NTSB Safety Recommendation Letter P-93-009

Page 1Official PDFNATIONAL TRANSPORTATION SAFETY BOARD Wasliingrorz, D. C. 20594 Safety Recommendation Date: December 15, 1993 In Reply Refer To: P-93-9 Ms. Rose McMurray Acting Administrator Research and Special Programs Administration 400 Seventh Street, S.W. Washington, D.C. 20590 On April 7, 1992, an uncontrolled release of highly volatile liquids (HVLs) from a salt dome storage cavern in the Seminole Pipeline System near Brenham, Texas, formed a large, heavier-than-air gas cloud that exploded. Three people died from in,juries sustained either from the blast or in the fire. An additional 21 people were treated for injuries at area hospitals. Damage from the accident exceeded $9 million.' During its investigation of this accident, the Safety Board found several systemic deficiencies in the design of Brenham station, the most important of which was the lack of a fail-safe cavern shutdown system. The Seminole Pipeline Company is a stock corporation in which MAPCO Natural Gas Liquids, Inc. (IviAPCO) has controlling interest. When MAPCO constructed Brenham station, no industry or government standards existed that described the type or design of equipment needed to provide a specified level of safety control. MAPCO engineers designed the station, including the configuration of the station's cavern safety system and selected equipment, after reviewing the practices of other' companies that were operating caverns at the time. Between the time that the Brenham station was originally constructed and the time of the accident, MAPCO had never performed a comprehensive safety analysis of the Seminole system, including Brenham station, to identify potential points of failure and product release. 'For more detailed informalion, read Pipeline Accident Report--Highly Volatile Liqiridr Rrlcnre From Undergrocriid Stornge Caw711 arid Erploriori, M A K O Noturd Gar L.iqiiidr, Itic., Breiihm!t, Tixnr, April 7, 1992 (NTSB/PAR-93/0 1). 5779B#

Page 2L During its investigation, the Safety Board searched recommended practices and guidelines of several pipeline-related organizations to determine what guidance had been provided by industry associations on the design, construction, operation, and emergency preparedness of underground storage systems. Section 6 of the Gas Processors Suppliers Association’s (GPSA’s) Engineering Dura Book, 1987 Edition, contains information on underground storage facilities, but not enough technical information to design or operate an underground storage facility. At a public discovery hearing held July 29-30, 1992, in Austin, Texas, the Safety Board asked representatives of the Office of Petroleum Safety (OPS), the American Petroleum Institute (API), and the American Gas Association (AGA) what assistance they provided to their niernbers on underground storage. The API representative advised that since 1981, it has recognized the need to develop standards for solution-mined underground storage facilities. The API’s trans- portation committee appointed a task force that began developing standards for solution-mined storage facilities, but the task force halted work after several years, apparently because of an industry econoiiiic downturn. In December 1989, the task force resumed working on standards for design and construction, and in July 1990, resumed working on standards for operations and maintenance. According to a spokesperson, a draft of the design and construction standards includes recomniended practices on designer qualifications, cavern design parameters and criteria, wellhead safety equipment, cavern drilling and completion, cavern integrity testing, cavern product inventory measurement, cavern operation, and cavern abandonment. The API expects that both sets of standards will be issued by the end of 1993. The AGA witness stated that the present standards applicable to underground natural gas storage were developed for the exploration and production of oil and gas. The API, the Anier- ican National Standards Institute, and the International Association of Drilling Contractors have recommended practices on wellhead equipment, casing equipment, and drilling operations. The GPSA also has sonie educational materials on underground storage. The AGA representative identified agencies having some safety control over underground storage of natural gas, including the Federal Energy Regulatory Commission, which reviews both the environmental studies and facility construction and design proposals for interstate operations, and State utility regulatory commissions, which perform similar reviews for intrastate operations. In most cases, the States regulate the performance of wellhead and down hole equipment. The spokesperson stated that although the AGA does not develop standards, the association has an underground storage committee that reviews and disseminates to its inembers technical information on the safe and efficient operation of both cavern and aquifer storage facilities. The committee works with standard-writing bodies by reviewing and recommending improvements; maintains technical papers; meets biannually to exchange technical information, to review research, and to review environmental regulatory requirements; and collects and publishes statistics on underground storage operations. The Safety Board believes that System Safety Society and other professional organizations have greatly improved safety analysis techniques in use since the Board initially recommended their use. However, the pipeline industries have not adequateiy used the techniques even though ~#

Page 33 the Department of Transportation has advocated their use and tlie AGA has developed guidelines to make them easier to apply. The Safety Board is aware that tlie OPS is now developing a risk-based analysis and prioritization process that it believes will provide an analytical basis for selecting from among potential pipeline safety improvement projects those that will lead to optimal use of its pipeline safety resources. The Safety Board is encouraged by the OPS's action in using safety analysis techniques to improve the administration of the pipeline safety regulatory program. However, the Board believes that the OPS should extend its new-found appreciation of the advantages of system safety analyses by incorporating incentives into its pipeline regulations that will en- coui'age individual pipeline operators and pipeline standards-writing organizations to also in- corporate these techniques into their pipeline safety programs. The Safety Board believes that the OPS should require pipeline operators to apply system safety analyses to new and modified system designs and to evaluate tlie adequacy of existing underground storage systems., The OPS could motivate standards-writing organizations to use analysis techniques in assessing new or modified standards and practices by not incovorating into Federal regulations any standards that have not been appraised using safety analyses. This accident and the lack of underground storage regulatory public safety oversight posed by the more than 1,400 liquid and more than 400 natural gas underground storage facilities in the country demonstrate that the Research and Special Pi,ograms Administration needs to develop safety requirements for storage of highly volatile liquids and natural gas in underground facilities, Therefore, the National Transportation Safety Board makes the following safety recommendation to the Research and Special Programs Administration: Develop safety requirements for storage of highly volatile liquids and natural gas in underground facilities, including a requirement that all pipeline operators perform safety analyses of new and existing underground geologic storage systems to identify potential failures, determine the likelihood that each failure will occur, and assess tlie feasibility of reducing the risk; require that operators incoiporate all feasible improvements. (Class TI, Priority Action) (P-93-09) Also, the Safety Board issued Safety Recommendations P-93-10 through -14 to the MAPCO Natural Gas Liquids, Inc,; P-93-15 and -16 to Washington County; P-93-17 to tlie Texas Department of Public Safety; P-93-18 through -20 to the American Petroleum Institute; and P-93-21; P-93-22 to the American Gas Association; and P-93-23 to the International Association of Fire Chiefs. The Safety Board is also reiterating Safety Reconmiendation 1-88-1 to the Department of Transportation. If you need additional infoimation, you may call (202) 382-0612.#

Page 44 Ctiairman, VOGT, Vice Chairman, COUGHLIN, MembeIs, LAUBER and HAMMERSCHMIDT concurred in this recommendation. Member HART did not participate. By: Carl W. Vogt Chairman#