10.08.2013 Views

Code Manual for CONTAIN 2.0 - Federation of American Scientists

Code Manual for CONTAIN 2.0 - Federation of American Scientists

Code Manual for CONTAIN 2.0 - Federation of American Scientists

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Table 6-2<br />

Constants <strong>for</strong> the Tutu-Ginsberg Entrained Fraction Correlation<br />

Surry(no surly sully (all<br />

Watts-<br />

Cavity I structure) I (skirt) I structure) I Zion I Bar<br />

cl I 0.136 I 0.481 I 0.467 1 0.839 I 0.263<br />

G 1.886 1.818 0.601 1.512 1.618<br />

C3 0.748 0.652 0.133 0.464 0.440<br />

c, 1.248 0.575 0.336 2.32 0.273<br />

c, 1.024 0.680 0.992 0.324 1.630<br />

c, 1.0 0.350 3.019 0.0 3.783<br />

c, I 0.630 I 0.121 I 0.558 I 0.0 I 0.522<br />

C* I 0.5 I 0.472 I 0.777 I 0.296 I 0.497<br />

C9 0.915 0.688 0.0395 0.0813 0.858<br />

C,. 6.4 2.75 5.0 3.6 5.0<br />

c,, 0.5 0.528 0.223 0.704 0.503<br />

c,, 2.319 0.958 4.467 1.351 3.451<br />

c,, 1.8 8.75 3.0 6.6 3.0<br />

6.2.10.2.3 Entrainment Time. The entrainment time is the interval over which debris is entrained<br />

in the cavity. It can be specified directly through the TDISP keyword. If TDISP is not specified, the<br />

entrainment time is estimated from an expression <strong>for</strong> the RPV blowdown time [Lev91]:<br />

-Vv in ~<br />

td =<br />

P:<br />

[1<br />

(6-65)<br />

(0.6065) (Ah) w<br />

In <strong>CONTAIN</strong>, the pressure ratio in this equation is assumed to be 0.1, which represents the cut<strong>of</strong>f<br />

<strong>for</strong> entrainment. The blowdown time t~is taken to be the entrainment time, unless the user specifies<br />

through the TSTOP keyword that the RPV hole itself grows as a function <strong>of</strong> time, over the time<br />

interval given by TSTOP. In this case the entrainment time is taken to be t~+ “tstop,” to ensure that<br />

the entrainment time is adequate.<br />

The total fraction <strong>of</strong> debris dispersed from the cavity will not be affected by the entrainment time,<br />

since the entrainment rate is <strong>for</strong>ced to integrate to a specific total entrained fraction. It should be<br />

noted that while no debris entrainment can occur after the dispersal interval has passed, the debris<br />

entrainment rate might be large enough to disperse the desired fraction <strong>of</strong> debris be<strong>for</strong>e the dispersal<br />

interval has ended. Small entrainment times may lead to very high entrainment rates in the cavity,<br />

Rev O 628 6/30/97

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!