Proposed License Renewal Interim Staff Guidance LR-ISG-2008-01: Staff Guidance Regarding the Station Blackout Rule (10 CFR 50.63); Associated With License Renewal Applications; Solicitation of Public Comment, 13258-13261 [E8-4902]
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during this advisory phase of the
proceeding.18
Responses to this memorandum and
any other responses to information or
requests for input from the Advisory
PAPO Board must be submitted and
served electronically through the NRC’s
Electronic Information Exchange (EIE)
system, docket number PAPO–001.
Potential parties that already have been
participating in the PAPO proceeding,
docket number PAPO–00, and using the
EIE system do not need to do anything
additional to be able to file in this
Advisory PAPO proceeding. Those that
have not been participating in the PAPO
proceeding but wish to make
submissions before this Board should
consult the NRC’s Web site, which
provides detailed instructions on the
steps necessary to access and make EIE
submissions, including (1) obtaining a
digital certificate from the NRC Office of
the Secretary and installing that
certificate into the participant’s Web
browser (https://www.nrc.gov/site-help/
e-submittals/apply-certificates.html); (2)
loading the viewer software currently
needed to submit and view documents
in the EIE system (https://www.nrc.gov/
site-help/e-submittals/installviewer.html); (3) creating a document in
the portable document format (PDF)
suitable for EIE submission (https://
www.nrc.gov/site-help/electronic-subref-mat.html); and (4) accessing the EIE
Web site and submitting the document
(https://www.nrc.gov/site-help/esubmittals/submit-documents.html). A
potential party that is not currently
participating in the PAPO proceeding
and using EIE should begin this process
no less than five days before it wishes
to make an initial submission. In
submitting their responses, potential
parties should make sure they are filing
them on this docket, PAPO–001, which
is denominated as the ‘‘Advisory PAPO
Board’’ on the dropdown list of
proceedings that is part of the EIE filing
form.
We request that all potential parties
(including DOE and the NRC Staff)
provide us with a filing that includes
the information described above in Part
II.A and that in its filing DOE also
provide us with the information
described above in Part II.B. All filings
should be submitted through the
agency’s EIE system and served on the
service list for the Advisory PAPO
Board proceeding, docket number
PAPO–001, by Monday, March 24, 2008.
18 We caution that for potential parties that have
not already been participating in the PAPO
proceeding, docket number PAPO–00, filing a
notice of appearance with this Advisory PAPO
Board, docket number PAPO–001, will not suffice
for participation in the PAPO proceeding.
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March 6, 2008, Rockville, Maryland.
The Advisory Pre-License Application,
Presiding Officer Board.
Thomas S. Moore,
Chairman, Administrative Judge.
G. Paul Bollwerk, III,
Administrative Judge.
E. Roy Hawkens,
Administrative Judge.
[FR Doc. E8–4918 Filed 3–11–08; 8:45 am]
BILLING CODE 7590–01–P
NUCLEAR REGULATORY
COMMISSION
Proposed License Renewal Interim
Staff Guidance LR–ISG–2008–01: Staff
Guidance Regarding the Station
Blackout Rule (10 CFR 50.63);
Associated With License Renewal
Applications; Solicitation of Public
Comment
U.S. Nuclear Regulatory
Commission.
AGENCY:
ACTION:
Solicitation of public comment.
The U.S. Nuclear Regulatory
Commission (NRC) is soliciting public
comment on its Proposed License
Renewal Interim Staff Guidance LR–
ISG–2008–01 (LR–ISG) for clarification
to its previously issued LR–ISG–02,
‘‘Staff Guidance on Scoping of
Equipment Relied on to Meet the
Requirements of the Station Blackout
(SBO) Rule (10 CFR 50.63) for License
Renewal,’’ dated April 1, 2002, which
has been incorporated in the License
Renewal Standard Review Plan. This
LR–ISG provides additional clarification
to the staff position on the license
renewal scoping requirements regarding
the offsite power system for SBO
recovery. The NRC staff issues LR–ISGs
to facilitate timely implementation of
the license renewal rule and to review
activities associated with a license
renewal application. Upon receiving
public comments, the NRC staff will
evaluate the comments and make a
determination to incorporate the
comments, as appropriate. Once the
NRC staff completes the LR–ISG, it will
issue the LR–ISG for NRC and industry
use. The NRC staff will also incorporate
the approved LR–ISG into the next
revision of the license renewal guidance
documents.
SUMMARY:
Comments may be submitted by
May 12, 2008. Comments received after
this date will be considered, if it is
practical to do so, but the Commission
is able to ensure consideration only for
comments received on or before this
date.
DATES:
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Comments may be
submitted to: Chief, Rulemaking,
Directives and Editing Branch, Office of
Administration, U.S. Nuclear Regulatory
Commission, Washington, DC 20555–
0001. Comments should be delivered to:
11545 Rockville Pike, Rockville,
Maryland, Room T–6D59, between 7:30
a.m. and 4:15 p.m. on Federal workdays.
Persons may also provide comments via
e-mail at NRCREP@NRC.GOV. The NRC
maintains an Agencywide Documents
Access and Management System
(ADAMS), which provides text and
image files of NRC’s public documents.
These documents may be accessed
through the NRC’s Public Electronic
Reading Room on the Internet at
https://www.nrc.gov/reading-rm/
adams.html. Persons who do not have
access to ADAMS or who encounter
problems in accessing the documents
located in ADAMS should contact the
NRC Public Document Room (PDR)
reference staff at 1–800–397–4209, 301–
415–4737, or by e-mail at pdr@nrc.gov.
ADDRESSES:
Ms.
Stacie Sakai, Project Manager, Office of
Nuclear Reactor Regulation, U.S.
Nuclear Regulatory Commission,
Washington, DC 20555–0001; telephone
301–415–1884 or by e-mail at
sxs11@nrc.gov.
FOR FURTHER INFORMATION CONTACT:
SUPPLEMENTARY INFORMATION:
Attachment 1 to this Federal Register
notice, entitled Staff Position and
Rationale for the Proposed License
Renewal Interim Staff Guidance LR–
ISG–2008–01: Staff Guidance Regarding
the Station Blackout Rule (10 CFR
50.63) Associated with License Renewal
Applications,’’ contains the NRC staff’s
rationale for publishing the proposed
LR–ISG–2008–01. Attachment 2 to this
Federal Register notice, entitled
Proposed License Renewal Interim Staff
Guidance LR–ISG–2008–01: Staff
Guidance Regarding the Station
Blackout Rule (10 CFR 50.63)
Associated with License Renewal
Applications,’’ contains the additional
clarification to the current staff position
on the license renewal SBO scoping
requirements.
The NRC staff is issuing this notice to
solicit public comments on the
proposed LR–ISG–2008–01. After the
NRC staff considers any public
comments, it will make a determination
regarding issuance of the proposed LR–
ISG.
Dated at Rockville, Maryland this 5th day
of March, 2008.
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Federal Register / Vol. 73, No. 49 / Wednesday, March 12, 2008 / Notices
For the Nuclear Regulatory Commission.
Pao-Tsin Kuo,
Director, Division of License Renewal, Office
of Nuclear Reactor Regulation.
Attachment 1—Staff Position and
Rationale for the Proposed License
Renewal Interim Staff Guidance LR–
ISG–2008–01: Staff Guidance Regarding
the Station Blackout Rule (10 CFR
50.63) Associated With License
Renewal Applications
pwalker on PROD1PC71 with NOTICES
Staff Position
Consistent with the requirements
specified in Title 10, § 54.4(a)(3), of the
Code of Federal Regulations (10 CFR
54.4(a)(3)) and 10 CFR 50.63(a)(1), the
scope of license renewal should include
the offsite recovery path from the
transmission system to the Class 1E
distribution system. Accordingly, the
offsite recovery paths that must be
included within the scope of license
renewal, in accordance with 10 CFR
54.4(a)(3), consist of circuits from two
independent sources. Both paths start
from the switchyard breaker to the plant
Class 1E safety buses. This path
includes (1) switchyard circuit breakers
that connect to the offsite power system
(i.e., grid), (2) power transformers, (3)
intervening overhead or underground
circuits (i.e., cables, buses and
connections, transmission conductors
and connections, insulators, disconnect
switches, and associated components),
(4) circuits between the circuit breakers
and power transformers, (5) circuits
between the power transformers and
onsite electrical distribution system,
and (6) the associated control circuits
and structures.
Rationale
The license renewal rule, 10 CFR
54.4(a)(3), requires that the scope of
license renewal include ‘‘All systems,
structures, and components relied on in
safety analyses or plant evaluations to
perform a function that demonstrates
compliance with the Commission’s
regulations for * * * station blackout
(10 CFR 50.63).’’ The station blackout
(SBO) rule, 10 CFR 50.63(a)(1), states
that each light-water-cooled nuclear
power plant licensed to operate must be
able to withstand and recover from an
SBO of a specified duration that is based
on factors that include ‘‘(iii) The
expected frequency of loss of offsite
power; and (iv) The probable time
needed to restore offsite power.’’ In this
regard, the SBO rule is consistent with
the staff findings identified in the
statement of considerations for the SBO
rule and NUREG–1032, ‘‘Evaluation of
Station Blackout Accidents at Nuclear
Power Plants,’’ issued June 1988.
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During its evaluation of licensee
compliance with the requirements in 10
CFR 50.63, ‘‘Loss of All Alternating
Current Power,’’ the staff has assessed
the offsite power recovery paths that are
credited in the licensee evaluation of
SBO coping duration. The SBO coping
duration evaluation is based on the
criteria specified in 10 CFR 50.63(a)(1).
The staff’s regulatory assessment and
acceptance of licensees’ compliance
with the SBO rule for offsite power is
based on the site-related characteristics
and power design characteristics as
defined in Regulatory Guide (RG) 1.155,
‘‘Station Blackout,’’ issued August 1988,
and also the availability and reliability
of the offsite power including the
protective coordination of switchyard
breakers. The staff developed this
guidance to ensure that scoping of SBO
equipment in accordance with the
requirements of 10 CFR 54.4(a)(3) is
conducted in a manner consistent with
the original staff evaluations of licensee
compliance with the requirements of the
SBO rule (10 CFR 50.63) to include
equipment necessary for recovery.
Attachment 2—Proposed License
Renewal Interim Staff Guidance LR–
ISG–2008–01: Staff Guidance Regarding
the Station Blackout Rule (10 CFR
50.63) Associated with License Renewal
Applications
Staff Position
Consistent with the requirements
specified in Title 10, § 54.4(a)(3), of the
Code of Federal Regulations (10 CFR
54.4(a)(3)) and 10 CFR 50.63(a)(1), the
scope of license renewal should include
the offsite recovery path from the
transmission system to the Class 1E
distribution system. The offsite and
onsite power circuits must permit
functioning of structures, systems, and
components necessary to respond to the
event. The rationale for this position
follows.
Rationale
In the license renewal rule, 10 CFR
54.4(a)(3) requires that the scope of
license renewal include ‘‘All systems,
structures, and components relied on in
safety analyses or plant evaluations to
perform a function that demonstrates
compliance with the Commission’s
regulations for * * * station blackout
(10 CFR 50.63).’’ In the station blackout
(SBO) rule, 10 CFR 50.63(a)(1), states
that each light-water-cooled nuclear
power plant licensed to operate must be
able to withstand and recover from an
SBO of a specified duration that is based
on factors that include ‘‘(iii) The
expected frequency of loss of offsite
power; and (iv) The probable time
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13259
needed to restore offsite power.’’ In this
regard, the SBO rule is consistent with
the staff findings identified in the
statement of considerations and
NUREG–1032, ‘‘Evaluation of Station
Blackout Accidents at Nuclear Power
Plants,’’ issued June 1988. In particular,
with regard to factor (iv), the staff found
that restoration of offsite power (0.6
hours median time to restore) is more
likely to terminate an SBO event than
restoration of the emergency diesel
generators (8 hours median time to
repair).
In Appendix A, ‘‘General Design
Criteria for Nuclear Power Plants,’’ to 10
CFR part 50, ‘‘Domestic Licensing of
Production and Utilization Facilities,’’
General Design Criterion (GDC) 17,
‘‘Electric Power Systems,’’ requires that
two physically independent circuits
shall supply electric power from the
transmission network to the onsite
electric distribution system. These
circuits must be designed and located so
as to minimize to the extent practical
the likelihood of their simultaneous
failure under operating and postulated
accident and environmental conditions.
A switchyard common to both circuits
is acceptable. Each of these circuits
shall be designed to be available soon
enough after a loss of all onsite
alternating current (ac) power supplies
and the loss of the other offsite electric
power circuit to ensure that specified
acceptable fuel design limits and design
conditions of the reactor coolant
pressure boundary are not exceeded.
One of these circuits (the immediate
access circuit) shall be designed to be
available within a few seconds
following a loss-of-coolant accident to
ensure the maintenance of core cooling,
containment integrity, and other vital
safety functions.
Plants not licensed in accordance
with GDC 17 were licensed to satisfy
plant-specific principal design criteria
presented in the plant updated final
safety analysis report (FSAR). These
criteria are similar to GDC 17. The
electric grid is the source of power to
the offsite power system. Therefore, all
operating plants have offsite power
requirements similar to GDC 17. The
plant technical specifications embody
the operational restrictions for the
design requirements for the loss of
offsite power sources.
SBO is the loss of offsite and onsite
ac electric power to the essential and
nonessential switchgear buses in a
nuclear power plant. It does not include
the loss of ac power fed from inverters
powered by station batteries or loss of
ac power from an alternate ac power
source. The U.S. Nuclear Regulatory
Commission added the SBO rule to the
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regulations in 10 CFR part 50 because,
as operating experience accumulated,
concern arose that the reliability of both
the offsite and onsite ac power systems
might be less than originally
anticipated, even for designs that met
the requirements of GDC 17 and GDC
18, ‘‘Inspection and Testing of Electric
Power Systems.’’ The results of risk
studies indicate that estimated core melt
frequencies from SBOs vary
considerably between plants and could
be a significant risk contributor for some
plants.
As a result, the SBO rule required that
nuclear power plants have the
capability to withstand and recover
from the loss of offsite and onsite ac
power of a specified duration (the
coping duration). In their plant
evaluations, licensees followed the
guidance specified in Regulatory Guide
(RG) 1.155, ‘‘Station Blackout,’’ issued
August 1988, and NUMARC 87–00,
‘‘Guidelines and Technical Bases for
NUMARC Initiatives Addressing Station
Blackout at Light Water Reactors,’’ to
determine their required plant-specific
coping duration. The agency based the
criteria specified in RG 1.155 to
calculate a plant-specific coping
duration on the expected frequency of
loss of offsite power and the probable
time needed to restore offsite power, as
well as the other two factors (onsite
emergency ac power source redundancy
and reliability) specified in 10 CFR
50.63(a)(1). In requiring that a plant’s
coping duration be based in part on the
probable time needed to restore offsite
power, 10 CFR 50.63(a)(1) specifies that
the offsite power system be an assumed
method of recovering from an SBO.
Disregarding the offsite power system as
a means of recovering from an SBO
would not meet the requirements of the
10 CFR 50.63 rule and would result in
a longer required coping duration.
The use of the offsite power system
within 10 CFR 50.63(a)(1) as a means of
recovering from an SBO should not be
construed to be the only acceptable
means of recovering from an SBO. A
licensee could, for example, recover
offsite power or emergency (onsite)
power. It is not possible to determine
before an actual SBO event which
source of power can be returned first. As
a result, 10 CFR 50.63(c)(1)(ii) and its
associated guidance in RG 1.155,
Sections 1.3 and 2, require procedures
to recover from an SBO that include
restoration of offsite and onsite power.
Based on the above, licensees rely on
both the offsite and onsite power
systems to meet the requirements of the
SBO rule. Elements of both offsite and
onsite power are necessary to determine
the required coping duration under 10
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CFR 50.63(a)(1), and the procedures
required by 10 CFR 50.63(c)(1)(ii) must
address both offsite power and onsite
power restoration. It follows, therefore,
that both systems are used to
demonstrate compliance with the SBO
rule and must be included within the
scope of license renewal consistent with
the requirements of 10 CFR 54.4(a)(3).
The onsite power system is included
within the scope of license renewal on
the basis of the requirements under 10
CFR 54.4(a)(1) (safety-related systems).
The equipment that is relied upon to
cope with an SBO (e.g., alternate ac
power sources) is included within the
scope of license renewal on the basis of
the requirements under 10 CFR
54.4(a)(3). The offsite power system is
therefore necessary to complete the
required scope of the electrical power
systems under license renewal.
The staff has recently noted during
the review of license renewal
applications that some applicants have
not included all of the components and
structures within the scope of license
renewal needed for recovering the
offsite source from an SBO event as
required by 10 CFR 54.4(a)(3). Failure to
include all of the structures and
components within the scope of license
renewal will result in those structures
and components not being subject to
aging management review, and the
effects of aging will not be adequately
managed so that the intended
function(s) will be maintained
consistent with the current licensing
basis for the period of extended
operation in accordance with 10 CFR
54.21(a)(1) and (a)(3).
During its evaluation of licensee
compliance with the requirements in 10
CFR 50.63, ‘‘Loss of All Alternating
Current Power,’’ the staff has assessed
the offsite power recovery paths that are
credited in the licensee evaluation of
SBO coping duration. The SBO coping
duration evaluation is based on the
criteria specified in 10 CFR 50.63(a)(1).
The staff’s regulatory assessment and
acceptance of licensees’ compliance
with the SBO rule for offsite power is
based on the site-related characteristics
and power design characteristics as
defined in RG 1.155, and also the
availability and reliability of the offsite
power including the protective
coordination of switchyard breakers.
The offsite power systems of U.S.
nuclear power plants consist of a
transmission system component and a
switchyard that provides a source of
power and a plant system component
that connects that power source to a
plant’s onsite electrical distribution
system which powers safety equipment.
The staff considers each plant design
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individually, reviewing the plant’s
FSAR and associated electrical
drawings. The key to performing the
scoping for the SBO recovery path is
defining the boundary of the offsite
power source at the switchyard. A
switchyard can have multiple offsite
lines supplying the switchyard buses.
Although switchyard designs vary, most
plants have either a ring bus or breakerand-a-half scheme.
The scoping boundary, as outlined in
the Standard Review Plan-License
Renewal (SRP–LR), Section 2.5.2.1.1,
should be from the breaker or breakers
from the switchyard (connections to the
line side). If there is a circuit breaker
between the power transformer (startup,
reserve, auxiliary, or main transformer)
and the switchyard bus, and the circuit
breaker is directly bolted to the
switchyard bus, then that circuit breaker
is acceptable as the scoping boundary.
If there is a disconnect switch, but no
circuit breaker exists between the
transformer and the switchyard bus,
then the circuit breaker(s) connected to
the switchyard bus that feeds the power
transformer (startup, reserve, auxiliary,
or main transformer) should be
acceptable as the scoping boundary.
The circuit breaker, as the scoping
boundary, provides connection to offsite
power via the switchyard bus, which
can be powered by any of the incoming
transmission lines. This breaker should
be at the transmission system voltage to
ensure adequate protection of safety bus
and the recovery of offsite power. The
staff believes that the circuit breaker
needs to be within the scope of license
renewal because of its ability to provide
plant power, protect downstream
circuits and provide plant operatorcontrolled isolation and energization
ability. In addition, a circuit breaker
coordinates with other protective
devices to minimize the probability of
loss of offsite power and prevent
transients from affecting the onsite
distribution system as offsite power is
being restored. For these reasons, a
circuit breaker remains as the scoping
boundary. Using a disconnect switch or
other component downstream of the
breaker is not consistent with the staff
position of compliance with the SBO
rule and is not acceptable for meeting
the SBO scoping requirements for
license renewal.
As discussed above, for purposes of
the license renewal, the staff has
determined that the offsite recovery
paths that must be included within the
scope of license renewal, in accordance
with 10 CFR 54.4(a)(3), consist of
circuits from two independent sources.
Both paths start from the switchyard
breaker to the plant Class 1E safety
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Federal Register / Vol. 73, No. 49 / Wednesday, March 12, 2008 / Notices
buses. This path includes (1) switchyard
circuit breakers that connect to the
offsite power system (i.e., grid), (2)
power transformers, (3) intervening
overhead or underground circuits (i.e.,
cables, buses and connections,
transmission conductors and
connections, insulators, disconnect
switches, and associated components),
(4) circuits between the circuit breakers
and power transformers, (5) circuits
between the power transformers and
onsite electrical distribution system,
and (6) control circuit cables and
connections and structures associated
with components in the recovery path.
The SBO recovery path scoping
boundary ends at the line side of the
switchyard breaker(s) at transmission
system voltage. For the switchyard
breakers, bolted connections to the
switchyard bus and structural
components supporting the breakers are
within the scope of license renewal. The
control circuit cables and its
connections for the switchyard breakers
are not within the scope of license
renewal. Figures of different
configurations of the SBO offsite power
recovery path that are acceptable to the
staff and meet the license renewal
scoping requirements in accordance
with 10 CFR 54.4(a)(3) are available via
ADAMS at Accession No.
ML080520620.
The ownership of switchyard
components is not a factor in ensuring
that the effects of aging will be
adequately managed for components
and structures needed for recovering the
offsite circuits from an SBO event
consistent with the requirements in 10
CFR 54.4, ‘‘Scope,’’ and 10 CFR 54.21,
‘‘Contents of Application—Technical
Information.’’ The staff recognizes that
there are interface and control
agreements between the licensee and
transmission system operator. These
agreements do not preclude the
applicant from complying with
requirements specified in 10 CFR 54.4
and 10 CFR 54.21.
Designating the appropriate offsite
power system long-lived passive
structures and components that are part
of this circuit path as subject to an aging
management review will ensure the
maintenance of the bases underlying the
SBO requirements over the period of the
extended license. This is consistent
with the Commission’s expectations in
including the SBO event under 10 CFR
54.4(a)(3) of the license renewal rule.
[FR Doc. E8–4902 Filed 3–11–08; 8:45 am]
BILLING CODE 7590–01–P
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RAILROAD RETIREMENT BOARD
Proposed Data Collection Available for
Public Comment and
Recommendations
Summary: In accordance with the
requirement of Section 3506(c)(2)(A) of
the Paperwork Reduction Act of 1995
which provides opportunity for public
comment on new or revised data
collections, the Railroad Retirement
Board (RRB) will publish periodic
summaries of proposed data collections.
Comments are invited on: (a) Whether
the proposed information collection is
necessary for the proper performance of
the functions of the agency, including
whether the information has practical
utility; (b) the accuracy of the RRB’s
estimate of the burden of the collection
of the information; (c) ways to enhance
the quality, utility, and clarity of the
information to be collected; and (d)
ways to minimize the burden related to
the collection of information on
respondents, including the use of
automated collection techniques or
other forms of information technology.
Title and purpose of information
collection: Statement of Authority to Act
for Employee; OMB 3220–0034.
Under Section 5(a) of the Railroad
Unemployment Insurance Act (RUIA),
claims for benefits are to be made in
accordance with such regulations as the
Railroad Retirement Board (RRB) shall
prescribe. The provisions for claiming
sickness benefits as provided by Section
2 of the RUIA are prescribed in 20 CFR
335.2. Included in these provisions is
the RRB’s acceptance of forms executed
by someone else on behalf of an
employee if the RRB is satisfied that the
employee is sick or injured to the extent
of being unable to sign forms.
The RRB utilizes Form SI–10,
Statement of Authority to Act for
Employee, to provide the means for an
individual to apply for authority to act
on behalf of an incapacitated employee
and also to obtain the information
necessary to determine that the
delegation should be made. Part I of the
form is completed by the applicant for
the authority and Part II is completed by
the employee’s doctor. One response is
requested of each respondent.
Completion is required to obtain
benefits. The RRB proposes no changes
to Form SI–10.
The estimated annual respondent
burden is as follows:
Form: SI–10.
Estimate of Annual Responses: 400.
Estimated Completion Time: 6
minutes.
Total Burden Hours: 40.
Additional Information or Comments:
To request more information or to
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13261
obtain a copy of the information
collection justification, forms, and/or
supporting material, please call the RRB
Clearance Officer at (312) 751–3363 or
send an e-mail request to
Charles.Mierzwa@RRB.GOV. Comments
regarding the information collection
should be addressed to Ronald J.
Hodapp, Railroad Retirement Board, 844
North Rush Street, Chicago, Illinois
60611–2092 or send an e-mail to
Ronald.Hodapp@RRB.GOV. Written
comments should be received within 60
days of this notice.
Charles Mierzwa,
Clearance Officer.
[FR Doc. E8–4910 Filed 3–11–08; 8:45 am]
BILLING CODE 7905–01–P
RAILROAD RETIREMENT BOARD
Agency Forms Submitted for OMB
Review, Request for Comments
SUMMARY: In accordance with the
Paperwork Reduction Act of 1995 (44
U.S.C. Chapter 35), the Railroad
Retirement Board (RRB) is forwarding
an Information Collection Request (ICR)
to the Office of Information and
Regulatory Affairs (OIRA), Office of
Management and Budget (OMB) to
request a revision to a currently
approved collection of information:
3220–0195, Statement Regarding
Contributions and Support of Children.
Our ICR describes the information we
seek to collect from the public. Review
and approval by OIRA ensures that we
impose appropriate paperwork burdens.
The RRB invites comments on the
proposed collection of information to
determine (1) the practical utility of the
collection; (2) the accuracy of the
estimated burden of the collection; (3)
ways to enhance the quality, utility and
clarity of the information that is the
subject of collection; and (4) ways to
minimize the burden of collections on
respondents, including the use of
automated collection techniques or
other forms of information technology.
Comments to RRB or OIRA must contain
the OMB control number of the ICR. For
proper consideration of your comments,
it is best if RRB and OIRA receive them
within 30 days of publication date.
Section 2(d)(4) of the Railroad
Retirement Act (RRA), provides, in part,
that a child is deemed dependent if the
conditions set forth in Section 202(d)(3),
(4) and (9) of the Social Security Act are
met. Section 202(d)(4) of the Social
Security Act, as amended by Public Law
104–121, requires as a condition of
dependency, that a child receives onehalf of his or her support from the
stepparent. This dependency impacts
E:\FR\FM\12MRN1.SGM
12MRN1
]]>Agencies
[Federal Register Volume 73, Number 49 (Wednesday, March 12, 2008)]
[Notices]
[Pages 13258-13261]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-4902]
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NUCLEAR REGULATORY COMMISSION
Proposed License Renewal Interim Staff Guidance LR-ISG-2008-01:
Staff Guidance Regarding the Station Blackout Rule (10 CFR 50.63);
Associated With License Renewal Applications; Solicitation of Public
Comment
AGENCY: U.S. Nuclear Regulatory Commission.
ACTION: Solicitation of public comment.
-----------------------------------------------------------------------
SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is soliciting
public comment on its Proposed License Renewal Interim Staff Guidance
LR-ISG-2008-01 (LR-ISG) for clarification to its previously issued LR-
ISG-02, ``Staff Guidance on Scoping of Equipment Relied on to Meet the
Requirements of the Station Blackout (SBO) Rule (10 CFR 50.63) for
License Renewal,'' dated April 1, 2002, which has been incorporated in
the License Renewal Standard Review Plan. This LR-ISG provides
additional clarification to the staff position on the license renewal
scoping requirements regarding the offsite power system for SBO
recovery. The NRC staff issues LR-ISGs to facilitate timely
implementation of the license renewal rule and to review activities
associated with a license renewal application. Upon receiving public
comments, the NRC staff will evaluate the comments and make a
determination to incorporate the comments, as appropriate. Once the NRC
staff completes the LR-ISG, it will issue the LR-ISG for NRC and
industry use. The NRC staff will also incorporate the approved LR-ISG
into the next revision of the license renewal guidance documents.
DATES: Comments may be submitted by May 12, 2008. Comments received
after this date will be considered, if it is practical to do so, but
the Commission is able to ensure consideration only for comments
received on or before this date.
ADDRESSES: Comments may be submitted to: Chief, Rulemaking, Directives
and Editing Branch, Office of Administration, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001. Comments should be delivered to:
11545 Rockville Pike, Rockville, Maryland, Room T-6D59, between 7:30
a.m. and 4:15 p.m. on Federal workdays. Persons may also provide
comments via e-mail at NRCREP@NRC.GOV. The NRC maintains an Agencywide
Documents Access and Management System (ADAMS), which provides text and
image files of NRC's public documents. These documents may be accessed
through the NRC's Public Electronic Reading Room on the Internet at
https://www.nrc.gov/reading-rm/adams.html. Persons who do not have
access to ADAMS or who encounter problems in accessing the documents
located in ADAMS should contact the NRC Public Document Room (PDR)
reference staff at 1-800-397-4209, 301-415-4737, or by e-mail at
pdr@nrc.gov.
FOR FURTHER INFORMATION CONTACT: Ms. Stacie Sakai, Project Manager,
Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001; telephone 301-415-1884 or by e-
mail at sxs11@nrc.gov.
SUPPLEMENTARY INFORMATION: Attachment 1 to this Federal Register
notice, entitled Staff Position and Rationale for the Proposed License
Renewal Interim Staff Guidance LR-ISG-2008-01: Staff Guidance Regarding
the Station Blackout Rule (10 CFR 50.63) Associated with License
Renewal Applications,'' contains the NRC staff's rationale for
publishing the proposed LR-ISG-2008-01. Attachment 2 to this Federal
Register notice, entitled Proposed License Renewal Interim Staff
Guidance LR-ISG-2008-01: Staff Guidance Regarding the Station Blackout
Rule (10 CFR 50.63) Associated with License Renewal Applications,''
contains the additional clarification to the current staff position on
the license renewal SBO scoping requirements.
The NRC staff is issuing this notice to solicit public comments on
the proposed LR-ISG-2008-01. After the NRC staff considers any public
comments, it will make a determination regarding issuance of the
proposed LR-ISG.
Dated at Rockville, Maryland this 5th day of March, 2008.
[[Page 13259]]
For the Nuclear Regulatory Commission.
Pao-Tsin Kuo,
Director, Division of License Renewal, Office of Nuclear Reactor
Regulation.
Attachment 1--Staff Position and Rationale for the Proposed License
Renewal Interim Staff Guidance LR-ISG-2008-01: Staff Guidance Regarding
the Station Blackout Rule (10 CFR 50.63) Associated With License
Renewal Applications
Staff Position
Consistent with the requirements specified in Title 10, Sec.
54.4(a)(3), of the Code of Federal Regulations (10 CFR 54.4(a)(3)) and
10 CFR 50.63(a)(1), the scope of license renewal should include the
offsite recovery path from the transmission system to the Class 1E
distribution system. Accordingly, the offsite recovery paths that must
be included within the scope of license renewal, in accordance with 10
CFR 54.4(a)(3), consist of circuits from two independent sources. Both
paths start from the switchyard breaker to the plant Class 1E safety
buses. This path includes (1) switchyard circuit breakers that connect
to the offsite power system (i.e., grid), (2) power transformers, (3)
intervening overhead or underground circuits (i.e., cables, buses and
connections, transmission conductors and connections, insulators,
disconnect switches, and associated components), (4) circuits between
the circuit breakers and power transformers, (5) circuits between the
power transformers and onsite electrical distribution system, and (6)
the associated control circuits and structures.
Rationale
The license renewal rule, 10 CFR 54.4(a)(3), requires that the
scope of license renewal include ``All systems, structures, and
components relied on in safety analyses or plant evaluations to perform
a function that demonstrates compliance with the Commission's
regulations for * * * station blackout (10 CFR 50.63).'' The station
blackout (SBO) rule, 10 CFR 50.63(a)(1), states that each light-water-
cooled nuclear power plant licensed to operate must be able to
withstand and recover from an SBO of a specified duration that is based
on factors that include ``(iii) The expected frequency of loss of
offsite power; and (iv) The probable time needed to restore offsite
power.'' In this regard, the SBO rule is consistent with the staff
findings identified in the statement of considerations for the SBO rule
and NUREG-1032, ``Evaluation of Station Blackout Accidents at Nuclear
Power Plants,'' issued June 1988.
During its evaluation of licensee compliance with the requirements
in 10 CFR 50.63, ``Loss of All Alternating Current Power,'' the staff
has assessed the offsite power recovery paths that are credited in the
licensee evaluation of SBO coping duration. The SBO coping duration
evaluation is based on the criteria specified in 10 CFR 50.63(a)(1).
The staff's regulatory assessment and acceptance of licensees'
compliance with the SBO rule for offsite power is based on the site-
related characteristics and power design characteristics as defined in
Regulatory Guide (RG) 1.155, ``Station Blackout,'' issued August 1988,
and also the availability and reliability of the offsite power
including the protective coordination of switchyard breakers. The staff
developed this guidance to ensure that scoping of SBO equipment in
accordance with the requirements of 10 CFR 54.4(a)(3) is conducted in a
manner consistent with the original staff evaluations of licensee
compliance with the requirements of the SBO rule (10 CFR 50.63) to
include equipment necessary for recovery.
Attachment 2--Proposed License Renewal Interim Staff Guidance LR-ISG-
2008-01: Staff Guidance Regarding the Station Blackout Rule (10 CFR
50.63) Associated with License Renewal Applications
Staff Position
Consistent with the requirements specified in Title 10, Sec.
54.4(a)(3), of the Code of Federal Regulations (10 CFR 54.4(a)(3)) and
10 CFR 50.63(a)(1), the scope of license renewal should include the
offsite recovery path from the transmission system to the Class 1E
distribution system. The offsite and onsite power circuits must permit
functioning of structures, systems, and components necessary to respond
to the event. The rationale for this position follows.
Rationale
In the license renewal rule, 10 CFR 54.4(a)(3) requires that the
scope of license renewal include ``All systems, structures, and
components relied on in safety analyses or plant evaluations to perform
a function that demonstrates compliance with the Commission's
regulations for * * * station blackout (10 CFR 50.63).'' In the station
blackout (SBO) rule, 10 CFR 50.63(a)(1), states that each light-water-
cooled nuclear power plant licensed to operate must be able to
withstand and recover from an SBO of a specified duration that is based
on factors that include ``(iii) The expected frequency of loss of
offsite power; and (iv) The probable time needed to restore offsite
power.'' In this regard, the SBO rule is consistent with the staff
findings identified in the statement of considerations and NUREG-1032,
``Evaluation of Station Blackout Accidents at Nuclear Power Plants,''
issued June 1988. In particular, with regard to factor (iv), the staff
found that restoration of offsite power (0.6 hours median time to
restore) is more likely to terminate an SBO event than restoration of
the emergency diesel generators (8 hours median time to repair).
In Appendix A, ``General Design Criteria for Nuclear Power
Plants,'' to 10 CFR part 50, ``Domestic Licensing of Production and
Utilization Facilities,'' General Design Criterion (GDC) 17, ``Electric
Power Systems,'' requires that two physically independent circuits
shall supply electric power from the transmission network to the onsite
electric distribution system. These circuits must be designed and
located so as to minimize to the extent practical the likelihood of
their simultaneous failure under operating and postulated accident and
environmental conditions. A switchyard common to both circuits is
acceptable. Each of these circuits shall be designed to be available
soon enough after a loss of all onsite alternating current (ac) power
supplies and the loss of the other offsite electric power circuit to
ensure that specified acceptable fuel design limits and design
conditions of the reactor coolant pressure boundary are not exceeded.
One of these circuits (the immediate access circuit) shall be designed
to be available within a few seconds following a loss-of-coolant
accident to ensure the maintenance of core cooling, containment
integrity, and other vital safety functions.
Plants not licensed in accordance with GDC 17 were licensed to
satisfy plant-specific principal design criteria presented in the plant
updated final safety analysis report (FSAR). These criteria are similar
to GDC 17. The electric grid is the source of power to the offsite
power system. Therefore, all operating plants have offsite power
requirements similar to GDC 17. The plant technical specifications
embody the operational restrictions for the design requirements for the
loss of offsite power sources.
SBO is the loss of offsite and onsite ac electric power to the
essential and nonessential switchgear buses in a nuclear power plant.
It does not include the loss of ac power fed from inverters powered by
station batteries or loss of ac power from an alternate ac power
source. The U.S. Nuclear Regulatory Commission added the SBO rule to
the
[[Page 13260]]
regulations in 10 CFR part 50 because, as operating experience
accumulated, concern arose that the reliability of both the offsite and
onsite ac power systems might be less than originally anticipated, even
for designs that met the requirements of GDC 17 and GDC 18,
``Inspection and Testing of Electric Power Systems.'' The results of
risk studies indicate that estimated core melt frequencies from SBOs
vary considerably between plants and could be a significant risk
contributor for some plants.
As a result, the SBO rule required that nuclear power plants have
the capability to withstand and recover from the loss of offsite and
onsite ac power of a specified duration (the coping duration). In their
plant evaluations, licensees followed the guidance specified in
Regulatory Guide (RG) 1.155, ``Station Blackout,'' issued August 1988,
and NUMARC 87-00, ``Guidelines and Technical Bases for NUMARC
Initiatives Addressing Station Blackout at Light Water Reactors,'' to
determine their required plant-specific coping duration. The agency
based the criteria specified in RG 1.155 to calculate a plant-specific
coping duration on the expected frequency of loss of offsite power and
the probable time needed to restore offsite power, as well as the other
two factors (onsite emergency ac power source redundancy and
reliability) specified in 10 CFR 50.63(a)(1). In requiring that a
plant's coping duration be based in part on the probable time needed to
restore offsite power, 10 CFR 50.63(a)(1) specifies that the offsite
power system be an assumed method of recovering from an SBO.
Disregarding the offsite power system as a means of recovering from an
SBO would not meet the requirements of the 10 CFR 50.63 rule and would
result in a longer required coping duration.
The use of the offsite power system within 10 CFR 50.63(a)(1) as a
means of recovering from an SBO should not be construed to be the only
acceptable means of recovering from an SBO. A licensee could, for
example, recover offsite power or emergency (onsite) power. It is not
possible to determine before an actual SBO event which source of power
can be returned first. As a result, 10 CFR 50.63(c)(1)(ii) and its
associated guidance in RG 1.155, Sections 1.3 and 2, require procedures
to recover from an SBO that include restoration of offsite and onsite
power.
Based on the above, licensees rely on both the offsite and onsite
power systems to meet the requirements of the SBO rule. Elements of
both offsite and onsite power are necessary to determine the required
coping duration under 10 CFR 50.63(a)(1), and the procedures required
by 10 CFR 50.63(c)(1)(ii) must address both offsite power and onsite
power restoration. It follows, therefore, that both systems are used to
demonstrate compliance with the SBO rule and must be included within
the scope of license renewal consistent with the requirements of 10 CFR
54.4(a)(3). The onsite power system is included within the scope of
license renewal on the basis of the requirements under 10 CFR
54.4(a)(1) (safety-related systems). The equipment that is relied upon
to cope with an SBO (e.g., alternate ac power sources) is included
within the scope of license renewal on the basis of the requirements
under 10 CFR 54.4(a)(3). The offsite power system is therefore
necessary to complete the required scope of the electrical power
systems under license renewal.
The staff has recently noted during the review of license renewal
applications that some applicants have not included all of the
components and structures within the scope of license renewal needed
for recovering the offsite source from an SBO event as required by 10
CFR 54.4(a)(3). Failure to include all of the structures and components
within the scope of license renewal will result in those structures and
components not being subject to aging management review, and the
effects of aging will not be adequately managed so that the intended
function(s) will be maintained consistent with the current licensing
basis for the period of extended operation in accordance with 10 CFR
54.21(a)(1) and (a)(3).
During its evaluation of licensee compliance with the requirements
in 10 CFR 50.63, ``Loss of All Alternating Current Power,'' the staff
has assessed the offsite power recovery paths that are credited in the
licensee evaluation of SBO coping duration. The SBO coping duration
evaluation is based on the criteria specified in 10 CFR 50.63(a)(1).
The staff's regulatory assessment and acceptance of licensees'
compliance with the SBO rule for offsite power is based on the site-
related characteristics and power design characteristics as defined in
RG 1.155, and also the availability and reliability of the offsite
power including the protective coordination of switchyard breakers.
The offsite power systems of U.S. nuclear power plants consist of a
transmission system component and a switchyard that provides a source
of power and a plant system component that connects that power source
to a plant's onsite electrical distribution system which powers safety
equipment. The staff considers each plant design individually,
reviewing the plant's FSAR and associated electrical drawings. The key
to performing the scoping for the SBO recovery path is defining the
boundary of the offsite power source at the switchyard. A switchyard
can have multiple offsite lines supplying the switchyard buses.
Although switchyard designs vary, most plants have either a ring bus or
breaker-and-a-half scheme.
The scoping boundary, as outlined in the Standard Review Plan-
License Renewal (SRP-LR), Section 2.5.2.1.1, should be from the breaker
or breakers from the switchyard (connections to the line side). If
there is a circuit breaker between the power transformer (startup,
reserve, auxiliary, or main transformer) and the switchyard bus, and
the circuit breaker is directly bolted to the switchyard bus, then that
circuit breaker is acceptable as the scoping boundary. If there is a
disconnect switch, but no circuit breaker exists between the
transformer and the switchyard bus, then the circuit breaker(s)
connected to the switchyard bus that feeds the power transformer
(startup, reserve, auxiliary, or main transformer) should be acceptable
as the scoping boundary.
The circuit breaker, as the scoping boundary, provides connection
to offsite power via the switchyard bus, which can be powered by any of
the incoming transmission lines. This breaker should be at the
transmission system voltage to ensure adequate protection of safety bus
and the recovery of offsite power. The staff believes that the circuit
breaker needs to be within the scope of license renewal because of its
ability to provide plant power, protect downstream circuits and provide
plant operator-controlled isolation and energization ability. In
addition, a circuit breaker coordinates with other protective devices
to minimize the probability of loss of offsite power and prevent
transients from affecting the onsite distribution system as offsite
power is being restored. For these reasons, a circuit breaker remains
as the scoping boundary. Using a disconnect switch or other component
downstream of the breaker is not consistent with the staff position of
compliance with the SBO rule and is not acceptable for meeting the SBO
scoping requirements for license renewal.
As discussed above, for purposes of the license renewal, the staff
has determined that the offsite recovery paths that must be included
within the scope of license renewal, in accordance with 10 CFR
54.4(a)(3), consist of circuits from two independent sources. Both
paths start from the switchyard breaker to the plant Class 1E safety
[[Page 13261]]
buses. This path includes (1) switchyard circuit breakers that connect
to the offsite power system (i.e., grid), (2) power transformers, (3)
intervening overhead or underground circuits (i.e., cables, buses and
connections, transmission conductors and connections, insulators,
disconnect switches, and associated components), (4) circuits between
the circuit breakers and power transformers, (5) circuits between the
power transformers and onsite electrical distribution system, and (6)
control circuit cables and connections and structures associated with
components in the recovery path. The SBO recovery path scoping boundary
ends at the line side of the switchyard breaker(s) at transmission
system voltage. For the switchyard breakers, bolted connections to the
switchyard bus and structural components supporting the breakers are
within the scope of license renewal. The control circuit cables and its
connections for the switchyard breakers are not within the scope of
license renewal. Figures of different configurations of the SBO offsite
power recovery path that are acceptable to the staff and meet the
license renewal scoping requirements in accordance with 10 CFR
54.4(a)(3) are available via ADAMS at Accession No. ML080520620.
The ownership of switchyard components is not a factor in ensuring
that the effects of aging will be adequately managed for components and
structures needed for recovering the offsite circuits from an SBO event
consistent with the requirements in 10 CFR 54.4, ``Scope,'' and 10 CFR
54.21, ``Contents of Application--Technical Information.'' The staff
recognizes that there are interface and control agreements between the
licensee and transmission system operator. These agreements do not
preclude the applicant from complying with requirements specified in 10
CFR 54.4 and 10 CFR 54.21.
Designating the appropriate offsite power system long-lived passive
structures and components that are part of this circuit path as subject
to an aging management review will ensure the maintenance of the bases
underlying the SBO requirements over the period of the extended
license. This is consistent with the Commission's expectations in
including the SBO event under 10 CFR 54.4(a)(3) of the license renewal
rule.
[FR Doc. E8-4902 Filed 3-11-08; 8:45 am]
BILLING CODE 7590-01-P
