Source: https://www.federalregister.gov/documents/2012/09/07/2012-21922/explosive-siting-requirements
Timestamp: 2016-09-30 10:16:27
Document Index: 299035647

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:: Explosive Siting Requirements
55108-55120
AGENCY: ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: Authority for This Rulemaking I. Overview of Final Rule II. Background III. Discussion of Public Comments and Final Rule Differences Between the NPRM and the Final Rule Regulatory Notices and Analyses
https://www.federalregister.gov/d/2012-21922
SUMMARY: This rule amends the requirements for siting explosives under a license to operate a launch site. It increases flexibility for launch site operators in site planning for the storage and handling of energetic liquids and explosives. DATES: Effective November 6, 2012. ADDRESSES: For information on where to obtain copies of rulemaking documents and other information related to this final rule, see “How To Obtain Additional Information” in the SUPPLEMENTARY INFORMATION section of this document. FOR FURTHER INFORMATION CONTACT: For technical questions concerning this final rule contact Yvonne Tran, Commercial Space Transportation, Federal Aviation Administration, 800 Independence Avenue SW., Washington, DC 20591; telephone (202) 267-7908; facsimile (202) 267-5463, email yvonne.tran@faa.gov. For legal questions concerning this final rule contact Laura Montgomery, AGC 200, Senior Attorney for Commercial Space Transportation, Office of the Chief Counsel, Federal Aviation Administration, 800 Independence Avenue SW., Washington, DC 20591; telephone (202) 267-3150; facsimile (202) 267-7971, email laura.montgomery@faa.gov. SUPPLEMENTARY INFORMATION: Authority for This Rulemaking The Commercial Space Launch Act of 1984, as amended and re-codified at 51 United States Code (U.S.C.) Subtitle V—Commercial Space Transportation, ch.509, Commercial Space Launch Activities, 51 U.S.C. 50901-50923 (the Act), authorizes the Department of Transportation (DOT) and thus the FAA, through delegations, to oversee, license, and regulate commercial launch and reentry activities, and the operation of launch and reentry sites as carried out by U.S. citizens or within the United States. 51 U.S.C. 50904, 50905. Authority for this particular rulemaking is derived from 51 U.S.C. 50905, which requires that the FAA issue a license to operate a launch site consistent with public health and safety. See also 49 U.S.C. 322(a), 51 U.S.C. 50901(a)(7). Section 50901(a)(7) directs the FAA to regulate only to the extent necessary to, in relevant part, protect the public health and safety and safety of property. I. Overview of Final Rule This final rule amends part 420 of Title 14 of the Code of Federal Regulations (14 CFR) Chapter III, updating the FAA's requirements for how to site explosives under a license to operate a launch site.[1] Part 420 establishes criteria for siting facilities at a launch site where solid propellants, energetic liquids, or other explosives are located to prepare launch vehicles and payloads for flight. These criteria are commonly referred to as quantity-distance (Q-D) requirements because they provide minimum separation distances between explosive hazard facilities, surrounding facilities and locations where the public may be present on the basis of the type and quantity of solid propellants, energetic liquids, and other explosives located within the area. Minimum separation distances are necessary to protect the public from explosive hazards. The FAA is making a number of changes consistent with the goals of Executive Order 13610, Identifying and Reducing Regulatory Burdens, 77 FR 28469 (May 14, 2012). First, the FAA is dispensing with its separation distance requirements at launch sites for storing liquid oxygen, nitrogen tetroxide, hydrogen peroxide in concentrations equal to or below 91 percent, and refined petroleum-1 (RP-1). If these energetic liquids are not within an intraline distance of an incompatible energetic liquid or co-located on a launch vehicle, the FAA is no longer imposing public area separation distances because the current separation requirements for storing these energetic liquids unnecessarily duplicate the requirements of the Occupational Safety and Health Administration. Second, the FAA is decreasing the separation distances required for division 1.1 explosives and liquid propellants with trinitrotoluene (TNT) equivalents of less than or equal to 450 pounds. Although decreased, the revised separation requirements will continue to protect against hazardous fragments, which are defined as having a kinetic energy of 58 foot-pounds, which is a level of kinetic energy capable of causing a fatality. The probability of a person six feet tall and one foot wide being struck by a hazardous fragment at a given separation from a given net explosive weight (NEW) is one percent, which is an equivalent level of safety to today's separation distances. Third, the FAA is reducing the separation distances for the storage and handling of division 1.3 explosives, while maintaining a level of safety equivalent to current requirements. Fourth, the FAA is eliminating its own separation distance requirements for storing liquid oxidizers and Class I, II and III flammable and combustible liquids because they duplicate the requirements of other regulatory regimes. Consistent with the current Department of Defense (DOD) Explosive Siting Board's (DDESB) and National Fire Protection Association (NFPA) practice, the FAA is dispensing with the hazard groups of tables E-3 through E-6 of appendix E of part 420 as a means of classification. This revision will conform the FAA's classification to the NFPA classification system, which is more commonly used to reflect chemical hazards of energetic liquids used at commercial launch sites. Finally, a site map must now be at a sufficient scale to determine compliance with part 420. II. Background In 2000, the FAA issued rules governing the storage and handling of explosives as part of its regulations governing the licensing and operation of a launch site. Licensing and Safety Requirements for Operation of a Launch Site; Final Rule, 65 FR 62812 (Oct. 19, 2000) (Launch Site Rule). The FAA has requirements for obtaining a license to operate a launch site in part 420. Part of the application for a license requires an applicant to provide the FAA with an explosive site plan that complies with the explosive siting requirements of part 420. The plan must show how a launch site operator will separate explosive hazard facilities from the public. It must identify the location of the explosives and how the public is safeguarded. The explosive siting requirements of part 420 mandate how far apart a launch site operator should site its explosive hazard facilities based on the quantities of energetic materials housed in each facility. Distances vary based on the quantities at issue, whether the energetic materials at a given facility are being handled or stored, and whether or not the distance being calculated is a distance to a public area or public traffic route. Since the original rulemaking, the FAA's experience with the requirements has led it to the current changes. At the time it promulgated the original requirements, the FAA anticipated that any new launch sites would have similar siting issues as launch sites devoted to expendable launch vehicles, and, therefore, relied on the siting requirements of the DDESB DOD Ammunition and Explosive Safety Standard, 6055.9-STD (1997) (1997 DOD Standard).[2] Instead, for the most part, the FAA has issued a number of licenses for the operation of launch sites at existing airports, such as Mojave Air and Space Port in California. At these airports, the presence of jet fuels regulated under existing FAA space transportation requirements created conditions requiring the FAA to reconcile and clarify its separation requirements for launch vehicle liquid propellant requirements with the presence of other industrial chemicals, such as aircraft fuels. Based on experience with these launch sites and on research on other regimes that address explosive materials, the FAA amends its own requirements as described above. III. Discussion of Public Comments and Final Rule The comment period for the NPRM closed on May 17, 2011. The FAA received comments from XCOR Aerospace (XCOR). XCOR's comments support the FAA's acceptance of a separation distance different from the one required by §§ 420.63 through 420.69 if an operator demonstrates an equivalent level of safety. XCOR also supports the FAA's proposal to abandon storage requirements for the types of liquid fuels and oxidizers that are already regulated by OSHA. The FAA also received a number of opposing comments from XCOR. They are discussed below and address the FAA's jurisdiction over explosive hazards, the nature of explosive hazards and whether energetic liquids are all explosives, the interplay between the definition of liquid propellants and aviation fuels, the appropriate license for dealing with explosive hazards and, lastly, stoichiometric ratios, the theoretical ratio of fuel and oxidizer at which the fuel is burned completely. As an initial matter, the FAA must address XCOR's objection to the FAA's jurisdiction over treating a location where static engine firing takes place as an explosive hazard facility. XCOR at 12.[3] Congress charged the FAA with licensing and regulating the operation of launch sites as well as launches. 51 U.S.C. 50904. Explosive hazards are present at launch sites and may threaten members of the public who are also present at the site, as well as persons outside of the launch site. Because static firing of an engine involves the handling of energetic liquids or explosives and all the hazards associated with their mixing, the FAA finds it necessary to require separation distances between the location and the public. At commercial launch sites, locations where static firing occurs are considered explosive hazard facilities under § 420.5. As it proposed in the NPRM, the FAA is adopting and defining the term “energetic liquids” to mean a liquid, slurry, or gel, consisting of, or containing an explosive, oxidizer, fuel, or combination of the above, that may undergo, contribute to, or cause rapid exothermic decomposition. XCOR opposes the FAA's proposed definition of “energetic liquids” on the grounds that there is no need for the FAA to regulate fuels and oxidizers, as explosives, because, according to XCOR, energetic liquids are not explosives. XCOR at 6. In 2000, the FAA found it necessary to regulate both explosives and liquid propellants, but did not define the latter. The FAA's use of both terms apparently created the erroneous impression that the FAA only regulated materials that do not require mixing to explode, notwithstanding the FAA's inclusion of liquid propellants in its part 420 requirements. As should be evident from the FAA's requirements for materials other than division 1.1 explosives, the FAA has not so limited itself. “Explosive” is a broad term, and the FAA is using it throughout part 420 as such. Because of past confusion, the FAA is now defining “energetic liquids” to encompass liquid fuels, oxidizers, and liquid propellants. XCOR believes that if a fuel and oxidizer are not mixed, the FAA's separation requirements for energetic liquids are not necessary. The FAA's requirements, however, are designed to mitigate harm caused by inadvertent mixing. Energetic liquids such as fuels and oxidizers may, when mixed, produce the reactions of and share characteristics with materials that are explosives in the truest technical sense. Explosions are due to the sudden release of energy over a short period of time and may or may not involve chemical reactions.[4] Three basic characteristics of an explosion are: a sudden energy release, a rapidly moving blast or shock wave, and a blast of a magnitude large enough to be potentially hazardous. Additionally, explosions may be purely a physical event involving a sudden release of mechanical energy, or a chemical explosion requiring a chemical reaction. Furthermore, an accident may happen without mixing. For example, liquid oxygen is an oxidizer and is usually stored in its liquid state at a very low temperature. Because liquid oxygen has a very large liquid-to-gas-expansion ratio, 1 to 860 at 68° F, it can undergo an explosion known as a boiling liquid expanding vapor explosion, commonly referred to as a BLEVE. The FAA recognizes that no one intends inadvertent mixing, but because it can happen and because not all accidents are the result of mixing, separation distances are necessary for energetic liquids. As proposed, the FAA now defines “liquid propellant” to mean a monopropellant or incompatible energetic liquids co-located for purposes of serving as propellants on a launch vehicle or a related device. In response to XCOR's comment that unmixed fuels and oxidizers do not explode, the FAA is clarifying that the co-location of incompatible energetic liquids makes something a liquid propellant only where the incompatible energetic liquids are housed in tanks connected by piping for purposes of mixing. The stored energy present when incompatible energetic liquids are connected by piping poses a hazard requiring separation distances because, under feasible conditions, the system may fail and cause fire, blast, and flying fragment hazards. It is because of these hazards that organizations such as the NFPA require a minimum separation distance of 20 feet between a liquid fuel and an oxidizer. Obviously, for launch, this is not possible, but the NFPA requirement underscores the importance of separating a fueled launch vehicle from the public. For most liquid fueled launch vehicles, incompatible energetic liquids such as fuels and oxidizers are housed in separate tanks on the vehicle. Pipes lead from each tank to a combustion chamber where combustion takes place to generate thrust. The presence of the piping is designed to ensure mixing in the combustion chamber in order to achieve propulsion. Accordingly, the FAA is revising its definition of liquid propellants from what it proposed to the following: A monopropellant or an incompatible energetic liquid co-located for purposes of serving as propellants on a launch vehicle or a related device where the incompatible energetic liquids are housed in tanks connected by piping for purposes of mixing. This new reference to “connecting piping” should alleviate concerns that the FAA intends the definition of liquid propellants to apply to aircraft or tanker trucks. See XCOR at 6, 7. XCOR claims that because a launch license will govern incompatible energetic liquids co-located on a launch vehicle, these issues should not be addressed through a site license. XCOR at 3, 8. The FAA does not dispute that the launch license will govern launch. That being said, the launch operator will also have to operate with separation distances in effect. This means the site operator's advance planning attendant to explosive siting will not go to waste. For example, § 417.411, which applies to launch operators, requires safety clear zones that would keep the hazards associated with a launch operator's vehicle from the public during launch processing.[5] Accordingly, a site operator must be able to provide appropriately sited facilities that permit a launch operator to comply with its requirements.[6] Similarly, XCOR maintains that, in the context of the definition of liquid propellants, energetic liquids are better addressed in the launch license where an appropriate hazard assessment will be conducted. The FAA agrees, but there still needs to be enough room to encompass the results of that assessment. For example, if a launch operator performs its hazard assessment and it, or the FAA, determines that it needs a great deal of room to encompass its hazards, the launch site operator's preliminary explosive siting should already have made sure that the necessary separation distances are in place at the launch site. Different launch vehicles may have different levels of quality, safety, and reliability, depending on the maturity of the technology and the organization, which means that the site operator's separation distances must account for a worst-case launch vehicle. XCOR suggests the FAA take into account launch vehicle design and construction when determining separation distances at a launch site where the launch vehicles may vary in reliability. XCOR at 3, 8. XCOR brings to light an issue that requires clarification. Part 420 addresses a different issue than a launch operator's safety clear zone. Under parts 417 and 437, a launch operator must establish a safety clear zone during pre- and post-flight operations. Part 420 requires there be room for such safety clear zones in the first place. Otherwise, when constructing or establishing a launch site, a site operator may fail to plan for the safety needs and regulatory requirements of its customers. The philosophy underlying the necessity for separation distance requirements is that there must be room for hazardous operations, even those covered by other licenses. Accordingly, the separation distances for the site operator must account for vehicles of varying quality and reliability. The FAA is amending its definition of “explosive hazard facility” to clarify that it includes locations and facilities at a launch site where solid propellants, liquid propellants or other explosives are stored or handled. XCOR objected to the proposed definition of an “explosive hazard facility” because it includes facilities containing energetic liquids, including liquid oxygen. XCOR at 4. XCOR maintains this conflicts with the FAA proposal that it would no longer require separation distances around liquid oxygen. Although the FAA will no longer require separation distances for many energetic liquids, a site operator must still, in its explosive site plan, identify all explosive hazard facilities where all energetic liquids will be located. The FAA has been regulating liquid oxygen as part of an explosive hazard facility since 2000, characterizing liquid oxygen as a liquid propellant, and will continue to do so under the new rule, while characterizing it as an energetic liquid. However, because the FAA has been attempting to reduce duplicative requirements, the FAA will rely on OSHA's regulations. Therefore, while the FAA will no longer require separation distances around liquid oxygen, OSHA will continue to do so, and for the FAA to fail to recognize that liquid oxygen is an energetic liquid would only create confusion. As discussed in the NPRM, OSHA's requirements are extensive and serve to protect the safety of the public as an ancillary benefit to OSHA's protection of worker safety. Lastly, XCOR comments that the net explosive weight (NEW) of liquid propellant should not be based on the total quantity of liquid fuel and oxidizer available on a launch vehicle, but only on the portion where the liquid fuel and oxidizer are at a stoichiometric ratio. XCOR at 10. For example, XCOR postulated a horizontal vehicle dumping unused oxidizer so that it returns to the runway with only 100 pounds of liquid oxygen and 1000 pounds of kerosene aboard. XCOR maintains that part 420 would require it to treat the amount of kerosene in excess of that which would react explosively as, in fact, exploding. Therefore, any excess should be ignored. XCOR's comments relate to existing requirements that the FAA did not propose to change. Therefore, its comments are outside the scope of this rulemaking. Additionally, part 420 addresses a site operator's location of its facilities, and XCOR raises an operational issue addressed not through a launch site operator license, but through a launch license. The FAA would assess NEW for scenarios hypothesized by XCOR under a launch license or permit. Differences Between the NPRM and the Final Rule This final rule is adopted for the reasons discussed in the NPRM, but with minor changes from what the FAA proposed. The FAA is defining “explosive hazard facility” to mean a facility or location at a launch site where solid propellants, energetic liquids, or other explosives are stored or handled. In the NPRM, the FAA proposed to define this facility as one where, in relevant part, solid explosives were stored or handled. However, this would have created redundancies with the references to “solid explosives” and “other explosives” being references to the same thing; the FAA is accordingly keeping the original reference to solid propellants. The FAA requires a launch site operator to submit a scaled map that shows the location of all explosive hazard facilities at the launch site, the actual and minimal allowable distances between each explosive hazard facility and all other explosive hazard facilities, each public traffic route, and each public area, including the launch site boundary. The NPRM incorrectly identified the public traffic route as a public area. This is relevant for division 1.1 explosives because the separation distances between an explosive hazard facility and a public traffic route are less than those between an explosive hazard facility and a public area. Likewise, § 420.63(d), which permits a site operator to demonstrate an equivalent level of safety now clarifies that this form of relief applies to separation distances to public traffic routes as well as to public areas. See also § 420.67(a) (separating incompatible energetic liquids from public traffic routes); § 420.69 (separating division 1.1 and 1.3 explosives co-located with liquid propellants from public traffic routes). The FAA is clarifying its requirement that a launch site operator must separate each explosive hazard facility where the NEW is greater than 450 pounds and less than 501,500 pounds from each public area containing any member of the public in the open by a distance equal to −1133.9 + [389 *ln(NEW)].[7] Accordingly, the final rule contains this requirement not only in section 420.65(c)(3), where it appeared in the NPRM, but also in sections 420.67(d)(3) and 420.69(b)(4), (c) and (d)(5), where it was inadvertently omitted. The FAA discussed the reasons for this provision in its original discussion. NPRM at 8928. The final rule, § 420.65(c)(3), which governs the handling of division 1.1 and 1.3 explosives, now requires each public area containing any member of the public in the open to be separated from an explosive hazard facility by a distance equal to −1133.9 + [389 *ln(NEW)] where the NEW is greater than 450 pounds and less than 501,500 pounds. The NPRM incorrectly [8] identified the range of NEW as less than 600,000 pounds, rather than 501,500 pounds. Above 501,500 pounds the NEW formulas for blast and fragments show that blast hazards, rather than fragment hazards, determine the separation distance. This means that an operator must use a blast formula rather than a fragment formula for quantities above 501,500 pounds. Table E-2 contains the formulas. In the NPRM, the FAA stated, in proposed footnote 3 of Table E-3 that a net explosive weight of greater than 500,000 pounds was not allowed for division 1.1 explosives because it was implied in the 2004 DOD Standard. Further investigation has disclosed, however, that the FAA misread the DDESB limitation. The FAA now understands that the limitation meant only that the table's intraline distances could not be used for division 1.1 explosives. In the interest of greater clarity, the FAA is modifying § 420.65(d)(2), from what it proposed in the NPRM to clarify that when a site operator has quantities of explosives that fall between table entries, the site operator may use a formula provided by the tables to find a separation distance different than the one listed for the specified quantity. For example, if a site operator has 17 pounds of division 1.1 explosives, table E-1 would require a separation distance for a public area of either 506 or 529 feet. However, the site operator may calculate a distance using footnote 1 that falls between these two distances. The FAA's change clarifies that the site operator must use the equation from the same table as the distance the site operator seeks to determine. In other words, the site operator may not use an equation from table 2 to calculate a distance for table 1. Similarly, for paragraph (e)(3), a site operator with existing structures who wants to calculate the maximum quantity of explosives permitted in those structures may not use an equation from another table to calculate for a quantity being calculated. Section 420.69 now clarifies that a launch site operator may, when determining separation distances for co-location of division 1.1 and 1.3 explosives with liquid propellants, employ a maximum credible event (MCE) assessment under paragraph (e) rather than using the separation distances prescribed by paragraphs (b), (c) and (d). The NPRM incorrectly described the MCE assessment as a requirement rather than an option. An MCE assessment is one way of demonstrating an equivalent level of safety. Finally, in table E-7 of Appendix E of part 420, the FAA inadvertently transcribed a footnote from the DDESB requirements that the FAA had not intended to propose. Specifically, footnote 3 of table E-7 in the NPRM, would have required sprinklers for Class 4 oxidizers inside a building. This final rule does not incorporate that requirement.
Changes to Federal regulations must undergo several analyses. First, Executive Order 12866 and Executive Order 13563 direct that each Federal agency shall propose or adopt a regulation only upon a reasoned determination that the benefits of the intended regulation justify its costs. Second, the Regulatory Flexibility Act of 1980 (Pub. L. 96-354) requires agencies to analyze the economic impact of regulatory changes on small entities. Third, the Trade Agreements Act (Pub. L. 96-39) prohibits agencies from setting standards that create unnecessary obstacles to the foreign commerce of the United States. In developing U.S. standards, the Trade Act requires agencies to consider international standards and, where appropriate, that they be the basis of U.S. standards. Fourth, the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4) requires agencies to prepare a written assessment of the costs, benefits, and other effects of proposed or final rules that include a Federal mandate likely to result in the expenditure by State, local, or tribal governments, in the aggregate, or by the private sector, of $100 million or more annually (adjusted for inflation with base year of 1995). This portion of the preamble summarizes the FAA's analysis of the economic impacts of this final rule.
Under current part 420, the FAA does not distinguish between public areas that are buildings, where people are sheltered, and those where people are out in the open. This final rule will result in greater distances for some public areas than are required under current rules, but should not result in increased distances for siting buildings. The operational constraints themselves should not increase costs because a launch site operator currently must ensure under § 420.55 that its customers schedule their hazardous operations so as not to harm members of the public. A site operator may incur minimal costs in performing these new calculations and updating its procedures to reflect any changes in distances.
The Trade Agreements Act of 1979 (Pub. L. 96-39), as amended by the Uruguay Round Agreements Act (Pub. L. 103-465), prohibits Federal agencies from establishing standards or engaging in related activities that create unnecessary obstacles to the foreign commerce of the United States. Pursuant to these Acts, the establishment of standards is not considered an unnecessary obstacle to the foreign commerce of the United States, so long as the standard has a legitimate domestic objective, such the protection of safety, and does not operate in a manner that excludes imports that meet this objective. The statute also requires consideration of international standards and, where appropriate, that they be the basis for U.S. standards. The FAA has assessed the potential effect of this final rule and determined that it will have only a domestic impact.
1. The authority citation for part 420 continues to read as follows: Authority:
2. Amend § 420.5 by revising the definition of § 420.5 Definitions.
3. Revise § 420.63 to read as follows: § 420.63 Explosive siting.
(a) Except as otherwise provided by paragraph (b) of this section, a licensee must ensure the configuration of the launch site follows its explosive site plan, and the licensee's explosive site plan complies with the requirements of §§ 420.65 through 420.70. The explosive site plan must include:
4. Revise § 420.65 to read as follows: § 420.65 Separation distance requirements for handling division 1.1 and 1.3 explosives.
5. Add § 420.66 to read as follows: § 420.66 Separation distance requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen and any incompatible energetic liquids stored within an intraline distance.
6. Revise § 420.67 to read as follows: § 420.67 Separation distance requirements for handling incompatible energetic liquids that are co-located.
7. Revise § 420.69 to read as follows: § 420.69 Separation distance requirements for co-location of division 1.1 and 1.3 explosives with liquid propellants.
(1) Determine the explosive equivalent weight of the liquid propellants by following § 420.67(c);
(1) Method 1. (i) Determine the explosive equivalent weight of the liquid propellants by following § 420.67(c);
(2) Method 2. (i) Determine the explosive equivalent weight of each liquid propellant by following § 420.67(c);
(2) Determine the total explosive quantity of each division 1.1 and 1.3 explosive by following § 420.65(a)(2);
8. Add § 420.70 to read as follows: § 420.70 Separation distance measurement requirements.
9. Revise Appendix E to part 420 to read as follows: Appendix E to Part 420—Tables for Explosive Site Plan
Table E-1—Division 1.1 Distances to a Public Area or Public Traffic Route for NEW ≤450 lbsNEW (lbs.)Distance to public area (ft) 1,2Distance to public traffic route distance (ft) 2≤0.52361420.72631581291175234620833782275419251744526710474284155063042052931730561337315633385060136170628377100658395150815489200927556300108565145012437461 To calculate distance d to a public area from NEW:NEW ≤ 0.5 lbs: d = 2360.5 lbs < NEW <100 lbs: d = 291.3 + [79.2 *ln(NEW)]100 lbs ≤ NEW ≤ 450 lbs: d = -1133.9 + [389 *ln(NEW)]NEW is in lbs; d is in ft; ln is natural logarithm.To calculate maximum NEW given distance d (noting that d can never be less than 236 ft):0 ≤ d < 236 ft: Not allowed (d cannot be less than 236 ft)236 ft ≤d < 658 ft: NEW = exp [(d/79.2)-3.678]658 ft ≤ d < 1250 ft: NEW = exp [(d/389) +2.914]NEW is in lbs; d is in ft; exp[x] is ex.2 The public traffic route distance is 60 percent of the distance to a public area.
Table E-2—Division 1.1 Distance to Public Area and Public Traffic Route for NEW > 450 lbsNEW (lbs)Distance to public area (ft) 1Distance to public traffic route (ft)450 lbs< NEW ≤ 30,000 lbs1,250750.30,000 lbs< NEW ≤ 100,000 lbs40*NEW 1/30.60*(Distance to Public Area).100,000 lbs< NEW ≤ 250,000 lbs2.42*NEW 0.5770.60*(Distance to Public Area).250,000 lbs< NEW50*NEW 1/30.60*(Distance to Public Area).1 To calculate NEW from distance d to a public area:1, 243 ft< d ≤ 1,857 ft: NEW = d3/64,0001, 857 ft< d ≤ 3,150 ft: NEW = 0.2162 * d1.73313,150 ft< d: NEW = d3/125,000NEW is in lbs; d is in ft.
Table E-3—Division 1.1 Intraline Distances1,2,3NEW (lbs)Intraline Distance (ft)5066707410084150962001053001205001437001601,0001801,5002062,0002273,0002605,0003087,00034410,00038815,00044420,00048930,00055950,00066370,000742100,000835150,000956200,0001,053300,0001,205500,00031,429700,0001,5981,000,0001,8001,500,0002,0602,000,0002,2683,000,0002,5965,000,0003,0781 To calculate intraline distance d from NEW:d = 18*NEW1/3NEW is in pounds; d is in feet2 To calculate maximum NEW from given intraline distance d:NEW = d3/5,832NEW is in pounds; d is in feet.3 NEW values of more than 500,000 lbs only apply to liquid propellants with TNT equivalents equal to those NEW values. The intraline distances for NEW greater than 500,000 pounds do not apply to division 1.1 explosives.
Table E-4—Division 1.3 Separation DistancesNEW (lbs)Distance to public area or public traffic route (ft) 1Intraline distance (ft) 2≤100075501,50082562,00089613,000101685,000117807,0001308810,0001459815,00016411220,00018012230,00020413850,00024016370,000268181100,000300204150,000346234200,000385260300,000454303500,000569372700,0006684281,000,0008005001,500,0009365772,000,0001,0086301 To calculate distance d to a public area or traffic route from NEW:NEW ≤1,000lbs d= 75 ft1,000 lbs< NEW ≤ 96,000 lbs d=exp[2.47 + 0.2368*(ln(NEW)) + 0.00384*(ln(NEW))2]96,000 lbs< NEW ≤1,000,000 lbs d = exp[7.2297−0.5984*(ln(NEW)) + 0.04046*(ln(NEW))2]NEW > 1,000,000 lbs d = 8*NEW 1/3NEW is in pounds; d is in feet; exp[x] is ex; ln is natural logarithm.To calculate NEW from distance d to a public area or traffic route (noting that d cannot be less than 75 ft):0 ≤ d < 75 ft: Not allowed (d cannot be less than 75 ft) for NEW ≤ 1000 lbs75 ft ≤ d≤ 296 ft NEW = exp[−30.833 + (307.465 + 260.417*(ln(d)))1/2]296 ft< d≤ 800 ft NEW = exp[7.395 + (−124.002 + 24.716*(ln(d)))1/2]800 ft< d NEW = d3/512NEW is in lbs; d is in ft; exp[x] is ex; ln is natural logarithm2 To calculate intraline distance d from NEW:NEW ≤ 1,000 lbs d = 50 ft1,000 lbs< NEW ≤ 84,000 lbs d=exp[2.0325 + 0.2488*(ln(NEW)) + 0.00313* (ln(NEW))2]84,000 lbs< NEW ≤ 1,000,000 lbs d= exp[4.338 − 0.1695*(ln(NEW)) + 0.0221*(ln(NEW))2]1,000,000 lbs< NEW d =5*NEW1/3NEW is in pounds; d is in feet; exp[x] is ex; ln is natural logarithmTo calculate NEW from an intraline distance d:0 ≤ d < 50 ft: Not allowed (d cannot be less than 50 ft) for NEW ≤ 1000 lbs50 ft ≤ d≤ 192 ft NEW = exp[−39.744 + (930.257 + 319.49*(ln(d)))1/2]192 ft<d≤ 500 ft NEW = exp[3.834 + (−181.58 + 45.249*(ln(d)))1/2]500 ft≤d NEW = d3
/ 125NEW is in pounds; d is in feet; exp[x] is ex; ln is natural logarithm
Table E-5—Energetic Liquid Explosive Equivalents1,2,3Energetic liquidsTNT EquivalenceTNT Equivalence Static Test StandsLaunch Pads.LO2/LH2See Note 3See Note 3.LO2/LH2 + LO2/RP-1Sum of (see Note 3 for LO2/LH2) + (10% for LO2/RP1)Sum of (see Note 3 for LO2/LH2) + (20% for LO2/RP1).LO2/RP-110%20% up to 500,000 lbs Plus 10% over 500,000 lbsIRFNA/UDMH10%10%.N2 04/UDMH + N2 H45%10%.1 A launch site operator must use the percentage factors of table E-5 to determine TNT equivalencies of incompatible energetic liquids that are within an intraline distance of each other.2 A launch site operator may substitute the following energetic liquids to determine TNT equivalency under this table as follows:Alcohols or other hydrocarbon for RP-1H2 O2 for LO2 (only when H2 O2 is in combination with RP-1 or equivalent hydrocarbon fuel)MMH for N2 H4, UDMH, or combinations of the two.3 TNT equivalency for LO2/LH2 is the larger of:(a) TNT equivalency of 8*W2/3, where W is the weight of LO2/LH2 in lbs; or(b) 14 percent of the LO2/LH2 weight.
Table E-6—Factors To Use When Converting Energetic Liquid DensitiesItemDensity (lb/gal)Temperature (°F)Ethyl alcohol6.668Hydrazine8.468Hydrogen peroxide (90 percent)11.668Liquid hydrogen0.59−423Liquid oxygen9.5−297Red fuming nitric acid (IRFNA)12.977RP-16.868UDMH6.668UDMH/Hydrazine7.568
Table E-7—Separation Distance Criteria for Storage of Hydrogen Peroxide in Concentrations of More than 91 Percent1,2Quantity (lbs)Intraline distance or distance to public area or distance to public traffic route (ft)10,00051015,00059220,00065130,00074650,00088470,000989100,0001114150,0001275200,0001404300,0001607500,00019051 Multiple tanks containing hydrogen peroxide in concentrations of greater than 91 percent may be located at distances less than those required by table E-7; however, if the tanks are not separated from each other by 10 percent of the distance specified for the largest tank, then the launch site operator must use the total contents of all tanks to calculate each intraline distance and the distance to each public area and each public traffic route.2 A launch site operator may use the equations below to determine permissible distance or quantity between the entries of table E-7:W > 10,000 lbs Distance = 24 * W1/3Where Distance is in ft and W is in lbs.To calculate weight of hydrogen peroxide from a distance d:d > 75 ftW = exp[−134.286 + 71.998*(ln(d)) −12.363*(ln(d))2 + 0.7229*(ln(d))3]
Table E-8—Separation Distance Criteria for Storage of Liquid Hydrogen and Bulk Quantities of HydrazinePounds of energetic liquidPounds of energetic liquidPublic area and intraline distance to incompatible energetic liquidsIntraline distance to compatible energetic liquidsPounds of energetic liquidPounds of energetic liquidPublic area and intraline distance to incompatible energetic liquidsIntraline distance to compatible energetic liquidsOverNot OverDistance in feetDistance in feetOverNot OverDistance in feetDistance in feet 60,00070,0001,2001301002006003570,00080,0001,2001302003006004080,00090,0001,2001353004006004590,000100,0001,20013540050060050100,000125,0001,80014050060060050125,000150,0001,80014560070060055150,000175,0001,80015070080060055175,000200,0001,80015580090060060200,000250,0001,8001609001,00060060250,000300,0001,8001651,0002,00060065300,000350,0001,8001702,0003,00060070350,000400,0001,8001753,0004,00060075400,000450,0001,8001804,0005,00060080450,000500,0001,8001805,0006,00060080500,000600,0001,8001856,0007,00060085600,000700,0001,8001907,0008,00060085700,000800,0001,8001958,0009,00060090800,000900,0001,8002009,00010,00060090900,0001,000,0001,80020510,00015,0001,200951,000,0002,000,0001,80023515,00020,0001,2001002,000,0003,000,0001,80025520,00025,0001,2001053,000,0004,000,0001,80026525,00030,0001,2001104,000,0005,000,0001,80027530,00035,0001,2001105,000,0006,000,0001,80028535,00040,0001,2001156,000,0007,000,0001,80029540,00045,0001,2001207,000,0008,000,0001,80030045,00050,0001,2001208,000,0009,000,0001,80030550,00060,0001,2001259,000,00010,000,0001,800310
The FAA published a notice of proposed rulemaking (NPRM) that proposed the changes to part 420 that the FAA is now adopting. Explosive Siting Requirements, 76 FR 8923 (Feb. 16, 2011).
The DDESB updated the DOD Standard in 2004. Notice of Revision of Department of Defense 6055.9-STD Department of Defense Ammunition and Explosives Safety Standards, 70 FR 24771 (May 11, 2005) (2004 DOD Standard). DOD released a new edition in 2008, but the 2004 changes are the ones relevant to this rulemaking. The 2004 DOD standard bases its separation distances for storage on Occupational Safety and Health Administration (OSHA) and NFPA standards for classes I through III flammable and combustible liquids and liquid oxygen, and on NFPA standards for classes 2 and 3 liquid oxidizers. The 2004 DOD Standard contains less restrictive requirements for explosive division 1.1 solid explosives with a net explosive weight of less than or equal to 450 pounds, and for energetic liquids with a TNT equivalence of less than or equal to 450 pounds. The FAA is mirroring these requirements now.
XCOR Aerospace, Comments to NPRM (FAA-2011-0105), Online posting, http://www.regulations.gov/#!searchResults;rpp=10;po=0;s=faa-2011-0105, (May 18, 2011) (referred to as XCOR).
Crowl, D.A., Understanding Explosions, AIAA Center for Chemical Process Safety (CCPS), 2, (2003).
Section 417.411(a)(1) requires a launch operator to establish a safety clear zone able to confine an adverse explosive event, based on a worst-case event, regardless of the fault tolerance of the system.
On a related note, XCOR raises the possibility of having to evacuate the public as a result of the FAA's regulations. XCOR at 7. As is the case under the current requirements, the better solution than evacuation would be to relocate a hazardous operation. If a site operator addresses the necessary separation distances, neither relocation nor evacuation should be necessary.
Although the NPRM characterized this as affecting operations rather than the siting of buildings, the FAA must note that it could apply to a site operator's initial planning because a site operator would be well advised to consider this formula when siting any bleachers for members of the public to view a launch.
When the FAA reviewed these numbers using a more refined analysis, it found that the separation distance increments could be expressed with greater precision.