The site occupies an area of approximately 607 acres. The total peak instant gas load for the site is estimated at 20 MW. The gas mains and services across the site have been installed over a period between 1960 and There is no cast or ductile iron. All the medium pressure ductile iron main was decommissioned in 2003 following a safety notice from the HSE dated February In 1985 a major replacement programme was undertaken on the central campus to replace cast and ductile iron pipe with MDPE. Construction of the distribution network has been generally to IGE/TD/3 or TD/4 standards edition current at the time of construction. The majority of the gas main under the management of Keele University operates at low pressure (21mb 30mb) and the LP mains are mostly of MDPE with 721metres of Steel pipe located in MZ1. The steel pipe ranges from 4 inch to 8 inch in diameter. There are 680 meters of MDPE gas main that operate at medium pressure (140mb) To facilitate the Hydeploy project Keele University will adopt 175 meters of existing 6 steel main and construction of 89 meters of 180mm MDPE main at medium pressure 1.5 bar supplying MZ3 network from a new compound sited behind the Keele University Sports Centre The construction of the new main is anticipated to take place Autumn 2018 with adoption of the steel main Spring These assets will continue to form part of the Keele gas network until Summer 2020 Service pipes, which connect the mains to the secondary meters (or to the internal pipework where there are no secondary meters), are MDPE, steel or MDPE/steel. A survey has been carried out to check if external service isolation valves are fitted in accordance with IGE/TD/4 and installed as required. A planned maintenance event takes place biannually to check service pipe condition on Keele University owned assets. Any faults observed during the survey are rectified on a planned basis. A gas service replacement policy has been developed as detailed in KU/Gas/8 Gas Service Replacement Policy. 4.2 The campus comprises four separate networks each supplied via a single primary meter and referred to as meter zones (A list of drawings can be found in Appendix 1 - Site Drawings. The meter zones are zones are identified as follows: - MZ1 comprising a medium pressure main from Clock House supplying two separate low-pressure networks as follows: - 2

6 o o o o o Lyndsay Boiler House Horwood accommodation and student s union Keele Hall Horwood staff housing Springpool MZ3 currently comprises a low-pressure network serving the central academic campus For the Hydeploy project trial, Keele University will adopt and include a medium pressure main (1.5 bar) and the G3 twin stream governor station as part of the Keele University network for the period of the trial as detailed in the exemption documentation MZ7 comprises a low-pressure main serving Barnes W & X blocks MZ8 comprises a low-pressure main serving Barnes Halls Note: - MZ5 and MZ6 Networks were legally transferred to a third party in January 2018 A request made to CADENT seeking information on the standards to which the meters have been designed and a description of the maintenance regime being applied produced the following response: As there are a number of different types of installation on the campus there are as many maintenance regimes; rather than try to detail the exact regime associated with each site we have described what is done by type. National Grid Metering and our predecessors have used internal documents for the design, construction and maintenance of metering equipment; over recent years these documents have been up dated and adopted by the Institution of Gas Engineers and Managers - these documents refer where possible to the relevant British and International standards - these are many and various. All inspections and maintenance are carried out broadly in accordance with the appropriate recommendations and procedures published by the Institution of Gas Engineers and Managers. A long history of operating metering equipment and the application of Reliability Centered Maintenance techniques has led to the formulation of the maintenance procedures and frequencies employed. All metering installations are subject to an inspection, usually carried out by the meter reading agency, on at least a two-year frequency. 4.3 Low pressure supplies with diaphragm meters No programmed maintenance is carried out, the performance of the installed population is monitored and policies to replace this type of equipment due to reliability or accuracy are formulated from the collected information. 4.4 Low pressure rotary and turbine meter installations All such installations are checked on a five-year cycle; the maintenance procedure includes general condition, pressure losses, noise, oil level and condition. Labelling and safety equipment is also checked. 3

7 4.5 Medium pressure installations (such as Clock House) There are 4 gas pressure control installations with an inlet pressure of greater than 75 mbar therefore attracting the designation medium pressure installation. The installations are located as follows: - Walled Garden Station No 1 (GGS1) Horwood Station No 2 (GGS2) Horwood Station No 3 (GGS3) Recently uprated and supplies the Horwood Energy Centre Lyndsay Station No 4 (GGS4) The Lyndsay installation has been upgraded which confirms all governor installations meet current standards. The medium pressure regulator installations are subjected to a maintenance regime in accordance with the recommendations stipulated in IGEM/TD/13. The University maintenance policy is specified in document KU/Gas/9. The maintenance contract and results of the most recent maintenance inspection for the above installations can be found in Appendix 7 For the Hydeploy project Keele University will adopt the medium pressure governor station, inlet pressure 1.5 bar, referred to as the G3 governor station, which supplies the MZ3 low pressure network for the duration of the Hydeploy trial. The maintenance of this asset will be contracted out to CADENT CADENT will supply details of the maintenance regime, frequencies and competencies of service personnel. Keele University shall conduct technical due diligence on assets to be transferred including maintenance procedures, competencies and records The principal characteristics of each meter zone are as follows: Meter Zone No. 1 - Drawing No. SG-MZ-1 Meter No. G1 Clock House Main Meter The gas to MZ1 is supplied from a 6 diameter, medium pressure; steel main owned by CADENT. Gas enters the network through CADENT s twin stream meter rig ref no. G1. The rig operates at an inlet pressure up to 2 bar and an outlet pressure of 140mb. The slam shuts are set by CADENT to go off at 210 mbar. Within MZ 1 there are a number of halls of residence and a range of commercial buildings housing the Students Union and a café bar (See drawing MZ 1 for details). This is the only MZ that comprises sections of medium pressure mains. The MP main carries supplies to the following gas governors which supply student flats, boilers or commercial buildings. 1. Approximately 680m of 250 mm diameter MDPE medium pressure main supplying Horwood complex. This gas main supplies two regulator module as follows: - a. Twin stream active slam shut pressure reduction module (GGS2) with outlet pressure set at 28 mbar supplying Horwood flats and, Students Union Catering, Keel Hall, Horwood Staff Housing and Springpool. The low-pressure network comprises the following: - 4

8 i. Approximately 750m of low pressure MDPE main of varying sizes at Horwood flats and Students Union. ii. Approximately 160 metres of low pressure 8 steel main and 311 meters of varying sizes of MDPE main supplying Keel Hall, Horwood Staff Housing and Springpool. b. Twin stream active slam shut module (GGS3) with outlet pressure set at 70 mbar supplying Horwood main boilers and a newly installed CHP 2. Approximately 200 metres of 180mm diameter MDPE medium pressure main supplying Lindsay boiler house The pressure regulator and meter installation (GGS4) has been upgraded to supply the existing boiler house and make provision for a future CHP 3. A pressure regulator installation (GGS1) supplying the Green house boiler, Clock house kitchen, Music Department and Firshill. The outlet pipework comprises approximately 175 metres of 90mm, 63mm and 32mm PE pipe. This system operates at a pressure of approximately 30 mbar There are no industrial processes and the supply is via a firm gas contract. It is an all plastic system, 4.7 Meter Zone No.3 - Main Campus drawing no. SG-MZ-3 Meter No. G3 Main Campus This is by far the largest network on the site. It is a low-pressure system. Currently the gas is supplied from a 6 diameter, medium pressure, steel main (owned by CADENT) and enters the network through CADENT s twin stream meter rig ref no. G3. The CADENT rig operates at an inlet pressure up to 2 bar and an outlet pressure of 28mb. The slam shuts are set by CADENT to trigger at 70 mbar. The total length of the MZ 3 network is 4381 meters and is constructed of MDPE of varying sizes For the Hydeploy trial Keele University will adopt the G3 governor together with 175 meters of existing CADENT owned 6 diameter, medium pressure, steel main and this will be supplied from a new site grid entry unit via a new section of 180mm MPDE medium pressure pipe approximately 170 meters in length (which includes a volume loop) The pressure in this network will be limited to 1.5 bar Details of the proposals can be seen on drawing S-G-011 in Appendix 1 MZ 3 comprises domestic type dwellings including staff houses, a number of halls of residence and a range of commercial buildings housing lecture theatres, science laboratories, a leisure centre and administration staff offices. All supplies to domestic type dwellings and commercial buildings are separately metered via the University-owned secondary meters. There are no industrial processes and the supply is via firm gas contracts Meter Zone No. 7 Drawing No. SG-MZ-7 Meter No. G340 (Barnes W & X ) 5

9 This is an all LP system. There is 103 metres of 125mm MDPE main operating at a pressure of 27mb. The gas is supplied from a 4 diameter medium pressure, steel main owned by CADENT and enters the network through CADENT s single stream meter rig ref no. G340. The system supplies two halls of residence, both of which are separately metered via the University -owned secondary meters. These residences are designated blocks X and W 4.09 Meter Zone No.8 - Main Campus drawing no. SG-MZ-8 Meter No. G360 Barnes This is a low-pressure distribution system. The gas is supplied from a 180mm diameter, medium pressure, PE main (owned by CADENT) and enters the network through CADENT s twin stream meter rig ref no. G360. This rig was replaced with one of larger capacity in 2017 to accommodate new developments. The CADENT rig operates at an inlet pressure up to 2 bar and an outlet pressure of 28mb. The slam shuts are set by CADENT to trigger at 70 mbar. The MZ 8 network comprises 734 meters of MDPE. MZ 8 supplies the Barnes Halls of Residences, blocks A-V and social space, bar and launderette. Two additional blocks were added to this network in 2017 and designated blocks Y and Z All supplies to domestic type dwellings and commercial buildings are separately metered via the University-owned secondary meters 5. SITE GENERAL 5.1 There are no interruptible customers on the site and no industrial processes and there are no single, very large volume consumers on site. The largest (downstream) consumer is meter G041A 372,000 cubic meters per annum. It is in MZ 1. The main items of safety critical plant are the pressure regulators and slam-shut valves owned and maintained by CADENT and located at the primary meter installations. Meter No. G007 is owned by CADENT and embedded in system. In addition, there are low pressure meter regulators at the inlet of the secondary meters. These are owned by the University and maintained by the Director of Estates and Development (see Management Organisation section 7.1). Note: Some secondary meters may not have pressure regulators. A survey of secondary meters is proposed and this will include a check for meter regulators. The University metering standard is set out in KU/Gas/14 University gas Metering Policy. There are no control centers required to ensure the safe flow of gas since CADENT is responsible for maintaining inlet pressures to the primary meter installations and any reports of low pressure on the network will immediately be reported to the NG gas emergency service on Safe gas flow from the primary to the secondary meters is maintained by ensuring there is sufficient capacity within the network to meet peak demand. A Network Analysis exercise has been completed by Wilcock Consultants Ltd using the Small Network Analysis Programme (SNAP) to assess how the University-operated systems meet peak demand; no reduction in demand to allow for diversity was built in to this exercise. Validation of Network Pressures has been carried out. Loggers have been installed at the lowest pressure points predicted in the network analysis. A list of logger locations and an example of the plots from the loggers is included in Appendix 11. The data from the loggers is used to validate the network analysis findings to ensure adequate pressures are maintained. 6

10 The minimum design pressure for the system at peak demand is 19mbar. The following table shows the minimum pressures calculated for the system using network analysis. It is demonstrated that pressures in the networks are greater than the minimum design pressure at all locations. Min Pressure Summary Meter Zone Node Min Pressure MZ1 - MP MZ1 Clock House MZ1 Horwood MZ MZ MZ Note: - MZ5 and MZ6 have been legally transferred to a third party and are not now included in the table above. The results of the network analysis are tabulated in Appendix 5 and the node references are shown on drawing numbers: S-G-MZ1 S-G-MZ3 S-G-MZ7 S-G-MZ8 There are no other technical specifications, procedures or arrangements relating to the management of the safe flow of gas or safety critical plant on the site. For the Hydeploy trial, 6 off gas monitoring stations will be constructed on the MZ3 network, refer to drawing S-G-012 in Appendix 1, these stations will be utilised to determine gas pressure on the network and provide sample points to determine gas composition. 6. OPERATION AND MAINTENANCE PROCEDURES 6.1 Operational Procedures Gas flows are managed by the pressure regulation equipment at the primary meter installations and these are owned and maintained by CADENT. There is no other associated plant on either the CADENT or the University systems that is likely to affect the safe flow of gas through the network. The University has installed its own Pressure Reduction Equipment in certain instances and this equipment is inspected and maintained in accordance with procedure KU/Gas/9 Gas Governor Maintenance Policy In the event of a plant failure on equipment affecting gas flows (e.g. a slam-shut failure or loss of pressure on CADENT s system) an attempt will be made to maintain positive pressure within the affected section/s of the University network in the first instance by appealing to consumers to stop using gas. 7

11 Where there is a general requirement to reduce gas demand on the Campus then load shedding will be carried out in accordance with the schedule listed in KU/Gas/10 Load shedding data sheets If, after doing this, pressures fall below 19mb consumers, supplies will be turned off at the secondary meter emergency control valves. If this is necessary, the University s Gas Safe registered plumbers will be dispatched to turn off meter control valves. The University does not have a census of gas users but there are no atrisk institutions such as care homes and there are believed to be few elderly consumers on the site. (Please note the nursery is on CADENT supply) If pressure falls to zero mbar, the section/s of the network affected will be isolated by closing the appropriate valves, disconnecting or squeezing off the mains concerned. Before restoring gas flows, the isolated sections of the network will be tested, reconnected and then purged before restoring supplies to consumers (see Document KU/Gas/4 - Procedure for restoring gas supplies This work will be undertaken using competent contractors working to approved codes of practice (see section 10 Management of Contractors). During routine operations (such as mains cut-outs for new connections or for mains replacement and repairs) gas flows are maintained by installing a suitably sized bypass and monitoring gas pressures either side of the isolated section. Again, this work is carried out using competent contractors working to approved codes of practice. The principal codes used are: - Gas networks IGE/TD/3 Edition 5 Steel and Polyethylene pipelines for Gas Distribution, IGE/TD/4 Edition 4- Gas Services Gas installations IGE/UP/1 Edition 2 Strength testing, tightness testing and direct purging of industrial and commercial gas installations. 6.2 Maintenance Procedures and Safety Inspections As stated above, all mains and services supplying primary meter installations and the installations themselves are owned by CADENT and maintained in accordance with their procedures. For the Hydeploy project, the CADENT G3 primary meter installation, although legally seconded to Keele University for the period of the Hydeploy trial, shall be contracted to CADENT for maintenance under their standard procedures with supplementary guidance. The University-owned system is inspected by a walking leakage survey using hand-held gas detection equipment. (Please see Document KU/Gas/1 Leakage Survey Procedure) 8

12 Any leaks detected are repaired and the details recorded on the site plans using a CAD system. If it is necessary to excavate, a visual inspection of buried pipes is made and the results are also recorded. The University records the location of any gas leaks on drawing number S-G-005 Rev H Gas Dates and Leaks Positions. Leakage history and pipe condition is considered when determining the University gas infrastructure replacement policy. The University s mains replacement policy is set out in Document KU/Gas/2 Mains and Service Replacement Policy. Currently there is no cathodic protection on existing steel mains, blow ground steel pipes being protected by wrapping. Wherever practical below ground steel pipe is eliminated for new/replacement designs. Where this is not possible Cathodic protection is installed. All metallic pipes within 30 metres of buildings have been identified for replacement. They will be replaced if there is evidence of poor condition and/or leakage or they will be abandoned if rendered redundant. It is the policy of the University to remove all metallic mains and services in this category by the year 2032 at the latest. Procedures for dealing with reported leaks (both upstream and down steam of the consumer s emergency control valve) and reports of possible CO emission are covered in Gas Escapes and Investigations section 13 The University has installed Natural Gas and CO detectors in plant rooms at selected Halls of residence. A list of installations where detectors have been installed is as follows: - Barnes o Blocks W, X, G, H, J, K, L O, P Q, R, S, T, U, N, V Holly Cross o Holly Cross Halls Horwood o Blocks T, V, W, X, Y o House 99 o Horwood Z1 Z21 blocks Lindsay o Sneyd house o Taylor house Oaks A and B The interfaces between CADENT, the University and the University s gas supplier are managed by the Director of Estates. Audits of work affecting gas flows (i.e. flow stopping and valve operations) are carried out by the Gas Emergency Controllers and third-party consultants to ensure work carried out by staff and contractors is undertaken in a safe and efficient manner and in accordance with the relevant codes and procedures. Checks are carried out on work in progress, completed work and on the condition and availability of the contractors plant and equipment. 9

13 The results of the audits are collated and corrective action taken when necessary. Liaison with enforcing authorities and emergency services is undertaken by the Estates and Development Department. The low volumes of work and their routine nature mean that regular meetings with police and fire officers and the CADENT is not warranted by the level of risk involved. However, should the situation warrant it, the relevant organisations will be contacted. The appointment, training and ongoing assessment of safety critical staff is covered in section 9 - Competency and Training. 7. RISK ASSESSMENT 7.1 A risk assessment has been carried out by the Senior Operations Manager and his staff. All risks that may affect the safe management of the flow of gas and the provision of an emergency response have been identified and preventative and protective measures built into this document. This assessment will be reviewed annually and immediately before any significant change in the management team. If, for example, the Senior Operations Manager were to leave, a new risk assessment would be undertaken with both the leaving and incoming managers present. This would form an important part of a handover of responsibilities process. Note: Incident means fire, explosion or CO poisoning. The ratings (R) have been derived by assessing the probability (P) and the consequences (C) of the event using a range of 1 to 5 for each factor. (The higher number indicates higher probability and consequence). The major risks identified are as follows: - A failure of the CADENT network resulting in significant reduction in gas pressures. P=2; C=2; R=4 A failure in the CADENT network resulting in the complete cessation of gas supplies. P=1; C=3; R=3 An interruption of supplies due to primary meters being turned off by NG emergency service engineers. P=4; C=3; R=12 A failure in the University network due to interference damage during on-site construction works. P=2; C=3; R=6 An incident due to a failure to communicate the action to be taken by site occupiers and visitors in the event of a gas emergency. P=2; C=5; R=10 An incident due to failure to respond adequately to a report of a gas emergency. P=2; C=5; R=10 An incident resulting from a pipe fracture, a failed joint or corrosion hole. P=1; C=5; R=5 An over-pressurization of the system due to the unintentional connection of a higherpressure system to a low-pressure system. P=1; C=5; R=5 Having identified the risks, the following preventative and protective measures are in place: - 10

14 7.2 A failure of the CADENT network resulting in significant reduction in gas pressures Preventative Measures: CADENT have preventative measures in place to ensure they maintain sufficient capacity in their system to meet the University s demand requirements. They also take steps to minimise the risk of third party damage or loss of capacity whist working on their system. Protective Measures: If, for any reason, the minimum design pressure of 19mb cannot be maintained during full load conditions, steps will be taken to maintain the 19mb by progressively terminating supplies to secondary meters. Every attempt will be made to maintain positive pressure in the system. Once pressures return to normal the University s Gas Safe registered plumbers will test and purge all secondary meter installations and downstream installations and appliances and then re-commission supplies. 7.3 A failure in the CADENT network resulting in the complete cessation of gas supplies Preventative Measures: CADENT have preventative measures in place to ensure they maintain sufficient capacity it their system to meet the University s demand requirements. They also take steps to minimise the risk of third party damage or loss of capacity whist working on their system. Protective Measures: If pressure on the network falls to zero there is a possibility that air may get into the system. In these circumstances, that part of the network affected will be isolated at the primary meter/s emergency control valve/s. Once pressure on the CADENT system is restored, supplies will be reinstated using the procedure set out in Document KU/Gas/4 - Procedure for restoring Gas Supplies 7.4 An interruption of supplies due to the inlet valve/s to primary meters being turned off by CADENT emergency service engineers Preventative Measures: To avoid supplies being turned off unnecessarily, close liaison with CADENT is undertaken. In the event of a gas leak on the University s network, CADENT s national emergency service will be called and they will take immediate action to protect life and property. If, following a suitable risk assessment, it is unnecessary to turn off supplies at the primary meter/s, responsibility for dealing with the leak will be transferred to a University competent person. See section 13 Gas Escapes and Investigations and Document KU/Gas/3 Transfer of Responsibility & KU/Gas/4 -Procedure for Restoring Gas Supplies Protective Measures: If pressure on the network falls to zero there is a possibility that air may get into the system. In these circumstances, that part of the network affected will be isolated at the primary meter/s emergency control valve/s. Once pressure on the CADENT system is restored, supplies will be reinstated using the procedure set out in Document KU/Gas/4 11

15 7.5 A failure in the University network due to interference damage during on-site construction works Preventative measures: All construction work carried out on the University site is planned and coordinated via the Estates and Development Directorate. All University staff, operatives and contractors, where applicable, are briefed on the whereabouts of gas network pipes, plant and equipment, and are issued with gas network location plans and are familiar with safe digging practice. Before using mechanical excavators, all underground plant is located using plant location equipment and where necessary it is exposed by hand dug trial holes, utilising a Permit to Dig Procedure Protective Measures: If the gas network is damaged, site operatives will call the CADENT emergency service on and inform the site security office who will contact the gas duty competent person immediately. See also section 13 Gas Escapes and Investigations. If, as a result of the damage, the pressure in the network falls below 19 mbar but remains above zero mbar protective measures will be as in 6.1. If the pressure falls to zero mbar protective measures will be as in 6.2. Any incident of this type will be reported to the Director of Estates who will inform the University Safety Advisor, who will in turn inform the HSE and will arrange an investigation into the cause of the incident and ensure any actions considered necessary to avoid a recurrence are implemented. 7.6 An incident due to a failure to communicate the action to be taken by site occupiers and visitors in the event of a gas emergency For Preventative and Protective measures see section 13 Gas Escapes and Investigations. 7.7 An incident due to failure to respond adequately to a report of a gas emergency For Preventative and Protective measures see section 13 Dealing with Gas Escapes. 7.8 An incident resulting from a pipe fracture, a failed joint or corrosion hole For Preventative and Protective measures see section 13 Dealing with Gas Escapes 7.9 An over pressurization of the system due to the unintentional connection of a higherpressure system to a low-pressure system Preventative Measures: No connections will be made between pipes unless the operating pressures within the pipes have been established by reference to drawings and the actual pressure has been verified by the installation of pressure monitoring points. 12

16 Protective Measures: If pressure higher than its design limit is introduced into a pipe, the connection will be removed and the pressures returned to normal as quickly as possible. Meter control valves to all meters connected to the pipe will be closed. A walking leakage survey will be carried out. Before supplies are re-commissioned, all meters, internal pipe work, fittings and appliances will be inspected and tested for gas tightness using Gascoseeker (or similar instruments) and a function test will be carried out on appliances and meters to ensure they are working correctly. Any pipes, meters, fittings or appliances found to have been damaged by the overpressurization will be decommissioned or replaced before purging and re-commissioning processes commence. In the event of a network failure arising from any of the risks identified above, an investigation would be initiated and if necessary a competent third party would be called in to conduct an inquiry (Please see Document KU/Gas/5 - Incident Investigations.) 7.10 Additional risks due to the installation of equipment and conveyance of hydrogen enriched natural gas associated with the Hydeploy project have been identified as follows:- 1. Failure of hydrogen processing equipment and grid entry unit leading to a release of gas, P=2; C=5; R=10 2. Over pressure of the University MZ3 network due to failure of the Grid Entry Unit to control gas pressures P=1; C=4; R=4 3. Gas quality excursions due to failure of process monitoring in the Grid Entry Unit P=1; C=3; R=3 4. Risk of damage to life and/or property due to conveyance of hydrogen enriched natural gas P=2; C=5; R=10 5. Risk to persons working on MZ3 due to conveyance of hydrogen enriched natural gas P=2; C=5; R=10 The probability of occurrence and resultant consequences of the additional risks identified have been mitigated by the following:- 1. Failure of hydrogen processing equipment and grid entry unit leading to a release of gas Basis of design, HAZOP and HAZID study on the Hydeploy process equipment the results of which have been made available to the University 2. Over pressure of the University MZ3 network due to failure of the Grid Entry Unit to control gas pressures Basis of design, HAZOP and HAZID study on the Hydeploy process equipment the results of which have been made available to the University 3. Gas quality excursions due to failure of process monitoring in the Grid Entry Unit - Basis of design, HAZOP and HAZID study on the Hydeploy process equipment the results of which have been made available to the University. Installation of sampling points at strategic location on the MZ3 network 4. Risk of damage to life and/or property due to conveyance of hydrogen enriched natural gas Modification to Cadent gas escape management procedures which have been incorporated into University procedure KU/ Gas/ 17 (New procedure) including training and accreditation of staff and operatives 13

17 5. Risk to persons working on MZ3 due to conveyance of hydrogen enriched natural gas - Modification to Cadent gas escape management procedures which have been incorporated into KU / Gas 4 and KU/Gas /17. These changes are summarised as follows:- a. Use of bottled natural gas for all purging operations b. Addition of the pipework associated with Hydeploy connections into the testing and purging procedures for MZ3 c. All routine and non-routine operations procedures for work carried out on the MZ3 network to incorporate specific requirements for utilisation of bottled gas for purging d. All routine and non-routine operations procedures for work carried out on the MZ3 network to incorporate revised safe distances associated with hydrogen enriched natural gas e. Revised safety distances and trigger values incorporated into KU/Gas/17 14

18 8. HEALTH AND SAFETY ARRANGEMENTS 8.1 Management Organisation (Gas Safety) The Estates & Development Directorate has a wide management brief which includes gas, water, electricity, buildings and grounds. His gas management team work under the umbrella of the University- wide Health and Safety Management system. There is a health and safety committee and safety officers whose remit includes gas safety matters. MANAGEMENT ARRANGEMENTS 2017/ 2018 Vice-Chancellor Prof Trevor McMillan Duty Holder Occupational Health Manager Mrs B Allan Occupational Health Advice Mr P Butters Director- Estates & Development UEC Representative Head of DOHS Ian Williamson Health & Safety Advice Greg Dargue Assistant Director Estates & Development Monitoring Simon of Keeling Operational Plans & Actions Simon Keeling Health & Safety / Internal Auditing Wilcock Consulting Appointed gas network consultancy Paul Richards Responsible Person Gas Network Controller Nick Salt Team leader. Authorised Gas Safe Engineer and Deputy Network Controller Penspen Ltd. Approved Contractor North Staffs Pipe Services Approved Contractor Keele Gas Safe Duty Engineers 15

19 8.2 Management System The Health and Safety arrangements set out in this Safety Case include the Gas Safety Management System. These arrangements are in place to identify and manage the gas-related risks (see section 6) and to discharge the University s responsibilities under the GSMRs, i.e. to maintain safe gas supplies and provide a safe and effective emergency service. The arrangements will be independently audited every 12 months to ensure they are effective and any required actions identified by the auditor implemented by the Director of Estates. 9. MONITORING HEALTH AND SAFETY PERFORMANCE 9.1 Objectives The (Gas) Health and Safety objectives are to: - Minimise the risk of gas supply failures target = zero; Respond quickly to restore interruptions in supply as a result in University network failure target = 24 hrs; Ensure there is an effective system for reporting and dealing with gas escapes target = 100% reported to CADENT gas emergency service within 10 minutes of receiving report. Performance against the above objectives is monitored by the Management team and the Safety Committee. Any abnormal events are reported to the management team and the Safety Committee. The University maintains a record of gas escapes and incidents. During the period 1 st January 2017 to 1 st January internal escapes on fittings and pipework to Keele University owned assets 2 External escapes on Keele University owned assets (1 escape being identified from FID survey) 1 Escapes on National Grid Assets There have been no supply failures and no on-site interference damage. 9.2 Information Flows It is the policy of the University to consult and co-operate with the HSE, CADENT and its own staff on all matters relating to gas safety. Despite the low levels of activity, there is a forum for co-operating and sharing information from other Universities. The Principal Mechanical Engineer and Gas Network Controller is a member of the Association of University Engineers where relevant issues are discussed. The competent Persons also attend Forum meetings with National Grid. Relevant gas-related issues are communicated to Keele s staff and contractors via line managers and at safety committees and feedback passed to the Gas Network Controller and Director of Estates & Development. Special attention is paid to incidents, dangerous occurrences involving gas leaks, CO emissions and partial or complete loss of system pressure. Any dangerous occurrences such as loss of network pressure, CO related incidents, large volume gas releases, explosions or gas related fires will be reported to the Health and Safety Executive under RIDDOR. As advised by the Keele University Health and Safety Advisor. 16

20 The definition of a large volume gas release is: the sudden, uncontrolled release in a building of 10kg or more of natural gas or of 500kg if the release is in the open air. In the event of a partial or complete loss of supplies a message will be sent to all gas consumers on the site informing them of the situation and asking them to turn off at the emergency control valve and not to use gas until further notice. In relation to the Hydeploy trial project, specific information will be collected and collated to inform the Keele University Project Operational Group (POG) and the relevant Hydeploy team The information requirements are yet to be defined but would typically include functional and performance analysis eg Maintenance task compliance Gas and CO incident reporting Gas blend composition and any non-conformance issues Appliance breakdown analysis Operational run time of blending equipment 10. COMPETENCE AND TRAINING 10.1 Director of Estates and Development The Director of Estates and Development manages a multi-functional management team. For gas safety, the role is one of general management, i.e. responsible for securing sufficient resources to run and maintain the network, employing sufficient staff with the necessary competency i.e. qualifications, training, knowledge and experience and to ensure those staff are properly focused on gas safety by setting and monitoring appropriate targets and objectives Principal Mechanical Engineer Gas Network Controller The Principal Mechanical Engineer Gas Network Controller maintenance of all gas utility infrastructure is responsible for the For natural gas infrastructure the incumbent requires a detailed knowledge of the natural gas network (i.e. the location, materials of construction and the age of the pipe system) and an understanding of specific gas distribution operations, i.e. Pressure regulation, Flow stopping and mains cut out procedures, Pressure testing, network purging and re-commissioning, Procedures for reporting, locating and repairing gas leaks. The incumbent is not expected to write routine or non-routine procedures for network operations or perform the role of Authorising Engineer* but must have an understanding of, and access to, the following Institution of Gas Engineers procedures: IGE/TD/3 Edition 5 Steel and Polyethylene pipelines for Gas Distribution IGE/TD/4 - Gas Services IGE/TD/13 Pressure Regulating Installations for Transmission and Distribution IGE/SR/20 Dealing with Reported Gas Escapes 17

21 IGE/SR/10 Edition 2 Procedures for Dealing with Escapes of Gas in Underground Plant. *The role of Authorising Engineer is performed by the Universities competent authority for the safety case 10.3 The Gas Network Controller and Deputy To perform the role of gas Network Controller and accept the Transfer of Responsibilities (see section 12.2 and Document KU/Gas/3 Transfer of Responsibility) the individual needs to have a detailed knowledge of the University s natural gas network and be competent to assume responsibility for dealing with gas escapes. He/she will need to be able to assess the risks and decide on the actions required. He/she will be required to liaise with the CADENT s gas emergency service engineer and formally accept responsibility for, and take control of, the emergency. The individual (or individuals) need the following competencies: - Be familiar with the procedures for locating and repairing outside gas escapes and reports of Carbon Monoxide (CO) spillage from appliances. Be capable of selecting and supervising a competent contractor or direct labour operatives to carry out the work. For the Hydeploy trial project, have sufficient knowledge and training of the characteristics of blended gas and its operational requirements and to ensure appointed contractors and consultants are approved and accredited via competency assessments In order to do this, he/she must also have a working knowledge of the following technical standards: IGE/SR/20 Dealing with Reported Gas Escapes IGE/SR/10 Edition 2 Procedures for Dealing with Escapes of Gas in Underground Plant Direct Labour The University is a Gas Safe registered installer The University has an in house plumbing workforce. Each plumber is Gas Safe registered and holds certificates for work on low-pressure meter installations and associated internal pipe work and appliances. These plumbers are competent to locate and repair gas escapes when they occur on secondary meter installations and downstream fittings, pipes or appliances and deal with CO spillage from appliances. They have the relevant qualifications, i.e. Gas Safe Registration and accreditation under the Nationally Accredited Certification Scheme (ACS) as competent to deal with gas escapes and Carbon Monoxide spillage, downstream of a gas emergency control valve Contract Labour Work upstream of the secondary meter emergency control valve, i.e. on the distribution system, is carried out by competent contractors. See section 11 Management of Contractors and KU Gas 16 18

22 Policy for engaging companies /organisations on new works or modifications to the gas network and associated equipment 11. MANAGEMENT OF CONTRACTORS 11.1 Selection of Contractors The size of the network and the low work volumes do not warrant a direct labour resource for gas distribution operations. The Gas Network Controller has a wide brief and is not a professional gas engineer. However, he/she is competent to perform the role of informed buyer of gas operations services which are contracted out by tender. Invitations to tender are only sought from organisations who can demonstrate the required competencies. They must have suitably qualified operatives and managers that have the necessary competencies to ensure the safe control of operations i.e. the ability to write, authorise and supervise routine and non-routine procedures (such as flow stopping operations) and to locate and repair above and below ground gas leaks. The University procedure for the selection of contractors is set out in KU/Gas/14 University Network Improvement specification 11.2 Training and Qualifications For gas operatives who entered the industry before April 2002 the following qualifications (as issued by the Gas and Water Industry National Training Organisation (GWINTO) provide evidence of competency: GD 1 (act as a mate only) GD 2 (act as a mate only) GD 3 (assist in main laying operation) GD 4 (lay services up to and including 63mm) GD 5 (lay mains) Where an individual holds GD4 and also GD5 they can lay gas mains and services for all diameters. Certificates for these qualifications last for five years. For operatives entering the gas industry after April 2002 the following provide evidence of competency: Operatives with NVQ levels 1 and 2 (in Mains or Service Laying) in Gas Network Operations. Operatives with NVQ Level 3 (Technician) in Gas Network Operations or the equivalent. Supervisors/Managers with NVQ level 4 in Gas Network Operations. The NVQ Level 4 is a relatively new qualification awarded by the Open University. Traditionally supervisors and line managers have either come through the ranks (and have held GD qualifications); others have entered with academic qualifications such as national certificates or degrees in an engineering discipline. It is difficult to be prescriptive regarding qualifications but as a guide Supervisors should have GD 3/4/5 and/or Ordinary National Certificate (ONC) in Mechanical/Civil Engineering and Managers Higher National Certificate (HNC) or a degree in Civil/Mechanical engineering. Both should have at least 3 years relevant 19

23 experience and must be competent to write and supervise non-routine procedures for flow stopping and operations. For the HyDeploy trial project any contractor commissioned to work on the blend network MZ3 and incoming medium pressure assets shall have received sufficient training in any deviations from standard operational procedures and safe use of recommended equipment (ie detection equipment) and have demonstrated proficiency via written assessment 11.3 Management System The contractor s health and safety management system will be reviewed as part of any audits to ensure they have procedures in place to promote and monitor health and safety and to ensure competency and training requirements are maintained Division of Responsibilities The contractor is required to set up safe systems of work, including the provision of suitable plant and equipment; to undertake work in accordance with the Institution of Gas Engineers standards and procedures, Health and Safety Legislation and Codes, and to supervise the work themselves. If there is any doubt regarding a particular course of action or circumstance they must consult the Gas Network Controller before proceeding Resources Although the volume of gas leaks and emergencies is low, the contractor must have sufficient resources to provide competent operatives and supervisors to be able to respond to a request to have personnel on site within 2 hrs on a 24/7 basis. See section 13 Dealing with Gas Escapes Monitoring and Review of Contractors Performance Because work volumes are low, a review of contractors competencies is carried out on an annual basis. Risk assessments and method statements (i.e. routine and non-routine procedures) for flow stopping procedures are inspected prior to any works commencing and a check during the operations will also be made. 20

24 12. AUDIT AND REVIEW OF MANAGEMENT SYSTEMS 12.1 The management systems, processes and procedures contained in this manual are audited by a suitably qualified and independent person annually. The objectives of the audit are: To check for compliance with the procedures in this manual, To check that safety performance is being maintained and To identify ways in which safety performance can be improved. During the audit, particular emphasis is placed on: Risk assessment processes Systems for maintaining gas flows The procedure for dealing with gas escapes Competency levels within direct and contract organisations Leakage survey results Pressure survey results Performance against gas safety objectives Compliance with mains and service replacement policy Verification of the correct contents and characteristics of the gas as published on CADENT s web site. The results of the audit, together with any recommendations, are passed to the Director of Estates who is responsible for implementing any actions arising, reviewing this manual and updating as required. The results of the most recent audit can be found in document number KU/Gas/ Gas Audit Results 13. CO-OPERATION WITH OTHER PARTIES 13.1 The network is used to convey gas to University-owned buildings across the campus. The network is also used to convey gas to 22 privately owned domestic houses (Springpool). The occupants of these houses have the right to buy gas from different suppliers. These sub deduct arrangements date back to before the privatisation of the gas industry and at the time of writing are being discussed with Ofgem. Issues concerning gas flows (specifically a loss of supply from the CADENT network) and the provision of the emergency service are discussed with CADENT and the University s principal gas supplier. Arrangements are in place to reduce demand or stop using gas if the CADENT Network Emergency Controller or the gas supplier requests such action as a result of a local or national gas supply emergency. 21