-
Notifications
You must be signed in to change notification settings - Fork 10
/
ORNL-TM-0203.txt
3800 lines (2067 loc) · 34.6 KB
/
ORNL-TM-0203.txt
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
[skipped page]
MURGATROYD - AN IBM 7090 PROGRAM FOR THE ANALYSIS OF
THE KINETICS OF THE MSRE
I. Introduction
This report is a description of an IBM TO90 program based on a par-
ticular model of the Molten Salt Reactor Experiment. The differential
equations of motion are discussed in Section II; since much of the de=-
rivation has appeared elsewhere,l only the additional derivations nec-
essary in the present problem are included. The fifth-order Runge-Kutta
procedure is a‘standard one which can be found in many numerical analysis
3
textbooks.2 Tts previous successful use in the TO4 program PET- indicated
applicability to the present problem and no revision has as yet been found
either desirable or necessary. The use of the program is discussed in
Section'III, with instructions for the preparation of input data; sample
input forms and output sheets are included.
II. Differential Equations of Motion
A. Power, Fuel and Graphite Temperatures
The reactor model used as the basis of the program is a one=-point,
one=-energy group representation, with up to seven delayed neutron pre-
cursors, which is described by the following set of differential equations:
(all symbols are defined in the Nomenclature; a dot over a symbol denotes
time derivative)
: k (1-p)~-1 N
P = S - P + Z ATy (1)
-l
. Si P
r, = 35— "ML ,i=1, N (2)
The effective multiplication constant ké is assumed to be of the form
ok ok
- - e - s e - :
k= 1+4+bt ST (Tp = Tpl) B—Tg ('rg Tgo) . (3)
(The subscript zero denotes the steady state value.)
(&)
N
e
i
fP - wc_P_(tr.'2 - Tl) + h('rg - Tf)
(5)
n
i
(1-f) P - h(Tg - 'I'f)
It is now necessary to specify some connection between the mean fuel
1
The assumption is made that the mean fuel temperature is a weighted mean
of the inlet and outlet; i.e., that
temperature Tf, the inlet temperature T, and the outlet temperature T2.
T, = al) + (1-a) T, ; (6)
the weight a(0 < a < 1) is an input number in the T090 programn.
Further it is assumed that the inlet temperature Tl is a constant.
With the definitions
s (T, - T, )
. — £ 3 f fo
Yo = = (7)
O
- Sg(Tg - Tgo) :
yg - (l-f) Po ( )
and the initial condition
h(T - T
go go) = (1-T) By : (9)
the following equations may be obtained
. fP_ Weo h(l-—f)Po
fPOyf = f(P - PO) - “S“;"‘ yf<i-_-_—é- + h>+ "--é-g-myg (10)
i h(l-f)Po hfP
(l-f)Poyg = (l-f)(P-PO) - —-"-é'g-'-“-" yg + --é}-- Vg (11)
which, with the definition
x = P[P (12)
may be further transformed to obtain the equations used in Murgatroyd:
L d
. 1 h h 1-f |
‘ Vp = %=L [Zl~a§tc ¥ S, } Yp ¥ Sg r g (13)
. © L o, £
Vg = XL -5Vt T8 I s (1)
g f
Similarly equations 1 thru 6 may be transformed with the definitions
Cl = I'J'./Po
and 7, = f3i/£
to
k (1-B) -1 N
¢« e |
X = 7 X + .23 %i C, (15)
i=1
c'i = 7, x-AC, , i=1, N. (16)
If the definitions of yp and Vg equations (7) and (8), are introduced
into equation (3) the effective multiplication constant becomes
‘ ak_e fP_ ake (1-f )Po
k = 140 +bt=|c=| —=— y.- —_— Y. ; aT7)
e 5Tf Sf f 3Tg Sg g
with the definitions
> ake fP_
e = |5T.| 52 (18)
£r| f
-f )P
W82 = 65:8 (lsfi > (19)
g g
[These are similar to the parameter WNE in reference 1;}
. the equation for the normalized power becomes
( )( ) | :
o c L+6+Dbt)(1 -B) -1 2 2
X = [ ) - (1 - 6)(Wf Ve + Wé yg)} X +123 A, Cy
(20)
The differential equations actually used in the program are the set
20, 16, 13, and 1h4.
B. Pressure
The simplified model of the primary fuel salt system is shown in
Fig.III. It is assumed that compression of the gas in the pump bowl
is adiabatic, and that the behavior of the molten salt is adequately
described by the linear equation of state
p(Tp) = p + g%f (Tp = Tpo) - (21)
A force balance on the liquid in the outlet pipe yields the equation
M
r . - 2 .
m: U = A(pc - Pp - 8, u) (22)
in steady state
2
p.(0) = p (o) +a, U . ‘ (23)
The assumption that compression of the gas in the pump bowl is adiabatic
can be stated as
p_ V" = pp(O) [VP(O)]n (24)
oo
P P
if we assume that VP - Vp(o)'<<: Vp(o) and neglect second order terms,
we obtain
nAv
P, = PP(O) [l ~ \7;(%5] . (25)
The change AV? in the pump bowl gas space volume is now assumed
to be equal to the change in volume of the core fuel salt due to the
change in temperature of the core fuel salt during a transient; i.e.,
compression of the molten salt is neglected, as is heating of the ex-
ternal loop. The change in volume AVc is expressed as
ko
-6V, = AV, - I 5
and substituting in (25) we obtain
nv
Py = P(0) [l * \7—%5'5—
b
0 T
%—- g,%-\(Tf - Tfo)] ‘. (26)
Solving equation (22) for the core pressure we obtain
M
2 T .
Po = Pypta,U + iflfluézfif' U ;
subtracting equation (23), we obtain
pp= b -0 (0)= b -p(0)+a (P-U2)s T 7 ; (27)
p= P, =P, - pp pp f o iflflfiézzf ’
the term pp - pp(c) is due to the compression of gas in the pump bowl, the
term af(U2 - an) is due to the increase in friction losses, and the last
term is the contribution from the inertia of the fluid in the outlet pipe.
In order to proceed, a relation between outlet velocity and fluid
density change is needed. The equation of continuity for the fuel salt
in the core is approximately
‘ A oy
P = - v;—-pO(U-UO), (28)
solving for the velocity U we obtain
_ . .1 % . .
U = U — S Te (29)
and taking time derivatives
Vc o *
= %...59.. T . (30)
U= =
We now substitute equations (29) and (30) into (27); after some re-
arrangement we obtain
Vv M
_ c 1 O r
Ap = - = 5;. 5%;'["IKE_§;K'Tf t Py (o) —~r-7- )
2 e, i -Vchp-é“ (3)
o f £ ZAUO Py Tf T
With the definitions of y. and X (equations 11 and 16) equation (31) is
transformed into
Ve Jp s M nA
bp = - Kk o 3. S [um *+2.00) Gy Ve
o T T p
‘ Vv P "
. 1l 93 o
+2Uay<l-—-—--—~c = 9 -—--—y)] (32)
o fvf 2AUO Py Tf Sf f
With the definitions
Lty M
A Py Tf 1 gcA. £
144 g A
dy = - Pp(o) v (o) M,
14 g A
al = 20U af T
T
amd.
Vv P
a = - MKS_. 1_ gQw —
3 2-UO Ps T Sa
we obtain the equation used in the program:
Sp =dl[>'<+d2yf+als’rf(l+d35rf)J (33)
In terms of the dimensional groups of reference 1 and the parameter ng
defined in equation (18), the constants, d,, d,,, and d3 may be written
* . e .
It is assumed that T, = .fP/Sr.
2
. fo \
4 = 2
7oy
a, = W°oc \ L)
2 H 2 (3
= 2 /
a, W /273
C. Effective Delayed Neutron Yields
In order to account for the reduction in delayed neutron production
in the core due to fluid flow, an effective yield is calculated for each
precursor, assuming constant flux and slug flow. The fraction v, of
delayed neutrons of the ith group which are released in the core is
given by(u)
ALt A by
1 1 ¢ 31 e
(35)
. e--?\i(tc + tL)
where t, is the core residence time, %i is the decay constant of the
ith precursor and t. is the external loop transit time.
L
III. Organization and Use of the Machine Program
The program is designed for use in parameter studies; therefore the
calculation is separated into two parts, the first of which deals with
the characteristics of the reactor which remain constant for a series
of cases, and the second of which deals with the characteristics which
change from case to case. Input forms are shown in Figures la and Ib;
in the usual procedure the first form would be filled out once to describe
the characteristics of the reactor, and a second form would be filled out
to describe each set of initial conditions and ramp insertions. The in-
put data symbols appearing on the input forms are listed in Tables 3 and kL,
with their definitions, the names given them in the program, and the format
with which they are read from the input tape.
The standard CDPF Monitor input (logical 10) and output (logical 9)
tapes are used; no other tapes are required.
10
Output for a typical case is displayed in Figures Ila and IIb.
Figure IJa is an edit of the input describing the reactor system, with
the calculated effective delayed neutron yields; Figure IIb is the in-
put for a particular case, and the continuations of Figure Ilb show the
time behavior of the reactor. The two columns headed
PCT DK REMOVED BY
FUEL GRAPHITE
show the percent reactivity removed from the system by the temperature
rise of the fuel salt and graphite, respectively. The quantity labeled
"(1/P)(DP/DT)" is calculated from the expression
o = EB(t) - P(t - At) 2
At " P(t) + P(t - At)
and is therefore approximately the inverse period at t - At/2, where At
is the input time step.
Since the frequency of printing is an input number, special provision
has been made for indicating the first power maximum, the first pressure
maximum and the subsequent pressure minimum. ("Meximum" and "minimum"
are to be taken here in the mathematical sense of points of zero first
derivative and negative or positive second derivative, respectively.)
The values labeled "VALUES AT POWER MAXIMUM" are the values at the time
t. when the power has first decreased, and the values at the two previous
3
times, t., and te, as shown in Table 1.
1
Table 1. Power Maximum Indication
Time Power (L/P)(DP/DT)
t, P(tl ) B
*,2
ts B(t,)
%,3
t3 P(t3 )
11
The criterion for printing is
>
P(tl) < P(ta) > P(t3)
and the quantities ai 3 are
2
. ] P(tj) - P(ti) o
i,3 At ’ P(tj) + P(ti) ’
Similar remarks apply, mutatis mutandis, to the values labeled "VALUES AT
PRESSURE MAXIMUM'" and "VALUES AT PRESSURE MINIMUM."
Acknowledgment
Thanks are due P. N. Haubenreich and J. R. Engel, for assistance in
the derivation of the equations and other helpful comments and suggestions;
to M. P. Lietzke, for considerable programming assistance; and to H. A.
MacColl, for preparation of the input forms.
References
l. P. R. Kasten, Operational Safety of the Homogeneous Reactor Test,
ORNL~-2088, July 3, 1956.
2. R. G. Stanton, Numerical Methods for Science and Engineering, Prentice=-
Hall, Inc., 1961.
3. S. Jaye and M. P. Lietzke, Power Response Following Reactivity Additions
to the HRT, ORNL CF-58-12-106, Dec. 30, 1950,
L. P. R. Kasten, Dynamics of the Homogeneous Reactor Test, ORNL-2072,
June T, 1956.
12
Table 2. Nomenclature
Definition
area of outlet pipe, ftz
friction factor, psi/(f“t/sec)2
initial ramp reactivity input
specific heat of fuel salt
fraction of power generated in fuel salt
conversion factor
product of heat transfer coefficient times
wetted area of graphite
effective multiplication constant
prompt neutron lifetime
mass of fluid in outlet pipe, 1lb
ratio of specific heats (CP/CV) for pump
bowl gas
power
core pressure, psi
pump bowl pressure, psi
initial core pressure, psi
initial pump bowl pressure, psi
fuel salt heat capacity
graphite heat capacity
fuel temperature
graphite temperature
time
core residence time
fuel salt inlet temperature
fuel salt outlet temperature
Eguation
22
22
22
24
22
22
23
23
1]
13
Table 2. = Cont'd
Definition
outlet speed in pipe, ft/sec
initial gas space volume in pump bovl, ft3
mass flow rate of fuel through core
total delayed neutron yield
yield of ith delayed neutron precursor
latent power due to ith precursor
initial step reactivity input
fuel salt density
Eguation
22
2l
Title
14
Table 3. Input for Description of Reactor System
l. Core characteristics
V
c
t
c
l (1/p0)(30/ an)l
AL
i
B.
1
salt volume, ftB
residence time, sec (if fuel is not circu-
lating, enter zero)
weighting factor for mean temperature
heat transferred from graphite to sale per unit
temperature difference, Mw sec/ F
fraction of power generated in salt
fuel heat capacity, Mw sec/°F
graphite heat capacity, Mw sec/oF
fue% te%perature coefficient of reactivity,
("F)”
graghitf temperature coefficient of reactivity,
("F)"
prompt neutron lifetime, sec
fuel density, lb/f‘b3
fuel expansion coefficient, (OF):';l
delayed neutron precursor decay constants, sec-l
delayed neutron precursor yields
2. External loop characteristics
t
residence time, sec (if fuel is not circulating,
enter zero)
outlet pipe area, ft2
outlet pipe length, ft
steady state outlet velocity, ft/sec
friction factor, psi/(ft/secz)
Fortran Name
HPLM
VC
TCORE
ATMX
FRACT
HCAPF
HCAPG
TCOF
FLT
DENSE
FLAM(I)
BETAS(T)
TLPPP
AREA
L3
PLGTH
VEL@X
15
Table 3. Cont'd
Title Fortran Name
3. Pump bowl characteristics
Vp(o) initial gas volume, £ VPRS
pp(o) initial pressure, psi | - PPRS
N ratio of specific heat at constant pressure
to specific heat at constant volume for
gas in pump bowl | CP@CV
Title card is read with format 12AG; others with TELO.O.
16
Table 4. Input for Individual Cases
Fortran name Format
Case number ICASE 16, 11AC
Title HPLC }
Symbol Definition
Po initial power, watts PZER(
Tfo initial fuel mean temperature, °F TFO |
Tgo initial graphite mean temperature, °F TGO 6ELO0.0, 2I5
Ak(o) initial step insertion, % STEP
b(o) initial ramp rate, %/sec RATE
ot time step, sec HH
NP@ printout frequency NP@
‘ KST@P number of time steps to be run after
power peak KST¢P
ST¢P TIME total time to run YEND }
| FE10.0, I5
NTC number of ramp rate changes NTC
3 pairs to a card)
time to change ramp rate, sec TC 6EL0.0
new ramp rate, %/sec BNEW
MURGATROYD INPUT |
. TITLE FOR SERIES OF CASES
T b
WHHH—HHIH‘IHHHHIHHHIHIHHIHIHlll'llll-ll'liHIHHHHHHHHIHH_L
CORE DATA
Ve t a ~h | f . S¢ | Sqg '
OO O O O O O L T T LT T T O T
|lake/an‘ 1 lake/aTgl 21 l‘ ‘31 P | l f' s 73 80
HEERRRER H'HHHlTHHHHHHllh_[HI RENEREREEEEERNEREREEERERERREEENERRREER
DELAYED NEUTRON DATA
Ay | N A3 l | e Ns re Az
! 5 71 80
T L T L T L L T T T
B Bs B B, Bs Be | B;
i 21 3 41 71
T O O T O OO T T T T T T T
EXTERMAL LOOP DATA
O T T
PUMP EuVIL DATA
L ‘ U as¢ G
ENANNRANNANAANSNNNNNARNN NN NNRARAR NN AN NN AR RNANE
Vp (0) Pp (0) n
T T LT T LTI
31
SENANNARANARERNNNARENNNNANNRNNNRRNNNRRRNINRNAEE
'F‘GJ Ia\ INP.UT DESC{Z\B(Q@ QGACT‘o{Z SYSTEM
1
LT
- MURGATROYD INPUT-2
CASE NO.
7
A o b PP
CASE TITLE
- ——
8c
TTIT
TITTT
IHIIHHIJHIHHH'IH"HHHIIHHHIJIilIIIIHUII[IHIIHIHU
Po
Tfo
Tgo
o A.< (0)
by
3t
NPO K STOP
TTITITL
LTI
mmm
HHHH]
m'mm
s'ml
L
TTIIIIL
NRNRNNNEE
STOP TIMF’ sec
30]
T
HHILHLHIHHIIHIHHHIHIIHAHHHHHIIHHHHH
TTTIIT
- TIME, sec.
NE‘I RAMP °/o/sec
TIME, sec.
NE\I RAMP °/o/sec
TIME, sec.
NE\I RAMP, "/o/scc'
T
[TITTIIIT
T
IIHIHH
TTTIITITS
,HHUH_[.
“TTITTTT