ML032510812

Indian Point Energy Center Development of Evacuation Time Estimates. Chapter 12, Confirmation Time

ML032510812
Person / Time
Site:	Indian Point
Issue date:	05/31/2003
From:	KLD Associates
To:	Entergy Nuclear Northeast, NRC/FSME
References
NL-03-139 KLD TR-369
Download: ML032510812 (4)

Text

Indian Point Energy Center12-1KLD Associates, Inc.Evacuation Time EstimateRev. 112. CONFIRMATION TIMEIt is necessary to confirm that the evacuation process is effective in the sense that the public iscomplying with the order to evacuate. Although the counties use their own procedures for confirmation, we will suggest an alternative.The procedure we suggest employs a stratified random sample and a telephone survey. The sizeof the sample is dependent on the expected number of households that do not comply with the order to evacuate. We believe it is reasonable to assume, for the purpose of estimating sample size that at least 80 percent of the population within the EPZ will comply with the order to evacuate. On this basis, an analysis could be undertaken (see Table 12-1) to yield an estimated sample size of approximately 300.The confirmation process should start at about 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> (6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> for snow) after the Advisory toEvacuate, which is after the mobilization activities are completed. At this time, virtually all evacuees will have departed on their respective trips and the local telephone system will be largely free of traffic.As indicated in Table 12-1, almost 8-1/2 person hours are needed to complete the telephonesurvey. If six people are assigned to this task, each dialing a different set of telephone exchanges (e.g., each person can be assigned a different set of ERPAs), then the confirmation process will extend over a time frame of about 85 minutes. Thus, the confirmation should be completed well before the evacuated area is cleared. Of course, fewer people would be needed for this survey if the Evacuation Region were only a portion of the EPZ.Should the number of telephone responses (i.e., people still at home) exceed 20 percent, then thetelephone survey should be repeated after an hour's interval until the confirmation process is completed.

Indian Point Energy Center12-2KLD Associates, Inc.Evacuation Time EstimateRev. 1TABLE 12-1ESTIMATED NUMBER OF TELEPHONE CALLS REQUIREDFOR CONFIRMATION OF EVACUATIONProblem DefinitionEstimate number of phone calls, n, needed to ascertain the proportion, P of householdsthat have not evacuated.

Reference:

Burstein, H., Attribute Sampling , McGraw Hill, 1971 Given:No. of households plus other facilities, N, within the EPZ (est.) = 100,000Est. proportion, F, of households that will not evacuate = 0.20 Allowable error margin, e: 0.05 Confidence level, : 0.95 (implies A = 1.96)Applying Table 10 of cited reference,Finite population correction:

Thus, some 300 telephone calls will confirm that approximately 20 percent of thepopulation has not evacuated. If only 10 percent of the population does not comply with the order to evacuate, then the required sample size, n F = 215.Est. Person Hours to complete 300 telephone callsAssume: Time to dial using touch-tone (random selection of listed numbers): 30 secondsTime for 8 rings (no answer): 48 seconds Time for 4 rings plus short conversation: 60 sec.

Interval between calls: 20 sec.Person Hours:300[30+20+0.8(48)+0.2(60)]/3600 = 8.4 0.75 = 1p = q 0.25; = e+p = p 306 = nN1 nN = n F 308 = e e+pq A = n 2 2