ML20064E960
| ML20064E960 | |
| Person / Time | |
|---|---|
| Site: | Three Mile Island  |
| Issue date: | 01/05/1983 |
| From: | Dobranich D LOS ALAMOS NATIONAL LABORATORY |
| To: | NRC |
| References | |
| RTR-NUREG-0937, RTR-NUREG-937 LA-UR-82-3238, NUDOCS 8301060189 | |
| Download: ML20064E960 (54) | |
Text
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$ Los Alarnos National Laboratory is operated by the Umversity of Cahfornia for the Uruted States Department of Energy under contract W-7405-ENG-36 4
TITLE: Steam Generator Tube Rupture Analysis for TMI-1 AUTHOP's) Dean Dobranich SUBMITTED TO:
g By SCCeptanCe of this artiC4. the publisher recognizes that the U S Goverernent retains a nonenclusive. royarty-free license to pubhsh or reproduce the published form of this contributeon, or to allow others to do so. for U S Government purposes The Los Alamos National Laboratory requests that the pubbsher identdy this article as work performed under the ausDices of the U S Depart-ent of Energy n@
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_GU __Ue Los Alamos National Laboratory Foau %o s3eme sv w an s ei 8301060189 830105 PDR ADOCK 05000289 P PDR s
r CONTENTS 4
P.a_lL, AESTRACT i I. INTRODUCTION 1 II. MODEL DESCRIPTION AND ASSUMPTIONS 1 III. STEAM GENERATOR TUBE RUPTURE (SGTR) RESULTS 6 A. General Results 6 B. Detailed Results 7
- 1. Five-SGTR 7
- 2. 10-SGTR 11
- 3. One-SGTR 13 IV. RESULTS OF MAIN STEAM LINE BREAK (MSLB) WITH CONCURRENT STEAM GENERATOR TUBE RUPTURE 16 A. General Results 16 B. Detailed Results 17
- 1. MSLB with one-SGTR 17
- 2. MSLB with five-SGTR 22
- 3. MSLB with 10-SGTR 22 V. CONCLUSIONS 26 i
REFERENCES 27 APPENDIX 9
_ _)
I. INTRODUCTION Steam generator tube ruptures (SCTR) with and without a main-steam-line o break (MSLB) were investigated for the Three Mile Island Unit-1 plant (TMI-1) using TRAC-PD2.I These transients recently have received attention from the Nuclear Regulatory Commission (NRC) bettuse of the relatively large potential for radionuclide. release to the atmosphere along with the possibility of core uncovery and subsequent damage. Main-steatrline breaks are relatively low probability events. Steam generator tube however, ruptures, occur frequently, as indicated by licensee event reports for operating plants. The NRC requires utilities to analyze both of these single failure accidents in their safety analysis reports, but multiple failure accidents involving both of these events have not been addressed. These analyses provide best-estimate evaluations of the severity and consequences of these transients. The ;oals of these calculations are to provide thermedynamic conditions for the detm:mination of iodine transport to the environment and to demonstrate the aderoacy of the plant safety systems and operating procedures for controlling these sccidents.
Additienc1 information and figures are included in the appes ix to provide the thermodynamic conditions for the calculation of the radionuclide releases to the atmosphere.
II. MODEL DESCRIPTION AND ASSUMPTIONS THI-I is a Babcox and Wilcox (B&W) lowered-loop Pressurized Water Reactor (PWR) and consists of a vessel, two once-through steam generators (SG), and two hot legs and four cold legs, all of which are included in the TRAC model.
1 Reactivity feedback from fuel and moderator temperature is included in the vessel model. The TRAC noding diagram for this model is shown in Fig. 1.
Information for this model was obtained from the TMI Final Safety Analysis Report.2 The two cold legs on each loop are modeled as one combined cold leg for computational efficiency. Also modeled on the primary side are the main coolant
. pumps, loop seals, surge line, pressurizer (with heaters), emergency core i
cooling (ECC) injection [ including high pressure injection (HPI), accumulators, and low-pressure injection (LPI)], primary volume makeup, hot-leg candy canes, and upper plenum vent velves. The secondary side of the model includes the steam lines, main feedwater (MFU), auxilliary feedwater (AFW) with steam l
generator level control, a,tmospheric relief valves, turbine stop valves and turbine bypass valves. A total of 141 mesh cells are used in the TRAC model of l
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e this plant. The turbine bypass valves were not allowed to open to provide consistency with similar analyses performed for other plants,3 which have the
. ability to bypass a larger fraction of steam to the condensers. It was assumed, therefore, that steam relief would be through the atmospheric relief valves
- (ARV) only.
Additional operating assumptions made for these analyses are summarized in Tables I and II. These postulations simulate automatic and operator-controlled responses during the respective incidents. To simulate operator action, TRAC was modified to allow water level control for both the AFW and HPI flows. The AFW delivers enough flow to maintain a specified secondary-side water level and the HPI flou is throttled when the pressurizer water level returns to normal.
These analyses include calculations of 1, 5, and ten steam generator tube ruptures with and without MSLB.
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TABLE I MAIN-STEAM-LINE BREAK-INDUCED STEAM GENERATOR TUBE RUPTURE FOR TMI-1
, Event Trip Comments
- 1. MSLB (Loop B) Pressure drops to 0.1 MPa SGTR (loop B) in 2 s; full break' size (1, 5, and 10 rubes) in 1 s
- 2. Reactor Scram 12% overpower 5.36% shutdown margin or primary pressure (reactivity feedback with
<13.1 MPa (0.5 s delay) EOLa coefficients)
- 3. Close turbine 12% overpower MSLB occurs upstream of MSIV stop valves or primary pressure on loop B; both SGs
<13.1 MPa (0.5 s delay; blow down until turbine stop 0.5 s close time) valves close b
- 4. Close main feed Steam Line pressure 20 s delay to account for water valves <4.1 MPa; trip MFW liquid between valves and pumps SG; 14 s coastdown of MFW pumps
~50 kg/s)
<11.1 MPa pressure decreases; Flow throttled as pressurizer refills
- 7. Reactor coolant 60 e after HPI Operators trip after HPI pump coastdown initiation starts
- End of Life b Loop-A blowdown terminated by closing of turbine stop valves. ARVs relieve l flow to atmosphere, if necessary.
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e TABLE II STEAM GENERATOR TUBE RUPTURE FOR THI-1 Event Trip Comments *
- 1. SGTR Full break size (1, 5, and 10 tubes) in 1 s
- 2. Reactor scram Primary pressure < 5.36% shutdown margin 13.1 MPa (0.5 s delay)
- 3. Close turbine Primary pressure turbine bypass valves stop valves <13.1 MPa (0.5 s delay) assumed unavailable (0.5 s closing time)
, 4. Trip MFW Primary pressure 20 s delay to account for
<13.1 MPa(0.5 s delay) liquid between valve and SG; 24 s coastdown of MFW pumps
- 5. Initiate AFW Af ter MFW flow has ~25 kg/s/SG full flow; flow ended as required to maintain SG 1evel
<11.1 MPa pressure decreases; Flow throttled as pressurizer refills
- 7. Reactor coolant 60 s af ter HPI Operators trip after HPI pump coastdown initiation starts
- 8. Open A loop ARV SG B full Operator action to to initiate of liquid decrease primary controlled pressure blowdown of SG
- 9. Isolation of Primary pressure Isolate affected SG (No affected SG <7.3 MPa primary loop isolation valves) e
e III. STEAM GENERATOR TUBE RUPTURE RESULTS A. General Results "The results for the rupture of 1,5, and 10 tubes generally are very similar. The major differences are the timing of the automatic trips and the amount of HPI flow required. The HPI flow determines the extent to which the ARVs will open to accommodate decay energy removal. The HPIs can provide a maximum of approximately 65 kg/s, which is the leakage rate for about three ruptured tubes. Ruptures involving more than three tubes will behave similarly because the pressurizer will not refill and the HPI flow will remain hig'n. If less than three tubes rupture, the pressurizer will refill and the HPI flow will be throttled. Decay energy will exceed the energy removal capability of the throttled HPI flow. To accommodate this excess, boiling of the SG secondary will occur, which in turn will open the ARVs and rele?se additional primary fluid to the environment.
The amount of liquid expelled through the loop-B ARV and through the tube /
rupture (for 1,5, and 10 tubes) is shown in Table III. This table was compiled assuming operator action (primary depressurization) for all cases at 700 s and that primary leakage ended at 1900 s.
TABLE III TOTAL LEAKAGE FLOW'S Number of Total Fluid Out Total Primary Fluid Out Tubes Ruptured Loop B ARV Tube Rupture M (kg) 1 12000 2.8x10 4 5 19000 1.0x10 5
. 10 17800 1.1x10 5 e
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- 3. Detailed Results The rupture of 1.5, and 10 steam generator tubes was assumed to be the initiating event of these transients. The tube ruptures occurred at the top of the once-through SG on the B-loop side and were modeled as double-ended breaks.
. The sequence of events for these transients is summarized in Table IV.
- 1. Five-SCTR. Initially, the pressurizer heaters and primary system sakeup flow turn on in response to the decreasing prima ry pressure and pressurizer water level. This was insufficient, however, to prevent the primary depressurization and a reactor trip signal was generated due to low system pressure.
TABLE IV SGTR SEQUENCE OF EVENTS Time (s)
EVENT 1-SGTR 5-5GTR 10-SGTR SGTR 0.0 0.0 0.0 Reactor scram 492.8 72.1 34.7 (Close turbine stop valves)
MFW coastdown 517.3 91.7 54.2
- Initiate HPI 523.4 94.6 54.0 I
Initiate AFW 522.3 96.7 59.2 (SG 1evel control)
Trip main pumps 583.3 154.5 113.8 Loop-B SG full 5600.0 1000.0 700.0 Primary leakage ends 6800.0 2200.0 1900.0 Figure 2 shows the system pressure for the five-SGTR case. Concurrent with the reactor trip was the closing of the turbine stop valves. This resulted in the opening of the steam line atmospheric relief valves as shown in Fig. 3.
When the system pressure decreased to 11.1 MPa, the HPI flow was actuated and began injecting subcooled liquid into the cold legs (Fig. 4). The HPI flow was l
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i sufficient to make up for the primary liquid being lost through the ruptured tube and the primary pressure leveled at a value of approximately 9.4 MPa.
Figures 5 and 6 show that the primary-to-secondary heat transfer had essentially ended at this time. D e core decay energy was being removed strictly by the HPI flow in a once-through fashion (the HPI liquid went in the vessel and through
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the tube ruptures). His was possible because of the relatively high HPI flow capacity at TMi. In fact, the HPI flow was sufficient to remove approximately 160 MW at maximum flow, and about half of that amount without boiling.
The loop-B steam generator secondary rapidly filled with liquid because of primary leakage and was full by 1000 s (Fig. 7). The assumption was made that the operators had identified the damaged SG by this time and initiated actions to prevent the steam line from filling. In an actual plant, the problen may have been identified sooner; however, waiting until the SG is full represents a maximum time allowed to initiate action without introducing the possibility of damaging the steam line.
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Fig. 3. Closing of turbine stop valves leads to secondary pressurization.
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Fig. 4. HPI flow initiated when pressure equals 11.1 MPa.
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Fig. 5. Primary-to-secondary heat transfer ends when HPI flow begins.
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Fig. 6. Primary-to-secondary heat transfer recovered when ARV is manually opened.
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Fig. 7. Primary leakage fills damaged stear generator.
The assumed action was the opening of the ARV on the intact loop, shown in Fig. 8. This allowed depressurization of that SG, which re-established primary-to-secondary heat transf er and in turn decreased the primary pressure.
The opening of the ARV was controlled so that the AFW could maintain the 50 water at the prescribed operating level. Once the primary pressure decreased to the loop-B secondary pressure, the tube rupture flow ended (Fig. 9), and the transient was terminated. This occurred at 2200 s for the five-SGTR case.
Because most of the decay energy was removed by the HPI flow, the ARVs opened only partially and actually stopped opening at approximately 700 s. If no operator action were taken, the steam line on the damaged loop would fill with liquid. The ARVs would then begin relieving liquid directly from the primary.
- 2. 10-SGTR. The 10-tube rupture case was very similar to the 5-tube case.
l The primary pressure (Fig. 10) dropped faster and thereby tripped the reactor and initiated the HPI socner. Given the higher leakage rate, the SG secondary filled at an earlier time also, approximately 700 s. Depressurization of the intact SG began at this time and the tube-rupture flow ended at about 1900 s.
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Fig. 9. Primary leakage ends when primary pressure decreases to secondary level-
e The depressurization of the intact loop SG began earlier, so the ARVs closed earlier. R us, the amount of liquid lost out the ARVs was slightly less than
. the amount for the five-tube case. If the operator action for the five-tube case had been taken at 700 s, the amount of liquid discharged through the ARV
. would have been about the same as in the 10-tube case.
However, later in the transient, the primary pressure dropped lower for the 10-tube case resulting in a slightly greater leakage rate. Also, the 5-tube case required longer to generate a reactor trip than did the 10-tube case, resulting in more energy transferred to the SG early in the transient and, therefore, increasing the opening of the ARVs.
- 3. One-SGTR. De 1-tube case was similar to the 5- and 10-tube cases except the sequence of events occurred more slowly. A few important diffcrences should be pointed out, however. A reactor trip signal was not generated for nearly 500 s af ter the initiation of the tube rupture because of the smaller leakage rate and hence slower primary depressurization. A greater amount of primary liquid, therefore, was leaked to the secondary before the turbine stop valves were closed. When the HPI flow began at approximately 500 s, the flow 16000000 , , , . .
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( Fig. 10. Rupture of 10 tubes leads to rapid primary depressurization.
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exceeded the leakage rate and the primary began refilling. H is is demonstrated in Fig. 11, which shows the net primary outflow, defined as the flow out of the primary minus the flow in. The HPI flow continued until the pressurizer water level recovered at approximately 1000 s, shown in Fig. 12. Once this occurred, the HPI flow was throttled to equal the leakage flow (about 20 kg/s) such that the net primary outflow was zero.
The pressurizer did not refill before operator action was taken to depressurize the intact SG for the 5- and 10-tube cases. Therefore, the HPI flow remained at its maximum value, which was sufficient to remove nearly all the core decay energy. Once the HPI flow was throttled for the one-tube case, this was no longer true,and the SGs were required to remove the excess decay energy. h is required opening of the ARVs as shown in Fig. 13. For this reason, the amount of primary liquid lost out the ARV was considerably more than would be expected compared to the 5- and 10-tube cases. This is true, even if it is assu::.ed that operator action is taken at 700 s.
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Fig. 12. HPI flow sufficient to refill pressurizer.
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Fig. 13. Throttling of the HPI flow results in opening of ARVs.
i It should be pointed out that, in this TRAC' calculation, the: pressurizer heaters were allowed to return to power when the pressurizer water level .
. recovered. This allowed repressurization of the primary to 15.0 MP4 and increased the leakage rate to 24 kg/s. If the operators had correctly diagnosed the accident at this stage, they would have disabled'the heaterd. The pressure would remain at.about 11.0 MPa and the leakage rate would equilibrate with the HPI flow at about 16 kg/s. Allowing the heaters to return to power, therefore, provides a conservative estimate of the primary leakage rate.
IV. MAIN-STEAM-LINE BP.EAK WITH CONCURRENT STEAM GENERATOR TUBE RL'PTURE A. General Results SGTRs concurrent with MSLB can be grouped into two catagories with respect to system response - transients that involve use of the accumulators and thuse which do not. If approximately five tubes or more are ruptured,' the primary will depressurize sufficiently to initiate accu =ulator flow. The primary leakage rate will decrease as the primary pressure decreases and as the system voids. The initiation of accumulator flow will help refill the primary and stabilize the pressure. The leakage rate will then . equilibrate with the ECC inflow and remain at that rate until operator actiun is taken to depressurize the primary. The time it takes for the ECC flow to equilibrate with the leakage depends on the number of tubes ruptured. Because the pressure drops f aster when more tubes rupture, this time lessens as the number of tubes ruptured increases.
For transients involving less than five ruptured tubes, the HPI ilow is sufficient to equilibrate with the primary leakage and prevent primary depressurization below the accumulator setpoint. As the number of tubes ruptured increases to 5 the amount of primary liquid initially lost out the steam line increases. The HPI must replenish this inventory,, requiring a longer time to equilibrate viffs the leakage ficw.
The total are at of liquid out the steam line at 2500 s (including the SG secondary f *.r e 6 f.* entory), along with the primary leakage rate at this time, is shown on table s f or the 1,5 , and 10-tube cases.
The leakage rate for 5 and 10 tubes is identical because it depends on the
. HPI flow, which remains at full capacity. The accumulators are controlled by static check valves that automatically close when the primary pressure stabilizes. The borated-water store e tank (BWST) contains sufficient liquid to maintain a flow of 60 kg/s for approximately 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />. This defines the maximum
TABLE V PRIMARY LEAKAGE FOR MSLB WITH SGTRs Nember of Tubes Total Flow Dut Primary Leakage Rate Ruptured Steam Line at 2500 s at 2500 s (kg) (kg /s) 1 8.6 x 10 4 29 5 22.0 x 10 4 60 24.0 x 10 4
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10 60 time available for the operators to depressurize the primary and end the pricary leakage.
B. Detailed Results As the initiating event for SGTRs, it was postulated that the main steam line on loop-B suf fers a double-ended break outside the containment and upstream of the main- s t eam-line isolation valve. Because the steam lines of both SGs connect into a common header, both SGs initially blow down to the atmosphere until the turbine stop valves are closed. This isolates the intact SG from the break. The sequence of events for these transients is shown on Table VI.
14, induced an overcooling of the primary system. The positive feedback from the resulting decreasing coolant temperature caused the reactor power to increase. The power continued to increase, as shown in Fig. 15, until a 12%
overpewer reactor trip was initiated. The decay power for the entire transient is shtwn in Fig. 16. The HPI flow, shown in Fig. 17, started at 14 s and immediately began refilling the primary. The pressurizer had emptied primarily from system contraction upon reactor scram. At 500 s, the pressurizer level recovered and the HP1 flow was throttled to approximately 15 kg/s/ loop. This was sufficient to equilibrate with the primary leakage flow. As in the SGTR case for one-tube without MSLB, the pressurizer heaters were allowed to turn on
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' TABLE VI SEQUENCE OF EVENTS FOR MSLB-INDUCED SGTRs Time (s)
Event 1-SGTR 5-SGTR 10-SGTR MSLB,SGTR 0.0 0.0 0.0 Reactor scr:s, 5.82 5.31 5.80 close loop-A turbine stop valve Initiate HPI 16.5 14.6 14.2 Main feedwater coastdown 21.5 21.5 21.5 Initiate AFW 26.5 26.5 26.5 Trip main pumps 76.5 74.4 74.1 Leakage equilibrates 1000.0 2350.0 1200.0 with ECC injection Accumulators 2400.0 1400.0 begin discharge j upon pressurizer level recovery. This increased the primary leakage rate to around 29 kg/s as shown in Fig. 18. The flow would have equilibrated at about 25 kg/s had this not been allowed.
l Opening of this ARV was necessary to accommadate the excess decay energy. This 1
is shown in Fig. 19. Once the leakage rate reached a constant value, the
, calculation was terminated. The leakage rate at this time would continue until the operators initiated depressurization. Because the steam line is ver. ting
. outside the containment, the primary pressure would have to be reduced to atmospheric to stop the leakage.
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Fig. 14. Break in steam line leads to secondary-side blowdown.
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Fig. 15. Blowdown of steam generator leads to overpower reactor trip.
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Fig. 16. Power continues to decay, no return to criticality.
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Fig. 17. HPI flow throttled when pressurizer refills.
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Fig. 18. Primary repressurization increases tube rupture flow.
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Fig. 19. Intact-loop ARV opens to relieve excess decay energy.
- 2. MSLB with 5-SGTR. The blowdown of the SG was essentially the same as the one-SGTR/MSLB case, with the overpower reactor trip occurring at the same time. Because of the much larger primary leakage rate, the pressure continued to drop and the upper plenum began voiding. This is shown in Figs. 20 and 21, respectively. The HP1 flow was at full capacity at this time, and was suf ficient to remove all the core decay energy. As the primary continued to cool and depressurize, the intact-loop SG switched from being a heat sink to being a small hest source. This is shown on Fig. 22 as the difference between the primary and secondary fluid temperatures. When this occurred, the loop flow reversed, and then stagnated, resulting in voiding of the candy cane, a-. shown in Fig. 23. The upper plenum slowly refilled due to HPI flow with the only circulation being that induced by the HPI flow entering the cold legs, mixing with the primary fluid and going out the tube rupture. The voiding, or draining, of the loop-A candy cane essentially isolated the intact SG from the vessel. Once this has occurred, the operators can no longer effectively use the intact SG to depressurize the primary. When the accumulators begin discharging, the loops will slowly refill and natural circulation can be re-established.
Because this is a very slow process, the operators may be required to use an alternate strategy to depressurize the primary, such as opening a primary pressure relief valve. Primary leakage will continue until this is accomplished and the primary pressure is reduced to atmospheric.
The HPI flow equilibrated with the primary leakage at approximately 2400 s, which is when the accumulators opened. The accuculators operate when a minimum of five SG tubes are ruptured. For rupture of less than five tubes, the HPI can equilibrate the leakage and maintain the primary pressure above the accumulator set point.
- 3. MSLB with 10-SGTR. The results of this transient are the same as the five-SGTR/MSLB case except the events occur on a shortened time scale. The primary pressure dropped much faster and the upper plenum liquid decreased to a lower level than in the other cases. The loop-A candy cane voided at 250 s and
, the BPI flow equilibrated with the primary leakage at 1200 s. Because of the large number of tubes ruptured, the primary continued to depressurize, venting
. liquid and steam out the rupture. The accumulator set point was reached at 1400 s, at which time the primary slowly began refilling and leakage remained constant. This is demonstrated in Figs. 24 and 25, which show the upper plenum liquid fraction and accumulator flow, respectively.
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o u -
H rt O C U tt l Y a
" 8 E 5 g- g-o .
g _
M W g
- r-g. r r-O m O n M.
~
m* ~ ^
n o
n x o 4- o g' De n 8 m 8 -
- 8 M 8 -
a -
m y C M M '4 N. c. 8 M 8 -
c
. 8 -
M M H R O M 0 m u c u 6, g - . . . , , , , , " 8 ' ' ' ' ' ' ' '
X.
ft e*
O D
e
i t . . . . .
g v
e- -
e.-
i e- s- -
Y o
6.J y _4 -
O h
- a. _e_ .
- a. .
8a -s- >
-to . , . . i o soo looo 150o 2ooo 250o 3'A o TIME (s)
Fig. 22. Cooling of primary leads to reverse heat transfer.
12 . . . . .
z O 1- r
~
~
u 4
E o.s - -
e o
n.
l 9 o.s - -
!E u ,,,. .
9 I
. u o.:- -
h
.a
- o. -
l
-n2 . . . . .
o soo sooo isoo 2t,oo 2500 sooo TIME (s)
Fig. 23. Flow reversal empties top of candy cane.
i I
u . . . . .
2 ~
0 l' co g o.e -
m j o.e -
d o.7 -
9 s
o o.s -
a 3
z 0.5 -
b a- c.4 - p ,
5 n.
g 0.3 -
0.2 0 500 1000 1500 2000 2500 3000 TIME (s)
Fig. 24. Upper plenu:n level remains constant due to suf ficient ECC flow.
4s . . . . .
Q 40- -
, N l
o 6 35- -
W 4 30- -
a:
3 3
w 25- -
$ 20-3 d is -
3 8
.- v -
1 8D -
t-lI 3 .,
- n. i O if 3 0 E I]U U -
-s .
O S00 1000 1500 2000 2500 3000 TIME (s) i Fig. 25. Accumulators open and close as primary slowly depressurizes.
1
V. CONCLUSIONS Steam generator tube ruptures with and without main-steam-line break for the TMI-1 plant are relatively severe accidents with respect to the potential f or radionuclide release to the environment. However, they do not represent accidents that existing safety systems cannot mitigate. Operator action will be required to depressurize the plant and terminate the transient; but, automatic actions are sufficient to maintain the plant in a safe condition until such action is taken. The ECC system will provide sufficient time for operators to evaluate the situation and to take appropriate steps.
The HPI injection system is sufficient for the SGTR transients involving rupture of as many as 10 tubes. We estimate that the rupture of approximately 25 tubes would be required to initiate accumulator flow.
Transients that involved SGTRs with MSLB were found to initiate accumulator flow when more than five tubes ruptured. This flow was necessary to replenish the primary inventory lost out the rupture. HPI flow is suf ficient when less than five tubes are ruptured.
The HPI capacity, in many instances, is greater than the flow required to mitigate the accident. In general, as long as the HPI flow is sufficient to equilibrate the leakage flow, partial unavailability of the HPI will not impede recovery of the plant. Sufficient cooling capacity is available fro = the 12maining intact steam generator, if the HPI flow is throttled.
With respect to the amount of primary leakage, the results, though reasonable, are not what one might expe ct. The amount of leakage is not a linear function of the number of tubes ruptured. The principal factors that influence the leakage are the throttling of the HPI flow and the operator response time. The amount at HPI flow determines the opening of the ARVs and affects the equilibrium leakage rate of the system. The operator response time determines the termination of leakage and, therefore, the total amount of primary lost.
l i
REFERENCES
- 1. Safety Code Development Group, " TRAC-PD2, An Advanced Best-Estimate Computer Program for Pressurized Water Reactor Loss-of-Coolant Accident Analysis",Los Alamos National Laboratory report LA-8709-MS (May 1981).
- 2. "Three Mile Island Final Safety Analysis report," Metropolitan Edison Co.
(Ma rch, 1970) .
- 3. " Analysis of Steam-Line-Break-Induced Steam Generator Tube Rupture," Los Alamos National Laboratory report LA-UR-80-3682 (June,1981).
O I
l D
APPEND 1X A primary goal of these analyses was to provide thermodynamic source conditions for the determination of iodine transport to the environment. The following tables and graphs are intended to supply additional information necessary for that analysis.
Selected initial conditions are given in Table 1A. These represent values given in FS AR data. Plots are not duplicated if they are included in the main text. When there is more than one curve on a plot, the solid curve is the first curve listed on the ordinate label. The plots of SG primary flow indicate negative flow because of the way the system is noded. This represents flow in the normal, steady-state direction'. Additional information, if required, can be obtained f rom the TMI FSAR.
S
TABLE 1A.
TMI-1 STEADY STATE DATA Power 2568. MW Linear generation rate 5.66 kW/ft Cold leg temperature 563. K Hot leg temperature 590 .8 K Hot leg flow 8270. kg/s Hot leg pressure 15.0 MPa Vessel AP .47 MPa Pump AP .85 MPa Secondary pressure 6.37 MPa Secondary exit temperature 553. K Initial water level 4.556 m Total SG secondary volume 96.6 m3 Height of SG secondary 15.9 m Total primary coolant volume 325. m3 e
9 e
t"000000 . . . . .
m O
65000000- ,
. w D
\
ta
- bl4000000- _
m n.
w o \
13000000- _
iii 2
3 12000000- .
w
._2 c.
m U 11000000- _
a.
D L
10000000 , , ,
0 500 1000 1500 2000 2500 3000 TIME (s)
Fig. lA. Upper plenu= pressure, one-SG~R.
640 . , , , ,
^ 620- .
M '
v
~~ .....
u ....' .... ~ ........ -
l g soo. ; ,,,.... . ....... - ,
v :
z
~
580- .
I 560- .
w Ln i N Sa0-o J
. W o 520- .
5 i
t
~
k 500- .
480 , , ,
0 500 1000 1500 2000 2500 3000 TIME (s)
Fig. 2A. Primary temperatures, one-SGTR.
1 l
I
26 . . . . .
l 2a- -
7 ,
Np /
22-6
- u
$ 20- -
= ef g 18 -
u w
S is - -
c.
S u H- -
m
? [f'g 12 -
90 , . . . . ,
0 500 1000 1500 2000 2500 3000 TIME (s)
Fig. 3 A. Primary leakage rate, one-SGTR.
1000 . , , ,
0-q ____ _
[
v
-1000- -
w Q -2000- -
a R
O -3000- -
J b.
g -4000- -
2 g -5000- -
n.
$ -6000- -
a g -7000- -
. O O g 3
-8000- -
l l
l -9000 . , , , ,
1 0 500 1000 t$00 2000 2500 3000 TIMC (s)
Fig. 4 A. Flow through intact SG tubes, one-SGTR.
~
q y .
11 . . . . .
^ 10 - -
2 d
B a
5
- a- -
h 4
m O
g 7- -
U w
M
~
m o.
O O
-.s 5 --
~
4 , , . , , .
0 500 1000 1500 2000 2500 3000 TIME (s)
Fig SA. SG water level, one-SGTR.
580 , , , , ,
v n.
2 w
t-g 540- -
4 M
N O
~
- 520- -
U w
M
$ Soo- -
m G.
O
. . O 430- .
460 , , , , , ,
O 500 1000 1500 2000 2500 3000 TIME (s)
Fig. 6A. Secondary temperatures, one-SGTR.
8000000 . . . . .
z- .,: :,m ,. .
3 . - _.. -- , .- , -
67000000-w E
D m
C6000000-a-
G.
E 3 5000000- -
2 4
w F
" 4000000- -
en N
4 c.
O 3000000- -
O
_J 2000000 . . . . .
0 500 1000 1500 2000 2500 3000 TIME (s)
Fig. 7 A. Secondary pressures, one-SGTR.
40000 . . . . .
35000- -
n
[ 30000-v 3
oJ 25000- -
L
$ 20000- -
4 15000-l O-O i
O
' 90000-I 3
. 4 6-
- O 5000-l 0- -
l
-5000 i . . . .
0 500 1000 1500 2000 2500 3000 i
TIME (s)
Fig. 8a. Total flow out ARV, one-SGTR.
l
860- . . . . -
640- -
n, v
o 820- -
u 800- I -
2 1
Se0- . -
560- ....,'*-. -
y m
g 540- -
.O 520- -
w o '
4 er 500- -
w N
480- -
460 , , , , .
0 500 1000 1500 2000 2500 3000 TIME (s)
Fig. 9 A. Upper plenum pressure, five-SGTR.
1000 . . . . .
m 0- --- -
p
, .,000 , .
v
[
I N 4 -2000- -
E R
O -3000- -
J
>- -4000- -
E 4
2
-5000- -
k
$ -4000- -
ED 7000 .
8
-A E 3000 .
l -9000 , , , , ,
t 0 500 1000 1500 2000 2500 3000 TIME (s) l Fig. 10A. Flow through intact SG tubes, five-SGTR.
i
g 300 . , , , ,
n Sa0-E V
j -- -
- -- .. .. s, y '.,'. l'. . ,. -,
( /
m g 340- '.....-l O.
_J 8
v1 520- -
0 vi e 500-
- n.
O O
_a 480- -
460 , , , , ,
0 500 t000 1500 2000 2500 3000 TIME (s)
Fig. IIA. Secondary temperatures, five-SGTR.
9000000 , , . . .
Q8000000-n.
v y e - n w r.e ,; %* s,5,.p ... ... ,* ..
c: 7000000- 1 ., -
D .
+
t M '.-
l 0 -
'. ;nl',j....'., -
[ 6000000-
'. /
W '.* !
Z ..
~
* 'l -
J 5000000-2 4
4000000-l m N -
< 3000000- .
R.
8; 2000000- -
200000 , , , , ,
0 500 1000 1500 2000 2500 3000 TIME (s)
Fig. 12A. Secondary pressures, five-SGTR.
TOTAL PRIMARY LEAKAGE (Kg) TOTAL LOOP'9 ARY FLOW (Kg)
A u . . . s n e a . s a a 3
8 8 8 8 8 8 8 8 8 8 8 o.
8 e 8, 8, , y 8 , 8 o e
I e e e f. -
m 00 M e >
> w
> [. w O
w
. o '
g 4 O
bl
'DD O M et be M o O
c 40o %
- -e 8 ~
0 kE Y
?
O n N^
C b 3 - %
a g e; -
. 8~
e o
< t if tn
=
m S a
a 8 o -.
- x. 8-o u .
%s M f f i e t t I f , , , , o o
TUBE RUPTURE FLOWRATE (Kg/s) AVERAGE LIO/ SAT TEMP IN CORE (K)
A 8 E T R E E 5 g O O o
sO a O
M O
N O
O O O
O o
o s
o e
n e
o
' ' ' ' ' O O " ,.......... -
l l
e
- =s r M LA l qpp 4A O-
. O- ~
o.o O g O e 0
e=e 9d Q w j l
- e
. 9 O .e
- W *o .
es 8_ - n g :
a 8 -
U Os b e n *1 ,
M 4
x w _
w - " r /
i
- I o M E- s' EM E-ap O M. ^
O
- o. ^M n
=v* l m v ** l c .
n.
e *1 n M
.m M
O' . .tn 0
O' $*
O O .
w O e.*
O o :
e ;
e .
to tn a O :
H :
? ~ W
~.
v -
v..
O
- O O
O 1,e ,
I s e e e Os O. e o e g , , ,
O O
2000 , , , , ,
, 1000-
. i v
Kw - 1 g -1000- -
hO
-2000-a
' -3000-sr ~
4 -4000-2 E -5000-0 M -4000-8D ,
g
-7000-O 3000- h
-9000 , , . . ,
o 500 1000 1500 2000 2500 3000
.i TIME (s)
Fig. 17A. Flow through intact SG tubes,10-SGTR.
18 , , ,
n M- _
[
d 14 -
W J
12 -
5 -
g to -
o m -
o e-d
= .-
i n.
O
. o
. /
4 --
2 . , ,
500 1000 1500 2000 2500 3000 0
j l TIME (s)
Fig. 18A. SG water level, 10-SGTR.
580 . . . . .
e
- I ........,,,,
gg , ,
ac .
v .
y ..
yan. .
4 m
N 520- -
o a
b m
S00- -
o m
g 480- -
ki O
J 460- -
440 . , , . . .
0 500 1000 1500 2000 2500 3000 TIME (s)
Fi g. 19A. Secondary te=peratures, 10-SGTR.
8000000 . . . . .
g --
- y /,* V... ..,,,
67000000- ' ., t L.)
E
- p
- m .
d6000000- \.
! E '.
n.
/\
y '.....: '......... ----- -
3 5000000-3 4
4 i 4000000-l m
- N
- a. -
. C) 3000000-O l J 2000000 . . . . .
0 500 1000 1500 2000 2500 3000 TIME (s)
Fig. 20A. Secondary pressures, 10-SGTR.
20000 - -
i , , .
^ 15000- -
. p ac v
. I oJ
' 10000- -
se so CL o 5000- -
o
_J J
4
,o
_ o- .! .
-5000 , - -
0 500 1000 1500 2000 2500 TIME (s)
Fig. 21A. Total flow out ARV,10-SGTR.
100000 100000-m O
M v
80000-LJ O
4 '
x b, 60000-Cr
$ 40000-tr CL N 20000- 4 C
o- -
-00000 -
0 500 1000 1500 00C3 0500 TIME (s)
Fig. 22A. Total flow out rupture, 10-SGTR.
5000000 , , , , ,
O 65000000- -
14000000- -
W O
15000000- -
212000000-W J
n.
CE EIt000000- -
u.
D 10000000 , , , , ,
D 500 1000 1500 2000 2500 3000 TIME (s)
Fig. 23A. Upper plenu: pressure, one-SGTR/MSLB.
460 , , , , ,
640- -
m v
x w S20- -
cc ...-------------------
o O Soo- --~~~~~~'"~~.....--***... -
2_ ........ **... .....--
580- -
560- -
4 in N S40- -
O 520- -
w O
er 500- -
E 480- -
460 , , , , ,
D 500 9000 1500 2000 2500 3000 TIME (s)
Fig. 24A. Primary temperatures, one-SCTR/MSLB.
1000 . . . . .
q *~ ~
N O
. w v
-1000- -
N 4 -2000- -
EE 3:
o -3o00- -
d g -4000- -
2 g -5000- -
G.
C -6000- -
CD .
g -7000- -
O O
-8000- -
V
-9000 . . . , ,
0 503 1000 1500 2000 2500 3000 TIME (s)
Fig. 25A. Flow through intact SG tubes, one-SGTR/MSLB.
4.5 . . . . . . . . i 4 -
n 2
3.5 -
- d w 3- -
! _J 2.5 - -
3:
y 2- -
o_.
M 15- -
U w
M -
1 m
- a.
- O D b" ~
. O J
0-
-0.5 . . . . . . . . .
0 5 to 15 20 25 30 35 40 45 50 TIME (s)
Fig. 26A. SG water level, one-SGTR/MSLB.
500 . . . . i m
E
. 550-S.
9 4 -
m 500-N O
J .
U '
O m
m L -
g 400-350 . . . . . . .
50 0 5 10 15 20 25 30 35 40 45 TIME (s)
Fig. 27A. Secondary temperatures, one-SGTR/MSLB.
4500 . . . . . . . , .
n 4000-M N
E 3500-v W -
F 3000-4 m
R -
O 2500-J La.
W 2000-Z
.J -
1500-2 4
N g 1000-m -
g 500-O O
d 0-
-500 . . , , , . , , ,
0 5 10 15 20 25 30 35 40 45 50 TIME (s)
Fig. 28A. Steam line flow, one-SGTR/MSLB
120000 . . . . .
m y' 100000-e v 3
O -
. .8 an.
80000-N 3
60000-3 4
w t-
~
M 40000-to EL O -
O 20000-
.J J
4 6- ~
O O-6-
-20000 . , , i .
0 500 1000 1500 2000 2500 3000 TIME (s)
Fig. 29A. Total flow, one-SGTR/MSLB.
540 , , , , ,
n 620- -
v x
@ 600- -
O i U 2 560- '; -
560- . -
< 540- '* - ..........,~~'-- ..- -
m N ....' .,*
O
. ,,2 820- . ' * . . ... -
w o
4 500- - -
a:
w k 480- -
460 , , . .
D 500 1000 1500 2000 2500 3000 TIME (s)
Fig. 30A. Primary temperatures, five-SG'IR/MSLB.
n
1000 . . . . .
~
q _
m -3000- -
- v g -2000- -
0:
3: -3000- -
O J
&a- ~4000- -
oc
< -5000- -
2 E -4000- -
0 VI -7000- -
m g -8000- -
O /
-9000- -
- 2000 , , , . .
0 500 1000 1500 2000 2500 3000 TIME (s)
' Fig. 31A. Flow through intact SG tubes, five-SGTR/MSLB 12 0 . , , , ,
110 -
7
- N 1 O E
10 0 -
I" to-0 1 $
g 80- -
D l W 70- -
l 60- -
l 50 , , , , ,
0 500 1000 1500 2000 2500 3000 l
l TIME (s) l Fig. 32A. Primary leakage rate, five-SGTR/MSLB.
4.5 i > > > > > > > >
4- ~
m 2
. 3.5 - ~
W 3- ~
e y 3.5 - ~
f y 3- ~
O.-
m 15- ~
O W
m 1 ~
m o 0.5 - ~
O
.J 0-
-0.5 -i e i e i i i .
O 5 to 15 20 25 30 35 40 4'5 50 TIME (s)
Fig. 33A. SG water level, five-SGTR/MSLB.
600 . i e i i i e i i 2
V 550- ~
W 9-
$ 500- ~
N
.O_
J u
..' , ..~
m 450- '
~
c m
- m
- a. .
' ~ .
. 8 >
350 i i i i i i 1 - 1 0 S to 15 20 25 30 35 40 45 50 TlWE (s)
Fig. 34A. Secondary temperatures, five-5GTR/MSLB.
s000000 , . . . . . . a '
g 5000000-6 I4000000-3000000-Y 3 -
3 2000000-4 Ne -
g 1000000-S.
8J 0-
-1000000 , , , , , , , ,
0 5 10 15 20 25 30 35 40 45 50 TIME (s)
Fig. 35A. Secondary pressure, five-SGTR/MSLB.
4500 , , , , , , , , ,
n 4000-m N
E 3500-3000-tt E 2500-o d
y 2000-s J g 1500-4 1000-500-
. O
" 0-
- HO , . . , , , , .- ,
50 0 5 to 15 20 25 30 35 40 45 TIME (s)
Fig. 36A. Steam line flow, five-SGTR/MSLB.
l 1
250000 . i i i i 9
6 200000-o 150000-N ,
, 1 1
2 -
g 100000-H W
ID EL 50000-O O
a J \
4 -
>- 0-O w
-50000 , . . . .
O $00 1000 1500 7000 2500 3000 TIME (s)
Fig. 37A. Total flow released, five-SCTR/MSLB.
12000000 . . . . i n 11000000-0 10000000- -
tr D -
$ 9000000-E \
' 8000000- -
W O
$7000000-w k 6000000- -
2 3
Z -
g5000000-CL Eg 4000000-ib 3000000-2000000 . . . .
O 500 1000 1500 2000 7500 3000 TIME (s)
Fig. 38A. Upper plenum pressure,10-SGTR/MSLB.
54 0 . . . . .
^ 620- -
E v
w o 500- -
. o 2
~
580- -
Si .
w ,
560- '.
6- .
M g N 540- N. -
O J
w .... ..., - .
O 520- ..,
m
- w N 500- -
4:0-0 500 1000 1500 9000 2500 3000 T I Mr. (,)
Fig. 39A. Primary temperatures,10-SGTR/MSLB.
1000 , , , ,
0~ -
W. -
m -1000- -
M v
W -2000- -
4 m
3: -3000- -
o)
' -4000- -
x 4 -5000- -
_2 E -6000- -
0 0 M -7000- -
. Q- -8000- -
O O V
-9000- -
-10000 . .
0 500 1000 1500 9000 2500 3000 TittE (s)
Fig. 40A. Flow through intact SG tubes, 10-SGTR/MSLB.
220 . . . , ,
200- i 7 -
- N 3o-o 6 -
w 20-a:
3 14 0 -
oJ 6
w 12 0 -
c:
10 0 -
w -
to 80-3
(
60-40 1
o son 1c00 if,::o 1000 ?500 2000 TIME (c)
Fig. 41A. Primary leakage flow,10-SGTR/MSLB.
4.5 . . . . . . . . .
4 m
2 3.5 -
d w 3-
\
er W 2.5 -
4 R -
w 2-
.O.
M t3 O
w
- 1-o m o 0.5 -
. O J
0-
-0.5 . . . . . . . .
5 to 20 25 30 35 40 45 So o 15 TIME (s)
Fig. 42A. SG water level, 10-SGTR/MSLB.
600 . . . . . . . . .
2 o 550- -
W o >-
t-4 m 500- -
N o
3 y .......,
$ 450- -
8 %
=
0.
O 400- -
O
_J 350 0 5 to 15 70 75 30 35 40 45 50 TIME (s)
Fig. 43A. Secondary te=peratures, 10-SGTR/MSLB.
6000000 , . . . . . . . .
^ 5000000- -
O b
u
$4000000- -
en M
W Ek:
E 3000000- -
N 3
3 2000000- -
4 m
, g 900000- -
8.
. 8 J 0- -
-9000000 . . . . . .
0 5 to 15 20 25 30 35 40 45 50 TIME (s)
Fig. 44A. Secondary pressure,10-SGTR/MSLB.
6000 . . . . . . . . .
n
(. $000- -
) U
.a 4000- -
EE R
O J 3000- 1 k.
J 2000- -
2 4
m 1000- -
ID n.
o 0- -
-1000 . . , , .
D 5 to 15 20 25 30 35 40 45 50 TIME (s)
Fig. 45A. Steam line flow, 10-SGTR/MSLB.
250000 . , , , , , , , .
m o
/
6 200000- -
O
.a L
g 150000- -
2 3
? 1 -
$ 100000-t-
M ED Q- 50000- -
O O
O J a >
( -
4 t- 0-O t-
-50000 . . . . .
0 700 400 000 800 1000 1?00 1400 1600 1830 2000 TIME (s)
Fig. 46A. Total flow out, 10-SGTR/MSLB.
-