PRINCIPLES OF EMERGENCY PROCEDURES IN THE GAS TRANSMISSION: THE SNAM RETE GAS EXPERIENCE

Transcription

1 PRINCIPLES OF EMERGENCY PROCEDURES IN THE GAS TRANSMISSION: THE SNAM RETE GAS EXPERIENCE PRINCIPES DES PROCEDURES D ALERTE POUR LE TRANSPORT DU GAZ: L EXPERIENCE DE SNAM RETE GAS A. Cappanera, Snam Rete Gas, Italy 1. INTRODUCTION Pipelines are generally recognised to be one of the most safe and economical way of carrying liquid and gas substances. In particular the carriage of large natural gas quantities through pipelines to industry and to commercial and domestic consumers represents a safe and reliable mode of transporting. The European Gas Industry has always placed great emphasis on the safety and integrity of its plants and pipelines. Within Western Europe there are approximately km of high-pressure gas pipelines which operate up to 80 bar. The historical data base for incidents on this transmission network shows that the number of incidents occurring is very low: the failure frequency is constantly decreasing and there has not been a fatality to the general public attributed to a failure [1]. All the technical measures in the design, construction, operation and maintenance put into effect by the gas companies to guarantee the safety of the pipelines and prevent possible incidents have proved their quality and effectiveness over the years. The prevention of damages and of unintentional leakage of gas is the actual hinge of the technical policy in the European gas industry for the safety and continuity of supply [2]. Nevertheless, in order to increasing the safety level for people and for the protection of the environment, the Gas Transmission Companies operate, verify and update emergency procedures for the whole pipeline system to handle incident scenarios. These emergency procedures constitute the company emergency response plans where the availability of trained personnel and necessary resources are established and reviewed. They cover all the procedural and organisational matters, related to the transmission network, relevant for the safety of public, the protection of the environment, the health and safety for workers and the supply reliability. In SNAM RETE GAS it can be possible to distinguish between two different sets of emergency procedures, strongly integrated each other, mainly to manage: the Health and Safety for workers; the Safety for people, the protection of environment, the continuity of supply. Emergency planning for workers includes fire prevention, emergency response and evacuation employees from workplaces (like buildings and compressor stations). More than 110 contingency plans are in place, operated by dedicated structures involving more than 450 suitable trained employees. In addition periodic fire-drillings are organised as required by Italian law. However the aim of the present paper is to describe the main characteristics and the principles of the emergency procedures developed in SNAM RETE GAS addressed to face up with undesired scenarios related to safety, environmental and supply aspects, focusing, when relevant, on the 1

2 connection elements existing with the safety and environmental management systems implemented in the company. All these procedures are collected in an ad hoc document (identified in this paper as Emergency Response Plan ) available, also through the Intranet network, in the whole Company. In more detail the themes, about emergency procedures developed in this paper will be related to: Goals; Basic elements and principles; Improvement of the effectiveness. 2. SNAM RETE GAS AND THE ENVIRONMENTAL AND SAFETY MANAGEMENT SYSTEMS SNAM RETE GAS, a ENI Company, is the leading provider of natural gas transmission and dispatching services in Italy and owns more than kilometres of pipeline in the high and medium pressure transmission network, out of the total of approximately kilometres. In addition, with the LNG terminal at Panigaglia (managed by the controlled company, GNL Italia), SNAM RETE GAS is currently the only provider of liquefied natural gas re-gasification and storage services in Italy. The pipeline network extends over most of Italy, with pipes ranging from 100 mm to 1200 mm in diameter operating at a pressure up to 75 bar. It has 11 compressor stations and 560 reduction plants (2001). The volume of gas transmitted, comprising gas sent into transmission network from imports and Italian production fields, is about 70 billion cubic metres (2001). SNAM RETE GAS NETWORK 2

3 The SNAM RETE GAS transmission system is managed by a Dispatching Centre and 8 regional centres (Districts) which, by means of 74 local operating units, are in charge of the operation, maintenance and supervision of the whole system. The local units are responsible for ensuring that the network functions in accordance with Company technical standards and with current legislation and regulations, guaranteeing the required level of service, safety and environmental protection. The health and safety of employees, of third parties, and the protection of the environment, are prime and constant objectives for the Company whose commitment is to bring about a continuous improvement in all its activities. In order to achieve these objectives SNAM RETE GAS operates also adopting some management systems, strongly connected each other, as: the environmental management system for compressor stations that has received UNI EN ISO certification; the management system regarding the health and safety of employees that has been developed in compliance with the BS 8800 standard and ENI guidelines; the safety management system for the whole pipeline network, developed according to the principles of Pipeline Integrity Management System (PIMS) of Marcogaz [2, 3]. Particularly the two legs of the safety management system are prevention of incidents and mitigation of consequences. The prevention incident measures are carried out in order to guarantee the integrity of pipeline network by way of appropriate design, construction, operation, maintenance and inspection. The mitigation measures are foreseen, in order to control accidents/incidents, to limit their consequences for man and environment and to open up the pipeline again in the safe condition. The procedural and organisational instructions in order to carry out these measures are mainly covered by the Emergency Response Plan of SNAM RETE GAS, whose characteristics are schematically described in this paper. 3. GOALS OF THE EMERGENCY RESPONSE PLAN The Emergency Response Plan is in agreement and in compliance with the Health, Safety and Environmental Policy by SNAM RETE GAS [4]. The principles of this HSE Policy, which the Emergency Response Plan refer to, are mainly: To identify the health, safety and environmental hazards arising from ongoing and new activities, assess the associated risks and take steps to prevent and manage them; To establish procedures, alongside the preventive measures, in order to identify and respond to emergencies and control the consequences of any accidents; To train and inform employees, raise their awareness and involve them, so that they take part actively and responsibly in the implementation of principles and achievement of objectives; To carry out, at different levels, environmental monitoring and periodic revisions and updates of procedures, using audit and reporting system which make it possible to assess performance and review objectives and programmes; To employ the services of qualified suppliers and contractors who can contribute to continuos improvement in health, safety and environmental standards. 3

4 All these principles are taken into account and developed in the Emergency Response Plan in order to get the following main goals: to remove, in the shortest time, every cause that can compromise the safety of the people and the protection for the environment; to intervene, in the shortest time, in order to avoid the enlargement of incident extent or of the linked consequences; to contain the cases where is necessary to interrupt the gas supply, and anyway its duration time; to carry out what is necessary, according to the kind of emergency, for maintaining or the restoring of the gas supply. 4. BASIC ELEMENTS IN THE EMERGENCY RESPONSE PLAN The organisation and responsibilities for the management of topics related to the safety for people and environment are defined in the management systems of SNAM RETE GAS: set of technical standards, procedures, instructions constitute the complete reference tools in order to manage all the aspects linked with these topics. In particular the Emergency Response Plan entirely defines the role, responsibility, authority and interrelation of personnel who shall be involved in the management and in the control of abnormal situations including emergencies. The organisational structure to put in practice the procedures described in the Emergency Response Plan is developed through a Dispatching Centre and 8 Districts with a total of 74 local operating units that constitute the same structure in charge of the management of pipeline network in normal situation. In addition two main Territorial Areas (Centre-Northern and Centre-Southern) are then defined in order to guarantee, during anomalous relevant situations (i.e. relevant problems on the network or on the compressor stations), the adoption of appropriate measures. Besides they are in charge of co-ordinating and giving a decisional support to the regional and local units, including the management of relationship with the Authorities. SNAM RETE GAS -The 8 Districts SNAM RETE GAS The 2 Territorial Area 4

5 This structure with the support of some Headquarters units constitute the real core of the resources appointed to face the emergency scenarios. All the relationships among the different units are clearly defined in order to avoid overlapping in the decision and responsibility and to assure a quick and effective intervention. The Emergency Instructions are structured including among other things: the system for surveillance and alarm; the arrangements for receiving at the operating system warnings of incidents and accidents; the responsibility for planning the equipment and the resources; the responsibilities for setting intervention procedures in motion, the responsibilities for taking charge of, and co-ordinating offsite actions; the availability and training of personnel and material intervention; arrangements for co-ordinating resources necessary to implement the intervention plan. The responsibilities about the updating of the instructions contained in the Emergency Response Plan are included as well. Since it is quite impossible to foreseen all the incident scenarios that can happen on more than km pipeline network, the Emergency Response Plan is developed and planned following the principle of the flexibility. In fact it is not manageable and, above all, can be dangerous, the definition of rigid and specific procedures in order to face a set of pre defined incident scenarios: too many are the variables and the uncertainties to be considered. In addition gas transmission pipelines differ in some respect from the other plant because they pass through land which is not generally owned by the operator and to which the general public may have access. Therefore every emergency intervention assumes generally specific characteristics. For that reason the elements belonging to the procedures shall be managed assuring all the tools and resources reasonably necessary but avoiding to fix and code, when not essential, rigid behaviours of people and organisation. In the mean time the roles and the responsibilities have to be clearly defined in order to take the decision without delay, overlapping and conflicting. The Emergency Response Plan presents thus a structure that can seem very different to the one that can be used for an emergency plan developed for a fixed and localised plant where the boundary conditions, both inside and outside the fences, are surely better identifiable and controllable. In accordance to this formulation, for instance, the resources are trained according to maintenance and operational standard procedures; this standard training is then integrated with the actions (procedural and organisational) described in the emergency Response Plan in order to manage the specific incident scenario with the correct behaviour. 5. MANAGEMENT OF EMERGENCY SCENARIOS The responsibilities and the behaviours to be followed in case of emergency are clearly defined, by written procedures, in the Emergency Response Plan for gas pipeline. In this document the following matters are included: 1) Activation of the Emergency Instructions: General criteria The state of emergency, and therefore the conditions for the carrying out of the actions to face it, is definite and described. 5

6 About that it is important to point out the role of the Dispatching Centre. The Dispatching Centre, located at San Donato Milanese, continuously controls the set up of the strategic points of the network in real time ; a well-trained personnel is present at the Dispatching Centre 24 hours a day, everyday. This is particularly possible trough a remote control system which is linked to the Dispatching Centre and which performs the twin functions of telemetering and remote control. This system operates by means of a remote data processing consisting of more than 1540 remote controlled plants. In addition to the automatic alarm signals, the Dispatching Centre gathers and manages the information about anomalies and incidents coming from: the regional centres and the local operating units (during normal working time), the public (after hour, all the telephone numbers belong to local units are switched over the Dispatching Centre in S.Donato); the Authorities. Therefore interventions can be made at any moment, whether the situation is normal or unusual (and thus even in emergencies), both during normal working time and after hour. On 24 hours continuos basis it is possible to activate the alert and call out procedures by the Emergency Responsible, locally competent, as soon as the incident/accident has been identified. Besides on the whole network system all the main components of the transmission system have to be monitored in order to get information about possible problems arising in the network. Monitoring the pipeline networks entail cathodic protection inspections, helicopter and above ground surveillance, geological surveys, periodical maintenance and inspection of pipelines, plants and Compressor stations. 2) Responsibilities All the roles and responsibilities during the emergency are identified. The main players in the managing of an emergency situation belong to different levels: Dispatching Centre Dispatching Centre Emergency Responsible who puts into practice the suitable measures about the intervention on the network grid in relation to fortuitous and incidental circumstances. In more detail he assures the operating balancing of the system following the emergency (to be carried out both by remote control and by the intervention of local unit personnel), coordinates the operations towards the connected network systems (i.e. foreigner network, network managed by other operators and so on), furnishes information to the SNAM RETE GAS top management and ENI, assures the information to the clients about the reduction or interruption of the transport supply. Local Emergency Responsible belonging to the local operating unit, who is responsible of the first intervention; Emergency Responsible of the Compressor Stations, who is responsible of intervention inside the stations; Regional Regional Supporting Emergency Responsible who assures the technical and operational support to the local operating unit and, if necessary, co-ordinates different units involved in the emergency; 6

7 Territorial Territorial Area Emergency Responsible who assures the co-ordination and the technical support in case of major incidents (i.e. involving more Regional Centres or a Compressor Station) and manages the relationship with the Authorities and the public information. 3) Arrangement of personnel, means of transport, means of communication The Emergency Response Plan for gas pipeline includes the organisational procedures (workshift and availability criteria, logistics, modality for the definition of roles and responsibilities) for the arrangement of means of transport, communication and of personnel that shall be involved in case of emergency. After hours these elements are assured by a service for availability of personnel after hours" appropriately prepared. Qualitative and quantitative standards about means and personnel are defined as well. 4) Arrangements of equipment and materials, their requirements and documentation necessary during the emergency. In the Emergency Response Plan the responsibilities and the organisational matters in order to make available the equipment, the spare materials, and the necessary documentation are completely defined. What necessary is opportunely located and periodically maintained by the local operating units and by the central storage, according to specific procedures. 5) Liaison with authorities The responsibilities for the management of the relationship with the relevant Authorities are clearly defined. 6) Gathering, distribution and updating of information relevant to emergencies. The responsibilities, the tools and the organisational procedures in order to carry out the collection, the distribution and the updating of relevant data in case of emergency are defined. All the data shall be available both at the local and central organisational level. All the emergencies shall be documented through appropriate reports to be analysed and properly stored. 7) Personnel training Responsibilities and organisational procedures are defined for the convenient training of personnel both in the regional and local offices. The criteria and the training programme about technical matters, internal standards, responsibilities and what is necessary to guarantee the timeliness of an intervention and to manage, by the correct behaviour, the emergencies even in unfavourable circumstances, have to be clearly stated. It is important to point out, once again, that the training programmes do refer to the standard operational instructions for operating and maintenance of pipelines and plants. Any extreme and dangerous actions, like for instance to put out a fire due to ignited gas released from a pipeline damage, are not covered in these programmes. The Emergency Response Plan defines the responsibility in order to involve, when necessary, and support the competent Authorities (i.e. the Fire Brigade) without any delay in order to face up the scenario, warranting the safety of people and the protection of environment. A correct co-ordination and collaboration between the Company s and the Authority s skill is the best and effective way to solve any kind of incident scenarios 7

8 8) External Contractors The Emergency Response Plan defines supporting requirements of the intervention to be carried out by outsourcing and the responsibilities for selecting the external suitable contractors. In particular SNAM RETE GAS implements procedures in order to select external contractors that are able to warrantee specific requirements about their technical skill and the maximum notice time for getting its effectiveness on the network. 6. MONITORING AND REVIEW OF EMERGENCY PROCEDURES FOR GAS PIPELINE On a regular basis all the causes of incidents or dangerous occurrences are shared and reviewed to learn lessons and improve the efficiency of the Emergency Response Plan. All incident scenarios are investigated and staff trained in order to prevent reoccurrence or improve the intervention actions. This improvement process is got following the management loop of the safety and environmental management systems (Plan, Do, Check and Act) whose the Emergency Response Plan is fundamental element. Incident investigation and meetings are organised both at the local and central level for discussing and analysing the incident scenarios and they shall improve the behaviour and the efficiency of the emergency response. These improvements will be then implemented in a new and updated version of the Emergency Response Plan document. The safety and environmental management systems of SNAM RETE GAS state the roles and responsibilities for: Analysing the incidents; Organising the meetings; Defining and approving the modifications; Assigning the resources. When necessary the technical and organisational improvement can be discussed and defined during the Review phase foreseen in the safety management system as well. 7. CONCLUSION SNAM RETE GAS, and more generally all the western European Gas industry, consider the safety and the continuity of supply a basic and strategic point of the transport activity, also in the new European gas market oriented to a greater economic efficiency. Safety is not matter of competition among the companies but on the contrary it does still represent a very important collaboration field. Huge quantities of sources are spent to assure during construction and operation of pipeline network an high safety standard level. Prevention of incidents and mitigation of consequences are a must in the policies of the European Company. Both these aspects are covered by the company management systems, that even if different in Europe, present generally the same fundamental structure (Plan, Do, Check and Act). The mitigation of possible consequences and the intervention actions during emergencies are planned and carried out through emergency instructions suitable for each different country and company situation, but with the same proved good results and efficiency level. 8

9 These plans take into account the peculiar characteristic of the transportation network that is not comparable with an industrial localised site. The safety management systems are the tools for maintaining and even improving these achieved results. 8. REFERENCES 1. EGIG Pipeline Incident database EGIG shows its continuing improving safety performance 5 th reports IGU MARCOGAZ Pipeline Integrity Management System WOC 4 Frame of reference regarding Pipeline Integrity Management System (PIMS) IGU SNAM RETE GAS Health, Safety, Environment 2001 Report 9