ML20024C659

Advises That Info Re Evaluation of 780423 Transient Being Developed & Accumulated.Conclusions Re Level Transient in Pressurizer Discussed

ML20024C659
Person / Time
Site:	Crane
Issue date:	05/05/1978
From:	Rogers L BABCOCK & WILCOX CO.
To:	Geoffrey Miller METROPOLITAN EDISON CO.
References
TASK-*, TASK-GB GPU-2048, SOM-II-143, NUDOCS 8307120933
Download: ML20024C659 (4)

Text

-

? cdsW$s' Eth. 2.OW

..::.T w,

s b-~-

P dad 1.

e

~

I

,46 eIps

'4

?a-F m

~

me wg e.e BabcocktaWilcox Rt*.f J.

1%

PA tes 1260.Lg.. erg,Va.2450S h.igr.

g.d Tehphones 8041366S111 g

gg s'%

J SON.II 1k3 SWikh.

1" *

$WC w:,:43

~

M;y Ud ~*

L~::

~

ur a. v. u111er D'if 8tation Superintendent

Qil, Metropolitan Edison Compaar g#

post Office has 480

->i b.

e rd<

-c Middletown, PA 17057 h

Reactor Trip /I.S./Cooldown Incident of 23 April 1978 Subjects g

ogg 5,W Dear Gary fdy??+-

m Information relative to the BW evaluations of W subject transient is CMY continuing to be developed and accumlated at both the Nuclear Service section in Zynchburg and the T(I Site Cffice. The fo11oving information DM

^

naq cautains conc 1usions rega.rding h-level transient in the pressuriser g

$q euring the subject plans transient.

M C

lusions Cenee@r Voidint of Pressurizar k~;g-gf,

-e :

bD

, there are four observations or calculations which can be drawn to ascertain L%)M i,,)

vbether or not the pressuriser-surge line emptied during h transient.

q%

g 3hch of these suggests that. in fact, no steen hbble was drawn into the pg.;

Reactor Coozant Systen proper fran h pressuriser of forned spor.taneously i

,I p I

during the depressurisstion.

parsaeters to deternir.e the rate of and enount of Reactor Coolant,3ysten y[g.g etg Caletlations were made eased on W measured Reactor Coolant Systes

'e coolaat shrinkage er. ring the first two ainutes of the transient, which p..

includes most of W period when pressuriner level' was low-off-seale.

These en1culations considered h effects of the Makeup System and the

~

opera *.or initiation of EPI, estimations of the effects of temperature p

measurement arrars, and flashing and subsequent cooling of liquid in the a

prassuriser as W pressure rapidly dropped. Using conservative estinates i@:V=d

)

- ' ( {,

for these effects. the emiculation showed that the 3ressuriser steen ma wm. -hed m.,,er s.cmn.f the sur,e 2ine, i.e., m,ressuri.er M

w.

did empty kt the kbble did act reach W bot leg.

yiB

b. /g h.-

~~

y

~

f..

a 4

?SN 8307120933 780505 LvA PDR ADOCK 05000289 d

jJ&. 0/0 6 c

u. sw wa c

, o u-~< ms

>~

9. g( ).7 g.

w+was-swarmasremiggqqLeggyg

• .]*

p.

2M

.' ~

W~Ybh.

t*

f:a E5 5/5/78 G. P. Mi2ler v.

,qfi k.

d)

N.

De second iten of note is ht the Reactor Coolant System pressure was q$75 In-house codes 3.$

a smoothly varying parameter throughout the transions.

(e.g., Tinp2) have shown that following the pressuriser-surge line 4*C e.. <r%;

emptying, the Reactor Coolant System pressure promptly flattens as bot

%g{

f less flash to steen, thus maintaining the Reactor coolant Systen at T

saturation pressure for the highest temperature in the Reactor Coolant k;%g d

g This sort of phencc:enon did not occur at ':MI-II as can be seen h]P System.

from the loop Reactor Coolant System pressure traces.

The third indication that no bubble was drawn in the Reactor Coolant system

@d dy M

is that the botter of the two Reactor Coolant System hot legs (loop "A")

hw;g.

~

nner got within 20*F of saturation temperature as the Reactor CoolantAt the 3 4';

~ ~~ V Systas pressure fell. turned sharply upward and this aspect of the problem ceased to be a con

.,v.h, M

y The fourth itus is a qualitative agreasent based on the reactineter data l@r,@

l*th yor purposes of explanation, the plot of pressuriner

$@1'W h

from the site.

level, Reactor Coolant System pressure and pressuriser temperature are P3 QQ Q

. W IPI isolation valves ware opeiied and the second makeup pump was started.

p,%

attached.

b[U Design his point is marked with sa "A" on the pressuriser level plot. stroke tim

,g f.$

s 6 Derefore, it seems reasonable to assume that

$. 'i.

G[M F,

makeup pumps is 6 seconds.

Since the full EPI flow was achieved well before the 1 minute mark.

!Q$

TY makeup pumps are centrifugal pumps, their flow rate increases as ReactorNotice on 4.U

%4 i

k@*d?y

{gG Cralant System pressure decreases.

that when it comes back on scale (t = 2.2 minutes), its slope is relativelyAt t =

ii gg,

linear for abcut half a minute.Eotice that, at that time,the slope decreased as one vould z,

How look at the dashed curve which covers that range in time when p@r.

down EPI flow.

i For the level to have behaved in this way, makeup erpect.

level was off scale.

tiov rate would have had to decrease sometine before level cane b y.g:

T y

g#"H,

throughout this time, and the EPI valves were at 'a fixed position, this M

scale.

The only curve shape cone.lusion does not seus physically realizable.which meets the physical cc i

iN According to the EPI flow Q

1i >

49 This alternative is shown as a dotted line.versus Reactor Coolant System pres Ym ing, the HPI flow rate should be continuous 3y increasind as the Reactor >

Coolant Systes pressure falls, thus a concave curve shape seems most logical.

fit;r De conclusion from this line of reasoning is that pressuriser level could

~

M not have dropped very far below the lower level tap when MPI turned the Y6!

level decrease around.

l two fact of W lower level tap.

6' m

1 W

a I

is l

m L /A171 jig yo,oy

. -~ m

5/5/78

9 4-Y '.'W' *

' O. P. M131er r

l3 r.

D 3ased on the arguments and observations outlined above, 3W's conclusion T-4 P

It appears that only the h:$

is that the pressuriser was never emptied.

operator's timely initiation of EPI prevented this from occurring, but 4 ?. % :

the data seems to support our contention that the pressuriser was never

$m$e h,

g';,

J.E entirely drained.

NJ '

-r As a&iitional information becomes available. I will forward it ta you 1 :

i ti iWMG t

I f.%

for your reports saa files.

[ 7 '$

If you have may further questions, ple.ase do not hesitate to cantact ze.

h I

Very truly yours.

j f.C.

.gige r

L C. Rogers s"

j

.Jtite Operations Managar

[g&

'l gg:ajusy

..y, (N

M eet b R. Pletta

>3 M

5;

v. m. epansler r',

C. L linnaling

,j %.,d J. C. Eerbein 1Ji WA R. K Zling.naa

,,. E '

N L b Lawyer f'h' iI:

J. 1. Logma ll J. L Seelinger E;

'J

%g M

e

..m 3

,s l

E G

rh

\\

M g-e R& L&saja

. pggym.g

(

Nh*,

s*

-a.

.__..3,..

3

3. A-. S.1 f,

d J

.. ; e J

$I. )

q e-1 i

...l.....r..4..

\\......-

h.. "g;., * " *.... r

. I

-e up-t..

.............i.............g....................l...

..:: :~... -.

..,w e.4

.~

...... e.

....M.=...............

...g.o.n.

,e..

., i :=, )

..... =......

n

......t....

......e........t...................,..........

.......i

..o..

l

.:~.!,.

t..,

......o. t....

.4...........

,e,.,.

. 4,@_

f.

saw e,.e,.

_f,f. ".

_. m. t_{.,.

]

,................8..._....

je

..m.

.s..

..l..........

....E...

i

,a

.9 g.o..o..a..,.._........,.3

o..

• * ~ =

4

..o.....

....m.

_..J...............

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

.U......*'.*.

\\ C*r M

.,,.......3.

s=

n

.. ~...........

n

.... ~..:........_........

......=.o

.m._.

...... s.........a....... s..,,l: g

....~ p....

• '.g.._.

n.,.,,

,L

.~~...........l~ -.....

i r

=.r..s. =.,,..~ ~.r=.=.......

........._g,,...

i L. -

..........1m

..,.... ~.,.

i

...... O _, -

...............8.

...s......,.,.,.,.,.,.,.:la..

.~

ffg.

..;,g ~.n...........;.3T :.

3.

.i

~ " ". "... '. ".

4

...- -. =

,n g ]

.......g."g,..gg.,3.=:...

............$..'."..".g.e:.....

.....t.,..:.

!.":l

.......,.3.,,g..,.......

......_. l...J".J.:.:.r*.~...........-......m..

. 1 3.E.b....d.s. i-:p(;igs:.i,li;. M.bri=.._,.!G$,

......t 3."....

i:

5._.= =_is!"F. =.:..: '"...nd i dE4:;

_._.......r:...,......,

y.

j

==:. : ?. muj 4..'iiiiii_._ 5:

ii-:. Hi.:.mn:==

@s_

==;;,L n

_ = :w=,:..

._..s.:=.:. g-..=_,

g%a,,',

.. _.... _ _. 9.M -.

. u :__

t wW _ _ _ ',. ~. : o.t..

........,.....,_.r--

--_r.-..

a:

k3.%. )

ll

. e n,..

d

, * *"_" " *d 3';j*,Y.,:,". Eg.k.;'.** J.*. W. I *~ i, ~/j.",,'"!'".'

~

g,

_g g_g.=.:.:g;.

p

...,......i.__....__

..s..,

. _ _. _ _ ~ _. _. -. * ~' ll 4. - -

._.."l0.*"*..C".*'

3... - m.-

I p

.=... M *.W4A g nerog g... _...

= * ' = * *

... s l

I, 2

..i

==. d.. -.1rnM.

@?/Rh3,'Ifr;p j

l:

-g g. coy.

--= x. ~. ": r.;:. T.._ _ _4 -.-.. -, _.. -._..

_ _ _.. _._/E. L_- C.S.....M..._

~~==3.rcT"_-yM p,,

o '

t u.....

...... _ : :=.:-=s c;m,.,

-1.._

_.3

.nz:.

2..-

w i

_g.=:u

._..,==x

.._.. =.., _.:n..a.n..n.

_a....., _..... _. - :,

_.c.._ d...._

I r s

_ m~

1.-

m.,. 6e

_.e.__.._._..,.

a l

..a n..-

....t._............... _

i

~_

t.

._t._m

. _ _.,...t m

~......._._..:.4.....

r.=..._

%,,,,.s.

,yp,..

i._,.,-.3..

i

.f.._...

. =.. __...s.. 3 y_ a3..,. n.t._.._.......eu- )..t c i

,.,.3 l....

i t.

-... A l

.~

. t.

t --

. -.r.

4...-

e.

......_.._.....=ll3 a.

...._7-

.,.-.t...

p, p L

Q,

. 4___ _ _ -

7

~.

s s-_

-.i

- C ': ~ ~ ;

' _c. : = = A M..

't un"8"'*;

..'I' s.i...-_ --..- ?

_-.. w 1

.q s...

,. t k:= 4 E4W

..g:::=[BrYff8:- -.gi.Ilh f.a..===s

~%.

-_._..f-

- +p.

j

. " ",: =.=.=._.. ;f.. ' 4 :..

(< :.

pg,

. =

,w-

~..

~ ~ ~ _, _

,..,/

w s_ i

., r. -i...._

u..

...:==

........~.:.............;.

l. ::.,,

-n,

_-.-a.,_,..._

- -.. _ 7:p

-:::a**.J:..--

=t--==.::,:,'. g r f. __

3-. g _

}L

,)_

a rw,

...4

-.q:

u-p *..,,

It_

.1

-- - - -.:..::=::;

r

~ ~ t c 4.,

>= G.

g f QM. _- _ :::-w,

.r.

-/-,.,=-.....7

==

., _ y -...

t

..r..-

- _ -...... m.

-n:

. i 4.1

.. 4,

-__.4_

.~

E.._..

f.

-y

..-.--..g+

88

. : :.:t ye' f

-..j - s -

.---1.--

-h.. _ _

- r3 --

w.,J.:. ;

".A t - r -

'g.- _.,,.

r,

-= -

..L."..s......

m t

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

. -u:= :.1

. rw.,,...

= ~ ~" ;. _ -

s I

e :=.

1

..... : :.:: :.2..:=.:::g, ;.:r\\ :r

_... 4.= ~...o.~... :a...r.n. :.

.g

- -: n ::~ 22:-:

=.a.;:.r.---. -!: &

. ~.. * ".

~

c:.;:

g

~

.':2..

w>

.~.-

.....a.....

• .~...

..- ~ --'.:.::: = n::.

= g'.u."t

...~

.... U r.

==

.. ~ ~ ~ s:~

1 yp g..f..c. :_n;:. :n==

~.

I p

.i....T...

........ g..-

- v L

==

..=:2...... ;:.:::g7. :n:.p". n....;

~ ar -

g aa.-

~~

=_ _.:r, :,:::n:

.... r+ ~ y a.... _ _

-. -. ~.~~

..p.. 7 -....;,. g,4 s.._...

7

~~

Q,.

. :.. ::... t....:... E.i.;....

...._..y;;.....

. c........, ; :n:

..o. ~.u.t;n.:.:.:n:n.

L

q.,a.:-.. =.

...>,."...g..._...(........~v....

..~~--~.

.-e-

.:: ;;$n;:

• .::n:;

"". n~:t:::g":ern:m

,I g. :.;:. u,_. 3.,;

... ~ig..g;%y-.g::p:g;;;; g*::.

l

=...- _ =-e.:: :$.~1:-= s.... : h en.~.=:-u r-

.3.*;*;.

a.....,.,,=

,. M,

> g.g.:.;;.. ;.

g.;;.:..

u.:..... -..

n2=1. nn~.

..n n'. *....n..I. ::: =...t".. :..:In.."....

4,,,;;;:. n:.*.

l4

.v" r:-r-.2 M

r..:...:.:.. " ;..

....g....

32. ;C..f...:: n... :.:...:.:l.:":*a.:"a..u.

• • : 3 a u. =.

F. -... ~.. ---... o o"..n-"3.n..s..~

3::."';:t.."n t::.:.:..g;;

4

.... g...

...~

s..

..l.

.g....;;

....3.......

....~... -.i.......~ a.a -u n.n:r :n

> :...w:a t

..g...

.g...

. -...a :....a.. "...=

.g-

.:.a :...r.:n g

)

33.y,g.n.r ernxt::,......... ~--.wi~n.. m.:.:n,. _g..

4_.

....x......

.....g......

..r: n-nn:t=s

.... _ a. s....

j u..-.. s.

-n a pyrarn:r.,

nr: -.

2.. : :..... u..n..~::n. :n...a.na..=..:. :...n..

n..

1.n

.d.. g :.:h..

8

u. :t:...QCQ

. u...n...

a..d.4.: :.:.....I....r a.

4

.. :.:.:.:=....a n,.=..=......a..... n::.. =... :....n.. n..

..n... s...=..: : 3.....i.a..:

.....g. ~ 2..n.... - Q...:.:.g...a.:...+...=.. :.....

=.

~ r.

a

@4

.y7

a...:..

n n :..a.; e g:.n.r,:n : u r g g g g g g g g g y 3 g.,%..:n

.a..a :.. a.n..a

r...... 1...u..p..u..:..a..a..;::.::;.n.,,. L.,.r. r._

, n..n.:.:::.:a.

.I'.

h-.a

-. : ;:s :.

1 p

t g

......s..,,.,.,,.,.,........

... ~.....

.....:.. l

....... ~. =....

...l...........

..r.....................

. i....

. //f W lc 9 E

%m.,

1 (A } ? 7

==

E b

k f h