L-2011-516, Impact of Containment Spray System Modification on Extended Power Uprate License Amendment Request

Impact of Containment Spray System Modification on Extended Power Uprate License Amendment Request

ML11340A029
Person / Time
Site:	Saint Lucie
Issue date:	12/01/2011
From:	Richard Anderson Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2011-516
Download: ML11340A029 (24)

Text

0 Florida Power & Light Company, 6501 S. Ocean Drive, Jensen Beach, FL 34957 FP1L L-2011-516 December 1, 2011 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Re: St. Lucie Plant Unit 1 Docket No. 50-335 Renewed Facility Operating License No. DPR-67 Impact of Containment Spray System Modification on Extended Power Uprate License Amendment Request

Reference:

(1) R. L. Anderson (FPL) to U.S. Nuclear Regulatory Commission (L-2010-259),

"License Amendment Request for Extended Power Uprate," November 22, 2010, Accession No. ML103560419.

By letter L-2010-259 dated November 22, 2010 [Reference 1], Florida Power & Light Company (FPL) requested to amend Renewed Facility Operating License No. DPR-67 and revise the St. Lucie Unit 1 Technical Specifications (TS). The proposed amendment will increase the unit's licensed core thermal power level from 2700 megawatts thermal (MWt) to 3020 MWt and revise the Renewed Facility Operating License and TS to support operation at this increased core thermal power level. This represents an approximate increase of 11.85% and is therefore considered an Extended Power Uprate (EPU).

Subsequent to the submittal of the License Amendment Request (LAR) presented in Reference 1, FPL determined that the containment spray (CS) system must be modified to address excess CS pump discharge flow. This excess CS system flow condition is a current plant condition that was discovered and evaluated as part of the St. Lucie Unit 1 corrective action program. The corrective action to address this condition involves the addition of a flow restricting orifice in each of the CS pump discharge lines. The installation of the flow restricting orifices prior to operation at EPU conditions will reduce the minimum CS system flow assumed in the associated EPU analyses. This change will be implemented in accordance with 10 CFR 50.59 and FPL's modification process.

The attached information supplements the EPU LAR submittal [Reference 1] relative to the impact of the proposed CS system modification upon analyses performed for the design basis Loss of Coolant Accident (LOCA) and Main Steam Line Break (MSLB) containment analyses. The attachment also contains the results of calculations and evaluations performed for EPU analyses impacted by the proposed CS system modification, including the revised emergency core cooling system (ECCS) boric acid precipitation analysis.

an FPL Group company T

L-2011-516 Page 2 of 2 The information presented in the attachment demonstrates that all EPU LAR acceptance criteria are met when taking into consideration the proposed modification to the CS system.

In accordance with 10 CFR 50.91 (b)(1), a copy of this letter is being forwarded to the designated State of Florida official.

This submittal does not alter the significant hazards consideration or environmental assessment previously submitted by FPL letter L-2010-259 [Reference 1].

This submittal contains no new commitments and no revisions to existing commitments.

Should you have any questions regarding this submittal, please contact Mr. Christopher Wasik, St. Lucie Extended Power Uprate License Amendment Request (LAR) Project Manager, at 772-467-7138.

I declare under penalty of perjury that the foregoing is true and correct to the best of my knowledge.

Executed on 0f - baca-,i(w,)- - -LO i I Very truly yours, Site Vice President St. Lucie Plant Attachment cc: Mr. William Passetti, Florida Department of Health

L-2011-516 Attachment Page 1 of 22 Supplemental Information for EPU LAR Attachment 5 Section 2.6.1 "Primary Containment Functional Design"

1. Summary of Change To address an existing plant condition, FPL plans to install a restriction orifice in each of the containment spray pump discharge lines upstream of the shutdown cooling heat exchangers. These restriction orifices will limit the containment spray (CS) flow such that minimum flow and brake horsepower (BHP) requirements are met with minimum pump performance and maximum flow and BHP requirements are met with maximum pump performance. This modification results in a minimum CS flow delivery that is different than that utilized in Extended Power Uprate (EPU) analyses.

2. Input Consideration Containment Spray A comparison of the CS flow delivery data used in the analyses prior to the CS system modification and that resulting from the CS system modification is provided in Table 1.

The Loss of Coolant Accident (LOCA) and main Steam Line Break (MSLB) analyses prior to the CS system modification used a constant CS flow rate of 2700 gpm pre-Recirculation Actuation Signal (RAS) and 2750 gpm post-RAS after the specified delays.

The revised LOCA and MSLB analyses for the EPU with the proposed CS system modification used a partial CS flow delivery curve that was developed as a part of the CS system modification. Table 1 provides the supplemental information to EPU License Amendment Request (LAR) Attachment 5, Table 2.6.1-1. Table 2 compares the CS flow delivery related data for the LOCA and MSLB containment analyses. The flowrate and delay time values labeled as "CS Mod" in Table 2 supersede those in EPU LAR , Table 2.6.1-1.

Containment Passive Heat Sink The following is an addendum to EPU LAR Attachment 5, Section 2.6.1.2.2.1. The MSLB analysis performed for the EPU prior to the CS system modification did not consider the containment vessel liner as a heat sink. However, for the MSLB analysis with the modified CS flow delivery as with LOCA analysis, the containment vessel liner heat sink input data was modified to make the liner functional. The inclusion.of the containment liner heat sink improved the containment response for the MSLB analysis with the modified CS flow delivery.

3. Summary of Results The EPU LOCA and MSLB containment integrity analyses were revised to address the modified CS flow delivery. In addition, the revised MSLB containment integrity analysis added the containment vessel liner passive heat sink. The revised analysis results were evaluated against the previous EPU evaluations.

L-2011-516 Attachment Page 2 of 22 LOCA Results As seen from Table 3-A, the reanalysis did not result in -ny change to the containment peak pressure and temperature for the limiting peak pressure case (double ended hot leg slot (DEHLS) break with minimum safeguards) and limiting long-term limiting temperature response case (double ended discharge leg slot (DEDLS) break with minimum safeguards) because the peaks occurs prior to initiation of the CS flow.

However, as seen from Figures 1 and 2, there was a slight adverse impact on the long-term pressure and temperature response. In addition, as seen from Table 3-B, the pressure at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> increased by 0.2 psi to 7.55 psig for DEHLS and 7.64 psig for DEDLS. These values supersede the values of 7.35 psig for DEHLS and 7.44 psig for DEDLS in EPU LAR Attachment 5, Section 2.6.1.2.1.3. Also, the containment vessel liner temperature increased by 1 OF to 230 OF for DEHLS and 246 OF for DEDLS which supersede the values of 229 OF and 245 OF, respectively, in EPU LAR Attachment 5, Section 2.6.1.2.1.3. These results are as expected because the CS flow is lower and initiates later in the revised analysis.

The acceptance criteria for the results of the LOCA containment integrity analysis is that the calculated peak containment pressure remains below the current containment design value of 44 psig. The calculated containment pressure at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> shall be less than half of the peak calculated pressure and the containment vessel liner temperature shall be maintained below its design temperature of 264 OF. As seen from Tables 3-A and 3-B, all the containment acceptance criteria are met.

The data in the column labeled "EPU + CS MOD" in Table 3-A supersede the DEHLS and DEDLS Peak Containment Pressure and Vapor Temperature values in EPU LAR , Table 2.6.1-2. The data in the column labeled "EPU + CS MOD" in Table 3-B supersede the DEHLS and DEDLS Containment Pressure @ 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and Peak Containment Vessel Temperature values in EPU LAR Attachment 5, Table 2.6.1-2.

Figures 1-4 supersede EPU LAR Attachment 5, Figures 2.6.1-1 through 2.6.1-4, respectively.

MSLB Results As seen from Table 4-A and Figures 5 and 6, the MSLB reanalysis resulted in a decrease in the containment peak pressure for the limiting peak pressure case (MSLB at full power with failure of 1 cooling train) and peak Equipment Qualification (EQ) temperature case. This is expected because although the CS flow is reduced, adding the containment vessel liner passive heat sink provides additional heat removal from the containment atmosphere. As seen from Table 4-A, the peak pressure decreased by 0.35 psi to 42.73 psig which supersedes the value of 43.08 psig in EPU LAR Attachment 5, Table 2.6.1-2. Also, the peak EQ temperature decreased by 11.49 OF to 387.0 OF which supersedes the value of 398.49 OF in EPU LAR Attachment 5, Table 2.6.1-2. In addition, as seen from Table 4-B, the peak containment vessel liner temperature decreases by 7.1°F to 232.3 OF. This supersedes the value of 239.4 OF in EPU LAR , Table 2.6.1-2.

The acceptance criteria for the results of the MSLB containment integrity analysis are that the calculated peak containment pressure remains below the current containment design value of 44 psig and the containment vessel liner temperature shall be

L-2011-516 Attachment Page 3 of 22 maintained below its design temperature of 264 'F. As seen from Tables 4-A and 4-B, both of these acceptance criteria are met. Figures 5 and 6 supersede EPU LAR , Figures 2.6.1-5 and 2.6.1-6, respectively.

Table 1 Containment Spray Flow Delivery Containment Spray (gpm) Time after Flow Initiation (sec)

EPU EPU + CS Mod EPU EPU + CS Mod 0 0 *16 0 500 30 0 900 35 0 1225 40 2700 (injection phase) 2550 33.5 > 46 Table 2 Containment Response Analysis Parameters Parameter LOCA Value MSLB Value Flowrate - Steady State (gpm)

Injection Phase (per pump) 2700 (EPU) 2700 (EPU) 2545(1) (CS Mod) 2545(1) (CS Mod)

Recirculation Phase (per pump) 2750 (EPU) NA 2545 (CS Mod) NA Delay Time after the Setpoint is Reached (sec)

Without Offsite Power 63.5 (EPU) 63.5 (EPU) 78.5 (CS Mod) 78.5 (CS Mod)

With Offsite Power NA 52 (EPU)

NA 67.0 (CS Mod)

Notes:

(1) The actual value is 2550 gpm; however, it is conservative to use a slightly lower value of CS flowrate for the containment pressure/temperature response analysis.

L-2011-516 Attachment Page 4 of 22 Table 3-A LOCA Containment Peak Pressure and Temperature Results for Lirniting Pressure and Temperature Cases EPU EPU + CS MOD Peak Peak PeakCotimn Peak Case Containment Containment Containment Vapor Vapor Pressure Vapor Pressure Temperature Temperature

@ Time @ Time @ Time @ Time LOCA DEHLS - 42.77 psig 265.57 OF 42.77 psig 265.57 OF (peak pressure responsecase) @ 18.17 sec @ 18.17 sec @ 18.17 sec @ 18.17 sec LOCA DEDLS -

(long-term 40.16 psig 261.64 OF 40.16 psig 261.64 OF temperature @ 13.97 sec @ 13.97 sec @ 13.97 sec @ 13.97 sec response case) I I_

Table 3-B LOCA Long-Term Containment Response Results for Limiting Pressure and Temperature Cases EPU EPU + CS MOD Peak Peak Case Containment Containment Containment Containment Pressure Pressure Vessel Vesl@ 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Vessel Vse

@ 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Temperature Temperature LOCA DEHLS - 229 OF@1449 230OF @1449 (peak pressure 7.35 psig sec 7.55 psig sec response case)

LOCA DEDLS -

(long-term 7.44 psig 245 OF @ 1249 7.64 psig 246 0 F @ 1299 temperature sec sec response case) I

L-2011-516 Attachment Page 5 of 22 Table 4-A MSLB Containment Peak Pressure and Temperature Results for Limiting Pressure and EQ Temperature Cases EPU EPU+ CS MOD, Peak Peak Peak Peak Case Containment Containment Containment Containment Pressure Vapor Pressure Vapor Presue Temperature Presue Temperature

@ Time @@ Time Time @Time MSLB (peak pressure response 43.08 psig NA 42.73 NA case) 387.0 F MSLB (EQ case) NA 398.49 °F NA 387.0 °F Table 4-B MSLB Containment Temperature Results for EQ Temperature Cases EPU EPU + CS MOD Case Peak Containment Peak Containment Vessel Temperature Vessel Temperature MSLB (EQ case) 239.4 OF @ 119 sec 232.3 °F @ 104 sec

L-2011-516 Attachment Page 6 of 22 Figure 1 Containment Pressure, LOCA DEHLS (Peak Pressure Response Case) 45 40 35 30 25 S20 15 10 5

0 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 TIME (see)

L-2011-516 Attachment Page 7 of 22 Figure 2 Containment Atmosphere Temperature, DEHLS LOCA (Peak Pressure Response Case) 300 250 200 150 100 50 0

1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 TIME (sec)

L-2011-516 Attachment Page 8 of 22 Figure 3 Containment Pressure, LOCA DEDLS (Long-Term Temperature Response Case) 45 40 p * ,*

- EPU + CS MOD

--- EPU 35 30 25 20 15 I0 5

1.E-0I l.E+00 1.E+0I I.E+02 I.E+03 l.E+04 I.E+05 I.E+06 I.E+07 TIME (sec)

L-2011-516 Attachment Page 9 of 22 Figure 4 Containment Atmosphere Temperature, LOCA DEDLS (Long-Term Temperature Response Case) 300 250 200

- 150 100 50 O L, 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 TIME (sec)

L-2011-516 Attachment Page 10 of 22 Figure 5 Containment Pressure - Main Steam Line Break at Full Power Failure of 1 Cooling Train 50 45 EPU + CS MOD 40

/*'* * -- EPU 40 35 - -

.I) 25

• 20 30 15 10 5

0 50 100 150 200 250 300 TIME (sec)

L-2011-516 Attachment Page 11 of 22 Figure 6 Containment Temperature - Main Steam Line Break Equipment Qualification 450 400 350 300 250 200 150 100 50 0

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 TIE (sec)

L-2011-516 Attachment Page 12 of 22 Supplemental Information for EPU LAR Attachment 5 Section 2.6.3.2 "Mass and Energy Release Analysis for Secondary System Pipe Ruptures"

1. Summary of Change The installation of a restriction orifice in the containment spray pump discharge lines upstream of the shutdown cooling heat exchangers will result in a CS flow delivery that is different than that utilized prior to the proposed CS system modification.

2. Input Consideration Containment Spray A comparison of the CS flow delivery data used in the analyses prior to the CS system modification and that resulting from the CS system modification is provided above in Table 1 of the Supplemental Information for EPU LAR Section 2.6.1, "Primary Containment Functional Design." A comparison of the CS flow analysis parameters for the Main Steam Line Break (MSLB) is presented above in Table 2 of the Supplemental Information for EPU LAR Section 2.6.1, "Primary Containment Functional Design."

Containment Passive Heat Sink The MSLB analysis performed for the EPU prior to the CS system modification did not consider the containment vessel liner as a heat sink. However, for the MSLB analysis with the modified CS flow delivery, the containment vessel liner passive heat sink was considered as described above in the Supplemental Information for EPU LAR Section 2.6.1, "Primary Containment Functional Design." This consideration is added as an assumption to EPU LAR Attachment 5, Section 2.6.3.2.2.2.

3. Summary of Results The MSLB mass and energy release analysis was revised to address the modified CS flow delivery. In addition, the revised MSLB containment mass and energy release analysis considered the containment vessel liner as a heat sink. The revised analysis results were evaluated against the previous EPU evaluation.

MSLB Results Table 5 provides the comparison of the mass and energy releases generated for the EPU and that with CS system modification. The data in the columns of Table 5 labeled "EPU + CS Mod" supersedes that in the columns labeled "EPU" in EPU LAR Attachment 5, Table 2.6.3.2-1. As seen from Table 5, there are no significant changes in the MSLB mass and energy releases. Table 6 provides the comparison of the various milestones during the MSLB event. The data in the column of Table 6 labeled "EPU + CS Mod" supersedes the data in the column labeled "EPU" in EPU LAR Attachment 5, Table 2.6.3.2-2. As seen from Table 6, differences of interest are the times at which the peak pressure and temperature occur. The peak pressure for the revised analysis occurs at 86.99 seconds, approximately 2.5 seconds earlier than the EPU analysis time of 89.5 seconds. Also, the peak temperature for the revised analysis occurs at 59.3 seconds, approximately 0.9 seconds earlier than the EPU analysis time of 60.23 seconds. As

L-2011-516 Attachment Page 13 of 22 documented above in the Supplemental Information for EPU LAR Section 2.6.1, the peak pressure and temperature are lower because of greater heat removal from the containment atmosphere by the containment vessel liner heat sink and, therefore, are expected to occur earlier. The difference in time of the initiation of the auxiliary feedwater (AFW) flow to the intact steam generator (SG) is inconsequential since the transient is nearly over.

There are no acceptance criteria for the MSLB containment mass and energy release analysis.

L-2011-516 Attachment Page 14 of 22 Table 5 Blowdown M&E Release Rates to Containment for the Limiting Main Steam Line Break EPU EPU + CS EPU EPU-+ CS Mod Time Mod (Sec) Mass Rate Mass Rate Energy Rate Energy Rate (Ibm/sec) (Ibm/sec) (BTU/sec) (BTU/sec) 0 6811 6810 8.15E+06 8.15E+06 1 6056 6056 7.26E+06 7.26E+06 2 5499 5499 6.61 E+06 6.61 E+06 3 5094 5094 6.13E+06 6.13E+06 4 4782 4782 5.75E+06 5.75E+06 5 4543 4543 5.47E+06 5.47E+06 6 4360 4360 5.25E+06 5.25E+06 7 4218 4218 5.08E+06 5.08E+06 8 4107 4107 4.95E+06 4.95E+06 9 4007 4007 4.83E+06 4.83E+06 10 3908 3908 4.71E+06 4.71E+06 11 3806 3806 4.59E+06 4.58E+06 12 3703 3703 4.46E+06 4.46E+06 13 3606 3606 4.34E+06 4.34E+06 14 3519 3519 4.24E+06 4.24E+06 15 3444 3444 4.15E+06 4.15E+06 16 3380 3380 4.07E+06 4.07E+06 17 3321 3321 4.OOE+06 4.OOE+06 18 3265 3265 3.93E+06 3.93E+06 19 3208 3208 3.86E+06 3.86E+06 20 3152 3152 3.80E+06 3.80E+06 30 2707 2707 3.26E+06 3.26E+06 40 2394 2394 2.88E+06 2.88E+06 50 2152 2152 2.59E+06 2.59E+06

.60 1920 1920 2.30E+06 2.30E+06 70 1712 1712 2.05E+06 2.05E+06 80 1531 1531 1.83E+06 1.83E+06 90 1205 1205 1.45E+06 1.44E+06 100 418 436 492672 513711 110 145 146 170454 171477 120 174 136 207730 164581 125 3.584 3.498 4514 4408 150 1.589 2.102 2013 2664 200 1.091 1.452 1390 1851 250 0.794 1.099 1014 1406 300 0.628 0.803 804 1029 241536 241665 2.90E+08 2.90E+08 INTEGRAL 1 (Ibm) (Ibm) 1 2 (BTU) (BTU)

B

L-2011-516 Attachment Page 15 of 22 Table 6 Sequence of Events for Limiting Main Steam Line Break Inside Containment EPU EPU + CS Mod Event (Sec) (Sec)

Break occurs 0.00 0.00 Reactor trip analytical setpoint reached, 2.43 Containment High Pressure AFW isolation to the affected SG (high SG AP) 10.78 10.78 analytical setpoint reached Control Element Assemblies (CEAs) beginentering 3.83 3.83 core SIAS analytical setpoint reached, Containment High 373 Pressure Turbine Stop Valves closed 4.09 4.09 Main Steam Isolation Signal (MSIS) analytical 5.21 5.21 setpoint reached, SG Low Pressure Containment Spray Actuation Signal (CSAS) analytical setpoint reached, Containment High-High 8.30 8.30 Pressure Main Steam Isolation Valve (MSIV) Closure 12.11 12.11 Main Feedwater Isolation Valves closed 23.73 23.73 Containment peak temperature occurs 60.23 59.30 Containment Sprays on 61.0 (full) 61.0 (partial) 76.0 (full)

Containment peak pressure occurs 89.50 86.99 AFW to Intact SG initiated 237.00 251.00 End of simulation of the transient 300.00 300.00

L-2011-516 Attachment Page 16 of 22 Supplemental Information for EPU LAR Attachment 5 Section 2.8.5.6.3.5 "Technical Evaluation - Post-LOCA Boric Acid Precipitation"

1. Summary of Change To address an existing plant condition, FPL plans to install a restriction orifice in each of the containment spray pump discharge lines upstream of the shutdown cooling heat exchangers. These restriction orifices will limit the containment spray (CS) flow such that minimum flow and brake horsepower (BHP) requirements are met with minimum pump performance and maximum flow and BHP requirements are met with maximum pump performance. This modification results in a minimum CS flow delivery that is different than that utilized in Extended Power Uprate (EPU) analyses.

2. Input Consideration Containment Spray A comparison of the CS flow delivery data used in the Emergency Core Cooling System (ECCS) boric acid precipitation analysis prior to the CS system modification and that resulting from the CS system modification is provided below.

Input Parameter Previous Value (EPU) New Value (EPU plus CS Mod)

Containment Spray Pump 2750 2550 Flow (gpm per pump)

3. Summary of Results The ECCS boric acid precipitation analysis was revised to address the modified CS flow delivery. The revised analysis results were evaluated against the previous EPU evaluation.

Boric Acid Precipitation Results The boric acid precipitation analysis was revised to address the revised input conditions documented above and the revised results were evaluated against the previous EPU evaluations. The reanalysis only saw a change in the results of one case, which was the case with 250 gpm of hot side injection initiated at 6.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> post-LOCA. The time for maximum boric acid concentration for this case decreased by 0.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, from 7.4 to 7.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. The maximum boric acid concentration continues to be 26.6 wt%, which is less than the solubility limit of 27.6 wt%. Therefore, the proposed EPU remains acceptable with the revised EPU boric acid precipitation analysis.

L-2011-516 Attachment Page 17 of 22

4. EPU LAR Changes Based on the above changes due to the updated CS flow rate, the following changes are made to EPU LAR Attachment 5, Section 2.8.5.6.3.5. Entries are updated in EPU LAR , Tables 2.8.5.6.3-10 and 2.8.5.6.3-11, and EPU LAR Attachment 5, Figures 2.8.5.6.3-14 and 2.8.5.6.3-15 are replaced. These changes and updates are shown in the Tables and Figures below. Note that the tables are not reproduced in their entirety; only the information that is updated is shown below.

EPU LAR Table 2.8.5.6.3-10 PLANT DESIGN DATA USED IN THE BORIC ACID PRECIPITATION ANALYSIS Pump parameters Minimum containment spray pump flow rate 2550 gpm EPU LAR Table 2.8.5.6.3-11

SUMMARY

OF RESULTS.

FOR THE BORIC ACID PRECIPITATION ANALYSIS EPU Analysis CENPD-254-P-A Methodology Modified by the Waterford Approach Parameter EPU Result Maximum core boric acid concentration with 250 gpm of 26.6 wt% at 7.3 simultaneous hot and cold side injection started at 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> hours post-LOCA

L-2011-516 Attachment Page 18 of 22 EPU LAR Figure 2.8.5.6.3-14 Boric Acid Concentration in the Core versus Time 40 30 z

0 o 20\

\ ,, ',.,.

2 \0 10 NO HSI \ N .

- Solubility mit (2"7.6-wt%) ..

260 gpm FSl at 6 hrs 275 gpm FSl at 6 hrs

......................... 250 gpm FSl at 6 hrs

...... 20 gpm FI shing Flow at 6 hrs 0 4 8 12 16 20 m_

TIME AFTER LOCA, HOURS

L-2011-516 Attachment Page 19 of 22 EPU LAR Figure 2.8.5.6.3-15 Core Boil-off and Simultaneous Hot/Cold Leg Injection versus Time 600 500 400 n

0~

300 0,J L-200 100 BOIL OFF CURVE HSI 250 GP At 6hrs -------

0 0 5 10 15 20 25 TIME AFTER LOCA, HOURS

L-2011-516 Attachment Page 20 of 22 Additional Sections of Attachment 5 of the EPU LAR with Revised Analyses 2.1.7 Protective Coating Systems (Paints) - Organic Materials Protective coating systems (paints) provide a means for protecting the surfaces of facilities and equipment from corrosion and from contamination by radionuclides and also provide wear protection during plant operation and maintenance activities. Table 2.1.7-1 of EPU LAR Attachment 5 provides a comparison of the EPU containment LOCA parameters versus the Service Level 1 coating design basis accident (DBA) test conditions. The St. Lucie Unit 1 containment coatings minimum qualifying DBA test temperature is 286 OF (0 to 2.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />) and 219 OF (2.8 to 23.9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />). The minimum qualifying DBA test pressure is 54 psig. As can be seen from Figures 1 through 4 above, these DBA test conditions bound the revised LOCA containment temperatures and pressures. An assessment of the post-LOCA containment radiation dose concludes that the reduced containment spray flow modification does not impact the integrated EPU dose of 2.25 x 107 Rads presented in EPU LAR Attachment 5, Table 2.1.7-1. The effects of reduced containment spray and sump pH changed were analyzed to determine an impact to the qualification of the containment coatings. The results of the reanalysis conclude that the minimum containment sump pH will remain at approximately 7. In conclusion, the containment coatings system parameters remain within the acceptance criteria for EPU when considering reduced CS system flow.

2.6.5 Containment Heat Removal Section 2.6.5 of EPU LAR Attachment 5 evaluated the effects of the proposed EPU on the analyses of available net positive suction head (NPSH) to the containment heat removal system pumps. Analyses at EPU conditions showed that the available NPSH exceeds the NPSH required with adequate margin in both the injection and the recirculation phases of a LOCA for the CS, high pressure safety injection and low pressure safety injection pumps. The existing NPSH analysis demonstrates sufficient margin to meet the NRC requirement of 21%. A lower CS pump flow rate will increase NPSH available and reduce NPSH required. In addition, an assessment of the post-LOCA containment sump level has been performed assuming a reduction in CS pump flow. The results of the assessment conclude that the containment sump level results presented in the EPU LAR are unchanged. Therefore, the EPU LAR pump NPSH results bound the NPSH conditions that will exist after the CS system modification is implemented.

2.9.2 Radiological Consequences Analyses Using Alternative Source Terms (AST)

The results of the EPU LAR radiological analyses using the AST methodology were originally presented in Section 2.9.2 of Attachment 5 to the EPU LAR. These EPU radiological analyses were revised to include updated site meteorological data and associated revised atmospheric dispersion factors (X/Q's). The results of the revised radiological consequences analyses were submitted to NRC via FPL letter L-2011-360

[Reference 2] and the analyses included consideration of reduced CS system flow. The radiological analysis results meet all applicable EPU regulatory acceptance criteria.

L-2011-516 Attachment Page 21 of 22 Other Sections of Attachment 5 of the EPU LAR Assessed for Impact 2.3.1 Environmental Qualification of Electrical Equipment The impact of reduced CS system flow on the containment response for the LOCA and MSLB events is presented above in the Supplemental Information for EPU LAR Section 2.6.1 "Primary Containment Functional Design." As shown in Table 3-A, the peak containment pressure and temperature for the limiting LOCA DEHLS and DEDLS cases are unchanged as a result of reduced CS flow. Although the Table 3-B results for long-term post-LOCA containment response show a slight increase in containment pressure and temperature 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> into the event for the "EPU + CS Mod" case, these results are still bounded by the equipment Environmental Qualification (EQ) curve. Tables 4-A and 4-B show that the peak pressure and temperature results of the revised MSLB analysis with consideration of reduced CS system flow are below the peak values presented in EPU LAR Attachment 5. It is therefore concluded that the revised containment pressure and temperature response for EPU considering reduced CS system flow remain bounded by the existing EQ curves and no additional analysis is required.

In addition to the above, the following EQ evaluations were performed for the EPU taking into account a reduction in CS system flow rate:

a) An assessment was performed to determine the validity of the EPU EQ radiation zone maps. The results of this evaluation demonstrate that the 1 day, 30 day, and 1 year integrated EPU dose estimates in each of the St. Lucie Unit 1 EQ radiation zones were not impacted by the reduction in CS flow rate.

b) An assessment was performed that determines the revised integrated dose for specific HVAC components listed in EPU LAR Attachment 5 Table 2.3.1-1 assuming reduced CS system flow. The results of the evaluation conclude that the estimated shielding requirements remain unchanged. In addition, components considered to be in a mild environment post-EPU are not impacted by the reduction in CS flow rate.

c) The containment flood level analysis addresses the maximum flood level for EQ of equipment located within containment. The maximum flood level calculation does not consider the CS pump flow rate in determining the flood level; therefore, analysis results prior to the proposed CS system modification are unchanged.

2.5.4.3 Reactor Auxiliary Cooling Water Systems The proposed CS system modification (addition of flow restricting orifices) results in a decrease in CS flow during both the injection and recirculation phases of a Loss of Coolant Accident (LOCA). This CS flow reduction will increase the time to recirculation actuation signal (RAS) since the CS pumps will be drawing less volume from the refueling water tank (RWT). This increased time to RAS will decrease the heat load on the shutdown cooling heat exchanger (SDCHx) when the pump suction is switched to the sump since the temperature of the water in the sump will decrease over time. The SDCHx is cooled by the component cooling water (CCW) system; therefore, a decrease in the SDCHx heat load will decrease the CCW system temperatures as well. The CCW temperatures reported in EPU LAR Attachment 5 remain bounding due to the reduction in CS flow rate.

L-2011-516 Attachment Page 22 of 22 2.7.2 Engineered Safety Feature Atmosphere Cleanup The shield building ventilation system is part of the Engineered Safety Feature Atmosphere Cleanup systems and is designed to limit the pressure rise and establish and maintain a slight negative pressure in the shield building annulus following a LOCA.

An assessment was performed to determine the increase in the pressure in the shield building annulus relative to a reduction in CS flow rate. The results of the assessment conclude that the pre-CS system modification analysis results presented in EPU LAR are unchanged.

2.7.6 Engineered Safety Feature Ventilation System The emergency core cooling system (ECCS) area ventilation system is part of the Engineered Safety Features (ESF) ventilation systems. The ECCS area ventilation-system is designed to provide post-LOCA filtration and adsorption of fission products in the exhaust air from areas of the reactor auxiliary building (RAB). An assessment was performed to determine the post-LOCA temperatures in the various ECCS areas of the RAB relative to a reduction in CS flow rate. The results of the assessment conclude that the pre-CS system modification analysis results presented in EPU LAR Attachment 5 are unchanged.

2.10.1 Occupational and Public Radiation Doses Section 2.10.1 of Attachment 5 to the EPU LAR includes the analysis that determines the post-accident dose to operators for specified vital missions. The result of the analysis for the EPU concludes that the limiting calculated dose to an operator performing a vital task is in compliance with the regulatory limit of 5 rem whole body. An assessment has been performed on the vital operator mission dose with consideration for reduced CS system flow. The results of the assessment conclude that vital mission dose for EPU is unchanged.

References

1. R. L. Anderson (FPL) to U.S. Nuclear Regulatory Commission (L-2010-259),

"License Amendment Request for Extended Power Uprate," November 22, 2010, Accession No. ML103560419.

2. R. L. Anderson (FPL) to U.S. Nuclear Regulatory Commission (L-2011-360),

"Response to NRC Accident Dose Branch Request for Additional Information Regarding Extended Power Uprate License Amendment Request," September 2, 2011, Accession No. ML11251A159.