ML19221A197
| ML19221A197 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/28/1979 |
| From: | Stello V Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUDOCS 7905210004 | |
| Download: ML19221A197 (2) | |
Text
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HRO."0 LOGY OF TMI-2 ACCIDENT d;UNTIL CORE CCOLING RESIROED
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WECNESDAY MARCH 28, 1979
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FIGURE TIME EVE,'vT ri N
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1 abou t 4 A.'i
- Loss of Condensate Pump sy 4
h.
- Loss of Feedwater C /- o# 3C
/
i 1
Start + 5 sec.
POV opens (2255 psi) to relieve pressure iin RCS 1
+12 sec.
Reactor trip cn high pressure (2355 psi) 1
+15 sec.
,RCS pressure dec vs to 2205 psi (POV t
j f,L should have close'd) l /' [ '
.c
\\
2
+15 sec.
RCS hot leg temperature peaks at 612F I
(prassure of 2150 psi, 450 psi cver f'j
"' ' *"h Q 9 L.fo 2 m.)c W) 5 9 0 S
^
')
10
+ 6 sec.
All h e3 ux. feed,,ater punps start as N Tf I
V d
designad7.nd running at discharge had W j
/
L 8( Y no ficw was injected since disc 5.arge c.r.~
y J
y?
r 'b M' N,
/
valves closed l
fa d
\\' V[01 a 4x ^60 sac.
Pressurizer level indicatien begins to
<?
s./
'P rise faster than HPI injecticn rate usuld g
}
IJN s.) 'shTOTN h1 indicate
[
t
+1 mi r*
Steam Generators A and 3 are essentially dry b
'SV 3
{V\\{y.)
4 ' ~.,,:., a+3 min.
ECCS initiatien (HPI) at 1500 psi a?
- h', _Q d j j SC 4
+6 min.
Pref suriza ic.ci off ccala - hPI ficy j'h[q
' s ic? ped - ECCS.plc;ca t si : :-a t i;o! a t iep ].
,/
resat,- Auto pu ping miy have tegun to 1
/
Aux. B!dg.
e
'h *
'/
i
! k.)
12
+5 min.
/
RCS f D.shes as pressura tottc.?s cut a t
,' 07ji
/
,1350 psi (Kat leg terpareture of SSW)
I 4
+6 min.
Pressurizer level indicccion is off scale 1
l -
iCCS injection stopp d due to high pressurizar 5
+5 nin.
level indication I
10
- 3. min.
Aux, fs.,a ter ficw is 'ini ti: L ad by y
y cpening closed valves f
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i
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s e
r
,,1 n
- / (l( f 7005 Q..
210cc t,
3, N n s
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v
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s "i,7
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b I
'$ f
.d FIGURE TIME EVENT
.1
..fi 4&5
+9 min.
ECCS ficw (HPI) restarted by cperators 1i
+10 min.
S.G. pres 3ure recovered 'oy aux feedwater n
h'
.i
+15 min.U, vo!N-RC Drain Tank diaphragm ruptures at 190 psi S bf. 7.M -
due to continued discharge of F0V j
(jg;/ : %s
./ 1
+1.
cur Operator trips RC pumps in loop TB
.l [ 4/'11
+1.8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> i
vi Operator trips RC pumps in Loo; A J
Q5 14 '
+1.8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> (es timated}
CORE EEGINS HEAT UP TPaNSIENT - Hot leg
l(5g\\
}
g[\\,
,,o temperature begins to rise to 620'F l
(off scale) and cold leg temperature drops
{
to 150 F (HPI water)
}
I 15
+2.3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> (estimated)
POV isolated by cperator after S.G.-3
-i isola ted to prevent leakage f
19 & 18
+3.2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> RCS pressure increases to 2150 psi and POV a
oper.ed - RC Drain Tank pressure spike cf 5 psi I
18
'-3.3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> l
RC Crain tank pressure spike of 11 psi tP, (unexplained) - RCS pressure cnly 1750; V /
i
~
Containment pressure increases frcm 1 to s rd fj 3 psi
/'
-I. Peak containment pressure of 4.5 psi p. [d5 15
+5 hcur P
s' e'
y 's,p s 19
+5.5 to 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> e s RCS pressure increased frca 1250 psi to (p /. <-
v j
+8 hour i
Operator opens POV to depressurize PCS to N.V attespt initiation of RHR at 400 psi C40'.[
)
vJ 19
+3-9 h:ur RCS pressure decreases to 500-450 psi;
\\,4 '
3 CFT discharge 1s Y
15
+9.9 hour1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> 28 psi containment pressure spike, sprays 48 /
i initiated and stoppwd efter SC00 gal, of
'Sf NaCH injected (about 2 ninutes of gcratica)hi-l [ s, s
c 19
+13.5 bcue POV cles,-d to repressurize ECS, collapse
/
voids and start RC pump
'7 I,
19 413.5-lu. cur RCS pressure increased form 650 psi to 2E0 psi l4 Fl6 hCur RC p'f/p in LCnp $ StarICd hot leg t e,crems a we 2nd cold a u.,'f',;r3 %ra s
r m re I
incr0ases to v0'F indicit'ng flow 1
b^
l b, j.ul ' U{
be Y yn
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