ML20211E058

Effect of Delayed Firewater Cooldown W/Loss of Liner Cooling on Pcrv Temps

ML20211E058
Person / Time
Site:	Fort Saint Vrain
Issue date:	09/30/1986
From:	Betts W GENERAL ATOMICS (FORMERLY GA TECHNOLOGIES, INC./GENER
To:
Shared Package
ML20211D893	List: ML20211D890 ML20211D992 ML20211E058 ML20211E084 ML20211E110
References
909041, TAC-63576, NUDOCS 8702240222
Download: ML20211E058 (19)

Text

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ISSUE

SUMMARY

TITLE THE EFFECT OF DELAYED FIREWATER C00LDOWN OR&D 2 O OV & S APPROVAL LEVEL WITH LOSS OF LINER COOLING ON PCRV TEMDERATfM M g ESIGN OlSCIFLINE SY3 TEM 00C, TYPE PROJECT M (DOCUMENT NO. ISSUE N0/LTR.

11 CFL 1900 E 909041 N/c QUALITY ASSURANCE LEVEL SAFETY CLASSIFICATION SEISMIC CATEGORY ELECTRICAL CLAS$1FICATl0N 1 FSV-1 FSV-1 N/A APPROVAL PREPARED ISSUE ISSUE DATE gy FUN 0 LNG APPLICARLE DESCRIFTION/

ENGINEERING OA N NO.

N PROJECT PROJECT

-n .A ./ m Qf AV)($ k * -

N/C SEP 3 01966 W.S.Betts C. cDonald Q. K--

J.KeEedy

! init al Release:

2970503

.Pettycori CONTINUE ON GA FORM 14851 NEXTINDENTURED DOCUMENTS Issue Sumary 1 = 1 P.O. N6082 Text 2- 5 = 4 Calc. Rev. Rpt. 6 = 1 App. A A A-13 = 13 Total pages 19 B702240222 870217 PDR ADOCK 05000267 p PDR REV SH ,

REV SH 29 30 31 32 33 34 34 38 37 3 3 40 41 42 43 44 44 47 44 44 48 54 51 52 53 54 55 56 REV SH 1 2 3 4 5 6 7 8 8 10 11 12 13 14 18 14 17 18 18 20 21l22 23 l 24 25 l 28 l 27 l 28 GLASNAPP.V4 (6) l PAGE 1 0F 19

e 90904' N/0 e.

CONTENTS SUtWARY.......................................................... 3 INTRODUCTION ..................................................... 3 D I S CUS S I O N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 . . . . . . . . .

RE FE REN C E S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 . . . . . . .

APPENDIX A.

BASIS OF MAXI!1]M TEMPERATURE ESTIMATE FOR THE PCRV A-1 ..

4 Page 2

e l 90900 N/C l 0

SUMMARY

This document presents the results of a study to determine the effect on the PCRV of not having liner cooling available during a delayed cooldown of the Fort St. Vrain plant using boosted firewater to drive a circulator and to remove the residual heat from the reactor.

This study concludes that the PCRV temperatures stay well within ASME ,

Code allowables for faulted conditions. This calculation does not apply  !

to the core support floor which is the subject of a separate study. l INTRODUCTION i

The updated FSAR for the Fort St. Vrain plant (Ref.1) discusses in '

Section 14.4.2.2 the matter of cooling with one water-turbine driven circulator powered by boosted pressure firewater following a 1.5-hour delay. This event has been evaluated (Ref. 2) if the liner cooling water system were inoperative during this event. This evaluation showed that the lack of liner cooling, even for an indefinitely long time, has no significant effect on either orifice valve temperatures or on maximum fuel temperature. This study addresses the effect of the above-defined accident on the PCRV.

DISCUSSION This study evaluates the ability of the PCRV to remain within ASME Code temperature limits during a reactor cooldown using the firewater system (as defined in Ref. 2) without liner cooling. This is considered a faulted condition which is being evaluated to ensure the health and safety of the public are protected.

The ASME Code temperature allowables for the PCRV for a faulted event are (per Ref. 3):

Temperature Limits, 'F Bulk Concrete Unpressurized condition 400 t

Pressurized condition 600 Analysis results (Ref. 2) have shown that during the event the top head liner reaches a maximum temperature of 239'F. This value which is shown in Table 1 occurs 2.05 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> into the transient and results mainly from the high temperatures during the first 1.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> when there was no primary coolant flow.

After 1.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> the analysis reported in Ref. 2 predicts a primary coolant flow rate of approximately 1 3 x 10' lb/h (approximately 3 75 of full flow rate) and a temperature of 120*F as it exits the circult. tor.

A conservative analysis given in Appendix A shows that for this condi-tion the PCRV temperature will not exceed the 239'T anywhere along its side wall or bottom head.

Pase 3

90904' N/0

TABLE 1 Case FSV4, no liner cooling 175 psig firewater, delayed 1.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> Core orificed for 250CP Temperatures (*)F Oas in Time Coverplate Liner Upper Plenum 4 - ..

0.00 770. 129 773 0.02 765. 131. 776.

0.05 75 7. 136. 783 0.10 752. 141. 789.

0.16 750, 146, 797.

0.22 752. 151. 80 6.

0.30 760. 157. 824.

0 39 771, 162. 846.

0.47 785. 167. 870.

0.95 902. 192. 1035.

1 36 1012. 213 1171.

1.49 1047. 218. 1214 1.53 903 223 640.

1.70 485. 232. - 261.

i 1.87 321, 237. 176.

2.05 262. 239. 156, 2.45 220. 236. 140.

3.19 187. 221. 123.

3.71 182. 21 5. 123 3 99 180. 208. 123 4.79 178. 198. 124 5.99 187. 189. 131.

7.19 203. 183 136.

8.79 21 8, 180. 136.

11.59 223. 179. 135.

i

, 13.99 21 9. 179. 134 19.99 204 177. 131.

l Page 4 l

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90904' N/~

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This is well within the 600*F code allowable for a pressurized i faulttd conditions. This implies that the PCRV liner could withstand  !

i more severe conditions. It is estimated (in Appendix A) that even if primary coolant epiting the circulator reached a temperature (Tg) of  ;

400'F the ASE Code allowable for the PCEV 'would.aot be exceeded as along asithe primary coolant flow rate exceeded 2% of full flow rate.

It is likely that even higher values of Tg could be shown to be acceptable. However, this would require more detailed kne'viedge of the exact conditions together with a more detailed anal;' sis.

mThe:1bove conclusions do not apply to the concrete core support floof, which is being evaluated in another study. ,

FCFENENCES

s. l 1.

Fort St. Vrain Nuclear Power Generation'3tation Updated final Safety Analysis . Report, Revision 4.

1

2. 'Gulde, R.,

"FSV: Delayed Firewater Cooldown; Effect of Liner

Cooling on Oritice Valve ' Temperatures," GA Doc. 907935 A.

February 20, 1986.

+ '

3 "ASME Boiler and Pressure Vessel Code,Section III, Division 2 "

4 Table G3-3430-1. '

k s ,

4 5

s e

\

Page 5

, GA1543tREV. I1/908 CALCULATION REVIEW REPORT l TITLE: y/,g g//cef o pg/syd/ httwddi Ce,//stuv1 w'D APPROVAL LEVEL '

[#SS * + int et, *N Y&A V TdWPtTNWI OAL LEVEL I nlSCIPLINE SYSTEM 00 C. TYPE PROJECT 00CUMENT NO. ISSUE NO LTR I M ll C f f., I 90 0 90 99 Y/ Y/c INDEPENDENT REVIEWER:

NAME N' $. YJ"D fM! d ORGANIZATION Code OE_r rad ,

1 REVIEWER SELECTION APPROVAL: BR MGR

\

DATE [b

,. REVIEW METHOD: YES NO ERROR DETECTED ARITHMETIC CHECX p.)GIC CHECK Y

AL'ESNATE METHOD USED X "

0$T talCK PERFORMED I #

COMPUTER PROGRAM USED I ~

REMARXS: (ATTACH LIST OF DOCUMENTS USED IN REVIEW)

OALCULATIONS FOUND TO 8E VAll0 AND CONCLUSIONS TO 8E CORRECT:

INDEPENDENT REVIEWER DATE 9 2G FZ SIGNATURE Page 6

9C904* N/0 APPENDIX A BASIS OF MAXIMUM TEMPERATUARE ESTIMATES FOR THE PCRV This appendix conservatively estimates the maximum temperature of the PCRV during a delayed firewater cooldown with no liner cooling.

This is a faulted condition.

During the initial 1-1/2 hours with no forced circulation of the primary coolant, hot helium rises to the upper plenum located above the active core shown in Fig. 1. During this time the maximum temperature of the coverplate and PCRV liner occurs in the upper plenum region.

These temperatures have been predicted and the results documented in Ref. 1. The results show that at 1.49 hours5.671296e-4 days <br />0.0136 hours <br />8.101852e-5 weeks <br />1.86445e-5 months <br /> the coverplate reached 1047'F while the liner increased to 218'F. Within the next hour the coverplate temperature decreased to approximately 220'F. During this time the PCRV liner reached a maximum value of 239'F. These are shown in Table 1 of the main text.

After forced circulation is initiated at 1.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />, the highest primary coolant temperatures are in the lower plenum and in the inlet ducts to the steam generators. These temperatures lead to high temperattres on the core support floor which is the subject of another study.

An analyses has been done (Ref.1) which predicts that after the 1.5-hour delay in forced circulation the primary coolant exits the circulator at a temperature (Tg) of approximately 120'F with a flow rate (m) of over 21 of the total circulator flow at 100% power. This primary coolant flowing over the PCRV themal barrier helps insure that the PCRV does not exceed the ASE Code temperature allowable of 600'F for a pressurized faulted condition.

The following analysis estimates conservatively high values for the maximum PCRV temperature for selected conditions. Some of the conserva-tive assumptions are:

! 1. After the 1.5-hour delay to initiate forced circulation, the l PCRV temperature reaches the toepcrature of the themal barrier coverplates which protect the PCRV.

2. The temperatures of the coverplate are predicted o Nerglecting heat flow from the coverplate to the PCRV.

o Asstming steady state conditions at the conditions with the highest boundary temperatures.

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9C9Ca' N/C Estimate of Temperature of Coverplate on PCRV Sidewall Basis: Delayed Firewater Cooldown RECA Analysis Results (Ref. ')

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m = primary coolant flow rate = 1 3 x 10' lb/h (af ter 1/2 h)

= 36 lb/s Tg = temperature of primary coolant gas = 120'F However, to be conservative, set Tg - 200*F for first set of of calculations d = hydraulic diameter of annulus = 2(r. - r ) = 2.71 f t A = flow area = w(ra.pa) = 124 f ta p - pressure of primary coolant - 705 psi Page A-3

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90900 N/C RECA run LT0592 which supports Ref.1 is the basis for the value of a and the temperature (T i ) of the side reflecter at r . The maximum salue of T occurred at elevation F5 or SB as shown in Fig. 4 (from i Xef. 3). The values changed with time (t) as shown belcw:

Time Max T (*F) i 5 (h) 5 SB lb/h x 108

0. 1104 1088 0.165 1105 1090 0.495 1110 1093 0.901 1115 1097 1.47 1121 1103 2.23 1130 1110 1.16 3.63 1127 1120 1.27 5*.31 1105 1120 1 31 6.99 1079 1107 Mg, 8.67 1053 1088 10 35 1029 1065 12.03 1004 1040 '

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Fig. 4 Schematic elevation view of a core model radial regian l showing typical axial subdivision used in the PCRV top head and liner cooling simulations for FSV Page A-7

90904' N/

Conservatively neglect heat flow to liner 1/R = R /r, - ri) kg = thermal conouctivity of reflector graphite - 25 Stu/h-f t-*F 1/Ri - 25/1.82 = 14 + R = 0.071 Estimate R, = (r, - r,)/k, k, = thermal conductivity of 2-1/4 Cr-1 Mo k, = 18.91 + 6 35 x 10-3 T - 4.1 x to T2 Stu/h-f t-* F T = temperature, 'R (per Ref. 4)

Based on T = 800*F = 1266*R

• k, = 20.4 Stu/h-ft-*F R, = 0.011 = 1/91 Estimate R. = 1/hp hp =

F a(T] - T*)/(T - T.)

Assume F = (1/c, + 1/c. - 1) ~I = 0.667

~

a = 0.1713 x 10

• Based on T, = 800*F = 1260*R T. - 400*F = 860'R Estimate convection resistances R. and R.

Assume T, = 800*F T. - 400' Therefore, gas propertise based on Tg =

(800 + 200)/2 = 500*F = 960*R Tg =

(400 + 200)/2 = 300*F = 760*R For helium

~

u = 1.86 x 10 ' T

• lb/ f t-s k = 1.29 x 10 s T

• I S tu/ h-f t-* F 1

Page A-8

9090a* v:

~

u, = 1.98 x 10 '

u. = 1.69 x 10 5 k, = 0.132

k. - 0.113 Re = = 36 lb/s x 2.71 ft , 0.787 Au 124 fta xu u Re, = 3.97 x 10' Re. - 4.65 x 10' Assuming forced convection Nu = 0.022 Pr

• 0 Re0 .8 = 0.018 Re

• Nu = 5

• h = 0.018 Rec .8 k k 2.71 h, = 4. 2 Stu/h-f t R. = 1/h,

h. - 4.1 Btu /h-ft8 R = 1/h.

These h values are low for pressurized helita since expect natural convection h to be larger. Now estimate natural convection h.

Or U AT L' v2 g , 32.2 p*

va RS T' u 8 R = 386 ft-lb/lbe-*R R , 32.2 x (705 x 144)*

v* 386* T' u*

T g* = 960*R [U\='6.4x10*

_ (98),

u, = 1.98 x 10

• T, = 760*R

[(M\v ). = 17.8 x 10' l

8

u. = 1.69 x 10

• Page A-9

909C; N/

Based on L = 8 f t Gr, = 6.4 x 10' (600) 88 = 2 x 10 8 1 Gr. = 17.8 x 10* (200) 88 - 2 x 1058 c 3

= 0.13 (Cr Pr) = 1454 K

k, = 0.132 Stu/h-f t-*F -h c, = 24 Btu /h-f t *-

• F - R. = 1/24

k. - 0.113 -Ec, = 21 R, = 1/21 Since (see Ref. 5)

Gr 1 3 x 1088

, ), , ,

Re8 (1.8 x 10')* .

this indicates natural convection is controlling. ,

Note buoyancy effect and the free streas velocity are going in the same direction since plate is heated and the flow is upward.

Ti -T,

= T, - TE + T, - T 8

+ R, R R. R, + R.

Based on Ti = 1100*F High estimate of R. and R based on forced convection 1100 - T, , T, - 200 T, - 200 0.082 1/4.2 1/4.1 + 1/5.6 12.2 (1100 - T.) = 6.57 (T. - 200) 2243 = 2.86 T, - T - 784'F T,-T. T. - T 8

=

R. R, 784 - T. , T. - 200 1/5.6 1/4.1 1 36 (784 - T.) = T. - 200 - T. = 1271/2.366 = 537'F Page A-10

90904' N/0 Based on more realistic value of R. and Rs based on natural convection.

Assume R. = R. = 1/20 12.2 (1100 - T,) = (T, - 200) 20 +

1/20 + 1/5.6 -

0.5 (1100 - T.) = (T, - 200)

T, - 500'F 5.6 (500 - T.) = (T. - 200) (20) 1.28 T. - 340 +

T. = 266*F Now reestimate R = 1/h p based on T, = 500*F = 960*R T. - 266*F = 726*R hp = 2.8 +

R = 1/2.8 Or, = 1 x 10 *

• T f, = 350*F = 810*R Or. - 0.7 x 108* Tf, = 233*F = 693*F k, = 0.118 h = 17 R. = 1/17 K. - 0.106  % h, = 15 --+ R - 1/15 Based on these new values 12.2 (1100 - T,) = (T - 200) 17 +

, 1/2.8 + 1/15, 0.63 (1100 - T,) = T, - 200 + T, - 548'T 2.8 (548 - T.) = (T. - 200) 15 T. = 302/1.187 = 255'F Estimate temperature rise of gas as it flows up annulus.

g ,, , Ti - T. ,1100 - 548 = 6800 Stu/h-f t' Ri + R. 0.082 A, - surface area = wDL = w x 27.79 x 8 = 698 f t*

k = k" A3= 4.7 x 108 Stu/h = 1300 Stu/s k = [n Cp AT AT = temperature rise of gas Page A-11

90904' N/~

Cp = 1.24 Btu /lbe *F AT = 1300/36 x 1.24 = 29'F The above is very conservative since it is a (1) steady state analysis (2) neglects any heat flow to the liner, and (3) based on max side reflector temperature.

Rough estimate of Tg which would yield T. - 600*F, try Tg = 500*F.

Note T i = 1100*F, based on Tg = 120*F. So.

assume Ti = 1100 + 500 - 120 = 1480*F assume same flow rate a = 1 3 x 10' lb/h First guess T = 800*F = 1260*R T. = 600*F = 1060*R Estimate natural convection coefficients T, = 800 + 500

= 650*F = 1110*R 2

T f,

=

600;500 = 550*F = 1010*R u, = 2.2 x 10

u. - 2.1 x 10 k, = 0.146 l

k. = 0.137

[Uh=336x10'

\v*},

+

or. - 3 36 x 10' x 300 x 88 = 5. 2 x 10 5 5

!A\=4.90x10' +

Gr. = 4.9 x 10' x 100 x 88 = 2.5 x 1055

\v8 /.

h 0.146 ce

=

x 928 = 17 =

R. = 1/17 g

h 0.137 c.

=

x 727 = 12 + R, = 1/12 8

R = 1/h p

' ~

hp = 0.667 x 0.1713 x 10 * (1260 * - 1060*)/200 = 7.2 Page A-12

o 9C 9C 4

• N/

1400 - T, T, - T T,-T

= E. E 0.082 1/17

= (T - T g) (17 + 4.5) 1/7.2 + 1/12 0.567 (1400 - T ) - T, - 500 3

1.567 T, - 1294 +

T - 826*F 826 - T , T, - 500 +

1.6 T. - 996 +

T. - 622'F 1/7.2 1/12 While this value exceeds the 600*F code temperature allowable, it is probable that a more detailed transient analysis would show that the condition where Tg - 500*F is acceptable as long as the primary coolant flow a 4 21 of core full power flow. However, at this time it is conservative to estimate that the PCRV will not exceed the 600'F ASME Code allowable as long as Tg 5 400*F and a 4 2% of core flow at full power.

REFERENCES

1. Gulde , R. , "FSV : Delayed Firewater Cooldown: Effect of Liner Cooling on Orifice Valve Temperatures," Doc. 907935/A, February 20, 1986.

2. "KTGR (Fort St. Vrain) Technology Course," GA-C18445, April 1986.

3 Petersen, J. F.,

"RECA3: A Computer Code for Thermal Analysis of NTGR Emergency Cooling Transients," GA-A14520 (GA-LTR-22),

August 1977.

4 Henderson, M. C., " Misc. - Update of VEB/ RIB Thermal Analysis Guideline," SED:VEB:873:75, August 28, 1975.

5. Kreith, F. Principles of Heat Transfer, second edition, January 1966, p. 355.

Page A-13

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