Information Notice 2002-07, 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