Code Manual for CONTAIN 2.0 - Federation of American Scientists

Table 8-4
Illustrative Fission Product Targeted Release Rates
Process Nuclide From To Rates (s-l ) Process Represented
1.
137
I LAYER 1 POOL
1o-1
Dissolution
(scrubbing)
2.
137
I LAYER 1 GAS
10-3
Vaporization
3.
137
I LAYER 1 AEROSOL 1
1o-1
Aerosolization
4.
137
I POOL GAS
~~-5
Partitioning
5.
137
I POOL AEROSOL 1
lo-s
Aerosolization
6. 137Xe LAYER 1 GAS
~*-3
Outgassing
7.
137xe AEROSOL 1 GAS 5.0 Rapid gas escape
8. 137Xe WALL GAS 5.0 Rapid gas escape
9. 137Xe POOL GAS 1.0 Rapid gas escape
10. 137CS LAYER 1 POOL
1o-1
Dissolution
(scrubbing)
11. 137CS LAYER 1 GAS
lo-s
Vaporization
12. 137CS LAYER 1 AEROSOL 1
~()-1
Aerosolization
13. ‘37CS POOL GAS
~()-s
Partitioning
14. 137CS POOL AEROSOL 1
~()-5
Aerosolization
15.
137(ls GAS AEROSOL 1
1o-1
Adsorption
8.6). Finally, deposition mechanisms cause fission products in aerosol form to deposit on the heat
structures (such as walls).
In the CONTAIN input description, the hosts involved in this illustrative example are called GAS
(for the upper cell atmosphere), AEROSOL 1 (for aerosol component 1), WALL (for the collective
heat structure wall area), LAYER 1 (for a lower cell layer representing core debris), and POOL (for
the overlying water pool).
The processes simulated in this example are listed in Table 8-4. The gaseous iodine and xenon are
assumed to transfer from the core debris to the atmosphere (processes 2 and 6) at the rate of 0.1%
per second. The transfer rate of cesium vapor (process 11) is assumed to be two orders of magnitude
lower at 0.001% per second. The rapid release of iodine and cesium from core debris in the form
of aerosols (processes 3 and 12) is assumed to occur at the rate of 10% per second. Iodine and
cesium can be trapped in the pool (processes 1 and 10) and xenon generated in the pool by decay
processes can be released to the upper cell atmosphere (process 9). Any xenon hosted to the
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