ML20134M313

Revised SG Tube Rupture Analysis for Byron/Braidwood

ML20134M313
Person / Time
Site:	Byron, Braidwood
Issue date:	11/13/1996
From:	Wong A COMMONWEALTH EDISON CO.
To:
Shared Package
ML20134M301	List: ML20134M299 ML20134M313
References
NFSR-0114, NFSR-0114-R00, NFSR-114, NFSR-114-R, NUDOCS 9611250022
Download: ML20134M313 (36)

Text

.. . .

l I

NFSR-0114 REV.O l

Revised Steam Generator Tube Rupture Analysis  !

for Byron /Braidwood November,1996 By Annie W. Wong Commonwealth Edison Prepared by: 't '

fb[ 0 I

I i 1 1 Reviewed by: \R!wk @ I b M k9K Supervising Engineer i

Approved by: A r## ////S/M Nuclear Fuel Services Manager 'Da(e

)

1 I

l Nuclear Fuel Services Commonwealth Edison Company 1400 Opus Place, Suite 400  !

Downers Grove, Illinois 60515 l l

9611250022 961113 PDR ADOCK 05000454 P PDR

NFSR-0114 REV.O Abstract j The plant specific analysis required by the NRC to resolve the Steam Generator Tube Rupture (SGTR) licensing issues for the Byron /Braidwood plants was provided in Reference 1. The NRC approved the Reference 1 Comed methodology by issuing an SER for the Byron /Braidwood SGTR transient analysis in Reference 2.

The Byron Unit 1 and Braidwood Unit 1 Generating Stations steam generators are l being replaced with BW; replacement steam generators (RSGs). The SGTR event is being reanalyzed to support the Byron /Braldwood steam generator replacement project.

This reanalysis, which is based on the previously NRC approved methodology ,

(References 1 and 2), is necessary to verify that the RSGs meet the same acceptance I criteria as the D-4 and D-5 steam generators (OSGs) which are currently in place at the Byron and Braidwood stations.

This analysis includes the following changes to the Reference 1 analysis' assumptions:

1. addition of a RSG model,

2. revised average Reactor Coolant System (RCS) temperature (TAVG) to 575 F,

3. revised operator response times,

4. added uncertainty for initial values for power, TAVG and Steam Generator (SG) level,

5. revised turbine runback power to 70%, and l

6. added OTDT case to verify most conservative approach is utilized.

In the Reference 1 analysis, a bounding case was performed for the D-4 and D-5 steam generators. This OSG case is reanalyzed to the same set of assumptions as the j RSGs. Prior to RSG installation, the OSG reanalysis bounds all four Byron and Braidwood Units. After RSG installation, the OSG reanalysis bounds Byron Unit 2 and Braidwood Unit 2 and the RSG analysis bounds Byron Unit 1 and Braidwood Unit 1.

The results of this reanalysis show that the steam generators do not overfill and that the Offsite Dose (OD) cases have adequate margin to the 10 CFR 100 requirements.

ii

NFSR-0114 l REV.0 l 1

Table of Contents .

1 1

1. Introduction..............................................................................................................6  :

2. M odel/Assu m ptio n C h a n ges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1 U pd ate s t o R e fe re n ce 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.2RSGMode1.....................................................................................................7

2. 3 Ad d it io n a l C a s e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2. 4 As s u m pt ion C h a n g e s . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2. 4.1 U n ce rt ai n t i e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.4.2 I nitia l C o n d it i on s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.4.3 Ope rato r R es pon se Tim e s . . . . . . . . .. ...... .. . ... . .. . . . . . . .. . . . . .. . . . .. . ... . .. .. . .. . . . . . . 9 2.4.4 Tu r b in e R u n b a c k . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.Results....................................................................................................................11 3.1MTOCase...................................................................................................11 3.1.1 O S G R e s u It s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 3.1.2 R S G R e s u It s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1

3. 2 O D C a s e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

3. 2.1 O S G R e s u lt s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3. 2. 2 R SG R e s u lt s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.2. 3 D o s e C a lc u lat io n . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . . . . 13

4. C o n c l u s io n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5. R e f e r e n c e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

i l

i l

4 i

til 1

J

_ . . = _ - - - _

NFSR-0114

$ REV.0 List of Tables Table 1 - Key Physical Differences between OSG and RSG...... ................... .............17

' Table 2 - M odel/ Ass u m ption Difference s . . . . .. . . ... . .. . . . . . . . . .. . . . . . . . .. . . . . . .... ... .. ... . .... .... . . . .. . ... 18 Table 3 - Analysis Operator Response Times (MTO Case)............................... ..........19 Table 4 - Analysis Operator Response Times (OD Case) .................................... .......19 Table 5 - Sequence of Events (OSG MTO Cases) ....................................................... 20 d

Table 6 - Sequence of Events (RSG MTO Cases) .................. ........ ....... ................... 21 Table 7 - Sequence of Events (OD Cases) ....... .. .. .... ...... . .. . .. . .. ... .... . . . .. . .. . . . . . . .. . ... .... .... . 22 Table 8 - Offsite Do se R es uits (Th yroid). . .. .. .. .... .. ..... . ..... ... .... . .. . . . .. . . .. . . . . . . . ... .... ... . .. .. ... .. 2 3 Table 9 - Offsite Dose Results (Whole Body) .......................... .................................... 23 4

T t

s 4

A 4

4 i.

I 4

1 i

y .._ . _ _ .. _ _ _ _ . _ _ _ _ _ _ _ ______.______.._._.._m .

NFSR-0114 -

l REV. O a

l List of Figures i

j Figure 1 - SGTR Analysis Noding Diagram .................................................................. 24 l Figure 2 - Pressurizer / Ruptured SG Pressure (OSG MTO Low Pzr. Pressure Case) .. 25

{ Figure 3 - Ruptured Tube Flow (OSG MTO Low Pzr. Pressure Case) ......................... 25 i Figure 4'- Ruptured SG Liquid Volume (OSG MTO Low Pzr. Pressure Case)............. 26 j Figure 5 - Pressurizer / Ruptured SG Pressure (OSG MTO OTDT Case)...................... 27 Figure 6 - Ruptured Tube Flow (OSG MTO OTDT Case)............................................. 27

Figure 7 - Ruptured SG Liquid Volume (OSG MTO OTDT Case) ....................... ........ 28 l 3

Figure 8 - Pressurizer / Ruptured SG Pressure (RSG MTO Low Pzr. Pressure Case)... 29 L Figure 9 - Ruptured Tube Flow (RSG MTO Low Pzr. Pressure Case) ....................... . 29 i Figure 10 - Ruptured SG Liquid Volume (RSG MTO Low Pzr. Pressure Case) ........... 30 .

! Figure 11 - Pressurizer / Ruptured SG Pressure (RSG MTO OTDT Case).................... 30

! Figure 12 - Ruptured Tube Flow (RSG MTO OTDT Case)........................................... 31 ,

Figure 13 - Ruptured SG Liquid Volume (RSG MTO OTDT Case).................. ... ........ 32 '

Figure 14 - Pressurizer / Ruptured SG Pressure (OSG OD Case) ................................. 33 l Figure 15 - Ruptured Tube Flow (OSG OD Case) ........................................................ 33

Figure 16 - Ruptured SG Steam Release Rate (OSG OD Case) ................................. 34 ,

i Figure 17 - Intact SG Steam Release Rate (OSG OD Case) ....................................... 34 l i Figure 18 - Pressurizer / Ruptured SG Pressure LR.SfqOD Case) ................................. 35 j~ Figure 19 - Ruptured Tube Flow (RSG OD Case) ........................................................ 35 l

! Figure 20 - Ruptured SG Steam Release Rate (RSG OD Case).............. ................... 36 i i Figure 21 - Intact SG Steam Release Rate (RSG OD Case)........................................ 36 i i

l 1

1 4

5 i

5 a .

1 q

o V  !

i NFSR-0114 REV.0

1. Introduction  !

.Following the 1982 Ginna SGTR event, the NRC expressed concerns over traditional FSAR assumptions and methodology used for this transient. In response to the NRC's concerns,- the Westinghouse Owners Group (WOG) addressed-the SGTR licensing issues on a generic basis by issuing WCAP-10698 and Supplement 1 to WCAP-10698

. (References 3 and 4, respectively). Subsequently,: Comed submitted plant specific SGTR analysis for Byron and Braidwood (Reference 1) in accordance with the NRC SER.

- requirements for the referenced WCAPs. The NRC approved the Comed methodology by issuing an SER for the Byron /Braidwood SGTR transient analysis (Reference 2).

Currently, Byron Unit 1 and Braidwood Unit 1 have Westinghouse model D-4 SGs while Byron Unit 2 and Braidwood Unit 2 have Westinghouse model D-5 SGs. The Reference 1 analysis bounds both D-4 and D-5 SGs (OSGs). Since the Byron Unit 1

' and Braidwood Unit 1 D-4 SGs are being replaced with BWI replacement steam generators (RSGs), the SGTR event is being reanalyzed. ' This revised analysis, which is based on the previously NRC approved methodology (References 1 and 2), is necessary since the OSGs and RSGs have different physical characteristics which impact the previous SGTR analysis results.

The differences between OSGs and RSGs that impact the SGTR analysis are summarized in Table 1. The smaller RSG tube diameter leads to reduction in break ,

flow, which increases the Margin to Overfill (MTO) and lowers the rate of transfer of )

primary coolant activity to the secondary. The larger heat transfer area increases the steam generator pressure for the same TAVG. This increase in secondary pressure  ;

also leads to a reduction in break flow. But the RSGs have more moisture separators in the generator which reduces secondary side volume which in turn reduces the MTO.

To assess the impact of these differences, the SGTR event has been reanalyzed.

Some of the assumptions used in the Reference 1 analysis have been revised for this analysis. The bounding case performed for the OSGs in Reference 1 has been j reanalyzed in this analysis in order to use a single and consistent set of assumptions for both OSGs and RSGs. Prior to RSG installation, the OSG reanalysis bounds all four i Byron and Braidwood Units. After RSG installation, the OSG reanalysis bounds Byron  !

Unit 2 and Braidwood Unit 2 and the RSG analysis bounds Byron Unit 1 and Braidwood l Unit 1. Section 2 describes the changes from the Reference 1 analysis. Section 3 presents the results of this reanalysis. Section 4 presents the conclusions of this revised l SGTR analysis.

6 of 36

NFSR-0114 REV. o

2. Model/ Assumption Changes The following subsections provide detailed descriptions of the differences between the Reference 1 SGTR analysis and this revised SGTR analysis. Table 2 is a summary of these differences. Figure 1 is a noding diagram of the RETRAN model used in this reanalysis.

2.1 Updates to Reference 1 The Reference 1 analysis has previously been updated due to an increase in OSG tube plugging level, reduction in Thermal Design Flow (TDF) and use of RETRAN-02 MOD 5.1. These minor changes were performed under the 10 CFR 50.59 process. The most recent analysis documented in Reference 5 is used as the base case for this reanalysis.

The Reference 1 analysis was performed at 0% tube plugging level for the OSGs and supplemented by an analysis which supported a 10% tube plugging level (Reference 6).

The tube plugging level was increased to 30% in the Reference 5 model. This change involved reduction in heat transfer area and decrease in SG pressure. The 30% tube plugging model is used in the OSG cases for this analysis.

The reduction in TDF for the OSGs in Reference 5 is part of the OSG tube plugging increase program. This analysis uses the Reference 5 TDF for both RSGs and OSGs since the RCS flow requirement remains the same for Unit 1 and Unit 2 after RSG installation.

The Reference 1 analysis was performed using RETRAN-02 MOD 3. The Reference 5 analysis used RETRAN-02 MOD 5.1. For the use of RETRAN-02 MODS.1, benchmark cases were performed in Reference 5. The conclusion was there were no significant differences between RETRAN-02 MOD 3 and RETRAN-02 MODS.1 and the model developed for MOD 3 can be used for MODS.1.

2.2 RSG Model The physical characteristics of the RSGs have been incorporated into the Reference 1 RETRAN model for the RSG analysis. The same modeling techniques and RETRAN options used for the OSG model in Reference 1 are used for the RSG model in this analysis.

2.3 Additional Case An additional MTO case which trips on OTDT instead of low pressurizer pressure is included in this analysis to verify that the most conservative approach is utilized. As the primary side depressurizes after a steam generator tube ruptures, the OTDT reactor trip setpoint is reached earlier than the low pressurizer pressure reactor trip setpoint. Since 7 of 36

NFSR-0114 REV. O the time from tube rupture to AFW isolation is an assumed operator response time, an early reactor trip results in AFW going into the ruptured generator for a longer period of

~

time which leads to a reduction in MTO. However, the amount of turbine runback is less if a OTDT reactor trip is assumed instead of a low pressurizer pressure reactor trip.

f Both cases are analyzed to ensure the most conservative approach is utilized .

For the OTDT trip scenario, this analysis uses turbine runback to 95% power. This amount of runback is based on the difference in time between the first runback and the OTDT reactor trip.

2.4 Assumption Changes 2.4.1 Uncertainties The Reference 1 analysis included 30 psi uncertainty in RCS pressure. This reanalysis uses an updated pressure uncertainty of 43 psi and includes uncertainties on initial values for TAVG , SG level and power. The uncertainties used are consistent with those used for the OSG tube plugging increase program (Reference 7).

A TAVG uncertainty of -8 F is used since lower TAVG leads to lower SG pressure. The reduced SG pressure results in higher break flow, which is conservative for both MTO and OD cases. The model is initialized at 567 F, corresponding to a nominal TAVG of 575 F. The SG pressure at a nominal TAVG of 575 F is then lowered by a pressure uncertainty of 43 psi. i The SG level uncertainty applied is 5%. For the MTO case, the nominal SG level is increased by 5% to reduce the initial MTO. For the OD cases, the nominal SG level is  ;

reduced by 5% to increase the release of offsite dose activity.

The power level uncertainty applied is +2%. The initial power of 100% is increased to .

102% for all cases since higher core heat flux leads to higher primary pressure and higher break flow.

2.4.2 Initial Conditions The following initial conditions are changed:

1. The nominal TAVG s revised from 569.1 F to 575 F. Byron and Braidwood has been analyzed for a TAVG Window of 569.1 F to 588.4 F as part of the T-HOT reduction program. The Reference 1 analysis used the nominal TAVG (low end of the T AVG Window) as the analysis TAVG. For this analysis, the analysis TAVG includes a -8 F uncertainty to the nominal TAVG. The net impact is that the analysis TAVG decreased by 2 F for this analysis. The use of a lower TAVG is a more conservative assumption.

8 of 36

NFSR-0114 REV.0

2. The initial steam generator pressure and mass are revised to correspond to the revised nominal T AVG. The revised pressure and mass are more conservative than the Reference 1 analysis.

3. The steam generator tube plugging level of 20% is used for the RSGs. The steam generator tube plugging level for the OSGs remains at 30%.

2.4.3 : Operator Response Times The operator response times have been changed based on demonstrated performance to draft revised Emergency Operating Procedures (EOPs). In the E-0 procedure, draft revisions were made to allow the operators to isolate the ruptured SG earlier once a tube rupture is suspected. The draft revised procedure was tested on two licensed reactor operator crews from Byron and two licensed reac+or operator crews from Braidwood. The draft revisions are scheduled to be approved in early 1997. . it should be noted that only the MTO scenario is exercised at the simulator. The OD case uses the same assumed time for initiating RCS cooldown and depressurization as the MTO case.

The analysis response time used in the MTO and OD cases, along with the observed operator response time at the simulator, are summarized in Tables 3 and 4, respectively. The analysis response time to isolate AFW to the ruptured SG is more than 200 seconds longer than the average operator response time observed at the simulator. This is a conservative assumption since the time to isolate AFW has the most significant impact on the MTO case. The remainder of the response times used in

' the analysis are closer to the average times observed at the simulator. This is acceptable since the AFW isolation and the total overall response times are conservative.

The analysis response time for AFW isolation is shorter than the Reference 1 analysis by 5 minutes. This is supported by the proposed revisions to the EOPs which allowed the operators to isolate AFW earlier once the accident is identified. This shortened response time is also met by the simulator demonstrations performed for the Reference 1 analysis (see Reference 2). The total analysis response time for the remainder of the operator actions is longer than the Reference 1 analysis by 10 minutes. These two time requirements are more conservative than the Reference 3 WOG analysis assumptions.

2.4.4 Turbine Runback in the Reference 1 analysis, the amount of turbine runback used is 60%. This assumption was based on the reactor tnps on low pressurizer pressure approximately 300 seconds after a tube rupture. This analysis changes the turbine runback assumption to 70% for the low pressurizer pressure reactor trip case to be consistent with the Reference 3 WOG analysis. The observation at the simulator is that the reactor is tripped manually by the operators without any turbine runback. The operators are expected to trip the reactor if a trip setpoint is exceeded. Therefore, it is justified to 9 of 36

NFSR-0114 REV.0

']

1 limit turbine runback to zero. However, to be conservative, this analysis uses runback l to 70% power for the low pressurizer pressure reactor trip case.

1 l

1 i

l I

l l

I

'l I

i 10 of 36

NFSR-0114 REV.o

3. Results This section describes the results of the revised SGTR analysis.

3.1 MTO Case 3.1.1 OSG Results The sequence of events for the OSG MTO cases are shown in Table 5. Figures 2 to 4 are plots of key parameters for the OSG low pressurizer pressure reactor trip case.

2 The results from the Reference 1 analysis are included for comparison purposes.

Since the isolation of the ruptured SG is earlier in this analysis than the Reference 1 analysis, the rate of increase in ruptured SG liquid volume is less (Figure 4). The gain in MTO is maintained through the end of the event. The operator response time to initiate RCS cooldown is longer in this analysis than the Reference 1 analysis. Figures 2 and 3 snow the RCS pressure and break flow remain higher during this part of the event.

1- For the OTDT case, the time of the first turbine runback is compared to the time of the OTDT reactor trip. The OTDT reactor trip occurs later than the first turbine runback by less than 30 seconds. Since power decreases by 5% for each 30 second interval after the runback setpoint is reached, it is appropriate to use runback to 95% power for the

. OTDT case.

Figures 5 to 7 are plots of key parameters for the OSG OTDT reactor trip case. The results from the OSG tow pressurizer pressure reactor trip case are included for comparison purposes. Since the OTDT reactor trip occurs much earlier than the low pressurizer pressure trip, the Si initiation is much later after reactor trip for the OTDT reactor trip case. Figures 5 to 7 show that, except for the earlier reactor trip for the OTDT case, the results of the two cases follow the same trend.

The SGTR transient ends when charging and letdown is established and break flow is terminated. At the time the SGTR transient is terminated, the ruptured SG contains 290 cubic feet of gas volume as the MTO for the low pressurizer pressure reactor trip case and 293 cubic feet of gas volume as the MTO for the OTDT reactor trip case.

3.1.2 RSG Results The sequence of events for the RSG MTO cases are shown in Table 6. Figures 8 to 10 are plots of key parameters for the RSG low pressurizer pressure reactor trip case.

l The results from the OSG low pressurizer pressure reactor trip analysis are included for comparison purposes. Since the RSGs have smaller tube diameter, the initial break flow is smaller than the OSGs (Figure 9) and the depressurization of the RCS is also  !

i slower for the RSGs. Figure 8 shows that the low pressurizer pressure reactor trip occurs about 100 seconds later for the RSGs than the OSGs. This results in less AFW .

l 11 of 36

NFSR-0114 REV.o going into the ruptured RSG than into the ruptured OSG. At the time of AFW isolation, the amount of liquid in the ruptured generators is about the same for the RSG and the OSG (Figure 10). After the AFW isolation, the ruptured OSG is filled at a faster rate due to the higher break flow rate. However, since the RSG has a smaller secondary side volume, the final MTO for the RSG is smaller than the OSG.

For the OTDT case, the time of the first turbine runback is compared to the time of the OTDT reactor trip. The OTDT reactor trip occurs later than the first tudine runback by less than 30 seconds. Since power reduces by 5% for each 30 second interval after the runback setpoint is reached, it is appropriate to use runback to 95% power for the OTDT case.

Figures 11 to 13 are plots of key parameters for the RSG OTDT reactor trip case. The results from the OSG OTDT reactor trip analysis are included for comparison purposes.

Similar to the low pressurizer pressure reactor trip case, the RSG case reached the OTDT reactor trip setpoint later than the OSG case. The difference in reactor trip time is around 50 seconds. At the time of AFW isolation, the ruptured RSG has more liquid.

After the AFW isolation, the ruptured OSG is filled at a faster rate due to the higher Dreak flow rate. However, since the RSG has a smaller secondary side volume, the final MTO for the RSG is smaller than the OSG. Figure 11 shows the RSG case RCS pressure rises between AFW isolation and initiation of RCS cooldown while the OSG case shows a falling trend. This is due to the smaller break flow for the RSG case.

At the time the SGTR transient is terminated, the ruptured SG contains 226 cubic feet of gas volume as the MTO for the low pressurizer pressure reactor trip case and 60 cubic feet of gas volume as the MTO for the OTDT reactor trip case. Therefore, the limiting case is the OTDT case with 60 cubic feet of MTO.

3.2 OD Cases 3.2.1 OSG Results The sequence of events for the OD cases is show in Table 7. Figures 14 to 17 are plots of key parameters for this event. The results from the Reference 1 analysis are included i? the plots for comparison purposes. This analysis uses a longer response time to initiate RCS cooldown. The impact is higher pressure and break flow as shown in Figures 14 and 15.

3.2.2 RSG Results The sequence of events for the OD cases is shown in Table 7. Figures 18 to 21 ere plots of key parameters for this event. The results from the OSG reanalysis are included in the plots for comparison purposes. For the RSGs, because the break flow is smaller than the OSGs, the reactor trip occurs later than the OSGs (Figure 18).

12 of 36

NFSR-0114 REV.0 3.2.3 Dose Calculation The release of offsite dose activity occurs mainly when the SG PORV on the ruptured SG fails open and during the release of steam through the intact SG PORVs.

Consistent with Reference 1, the release during the time the ruptured SG PORV fails  :

open is reported. The amount of release during the RCS cooldown period is  !

! insignificant compared to the margin available to the acceptance criteria in SRP 15.6.3.

The offsite doses are calculated using the same methodology as in the Reference 1 l r analysis.

\

The offsite dose results are shown in Tables 8 and 9. The OSG analysis resulted in slightly higher dose than the Reference 1 analysis due to a slightly delayed reactor trip i and revised ir!tial OSG conditions. The slight increase in dose release is considered i

insignificant when compared to the acceptance criteria in SRP 15.6.3. Although the  !

reactor trip occurs later for the RSGs, smaller break flow and higher initial SG mass for

. the RSGs combined to result in lower dose reiease than the OSGs and the Reference 1

analysis.

l l

l l

l 2

j 13 of 36

NFSR-0114 REV.0

4. Conclusions

The rupture of a single steam generator tube for the OSGs and for the RSGs at the B/B plant has been evaluated. Some of the assumptions used in the Reference 1 analysis are modified in this analysis . The initial conditions which are revised for this analysis 1 include initial RCS TAVG, and initial SG pressure and mass. An additional case crediting  !

OTDT reactor trip for the MTO case is included. The amount of turbine runback for the low pressurizer pressure trip case is revised to 70%. The appropriate uncertainties are added to the initial values for TAVG, SG level and power. The operator response times are revised to reflect the draft revised EOPs. The critical time requirement established

. in Reference 8 is revised to: isolating the ruptured SG within 11 minutes and completing the remaining mitigation actions within an additional 31 minutes.

The results of this reanalysis show that the offsite doses do not exceed 10 CFR 100 limits or the acceptance criteria of SRP 15.6.3 and that margin to SG overfillis available.

In accordance with the NRC acceptance letter of WCAP 10698-P-A and Supplement 1 to WCAP 10698-P-A, the following plant specific submittal requirements for this i analysis were completed- l l

1. Licensed operators utilizing the Byron simulator and Braidwood simulator perforrned comparable SGTR runs demonstrating the operator response times used in this analysis for both the MTO and OD cases were realistic. The operator response ,

times used in this analysis are discussed in Section 2. I

2. A site specific SGTR offsite radiation consequence analysis was performed using the Reference 1 methodology, consistent with WCAP 10698-P-A Supplement 1 methodology. The offsite dose was calculated based on the Standard Review Plan (SRP) 15.6.3 guidelines and it was determined that the offsite dose does not exceed the 10 CFR 100 limits and meets the SRP 15.6.3 acceptance criteria. The offsite dose results are discussed in Section 3. ,

3. An evaluation of the main steam line and associated piping supports has been performed for the OSGs as part of the submittal for Reference 1. Since the main steam line and associated piping supports are not changed as part of the RSG installation, the Reference 1 evaluation is applicable to the RSGs. The structural ,

adequacy under water filled conditions should a SGTR occur has been verified.  !

4. A list of systems, components and instrumentation which the analyses assume are necessary for SGTR mitigation has been compiled in Reference 1. The list includes the safety /non-safety related classification of the equipment and the source of power for the required PORVs and control valves. Since this analysis did not change any assumptions for the systems, components and instrumentation assumed in the Reference 1 analysis, this list is applicable for this analysis.

14 of 36

.. . _. ___ . _ _ _ _ _ __ ._ _ - _ ._.. .~ . .. . ._._ _

NFSR-0114 REV. o 2

5. The compatibility of the Byron /Braidwood systems with WCAP 10698-P-A bounding l plant analysis has been evaluated in Reference 1. The conclusion that no major design differences affecting the MTO exist and the use of the same limiting single failures as identified in WCAP 10698-P-A and Supplement 1 of WCAP 10698-P-A are applicable for this analysis.

Therefore, based on the results presented in this report, it is concluded that the Byron /Braidwood plants demonstrate compliance with the licensing requirements established by the NRC for the mitigation of a SGTR event.

I 4

15 of 36

I NFSR-0114 REV.0

5. References

1) Comed Report, " Steam Generator Tube Rupture Analysis for Byron and Braidwood Plants, Revision 1", February 1990.

2) NRC Safety Eva!uation Report for Byron Uriits 1 and 2 and Braidwood Units 1 and 2 Steam Generator Tube Rupture (SGTR), Docket Nos. STN 50-454,50-455,50-456 and 50-457, dated April 23,1992.

3) WCAP-10698-P-A, "SGTR Analysis Methodology to Determine the Margin to Steam Generator Overfill", August 1987.

4) Supplement 1 to WCAP-10698-P-A, " Evaluation of Offsite Radiation Doses for a Steam Generator Tube Rupture Accident", March 1986.

4

5) Comed Nuclear Fuel Services Calcnote PSA-B-95-09, "B/B Steam Generator Tube Rupture Analysis to Support 30% Tube Plugging", Rev.1, dated 10/1/95.

I

6) Comed Nuclear Fuel Services Calenote RSA-B-90-02, " Byron and Braidwood  !

Steam Generator Tube Rupture Analysis with 10% SG Tube Plugging", Rev. O, dated May 18,1990.

. 7) Comed memo NFS:PSS:93-305, " Byron /Braidwood RTDP Uncertainties," dated

. October 29,1993.  !

8) Comed Memo," Response to Request for AdditionalInformation on

. Byron /Braidwood SGTR Analysis, TAC Nos. M57080/63247 and M64026/64053,

. NRC Docket Nos. 50-454/455 and 50-456/457", dated January 17,1992.

?

16 of 36

NFSR-0114 REV.O Table 1 - Key Physical Differences between OSG and RSG Parameter OSG RSG Impact on SGTR Analysis Tube Inside Diameter (in) 0.664 0.605 increase MTO decrease dose Heat Transfer Area (ft") 48300 79800 increase MTO decrease dose Secondary Side Volume (ft") 5949 5221 decrease MTO l

1 l

17 of 36

NFSR-0114 REV.0 Table 2 - Model/ Assumption Differences

! Item Reference 1 Revised Analysis

Analysis OSG OSG RSG SG Tube Plugging Level 10* 30 20

(%)

4 Thermal Design Flow '

! s 8 8 (Ibm /hr) 144.2 x 10 137.3 x 10 137.3 x 10 Computer Code Version RETRAN-02 RETRAN-02 RETRAN-02 MOD 3 MODS.1 MODS.1 SG Model OSG Model OSG Model RSG Model I

(bounds D4 and (bounds D4 and

, D5 SGs) D5 SGs) i ,

MTO OTDT Reactor Trip n/a included included Case 1

initial TAVG ( F) 569.1 567 567 4

(575 nominal) (575 nominal) i Initial SG Level nominal nominal +/- 5% nominal +/- 5fo

Initial Power (%) 100 102 102 Operator Response see see see a Times Tables 3 and 4 Tables 3 and 4 Tables 3 and 4 Turbine Runback - MTO 60 70 70 Low Pzr. Press. Reactor Trip Case (% power) i Turbine Runback - MTO n/a 95 95 OTDT Reactor Trip Case (% power)

{

• as supplemented by Reference 6.

18 of 36

NFSR-0114 REV.0 Table 3 - Analysis Operator Response Times (MTO Case)

Operator Action Reference 1 Revised Observed Analysis Analysis Average Response Response Response Time (sec) Time (sec) Time (sec)

Isolate AFW to Ruptured SG 960 660 430 Initiate RCS Cooldown 540 1080 1084 Initiate RCS Depressurization 240 120 99 Terminate ECCS Flow (except 60 120 112 1 Centrifugal Charging Pump)

Establish Charging 60 120 121 Establish Letdown 240 180 181 Reopen Pressurizer PORV 120 240 237 i

Table 4 - Analysis Operator Response Times (OD Case)

Operator Action Reference 1 Revised Observed ,

Analysis Analysis Average l Response Response Response l

Time (sec) Time (sec) Time (sec)  !

Isolate Ruptured SG PORV 1200 1200 n/a (after SG (after SG PORV opens) PORV opens)  ;

Initiate RCS Cooldown 540 1080 1084 initiate RCS Depressurization 240 120 99 Terminate ECCS Flow not modeled not modeled n/a 19 of 36

l NFSR-0114 REV.O l

Table 5 - Sequence of Events (OSG MTO Cases) l Reference 1 OSG Revised OSG Revised OSG  !

System Response / Operator Action low pzr press. trip low pzr press. OTDT trip Time (sec) trip Time (sec)

Time (sec)

SG Tube Rupture Occurs 0 0 0 Reactor Trip 314 306 171 Auxiliary FW Injection 324 315 171 j

Safety injection 324 315 418 l I

Ruptured SG AFW lsolated 960 660 660 RCS Cooldown Initiated 1500 1740 1740 RCS Cooldown Terminated 2457 2629 2616 RCS Depressurization Initiated 2697 2749 2736 RCS Depressurization Terminated 2810 2854 2842 )

l ECCS Flow Terminated 2870 2974 2962 )

70 GPM Charglig Flow Established 2930 3094 3082 RCS Letdown Established 3170 3274 3262 Reopen Pressurizer PORV 3290 3515 3502 Reclose Pressurizer PORV 3315 3547 3534 I

20 of 36

i NFSR-0114 REV.O Table 6 - Sequence of Events (RSG MTO Cases) l RSG RSG System Response / Operator Action low pzt. press. OTDT trip l trip Time (sec) i Time (sec)  !

SG Tube Rupture Occurs 0 0 Reactor Trip 410 228 l

Auxiliary FW Injection 421 228 l Safety injection 421 642  !

l Ruptured SG AFWlsolated 660 660 '

I RCS Cooldown Initiated 1740 1740 l RCS Cooldown Terminated 2690 2679 RCS Depressurization Initiated 2810 2799 )

l RCS Depressurization Terminated 2940 2928 ECCS Flow Terminated 3061 3048 70 GPM Charging Flow Established 3181 3168 RCS Letdown Established 3361 3348 Reopen Pressurizer PORV 3602 3589 Reclose Pressurizer PORV 3638 3625 21 of 36

NFSR-0114 REV.O Table 7 - Sequence of Events (OD Cases) l Reference 1 OSG Revised OSG RSG System Response / Operator Action Time (sec) Time (sec) Time (sec) l SG Tube Rupture Occurs 0 0 0

)

Reactor Trip 466 482 666 Safety injection 471 487 671 Ruptured SG PORV opens 497 515 681 Auxiliary FW Injection 557 575 741 i Ruptured SG PORV isolated 1697 1715 1881 Auxiliary FW lsolated 1757 1775 1941 RCS Cooldown Initiated 2247 2795 2961 RCS Cooldown Terminated 2991 3534 3658 RCS Depressurization Initiated 3231 3654 3778 j RCS Depressurization Terminated 3393 3763 3881 l

I l

22 of 36

NFSR-0114 REV.O Table 8 - Offsite Dose Results (Thyroid)

Case SRP 15.6.3 Reference 1 Revised Acceptance OSG OSG RSG Criteria  !

(rem) (rem) (rem) (rem) ]

Byron Preaccident lodine Spike - EAB 19.11 19.72 14.71 300.0 i Byron Preaccident lodine Spike - LPZ 0.57 0.59 0.44 300.0 Byron Concurrent lodine Spike - EAB 18.11 18.46 13.82 30.0 Byron Concurrent lodine Spike - LPZ 0.54 0.55 0.41 30.0 l Braidwood Preaccident lodine Spike - EAB 25.81 26.64 19.87 300.0 Braidwood Preaccident lodine Spike - LPZ 2.38 2.46 1.83 300.0 Braidwood Concurrent lodine Spike - EAB 24.46 24.93 18.67 30.0 Braidwood Concurrent lodine Spike - LPZ 2.26 2.30 1.72 30.0 Table 9 - Offsite Dose Results (Whole Body)

Case SRP 15.6.3 Reference 1 Revised Acceptance OSG OSG RSG Criteria (rem) (rem) (rem) (rem)

Byron Preaccident lodine Spike - EAB 0.2100 0.2111 0.1797 25 Byron Preaccident lodine Spike - LPZ 0.0063 0.0063 0.0054 25 Byron Concurrent lodine Spike - EAB 0.2079 0.2094 0.1729 2.5 Byron Concurrent lodine Spike - LPZ 0.0062 0.0062 0.0052 2.5 Braidwood Preaccident lodine Spike - EAB 0.2837 0.2852 0.2428 25  !

Braidwood Preaccident lodine Spike - LPZ 0.0262 0.0263 0.0024 25 Braidwood Concurrent lodine Spike - EAB 0.2808 0.2829 0.2336 2.5 i Braidwood Concurrent lodine Spike - LPZ 0.0259 0.0261 0.0215 2.5 23 of 36

u. _ _ ___

NFSR-0114 REV.O Figure 1 - SGTR Analysis Noding Diagram

4 =i *u g  != " i= i

e 5 0 e

= = -, , . .

"\ / ,. 1 y_ \ /"

P,y II ShR 3, 3

N I f e 2 $ N

? U *

• bNw

-l J "

• I@ F 'l- @ f. * .

I l' s ~Dt 1 @

%gF 2s m% cgip ; s y ,. e J '

2 2 O

'fS g @ CUM e l

@ lD iLC,. l O G' @ 0 1

. O V 'I l

i 24 of 36

W NFSR-0114 REV.0

' Figure 2 - Pressurizer / Ruptured SG Pressure (OSG MTO Low Pzr. Pressure Case) 4.

! m 2500 i , , , , , ,

! 9  : 1 I I I i l l

! E. 1 a- - 1 I I I l -- "-l- - L hJ, - - - - - L - - J - - - - -

} 2000 - ,.p -

E  : 1 I i l l l 8 . I I I I - r -- l 1 1

2 1500 -- - - - H - - - - + - - - - l- - - - -l - - - - + 'g- - VCO a 1- - - - - '

1 I I l l g 11 0- 1 I I l I /I 13 i W 7 > i -h

%q -

i i i y 1000 -- - - - - r- - - - - r - - - r- - - - -l - - - - -

t.  :.

. I I I OSG Reference 1 (PZR) i 3 1 I I I a -

J--- 4--- OSG Reference 1 (SG) ---J-----

s 500 ---- 1-g i I l - - - OSG low press. (PZR) I h I I I --- OSG low press. (SG) -1 A ..,,l,....l,....l....i... i....i,,, l....

0 , , , , ,

1 O 500 1000 i300 2000 2500 3000 3500 4000 I Time (sec)

Figure 3 - Ruptured Tube Flow (OSG MTO Low Pzr. Pressure Case) 70 , , i i i i i o  : 1 I I I I I I

$ 60 -~ - - l- - - - J - - - l - - - l- - - - L - -

. 1 l l l l OSG Reference 1

$, 50 -- - - - !-- -- ' l E' - Y wr--- l- - ~ ~ ~~ OSG low pfess.

g  : b i 1

\1 1 1 1

.9 ~---l-----l--- l--

u. 40 -

- -- 4 -L) - - l- - - - l - - - - -

1 I I i - _. g I I j,30 - - - - - -i- - - - -i - - - - - - r - - - - r -

1 I I i l 1 1 /...' It 1

>-  : 1 I 1 l l 11 1w 20-'---I l--- J---

I l---

I L---

I L-I

\/J--- - l'i- - - - -

if I i 3 Il n 10 1 I I

- - - -t - - - - + - - - - r - - - - t- - -

I I

I 1 -t - - - - -t lL----

l 1

l.,,

I

l. ,,I i

,,.I,

.I I

..l..

il I d, I.,,

l 1 1,. ., ...

0 5 B B B 5 B ,

0 500 1000 1500 2000 2500 3000 3500 4000 Time (sec) 25 of 36

NFSR-0114 REV.O Figure 4 - Ruptured SG Liquid Volume (OSG MTO Low Pzr. Pressure Case)

E 7000 , , , , , , ,

.2  : 1 1 1 I l l l

~

$o 6000 e i i

I I I i 1 l-E s

5000 -b---l---

. I 4----l----

I

- - 4 <:-: . I -__-l____.

~~~ll , - 'i i 1 1

'5  : 1 i 1. l l

> 4000 -------l---- '- - t- - - - -l - - - - + - - - - t- - - - -l - - - - -

V -

1 - 1 I I I I I

'5  : / I 1 1 i i i

.g 3000 - - - - - - --

T--- l----l---- OSG Reference 1 d E- - 1 I l l C OSG Volume M 2000 -?-- J--- l 1---

l l---

l J----

l --- OSG low press.

] I I i 1 l l I g ,ooo _ '_ _ _ _ _i _ _ _ _ .i. _ _ _ _ p _ _ _ a _ _ _ _ + _ _ _ _ i_ _ _ _ _; _ _ _ _ .

l 1 I I I I I

~.

a .

= ..

oc 0 ..l.....l....l....l....l.....l....l.....

0 500 1000 1500 2000 2500 3000 3500 4000 Time (sec) 26 of 36 .

1

y I

i 1

NFSR-0114 i

REV.O Figure 5 - Pressurizer / Ruptured SG Pressure (OSG MTO OTDT Case) i i, ,

i

2500 , , , , , , , j

-lcL I I

l i I 1

I I

I I

i i

J-- J---1---L--J-----

j d i - - - - ,- - -

2 2000 -' .

!=

1 I I I i 1 l

l l 1 -

l 1 1500 ------l----+----t-----1----+- - -- - - - - -

i a 1 i i 1 i

! O l i I I 1 l  ;

m _ _1 - , , , , . , , _ - _ ,

y '1000 - --[,_P r - T-~~ r-- '--~~--- r-- l----'

. g 1 l l l OSG low press. (Pzr) l l 3 I l l OSG low press. (SG) l I l

@ 500 -F---j--- 1----f ------ OSG i i OTDT (Pzr)

OSG OTDT (SG) a

.  : i i

O ....l,....!,....l....l,....l,....l....l,.... , ,

! O 500 1000 1500- 2000 2500 3000 3500 4000

Time (sec) i I

i Figure 6 - Ruptured Tube Flow (OSG MTO OTDT Case) 1 l

70 , , , , , , ,

^

2 g  : 1 I I I i 1 I i 5 60 -' - - - l- - - - l - - - - L - - - L- - - J - - - - - - -

I I l l OSG fow press.

{ }  ;

l l $, 50 q --

TJ: T t- - - - r-

- - - OSG OTDT ._.

j g  : ' -t -" ' I I l l l 1 o 40 - '---1 - l--- J____.1____ ___L___J____J____.

E i  : I l J- -

I I l I j330 -  : 1 I I

- - - - -l- - - - - - - t - - - - t- - - - - l- -

I I I

i H  : .I I I I I l 3 E 20

'- - - J _ _ _ _.1 I _ _ _ _ I 1. _ _ _l _ L _ _)_ l_ _ _ _ _ _ _ _ .

a w  : 1 1 1 J'

' 3  : 1 I I I I I

i 1 o.10 -- - - - -t- - - - - l - - - - -t - - - - t - - - - t- - - h H---- - - - - -

0 '

i 0 500 1000 1500 2000 2500 3000 3500 4000

! Time (sec) i i

o 27 of 36 J

4 e . . - . , -

, , . , , r- , - ,

l l

I NFSR-0114 REV.O  !

Figure 7 - Ruptured SG Liquid Volume (OSG MTO OTDT Case) n C

o 7000 , , , , , , ,

2i  : 1 I I I I I l v

8 6000 - '- . I 1---'--*--1---'--L----

I I I I I --

0  : 1 1 1 I I l 2

E 5000 -- - - - - T - - - - r- - - - - - - - r- - - - - - - i

I I 1 1 l l l s 4000 ----J-----

-- - - J - - - - t- - - J - - - - - i

' ' l l l  !  !

g 3000 -

8 F - - - [- - - - t - - - - t- - - - -1OSG 1 I I I

- -low-press.

OSG Volume <

@ 2000 - --d----y----f---d---- - - - OSG OTDT ---'

I I I I I i l E 1000 - -----1----+----t-----1----+----t-----1-----  !

3a.  : 1 I I l l I I I s 0 ....I,,,,,1,,,,,1,,,,1,....I,,,,,1....l....

E.

0 500 1000 1500 2000 2500 3000 3500 4000 Time (sec) 28 of 36

. . _ =_ __ ._. _ .,_-_ . _ . - . - . _ _ _ _ . - _ __ _ _ _ --

. . _ . . . ~ . ,

i l

NFSR-0114 i REV.O i

Figure 8 - Pressurizer / Ruptured SG Pressure (RSG MTO Low Pzr. Pressure Case) l i l 4

1 l

l

e 2500 ,

, , , i , , , l 1 I .,. L . I I I I I l'~ / _ _'l-J 1 1 1 I )

' .'- ' \ L ---l---

, L--- -- L__-.1-___ '

n. . 2000 -- . I i 4 I I l '

g* l l l g --h_..,y l p ~.h j v# *C 1500 -- - - - - - - L- - - - -4 --- L- - - - -l - - - --- l--- '

1 I I I g

l

' l

'$a. 0c I l I I I I 1

l. / g l 3  :  :  : .-- 1.  !

=E h l.1000F-- -p"V.i_ l -

- t- - - - -i - - - - r - - - -* - - - - - - - - + - - - -

l 4 OSG low press. (Pzr) j l l l j- .O ----g l l OSG low press. (SG) l

3 500 - i - - - - l- - - - r - --- RSG low press. (Pzr) - ~ ~ ~I ~ - - -

4 j.

$  : l, i I

--- RSG low press. (SG) I i g g g _

g

n.

0 !'!'!'!'!'!'!'

O 500 1000 1500 2000 2500 3000 3500 4000 l Time (sec) j 1

l I

l Figure 9 - Ruptured Tube Flow (RSG MTO Low Pzr. Pressure Case)

}

'4 70 - i i i i i i i

! u  : 1 I I I I I I

)$ 60 -: - - -

l- - - - - - - L - - - L - - - .J - - _ _ _1_ _, _ .

l l 1 I OSG low press.

l l j $. 50 -- -- -

- - - - h - - - - y' - - - RSG low press. . _ .

3 I I I I i I i

. 40 E ,'Nb efTZ-~;-1:

• - -- L---1---_J--___

l 14

'v4 1

I 1

I NIh, i I

l l

I j330 -- - - - -l- - - - - - - + - - - - +. : r +

1

w y:: : gu--_.

\ i I F -

1 I l l l l l ] 20 -h----l----d----y----h---lp- Il[---

-__. l i 3  : 1 I I I I l l g.10 -. - - -- l- - - - l - - - - L - - - L - - - - L- - - .

I I I I tli

- _-4 _g _ _ _ .

g

:

I l

o

. . . 1 . . . . l . . . . I . . . . l . . . . l . . . .'j. l , , . . I a i e i . ,

lli a u ,

l 0 500 1000 1500 2000 2500 3000 3500 4000 1 l Time (sec) 1 1

4 29 of 36 4

[

- , , , . ~. .n. . . - - -

.. . . _ - . = . _ _ _ - . . - - - - - ..-.. --- - - -.. .

1 1

l NFSR-0114 i l REV.0 2

Figure 10 - Ruptured SG Liquid Volume (RSG MTO Low Pzr. Pressure Case) )

I i

n j j 7000 , , i , , , ,

3  :

1 I I 1 - -- - '- - - - -

I I I i 8-6000 - - - - -

- . I I __

e  : .. __ __ _.L _ _ _ _ _1_ _ _ _ _ _ L _ _ _ _ _ _L _ _ _ _ _ J_ __ _ - -

E 5000 ------l----+----l----H---- -

Z L ...

- t- - - . - e - - -

.2  : I I I l .. .i 1 o  : I i 1 i l ,

m 4000 -- - - - -)I _ . . ,- , ,- _ .g _ q "T--- '-

l. .

F-- l----' l

'5 osa low press. '

cr 3000 --' - - - -

---

- - - - - l- - - - -l - - - - - ----

1 4

3 1 I I I OSG Volume {

^

' --- RSG low press.

@2000 - - - N - - - - - - - l- - - - M - - - - - --- RSG Volume l

I I I l 1000 ----

~

J--- l--- L-- J--- l--- L-- J____.

m -

1 I I I I I I Es l i

[ ''''''''''''''''''''''''''''''''''

I I I I I l 3 g 0 , , , . . , ,

i 0 500 1000 1500 2000 2500 3000 3500 4000

. Time (sec) i l I

i i

?

30 of 36

l l NFSR-0114 REV.0

Figure 11 - Pressurizer / Ruptured SG Pressure (RSG MTO OTPT Case)  ;

i l i

i i'

g 2500 ,

ig -

1 I I I i i 1 1

a l 'i l l I I E 2000 - ..

--- 1--- E'3 ---l---L---J-----

. 1 I s l 1 E

m

1 1 1 4 , ,, '- -l 8 1 I 1 I I I l----s 1 ~~'

2 1500 - --:- ----

E G - - - - - - I - t - - -I - t- - - - - l - - - - t "k 1

1 1 l l I

l I g

1. - f Il

', jogo . :7 d _y____[___J____4__ ___ __'_'__.

t  :._, 1 I I RSG OTDT (Pzr) g g j g  : 1 I l RSG OTDT (SG) l l

! s 500 -------i----+----F- --- OSG OTDT (Pzr) ~ h ~ ~ - -i - - ~ ~

G: 1 I I I I 3  : 1 I I --- OSG OTDT (SG) l I l

i n.

0 ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' I, ' ' ' ' ' ' ' ' ' ', ' ' '

I

) 0 500 1000 1500 2000 2500 3000 3500 4000

Time (sec)

'i

Figure 12 - Ruptured Tube Flow (RSG MTO OTDT Case) 1

{ 70 , , , , , , ,

t I

7  : 1 I I I I I I

' $ 60 -[,,M - - - il- - - - ll - - - - lI - - - l- - - - L - - - l - - - - l - - - - -

l I RSG OTDT I

}

g 50 -

5 -(-- ,

' -i -- '"'--!- - #-d l l

= hm r - - - ri' - - - - OSG OTDT 1

' \l 1 Eo 40 --:

l- - - - J -- l- - - - l - - - - -

4 1 b = - -L4 -__ - -

I 1 I

{ j3 30 -: - - -

1 I I i 1/'~~'--I - ----

l- - - - l - - - - r - - - r - - - - -r-l-  : 1 I I I I I il f

] 20 -[----l-----l----y----f---

3 1 I I I L-I

'[J ---j'-

i I l

o. 10 - : -

- - - -l- - - - -l - - - - -r - - - r - - - - r - d - - - - - -t'- - - - -

$  : 1 I I I I

' ' ' ' ! ' ' ' ' ! ' ' ' ' ! ' ' ' ' ! ' ' ' ' ! ' ' ",i" ! ' ' ' ' ,g g '

I

'l 0

0 500 1000 1500 2000 2500 3000 3500 4000 Time (sec) 31 of 36

l 1

1 NFSR-0114 REV.O Figure 13 - Ruptured SG Liquid Volume (RSG MTO OTDT Case) 1 m 1 j 7000 , , , , , , ,

f

'5

i i l i I I i 1 8 6000 -- -- '-~ ~4-~ L.- -- l--- A-- L-e l

i 1

i 1 1 i

I i L __ - -

',,J 1 e i t _. i E 5000 -- - - < - - - - + - - - - r - - - - -" -" +' - = r- I-- - ----- l

.2 -

l l 1 . .l l

$0 4000 -!- - - - 'i- - - .h *~$ ~ ~ ~- - - - - - f - - - '- - - - d - - - - -

/ --

'5  : I I I I RSG OTDT cr 3000 - A - - - - + - - - - l- - - - -l - - - - + -----

'j -- / l l l l l RSG Volume

..J, i g 2000 -- - - ,l ---

T---

I r--

I 7--- T I

- - - OSG OTDT - - - - -

;  ; g l l

--- OSG Volume 1000 ---- J---

l--- L___J____.l.____L __J____.

~

3  : i I I I I I I

o.  : ' 1 I I I I I I 3 l' ' ' '

m 0 'l'l'l'l'l'

0 500 1000 1500 2000 2500 3000 3500 4000 Time (sec) i l 1

1 4

9 4

1 32 of 36 1 4

NFSR-0114  !

l REV.0 l Figure 14 - Pressurizer / Ruptured SG Pressure (OSG OD Case) 1 g 2500 _ i i i i l 3 i l 1 I e

m -

1 1 1 I i 2 2000 - -- --- L----- l- ---- ----- l-------

, A 1 i N I i 0E -

N ,' T ' I I ME  : I l I V

• 1500 --------h------4-------+---- ------

'. 2E s  : I i

I I I Eec i

l i

i i l

y 11000 - ---t - r - - - - - T- - - - - - - u- i-------  ;

tE .

J l 1 --T- - i

$j ,- 1 OSG Reanalysis (Pzr)

• s 500

---

f-l

-f------f-l g OSG Reanalysis (SG)

--- OSG Reference 1 (SG) I 2  : I I 1 --- OSG Reference 1 (Pzr)

n. o

l ' '

0 1000 2000 3000 4000 5000 Time (sec) ,

1 l

i Figure 15 - Ruptured Tube Flow (OSG OD Case) 70 i i i 9 -

l l l OSG Reanalysis

---

l-------L------- .1- - --- OSG Reference 1 ---

p% 60: -- __

%d T I i e 50 -- - - -1 -- ------- -- h  :

S

u. 40 -

1 I l

1 I I I g3 30 - - - - - - -l - - - - - - - - - - - - I- -

t F -

1 1 1 g 1 20 -- - - - - - - -l- - - - - - - - - - - - ;- - - t ,- - --------

3  : 1 1 1 31 E3 10 - '

- - - - - J - - - - - - - L - - - - - - l- - - 1 .. I--------

at  :

1 1 1 Il I 1 - - - - I ' ' I -

ii

' l - - ' '

o O 1000 2000 3000 4000 5000 Time (sec) 33 of 36

NFSR-0114 REV.O Figure 16 - Ruptured SG Steam Release Rate (OSG OD Case) 2 300 , , , .

y  : 1 I I OSG Reanalysis

$ 250 -} - - - - - T - - - - - - $ - - - - - - -!- . - - - SG Ref erence 1 .

B  : I I I I TD E ^o 200 -? - - - - - -l l- - - - - - -i I - - - - - - l' - - - - - - LI - - - - - - -

E - 1 I I I 150 -E----- 1------1------1------ 1--------

.E 1 I I I MS  : I I I I I e

M 100 _p__J _.l._______t_______I_______l_______.

I

. I I i 1

- I

'@ I I I g 50 -E- J ---+-----a-------i-------s-------

I I I i 1 1

S'  : ' ' '

1 1 I I e 0 l l l

l '

O 1000 2000 3000 4000 5000 Time (sec)

Figure 17 - Intact SG Steam Release Rate (OSG OD Case) 350 , i i i 3  : 1 I I I y 300 -'-------j------j------L------j-------

8 -

1 I I I E 250 ------- T- - - - - 1I - g- --- r- - - - - - t - - - - - - -

m '

I l g i E 8 200 -. ----

OSG Reanalysis

-Y-- g' -----f-------

Ej.o 150 - '- - - - ---- -oSG E  : Reference 1 1

- t - - - - - - -f- - -\ ,ll---

\

---t-------

i MC  : 1 1 1  % i e

W 100

~

--l------l J---- ll--- ---l-------

I i i 11 1 5e -

1 I I il I 50 -- ----

--+-------t--F---- -H--- ---+-------

E -

i l I l 11 1 0 ' '

! ' ' ' ' ! ' ' '  ! ' l' '

O 1000 2000 3000 4000 5000 Time (sec) 34 of 36

NFSR-0114 REV.O Figure 18 - Pressurizer / Ruptured SG Pressure (RSG OD Case)  ;

e w 2500 , , g ,

3

• 1 1 is I 1 I e' I\' l A

E 2000 - -- ' , L-----L/---- -s----L-------

.1 ,, I g .,g -

___ 1 1 N,- g I Wa  : 1 I I I I iw 7 1500 --------*------+------+---- y4-------

3 ,o 2 I

1 I

I l

I

/

E I I I g a' 1000 - i---Ir-----r----- N r'~--~~- r ------

l

)l ['~T 'sj l OSG Reanalysis (Pzr)

.t! O -

OSG Reanalysis (SG) 500 -h----- L-l d'-----

i I

I --- RSG Analysis (SG)

I I I

$ I I

--- RSG Analysis (Pzr) u . I A 0

'l ' '

l ' ' ' '

l l

O 1000 2000 3000 4000 5000 Time (sec)

Figure 19 - Ruptured Tube Flow (RSG OD Case) 70 , , , ,

^

1 g 1 1 1 60 -- ----J-------.L--_---L------1-------.

1

$. 50 -

i l Y N l

---1-------+-,,______h -------l--------

p .N , ,L_____ -L I G" 40 -' - '-N 'll'c' i

' - - - - - - - il - - - - - - l 'A 's- - -

1 I

- l

i i i I r' - I g3 30 -- - - - - - - - l - - - - - - - - - - - - I- - - - - T g i

F-  : 1 OSG Reanalysis I g

]20 - - - - - - -l- - - - - RSG Analysis -h--- --------

3  : 1 I I I a '------3-------1------L------

3 10 -

I--------

1 I I I cc  :

0' ' ' ' '

O 1000 2000 3000 4000 5000 Time (sec) 35 of 36

3 NFSR-0114

REV.O j

l Figure 20 - Ruptured SG Steam Release Rate (RSG OD Case) 3e 3M . , , , ,

1 I I I I E  : 1 I I I

---

r,-----

g 250 -. OSG Reanalysis r-------

R ~

1 --- RSG Analysis l J g _ 200 --------i-----,------i------r-------

1 I I I E  : i i i i 8 150 . T------r------l------ r------'

(t) m -

is 1 I I i

\

I l l I

@C 100 - ----

Ny------lr- _i------ r------'

1 50

l ,' l l l 3O. .

r T-- 0----- 7------ r------'

1 I II I I

$ 0 ' '  !!''!'!'

O 1000 2000 3000 4000 5000 Time (sec)

Figure 21 -Intact SG Steam Release Rate (RSG OD Case) 350 , , i i e  : 1 I I I is E

8 300 --

---

1i.------i-------&------i-------

1 I

I pg l

is:

i I

250 t -

v-----t-------

I OSG Reanalys.is s m . s I 1- --- RSG Analysis _;[_ L___1_______

a: 200 __

1 I il NN I E -

1 I il s 150 +------+------ ------ i i--- -+I -------

</) C  : 1 I il i I g 100 .____;_4__ ____l_____- _;p___ -p_4_______

5  : I 11 I I il l 3c 50 - ---- '

n-4-------l------ -*--- -lr - +1 -------

I il is i i 0

. . ki .\ l

,l . . . , il ,

. . Li. l 0 1000 2000 3000 4000 5000 Time (sec) 36 of 36

- __ ,