Information Notice 2002-07, Use of Sodium Hypochlorite for Cleaning Diesel Fuel Oil Supply Tanks

Use of Sodium Hypochlorite for Cleaning Diesel Fuel Oil Supply Tanks

ML013450182
Person / Time
Issue date:	01/28/2002
From:	Beckner W NRC/NRR/DRIP/RORP
To:
Freeman, S, NRR/DRIP/REXB, 415-1175
References
TAC MB3345 IN-02-007
Download: ML013450182 (6)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 January 28, 2002 NRC INFORMATION NOTICE 2002-07: USE OF SODIUM HYPOCHLORITE FOR

CLEANING DIESEL FUEL OIL SUPPLY TANKS

Addressees

All holders of operating licenses for nuclear power except those who have ceased operations

and have certified that fuel has been permanently removed from the reactor vessel.

Purpose

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

addressees to the potential problems related to the use of sodium hypochlorite solutions for

cleaning diesel fuel oil supply tanks. Use of this chemical in higher concentrations can cause

the release of significant amounts of chlorine gas. The NRC anticipates that recipients will

review the information for applicability to their facilities and consider taking appropriate actions.

However, suggestions contained in this IN do not constitute NRC requirements; therefore, no

specific action or written response is required.

Background

Nuclear plants are required to design and maintain an onsite electric power system in

accordance with Appendix B, Quality Assurance Criteria for Nuclear Power Plants and Fuel

Reprocessing Plants, to Part 50 of Title 10 of the Code of Federal Regulations (10 CFR

Part 50). One acceptable method for complying with these regulations for fuel oil systems for

standby diesel generators is described in Regulatory Guide 1.137, Fuel Oil Systems for

Standby Diesel Generators.

Position 2.f of Regulatory Guide 1.137 recommends that licensees clean fuel oil supply tanks at

least every 10 years and that they use sodium hypochlorite solutions or equivalent rather than

soap or detergents to avoid introducing surfactants (surface active agents) into the fuel system.

However, the use of sodium hypochlorite in higher concentrations can release appreciable

amounts of heat and chlorine gas.

Discussion

Sodium hypochlorite is generally available in two forms: as a commercial solution containing

12 to 15 trade percent available chlorine (a so-called bleaching solution), and as a household

solution containing 5 trade percent chlorine. Trade percent is defined as the amount of

chlorine, in grams, that is available for each 100 milliliters of sodium hypochlorite solution.

Sodium hypochlorite is a strong oxidizer and, when mixed with organic materials such as diesel

fuel oil, undergoes an exothermic reaction that generates heat and releases chlorine gas, sometimes violently. A solution with a concentration of 12 trade percent available chlorine can

produce up to 1 pound of chlorine gas for each gallon of solution that reacts. Since fuel oil

supply tanks are usually located underground and cleaning them may involve working in a

confined space, this release could be harmful to the cleaning personnel. Licensees should take

appropriate precautions to protect personnel.

Regulatory Guide 1.137 states that solutions equivalent to sodium hypochlorite can be used to

clean fuel oil supply tanks. The intent is to keep surfactants from soap or detergents out of the

tank. Therefore, to prevent personnel injury, other materials with cleaning properties equivalent

to sodium hypochlorite can be used to clean fuel oil supply tanks, provided they meet the intent

of the recommendation.

The technical specifications of some licensees may include the requirement to use sodium

hypochlorite to clean the fuel oil supply tanks. This requirement came from Revision 4 of the

Westinghouse standard technical specifications, but has been removed in subsequent

revisions. Therefore, any licensee with this requirement has an opportunity to remove it by

submitting a license amendment request. Alternatively, when a licensee converts to the

improved technical specifications, the cleaning requirement is moved, along with the other fuel

oil requirements, to a fuel oil program. Any licensee that has the requirement in a fuel oil

program can change it under 10 CFR 50.59.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts

listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

/RA/

William D. Beckner, Program Director

Operating Reactor Improvements Program

Division of Regulatory Improvement Programs

Office of Nuclear Reactor Regulation

Technical contacts: Krzysztof Parczewski, NRR M. Scott Freeman, RII

301-415-2705 864-822-6927 E-mail: kip@nrc.gov E-mail: msf1@nrc.gov

Attachment: List of Recently Issued Information Notices Sodium hypochlorite is a strong oxidizer and, when mixed with organic materials such as diesel

fuel oil, undergoes an exothermic reaction that generates heat and releases chlorine gas, sometimes violently. A solution with a concentration of 12 trade percent available chlorine can

produce up to 1 pound of chlorine gas for each gallon of solution that reacts. Since fuel oil

supply tanks are usually located underground and cleaning them may involve working in a

confined space, this release could be harmful to the cleaning personnel. Licensees should take

appropriate precautions to protect personnel.

Regulatory Guide 1.137 states that solutions equivalent to sodium hypochlorite can be used to

clean fuel oil supply tanks. The intent is to keep surfactants from soap or detergents out of the

tank. Therefore, to prevent personnel injury, other materials with cleaning properties equivalent

to sodium hypochlorite can be used to clean fuel oil supply tanks, provided they meet the intent

of the recommendation.

The technical specifications of some licensees may include the requirement to use sodium

hypochlorite to clean the fuel oil supply tanks. This requirement came from Revision 4 of the

Westinghouse standard technical specifications, but has been removed in subsequent

revisions. Therefore, any licensee with this requirement has an opportunity to remove it by

submitting a license amendment request. Alternatively, when a licensee converts to the

improved technical specifications, the cleaning requirement is moved, along with the other fuel

oil requirements, to a fuel oil program. Any licensee that has the requirement in a fuel oil

program can change it under 10 CFR 50.59.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts

listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

/RA/

William D. Beckner, Program Director

Operating Reactor Improvements Program

Division of Regulatory Improvement Programs

Office of Nuclear Reactor Regulation

Technical contacts: Krzysztof Parczewski, NRR M. Scott Freeman, RII

301-415-2705 864-822-6927 E-mail: kip@nrc.gov E-mail: msf1@nrc.gov

Attachment: List of Recently Issued Information Notices

Distribution:

PUBLIC

IN Reading File

ADAMS ACCESSION NO.: ML013450182 OFFICE PM:RORP:DRIP Tech Editor EMCB EMBC

NAME OTYazi* OTYazi/for* KParczewski* LALund*

DATE 01/25/02 01/25/02 01/25/02 01/25/02 OFFICE C:EMCB IQMB SC:REXB PD:RORP:DRIP

NAME WHBateman* GCCwalina* TKoshy* WDBeckner*

DATE 01/25/02 01/25/02 01/25/02 01/28/02 OFFICIAL RECORD COPY

Attachment 1 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

_____________________________________________________________________________________

Information Date of

Notice No. Subject Issuance Issued to

_____________________________________________________________________________________

2002-06 Design Vulnerability in BWR 01/18/2002 All holders of operating licenses

Reactor Vessel Level or construction permits for boiling

Instrumentation Backfill water reactors (BWRs).

Modification

2002-05 Foreign Material in Standby 01/17/2002 All holders of licenses for nuclear

Liquid Control Storage Tanks power reactors.

2002-04 Wire Degradation at Breaker 01/10/2002 All holders of operating licenses

Cubicle Door Hinges for nuclear power reactors.

2002-03 Highly Radioactive Particle 01/10/2002 All holders of operating licenses

Control Problems During Spent for nuclear power reactors, Fuel Pool Cleanout holders of licenses for

permanently shutdown facilities

with fuel onsite, and holders of

licenses for non-power reactors.

2002-02 Recent Experience with 01/08/2002 All holders of operating licenses

Plugged Steam Generator for pressurized-water reactors

Tubes (PWRs), except those who have

permanently ceased operations

and have certified that fuel has

been permanently removed from

the reactor.

2002-01 Metalclad Switchgear Failures 01/08/2002 All holders of licenses for nuclear

and Consequent Losses of power reactors.

Offsite Power

2001-19 Improper Maintenance and 12/17/2001 All holders of operating licenses

Reassembly of Automatic Oil for nuclear power reactors, Bubblers except those who have

permanently ceased operations

and have certified that fuel has

been permanently removed from

the reactor vessel.

______________________________________________________________________________________

OL = Operating License

CP = Construction Permit