[Federal Register Volume 71, Number 146 (Monday, July 31, 2006)]
[Notices]
[Pages 43225-43227]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-12169]
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NUCLEAR REGULATORY COMMISSION
[ Docket Nos. 50-424 and 50-425]
Southern Nuclear Operating Company, Inc.; Notice of Consideration
of Issuance of Amendment to Facility Operating License, Proposed No
Significant Hazards Consideration Determination, and Opportunity for a
Hearing
The U.S. Nuclear Regulatory Commission (the Commission) is
considering issuance of amendments to Facility Operating License Nos.
NPF-68 and NPF-81 issued to Southern Nuclear Operating Company, Inc.
(SNC), for operation of the Vogtle Electric Generating Plant (VEGP),
Units 1 and 2, located in Burke County, Georgia.
The proposed amendment would revise, Technical Specification (TS)
5.5.9, ``Steam Generator (SG) Tube Surveillance Program,'' to
incorporate changes in the SG inspection scope for VEGP, Unit 1 during
Refueling Outage 13 and the subsequent operating cycle and for Unit 2,
during Refueling Outage 12 and the subsequent operating cycle. The
proposed changes modify the inspection requirements for portions of SG
tubes within the tubesheet region of the SGs.
Before issuance of the proposed license amendment, the Commission
will have made findings required by the Atomic Energy Act of 1954, as
amended (the Act), and the Commission's regulations.
The Commission has made a proposed determination that the amendment
request involves no significant hazards consideration. Under the
Commission's regulations in Title 10 of the Code of Federal Regulations
(10 CFR) Section 50.92, this means that operation of the facility in
accordance with the proposed amendment would not (1) involve a
significant increase in the probability or consequences of an accident
previously evaluated; or (2) create the possibility of a new or
different kind of accident from any accident previously evaluated; or
(3) involve a significant reduction in a margin of safety. As required
by 10 CFR 50.91(a), the licensee has provided its analysis of the issue
of no significant hazards consideration, which is presented below:
1. Does the proposed license amendment involve a significant
increase in the probability or consequences of an accident
previously evaluated?
No. The previously analyzed accidents are initiated by the
failure of plant structures, systems, or components. The proposed
changes that alter the SG inspection criteria do not have a
detrimental impact on the integrity of any plant structure, system,
or component that initiates an analyzed event. The proposed changes
will not alter the operation of, or otherwise increase the failure
probability of any plant equipment that initiates an analyzed
accident. Therefore, the proposed change does not involve a
significant increase in the probability of an accident previously
evaluated.
Of the applicable accidents previously evaluated, the limiting
transients with consideration to the proposed changes to the SG tube
inspection criteria, are the SG tube rupture (SGTR) event and the
steam line break (SLB) accident.
During the SGTR event, the required structural integrity margins
of the SG tubes will be maintained by the presence of the SG
tubesheet. SG tubes are hydraulically expanded in the tubesheet
area. Tube rupture in tubes with cracks in the tubesheet is
precluded by the constraint provided by the tubesheet. This
constraint results from the hydraulic expansion process, thermal
expansion mismatch between the tube and tubesheet and from the
differential pressure between the primary and secondary side. Based
on this design, the structural margins against burst discussed in
Regulatory Guide (RG) 1.121, ``Bases for Plugging Degraded PWR SG
Tubes,'' are maintained for both normal and postulated accident
conditions.
The proposed changes do not affect other systems, structures,
components or operational features. Therefore, the proposed changes
result in no significant increase in the probability of the
occurrence of a SGTR accident.
At normal operating pressures, leakage from primary water stress
corrosion cracking (PWSCC) below the proposed limited inspection
depth is limited by both the tube-to-tubesheet crevice and the
limited crack opening permitted by the tubesheet constraint.
Consequently, negligible normal operating leakage is expected from
cracks within the tubesheet region. The consequences of an SGTR
event are affected by the primary-to-secondary leakage flow during
the event. Primary-to-secondary leakage flow through a postulated
broken tube is not affected by the proposed change since the
tubesheet enhances the tube integrity in the region of the hydraulic
expansion by precluding tube deformation beyond its initial
hydraulically expanded outside diameter.
The probability of a SLB is unaffected by the potential failure
of a SG tube as this failure is not an initiator for a SLB.
The consequences of a SLB are also not significantly affected by
the proposed changes. During a SLB accident, the reduction in
pressure above the tubesheet on the shell side of the SG creates an
axially uniformly distributed load on the tubesheet due to the
reactor coolant system pressure on the underside of the tubesheet.
The resulting bending action constrains the tubes in the tubesheet
thereby restricting primary-to-secondary leakage below the midplane.
The hydraulically expanded tube-to-tubesheet joints in Model F
SGs are not leaktight without the tube end weld. Considerations were
also made with regard to the potential for primary-to-secondary
leakage during postulated faulted conditions. However, the leak rate
during postulated accident conditions would be expected to be less
than that during normal operation for indications near the bottom of
the tubesheet based on an evaluation [by the Westinghouse Electric
Company dated July 11, 2006] which shows that while the driving
pressure increases by about a factor of almost two, the flow
resistance increases because the tube-to-tubesheet contact pressure
also increases. Depending on the depth within the tubesheet, the
relative increase in resistance could easily be larger than that of
the pressure potential. Therefore, the leak rate under normal
operating conditions could exceed its allowed value before the
accident condition leak rate would be expected to exceed its allowed
value. This approach is termed an application of the ``bellwether
principle.'' While such a decrease in the leak rate is expected, the
postulated accident leak rate could conservatively be taken to be
bounded by twice the normal operating leak rate if the increase in
contact pressure is ignored.
Since normal operating leakage is limited by the TS changes
proposed in SNC letter NL-06-0124 and by NEI 97-06 to less than 0.10
gpm [gallons per minute], (150 gpd [gallons per day]) throughout one
SG in the VEGP Units 1 and 2 SGs, the attendant accident condition
leak rate, assuming all leakage to be from lower tubesheet
indications, would be bounded by 0.20 gpm in the faulted SG which is
less than the accident analysis assumption of 0.35 gpm to the
affected SG included in Section 15.1.5 of the VEGP Updated Final
Safety Analysis Report (FSAR). Hence it is reasonable to omit any
consideration of inspection of the tube, tube end weld, bulges/
overexpansions or other anomalies below 17 inches from the top of
the hot leg tubesheet.
Based on the above discussion, the proposed changes do not
involve an increase in the consequences of an accident previously
evaluated.
2. Does the proposed license amendment create the possibility of
a new or different kind of accident from any accident previously
evaluated?
No. The proposed changes do not involve the use or installation
of new equipment and the currently installed equipment will not be
operated in a new or different manner. No new or different system
interactions are created and no new processes are introduced. The
proposed changes will not introduce any new failure mechanisms,
malfunctions, or accident initiators not already considered in the
design and licensing bases.
Based on this evaluation, the proposed change does not create
the possibility of a new or different kind of accident from any
accident previously evaluated.
3. Does the proposed amendment involve a significant reduction
in a margin of safety?
[[Page 43226]]
No. The proposed changes maintain the required structural
margins of the SG tubes for both normal and accident conditions.
Nuclear Energy Institute (NEI) 97-06, ``Steam Generator Program
Guidelines,'' and Regulatory Guide (RG) 1.121, ``Bases for Plugging
Degraded PWR Steam Generator Tubes,'' are used as the bases in the
development of the limited tubesheet inspection depth methodology
for determining that SG tube integrity considerations are maintained
within acceptable limits. RG 1.121 describes a method acceptable to
the NRC for meeting General Design Criteria (GDC) 14, ``Reactor
coolant pressure boundary,'' GDC 15, ``Reactor coolant system
design,'' GDC 31, ``Fracture prevention of reactor coolant pressure
boundary,'' and GDC 32, ``Inspection of reactor coolant pressure
boundary,'' by reducing the probability and consequences of a SGTR.
RG 1.121 concludes that by determining the limiting safe conditions
for tube wall degradation the probability and consequences of a SGTR
are reduced. This RG uses safety factors on loads for tube burst
that are consistent with the requirements of Section III of the
American Society of Mechanical Engineers (ASME) Code.
Application of the limited tubesheet inspection depth criteria
will preclude unacceptable primary-to-secondary leakage during all
plant conditions. The methodology for determining leakage provides
for large margins between calculated and actual leakage values in
the proposed limited tubesheet inspection depth criteria.
Therefore, the proposed changes do not involve a significant
hazards consideration under the criteria set forth in 10 CFR
50.92(c).
The NRC staff has reviewed the licensee's analysis and, based on
this review, it appears that the three standards of 10 CFR 50.92(c) are
satisfied. Therefore, the NRC staff proposes to determine that the
amendment request involves no significant hazards consideration.
The Commission is seeking public comments on this proposed
determination. Any comments received within 30 days after the date of
publication of this notice will be considered in making any final
determination.
Normally, the Commission will not issue the amendment until the
expiration of 60 days after the date of publication of this notice. The
Commission may issue the license amendment before expiration of the 60-
day period provided that its final determination is that the amendment
involves no significant hazards consideration. In addition, the
Commission may issue the amendment prior to the expiration of the 30-
day comment period should circumstances change during the 30-day
comment period such that failure to act in a timely way would result,
for example in derating or shutdown of the facility. Should the
Commission take action prior to the expiration of either the comment
period or the notice period, it will publish in the Federal Register a
notice of issuance. Should the Commission make a final No Significant
Hazards Consideration Determination, any hearing will take place after
issuance. The Commission expects that the need to take this action will
occur very infrequently.
Written comments may be submitted by mail to the Chief, Rules and
Directives Branch, Division of Administrative Services, Office of
Administration, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001, and should cite the publication date and page number of
this Federal Register notice. Written comments may also be delivered to
Room 6D59, Two White Flint North, 11545 Rockville Pike, Rockville,
Maryland, from 7:30 a.m. to 4:15 p.m. Federal workdays. Documents may
be examined, and/or copied for a fee, at the NRC's Public Document Room
(PDR), located at One White Flint North, Public File Area O1 F21, 11555
Rockville Pike (first floor), Rockville, Maryland.
The filing of requests for hearing and petitions for leave to
intervene is discussed below.
Within 60 days after the date of publication of this notice, the
licensee may file a request for a hearing with respect to issuance of
the amendment to the subject facility operating license and any person
whose interest may be affected by this proceeding and who wishes to
participate as a party in the proceeding must file a written request
for a hearing and a petition for leave to intervene. Requests for a
hearing and a petition for leave to intervene shall be filed in
accordance with the Commission's ``Rules of Practice for Domestic
Licensing Proceedings'' in 10 CFR part 2. Interested persons should
consult a current copy of 10 CFR 2.309, which is available at the
Commission's PDR, located at One White Flint North, Public File Area
O1F21, 11555 Rockville Pike (first floor), Rockville, Maryland.
Publicly available records will be accessible from the Agencywide
Documents Access and Management System's (ADAMS) Public Electronic
Reading Room on the Internet at the NRC Web site, http://www.nrc.gov/reading-rm/doc-collections/cfr/. If a request for a hearing or petition
for leave to intervene is filed by the above date, the Commission or a
presiding officer designated by the Commission or by the Chief
Administrative Judge of the Atomic Safety and Licensing Board Panel,
will rule on the request and/or petition; and the Secretary or the
Chief Administrative Judge of the Atomic Safety and Licensing Board
will issue a notice of a hearing or an appropriate order.
As required by 10 CFR 2.309, a petition for leave to intervene
shall set forth with particularity the interest of the petitioner in
the proceeding, and how that interest may be affected by the results of
the proceeding. The petition should specifically explain the reasons
why intervention should be permitted with particular reference to the
following general requirements: (1) The name, address and telephone
number of the requestor or petitioner; (2) the nature of the
requestor's/petitioner's right under the Act to be made a party to the
proceeding; (3) the nature and extent of the requestor's/petitioner's
property, financial, or other interest in the proceeding; and (4) the
possible effect of any decision or order which may be entered in the
proceeding on the requestor's/petitioner's interest. The petition must
also identify the specific contentions which the petitioner/requestor
seeks to have litigated at the proceeding.
Each contention must consist of a specific statement of the issue
of law or fact to be raised or controverted. In addition, the
petitioner/requestor shall provide a brief explanation of the bases for
the contention and a concise statement of the alleged facts or expert
opinion which support the contention and on which the petitioner
intends to rely in proving the contention at the hearing. The
petitioner/requestor must also provide references to those specific
sources and documents of which the petitioner is aware and on which the
petitioner intends to rely to establish those facts or expert opinion.
The petition must include sufficient information to show that a genuine
dispute exists with the applicant on a material issue of law or fact.
Contentions shall be limited to matters within the scope of the
amendment under consideration. The contention must be one which, if
proven, would entitle the petitioner to relief. A petitioner/requestor
who fails to satisfy these requirements with respect to at least one
contention will not be permitted to participate as a party.
Those permitted to intervene become parties to the proceeding,
subject to any limitations in the order granting leave to intervene,
and have the opportunity to participate fully in the conduct of the
hearing.
If a hearing is requested, the Commission will make a final
determination on the issue of no
[[Page 43227]]
significant hazards consideration. The final determination will serve
to decide when the hearing is held. If the final determination is that
the amendment request involves no significant hazards consideration,
the Commission may issue the amendment and make it immediately
effective, notwithstanding the request for a hearing. Any hearing held
would take place after issuance of the amendment. If the final
determination is that the amendment request involves a significant
hazards consideration, any hearing held would take place before the
issuance of any amendment.
Nontimely requests and/or petitions and contentions will not be
entertained absent a determination by the Commission or the presiding
officer of the Atomic Safety and Licensing Board that the petition,
request and/or the contentions should be granted based on a balancing
of the factors specified in 10 CFR 2.309(c)(1)(i)-(viii).
A request for a hearing or a petition for leave to intervene must
be filed by: (1) First class mail addressed to the Office of the
Secretary of the Commission, U.S. Nuclear Regulatory Commission,
Washington, DC 20555-0001, Attention: Rulemaking and Adjudications
Staff; (2) courier, express mail, and expedited delivery services:
Office of the Secretary, Sixteenth Floor, One White Flint North, 11555
Rockville Pike, Rockville, Maryland 20852, Attention: Rulemaking and
Adjudications Staff; (3) E-mail addressed to the Office of the
Secretary, U.S. Nuclear Regulatory Commission, [email protected];
or (4) facsimile transmission addressed to the Office of the Secretary,
U.S. Nuclear Regulatory Commission, Washington, DC, Attention:
Rulemakings and Adjudications Staff at (301) 415-1101, verification
number is (301) 415-1966. A copy of the request for hearing and
petition for leave to intervene should also be sent to the Office of
the General Counsel, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001, and it is requested that copies be transmitted either by
means of facsimile transmission to 301-415-3725 or by E-mail to
[email protected]. A copy of the request for hearing and petition
for leave to intervene should also be sent to Arthur H. Domby, Esquire,
Troutman Sanders, NationsBank Plaza, 600 Peachtree Street, NE., Suite
5200, Atlanta, GA 30308-2216, the attorney for the licensee.
For further details with respect to this action, see the
application for amendment dated July 20, 2006, which is available for
public inspection at the Commission's PDR, located at One White Flint
North, Public File Area O1 F21, 11555 Rockville Pike (first floor),
Rockville, Maryland. Publicly available records will be accessible from
the Agencywide Documents Access and Management System's (ADAMS) Public
Electronic Reading Room on the Internet at the NRC Web site, http://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 PDR Reference staff by telephone at 1-
800-397-4209, 301-415-4737, or by e-mail to [email protected].
Dated at Rockville, Maryland, this 25th day of July 2006.
For the Nuclear Regulatory Commission.
Christopher Gratton,
Sr. Project Manager, Plant Licensing Branch II-1, Division of Operating
Reactor Licensing, Office of Nuclear Reactor Regulation.
[FR Doc. E6-12169 Filed 7-28-06; 8:45 am]
BILLING CODE 7590-01-P