BUNKER GLOSSARY: 21 TECHNICAL TERMS EVERY BUYER SHOULD KNOW.

ANDAIR's three-stage filtration architecture: (1) pre-filter for large particulate, (2) HEPA filter capturing 99.97% of 0.3-micron particles including radioactive fallout and biological aerosols, (3) activated carbon for chemical vapor agents. Maintains positive pressure at +0.03 inches WC. Manual hand-crank blower operates at 70 cfm with zero electrical input.

AISC certification programs cover building structures, bridges, hydraulic structures, and complex steel. Certified shops maintain a documented Quality Management System covering material traceability, weld procedure specifications (WPS), procedure qualification records (PQR), inspection protocols, and equipment calibration cycles. Annual audits by AISC.

AWS D1.1 covers structural welding for carbon and low-alloy steel. Certification requires passing welder qualification tests for specific positions (1G flat, 2G horizontal, 3G vertical, 4G overhead) and procedures. Tests include guided bend tests, radiographic inspection, and visual examination. Recertification required every 6 months for active welders.

ASTM A572 Gr50 is a high-strength low-alloy (HSLA) columbium-vanadium structural steel. Minimum yield strength: 50 ksi (vs A36 at 36 ksi). Tensile strength: 65 ksi minimum. Elongation: 18% in 8 inches. Good weldability with low-hydrogen processes. Used at ⅜" plate thickness in our Fortress shell.

Overpressure ratings reference peak reflected pressure from a free-air burst. A 1-megaton detonation produces approximately 5-15 PSI overpressure at 5 miles depending on yield specifics. The Fortress's 17 PSI rating provides survivable overpressure protection at distances of 3-5 miles from a 1-megaton detonation. The Citadel's 25 PSI extends this to 1-3 miles. Below 1 mile, no civilian shelter provides realistic blast survival.

CBRN systems add real-time radiological dosimetry, gamma spectroscopy detection, and modular filter cartridges rated for specific agent classes. The TEMET FP-100C used in our Citadel includes ASZM-TEDA carbon for chemical warfare agents (CWA), HEPA particulate filtration to MIL-STD-282 standards, and integrated dose-rate monitoring with audible alarms.

Apex decon airlocks measure 4 ft × 5 ft minimum with sealed compartmentalization, dedicated NBC-filtered ventilation, integrated low-pressure shower with grey-water containment, and contaminated clothing storage in sealed bags. Both interior and exterior doors have positive-pressure seals to prevent contamination crossover during transition.

Apex EMP shielding architecture: continuous-weld A572 Gr50 steel shell, RF-sealed door gaskets with beryllium-copper finger stock, EMI-filtered cable penetrations rated MIL-STD-461F, and isolated grounding architecture. Provides 80+ dB attenuation across 1 kHz – 10 GHz range. Tested per MIL-STD-188-125 specifications for HEMP protection.

Apex ERVs provide 80% sensible heat recovery, 70% latent (moisture) recovery, with HEPA-grade filtration on incoming air streams. CFM rated to deliver 8 air changes per hour for design occupancy. Includes CO₂ sensors for demand-controlled ventilation and integrated frost-prevention bypass for cold-climate operation.

A complete Faraday cage requires shielding effectiveness above 60 dB at frequencies from 14 kHz to 1 GHz for HEMP threats. Achieved through continuous-seam welds (no bolted joints), conductive door seals, EMI-filtered electrical penetrations, waveguide-below-cutoff treatments on ventilation paths, and grounded EMI bonding straps on all internal equipment.

Layer 1: SBS-modified bitumen membrane (60 mil) torch-applied to exterior shell. Layer 2: HDPE dimple drainage mat with non-woven geotextile filter fabric. Layer 3: 3" closed-cell SPF at R-21 minimum, applied to every interior steel surface. Layer 4: 10-mil vapor barrier at warm-side wall. Layer 5: ERV plus condensate-pump dehumidifier set point 45% RH ±5%. Annual exterior membrane inspection included in maintenance contract.

A HANE detonation at 400 km altitude produces three EMP components: E1 (fast-rise, ~5 ns to peak, 50 kV/m), E2 (intermediate, similar to lightning), E3 (slow geomagnetic disturbance, lasts seconds). The E1 component damages semiconductors directly through induced voltages. The E3 component damages long-line infrastructure (power grid, telephone lines). Hardened systems must protect against all three.

SDC D requires design for SDS ≥ 0.5g and SD1 ≥ 0.20g (short-period and 1-second spectral response accelerations). Mandatory provisions include continuous load paths, redundant lateral force-resisting systems, ductile detailing of connections, anchor bolts engineered for combined shear and tension, and flexible utility connections at the foundation interface. Engineering basis: ASCE 7-22.

Three-stage filtration: (1) pre-filter for large particulate, (2) HEPA filter at 99.97% efficiency for 0.3-micron particles, (3) activated carbon bed with ASZM-TEDA impregnation for chemical vapor adsorption. Maintains positive pressure at +0.03 inches water column. Sentinel uses ANDAIR VA-150 (150 m³/hr). Fortress uses VA-200 (200 m³/hr) plus HEPA. Citadel uses TEMET FP-100C CBRN-rated system. All include manual hand-crank backup.

Beyond filtration architecture, CBRN systems add real-time radiological dosimetry, gamma spectroscopy with isotope identification, modular CBRN-specific filter cartridges, and digital alert/logging systems. The TEMET FP-100C in our Citadel is rated to MIL-STD-282 standards. Sentinel and Fortress use NBC; Citadel upgrades to full CBRN.

Apex OPVs use spring-loaded poppet valves rated for closure within 10 ms of detected overpressure at 5 PSI threshold or above. Reset is automatic once external pressure normalizes. Independent of electrical power — fully mechanical operation. Tested per Swiss BSV-SVS standards.

PE stamps require the engineer to be licensed in the state where the project is built. Apex maintains PE relationships covering California, Texas, Arizona, Nevada, Florida, and most other primary markets. Each set of plans includes structural calculations (gravity, seismic, blast, soil pressure), fabrication shop drawings, and erection drawings — all stamped, signed, and dated.

Apex maintains interior pressure at +0.03 inches water column (approximately 7.5 Pa) above ambient. Monitored via differential pressure gauge with audible alarm if pressure drops below threshold. Achieved by sizing intake blower CFM 15-20% above exhaust path leakage rate. Pressure relief through dedicated pressure-relief vents prevents over-pressurization.

Apex closed-cell SPF specification: 2.0 lb/ft³ density, R-6.5/inch (aged), 3.0" minimum thickness for R-19.5 nominal, applied at 100% surface coverage. Class I fire rating per ASTM E84. Acts as thermal break, vapor retarder, air barrier, and acoustic dampening — four functions in one application. Application performed per the SPFA-101 quality standard.

Self-sufficiency period combines: (1) potable water storage at 1 gallon/person/day, (2) caloric food storage at 2,400 kcal/person/day, (3) primary power (PV array + LiFePO₄ battery bank), (4) backup diesel generator with 14-30 day fuel storage, (5) NBC filtration with 90-day filter element life. Fortress targets: 1,000 gal water, 720 person-days food, 40 kWh battery, 10 kW diesel, 14-day fuel reserve.

The 7-10 rule approximates radioactive decay of mixed fission products from a nuclear weapon. Based on the Way-Wigner formula: I(t) = I(1) × t^(-1.2), where I(t) is intensity at time t hours after detonation. Conservative for short-half-life isotopes; underestimates decay for the longer-lived fraction. After 14 days, residual radiation is dominated by Sr-90 and Cs-137 with multi-decade half-lives but at radiation levels that are survivable with NBC filtration.