[Federal Register Volume 60, Number 123 (Tuesday, June 27, 1995)]
[Notices]
[Pages 33239-33243]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-15677]
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NUCLEAR REGULATORY COMMISSION
Proposed Generic Communication; Relocation of Selected Technical
Specifications Requirements Related to Instrumentation
AGENCY: Nuclear Regulatory Commission.
ACTION: Notice of opportunity for public comment.
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SUMMARY: The Nuclear Regulatory Commission (NRC) is proposing to issue
a generic letter regarding the relocation of selected technical
specifications requirements related to instrumentation. The NRC is
seeking comment from interested parties regarding both the technical
and regulatory aspects of the proposed generic letter presented under
the Supplementary Information heading. This proposed generic letter and
supporting documentation were endorsed for publication in the Federal
Register by the Committee to Review Generic Requirements (CRGR) on June
15, 1995. The relevant information that was sent to the CRGR to support
their review of the proposed generic letter is available in the NRC
Public Document Room under accession number 9506160308. The NRC will
consider comments received from interested parties in the final
evaluation of the proposed generic letter. The NRC's final evaluation
will include a review of the technical position and, when appropriate,
an analysis of the value/impact on licensees. Should this generic
letter be issued by the NRC, it will become available for public
inspection in the NRC Public Document Room.
DATES: Comment period expires July 27, 1995. Comments submitted after
this date will be considered if it is practical to do so, but assurance
of consideration cannot be given except for comments received on or
before this date.
ADDRESSES: Submit written comments to Chief, Rules Review and
Directives Branch, U.S. Nuclear Regulatory Commission, Washington, DC
20555. Written comments may also be delivered to 11545 Rockville Pike,
Rockville, Maryland, from 7:30 am to 4:15 pm, Federal workdays. Copies
of written comments received may be examined at the NRC Public Document
Room, 2120 L Street, NW. (Lower Level), Washington, DC.
FOR FURTHER INFORMATION CONTACT: William D. Reckley, (301) 415-1314.
[[Page 33240]]
SUPPLEMENTARY INFORMATION:
NRC Generic Letter 95-XX: Relocation of Selected Technical
Specifications Requirements Related to Instrumentation
Addressees
All holders of operating licenses or construction permits for
nuclear power reactors except Crystal River, Grand Gulf, Clinton, and
Hatch, Units 1 and 2.
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this
generic letter to advise those licensees that have not converted or are
not in the process of converting to the improved Standard Technical
Specifications that they may request a license amendment to relocate
selected instrumentation requirements from their Technical
Specifications (TS).
Description of Circumstances
This line-item TS improvement was developed in response to TS
amendments proposed by licensees and ongoing NRC TS improvement
programs. The intent of this generic letter is to reduce the time and
costs spent by licensees and the NRC staff in amending requirements
related to the selected instrumentation-related TS. Licensees will
reduce cost by relocating requirements to a licensee-controlled
document or program so that future changes to those requirements would
not necessarily involve a license amendment. The time and cost of NRC
staff review is reduced by the use of internal guidance for the review
of generic letter-related amendments and the reduction in the number of
plant-specific changes to the affected TS.
Discussion
Section 182a of the Atomic Energy Act (the Act) requires applicants
for nuclear power plant operating licenses to include TS as part of the
license. In Section 50.36 of Title 10 of the Code of Federal
Regulations (10 CFR 50.36), the Commission established the regulatory
requirements related to the content of TS. That regulation requires
that the TS include items in five specific categories, including (1)
safety limits, limiting safety system settings and limiting control
settings; (2) limiting conditions for operation; (3) surveillance
requirements; (4) design features; and (5) administrative controls.
However, the regulation does not specify the particular requirements to
be included in TS.
The NRC developed criteria, as described in the ``Final Policy
Statement on Technical Specifications Improvements for Nuclear Power
Reactors'' (58 FR 39132), to determine which of the design conditions
and associated surveillances should be located in the TS as limiting
conditions for operation. The four criteria provided in the Final
Policy Statement are:
(1) Installed instrumentation that is used to detect, and indicate
in the control room, a significant abnormal degradation of the reactor
coolant pressure boundary;
(2) a process variable, design feature, or operating restriction
that is an initial condition of a Design Basis Accident or Transient
analysis that either assumes the failure of or presents a challenge to
the integrity of a fission product barrier;
(3) a structure, system, or component that is part of the primary
success path and which functions or actuates to mitigate a Design Basis
Accident or Transient that either assumes the failure of or presents a
challenge to the integrity of a fission product barrier;
(4) a structure, system, or component which operating experience or
probabilistic safety assessment has shown to be significant to public
health and safety.
The Commission recently promulgated a proposed change to 10 CFR
50.36 pursuant to which the rule would be amended to codify and
incorporate these criteria (see Proposed Rule, ``Technical
Specifications,'' 59 FR 48180 (September 20, 1994)).
The Commission's Final Policy Statement acknowledged that its
implementation may cause some requirements presently in TS to be moved
out of existing TS to documents and programs controlled by licensees.
This generic letter addresses the relocation of selected TS
requirements related to instrumentation as a result of the
consideration of the final policy statement criteria. Upon review of
typical TS for nuclear power reactors, the staff determined that, in
accordance with the policy statement criteria, several specifications
did not warrant inclusion in TS. The staff also concluded that the
instrumentation addressed by these specifications are not related to
dominant contributors to plant risk. The following typical TS are among
the candidates for relocation to licensee-controlled documents:
Incore Detectors (Movable Incore Detectors, Transversing
Incore Probe).
Seismic Monitoring Instrumentation.
Meteorological Monitoring Instrumentation.
Chlorine Detection System.
Loose-Part Detection System.
Explosive Gas Monitoring Instrumentation.
Turbine Overspeed Protection.
Requested Information
Licensees who voluntarily choose to use the guidance in this
generic letter will need to submit license amendment requests in order
to relocate the affected technical specifications. These licensees are
encouraged to propose TS changes consistent with the guidance in
Attachment 1 to this generic letter.
Licensees who do not wish to amend technical specifications are not
expected to submit any response to this generic letter.
Required Response
Licensees who voluntarily choose to use the guidance in this
generic letter are required to submit license amendment requests in
order to relocate affected technical specification requirements.
Licensee requests should be submitted to the U.S. Nuclear
Regulatory Commission, ATTN: Document Control Desk, Washington, D.C.
20555, under the provisions of 10 CFR 50.90.
Backfit Discussion
This generic letter only requests information under the provisions
of 10 CFR 50.90 from addressees who voluntarily choose to use the
contained guidance to seek an amendment of an operating license. Any
action by licensees to propose TS changes in accordance with the
guidance of this generic letter is voluntary and, therefore, not a
backfit under 10 CFR 50.109. Therefore, the staff has not performed a
backfit analysis.
Attachment 1--Guidance for a Proposed License Amendment to Relocate
Selected Technical Specifications Requirements Related to
Instrumentation
Introduction
The NRC is issuing the following guidance for preparing a proposed
license amendment to relocate from Technical Specifications (TS)
selected requirements related to instrumentation. As discussed in the
Final Policy Statement, licensees submitting amendment requests should
identify the location of and controls for the relocated requirements.
It is expected that most of the TS addressed by this generic letter
will be relocated to the Updated Final Safety Analysis Report (UFSAR)
and changes to those provisions will be performed in accordance with 10
CFR 50.59, ``Changes, tests and experiments.'' If requirements are
relocated to other documents (e.g., the emergency plan), controls may
be [[Page 33241]] provided by regulatory requirements such as 10 CFR
50.54, ``Conditions of licenses.'' The adequacy of controls for
relocated provisions which do not fit in the above categories will be
reviewed and approved by the NRC staff on a case-by-case basis.
License amendment requests should contain a commitment to relocate
each selected requirement to a particular licensee-controlled document
or program, (e.g., the UFSAR or the emergency plan). The commitment
should also address the submittal of the revised documents to the NRC
in accordance with the applicable regulation (e.g., 10 CFR 50.71(e)).
In the amendment request, the licensee should clearly describe the
program it will use to control changes to relocated provisions (e.g.,
10 CFR 50.59 or 50.54(q)). Control of the relocated provisions in
accordance with the applicable regulation ensures that NRC review and
approval will be requested for changes exceeding the stated regulatory
threshold (e.g., unreviewed safety question or decrease in
effectiveness).
Licensees should note that this generic letter supersedes TS-
related guidance contained in several previously issued NRC documents,
such as regulatory guides and the Standard Review Plan (NUREG-0800).
Commitments contained in the UFSAR or other docketed correspondence may
need to be revised to reflect the deviations from these NRC documents.
However, this generic letter addresses only the need to include
requirements related to the affected systems in TS. Staff positions on
matters other than TS content that are contained in the regulatory
guides or other documents are not affected by the issuance of this
generic letter.
The NRC has approved the relocation of most of these specific
instrumentation requirements in various amendments issued to specific
licensees. The improved standard TS also reflect the staff position
that these requirements do not satisfy the final policy statement
criteria for inclusion in TS. The staff has also concluded that these
provisions are not related to dominant contributors to plant risk.
Additional discussions follow for each of the selected relocated
instrumentation requirements.
Incore Detectors
The relocation of requirements related to incore neutron detectors
affects the TS sections entitled ``Incore Detectors'' or ``Movable
Incore Detectors,'' for pressurized water reactors (PWRs), or
``Transversing Incore Probe,'' for boiling water reactors (BWRs).
Incore instrumentation is used periodically to calculate power peaking
factors in order to verify nuclear design predictions, ensure operation
within established fuel performance limits, and to calibrate other
nuclear instrumentation. The measurements are used in a confirmatory
manner and do not provide direct input to reactor protection system or
engineered safety features actuation system functions.
These instruments are neither used for, nor capable of, detecting a
significant abnormal degradation of the reactor coolant pressure
boundary prior to a design basis accident nor do they function as a
primary success path to mitigate events which assume the failure of or
challenge the integrity of fission product barriers. Although the core
power distributions (measured by the incore detectors) constitute an
important initial condition to design basis accidents and therefore
need to be addressed by TS, the detectors themselves are not an active
design feature needed to preclude analyzed accidents or transients. The
staff has determined therefore, that the incore detector requirements
do not satisfy the criteria of the Final Policy Statement for inclusion
in TS. Licensees may propose to relocate the incore detector
requirements to the UFSAR and control changes to those provisions in
accordance with 10 CFR 50.59.
Relocation of the incore detector requirements from the TS to the
UFSAR does not imply any reduction in their importance in confirming
that core power distributions are bounded by safety analysis limits. It
is expected that licensees will continue to maximize the number of
available incore detectors. Evaluations related to changes in incore
detector requirements are expected to consider such factors as the need
to identify the inadvertent loading of a fuel assembly into an improper
location, the calibration of protection systems using incore
measurements, and the allowances for measurement and nuclear design
uncertainties. Should these or other considerations lead to the
identification of a proposed change as an unreviewed safety question,
the licensee should request NRC review and approval in accordance with
10 CFR 50.59(c).
Seismic Monitoring Instrumentation
Section VI(a)(3) of Appendix A to 10 CFR Part 100 requires that
seismic monitoring instrumentation be provided to promptly determine
the response of those nuclear power plant features important to safety
in the event of an earthquake. This capability is required to allow for
a comparison of the measured response to that used in the design basis
for the unit. Comparison of such data is needed to (1) determine
whether the plant can continue to be operated safely, and (2) permit
such timely action as may be appropriate. However, seismic
instrumentation does not actuate any protective equipment or serve any
direct role in the mitigation of an accident.
The capability of the plant to withstand a seismic event or other
design-basis accident is determined by the initial design and
construction of systems, structures, and components. The
instrumentation is used to alert operators to the seismic event and
evaluate the plant response. The Final Policy Statement explained that
instrumentation to detect precursors to reactor coolant pressure
boundary leakage, such as seismic instrumentation, is not included in
the first criterion. As discussed above, the seismic instrumentation
does not serve as a protective design feature or part of a primary
success path for events which challenge fission product barriers. The
staff has concluded that the seismic monitoring instrumentation does
not satisfy the final policy statement criteria and need not be
included in the TS. Licensees may propose to relocate the seismic
monitoring instrumentation requirements to the UFSAR and control
changes to those provisions in accordance with 10 CFR 50.59.
Meteorological Monitoring Instrumentation
In 10 CFR 50.47, ``Emergency Plans,'' and 10 CFR Part 50, Appendix
E, ``Emergency Planning and Preparedness for Production and Utilization
Facilities,'' the Commission requires power plant licensees to provide
reasonable assurance that adequate protective measures can and will be
taken in the event of a radiological emergency. Timely access to
accurate local meteorological data is important for estimating
potential radiation doses to the public and for determining appropriate
protective measures. In 10 CFR 50.36a(a)(2), the Commission requires
nuclear power plant licensees to submit annual reports specifying the
quantity of each of the principal radionuclides released to
unrestricted areas in liquid and airborne effluents and such other
information as may be required by the NRC to estimate maximum potential
annual radiation doses to the public. A knowledge of meteorological
conditions in the vicinity of the reactor is important in providing a
basis for estimating annual radiation doses resulting from
[[Page 33242]] radioactive materials released in airborne effluents.
Accordingly, the meteorological monitoring instrumentation serves a
useful function in estimating radiation doses to the public from either
routine or accidental releases of radioactive materials to the
atmosphere.
The meteorological monitoring instrumentation does not serve such a
primary protective function as to warrant inclusion in the TS in
accordance with the criteria of the final policy statement. The
instrumentation does not serve to ensure that the plant is operated
within the bounds of initial conditions assumed in design basis
accident and transient analyses or that the plant will be operated to
preclude transients or accidents. Likewise, the meteorological
instrumentation does not serve as part of the primary success path of a
safety sequence analysis used to demonstrate that the consequences of
these events are within the appropriate acceptance criteria.
Accordingly, the staff has concluded that the meteorological
instrumentation does not satisfy the final policy statement criteria
and need not be included in TS. The staff has determined that
requirements related to the meteorological monitoring instrumentation
can be moved from the TS to the UFSAR, and that any subsequent changes
to the provisions would be controlled pursuant to 10 CFR 50.59.
Licensees may alternately choose to relocate the meteorological
monitoring instrumentation requirements from the TS to the facility's
emergency plan. In this case, subsequent changes would be made in
accordance with 10 CFR 50.54(q).
Chlorine Detection System
Chlorine detection systems ensure that sufficient capability is
available to promptly detect and initiate protective action to isolate
the control room in the event of an accidental chlorine release. Some
plants may also have systems to detect other toxic gases which have the
potential to hamper plant operation in the case of their accidental
release from onsite or offsite sources. The relocation of TS related to
other toxic gas detection systems is included in this discussion for
the typical chlorine detection systems. Staff positions regarding the
relationship of the chlorine detection systems to the general design
criteria (GDC) appear in NUREG-0800, ``Standard Review Plan'' (SRP);
Regulatory Guide (RG) 1.78, ``Assumptions for Evaluating the
Habitability of a Nuclear Power Plant Control Room During a Postulated
Hazardous Chemical Release''; and RG 1.95, ``Protection of Nuclear
Power Plant Control Room Operators Against an Accidental Chlorine
Release.''
As discussed above, chlorine detection systems may serve an
important role in the protection of control room personnel from
internal or external hazards related to toxic gases. However, the
release of chlorine or other hazardous chemicals is not part of an
initial condition of a design basis accident or transient analysis that
assumes a failure of or presents a challenge to the integrity of a
fission product barrier. Since the release of toxic gases is not
assumed to initiate or occur simultaneously with design basis accidents
or transients involving challenges to fission product barriers, the
chlorine detection system is not part of a success path for the
mitigation of those accidents or transients. The staff has, therefore,
concluded that requirements for this system do not satisfy the final
policy statement criteria and need not be included in TS. Licensees may
propose to relocate the chlorine detection system requirements to the
UFSAR and control changes to those provisions in accordance with 10 CFR
50.59.
Loose-Part Detection System
The loose-part detection system identifies the existence of
possible loose parts in the reactor coolant system. Early detection can
provide operators time to take corrective actions and avoid or mitigate
damage to or malfunctions of primary system components. However, as
discussed in the final policy statement, the loose-part detection
system does not function to detect significant abnormal degradation of
the reactor coolant pressure boundary. The loose-part detection system
does not serve as an active design feature for establishing initial
conditions or mitigation of design basis accidents or transients. The
staff has concluded that requirements for this system do not satisfy
the final policy statement criteria and need not be included in TS.
Licensees may propose to relocate the requirements related to the
loose-part detection system from the TS to the UFSAR and control
changes to those provisions in accordance with 10 CFR 50.59.
Explosive Gas Monitoring Instrumentation
The relocation of most of the instrumentation related to
radioactive gaseous effluent monitoring was addressed in Generic Letter
89-01, ``Implementation of Programmatic Controls for Radiological
Effluent Technical Specifications [RETS] in the Administrative Controls
Section of the Technical Specifications and the Relocation of
Procedural Details of RETS to the Offsite Dose Calculation Manual or
the Process Control Program.'' Relocation of the requirements for
explosive gas monitoring instrumentation was not addressed in the
guidance provided by Generic Letter 89-01. Staff positions regarding
the monitoring of explosive gases within the radioactive waste
management systems are outlined in SRP Section 11.3 and Branch
Technical Position ETSB-11-5, ``Postulated Radioactive Releases Due to
a Waste Gas System Leak or Failure.''
The actions required by existing TS typically require alternate
sampling, limited operation of the gaseous waste system, and submittal
of a special report if the explosive gas monitoring instrumentation
does not conform to the limiting condition for operation. The explosive
gas monitoring instrumentation requirements address detection of
possible precursors to the failure of a waste gas system but do not
prevent or mitigate design basis accidents or transients which assume a
failure of or present a challenge to a fission product barrier.
Acceptable concentrations of explosive gases are actually controlled by
other limiting conditions for operation (e.g., Gaseous Effluents,
Explosive Gas Mixture) or by programs described in the ``Administrative
Controls'' section of TS. The requirements related to explosive gas
monitoring instrumentation do not conform to the final policy statement
criteria for inclusion in the TS. Therefore, licensees may propose to
relocate the explosive gas monitoring instrumentation requirements to
the UFSAR and control changes to those provisions in accordance with 10
CFR 50.59.
Turbine Overspeed Protection
Existing TS typically include limiting conditions for operation and
surveillance requirements for the turbine overspeed protection system.
The turbine is equipped with control valves and stop valves which
control turbine speed during normal plant operation and protect it from
overspeed during abnormal conditions. The turbine overspeed protection
system consists of separate mechanical and electrical sensing
mechanisms which are capable of initiating fast closure of the control
and stop valves. Current TS may require particular operability and
surveillance requirements for these steam control and stop valves to
minimize the potential for fragment missiles that might be generated as
the result of a turbine overspeed event. [[Page 33243]] General Design
Criterion 4 of Appendix A to 10 CFR Part 50 requires that structures,
systems, and components important to safety be appropriately protected
from the effects of missiles that may result from equipment failures.
Application of the design criteria to turbine missiles is described in
SRP Section 10.2 and in subsequent safety evaluations related to
probabilities of turbine failures, turbine orientations, and
surveillance requirements for turbine overspeed protection systems. In
NUREG-1366, ``Improvements to Technical Specifications Surveillance
Requirements,'' the staff discusses the benefits, resultant costs, and
the safety impact of performing turbine overspeed protection
surveillances.
Although the design basis accidents and transients include a
variety of system failures and conditions which might result from
turbine overspeed events and potential missiles striking various plant
systems and equipment, the system failures and plant conditions are
much more likely to be caused by events other than turbine failures. In
view of the low likelihood of turbine missiles, assumptions related to
the turbine overspeed protection system are not part of an initial
condition of a design basis accident or transient that either assumes
the failure of or presents a challenge to the integrity of a fission
product barrier. The turbine overspeed protection system is not relied
upon in the design basis accident or transient analyses as a primary
success path which functions or actuates to mitigate such events.
Probabilistic safety assessments and operating experience have
demonstrated that proper maintenance of the turbine overspeed control
valves is important to minimize the potential for overspeed events and
turbine damage; however that experience has also demonstrated that
there is low likelihood of significant risk to public health and safety
because of turbine overspeed events. Further, the potential for and
consequences of turbine overspeed events are diminished by factors such
as the orientation of the turbine relative to plant structures and
equipment, licensee inservice testing programs, which must comply with
10 CFR 50.55(a), and surveillance programs for the turbine control and
stop valves derived from the manufacturer's recommendations.
Accordingly, the staff has concluded that the turbine overspeed
protection system does not satisfy the final policy statement criteria
and need not be included in TS. Licensees may propose to relocate the
turbine overspeed protection requirements to the UFSAF requirements to
the UFSAR and control changes to those provisions in accordance with 10
CFR 50.59.
Dated at Rockville, Maryland, this 20th day of June 1995.
Brian K. Grimes,
Director, Division of Project Support, Office of Nuclear Reactor
Regulation.
[FR Doc. 95-15677 Filed 6-26-95; 8:45 am]
BILLING CODE 7590-01-P
