Major Hazard Plant ( Seveso Installations)

Transcription

1 Major Hazard Plant ( Seveso Installations) Safety Report (Law 334/1999 Implementation of EU Seveso Directive) Ufa, 1-2 March 2005

2 Safety Authorization Process D.Lgs.334/99 (Seveso II) Preliminary Safety Report New Plant New or modificat.? Modification of existing plant Increase in haz. Subst. quantity? > 25% Safety Report Approval process by CTR (Regional Technical Committe.) on the basis of technical review and compatibility with territory Declaration END no Approved? yes Building Permit (with possible requirements) Safety Report (RdS) Approval Process by CTR Approved? no yes Operating Permit

3 The Safety Report shall be developed according to specific requiremetns and Table of contents by LAw. It contains: Identification data and Plant Location; General information on plant management and technology; Analisi ad Indici (Risk Indexes) and Historical analysis; Accidental events identification and consequence analysis; Design criteria; mitigation and protection measures

4 Compatibility The Safety Reports results are judged on the basis of the Ministry Decree 9/5/2001 on Land use compatibility Criteria: Probability of events Damage category Classe di probabilitа degli eventi Lethality Categoria di effetti Beginning Serious wounds lethality Elevata letalitа Inizio letalitа Lesioni irreversibili Wounds Lesioni reversibili < 10-6 DEF CDEF BCDEF ABCDEF EF DEF CDEF BCDEF F EF DEF CDEF > 10-3 F F EF DEF A F correspond to Land Use types (A = highly populated; F = Industrial areas)

5 Layout

6 Main Information Plant Operator ( Owner ): Responsible for the Report issue and the Plant Operation Rules and Standards adopted in design Production capacity and hazardous substances present (quantity in storage adn process) Detailed process and safety systems description

7 Main Information Hazardous Substances: Thresholds (Law) Quantities (Total, Storage, Process) SOSTANZA ALLEGATO I - PARTE 1 Gas liquefatti estremamente infiammabili e gas naturale D. Lgs. 334/99 Soglia Art. 8 (t) 200 Quantitа presenti (t) Totale Stoccaggio Impianto Propilene Etilene Gas Naturale liquefatto , ALLEGATO I - PARTE 2 6. INFIAMMABILI Gasolio 8 8 Note

8 Risk Indexes ( Analisi per Individuare Aree Critiche ) Analysis according to specific decrees (for processes and storage) (Ministry Decrees DM 15/5/96 and 20/10/98) Plant divided into Units (homogeneous) Risk index classified according to substances, characteristics of processes, safety systems, specific conditions

9 The Safety Report to be developed according to Law 334/99 contains: Identification data and Plant Location; General information on plant management and technology; Analisi ad Indici (Risk Indexes); Accidental events identification and consequence analysis; Design criteria; mitigation and protection measures

10 Safety Analysis - Main Assumptions To define a lower bound for frequency to discriminate between credible and non-credible events (usually 1.E-07 /year). For on credible events no consequence analysis is done; Process generated accidents identified by HAZOP; frequency calculated by Fault Tree analysis; Accidental events related to loss of containment events postulated on the basis of historical data. Usually a set of cases (e.g. two cases considered : hole diameter 5% and 20% of pipe diameter) are considered for each isolatable section; Historical analysis to check past experiences and show if design can avoid past experiences.

11 Isolatable Sections For each section, process and design data are collected for the probability and consequence analysis

12 Safety Analysis - Main Assumptions Event Tree (ET) Analysis to identify Accident Scenarios and associated probabilities. The ET analysis considers meteorological conditions, safety systems, ignition sources

13 Accidental Scenario identification Ignition probability in Event Tree Analysis from literature data: Leak Flow rate Portata del Rilascio Probabilità di Innesco Immediato (kg/s) Rilascio Liquido Rilascio Gassoso < > Massa Infiammabile (kg) Probabilità di Innesco Ritardato < > Immediate ignition Liquid Gas Delayed ignition Flammable Mass Massa Infiammabile (kg) Probabilità di Esplosione se innescata < Probabilità di Flash Fire se innescata UVCE Flash Fire

14 Loss of Containment cases Release cases are considered for Isolatable Sections, where process conditions and inventory ( duration of releases) vary

15 Frequency Analysis Main Data: PROCESS LINES: Historical data abses, e.g. API 581, E&P Forum, TNO etc. Pipelines: EGIG (European Incident Data gropu for Gas), CONCAWE (for Oil lines) External events (e.g. collisions): probabilistic analysis. Considering actual design and site conditions, including effect of Safety Management Systems

16 Events Localisation on Map

17 Consequence Analysis Damage levels defined by Law on the basis of International Literature: Soglie di Danno a Persone e Strutture Scenario Incidentale Incendio (radiazione termica stazionaria) Flash-fire (1) (radiazione termica istantanea) UVCE (3) (Sovrappressione di picco) Elevata letalità Inizio letalità Livello di Danno Lesioni Lesioni irreversibili reversibili Danni alle strutture Effetti Domino 12,5 kw/m 2 7 kw/m 2 5 kw/m 2 3 kw/m 2 12,5 kw/m 2 LFL (2) 0,5 LFL ,3 bar (0,6 bar in spazi aperti) Rilascio tossico LC50 30 min (4) IDLH (5) 0,14 bar 0,07 bar 0,03 bar 0,3 bar Fireball/BLEVE Raggio fireball 350 kj/m kj/m kj/m m da parco bombole 600 m da stoccaggio in sfere 800 m da stoccaggio in cilindri High Mortality Minor injuries Domino effects

18 Consequence Analysis Damage distances for each accidental scenario are calculated

19 Consequence Analysis Mapping Events are mapped on the site to allow assessment of land use compatibility, analysis of domino effects, emergency planning etc.

20 Compatibility

21 Risk Contours (UK, Netherlands) Risk Contours can be used to assess the Plant Safety (together with Social Risk criteria)