ML19289G128

Submits Addl Info to 790413 Presentation Re Contingency vent-filter for TMI-2 Reactor

ML19289G128
Person / Time
Site:	Crane
Issue date:	05/08/1979
From:	Benjamin A SANDIA NATIONAL LABORATORIES
To:	Disalvo R NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
Shared Package
ML19289G127	List: ML19289G126 ML19289G128
References
NUDOCS 7906260510
Download: ML19289G128 (27)

Text

_

6 Sandia laboratories AibuaverQue. New VeoCJ 37115 May 8, 1979 E

Dr. Raymond di Salvo Probabalistic Analysis Staff U.S.

Nuclear Regulatory Cornissicn Maryland National Bank Slfg. M/S 3106 Washington, D.C.

20555 Re:

Ccnt;.ngency Vent-Filter for Three-Mile Island Unit II Reactor Cear Rav:

n respcnding to your request regarding a contingency vent-filter system fcr the Three-Mile Islanc Cai-Oeactor, we did.ct have t're On the first :c-around to present anything =cre than rough sketches.

Scw that the dust has settled, figuratively speaking, I wc"'d

ke to present a acre creanized account of the basic system that we proposed for you on April 13 and the cptions that go with it.

The primary centributors to this task, beside myself, were Walt Murfin (4413) and Harold Walling (1114).

I hope that the enclosed material will provide you with useful information to support the sketches we sent you earlier.

Please feel free to call upon us at any time.

Sincerely, a

m

,l Y~W.~,,_

Allan S.

Benjamin Nuclear Facility Analysis Division 4414 Enc :

(1)

"Centingency Vent-Filter for the Three-Mile Island

~

Cnit II Reacter," 'with attached appendix.

(2)

Blueprint of Vent-Filter Svstem

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Distribution-NRC:

Mark Cunningham (PAS)

SCL:

R.

S.

Denning

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Cybulskis Sandia:

1110 J.

D.

Kennedy 1114 J.

H.

Davis

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1114 H.

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Walling 4400 A.

W.

Snyder 4410 D.

J.

McCloskey 4412 J.

W.

Hickman 4412 S.

V.

Asselin 4412 D.

D.

Carlsen 4412 D.

J.

Murphy 4413 W.

3.

Murfin 4414 G.

3.

Varnado 441% A.

S.

Benjamin S

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CCNTINGENCY VENT-FILTER FOR THE THREE-MI*.E ISLAND UNIT II REACTOR To handle the unlikely but postulated escalation of the Three-Mile Island accident to a core meltdown, Sandia Labs was asked by the NRC Prchab.41istic Analysis Staff on A ril 10, 1979, to rac.idiv.c r e c. a r e e

c. r eliminarv. desie.ns of vented filter systems that could be retrofitted

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exhaust line (36-inch diameter).

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All other lines above the water level are valved to prevent exhaust.

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There are four 36-inch normal purce lines that penetrate contain-

,ent fairly close to one another at the interface with the auxiliarv building.

• wo of these lines are norrilly used for exhaust and two for intake.

At the time of the design effort, according to reports f rom the site *, one of the exhaust and one of the intake lines were being used for hydrogen recombination and recirculation.

The plan for the vent-filter was to utili:e the other containment exhaust line as an intake for the vent-filter and the other containment intake line as a

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l' 1 redundant intake for the vent-filter.

In case all the valves should fail closed and the instrument air should fail to cpen them, e.,,.. w

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.". e 2.a flow, since the system is not designed to accomodate large flow rates 4 a

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e bility of excessive flow rates that could blow out the system.

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Harold Wallinc. of Sandia conducted several telec.hene conversations with Jim Thesing, Sechtel Corp., between April 11 and 13 to ascertain

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the exhaust flow to about 3000 cfm at a containment pressure of 45 t

psia.

Operating in the release =cde, the time to reduce the con-tainment pressure from 45 psia to 35 psia would be about eight hours, assuming that the water inventory in the containment sump is 700,000 gallons (i.e.,

acc.roximately two refuelinc. water storage tank loads).

After 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the pressure wculd be reduced to about 29 psia.

These

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calculations are based on utilizatica of the system at 21 davs after Ocwer shutdown: the details are c.iven in the attached accendix.

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thicsulface) to enhance icdine capture.

The advantages of water pccis in this instance are as follcws:

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(>981) and for capture of elemental iodine (>90%).

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They can be easily cceled by means of standard heat exchangers.

(5)

• dater is readily available and requires no special

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The erima rv. disadvantage of water pools is that thev.

.u s t be kec.t subcccled in crder to maintain their capacity for condensing the steam and capturing the entrained fission prcducts.

Sand filters with everlying and underlying gravel layers are also attractive for fission product decontamination unde: high ficw leadings, but they have the following disadvantages-.

(1) they require large amounts of gravel in order to maintain their heat sink capabil-ity, since they cannot be readily cooled by heat exchangers, (2) they The flow will not be choked under this cc..dition.

The maximum isentropic choked flow :s about 13,300 cim.

ficw rate correspending to see ac.c. enc 1x.

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must be carefully graded and free from impurities that could cause excessive pressure drops, and (3) they have not been adequately tested in certain areas, such as their ability to drain the condensed water without becoming clogged.

On the other hand, their efficiency for capturing particles is so reat (>99.9%) that their use as backup v

to the water pools should be considered (see Fig. 1 and blueprint).

Other considerations regarding the choice of filtering media and the design of the system may be found in a draft report that was forwarded

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. articles that beccme disicdc.ed and entrained in the flow.

For the Three-Mile Island situation, the water pocls and gravel /

sand filter were desic.ned to be contained in cr:able tanks that were repcrtedly available en site.

Initially, consideration was given to locating the water pecl in a single large tank, such as the refueling water stora-e tank, the sc.ent fuel storac.e ecol, or the condensate v

storage tank for L' nit I.

For one reason or another, hcwever, these tanks were all unavailable.

The design shcwn in the blueerint uti-lizes ten 50,000-gallon water tanks in parallel to achieve a total water eccl ca acity of 500,000 allons.

Assuming that the tanks are 3

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Ben; amin, " Issues Affecting the Feasibility and Effective-ness of 7ent-Filtered Containments," draft Sandia report dated March 1979.

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nitially half full, calculations show that the system can operate for at lease 14 dav.s in the recirculation mode and 23 davs in the release mode before the tanks fill uo. and rec.uire drainin.g (see ac. "endix).

Based on these results it would be easilv c.ossible to e

o operate with fewer tanks, if necessarv.

The water tanks are designed with a single-lcop direct heat

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A. a.i.". ed

_4.".

• o '. '.". k c a. 2

- s ca ac-y".is i*

-o y

After water scrubbing, the remaining noncondensible gases are expected to consist largely of hydrogen, carben dicxide, air, and

.ncb e gases.

If one is operating in the recirculation mcde, it would l

of course be inadvisable to, inject a hydrogen-rich eas mixture back into the containment, due ' o the explosion hazard.

Even in the re-lease mcde, it would be desirable to reduce the risk of a hydroge.-

exc.l0sion in the lines that could dama9e the system.

For these O

e I

e e

reasons, hydroc.en recombiners are orovided in the design, followed bv an additional water tank to cool the c.ases emitted from the recombiners.

It would be preferable to have several recombiners operating in parallel, as opposed to a single one, so that relatively high rates of flow could be acccmodated.

It should also be mentioned that the cic.in9 and valvin9 used between the recombiners and the cooling tank would be required to sustain very high temperatures.

As an alternative to hydrogen recombination, it has been

-..,- e c. n a

~..".a a n.'.. ; e..ic r. o.#

r..

du

.^.~'a u.a.' a n 1 3 0.'

.i...o

". e o

c a-

....o.

.. 4,.w...

-.a".en-

.o s a.4 "l e k..": d -,- e..

o..x e lo s.i.. h e c ' "- a e c.#

- - a" i-kncwn anti-deflagration cnaracteristics.

Since it has tot been

-os eA.

a ad.4a. 4 o o...u. 4 m. "le.n. u,

k..r W e,<.e.,

4

• a-sa,.

• wi.n

• 4... e v

w v

- - ^ " a ~" ~' v, 1 ' - a d v.' a e d.

. a' y.--

. ~" e C.. av e. l / a a r.d

.#.i.l

• o. "

.'.. C.' u d e d-

-a

. n " e w.' ^ ".

"e "..'...a.".i.' Y

1. ^-

.a

..". e - a.' a. ' c e -..- d e 4.. o."e-wo

.-cv.ida a..

=d"ad-

.#.4.'.. a..' -- u ' e ' ~"..'.4. v

~

p and to dry the water-saturated gas flow prior to its encounter with

. a. e

...--. a.

.#.i.' *. a..- e.

~..h e - a -u.i. e A w,

sA.e o#

~.".a c. ave ',/ a a..d

.#.i.' ~. o -

i

.-3

a..:....s a

• o d "e

s C,.

.i.. a G'

a..u o'

4.".

h, e i..". *, "ased o".

d a

-u s.

g u

. a. e2 2 c. -,. m - 4e..c.i

• w-..a

a. 7 1

.w 2

...e a w e m o. w, L, s-. e A.

.c m mon *w-....en..4-om

-s..-

a

- -..a. e..s ed 4..

"ie ues * - a..',. wa a-

• a...ka.

The water tanks, hydroc.en recc=biners, and sand filter are located below 9rade to reduce radiation exc.esure to cersonnel at c.rcund level.

It was understood that sic.nificant excavation had already been acccmplished for purposes of centamination control and that excavation was in c.eneral no croblem.

While olacement below-grade is recommended, a complete burial of the system is censidered unnecessary.

As nentioned eariter, tne vent-:tleer system incorporates

.a dual capabiltty for recirculating the acncendensibles bac.'s into containment or for venting 'them via the sta icn vent to the atr.o-sphere.

In the recirculation mcde, the ficw 's sustained by a t

7

<. u -

e blower, and a nitrogen in]ection capability is provided to purge the containnent and reduce the likelihood of hydrogen explosion.

The blower can also be used in the release mode.

In the release =cde, the vent-filter snould be effective against a containment overpressuri:ation for an indefinite period of time if the water tanks are d.aiaed periodicall".

In the recirculation mcde.

1 however, containment everc.ressurization mav. eventually occur as a result of the accumulation of noncendensibles in containment.

The

Ime to containment failure after the initiation of recirculation is

-,,-o.,a*ad o "e -o-a

.. ". '.. "O days, u' s s -...ea.- a. d.

- c"

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

~ - -

~

nc venting of any kind (see appendix).

"'.4cus de 4,n oe-'-..s "..'va

- -ee- -

e....

ed a.. d.

n 4"

- =_ 'i-e" a

.3w.e

. o s '

"e ' ' v.

--e s":s aa.

o.. a. - u ' "

u" e.' a. a.

..". e 4--"'

i

- _ - - - - - - = - -. -

-o

_' _4.. p,. k. o_

san-341.p A

3 4/

J;

-.. - / c.-._.a. e r.h., - - a 1 ors (C.-

-.e 1,

m..A r.--

,,s

- - -.x - -.4.'.4. v

1. 'a

--~e e.x e..se. '..

c'e'""-;.

.'. a-ow-r

a.. "

uw alternative to release or recirculaticn, one could direct tr.e exhaus:

...,. a. m_

u n.,.4.

..e.,..

c < r.n.4.. i, w..4 n-e m..

s.w.t.

det.v..

.e -. _,,.

o__

nad a v

w

. e nance (Cption 5).

A summary of the advantages and disadvantages of s

n, _s.,p n.i.,. m,c 1 a_

n..u.a. a e.

. c n s n

It would be worthwhile to reemphasize that this system was designed for ex'edience to serve as a centingency at Three-Mile Island.

e It therefore lacks many of the automatic controls and sophistications that ene would want to include in a system of this sort given more time to desicn and construct it.

The oceration of the system rec.uires intellivence and forethought.

The opera:Or must be prepared to execute the following actions at certain times.

(1)

Drain any water tank or sump in the system that accu.aulates too much water.

Do not let the tanks overflow.

(2)

Valve cut any tank if the water temperature approaches saturatien (212* F).

~

(3)

Limit the flow rates to levels that do not jeopardize the system.

(4)

Do no t recirculate a hydrogen-rich mixture back into containment.

c ')

h

.1-c-i

s

e rn 1

e e

oi i

n ns d

bfl o

aa yo a

s i

Ce t m

, pet e

t l

li yacn I

g c

e al e t cne a

a

.r nis i

av t

t r'

y oba l nh i

n t

t n i ae iocn n

a s

ii t pl bi i

U 4

v n

l i ae i t r e

d o

id dcr xaen s

a c

be d

ert o et e

s i s anr l t ai t n i

f xu oo f1 es ae D

od e

sif i ro nm e

l e t L mf Gl i n t r fb ad u

p mi i

ni ere mr x

a a.

uu sye ftd ie

.e t t oq sl d rie nwy nn me no oie i ot 1,-

oo

e. o m Ar F1 n Ml i

1 C c 1

l

- n abo i o s-rrt k

ir t

epc n

.cf e

n o

a t

naith eet anpe i

u a

ob nL gvo t

momd L

a e

t eOt n

o t

i ii t

s g

t eni an e

f L m

n s

n a

at es, hoe m

ocl r

e o

t ramndcig n

uan L

g n

tl naist r.

i s yrmo s

a I

i t

a l u i r pi a u L an t tii n

t p

v i cat adt pn t o snL o

n i

l.

l O

d f rt r

s e

ni nia c

a l

l A

ne n

nn ot t

i oMl v1 i

u A

n mcoroahen ca bc n

n d

u T

g u e c u o c g gi r

a e

' L an mr st uoa rt r

.r

m. c o

i l

os eor t ee u

a ei n

esi i

i e

xnt et srt i wn awme np mt D

aanroibio ee veee m

ap i

MCipnwt c

Fp AFl r Mi SO J

t s

.s 1 r r

ae nn e

on oi n

t nci i a orb t t o

l am an 1

i ri i

n t

ef tho l o o

a t

acc uc i

g l r l l l

e c

t i

ue i a udr r1 p

F cw f o cn i

ro c

rad cL ir n

il d r i

n ei c

i cb na cda rn s

e ah en U

e n

rd sc ra t

D w

n ss co o

ea er e

r et h

t t o t,e r

s ee e/

eet i et l n l d l nl dtin s

ei en eii eie e

A Dl D a D1f Rl m nr oe ib t in 1

2 4

4 5

pu Ol l

N L N

],2_

a n

a 8

(5) Watch for leaks and monitor radiation.

Care must be taken as well in the construction of the system, particularily in the following areas:

(1)

Provide adequate pipe diameters throughout system.

(2)

Spike water tanks with uppropriate additives.

(3)

Watch materials in high-ttmperature section following recombiners.

(4)

Connect to more than cr.e outlet frc= containment.

(5)

Have contingency available for hot-tapping containment.

j ~.f:i

-a 10 6

APPENDIX Estimation of Vent-Filter Recuirements as a Contingency for the Three-Mile Island Unit II Reactor s

C C KLm _r%.T* Q Pace 1.

Sc=enclature

^-

2.

Intrcducticn

^

2.

Cesign Basis Approximations (Release Mcde)

A6 4.

Containment Response (Release or Recircu12 icn Mcde) n'9 O

e 91 Ma r

/-a3) i?

l e-

1.

NCMENCLATURE Symbols Definitions A

Area (ft')

3 Dimensionless function defined by Eqn. (10) c_

Specific heat at c o n s t r.n t pressure (BTU /lbe

• R)

C, Discharge coefficient a

F Dimensionless function defined by Egn. (11) f.,

Conc Mass fraction of noncondensible ccmponents in concrete

s. A,

3 g

Acceleratica of gravity (ft/sec")

c Conversion ccnstant (32.2 lbm-ft/lb-sec~)

"O M

Height of water (ft) h Specific enthalpy (BTU /lb=)

H Effective heat of ablation of concrete (BTU /lbm) e,,

h,_

Latent heat of vaporization of water (BTU /lbm)

~=

y Molecular weight m

Mass of water in the sure (lbm)

.a-...-

Mass ficw rate (lb=/=in) p Absolute pressure (lb/f t')

3 O,

Venting rate (ft / min) g Heat rate (BTU / min)

E Universal gas constant (1545 ft-lb/lb mole *R)

T Absolute temperature (*R)

Time (min)

V Free volume in containment (ft3) c Ratic of specific heats v

Mass concentration, or density (lbm/ft )

ndex indicating release mcde (if a

0) er

=

1) recirculation mcde (if w

=

& v)

A2 6

1.

NOMENCLATURE (Continued)

Subscript _s Definitions ch Choked flow cire Circulated into the containment atmosphere dec Decay HX Heat exchanger in Injected into the containment atmosphere 9C Noncendensibles o

Cutside (ambient:

cr Crifice sat Saturation st Steam u

Nater O

W o

A3

.p-

1. ' ', ')

/

ni -

l [ ',)

6

2.

INTRODUCTION This appendix provides supporting calculations for the estimates of design requirements for the Three-Mile Island contingency vent-44.,

e The assumed situaticn inside containment is shown schematically in

..-a-

.s

.3

..w.e c,,., e

.4 s a, a -, ea c

. a v e -..e. e ;

w. -.,,..,

...e eac

.w a...

vessel and is interacting with the concrete in the reacter cavit"2 m %..; s.i.e.. e a c *.; m n m e. m A, C e s an on pp..4 On C.

.m.e e.c e. A a.n. s.4 %.T a. yases (y 4.

4 4

y.-ub w

w.

w-

..a..4.' v ", and CO,< )

-^ *

^_

.'... o... e m... '.'... o..r.. =..~ c,.".e.- a -. 2

'. a....,.C,.,.,,..

^"ec-...'....s w

^..'

...'v.".-=.

^#

• e... y e.- a "-. = '...c.a y.. e.- a., c v. s.' m-..'..,

r

.d e.. s.'.".' a.

,asa.s I....'.'...'".

c. o '.. )

a..d

-.. '.d e..a.' -'.7 =.

,.= a_ a r..'.-."...'./

'i.,

a

.u. 3., Ln a.d e.mw.e

-acas,,

-a e.r.. e m a.

...e s

a w

.-rvent aa.;.-

-_a._

x,

~

time t The steam is condensed outside contairment, whereas the non-o c.. d a_.. o ' " ' a a-

.. ' "; 'e. e c_.'.-. ".' '. e d " a c k 4..

• o - c..'..'.

..a...,

'- - '. a..'.e c,. C :.,. a _..., or e.ay be released throu3-h the station vent.

The containment

-"..8

.N. O..," Q.

. 89 p /"., '

1.h.ea.99.9M..

w.t E ge.w.

.wg 9Ja $, e.9

.h.M.

w w

.m...

.d.gg. u..e.%..= a,

w. m,

p p.y y

-e, y

_n

.g p

.e which re.claces a certion cf the vented steam at a rate of m.

g

%. f..,.

M e

6 N *$

/J)

4 p

Q NC vent (IF RECIRCULATING) pst' pNC' "' '-

(?. + 9NC)Q s-ven+u

'"s t, i n i

II

"'N C, i n SUMP WATER CORE MELT Figure A-1.

Schematic of Containment During Core Meltdown e

f j f',

fJ!s?D7 i

6

3.

DESIGN BASIS APPROXIMATIONS (RELEASE MODE)

Becau 2 the water content in the sump is expected to be much greater than the steam inventory in the containment (i.e.,

700,000 gallons in the sump as compared to an equivalent 17,000 gallons water content in the atmosphere), it is possible for design purposes to make the conservative assumption that the sump reservoir is infinite.

Assuming as well that the sump water maintains ecuilibriam with the certainment acmosphere, the temperature and hence the partial pressure of water vapor in the containment remains constant.

Thus any steam that is vented from containment is replaced by vaporization frcm the sump, lit.

Q m

~'

'st,in ~ ~st vent The pressure variation in containment is then gcVerned b'.

the 'tentir7 cf ncncendensibles, and the minimum design venting rate (i.e.,

that which arrests the containment pressure withcut reducing it) is (Qvent) men -_ "MC,in 2,iC The mass influx of noncondensibles can be estimated by assuming that 100% of the decay heat in the molten core is transmitted to the ccncrete and that the concrete is thermally in c.uasi-ec.uilibrium (i.e.,

that the penetration rate of the isetherms is equal to the melting rate of the surface).

Thus Adec

'"NC, in ~~ <NC, ecnc H --

e =n e

=

e A6

' r

/- v) J i~, c,l 6

Assuming that

(

c calc'dations correpend ng to qdec =

the 7.:ree-Mile Island core after 20 decay davs), that H.=

1330 STU/

Ibn (from considerations of the sensible heac and heats of -feccmposi-tien and.elting in concrete) and that f,,

0.27 (a representa-

=

tive value for limestone concrete), it follows that

.'NC'in 3

E'urther assuming that ;NC 0.067 lbm/ft (from Battelle calculations

~

=

at a 21-day decay time), it follows that ( O.. a.. ), 4.. = 470 cfm.

. w. a a

3.....

-g, 4

,,4 4.,,. g. 3. e u m, 7,.

u, g

-.. s. d e." '."..' ;'

'- - ~-. e. '.. ". ' -

-^

....o.

o...

-.u. g.. 4..;...g.,....,1..g 1

.g 3

...a

u. g,

n e.

u.,.,.g g

.3

-3 3e.a.

.-a...~-o......

w k1

-a

..k. e 1,na

-.a. u.e s.e_,...

n.u.a..

.a

.--_.n.e

u. e,..

.n-p

,. a n. a_.-

u_,. u..

e.. sea

.u. a

(

A.

g A a r,,7

u..g a.

e.'.., u. p d u,,j.

.c 4. 3 a. 4 r,,.

., gor.-

w

- e.. - _

y

-a

.-2.A-4..

• .g

.3 g.-

y-a.A.

..e.,

ug y a..-.. 3,.i.

4,

-,,...e a.".i " v -.'

"..".'.'a'

.e.c.

a.

s

,..,a...'..,,

,.a.,'.

-.s g

a.

n.: '..' z

.'m' nssg,,, -

u. a,.

a..,z

k. :.. y a

e. 3, g m.a.....

.c e;

-. 'v i u..-

?

u. e

, f <,- -...,

=

,/

4 7

o. t, 3...

e..a.-;

n.. e ; o-.u.,"

. u. a a,e....

e... e.- -, C.7

, C.,.;

r...

2.,)

a,A a u.

s.

v.

3 a;a.

.u r

r e -,...

-..,.,,. 3

,,,.s,i,

.#. ^,'.' c w s.. ". " / r.,

'..' v' - 3. #....

n..a a

s.

s-..

h, s o e.. *. 4..3

. a *m e,

...e

, e.

wa e ac,-....

7a-4n..

w u.e

..,.a.-

.a..,

n.

..cu'd 4..4 4 .' / be a."cu' 3o,000 yal'cnse' day, a ' *..". c ".".. ..' a"

".'.a.

~~ ^ ".' #

3

~

decrease during cperation (see next section)

. c

.- a,. a... p < u a s s.4,t e.. a.

. - a s u.- - n,,.a c -....-.. a e..u. a a ; a. a....,

m 2 ". c..4.#.i e

.'a*a s.".c u.' d ". e.;.. c.' " AeA

.". e - -... e e...... c e '.. - ~..". e s "2 s a..

e The ficw through this crifice, even at the centainment venting pressure of 45 psia, is not expected to be choked, and so the ficw rate can be d

e<-

essed ""

..".a.

1. ^ ' ' r w.i....,.i s e n -

v~e'.i -

.#1 w.- a..l,.i c 1

..c d.4#. 4 a.d-a

-.i -

a e.

~2 e.k.a.v n p C n e.:..:.4 m.;e..u 3

0 t o,.(y -1) /v - c o ' 72 c-vent

<v

=

=

or

.m

'J w

i el j,'

.)

s

The pressure upstream of the orifice, p,

can be taken to be the con-tainment pressure, but the dcwnstream pressure,

c. ', depends upon the details of the venting system (i.e.,

the pressure drops through the ducts, valves, pumps, water lutes, water pools, sand f.4.lter, etc.).

If the system is desi ned to minimize.cressure drops (i.e., lar3e

~

w e

ducts, efficient lutes, e.t.:. ), then the major pressure drop in the system can be taken to be -he hydrostatic pressure difference in the water tanks.

Hence,

., e

- ~~

o.,

- a t,

-e, w-

-- 3 0 0 0 m.#...,

. o c._,

- 43,s;a,

..s.

e e

. ~...,f e r_ s. g

.a.

S

...A r*

- g.g,

--wu. O.nA'.

,w-1. w,

. w..'

-1

-. 3

.w,.

a.w.r, 1.a w

., =

,g n,,

.w v

.a w

. a... v -

.w,.

.6.e.. a..: e

_.1_4 _,.,.e o_

a__.._.

7.7

... - w. a s.

-w s..c u,.' _a w

w

.o

_e

.c,

... a.

a. c - n. A.:.. -

ag..

4, w,.< a_ d..9 o W ". A.".*. 4.".";

.".'~.e,

~.'.*A".

" 'y

. y y

. ~

yv.

y 7 /'

p

\\

ai ven:

v(v + 1) $ce

=

s O

Y w

,y s

a w

7 r=,.1.

e A.

4.

e 1.J', s v v s,em.

7^A w

= =,

c.

.a w.

e F,

- #)

. 9 4

i.a~

v A8 6

4.

CONTAINMENT RESPCNSE (RELEASE OR RECIRCULATICN MCDE)

Dropping the assumption about an infinite water sump, it is pos-sible to write down the equations of mass and energy censervatien in che containment in a fairly simple form if it is assumed that (1) the heat transfer to the building structures is small and (2) the sump water remains in equilibrium with the atmosphere.

These equations are as follows:

Ccnservation of Species:

Steam 6: 3

~

r

( ~1.

r-

~- -

'c dt

"'st,in - ~ st " tent Ccnservat..c. of Species:

Noncendensibles d""C r

('~

a' (2) s y

= -

c dt

"'NC, in - ~NC " vent Ccnservation of Energy:

Sump and Atmosphere d(m h) d(ch) sumo w

w

-

• vent" c

dt dt "liC,in "NC,in _ ~n w

= -

g w

+,

a "NC vent"NC, circ (3) e

, r

)

i

~

$o ns

,J s-e

where p= p

+

"e st NC ph=p th

+h

) + ;

st g

'.g,C h

= c T

w p,w h

= c m

"NC p,NC b

p,NC 'NC,in

"'iC, in - c (4) u

- C "NC. circ p,NC ' circ dmsump m

= -

dt st,1n 0 for release mcde w=

1 for recirculation mode Introducing Equations (1), (2), and (4) into Equation (3), the equaticn for energy conservation can be written as follows:

d*^

I (o e

p,NC)

V

-m c

l st p,w

NC c

+

c sump p,w dt st,in '5fg + % c,in p,NC ( *' NC, in

• )

= -m c

si

+0 Q

c (T.

- T)w (5)

NC vent p,NC circ Together with these is the equation for phase equilibrium: -

do do sat sat dT ct cT (6)

=

dt

)_%r.; 7 A10 O

6

as well as the perfect-gas equations of state:

p s.

(,,.,

A.

sat -.b.3_

0 s

..C a

o=

g7 (g)

' 'ri, 0

'bC By cctbi :ng Equations (1), (6), and (7), solving for dT/dt, and sub-stituting into Equation (5), one can derive the following equation for

.m s t,

',.3 n

"s t, in - ~ sc

• vent ^

.n

.,f (9)

~

where

~t,.C,.4 c. c,..C ( T.,.C. 4.,. - TI 2

C Q

n-st vent rg

+

-c,NC\\' circ - *)~

/*

o Q

c NC vent o

(10) n "st" vent"fg and dc sat

-1 0

Vh p

dT st c fg sa.-

,,,)

t.

(c V

+ msump)c Vc T

p,w

• 0,,C c p,NC st c Closure is formed by borrowing the following expressions from the pre-ceding section:

=dec (12)

"hC,in NC,ccnc li e.,.,

• 1i Ass

~,s

_, c j

)

1/,-

( *r

., ),/ y '

c o 2v c'

-o-cA 1-Q (13)

=

vent D or y

-1 o

0 c'

gH/c (14) a

+

=

o w

o The solution of these ecuations involves a straigltforwari first-e.

~.4.-..e 4.'..a c.

' *. i o n..

.A a

a.-..ic".'a.-

~ _4...e,..='.u'=.e..,.,..

a..d-a

..u

n... e.,,...c..,,.

r.e-.,. 4

.. s ( _7 7 ) * "..- ^ u c. k.

('4),

o " ' _4.. - e, m,,

,/ d "'

• ..- ^... s e -...

--.s o.

,3,as, a '. c u ' '. e,.

1. .~.

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a m ext.ected reduction of *.his value with time.

The molc~ular weic.ht of ncncendensible gases was~taken to be 29, their temperature emerging

.c,-.-

..w.e

.,c i. e.,. c

o...a s ' ' k. a.. as 2000*

.7, a. ~d

..".e.'.-=..+..'"-a " c.".

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4

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.f a.,, e,.

-e, v_.e,

. a. w,_

2-

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3

--,,,s

..... a 9 ?ss estimates.

It is to be understocd chat these calculations give an indication

..".a.

_' _d k e ' v,

a..#.# e " *..' v e..a s s o.#

. '...i s v a..n '

.#.i.'. e -

4.. a 4 ". ". a - a.e_'a_ase o_-

^

recirculating =cde, but have several shortcomings that would have to be

.~ ^..- a c. e d ;

a

....e de*.aiied

=..a.

s.4

".' h e

...'....'.-v, a.-e a s w".e.-a

.'...e. v v e -

-^

v e

me. hts are nee ec are as :clicws:

s -

~

(1)

Setter representation of the pressure drop in the' vent-filter

-n s..-.Cae..

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e i.

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a 6

300 P

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w=

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5 250 s

s E

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/ VENTING-RELEASE

~

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w E

a W

200

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h 2

G

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g 5

VENTING-RECIRCULATION P

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t f

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\\

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.)

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5 50 3=

w

=

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=

m e

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==

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' ~ ~ - - - - - ~ ~

~

v

=

u o

a u

m

~

VENTING-RELEASE

'[

20 0

O 1

2 3

4 5

TIME FRCM INITIATICN CF VENTING (DAYS)

' '~

A13

,n 7 i

3

/_ J c l

6

i i

i i

{

3

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\\

S VENTING-RECIRCULATICN

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e 2

52 0

VENTING-RELEASE s

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=

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3

=

4 i

i 1

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5 o.

C u s-

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o

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/

=

a

/

v=

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3?

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/

e

/

c-VENTING-RECIRCULATION s

/

5C e

N/

E 60

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/

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d*

/

cm2 l

55

=

/

s

/,/

/

I

=

5

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y g

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/

- VENTING-RELEASE j

2

/

5

/

~

d

/

/

O 5

/

G

/

2 h

[

0 O

1 2

3 4

5 TIME FRCM INITIATION OF VENTING (CAYS)

A14 f a; u', r 7 ;

e, i)

(2)

Cocrdination with concrete thermal respense.cdel to g fe better estimate of ncncondensible gas generat;cn.

(3)

Better characterization of noncondensible species, particu-larly to define equivalent molecular weight.

'4)

Better estimates of T,.C,in and T NC,cire.

(5)

Inclusien cf containment structural heat sinks.

S a

} ' '/

o F.

A15

(_ J L 6