ML20125D065

Responds to Re R Davis Concern About Water Level in Containment Bldg.No Emergency Situation Foreseeable Due to Vol of Bldg & Sources of Leakage.Decay Heat Removal Sys Is Available.R Davis Encl

ML20125D065
Person / Time
Site:	Three Mile Island
Issue date:	11/08/1979
From:	Gossick L NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
To:	Walker R HOUSE OF REP.
References
NUDOCS 8001130194
Download: ML20125D065 (3)

Text

l

• * # I '" ~. . . . . . . , .

g ~ s' *

. . '_ "" ,7l,

. ==: . :

=...

= = . ;

' ==-

3 ~- c =

=:=..:..' :

'The Honorable Robert S. Walker , ,.

p,

• 7';:::

...n_ . .

.r ...

;;i.;

_ .. cinic. : EE.h Distribution Copies:. . ._.2 . e _. ==

Docket No. 50-320 FC EFT NRC PDR' . , i.!IE ' Hi Local PDR .

~ ~ - di: : EE::

4 .: : : - -- .- g EDO r/f - O ; 11...~

SEP/THI r/f .

.a TMI Site r/f -

' ~ ' '

PSB/TMI.r/f-P-433 Z..

RVol1mer .

4 EI:...

JCollins SMiner Jhu111n

. LVGossick '

HDenton _

ECase-Hberkow/WRussell .

DVassallo -

unuller 90018200 FSchroeder JCook LChandler . . . E Attorney / ELD '

. f , . E.

. OCA (3) .

_.ff.f. W GErtter (ED0t7513) f. 56 E'.)

R MGroff ~t .W DEisenhut -?. = EE I

RTedesco C Ee RReid

.~5 2 c- < b DDilanni ,

=

Clielson PKreutzer 2=..

l .

. l .2r : f,, .:-

=

- w

. .. ~ , '.1, ..

'.~:. . .

._ x1

.x . . ~ , . ==. :

.~.~.' ""::.

_. . L

. 5.. . .

' ; . 7

• '.~_; ...,.y r:.. ."

~

• mes > ........................ ........................ ......................... ........................ . . . . . . . . . . . . . . . . . . . . .... . .

]

i

...................$.(f.Q..}...g.g.g. ...;.. --

sumanus k ......................... ........................ .......................... .

.............................................................../.. t NM* MMM 318 (9 76) NRC38 9340 - 8 v.s. ** vs a an s at Pa'at'a* *ar'.es ' 8 ' * ** * * ..' _..

II

- ::=. =,:- -  :.. .. ::. ; ::=  ;== . ""==-

~~

" ^ * ^ ' * " " ~ '

.}' ??*?' ' , ' . ' . .* :- ~. m - :u :7-

' b -

fl0V 8 1979 .j.:/ _

..g-The Honorable Robert S. Walker ' -

~

United States House of Representatives .

Washington, D.C. 20515

Dear Congressman Walker:

This is in response to your transmitt'ai dated OctoDer 2,1979, which referred a letter from your constituent, Mr. Ronalo Davis, to the NRC for reply. ~

Jir._ Davis refers to theLpotential for an emergency situation to develop if the water level in the containment building at Three Mile Island, Unit 2, reaches a certain level. The water in the containment builoing has already disableo a substantial amount of instrumentation as well as some electrical components.

Because of mooifications made following the accident and different requirements for post-accident operation, tne reactor is safely shutcown and coolea without ,

the failed equipment. There are, however, certain motor-operated valves which ,

are part of the decay heat removal system, the first of which would likely fail if the water level increases by 2.5 feet. Although the decay heat removal system  !

) is not currently in use, its availauility is important.

In response to the specific questions raised by Mr. Davis, the current water 9 The --

level in the Unit 2 containment is 7.6 feet above the basement floor. M-I water level is rising at about 2We inches do not per month foresee baseo any " on the current emergency" situation level , - .+

of leakage into the building.

ceveloping for several reasons. The volume of the containment building is very e -

large, and the sources of leakage are limited and currently small; therefore, any' increase in the height of 'the water is slow. Since the height of the water in the containment building is measured each day, action could be taken to either stop the source of water or operate the motor-operatea valves to the "open" posi tion. We would expect this latter action to be initiateo before the water -

j level was within one-half foot of the valve's electrical components. This woulo ,_

not compromise safety since a closed, oack-up isolation valve exists outside the .

containment building which is not suDject to failure from containment water ' $f, j 4 c_

o l evel . .2 I hope this has been responsive to the questions raiseo oy Mr. Davis. ,

1 Sincerely, [

_Q _ . '

Oridnnt acyd hv R. n. Smith o

-)

~

/Leev.hossics

• ==> ..

.g.g.g.g.d'd "' '

JM"*'"i "e..ogctor...f.o c.. g t1.ans.. . .......g....... j o.nme,g. 3m.. . _ . . . . . . . . . . . . .... d'a,........___ _ _H De,t,. ._. . . _.,, o s ,i _.____.__ .

.1.1/......g.7.g... l'

. = > .. 14 ..... 7.9... . . l......n.9.......,1.1J......J.7.R........ 2.1J......./.7.9........ .1.1J....../.7.9.......

une romu m mm num um ~ E'~ ~ ~

}%+=

_3 is.=; ;

"L .:;.y p...

(.:.

.:w l } .. 3 _

- 'wr