ML032510791
| ML032510791 | |
| 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: ML032510791 (17) | |
Text
Indian Point Energy Center5-1KLD Associates, Inc.Evacuation Time EstimateRev. 15.ESTIMATION OF TRIP GENERATION TIMEFederal Government guidelines (see NUREG 0654, Appendix 4) specify that the plannerestimate the distributions of elapsed times associated with mobilization activities undertaken by the public to prepare for the evacuation trip. The elapsed time associated with each activity is represented as a statistical distribution reflecting differences in activity times among members of the public. The quantification of these activity-based distributions relies largely on the results of the telephone survey (Appendix F). We define the sum of these distributions of elapsed times as
the Trip Generation Time Distribution.BackgroundIn general, an accident at a nuclear power station is characterized by the following EmergencyClassification Levels (see Appendix 1 of NUREG 0654 for details):
- 1. Unusual Event
- 2. Alert 3. Site Area Emergency
- 4. General EmergencyAt each level, the Federal guidelines specify a set of actions to be undertaken by the Licensee,and by State and Local offsite authorities. As a planning basis, we will adopt a conservative posture, in accord with Federal Regulations, that a rapidly escalating accident will be considered in calculating the Trip Generation Time. We will assume:
- a. The Advisory to Evacuate will be announced coincident with the siren alert.
- b. Mobilization of the general population will commence up to 10 minutes after thesiren alert.
- c. Evacuation Time Estimates (ETEs) are measured relative to the Advisory toEvacuate.A rapidly escalating accident scenario assumes that the general population will evacuate over thesame time frame as do the school children, the transit-dependent population, the employees who live outside the EPZ, and the special facility population. This assumption generally leads to longer evacuation time estimates than those for scenarios that escalate more slowly.We emphasize that the adoption of this planning basis is not a representation that these eventswill occur at the Indian Point Energy Center (IPEC) within the indicated time frame. Rather,these assumptions are necessary in order to: Establish a temporal framework for estimating the Trip Generation distribution inthe format recommended in Appendix 4 of NUREG 0654.
Indian Point Energy Center5-2KLD Associates, Inc.Evacuation Time EstimateRev. 1 Identify temporal points of reference for the purpose of uniquely defining "ClearTime" and Evacuation Time Estimates (ETE).It is more likely that a longer time will elapse between the various classes of an emergency atIPEC. For example, suppose two hours elapse from the declaration of a General Emergency to the Advisory to Evacuate. In this case, it is reasonable to expect some degree of spontaneous evacuation by the public during this two-hour period. As a result, the population within the Emergency Planning Zone (EPZ) will be lower when the Advisory to Evacuate is announced, than at the time of the General Emergency. Thus, the time needed to evacuate the EPZ after the Advisory to Evacuate will be less than the estimates presented in this report.
The notification process consists of two events: Transmitting information (e.g. using sirens, tone alerts, EAS broadcasts, loud speakers). Receiving and correctly interpreting the information that is transmitted.The peak population within the EPZ exceeds 300,000 persons who are deployed over an area ofapproximately 370 square miles and engaged in a wide variety of activities. It must be anticipated that some time will elapse between the transmission and receipt of the information advising the public of an accident.The amount of elapsed time required for each activity will vary from one individual to the nextdepending where that person is, what that person is doing, and related factors. Furthermore, some persons who will be directly involved with the evacuation process may be outside the EPZ at the time that the emergency is declared. These people may be commuters, shoppers and other travelers who reside within the EPZ and who will return to join the other household members upon receiving notification of an emergency.As indicated in NUREG 0654, the estimated elapsed times for the receipt of notification can beexpressed as a distribution reflecting the different notification times for different people within, and outside, the EPZ. By using time distributions, it is also possible to distinguish between different population groups and different day-of-week and time-of-day scenarios, so that more accurate assessments may be obtained.For example, people at home or at work within the EPZ will be notified by siren and radio. Those well outside the EPZ will be notified by telephone, radio, TV and word-of-mouth, with potentially longer time lags. Furthermore, the spatial distribution of the EPZ population will differ with time of day -- families will be united in the evenings, but dispersed during the day. In this respect, weekends will differ from weekdays.
Indian Point Energy Center5-3KLD Associates, Inc.Evacuation Time EstimateRev. 1Fundamental ConsiderationsThe environment leading up to the time that people begin their evacuation trips consists of asequence of events and activities. Each event (other than the first) occurs at an instant in time and is the outcome of an activity.Activities are undertaken over a period of time. Activities may be in "series" (i.e. to undertake anactivity implies the completion of all preceding activities) or may be in parallel (two or more activities may take place over the same period of time). Activities conducted in series are functionally dependent on the completion of prior activities; activities conducted in parallel are functionally independent of one another. The relevant events associated with the public's preparation for evacuation are (snow clearance excluded):Event NumberEvent Description1 No-accident condition2 Awareness of accident situation 3 Depart place of work to return home 4 Arrive home 5 Leave to evacuate the area Associated with each sequence of events are one or more activities, as outlined below:Event SequenceActivityDistribution 1 2 Public receives notification information1 2 3 Prepare to leave work2 2,3 4 Travel home3 2,4 5 Prepare to leave for evacuation trip4Snow clearance5These relationships are shown graphically in Figure 5-1.An employee who lives outside the EPZ will follow sequence (e) of Figure 5-1; a resident of theEPZ who is at work and will return home before beginning the evacuation trip will follow sequence (c) of Figure 5-1. Note that event 5, "Leave to evacuate the area," is conditional either on event 2 or on event 4. That is, activity 2 --> 5 by a resident at home can be undertaken inparallel with activities 2 --> 3, 3 --> 4 and 4 --> 5 by a commuter returning to that home, as shown in Figure 5-1 (a) and (c). Specifically, one adult member of a household can prepare to leave home (i.e. secure the home, pack clothing, etc.), while others are traveling home from work. In this instance, the household members would be able to evacuate sooner than if such trip preparation were deferred until all household members had returned home. For this study, we
adopt the conservative posture that all activities will occur in sequence.
Indian Point Energy Center5-4KLD Associates, Inc.Evacuation Time EstimateRev. 112345Inland & Residents125Park Vacationers & Transients(a) Accident occurs during midweek, at midday; summer season125Park Vacationers & Transients(b) Accident occurs during weekend, at midday; summer season125Inland & Residents12345(c) Accident occurs during midweek, at midday; non-summer season(d) Accident occurs in the evening; non-summer season125(e) Employees who live outside the EPZ123See Text for DefinitionsEventActivityIncreasing TimeFigure 5-1. Events and Activities Preceding the Evacuation Trip Indian Point Energy Center5-5KLD Associates, Inc.Evacuation Time EstimateRev. 1It is seen from Figure 5-1, that the Trip Generation time (i.e. the total elapsed time from Event 1to Event 5) depends on the scenario and will vary from one household to the next. Furthermore, Event 5 depends, in a complicated way, on the time distributions of all activities preceding that event. That is, to estimate the time distribution of Event 5, we must obtain estimates of the time distributions of all preceding events.Estimated Time Distributions of Activities Preceding Event 5The time distribution of an event is obtained by "summing" the time distributions of all priorcontributing activities. (This "summing" process is quite different than an algebraic sum since we are operating on distributions - not scalar numbers).Time Distribution No. 1, Notification Process: Activity 1 2It is reasonable to expect that 85 percent of the people within the EPZ will be aware of theaccident within 30 minutes with the remainder notified within the following 20 minutes. The resulting distributions for this notification activity are given below.ElapsedTime (Min)Percent ofPopulationNotifiedElapsedTime (Min)Percent ofPopulationNotified00308557359010134095152645982046501002565 Indian Point Energy Center5-6KLD Associates, Inc.Evacuation Time EstimateRev. 1Distribution No. 2, Prepare to Leave Work: Activity 2 3It is reasonable to expect that the vast majority of business enterprises within the EPZ will electto shut down following notification and most employees would leave work quickly. Commuters, who work outside the EPZ could, in all probability, also leave quickly since facilities outside the EPZ would remain open and other personnel would remain. Personnel responsible for equipment would require additional time to secure the facility. The distribution of Activity 2 --> 3 reflects data obtained by the telephone survey. This distribution is plotted in Figure 5-2 and listed below.
Elapsed Time(Min)Cumulative PercentEmployees Leaving Work Elapsed Time(Min)Cumulative PercentEmployees LeavingWork0040885134590103350911553559220736093257765973081701003585NOTE: The survey data was normalized to distribute the "Don't know" responseDistribution No. 3, Travel Home: Activity 3 4These data are provided directly by the telephone survey. This distribution is plotted in Figure 5-2 and listed below.
Elapsed Time (Min)Cumulative PercentReturning Home Elapsed Time(Min)Cumulative PercentReturning Home00508059558410206087153165902044709525507596306180973565859840709099457695100 Indian Point Energy Center5-7KLD Associates, Inc.Evacuation Time EstimateRev. 1Distribution No. 4, Prepare to Leave Home: Activity 2,4 5These data are provided directly by the telephone survey. This distribution is plotted in Figure 5-2 and listed below.
Elapsed Time(Min)Cumulative PercentReady to Evacuate Elapsed Time(Min)Cumulative PercentReady to Evacuate006590587092101575941528809520408596255090963060959735671009740731059845761109850781159955831201006087NOTE: The original data were obtained in 15-minute increments. The above figures were interpolated.Snow Clearance Time DistributionInclement weather scenarios involving snowfall must address the time lags associated with snowclearance. Discussions with local officials indicate that snow plow equipment is mobilized and deployed during the snowfall to maintain passable roads. The general consensus is that their efforts are generally successful for all but the most extreme blizzards when the rate of snow accumulation exceeds that of snow clearance over a period of many hours.Consequently, it is reasonable to assume that the highway system will remain passable -- albeit ata lower capacity -- under the vast majority of snow conditions. Nevertheless, for the vehicles to gain access to the highway system, it may be necessary for driveways and employee parking lots to be cleared to the extent needed to permit vehicles to gain access to the roadways. These clearance activities take time; this time must be incorporated into the trip generation time distributions. These data are provided directly by the telephone survey. This distribution is plotted in Figure 5-2 and listed below.
Indian Point Energy Center5-8KLD Associates, Inc.Evacuation Time EstimateRev. 1Distribution No. 5, Time to Clear Driveway of SnowElapsed Time(Min)Cumulative PercentDriveways ClearedElapsed Time(Min)Cumulative PercentDriveways Cleared008591559092101095921523100922035105922545110923055115923560120934065125944569130955072135965577140976082145976585150987087155987589160998091165100 Indian Point Energy Center5-9KLD Associates, Inc.Evacuation Time EstimateRev. 1Mobilization Activities 0 10 20 30 40 50 60 70 80 90 1000306090120150180Elapsed Time From Start of Mobilization Activity (Min.)
Percent Po p ulationNotificationPrepare to Leave WorkTravel Home Prepare Home Clear SnowFigure 5-2. Mobilization Activity Time Distributions Indian Point Energy Center5-10KLD Associates, Inc.Evacuation Time EstimateRev. 1 Calculation of Trip Generation Time DistributionThe time distributions for each of the mobilization activities presented herein must be combinedto form the appropriate Trip Generation Distributions. We assume that the stated events take place in sequence such that all preceding events must be completed before the current event can occur. For example, if a household awaits the return of a commuter, the work-to-home trip(Activity 3 4) must precede Activity 4 5.To calculate the time distribution of an event that is dependent on two sequential activities, it isnecessary to "sum" the distributions associated with these prior activities. The distribution "summing" algorithm is applied repeatedly as shown below to form the required distribution. As an outcome of this procedure, new time distributions are formed; we assign "letter" designations
to these intermediate distributions to describe the procedure.Apply "Summing" Algorithm To:Distributions 1 and 2To Obtain Distribution AThat definesEvent No. 3Distributions A and 3To Obtain Distribution BThat definesEvent No. 4Distributions B and 4To Obtain Distribution CThat definesEvent No. 5Distributions A and 4To Obtain Distribution DThat definesEvent No. 5Distributions C and 5To Obtain Distribution EThat definesEvent No. 5Distributions D and 5To Obtain Distribution FThat definesEvent No. 5Distributions A through F are described below and shown in Figure 5-3:DistributionDescriptionATime distribution of commuters departing place of work (Event 3). Alsoapplies to employees who work within the EPZ and live outside, and to Transients within the EPZ.BTime distribution of commuters arriving home.
CTime distribution of residents with commuters who return home, leavinghome to begin the evacuation trip.DTime distribution of residents with no commuters returning home, leavingto begin the evacuation trip.ETime distribution of residents with commuters who return home, leavinghome to begin the evacuation trip, after snow clearance activities.FTime distribution of residents with no commuters returning home, leavingto begin the evacuation trip, snow clearance activities.
Indian Point Energy Center5-11KLD Associates, Inc.Evacuation Time EstimateRev. 1Figure 5-3 presents the combined trip generation distributions designated A, C, D, E, and F. These distributions are presented on the same time scale. The PCDYNEV simulation model is designed to accept varying rates of vehicle trip generationfor each origin centroid, expressed in the form of histograms. These histograms, which represent Distributions A, C, D, E, and F, properly displaced with respect to one another, are tabulated in Table 5-1. (Distribution B, Arrive Home, omitted for clarity).
Indian Point Energy Center5-12KLD Associates, Inc.Evacuation Time EstimateRev. 1Evacuation Trip Generation for Various Population Groups 0 10 20 30 40 50 60 70 80 901000306090120150180210240270300330360Elapsed Time From Evacuation Advisory (Min)Percent of Population EvacuatingEmployees or TransientsResident, CommutersResidents, No CommutersResidents, Commuters, SnowResidents, No Commuters, SnowFigure 5-3. Comparison of Trip Generation Distributions Indian Point Energy Center5-13KLD Associates, Inc.Evacuation Time EstimateRev. 1Table 5-1. Trip Generation Time Histograms for Midweek and Weekend ScenariosDistribution AEmployeesDistribution ATransientsDistribution CResidents,CommutersDistribution DResidents, NoCommutersDistribution EResidents,Commuters, SnowDistribution FResidents, NoCommuters, SnowTime PeriodRelative to Timeof Order toEvacuate (Hr:Min)TripsRateTripsRateTripsRateTripsRateTripsRateTripsRate0:00 - 0:15104010400041600000:15 - 0:301560156000114400280:30 - 1:005911859118816501001218361:00 - 1:30132613262754255091832641:30 - 2:0036362958816204026522:00 - 3:000000313122454515153:00 - 4:00000055001818774:00 - 5:000000000077005:00 - End000000000000Units:Trips, percent of total trips generated at the origin centroids during indicated Time PeriodRate:Percent of total trips per hour during indicated Time PeriodThese tabulations present the trips generated and the rates of trip-making within each indicated time period, both expressed as apercentage of the total number of trips to be generated at each centroid. The rate of trip making is found by:Trips generated in Time Period (percent)
Duration of Time Period (hours)Rate =