ML20028C414
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ATOMIC ENERGY COMMISSION'~
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1973 -
6' R. Tedesco, Assistant Director for Contain=ent Safety, L Harold R. Danton, Assistant Director for Site Safety,Y.h,b
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KADIOLOGICAL,CONSLQUENCES OF POSTULATED RECOMSINER FAILURE AT LIMERICK
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As orally requested by tha.. Effluent Trestment Systc=s Branch on July 24, 197 the consequences of a reco=biner failure a: L1=erick were avalus:ed.-. This is a part of the Staf f's analysis, in the enviren= ental state =ent. of the applicant's proposed changes to their effluent treattent syste=.
Both a shine dose and an (=mersion dose ucro calculated for the assu=ed ten secsnd release.
(The time foc~ automatic closure of.the shut-off valve is :en seconds.) The core release rates of nobla gases were based on the NEM-1072
.~ Isotopic distribution assu=ing a total noble gas release rate of 100,C Z uCi after 30 =inutes decay;.the activation gas activities ucre also taken fro:
MEDO-10734.
A 15 second delay fro the core to the failed line was assu=sd.
Table I lists the consequences of the shine and it..r.e:sion doses, and Table $
lists the isotopes considered and the total activity released.
As shown in Table I, the shine dose is not a significant contributor to the total dose for large noble gas release rates.
The i==ersion dose f c= nobic gases is directly proportional to the noble gas release rate (assu=ing no
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change in the isotopic distribution).
Therefore, for a significantly,1 cue:
. release rate, e.g.,10,000 uCi/sec af ter 30 =inutes, the shine ' dose beco=cs a significant contributor to the site boundary, dose since the shine dose is independent of the noble gas release rate.
The it=nersion dose for the environ = ental stata=ent was calculated assuming a wind speed of four tacters per second and -decay enroute to the site beundas As discussed in a =eeting with I. Van der Hoven of NOAA (see June 5, 1973 m.emo fro: R. Loose to D. R. Muller " Department of Co==arce (MOAA) Meetin; Report"), the =eteorological assu=ptions used for dete==ining compliance with Appendix I guidelines for this uncontrolled but anticipa:ed release were those stated in the proposed Annen to Appendix D of 10 C.:R Part 50, i.e.,
one-tenth the Safety Guida 3 ground level release value at the 2500 foot site boundary.
4s reco==end that this meteorology also be used fe s :(
releases during load rej ections at PWR's.
Of course the consequences cust be weighted by the saticipated yearly frequency of the respective events.
lin shine dose for the en tiron = ental statc=cnt was calculatcd by assuming o linc source frw thu tucbine building vent with a four =ctc per second
(
wind speed, an averagu activity and an avarage gar =a enc gy.
, Sac June 20,,
1973 =a=o fro: H. Denten to R. Engelken, " Dose Calculations Relating to the Guad-Cities 2 Rupture Dish Failure," for a discussion of the =ethod used to calculate the sbinn d Me).
Calculations were perforned at the site bounde.)
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l and a distance of.1000 feu (Table I) for 1 and 10 meter pc: second wind l
l 5peeds which establi.simd Ihat the shine dose is not a particularly signific<
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co.tsideration in clu:s couputations.
Future dose esticates using the 10 8301100088 821207 PDR FOIA
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HIATTB2-545 PDR
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R. Tedcaco-...gg.g 3 g7y percentile mateorology can therefore be obtained from the Radiological Assess =cnt Branch, as conventional i=cersion dose calculation techniques are adequate.
The following uords were infor= ally transmitted to A. Lyle of Environ = ental Projects for inclusion in Section 3.4 of the L1=erick Draft Environ =cntal Statement:
"In the evaluation of the performance of this systc=,
the sta f f assu=ed that in the event of a recombiner f ailure ten seconds would be required for the auto =stic closing of isol.ation valves, allouing the release uichout treat-cent of radioactive noble and activation gases.
Assu=ing the meteorological dispersion which would be expected to occur 50% of the time and prior operation at an equivalent offp.as cate of 100,000 uCi/see at thirty minutes, the staf f esti=nted a whole body dose of less than 1 cre= at 2500 feet from the turbine building."
This work was perfor=ud by E. Adensam and R. Zavadoski of.the Accident Analysis Branch.
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ss' Brian Crices, Chief Accident Analysis 3 ranch Directorate of Licensing
Enclosure:
Table I, Table II cc:
w/ enc 1.
J. Hendrie V. Benaroya J. Kastner A. Lyle J. Collin, D. Muilur EP B/C'.s I
R. Zavadu. ski l
E. Ade: sam /
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TABLE I ESTIMATED DOSE CONSEOUENCES FOR A l'OSTU' ATED RECOMSINER FAILURE AT LIMERIC'd Site Boundar~y (2500 feet) Doses, mean 3
Wind Spaed, m/sec X/Q, sec/m Ic= ersion Shine e
~4 1.0 5.95 X 10 3.3 0.01 4.0 5.'95 X 10-5
.0.85 0.04 1.9 X 10-5 0.45 0.10 10.0
, Doses at 1000 feet, mren Wind Speed, m/sce X/Q, sec/c I=cersion Shine 1.0 1.6 X 10-3 17.
0.02 4.0
- 1.6 X 10-4 3.9 0.08 10.0 6.4 X 10-5 2.8 0.2 9
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Table II.
Source Used toEstiente Dose Conscouences From a Pot:tulated P.ccombiner Failura st Limerick t.uclide Total Activity Released, curies
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Kr83m
- 0. 3.4' b<
Kr85m 0.61 KrSS 0.002
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KrS7 2.0 Kr88
'2.0 Kr89 12.3 i
Kr90 17.
Kr91 9.8 0.0015 Xe131m Xel33m O.029 Xe133 0.82
'.6 2
xe135m Xel35 2.2 Xe137 14.
Xel38 8.7 Xe139 19.2 Xel40 14.
ti-13 0.15 tt-16 66.
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'o-19 14.9 4
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