Boeing/Rocketdyne SSC Test Stands A2 and B1 - Executive Summary
Accidental Release Prevention and Emergency Response Policies at SSC Test Stands A2 and B1 |
A Risk Management Program has been implemented at the John C. Stennis Space Center (SCC) Test Stands A2 and B1 (Test Stands A2/B1) to reduce the risk of accidental releases of hazardous materials. This Risk Management Plan (RMP) summarizes the management, administrative, procedural, and technological controls that work together to minimize the risk to the community of hazardous hydrogen releases.
As stated by Jim Albaugh, President of the Boeing Space and Communications Group, "Considering the criticality and complexity of our products and systems, quality and safety are core values for every one of us in the Space & Communications Group. Emphasis is shifting from detection to the prevention of problems and hazards through a systematic approach to quality and safety. This emphasis, starting with design and development, continues through procurement, manufacturing, and operational/customer support
This emphasis on safety is implemented by the Boeing/Rocketdyne Safety, Health, and Environmental Affairs (SHEA) organization, which develops and assembles EPA RMP and OSHA Process Safety Management (PSM) plans in coordination with the facility involved. The facility manager implements the RMP and PSM programs, fulfilling the Boeing/Rocketdyne commitment to protect workers and the community. The SHEA emergency response policy involves the preparation of response plans, which are tailored to each facility and to the emergency response services available at SSC and the surrounding community, and are in compliance with the EPA and OSHA Emergency Response Program requirements.
Test Stands A2/B1 and Regulated Substances Handled
Test Stands A2/B1, located within SSC, are owned by the National Aeronautic and Space Administration (NASA) and operated by Rocketdyne Propulsion & Power, a unit of the Boeing Company.
SSC is located near the Gulf of Mexico in western Hancock County, Mississippi,
approximately 55 miles northeast of New Orleans, Louisiana, and 30 miles west of Gulfport, Mississippi. The facility consists of two areas totaling 138,801 acres. The "Fee Area" encompasses approximately 13,800 acres and represents the gated area of SCC. The "Buffer Zone" encompasses approximately 125,071 acres and extends in a five-mile radius around SSC. The majority of the Buffer Zone is located in Hancock County, Mississippi, with portions extending into Pearl River County, Mississippi, and St. Tammany Parish, Louisiana. A perpetual restrictive easement prohibiting dwelling construction covers the Buffer Zone for safety and acoustic considerations.
Test Stands A2/B1 are located in the southeastern section of SSC, at the end of Saturn Drive. Access to the stands features specific 24-hour control by guard station, and is restricted to official business.
One regulated substance, hydrogen, a flammable material, is handled at Test Stands A2/B1 in the combined maximum amount of 118
,000 lb. The following units store this substance:
Vessel Volume Physical Form Density Weight
A2 - V-201 110,000 gal Liquid 0.59 lb/gal 64,900 lb
B1 - V-151-LH 90,000 gal Liquid 0.59 lb/gal 53,100 lb
Both vessels are vacuum-jacketed vertical tanks, which store cryogenic hydrogen at a temperature of minus 4230F.
Test Stands A2/B1 test rocket engines using a highly instrumented system, which feeds liquid hydrogen and liquid oxygen to the test article, where an ignition source initiates their combustion to form water (steam). Liquid hydrogen is transferred using compressed gaseous hydrogen. A computerized program controls test conditions, including stopping the test (the flow of chemicals) 2.5 seconds after levels fall outside preset ranges (an active mitigation measure).
All personnel monitor tests from inside a reinforced control room (block house). The equipment is used intermittently, when tests (commonly lasting a few minutes) are performed.
An offsite con
sequence analysis was performed for a worst-case scenario, using procedures recommended by EPA in their "Risk Management Program Guidance for Offsite Consequence Analysis," April 1999 (OCA Guidance).
This worst-case scenario involves, in compliance with EPA regulations [40 CFR 68.25(e)], vaporization of the greatest amount of hydrogen held in a single vessel, namely 64,900 lb (Tank V-201) for Test Stand A2, and 53,100 lb (Tank V-151-LH) for Test Stand B1, resulting in a vapor cloud explosion. It should be noted that, due to the unconfined equipment arrangement at Test Stands A2/B1, this occurrence can be considered highly unlikely. The distance to the EPA-specified endpoint (an overpressure of 1 psi) was determined using EPA-supplied equations (OCA Guidance, Equation C-1) based on TNT equivalency, with a 10% yield factor. At an overpressure of 1 psi, shattering of glass windows and failure of wood siding and corrugated steel or aluminum would be expected, with hazard to personnel limi
ted to what may result from flying glass. No offsite effects were observed.
General Accidental Release Prevention Program and Chemical-Specific Prevention Steps
A prevention program is in place to minimize the risk of hydrogen releases in accordance with the OSHA PSM rule. This program is based on the following key elements:
7 High level of training of the operators
7 Preventive maintenance program
7 Use of state-of-the-art process and safety equipment
7 Use of accurate and effective operating procedures, written with participation of the operators
7 Performance of a hazard review of equipment and procedures
7 Implementation of an auditing and inspection program.
Chemical-specific prevention steps include availability of self-contained breathing apparatus (SCBA), fire-resistant suits, face goggles and face shields, awareness of the hazardous properties of hydrogen, and presence of hydrogen detectors.
Five-Year Accident History
No accidental releases from hydrogen processes that r
esulted in deaths, injuries, or significant property damage onsite, or known offsite deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage (40 CFR 68.42) have occurred at Test Stands A2/B1 in the past five years.
Two accidents which did not meet the EPA definition occurred in the last five years involving hydrogen handling. Both accidents occurred at Test Stand B1. In both cases, an explosion/fire occurred in a vent line, which then vented burning hydrogen to the atmosphere. In the February 9, 1995 accident, the fire was extinguished after four hours and twenty minutes and the property (equipment) damage was estimated at $134,000. In the February 8, 1996 accident, the fire was extinguished after two hours and fifty minutes and the property (equipment) damage was estimated at $150,000. No one onsite or offsite was injured in other accident, no offsite consequences occurred and all released hydrogen was consumed in both fires.
Two emergency response plans are in place: the SSC Master Emergency Plan and the Test Stands A2 and B1 Emergency Response Plans. The latter include alert systems, notification procedures, and evacuation plans. SSC participates in the activities of the Local Emergency Response Planning Committee. Emergency response drills and drill evaluations are conducted periodically. Emergency operation and response procedures are also reviewed at the start of a new test series.
Planned Changes to Improve Safety
A Process Hazard Analysis of the hydrogen systems was performed, using the Hazard and Operability (HAZOP) procedure, in August 1998 for Test Stand A2 and in February 1999 for Test Stand B1. Action items requiring replacements or modifications, review, or further investigation, were identified and addressed. These included technical items, such as installation of new mitigation or control equipment, and procedural/managerial items, such as improved maintenance or training.