[Federal Register Volume 84, Number 223 (Tuesday, November 19, 2019)]
[Proposed Rules]
[Pages 63816-63819]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-25018]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 84, No. 223 / Tuesday, November 19, 2019 /
Proposed Rules
[[Page 63816]]
NUCLEAR REGULATORY COMMISSION
10 CFR Part 50
[Docket No. PRM-50-111; NRC-2015-0124]
Power Reactor In-Core Monitoring
AGENCY: Nuclear Regulatory Commission.
ACTION: Petition for rulemaking; denial.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is denying a
petition for rulemaking (PRM), dated March 13, 2015, submitted by Mark
Edward Leyse (petitioner). The petition was docketed by the NRC on
April 24, 2015, and assigned Docket No. PRM-50-111. The petitioner
requested that the NRC require all holders of operating licenses for
nuclear power plants to operate them with in-core temperature-
monitoring devices (e.g., thermoacoustic sensors or thermocouples)
located at different elevations and radial positions throughout the
reactor core. The NRC is denying the petition because current
regulations provide a sufficient level of safety, such that additional
requirements for in-core temperature-monitoring devices as specified in
the petition are not needed.
DATES: The docket for the petition for rulemaking, PRM-50-111, is
closed on November 19, 2019.
ADDRESSES: Please refer to Docket ID NRC-2015-0124 when contacting the
NRC about this petition. You may obtain publicly-available information
related to this action by any of the following methods:
Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2015-0124. Address
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; email: [email protected]. For technical questions, contact
the individual listed in the FOR FURTHER INFORMATION CONTACT section of
this document.
NRC's Agencywide Documents Access and Management System
(ADAMS): You may obtain publicly-available documents online in the
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search select ``Begin Web-based ADAMS
Search.'' For problems with ADAMS, please contact the NRC's Public
Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737,
or by email to [email protected]. For the convenience of the reader,
instructions about obtaining materials referenced in this document are
provided in Section III, ``Availability of Documents,'' of this
document.
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.
FOR FURTHER INFORMATION CONTACT: James O'Driscoll, Office of Nuclear
Material Safety and Safeguards, U.S. Nuclear Regulatory Commission,
Washington, DC 20555-0001; telephone: 301-415-1325; email:
James.O'[email protected].
SUPPLEMENTARY INFORMATION:
I. The Petition
Section 2.802 of title 10 of the Code of Federal Regulations (10
CFR), ``Petition for rulemaking--requirements for filing,'' provides an
opportunity for any interested person to petition the Commission to
issue, amend, or rescind any regulation. The NRC received a petition
dated March 13, 2015, from Mark Edward Leyse and assigned it Docket No.
PRM-50-111. The NRC published a notice of docketing in the Federal
Register on July 16, 2015 (80 FR 42067). The NRC did not request public
comment on PRM-50-111 because the staff had sufficient information to
review the issues raised in the petition.
The NRC identified three issues that provide the bases for the
request in PRM-50-111:
1. Measurement of the temperatures at various locations within the
reactor core would enable nuclear power plant operators to better
understand the condition of the core under normal and transient
conditions and to more clearly foresee incipient or impending damage to
the reactor core.
2. The use of in-core temperature-monitoring devices is needed in
boiling-water reactors.
3. The use of in-core temperature-monitoring devices would satisfy
recommendations regarding enhanced reactor instrumentation made in the
near-term task force report, ``Recommendations for Enhancing Reactor
Safety in the 21st Century: The Near-Term Task Force Review of Insights
from the Fukushima Dai-ichi Accident,'' dated July 12, 2011 (ADAMS
Accession No. ML111861807).
The petitioner requested that the NRC amend its regulations at 10
CFR part 50, ``Domestic Licensing of Production and Utilization
Facilities,'' to require all holders of operating licenses for nuclear
power plants to operate them with in-core temperature-monitoring
devices (e.g., thermoacoustic sensors or thermocouples) located at
different elevations and radial positions throughout the reactor core.
The petitioner stated that the use of the devices would enable nuclear
power plant operators to accurately measure in-core temperatures,
thereby providing crucial information to help them track the
progression of core damage and manage an accident (e.g., by indicating
the correct time to transition from emergency operating procedures to
implementing severe accident management guidelines).
The petitioner stated that installing in-core temperature-
monitoring devices would satisfy the recommendations in the near-term
task force report, ``Recommendations for Enhancing Reactor Safety in
the 21st Century,'' dated July 12, 2011, regarding enhanced reactor
instrumentation. Specifically, the petitioner referenced the following
from the report:
[A] new and dedicated portion of the regulations would allow the
Commission to recharacterize its expectations for safety features
beyond design basis more clearly and more positively as `extended
design-basis' requirements.
The petitioner asserted that a new regulation is needed, requiring
that a wide range of in-core temperatures be accurately measured in the
event of a severe accident.
II. Reasons for Denial
As discussed in this document, the NRC is denying PRM-50-111
because the petitioner does not demonstrate the need for a regulation
that requires the use of in-core temperature-monitoring devices in
nuclear power plants. The
[[Page 63817]]
NRC addressed a substantial portion of the request in this petition in
its response to a previous petition. PRM-50-105 was submitted on
February 28, 2012, and the NRC published a notice of receipt and
request for comment in the Federal Register on May 23, 2012 (77 FR
30435). In PRM-50-105, the petitioner requested that the NRC require
all holders of operating licenses for nuclear power plants to have in-
core thermocouples at different elevations and radial positions
throughout the reactor core to enable the operators to accurately
measure a large range of in-core temperatures in nuclear power plant
steady-state and transient conditions. The NRC limited the scope of the
review of PRM-50-105 to only the use of in-core thermocouples in
pressurized-water reactors because that was the primary focus of that
petition, although the petitioner also mentioned boiling-water
reactors. The NRC denied PRM-50-105 on September 12, 2013 (78 FR
56174).
NRC's Response to Issue 1
In its denial of PRM-50-105, the NRC evaluated the petitioner's
claims that, in the event of a severe accident, in-core thermocouples
would enable nuclear power plant operators to accurately measure in-
core temperatures better than core exit thermocouples, and would
provide crucial information to help operators manage the accident. In
PRM-50-111, the petitioner reiterated the same assertions and updated
the previous request by including other instrument types that might be
used in the measurement of in-core temperatures (e.g., thermoacoustic
sensors).
The NRC denied PRM-50-105 because the NRC concluded that knowledge
of core temperatures at various elevations and radial positions would
not enhance safety or change operator action. Core-exit thermocouples,
despite known limitations, are sufficient to allow nuclear power plant
operators to take timely and effective action in the event of an
accident. In pressurized-water reactors, they provide an indication of
initial core damage during accident conditions and provide the
necessary indication to make operational decisions with respect to the
approach to imminent core damage.
The current suite of instrumentation used in pressurized-water
reactors, which includes core-exit thermocouples, provides sufficient
information to determine the need for operator action well before the
onset of significant core damage. Other indications include reactor
coolant system level and containment pressure. A more comprehensive
description of the applications of core-exit thermocouples is provided
in NRC's denial of PRM-50-105, Issue 1. In its denial of PRM-50-105,
the NRC concluded that there is no need for more accurate measurement
of temperatures throughout the core in pressurized-water reactors. The
NRC concludes that the reasons for that decision remain valid and are
applicable to PRM-50-111.
In PRM-50-111, the petitioner discussed core temperature
measurement devices other than thermocouples. The NRC evaluated this
information and concludes that the nature of the device is not relevant
to the decision of whether or not to require the use of in-core
temperature instrumentation.
As in the denial of PRM-50-105, the NRC has determined that precise
in-core temperatures would not provide information that would enable
nuclear power plant operators to better respond to and manage a reactor
accident.
The NRC therefore concludes that more accurate and precise
temperature distribution information within the reactor core that would
be provided by such instrumentation is not necessary to provide
adequate protection to the health and safety of the public or nuclear
power plant staff, nor would it provide a substantial safety
enhancement at nuclear power plants. Therefore, installation of such
instrumentation need not be required by regulation.
NRC's Response to Issue 2
The petitioner asserted that in the event of a severe accident at a
boiling-water reactor, in-core temperature-monitoring devices would be
more accurate and immediate for detecting inadequate core cooling and
core uncovery than readings of the reactor water level, reactor
pressure, containment pressure, or wetwell water temperature. The
petitioner also asserted that, after the onset of core damage, water
level indicators in boiling-water reactors are unreliable.
The NRC determined that the current means to detect and respond to
inadequate core cooling is already anticipatory in nature, and
emergency operator actions would be no different if in-core
temperature-monitoring devices were present. Therefore, no safety
benefit would result from the availability of such devices.
Existing boiling-water reactor emergency operating procedures
(EOPs) do not require operator assessment of core cooling. Instead,
operators use specific parametric data, such as the water level,
containment pressure, containment radiation, and reactor pressure, in
conjunction with the EOP actions to respond to the event. Under
accident conditions, reactor vessel water level is an acceptable
indication of conditions relating to imminent core damage, and drywell
radiation monitors are typically the primary method for determining the
presence of core damage and severe accident management guideline entry
conditions. For boiling-water reactors, severe accident management
guideline entry conditions are also tied to parameters such as water
level, containment hydrogen concentration, and component failures. If
reactor water level is unknown or conditions render water level
instrumentation unreliable, then the EOPs require the operators to
proactively flood the reactor vessel. In addition, the EOPs for
boiling-water reactors describe steam cooling as a method of cooling
the core when there is insufficient water to cover the core, typically
available when water level is at or above two-thirds of core height.
This method allows additional time to restore reactor coolant injection
and reduce the likelihood of emergency reactor depressurization, which
would be necessary for the injection of low pressure sources.
The intent of the NRC's regulations is to prevent or minimize
significant core damage. The detection of inadequate core cooling and
actual core uncovery is not necessary for managing emergency and
accident scenarios. Nuclear power plant operators are directed by EOPs
to take proactive emergency operating actions based on the indication
of parameters that are anticipatory to actual inadequate core cooling
conditions, while the instruments reading those parameters are still
functioning within their acceptably-accurate performance ranges. If
significant core damage were to occur, water level instrumentation and
in-core temperature instrumentation (if installed) would no longer be
relied upon for operator action.
The NRC has determined that boiling-water reactor operators do not
need in-core temperature-monitoring devices to safely navigate
emergency and accident scenarios. Because the use of water level
instrumentation is sufficient to inform operator actions prior to
significant core damage, the NRC finds that the information
representing the temperature within specific core locations would not
provide an improvement in the prevention of an accident or the
mitigation of the consequences of an accident. The NRC
[[Page 63818]]
has further determined that having the core temperature data would not
provide any additional safety margins in managing post accident or
severe accident conditions. Therefore, the NRC concludes that more
accurate and precise temperature distribution within the reactor core
that would be provided by such instrumentation is not necessary to
provide adequate protection of the health and safety of the public or
nuclear power plant staff, nor would it provide a substantial safety
enhancement at nuclear power plants. Therefore, installation of such
instrumentation need not be required by regulation.
NRC's Response to Issue 3
The petitioner stated that in-core temperature-monitoring devices
would satisfy the July 12, 2011, near-term task force report
recommendations for enhanced reactor instrumentation. To support this
claim, the petitioner cited Recommendation 8, in Section 4.2.5 of the
report, which recommends strengthening and integrating onsite emergency
response capabilities such as emergency operating procedures, severe
accident management guidelines and extensive damage mitigation
guidelines. The petitioner also cited Volume 10 of NUREG-1635, ``Review
and Evaluation of the Nuclear Regulatory Commission Safety Research
Program: A Report to the U.S. Nuclear Regulatory Commission,'' dated
October 31, 2012. The petitioner quoted sections from pages 11 and 12
of this report, in which the Advisory Committee on Reactor Safeguards
stated that the NRC recognized the need for enhanced reactor
instrumentation, that such instrumentation would help clarify the
transition points of various onsite emergency response capabilities,
and that the NRC was in the process of adding this to the
implementation of the near-term task force report recommendations. The
petitioner gave, as an example of a transition point, the point at
which nuclear power plant operators should transition from EOPs to
implementing severe accident management guidelines.
The staff proposed plans to the Commission for resolving open near-
term task force recommendations in SECY-15-0137, ``Proposed Plans for
Resolving Open Fukushima Tier 2 and 3 Recommendations,'' dated October
29, 2015. In SECY-15-0137, the staff described how remaining open
recommendations from the near-term task force report should be
resolved. The staff specifically assessed the need for enhanced reactor
instrumentation for beyond-design-basis conditions in Enclosure 5 of
SECY-15-0137. The staff recommended that the Commission not pursue
additional regulatory action beyond the current requirements, including
those imposed by orders EA-12-049, ``Order Modifying Licenses with
Regard to Requirements for Mitigation Strategies for Beyond-Design-
Basis External Events,'' and EA-12-051, ``Order Modifying Licenses with
Regard to Reliable Spent Fuel Pool Instrumentation.'' In SRM-SECY-15-
0137, dated February 8, 2016, the Commission approved the staff's
closure plan for these items. On January 24, 2019, in SRM-M190124A, the
Commission directed agency staff to publish a final rule based on
lessons learned from the March 2011 accident at Japan's Fukushima
Daiichi plant; the final rule was published in the Federal Register on
August 9, 2019 and became effective on September 9, 2019 (84 FR 39684).
That final rule made generically applicable the requirements from
orders EA-12-049 and EA-12-051, taking into account lessons learned in
the implementation of the orders and feedback received from
stakeholders.
As discussed under Issues 1 and 2, the NRC evaluated the potential
contribution that more accurate and precise temperature information
would have on improving nuclear power plant safety for both boiling-
water reactor and pressurized-water reactor plants. The NRC has
determined that the availability of such information would not improve
operator actions to prevent or mitigate a reactor accident. The NRC
finds that the Commission's conclusions in SRM-SECY-15-0137 apply to
the instrumentation proposed by the petitioner. The NRC concludes that
more accurate and precise temperature distribution information that
would be provided by such instrumentation is not necessary to provide
adequate protection to the health and safety of the public or nuclear
power plant staff, nor would it provide a substantial safety
enhancement at nuclear power plants. Therefore, installation of such
instrumentation need not be required by regulation.
III. Availability of Documents
The documents identified in the following table are available to
interested persons as indicated. For more information on accessing
ADAMS, see the ADDRESSES section of this document.
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ADAMS Accession
No./website/
Date Document Federal Register
citation
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Petition Documents:
March 13, 2015............... PRM-50-111--Petiti ML15113B143.
on for Rulemaking
from Mark E.
Leyse Regarding
In-Core
Temperature
Monitoring at
Nuclear Power
Plants.
July 16, 2015................ Federal Register 80 FR 42067.
notice: Petition
for Rulemaking,
Notice of
Docketing, Power
Reactor In-Core
Monitoring.
February 28, 2012............ Petition for ML12065A215.
Rulemaking
submitted Mark
Edward Leyse, on
PRM-50-105,
Request NRC
Require all
Holders of
Operating
Licenses for
Nuclear Power
Plants to Operate
with In-Core
Thermocouples at
Different
Elevations and
Radial Positions.
May 23, 2012................. Federal Register 77 FR 30435.
notice: Petition
for Rulemaking;
Receipt and
Request for
Comment, In-core
Thermocouples at
Different
Elevations and
Radial Positions
in Reactor Core.
September 12, 2013........... Federal Register 78 FR 56174.
notice: Petition
for rulemaking;
Denial, In-core
Thermocouples at
Different
Elevations and
Radial Positions
in Reactor Core.
Other Documents:
October 30, 1979............. The Need for https://
Change, the tmi2kml.inl.gov/
Legacy of TMI: Documents/Common/
Report of the PresidentsCommis
President's sion,(MainReport
Commission on the )TheNeedForChang
Accident at Three e,The
Mile Island. LegacyofTMI-
2(1979-10-
30).pdf.
[[Page 63819]]
July 12, 2011................ SECY-11-0093--Encl ML111861807.
osure: The Near
Term Task Force
Review of
Insights from the
Fukushima Dai-
Ichi Accident.
October 31, 2012............. NUREG-1635, Volume ML12311A417.
10, ``Review and
Evaluation of the
Nuclear
Regulatory
Commission Safety
Research Program:
A Report to the
U.S. Nuclear
Regulatory
Commission''.
October 29, 2015............. SECY-15-0137, ML15254A006.
``Proposed Plan
for Resolving
Open Fukushima
Tier 2 and 3
Recommendations''.
March 12, 2012............... EA-12-049 ``Order ML12054A735.
Modifying
Licenses with
Regard to
Requirements for
Mitigation
Strategies for
Beyond-Design-
Basis External
Events''.
March 12, 2012............... EA-12-051, ``Order ML12056A044.
Modifying
Licenses with
Regard to
Reliable Spent
Fuel Pool
Instrumentation''.
February 8, 2016............. SRM-SECY-15-0137-- ML16039A175.
Proposed Plans
for Resolving
Open Fukushima
Tier 2 and 3
Recommendations.
January 24, 2019............. SRM-M190124A: ML19024A073.
Affirmation
Session-SECY-16-
0142: Final Rule:
Mitigation of
Beyond-Design-
Basis Events (RIN
3150-AJ49).
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IV. Conclusion
For the reasons cited in Section II of this document, the NRC is
denying PRM-50-111. The NRC finds that the existing regulations provide
a sufficient level of safety such that additional requirements are not
necessary. Therefore, installation of in-core temperature monitoring
devices need not be required by regulation.
Dated at Rockville, Maryland, this 14th day of November, 2019.
For the Nuclear Regulatory Commission.
Annette L. Vietti-Cook,
Secretary of the Commission.
[FR Doc. 2019-25018 Filed 11-18-19; 8:45 am]
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