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OLR Research Report


March 31, 2010

 

2010-R-0125

SAFETY MEASURES CONCERNING
HIGH PRESSURE NATURAL GAS PURGES

By: Paul Frisman, Principal Analyst

You asked several questions following the February 7, 2010 natural gas explosion at the Kleen Energy plant in Middletown. We answer them individually below. The Office of Legislative Research is not authorized to issue legal opinions and this should not be considered one,

1. What specific measures have the Chemical Safety Board (CSB) and the National Fire Protection Association (NFPA) recommended to ensure adequate safety related to high pressure natural gas blows or gas purges?

The CSB approved urgent safety recommendations concerning the purging of fuel gas piping at industrial, commercial, and public facilities in February 2010 as the result of a June 9, 2009 explosion at the ConAgra SlimJim plant in Garner, North Carolina that killed four people and sent 67 people to the hospital. CSB determined the explosion was caused by purging gas indoors, near numerous possible ignition sources. Purging uses natural gas to displace the air in a pipeline before the gas line is put into service. This is different than a “gas blow,” such as occurred at Kleen Energy, where workers used natural gas at a high pressure to remove debris from gas pipes.

The recommendations will be incorporated in the 2012 edition of the National Fuel Gas Code (“NFPA 54”), and also form the basis for proposed interim, emergency revisions of the current, 2009 edition of the code. A number of states, including Connecticut, adopt and follow the fuel gas code.

According to NFPA, the proposed tentative interim amendment (attached) was published in the March 5, 2010 issue of NFPA News, with a closing date for public comment of April 26, 2010.

According to NFPA's Guy Colonna, if approved by NFPA's Standards Council, the interim amendment becomes effective for the current 2009 edition and makes the more stringent gas purging requirements part of the code at that time. It is then up to those jurisdictions (such as states or other enforcing authorities that have adopted NFPA 54) to adopt the interim amendment.

The recommendations essentially require that purged fuel gases be directly vented to a safe, outdoors location, away from people and ignition sources. If it is not possible to purge gases outdoors, purging gas inside a building will be allowed only with the approval of the authority having jurisdiction of a documented risk evaluation and hazard control plan. In addition, combustible gas detectors must be used to continuously monitor the gas concentration at appropriate locations in the vicinity of the purged gases, and workers must be trained to not rely on odor alone to detect gas releases. We have attached a copy of the background and finding of CSB's urgent recommendations.

CSB Investigations Supervisor Don Holmstrom, at a February 25, 2010 press conference on the Kleen Energy investigation, stated that the gas blow that occurred at Kleen Energy, in which workers sought to remove debris from natural gas pipes, differs from the gas line purging that occurred at ConAgra. He also noted that power plants such as Kleen Energy are exempt from the National Fuel Gas Code. Holmstrom said CSB is investigating what regulations, codes, and good practices might apply to type of gas blows that caused the Kleen Energy accident.

NFPA's Colonna notes that paragraph 1.1.1.2 (10) of NFPA 54 excludes electric utility power plants. In addition, Colonna states, NFPA 54 only applies to operating pressures of up to 125 pounds per square inch (psi), while CSB states that the Kleen Energy gas blow occurred at about 650 psi.

“The revisions to NFPA 54 through the [temporary amendments] and the next edition of the code would still not apply to power plants unless a change in the scope of NFPA 54 is included,” Colonna said. “At this time no change in scope has been proposed and no change in the operating pressure limitation has been proposed.  The changes to NFPA 54 could be used by the utility industry voluntarily as guidance in developing facility safety practices, but unless a scope change is made in the code, such facilities will remain outside the scope of the National Fuel Gas Code.”

2. Does federal law (perhaps the Natural Gas Act or the Natural Gas Pipeline Safety Act) limit the ability of Connecticut to regulate high pressure natural gas blows / gas purges in industrial and power plant settings?

It does not appear that either the Natural Gas Act (15 USC 717) or the Natural Gas Pipeline Safety Act (49 CFR 192) preclude Connecticut from regulating high pressure natural gas blows such as that which occurred at Kleen Energy. The Natural Gas Act deals primarily with market regulation and the wholesale transmission of natural gas. According to the U.S. Department of Transportation's Office of Pipeline Safety, its jurisdiction does not extend to piping within a power plant.

The U.S. Occupational Health and Safety Administration (OSHA) regulates worker safety at private plants in Connecticut. OSHA is one of several agencies investigating the explosion. Under federal law (29 CFR 1953) states may “opt out” of federal OSHA enforcement and develop and operate their own job safety and health programs. The state standards must be at least as effective as comparable federal standards. States also could promulgate standards covering hazards not addressed by federal standards.

Connecticut is one of a number of states that have enacted a state plan, but Connecticut's plan covers only state and municipal employees. We have attached more information about OSHA's state plan option, and Connecticut's plan in particular.

3. Do other states regulate high pressure natural gas blows / gas purges? Do states adopt the NFPA codes? Which states, if any, have adopted the NFPA Fuel Gas Code?

Connecticut is one of a number of states that have adopted the NFPA National Fuel Gas Code (NFPA 54). As noted earlier, the code does not apply to power plants. Connecticut regulations incorporate the 1996 edition (Conn. Agency Regs. 29-329-3).

According to NFPA, 39 states have adopted NFPA 54, with some states, such as Connecticut, adopting an earlier version, rather than the most current. Besides Connecticut, these states are: Alabama, Arkansas, California, Colorado, Delaware, Florida, Georgia, Hawaii, Iowa, Illinois, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Mississippi, Missouri, Nebraska, Nevada, New Hampshire, New York, North Dakota, Ohio, Oklahoma, Oregon, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, West Virginia, Wisconsin, and Wyoming.

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