ML19221A540
| ML19221A540 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 05/17/1979 |
| From: | Jay Collins Office of Nuclear Reactor Regulation |
| To: | Stello V Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7905230157 | |
| Download: ML19221A540 (4) | |
Text
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Victcr 5tello, Jr.
FRCM:
John T.
Collins
SUBJECT:
RADIOLOGI CAL ASSESSMENT OF OPERATION OF OTSC-B IN SOLID MCDE The radiological consecuences of operation of OTEG-B in a solid made have been identified anJ evaluated as follows:
F.acicactive Material inventorv The wa:er volume of the solid system was calculated to be 23,000 8
Based on a steam generator water sample taken gal or 1.l m 10 cc.
on 4/19/7c, the inventory of the princioal radionuclides in the system is:
1-131' Sn Ci rs-134:
0.57 Ci Cs-136:
0.57 Ci Cs-137:
2.6 Ci f rj nc i oal Leakace Faths Tne orincipal potential leckage path for escape of radici.t ive c.a:erials gases evolved as from t?.e system to the enviror. ment is the release of the system wcter f l ow pessis through the main condenser, with the gases beine removed from the system by the mechanicc1 vacuum punos.
Liould leakage, such as may be expected fro oumo seals and valve stens, will be collected in the tu -bine building sumps.
If the solid ande is used, all turbine building sumps will be aligned with the condensate colishino regeneration sump and then routed to the Miscellencous da e r Holcup Tank for pro:essing, if required prior to discharge.
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Gaseour Effluentt Non-condensible gases will be removed from the main condenser by the mechanical vacuum pumps.
Output from the pumps is ducted through a treatment system consisting, sequentially, of a HEPA' filter, charcoal adsorber, and HEPA fil ter, before being vented to the atmosphere through the Unit 2 vent.
All Unit 2 vent releases are monitored by the plant vent monitor, HPR-219 for noble gases, radiciodine and particulates.
Potential releases via this pathway were calculated, based on the foll owing assumptions:
1.
1-131 concentration in the solid system is 0.54 oci/cc (based on 4/19/79 inventory of 59 ci).
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2.
Partition Factor in the steam generator is 1, since no steam generatio'n occurs, i,. e., all activity present would carry-over to the condenser.
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3 No plateout in the bypass lines to the condenser.
4.
Althovah in the water-solid condition little evaporation would occur, evaporation in the main condenser is assumed to be of 1% of flow.
At the expected fl ow of 1,500 gom; evaporation is 15 gpm.
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P.rtitioning of iodine to the vapor phase during evaporation 3.
of 0.0001 (PF = 0.0001).
6.
Efficiency of charcoal adsorber of o9% for radiciodine.
7.
Plant vent total fl ow of 87,000 cfm.
CAL CULATI ON Release = 15 cal x 3.8 x 103 10-4 x 0.54 uCi/cc cc x min gal
= 3.1 uCi/ min Treatment DF of 100 3.1
= 0.031 uti/ min 100 S t a c'.
fl ow 87,000 c.i:
Cmc
= 0.031 uCi/ min
= 1.3 x 10~II uCi/cc 8.7 x 10" ft>/ min x 2.83 x 10" cc/fta This result, 13% of unrest ricted MPC at the plant vent, assumes that a constant source of I leak,s.from the primary system to the secondary to replentish the I lost by radioactive decay and discharge.
Even if a 20 gallon / day leak were to occur in the steam generator with an initial primary I leve' of 3 x 103 uCi/cc, the contribution to
's the I release at the plant vent would not exceed 2 x MPC.
At off-site locations, the concentrations would be less than 0.2% of MPC.
Summarv Operation with B steam generator in the solid mode, with cooling flaw through bypass to the main condenser, would result in generation 164 058
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These releases, however, are calculatad to be less than 2 x MPC at the release point, and less than 0.2% of MPC of f-site even for significant steam generator leakage from the primary 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 and processing systems.
No environmental impact would be expected f rom l iquid l eakage.
W John T. Collins 1
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