Accidents pipeline

The new Bayview Terminal had a design operating pressure of 740 pounds per square inch (50 atmospheres or 50 bar) and the accident pipeline was designed for much higher pressures, so it was necessary to install pressure-reduction equipment where the pipeline joined the new terminal. There were three layers of control and safety devices (i) a control valve to throttle the incoming flow, (ii) a pilot-operated spring-loaded relief valve, and (iii) three motor-operated isolation valves. This triple-barrier approach is sound design - a control system, backed-up by two protection systems (the relief valve and the isolation valves). In the event of a problem with the control valve, the relief valve should operate quickly, and only in the event of a fault with the relief valve should the isolation valves ever have been required to operate. 

On the oil and gas pipelines more than 100 big accidents happens yearly and, unfortunately, the situation will become even worse in the nearest future. 

Much of the damage and loss of life in chemical accidents results from the sudden release of material at high pressures which may or may not resiilt from fire. Chemical releases caused by fires and the failure of process equipment and pipelines can form toxic clouds that can be dangerous to people over large areas. 

Fire Plant specific requires detailed study Pipeline accident Site specific requires detailed study... 

Transportation accidents were analyzed. An aircraft could directly impact the reactor. The K-Reactor is >20 miles from an airport, not on an airway and built with blast resistant construction. The nearest public highway is 2 miles away, the nearest pipeline 17 miles away, the nearest public... 

Before entry is allowed into a vessel or other confined space, the vessel should be isolated from sources of hazardous material by slip-plating or physically disconnecting all pipelines and by isolating all supplies of electricity, preferably by disconnecting the cables. On the whole, these precautions seem to be followed. Accidents as the result of a failure to isolate are less common than those resulting from a failure to remove hazardous materials or from their deliberate reintroduction as described in Sections 11.1 and 11.2. However, the following are typical of the accidents that have occurred. 

Lewis (1989) describes the accident, which occurred in Siberia on the night of June 3 and early hours of June 4, 1989. Late on June 3, 1989, engineers in charge of the 0.7 m (28 in.) pipeline, which carried natural gas liquids from the gas fields in western Siberia to chemical plants in Ufa in the Urals, noticed a sudden drop in pressure at the pumping end of the pipeline. It appears that the engineers responded by increasing the pumping rate in order to maintain normal pipeline pressure. 

The investigation following the accident showed that the pipeline rupture was due to stresses induced in, and possibly by damage to, the pipeline resulting from its repositioning three months before. This work had occurred in conjunction with road work on the highway adjacent to the accident site. The pipeline had been dented and gouged. 

National Transportation Safety Board. 1979. Pipeline Accident report—Mid-America Pipeline System—Liquefied petroleum gas pipeline rupture and fire, Donnellson, Iowa, August 4, 1978. NTSB-Report NTSB-PAR-79-1. 

National Transportation Safety Board. 1972. Pipeline Accident Report, Phillips Pipe Line Company propane gas explosion, Franklin County, MO, December 9, 1970. National Transportation Safety Board, Washington, DC, Report No. NTSB-PAR-72-1. 

Military/government type publication. It lists accidents with fatality scenarios that occurred during operation and maintenance of U.S. interstate gas pipelines from 1950 to 1965. Also listed are individual pipework failures during that time, about 3000 entries, that have been compiled from various sources by the study committee. 

This study investigated risks to the public from serious accidents which could occur at the industrial facilities in this part of Essex, U.K. Results are expressed as risk to an individual and societal risk from both existing and proposed installations. Risk indices were also determined for modified versions of the facilities to quantify the risk reduction from recommendations in the report. Nine industrial plants were analyzed along with hazardous material transport by water, road, rail and pipeline. The potential toxic, fire and explosion hazards were assessed for flammable liquids, ammonia, LPG, LNG, and hydrogen fluoride (HE). The 24 appendices to the report cover various aspects of the risk analysis. These include causes and effects of unconfined... 

Fire is more likely tlian an explosion where tliere is a loss of contaimiient of a flammable material from a railroad car, barge, ship tank, or from a pipeline. However, both unconfmed vapor cloud explosions (UVCES) and boiling liquid-e.xpanding vapor e.xplosions (BEEVES) can occur as a result of transport accidents, (see Section 7.5)... 

Oil Spills. Oil spills occur from oil pipeline leaks, oil tanker accidents, or submarine oil drilling operations. The two major ocean drilling accidents—oil wells blowing out—were the 1969 Santa Barbara Channel spill and the 1979 Yucatan Peninsula spill, in Mexico. The Yucatan spill spewed out more than three million barrels before being capped in 1980. Both caused damage to beaches and marine life, but the smaller Santa Barbara spill was far more devastating because of unfavorable winds following the accident. 

Although the pipeline from the North Slope to the port of Valdez was the route chosen and completed in 1977, the scientific community preferred the trans-Alaska-Canada route its use would have prevented the Exxon Valdez ianker accident of 1989. 

Some environmentalists anticipated a major accident like that of the Exxon Valdez. When plaiiiiing for the Trans-Alaska Pipeline took place during the energy crisis of the early 1970s, it was controversial because of the conflicts of balancing the needs of oil... 

Accidents may be caused by impact, failure of container or pipeline, or during loading/unloading. The hazards arise from ... 

There are several different situations in which petroleum hydrocarbons pose a threat that has attracted solution by bioremediation. These include (1) oil-refinery waste and contamination of the surrounding soil, (2) leakage from oil pipelines and underground storage tanks or basins, and (3) spillage of crude oil in the marine enviromnent after accidents at sea. 

An accident occurred in a gas pipeline in which the pressure of ethylene radically changed from 1 to 88.5 bar. The explosion which followed caused the gas pipeline to break by increasing the temperature of its walls to 700-800°C. The sudden temperature rise caused by the pressurisation and the fall of temperature at which gas combusts can be another factor (see p. 241). 

There are also other clouds on the horizon. In 1971 there were over 10,000 train accidents.9 Many of these involved hazardous chemicals. There were also similar accidents involving barges, pipelines, and trucks. As a result the federal govern-... 

Missiles are frequently a means by which an accident propagates throughout a plant facility. A localized explosion in one part of the plant projects debris throughout the plant. This debris strikes storage tanks, process equipment, and pipelines, resulting in secondary fires or explosions. 

For quantitative prognosis of emission rate from natural gas pipeline Yamal-West both emission from possible accidents and stationary sources were taken into account (Chernyaev et al., 1991). 

Isolation - It has been shown that the addition of isolation valves at periodic intervals is not as cost effective as prevention measures such as thickness inspections or tests. However all pipelines should be provided with a means for emergency isolation at it entry or exit from a facility. Offshore facilities may be particularly vulnerable to pipeline incidents as the Piper Alpha disaster has shown. In that accident a contributing factor to the destruction was the backfeed of the contents of the gas pipeline to platform once the topside isolation valve or piping lost its integrity. Further isolation means (i.e., a subsea isolation valve SSIV) were not available. 

Hydrogen gas is odorless and colorless. It burns almost invisibly and a fire may not be readily detected. Compressed hydrogen gas could be ignited with the static discharge of a cell phone. But, an accident may not cause an explosion, since carbon fiber reinforced hydrogen tanks are nearly indestructible. There is always the danger of leaks in fuel cells, refineries, pipelines and fueling stations. 

---