ML19317G577

Effects of High Energy Piping Sys Breaks Outside Reactor Bldg, Revision 1 to GAI-1811

ML19317G577
Person / Time
Site:	Crystal River
Issue date:	11/06/1973
From:	GILBERT/COMMONWEALTH, INC. (FORMERLY GILBERT ASSOCIAT
To:
Shared Package
ML19317G575	List: ML19317G574 ML19317G577
References
GAI-1811, GAI-1811-R1, NUDOCS 8003191153
Download: ML19317G577 (4)

Text

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Docket 50-302 November 6, 1973 REVISION Effects of High Energy Piping System Breaks outside the Reactor Building GAI Report #1811 FLORIDA POWER CORPORATION CRYSTAL RIVER III Remove the following sheets: Insert the following sheets:

Page: 38. M: 38 and 38a.

Pages: 50 and 51. Pages: 50, 51, Sla, and 51b.

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g / . <* - pt, _ J/ 3 hydraulic model, it is considered unreasonable to neglect the jet for the sake of additional conservatism. Also, the estimate s

of pressure is conservatively low and should be included. -

everal models are investigated with the loading combination se ce described to datermine the relative effect of the various force

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Earthquake d initial pipe stresses are 'found to be insignificant in the restrain dynamic response. Consequently, rupture thrust, .

jet, and pressure ansients are used to evaluate the dynamic response of all propos restraint configurations.

4.5.1.7 Acceptance Criteria \

Subsequent to modeling and ecuting ex\the dynamic transient, N

the details of a trial restraint salution are considered in j two parts before the solution is acce ted as final design.

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Different criteria are applied to transi\nt and steady state behavior. -

During'the dynamic transient, all elements are examined to ensure that the restraint system is not approachi

\ failure.

This is accomplished by limiting the curvature and s aring

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strain of flexural elements to approximately 50 percent of _

' their corresponding ultimate values. To be consistent wit this criteria, the maximun strain and deformation of axial

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and rotational bilinear or special springs are such that they

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do not exceed 50 percent of their ultimate values. Once an \

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c. Circumferential breaks are perpendicular to the pipe axis, and the break area is equivalent to the cross-sectional flow area of the ruptured pipe. Although the effect of jet forces on structural elements from the circumferential break is debatable, in most cases it is conservatively assumed that the full jet magnitude is effective to each side of the break. However, in a few critical cases where structure and restraint keep the two halves of the rupturing pipe approximately aligned, it is reasonable to assume that the .

jets are partially aligned and tend to stagnate one another. -

The possibility of the stagnation effect being terminated by the action of valves to one side of the break or the other is taken into consideration.

d. Live load is included as 40 lbs/sq. ft. , in conjunction with the pressure. However, for upward pressure the live load is completely ignored.

e. The following load combinations are used to evaluate the required capacity of the structural element. .

U = DL + LL + 1. 5 (Pa ) * * * * * * **** - (1) -

U = DL + LL + 1.25 (Pa ) + 1.0 (2 xYj) + 1.25 F0BE. (2)

U = DL + LL + 1.0 (Pa ) + 1.0 (2 xY 3) + 1.0 FSSE' * (3) 9 DL - Dead load of structural framing system including aity permanent equipment, pipe loads, etc.

LL - Live load during pipe rupture event.

t G I L 8 E R T A S 9 0 C I A F E S. I N C.

. . ~. , - - . . - -. - ,.

Pa - Maximum peak, differential pressure during postulated break with appropriate dynamic load factor.

Yj - Maximum jet load .

F0BE - Load gener stel by operating basis earthquake. The value assumed for investigations are as follows:

1. Ground horizontal acceleration = .05g

2. Vertical accel-retion = 2/3 cf horizontal ,

acceleration for all cases and assumed to act simultaneously.

3. For walls above Elevation 119' horizontal acceleration = 0.165g

4. For walls below Elevation 119 '

horizontal acceleration = 0.lg

5. For slab at Elevation 119' horizontal acceleration = .lg

6. For roof at Elevation 149' horizontal acceleration = 0.2g FSSE = Safe Shutdown Earthquake assumed = 2 X OBE.

f. The reaction load at a restraint because of whipping pipe is -

not considered in the equivalent static check. Those cases, where applicable, are analyzed separately, by using dynamic time history analysis.  ;

Table 4.5.1 gives the summary of typical results of the required i

capacities of the elements under different load combinations. l Required capacity from Equation 1, 2, or 3 is compared' with the l l

1 available capacity. l l

1 GILA t af A S SOCI A T ES. INC

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