[Federal Register Volume 61, Number 104 (Wednesday, May 29, 1996)]
[Notices]
[Pages 26936-26938]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-13385]
=======================================================================
-----------------------------------------------------------------------
NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-498 and 50-499]
Houston Lighting & Power Company, City Public Service Board of
San Antonio, Central Power and Light Company, City of Austin, Texas;
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 an amendment to Facility Operating License Nos.
NPF-76 and NPF-80 issued to Houston Lighting & Power Company, et. al.,
(the licensee) for operation of the South Texas Project, Units 1 and 2,
located in Matagorda County, Texas.
The proposed amendment would modify Technical Specification (TS)
Section 3/4.4.5, Steam Generators, 3/4.4.6, Reactor Coolant System
Leakage, and associate Bases to allow the installation of tube sleeves
as an alternative to plugging to repair defective steam generator
tubes.
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 10 CFR 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 change involve a significant increase in the
probability or consequences of an accident previously evaluated?
The laser welded sleeve has been designed and analyzed in
accordance with the requirements of the ASME [American Society of
Mechanical Engineers] Code. The applied stresses and fatigue usage for
the sleeve are bounded by the limits established in the ASME Code. ASME
Code minimum material property values are used for the structural and
plugging limit analysis. Ultrasonic inspection is used to verify that
minimum weld fusion zone thicknesses are produced. Mechanical testing
has shown that the structural strength of Alloy 690 laser welded
sleeves, under normal, upset, and faulted conditions provides margin to
the acceptance limits. Leakage testing for \3/4\-inch and\7/8\-inch
tube sleeves has demonstrated no unacceptable levels of primary-to-
secondary leakage are expected during any plant condition, including
the case where the seal weld is not produced in the lower joint of the
tubesheet.
The sleeve nominal wall thickness (used for developing the depth-
based plugging limit for the sleeve) is determined using the guidance
of Regulatory Guide 1.121 and the pressure stress equation of Section
III of the ASME Code. The limiting requirement of Regulatory Guide
1.121, which applies to part throughwall degradation, is the minimum
acceptable wall to maintain a factor of safety of three against tube
failure under normal operating (design) conditions. A bounding set of
design and transient loading input conditions was used for the minimum
wall thickness evaluation in the generic evaluation. Evaluation of the
minimum acceptable wall thickness for normal, upset, and postulated
accident condition loading per the ASME Code indicates these conditions
are bounded by the design condition required minimum wall thickness.
A bounding tube wall degradation growth rate per cycle and an eddy
current uncertainty has been assumed for determining the sleeve
Technical Specification plugging limit. The sleeve wall degradation
extent determined by eddy current, which would require plugging sleeved
tubes, is developed using the guidance of Regulatory Guide 1.121 and is
defined in Westinghouse Letter Report NSD-JLH-6146 to be 42%
throughwall. Conservatively, South Texas will plug 40% sleeve wall
degradation as determined by eddy current.
The effect of sleeving and plugging will remain below the plugging
limit assumed in [the] Chapter 15 accident analysis of the South Texas
Project Safety Analysis Report. The proposed change will not increase
the consequences of these accidents.
The results of the analyses and testing demonstrate the laser
welded sleeve is an acceptable means of maintaining tube integrity.
Further, per Regulatory Guide 1.83 recommendations, the sleeved tube
can be monitored through periodic inspections with present non-
destructive examination techniques.
[[Page 26937]]
These measures demonstrate installation of sleeves spanning degraded
areas of the tube will restore the tube to a condition consistent with
its original design basis.
Conformance of the sleeve design with the applicable sections of
the ASME Code and results of the leakage and mechanical tests, support
the conclusion that installation of laser welded sleeves does not
increase the probability or consequences of an accident previously
evaluated.
2. Does the change create the possibility of a new or different
kind of accident from any accident previously evaluated?
Sleeving will not adversely affect any plant component. Stress and
fatigue analysis of the repair has shown the ASME Code and Regulatory
Guide 1.121 criteria are not exceeded. Implementation of laser welded
sleeving maintains overall tube bundle structural and leakage integrity
at a level consistent with that of the original tubing during all plant
conditions. Leak and mechanical testing of sleeves support the
conclusions of the calculations that each sleeve joint retains both
structural and leakage integrity during all conditions. Sleeving of
tubes does not provide a mechanism resulting in an accident outside of
the area affected by the sleeves. Any accident as a result of potential
tube or sleeve degradation in the repaired portion of the tube is
bounded by the existing tube rupture accident analysis.
Implementation of laser welded sleeving will reduce the potential
for primary-to-secondary leakage during a postulated steam line break
while not significantly impacting available primary coolant flow area
in the event of a LOCA [loss of coolant accident]. By effectively
isolating degraded areas of the tube through repair, the potential for
steam line break leakage is reduced. These degraded intersections are
returned to a condition consistent with the Design Basis. While the
installation of a sleeve reduces primary coolant flow, the reduction is
far below that caused by plugging. Therefore, far greater primary
coolant flow area is maintained through sleeving versus plugging.
Therefore, the possibility of a new or different kind of accident
from any accident previously evaluated is not created.
3. Does the change involve a significant reduction in a margin of
safety?
The laser welded sleeve repair of degraded steam generator tubes
has shown by analysis to restore the integrity of the tube bundle
consistent with its original design basis condition (i.e., tube/sleeve
operational and faulted condition stresses are bounded by the ASME Code
requirements and the repaired tubes are essentially leaktight). The
safety factors used in the design of the sleeves for the repair of
degraded tubes are consistent with the safety factors in the ASME Code
used in steam generator design. The portions of the installed sleeve
assembly which represent the reactor coolant pressure boundary can be
monitored for the initiation and progression of sleeve/tube wall
degradation, thus satisfying the requirements of Regulatory Guide 1.83.
The portion of the tube bridged by the sleeve is effectively removed
from the pressure boundary, and the sleeve then forms the new pressure
boundary. The areas of the sleeved tube assembly which require
inspection are defined in WCAP-13698, Revision 2 and Westinghouse
Letter Report NSD-JLH-6146.
The effect of sleeving and plugging will remain below the plugging
limit assumed in [the] Chapter 15 accident analysis of the South Texas
Project Safety Analysis. The change will not reduce the margin of
safety for these accidents.
Provisional requirements cited in other Nuclear Regulatory
Commission Safety Evaluation Reports addressing the implementation of
sleeving have required the reduction of the individual steam generator
normal operation primary-to-secondary leakage limit from 500 to 150 gpd
[gallons per day]. Consistent with these evaluations, the South Texas
Project will reduce the per steam generator leak rate limit of 500 gpd
in Technical Specification 3.4.6.2.c to 150 gpd. The establishment of
this leakage limit at 150 gpd provides additional safety margin.
Therefore, it is concluded that the proposed license amendment
request does not result in a significant reduction in the margin of
safety as defined in the South Texas Project Final Safety Analysis
Report or Technical Specifications.
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 the 30-day notice period. However, should circumstances
change during the notice period such that failure to act in a timely
way would result, for example, in derating or shutdown of the facility,
the Commission may issue the license amendment before the expiration of
the 30-day notice period, provided that its final determination is that
the amendment involves no significant hazards consideration. The final
determination will consider all public and State comments received.
Should the Commission take this action, it will publish in the Federal
Register a notice of issuance and provide for opportunity for a hearing
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 Rules Review and
Directives Branch, Division of Freedom of Information and Publications
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 6D22, Two White Flint North, 11545 Rockville Pike,
Rockville, Maryland, from 7:30 a.m. to 4:15 p.m. Federal workdays.
Copies of written comments received may be examined at the NRC Public
Document Room, the Gelman Building, 2120 L Street, NW., Washington, DC.
The filing of requests for hearing and petitions for leave to
intervene is discussed below.
By June 28, 1996, 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 2.714 which is
available at the Commission's Public Document Room, the Gelman
Building, 2120 L Street, NW., Washington, DC, and at the local public
document room located at the Wharton County Junior College, J.M. Hodges
Learning Center, 911 Boling Highway, Wharton, TX. If a request for a
hearing or petition for leave to intervene is filed
[[Page 26938]]
by the above date, the Commission or an Atomic Safety and Licensing
Board, designated by the Commission or by the Chairman of the Atomic
Safety and Licensing Board Panel, will rule on the request and/or
petition; and the Secretary or the designated Atomic Safety and
Licensing Board will issue a notice of hearing or an appropriate order.
As required by 10 CFR 2.714, 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 factors: (1) the nature of the petitioner's right under the
Act to be made party to the proceeding; (2) the nature and extent of
the petitioner's property, financial, or other interest in the
proceeding; and (3) the possible effect of any order which may be
entered in the proceeding on the petitioner's interest. The petition
should also identify the specific aspect(s) of the subject matter of
the proceeding as to which petitioner wishes to intervene. Any person
who has filed a petition for leave to intervene or who has been
admitted as a party may amend the petition without requesting leave of
the Board up to 15 days prior to the first prehearing conference
scheduled in the proceeding, but such an amended petition must satisfy
the specificity requirements described above.
Not later than 15 days prior to the first prehearing conference
scheduled in the proceeding, a petitioner shall file a supplement to
the petition to intervene which must include a list of the contentions
which are sought to be litigated in the matter. Each contention must
consist of a specific statement of the issue of law or fact to be
raised or controverted. In addition, the petitioner shall provide a
brief explanation of the basis of 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 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. Petitioner must provide 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 who fails to file such a supplement which satisfies 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, including the opportunity to present evidence and cross-
examine witnesses.
If a hearing is requested, the Commission will make a final
determination on the issue of no 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.
A request for a hearing or a petition for leave to intervene must
be filed with the Secretary of the Commission, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001, Attention: Docketing and
Services Branch, or may be delivered to the Commission's Public
Document Room, the Gelman Building, 2120 L Street, NW., Washington, DC,
by the above date. Where petitions are filed during the last 10 days of
the notice period, it is requested that the petitioner promptly so
inform the Commission by a toll-free telephone call to Western Union at
1-(800) 248-5100 (in Missouri 1-(800) 342-6700). The Western Union
operator should be given Datagram Identification Number N1023 and the
following message addressed to W. D. Beckner: petitioner's name and
telephone number, date petition was mailed, plant name, and publication
date and page number of this Federal Register notice. A copy of the
petition should also be sent to the Office of the General Counsel, U.S.
Nuclear Regulatory Commission, Washington, DC 20555-0001, and to Jack
R. Newman, Esq., Morgan, Lewis & Bockius, 1800 M Street, NW.,
Washington, DC 20036-5869, attorney for the licensee.
Nontimely filings of petitions for leave to intervene, amended
petitions, supplemental petitions and/or requests for hearing will not
be entertained absent a determination by the Commission, the presiding
officer or the presiding Atomic Safety and Licensing Board that the
petition and/or request should be granted based upon a balancing of the
factors specified in 10 CFR 2.714(a)(1)(i)-(v) and 2.714(d).
For further details with respect to this action, see the
application for amendment dated May 17, 1996, which is available for
public inspection at the Commission's Public Document Room, the Gelman
Building, 2120 L Street NW., Washington, DC, and at the local public
document room located at the Wharton County Junior College, J. M.
Hodges Learning Center, 911 Boling Highway, Wharton, TX.
Dated at Rockville, Maryland, this 22nd day of May 1996.
For the Nuclear Regulatory Commission.
Janet L. Kennedy,
Project Manager, Project Directorate IV-1, Division of Reactor Projects
III/IV, Office of Nuclear Reactor Regulation.
[FR Doc. 96-13385 Filed 5-28-96; 8:45 am]
BILLING CODE 7590-01-P