Information Notice 2002-15, Potential Hydrogen Combustion Events in BWR Piping
| ML031210054 | |
| Person / Time | |
|---|---|
| Issue date: | 05/06/2003 |
| From: | Beckner W NRC/NRR/DRIP/RORP |
| To: | |
| Dozier J, NRR/RORP 301-415-1014 | |
| References | |
| IN-02-015, Suppl 1 | |
| Download: ML031210054 (6) | |
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, DC 20555-0001 May 6, 2003 NRC INFORMATION NOTICE 2002-15, SUPPLEMENT 1: POTENTIAL HYDROGEN
COMBUSTION EVENTS IN BWR
PIPING
Addressees
All holders of operating licenses for light water reactors, except those who have permanently
ceased operations and have certified that fuel has been permanently removed from the reactor.
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this supplement to inform
addressees about the status of the followup actions taken by the staff and the Boiling Water
Reactor Owners Group (BWROG) after the issuance of Information Notice (IN) 2002-15 on
April 12, 2002. The original information notice discussed hydrogen combustion events in piping
at foreign boiling water reactors (BWRs).
The NRC expects recipients to review the information for applicability to their facilities and
consider actions, as appropriate, to avoid similar problems. However, suggestions contained in
this IN are not NRC requirements; therefore, the NRC requires no specific action or written
response .
Background
The NRC issued IN 2002-15, Hydrogen Combustion Events in Foreign BWR Piping, on
April 12, 2002, to inform addressees about the hydrogen combustion events at two foreign
BWRs. The NRC requested that recipients review the information and consider actions, as
appropriate, to avoid similar problems in U.S. plants. At a BWROG/NRC senior management
meeting on July 25, 2002, the NRC staff asked the BWROG to submit a written report about the
groups followup activities in response to the foreign events. The BWROG submitted the
information to the staff in a letter dated December 20, 2002 (ADAMS Accession No.
Description of Circumstances
In response to the foreign hydrogen combustion events, General Electric (GE) convened a task
force. The BWROG participated in the GE task force to study the events. The task force
concluded that although the probability of similar events in U.S. BWRs is small, such events
cannot be completely precluded. GE issued GE Service Information Letter (SIL) No. 643, Potential for Radiolytic Gas Detonation, dated June 14, 2002, to all BWR licensees
recommending that piping systems (primary and secondary ) susceptible to accumulation of
noncondensable gases be reviewed and actions taken where necessary to avoid the problem.
IN 2002-15, Sup 1 Based on its review of GE SIL No. 643, the BWROG concluded that piping configurations and
conditions conducive to radiolytic gas accumulation are expected to be rare, and therefore the
likelihood of hydrogen combustion events in U.S. BWRs is small. However, the possibility could
not be ruled out, particularly in the case of degraded performance that may not be immediately
recognizable. Very unusual combinations of geometry and plant material condition are required
for radiolytic gas to accumulate, but should the gas accumulate, there is a potential for
detonation, resulting in piping failure.
Consequently, the BWROG formed a Hydrogen Accumulation Committee to develop detailed
guidance for U.S. BWR utilities on identifying, disposing of, and mitigating potential radiolytic
hydrogen and oxygen in plant piping and equipment. The committee did the following:
1.
Identified the most significant generic plant equipment that could be subject to rapid
hydrogen accumulation.
2.
Surveyed BWR licensee members about plant areas with the greatest potential for
hydrogen/oxygen accumulation and about actions taken to address this configuration.
3.
Reviewed the recommendations of Generic Letter (GL) 91-18, Information to Licensees
Regarding NRC Inspection Manual Section on Resolution of Degraded and
Nonconforming Conditions, to ensure that operability with hydrogen accumulation is
properly addressed.
4.
Developed a guidance document, BWR Piping and Component Susceptibility to
Hydrogen Detonation, which provides detailed guidance on identifying equipment subject
to hydrogen accumulation and potential rupture. This document also identifies short-term
and long-term mitigation strategies for such equipment.
At the February 2003 BWROG/NRC senior management meeting, the BWROG said it will
provide a final summary report to the NRC later in 2003 to document the results of the
implementation of the BWROG guidance on this issue.
Conclusion
This IN provides a summary of the actions taken by the BWROG and NRC in response to the
hydrogen combustion events in foreign BWRs initially described in IN 2002-15. The NRC staff
is continuing to monitor the BWROG activities related to hydrogen accumulation.
Related Generic Communications
The following documents describe reactor operating experience with gas intrusion and
combustion events:
IN 88-23, Potential for Gas Binding of High-Pressure Safety Injection Pumps, with five
supplements, the latest dated April 23, 1999.
IN 90-64, Potential for Common-Mode Failure of High Pressure Safety Injection
Pumps, dated October 4, 1990.
IN 2002-15, Sup 1 *
GL 93-06, Research Results on Generic Safety Issue 106, Piping and the Use of
Highly Combustible Gases in Vital Areas, dated October 25, 1993.
IE Bulletin No. 78-03, Potential Explosive Gas Mixture Accumulations Associated With
BWR Offgas System Operations, dated February 8, 1978.
This information notice does not require any 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 project manager in the NRCs Office of Nuclear Reactor
Regulation (NRR).
/RA/
William D. Beckner, Program Director
Operating Reactor Improvements Program
Division of Regulatory Improvement Programs
Office of Nuclear Reactor Regulation
Technical contacts:
George Thomas, NRR Jerry Dozier, NRR
(301) 415-1814
(301) 415-1014 E-mail: gxt@nrc.gov E-mail: jxd@nrc.gov
Attachment: List of Recently Issued NRC Information Notices
ML031210054 DOCUMENT NAME: G:\\RORP\\OES\\Staff Folders\\Dozier\\HdrogenIN.wpd
- See previous concurrence
OFFICE
OES:RORP:DRIP
Tech Editor
SRXB:DSSA
SRXB:DSSA
SRXB:DSSA
NAME
IJDozier
PKleene /pk/
GThomas*
FMAkstulewicz*
JSWermeil*
DATE
/ /2003
04/21/2003
04/22/2003
04/25/2003
04/28/2003 OFFICE
SC:OES:RORP:DRIP
PD:RORP:DRIP
NAME
TReis
WDBeckner
DATE
05/02/2003
05/06/2003
______________________________________________________________________________________
OL = Operating License
CP = Construction Permit
Attachment
IN 2002-15, Sup 1 LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
_____________________________________________________________________________________
Information
Date of
Notice No.
Subject
Issuance
Issued to
_____________________________________________________________________________________
2002-21, Sup 1 Axial Outside-diameter
Cracking Affecting Thermally
Treated Alloy 600 Steam
Generator Tubing
04/01/2003
All holders of operating licensees
for nuclear power reactors, except those who have
permanently ceased operations
and have certified that fuel has
been permanently removed from
the reactor vessel.
2003-04 Summary of Fitness-For-Duty
Program Performance Reports
for Calendar Year 2000
02/06/2003
All holders of operating licensees
for nuclear power reactors, except those who have
permanently ceased operations
and have certified that fuel has
been permanently removed from
the reactor vessel.
2003-03 Part 21 - Inadequately Staked
Capscrew Renders Residual
Heat Removal Pump
01/27/2003
All holders of operating licenses
or construction permits for
nuclear power reactors.
2003-02
Recent Experience with
Leakage and Boric Acid
Corrosion
01/16/2003
All holders of operating licenses
or construction permits for
pressurized water reactors
(PWRs).
2003-01
Failure of a Boiling Water
Reactor Target Rock Main
Steam Safety/Relief Valve
01/15/2003
All holders of operating licenses
or construction permits for
nuclear power reactors, except
those that have permanently
ceased operations and have
certified that fuel has been
permanently removed from the
reactor.
Note:
NRC generic communications may be received in electronic format shortly after they are
issued by subscribing to the NRC listserver as follows:
To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the following
command in the message portion:
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