ML19208A389
| ML19208A389 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/22/1979 |
| From: | Jay Collins Office of Nuclear Reactor Regulation |
| To: | Stello V NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| References | |
| NUDOCS 7909130504 | |
| Download: ML19208A389 (4) | |
Text
..
April 22, 1979 TO:
Victor Stello, Jr.
FRCM-John T.
Collins
SUBJECT:
PADl0 LOGICAL ASSESSMENT OF OPERATION OF OTSG-B IN SOLID MODE ine radiological consequences o# ope ration o# OTSG-9 in a solid made have been identified and evaluatec as follows-2.ac;oactive hateria inventorv TF e.ve : e r volu.re of the solid system was calculatec to ce 28,000 3
cal or 1.1
- 10 c:.
Basec on a steam generator water sanole taken on 4/19/79, the i n ve r. t o r v o# the princical radionuclides in the svstem is:
1-131:
59 Ci C s - 13!- :
0.57 Ci Cs-136:
0.:2 Ci Cs-l?'-
2.6 Ci
- -;n:::a' 'eaLace Pctrs Tne principal ootential leckage cath for escape of radinactive.a:e-ials
'r:- the svstem to the environment is the elease o# cases evolvec 3s
- ,e svste, acter # 10w passes through tne main concense, with the gIses being removec # rom the system bv the mechanical vacuum puros.
.icuic ieakage, rach as nas be exoected # rom cumo seal s and valve ste s, will ce colle :ed i r.
the turoine cuilcino sa os.
l' the solid moce is asec, al! turbine building sumos will be aligned with the c:in c e r s a t e
- Clis:ing regene ation sano and :"en routec to the Misce!'aaecus
..c t e r Hol cus Tank for o ocessing, i' requi ed o-ior to discharge.
D (0).1; [g].
7 9 0 913 0 g'y (in cn 1
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. c@.-- ;fl lll [,
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> Gaseous E#fluents Non-condensible gases will be removed from the main condenser by the mechanical vacuum pumos.
Outout from the cumps is ducted through a treatment system consisting, sequentially, of a HEPA filter, charcoal adsorber, and HEPA 'il ter, be' ore being vented to the atmospaere througn the Unit 2 vent.
All Unit 2 vent releases are monitored by the plant vent monitor, HPR-219 'or noble gases, radiciodine and carticulates.
Potential releases via this pathyay were calculated, based on tne following assumptions:
1, 1-131 con:antration in the solid system is 0.54 uCi/cc (based on 4/19/79 inventory of 59 Ci).
2.
Pa -t i t ion Fact or in the steam generator is 1, since no steam generation occurs, i.e.,
all activity present would carry-over to the condenser-3.
No plateout in the bvpass lines to the condenser.
4 Althougn in the water-solid condition little evaporation would occur, evaporation in :ne main condenser is assumed to ce of 1% of flow.
At the expected fl ow of 1,500 gom; evaporation is 15 9pm.
h u t, l -; _nj J,
'3 T l @7 nT g g a,,u w,,
w Uh j UL 1/.rd __a i
e u
. 5.
Partitioning of iodine to the vapor phase during evaporation of 0.0001 (PF = 0.0001).
6.
Efficiency of charcoal adsorcer of 99% for radiciodine.
7.
Plant vent total flow of 37,000 cfm-CAL CULATI ON
?,elease = 15 c61 x 3.8 x 103 10-4 x 0.54 uti/cc cc x min gal
= 3.1 uCi/ min Treatrent DF of 100 3.1
= 0.031 uti/ min 100 Stack fl ow 87,000 cfm:
Cmc
= 0.331 uCi/ min
= 1.3 x 10-II uCi/cc 8.7 x 10- f 3/ min x 2.83 x 10 cc/ft This resul t, 13% of unrest ricted MPC at the plant vent, assumes that a constant source of I leaks from the primary system to the secondary to reolentisn the I lost by radioactive decay and discharge.
Even i' a 20 gallon / day leak were to occur in the steam generator with an initial primary I level of 3 x 10'2 uCi/cc, the contribution to tne i release at the plant vent would not exceed 2 x MPC.
At of'-site locations, the concentrations would be less than 0.2% of MPC.
Summarv Operation with B steam gene ra to r in the solid mode, with cooling f l ow througn bypass to tne main conaenser, would result in generation J
su 3480 %
(], ric g, 4.,i 4. p e
b _ b b..;
Nj b S
4 of additional iodine releases to the Unit 2 vent.
Tnese releases, however, are calculated to be less than 2 x MPC at the release point, and less than 0.2% of MPC off-site even for significant steam generator leakage from the prinary system.
Liquid leakage is expected to occur; however, such leakage is expected to be of small volume and would be collected for processing within existing unit collection i
and processing systems.
No environmental impact would be expected I
from liquid leakage.
M John T. Collins
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