ML20140G236
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UNITED STATES [
NbCLEAR REGULA TORY CO.*.1 Mission W ASHINGTON. D. C. 20555 l
< DCT 0 61975 i E. Butcher, Program flanager, LWR 21-2, RL l
REVIEWOFGEllERALELECTRICTOPICALREPORTNEDE-2094-P(TAR-1270)
Report Number: NEDE-2094-P Report
Title:
Safety Relief Valve Discharge Analytical !!odel Responsible Branch: LWR l-2 ;
j DRL Program tianager: E. Butcher i Requested Completion Date: N/S
{ Review Status: Incomplete 4
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- As requested, the Containment Systems Branch has reviewed the GE Topical l Report (NEDE-2094-P) and has prepared the enclosed question list regarding i
additional information.
- In the course of our review we have identifid the following es sig.1f ficar.t review items
l f 1. The applicant has not provided sufficient evidence to j prove that air bubbles discharging from relief j valve lines will oscillate randomly. The combined t pressure loads from several relief valve operation will
! be significantly higher if the bubbles would oscillate j in phase.
- 2. The applicant has not considered several parameters which .
may be important in the relief valve analysis. We believe that the following effects should be included.
l
, (a) pool motion; (b) pressure wave from adjacent relief valve
- operation; and
, (c) sequential actuations of relief valve.
J j '3. The applicant has not justified the negligence of sona key i parameters such as bubble size and bubble distance from the wall in the method of images, which was employed to analyze boundary effects on bubble motion. .
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! / .
l .j. .
7 Gus C. L11nas, Chief -
Containment Systems Branch
] Division of Technical Review i
1 g 40 g 1 340114 -
- FIREST005-465 POR
I E. Butcher
Enclosure:
As stated cc: S. Hanauer R. Heineman R. Tedesco J. Glynn W. Butler R. DeYoung J. Kudrick J. Shapaker fl. Su R.Boyd(w/oencl.)
W. itcDonald (w/o encl.)
E. Jaco's a
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4 REQUEST FOR ADDITIONAL INFORMATION Report Number: NEDE-2094-P
, Report
Title:
Safety-Relief Valve Discharge Analytical Model, May 197S 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 length, opening time, submergence, etc., are sufficient to give a random distribution of the phase angle among bubbles produced by cimultaneous activation of several valves. The resulting load at any point is, therefore lower than it would be if all bubbles were in phase."
(a) Analytically show tnat bubble oscillations can not 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 could result in bubble oscillation in phase; (b) Provide an analysis to show that the pressure oscillation resulting from the two bobbles generated from the same ramshead will not be in phase.
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- 2. Provide an analysis for predicing vent clearing. transient, pool dynamic and bubble pressure as a result of multiple actuations of relief valve. Include the following: .
l a, v pien <} 4 a,ed yt. ca f M s~fe b". N'I'y Wl (1) Provide the anaTytical model including all assumptions and a >iu & 6 ./ cya/cm equations; (i l
_____---__-______.._____---- --..-.- -.- --- -_ - _ A
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y; j ., ,
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f,qhsdexpc. n /f & g y A " Ob ~~ l'?)V Y' '
- 3. OnJage4,JEqueuvrF(d) for/the motion of the viater plug appeees
-the*=t4 was not develope [ sed he assumptions used in the model.
According to the assumptions, the velocity of water leg is not a function of the water leg length. Clarify this discrepancy.
- 4. On Pagel, Section 3.1.3 it is assumed that the pool initially remains motionless and that pool pressure and temperature are at normal operating conditions. Provide the effect on the calculation if the
! i following conditions should be considered: '
t (a) Pool is in motion such as agitated by adjai:ent relief valve (s) operation; and ,
(b)
- Suppression chamber pressure and temperature have' been elevated due to other relief valve (s) operation. t '
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- 5. On Page 16, Section 3.2.3, the initial bubble radius is taken to 1
be the same as the inside radius of the ramshead. !!ith this assumed bubble size and the bubble initial pressure calculated from the vent clearing model, the bubble mass is completely determined. Does this determined bubble mass agree with the air inventory initially inside j the pipe?
i
- 6. On Page 22, Section 3.3.3, it is stated that "The following function meets all tha requirements, provided the distu:ce between idjacent i
j bubbles and sinks is much greater than the bubble diameter."
! %nh //a / sin.% en m "i .s n.c c / 9,v .+ < G //n c ~
a ~
Provide e criteria to which this statement c8'n be applied.
-flo.1 s-N .4 . ~~ ~+
! 7. Equation (35) appears to be extrapolated from the equation (34),
i which was developed from the analytical model by assuming single i
buSole theory without boundary effects. On the other hand, equation (36) is intended to include the boundary* aeffect/r c~ ((Method J D
- e v' of WurImages).
b c" b-I Discuss and justify analyticall[h m the ap icability of equation (33).
\ .
,4.*ch </s h mi dcs~/ e//c ch-i
- 8. The flethod of Images has been developed by sinply neglecting many j parameters such as bubble size, bubble distance from the boundaries I .
and the flow from adjacent bubbles such as the bubble fonned in the I other end of the ramshead. Justify this simplicity of your analytical i
model.
- 9. On Page 25, Section 3.4, it is stated that the buoyan:y force
, acting on the bubble is assumed to be one-half the displaced ecss.
e d
l 1
e Justify this assumption analytically.
- 10. Identify whicii test of the Quad Cir,tes' tests iias been u:ed for l Figure 11.
- 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 leavas the pipe
. at sonic velocity." The inconsistency of these two stateraanti cetrl+
is '/h :d M h*I O M F IN'& y be-::itlytxplained by dw fol-hr. ring grapn:
l l
L^ '
V Yo l i l V
p ,. ; . 'Is
_= l v i i Appendix B specifies that the velocity Vj is sonic, while Section 3.14 says V is sonic. Since Aj is equal to A ar.d flow rate passing
, Aj is equal to one-half of that flowing through Section A, the velocity V) should be one-half of the velocity V. Explain this discrepancy and reanalyze the pool response if necessary.
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