ML19221A442
| ML19221A442 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/08/1979 |
| From: | Hurley J INDUSTRY ADVISORY GROUP |
| To: | Levison M METROPOLITAN EDISON CO. |
| References | |
| OSP-790408, NUDOCS 7905230021 | |
| Download: ML19221A442 (3) | |
Text
t To:
Milt Levenson Date: April S, 1979 Murl ey!/
Subject:
Removal of Airborne From:
J. L.
n Radicactivity From Containment Of:
TH!-IAG Ccpy-J. W. Thiesing Recovery frc the TMI-2 incident includes reduction and eventual removal of air-borne radionue: ides frce containment. The potential for calfunction of the con-tainment or its appurtenances, however slight, also necessitates formulation of a plan for protection of the public from this activity.
Hence outlined below are several cencepts for removal of airborne activity from the tuilding.
Assumation:
1.
Removal is intended primarily to protect the public.
Ecduction of equipment exposure is not a criteria, although it certainly is a secondary effect.
2.
Deliberate attempts to reduce airborne activity may not begin until about 30 days after the incident, except for emergency actions.
3.
Cost is not a major consideration.
Removal of Activity Frior to 30 Davs After the Incident This concept is based on the premise that the nost significant noble gas contributo are xenon isctcpes.
The system will also recove sone iodine, krypton, anu partiEulates.
The system would use recirculation throu;h pressurized charecal at ambient terperatures.
It would be operated as follow s:
[l (1) Using a 6 to S inch line from contain cnt, cenpress the effluent h
to about 150 psig and cool it to about 95 T.
(2) After cooling, reduce stream pressure to 75 to 100 psig to lower its relative hunidity.
&n (3)
Without further reduction of pressure or temperature,,the streac through a large, long charcoal bed.
Ic is esti=2ted that rany tons of charcoal filling an approxi ately 6 feet diameter, 20 feet long tank would be used. This charcoal bed would be used until xenen breakthrough is cbserved.
(4)
Return the process strean to containment.
Equipnent would te expected to include:
(1) One cc: presser rat ed in excess of 150 psig and 20C0 fm with en after ceoler capable of reducing stream temperature to 950F.
162 256 9h i
T
- (2)
A pressure-reductica station capab12 of dropping 2000 f: fran 150 psig to 75 psig.
(3)
A 6 feet diameter, 20 feet long tank filled with charcoal.
(4) 6 to 8 inch:2 piping, valves,and penetrations rated at about 200 psig.
It is believed one bed of charcoal would re:ove the xtnon activity in about Ib days of recirculating.
It would also remove some iodine and krypten, and act as a filter to re=cve particulate activity.
Further design would address if the charcoal bed needs to be cooled. Chilling of the stream is not included to avoid the need for equipment to remove H;0 and CO2 Removal of Activity After 30 Days Af ter the Incident The scheme takes into acccent that by 30 days after the incident the only significant ncble gas activity is due to KrF The systen uses charcoal at low te perature with the effluent released to the atmosphere.
It would be cperated as follows:
(1), Using a 200 cf: blower, force the process stream through dessicant dryers and possibly a CO: freeze-out heat exchanger.
(Detailed design would determine the need for the heat ex c han g e t". )
(2)
Force the stream through a tank of charcoal bathed in liquid N3 to bring its temperature to -100 F.
~
0 (3)
Release the output of the charcoal tank to atmosphere.
Equipment would be expected to include:
1.
One low pressure blower rated at about 200cfa.
L 2.
Dessicant dryers 3.
Possibly a CO2 free:e-out heat exchanger 4.
1 - 2 feet diameter tank full of charecal.
Tank length and liquid N2 requirements to be determined during engineering.
This systes would be operated until KrSS breakthrough is detected.
It is believed that os;, if not all Kr83 activity would be retained in the charcoal.
Another sche e for long ters activity recoval would be to bubble effluent from the containment thrc2;h an organic solvent and back to contairacnt.
It is felt that the solvent would retain the activity; however, this concept is cuch nore theoretical with pcssible exposurer as yet unexplcred.
Iodine and Particulat e Renoval c
Since an accilertal release in the near future v uld ccntain significant quantities of iodine :nd particulate activity, it may be worth censidering installing a systes now to begin cleanup of these radionuclides.
2 cr 4 inch deep trays could be coupled with an upstrear liEPA ff! er in a recirculation loop.
Removal rste is felt to be approximately proportionsJ to flow rt t e.
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t It rust be emphasized that all the abcve are conceptual in nature with detailed engineering vet to be perfomed.
1-le estimate that such engineering would take about three days.
The concepts =ight also be useful in educin; gas decay tank activity and for total content.
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