[Federal Register Volume 62, Number 157 (Thursday, August 14, 1997)]
[Notices]
[Pages 43556-43559]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-21517]
-----------------------------------------------------------------------
NUCLEAR REGULATORY COMMISSION
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
[Docket Nos. 50-498 and 50-499]
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 revise Technical Specification (TS)
[[Page 43557]]
Table 2.2-1 and 3/4.2.5 to allow the reactor coolant system (RCS) total
flow to be determined using cold leg elbow tap differential pressure
measurements. The proposed amendment was initially submitted via letter
dated July 16, 1997. The July 16, 1997, submittal contained proprietary
information that had not been properly identified. The July 16, 1997,
submittal was retrieved and discarded from all NRC files by the NRC
staff. Notification of the July 16, 1997, submittal was made in the
Federal Register on July 30, 1997, (62 FR 40850). This notice
supersedes the one previously published on July 30, 1997.
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:
Pursuant to 10[]CFR[]50.92 each application for amendment to an
operating license must be reviewed to determine if the proposed
change involves a Significant Hazards Consideration. The amendment,
as defined below, describing the Technical Specification change
associated with the change has been reviewed and determined to not
involve Significant Hazards Considerations. The basis for this
determination follows.
Proposed Change: The current Technical Specification Table 2.2-1
(page 2-4) ``Reactor Trip System Instrumentation Trip Setpoints,''
provides the Trip Setpoint and Allowable Value for the RCS Flow-Low
trip. The Allowable Value will be changed to reflect the increased
uncertainty associated with the correlation of the elbow taps to a
previous baseline calorimetric. In addition, Technical Specification
3.2.5 (page 3/4.2-11), ``Power Distribution Limits, DNB
Parameters,'' will be changed to allow the RCS total flow to be
measured by the elbow tap delta p method. These changes will include
the modification of surveillance requirement 4.2.5.3, which
currently requires performance of a precision heat balance every 18
months, to allow use of the elbow tap delta p method for RCS flow
measurement. Appropriate Technical Specification Bases sections will
also be revised to reflect use of the elbow tap delta p method for
flow measurement and to provide clarification. The revised Technical
Specifications are in Appendix C.
Background: The 18-month total RCS flow surveillance is
typically satisfied by a secondary power calorimetric-based RCS flow
measurement. In recent cycles, South Texas Project has experienced
apparent decreases in flow rates which have been attributed to
variations in hot leg streaming effects. These effects directly
impact the hot leg temperatures used in the precision calorimetric,
resulting in the calculation of low RCS flow rates. The apparent
flow reduction has become more pronounced in fuel cycles which have
implemented aggressive low leakage loading patterns. Evidence that
the flow reduction was apparent, but not actual, was provided by
elbow tap measurements. The results of this evaluation, including a
detailed description of the hot leg streaming phenomenon, are
documented in Westinghouse report SAE/FSE-TGX-0152, ``RCS Flow
Verification Using Elbow Taps.''
South Texas Project intends to begin using an alternate method
of measuring RCS flow using the elbow tap delta p measurements. For
this alternate method, the RCS elbow tap measurements are correlated
to precision calorimetric measurements performed during earlier
cycles which decreased the effects of hot leg streaming.
The purpose of this evaluation is to assess the impact of using
the elbow tap delta p measurements as an alternate method for
performing the 18-month RCS flow surveillance on the licensing basis
and demonstrate that it will not adversely affect the subsequent
safe operation of the plant. This evaluation supports the conclusion
that implementation of the elbow tap delta p measurement as an
alternate method of determining RCS total flow rate does not
represent a significant hazards consideration as defined in
10[]CFR[]50.92.
Evaluation: Use of the elbow tap delta p method to determine RCS
total flow requires that the delta p measurements for the present
cycle be correlated to the precision calorimetric flow measurement
which was performed during the baseline cycle(s). A calculation has
been performed to determine the uncertainty in the RCS total flow
using this method. This calculation includes the uncertainty
associated with the RCS flow baseline calorimetric measurement, as
well as uncertainties associated with delta p transmitters and
indication via QDPS [qualified display processing system] or the
plant process computer. The uncertainty calculation performed for
this method of flow measurement is consistent with the methodology
recommended by the Nuclear Regulatory Commission (NUREG/CR-3659,
PNL-4973, 2/85). The only significant difference is the assumption
of correlation to a previously performed RCS flow calorimetric.
However, this has been accounted for by the addition of instrument
uncertainties previously considered to be zeroed out by the
assumption of normalization to a calorimetric performed each cycle.
Based on these calculations, the uncertainty on the RCS flow
measurement using the elbow tap method is 2.6% flow which results in
a minimum RCS total flow of 391,500 gpm and must be measured via
indication with QDPS or the plant process computer at approximately
100% power.
The specific calculations performed were for Precision RCS Flow
Calorimetrics for the specified baseline cycles, Indicated RCS Flow
(either QDPS or the plant process computer), and the Reactor Coolant
Flow--Low reactor trip. The calculations for Indicated RCS Flow and
Reactor Coolant Flow--Low reactor trip reflect correlation of the
elbow taps to baseline precision RCS Flow Calorimetrics. As
discussed above, additional instrument uncertainties were included
for this correlation.
The uncertainty associated with the RCS Flow--Low trip increased
slightly. It was determined that due to the availability of margin
in the uncertainty calculation, no change was necessary to either
the Trip Setpoint (91.8% flow) or to the current Safety Analysis
Limit (87% flow) to accommodate this increase. The Allowable Value
is to be modified to allow for the increased instrument
uncertainties associated with the delta p to flow correlation.
Since the flow uncertainty did not increase over the currently
analyzed value, no additional evaluations of the reactor core safety
limits must be performed. In addition, it was determined that the
current minimum Measured Flow (MMF) assumed in the safety analyses
(389,200 gpm) bounds the required MMF calculated for the elbow tap
method (391,500 gpm).
Based on these evaluations, the proposed change would not
invalidate the conclusions presented in the UFSAR [Updated Final
Safety Analysis Report].
1. Does the proposed modification involve a significant increase
in the probability or consequences of an accident previously
evaluated?
Sufficient margin exists to account for all reasonable
instrument uncertainties; therefore, no changes to installed
equipment or hardware in the plant are required, thus the
probability of an accident occurring remains unchanged.
The initial conditions for all accident scenarios modeled are
the same and the conditions at the time of trip, as modeled in the
various safety analyses, are the same. Therefore, the consequences
of an accident will be the same as those previously analyzed.
2. Does the proposed modification create the possibility of a
new or different kind of accident from any accident previously
evaluated?
The proposed change revises the method for RCS flow measurement,
and therefore does not introduce any new accident indicators or
failure mechanisms.
No new accident scenarios have been identified. Operation of the
plant will be consistent with that previously modeled, i.e., the
time of reactor trip in the various safety analyses is the same,
thus plant response will be the same and will not introduce any
different accident scenarios that have not been evaluated.
[[Page 43558]]
3. Does the proposed modification involve a significant
reduction in a margin of safety [?]
There are no changes to the Safety Analysis assumptions.
Therefore, the margin of safety will remain the same.
The proposed change does not impact the results from any
accidents analyzed in the safety analysis.
Conclusion: Based on the preceding information, it has been
determined that this proposed change to allow an alternate RCS total
flow measurement based on elbow tap delta p measurements does not
involve a Significant Hazards Consideration as defined by 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 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 Chief, 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 September 15, 1997 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 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 bases 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: Rulemakings and
Adjudications Staff, or
[[Page 43559]]
may be delivered to the Commission's Public Document Room, the Gelman
Building, 2120 L Street, NW., Washington, DC, by the above date. 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,
N.W., 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 August 6, 1997, 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 8th day of August 1997.
For the Nuclear Regulatory Commission.
Thomas W. Alexion,
Project Manager, Project Directorate IV/1, Division of Reactor Projects
III/IV, Office of Nuclear Reactor Regulation.
[FR Doc. 97-21517 Filed 8-13-97; 8:45 am]
BILLING CODE 7590-01-P
