14 HAZARD RISK ASSESSMENT

Transcription

1 14 HAZARD RISK ASSESSMENT 14.1 Introduction Intel Ireland proposes to apply to Kildare County Council for permission to extend its manufacturing operation in Leixlip, Co. Kildare. This development is referred to as FAB AWN Consulting Ltd has conducted an initial screening qualitative assessment to determine the likely impact of the expansion with respect to off-site land use planning impacts. This assessment focused on the location of the off site receptors and the location and nature of the on-site hazardous areas, and assessed in a qualitative fashion the possible impacts of the expansion on these receptors. AWN Consulting has conducted extensive modelling of the existing Intel site with respect to major accident hazard scenarios and have applied this knowledge in the current assessment Study Methodology The proposed new FAB will not require the construction of additional bulk gas storage or solvent storage tanks (these materials will be supplied from existing installations on the site). Therefore it is assumed that the only likely source of a Major Accident Hazard (MAH) scenario is likely to be the activities at the new FAB Gas Pad, at the Silane Pad or an accident involving the spillage of material during delivery of drums to the new FAB. The materials that could lead to MAH scenarios and that are likely to be stored or handled in the Gas Pad or are likely to be delivered to the FAB are: l Chlorine gas;. Dichlorosilane gas; l HCl Gas; l Ammonia gas; l Silane: and. HF liquid Assessment of Significance The assessment of significance of impact, in terms of the off site impact of major accidents, involves the prediction of the consequences of a major accident, in terms of toxic gas concentrations off site, explosion over pressure or burns associated with thermal radiation and then the calculation of the risk of that accident scenario occurring. Baseline risk data in the context of risk assessment and off site accident impacts, comprises the known annual risk of fatality, which each individual experiences in their daily lives. FISK ENSR Environment Ltd 14-1

2 It is widely accepted that no risk scenarios do not exist. For example, the occupier of a house with gas-fired central heating is exposed to the risk posed by the presence of a natural gas supply in the house. Statistics from the UK Health and Safety Executive (UK HSE Risks associated with Gas Supply, 1993) show that the risk of death from gas supply events in the UK (risks include explosion, asphyxiation by fumes from poorly vented heaters, poisoning by gas leaks) is approximately 1.1 in a million. In other words, for every 10 million persons living in houses with a gas supply, 11 will die from events related to the supply. Trevor Kletz, in his seminal work on risk assessment (HAZOP and HAZAN, Kletz, 1983) lists a number of studies which define the annual risk of fatality experienced by a typical industrial worker in a western industrial society to be in the region f 1 in 1000 per annum or 1 x 10-3/annum. Individuals which take part in dangerous activities or work in dangerous environments experience a higher annual risk of fatality. The following Table (Table 14.1), from CIRIA Report No. 152, published by CIRIA, the Construction Industry Research and Information Association in the UK in 1994, lists the annual risk of fatality for a number of activities. Table 14.1: Typical Annual Risks Activity Motorcycling Smoking (all causes) Smoking (cancer) Fire fighting Farming Police work (non-cletical) Natural Road accidents Fires supply to house gas Lightning strike Annual Fatality Rate (per 1000,000 people at risk) 20, Annual Risk of Fatality 1 in50 1 in in in in in in 10,000 1 in 35,700 1 in 909,090 1 in 2,000,OOO It can therefore be seen that no risk activities do not exist and that all of us experience a certain level of risk as we go about our daily activities. It is recognised that accidents at industrial establishments can cause on site risks to employees and off site risks, in some instances, to people in the vicinity of the industrial establishment. Intel are committed to reducing risks to both employees and off site receptors, to a level which is as low as reasonably practicable and to taking all necessary measures to ensure that on site and off site risks are minimised on all Intel sites. The Health and Safety Authority (HSA) in Ireland is responsible for assessing off site consequences of major accident and the risks associated with consequences of these accidents. The HSA uses the annual risk of fatality posed by a facility to RSKENSFt/HE/P40126/04/Rev

3 determine the most appropriate land use for the lands surrounding a facility. Should a facility wish to expand, the HSA will assess whether any additional risk is posed to surrounding lands by the expansion and advise the Planning Authority as to whether or not the expansion will have a negative impact on the use of surrounding lands, in terms of increased risk to the users of these lands. The HSA risk criteria are listed Tables 14.2 and Table 14.2: Risk Zones Zone Zone 1. Zone 2. Zone 3. Zone 4. Annual Risk of Fatality Criteria > 10-4 IO.54 <IO-4 lo Rc 10 Table 14.3: Land Use Planning Advice for each Risk Zone Zone Zonei: R>10-4 Zone 2: -1 o-5 CR <l O-4 Zone 3: IO-6tR <lo-5 Zone 4: Rc IO-6 HSA Land Use Planning Advice Advise against residential, office and retail, permit occasionally occupied developments e.g. pump houses, transformer stations. Consult with HSA re. Industrial development; Advise against residential. Permit industrial developments or non-intensive office type development of a type not involving Increase above prevailing heights so as to avoid a major increase in the volume of accommodation, Likelihood of substantial number of visitors (rather than employees). Permit modest retail and ancillary local services Permit office and industrial development without restriction unless identified as a Seveso establishment, Permit residential densities from 28 to 90 persons /ha., density increasing as risk decreases across the zone and 22 to 70 persons/ha. in less developed areas. Advise against shopping centres, large-scale retail outlets, undue concentration of restaurantlpub facilities No restrictions except for sensitive developments, which would be subject to consultation if inside the consultation range and should not be at a risk greater than 0.3 x 1 O-7 Sensitive developments include creches, schools, hospitals, nursing homes and locations of major public assembly. This guidance assumes an acceptable level of risk to off site receptors such as creches, schools, hospitals and nursing homes, to be an annual risk of fatality of 0.3 x 10-6 per annum. Should an existing establishment wish to expand, an assessment must be carried out as to whether the expansion will increase the diameter of the risk zones around the site and if, for example, the expansion were to lead to the existing Zone 3 expanding 14-3

4 such that it now encompassed a school, hospital or other sensitive development, this would be considered an unacceptable level of risk and an unacceptable land use impact, and the development would have to be re designed such that the expansion in risk zone diameter did not take place. The assessment criteria detailed in Tables 14.4 to 14.6 have been used and an assessment has been made on magnitude of the residual impact combined with receptor sensitivity to determine the significance of the impact Magnitude of impact The magnitude of the potential impact is defined in Table 14.4 below I. 2 Sensitivity of receptors No significant off site receptors were identified within the MAH scenarios modelled Potential significance The potential significance is described in Table Existing Environment The existing environment, in terms of (Major Accident Hazard) MAH is determined by the existing possible MAH on site. Characteristics During Construction of the Proposed Development No MAH scenarios with off site impacts are envisaged during the construction phase During Operation The following MAH scenarios could potentially occur at the proposed facility. 14-4

5 Environmental ImDact Assessment Table 14.4: Magnitude of MAH Impacts Scenario 1 Hazard Range from Source Maximum calculated Individual Risk of of Incident and (ERPG3)(m) theoretical hazard range Fatality at furthest and Location outside Intel lands using point of impact of ERPG3 value(m) 2 accident HCI.Gas 281 m 50m (outside the Intel north., (FAB 24 Gas Pad) east boundary) 3 x 1 O-Yyr Chiorine &as 316m 0 3 x 1 O-Vyr (FAB 24 Gas Pad) Ammonia Gas Om 0 3 x 1 O-Vyr (FAB 14 East GasYard) Dichlorosilane Om 0 N/A Gas (FAB 24 Gas Pad) HF Liquid 202m 0 3 x 1 O-Vyr Spill (rear of FAB 10) Silane 22m (rear of FAB 14) se incidents is assumed to be the gas pad or unloading area where these materials are handled at the rear of FAE5s lo,14 and 24 2 The ERPG3 Value is used by the US EPA and is defined as the concentration which may be fatal to a few susceptible individuals x IO - /year The HSA has defined risk zones for the Intel site, in guidance issued to Kildare County Council. The maximum extent of the 0.3 x 10m6 per annum risk zone extends outside the Intel boundary in one area only, into the meadow adjacent to the north eastern boundary of the Intel site. Areas outside this outer zone are deemed to be at no significant risk from the Intel site and the effective consultation distance around the Intel site, with respect to land use planning around the site, can be deemed to be within the Intel site boundary, apart from this area of small area of Intel owned land. The current consultation distance is being considered by the HSA, which has prepared a draft report on land use considerations for the Intel site. This report has been submitted to KCC and Intel for comment, with the closing date for comments of the 21st February Based on the defined risk zones and modelling identified within this section, the consultation distance should be either not applicable or no greater than 300m from the site boundary. RSKENSWHVP40126/04/Rev

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7 14.6 Proposed Mitigation No additional mitigation is required Residual Impacts The residual impact is neutral when compared to current activities EPA Export :14:22:31