ML17349A877

Application for Amends to Licenses DPR-31 & DPR-41,modifying TS 5.2.2, Design Pressure & Temp & Associated Bases to Correct Ref to Max Containment Design Internal Pressure from 59 Psig to 55 Psig

ML17349A877
Person / Time
Site:	Turkey Point
Issue date:	05/21/1993
From:	Plunkett T FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17349A878	List: ML17349A877 ML17349A879
References
L-93-133, NUDOCS 9306020381
Download: ML17349A877 (29)

Text

ACCELERAT DOCUj'WENT MSTRIUTION SYSTEM REGULAT .. ZNFORMATZON DZSTRZBUTZONOISTEM (RZDS)

F ACCESSION NBR:9306020381 DOC.DATE: 93/05/21 NOTARIZED: YES FACIL:50-250 Turkey Point Plant, Unit 3, Florida Power and Light DOCKET I C 05000250 50-251 Turkey Point Plant, Unit 4, Florida Power and Light C 05000251 AUTH. NAME AUTHOR AFFILIATION PLUNKETT,T.F. Florida Power 6 Light Co.

RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Application for amends to Licenses DPR-31 6 DPR-41,modifying TS 5.2.2, "Design Pressure 6 Temp" a associated bases to D correct ref to max containment design internal pressure from 59 psig to 55 psig.

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RECIPIENT COPIES RECIPIENT COPIES D ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD 1 1 RAGHAVAN,L 2 2 D INTERNAL: NRR/DE/EELB 1 1 NRR/DORS/OTSB 1 1 NRR/DRCH/HICB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 NUDOCS-ABSTRACT 1 1 0 1 0 OGC/HDS3 1 0 RE FIL 01 1 1 EXTERNAL: NRC PDR 1 1 NSIC 1 1 D

D D

NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTEI CONTACI'HE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEEDl TOTAL NUMBER OF COPIES REQUIRED: LTTR 15 ENCL 13

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.0. Box 029'i00, Miami, FL, 33102-9100 Me S113S3 L-93-133 10 CFR 50.36 10 CFR 50.90 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

Re: Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 Proposed License Amendments Maximum Containment Pressure In accordance with 10 CFR 50.90, Florida Power and Light Company (FPL) requests that Appendix A of Facility Operating Licenses DPR-31 and DPR-41 be amended to modify Turkey Point Units 3 and 4 Technical Specification 5.2.2, Design Pressure and Temperature and the associated bases. The proposed revision to the Technical Specifications corrects the Technical Specification reference to the maximum containment design internal pressure from 59 psig to 55 psig as well as other administrative corrections.

A safety analysis of the amendments request is provided in Attachment 1.

FPL has determined that the proposed license amendments do not involve a significant hazard pursuant to 10 CFR 50.92. The no significant hazards determination in support of the proposed Technical Specification change is provided in Attachment 2. Attachment 3 provides the proposed revised Technical Specification changes. Attachment 4 provides the proposed corrected Technical Specification pages.

In accordance with 10 CFR 50.91 (b)(1), a copy of these proposed license amendments are being forwarded to the State Designee for the State of Florida.

The proposed amendments have been reviewed by the Turkey Point Plant Nuclear Safety Committee and the FPL Company Nuclear Review Board.

Should there be any questions on this request, please contact us.

Very truly yours, T. F. Plunkett Vice President Turkey Point Nuclear TFP/RJT/rt Attachments CC: S. DE Ebneter, Regional Administrator, Region II, R. C. Butcher, Senior Resident Inspector, USNRC, Turkey Point USNRC W. A. Passetti, Florida Department of Health and Rehabilitative Services c,oO04~

'930b020381 930521 PDR ADOCK 05000250 P , PDR an FPL Group company

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STATE OF FLORIDA )

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COUNTY OF DADE )

T. F. Plunkett being first duly sworn, deposes and says:

That he is Vice President Turke Point Nuclear, of Florida Power and Light Company, the Licensee herein; That he has executed the foregoing document; that the statements made in this document are true and correct to the best of his knowledge, information and belief, and that he is authorized to execute the document on behalf of said Licensee.

T ~ F. Plunkett Subscribed and sworn to before me this day of 1993.

Name of Notary Public (Type or Print)

NOTARY PUBLIC, in and for the Count of Dade, State of Flori  :"~lir'"". CHERYL A. KELLY MY COINIISSION 8 CC 22378t EXPIRES: September 27, t999

'p!j,i~" Boodedlhtt Hotery Pub@ Undewdtero My Commission expire Commission No.

T. F. Plunkett is personally known to me.

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ATTACHMENT 1 SAFETY ANALYSIS

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L-93-133 Page 1 of 7 SAFETY ANALYSIS INTRODUCTION During the performance of the twentieth year tendon surveillance of the Turkey Point Units 3 and 4 containment post-tensioning system, several surveillance tendons from both the hoop and dome tendon groups were found to have measured normalized lift-off forces below the predicted lower limits and below the minimum required prestress limit required at the end of the 40 year design life of the structure (references 1 and 2) .

Consequently, Turkey Point Units 3 and 4 entered the 15 day ACTION Statement to the LIMITING CONDITION FOR OPERATION (LCO) for Technical Specification (T.S.) 3.6.1 ' for each of these separate tendons, and Special Reports were submitted to the staff as required by Technical Specifications. These tendons were restored to their required level of integrity by re-tensioning each tendon to a level equal to or above the twentieth year predicted lower limits Containment tendon surveillance inspections performed to date for Turkey Point Units 3 and 4 have assured a containment internal pressure of 59 psig for calculating the minimum required prestress forces for the tendons.

In response to the measured low lift-offvalues, an engineering review of the Unit 3 and 4 containment structural analysis was performed which focused attention on the maximum containment pressure assumed in the containment structural analysis and the licensing basis for this design parameter. The review identified that the post-tensioning system had experienced greater time-dependent losses (i.e., tendon wire relaxation) than were originally predicted. This engineering review also revealed that Turkey Point was originally licensed by the Atomic Energy Commission (AEC) for a maximum containment design pressure of 55 psig for use in determining the acceptability of the containment post-tensioning system (Section 5.4 of reference 5).

This safety analysis demonstrates that a maximum containment design pressure of 55 psig is the current licensing and design basis for Turkey Point Units 3 and 4 containment post,-tensioning system and the associated Technical Specification Surveillance Requirements, and that this pressure is an appropriate basis for calculating minimum required prestress forces for the containment post-tensioning system on both Turkey Point Units 3 and 4. In addition, justification is provided for a clarification of the maximum containment design basis pressure as contained within the Technical Specifications.

LICENSING BASIS FOR CONTAINMENT DESIGN PRESSURE

1. 0 Background The containment design pressure of 55 psig was established during plant licensing and has been maintained through to the current licensing documents. The Preliminary Safety Analysis Report (PSAR) and Final Safety Analysis Report (FSAR) indicated that a 55 psig reference containment design pressure was conservatively established for the design basis (29-inch double-ended pipe break) loss-of-coolant accident (LOCA), based on a 49.9 psig calculated peak pressure plus a 10% safety margin; and the structural proof test would be conducted at 115% of design pressure to

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L-93-133 Page 2 of 7 check structural integrity. [Refer to PSAR Sections 5.4.1.a and 12.2.3 (reference 15); and to the original (1970) FSAR Section 5.1.1, (reference

3) ]

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Other early LOCA study cases, assuming partial safeguards availability, were also considered. These study cases did not constitute design basis accident scenarios, but rather provided an indication of potential containment performance capabilities beyond-the-licensing-basis for purposes of establishing conservative design margins for the Unit 3 and 4 containment structures. These scenarios were developed in response to AEC questions, and to address uncertainties as to the availability of primary system accumulators. As a result, some of these study cases assumed partial safeguards operation with no core cooling, which were conditions that are beyond the required postulation of a single active or passive failure. [Refer to PSAR Supplement 2, Questions 1.0 and 3.0 (reference 4).] For instance, the AEC requested that a "no-core-cooling" case be considered, in which partial safeguards equipment, operating on diesel power, introduced all the safety injection water directly into the sump.

This case resulted in a maximum pressure of 58.5 psig. To accommodate these hypothetical, beyond-the-licensing basis scenarios, the containment structure was designed to withstand a pressure of 59 psig; however, the design and licensing basis LOCA analysis calculated peak containment pressure was 49.9 psig, and "55 psig [was] considered as nominal structural design pressure, thus allowing a margin of 10% over the calculated peak accident pressure." [1970 FSAR Section 5.1.1 (reference

3) ]

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The containment internal pressure value of 55 psig originated and was licensed by the AEC as the result of the design basis analysis which assumed that partial safeguards equipment, operating on diesel power, provided core cooling with two of the three safety injection water flow paths reaching the core (1970 FSAR Section 5.1.1, reference 3).

Based on the preceding, 55 psig is clearly the original containment design and licensing basis pressure; this value is based on a calculated design basis large break LOCA peak pressure of 49.9 psig with a safety margin.

The internal pressure of 59 psig was based on early non-licensing basis LOCA capability study scenarios. This is consistent with the AEC conclusions presented in the original plant Safety Evaluation Report (Section 5.4 of reference 5), which states:

Although the building is designed to withstand a pressure of 59 psig, the preoperational structural proof test was performed at about 63 psig rather than at 68 psig (115% of 59 psig) . The design pressure was established at the construction permit stage based upon an early containment pressure transient analysis which did not take credit for the action of the accumulators in suppressing a secondary pressure peak. The applicant has now calculated that the peak accident pressure would be 50 psig. Since our current guidelines for containment design suggest that the design pressure should be at least 10% higher than the calculated peak accident pressure, 55 psig would be an acceptable design pressure. On this basis we have accepted the 63 psig proof test (115% of 55 psig) o

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L-93-133 Page 3 of 7 It is important to note that the original AEC operating license Safety Evaluation Report (reference 5) did not include the beyond-the-licensing-basis LOCA cases, beyond-the-licensing-basis main steamline breaks (MSLB) accident analysis or other transients as a basis for containment design pressure. In addition, the 10% containment design pressure margin is consistent with the NRC's current margin requirements.

Much of the early text appears in the Updated Final Safety Analysis Report (UFSAR) and is consistent with current Technical Specification supporting analysis and requirements. The LCO for structural integrity ensure that the containment will withstand the maximum analyzed internal pressure in the event of a LOCA (T.S. BASES 3/4.6.1.6; and UFSAR Section 5.1.1).

2.0 Peak Containment Pressure Response The original containment analysis for Main Steam Line Break (MSLB) demonstrated that the energy released to containment would not cause the failure of containment. The peak containment pressure reported in Section 14.2.5 of the original FSAR (reference 12) was 42 psig.

This original licensed MSLB analysis was later supplemented (revision 0 of the UFSAR Section 14.2.5.3 reference 13) to reflect the results of a worst case MSLB analysis, which was performed in response to IE Bulletin 80-04 (reference 11). This worst case MSLB analysis contained significant conservatisms related to the assumptions about post-accident continued feedwater and auxiliary feedwater addition. Although the results of this documented MSLB analysis (UFSAR Section 14.2.5.3) indicate a peak containment pressure of 56.1 psig, more recent sensitivity studies have been performed based on "best estimate" techniques and NRC-approved computer codes which indicate peak pressures significantly lower than the licensed peak containment LOCA response pressure of 49.9 psig.

These recent sensitivity studies for steamline breaks within containment were performed by Westinghouse and are documented in WCAP-12262 (reference

14) . These analyses were performed using NRC-approved codes for a range of break sizes at various power levels and considering various single failures. The limiting case for peak containment pressure was determined to be a 1.4 ft'ouble-ended main steamline break at zero percent power with a single failure of the main steam check valve and offsite power available. This limiting analysis case resulted in a peak containment pressure of 45.1 psig, based on an initial containment pressure of 0.3 psig (consistent with the LOCA analysis). These conservative sensitivity studies demonstrate that the peak containment pressure response, following a main steamline break, remains within acceptable design limits, and the peak containment pressure transient response is bounded by the Large Break LOCA analysis of record documented as 49.9 psig in UFSAR Section 14.3.4.

In addition to the Westinghouse sensitivity studies discussed above, a revised MSLB analysis, using conservative estimates of feedwater addition and NRC-approved codes, has been recently performed for Turkey Point Units 3 and 4. The results of this analysis indicated a peak containment pressure of 42.8 psig. This result supports the conclusion that the peak containment pressure will remain below the current licensed LOCA analysis peak pressure of 49.9 psig.

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L-93-133 Attachment. 1 Page 4 of 7 3.0 Offsite Dose Estimates and Containment Leakage The Turkey Point offsite and control room dose assessments, documented in UFSAR Section 14.3.5, were performed 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. Similarly, the Technical Specification requirements for maintenance of containment integrity and allowable penetration leakage are based on the maximum analyzed post-accident containment transient and are independent of the containment design pressure. Consequently, the use of a containment design pressure equal to the original value of 55 psig will have no effect on either analyzed offsite dose estimates or current Technical Specification Surveillance Requirements associated with containment integrity and containment leakage.

4.0 Licensing Basis Conclusions As discussed in the previous section, early pressure performance requirements for the containment (i.e. those beyond-the-licensed design basis) were included in the design capabilities of the Units 3 and 4 containment structures to address the uncertainty in component availability for LOCA scenarios. Nevertheless, the licensing basis for containment design pressure clearly remains 55 psig based on a calculated design basis Large Break LOCA peak pressure of 49.9 psig plus a 10% margin of safety. Because the calculated peak pressure (49.9 psig) is less than the licensing basis containment design pressure of 55 psig, which was required at the operating license stage, using 55 psig for calculating minimum required tendon prestress forces is in accordance with the licensed design basis of the plant and, therefore, does not reduce the containment structure's licensed design margin of safety.

PROPOSED LICENSE AMENDMENT REVISIONS FPL proposes to change the following Technical Specifications in support of the proposed amendments:

Technical S ecification 5.2.2: Change the description for the containment building design pressure from "maximum internal pressure of 59 psig" to read "maximum design internal pressure of 55 psig."

Justi fication:

The LCO for containment. pressure integrity and leakage; containment airlock operability; and containment ventilation operability stem from the 49. 9 psig (or, nominally, 50 psig) containment peak internal pressure calculated based on the analyzed design basis LOCA. The containment structural integrity LCO is also based on a 49.9 psig post-LOCA peak pressure. Only the BASES for containment internal pressure (T. S. 3/4.6.1.4) and the DESIGN FEATURES section (T.S. 5.2.2) discuss a value of 59 psig. These two Technical Specifications are proposed for revision to replace 59 psig with the maximum licensed design pressure of 55 psig. A revision to T.S.

3/4.6.1.6 is proposed to clarify that the pressure of 49.9 psig is the licensed transient "analysis" value and not the "design" value for containment.

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L-93-133 Page 5 of 7

2. Technical S ecifications 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 ' psig," to read "maximum analyzed peak pressure calculated for a LOCA event is 49.9 psig ll (c) Change the wording "initial positive pressure of as much as 5 psi," to read "initial positive pressure of as much as 3 psi."

Justification:

The LCO for containment pressure integrity and leakage; containment airlock operability; and containment ventilation operability stem from the 49.9 psig (or nominally 50 psig) containment peak internal pressure calculated based on the analyzed design basis LOCA. The containment structural integrity LCO are also based on a 49.9 psig post-LOCA peak pressure. Only the BASES for containment internal pressure (T. S. 3/4.6 '.4) and the DESIGN FEATURES section (T.S.

5.2.2) discuss a value of 59 psig. These two Technical Specifications are proposed for revision to replace 59 psig with the maximum licensed design pressure of 55 psig.

In addition, a technical change is proposed in BASES 3/4.6.1.4 to limit the bases for initial conditions to be consistent with the stated Limiting Conditions for Operation of T.S. 3.6.1.4. The LCO states that "primary containment internal pressure shall be maintained [below] +3 psig." The BASES state that "limitations on containment internal pressure ensure that...the containment peak pressure does not exceed the design pressure of 59 psig during LOCA conditions" (T.S. 3.6.1 4 and BASES 3/4.6.1.4). The BASES also

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states that "maximum peak pressure expected to be obtained from a

[analyzed] LOCA event is 49.9 psig assuming an initial containment pressure of 0.3 psig. An initial positive pressure of as much as 5 psi would result in a maximum containment pressure that is less than design pressure and is consistent with the "safety analysis" (BASES 3/4.6.1 4).~

The "5 psi" value for initial containment pressure indicates a containment performance capability and provides an indication of the parametric sensitivity to initial pressure variations for transient analysis. This value, however, is not consistent with the licensing bases. Rather, it is more appropriate for the BASES to specifically support the +3 psig LCO. Generic parametric analyses have been performed to consider the effects'f changing initial containment conditions (references 8 and 10). Based on this experience, similar analysis was performed for Turkey Point, a +3 psig initial if a containment pressure would be expected to increase the calculated

t L-93-133 Page 6 of 7 peak pressure by less than 4 psi, which results in a peak calculated containment pressure that is still pressure of 55 psig (reference 9).

less than the containment design

3. Technical S ecifications 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."

Justification:

A revision to T.S. 3/4.6.1.6 is proposed to clarify that the pressure of 49.9 psig is the licensed transient "analysis" value and not the "design" value for containment.

The above changes in the Turkey Point Technical Specifications will ensure that the licensed conditions for peak containment design pressure, based on a peak LOCA analysis containment transient response pressure of 49.9 psig, are properly reflected in plant Technical Specifications.

Summary And Conclusions This evaluation involves a clarification of the maximum containment design pressure which is contained within Turkey Point's Technical Specifications. Consequently, these changes have been evaluated under 10 CFR 50.92.

The proposed changes to Turkey Point's Technical Specifications clarify the licensing basis for the containment structural analysis pressure of 55 psig. This analysis demonstrates that the containment design pressure is the current licensing and design basis for the containment post-tensioning system and associated Technical Specification Surveillance Requirements.

In addition, this licensed design pressure provides a clear basis to meet the AEC's original SER (and current NRC) criteria for design margins associated with the calculation of minimum required prestress forces for the containment post-tensioning system.

~ t L-93-.133 Page 7 of 7 Letter from T. F. Plunkett (FPL) to USNRC, concerning "Turkey Point Unit 3 Twentieth Year Tendon Inspection Report, Hoop Tendons Low Lift-Off Force," L-92-262, dated September 14, 1992.

2. Letter from T. F. Plunkett (FPL) to USNRC, concerning "Turkey Point Unit 4 Summary of Twentieth Year Tendon Surveillance Low lift-Off Force on Hoop and Dome Tendons," L-93-002, dated January 25, 1993.

3. Turkey Point Units 3 and 4 (original) Final Safety Analysis Report (FSAR), Section 5.1.1, "Containment Structure Design Bases,"

Revision 4, dated August 12, 1970.

4 ~ Turkey Point Units 3 and 4 PSAR Supplement 2, Questions 1.0 and 3.0, dated September 2, 1966.

5. Letter from R. C. Young (Atomic Energy Commission) to Dr. J.

Coughlin (FPL), Safety Evaluation by the Division of Reactor Licensing, Turkey Point Units 3 and 4, dated March 16, 1972.

6. Turkey Point Units 3 and 4 Technical Specification Section 3/4, "Limiting Conditions for Operation/Surveillance Requirements and associated Bases Sections, Amendments 153/148, ef fective March 3, 1993.

7. Turkey Point Units 3 and 4 Updated Final Safety Analysis Report (UFSAR), Revision 10, dated July 1992.

8. Bechtel Topical Report BN-TOP-3, Table 15, "Performance and Sizing of Dry Pressure Containments", Revision 4.

9. Engineering Evaluation JPN-PTN-SECJ-92-041, "Twentieth Year Tendon Surveillance Low Lift-Off Force On Hoop Tendon 35H38, " Revision 0, dated December 14, 1992.

10. Engineering Evaluation JPN-PTN-SENJ-88-052, "Containment Bulk Ambient Temperatures, " Revision 3, dated April 13, 1989.

Letter from R. E. Uhrig (FPL) to USNRC, concerning "NRC I & E Bulletin 80-04," L-81-211, dated May 19, 1981.

12. Turkey Point Units 3 and 4 (original) Final Safety Analysis Report (FSAR), Section 14.2.5, "Rupture of a Steam Pipe, " Revision 0, transmitted to the AEC on May 12, 1969.

13. Turkey Point Units 3 and 4 Updated Final Safety Analysis Report (UFSAR), Revision 0, dated July 1982.

14. Westinghouse WCAP-12262, "Analysis of Containment Response Following a Main Steamline Break for Turkey Point Units 3 and 4," dated August 1989.

15. Turkey Point Units 3 and 4 Preliminary Safety Analysis Report (PSAR), Sections 5.4.1.a and 12.2.3, submitted by Application dated March 22, 1966.

ATTACHMENT 2 DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION

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L-93-133 Page 1 of 3 DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION DESCRIPTION OF PROPOSED LICENSE AMENDMENTS The proposed revision to the Technical Specifications corrects the Technical Specification reference to the maximum design internal pressure from 59 psig to 55 psig. In addition the BASES for T.S. 3.6.1.4 is revised such that the initial containment positive pressure is changed from "as much as 5 psi" to "as much as 3 psi." (The LCO for T.S. 3.6.1.4 does not require a change as a result of revising the BASES.) The licensed design pressure of 55 psig meets the Atomic Energy Commission's original Safety Evaluation Report (and current NRC) criteria for design margins associated with the calculation of minimum required prestress forces for the containment post-tensioning system as derived from accident analyses.

INTRODUCTION The Nuclear Regulatory Commission has provided standards for determining whether a significant hazards consideration exists (10 CFR 50.92(c)). A proposed amendment to an operating license for a facility involves no significant hazards consideration, if 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. Each standard is discussed below for the proposed license amendments.

DISCUSSION (1) Operation of the facility in accordance with the proposed amendment would not involve a significant increase in the probability or consequences of an accident previously evaluated.

The containment structure has been designed as one of three principal fission barriers to ensure 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. The maximum containment design pressure criterion establishes a basis to ensure that the structural integrity of containment is not compromised following an accidental pressurization of this structure.

Consequently, a clarification of the maximum containment design pressure criteria and associated containment structural integrity will have no effect on the probability of occurrence of any initiating accident; and the probability of occurrence of any accident or plant event previously evaluated in the Updated FSAR has not been increased.

Since the Large Break Loss of Coolant Accident (LOCA) analysis remains the bounding containment transient analysis case with a peak containment pressure of 49.9 psig and the containment design

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L-93-133 Page 2 of 3 pressure of 55 psig continues to satisfy the original (and current)

Atomic Energy Commission (AEC) structural margin criterion of 10%,

the use of a containment design pressure equal to the original licensed value of 55 psig (and the associated minimum required prestress forces for the containment post-tensioning system) will not increase the consequences of an accident previously analyzed in the Updated FSAR.

A minor technical change has been proposed for BASES 3/4.6.1.4 to limit the initial containment pressure conditions to be consistent with the stated Limiting Conditions for Operation (LCO) of T.S.

3.6.1.4. This will require changing the conservative bounding value of +5.0 psig to +3.0 psig for maximum initial containment pressure.

T.S. 3.6.1.4 states that "primary containment internal pressure shall be maintained (below) +3 psig." The original bounding LOCA analyses did not rely on the value of +5.0 psig, and an initial containment pressure of up to +3.0 psig (which supports the LCO requirements) will not result in a post-accident pressure that exceeds the licensed design pressure of 55 psig. For these reasons, this change in BASES 3/4.6.1.4 will have no effect on the probability of occurrence of any initiating accident and it will not increase the consequences of an accident previously analyzed in the Updated Final Safety Analysis Report (UFSAR).

In addition, the capabilities of Engineered Safety Features equipment to operate within the post-accident containment environment and the conclusions of UFSAR Sections 6.3 and 6.4 remain unchanged. Engineered Safety Features 'equipment has been designed to provide acceptable performance and is qualified for a pressure of 59 psig, which envelopes the original licensed containment design pressure of 55 psig. Consequently, no increase in equipment failures or reductions in performance associated with a revised containment design pressure would occur, and no increase in the consequences of any accident would be expected.

(2) Operation of the facility in accordance with the proposed amendment would not create the possibility of a new or different kind of accident from any accident previously evaluated.

The containment structure has been designed as one of three principal fission barriers to ensure 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. The maximum containment design pressure criteria establishes a basis to ensure that the structural integrity of containment is not compromised following an accidental pressurization of this structure.

Since the Large Break LOCA analysis remains the bounding containment transient analysis case with a peak containment pressure of 49.9 psig and the licensed containment design pressure of 55 psig continues to satisfy the original AEC containment structural margin criterion (which remains the current NRC criterion) of 10%, no new or different kind of accident has been created., Consequently, the use of a containment design pressure equal to the original licensed pressure of 55 psig (and the associated minimum required prestress

A L-93-133 Page 3 of 3 forces for the containment post-tensioning system) will not create the possibility of a new or different kind of accident from any accident previously evaluated in the Updated FSAR.

A technical change has been proposed for BASES 3/4.6.1.4 to limit the initial containment pressure conditions to be consistent with the stated LCO. This will require changing the conservatively bounding value of +5.0 psig to +3.0 psig for maximum initial containment prcssure'he original bounding LOCA analyses did not rely on the value of +5.0 psig, and an initial containment pressure of up to +3.0 psig (which support the LCO requirements) will not result in a post-accident pressure that exceeds the licensed design pressure of 55 psig. For these reasons, this change in BASES 3/4.6.1.4 will not create the possibility of a new or different kind of accident from any accident previously evaluated in the Updated FSAR.

(3) Operation of the facility in accordance with the proposed amendment would not involve a significant reduction in the margin of safety.

Since the Large Break LOCA analysis remains the bounding containment transient analysis case with a peak containment pressure of 49.9 psig and the licensed containment design pressure of 55 psig continues to satisfy the original (and current) AEC structural margin criterion of 10%, the use of a containment design pressure equal to the original licensed pressure of 55 psig (and the associated minimum required prestress forces for the containment post-tensioning system) will have no effect on the margin of safety from that previously licensed by the AEC and documented in the original operating license SER.

A minor technical change has been proposed for BASES 3/4.6.1.4 to limit the initial containment pressure conditions to be consistent with the stated Limiting Conditions for Operation of T.S. 3.6.1.4.

This will require changing the conservatively bounding value of +5.0 psig to +3.0 psig for maximum initial containment pressure. The original bounding LOCA analyses did not rely on the value of +5.0 psig, and an initial containment pressure of up to +3.0 psig (which support the LCO requirements) will not result in a post-accident pressure that exceeds the licensed design pressure of 55 psig. For these reasons, this change in BASES 3/4.6.1.4 does not involve any reduction in a margin of safety.

Based on the above discussion, FPL has determined that the proposed amendments do not (1) involve a significant increase in the probability or consequences of an accident previously evaluated, (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; and therefore the proposed changes do not involve a significant hazards consideration as defined in 10 CFR 50.92.