MN471011, Explosives Safety Manual
Sponsor: Michael W. Hazen, 4000
Revision Date: July 29, 2009
Replaces Document Dated: November 9, 2007

This document is no longer a CPR. This document implements the requirements of Corporate Procedure ESH100.2.EXP.1, Manage Explosives Safety

IMPORTANT NOTICE: A printed copy of this document may not be the document currently in effect. The official version is the online version located on the Sandia Restricted Network (SRN).

Sandia Explosives Safety Manual

CHAPTER II – OPERATIONAL SAFETY - PART 1

Subject Matter Expert: Danton Humphries; CA Counterpart: Herman Armijo Contributors: Timothy Wallace and Ronald O’Hara
MN471011, Issue H
Revision Date: July 29, 2009; Replaces Document Dated: November 9, 2007
Review Date: July 17, 2006
Administrative Changes: August 11, 2009, March 4, 2010, April 9, 2010, and January 23, 2012

2-1.0 GENERAL OPERATIONS SAFETY GUIDELINES

2-1.1 Protection of Explosives

  1. Explosives are energetic materials that can react violently and should be protected from abnormal stimuli or environments, including:
    2. 1.
    2.
    3.
    4.
    5.
    6.
    7.    		 Friction forces.
    Excessive pressures and temperatures.
    Impact, shock, and pinching.
    Deformation.
    Electrical sparks, abrasive or welding sparks, and open flame.
    Contamination.
    Contact with incompatible materials.

2-1.1S General and Specific Requirements

  1. In addition to the rules set forth in this manual and Occupational Safety and Health Administration (OSHA) regulations (29 CFR 1910), certain general rules apply to all personnel working with explosives and these include:
    2.  1. Evaluate explosive operations and document them in an appropriate technical work documents (TWD). ES&H SOPs and changes to ES&H SOPs require management approval and Explosives Safety Engineering review before starting operations. ES&H SOPs for the use of explosives must be readily available in all locations where explosive work is conducted.
     2. Use the smallest amount of explosives necessary to complete the task.
     3. When working with new or modified explosives or mixtures of known explosives where the sensitivity of the mixture is unknown, assume the worst possible sensitivity and output characteristics until adequate information can be developed in coordination with the Explosives Development Committee (EDC).
     4. When wrist straps are required, refer to section 7.4S of this chapter.
     5.

    Wear approved safety glasses when in close proximity to operations involving exposed primary explosives, exposed powders, fragment producing actuators, initiators, and detonators, or when directed to by department management.
     6. Do not hand an explosive device to another person. Place it on a conductive surface so that the person can pick it up. This is to ensure that both operators and the item are at the same electrical potential, reducing unintentional initiation from static electricity.
     7. Follow the operational ES&H SOP and good practices outlined in this document when storing explosives and explosive devices being prepared for testing.
     8. All firing of explosives or explosive components must be performed with approved firing sets. For details, refer to Section 2-13 of this manual.
     9. When firing explosives, use exploding bridgewire initiators, slapper initiators, or similar high-energy device to the maximum extent possible.
    10. When wrist straps are required, refer to section 7.4S of this chapter When packaging and transporting explosive materials for shipments, follow the Department of Transportation provisions and SCM100.3.19, Move Non-Waste Hazardous Material Onsite and Offsite. Each explosives shipment requires specific instructions from a Packaging and Transportation Specialist.
    11. Follow an approved ES&H SOP for onsite shipments. Onsite includes Kirtland Air Force Base, DOE-controlled property, or property controlled by another federal agency where SNL is operating. See SCM100.3.19, Move Non-Waste Hazardous Material Onsite and Offsite.
    12. Verify the explosives or explosive devices received match the shipping documents before you use them.
    13.

    The cognizant Senior Manager must approve any mating or unmating of connectors carrying current or having a voltage potential when performed in the hazard zone of explosive material.
  2. Where testing requires the use of War Reserve (WR) units to provide either the fire signal or the actual firing pulse, the SOP will note this requirement.
  3. Specific requirements apply to any site where explosives will be used, including the following:
    4. 1.
    2.    		 Work on, test, or formulate explosives only in approved locations.
    Obtain approval from the line organization and Safety Engineering and be consistent with criteria specified in this document.

2-1.2 Equipment Checks

  1. Before being used in the explosives process, and at established intervals, processing and test equipment shall be checked for:
    2. 1.
    2.
    3.
    4.
    5.
    6.
    		 Proper design.
    Proper function.
    Specified clearances between parts in relative motion.
    Abnormal metal-to-metal rubbing of moving parts potentially contacting explosive materials.
    Cracks, voids, or screw threads where explosives may accumulate.
    Contamination incompatible with the materials to be introduced.
  2. This checkout may require the use of mock explosives in process or test conditions.
  3. Explosive materials must not be pinched or confined between equipment lids or covers and their mating surfaces. These surfaces shall be cleaned before cover placement. This includes pressing operations.

2-1.3 Inspection Frequency

  1. When this Manual calls for an inspection, but the inspection interval is not specified, such inspection interval shall be established by local facility management. Inspection intervals shall be modified when experience dictates a need.

2-1.4 Laboratory Operations

  1. The special safety guidelines applicable to general laboratory operations involving explosive materials are contained in Section 2-21.0 of this manual.

2-1.5 Toxicity Hazards

  1. Explosives materials, explosives components (additives or adhesives), and materials such as organic solvents used in explosives processing can be toxic when inhaled, ingested, or absorbed through the skin. Skin contact with explosives materials, or with solvents and adhesives used in conjunction with explosives operations, can result in a skin rash. This is the most frequently reported effect from working with these materials. The following general precautions should be used to prevent overexposure to these materials during explosives processing and handling:
    2. 1. Know the health hazard and controls before beginning operations.
    2. Evaluate the operation during startup to ensure that occupational exposure limits are not exceeded; routine operations should be monitored periodically.
    3. Handle in a well ventilated area; local exhaust ventilation is preferred.
    4. Avoid skin contact; use appropriate protective clothing.
    5. Practice good personal cleanliness; wash before eating, smoking, or using toilet facilities. End of shift showers may be required for some operators.

2-1.6 Hazard Identification and Communication

  1. Before beginning explosives operations, managers shall ensure the following:
    2. 1. Identify and maintain a current list of explosives and other hazardous materials used in conjunction with their operations.
    2. Determine the hazardous properties and toxicity of these materials through the use of the manufacturer's Material Safety Data Sheets (MSDSs) or other information sources and through consultation with the facility Industrial Hygiene staff. For explosives without published toxicological data, guidance can be obtained through the DOE Toxic Materials Advisory Committee (TMAC). Health hazard information must be communicated to employees who work with or generate hazardous materials.
    3. Educate and train employees in the hazards and precautions required for handling explosives and materials used in conjunction with explosives operations. This training should be part of the employee training and qualification program specified in Chapter V of this manual.

2-1.7 Process Hazard Analysis

  1. Before beginning any explosives synthesis, formulation, manufacturing, testing, or disposal operation, a process hazard analysis shall be performed. A single process hazard analysis may be performed for similar processes performed in a single facility, provided that the "worst-case" process is the basis for the hazard analysis. If required, a shield or other protective measure shall be employed. Selection criteria for the worst-case process are:
    1. Sensitivity of materials.
    2. Quantity of materials.
    3. Number of personnel potentially affected.
    4. Impact on other operations/activities
  2. The process hazard analysis shall be performed as a team effort. The team shall consist of a minimum of three persons and should not include more than seven. The team shall include at least one engineer and one operator, and should have the following makeup:
    3. 1. Team Leader, who is familiar with the analysis methodology used.
    2. Technical Member(s), who is familiar with the process being analyzed.
    3. Scribe, who writes notes of meetings and interviews and drafts reports.
  3. The facility manager or team leader may select the analysis methodology used, which should be one of the following:
    4. 1.
    2.
    3.
    4.
    5.
    6.
    7.    		 Preliminary Hazard Analysis.
    Checklist (usually for similar batch operations).
    What-if Analysis
    Hazard and Operability Study (HAZOP).
    Failure Modes, Effects, and Criticality Analysis (FMECA).
    Fault Tree Analysis
    Event Tree Analysis
  4. The process hazard analysis shall be formally documented.
  5. Employees and employee representatives shall be consulted on the process hazard analysis. The result of the process hazard analysis shall be provided to employees involved or affected by the operation.
  6. The process hazard analysis shall be updated and revalidated at least every 5 years by a team meeting the above criteria.
  7. The facility manager shall be responsible for establishing a system to address promptly the team's findings and recommendations promptly. Corrective actions, schedules for corrective actions, and completion of corrective actions shall be formally documented. Such documentation shall be filed with the process hazard analysis.
  8. Files containing process hazard analyses, updates, and corrective action statuses shall be maintained for the life of the process.

2-1.7S Process Hazard Analysis

  1. The hazard analysis (HA) can either be a standalone document that explicitly follows the process outlined in this manual and referenced in the PHS/HA, or it can be accomplished within the PHS/HA software as long as it satisfies the requirements outlined in this manual.
  2. The HA shall consider the following (minimum) topics before explosive work is conducted:
    3. 1. Heat (e.g., radiation, convection, conduction, flame).
    2. Shock or Impact (e.g., drop, rough handling).
    3. Friction (e.g., machining, mixing, pinching, cutting).
    4. Electrical (e.g., AC/DC power, power supplies, batteries, RF, ESD, bonding, grounding, mating/unmating of connectors, ground plan).
    5. Reaction (e.g., compatibility, confinement, contamination).
    6. Physical Environment (e.g., humidity, weather, lightning, PGEWS, location).

2-2.0 WORK ENVIRONMENT

2-2.1 General Requirements

  1. Workspace shall be adequate to perform operations safely and efficiently.
  2. Work shall be organized to eliminate clutter in the area while operations are being performed.
  3. Walkways should be kept clear.
  4. In work environments where solid, bare explosive pieces are handled, the floor should be cushioned, and all hard objects that may be struck by explosives in a handling incident should be cushioned where it is practical. Physical safety systems demonstrated to preclude the explosives from being dropped or struck can meet these requirements.
  5. An accounting procedure should be established for hand tools that may be inadvertently dropped into an explosives processing operation, thus creating a hazard.
  6. Personnel shall be assigned in such a manner that each worker's presence is frequently monitored and assistance can be provided or aid summoned in an emergency.
  7. Safety analysis of explosives facilities shall be performed. The safety analysis shall be performed during the design of new explosives facilities or the redesign of existing facilities. Facility management shall maintain readily available analyses documentation.
    8. 1. For Sandia-specific Site Plans, refer to Chapter VI of this manual.
  8. Noisy environments caused by explosives testing operations or process and handling equipment shall be evaluated. Areas with noise above the allowable occupational exposure limits must be posted and appropriate control measures instituted (e.g., engineering controls, protective equipment, and a hearing conservation program).

2-2.2 Emergency Exit Requirements for Explosives Operations

  1. Exit requirements for any building or structure containing explosives shall comply with the Life Safety Code, NFPA 101, except as otherwise permitted in this section.

2-2.2.1 Building or Structure Occupancy

  1. In determining occupancies:
    2. 1. Explosives operating buildings shall be classified as industrial occupancies (NFPA 101, Chapter 28).
    2. Explosives storage or staging buildings or structures shall be classified as storage occupancies (NFPA 101, Chapter 29).

2-2.2.2 Hazards of Contents Classification

  1. The hazard of contents classification of any explosives occupancy shall be determined using the requirements given in NFPA 101 and the following guidelines:
    2. 1. High-hazard explosives contents are those that, because of form, character, or volume, are likely to burn with extreme rapidity or from which poisonous fumes or explosions can be expected in the event of fire. The expectation of poisonous fumes or explosions is a relative matter to be determined on a case-by-case basis. Operating buildings containing propellant, pyrotechnic, or explosive powders shall be classified as high-hazard occupancies unless a reduced hazard classification can be justified.
    2. Reduced-hazard explosives contents are those that burn with moderate or less rapidity and will not produce poisonous vapors. This criterion shall be documented by a hazard analysis.

2-2.2.3 Personnel Protective Restrictions and Requirements

  1. DOE occupancies containing high explosives dictate personnel protection from blast overpressures and fragments (and spread of plutonium in some occupancies) from an accidental detonation. This accidental detonation of explosives is usually the result of stimuli other than a fire.
  2. Noncompliance with some NFPA 101 provisions (such as those covering exit doors, exit travel distance, number and location of exits, and common path of travel to exits) is authorized where required to provide protection from blast overpressure and fragments. When NFPA 101 requirements are not met the following additional personnel protective restrictions or requirements should be imposed.
    3. 1. The building and means of egress should be protected by supervised automatic sprinkler systems connected to sound evacuation alarms. This requirement is not applicable to explosives storage magazines, firing chambers, or rooms used as firing chambers, within explosives operating buildings.
    2. Explosives operating buildings and their means of egress should have automatic, early warning fire detection systems connected to sound evacuation alarms where such early warning might reasonably aid in prevention or mitigation of personnel injury. This requirement is not applicable to explosives storage magazines, firing chambers, or rooms used as firing chambers within explosives operating buildings.
    3. Personnel limits within the explosives work area (bay, cell, etc.) shall be established and controlled. These should not exceed 20 for reduced hazard occupancies or 6 for high-hazard occupancies. The need for personnel in numbers greater than these limits shall be documented in a hazards analysis based on the criteria of Section 2-2.2.5 of this chapter.

2-2.2.4 Requirements for Existing Facilities

  1. Existing facilities may deviate from current NFPA 101 requirements in the following situations.
    2. 1. Current code requirements were not in effect when the building was constructed. The building, however, is still required to meet the code of record.
    2. Deviations were made to meet the level-of-protection and design criteria in Section 6-6.0 of this manual.
    3. Building construction predates both current and level-of-protection criteria, but a hazards analysis has shown the risk of operations to be at an acceptable level.
    3. The risk from deviation has been analyzed and accepted by current hazards analysis.

Note: Those facilities requiring hazards analysis to determine whether a deviation from the Life Safety Code is acceptable shall follow the considerations and criteria described in section 2.2.5 of this chapter.

2-2.2.5 Requirements for New Facilities

  1. New facilities shall comply with the requirements of NFPA 101, except when deviation is necessary to provide personnel protection from blast overpressure and fragments per Chapter VI of this manual.
2-2.2.5.1 If deviations from NFPA 101 requirements are made, the Fire Hazards Analysis required by Chapter VI of this manual shall document the following aspects related to each explosives operation, bay, and/or workroom where a deviation exists:
  1. Clear pathway to exit in explosives bay or workroom.
  2. Potential for sustained fire in work environments from the presence of combustible and flammable materials and the presence of ignition sources.
  3. Total time required to exit the bay or workroom.
2-2.2.5.2 The criteria considered acceptable for the components of the analysis in Section 2.2.5.1 of this chapter are, respectively:
  1. No obstruction shall limit the width of the pathway to less than 36 in (91.44 cm).
  2. Combustible and flammable material quantities shall be minimized, justified, documented, and reviewed by site fire protection personnel and approved by line management. Ignition sources shall be identified and eliminated where possible.
  3. The total time for 6 people to exit the workroom or bay is 30 seconds or less, including the opening of doors where necessary. The total time for 20 people to exit the workroom or bay is 90 seconds or less. Noncompliance with this criterion shall be evaluated and justified during the conceptual design review.

2-2.2.6 Single Exits

  1. Where at least two exits are required by NFPA 101 and provisions for personnel protection from a blast will not permit at least two exits from a room or structure, a single exit is acceptable, provided the requirements of Sections 2-2.2.3 and 2-2.2.4 of this chapter and the following are met:
    2. 1. The path of exit travel shall be arranged so it is not through or toward a hazardous operation.
    2. The room containing a high-hazard explosive occupancy shall not exceed 500 ft2 (46.45 m2), and the occupant load of the room shall be restricted to two operators and two casuals.
    3. The room containing a reduced-hazard explosives occupancy shall not exceed 1,000 ft2 (92.9 m2).
  2. Explosives storage magazines may have only single exits for the purpose of maintaining integrity of design. The conditions of this section do not apply to these magazines.

2-2.2.7 Blast-Resistant Doors

  1. Blast-resistant doors required for the purpose of personnel protection from the effects of an accidental detonation may be located in the means of egress, provided the requirements of Sections 2-2.2.3 through 2-2.2.5 of this chapter and the following are met.
    2. 1. Where power-operated doors are required to accomplish unlatching and opening, they shall have reliable power supplies and shall be capable of being opened manually (to permit exit travel) or closed where necessary to safeguard the exits.
    2. The time required to fully open or close a door shall be as short as reasonably possible.
    3. A revolving door is acceptable if a secondary means of escape (with swinging doors) is provided at the same location. The revolving door must also be prevented from rotating at too rapid a rate in order to permit orderly exit of personnel.
    4. The following exceptions to NFPA 101 may be allowed when justified and documented.
    a. Swinging doors may exceed 48 in (122 cm) wide.
    b. It is acceptable to omit the NFPA-required swinging doors adjacent to a revolving blast door.
    c. Revolving blast doors need to be designed to collapse into book-fold position.
    d. Where fire-rated doors are required, blast doors are considered to have the required fire rating.
    e. An airlock with two or more doors with the intended purpose of preventing continuous and unobstructed passage by allowing the release of only one door at a time shall be permitted in a means of egress where there are provisions to allow for continuous and unobstructed travel during an emergency egress condition.
    f. Panic hardware is not required on blast doors.

2-2.2.8 Slide Escapes

  1. Slide escapes should be provided for elevated explosives operating locations from which rapid exit may be vital and cannot be obtained by other means. Slide escapes should be located on opposite sides of the explosives operation to reduce the likelihood of personnel being trapped by fire between them and a single slide.
  2. Exits to slide escapes must open onto platforms that are not less than 3 ft2 (.0914 m2) and the platforms must be equipped with guardrails. The slides shall begin at the outside edge of the platform, not at the edge of the buildings. Slide escape landings shall be located at selected places leading directly to escape routes that are free from tripping hazards, low guy lines, drains, ditches, or other obstructions. Manually or automatically controlled devices (trips) that sound an alarm in the operating building shall be installed at or near the entrances to slide escapes. These devices may also actuate deluge valves and water curtains in the building or room affected. Recommended slide escape specifications:
    3. 1.
    2.
    3.
    4.    		 Angle, 40º to 50º horizontal.
    Slide depth, 24 in (61 cm).
    Radius at bottom of slide, 12 in (30.48 cm).
    Height at lower end of slide, not over 24 in (61 cm) above the landing.
  3. If necessary, the end of the slide shall have a horizontal run sufficient to prevent an employee injury because of exit speed without the use of landing cushions (that are unsatisfactory in cold weather). One foot of horizontal run is required for a 15-ft (4.57 m)-long slide. One additional foot of horizontal run will be provided for each additional 5 ft (1.524 m) of slide length. The juncture of the two sections must be well rounded. Metal sheets constructing the slide must overlap in the direction of travel.

2-3.0 BUILDING AND EQUIPMENT MAINTENANCE

2-3.1 Cleaning

  1. Structures containing explosives shall be kept clean and orderly.
  2. Explosives and explosives dust shall not be allowed to accumulate on structural members, radiators, heating coils, utility lines, equipment, or electrical fixtures.
  3. To maintain safe conditions, there shall be a regular cleaning program for building interiors to prevent explosives dust and waste accumulation. This program should not be conducted in any bay where a hazardous operation is being conducted.
  4. In buildings containing explosives, hot water or water-steam mix should be used wherever practical for cleaning floors. Sweeping compounds that are nonabrasive and compatible with the explosives involved may be used when the use of water-steam mix or hot water is not practical. Such compounds may be combustible but must not be volatile (closed-cup flash point must not be lower than 230° F (110ºC). Sweeping compounds containing wax shall not be used on conductive flooring. Where nitrated organic explosives (which may form sensitive explosive compounds with some alkalis) are involved, the use of cleaning agents containing those alkalis is prohibited.
  5. Before beginning explosives decontamination activities that involve the use of large amounts of organic solvents [generally over 2.113 pt (1 L)], provisions must be made for (1) adequate ventilation or respiratory protection, (2) fire protection, and (3) adequate protective clothing.

2-3.2 Maintenance and Repair

  1. Records shall be maintained for inspection, repair, and servicing of process and handling equipment and fire protection systems.
  2. Maintenance operations involving major repairs, changes, or the use of hazardous equipment should not be performed within bays (rooms) while explosives are present. Before these operations, explosives should be removed and the area prepared. An approval procedure shall be established to ensure that the area has been inspected and is safe for these operations.
  3. Maintenance or construction operations performed by non-DOE facility personnel shall be at least intraline distance from any explosives operation and should be at least intraline distance from any building containing explosives. This requirement does not apply to personnel (e.g., technical representatives, architect-engineering surveyor, etc.) making job site inspections or equipment repairs requiring less than 8 hours. (Intraline distance separation may be satisfied by providing equivalent protection.) Transportation of explosives is permitted on roadways at less than intraline distance.
  4. For non-DOE facility personnel making job site inspections or equipment repairs requiring less than 8 hours, e.g., technical representatives, service representatives, architect-engineering surveyors, etc., management shall determine the minimum practicable distance by which such personnel will be separated from explosives operations. Facility management shall control explosives operations so that the chance of an explosion shall be kept to a minimum. Documentation of the rationale for establishing the minimum practicable distance and additional control measures taken shall be maintained until operations have been completed and personnel have permanently vacated the work site. All such personnel shall be informed of the risk of working at less than intraline distance and agree to accept such risk.
  5. New equipment or equipment subjected to major repair or modification shall be test-operated, and handling equipment shall be tested before being returned to operations. DOE-STD-1090 may be used as a guide.
  6. Maintenance work shall be performed by authorized personnel only.
  7. Before resuming operations following maintenance, the area shall be cleaned and approved by the operations supervisor.

2-3.2S Maintenance and Repair

  1. Organizations must designate a representative, normally customer support, to coordinate with Explosive Safety Engineering. The facility manager is responsible for work orders, required siting paper work, building design requirements, and lightning protection systems on explosives facilities.
  2. Managers of organizations using the facility are responsible for ensuring that lease/use DoD facilities are maintained and repaired according to agreements. Additional clearances and approvals must be obtained before beginning construction on Air Force-title land.
  3. The implementing documents for the Hoisting and Rigging Safety Program at SNL are the corporate procedures ESH100.2.IS.21, Manage Hazards for Overhead and Mobile Cranes and Hoists, ESH100.2.IS.22, Manage Hazards for Forklifts, and ESH100.2.IS.6, Procure Cranes, Hoists, Rigging Equipment, and Forklifts.

2-3.3 Hot Work Permits

  1. Where explosives are involved, a written permit shall be required for the temporary use of portable, heat-producing equipment that generates temperatures higher than 109ºC. Explosives decontamination of the immediately affected work areas and explosives removal shall be required before hot work operations. The permit should state the location, time, duration, purpose of use, details of safety, and fire-fighting equipment required. The permit shall be kept at the named location for availability and checkout by supervisory personnel.
    2. 1. Authorization of permits shall be by signature of personnel designated by the local facility managers. Designated personnel should be qualified by experience in explosives work, fire prevention, and general safety precautions, particularly with regard to the purging of equipment, presence of flammable mixtures, and the avoidance of electrical and mechanical hazards that could be incident to repair work.
    2. Designated personnel should represent supervision of the location where the work is being performed, supervision of personnel performing the hot work, and a third group independent of the first two (usually the local safety and fire protection group).
    3. Someone should remain at the site of a cutting or welding job for approximately 30 minutes after the job has been completed to extinguish or report any fires that develop. Designated supervision should inspect the job site before job initiation, during the job, and after job completion.

2-3.4S Explosive to Nonexplosive Building Notification

  1. When facilities involved with housing explosives are no longer required for use, the owning organization of that facility must advise the appropriate safety and facilities organizations. These are:
    2. 1. Facilities at SNL/NM, TTR, KTF, and Pantex notify the Safety Engineering and Space Management Office.
    2. Facilities at SNL/CA notify the Health and Safety Department.

2-4.0 REMOTE OPERATIONS

2-4.1 Personnel Protection

  1. Explosives operations judged to present such a significant level of risk that they must be performed remotely shall be conducted in facilities where the construction of the operating bay or the control room is capable of affording sufficient protection to personnel to prevent serious injuries. Criteria for the prevention of serious injuries are specified in Section 6-4.2.1d of this manual.
  2. Personnel involved in remote operations shall be provided protection from serious injury and transient personnel shall be provided protection in accordance with the requirements in DoD 6055.9 STD.

2-4.2 Access and Equipment Controls

  1. Control procedures and equipment shall be used to prevent personnel from entering the hazardous bay or area in which a remote operation is occurring or to prevent the operation from proceeding when personnel enter, as follows:
    2. 1. Roads shall be blocked at a minimum of Public Traffic Route Distance (K24) or Hazardous Fragment distance from buildings where hazardous (remote) operations are being performed, whichever is greater. The hazardous fragment distance may be satisfied by providing equivalent protection.1.
    2. Corridors leading to bays in which hazardous (remote) operations are being performed shall be marked to warn of the danger. Barriers shall also be set up.
    3. Visual methods such as closed circuit television should be used to monitor remote operations and to enable viewing of the operating area conditions before entering. Remote audio monitoring and video recording should also be considered.
    4. Interlocking of remote operating equipment to access doors should be required for each remote operation.
    5. Lights or similar warning devices shall conspicuously identify buildings or bays in which remote operations are performed to indicate when remote operations are under way.

2-5.0 GENERAL EXPLOSIVES AREA CONTROLS

2-5.1 Smoking, Matches, Lighters, Metal Articles

  1. There shall be no smoking in explosives storage, processing, or test areas, except in designated locations.
  2. No matches, lighters, or other fire-, flame-, or spark-producing devices shall be taken into an explosives control area except with written authorization. If authorized to be carried, matches shall be contained in a metal carrying device too large to fit into pockets. Kitchen ("strike anywhere") matches shall not be used.
  3. In explosives processing areas, metal articles (keys, jewelry, knives, coins, etc.) should not be carried by operating personnel where such items could constitute a hazard if dropped into the process operation.

2-5.2 Cooking and Eating

  1. Food or beverages shall not be consumed in explosives buildings, except in designated areas.
  2. There shall be no personal dishes or utensils in an explosives building, except in designated eating areas.
  3. Coffee pots, hot plates, ovens (including microwave), and portable electric heaters shall not be permitted in rooms where:
    4. 1. Explosives may be present.
    2. Combustible vapors or dust may be present.
    3. Smoking or drinking is prohibited because there are toxic materials present.
    4. Electrical classification of appliances is not compatible with the area.

2-5.3 Access to Explosives Areas

  1. Access control procedures shall be established for entry to all explosives areas.

2-6.0 PROTECTION OF ELECTROEXPLOSIVE DEVICES (EED) FROM ELECTROMAGNETIC RADIATION

  1. EEDs are vulnerable to initiation from a variety of sources. One potential hazard associated with EEDs is the accidental initiation by stray electromagnetic energy. This hazard exists when an electromagnetic field of sufficient intensity is generated to induce or otherwise couple currents and/or voltages of magnitudes large enough to initiate electroexplosive devices or other sensitive explosive components of weapon systems, or other explosive devices. This unintended actuation could have safety (premature firing) or reliability (duding) consequences.
  2. A large number of these devices are initiated by low levels of electrical energy and are susceptible to unintentional initiation by many forms of direct or induced stray electrical energy, such as from lightning discharges, static electricity, or tribo-electric (friction generated) effects, and radio frequency (RF) energy. Hazards from lightning discharges are covered in Chapter X. Lightning protection systems and requirements normally preclude the inadvertent initiation of EEDs by direct lightning strikes. Precautions for static electricity discharges are addressed in section 7 of this chapter. Stray energy, such as transients and other forms of induced energy, can be imposed on circuits affecting EEDs from other subsystems by various methods. Examples are inductive or capacitive coupling; sneak ground circuits; defective components or wiring; errors in design, modification, or maintenance.
  3. The degree to which EEDs are susceptible to unintentional initiation by exposure to the radiated fields of RF emitters depends on many variables. These variables include the ability of the leads, circuit, or installation to capture RF energy; the type and characteristics of RF energy; and methods of coupling which can introduce this energy into the EED.
  4. Emitter operating frequencies, power levels, modulation, and illumination angles are some of the factors that affect the vulnerability of EEDs to RF energy.
  5. As a precautionary measure, EEDs should normally be left inside their containers until ready for use. Shorting clips or other safety devices should not be removed until the EED is actually ready for use.
  6. For precautionary separation distances, see Section 2-13, Tables II-1, II-2, and II-3.

2-7.0 STATIC ELECTRICITY

2-7.1 General

  1. Positive steps must be taken to control or eliminate static electricity in areas where materials that are ignitable by static spark discharge are processed or handled. This includes spark-sensitive explosives, propellants, and pyrotechnics as well as solvent vapors and flammable gases.

2-7.1S General

  1. Explosive materials and explosive devices require special care in handling and packaging because they can be set off by discharges of static electricity at levels commonly found in the work environment. In all cases, take special care to maintain the item and all of its electrically isolated parts in electrostatic equilibrium with their environment and anyone who may touch them.

    2. Caution: If it is unknown whether an electroexplosive device is sensitive to static, treat it as though it is.

  2. When handling explosive materials and devices, adhere to the following guidelines:
    3. 1. Administer tests prescribed by the Explosives Development Committee (EDC) on all new explosive devices before using them and have all new explosives devices approved by the EDC before use. Items sensitive to static exhibit a discernible reaction when subjected to the tests described in SS302365, "Test Specification, Electrostatic Sensitivity,” or SS392498, “Testing Specification, Electrostatic Discharge Sensitivity, Electroexplosive Devices.”
    2. Treat all items that do not meet the criteria of SS302365 and SS392498, or that are untested as "static sensitive."
    3. Keep conductive surfaces and tools free of dust.
    4. Do not wax the surfaces.
    5. Do not take static-generating materials into an area while static-sensitive materials are being handled. Examples of static-sensitive materials include100-percent polyester, nylon, rayon, silk, wool and polystyrene cushioning material.

2-7.2 Bonding and Grounding of Equipment

  1. Bonding straps can be used to bridge locations where electrical continuity may be broken by the presence of oil on bearings, paint, or rust at any contact point. Pressure contact alone is not adequate grounding for permanent equipment in contact with conductive floors or table tops. Static grounds shall not be made to gas, steam, or air lines; dry pipe sprinkler systems; or air terminals of lightning protection systems. Static grounds can be made to water pipes, ground cones, buried copper plates, or driven ground rods of lightning protection systems. If a structure is equipped with a lightning protection system, all grounds shall be interconnected. Wires used as static ground conductors should be at least No. 10 AWG or equivalent.

2-7.3 Testing Bonded Equipment Grounds

  1. Grounding systems shall be tested for electrical resistance and continuity when installation has been completed and, in the case of active equipment, at intervals to be locally determined. If the equipment has been inactive for more than one month, the ground system shall be visually inspected for continuity before reactivation of the system. All exposed explosives or hazardous materials shall be removed before testing. When testing for resistance-to-ground, equipment should be considered as a unit, except in the case of an electrically isolated device or a belt-driven machine. In measuring the total resistance-to-ground for belt-driven machinery (to assure compliance with the section below), resistance of the belting is to be excluded. The maximum resistance-to-ground permitted for different types of equipment is as follows.
  2. Hazardous locations (operations where a static spark discharge may be dangerous). All conductive parts of equipment shall be bonded so that resistance to ground does not exceed 25 ohms, unless resistance is not to exceed 10 ohms because of a lightning protection installation. For existing equipment, the rate of static generation should be considered before making changes in grounding systems. The resistance of conductive rubber hose should not exceed 250,000 ohms.

2-7.4 Conductive Floors, Shoes, Mats, and Wristbands

  1. Conductive floors and shoes should be used for grounding personnel in operations involving explosives, propellants, pyrotechnics, etc., that are sensitive to initiation by the electrostatic spark discharge from a person. These include lead azide, lead styphnate, mercury fulminate, CP, some propellants, some pyrotechnics, etc. Many flammable liquids and air mixtures can be ignited by static discharge from a person. When personnel come into the proximity of (possible contact with) static-sensitive explosives or vapors, conductive floors shall be installed except where the hazards of dust-air or flammable vapor-air mixtures are eliminated by adequate housekeeping, dust collection, ventilation, or solvent recovery methods. Conductive floors may also be required in areas where operations involve EEDs that contain a static-sensitive explosive.
  2. Conductive floors are not required throughout an entire building or room if the hazard is localized. In such cases, conductive mats or runners may be used where required. These mats or runners will be subject to all the specifications and test requirements that apply to conductive floors. Conductive wristbands may be substituted for conductive mats and footwear at fixed, grounded work stations or outdoor locations.

2-7.4S Conductive Floors, Shoes, Mats, and Wristbands

  1. The use of wristbands during all operations involving static-sensitive explosive materials is mandatory. The functional check should be between the wearer contact point and the wristband attachment to ground.
  2. Managers are responsible for approving the use of conductive floors for explosives operations and ensuring that conductive floors, shoes, and mats are properly tested by the users.
  3. Wristbands shall be functionally checked prior to each use. Wristbands without resistors should be visually inspected prior to each use; at least once per year, their conductivity should be verified to be less than 1,200,000 ohms; and this verification shall be recorded.

2-7.5 Conductive Floor, Work Surface, and Wristband Specifications

  1. Conductive floors must be made of nonsparking material such as conductive rubber or conductive flooring composition and shall meet the following requirements:
    1. The flooring and its grounding system must provide for electrical resistance not to exceed 1,000,000 ohms (measured as specified in Section 2-7.6 below.
    2. The surface of the installed floor must be free from cracks and reasonably smooth. The material must not slough off, wrinkle, or buckle under operating conditions. Conductive tiles are not recommended for use in areas where contamination can be caused by explosive dust. The large number of joints and the tendency of tiles to loosen provide areas in which explosive dust can become lodged that are not easy to clean with normal cleanup procedures.
    3. Where conductive floors and shoes are required, resistance between the ground and the wearer shall not exceed 1,000,000 ohms (i.e., total resistance of conductive shoes on a person, plus the resistance of floor to ground). (See Figure II-1 for testing method.) Where conductive floors and shoes are required, tabletops on which exposed explosives or dusts are encountered should be covered with a properly grounded conductive material meeting the same requirements as those for flooring.
    4. Conductive floors must be compatible with the explosive materials to be processed.
    5. Conductive wristbands shall not exceed a resistance between the wearer and ground or bonding point of 1,200,000 ohms. This resistance shall be measured with a suitably calibrated ohmmeter. Wristbands shall be of a design that maintains electrical contact with the wearer when used.
    6. Table-top work surface mats that are not part of a total conductive system (Section 2-7.5a(3)) shall have a resistance not to exceed 1,200,000 ohms. This resistance shall be measured by a method similar to that outlined in Section 2-7.6 and records shall be maintained.

[Figure II-1. Testing Shoes on Wearer]

Figure II-1. Testing Shoes on Wearer

2-7.6 Conductive Floor Tests

  1. Initial tests shall be made of all conductive floors, and subsequent tests shall be made at least semiannually. Test results shall be permanently recorded and a copy filed in a central location. Instruments used in making tests shall be used only when the room is free from exposed explosives and flammable gas mixtures.
  2. Maximum floor resistance shall be measured with a suitably calibrated ohmmeter that operates on a normal open circuit output voltage of 500 volts dc and a short circuit current of 2.5 milliamperes with an effective internal resistance of approximately 200,000 ohms. Minimum floor resistance will be measured with a suitably calibrated ohmmeter appropriate for the task.
  3. Each electrode shall weigh 5.07 lbs (2.3 kg) and shall have a dry, flat, circular contact area 2.56 in (6.5 cm) in diameter, which shall comprise a surface of aluminum or tinfoil .05118 to .0984 in (1.3 to 2.5 mm) thick, backed by a layer of rubber .2362 to .2559 in (.6 to .65 cm) thick and measuring between 40 and 60 durometer hardness as determined with a Shore Type A durometer (ASTM D-2240-68).
  4. The floor shall be clean and dry. "Electrode jelly" such as brushless shaving soap or saline solution shall not be used.
  5. The resistance of the floor shall be more than 5,000 ohms in areas with 110-volt service and 10,000 ohms in areas with 220-volt service, and less than 1,000,000 ohms in all areas, as measured between a permanent ground connection and an electrode placed at any point on the floor and also as measured between two electrodes placed 3 feet apart at any points on the floor. Measurements shall be made at five or more locations in each room. If the resistance changes appreciably with time during a measurement, the value observed after the voltage has been applied for about five seconds shall be considered as the measured value.

2-7.6S Conductive Ground-Plane Tests

  1. Line managers are responsible for ensuring that conductive ground-plane surfaces are tested every 10 to 14 months for proper resistance to ground in accordance with this chapter.

2-7.7 Humidification

  1. Humidification for preventing static electricity accumulations and subsequent discharges is usually effective if the relative humidity is above 60%. However, certain materials such as metallic powders and some pyrotechnic mixtures cannot be exposed to air with 60% relative humidity due to the possibility of spontaneous ignition. Where this technique is used to prevent static electricity accumulations, a daily preoperational check of the humidity levels will be accomplished before work starts.

2-7.8 Ground Fault Circuit Interrupter

  1. Ground fault circuit interrupter protection shall be provided in static grounded areas where personnel may come in contact with ac-powered electrical equipment.

2-7.8S Ground Fault Circuit Interrupter

  1. Do not use 110V or greater AC-powered equipment in a ground-plane work area unless the electrical service outlets are protected by a ground fault circuit interrupter (GFCI) and only then if the equipment is approved by Safety Engineering. Operators must trip test GFCIs using the test button on the unit at least once a month and record the results and the dates of tests on a test record label according to the National Fire Protection Association (NFPA) 70 B.
  2. When using portable GFCIs that are plugged into a receptacle or are part of an extension cord, trip test the unit each day before use. This daily (before use) test need not be recorded. If there are any doubts concerning the GFCI operation, press the test button before use.

2-8.0 ELECTRICAL EQUIPMENT AND WIRING

2-8.1 Location/Operation Electrical Hazard Classification

  1. The National Electric Code (NFPA 70) shall be followed in all situations where the code normally applies. Although the NFPA 70 does not specifically address explosives. NFPA 70, Article 500, "Hazardous (Classified) Locations," requirements for the design and installation of electrical equipment and wiring in "classified" locations shall be used for the installation of rated equipment and fixtures where required by this section. The use of rated wiring, fixtures, equipment, and instrumentation where the code normally does not apply, provides additional safety for work with explosives materials by (1) restricting electrical ignition sources, such as sparks, electrical faults (shorts, power surges, etc.), (2) controlling surface temperatures of electrical items, and (3) reducing the potential for electrically initiated fires. Rated wiring, fixtures, equipment, and instrumentation shall be used for the operations specified below unless demonstrated unnecessary through analysis for a specific operation and location. The analysis shall be performed and documented per Section 2-8.4 and 2-8.6 of this chapter.
  2. Explosives do not normally fit the NFPA 70 definitions for groupings, classes, divisions, and area classifications. In order to apply NFPA 70, Article 500 as a guide, vapors containing explosives shall be treated as Group D (unless NFPA 70 requires a higher classification because of other components of the vapor) and dusts of explosives or solid explosives shall be treated as Group G. Class, division, and area classification determinations shall be based on the explosives operation being performed, as specified below, and not on the location or surrounding atmosphere, nor its potential for producing an ignitable or explosive mixture. Maximum temperature limits shall be based on the thermal analysis of the explosives used in the operation. Division 1 items can be substituted for Division 2 items, but never Division 2 for Division 1 items. Where there is a conflict between the requirements of this Manual, the more stringent of the two applies.
  3. Rated wiring, equipment, and instruments shall be approved for use by a nationally recognized testing laboratory. Rated items shall have labels and/or clearly identifiable markings to show Class, Division, Group and Temperature Range for which they are approved. Equipment approved for one Hazard Class is not interchangeable with another Hazard Class.
  4. The operations discussed below shall comply with the recommended class/division unless it is determined unnecessary through documented analysis for a specific operation and location:
    5. 1. Class I Division 1 wiring, fixtures, and process equipment and instrumentation are recommended for operations involving flammable gases, chemicals, or materials expected to produce flammable vapors with explosives present.
    2. Class I Division 1 and Class II Division 1 (dual rated) wiring, fixtures, and process equipment and instrumentation are recommended for synthesis, formulation, mixing, wet blending, and casting explosives, heating or drying of uncased explosives, plus any explosives processing that is expected to produce sublimation.
    3. Class II Division 1 wiring, fixtures, and process equipment and instrumentation are recommended for screening, grinding, blending, pressing, dry machining explosives, and weighing of explosives powders, the use of explosive or ignitable dust mixtures with explosives present, plus any explosives process that is expected to produce dust from explosives that is suspended in the air.
    4. Class II Division 2 wiring, fixtures, process equipment and instrumentation are recommended for storage, inspection, assembly, and wet machining of explosives, heating of fully encased explosives, plus, any explosives operation capable of producing dust of explosives that can accumulate on electrical equipment or apparatus. Class II, Division 1 or dual-rated equipment and wiring can be substituted.
    5. General Purpose wiring, fixtures, and process equipment and instrumentation are allowed for shipping and receiving operations with fully encased explosives or explosives packaged in DOT/DoD approved shipping containers and areas in explosives facilities where no explosives are present (e.g., offices, control rooms, halls, rest rooms and mechanical equipment rooms). General Purpose Areas may be established in explosives locations if facility management can determine, based on documented analysis of the processes involved and the separation between explosives operations requiring Class I or Class II rated electrical wiring, fixtures, process equipment and instrumentation and the General Purpose Area is established and maintained such that:
    a. Migration of explosive or ignitable gases, vapors or dust mixtures into the General Purpose Area from the rated area (not to be confused with the NEC Classified locations) will not occur under normal operating conditions.
    b. Ignition energy that may be developed in the General Purpose Area will not be transferred to the rated area (not to be confused with the NEC Classified locations), even under electrical fault conditions.
    6. Due to the potential for unacceptable consequences concerning operations with nuclear explosives, subassemblies, or components, they shall be evaluated in accordance with section 8.6 to determine the appropriate electrical hazard classification.
    7. Facility management shall evaluate, by using the principles given above, all explosives operations not specified elsewhere in this section to determine the appropriate electrical classification. The analysis shall be documented.

2-8.2 Electrical Supply System

  1. Mutual hazards may exist where explosives facilities are located near electrical supply lines and stepping equipment. To protect against these hazards, the NFPA 70 and the following requirements apply to all new construction or major modifications, and should be considered for existing facilities. Quantity distance requirements are based on air blast overpressure only and fragment distances are not considered. Electrical supply lines that can be interrupted without loss of power, i.e., power is rerouted through existing lines and/or networks, can be separated from explosives sites in accordance with section 8.2a(3) below. Electrical supply lines are classified by purpose as to transmission, distribution, or service.
    2. 1. Electrical transmission lines are those supplying locations outside the facility uniquely, or in common with the facility. Any line carrying 69 kV or more shall be classified as a transmission line for Q-D purposes. Electrical transmission lines and the tower or poles supporting them shall be located no closer to explosives facilities than:
    a. Inhabited-building distance if the line in question is part of a grid/system serving a large, offsite area.
    b. Public traffic route distance if loss of the line will not create serious social or economic hardships to offsite areas.
    2. Electrical distribution lines (electrical lines carrying less than 69 kV) supply multiple facility locations.
    a. Electrical distribution lines and the tower or poles supporting them shall be located no closer to explosives facilities than public traffic route distance.
    b. Electrical supply lines which jointly supply power (regardless of voltage) to off-site non-facility locations shall be considered transmission lines for Q-D purposes.
    c. If an electrical distribution line exclusively supports a storage/operations area and it has been determined that the loss of the line would be acceptable should an accident occur, it can be separated from explosives sites in accordance with service line criteria below (8.2.a.3).
    3. Electrical service lines are those supplying individual facility locations. Aboveground, DOE-controlled electrical service lines required to be in close proximity to a combustible constructed or uncovered explosives facility shall be no closer to that facility than the length of the lines between the poles or towers supporting the lines, unless an effective means is provided to ensure that broken, energized lines cannot come into contact with the facility or its appurtenances. Acceptable controls include, but are not limited to, geographic terrain features, instantaneous circuit interrupters, cable trays, and linking lines together. Equivalent underground electrical service lines shall be located as specified in Chapter VI, Section 6-3.2.4 and Table VI-2 of this manual.
    4. Electrical lines serving explosives facilities shall be installed underground from a point not less than  50 ft (15.24 m) away from such facilities.
    5. Unmanned privately owned or contractor-owned electrical substations (not to include building transformers and associated switch gear) shall be no closer to explosives facilities than public traffic route distances.
    6. Certain types of auxiliary power facilities, transformer stations, etc., present fire hazards to explosives facilities. Transformers and associated electrical switching apparatus serving one explosives facility or complex that do not present a fire hazard to the facility (i.e., dry-type, "less flammable" oil-insulated, etc.) shall be located as specified by NFPA 70 and Factory Mutual Data Sheet 5-4/14-18. Normal oil-insulated transformers shall be located at least 50 ft (50.24 m) from an explosives facility or as specified in DoD 6055.9-STD.
    7. Uninterrupted Power Supply (UPS) should be provided if electrical power is critical to an explosives operation during a power shut down or interruption.

2-8.3 Building Electrical Service Entrance

  1. Each electrical service entrance for explosives facilities should be provided with the following protection:
    2. 1. Arrestors
    a. An intermediate lightning arrestor shall be provided on the primary side of the transformer located in, on, or near the facility. See Chapter X for additional lightning protection guidance.
    b. Surge arrestors and surge capacitors shall be provided on the supply side of the main service disconnect.
    2. Grounding
  2. The lightning arrestor, surge arrestor, surge capacitors, service entrance ground, and building ground shall be interconnected. This interconnection shall be made outside the building.

2-8.4 Permanent Wiring, Fixtures, and Equipment

  1. Permanent facility wiring includes installed electrical wiring, communications wiring, security systems wiring, and fire protection systems alarm and response wiring. Permanent equipment includes the installed electrical fixtures and equipment associated with this wiring. Permanent equipment also includes equipment such as (but is not limited to) HVAC, hoods, vacuum pumps, hydraulic pumps, etc.
  2. New Facilities and Renovations
    3. 1. All permanent equipment and wiring of a room shall conform to Section 2-8.1 for the operations for which the room is designed.
    2. To maintain maximum, long-term flexibility of use of facilities, facility management is encouraged to consider installation of dual-rated (i.e., Class I, Division 1 and Class II, Division 1) permanent wiring and equipment in explosives operating rooms. As a minimum, installation shall allow for easy conversion to dual-rated wiring and equipment
    3. Rated electrical fixtures shall not be painted.
    4. Where equipment cannot meet the above requirements, the equipment should be located outside the hazardous environment. Otherwise, the equipment shall be analyzed and controlled as specified for electrical equipment and instrumentation in Section 2-8.6.
  3. Existing Facilities
    4. 1. Permanent wiring and equipment shall meet the requirements in effect at the time the facility was built. The wiring and equipment shall be brought into conformance with Section 2-8.4b if remodeling or renovation affect the wiring or equipment.
    2. As a minimum, the permanent wiring and equipment shall meet the requirements of Section 2-8.1 for the explosives operations performed.
    3. Where equipment cannot meet the above requirements, the equipment should be located outside the hazardous environment. Otherwise, the equipment shall be controlled as specified for electrical equipment and instrumentation in Section 2-8.6.

2-8.5 Flexible Cords/Wiring

Wiring from the permanent premises wiring to process equipment or process instrumentation should be rated for actual explosives operation being performed per Section 2-8.1 of this chapter. As a minimum, flexible cords shall be type SO hard service cord or rubber-covered heater cord type HSJ. Splices are not allowed. In addition, all flexible cords, receptacles, and attachment plugs must be equipped with three prongs so that the third prong (green wire) acts as ground. The cord shall be supported so that there is no tension on the terminal connections. Seals shall be provided where the cord enters explosion-proof enclosures. For Hazard Class I Division 1, Class II Division 1, or dual-rated operations, the cord shall also be equipped with explosion-proof attachment plugs. Flexible cords shall not be used where fixed installed electrical wiring is required by equipment design.

2-8.6 Electrical Equipment and Instrumentation

  1. Non-permanent electrical equipment and instrumentation shall comply with the following:
    2. 1. Process instrumentation and process equipment should be rated for the actual environment based on the explosives operation being performed as defined in Section 2-8.1.
    2. If the thermal properties of an explosive are such that Group G or Group D equipment provides inadequate surface temperature limits, special protection shall be provided, or the equipment shall be excluded from the hazardous location. This equipment shall not have a surface temperature exceeding the lowest onset of the exotherm of the explosive, as determined by the differential thermal analysis (DTA) test or the differential scanning calorimetry (DSC) test in Section 2-12.1.1.c of this chapter and Section 8-2.2.d. Approved instrumentation and equipment shall be administratively controlled and marked accordingly.
    3. When Hazard Class I or II, as applicable, equipment or instrumentation is required, but not available, the substitute equipment should be purged or pressurized in accordance with NFPA 496, or be determined intrinsically safe (without regard to voltage) in accordance with NFPA 70, Article 504/ANSI 913/NFPA 493 by facility management, or in Hazard Class II locations sealed to prevent explosives contamination. When the equipment is purged or sealed, the surface temperature shall not exceed 248º F (120º C) for normal operations, or 329º F (165º C) for overload conditions.
    4.

    All electrical equipment or instrumentation in hazardous locations that do not meet the requirements of paragraph 8.6.a (3) shall be evaluated and documented as to their suitability for use in the specific area and operation. The following are suggested areas for evaluation:

    a.

    Malfunction of electrical equipment or process instrumentation.

    1. Consequences of electrical initiated fire.
    2. Initiation of explosives by electrical current.
    • Initiation of explosives by electrical fault.
    • Breach of containment resulting in exposed explosives or spillage of explosives.
    • Ignition sources arising from physical damage to the wiring method used (e.g., crushing by forklift or other material handling equipment, frayed cords, etc.).
    • Exposed electrical conductors or connectors that could make contact with leg wires or cables of explosive devices during routine handling.
    • Exposed electrical conductors or connectors on which explosives dust or vapors could collect.
    • Collection of explosives dust on or in the equipment.
    • Sensitivity to heat and spark, and thermal stability of explosives involved.

    If the equipment is purged, the air flow shall be monitored per NFPA 496 and interlocked to the equipment, or alarmed, if operator shutdown of the machine can be reliably performed immediately upon receipt of that alarm.

    A waiver is not required when the equipment or instrumentation meets the requirements of either Section 2-8.6a.3 or Section 2-8.6a.4 of this chapter. If the wiring, equipment or instrumentation cannot meet these criteria or has not been evaluated by facility management, it shall meet the appropriate electrical hazard class requirements.

Watertight equipment (that would pass a NEMA 4 hose test) should be provided in those locations where water-explosives mixtures may come in contact with the electrical equipment and wiring.

2-8.7 Electrical Requirements for Outdoor Test Areas

  1. Requirements for outdoor test areas shall be contained in the specific test procedures.

2-8.8 Hand-held, Battery-Powered Lights and Instruments

  1. Flashlights and hand lanterns powered by low-voltage dry cell batteries and "miner cap lamps" approved as permissible by the U.S. Mine Safety and Health Administration (MSHA), UL, or those previously approved by the U.S. Bureau of Mines, for NEC Class I hazardous locations, are authorized for use in both Class I and Class II locations. Devices that provide "cold light" through chemical action are acceptable for use in any location.
  2. Hand-held instruments, watches, calculators, hearing aids, cameras, self-contained flashes, and communication devices powered by low-voltage dry cell batteries are authorized for use in the vicinity of Hazard Class II, Division 2 rated hazardous operations and during setup of NEC Class I or Class II, Division 1 hazardous operations. They shall be evaluated as to their intrinsic safety and approved by facility management prior to use during Hazard Class I or Class II, Division 1 hazardous operations.
  3. Hand-held, battery-operated equipment shall not come in direct or indirect contact with bare explosives. Batteries shall not be removed or replaced in a NEC hazard rated area (see Section 2-8.1).

2-8.9 Non-Rated Extension Lighting

  1. When it is necessary to use extension lights within  10 ft (3.048 m) of exposed explosives, where no airborne dust exists, the following requirements shall apply:
    2. 1. Lights shall be mounted on heavy tripod stands.
    2. The lights shall be fitted with exterior globes to prevent the falling of hot sparks or particles that might ignite the explosives.
    3. The lights shall be fitted with adequate guards to protect the globes from physical damage.
    4. The wire providing power to the lights shall be positioned so as to prevent vehicles and personnel damaging the cord.
    5. The flexible cord shall comply with Section 2-8.5.
    6. The light stand shall be secured to prevent tipping.
    7. Neither the light nor the power cord shall be allowed to come in direct or indirect contact with the explosives.
    8. Lights shall be positioned outside the fall-down distance to the explosives.

2-8.10 Laboratories

  1. Permanent wiring and equipment for existing laboratory areas are not required to meet the requirements of Section 2-8.4, except as noted in Section 2-8.4c.1.
  2. Process equipment used for synthesis, heating, drying, mechanical mixing, and blending shall be dual-rated. Weighing equipment shall be Class II, Division 1 or mechanical. These operations shall be isolated from non-rated wiring, electrical equipment and instrumentation in a manner that prevents dust or vapors reaching an ignition source.
  3. When laboratory equipment cannot meet Section 2-8.10b requirements, apply Section 2-8.6a.3 or 2-8.6a.4 of this chapter.

2-8.11 Modifications

  1. Operating buildings and magazines are constructed to perform a specific function that dictates the requirements for electrical installation. Procedures shall be established by each DOE facility to control the use and modification of electrical equipment in explosives areas and ensure that uniform standards are adhered to throughout the facility.

1Exclusion areas for protection from hazardous fragments are based on Hazard Division 1.1 Hazardous Fragment Distance Table (Table C9T2) of DoD 6055.9-STD, version of October 5, 2004.

(Continue, starting at 2-9.0, Vacuum Equipment)

Roger Smith, rogsmit@sandia.gov
Al Bendure, aobendu@sandia.gov

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