[Federal Register Volume 78, Number 227 (Monday, November 25, 2013)]
[Notices]
[Pages 70356-70358]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-28226]
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NUCLEAR REGULATORY COMMISSION
[NRC-2013-0215]
Compliance With Order EA-13-109, Order Modifying Licenses With
Regard to Reliable Hardened Containment Vents Capable of Operation
Under Severe Accident Conditions
AGENCY: Nuclear Regulatory Commission.
ACTION: Interim Staff Guidance; Issuance.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing Japan
Lessons-Learned Project Directorate Interim Staff Guidance (JLD-ISG),
JLD-ISG-2013-02, ``Compliance with Order EA-13-109, Order Modifying
Licenses with Regard to Reliable Hardened Containment Vents Capable of
Operation under Severe Accident Conditions.'' Agencywide Documents and
Management System (ADAMS) Accession No. ML13130A067). This ISG provides
guidance and clarifies the requirements in the order to assist the
licensees that have Boiling Water Reactors with Mark I and Mark II
Containments in the design and implementation of a containment venting
system that is capable of a operation under severe accident conditions.
This ISG also endorses, with clarifications, the industry guidance
contained in Nuclear Energy Institute (NEI) 13-02, ``Industry Guidance
for Compliance with Order EA-13-109,'' Revision 0 (ADAMS Accession No.
ML13316A853).
ADDRESSES: Please refer to Docket ID NRC-2013-0215 when contacting the
NRC about the availability of information regarding this document. You
may access publicly-available information related to this action by the
following methods:
Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2013-0215. Address
questions about NRC dockets to Carol Gallagher; telephone: 301-287-
3422; email: [email protected]. For technical questions, contact
the individual(s) listed in the FOR FURTHER INFORMATION CONTACT section
of this document.
NRC's Agencywide Documents Access and Management System
(ADAMS): You may access publicly available documents online in the NRC
Library at http://www.nrc.gov/reading-rm/adams.html. To begin the
search, select ``ADAMS Public Documents'' and then select ``Begin Web-
based ADAMS Search.'' For problems with ADAMS,
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please contact the NRC's Public Document Room (PDR) reference staff at
1-800-397-4209, 301-415-4737, or by email to [email protected]. The
ADAMS accession number for each document referenced in this notice (if
that document is available in ADAMS) is provided the first time that a
document is referenced. The JLD-ISG-2013-02 is available in ADAMS under
Accession No. ML13304B836.
NRC's PDR: You may examine and purchase copies of public
documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555
Rockville Pike, Rockville, Maryland 20852.
NRC's Interim Staff Guidance Web site: JLD-ISG documents
are also available online under the ``Japan Lessons Learned'' heading
at http://www.nrc.gov/reading-rm/doc-collections/#int.
FOR FURTHER INFORMATION CONTACT: Dr. Rajender Auluck, Japan Lessons-
Learned Project Directorate, Office of Nuclear Reactor Regulation, U.S.
Nuclear Regulatory Commission, Washington, DC 20555-0001; telephone:
301-415-1025; email: [email protected].
SUPPLEMENTARY INFORMATION:
Background Information
The NRC staff developed JLD-ISG-2013-02 to provide guidance and
clarification to assist nuclear power reactor applicants and licensees
with the identification of methods needed to comply with requirements
to mitigate challenges to key safety functions. These requirements are
contained in Order EA-13-109, ``Order Modifying Licenses with Regard to
Reliable Hardened Containment Vents Capable of Operation under Severe
Accident Conditions'' (ADAMS Accession No. ML13130A067). This ISG is
not a substitute for the requirements in Order EA-13-109, and
compliance with the ISG is not a requirement.
On September 18, 2013 (78 FR 57418), the NRC staff issued a Federal
Register notice (to request public comments on draft JLD-ISG-2013-02
(ADAMS Accession No. ML13247A417)). In response, the NRC received
comments from the Pilgrim Watch by letter dated October 18, 2013 (ADAMS
Accession No. ML13294A461), Beyond Nuclear by letter dated October 18,
2013 (ADAMS Accession No. ML13295A225), and Nuclear Energy Institute by
letter dated October 18, 2013 (ADAMS Accession No. ML13295A494).
Several of these comments have been previously submitted to the NRC for
staff's consideration. The resolution of these comments is documented
and publicly available (ADAMS Accession No. ML13310B299).
The events at the Fukushima Dai-ichi nuclear power plant following
the March 2011, earthquake and tsunami highlight the possibility that
events such as rare natural phenomena could challenge the traditional
defense-in-depth protections related to preventing accidents,
mitigating accidents to prevent the release of radioactive materials,
and taking actions to protect the public should a release occur. At
Fukushima Dai-ichi, limitations in time and unpredictable conditions
associated with the accident significantly hindered attempts by the
operators to prevent core damage and containment failure. In
particular, the operators were unable to successfully operate the
containment venting system. These problems, along with venting the
containments under challenging conditions following the tsunami,
contributed to the progression of the accident from inadequate cooling
of the core leading to core damage, to compromising containment
functions from overpressure and over-temperature conditions, and to the
hydrogen explosions that destroyed the reactor buildings (secondary
containments) of three of the Fukushima Dai-ichi units. The loss of the
various barriers led to the release of radioactive materials, which
further hampered operator efforts to arrest the accidents and
ultimately led to the contamination of large areas surrounding the
plant. Fortunately, the evacuation of local populations minimized the
immediate danger to public health and safety from the loss of control
of the large amount of radioactive materials within the reactor cores.
The events at Fukushima reinforced the importance of reliable
operation of hardened containment vents during emergency conditions,
particularly, for small containments such as the Mark I and Mark II
designs. On March 12, 2012, the NRC issued Order EA-12-050 \1\
requiring the Licensees identified in Attachment 1 to this order to
implement requirements for a reliable hardened containment venting
system (HCVS) for Mark I and Mark II containments. Order EA-12-050
required licensees of BWR facilities with Mark I and Mark II
containments to install a reliable HCVS to support strategies for
controlling containment pressure and preventing core damage following
an event that causes a loss of heat removal systems (e.g., an extended
loss of electrical power). The NRC determined that the issuance of
Order EA-12-050 and implementation of the requirements of that order
were necessary to provide reasonable assurance of adequate protection
of the public health and safety.
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\1\ ``Order Modifying Licenses With Regard To Reliable Hardened
Containment Vents (Effective Immediately),'' EA-12-050 (March 12,
2012) (ADAMS Accession No. ML12056A043).
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While developing the requirements for a reliable HCVS in Order EA-
12-050, the NRC acknowledged that questions remained about maintaining
containment integrity and limiting the release of radioactive materials
if the venting systems were used during severe accident conditions. The
NRC staff presented options to address these issues, including the
possible use of engineered filters to control releases, for Commission
consideration in SECY-12-0157, ``Consideration of Additional
Requirements for Containment Venting Systems for Boiling Water Reactors
with Mark I and Mark II Containments'' (issued November 26, 2012).
Option 2 in SECY-12-0157 was to modify EA-12-050 to require severe
accident capable vents (i.e., a reliable HCVS capable of operating
under severe accident conditions). Other options discussed in SECY-12-
0157 included the installation of engineered filtered containment
venting systems (Option 3) and the development of a severe accident
confinement strategy (Option 4). In the Staff Requirements Memorandum
(SRM) for SECY-12-0157, dated March 19, 2013, the Commission approved
Option 2 and directed the staff to issue a modification to Order EA-12-
050 requiring licensees subject to that order to ``upgrade or replace
the reliable hardened vents required by Order EA-12-050 with a
containment venting system designed and installed to remain functional
during severe accident conditions.''
The requirements in this order, in addition to providing a reliable
HCVS to assist in preventing core damage when heat removal capability
is lost (the purpose of EA-12-050), will ensure that venting functions
are also available during severe accident conditions. Severe accident
conditions include the elevated temperatures, pressures, radiation
levels, and combustible gas concentrations, such as hydrogen and carbon
monoxide, associated with accidents involving extensive core damage,
including accidents involving a breach of the reactor vessel by molten
core debris. This order requires installation of reliable hardened
vents that will not only assist in preventing core damage when heat
removal capability is lost, but will also function in severe accident
conditions (i.e., when core damage has occurred). The safety
improvements to Mark I and Mark II
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containment venting systems required by this order are intended to
increase confidence in maintaining the containment function following
core damage events. Although venting the containment during severe
accident conditions could result in the release of radioactive
materials, venting could also prevent containment structural and gross
penetration leakage failures due to over pressurization that would
hamper accident management (e.g., continuing efforts to cool core
debris) and ultimately result in larger, uncontrolled releases of
radioactive material.
On November 7, 2013, NEI submitted NEI 13-02, ``Industry Guidance
for Compliance with Order EA-13-109,'' Revision 0 (ADAMS Accession No.
ML13316A853) to provide specification for the development,
implementation, and maintenance of guidance in response to the order
regarding reliable hardened containment vents capable of operation
under severe accident conditions. This ISG endorses, with
clarifications, the methodologies described in the industry guidance
document NEI 13-02.
For the Nuclear Regulatory Commission.
Dated at Rockville, Maryland, this 14th day of November 2013.
David L. Skeen,
Director, Japan Lessons-Learned Project Directorate, Office of Nuclear
Reactor Regulation.
[FR Doc. 2013-28226 Filed 11-22-13; 8:45 am]
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