ML20127C666

From kanterella
Jump to navigation Jump to search
Methodology for Calculating Enable Temp Setpoint for Zion Units 1 & 2
ML20127C666
Person / Time
Site: Zion  File:ZionSolutions icon.png
Issue date: 08/31/1992
From: Malone M
WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To:
Shared Package
ML20127C650 List:
References
NUDOCS 9209100013
Download: ML20127C666 (31)
v • d • e


Text

___

FDRT SRPLO 229(92)

WESTINGHOUSE PROPRIETARY CLASS 3 Methodology For Calculating Enable Tcmperature Set Point For Zion Units 1 & 2 August 1992 Prepared by:

M 2M N M. J. Malone Structural Reliability & Plant Life Optimization WESTINGHOUSE ELECTRIC CORPORATION Nuclear and Advanced Technology Division P. O. Box 355 Pitburgh, Pa.nnsylvania 15230-0355 l

@ 1992 Westinghouse Electric Corporation All Rights Reser>ed

[$0

$O0Ck O f

P

. ~.. -

e 4.

3 Method wingy For Calculating Enable Temperature Set Point For Zion Units 1 & 2 a

TABLE OF CONTENTS 1

i Sunon Tide Eage List of Tables ii l

List of Figures iii 1.

Introduction 1

2.

Basis for Determining Enable Temperature 1

3.

Basis for Determining Controlling Location 2

4.

Calculation of Enable Temperature for 32 EFPY 4

4 5.

References 16 6.

Appendix A: Data Points and Graphs of RTNDT vs EFPY for 1/4T Location 2

1 1

4 9

d

+

6 1

Methodology For Calculating Enable Temperature Set Point For Zion Units 1 & 2 LIST OF TABLES Inble Iltle Page 1.

Zion Units 1 & 2 Temperature Variations For 7

60 Deg. F per Hour Heatup Rate 2.

Zion Unit 1 Temperature Ranges For 12 Appendix 0 Controlling Locations (With Instrumentation Error Margins)

A1.

RTmg @l/4T vs EFPY For Zion Units 1 & 2.

Al l

l

\\

~

ii

,..~

Methodology For Calculating Enable Temperature Set Point For Zion Units 1 & 2 LIST OF FIGURES 4

1 Eigute Title Eage 1.

Vanation of Metal Temp. Difference with Reactor 5

Vessel Fluid Temp. For Zion Units 1 & 2 Using a 60 Deg. F per Hour Heatup Rate 2.

Variation of Metal Temp. Difference with Time 6

4 For Zion Units 1 & 2 Using a 60 Deg. F per Hour Heatup Rate Al RTNDT @l/4T vs EFPY For Zion Unit 1 A2 A2 RTsor@l/4T vs EFPY For Zion Unit 2 A3 i

s l

j l

i iii

1. INTRODUCTION The purpose of this report is to desenbe the methodology for calculating the enable temperature set point (ET) that defines a temperature range,(T uaj s T s ET), for which im the low temperature overpressure protection system (LTOPS) must be operable during plant startup an:! shutdown conditions. The basis for detennining the enable temperature is desenbed first, followed by the basis for determining the Appendix G controlling locationW (i.e.,1/4T or 3/4T) in the reactor vessel beltline dunng plant heatup and cooldown events. An example is then provided showing the method for calculating the 4

enable temperature set point for Zion Unit 1.

2. BASIS FOR DETERMINING ENABLE TEMPERATURE 4

The enable temperature set point, as defined in the Standard Review Plan, Branch Technical Position RSB 5-2,"Overpressurization Protection of Presstuized Water Reactors While Operating at Low Temperatures"[21,is the water temperature corresponding to a metal temperature of at least RTso7 + 90'F at the beltline location (1/

4T or 3/4T) that is controlling in the 10 CFR Part 50 Appendix GUI fracture toughness limit calculations. Its purpose is to set a temperature range for which the low temperature overpressure protection system (LTOPS) should be operable during plant startup and shutdown conditions in order to assure the Appendix G limits for the reactor coolant system are not exceeded while operating at low temperatures. The temperature range, for which LTOPS should be operable, is defined to be all temperature values below the enable temperature.

The calculation of the enable temperature, using the definition described above, requires that the metal temperature difference (AT) betwcen the reactor vessel bulk fluid and the controlling location be added to the value RTuo7+ 90'F, when the metal temperature at

  • he controlling location reaches a temperature value of RTsor + 90*F. De rnetal

'emperature difference must be added in order to have the water temperature correspond to the contro!1ing location metal temperature. Furthermore, the effect that the metal teinperature difference has on enable temperature calculations is different for the reactor vessel heatup and cooldown processes.

During a plant cooldown, the controlling location is always at the 1/4T position and has a higher temperature value than the fluid adjacent to the vessel inner diameter. It follows that the AT (Tnoi,-T

,,3) metal temperature induced during cooldown is negative and m

results in a lower or less conservative enable temperature set point when included in the equation ET - RTso7+ 90'F+ 4T.

During a plant heatup, the controlling location switches between the 1/4T and 3/4T positions. _ However, these vessel locations are at a lower temperature than the fluid adjacent to the vesselinner diameter. It follows that the AT (T.w-T,,,,i> metal n

temperature difference induced during heatup are positive and result in a higher or more i

1

i 4

conservative enable temperature set point when included in the equation ET - RTuor + 90'F+ AT.

From the above descriptions, and taking into account that the 1/4T RT value is greater 3or than the 3/4T RT or value, the maximum required enable temperature can be calculated N

during heatup when the largest AT metal temperature value at the 1/4T controlling location is added to the value RTuo7 + 90*F. However,if a large enough heatup rate is used, the maximum enable temperature can be calculated at the 3/4T controlling location due to the large AT metal tempetature values at the 3/4T locanon. As a result, when the difference between the AT metal temperature values is greater than the difference between the RT337 values at the 1/4T r-d 3/4T locations, the maximum required enable temperature is calculated at tho 3/4T controlling location. If the RTuor and AT differences between the 1/4T and 3/4T locations are the same. then the calculated enable temperature for both locations will be the same. Furthermore, when the enable temperature is calculated at the 3/4T controlling location, one must also verify that the value obtained bounds (i.e., be g1 eater than) the enable temperature for all possible l

cooldown rates at the 1/4T location.

!~

3. BASIS FOR DETERMINING CONTROLLING LOCATION The method for detemiining the reactor vessel controlling location (1/4T or 3/4T) dunng plant heatups and cooldowns is described below in accordance with the ruies outlined in l

ASME Code,Section III, Appendix Ol9 and the fracture toughness requirements as i

defined in Appendix 0 of10 CFR Part 50lU. The methods used are,in detail, documented in WCAP-7924-AIN.

J Heatup In a heatup analysis, two distinct situauons are analyzed. First, allowable pressure temperature relationships are devcL pd for steady state (i.e., zero rate of change of temperature) conditimis as well as finite heatup rate conditions, assuming a 1/4T deep flaw at the inner diameter of the reactor vessel. Durinh a heatup of the teactor vessel, the thermal gradients in the vessel wall tend to produce compressive stresses at the 1/4T location, and as a result, the tensile stresses induced by internal pressure are somewhat alleviated. Therefore a pressure-temperature heatup ctuve based on steady-state conditions (i.e., no thermal stresses) represents a lower bound of all similar curves for finite heatup rates when the 1/4T flaw is considered. However, during heatup, especially at the end of the heatup trai...ent, conditions may exist :10 diat the effects of compressive thermal stresses and tensile pressure stresses do not offset each other, and the pressure temperature curve based on steady state conditions no longer represents a lower bound of all similar curves foi finite heatup rates when the 1/4T flaw is considered. Therefore, both cases (i.e., steady state and finite heatup) have to be 2

i 4

analyzed in order to ensure that the lower value of the allowable pressure

)

calculated for steady-state and finite Featup rates is obtained.

Secondly, allowable pressure temperature relationslups are developed for a firute heatup rate, assuming a 1/4T deep flaw at the outer diameter of the reactor vessel (i.e., the 3/4T locstion). Unlike the situation at the inner diameter, at the outer 4

diameter position the thermal gradients established during heatup produce stresses which are tensile m nature and thus tend to reinforce the pressure stresses present.

These thermal stresses are dependent on both the rate of heatup and the time along 4

the heatup ramp. Funhermore, since the thermal stresses at the outer diameter are tensile and increase with increasing heatup rate, a lower bound curve simihr to that described above cannot be defined. Rather, each heatup rate ofinterest must be analyzed on an individual basis.

Following the generation of pressure temperature relationships for both the i

steady state and finite heatup rate situations, a composite heatup curve of prenure.

1 temperature values is constructed based on a point by point comparison of the j

steady state and finite heatup rate data. At any given temperature, the allowable pressme is taken to be the lesser of the values taken from the heatup curves under consideration (i.e., steady state,1/4T and 3/4T finite heatup).1he locations under consideration having the lowest pressure for a given temperature determines the reactor vessel controlling location.-

i During the generation of the heatup composite curve, the outer diameter (3/4T position)is initially the controlling location. However, the possibility exists for the controlling location tc stch from the 3/4T to the 1/4T position during the

^

reactor vessel heat up process. In addition, the reactor vessel fluid temperature in which the switch over occurs also changes as the effective full power years (EFPY) of the vessel change, there' ore, the switch over temperature is not a fixed value but changai with RTuor.

Cooldown The cooldown analysis proceeds in the same fannion as that for heatup, with the 4

exception that the controlling Ic ation is alnays at the inner diameter. The thermal i

gradients induced during cooldown tend to prodace tensile stresses at the inner diameter location (1/4T) and compressive stresses at the outer diameter location (3/4T). Thus, the inner diameter flaw is clearly the worst case, and as a result, the 1/4T position is always the controlling location for a reactor vessel cooldown process.

. F

4. CALCULATION OF ENABLE TEMPER ATURE FOR 32 EFPY Results from WCAP-13406 "Heatup and Cooldown Limit Curves for Normal Operation For Zion Units 1 & 2"W, ar, used to calculate an enable temperature set point for 32 e

EFPY with instrumentation error uargins, assuming a heatup rate of 60 F per hour. De vanations of the metal temperature difference (AT) between the reactor vessel bulk fluid and the 1/4T and 3/4T controlling locations for a 60 *F per hour heatup rate are providt.d in Figures 1 and 2. Figure 1, entitled " Metal Temperature Difference ('F) vs. Reactor Vessel Fluid Temperature ('F)", shows the metal temperature difference for the 1/4T and 3/4T positions corresponding to a tiuid temperature adjacent to the reactor vessel inner diameter. Similarly, Figure 2, entitled " Metal Temperature Difference ('F) vs. Time (Hours)", shows the metal temperature differences as a function of time throughout the reactor vessel heatup process. Figure 2 is provided for information pumoses only and is not sequired to calculate the enable temperature set point. Table 1 contains the data points used to generate the curves in Figures 1 and 2 and will be used to calculate the metal temperature difference (AT)in the etiable temperature calculation process.

4

s 50 100 150 200 250 300 350 400 450 500 550 600 I

I I

I I

i i

I I

i

./

35- -

35 Delta T@3/4T 1.ocation 30 30 C

25- -

25 2

m Q

l 20-t 5

20 h

e 15- ~

j Delta T@1/4Tlacation 15

.c 10-10 5--I 5

0 50 100 150 200 250 300 350 400 450 500 550 600 O

Reactor Vessel Fluid Temperature (F)

Figure 1 Variation of Metal Temp. Difference with Reactor Vessel Fluid Temp.

For Zion Units 1 & 2 Using a 60 Deg. F per Hour Heatup Rate 5-

0 1

2 3

4 5

6 7

8 9

10 11 40 i

i j

j g

g i

40 35- -

35 Delta T @3/4T Location 30- -

30 C5 8

25- -

8 25

$6 h

20- -

20 2

8.

E 15-j

{

Delta T @l/4T Location 15 4

10--

10 5- -

S 0

0 1

2 3

4 5

6 7

8 9

10 11 0

Time (houn)

Figure 2 Variation of Metal Temp. Difference with Time For Zion Units 1 & 2 Using a 60 Deg. F per Hour Heatup Rate

'f 6-4 i

(

.. - _ -.. ~.. - - -

.o i

1 j

Table 1: Zion Units 1 & 2 Temperature Variations For 60 *F per floar lleatup Rate i

Time Time Water Temp, 1/4T Temp. 3/4T Temp. AT@l/4T AT@3/4T (sec.)

(hours)

('F)

.('F)

('F)

('F)

( F) 300 0.083 75 71 70 4

5 600 0.167 80 75 71-5 9-900 0.250 85 78 72 7

13 1200 0.333 90 82 74 8

16 1500-

-0.417 95 86 77 9

18 4

I800 0.500 100 90 80 10 20 2100 0.583 105 :

94 84 11 21-2400 0.667 110 99 87-11 23 2700 0.750 115 103 91 12 24 3000 0.833 120 108 95 12.

25 3300 0.917 125 113 100 12 25 3600 1.000 130 117 104 13 26 3900 1.083 135 122 108 13 27 4

4200 1.167 140-127.

.I13 13 27' 4500 1.250 145 132 118 13-27 4800 1.333 150 137 122 13 28 l

5100-1.417 155 142 127

=13 28 5400 1.500 160-146 132 14 -

28 5700 1.583.

165 151 137-14 28:

6000-1.667 170-156

-141-14 29 6300---

1.750-175 161 146 14 29 6600~

1.833 180 166 151

'14 29 6900--

1.917 185

-171 156

-14 29 7200 2.000 190 176 161 14 29 7500 2.083-195 181 166-14 -

29' 1

P

\\.

7 I

.. _. m. _;.

- =.. -

_.. ~,. -, _

i t

Table 1: Zion Units 1 & 2 Temperature Variations For 6a 'F per llour ifcatup Rate (Cont.)

Time Time Water Temp.

1/4T Temp. 3/4T Temp. AT @l/4T AT @3/4T (sec.)

(houn)

('F)

( F)

( F)

( F)

( F) 3 7800 2.167 200 186 170 14 30 8100 2.250 205 191 175 14 30 8400 2.333 210 196 180 14 30 8700 2.417 215 201 185 14 30 e

9000 2.500 2?0 206 190 14 30 9300 2.583 225 211 195 14 30 9600 2.667 230 216 200 14 30 9900 2.750 235 220 205 15 30 10200 2.833 240 225 210 15 30 10500 2.917 245 230 214 15 31 10800 3.000 250 235 219 15 31 11100 3.083 255 240 224 15 31

!!400 3.167 260 245 229 15 31 4

11700 3.250 2d5 250 234 15 31 12000 3.333 270 255 239 15 31 12300 3.417 275 260 2 14 15 31 12600 3.500 280 265 249 15 31 12900 3.583 285 270 254 15 31 13200 3.667 290 275 259 15 31 13500 3.750 295 280 263 15 32 13800 3.333 300 285 268 15 32 14100 3.917 305 290 273 15 32 14400 4.000 310 295 273 15 32 14700 4.053 315 300 283 15 32 15000 4.167 320 305 288 15 32 15300 4.250 325 310 293 15 32 8-

.x. - -

L I

Table 1: Zion Units 1 & 2 Temperature Variations For 60 F per flour lleatup Rate (Cont.)

e i

Time Time Water Temp.

1/4T Temp. 3/4T Temp. AT @l/4T AT@3/4T

[

(sec.)

(hours)

('F)

( F)

( F)

( F)

( F)

)

15600 4.333 330 315 298 15-32 15900 4.417 335 320 303

-15 32 1

{

16200 4.500 340 324 308 16 32 j

16500 4.583 345 329 312 16 33 J

16800 4.667-350 334 317 16 33 i

17100 4.750 355 339 322 16 33 17400 4.8?3 360 344 327 16 33'

~

t 17700 4.917 365 349 332 16 33 i

18000-5.000 370 354

-337 16 33 18300 5.0S3 375 359 342 16 33 9

i 18600 5.167 380 364 347 16 33 18900 5.250 385 369 352 16 33 19200 5.333 390 374 357 16 33 19500 5.417 395 379 361 16 34 i

19800 5.500 400 384 366 16 34

[.

20100 5.583 -

405 389 371' 16-34 20400 5.667 410 394 376-16-34 j

20700 5.750 415 399 381 16-34 i

21000 5.833 420-404-386=

16 34-21300 5.917-425 409 391 16'

~ 34 :.

1 l-21600 6.000 430-414-396-16 34

(

21900 6.083 435 419-401 16 34 1-1 22200 6.167_

440 423

.405-17 35 l

22500 6.250 445 428 410-17-35 j-22800.

6.333 450-433 415 17-35 l.

23100

- 6.417 455 438 420-17 35 9

l

Table 1: Zion Units 1 & 2 Temperature Variations For 60 'F per llour IIcatup Rate (Cont.)

Time Time Water Temp.

1/4T Te_mp. 3/4T Temp.

AT@l/4T AT@3/4T (sec.)

(houn)

('F)

('F)

( F)

( F)

('F) 23400 6.500 460 443 425 17 35 23700 6.583 465 448 430 17

.35 24000 6.667 470 453 435 17 35 24300 6.750 475 458 b

17 35 24600 6.833 480 463 445

-17 35 24900 6.917 485 468

/30 17 35 25200 7.000 490 473 454 17 36 25500 7.083 495 478 459 17-36

' ~ X) 7.167 500 483 464 17.

36 0

7.250 505 488 469 17 36

,00 7.333 510 493 474 17 36 26700 7.417 515 498 479 17 36 27000 7.500 520 503 484 17 36 27300 7.583 525 508 489 17.

36 27600 7.667 530 513 494 17 36-i 27900 7.750 535 517-498

-18 37 28200 7.833 540

-522 503 18 37 i

28500 7.917 545 527 508 18-37-28800 8.000 550 532 513-18 37 29100 8.083 550 536 518 14:

32 29400- - 8.167 550 538 522-l'2 - 29700 8.250 550 540 526 10 24 30000 8.333 550 541 530 9

20' 30300

.L4 l'.

550 543 533

_7 17 30:G 150 550' 544-535 6

15 30900 S.583 550 544 537 6

13.

)

- 10

m.

1 i

i Table 1: Zion Units 1 & 2 Temperature Variations For 60 F per llour IIeatup Rate (Cont.)

l Time Time Water Temp.

1/4T Temp. 3/4T Temp.

AT @l/4T AT @3/4T (sec.)

(hours)

( F)

(oF)

(*F)

(*F)

('F) 31200 8.667 550 545 539 5

11

)

i 31500 8.750 550 546 540 4

10 i

31800 8.833 550 547 542 3

8

{

32100 8.917 550 547 543 3

7 f

32400 9.000 550 547 544 3

6 32700 9.083 550 548 545 2

5 33000 9.167 550 548 546 2

4 L

33300 9.250 550 548 546 2

4 a

33600 9.333 550 549

$d7 1

3 33900 9.417 550 549 547 1

3 34200 9.500 550 549 548 1

2-34500 9.583 550 549 548 1

2 34800 9.667 550 549 548 1

2

'~

35100 9.750 550 549 548.

I 2

i 35400 9.833 550 549 549 1

1 35700 9.917 550 550 549 0

1 36000 10.000 550' 550 549 0

1 l

36300 10.083 550 550-549-0 1

~

,_.J.

. _. +. - +,.... - -

-,., - ~

.....r~..,_.,_,..

In order to determine which Appendix 0 controlling location is controlling for a given rcac:or vessel fluid temperature during a heatup process, the following table was constructed. Table 2 provides the Zion Unit I controlling locations for a given reactor vessel fluid temperatwe for 14,20,25 and 32 EFPY using 20,40,60, and 100 *F per hour heatup rates. The temperature ranges in Table 2 reflect which controlling location has the limiting allowable pressure dunng the reactor vessel heatup process. Note, this table can b, generated with or without instrumentation errer margins without effecting the end result of the enable temperature set point calcolation.

Table 2: Zion Unit 1 Temperature Ranges for Appendix G Controlling locations (M1th Instrumentation Error Margins)

Finite Temp. Range For Temp; Range For Temp. Range For ticatup Rate - 3/4T Contro!!ing Loc.

1/4T Connolling Loc.

1/4T Controlling Loc.

EFPY Under Steady State Conditions

(*F/ Fir) _

(*F)

(*F) *

' (*F) '

14

'20 95s T s 115 120 s T s 300 303 s T s550 40 90 s T s 200 -

205 s T s 305-310s Ts550 60 90 s T s 275 -

280s Ts305 310s Ts550 100 95 s T s 385 390s Ts550 20 20 90s T s 130 135 s T s 315 320 s Ts 550 40 90 s T s 210 215 s T:: 320 325s T s550 60 90 s T s 280 -

285s Ts320 325 s Ts 550 100-90s T s390 395s T s550 25 20 90s T s135 140 s T s 325 330s T s550 40 90 s T s 215 220s T s330 335 s T s 550 60 90 s T s 290 295r T s330 335s T s550 100=

90 s T s 400 405s T s550-32 20 90 s T s 145 150 sT s 335

'340s Ts550 40 90 s Ts 225 230 s T s 340 345s Ts550 60 90 s T s 295-

.300s Ts340 345s Ts550 100 90 s T s 410 415 s T s550

  • For this temp. range, the steady uate condition provided the limiting allowable pressure in the Appendix G calculations.

12

d The OPERLIM computer code (6) was used to calculate the temperature values induced in l

the reactor vessel beltline for the 60 F per hou: heatup process. The calculation procedures used by OPERLIM comply with the rules outlined in ASME Code,Section III, Appendix GIS as required by the enteria of Appendix G to 10CFR Part 50W.

Using Tables 1 and 2, the enable temperature: calculations for 32 EFPY using a 60 F per hour heatup rate are as follows:

o the RTsor values for the limiting heltline region are 242.88 F and 194.10 F j

for the 1/4T and 3/4T locations, respectively.

o From Table 2, the Appendix G controlling location temperature ranges are (90 F s T s 295 F) for the 3/4T position, (300 'F s T s 340 F) for the 1/4T position under steady-state conditions, ami(345 F s T s 550 F) for the 1/4T position.

l 4

i For the temperature range (90 '!F s T s 295 F), the 3/4T position controls, therefore, ET. RTuo7 + 90* F + aT l

ET = 194.10 F + 90 "F + 32 F = 316.10 *F where. AT = 32 F rr: presents the metal temperature difference 4

(Tnui,-T,'d7) when the 3/4T controlling locanon reaches a temperature g

value of 284 F(i.e., RTuor + 90*F).

4 For the temperature range (300 F s T s 340 F), the 1/4T position controls unde' steady-state conditions, therefore, d

ET - RTso7+ 90*F "T = 242.88 F + 90 F = 332.88 *F Note, the metal temperature difference, AT, is excluded due to steady-state conditions.

2 For the tempeuture ra ge (345 F s T s 550 F), the 1/4Tposition controls, therefore,-

ET = RTuo74 90*F + AT ET = 242.88 F + 90 F + 16 F = 348.88 F d

where, AT = 16 'F represents the metal temperature diffecact (Tnai,-T(t,'d7) when the 1/4T concolling location reaches a temperature value of 333 F(i.e., RTuo7 + 90 F). '

4

+

3 Taking into account the cooldown rates used in WCAP-13406 for 32 EFPY (20,40,60, and 100 F per hour), the ET calculations are as follows.

For Cooldown, ET - RTuo7+ 90'F + AT at the 1/4T position.

.L Using 20 'F/Hr cooldown rate:

ET = 242.88 *F + 90 F - 5 'F = 327.88 F where, AT = -5 F represents the metal temperature difference (Tno,,-T a 7) when the 1 MT controlling location reaches a temperature o

value of 333,F.

Using 40 %r cooldown rate:

j ET = 242.88 *F + 90 *F - 11 F = 321.88 F

~

where, AT = -11 F represents the metal temperature difference (Tnaio-T,'d7) when the 1/4T controlling location reaches a temperature n

value of 333 E Using 60 F/lir cooldown rate:

ET = 242.88 F + 90 F - 16 F = 316.88 F where, AT = -16 'F represents the metal temperature difference (T

i,-T""d r: when the 1/4T controlling loca. tion reaches a temperature n

value of 333 E 4

Using 100 F/Hr cooldown rate:

ET = 242.88 F + 90 F - 27 F = 305.88 F where, AT = -27 'F represents the metal temperature difference (T,i,-T

,'d ) when the 1/4T controlling location reaches a temperature ri n 7 value of 333 E The results vf this example show that the bounding enable temperature set point occurs at the 1/4T controlling location for 32 EFPY using a 60 F per hour heatup rate. The value calculated,348.88 F, supports up to 32 EFPY and heatup rates between 0 F and 60 F per hour In addition, this value defines the temperature range, (70 F < T < 348.88 F), in

which the LTOPS system must be tumed on during reactor vessel heatup and cooldown events to ensure safe operating conditions at low temperatures.

In conclusion, the enable temperature set moint must be calculated for the largest possible plant heatup rate using the equation, ET - RTuo7 + 90'F + 4T. This will ensure the

' LTOPS system operates within the required temperature range which prevents the reactor vessel from exceeding prenure-temperature limitations at low temperatures.

Appendix A contains a range of RT o7 + 90'F values at the 1/4T location for a given s

EFPY for Zion Units 1 & 2. Dese values can be used along with metal temperature differences provided in Table 1 to calculate the enable temperature set point. ;

l l

v

5. REFERENCES 1.

WCAP-13406. "Heatup and Cooldown Limit Curves for Nmmal Operation For Zion Units 1 & 2", bl. A. Ramirez, et al., July 1992.

2.

NUREG-0800,"Overpressurization Protection of Pressurized Water Reactors While Operating at Low Temperatures", Branch Technical Position RSB 5 2, Chapter 5.2.2 in Standard Review Plan, Revision 1, November 1988.

3. Code of Federal Regulations,10 CFR Part 50, Appendix G," Fracture Toughness Requirements", U.S. Nuclear Regulatory Commission, Washington, D.C., Federal Register, Vol. 48 No.104, hiay 27,1983.

4.

Appendix G to the ash 1E Boiler & Pressure Vessel Code,Section III," Protection Against Nonductile Failure", American Society of hiechanical Engineers, New Yerk,1989 Edition.

5. WCAP-7924-A," Basis For Heatup And Cooldown Lunit Curves", W. S.

Hazelton, et al, April 1975.

6. WCAP-9186," Documentation And Verification Of The OPERLlhi Computer Code", O. hieeuwis, et al August 1977.

i i-l l

l l

i-t 4

i 1

i 4

4 e

4

?

4 4

APPENDIX A Data Points and Graphs-i RTNDT vs EFPY for 1/4T Location 4-a 4

5 t

+

5 4

i a

d h

I e

d a

e y,-

7, y-wg.

---r re-rre -

f y-e r r e

~.-

4-L Table A1: RTNDT' @l!4T vs EFPY For Zion Units 1 & 2 f~

Zion Unit 1-Zion Unit 2 p

Cire. Weld WF-70 Cire. Weld SA 1769 -

i EFPY RTNDT @l/4T RTNDT @l/4T + 90 RTNDT@l/4T RTNDT @l/4T + 90

{

(Years)

( F)-

( F)

( F)

( F)

~

10 -

193 283

-184 274 I

i 12 200 290 192 282 l

14 206 296 199 289 j

16 212-302 205.

295-18 217'-

307.

211 301-

[

20-222 312-216 3%

j-22 226 316

'221 311 4

j 24 230 320 225 315 25 232-322 227-317-26 233 323-

-229 319 78 237 327 233 323

~

r j_

30.

240

- 330 237 327 32-243.

333

- 240' 330 34

'246-

. 336

- 243-333 36

=248 338'.

246 336

{;

.38 251 341-249:

339 f

f-40 253:

343 251 341

!~

42 255

.345-

' 2541 344 L-44 257-

. 347-256 L346 i

46

-259 349-259

349-48' 261

. 351

- 261

~351 f

i i

i i

a A1 1, :

+

1 Y w

  • v

---r-~*e e s-nem

-rm'w mwr yw - e two w're-

"'erw r

-w.res me,tir ee, am - re ww erssoo'm

  • N e' + w' rw -e *
  • r"' es-W a've e n *- Pr*W

+"

k t-.

1 I

6-4 i -

'0 5

10-15 20 25 30 35-40-45 50 375 j

j j

j j

j j

j 375 e.

350- -

f.-

350 a

4 i

'i 325- -

325 1

i i

- RTNDT + 90 i

g 30o.

300 i

8 1

o H-

{

275- --

275 i

4 9

i C

z.

250- -

250 i

225-c-

225 RTNDT

~200 200 I

I

.I i

1 l'

I I

t 175 175 1

0 5

1'O 1'5 20 -

2'5 30-35 40 -

45 50-

=

8 U

EFPY (Yems) i -;

4 Figure Al i

j

- RTNDT @1/4T vs EFPY For Zion-Unit 1 e

A2:

._-...,.a

.__a.-,._.--.__.,....,_..,_._a_...-.

ca... _,

0 10 15 20 25 45 2

375 375 350--

y-350 325- -

325 C

300-RTNDT + 90 300 E

l-3 275--

275 HC he 250- -

250 225- -

225 RTNDT 200- -

200 175 175 J

5 10 15 20 25 30 35 40 45 50 EFPY (Years)

Figure A2 RTNDT @1/4T vs EFPY For Zion Unit 2 A3

q I

1

(

1 ENCLOSURE 6 PRESSURE AND TEMPERATURE LIMITS REPORT i

t 5

4 l

l 4

4

- 20SR-242(51)

I

s.

T f'

COMMONHEALTH EDISON COMPANY ZION UNITS 1 & 2 j.-

t PRESSURE AND TEMPERATURE LIMITS REPORT-REVISION O 4

4 2

i i

e 1

a d

4 i

i p

l-f 5

]

ZOSR-242(52)

.i.

1.0 Pressure and Temperature Limits

?

This Pressure and Temperature Limits Report for Zion Units 1 and 2 has been prepared in accordance with the requirements.of Technical i

Specification Section16.6.1.G.

The pressure and temperatute itmits have been developed using the methodology described in the reference.

The following pressure and temperature. limits are included in this report:

1)

Allowable Heatup and Cooldown Rates 1

2)

Reactor Coolant System Heatup Limitations Curves 4

3)

Reactor Coolant System Cooldown Limitations Curves l

4)

Inservice Leak and Hydrostatic Test Limitations 2.0 Reference 1.

Westinghouse Electric Corporation, Topical Report WCAP-13406, "Heatup 2

and Cooldown Limit Curves for Normal Operation for-Zion Units 1 & 2",

1 July 1992, i

f I'

t t

i i

L Page 2 of 6 ZOSR-242(53) i

ALLOHABLE HEATUP AND C00LDOWN RATES NQIE These limits are referred to by Technical Specification 3.3.2.A.

a.

A maximum heatup rate of 20*F/hr applicable up to and including 180'F RCS indicated temperature. A maximum heatup rate of 60'F/hr applicable for RCS indicated terceratures greater than 180*F.

b.

A maximum cocidown of 100*F in any 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> period.

c.

A maximum temperature change of 1 10*F in any I hour period during inservice hydrostatic and leak testing operations above the heatup and cooldown limit curves.

1 a

ZOSR-242(54)

Lh _.

REACTOR COOLANT SYSTEM HEA10P LIMITATIONS 2500

4 i

i i i i 7;m 5

ii i

i i

I h

I LEAX TEST LIMIT I

li 2250

[

[j

_f' l

i i

lt I

i If I

I 2000

/

I i

1 I

UNACCEPTABLE'

/

/

1750 OPERATION

/

/

/

/

I

/

)

)

l 2 1500 l

l G

ACCEPTABLE S

/

4/

OPERATION g 1250 HEATUP RATES'

/

[

j UP TO

/

a

20*F/HR w

E 1000

/

l

/

i i

c i

/

W j

./

e 750 l

l

/

i

! /

CRITICALITY LIMIT BASED ON INSERVICE

/

500 l

f HYDR 0 STATIC TEST

~

TEMPERATURE (352*F)

-m l

FOR THE SERVICE i

PERIO0 UP TO 14 EFPY 250 l

l l

l i

i 4

t i

I I

l l

i 6

I 0O 50 100 150 200 230 300 350 400 450 500 INDICATED TEWPERATURE (DEG.F)

NQIE These curves are referred to by Technical Specification 3.3.2.A.

Applicable to Zion Units 1 and 2 for up to 14 EFPY and heatup rates up to 20*F/hr.

Curves contain margins of 10*F and 60 psig for instrumentation errors.

ZO5R-242(55)

1 p-R_EACTOR C00i. ANT SYSTEM HEATUP) LIMITATIONS 2500 i

i i

7,cs 3

5 i

i a-i i

ei e

4-I i

i 13 1

1 r

f 2250

-LEAK TEST LIMIT ~

,I j

l i

i I

.I i

i e

I I

I i

j i

I I

l

{--

I i

i 2000 1

1 4

1 I

i i

+

i i

i I

J i

it 1

1750 UNACCEPTABLE

'/

/

OPERATION i

ACCEPTABLE

/

,/

OPERATION

~

G 1500 f

f L-r r

(

/

/

i g

v

/

/

w 1250 l

HEATUP RATES

/

[

i 5

UP TO

/

i

[

{

l

- 60*F/HR

/'

E 10C0 l

j

/

/

o I

t i

j i

w h

s t

I )

CRITICALITY LIMIT-P O

150 i

E l

l l

/

l BASED ON INSEP.VICE i

1-l HYDROSTATIC TEST

[

TEMPERATURE (352'F)

~

/

i 500 l

{

FOR THE SERVICE PERIOD UP TO~14 EFPY

/

i-3 i

i l

l

-E 250 i

i i

i i

e i

i i

4 t

i I

I-0O

$0 100 150 200 250 300-350-400 450.

)<

INDICATED TEWPERATURE (DEG.F)

EKE

-These curves are referred to by_ Technical Specification-

I

'3 3;2.A.

Applicable to Zion: Unit's 1~and 2.for up to'14 EFPY and heatup: rates up to-60*F/hr. -Curves:contain margins of 10*F and 60 psig for instrumentation errors.

i 3'

2 l

D Page 5 of 6 ZOSR-242(56)

Ie

- -.. ~

.-.a...

z-

.. l

REACTOR COOLANT SYSTEM C00LDOWN LIMITATIONS F?

i l!' l l j !; i !ll l4H

,,i i

l

F 2

i i

> i i

,i i i

i i

~17 i

i.

i mean i..

i F

i i i i !

< i 1

i i!

i f

i

.i.

i <

i i

l i

i i i i

f i

i 4! I i+! i

.I

! i !

i i i i i ii i i

  • I I!

i li i i i i i i !

I *ii i 5

  • i

+

! i i

e

+

! i' i i

I' ie r

' ' i i '

' ' 'I i

' ' i '

006*

'i j[l'll l HH l

l' l!

i i

i i,

y1 i i ii.

7

>ii ;

i UNACCEPTARLE 1 i i i n5c OPERAT!DN

/

.l, li,t

'H/! l u i

, i i ill!

1

, i i i

e i

q

, i i j

, ii I i I i fj i

,j'I i

> a i

i 3

i i i. i !/ 3 i i

, i +

,cu g

i i

ii

'l!u i

3

' i o

! t i/

I i!

!f

, i a

  • i 3

/

t f I

'I

+

i k

k I

I

[1 I

! k

}

! I g

j

. I I

5 I

/l i i ! I ii g

3 r.

! r i

i j

l-i f,

i i!'

l

/_l. ;,l';

ACCEPTABLE l,!,

m t,

i i 10G l

l l

l l'.

ll l / -- JyA OPERATION gg o

4 i

i i,

i Or ii iiii

!i i

i i i

ii!

w 1

y-l

i

, 'I 75C I '

L- ' '

'I u

i <

f i i iiii i j

. i i

!i i

/U /.

i i i i i.I!

!i I

i i i i

- 1 i

I

! ! i /MI I

Ii i

i!!

J

{COOLDOWNRATE4 4

i. mq i

i

'i i MWD I~'

4 r" F 'F/HR

,i

! i!

! ! i' I '

sA:

-pff_-fo e'-7 ?

i.

i 1.

.1 i, i,, i

-~

0 i+-

i ;

; ij ;

e 4-20 T' "D __- w"r !

~~

V i

i f

A i

i ji 40 i,

,I i+3 1

' $ g.

L,_

,,,,,, f i

i y

i.A j

_a_._

60 uT i

I t

I' Y~M T li l

lil l

. i i

RO t,'!

ll i

i i

r i ! i i

50

'00 150 200

50 3b0 350 460 450 500 INDICATED TcWPERATURE (DEG.F) 1 4

4 E01E These curves are refe ed to by Technical Specification 3.3.2.A.

(

Applicable to Zion Units 1 and 2 for up to 14 EFPY and cooldown rates up to 100*F/hr.

Curves contain margins of 10*F and 60 psig for instrumentation errors.

Page 6 of 6 ZOSR-242(57)

Retrieved from "https://kanterella.com/w/index.php?title=ML20127C666&oldid=4269763"