January 1974

U.S. ATOMIC ENERGY COMMISSION 

'REGULATORY GUIDE 

DIRECTORATE OF REGULATORY STANDARDS 

REGULATORY GUIDE 3.16 

GENERAL FIRE PROTECTION GUIDE FOR PLUTONIUM 

PROCESSING AND FUEL FABRICATION PLANTS 

A. INTRODUCTION

Each applicant for a license to possess and use 

special nuclear material in a plutonium processing and 

fuel fabrication plant as defined in §70.4(r) of 10 CFR 

Part 70, "Special Nuclear Material," must satisfy the 

provisions of §70.23, "Requirements for the Approval 

of Applications." Paragraphs (aX3) and (4) of §70.23 

require that the applicant's proposed equipment and 

facilities and proposed procedures be adequate to 

protect health and minimize danger to life or property. 

At plutonium processing and fuel fabrication plants, 

a principal risk to health and safety is the release and 

dispersal of radioactive materials from a fire or 

explosion. Fire protection programs for these plants 

should prevent, detect, extinguish, limit, or control fires 

and explosions and their concomitant hazards and 

damaging effects. This guide presents methods 

acceptable to the Regulatory staff for complying with 

§§70.23(aX3) and (aX4) with respect to fire protection 

for plutonium processing and fuel fabrication plants. 

L. DISCUSSION 

The principal purposes of a fire protection program 

for a plutonium processing and fuel fabrication plant are 

the protection of the general public from radioactive and 

toxic material, protection of plant personnel, and 

protection against loss of confinement. 

Structures, systems, and components important to 

safety should be designed and located so they can 

continue to perform their safety functions effectively 

Under credible fire and explosion exposure conditions. 

Heat-resistant and noncombustible materials should be 

used wherever practical throughout the facility,

USAEC REGULATORY GUIDES 

Regulatomr Guides ae Issued to decibe and msks "laitis to tht pubic 

amtods acoeptable to the AEC Regulato suff of Imhpemnstn speaic parts of 

on. Commtisscn reaukatIiw. to delimete ftcUr.Iqu Wed bv the auW in 

ewauliagk gedhlic Probbemt of poatstatad accidents. or tlpovde- guidance to 

apkslwis. Reulatory Gwi dm nat Kmiautsia, ftor rtepulatiom a e wnpiere l 

mith them I not 8u8lird. Mathods Ond sohlusom different trom t at out in 

,Idmw~l besemlala Nthey proide a baue for the "Idnge oMgulai 01) 

=emi t" fa pulano prm or ",am by theCommission. 

Pubtishd =uldat will be revild parkodsllly. a appropriate. so accommodate 

eofwnwmi end to ma' fa w eorntrution or experience.

particularly in locations vital to the functioning of 

confinement barriers and systems, to methods of 

controlling radioactive materials within the facility, and 

to the maintenance of safety control functions. The 

adverse effects of fires and explosions on structures, 

systems, and components important to safety can be 

minimized by providing systems with sufficient capacity 

and capability for detecting and suppressing explosions 

and fires and. transmitting alarms to one or more central 

control areas. It is important in the design of the plant 

and fire-suppression systems to Include provisions to 

protect against adverse effects in the event of 

fire-suppression system operation or failure. 

Implementation of the above entails an evaluation 

of such factors as the expected maximum amount of 

combustible material in each area of the plant; severity, 

intensity, and duration of credible fires; assurance of 

confinement of radioactive and other potentially 

dangerous contaminants; arrangements and structural 

design features of buildings for control of smoke, heat, 

flame, and combustible and explosive gases; and systems 

for fire detection, confinement, control, and 

suppression. 

Water should be the principal fire suppressor, and 

special consideration should be given to selection of 

water sources, water distribution systems, fire pumps, 

and automatic and manual fire extinguidsing systems to 

control and extinguish a credible fire in any area. 

Automatic sprinkler or equivalent coverage should be 

provided throughout the facility with provisions for 

special hazard fire control measures where particular 

hazards exist.

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terdto the US. Awn*i 9 00 caiin~lon. mzWishnton VC- 20"58. 

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Attention: C¢i•. Pwdficv Rmeiap ant". 

The VAl*' we WooM i Me fo umbi On bind iXvidom: 

t. Poi•w Reactors L Podu 

2. Rmmerch mid Tast Reactors 7. 1importaon . Pueb and Materieal Pamltift 18. OMationl • asl 

4. Enrwronnental a•d "ot 3. Anttnat• Review 

L Maerisard Plant Pi ioan 10. General
Incipient fires may be controlled by portable fire 

extinguishers. This phase of fire control is particularly 

important, even though automatic sprinklers have been 

provided. Consideration should be given io the selection 

of portable fire extinguishers suitable for use on specific 

hazards that may be encountered. 

The need for fire detection devices and the type 

most desirable should be related to combinations of 

hazards involved, extinguishing controls available, and 

public and private fire departments. Various detection 

devices operating on different principles for detecting 

fire are available. These include the principles of fixed 

temperature, rate of temperature rise, presence of 

combustion and pyrolysis products, or various 

combinations of these principles. 

Fire protection systems may be subject to effects of 

natural phenomena such as seismic motion and floods, 

missiles, fire and explosion, and other accidents. These 

systems should continue to perform their safety 

functions effectively under credible accident conditions. 

Where possible, continuity of fire protection systems 

should be assured by such means as standby equipment 

and fail-safe control systems. 

The ability of the systems to perform their safety 

functions effectively can be assured by periodic testing 

of safety-related components during normal operation of 

the systems to demonstrate their ability to perform at 

design efficiency and to verify their availability for 

emergencies. 

An important aspect of a fire protection program is 

training of a fiue-fighting organization and maintenance 

of its competence with periodic drills. 

The fire protection program should provide for the 

ise of appliances, equipment, and materials listed by 

such testing organizations as the Underwriters' 

Laboratories, Inc. (UL) and the Factory Mutual 

Research Corp. (FM) as meeting their standards. 

Fire protection programs should conformnto the 

provisions of the following codes and standards as 

applicable: 

I. National Fire Codes of the National Fire 

Protection Association (NFPA). 

2. Fire Prevention Code of the American 

Insurance Association (AIA). 

3. Fire Protection Standards and Bulletins of the 

Factory Insurance Association (FIA). 

4. Standards of the American Petroleum Institute 

(API). 

5. One of the four model building codes: 

a. National Building Code of the AIA 

b. Uniform Building Code of the 

International Conference of Building 

Officials (ICBO) %

c. Southern Standard Building Code of the 

Southern Building Code Congress 

d. Basic Building Code of the Building 

Officials Conference of America 

C. REGULATORY POSITION 

Plutonium processing and fuel fabrication plants 

should be designed to assure the confinement of 

hazardous materials during normal or abnormal 

conditions including fires and explosions. The release of 

radioactive material to the environment or to an area in 

which levels of radioactivity are normally sufficiently 

low to permit personnel access should be reduced to a 

level as low as practicable in accordance with the 

provisions of 10 CFR Part 20. 

1. General Features 

a. Fire protection systems for plutonium 

processig and fuel fabrication plants should be designed 

to assure that any credible fire or explosion will not 

prevent the operation or use of structures, systems, 

equipment, and components whose continued integrity 

and/or operability are esential to assure confinement of 

radioactive materials, hereafter designated as "essential 

items." 

b. Where possible, each fire protection system 

should be designed so that the filure of any one 

component (equipment or control device) will not 

disable the entire fire protection system. Fire protection 

systems and components should have fall-safe features 

with provision for operation and trouble alarm 

indication. 

c. Onsite emergency power supply systems should 

be provided -to operate applicable fire protection systems 

and components as well as other systems and 

components important to safety. Fire protection 

systems should be capable of operating during normal 

power outage. The onsite emergency power sources and 

the electrical distribution circuits should have 

independence and testability to assre performance of 

their safety functions assuming any single failure. 

d. The design of fire-suppression systems should 

include provisions ,to protect agains adverse effects it 

the event of system operation or failure. For example, 

collection systems should be provided for runoff water 

in the event of normal or abnormal flow from an 

automatic sprinkler system. 

e. The fire protection systems should be designed 

to withstand tornado conditions without loss of 

operating capability due to mechanical damage to the 

systems or components to the extent that they will 

prevent the uncontrolled release of radioactive materials. 

f. Components of fire protection systems should 

be designed to withstand the effects of earthquakes and 

remain functional to the extent that they will prevent 

the uncontrolled release of radioactive materials. 

g. Criteria for fire protection equipment, systems, 

components, and programs should comply with the

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N.
inr t cr applicable provisions of the National Fit 

Cooe% of the NFPA. Fire protection appliance 

ecqaii.ment, and materials that have been examined b 

and meet the standards of such nationally recognize 

testing organizations as UL and FM should be used. 

2. Building Construction and Fadlities 

a. The plutonium processing and fuel fabricatio 

plant should be designed and constructed using buildir 

components of heat-resistant and noncombustibi 

material wherever practicable, particularly In locatiot 

vital to the functioning of confinement barriers an 

systems. 

b. Where practicable, materials and equipmer 

designed for minimum fire potential should be selectee 

Structural members including walls, partitions, column 

beams, floors, and roofs should be of noncombustibli 

fire-resistive construction with fire-resimace ratini 

sufficient for protection against credible fire exposure 

c. Assuming failure of any fire suppressio systei 

which is not designed as an essential item, the structur; 

shell (and Its supporting members) surrounding any ar4 

handling plutonium, where the plutonium could 1: 

accidentally dispersed and cause exposure to eith4 

operating personnel or the public, should be designe 

with sufficient fire resistance that it will remain standir 

and continue to act as a confinement structure durn 

any credible accident conditions resulting from fire 

The fire resistance rating of the shell shluld not be le: 

than 2 hours. I Penetrations in this shell thoul 

incorporate, as a minimum, equivalent protection again 

credible fire exposures. 

d. Suspended ceilings and their supports should t 

of noncombustible construction as listed by UL2 ( 

FM. 3 Insulation for pipes and ducts, sound attenuatir 

materials, and their adhesives should also t 

noncombustible. Concealed spaces should be devoid c 

combustibles. Materials used should have a rating of 2 

or less with respect to flame spread, fuel contributioi 

and smoke development. • 

e. Exits from plutonium processing areas an 

rooms should be strategically located so that radiatic 

exposure of personnel will be minimal during evacuatic 

of the area or room through a confinement barrier in tt 

event of a breach of processing equipment confinemem 

resulting from fires and explosions. Such a barrier woul 

be a partition separating two different air zones, Tt 

air flow through the barrier should be In the directio 

opposite to the exit travel. 

f Electrical wiring systems and their supportir 

members (i.e., conduits, trays, troughs, raceways, an 

distribution frames) servicing essential items should t 

protected against fire. Cable enclosures, fire stops at fu 

barrier walls, floors, and ceilings, an 

non-flame-propagating electrical insulation should I 

used in the design of electrical wiring systems t 

minimize the spread of fire. 

g. Structures, systems, equipment. an 

components in processing areas requiring hydraulii

e lubricating, cooling, and insulating fluids should be 

s, protected from fire and its spread by use of minimum 

y volumes of fluids, by use of fire-resistant fluids, by fire 

d barrier isolation, by provision for automatic fire 

suppression, and by installation of curbs, catch basins, or 

other confinement designs that minimize the spread of 

fluid leakage. 

h. Provision should be made for protection of the 

n plant against lightning damage. 

9g i. Protective barriers should be provided around 

k high-pressure or other potentially dangerous systems. 

is 

d 3. Ventilation Systems 

it The ventilation systems should be designed to 

d. withstand any credible fire and explosion and continue 

LS, to act as confinement barriers. Fire protection for 

C, ventilation systems is discussed in Regulatory Guide 

;s 3.12. 

n 4. Glove Boxes, Hoods, uad Other Pracem Endosuns 

:a a. Glove boxes and process'enclosures should be 

ie provided with fire stops in connecting tunnels to prevent 

er the spread of fire. The fire stops between enclosures 

:d should normally be dosed. Where operations require 

i that the fire stops be in the open position, they should 

4g be designed to be 'closed automatically upon operation 

s. of the fire-detection system. Provision should also be 

Is made for manual operation of fire stops. 

Id b. Chemical fume or particulate exhaust hoods 

st should be equipped with full-closing sashes and provided 

with fire detectors. Provisions should be made for 

ie manual fire suppression where fire or explosion hazards 

or exist. 

19 c. Additional fire protection features of glove 

le boxes and other process enclosures are disussed in 

)f Regulatory Guide 3.12. 

:5 

M9 S. Sprinkler System 

4d a. Automatic water sprinkler coverage ruing 

n components listed by UL ' or FM s' hiould be provided 

n throughout the facility except in areas where nuclear 

ke criticality or other hazards specifically preclude its use. 

it Nonaqueous systems, ruing components listed by UL ' 

d or FM 3 should be- used in areas not protected by 

Le automatic water sprinklers (see regulatory position C.6) 

n or for other special applications. 

b. Automatic water-type extinguishing systems 

Include wet-pipe, preaction sprinkler, open head deluge. 

d water spray, and systems utilizing automatic "on.off" 

e flow control. Selection of a specific type of system 

re should take into account parameters such as speed of 

d operation, ambient temperature, and required volume 

ie and optimum ue of water. 

0o c. Wet-pipe conventional automatic sprinklers 

should be used in nonprocess areas of the facility. 

d d. For process areas, the sprinkler system selected 

a, should minmnsze the quantity of water used, the 

3.16-3
,unitentional operation of sprinkler heads, the spread of 

contamination by water, the extent of cleanup 

,operations, and the possibility of criticality. 

6. Special Automatic Extinguishing Systems 

a. Areas not protected by automatic water 

sprinklers should be protected by some other fire 

suppression agents such as inert gas, carbon dioxide, 

high-expansion foam, or , halogenated organic 

compounds. 

b. Selection of a carbon dioxide extinguishing 

system should take into account such considerations as 

type of fire hazard, protection of personnel, and process 

enclosure pressurization. 

c. Selection of a halogenated extinguishing system 

should take into account such considerations as process 

enclosure pressurization, protection of personnel, type of fire hazard, adverse reaction with pyrophoric metals, 

and corrosive thermal decomposition products. 

d. For other special applications, such as solvent 

extraction areas, consideration should be given to inert 

gas, dry chemical, high-expansion foam, and "wet 

water" fire extinguishing systems. Dry chemical systems 

should not be used in the vicinity of filter installations in 

order to minimize fouling of filters. 

7. Fire Protection Water Systems 

a. Potable and process water systems should be 

arranged so they can be shut down without affecting the 

water supply to the fire systems. Fire protection water 

supply and distribution systems required for essential 

item protection should be designed and constructed so 

that continuity of protection in the event of any credible accident conditions is assured. 

b. The water supply for the permanent fire 

protection installation should have a minimum of two 

reliable, independent sources and sufficient capacity 

(based on the maximum water demand) for fire fighting 

until other sources of water become available. Water 

supplies containing salt or other materials deleterious to 

the fire protection systems should be avoided wherever 

possible. 

e. Water for fire fighting and fire suppression 

systems should be furnished to the site by a loop 

distribution system encircling the site buildings. 

Hydrants served by this system should be strategically 

located around the loop. Valves or valve assemblies listed 

by UL' or FM3 should be provided for proper 

sectional control of the loop. 

d. Fire water pumps should be equipped with 

automatic-starting features and be listed by ULI or 

FM 3 for fire service. Where water supply pressure is 

provided by pumps only, there should be a minimum of 

two pumps, at least: one of which should be driven by 

nonelectrical means, preferably diesel engine. Emergency 

power should be supplied to an electric-driven fire pump 

in the event of failure of the normal power supply (see 

regulatory position CJ.c)- Multiple fire' water pumps

should be selected so that the maximum water demand 

for firo fighting will be supplied with the largest pump 

out of service. 

Alarms for pump startup and operation and for 

power failure should be provided for the pump system 

and arranged to sound in a constantly attended location. 

A small pressurizing pump should be provided to 

automatically maintain the desired static pressure on the 

fue protection water supply system and minimize 

unnecessary operation of the fire water pumps. 

e. Water should be supplied to each water spray 

extinguishing system from the water main loop around 

the facility. A water spray system may be used for heat 

removal for the high-efficiency filtration system serving' 

as a final means of effluent cleaning for the ventilation 

systems. This water spray system should have a 

dedicated water supply, in addition to the normal water 

supply, sized to operate the system during a credible fire 

or explosion even if all other water supplies fail. 

f. Collection systems should be provided for 

runoff water from fire-fighting activities and all other 

water breaks or leaks in process areas. Nuclear criticality, 

confinement, sampling, volume determination, and 

retrievability of liquids and solids should be considered 

in the design of collection systems. The size of the 

collection system for fire-fighting water should be based 

on the maximum amount of water which could be used 

in fighting a credible fre. 

8. Manual Fire-Fighting Equipment 

a. Provision should be made for portable fire 

extingulshers listed by UL 6 or FM 3 and suitable for use 

on specific hazards that may be encountered. The 

number of fire extinguishers required should be 

determined considering the area and arrangement of the 

plant or occupancy, the severity of. the hazards, the 

anticipated classes of fires, and the distances to be 

traveled to reach extinguishers. 

b. Standpipe and hose systems using components 

listed by UL ' or FM 3 should be provided and Installed 

in both process and nonprocesa areas. Standpipes should 

be so located that they are protected against mechanical 

and fire damage. Hose outlets should be easily accessIle. 

9. Fin Detection, Signal, and Alrm Systems 

a. Provision should be made for fire detection and 

alarm systems using components listed by UL I or FM. ' 

These systems should consist of fire detectors, signaling 

devices, and audible and visual indicators in a constantly 

attended location, as well as in appropriate locations 

about the plant. A means should be provided to monitor 

the status and functioning of the fire-detection, signal, 

and alatm systems as well as other fire protection system 

components located throughout the plant. Provision 

should be made for periodic testing and checkout of 

these systems. 

b. A plant-wide public address and two-way 

communication system should be provided.

3.16.4

I'l.
c. Manual fire alarm stations should be installed 

throughout the facility at readily accessible locations. 

These stations should be connected to the plant-wide 

alarm system. 

d. Fires should be indicated audibly by alarms 

that are set off by fire suppression and detection 

systems. Each sprinkler system should be equipped with 

a flow alarm on the plant-wide alarm system. 

€. Glove boxes and enclosures should be equipped 

with fire and/or smoke detectors to provide both a local 

alarm and a zone and location signal on the plant-wlde 

alarm system. 

L. The inlet duct to a multistage high-efficiency 

filter plenum serving as a final means of effluent cleaning 

for the ventilation systems should be provided with heat 

and smoke detectors that actuate a local alarm and an 

automatic fire alarm station on the plant-wide alarm 

system. 

10. Gas-Handling Equipment 

a. Hydrogen should be prenixed to a 

-nonflammable percentage with inert gas prior to 

introduction into the plant. to control the potential 

hazard. The storage of unmixed gases should be external 

to the plant proper. Mixing should be performed before 

or at the plant entry point. 

b. A nonflammable inert-gas-H% mixture within 

the flammability limits of gases and vapors listed In 

Bureau of Mines Bulletins S03 1 and 627 9 should be 

used in reducing gas atmosphere furnaces to preclude a 

hydrogen explosion. This atmosphere should be 

monitored by a suitable continuous monitoring system 

as specified In Regulatory Guide 3.7. ' In the event that 

pure hydrogen is required for process reasons, an 

enclosed offgas burner or other suitable means of offgas 

disposal should be used. 

c. Entry of air into a furnace operating with 

reducing gas should be precluded by the ue of 

inert-ps-purged locks or other suitable means at the 

furnace entry and exit. Furnace gas should be exhausted 

through an enclosed, ditered offgas system. 

d. Process furnaces should be provided with a 

system for automatically shutting off the furnace gas 

and purging with inert gas in the event of power failure, 

loss of coolant water, loss of exhaust fan, 

overtemperature, or detection of hydrogen in the 

vicinity of the furnace. 

e. Flammable gas should not be introduced into 

plutonium processing'buildings except when specifically 

required for process reasons. 

11. Flammable Materials 

a. Special control should be exercised over the

handling of flammable, toxic, and explosive gases, 

chemicals, and materials admitted to the plutonium 

handling areas. Solvents and other flammable liquids, 

other than small quantities in use, should be stored in a 

separate building or unexposed storage area. Safety cam 

listed by UL I I or FM' should be used for flammable 

liquids. Where practicable, covered noncombustible 

containers listed by UL Ior FMs should be provided 

for combustible wastes. 

b. Provisions should be made for isolation 

between incompatible chemicals, materials, and, 

processes such a solvent extraction. 

c. Flammable and combustible materials should 

not be stored in finished product storage areas or 

shipping areas. 

12. Quality Anra= Program 

A quality assurance program should be established 

for the design, construction, testing, operation, and 

maintenance of all structures, systems, equipment, and 

components of fire protection systems in accordance 

with the criteria In Appendix B of 10 CFR Part SO. 

13. Procedures, Ospnlzation, and Training 

a. Fire emergency procedures should be 

established for plant personnel. A plant fire protection 

organization should be trained and equipped to deal 

effectively with fire or explosion emergencies. Selected 

personnel should be specifically tained in fire-fighting 

techniques, industrial hygiene, health physics, and 

nuclear safety. Operating personnel and new employees 

should be periodically inmtructed in the proper use of 

plant fire-fighting equipment and emergency fire 

procedure. Decontamination procedures should be 

covered in training programs. Drills should be held 

periodically. 

b. Arrangements should be made with offsite fie 

departments for assistance to the plant fire protection 

organization in the event of an onsite fire. Offilte fire 

departments should be familiarized with plant fire 

emergency procedures, fire protection organization. 

layout, and unusual hazards. Drills shiould be hell 

periodically. 

c. An approved recorded watchman service, 

central station supervisory service, or constant 

occupancy of all Important areas should be provided to 

maintain a satisfactory degree of surveillance of the 

property at all times. 

d. In establishing the programs in this section, 

consideration should be given to criteria implementing 

the Commission's regulations for the protection of 

special nuclear material in fuel manufacturing facilities. 

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. I I I I
REFERENCES

1. ANSI A2.1-1972, "Methods of Fire Tests of 

Building Construction and Maters," American 

National Standards Institute, (also designated ASTM 

El 19-71). Copies may be obtained from Am 

National Standards Institute, 1430 Broadway, Ne* 

York, N.Y. 10018. 

2. Underwriters' Laboratodes Building Materials List 

(latest edition). Copies may be obtained from 

Underwriters' Laboratorie Inc., 207 East Ohio 

Street, Chicago, Ill. 60611. 

3. Factory Mutual Approval Guide (latest edition) 

Copies may be obtained -from Factory Mutual 

Research Corporation, 1151 Boston-Providence 

Turnpie, Norwood, Mass. 02062. 

4. ASTM. E84-70, "Method of Test fot Surface 

Burning Characteristics of Building Materials," 

American Society for Testing and Materials. Copies 

may be obtained from American Society for Testing 

and Materials, 1916 Race Street, Philadelpha Pa. 

19103. 

S. Regulatory Guide 3.12, "General Design Guide for 

Ventilation Systems of Plutonium Processing and 

Fuel Fabrication Pats," Directorate of Regulatory 

Standards, USAEC.

6. Underwriters' Laboratories Fire Protection 

Equipment Lis (latest edition). Copies may be 

obtlined from Underwriters! Laboratories, Inc., 207 

East Ohb Street, ChicaSo, 1. 60611. 

7. IL F. Coward and G. W. Jones, "Limits of 

Flammability of Gases and Vapors," Bureau of 

Mines Bulletin 503. 1952. Copies may be obtained 

from the Superintendent of Documints, U.S. 

Government PAnting Office, Wuhington, D.C. 

20402. 

8.M. G. Zabetakis "Flammability Characteristics of 

Combustible Gum and Vapos," Bureau of Mines 

Bulletin 627, 1965. Copies may be obtained from 

the Superintendent of Documents, U.S. 

Government Printing Office, Washintoa, D.C. 

20402. 

9. Regulatory Guide 3.7. "Monitorin of Combustible 

Gases and Vapors in Plutonium Processing and Fuel 

Fabrication Pants," Directorate of Regulatory 

Standards, WSAEC. 

10. Underwriter' laboratories Gas and Oil Equipment 

List (latest edition). Copies may be obtained from 

Underwnters' Laboratories. Inc., 207 Fast Ohio 

Stree, Chicago, I1. 60611.

3.16-6

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