ML20129E533
| ML20129E533 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 09/30/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20129E480 | List: |
| References | |
| NUDOCS 9610030190 | |
| Download: ML20129E533 (3) | |
Text
_
i l
j#
ae 4
UNITED STATES j
j NUCLEAR REGULATORY COMMISSION 2
WASHINGTON, D.C. 2000N201 L
\\,...../
l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION
{
l RELATED TO AMENDMENT NOS. 52 AND 38 TO 4
{
FACILITY OPERATIhG LICENSE NOS. NPF-87 AND NPF-89 1
TEXAS UTILITIES ELECTRIC COMPANY COMANCHE PEAK STEAM ELECTRIC STATION. UNITS 1 AND 2 DOCKET NOS. 50-445 AND 50-446
1.0 INTRODUCTION
By application dated July 31,-1996 (TXX-96433), Texas Utilities Electric Company (TU Electric /the licensee) requested changes to the Technical Specifications (TSs) (Appendix A to Facility Operating License Nos. NPF-87 and NPF-89) for the Comanche Peak Steam Electric Station (CPSES), Units I and 2.
The proposed changes reflect revised core safety limit curves (TS Figure 2.1-la) and new N-16 setpoint values and parameters (TS Table 2.1-1) for Unit 1, and reference to topical report RXE-95-001-P as an approved methodology for small break loss of coolant accident (LOCA) analysis for Units 1 and 2.
Specifically, the following terms would be changed in Note I to TS Table 2.2-1 for Unit 1:
a)
K, from 0.0134/'F to 0.0173/*F, b) Kifrom 0.000719/psig to 0.000890/psig, c) q -q range from (-65% and +4%) to (-65% and +4.6%),
d) O,ver, temperature N-16 setpoint reduction from 1.81% to 0.0% for each percent that the magnitude of q q exceeds -65%,
e) -Overtemperature N-16 setpoint r,du,ction from 2.26% to 3.04% for each e
percent that the magnitude of q -q exceeds +4.6%,
f)_ Footnote identifying that no selpo, int reduction is required for the span
= of the AI indication.
In Note 2 to TS Table 2.2-1, the maximum amount by which the N-16 trip setpoint is allowed to exceed the computed trip setpoint would be increased from 3.51% to 3.64% for Unit 1.
In addition, TS 6.9.1.6b would be revised to allow the use of the methodology presented in the TU Electric topical report, "Small Break Loss of Coolant Accident Analysis Methodology," RXE-95-001-P, _to analyze the effects of the small break LOCA for CPSES, Units 1 and 2.
This topical report was reviewed and approved by the NRC staff in a safety evaluation dated September 4,1996.
9610030190 960930 PDR ADOCK 05000445 p
j j i
{
2.0 EVALUATION Based on analyses of the core configuration for CPSES, Unit 1, Cycle 6, TU l
j Electric has determined that revised core safety limit curves and j
overtemperature N-16 reactor trip setpoints are required. The core safety j
limits are the loci of points of thermal power, reactor coolant system (RCS) pressure and average temperature below which either the calculated departure i
from nucleate boiling ratio (DNBR) is no less than the safety limit value, or the average enthalpy at the vessel exit is less than the enthalpy of saturated i
liquid. The overtemperature N-16 reactor trip setpoint is calculated such 4
that a reactor trip will be initiated before the core safety limits are exceeded.
I i
The transient most affected by the change in the overtemperature N-16 trip i
setpoint is the control rod withdrawal event from full power conditions. TV Electric reanalyzed this event using NRC-approved methodologies, as specified i
in TS 6.9.1.6b, and the revised nyertemperature N-16 trip setpoint. The event was shown to terminate before a departure from nucleate boiling (DNB) 4 condition was reached. Since this limiting event, as well as the analyses of i
the revised core safety limits and the overtemperature N-16 trip setpoint, was performed in accordance with the NRC-approved methodologies listed in TS 6.9.1.6b, and satisfied all relevant acceptance criteria, the proposed TS l
changes to the core safety limits and the overtemperature N-16 trip are j
acceptable.
TS 6.9.1.6b would be revised to allow the use of the methodology presented in l
the TV Electric topical report, RXE-95-001-P, "Small Break Loss of Coolant i
Accident Analysis Methodology," to analyze the effects of the small break LOCA l
for both Units of CPSES. This topical report was reviewed and approved by the l
NRC staff in a safety evaluation dated September 4, 1996.
Use of the NRC approved methodology will ensure that values for cycle-specific parameters i
will be determined such that applicable operational transient and accident limits of the safety analysis are met. Therefore, the proposed change is l
acceptable.
3.0 CONCLUSION
i The staff has reviewed the proposed changes to the CPSES, Units 1 and 2 TS to i
reflect revised core safety limit curves (TS Figure 2.1-la), new N-16 setpoint 4
values and parameters.(TS Table 2.1-1), and the inclusion of RXE-95-001-P as an approved methodology for small break LOCA analysis.
Based on the NRC evaluation given above, the proposed changes are acceptable.
4.0 STATE CONSULTATION
i In accordance with the Commission's regulations, the Texas State official was i
notified of the proposed issuance of the amendments. The State official had no comments, d
i 1
1 I
?
f
5.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to installation or use of a 1
facility component located within the restricted area as defined in 10 CFR i
Part 20. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the i
amendments involve no significant hazards consideration, and there has been no public comment on such finding (61 FR 44362). The amendment also changes reporting and recordkeeping requirements. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR l
51.22(c)(9) and (c)(10).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the l
issuance of the amendments.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
L. Kopp Date: September 30, 1996