ML14323A176

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

OFFICE OF NEW REACTORS

WASHINGTON, DC 20555-0001

February 4, 2015

NRC INFORMATION NOTICE 2015-02: ANTIFREEZE AGENTS IN FIRE WATER 

SPRINKLER SYSTEMS 

ADDRESSEES

All holders of, and applicants for a specific source material license under Title 10 of the Code of 

Federal Regulations (10 CFR) Part 40, “Domestic Licensing of Source Material.”

All holders of an operating license or construction permit for a nuclear power reactor issued 

under 10 CFR Part 50, “Domestic Licensing of Production and Utilization Facilities,” including 

those that have permanently ceased operations and certified that fuel has been permanently 

removed from the reactor vessel.

All holders of, and applicants for an operating license for non-power reactors (research reactor, 

test reactor, or critical assembly) under 10 CFR Part 50, except those that have permanently 

ceased operations and have returned all of their fuel to the U.S. Department of Energy. 

All holders of, and applicants for a power reactor combined license, standard design approval, 

or manufacturing license under 10 CFR Part 52, “Licenses, Certifications, and Approvals for 

Nuclear Power Plants.” All applicants for a standard design certification, including such 

applicants after initial issuance of a design certification rule.

All holders of, and applicants for a fuel cycle facility license under 10 CFR Part 70, “Domestic 

Licensing of Special Nuclear Material.”

All applicants for a construction permit for utilization or production facilities intended for medical 

radioisotope production under 10 CFR Part 50 and 10 CFR Part 70.

PURPOSE

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to inform 

addressees of recent Tentative Interim Amendments (TIAs) issued by the National Fire 

Protection Association (NFPA) Standard Council to NFPA Standard 13, “Standard for the 

Installation of Sprinkler Systems” (NFPA 13), and NFPA Standard 25, “Standard for the 

Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems” (NFPA 25). 

The NRC expects recipients of this IN to review the information for applicability to their facilities 

and consider actions, as appropriate to avoid similar problems. However, suggestions 
IN 2015-02 

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contained in this IN do not constitute NRC requirements; therefore, no specific action or written 

response is required.

DESCRIPTION OF CIRCUMSTANCES

The intent of antifreeze sprinkler systems is to protect sprinkler piping that passes through areas 

that could be exposed to freezing temperatures. For example, antifreeze sprinkler systems may 

be used in freezers, loading docks, unheated warehouses, elevator shafts, or unconditioned 

areas. Sprinkler systems utilizing antifreeze agents may be present at some NRC licensed 

facilities; however, antifreeze sprinkler systems would not typically be installed in safety-related 

areas. The NRC is using this IN to heighten awareness and inform licensees of the issue. 

NFPA 13 only permits the use of non-toxic antifreeze solutions. NFPA 13 references NFPA 25 

for regular inspection, testing and maintenance requirements of antifreeze sprinkler systems to 

verify that an antifreeze sprinkler system has the proper concentration of antifreeze solution.

NFPA began researching the possible effects of antifreeze use in sprinkler systems in 2009. 

NFPA found that concentrations of 70 percent glycerine or 60 percent propylene glycol in water 

may be ignited when discharged through sprinkler systems resulting in a substantial fire event.

Glycerine and propylene glycol, in pure form, are Class IIIB combustible liquids having 

flashpoints of 390° Fahrenheit (F) (199° Celsius (C)) and 210° F (99°C) respectively. 

Depending upon concentration, the addition of water limits the flammability of each compound. 

NFPA 13 recognizes that in some instances antifreeze solutions may contribute to a fire 

condition, but that the supply of water following the antifreeze solution mitigates the contribution 

to the fire.

Following NFPA’s completion of full-scale fire tests, the NFPA issued TIAs in March 2011 on 

NFPA 13 and NFPA 25. The most current provisions regarding antifreeze are contained in 

the 2013 Edition of NFPA 13 and the 2014 Edition of NFPA 25. The changes to the NFPA 

codes that may be applicable to licensed facilities for existing construction are as follows1

:

New Sprinkler Systems (i.e., installed after September 30, 2012) Containing 

Antifreeze – NFPA 13 . . . Sprinkler Systems

With limited exceptions, all new antifreeze systems (systems installed after 

September 30, 2012) are required to use listed antifreeze solutions. The listing 

of the antifreeze solution must indicate that the solution will not ignite when 

discharged from a sprinkler. The exceptions to the requirement for listed 

antifreeze solutions are as follows:

• Factory premixed antifreeze solutions of propylene glycol in excess of 40%

by volume are permitted in ESFR (Early Suppression Fast Response) 

sprinkler systems where the sprinklers are listed for such use in a specific 

application. The listing will indicate the maximum percentage of propylene 

glycol that can be used with the specific sprinkler. . . . 

 1 The following text on existing and new sprinkler systems is an excerpt from www.nfpa.org/antifreeze, 

January 2014
IN 2015-02 

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• . . . New systems, once installed, must be annually tested in the manner 

required for existing systems, summarized below.

Existing NFPA 13 . . . Sprinkler Systems

The testing and maintenance provisions for NFPA 13...antifreeze systems are 

governed by NFPA 25. NFPA 25 provides that, by September 2022, existing 

systems (systems installed [before] September 30, 2012), like new systems, will 

be required to use only listed antifreeze solutions. Until then, traditional 

antifreeze solutions may continue to be used where certain conditions, confirmed 

by annual testing, have been met, summarized as follows.

Until a listed non-combustible solution is introduced into the system, antifreeze 

solutions in existing systems must be tested annually, prior to the onset of 

freezing weather.

• If it is determined, based on records, tests or other reliable information that 

the solution found in the system is no longer permitted or if the type of antifreeze cannot be reliably determined, the system must be drained and 

replaced with an acceptable factory premixed solution. 

• If the initial review indicates that the solution type is acceptable, test samples 

must be taken at the top and bottom of each system (in some cases an 

additional sample must be taken).

• If all the test samples indicate a concentration of glycerine not greater than 

38% by volume or propylene glycol not greater than 30% by volume, then the 

solution is permitted and may remain in the system. 

• Where the test samples indicate that the solution is between 38% and 50% 

glycerine or 30% and 40% propylene glycol, the solution may remain in the 

system pending the approval of a deterministic risk assessment (see NFPA 

25: 5.3.4.2.1(3)).

• If any of the samples indicate a concentration in excess of 50% glycerine or 

40% propylene glycol, the system must be emptied and refilled with an 

acceptable solution or an alternate method of freeze protection must be 

employed. An acceptable solution would be a solution that contains less than 

38% glycerine or 30% propylene glycol, or a solution that has been approved 

by the AHJ based on a deterministic risk assessment.

• All traditional antifreeze solutions must be replaced by listed antifreeze 

solutions, or alternative freeze protection methods, by September 2022.

BACKGROUND 

As stated in 10 CFR 50.48, “Fire protection,” each operating nuclear power plant must have a 

fire protection plan that satisfies Criterion 3, “Fire protection,” in Appendix A, “General Design 

Criteria for Nuclear Power Plants,” to 10 CFR Part 50. The purpose of these requirements is to 

minimize the probability and effects of fires. 
IN 2015-02 

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10 CFR 40.32, “General requirements for issuance of specific licenses,” and 10 CFR Part 70

Subpart H, “Additional Requirements for Certain Licensees Authorized To Possess a Critical 

Mass of Special Nuclear Material,” establish the NRC's fire protection program requirements for 

fuel cycle facilities. The purpose of these requirements is to safeguard any nuclear material on 

site and protect the public from radioactive releases due to a fire event.

NUREG-1537: Part 1, "Guidelines for Preparing and Reviewing Applications for the Licensing of 

Non-Power Reactors: Format and Content,” February 1996 (Agencywide Documents Access 

and Management System (ADAMS) Accession No. ML042430055) describes the fire protection 

guidance for non-power reactors. Fire protection guidance for medical radioisotope production 

facilities is described in the Final Interim Staff Guidance Augmenting NUREG-1537, Part 1, 

“Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors:

Format and Content,” for Licensing Radioisotope Production Facilities and Aqueous 

Homogeneous Reactors, October 2012 (ADAMS Accession No. ML12156A069). These 

facilities are expected, at a minimum, to be in compliance with all local building and fire codes. 

Although there is no NRC requirement to do so, these facilities may also make a commitment to 

follow nationally recognized codes and standards in order to demonstrate reasonable assurance 

of fire safety.

DISCUSSION

Existing research and testing performed by NFPA suggests that under certain conditions, 

antifreeze-water mixtures discharged from fire sprinklers can accelerate a fire when sprayed 

onto a flame. Increasing the concentration of the antifreeze in the antifreeze-water solution 

increases the combustibility of the solution. Additionally, existing research indicates that under 

certain conditions, the energy release rate of some fires increases upon interaction with 

antifreeze-water mixtures.

For nuclear power plants, non-power reactors, medical radioisotope production facilities, and 

fuel cycle facilities in areas where temperatures routinely go below freezing, some licensees 

may have determined that antifreeze is a necessary feature to ensure that sprinklers will 

operate in the event of a fire. NFPA standards indicate that annual testing is part of 

maintenance of sprinkler systems with antifreeze to determine the concentration of antifreeze 

agent present. NFPA recommends that samples be taken at the highest and lowest practical 

elevations of the system since antifreeze solutions can be unevenly distributed, resulting in 

pockets with high antifreeze concentrations. If the limits are above those from the NFPA TIA,

licensees may drain their sprinkler system and replace it with a premixed water-antifreeze 

solution as prescribed in the second TIA. Doing so would reduce the risk of fire-spread or 

explosion due to excessive concentration of antifreeze in the sprinkler discharge.

For locations where the new antifreeze concentration limits are not sufficient to prevent freezing 

of sprinkler systems, the NFPA suggests pipe insulation, heating systems, or the use of dry pipe 

or pre-action systems as alternatives. For existing antifreeze systems that have antifreeze 

concentrations that exceed the information in the recent NFPA TIA, NFPA states that the 

sprinkler system, “must be emptied and refilled with an acceptable solution or an alternative 

method of freeze protection must be employed.” “Information Notice 2013-06: Corrosion in Fire 

Protection Piping Due to Air and Water Interaction,” provides information regarding concerns 
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when fire protection piping is drained and refilled and air remains in the piping. In addition, 

although this IN is not a regulatory requirement, it informs licensees of the potential of antifreeze 

from such systems to be combustible, and therefore, consideration of antifreeze as a 

combustible would be treated in accordance with a facility’s fire protection program.

At the time this IN was issued, several listed factory premixed antifreeze solutions were on the 

market. For new sprinkler systems that require the use of antifreeze, NFPA recommends 

alternative measures, such as those described in the previous paragraph. NFPA 13, 9.2.2.3

states that the concentration of antifreeze solutions shall be limited to the minimum necessary 

for the anticipated minimum temperature

This is an ongoing issue, with updates available through NFPA (http://www.nfpa.org/antifreeze). 

It is recommended that licensees keep up-to-date with the newest developments. For additional 

information, licensees can read the applicable TIAs for the complete set of proposed code 

changes and visit the NFPA website for updates (http://www.nfpa.org/codes-andstandards/standards-development-process/tias-errata-and-fis).

CONTACTS

This IN requires no specific action or written response. If you have any questions about the 

information in this notice, please contact the technical contact listed below or the appropriate 

NRC regional office.

/RA/ /RA/

Michael C. Cheok, Director Lawrence E. Kokajko, Director

Division of Construction Inspection Division of Policy and Rulemaking

and Operational Program Office of Nuclear Reactor Regulation

Office of New Reactors

/RA/

Marissa G. Bailey, Director

Division of Fuel Cycle Safety, Safeguards,

 and Environmental Review

Office of Nuclear Material Safety

 and Safeguards

Technical Contact: Mollie Semmes, NMSS/FCSE

 (301) 287-9107

 mollie.semmes@nrc.gov
IN 2015-02

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when fire protection piping is drained and refilled and air remains in the piping. In addition, 

although this IN is not a regulatory requirement, it informs licensees of the potential of antifreeze 

from such systems to be combustible, and therefore, consideration of antifreeze as a 

combustible would be treated in accordance with a facility’s fire protection program.

At the time this IN was issued, several listed factory premixed antifreeze solutions were on the 

market. For new sprinkler systems that require the use of antifreeze, NFPA recommends 

alternative measures, such as those described in the previous paragraph. NFPA 13, 9.2.2.3

states that the concentration of antifreeze solutions shall be limited to the minimum necessary 

for the anticipated minimum temperature

This is an ongoing issue, with updates available through NFPA (http://www.nfpa.org/antifreeze). 

It is recommended that licensees keep up-to-date with the newest developments. For additional 

information, licensees can read the applicable TIAs for the complete set of proposed code 

changes and visit the NFPA website for updates (http://www.nfpa.org/codes-andstandards/standards-development-process/tias-errata-and-fis).

CONTACTS

This IN requires no specific action or written response. If you have any questions about the 

information in this notice, please contact the technical contact listed below or the appropriate 

NRC regional office.

/RA/ /RA/

Michael C. Cheok, Director Lawrence E. Kokajko, Director

Division of Construction Inspection Division of Policy and Rulemaking

and Operational Program Office of Nuclear Reactor Regulation

Office of New Reactors /RA/

Marissa G. Bailey, Director

Division of Fuel Cycle Safety, Safeguards,

 and Environmental Review

Office of Nuclear Material Safety

 and Safeguards

Technical Contact: Mollie Semmes, NMSS/FCSE

 (301) 287-9107

 mollie.semmes@nrc.gov

ADAMS Accession No.: ML14323A176 *concurred via-email

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NAME MSemmes CHsu* BSmith DMiller AMcIntosh* CErlanger AKlein* KHsueh*

DATE 11/19/14 12/9/14 12/3/14 11/19/14 10/28/14 12/4/14 1/7/15 1/5/15

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NAME ELee SStuchell* AMohseni LKokajko RCorreia* MCheok MBailey

DATE 1/5/15

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