ORNL-1816 - the Molten Salt Energy Technologies Web Site

ANP QUARTERLY PROGRESS REPORT
Sources of Energy
TABLE 2.2. SUMMARY OF KEY DATA ON ART HAZARDS
Heat from combination of 1000 Ib of No and NaK with water
Heat from combination of 1000 Ib of Na and NaK with air
Heat from combination of 1200 Ib of zirconium-base fuel with NaK
Heat from combustion of 34,000 Ib of shield kerosene with air
Heat from extreme nuclear accident
Fission-product decay gamma heat emitted during first 2 hr after shutdown (assuming no
fission-product removal)
Sources of Radioactivity
Total fission-product activity for saturation
Gaseous fission-product activity for saturotion
Sodium activity in moderator circuit for saturation
Sodium activity in NaK circuit for saturation
Temperatures Associated with Accidents
Flame temperature for stoichiometric NaK*-H20 reoction
Temperature of reoction products for Na*-zirconium-base fuel reaction
Temperature of atmosphere in 12,000-ft3 tank (assuming uniform dispersal of
combustion products from Na-H20 reaction)
ture rise of NaK-H 0 reaction products and shield water if uniformly mixed
2
Maior Radiation Sources and Doses for Typical Conditions**
Equivalent source for 011 fission products
Equivalent source for inert gases only
Rote of generation of activity in the form of inert gases (assuming 20-min holdup in
atmosphere of expansion tank)
Same as above but for 420-hr holdup time
Dose at shield surface during operation
Dose at shield surface 15 min ofter shutdown
Dose at shield surface 10 days after shutdown
Dose outside 24-in.-thick concrete wall 15 ft from center of reactor during operation
Same 15 min after shutdown
2.1 x lo6 Btu
2.4 x lo6 Btu
0.13 x lo6 Btu
635 x lo6 Btu
0.3 x lo6 Btu
8 x lo6 Btu
6 x lo8 curies
107 curies
io5 curies
35 curies
307OoF
3300'F
31OoF
62' F
4 x 108 curies
108 curies
1000 curies/sec
1 curie/sec
100 r/hr
4 r/hr
1 r/hr
0.025 r/hr
0.001 r/hr
*Initial temperature assumed to be 1500'F.
**These key data for typical conditions were developed for the major radiation sources and doses by assuming
1000 hr of continuous operation of the ART at 60-Mw power level with on1 the gaseous fission products coming
off and by assuming the reactor to be encased in an aircraft-type shield wiich gives a dose of 1 r/hr at 50 ft.
source of energy. The heat that could be released
from the combustion of the sodium and the NaK in
the moderator and heat dump circuit is relatively
small; thus it seems that water should be used as
the shielding material rather than kerosene, be-
cause, even if the water were to combine in stoi-
chiometric proportions with all the sodium and the
NaK in the system, the resulting energy would
still not present a difficult problem. The heat
that would be released from a nuclear accident
depends in large measure on the character of the
accident. However, the value presented in Table
2.2 is that for the worst accident that can be
36
envisioned, that is, one in which uranium abruptly
begins to precipitate out of the fuel in the core so
that the fuel is carried into the core at the normal
rate but no uranium leaves with the exit stream of
fluoride. While hardly a credible accident, this
does seem to represent the maximum rate of in- ' .
crease in reactivity and, hence, the extreme nuclear
accident conceivable for this reactor.
-
The second portion of Table 2.2 presents the a *
equivalent radiation sources for the various fluid
circuits. The values given for the sodium and NaK
P
activities have been obtained from multigroup
calculations.
5
F
*
; f
.