ML19261F075
| ML19261F075 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 09/21/1972 |
| From: | Harold Denton US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 7910180688 | |
| Download: ML19261F075 (4) | |
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SEP 211972 R. C. DeYoung, Assistant Director fcr WR's, L nsvihw METEOROLOGY SECTION - REPORT TO ACES PLANT NAME: Three Mile Island Nuclear Station, Unit 1 LICENSING STAGE: OL DOCKET NCGER: 50-289 RESPONSIELE BRANCH: NR #2 REQUESTED COMPLETION DATE: 9/15/72 APPLICANTS RESPONSE DAIE EECESSARY FOR KEXT ACTION PLANNED ON PROJECI': None DESCRIPTION OF RESPONSE: N/A REVIEW STATUS: Site Analysis Branch - Complete Theapplicanthassubmitted(Amendment 27 dated 8/15/72)oneyear of vertical temperature difference data which is the preferred data for defining atmospheric stability in making atmospheric diffusion estimates for a plant site. We have analyzed these new data and revised our estimates of I/Q for accidental and routine effluent releases from the plant.
Also, the Amendment contains I/q estimr tes for accidents based en
" site shape" rather than minimum site boundary distance and based on the SF6 tracer gas tests at the site. The site shape censidera-tion was rejected because it is insistent with standard practice for all plant sites. The model based on the tracer tests was rejected because the testa do not denonstrate conclusively that tM model is adequately conservative.
Original afgned by II. R. Denton Harold R. Denten, Assistant Director for Site Safety Directorate of Licensing
Enclosure:
As stated ec: See attached page.
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- R. C. DeYoun6 SEP 2 I 1972 ec: w/oenclosure A. Giambusso W. Mcdonald cc: w/ enclosure S. H. Hannuer J. Eecdtte W. P. Gamunill K. Kniel R. Schier'ing I. H. Ha2 me DISSIEUTICII M cket File 259 L - Rdg L:AD/SS - Edg L:SAB - Edg 1486 212 L
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Form AEC 318 (Rev. 4-5J) AECM 0240
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The plant is situated en an island in the Susquehanna River eith rolling hills en both sides cf the river. The prevailing air-ficw over the site is ncrthwesterly due to the influence of large scale weather patterns and the relatively shallcw river valley crientatien.
The accident and annual average diffusien cenditiens have been evaluated frcm measurements of wind directicn and wind speed at the 100-fcot level and vertical temperature difference 6dT) between the 150- and 50-fcot levels of an ensite tower. The wind speeds measured at the 100-foot level were extrapolated to the 33-fcot level using power law relationship; which are a function of atmospheric stability,for use in the staff's dif.^asien models. The onsite metecrolegical data collecticn program was initiated in May 1967 and the applicant has presented one year (April 1971 - March 1972) of t'rcse data in summary form as jcint frequency distributions for our evaluatien. The data recovery during the ene year pericd was 79fc.
Fcr evaluaticn of diffusien of short-term accidental releases frcm the plant, a grcund level release with a building wake o
factor, cA, of 1000 m was assumed. The relative ccncentraticn which is exceeded 5% of the time was calculated frem the 1
joint frequency distributiccsto be 1.2 x 10 ' sec/m-1486 213
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minimum at the/exclusien dia:ance of clC Ji h the aind : peed reduced s
to reprecent air =crentet at a level cf 10 meters abcve the gr: uni. This relati ce 2:ncentrati:n is equivelent Oc the dis-per:icn ccnditicn: prcduced by Fa: quill type F stability aith a wind speed cf 0.5 metere/seccnd.
The applicant has uced values 5thich are le:s 2:ncervt. ive by a fa :cr cf seven due tc hi: une of a light wind dif^::icn scdel during stable at=c:pheri:
and ecnditiens/which he l' eels is mere appropriate as a result of a cerie cf tracer tes : :::.r.; ad a: the cite.
The results cf there diffusien te::: have been evaluated by the 2:aff. Althcugh the tracer tests show relative ccncentratiens which are generally 1cwer than the values calculated frem the staff mcdel, the results of these tests do not justify the adcption of a new diffusien model for accidents at this site.
For lenger time pericd accidental releases the relative concen-traticns presented in Safety Guide L appear to prcvide adequately conservative estimates at the cuter bcundary of the 1cw pcpulatien sene (3218 =).
The limiting annual average relative cencentration of 1.3 x 10-5 sec/m3 was fcund at the nearest island 610 = ea:
of the plant. This value is a factor of two higher than the applicant's value due to his use of a clightly different diffusicn medel.
It is cur cpinien that the metecrclegical data presented in the FSAR provide an acceptable basis for the develcpnent of censerva-tive at=cspheric dilutien facters fer use in the staff's dose =cdels 1486 214 0
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