ML17352A496
| ML17352A496 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 03/30/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17352A493 | List: |
| References | |
| NUDOCS 9404060019 | |
| Download: ML17352A496 (4) | |
Text
~p,g RKQy 0
Cy n0 C
p
~O
++*++
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20666-0001 SAF T EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMEND ENT NO. 160 TO FACILITY OPERATING LICENSE NO.
DPR-31 AND AMENDMENT NO.
1 4TO FACILITY OPERATING LICENSE NO.
DPR-41 FLORIDA POWER 'AND LIGHT COMPANY TURK Y POINT UNIT NOS.
3 AND 4 DOCKET NOS.
50-250 AND 50-251
- 1. 0 INTRODUCTION By letter dated May 21, 1993, Florida Power E Light Company (FPL or the licensee) proposed license amendments to correct, the Technical Specifications (TS) 5.2.2, "Design Pressure and Temperature.".
The licensee proposed this revision to correct the TS reference to the maximum containment design internal pressure which is 55 psig.
The TS stated a maximum internal pressure of 59 psig to accommodate hypothetical, beyond-the-licensing basis scenarios.
- However, 55 psig was always considered the containment design pressure for the design and licensing basis.
Consistent with this request, the licensee proposed other administrative TS corrections and TS Bases changes.
By letter dated January 25, 1994, the licensee provided additional clarifying information which did not change the staff's initial no significant hazards determination.
- 2. 0 EVALUATION General Design Criterion (GDC) 50, "Containment design basis,"
requires that the containment be designed, with sufficient design margin, to accommodate the pressure and temperature conditions resulting from any loss-of-coolant accident (LOCA).
The containment structure which is one of three principal fission barriers ensures that offsite doses resulting from pipe break events within containment do not result in offsite doses in excess of the 10 CFR Part 100 limits.-.
During the p)ant licensing, the licensee performed safety analyses for various
/'ccident scenarios including LOCA resulting from the maximum hypothetical accident case of a double-ended break of the largest reactor coolant system (RCS) pipe, and a main steamline break (MSLB).
The results of these analyses are reported in the Turkey Point Units 3 and 4 Final Safety Analysis Report (FSAR).
These analyses resulted in a calculated peak containment pressure less than 49.9 psig for postulated ruptures in the RCS and 42 psig for MSLB.
Based on the above analysis and adding a lOX design safety margin, the licensee established a containment design pressure of 55 psig.
The 55 psig 94040b0019 940330 PDR ADOCK 050002SO P
design pressure was approved by the staff in its safety evaluation dated Harch 15, 1972.
The licensee's sensitivity studies using NRC-approved computer codes performed by Westinghouse and documented in WCAP-12262, "Analysis of Containment
Response
Following a Hain Steam line Break for Turkey Point Units 3 and 4,"
dated August 1989, resulted in a peak containment pressure of 45.1 psig.
This is lower than the licensed peak containment LOCA response pressure of 49.9 psig
~
The licensee has further revised the WCAP-12262 HSLB analysis with more realistic assumptions.
The revised analysis, "Westinghouse letter 93-JB-GL-
- 5091, Revised HSLB Containment Integrity Licensing Basis Analysis" dated Hay 18,
- 1993, assumed plant operation with the feedwater (FW) bypass valve at zero power condition and main steam isolation valve closing (HSIV) time of 5 seconds (which is consistent with the TS) instead of 15 seconds.
These assumptions resulted in a less severe condition compared to the mass addition with full main feed flow and slow closing of the HSIV assumed in the WCAP-
. 12262 analysis.
This revised analysis used NRC-approved codes and resulted in a peak containment pressure of 42.8 psig.
Therefore, the original licensing-'asis peak containment pressure of 55 psig remains valid.
The 55 psig licensing basis containment design pressure includes a
10X safety margin above the calculated pressure.
This safety margin is consistent with the Standard Review Plan (SRP) 6.2.1. 1.A, "PWR Dry Containments, Including Subatmospheric Containments,"
acceptance criteria for plants in the construction stage.
For plants at the operating. license stage, the SRP states that "...the peak calculated containment pressure following a loss-of-coolant
- accident, or a steam or FW line break, should be less than containment design pressure" and does not require a safety margin above the peak calculated pressure.
Therefore, the IOX safety margin is no longer necessary.
The proposed TS changes do not affect the offsite and control room dose assessments, documented in the UFSAR Section 14.3.5, since they are based on the assumption of fixed containment leakage rates and are independent of either the worst-case analyzed post-accident containment transient or the containment design pressure.
Also, the limiting condition for operation (LCO) for containment pressure integrity and leakage, containment airlock operability, and containment ventilation operability are independent of the containment design pressure and are based on a calculated containment peak internal pressure of 49.9 psig.
These LCOs are not changed.
Consequently, the use of a containment design pressure equal to the original licensing basis value of 55 psig will have no effect on either analyzed offsite dose estimates or current TS surveillance requirements associated with containment integrity and containment leakage.
Based on the above discussions, the staff concludes that the licensing basis for containment design pressure remains at 55 psig.
The reference to 59 psig in the TS was a result of beyond-the-licensing basis scenarios.
The proposed changes are administrative in nature and will not reduce the containment
structure's licensed design margin of safety.
Therefore, the proposed TS changes are acceptable.
3.0
~TS Chan es The proposed TS changes and the staff evaluations of them follow:
1.
TS 5.2.2 Correct the description for the containment building design pressure from "maximum internal pressure of 59 psig" to read "maximum design internal pressure of 55 psig."
The LCO for containment pressure integrity and leakage, containment airlock operability, and containment ventilation operability are independent of the containment design pressure and are based on calculated containment peak internal pressure of 49.9 psig.
These LCOs are not changed.
The proposed revision clarifies that the "design" value for containment is 55 psig.
Therefore, the proposed change is acceptable.
2.
TS BASES 3/4.6. 1.4:
Change the description in the BASES for the primary containment internal pressure to be consistent with the proposed change-in T.S. 5.2.2.
The specific changes are as follows:
(a)
Change the wording "containment peak pressure does not exceed the design pressure of 59 psig during LOCA conditions," to read "containment peak pressure does not exceed the design pressure of 55 psig during LOCA conditions."
(b)
Change the wording "maximum peak pressure expected to be obtained from a LOCA event is 49.9 psig," to read "maximum analyzed peak pressure calculated for a LOCA event is 49.9 psig."
(c)
Change the wording "initial positive pressure of as much as 5 psi,"
to read "initial positive pressure of as much as 3 psi."
These changes are consistent with the proposed change to T.S. 5.2.2.
The change in TS BASES 3/4.6. 1.4 to limit the bases for initial conditions is consistent with the stated T.S. 3.6. 1.4 LCO which states that "primary containment-internal pressure shall be maintained
[below] +3 psig."
Also based on it4 yeview of a generic report, "Bechtel Topical Report BN-TOP-3, Performance<and Sizing of Pressure Containments" Revision 4, dated March 1983, and applyin~the=Turkey Point conditions, the licensee concluded that the +3 psig initial containment pressure is conservative and will result in a peak calculated containment pressure that is less than the containment design pressure of 55 psig.
The proposed changes do not change the containment design pressure and, therefore, the proposed changes are acceptable.
3.
TS BASES 3/4.6. 1.6:
Add the words "analyzed peak" between the words "maximum" and "pressure" such that the revised sentence reads "Structural integrity is required to ensure that the containment will withstand the maximum analyzed peak pressure of 49.9 psig in the event of a LOCA."
The proposed change clarifies that the pressure of 49.9 psig is the licensed transient "analysis" value and not the "design" value for containment.
The proposed change is editorial and, therefore, acceptable.
4.0 STATE CONSULTATIO Based upon the written notice of the proposed amendments, the Florida State official had no comments.
- 5. 0 ENVIRONMENTAL CONSIDERATION.
These amendments involve a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The NRC staff has determined that the amendments involve no significant incr ease 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 amendments involve no significant hazards consideration, and there has been no public comment on such finding (58 FR 36434).
Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
6.0 CONCLUSION
Based on the staff evaluation in Section 2.0 above, the staff concludes that the proposed TS changes are acceptable.
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. Raghavan Date: March 30, 1994