CHAPTER 4.
FALLOUT AND BLAST SHELTERS
Sections:
4-4.02 Building Permits: Required
4-4.03 Building Permits: Applications: Accompanying Data
4-4.04 Building Permits: Applications: Fees
4-4.07 Construction and Sales: Advertising: Certificates of Acceptance
4-4.08 Construction and Sales: Advertising: Information Required
4-4.09 Construction and Sales: Advertising: Adoption of Guides for Advertising Fallout Shelters
4-4.10 Family Shelters: Design Standards: Structural
4-4.11 Family Shelters: Design Standards: Ventilation
4-4.12 Family Shelters: Blast-Resistant: Design Standards: Ventilation
4-4.13 Family Shelters: Design Standards: Shielding
4-4.14 Family Shelters: Blast-Resistant: Design Standards: Shielding
4-4.15 Family Shelters: Design Standards: Waterproofing and Drainage
4-4.16 Family Shelters: Design Standards: Access Openings
4-4.17 Family Shelters: Blast-Resistant: Design Standards: Access Openings
4-4.18 Family Shelters: Occupancy Standards: Capacity
4-4.19 Family Shelters: Occupancy Standards: Services
4-4.20 Group Shelters: Design Standards: Structural
4-4.21 Group Shelters: Design Standards: Ventilation
4-4.22 Group Shelters: Blast-Resistant: Design Standards: Ventilation
4-4.23 Group Shelters: Design Standards: Shielding
4-4.24 Group Shelters: Blast-Resistant: Design Standards: Shielding
4-4.25 Group Shelters: Design Standards: Waterproofing and Drainage
4-4.26 Group Shelters: Design Standards: Access and Egress Openings
4-4.27 Group Shelters: Blast-Resistant: Design Standards: Access and Egress
4-4.28 Group Shelters: Occupancy Standards: Capacity
4-4.29 Group Shelters: Occupancy Standards: Services
4-4.30 Group Shelters: Blast-Resistant: Occupancy Standards: Services
4-4.01 Definitions.
For the purposes of this chapter, unless otherwise apparent from the context, certain words and phrases used in this chapter are defined as follows:
(a) “Blast-resistant shelter” shall mean a fallout shelter designed to protect its occupants against the effects of blast and associated initial nuclear and thermal radiation for a design overpressure of at least thirty (30) pounds per square inch.
(b) “Dual-purpose shelter” shall mean a structure designed to include nonshelter uses which would not interfere with the use of such shelter as a shelter.
(c) “Fallout shelter” shall mean a structure, room, or space designed to protect its occupants from fallout gamma radiation and offer a protection factor of at least one hundred (100).
(d) “Family shelter” shall mean a shelter designed for the use of a family.
(e) “Group shelter” shall mean a shelter designed for the use of ten (10) or more persons.
(f) “Limited blast-resistant shelter” shall mean a fallout shelter designed to protect its occupants against the effects of blast and associated initial nuclear and thermal radiation for a design overpressure of at least five (5) pounds per square inch.
(g) “Protection factor” shall mean the relative amount of fallout gamma radiation which would be received by a person in a shelter compared to the amount which he would receive if unprotected. For example, an unprotected person would be exposed to one hundred (100) times more radiation than a person in a shelter with a protection factor of one hundred (100).
(h) “Single-purpose shelter” shall mean a structure designed to shelter persons only during and subsequent to a war-caused disaster (extreme emergency).
(Sec. 7.10, E.T.C., as added by Sec. 1, Ord. 484)
4-4.02 Building Permits: Required.
No person shall construct a fallout, blast-resistant, or limited blast-resistant family shelter without first having obtained a permit from the City Engineer.
(Sec. 7.11, E.T.C., as added by Sec. 1, Ord. 484)
4-4.03 Building Permits: Applications: Accompanying Data.
An applicant for a building permit pursuant to Section 4-4.02 of this chapter shall submit to the City Engineer two (2) sets of plans which shall include the following:
(a) A plot plan showing the location of:
(1) The proposed shelter,
(2) The sewer, gas, and water lines,
(3) The drainage channels,
(4) The easements, and
(5) The other buildings on the property;
(b) A statement of the protection factor in the space to be occupied in the shelter, expressed as a whole number;
(c) A statement of the design overpressure loads;
(d) A statement of the design occupant capacity of the shelter; and
(e) The computations, stress diagrams, and other data sufficient to show the correctness of the plans.
(Sec. 7.12, E.T.C., as added by Sec. 1, Ord. 484)
4-4.04 Building Permits: Applications: Fees.
An application for a building permit pursuant to Section 4-4.02 of this chapter shall be accompanied by a permit fee determined in accordance with applicable City laws.
(Sec. 7.12, E.T.C., as added by Sec. 1, Ord. 484)
4-4.05 Locations.
(a) Underground Portions. Underground portions of a shelter, subject to structural requirements, may be located anywhere on a parcel of property. Mound covers, entrances, or exits aboveground shall not be located within any required side yard if the aggregate width of the side yard is fifteen feet (15') or less. Mound covers or accessory portions located in any required setback (front yard) shall not exceed thirty-six inches (36") in height.
(b) Aboveground Shelters. Aboveground shelters shall be subject to the zoning requirements for accessory structures as set forth in Chapter 4 of Title 9 of this Code and to the requirements of this chapter.
(c) Variances. Variances from the provisions of this section may be granted in accordance with applicable City laws.
(Sec. 7.15, E.T.C., as added by Sec. 1, Ord. 484)
4-4.06 Occupancy Standards.
A family shelter designed for single-purpose use only shall be considered a Group J Occupancy under the Uniform Building Code provided such shelter does not exceed two hundred fifty (250) square feet in gross floor area in the portions of the shelter to be occupied. A shelter designed for dual-purpose use shall conform to the occupancy standards set forth for the use of the structure, other than as a shelter.
(Sec. 7.13, E.T.C., as added by Sec. 1, Ord. 484)
4-4.07 Construction and Sales: Advertising: Certificates of Acceptance.
Any person offering for sale a shelter or any structure purporting to be a shelter, or offering to construct or install a shelter, shall not represent or advertise such shelter as an approved shelter, unless he shall have obtained a certificate of acceptance from the City Engineer.
(Sec. 7.14, E.T.C., as added by Sec. 1, Ord. 484)
4-4.08 Construction and Sales: Advertising: Information Required.
Any person offering to sell or construct a shelter pursuant to the provisions of this chapter shall include the following information in all plans, brochures and other advertising:
(a) A statement of the radiation attenuation factor in the occupiable portion of the shelter, expressed as a number;
(b) A statement of the design overpressure loads, determined from a review of the advertised plans submitted to the City Engineer;
(c) A certificate of a registered civil engineer stating that the plans are structurally adequate for all necessary live and dead loads and earth or fluid pressures and that the design conforms to the structural requirements of the Uniform Building Code for loads, stresses, and materials and, in addition, the design overpressures for blast shelters; and
(d) A statement of the design occupant capacity of the shelter.
(Sec. 7.14, E.T.C., as added by Sec. 1, Ord. 484)
4-4.09 Construction and Sales: Advertising: Adoption of Guides for Advertising Fallout Shelters.
That certain document entitled “Guides for Advertising Fallout Shelters,” adopted by the Federal Trade Commission in December of 1961, is hereby adopted by reference and made a part of this chapter as though set forth in this chapter in full.
(Sec. 7.14, E.T.C., as added by Sec. 1, Ord. 484)
4-4.10 Family Shelters: Design Standards: Structural.
Family shelters shall comply with the following structural design standards:
(a) Load. All family shelters shall be strong enough to withstand all necessary dead loads and superimposed live loads, including earth and fluid pressures, in accordance with the appropriate requirements of the Uniform Building Code.
(b) Type of Construction. The main and secondary members of the structure shall be of incombustible materials. The combustible materials shall be limited to furniture, shelving, cabinets and nonbearing partitions.
(c) Stress. The stresses to be used in the materials for limit load conditions and the design procedures to be used shall be as approved by the Department of Defense, Office of Civil Defense, as set forth in Pamphlet TR-11, dated May 1961, and entitled “Recommended OCDM Specifications for Blast-Resistant Structural Design.” The concepts of “ultimate design,” “limit design,” and “plastic design” and the procedures of design which are set forth in said Pamphlet TR-11 are hereby adopted by reference and made a part of this chapter as though set forth in this chapter in full as such concepts and procedures apply to single-purpose shelters and dual-use shelters, so long as the resultant design complies with said Building Code requirements for nonshelter use. Family shelters offering resistance to blast shall be capable of withstanding the design overpressure without structural collapse. Vent pipes, doors, and other equipment associated with such shelters shall be designed to perform satisfactorily at the same overpressure range.
(Sec. 7.16, E.T.C., as added by Sec. 1, Ord. 484)
4-4.11 Family Shelters: Design Standards: Ventilation.
Family shelters shall comply with the following ventilation design standards:
(a) Standards. All family shelters shall be provided with a ventilation system capable of manual operation which will, under service conditions, maintain the effective temperature at or below eighty-five degrees Fahrenheit (85 F) effective temperature and the carbon dioxide (CO2) buildup at or below three percent (3%). Intake and exhaust systems shall be at opposite ends of the shelter with the intake opening twelve inches (12") above the floor and the exhaust opening not more than twelve inches (12") below the ceiling.
(b) Filters. Each ventilation intake system shall be provided with a dust filter capable of screening out at least ninety percent (90%) of fifty (50) micron particles or larger. Filters shall be placed or shielded so that the radiation contribution from the filter will not exceed the design shielding of the entire shelter.
(c) Intake and Exhaust Pipes. Ventilation intake and exhaust pipes shall have a minimum diameter of three inches (3"), protrude a minimum of two feet (2') above the ground surface, and be hooded in such a manner as to preclude the direct entry of particles. Intake and exhaust pipes shall have direct access to the atmosphere outside of any building.
(Sec. 7.16, E.T.C., as added by Sec. 1, Ord. 484)
4-4.12 Family Shelters: Blast –Resistant: Design Standards: Ventilation.
Family shelters offering resistance to blast shall be constructed so that the openings to the atmosphere shall be provided with appropriate devices to prevent a buildup of pressure within the shelter to no greater than five (5) pounds per square inch. The intake and exhaust shall be capable of manual retraction to a protected position at or below the external surface of the shelter or shall be otherwise adequately protected against flying objects incident to nuclear detonations. Intake and exhaust shall be so located as to make it unlikely they will be covered with rubble.
(Sec. 7.16, E.T.C., as added by Sec. 1, Ord. 484)
4-4.13 Family Shelters: Design Standards: Shielding.
Family shelters shall have a protection factor of at least one hundred (100) in the portion of the shelter to be occupied. In the calculation of the protection factor, the radiation dose contribution to the shelter occupants coming from the entrance ways, ventilation ducts, or other openings in the barriers of the shelter shall be considered. Entrances shall be adequately offset or baffled.
(Sec. 7.16, E.T.C., as added by Sec. 1, Ord. 484)
4-4.14 Family Shelters: Blast –Resistant: Design Standards: Shielding.
Blast-resistant and limited blast-resistant family shelters shall have a protection factor of at least one thousand (1,000) in the portion of the shelter to be occupied and shall comply with the provisions of Section 4-4.13 of this chapter.
(Sec. 7.16, E.T.C., as added by Sec. 1, Ord. 484)
4-4.15 Family Shelters: Design Standards: Waterproofing and Drainage.
Family shelters shall be adequately protected against the seepage of groundwater or flow of surface water into the structure. The shelter covers shall be graded, drained, or otherwise arranged so that the water will not drain onto adjacent property or cause erosion.
(Sec. 7.16, E.T.C., as added by Sec. 1, Ord. 484)
4-4.16 Family Shelters: Design Standards: Access Openings.
One (1) access opening to family shelters shall comply with the following requirements:
(a) Open to the outside without passing through a dwelling or other structure;
(b) Be at least twenty-four inches (24") in its minimum dimension; and
(c) Be operable from inside the shelter without the use of a key.
(Sec. 7.16, E.T.C., as added by Sec. 1, Ord. 484)
4-4.17 Family Shelters: Blast –Resistant: Design Standards: Access Openings.
Access openings in blast-resistant and limited blast-resistant family shelters shall have an attached overlapping closure properly constructed to withstand the design overpressure. A secure latching device shall be provided to sustain the negative pressures incident to the detonation. Such shelters offering resistance to blast with access ways to existing buildings shall be provided with closures which will heat-isolate the shelter chamber from the associated building.
(Sec. 7.16, E.T.C., as added by Sec. 1, Ord. 484)
4-4.18 Family Shelters: Occupancy Standards: Capacity.
Family shelters shall provide a minimum of ten (10) square feet of floor area and sixty-five (65) cubic feet net of volume per person sheltered. The ceiling heights shall be a minimum of six and one-half feet (6-1/2') for rectangular construction or at the crown of arched construction. In addition, one and one-half (1-1/2) cubic feet of space per person shall be provided for the storage of basic shelter supplies.
(Sec. 7.17, E.T.C., as added by Sec. 1, Ord. 484)
4-4.19 Family Shelters: Occupancy Standards: Services.
Family shelters shall comply with the following occupancy standards for services:
(a) Movable Equipment and Supplies. Movable equipment and supplies should be provided as recommended by the Director of Civil Defense and Disaster.
(b) Water Storage. Water storage containers shall be nonfrangible unless special provisions are made to minimize the possibility of breakage. In fallout shelters, water may be stored in the shelter itself.
(c) Water Storage, Blast-Resistant Shelters. In shelters offering resistance to blast, water shall be stored by either of the following methods:
(1) In suitable containers within the protected areas; or
(2) In buried tanks outside the shelter, in which case the storage tanks and associated piping shall be able to sustain the design overpressure without leakage.
(d) Garbage, Trash and Waste Disposal. Provisions shall be made for the collection and disposal of garbage, trash and human waste in such a manner as to preclude the creation of insanitary conditions and offensive odors within the shelter. In all shelters such system shall be self-contained and not connected with any public sewer system.
(e) Lights, Radios and Heating Appliances. Battery-operated lights and radios may be used. No light source or heating appliance capable of depleting the oxygen content of the air shall be installed or used.
(Sec. 7.17, E.T.C., as added by Sec. 1, Ord. 484)
4-4.20 Group Shelters: Design Standards: Structural.
Group shelters shall comply with the following structural design standards:
(a) Load. All group shelters shall be strong enough to withstand all necessary dead loads and superimposed live loads, including earth and fluid pressures, in accordance with the appropriate requirements of the Uniform Building Code.
(b) Type of Construction. The main and secondary members of the structure shall be of incombustible materials. The combustible materials shall be limited to furniture, shelving, cabinets and nonbearing partitions.
(c) Stress. The stresses to be used in the materials for limit load conditions and the design procedures to be used shall be as approved by the Department of Defense, Office of Civil Defense, as set forth in Pamphlet TR-11, dated May 1961, and entitled “Recommended OCDM Specifications for Blast-Resistant Structural Design.” The concepts of “ultimate design,” “limit design,” and “plastic design” and the procedures of design which are set forth in said pamphlet are hereby adopted by reference and made a part of this chapter as though set forth in this chapter in full as such concepts and provisions apply to single-purpose shelters and dual-use shelters so long as the resultant design complies with said Building Code requirements for nonshelter use. Group shelters offering resistance to blast shall be capable of withstanding the design overpressure without structural collapse. Vent pipes, doors and other equipment associated with such shelters shall be designed to perform satisfactorily at the same overpressure range.
(Sec. 7.18, E.T.C., as added by Sec. 1, Ord. 484)
4-4.21 Group Shelters: Design Standards: Ventilation.
Group shelters shall comply with the following ventilation design standards:
(a) Prevention of Vitiated Air. Provisions shall be made to prevent the buildup of vitiated air to a level hazardous to the occupants. The buildup of carbon dioxide (CO2) shall not exceed three percent (3%).
(b) Intake and Exhaust. Ventilation intake and exhaust shall be designed in such a manner as to preclude the direct entry of particles and shall have direct access to the atmosphere outside any building at a minimum height of two feet (2') above the surface.
(c) Filters. Filters capable of removing at least ninety percent (90%) of fifty (50) micron particles shall be provided in the air intake. The filters shall be placed or shielded so that the radiation contribution from the filter shall not exceed the design shielding of the entire shelter.
(d) Temperature Maintenance. The ventilation system shall be so designed that the effective temperature in the shelter when fully occupied shall not exceed eighty-five (85)(E T), nor shall it be maintained for periods longer than four (4) hours during the twenty-four (24) hour design period.
(e) Design Criteria. The design shall be based on the following criteria:
(1) A twenty-four (24) hour “steady state” heat transfer condition, whereby the net input does not exceed the output, is assumed; and
(2) Static conditions for the twenty-four (24) hour design period:
(i) Outside dry-bulb (DB) and wet-bulb (WB) temperatures in degrees Fahrenheit shall be taken at the ten percent (10%) level of temperature design data which are included in the following table:
|
|
DB |
WB |
|---|---|---|
|
Alameda |
80 |
59 |
|
Berkeley |
70 |
61 |
|
Fairfield |
84 |
65 |
|
Oakland |
70 |
61 |
|
Pittsburg |
90 |
67 |
|
Pleasanton |
89 |
64 |
|
San Francisco |
67 |
60 |
|
San Rafael |
77 |
66 |
|
Santa Rosa |
71 |
61 |
|
Sunnyvale |
84 |
65 |
(ii) The heat transfer rate for underground shelters shall be taken nominally as five (5) BTU per hour per square foot of surface of the occupied enclosure immediately adjacent to soil of normal thermal state. Such figure shall not preclude the use of higher or lower values known for the specific construction site.
(iii) The heat transfer rate for aboveground shelters shall be taken from the “American Society of Heating and Refrigeration Engineers (ASHRAE) Guide.”
(iv) The heat input per person at eighty-five (85) (E T) is assumed as one hundred eighty (180) BTU per hour sensible, two hundred twenty (220) BTU per hour latent.
(v) Miscellaneous heat input may be determined from said ASHRAE Guide or be computed for actual conditions.
(vi) In the event the ventilating conditions cannot be met, the designer shall present air treatment plans suitable for the shelter at the construction site proposed.
(Sec. 7.18, E.T.C., as added by Sec. 1, Ord. 484)
4-4.22 Group Shelters: Blast –Resistant: Design Standards: Ventilation.
Group shelters offering resistance to blast shall be constructed so that openings to the atmosphere shall be provided with appropriate devices to prevent an increase of pressure within the shelter of no greater than five (5) pounds per square inch. The intake and exhaust shall be constructed for manual retraction, or be automatic with auxiliary manual retraction to a protected position at or below the external surface of the shelter, or be otherwise adequately protected against flying objects incident to nuclear detonations. The intake and exhaust shall be so located as to make it unlikely they will be covered with rubble.
(Sec. 7.18, E.T.C., as added by Sec. 1, Ord. 484)
4-4.23 Group Shelters: Design Standards: Shielding.
Group shelters shall have a protection factor of at least one hundred (100) in the portion of the shelter to be occupied. In the calculation of the protection factor, the radiation dose contribution to the shelter occupants coming from the entranceways, ventilation ducts, or other openings in the barriers of the shelter shall be considered. Entrances shall be adequately offset or baffled.
(Sec. 7.18, E.T.C., as added by Sec. 1, Ord. 484)
4-4.24 Group Shelters: Blast –Resistant: Design Standards: Shielding.
Blast-resistant and limited blast-resistant group shelters shall have a protection factor of at least one thousand (1,000) in the portion of the shelter to be occupied and shall comply with the provisions of Section 4-4.23 of this chapter.
(Sec. 7.18, E.T.C., as added by Sec. 1, Ord. 484)
4-4.25 Group Shelters: Design Standards: Waterproofing and Drainage.
Group shelters shall be adequately protected against the seepage of groundwater or flow of surface water into the structure. The shelter covers shall be graded, drained, or otherwise arranged so that the water will not drain onto adjacent property or cause erosion.
(Sec. 7.18, E.T.C., as added by Sec. 1, Ord. 484)
4-4.26 Group Shelters: Design Standards: Access and Egress Openings.
Access and egress openings to group shelters shall be so designed that, as a minimum, the total number of persons constituting the designed capacity of the shelter may enter in approximately five (5) minutes, using aisleways based on a twenty-two inch (22") unit width, the space required for the free travel of one file of persons. In no case shall a single-file access or egress width be less than twenty-four inches (24"); nor shall there be less than two (2) widely separated means of egress. Egress openings shall be operable from the inside without the use of a key or special knowledge or effort.
(Sec. 7.18, E.T.C., as added by Sec. 1, Ord. 484)
4-4.27 Group Shelters: Blast –Resistant: Design Standards: Access and Egress.
Access and egress openings in blast-resistant and limited blast-resistant group shelters shall have an attached overlapping closure properly constructed to withstand the design overpressure. A secure latching device shall be provided to sustain the negative pressures incident to the detonation. Such shelters offering resistance to blast with access ways to existing buildings shall be provided with closures which will heat-isolate the shelter chamber from the associated building.
(Sec. 7.18, E.T.C., as added by Sec. 1, Ord. 484)
4-4.28 Group Shelters: Occupancy Standards: Capacity.
Group shelters shall provide a minimum of ten (10) square feet of floor area and sixty-five (65) cubic feet net of volume per person sheltered. The ceiling heights shall be a minimum of six and one-half feet (6-1/2') for rectangular construction or at the crown of arched construction. In addition, one and one-half (1-1/2) cubic feet of space per person shall be provided for the storage of basic shelter supplies.
(Sec. 7.19, E.T.C., as added by Sec. 1, Ord. 484)
4-4.29 Group Shelters: Occupancy Standards: Services.
Group shelters shall comply with the following occupancy standards for services:
(a) Movable Equipment and Supplies. Movable equipment and supplies should be provided as recommended by the Director of Civil Defense and Disaster.
(b) Water Storage. Water storage containers shall be nonfrangible unless special provisions are made to minimize the possibility of breakage. In fallout shelters, water may be stored in the shelter itself.
(c) Garbage, Trash and Waste Disposal. Provisions shall be made for the collection and disposal of garbage, trash, and human waste in such a manner as to preclude the creation of insanitary conditions and offensive odors within the shelter.
(d) Emergency Power. Emergency power shall be provided to operate at least the following systems for a period of fourteen (14) days of continuous operation:
(1) Required ventilation demand;
(2) Required lighting;
(3) Emergency water supply when a well is provided; and
(4) Emergency sewage ejection when provided.
Engine generators set for emergency power shall have separate vents to the outside air and be heat-isolated from the main shelter chamber. Proper consideration shall be given to the installation of engine generator sets and fuel tanks to minimize hazards from exhaust gases and fire. A fourteen (14) day supply of fuel shall be provided. Minimum repair parts for the engine generator set shall be provided.
(e) Emergency Lighting. Emergency lighting shall be provided at the following minimum levels:
(1) For sleeping areas, two (2) footcandles;
(2) For activity areas (floor level), five (5) footcandles; and
(3) For administrative and medical areas (desk level), twenty (20) footcandles.
(f) Light Sources and Heating Appliances. No light source or heating appliance capable of depleting the oxygen content of the air shall be installed or used.
(g) Electrical Systems. The electrical system may be connected to standard commercial power sources.
(Sec. 7.19, E.T.C., as added by Sec. 1, Ord. 484)
4-4.30 Group Shelters: Blast –Resistant: Occupancy Standards: Services.
Group shelters offering resistance to blast shall comply with the following occupancy standards for services:
(a) Water Storage. Water shall be stored by either of the following methods:
(1) In approved containers within the protected area;
(2) In buried tanks outside the shelter, in which case the storage tanks and associated piping shall be able to sustain the design overpressure without leakage; or
(3) In a properly protected well with associated piping and storage tanks, so designed as to permit drawing water inside the shelter.
(b) Sewage. Sewage systems connected to public sewage lines shall contain appropriate check valves capable of withstanding the design overpressure.
(Sec. 7.19, E.T.C., as added by Sec. 1, Ord. 484)