ML20140G231

Requests Addl Info Re NEDE-20942-P, Safety Relief Valve Discharge Analytical Model, Including Evidence Demonstrating Random Oscillation of Air Bubbles Discharging from Relief Valve Lines

ML20140G231
Person / Time
Issue date:	10/16/1975
From:	Butler W Office of Nuclear Reactor Regulation
To:	Stuart I GENERAL ELECTRIC CO.
Shared Package
ML20140F372	List: ML20140F369 ML20140F376 ML20140F485 ML20140F505 ML20140F512 ML20140F516 ML20140F522 ML20140F533 ML20140F546 ML20140F559 ML20140F580 ML20140F593 ML20140F603 ML20140F628 ML20140F657 ML20140F689 ML20140F695 ML20140F724 ML20140F750 ML20140F770 ML20140F788 ML20140F807 ML20140F950 ML20140F981 ML20140G002 ML20140G028 ML20140G069 ML20140G098 ML20140G110 ML20140G170 ML20140G175 ML20140G183 ML20140G188 ML20140G202 ML20140G215 ML20140G221 ML20140G226 ML20140G231 ML20140G236 ML20140G241 ML20140G253 ML20140G259 ML20140G264 ML20140G268 ML20140G274 ML20140G280 ML20140G286 ML20140G303 ML20140G325 ML20140G330 ... further results
References
FOIA-85-665 NUDOCS 8604020029
Download: ML20140G231 (8)

Text

_ _ _ _ . - -

/ 'M"

'l: .? ' - '

C Qa . /-

n.) _

tT 1 6 spistribution i Central File NRC PDR LWR 1-2 File Central Files - Topical Reports R. Boyd 7 G. Lainas -

.,f E. Butcher

. Mr. Ivan F. Stuart, Manager S. Hanauer g V [,,0 p" DTIE

• j Safety and Licensing NSIC /27 (/./

i Nuclear Energy Division TIC 175 Curtner Avenue

.'! San Jose, California 95114 M 8"

~~ ~~ ~~

Dear Mr. Stuarts 1 ["~~

We have. reviewed the deneraLElectric Company topical report NEDE-20942-P,'

" Safety Relief Valve Discharge'5nalytiical Model," .and have identified the following three areas where additional information is required:

. 1. The topical report does not provide sufficient evidence to demonstrate

' that air bubbles discharging from relief valve lines vill oscillate i in a random manner. The combined pressuro loads frors several relief l' valve operations will be significantly higher if the bubbles oscillate in phane.

2. The topical report does not consider several parameters which may

be important in the relief valvo analysis. We believe that the following effects should be included.

I .(a) pool motion;

, j (b) pressure wave from adjacent relief valve operation; and ,

, (c) sequential actuations of relief valve.

j 3. The topical report does not justify neglecting some key parameters, 4 .,such as bubble size and bubble distance from the wall,'in the method

. j of innges employed to analyze boundary effects on bubble antion'.

! We require your response to the enclosed Request for Additional Infomation to continue our review of tiEDE-20942-P.

i Sincerely,

-l Ort:innt =fgned by m'rrtutbr

~'

. 8604020029 060114 Walter R. Butler, Chief

'l' @ES 5-665 PDR E * ""*** ** * " "#""""

Division of Reactor Licensing Euclosures i As stated -

u ,..

. 2

.,,,e., L: LWR 1-2 LaLWR 1-2

{

, , . . . , EJher/

7791 red .,%,.

_TR_

Su

) h WRButler V

. .n > 10/)5/75 10/p/75 1,0/875 _ _ . . .

A - Arc iniTC,m AFCM 0244 . . W u.s.a**ve. mur o .r.:me eersc ar o m . ..*. t pe , * . _ . - . . _ .

n

1.

! 4 f*

.- n.' q. .

t  ! *

- 2- OCT 161975 itr. Ivan F. Stuart I

t ,

l .

j  : cet ifr. L. Gifford

! General Electric Cosipany I ' 4720 !!ontgomery Lane, Suite 1107 l

-' Bethesda, Maryland 20014

~

r

. . . ,1 4

Ji *. I i  :

4

.: 6 I .

l  !

I t

. 2 I

.i 4

j

• t

. . i, j

i i .

1

-l t l 1 e .

! l t i -

1 t

i i

l

.f 1

i

• =i ,

t 1 .

. 1

, 1 .

2 s

.. 1 1  !

j '

j .

1 > , .

1 .

4

)

I ,

1 1

i ,

o** < e v . . .:..

l . . . . . - . ..- - . . . . . . .--

i. *

.u . . e

• I e...=- . _ . . . . . .

> .. r, 4 t .: . s a,. o * . . A rt er r

• sa ._.*.....a-o.a--**---a**=.......... -- --

- . - - - - - , - - . , --,_,, ,,,-..,,w-n.--,--.,----e -,-----.w-,.. - - , , . - - - - . . . ,-we,---.w---s-,--.=....v---- ..e,.m-mev-~-

--c ,- -

l d .

l p' ..

b .

i .

4

l. REQUEST FOR ADDITIONAL INFORMATIOT.

Report Number: NEDE-20942-P j Report

Title:

Safety-Relief Valve Discharge Analytical Model, May 1975

. .! Originating Organization: General Electric Company

] Reviewed By: Containment Systems Branch

. ., 1. On Page 5, Section 2.5, it is stated that "Since one complete cycle of bubble oscillation is about 0.1 seconds, variations in pipe

~

j length, opening time, submergence, etc., are sufficient to give

't

' I a random distribution of the phase angle among bubbles produced i by simultaneous activation of several valves. The resulting load at any point is, therefore lower than it would be if all bubbles

. wdre in phase."

,' (a) Analytically show that bubble oscillations cannot be in phase if two lines have different pipe length, valve opening time and submergence. It should be noted that a relatively  ;

., short pipe length coupled with relatively deep submergence ,

I J could result in bubble oscillation in phase; .

i t

(b) Provide an analysis to show that the pressure oscillation *

. , resulting from the two bubbles generated from the same ramshead will not be in phase.

i -

.i

1 l 2. Provide a transient analysis of vent clearing, pool dynamic, and '

- - *. bubble pressure phenomena-as a result of multiple actuations of  !

i

.! relief valves. Include the following

.; ,'; (a) Description of the analytical model, including all assumptions and equations.

• i .

q ..

s i

e , ,

.. . . . . . . . . - . . . - . . . . . - . . . . . . . . . . + = . - - . . =* - -. - .-- * + - " - - ~ + - *--~ ~

i l

< .1; .

(

(b) Graph showing the vent clearing time and pool dynamic and

.' bubble pressure as a function of the sequential actuations

. 1

-1 of relief valves. The number of sequential actuations of relief valves analyzed should be large enough to clearly indicate that the bubble pressure due to multiple'actuations has

• -y reached the maximum value.

1

. (c) Graph showing the peak wall pressure, positive as well as t

. ') negative. as a function of.the sequential actuations of 1

, ,-,j relief valves.

(d) Verification of the analytical results by comparing them with experimental data.

3. It appears that equation (8), on page 9, describing the motion

, of the water plug, was not developed using the assumptions in the model. According to the assumptions, the velocity of the ,

water leg is not a function of the water leg length. Clarify -

this discrepancy.

] 4. On Page 9, Section 3.1.3, it is assumed that the' pool initially

,' is motionless and that pool' pressure and temperature are at normal operating conditions. Provide the effect on the calculation if the

following conditions are considered

,- (a) Pool is in motion such e agitation by adjacent relief valve (s) operation; and (b) Suppression chamber pressure and temperature have been elevated due to other relief valve (s) operation.

t #

.. I

~

_.__........-.-._.._..._,_m.._..__...._. . . . . . . -.

n e

i  !

)

o. o -

l

- 3-

5. On Page 16, Section 3.2.3, the initial bubble radius is taken to I

be the same as the inside radius of the ramshead. With this assumed l d

1

. bubble size and the bubble initial pressure calculated from the vent l ~'.j clearing model, the bubble mass is completely determined. Does this

, v determined bubble mass agree with the air inventory initially inside 1

the pipe?

j 6. On Page 22, Section 3.3.3, it is stated that, "The following function 4

, meets all the requirements, provided the distance between adjacent

,j bubbles and sinks is much greater than the bubble diameter."

l Quantify the limits on the "is much greater" criterion in this i statement.

i l

!, 7. Equation (35) appears to be extrapolated from the equation (34), .

i which was developed from the analytical model by assuming single l bubble theory without boundary effects. On the other hand, equatioh 4

.. (35) is intended to include the boundary effect (Method of Images). ,

s

Discuss and justify analytically how equation (35) was derived to

.i .

include boundary effects.

8. The Method of Images has been developed by simply neglecting many

.)f

,j parameters such as bubble size, bubble distance from the boundaries , '

l

., and pool water motion due to adjacent bubbles such as the bubble

_I formed in the other end of the ramshead. Justify this simplification

.k

! in your analytical model.

)

. I

. 9. On Page 25, Section 3.4, it is stated that the buoyancy force

• l 1

acting on the bubble is assumed ta be one-half the displaced mass.

O I

I. I Q

l

]

Justify this assumption analytically.

, 10. Identify which test of the Quad Cities' tests has been'used for Figure 11.

1

11. On Page 50, Appendix B, it is stated that "the flow is sonic at _

, both sections. . . ." , while it is also stated on Page 11, Section

'! 3.14 that "After the water plug is expelled, the air leaves the pipe

.g .

s at sonic velocity." The inconsistency of these two statements is I

illustrated by the following:

t i

1 c .

y

_A__

I I

. V, y a v',

. A,

i g

. 1 4

j -

}

{ Appendix B specifies that the velocity Vy is sonic, while Section l

. t 3.14 says V is sonic. Since Ay is equal to A and flow rate passing A g is equal to one-half of that flowing through Section A, the t

velocity Vg should be one-half of the velocity V. Explain j this discrepancy and reanalyze the pool response if necessary.

. I 1

. .'j ,

1 d .

flYrtl22 3 I

MARK I HEADER LOAD C0:1SERVATISMS'r/-j BOU:lDARY C0:lDITI0tlS ASSUMED ALL AIR CARRY OVER USED BREAKTHROUGH liEIGHT OF 2 X SUBMERGEtlCE BODEGA IllDICATED 1,,5 X USEDIf1FlflITEOCEAtl(SOLIDWhTER) 1-2'LIGAMEilT EXPECTED AT HEADER ELEVATION PEAK DN PRESSURE CollSERVATISMS MODEL CALCULATED LOAD IS 20% HIGHER THAf1 MEASURED (USIflG T BOUMDARY CO.1DITI0ils)

CO.'!CLUSIO:1:

TOTAL C0:lSERVATISM MAY BE AS HIGH AS FACTOR

~

OF TWO D4R 11.9.75 4 e