In Siliguri, West Bengal, M/s. Indian Oil Corporation Limited has an terminal for isolated storage and distribution of Petroleum products. The terminal is flanked by a connecting road leading to a bypass for Sikkim on the western side, an FCI Godown on the northern side, a BPCL terminal and a railway track on the eastern side, and army land and the New Jalpaiguri Railway station on the southern side.
Receiving, storing, and distribution of finished Petroleum products including Motor Spirit, High Speed Diesel, Superior Kerosene Oil, Aviation Turbine Fuel, Ethanol and Bio-Diesel are all done at this terminal.
The Major Objective of this study is to assess the potential risk levels for workers resulting from unintentional discharge of hazardous materials from Facilities under loss of containment scenarios and to show that individual risks fall within generally acceptable range.
The following are QRA’s goals:
- Hazard identification and major loss of containment occurrences
- Physical repercussions of failure case scenarios
- Evaluation of failure frequency
- Perform a risk assessment to determine that risk can be minimized in accordance with the ALARP concept
- Recommend risk-reducing strategies.
The scope of work awarded to iFluids Engineering is to conduct QRA study for the following facilities.
• Product receipt through a facility for unloading Rail wagons and Pipelines.
• Product storage tanks with sufficient capacities.
• Equipment for loading materials using loading arms into tank vehicles.
As part of QRA study, Hazard scenarios for the Facility were identified, DNV PHAST software was utilized for consequence analysis. DNV SAFETI software was utilized for risk analysis. The Risk outcomes were evaluated in accordance with the Risk Acceptance Criteria.
Depending on the availability of the products, IOCL Siliguri Terminal gets MS, HSD, and SKO from refineries at Paradeep, Haldia, Bongaigaon, and Barauni via GSPL Pipeline and by rail tank wagon. Ethanol and biodiesel are delivered from several designated vendors by road Tankers.
Two 2 x 8 Bay TLF Gantries are present to meet safety distance. For supply of goods to TLF gantries as well as the unloading and loading of railway tank wagons, there is a manifold arrangement and a pump house.
The Final Outcomes of QRA Study are as follows
Location Specific Individual Risk
The individual risk at different locations round a particular plant varies. Among the Risk ranking locations considered all risk ranking points lies in the ACCEPTABLE Region.
Individual Risk for people
The Individual Risk gives a measure of risk that will apply to each location (in this case, each area, generally), independent of the population.
The Individual risk results for people concerned is the individual contour of 1E-07/Avg.Year, 1E-08/Avg.Year and 1E-09/Avg.Year extends up to 224.65m, 249.6m, and 367.8m in radius from the centre of the of Siliguri Terminal, respectively.
The Individual Risk Per Annum for people at risk ranking locations taken for this study lies in the ACCEPTABLE region.
Societal Risk
The correlation between frequency and the number of people experiencing a specific level of harm in a given population as a result of realization of a specific danger is provided by societal risk. The study’s findings lead to the conclusion that the societal risk for the study’s entire population is, on the whole, in the ACCEPTABLE range.
Recommendations
Based on the observations and conclusions following are the recommendations of this QRA study:
- Ensure Hydrocarbon detectors are placed in the Pump Shed and Class A Tank Farm Area.
- Ensure Emergency Shutdown system is available.
- Ensure Centralized Foam Fighting System is available for Tanks.
- Ensure Vehicles entering near the facilities are fitted with spark arrestors, as a mandatory item and proper barricading near the facility.
- Ensure personnel entering the facility should not be allowed carrying any ignition sources like Mobile phone, lighter etc.
- Procedures regarding “Work Permit” to be followed by maintenance personnel to ensure protection of property from fire and destruction, etc.
- Training and awareness on Emergency Response and Disaster Management Plan to be ensured by the management to Tank Truck Drivers. All Truck Drivers should be given safety briefing before entering the facility. The Drivers should be provided refresher course to ensure actions required during emergency.