ML19345C619

Public Version of Draft Seabrook Station Evacuation Analysis,Final Rept,Estimate of Evacuation Times, Prepared for FEMA

ML19345C619
Person / Time
Site:	Seabrook
Issue date:	07/31/1980
From:	PLANNING RESEARCH CORP.
To:
Shared Package
ML19345C615	List: ML19345C616 ML19345C619 ML19345C819
References
NUDOCS 8012080012
Download: ML19345C619 (150)

Text

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' SEAEROOK STATION  ;

l EVACUATION ANALYSIS -i i

+- i i REPORT . l 1: l

{ ESTIMATE OF EVACUATICN TIMES .1 i

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Prepared For FEDERAL EMERGENCY MANAGEMENT AGENCY I

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{ . Prepared by i ~

ALAN M. VCORHEES & ASSCCIATES~

A Division of PRC Planning & Econcmics .

l 7798 Old Springhouse Road l McLean, Virginia 22102 .;

.t l JULY 1980 SONAL PRIVACY INFORMATION E

t yygN OF INFORMATION ACTI i

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, ,A TABLE OF CONTENTS Chapter P_ age I. INTRODUCTION . . . . . . . .. . . . . . . . . . . . . 1 o

Study Objectives . . . . ... . . . . . . . . . . 1 Location of the Seabrcok Station . . . . . . . . . 1 Background and Chronology . . . . . . . . . . . . 1 Other Stadies of Evacuation Times . . . .. . . . 3 -

Local Preparedness and Evacuation Planning . . . . 3 -

The Emergancy Planning Zone (EPZ) Boundary . . . . 4 Summary of Estimating Techniques . . . . . . . . . 4

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Summary of Evacuation Times . . . . . . . .. . . 5 Issues Related to Evacuation Time Estimates . . . 7 Recommendations . . . . . . . . . . . . . . .. . 8 II.

CHARACTERISTICS OF THE SEABROCK STATION VICINITY . . . 9 Highway System in the Seabrook Station Vicinity . 9 Existing Traffic Volumes . .. . . . . . . .. . . 9 Other Transportation Facilities in the Seabrook Station Area . . . . . . . . . . . . . . . . . . . 11 Governmental Jurisdictions . . . . . . . . . . . . . 11 III.

THE EMERGENCY PLANNING ZONE FOR SEABROCK STATICN . . . '5 General Guidelines for Cefining the Emergency Planning Zone (EPZ) . . . . .  : . . . . . . . . . 15 The EP Boundary for the Seabrook Station . . . . 15 -

Criteria for Defining Sectors Within the EPZ . . . 16 Selective Evacuation Sectors for the Seabrook Station .. . . . . . . . .. . . . . . . . . . . 19 Sector 1: 1-Mile Radius from the Seabrook Station . . . . . . . . . . . . . . . . . . . 19 Sectors 2 and 3: 2-5 Miles frem the Seabrook Station . . . . , . . . . .

.. . . ._. . . . . . . 21 Sectors 4 and 5: 5-10 Miles from the Seabrook Station . . . . . .. . . . . . . . . . . . . 21 IV. ,

POPULATION OF THE SEABROCK STATION EP:: . . . . . . . . 23 Total Population Characteristics . . . . . . . . . 23 Seasonal and Transient Population . . .. . . 23

' Automobile Ownership . . . . . . . . . . . .. . . 23 Population Segments as Defined for Evacuation Analysis .

. . . . . . . . . . . . . . . . .. . . . 26 i

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TABLE OF CON"ENTS (Continued)

Chaoter Page V. THE EVACUATION SEQUENCE FOR SEABROOK STATION . . .. . 29 General Concept of Evacuation . . .. ... .. . 29 ..

Possible Evacuation Time Periods . . . . ... . . 30 Nighttime Evacuation- . . .. . . ..... . 30 ,.

Daytime on a Summer Weekend ("Su=mer Sunday" Case) . . . . . .. . . . ... . ... ... . 31 Daytime / Weekday Evacuation (" Winter Weekday" -

Case) '.. . . . . ... .... .. . . ... 31 ,

critical Time Periods . . .. . ....... 31 Population Segments to be Evacuated . .... .. 32 Family Units . . ... . .. . . ..... . 32 Evacuation Action Steps . . . .. . . . . .. .. 33 Public Agency and Private Steps . .... . . 33 <

Evacuation of Auto Owning Population . .. .. . . 35-Receive Brr;adcast.Information . ... . ... 35 Lea"* Place of Work'. . ... . . .... .. 35 Work-to-Home Travel . . . ... . ... ... 36 Prepare for Evacuating Ecme . . . . . .. . . 36 Travel Out of the EPZ . . .. . . .. .. . . 37 Evacuation of School Population . . . . .. .. . 38 Receive Broadcast Information . . . ... . . 38 Evacuate School Population in Buses . . .. . 38 Non-Auto Owning Households . . .. . . . . ... . 38 Receive Broadcast Information . . .... . . 38 Prepare for Evacuating Homs . . .. . ... 39 Assemble at Collection Points . .. .... . -39 I

Evacuate Non-Auto Owning Households in' Buses. 39 Population in Institutions . .... . . ... . . 40

, _ Receive. Broadcast Information . ... ... . 40 Mobilize Population . . .. . . .. . .. .. 40

-Evacuate Institutional Population in Buses or Special vehicles . . . ... . .. . .. ..

• 40 Sirmmary of Evacuation Process .. . . . .. ... 41 VI. EVACUATION ROUTES . .. . . .. . . .. . . .. .. .. 43  ;

General Strategy of Evacuation Routing . . . . .. 43 Road Network for Vehicle Evacuation . . . ... . 45 Forecasting Evacuation Traffic . . . .. ... . . 47 Individual Evacuation Routes . .. . .. ..... 49 Performance of the Evacuation Traffic System . . . 53 1

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-r TABLE OF CCNTENTS (Continued)

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Page Chapter

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SUMMARY

OF EVACUATION TIME ESTIMATES Method for Estimating Evacuation Times . . . . . . 55 -

Population Segments . . . .. . . . . . . . . 55 55 Time Periods . . . . . . . . . . . . . . . .

Action Steps . . . . . . . . . . . . . . . . 55 Time Required for a Series of Action Steps . 56 i -

Assignment of the Traffic to the Evacuatton-

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Routes 56 Evacuation Times for Case A: Sanmer Sunday . . .

Formation of Traffic Congestion . . . . . . . 58 Extent of. Traffic Congestion . . . . . . . . 59 Traffic Congestion and Driver Behavior . . . 63 Evacuation Times for Case B: Winter Weekday . . . 66 Traffic Congestion in a Winter Weekday Evacuation . . . . . . . . . . . . . . . . . 66 Evacuation of the 3chool Population . . . . . . . 68 Evacuation of the Non-Auto Owning Households . . . 68 Evacuation of the Population in Institutions . . . 69 Selective Evacuation of Areas Within the EPZ . . . 69 l

Impact of 15-Hinute Motification on Evacuation Times .. . .. . . . . . . . . . . . . .. . . . 71 Impact of Severe Weather on Evacuation Times . . . 72 Su= mary of Evacuation Times . . . . . . . . . . 72 Problem, Issues and Recommendations *

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Beach Traffic Congestion .. . . . . . . . . 72 Mer:e Use of I-95 . . . .. . . . . . . . . . 75 Buses for the Transit-Dependent Population . 75 t

VIII. VEHICLES AND MANPOWF.R REQUIRED FOR EVACUATING THE SEABROCK STATICN EPZ . . . . . . . .. . . . . . . . . 76

- Introduction . . . . . . . .. .. .. ... . . . . 76 Vehicle Requirements . . . . .. . . . . . . . . . 76 School Buses . . . . . . . . . . . . . . . . 76 Transit Buses . . . . . . . . . . . . . . . . 77 ~

Ambulances . . . . . . . . . . . . . . . . . 77  !

Traffic Control and Towing vehicles . . . . . 78

' Manpower Requirements . . . .. . . . . . . . . . 78

' Schcol Bus,' Transit Bus and Ambulance Drivers 78 Traffic Control . .. . . .. . . . . . . . . 78 Tow Truck Operators . . . . . . . . . . . . . 78

- Supervisory and Coordinating Personnel . . . 79

' Summary of Vehicle and Manpower Requirements . . . 79 f

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' TABLE OF CONTENTS (Continued) 4

. Chapter- ~ Page IX. CONFIRMATION OF EVACUATION . . . . . . . . - . - . . . . . 81 Confirmation Process . . . . . . . . . . . . . . . 81 -

. Possible Approaches to Confirming the Evacuation-4 of the EPZ . . . . . . . . . . . . . . . . . . . . 81 Recomended Concept for. Confirming Evacuation in ,

the Seabrook Station EPZ . . . . . . . . . . . . . 82 .

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' LIST OF FIGURES Figure . Page 1 Location of the Jaabrook Nuclear Power Station . . . . 2

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2 Highway' System in the Vicinity of the Seabrook Station. 10 3 Other Transportation Facilities in the Vicinity of the Seabrock Station . . . . . . . - . . . . . . . . . . . . 12 ,

.4 Local Government Jurisdictions . . . . . . . . . . . . 14

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5 Plume Exposure EPZ Boundary . . . . . . . . . . . . . . 17 4

6 Selective Evacuation Sectors for the Seabrook Station EPZ . . . . . . . . . . . . . . . . . . . . . . . . . . . _ 20 4

7 Population Segments and Evacuation Sequences . . . . . 34 8 Evacuation Routing Strategy . . . . . . . . . . . . . . 44 9

9 Evacuation. Gateways and Capacities . . . . . . . . . . 46 l 10 Evacuation Routes: Case'A, Su=mer Sunday . . . . . . . 51 11 Evacuation Routes: Case B, Winter Weekday . . . . . . 52 12- Evacuation Ti=es: Case A,lSu==er Sunday . . . . . . . 57 ,,

13 Traffic Congestion Analysis . . . . . . . . . . . . . . 60 14 Traffic Congestion: Case A, Summer Sunday . . . . . . 61 15 Evacuation Times: Case B, Winter Weekday . . . . . . . 67

'16 Selective Evacuation Times. . . . . . . . . . . . . . . 70 j om d .

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't LIST CF TABLES Table Page 4

'l Summary of Evacuation Times . .. .. . . . . .. . . . 6 2 Governmental Units'Within the 10-Mile Radius and EPZ of

, the Seabrook Station . . . . . . . . . . . . . .. . . 18-

.3 Total Resident Population of the Seabrook Station EPZ . 24 4 Auco ownership in the Seabrook Station EPZ . . . . . . 25 5 5eabrook Station EPZ Population by Segments . . . . . . 28 6 Simary of Evacuation Action Steps . . . . . . . . . . 42 7 Evacuation Traffic Forecast . . . . . . . . . . . . .. 48 8 Evacuation Times for Seabrook Ssation . . . . . . . . . 73 i

9 Vehicle and Manpower Requirements for Evt.Taating Seabrook Station EPZ . . . . . . . .. . .. . . . . . 80 e'

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• .~a I. INTRODUCTION Y

. STUDY.CBJECTIVES This. report describes the estimaticr. of the time required to evacuate the population from about a 10-mile radius of the Seabrook, New Hampshire, '~

Nuclear Power Station.

4 Two objectives are served by this analysis:

(1) An independent assessment of evacuation times to serve ,

as an additional. viewpoint to the evacuation time estimates developed by the utility.

(2) To-further develop a standardized approach, to estimating evacuation times, that can be applied to other locations.

LCCATION OF THE SEABROCK STATION The Seabrook Station is located on the Atlantic doastline, in the town of Seabrook, New Ha=pshire, 40 miles north of Bosten, MA, and 15 miles south ~

of Portsmouth, NH. The station is 2 miles north of the Massachusetts-New Hampshire State Line. (See Figure 1.)

BACKGROUND AND CHRONOLOGY The Seabrook Station is being developed by a consortium of New England utilities, under the leadership of Public Service of New Hampshire. -~J Application for licensing was begun in 1972, and construction started in 1976.

4 Start-up of the plant, criginally planned for 1979, has been delayed by environmental opposition, court actions and work stoppaess. The currently projected' start-up date is 1983. I 1

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l Figure 1. Location of the Seabrook Nuclear Power Station _

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< o OTHER STUDIES OF EVACUATICN TIMES An evacuation time estimate for the 10-mile radius of the plant is in the process of being prepared by New Hampshire Public Service. A preliminary estimate of slightly over 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />s-for the " clear time" for the population evacuating in private vehicles has en made. (" Clear time" is defined as the time required for ev::uation, given that the population has already received the necessary information. )

4 LOCAL PREPAREONESS AND EVACUATION PLANNING ,

An evacuation time estimate assumes that an effective local preparedness plan is in operatien. Among tha elements of such a local preparedness plan, some of the more critical elaments are identified:

o Detailed evacuation plans, addressing notification, routing, manpower and rescurce requirements, confirmation of evacuation and transportation of non-vehicle owning population (schools, non-auto owning households and persons in institutions).

s o Local notification procedures and hardware, including siren, _.

public address and telephone notification, precedures for broadcasting radio and television information.

o Communication within EP3, and between Seabrook Station,

, State Civil Defense Agencies and towns, and within towns themselves. *

-1 oI Local (town) mobilization and decision-making.

o Detailed traffic control plan.

l o Securing buses for transporting tho'schcol population.

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l o Securing buses or other vehicles for transporting non-auto owning households and persons in institutions.

O Securing ambulances for non-ambulatory pcpulations.

o Reception centers and procedures for clearing evacuated population through them.

o Manpower (traffic control, supervisory, security emergency senices) for conducting the evacuation.

It is assumed that, by the projected start-up of Seabrook Station in 1983, local preparedness planning will be developed to a level comparable to that now observed at operating plants with similar EPZ populations. In the absence of effective preparedness planning, the evacuatian time estimates given in this report are invalid.

THE EMERGENCY PLANNING ZCNE (EPZ) BOUNDARY The Seabrook Station E=ergency Planning Zone (EPZ) boundary is defined almost entirely along town boundaries. The only exceptions are the inclusion of small and lightly populated parts of the cities of Portsmouth, NH, and Haverhill, MA.

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SUMMARY

CF ESTIMATING TEC'NIQUE The method used in developing these evacuation time estimates is based on .

separating the-population into segments, according to how they evacuate ,

the area. For each population segment, a series f discre *.e action steps is identified, and the completion ti=es for each step deten *.ned.

These ti=es for ccmpleting each step are then linked together statis-tically tc y-icld the total- evacuation time -for that pcpulation segment.

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, The advantage of this method is that travel times are estimated for each individual step of the evacuation sequence (for which data is readily available). rather than for the entire evacuation as a single entity (for which~ data is non-existent).

Two cases of evacuation time estimates are made: (1) for evacuation ~ -:

during a Su=mer Sunday, .when temporary (beach) population is greatest, .

and - (2) for evacuation.on a Winter weekday,.when schools are in session. .

SUMMARY

OF EVACUATION TLMES -

For the critical time period (Summer Sunday) , the total evacuation time (Table 1) is 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 10 minutes. Times are measured from the beginning of notification until all population has cleared the EP2. The critical ecm-ponent of this time is the evacuation of beach-area traffic; all non-beach areas of the EPZ can be cleared in 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 55 minutes or less.

For the second most critical time period (Winter weekday) the total evacu-ation time is 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 40 minutes after start of notification.

Evacuation times by sector range from 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> 10 minutes to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 10 minutes -

af ter start of notification, depending on ecmbination of sectors considered.

Under severe weather cond.itions (Winter stor=) the total evacuation time is 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> 30 minutes after start of notification, or 123 percent of the time for a Winter weekday evacuation under normal weather conditions.

For the critical time period (Su=mer Sunday), notification of the entire population within 15 minutes does not reduce the total evacuation time noticeably. The evacuation time for the Su=mer Sunday situation is deter-

. mined almost totally by the rate at which the beaches can be evacuated; speeding up the notification precess, under these circumstances, simply accelerates the rate at which motorists enter the existing traffic cengestion.

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}; TABLE 1

SUMMARY

OF EVACUATION TLVES i

Timel/ Required To Evacuate All-Conditions Pooulation Su:nmer Sunday 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> 10 minutes Winter Weekday, Nor:nal Weather 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 40 minutes -

J Winter Weekday, Severe Weather 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> 30 minutes a

Selective Evacuation, 2-Mile Radius 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> 10 minutes a

I- Selective Evacuation, 5-Mile Radius 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> 10 minutes to 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> 40 minutes 1

Selective Evacuation,-10-Mile Radius 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> 10 minutes to

! 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 10 minutes 4

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ISSUES RELATED TO EVACUATION TIME EST!?GTES In estimating evacuation times for the Seabrook Station EPZ, several unresolve<1' issues were encountered:

I o Behavioral issues. In a Summer Sunday evacuation, a substantial ~ -

portion of all evacuating population is delayed by traffic con-gestion. In the beach area, this delay ranges up to a maximum ,

of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> 15 minutes. Most of the traffic caught in congestion -

is within 5 miles of the Seabrook Station, with a substantial -

portion within direct sight of the plant. The behavior of drivers under these conditions of delay and proximity to the Seabrook Station can only be guessed. Mcwever, any breakdown in orderly evacuation traffic flow will result in evacuation times greater than those estimated. For an evacuation in which traffic control is generally. ineffective, total evacuation times will range frem 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> 30 minutes to 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> 40 minutes.

o Local preparedness planning. Evacuation times estimated in this report assume.that an effective preparedness plan will be developed by 1983. However, the lack of funds at the local level for pre- --

paredness planning, as well as the shortage of manpewer resources (police, etc.) needed to conduct an evacuation, raise some concern as to the actual state of preparedness by 1983.

o Transit vehicles. The transit-dependent population (i.e, pert,ns who do not have access to a private vehicle for evacuation) in the Seabreok EPZ is substantial, and a sizeable fleet of buses ,

would be needed for their evacuation. Arranging for. a fleet of this si:e is a major undertaking, not yet addressed by local plans.

o Ambulance availability. Arranging for the nc=ber of ambulances d

needed to assure evacuation of the non-ambulatory transit-dependent population within a reasonable time is a major under-taking, which local preparedness planning has scarcely begun to address..

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o Evacuation routes. All available roads must be used as evacu- I ation routes, and in as balanced a manner as possible. Local plans, in subsequent iterations, need to reflect this.

PICC!t'4.ENCATIONS Some possible actions to improve the evacuation process were suggested by this analysis:

o Sequential evacuation of the beach area would ree:ce the _

length of queues in the beach area, as well as reduce the chance for a breakdown in orderly traffic flow. Sequential evacuation could be achieved by selective notification, broadcast infor- ,

mation and traffic control.

o Sheltering population in the beach area (at least for part of the evacuation period) may be preferable to allowing them to wait in craffic congestion. The trade-offs involved in this choice should be examined carefully.

o The use of I-95 as an evacuation route can be improved greatly -.

(and at low cost) by =eans of supplemental, evacuation-only entrance ramps.

o Securing of vehicles for the non-auto owning population needs

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t s II. CHARA',I.'RISTICS OF THE SEABRCOK STATION VICINITY HIGHWAY SYSTEM IN THE SEABROCK STATICN VICINITY 4

Some important features of the highway system in the 10-mile vicinity of .

, the Seabrook Station (Figure 2) are noted:

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o An intercity major trunk highway, I-95, runs the north-south .

! length of the area. This road is of little local travel .

significance (i.e. , for travel within the immediate area) .

However, it is the primary means of long-distance travel to and from the Seabrook area.

1 o Two other primary highways, US 1 and State Route 1A, also run the north-south length of the area. Both of these highways serve multiple functions: (1) as '.onger distance intercity routes, particularly to the Boston and Portsmouth area; and

2) as local arterial roads within the more populated coastal areas, - and as rural collectors outside the built-up areas. .

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o East-west and diagonal highways cross the region connecting most town canters.

o outside the built-up areas of towns there is little road system

, other than the major arterial system described- above.

Specifically, there is little network of local roads, unpaved

• farm roads, etc. -

EXISTING TRAFFIC VCLUMES '

l The existing traffic volumes (Figure 2) suggest some distinct patterns: 1

o Major intercity ficws on I-95 -- 25,000 to 40,000 Average Daily Traffic (ADT) in the Seabrook Station area. l i

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o Large traffic volumes on the other primary north-south highways (US 1 and State Route 1A). The largest component of this traffic is local; i.e., beginning or ending a trip within the Seabrook Station vicinity. The remainder of the traffic is more long distance in nature.

o On arterial streets wichin the urbanized areas (Newburyport,

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Amesbury), daily traffic volumes typical of small urban areas.

o Light volumes on the east-west highways that do not peneti_ . ,

a major tcwn; for example, F.xeter.

o Substantial volumes on east-west highways that penetrate major towns; for example, State Route 51 to Exeter.

OTHER TRANSPORTATICN FACILITIES IN THE SEABROOK STATION AREA Two active rail alignments run in the north-south direction through the region (Ficure T, Some small general aviation airports are located in the region. No scheduled carrier service is operated at these airports. A major military air base (Pease Air Force Base) is located slightly outside the 10-mile radius of the Seabrook Station.

Several harbor facilities for small vessels are located in the region.

However, no harber of commercial significance is located wAthin the 10- .

mile r'adius of the Seabrook station.

GOVERNMEh'TAL JURISDICTICNS l

The area, defined by a IC-mile radius frcm the Seabrook Station, includes i

parts of two states, two counties, and two cities. The area of the i

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1 Figure 3. Other Transportation Facilities in the Vicinity of Seabrook Station

Atlantic Ocean within 10 miles of the Seabrook Station is under control of the U.S. Coast Guard.

Governmental jurisdictions are shown on Figure 4.

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Figure 4. Local Government Jurisdictions ei \ 14

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+

III. 'n!E EMERGENCY PLANNING ZCNE FOR SEABROOK STATION  !

GENEPAL GUIDELINES FOR CEFINING THE EMEPGENCY PLANNING ZONE (EPZ)

The Emergency Planning Zone (EPZ) is established by federal regulations --

as a 10-mile radius for the protection of population from direct radia-j tion exposure.

In adapting this 10-mile radius to sny particular site, some general . ,

guidelines are observed:

o The EPZ must include at least the 10-mile radius of the power station.

o The EPZ must be easily identifiable. Pather than strictly following an intangible radius, the EPZ boundary should follow natural features (shorelines, streams), man-made features (highways, railroads) , or governmental boundaries.

, c' The EPZ boundary should not split major coherent populations, --

such as the cities of Haverhill or Portsmouth. Rather, the EPZ boundary should either include or exclude such concentra-tions in their. entirety.

o The EPZ boundary should be regular and consistent,~with support--

able reasons for including areas. Evacuation of large popula- ~

tion groups well beyond the 10-mile radius should be avoided. ..

1 THE EPZ BOUNDARY FCR THE SEABROCK STATION Scveral features of the area around the Seabrook Station help establish the plane exposure EPZ:

15

o Cther than the Atlantic shoreline, there are few dominant f natural or man-made physical features which could serve as portions of an EPZ bounda.rf.

i

o There are a number of town boundaries in the area, and a strong awareness of towns as the primary governmental ~

e>

jurisdiction.

! o " o concentrations of population (Haverhill and Portsmouth)

J are just beyond the south and north extremities of_ the EPZ. -

l

, In light of these featutes, an EPZ boundary is proposed (Figure 5) to:

I o Follow town lines for almost all of the proposed EPZ boundary, i

o Include only those portiens of the cities of Haverhill and Portsmouth which are within the 10-mile radius of Seabrook Station.

The resulting EPZ boundary enccmpasses at.least the 10-mile radius frem -

Seabrook Station. At some points, si:able areas beyond a 10-mile radius --

are included, particularly along the western border of the EPZ. How-9ver, these areas contain negligible population.

The proposed EPZ boundary falls almost entirely along local government (town or city) lines, and consequently only two such local'jurisdic-tiens are divided by the EPZ boundary. Table 2 summarizes local '

government jurisdictions within the 10-mile radius of the Seabrook -

Station and also within the proposed EPZ.

CRITERIA FOR DEFINING SECTCRS WITHIN THE EPZ Federsi guidelines call for establishing, within the plume exposure EPZ, a series of sectors as follows:

16

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e ..

l TABLE 2 GCVERNMENTAL UNITS WITHIN THE 10-MILE RADIUS AND EPZ CF THE SEABRCCK STATICN PCRTICN CF TOTAL LAND AREA WITHIN 10-MILE RADIUS SEABROCK CF SEABROCK STATICN IPZ -

NEW HAMPSHIRE -

COUNTIES .

Rockingham part part CITIES Portsmouth part part TCWNS Brentwood part all East Kingston all all Exeter part all Greenland part .

all Hampton all all Hampton Falls all all Kensington all all Kingston part all Newfields ,

part all Newton part all -

North Hampton all all Rye part all Seabrook all all South Hampton all all Stratham part all MASSACHUSETTS CCUNTIES Essex part part CITIES Haverhill part part Newburyport all all TOWNS Amesburf all all Merrimac part all Newbury part all Salisbury all all West Newbury part all l

la

. 2 Distance from Power Definition of Station Sectors 2 miles Two - 180-degree sectors 5 miles Two < 90-degree sectors To Boundary of Plume Four degree sectors Exposure EPZ

~~

(about 10 miles)

These criteria are guidelines only. Actual sector boundaries depend .

on the shape of population concentrations and physical features. In -

particular, it is desirable that sectors not divide centiguous concen- -

trations of pcpulation.

Selective evacuation sectors should also recognize wind patterns, so that areas of high probability of beind downwind from the power station can be evacuated separately, without the need for evacuating an unnecessarily wide area of the total EPZ.

SELECTIVE EVACUATICM SECTORS FOR THE SEABRCCK STATICN Figure 6 illustrates one possible division of the Seabrook Statien EPZ into sectors for selective evacuation. These sectors follow the -

general guidelines above (2-mile, 5-mile and 10-mile radius frem the Seabrook Statien). In general, sector boundaries are defined along town boundaries, so that -in any selective evacuation most towns are evacuated in their entirety. In a few instances, selective evacuation sectors are defined along a majo'r highway.'

~ ' '

Sector 1: ' 2-Mile Radius frcm the ' Seabroc'; Station .,

The basis for this sector is the 2-mile radius from the Seabrook Station.

The north boundary of this sector is defined by the Hampton Falls town line, except at the eastern extremity, where the populated area of Hampton Beach is included. On the west, Sector 1 is bounded by I-95 (New Hampshire Turnpike). The Seabrook town line is the southern boun-dary of this sector.

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SELECTIVE EVACUATION SECTOR e NUMBER Figure 6. Selective Evacuation Sectors for the Seabrook Station EPZ 20 a

Sector 1 includes most of the town of Seabrook, a small part of Hampton and that portion of Hampton Falls east of I-95. The dominant popula-tion feature of Sector 1 is the beach area (Seabrook Beach and Hampton Beach).

Sectors 2 and 3: 2-5 Miles from the Feabrook Station -

Sector 2 is based on the northern half of the 2-5 mile band frem the .

Seabrook Station. The eastern edge of this sector is the Atlantic .

shoreline. On the North, Sector 2 is bounded by the Hampton, Hampton .

Falls and Kensington town lines. The Kensington town line also comprises the west boundary of Sector 2. Along the southern edge, Sector 2 is bounded by the Serbrook, Hampton Falls and Kensington town lines and by a short section of I-95.

Sector 2 includes the entire town of Kensingten. Most of Hampton and Hampton Falls are also included in this sector.

Sector 3 is based on the southern half of the 2-5 mile band from the Seabrock Station. The eastern edge of this sector is the Atlantic shoreline. Cn the north, Sector 3 is bounded by the Seabrook and South _.

Hampton town lines, and by a short section of I-95. To the west, Sector 3 is bounded by the South Hampton and Amesbury town lines. The southern boundary of Set: tor 3 is defined by the Amesbury and Salisbury town lines.

Sector 3 includes the entire towns of Amesbury and Salisbury. The ~

portion of the town of Seabrook to the west of I-95 is also included -

in this sector.

Sectors 4 and 5: 5-10 Miles from the Seabrook Station Sector 4 is the northern half of the 5-10 mile band from the Seabrook Station. The eastern boundary of Sector 4 is the Atlantic shoreline.

1 21 l

s -

The inner boundary is defined along the North Hampton, Exeter and East Kingston town lines. The outer border of Sector 4, identical to the EPZ boundary, is defined by the Rye, Greenland, Newfields, Brentwood and Kingston town lines.

Sector 4 includes the entire towns of Rye, North Hampton, Greenland, --

Stratham, Newfields, Exeter, Brentwood, Kingston and East Kingston. A small portion of the City of Portsmouth is included. ,

The major population feature of Sector 4 is Exeter Center. .

Sector 5 is the southern half of the 5-10 mile band from the Seabrook Station. The eastern boundary of this sector is the Atlantic shoreline.

The inner boundary of Sector 5 is defined along the Salisbury, Amesbury and South Hampton town lines. The outer border of Sector 5, identical to the EPZ boundary, is defined by the Newbury, West Newbury, Merrimac, Newton and ,1st Kingston town lines. A small portion of the City of Haverhill is also included.

Sector 5 includes the entire towns of Newburypert, Newbury, West Newbury, Merrimac and Newton. A small portion of the City of Haverhill -

is also included.

The major population feature of Sector 5 is Newburyport center.

, ma i

1 l

l 22

1 IV. POPUIATICN CF THE SEABRCCK STATION EPZ 1

TOTAL PCPULATION CHARACTERISTICS The total permanent resident population of the Seabrook Station EPZ, as defined for the purposes of this study, is 111,000 persons (Table 3).

This population is distributed to 41,000 households. -

The population of the EPZ is spread fairly evenly throughout the EPZ

• with no single concentration of population accounting for more than 15 '

percent of total EPZ population. Population along the coast is scmewhat more concentrated than in the inland areas. The coastal towns and cities,

, with 37 percent of the total area of the EPZ, have 50 percent of the total EPZ population.

The EP population is concentrated into the town centers and cities. For example, four such concentrations (Exeter, Hampton, Amesbury and Newburyport)

I account for 50 percent of all population.

Seasonal and Transient Population During the Sc=ner months, the population of the EPZ is greatly increased

] by seasonal' residents and transient persons visiting the area for short periods of time (overnight or day trips) . Under peak conditions, on a Summer Sunday, 78,000 seasonal and transient persons are added to the permanent EPZ population of 111,005. This ad'ditional population is con-4 centrated in the beach towns, with Hampton accounting for about 40,000 persons and Salisbury next with about 19,000 persons. -

~

AUTCMCBILE OWNERSHIP-

, Table 4 shows the distribution of automobile-owning and non-automobile owning households in the Seabrook Station EPZ. Some patterns of automobile ownership of interest in estbnating evacuation times are noted:

1 23

s ... 1 l

, TABZ.E 3 i TOTAL RESIDENT POPULATION CF THE SEABROOK STATION EPZ '

)

GOVEPJ3 MENT UNIT PCPULATION TOTAL TOTAL 1

NEW HAMPSHIRE, JURISDICTICN (1970) JURISDICTION (1980)* SEABROOK EPZ i BRENTWOOD 1468- 217e 2170 EAST KINGSTON 838 1190 1190 4

EXETER 8892 10720 10720 o

GREENLAND 1784 2210 2210

~

HAMPTON 8011 10820 10820 HAMPTCN FALLS 125e 1500 1500 .

2 KENSINGTON 1044 1350 1350 -

2 KINGSTCN 2882 4640 4640 NEWFIELDS 843 1000 1000 NEWTCN 1920 4060 4060 NORTH HAMPTON 3259 4910 4910 PCRTSMOUTH 25717 28430 1000 RYE 4083 5230 5230 SEABROCK 3053 6000 6000 SCUTN HAMPTCN 558 800 800 i STRATHAM 1512 2500 2500 MASSACHUSETTS --

AMESBURY 11388 16560 16560 l HAVERHILL 46120 46340 200 MERRIMAC _ . 4245 4710 4710 NEWBURY 3804 4920 4920 NEWBURYPORT 15807 16740 16740 .

SALISBURY 4179 5150 5150 WEST NEWBURY 2254 2690 2690 -

TOTAL 154915 184640 111070

• DATA SOURCES FOR 1980 ESTIMATES: New Hampshire Office of Ccmprehensive Plan-ning. Interim Revisions, New Hampshire Population Projections for Towns and Cities to the Year 2000. August 1977; and Massachusetts Department of Public H1alth Office of State Health Planning. Population Projections 1980-1985.

August 1978.

24

TABLE 4 AUTO OWNERSHIP IN THE SEABROCK STATION EPZ HOUSEHOLDS BY AUTCMCBILE ANALYSIS ZONE / SEABROOK EPZ AVAILABILITY GOVERNMENT UNIT POPULATICN HCUSEHOLDS O 1 2 3+

NEW HAMPSHIRE 1 BRENTWOOD 2170 804 67 443 247 47 2 EAST KINGSTON 1190 441 37 243 135 26 3 EXETER 10720 3970 619 2263 1004 84 ,

4 GREENLAND 2210 819 68 452 251 48 ,

5 HAMPTCN 10820 4C07 240 1851 1639 277 .

6 HAMPTON FALLS 1500 556 46 307 171 32 -

7 XENSINGTON 1350 500 42 276 154 28 8 KINGSTCN 4640 1719 143 949 528 99 9 NEWPIELDS 1000 370 31 204 114 21 10 NEWTCN 4060 1504 125 830 462 87 11 NORTH HAMPTCN 4910 1819 151 1004 558 106 12 PORTSMOUTH 1000 370 31 204 114 21 13 RYE 5230 1937 45 _1046 713 133 14 SEABROCK 6000 2222 209 1409 440 164 15 SCUTH HAMPTON -800 296 25 163 91 17 16 STRATHAM 2500 926 77 511 284 54 -

~

MASSACHUSET"'d 17 AMESBURY 16560 6133 1147 3434 1282 270 18 HAVERHILL 200 74 13 41 17 3 19 MERRIMAC' *4710 1744 309 959 338 ~78 20 , NEWBURY 4920 -

1822 - 322 -1002 415 83 21 NEWBURYPORr 16740 6200 1321 3292 1345 242 -

22 SALISBURY 5150 1907 248- 1064 494 101 _

~23 WEST NEWBURY. 2690 996 176 548 227 45 TOTAL 111070 41136 5492 22495 11083 2066 s

25

= ..

o Thirteen percent of the households in the EPZ do not own an automobile.

o A relatively large number of non-automobila owning

. t households are in Newburyport and Amesbury. These two areas, with less than one-third of the EPZ population, - -

have almost one-half of the non-automobile owning .

households in the EPZ.

o Relatively few non-automobile owning households are in .

the small towns and rural areas. For example, in Greenland, Kensington, North Hampton and Seabrook, the fraction of non-autcmobile owning households rangos frem 3 to 9 percent.

The seasonal and transient population is, for purposes of evacc.ation time estimating, assu=ed to be 100 percent automobile owning.

PCPULATION SEC1ENTS AS DEFINED FOR E7ACUATICN ANALYSIS In estimating evacuation ti=es, four population segments are identified on the basis of how persons are evacuated frem the EPZ (see Chapter VI):

(1) Auto owning populatien. This population segnent consists of all members of car owning families, except ' children in school at the time of notification.- ~ - ~

(2) School population. All children at school at the time of .-

notification, regardless of the automobile ownership status of their families.

(3) Non-automcbile owning households. All persons (except school children) in households where a car is not reasonably avail-

'able for evacuation.

I 26

. -. -._ _ ~= . . - _ _ . _ . _ . _ _ . . .

's .s

(4) Population in institutions such as hospitals and nursing homes, etc. and not having access to a private vehicle for evacuation.

Rearranging the EPZ population into these categories (Table 5) reveals that:

I o Most of the population (71 percent) is in the autemebile- - -

owning segment.

1 1 -

4 o The next largest population segment is school population, ,

accounting for about 19 percent of the EPZ population. .

I o Non-automobile owning population accounts for 7 percent of.Seabrook Station EP:: inhabitants. As noted above, this

, population is concentrated in the Amesbury and Newburyport

areas.

i w

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l 27

TABLE 5

, SEABROOK STATION EPZ POPULATICN BY SEGFE TS

(

.4 Percent of Populanion Segment Populationgj Total Population Automobile-Cwning 78,790 71 Population -

-l Schoc.1 Population 21,600 19 Non-Automobile Owning Households 7,180 7 i

Population in Institutions 3,500 '

3

)

e TOTAL 111,070 100 .

i

.. e 1/

- Permanent population. Seasonal and transient population of 78,000 persons not included. Seasonal and transient population is entirely r 1 in " Automobile-Owning Population" segment.

I 28 l

V. THE EVACUATICN SEQUENCE FOR SEABROOK STATION GENERAL CCNCEPT OF EVACUATICN

~ ~~

The overall purpose of the evacuation is simply to remove the popula-tion of the EPZ as rapidly as possible. The evacuated population is _

directed to reception centers, where it is temporarily lodged. Some .

of the evacuated population will go to che homes of nearby relatives -

and acquaintances. ~

Wherever possible, the evacuating population will leave the EPZ by means of private automobiles. Persons without automobile transportation will i

be transported by transit vehicles, ambulances and other available vehicles.

In general, motorists will leave the EPZ by the most direct route; that is, the shortest route out of the EPZ. Traffic direction at some key locations will help balance the traffic volumes on the evacuation routes.

Normal traffic flow Vill be observed, with streets cpen to all vehicles and functioning in their usual manners -'

In estimating evacuation times, the EPZ population is grouped according to how it evacuates: (1) auto owning population, (2) school population (3) non-auto owning population and (4) persons in institutions.

Each of these groups follows a different sequence in evacuating:

o the auto owning population, after receiving the notice to evacuate, assembles the family (except for children at school) at home, prepares for evacuating the home and drives out of the EPZ. Non-residents (for example, beach visitors) simply assemble the group with which they are traveling, and leave the area.

29

i-2 q o. the school population is transported out of the EPZ directly frca the schools. School buses are used to evacuate this r population.

o non-auto owning households prepare for leaving their home, i

1 assemble at collection locations, and are then transported --

out of the EPZ in' buses or other vehicles. ..

l '

o persons in institutions (hospitals, etc. ) are prepared for -

4 evacuatien, then transported out of the EPZ in buses and .

ambulances.

I i

POSSIBLE EVACUATICN TIME PERICDS I

4 The length of time needed for evacuation of the Seabrcck Station EPZ will vary, depending on the time of day, day of week and season of year in which the evacuation occurs. Four possible time periods are identified:

o Nighttime o Daytime on a summer weekend (" Summer Sunday" case) o Daytime on a winter weekend --

o. . Daytime on a " winter weekday" case In estimating evacuatior; tines, the " worst cases" of these four time l periods should be adepted; that is, evacuation time estimates should

reflect conditions likely to cause the longest evacuatibn times, j i

! Nighttime Evacuation -

In a night evacuation, the notification process would be slowed by people having to wake up and. comprehend the evacuation information i being broadcast. Additienal time would ':6-required.to prepare vehicles o

for evccuation in the dark. Cn the other hand, for most segments of

.I 30

.i

i the population, the families would be intact at the time of notifica-tion, since schools are not in sessien and relatively few employees are on the job. i Daytime on a Sumer Weekend ("Sumer Sunday" Case) 4 In any daytime evacuation, the notification time is at a minimum, since 4

most people are awake and many are already listening to radio and ,;

television broadcasts. Families are more likely to be nt the same loca- .

tion on weekends, since schools are not in' session and relatively few -

persons are at work. Outdoor recreatien is at amaximum during this season, and many non-residents are at the beach areas.

Daytime / Weekday E'n cuation (" Winter Weekday" Case)

! During a daytime / weekday evacuation, a majority of the employed population would be on the job. During most of the year, schools are in session and the transportation of students becotaes a large issue in any evacuation.

! For much of the population, a daytime / weekday evacuation creates additional .

action steps, since families must be assembled prior to leaving the home -

and evacuating the EPZ. Also, during the daytime / weekday period, the  ;

likelihood of persons being away frem hcme without a vehicle are greatest.  :

Critical Time Period's , .

For the evacuation of the Seabrook Station EPZ, the~ critical time period--

that is, the period for'which evacuation is likely to require the most time--is the " Summer Sunday".

During this period, the population and ,,.

4 vehicle accumulation in the EPZ is at a maximum.

The next most' critical time period is the " Winter Weekday" period.

During this period, the time needed to assemble family units is likely to be at its maximum. Furthermore, the daytime / weekday periods raises issues of-school population evacuation which de not exist in other time periods.

31

a ..

i Separate evacuation time estimates are prepared for both of these time  !

periods, i.e., for "Sammer Sunday" and " Winter Weekday".

POPULATION SEGMENTS TO BE EVACUATED As a first step in estimating The evacuation times for the Seabrook EPZ, - --

its population is divided into segments. A separate time estimate is made .

for each of these segments. This methed, by recognizing the various ways .

, in which pcpulation leaves the EPZ, allows a more precise prediction of ,

required times. The basis for the various population segments is HCW ,

that segment of population leaves the EPZ. Consequently, four population segments are identified:

(1) Auto cwning population, whc evacuate by driving out in private autemobiles. This pcpulation segment consists of all members of car-owning households, except children at school.

(2) School population; that is, all children at school. This population is evacuated directly from schools, in school buses.

(3) Non auto-owning households; all persons in households where a _,  :

i car is not reasonably available for evacuation. Some of this population is evacuated by friends and relatives. Those not evacuated by friends or relatives assemble at collection points, and are evacuated by bus.

i (4) Population in institutions such as hospitals, nursing homes, -

jails, etc. This population is evacuated directly from the .

institution, by bus or special vehicle.

Family Units Families (excluding children in school) are evacuated as units. On weekdays, assembly of the family units involves members returning home 32 v, ., - -

--_7-_

from thair jobs, shopping, etc. On weekends, many families are already assembled and can immediately prepare to leave home. Non resident families (for example, beach visitors) are already assembled, and evacu-ate with almost no further preparation.

EVACUATION ACTION STEPS "

For each population segment, the evacuation sequence consists of a ,

series of action steps. These are clearly defined actions, performed -

in a predictable sequence (see Figure 7) . -

Subdividing the evacuation process into these discrete steps improves the accuracy of the estimates et time needed for the entire evacuation.

In place of a single estimate of the entire evacuation process, for which data is not available, this process permits the estimation of times for each individual step, for most of which data is readily available.

i -

1 Public Agency and Private Steps i

Some of the evacuation steps identified in Figure 7 are performed by public agencies. For all population groups, the " Evacuation Notice" -

action is the responsibility of public agencies. For those persons evacuated by means other than privately owned vehicles, public agencies have the additional responsibility for the actual evacuation steps for example, " Evacuate School Population in Buses", " Evacuate Non-Auto Owning Households in Buses", etc.* For population in in~stitutions, the

" Mobilize Population" step is also a public agency responsibility. ~

1 Those action steps not the responsibility of public agencies are dene at the initiative of the individuals being evacuated. For the auto owning population, all steps after the initial " Receive; Broadcast Information" are private actions; that is, they are initiated by the individuals being evacuated. Similarly, two of the steps in the evacuation of non-auto owning households are private steps.

33

a ..

AUTO OWNING S C H O O L- NON AUTO OWNING POPULATION IN HOUSEHOLDS POPULATION HOUSEHOLDS INSTITUTIONS aECElvt RECE!VE RECE!VE RECE!VE BRCAOCAST BROACCAST SROACCAST SROADCAST INFORMATICN thFCRMATICN ZhFORMATICN '

INFORMATION Y Y Y V

~

EVACUATg PREPARE LEAVE PLACE SCHOOL FOR MO8ILIZE CF WORK POPULATICN EVACUATING POPULATION IN BUSES HOME ,

1F 1F 1P EVACUATE WORK TO HCME ASSEMBLE AT INSTITUTIONAL TRAVEL COLLECT!CN _

PCPULATICN p0!NTS IN BUSES OR SPECIAL VEHICLES Y V EVACUATE PRIPARE FCR NON. AUTO EVACUATING OWNING HCME HouSEHOLOS IN BUSES

~

ORIVE CUT OF EPZ ,,

, 6 Figure 7. Population Segments and Evacuation Sequences 34

l l

l EVAC"ATICN CF AUTO CWNING POPULATICN The action steps described in the f ollowing sections describe the sequence of evacuation for resident auto owning households, evacuating the area during the daytime / weekday period. For some other ccmponents of the auto owning population, the sequence is shortened and certain action steps are -

omitted. For example, non-resident beach population does not need to return home from work, nor to prepare for leaving a household. In the ,

calculation of evacuation times, only those action steps appropriate .

.1 to the population component are included. -

i Receive Broadcast Information i

Following the decision to evacuate, the first activity is the notification l of the public that an emergency exists. This is acccmplished by the

! sounding of sirens, and activation of other alert systems (such as NOAA) .

This notification alerts the public that an emergency exists, and that they should tune in to radio and television broadcasts for further 1

information.

The next activity is the broadcast of radio and television information, --

with specific instructions for evacuating.

Various other backup measures are used to inform the population which might not be reached by the above means. Mobile public address units will circulate through' built up areas of the EPZ. Public address systems

will be used at large concentrations of population, such as the beaches

• and race track. Seme households, particularly in the more remote rural -

areas, will be notified directly by telephone call.

1 Leave Place of Work The rate at which area workers will leave their jcbs to return heme to -

prepare for evacuation depends on the particular work envirenment and upon the responsibility level of the worker. It is to be expected that 35 . .

C

o ..

l d

l most of the work force will be able to leave their jobs almost immediately,

~

quite similar to a normal departure frem work at the end of the workday. ,,

A number of workers, however, will require some job "close-down" time in a work situations; for example, those that involve machinery, construction l' equipment, or cash registers in retail sales establishments. Supervisory employees, managers and independent business operators will generally -

i require the greatest amount of time to secure their place of work and to assure that all employees and others on the premises have departed. .

Work-to-Home Travel .

4 Travel of the employees from their place of work to hcme is essentially a normal journey-to-work travel time distribution. The maximum trip I

length for work trips in the EPZ is not likely to exceed 20 miles, and the average trip is less than three miles. An average travel speed of 20-30 miles per hour is typical for the travel hcme for area workers.

This movement of workers, because of the short time over which it occurs, can be expected to cause scme traffic congestion. This level of congestion y should be similar to that occurring during the twice-daily work travel .'

peak. It is expected that the road system will handle this volume of -

traffic with essentially the same level of service as during the peak hours on a typical working day.

Prepare for Evacuating Hcme People can be expected to react differently to any emergency situatien,

• and the conditions imposing an evacuation need on the area pcpulation ,-

are likely to generate great differences in the amount of time that people will spend in preparing to leave their home. Three factors in particular affect the amount of time needed to prepare for evacuating a household:

(1) Whether er not adults are at home when notice to evacuate is received. If so, preparation time is shortened (ccmpared to 36

_ _ . . _ . _ _ _ ._.. , _ _ _ . , . , _ __ . .~.

d households where no adul.ts are at home) since preparation for evacuation can begin before workers arrive at home.

(2) Number of children and other dependents at home. These increase the time needed to prepare the household for evacuation.

ea (3) The amount of property to be secured. Farms are the extreme case, and may require up to two hours to secure. on the other hand, small households, for example, in apartments, can be prepared for evacuation in minutes. .

Travel Cut cf the EP After households are secure, auto owning households will drive out of the EP by the most direct routes available.

The auto owning population will drive either to reception centers -

established outside the EPZ, or to other destinations (p'rimarily homes of friends. and relatives) of their own choosing.

Public agencies will give routing advice for this travel, by means of -

preparedness plans prior to the emergency and through information broad-

-casts during the actual evacuation. Police officers will also channel flows of traffic out of the EPZ.

Ev,acuating traffic will use all available roads out,of the EPZ. Traffic volumes are too large to permit evacuation to be confined to some selec- ,

ted roads. -

During the evacuation, normal traffic operations will generally prevail.

Specifically, two-way streets will continue in two-way operation, traffic signals will continue to function, and so forth. Some modifications might be mades for example, seme three-lane roads may be operated in an "imbalanced" manner, with two lanes flowing out of the EPZ and only one i lane used for inbound traffic.

37

l A

1 During much of the evacuation, traffic will flow freely, although 'at _

reduced speeds. However, at certain locations and during certain periods, y traffic congestion is expected.

EVACUATICN CF SCHOOL POPULATICN r

Receive Broadcast Information ,

Following the decision to evacuate, the local preparedness agencies -

notify schools directly of the need for evacuation. This is done through .

radio warning systems and telephone calls directly to the schools.

Siren systems will serve as a backup method of notifying schools. Coverage of the school population by this method is high, since almost all schools are in populated areas within siren range.

Evacuate School Poculation 1 Buses ,

The school population is transported directly by bus from school to -

reception centers. Generally, an entire school will be transported to the same reception center. School children will not return home prior -:

to evacuation. The picking up of school children at school by f anilles is discouraged.

School bus fleets from all districts within the Seabrook EPZ and from neighboring districts within about a 20 mile distance o~f the EPZ will be used for evacuation. All school buses u;ed in t.hese districts, whether publicly or ~ privately owned, will be used to evacuate students from the EPZ.

NCN-AUTO OWNING HCUSEHOLCS Receive Broadcast Information The procedure for receiving broadcast information is the same as for auto owning population (above). This includes the sounding of sirens, broadcast 38

information, mobile public address and possibly some direct notification by telephone calls. .

Prepare for Evacuating Home This step is the same as for auto owning population (above) . As in the --

case of auto owning population, primary factors in the time required _

for this action are whether or not an adult is at home at the tima of notification, the number of dependents to be evacuated and the extent .

of property to be secured. -

Assemble at Collection Points A significant fraction of the non-auto owning population (perhaps as much as 50 percent) will be evacuated as passengers in private vehicles driven by family, neighbors or friends. This component of the non auto-owning pcpulation could then be considered, in effect, as part of the auto-owning population.

Persons from non auto-owning households who do not evacuate as'passen-gors in private vehicles will assemble at locations (for example, churches --

and public buildings) designated as collection points. From the collec-tion points, buses-will transport them to the reception centers.

Most of the population in settled areas lives within one mile of a collec-tion point, and the majority of this population will walk there. Persons unable to walk to the collection point will, by telephone, request transit service from their hcme to the collection point. Rural non-auto -

cwning population will be taken to collection points in transit vehicles -

and in some cases, automobiles.

Evacuate Non-Auto Cwning Households in Buses Transit buses will pick up evacuees who have assembled at the collection points, and take them to the reception centers outside the EPZ.

l 39

~- _ . .. - - -

e ..

l Potential sources of buses include private common carrier fleets, public transit systems from within the EPZ, and public transit systems from ,

outside the EPZ, particularly from the Boston urban area.

POPULATICN IN INSTITUTICNS Receive Broadcast Information Following the decision to evacuate, the local preparedness agencies .

will notify institutions directly about the need to evacuate. This is .

done by radio warning system and telephone calls.

I i

4 The siren notification system is a secondary backup method of notifying institutions. Siren coverage of institutions is high, since almost all of them are located in populated areas and therefore within range of a siren.

Mobilize Pepulation The institutional population is instructed about evacuation precedures '

by the staff of that particular institution. Necessary personal effects --

are assembled. Essential medical records are gathered.

Evacuate Institutional Population in Buses or Special Vehicles Transit buses will pick up ambulatory hospital patients, nursing home residents and other persons not requiring ambulance transportation.

• These passengers will be transported directly to the reception centers. -

Generally, all residents of a given institution will be evacuated uo the same reception center. Potential sources of buses include private common carrier fleets, public transit systems within the EPZ and public transit systems frcxn outside the EPZ, particularly frcm the Boston urban area.

40

I . ..

I e

Non-ambulatory persons will be transported directly frem institutions a

by ambulance. These vehicles will be drawn from the fleets normally based within the EPZ, supplemented by ambulances from neighboring communities.

j Ambulances used in the evacuation of institutions will make three round c trips.

~

i

SUMMARY

CF THE EVACUATICN PROCESS .

In order to examine the " worst case" for which evacuation times are at a maximum, the evacuation is assumed to occur during the daytime on a summer weekend. The next most critical period, daytime on a weekday,-

] is also examined.

Four pcpulation groups, having distinctly different evacuation methods, t -

are recognized: ,

i

) (1) auto owning population, which evacuates in private automcbiles _

1

(2) school population, which evacuates in school buses -

4 1

I (3) non-auto owning households, which assemble at collection points

~

and evacuate ir) buses I

(4) persons in institutions,* who are evacuated directly from the inatitutions in bases and-ambulances.

• i .

7 For each population group, the evacuation sequence consists of a' number  !

4 of clearly defined. action steps as summarized in Table 6.

f i

41

e . . .

(

TABLE 6

SUMMARY

OF EVACUATION ACTION STEPS z

POPULATION SEGMENT ACTION STEPS AND DESCRIPTION AUTO OWNING POPUIATION 1. RECEIVE BROADCAST INFORMATION, (All members of households, including instructions for evacua-except school children, ting. ,

having a private vehicle

2.

• LEAVE PIACE CF WORK available for evacuation)

3.

• WORK-TO-HCME TRAVEL, similar to normal work trip .

~

4.

• PREPARE FOR EVACUATING HCME (close house, secure property) ..

5. DRIVE OUT OF THE EPZ in private vehicles, using most direct routes SCHOOL PCPUIATION 1. RECEIVE BROADCAST INFORMATION, (All persons in schools, including instructions for.evacua-whether public or private) ting

2. EVACUATE SCHOOL POPULATICN IN BUSES frcm districts in EPZ and other sources -

NCN-AUTO CWNING PCPUIATICN 1. RECEIVE BROACCAST INFORMATICN, (Persons not having a including instructions for evacua-private vehicle available ting r evacuadon) '

]

2. PREPARE FOR EVACUATING HCME (close house, secure property) -

3. ASSEMBLE AT COLLECTICN POINTS such as churches or public buildings

4. EVACUATE NCN-AUTO OWNING POPULATION IN BUSES from EPZ and other sources PERSCNS IN INSTITUTICNS , . 1. RECEIVE BRCADCAST INFORMATION, (Efospitals, nursing homes, including instructions for evacua-Naval Base, etc.) ting

2. MOBILIZE POPULATION, prepare popula- -

tion for evacuation

3. EVACUATE INSTITUTIONAL POPUIATION IN BUSES OR SPECIAL VEHICLES

• These steps emitted by non-residents; for example, beach visitors.

42

.- .. l l

l l

1 VI. EVACUATICN ROUTES __

GENERAL STRATEGY OF EVACUATICN ROUTING This chapter considers the evacuation of the largest population segment -

[ of the EPZ: those using private automobiles. The basic objective of evacuation routing for automobile traffic is to permit vehicles to exit as rapidly as possible from the EPZ. The overall evacuation strategy .

is derived from key geographic features of the EPZ such as the location .

of the Seabrook Nuclear Power Station and the constraint on eastward movement presented by the Atlantic Ocean, as well as from the characteris-tics and configuration of the road network. The basis of the strategy is the evacuation of principal year-round population centers by the most direct movement possible. The major components of this strategy are illustrated in Figure 8 and summarized belew:

o Newburyport, the largest population concentration of the EPZ, should be evacuate'd directly to the south.

o Amesbury, the second ranking population center, should be _ -

evacuated directly to the southwest.

o Hampton, the largest population center within a 5-mile radius of the power station, should be evacuated directly to the

-, north. - - - - -

o Exeter and its surrounding area should be evacuated directly .-

to the west and northwest.

i These four major movements define the corridors for evacuation of 50 percent of the winter weekday population of the EPZ. Clearly, this strategy provides for the separation of the major flows which is impor-

' tant to the minimization of traffic conflict.

43

a .e Town Bouncary l

...... d Freeway

• ArtertaJ Ptighway

. 10 - Miie Radius of Station littlig EPZ Bouncuy HAMPTON AND OTHER NORTHERN TO W N S EVACUATE NORTH

==

~ VIA US 1 AND 1-OS

.g e as-t' El ~

llityElks 1

$ngts

,y g, 8

=* - 3.c. .

EXETER AND OTHER NORTHWEST ARE AS MltilIIlllIIIIIII

• \

EV ACUATED vlA gurn;5

(

SR 101, 111. 10 S g'g AND 123 I ' tillt *,,.,,,.,g, / j

1. gg

,.- / , , ._

!=. ,

3 E -

8't ,'

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= =t* h e.ts .cc:

.( / 's r.

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== s C, __

f t .

5 ~

b Ea!*

3

=

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BE ACH POPut. ATIONS

\ } ,

-' 5 3 _C

" 5'ON gy ACU ATE VI A SR 51 e*:s - sve *:.. w AMD 266 TO 1*G5 AND US 1

• w b

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aw 59.*

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AMESBURY AND SOUTMi AST ,

AREAS EV ACU ATE VI A 1495 '-,,

AND SR 110 ', ,,,,, _, . g{gl4%

4 554 0909 IIII NEWBURYPORT AREA

/ EV ACU ATES VI A l-95.

US 1 AND 1A Figure 8. Evacuation Routing Strategy 44

t .

RCAD NETWCRK FCR VEHICI.E EVACUATION The characteristics of the road system within the EPZ were presented in Chapter II. A capsule description of the facilities available for evacuation traffic would note that the EPZ is served by a full range of facility types that includes two interstate highways, Federal primary ""

system routes as well as primary and secondary state roads. Examination ,

of the road network indicates that north-south movement is more direct ,

than east-west travel patterns. The major facilities, I-95 and Route 1 -

are continuous and offer high capacity fer traffic exiting the area to -

, the north or. south. Conversely, there in no facility of this capacity for east-west traffic and those roads that ao serve this movement are relatively indirect.

Figure 9 identifies the " gateway" points where roads crcss the boundary of the EPZ. This set of eighteen gateway points represents the total roadway' capacity for evacuation. In general, the capacity of a roadway is determined by the capacities of its intersections, rather than by its cross section at the non-intersection locations. In the case of evacua- -

tion routes, capacity is likely to be determined by a " critical inter- -

section". These are intersections that represent the " bottlenecks" on --

the evacuation routes.

In general, they are locations at which (1) the evacuation route has a high traffic volume, af ter having collected traffic from_various tributary road 2, and (2) cross-street traffic at the intersection is significant, reducing the amount of time available for evacuation traffic to move through the intersecfion'.

The capacity of an intersection is based en a maximum flow of 1500 vehicles per lane hourly, with full assignment of the right-of-way (or, in other words,1500 vehicles hourly if there is no cross street traf fic) . This capacity is then adjusted downward to reflect the demands of the cross traffic. At the critical intersections, which are establishing the capacity cn the evacuation routes, the tctal 45 m

~ ..

J J s%

200 IM 1200 s sta rt.:s '

= g, 01200 $~

-nosa, alllillh4EllifillIl ~ ? =.

=-- ......

N, _...- l**' '~ .+

l

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'l fI*

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sacsrwoco ,- 'y, ,,

[ ' .  ? " 2V"' s 3 i,, , ,

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f

1. + y en X, -

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= Nos es *l s.NorcN ""[:'$3 ,%

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a k'?^ '

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,,; ,, c , _c- . s c 4 e,. ~ -l

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.- ~ $, ',~, l 4

Cl ' ,

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l

""**'m freeway '

1. #1titiallilli tilllil'IIs m m m It'lil'lillllitt

- - -. f[. E,[*"** '"#

stessee EPZ gound S400 Figure 9. Evacuation Gateways and Capacities ,

46

J capacity is adjusted downward to 80 percent of the maximum to reflect r this cross street traffic. The resulting capacity is 1200 vehicles per -

lane per hour.

1 The total capacity of the Seabrook EPZ gateway points is approximately

'~

38,400 vehicles per hour. This estimate of total capacity is based upon the use of hard surface highways and primary and secondary roads as -

evacuation routes and does not include local urban streets and unpaved .

roads. The gateway capacity of three-lane facilities such as Routes 1

~

and 1A has been calculated on the basis of assumed two-lane operation cutbound.

FORECASTING EVACUATICN TRAFFIC The review.of data on the characteristics of the population of the EPZ included an assessment of auto ownership patterns in the area. At this _.

point in the analysis, we consider the generation of automobile vehicle trips for the evacuation of those households with an auto available.

It is important to recognize that automobile evacuation trips and total '

"}

autemebiles within the EPZ are not necessarily the sapp. '

The trip generation step is a calculation based upon the auto cwnership patterns of the year-round residents and the vehicles asscciated with beach visitors and seascnal residents. The patterns of auto ownership and the median household size (number of persons per household) indicate th'at there are households with fewer vehicle's than licensed drivers and .

households with more vehicles than licensed drivers. Recreational vehicles, for example, are often " excess" vehicles that are used only I for special purposes. The trip generation step is built up from the segments of the auto-owning population and recognizes that households

- with only one or two vehicles will utilize a greater proportion of their households with three or more vehicles. Table 7 presents the total vehicle trips forecast for each zone under the two different evacuation scenarios.

47 W -

e TABLE 7 EVACUATION TRAFFIC FORECAST ,

(VEHICLE TRIPS)

ANALYSIS ZONE / CASE A: SUMMER SUNDAY CASE B: WINTER WEEKDAY -

GOVERNMENT UNIT TOTAL PEAK HOUR TOTAL PEAK HCUR NEW HAMPSHIRE 1 BRENTWOOD 908 782 908 782 .

2 EAST KINGSTCN 498 429 498 429 ._

3 LETER 3937 3390 3937 3390 4 GREENLAND 925 796 925 796 5 HAMPTCN 18828 18152 4864 4188 6 HAMPTCN FALLS 628 541 628 541 7 M SINGTCN 563 485 563 .485 8 KINGSTON 1939 1669 1939 1669 --

]

J 9 NEWFIELDS 417 359 417 359 10 NEWTCN l'697 1461 1697 1461 -

JCRTH HAMPTCN 2053 1768 2053 1768 ..'

12 PCRTSMOUTH 417 359 417 359 -

! 13 RYE 2382 2051 2382 2051 14 SEA 3 ROCK 5419 5086 2397 -2064 I

15 SOUTH -HAMPTCN -

334 288 334 288 16 STRATHAM 1045 900 1045 900

MASSACHUSETTS .

17 AMESBURY 5897 5077 5897 5077 -

' ~

18 ' HAVEPJIILL '73 63 73 63 19 MERRIMAC 1712 1474 1712 1474 20 NEWBURY 1791 1542 1791 1542

-21 -NEWBURYPCRT 5794 4989 5794 4989 22 SALISBURY 7291 7012 2007 1728 23- WEST NEWBURY 979 843 979 843 TOTAL .65227 -

59516 43257 37246 i- 48

i This forecast level of auto vehicle trips averages approximately 85 .

percent of the estimated total number of vehicles in the EPZ. This level of vehicle utilization appears reasonable when allowances are

- made for vehicles being outside the EPZ at the time of evacuation, vehicles being out of service for mechanical problems, and the number of " excess vehicles" in households where there are not as many licensed -

drivers as vehicles. _

Table 7 also presents information on the distibution of the vehicle ,

demand. Estimates for the peak hour of travel are shown for each ,

evacuation scenario on a zone by zone basis. Demand peaking information is of interest because it places the total travel demand into the same temporal framework as capacity. The distribution of all evacuation activities over time is a central feature of the approach taken in this analysis, reflecting conditions as they are actually likely to occur.

Inspection of the activity distribution curves developed in this study for the evacuation of the Seabrook EPZ indicated that 86 percent of the population wou]d be attempting to exit within the peak hour of demand.

These. peak hour demand volumes can be related to the hourly capacities 7 of the road network to estimate supply / demand imbalances and consequent .-

traffic congestion and delay. _

INDIVIDUAI. EVACUATION ROUTES In order to assess the time required to evacuate the Seabrook EPZ,

-individual exit routes were developed for each of the analysis zones or towns within the area. This enables a relatively " fine-grained"

)

analysis that can be related to actual concentrations of population and _

the evacuation route options available to each subarea.

A series of individual evacuation routes are then determined for each

! zone following these guidelines:

9 o The route must lead fairly directly out of the EPZ, and should not have a circuity of greater than 150 percent. (Circuity is 6

49

the amount by which the actual road distance exceeds the straight-line distance). ..

o The routes must be at least collector streets in the urban areas, or at least paved secondary roads in the rural areas.

Local urban streets and unpaved rural roads are not designated as evacuation routes. -

The resulting system of evacuation routes for each case is shown in .

Figures 10 and 11. Some of_the roads are designated as the evacuation -

routes for more than one analysis zone. Also, some analysis :enes have multiple evacuation routes designated.

For each of the evacuation scenarios carried through the analysis, the forecert traffic volumes were assigned to the system of evacuation routes.

In the absence of a detailed local plan for the management of evacuation traffic, a number of assumptions must be made in order to reflect the conditions reasonably attainable with available local management resources.

Therefore, for the purposes of this analysis, it was assumed that overall,  ;

traffic facilities wculd be cperated in a relatively normal fashien. That is to say that few instances of special traffic management capability -

were assumed. Noteworthy exceptions include assumed two-lane entry to I-95 northbound at Route 51 and assumed use of the center left-turn lane as an outbound travel. lane on Route 1 and LA. In addition to these cperating characteristics, a relatively low-level of traffic control intervention and direction was assumed for a limited number ~of intersectier.s.

Beyond this, little effort was made to balance or optimize traffic flows. _-

, It is important to recognize that individual motorists will have very 2 imperfect kncwledge of traffic conditions elsewhere in the region and will only have a limited set'of route options for evacuation. Thus, significant imbalances and congestien are inevitable because severe peaking characteristics foreclose chances of a situation where available 50

e ..

I I

...... Town Boundary g 900 Freeway -

Anenal Highway .O l l

1196

. 10. Moe Pacius of Station v.  :- l ////##//f#1/ j fgjg i 1888199 EPZ Boundary 359 / I

\ G:E E N . *.

[

N -'

nu L

p200

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, =nununniun g ,_,

601 ,120 = \ _

f _T Ninf.4. . -A -

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1111111 11111 ,

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gjgin uluttillHinHHH l 1111111 5392 i 2931 f734 Figure 10. Evacuation Routes: Case A, Summer tiuncay

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~ ^_. Figure 11. Evacuation Routes: Case 8, Winter Weekday 52

[ ,

P .*

m roadway capacity would be utilized most efficiently. Still, it is worth noting that even under an ideal assumption of optimal traffic ,

balance with full utilization of gateway capacity, there would be 1.7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> of traffic flow thrcugh the gateways in the summer-Sunday case and 1.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> in the winter-weekday case. Of course, actual evacuation times will be much longer reflecting the effects of " bottlenecks" and --

traffic congestion. _

Figures 10 and 11 present the forecast peak hour traffic volumes by -

route for' each of the evacuation scenarios. These volumes represent a -

believable balance of demand, based upon the congestion and route alter- ,

natives presented to motorists evacuating each zone.

PERFORMANCE OF THE EVACUATICN TRAFFIC SYSTEM The traffic volumes' forecast for the evacuation routes indicate that there will be a broad range of traffic system operating _cenditions under both of the evacuation scenarios. The leading characteristics of the evacuation traffic systen are described generally below. A more detailed ~5 analysis of the traffic congestion and delay is provided in a subsequent chapter. An overall assessment of evacuation traffic conditions indicates --

that:

o The largest problems in the winter-weekday case are related to north-south movement. A few areas and roadways emerge as critical areas for estimation of evacuation times and traffic

~

delays.

o The largest prcblem in the summer-Sunday case is in westbound movement away from the beaches. The limited nature of the transportation network in beach areas means that the few available evacuation routes will be swamped with traffic. As vehicles clear the beach areas, problems will continue at north / south gateway points.

53

i

)

i I

O. Movement to the southwest, west and northwest are relatively unconstrained. Analysis indicates that backups will occur but j

?. hat these :hmuld be relatively limited in scope and duration because the capacity exists to accommodate anticipated peak hour flows.

o The major traffic facility in the EPZ, I-95 will experience ,

relatively poor utilization. As the largest facility in the ,

area it would be expected that I-95 would be utilized to the -

utmost. Analysis indicates, however, that there are serious -

problems associated with the use of I-95 for evacuation.

o The proximity of the Seabrook Nuclear Power Station to I-95 is one fac*.or limiting the use of this evacuatien route. A fundamental tenet of evacuation planning is that few motorists will drive toward the source of the radiation and thus increase their exposure to health hazards. As a result, use of the

~

access ramps to I-95 at Seabrook is largely precluded.

1..

o Lack of access points prevents greater use of I-95 for north- -

bound evacuees. The Hampton interchange at Route 51 is the only -

access to I-95 north of Seabrook within the EPZ. Thus the use of this major, multi-lane facility is constrained by the capacity of the on-ramps at a single interchange.

o As access routes to I-95' (both north and southI of Seabrook) become congested, traffic is forced onto Route 1. As a result this facility will experience a larger volume of demand relative 3 to its capacity than the interstate facility.

l l

1 54

-e ..

VII.

SUMMARY

CF EVACUATION TIME ESTL%TES .

METHOD FOR ESTIMATING EVACUATION TIMES Population Segments Evacuation times are estimated separately for each of the four popula- .

tion groups discussed earlier:

(1) Auto Owning Population (2) School Population (3) Non Auto Cwning Population (4) Population in Institutions .

Time Periods- =

m

~

Evacuation times are estimated for two different time periods (cases) as discussed previously in Chapter V:

(1) Daytime on a Summer Sunday", and

~ ~ ~ '

~'

(2) Daytime on a " Winter Weeicday"

. Action Steps-Each population segment follows a specific sequence of action steps in evacuating the EPZ. (See Chapter V for a detailed discussion of these steps). The times needed to ecmplete each of these steps is then estimated. For the auto owning households, for example, estimates are 55

-r made for the time required for (1) receiving broadcast information, .

(2) leaving place of work, and so_forth. <

The times needed to complete each step are not expressed'as a single value of time, such as an average or a median value. Rather, the times

~~

required-for each step are stated as the distribution of times, relating

. the fraction of the population completing a particular step to the ,

elapsed time after notice to evacuate. .

Time Required for' a Series of Action Steps -

The total, evacuation time is calculated by linking together the times required to ' complete the individual steps. The resulting total times for evacuations are stated, as are the times.for the-individual steps, as a_ distribution of times, showing the fraction of the population which completes the total evacuation process within a given amount of elapsed time. .

Assicnment of the Traf fic to the Evacuation Routes -

~

The traffic due to the evacuation'of the auto owning households is -

" assigned" (that is, distributed) to the available roads out of the EPZ, as shown in the previous chapter. Delays due to this traffic are calculated, and'the evacuation times are adjusted to reflect these delays.

~ ~ '

EVACUATICN TIMES FOR CASE A: SUMNER SUNDAY' Figure 12 shows the time needed' to evacuate the population of the entire. _.

Seabrook Station EPZ under a summer weekend condition (that is, under Case A Summer f Ny) .

The critical population element _ is the auto owning population; in other words, it is this element-of the pepulation that establishes the total evacuation time, other elements of the population (for example, popula-56

= .

l O r j ALL NON-BEACH POPULATICN ALL BEACH POPULATION -

EVACUATED WITHIN EVACUATED WITHIN .

3 HOURS 25 MINUTES 6 HOURS 10 MINUTES AFTER START OF AFTER START OF _

EVACUATION NOTICE EVACUATION NOTICE 100 E

C NON-BEACH l

< 80 *POPULATICN g

= i l '

BEACH '

I

$ 60 PCPULATICN E l u

N ~~

c. go y '

~

$ 20 l E l l .

00 .-

0:00 1:00 ,2:00 . 3:00 _ 4:00 _ 5:00_ 6:00 7:00 TIME AFTER START CF EVACUATION NOTICE (HOURS)

. Figure 12. Evacuation Times: Case A, Summer Sunday 57

e tion in institutions) can be evacuated in a shorter time than the auto -

owning population, provided that vehicles are available for their evacua- <

tion. Consequently, their evacuation does not add to the total evacua-tion time.

" ~~

As indicated in Figure 12, there are two distinct components of the evacuation traffic under the Summer Sunday case (1) beach traffic _

population and (2) non-beach population. The non-beach population is .

~

cleared within 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> and 55 minutes after the start of notification.

$ The beach traffic, on the other hand, is not cleared until 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 10 -

minutes after the start of notification.

Formation of Traffic Congestion At numerous points = within the Seabrook EPZ particularly in the beach areas, traffic backups (queues) will forn during some part of the evacua- .

tion process. These are- caused as the auto owning population completes the necessary preparations to leave their hcmes or the beach, and encers the street system at a rate greater than the capacity of that street l system to carry them (Figure 12). As a consequence, traffic begins, to

' "}

back up, starting at critical intersections (" bottlenecks") at which '

traffic demands are the greatest. Congestion then spreads rapidly from these critical intersections. Shortly after they first form, queues spread along-arterial streets, blocking traffic attempting to feed in from side streets. In the worst case, congestion spreads generally

~

throughout the area, with all arterial and collector stieetA and even some local streets blocked. At this point, numerous private and ccm-mercial driveways are blocked. -

During the period in which this congestion is occurring, the rate of evacuation is fixed by the capacity of the street system, and is no longer deternined by- the rate at which the population finishes prepara-tions to leave.their households or the beach. Motorists leaving their t

58 L

e

~

homes and entering the street system during such a period are simply ,

" stored" in traffic queues in t?e street system. Under such conditions, .

increasing the speed of notification and the clearing of households and beaches does not improve the total evacuation times, but rather merely puts more vehicles into the traffic congestion.

Two possible levels of congestion are illustrated in Figure 13. In the ,

less severe instance (upper diagram in Figure 13) the traffic queues ,

end as the rate of vehicles entering the street system diminishes. At -

this point, free traffic flow is restored, and the rate of evacuation -

is once again determie d by the rate at which the populaticn ecmpletes preparations to leave home. This situation, occurring on most of the inland' evacuation routes, results in a' total evacuation time of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 45 minutes after the start of the notice to evacuate.

In the more severe example of congestion (lower diagram in Figure 13) .

typical of beach area traffic, traffic queues are so large that they continue even after all auto owning households have left home and entered the street system. Once' started, this type of traffic congestien centinues until evacuation is complete.

Extent of Traffic Congestion Figure 14 illustrates the extent of traffic congestion and the length of delay during the evacuation period. These examples are focused on evacuation routes in the~beac1 area, where the maximum delays occur.

The 1,evel of congestion, the length of time spent in traffic backups _-

and the length of these backups are unlike anything that the population of the Seabrook EP" has encountered previously, and it is important that the dimensions of this congestion be understood:

59

! }

A. CONGE STION ENDING dEFORE ALL AUTO -

OWNING POPULATION LEAVES HOMF i

100 s l

$ , ( CONGESTION ENDS AT 6 RATE AT WHICH o THIS P olNT, in. V EHIC L E S ENTER O STREET SYSTEM FREE FLOW l RESTORED z

l ( l -

00 U _,

% INDIC ATES 3EVERITY OF OELAY .

= l .

m 40 ,gayE AT WHICH VEHICLES -

CAN EV ACU ATE. OUE 70 .

[- C AP ACITY OF STREET

< l SYSTEM

$ gn

$ CONGESTION SEGINS l 1:30 2:00 2:30 3:00 3:30 4:00 TIME FROM START OF NOTIFIC ATION S. CONGESTION CONTINUING AFTER ALL AUTO-OWNING POPULATION LEAVES HOME _

ALL V EHICL E S IN STREET SYSTEM l l l g p' f - %l ._

C O N G E S TION RATE AT WHICH SEVER 4Ty '

80 - ENDS AFTER VEHICLES ENTER OF DELAY 'ALL P'O P U L A TIO N STREET SYSTEM i -

HAS LEFT HOME 80 - " "  ! t RATE AT WHICH VEHICLES 40

% CAN EVACUATE ~

r ^ ~

20 CONGESTION SEGINS I 1:30 2:00 2:50 $00 3:30 4:00 l

Figure 13. Traffic Congestion Analysis ,__

60

\

\

\

LOCATION OF TRAFFIO QUEUES ,.

g (BACKUPS) DURING SUMMER 4 hjfj g.:: gp:.:.;5y.:.,egggg d SUNDAY EyACUATION, IN

g,g,,,

THESE QUEUES, TRAFFIC SPEEDS -

RANGE FROM IERO T0 s MILES MAmaton PER HOUR. z*.,:z"iz;

- ':i. -

• U n!!. ....'

P l - ,;f- -, _ ,

.E*

NORTH BEACH

~. %., -

4 ';;:

R ih. , $$ ' , ,

MAMPTON FALLS .

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WITHIN THE CITY OF .7 '

NEWBURYPORT, ABOUT 1o MILES OF QUEUE ARE

[' # ._'

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DISTRIBUTED ON THE LCCAL STREET SYSTEM.

NEvauRYPORT

/ .

h Figure p, Trattic Con 9'Stion Case A'summet sunday

\

61 I

== ...

et o length of delays: The maximum delay for the entire Seabrook ,.

Station EPZ will be experienced by traffic exiting from Salis- <

bury Beach. For a vehicle entering the end of the traffic congescion at its maximum, the delay will be 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and 15 minutes. In other words, a vehicle entering the street system

~~

at the peak of the congestions will not move (or *ctill scarcely move) for a period of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and 15 minutes. This is the _

maximum time,_which represents a worst case. Celay times for .

other motorists range downward frca this maximum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> -

and 15 minutes; nevertheless, the majority of the Salisbury- -

Beach populatien will have delay times in excess of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

The Hampten Beach traffic is next in order of length of traffic delay experienced, with a maximum delay of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> and 15 minutes. This is followed by Seabrook Beach, with a maximum delay.of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 45 minutes.

Other significant delays occur at the more inland locations.

For example, for the inland portions of Northampton, Hampton and Salisbury, the maximum delay is 30 minutes, while at Newburyport the maximum delay is 60 minutes. ~

o Iangth of Traffic Backup: In several locations, the amount of traffic that is attempting to enter the street system exceeds the space available on the entire road system. In other words,

~

there is not enough spac'e on the s'treets ts st' ore "the vehicles attempting to get onto the street system. Consequently, many

- vehicles will not be able to leave their parking' spaces, drive- Q ways, etc.

This situation is the most severe in the Hampton Beach area where a queue (backup) of 49 lane-miles of traffic is attempting

,1f A lane-mile of traffic is one lane of traffic backed up for one mile. A lane-mile of traffic contains about 200 vehicles.

62

1 e' .. I Q

to enter a road system of about 11 miles in length. Even if -

much of the road system were operated with two lanes outbound, there would still be space, on the entire road system, for less than one-third of the vehicles attempting to enter it.

~~

Next in terms of length of traffic backups are Salisbury Beach (27 lane-miles of traffic) and Seabrook Beach ~ (11 lane-miles of -

traffic) . -

On the inland portions of the coastal towns, the backups are about one mile for Hampten and North Hampton, and no queue at all for Seabrook.

At the larger inland towns, significant queues are expected to form. For example, 4 miles of backup will form at Newbuyport and about 7 miles will form in Amesbury. However, these backups .

are spread over numercus local streets, and are not concentrated on a single highway, as in the case of beach area congestion.

7 Traffic Congestion and Driver Behavior There is considerable uncertainty as to what might happen to driver behavior in 30 to 90 minute traffic backups under circumstances such as an evacuation. The existing evidence for this type of occurrence.is sketchy and uneven. In some more or less documented instances, such as evacuation'after chemical spills or evacuation related to natural disasters, generally orderly traffic flow has been reported. On the other hand, experiences such as major snowfalls (even in regions accustemed to such I type of weather) suggest that driver behavior deteriorates quite regularly under circumstances of 30 to 90 minute delays.

Some specific motorist behavior problems that could be caused by delays of the length expected in the Seabroek EP" evacuation include:

63

o Creation of more lanes in the outbound directions; in effect, a one-way system out of the area, as motorists impatient with the length of queue simply begin using the left hand (that is, inbound) lanes for travel out of the area. This is not neces-sarily a poor strategy, if planned, but could be chaotic if it occurs spontaneously. --

Furthermore, if a two-lane flow must be returned to a single .

lane at some downstream point, then there is no advantage in the .

two lane flow. To the contrary, the merging activity as the ..

two lanes are combined into one will cause a loss in capacity relative to a single smoothly flowing lane.

o Blocking cross streets at intersections: This is a common type of traffic disorder, even under normal traffic situations, and it can almost certainly be predicted that this will happen under evacuation circumstances, particularly since at times. the length of queue will extend back through several intersections, and will fill the entire road system of the beach area.

o Disregard of normal traffic control devices (such as signals, --

lane markings, signs, etc.) is a frequent consequ-nee of routine traffic congestion such as that occurring at sporting events, traffic accidents, construction locations, etc. Disregard of traffic control devices could be assumed to be evan more wide-

-- spread during evacuation of the Seabrook EPZ.

• Failure of traffic control causes a reduction of capacity, at a given location,_to about 50-70 percent of the capacity that is -

obtained under well disciplined traffic flow.

-o Total traffic stoppage: In this type of failure, traffic.is backed up through the entire network of intersections, and no traffic can be discharged out of the tie-up. It is possible, 64

r- ..

under this condition, that the total amount of traffic moved out of a given area (the beach, for example) becomes far less ,

than that under conditions where traffic is flowing. In fact, no traffic at all may move for some periods.

o Abandoning vehicles is frequently seen in situations no worse -

than routine large snowfalls. If vehicles are abandoned along the roadways, or;in the traffic lanes, they will seriously diminish the capacity of the roadway and cause bottleneck situa- .

tions. .

o nunning out of fuel: It is quite likely that in any sort of traffic tie-up, a number of vehicles will find themselves running out of fuel, particularly since there is no time to fill cars with fuel before starting. In this situation, aban-doned vehicles along the roadways seriously impair the capacities of those roads.

o Attempting to re-enter area: Despite instructions to the con-trary, some motorists will attempt to enter areas being evacuated, ..'

in order to gather family members, secure property, etc. Traffic __

caused by this activity will generate turning movements, cculd further reduce capacity at critical intersections and will ultimately be a,dded to the total evacuating traffic.

In the event of spontaneous one-way operationi re-entering traffic wculd cause a chaotic situation. In such a situation, -

even a few re-entering vehicles could result in the loss of an entire lane of outbound traffic.

I 1

I es

L e . .

4 EVACUATICN TIMES FOR CASE B: WINTER WEEKDAY c

Figure 15 shows the time needed to evacuate the pcpulation of the entire Seabrook EPZ under a working day during school hours (Case B: Winter Weekday). .

The critical population element in this evacuatien time is the auto-owning population; in other words, it is this element of the population that establishes the total evacuation time. Other elements of the population ,

(for example, population in institutions) can be evacuated in less time _

than the auto-owning population, provided only that vehicles are available for their transport. Consequently, their evacuation does not add to the total evacuation time.

As indicated in Figure 15, the entire EPZ population is evacuated within 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 40 minutec after the start of notification.

Traffic Concestion in a Winter Weekday Evacuation

,e Traffic congestion occurs on several evacuation routes during a Winter , '5 Weekday evacuation. However, under normal weather and traffic control _.

conditions, this congestion dissipates prior to the time that all house-holds have.left hcme and entered the street systew. (See upper diagram in Figure 13.), Consequen,tly, evacuation time is determined by the rate at which the population finishes preparations to leave their households, and is not determined by the capacity of the street system. - -

In a Winter Weekday evacuation, the road system is operating at capacity -

for a substantial part of the evacuation period. Any appreciable loss of capacity (for example, because of severe weather, uncontrolled traffic flow, etc.) would cause evacuation times to be extended beyond the 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 40 minutes estimated above. i 1

1 I

l I

l 66 i

,, = '

.c 1

ALL POPULATION '

EVACUATED WITHIN 3 HOURS 40 MINUTES ~

AFTER START CF EVACUATION NOTICE 100 E

80 A 5

b m .

g 60 E

w N 7

, $ 40 ---

s N

N 20 5

u 00 -

' 3e00

~

Os00 1800 ~2,00 '4:00 '5:00 ~ 6:00 7:00 TIME AFTER START OF EVACUATION NOTICE (HOURS) i i

i I

i

~

Figure 15/ Evacuation Times: Case 8, Winter Weekday 67 l

l

EVACUATION OF THE SCHOOL POPULATION The determining factor in the times for the evacuation of the school popu-lation is mobilizing the available school bus fleet. The school population can be notified well in advance of the arrival of school buses. After notification, preparation to leave the school premises is almost immediate -.

(similar to a routine fire drill). Buses will be loaded tmmediately upon arrival at the schools and will then travel directly out of the EPZ.

A bus fleet large enough to carry the entire school population in a single _

trip is assumed in estimating these evacuation times. This fleet will be drawn frem all districts within or partly within the EPZ. In addition, other buses will be drawn from districts not within the EPZ but in the close vicinity of it.

EVAC"ATICN OF THE NCN-AM O CWNING HOUSEHOLDS The determining factor in the rate of evacuation for the non-auto owning popula. tion is the availability of buses for transporting this segment of .

9 the population. The non-auto owning population can be assembled at ,'

collection points well in advance of the arrival of buses for their _ . .

evacuation. Buses will be loaded immediately upon arriving at the collection points, will travel directly to the reception center, and will return to the, collection; points for a second load.

A bus fleet sufficently large to evacuate the non-auto owning population in two trips is critical to achieving total evacuation times estimated -

above (6_ hours 10 minutes en a Summer Sunday, and 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 40 minutes on -

a Winter Weekday). If a sufficiently large bus fleet could not be mobili-sed, and a third trip out of the EPZ were needed (even if by only a few buses), the total evacuation time for the non-auto owning population would increase and could become the critical (i.e., determining) element of the evacuation time.

68

F s ,o d

Interestingly, a bus fleet larger than that needed to carry the non-auto owning population in two trips provides only marginal savings in total <

evacuation times. For example, a fleet large enough to carry 75 percent of the non-auto owning population at one time would improve total evacuation times by only 10 minutes.

EVACUATICN OF THE POPULATION IN INSTITUTIONS The determining factor.in the rate of evacuation for the population in ,

institutions is the availability of buses and ambulances for transporting ,

this s9gment of the population. The population in institutions can be mobilized for evacuation well in advance of the arrival of buses for their evacuation. Buses would be loaded immediately upon arrival at the institu-tions, would travel directl" to the reception centers, and would return to the institutions for a second load.

~

A bus (and ambulance) fleet large enough to evacuate the population in institutions in two and three trips, respectively, is critical to achieving the totsi evacuation times estimatad above. If a sufficiently large bus .

9 and ambulance fleet could not be mobilized, and additional trips out of ja the EPZ were needed (even if only by a few vehicles) , the total evacuation _

time for the population in institutions would increase and could become the critical (i.e., deter ining) factor in evacuation times.

SELECTIVE EVACUATION OF AREAS WITHIN THE EPZ Depending on wind conditions and the nature of the release at the Seabrook -

Station, the selective evacuation of the EPZ might be reasonable. Evacu- _

ation times for reasonable ecmbinations of sectors within the EPt are shown in Figure 16.

Evacuations within the two-mile and five-mile radius of the plant could be acccmplished in less time than evacuation of the entire EPZ, due primarily to the . availability, as evacuation routes, of several north-south roads

('for example, US 1, State Route lA) that would not be fully available to 69

O O

)

SECTORS TRIGGERING EVACUATION CONDITIONS TIME 2

O 1 ONLY V UAT

@j .

g 7 s HOURS to MINUTES ,

~

?$f 1,2 AND 3 V T P

p, @ OI 5 HOURS so MINUTES N -

t iMi s -'

{T EVACUATION TO 1,2 AND 4 to MILE RADIUS 3 NORTHWESTERLY

.5 HOURS 10 MINUTES WIND 1

.. EVACUATION TO

![k 1,3 AND 5 SOU S Y WIND Figure 16. Selective Evacuation Times 70

the two-mile and five-mile radius populations in the event of a full EPZ _

evacuation.

Two possible selective evacuatic a combinations extend to the 10-L le radius:

1. Sectors 1, 2, and 4, a possible pattern in the event of a northwesterly wind. .

2. Sectors 1, 3, and 5, a pattern in response to a southwesterly -

wind. -

For the 10-mile selective evacuation which includes the Newburyport urban area, the total evacuation tf=e is the same as for the evacuation of the full EPZ. This is because the maximum evacuation time for the entire EPZ is established by the level of traffic congestion in the Newburyport urban area, in combination with the beach traffic. In a selective evacuation which includes Newburyport, this same level of congestion and therefore same evacuation time prevail.

~7 For the selective evacuation to the 10-mile radius but not including the '

urban area of Newburyport, the evacuation ti=e is significantly less than for the full EPZ, and is the same as for the two-mile radius evacuation.

This is mainly a reflection of the lack of traffic congestion in the north-west part of the Seabrook-Station EPZ.

LMPACT OF 15-MINUTE NOTIFICATICN CN'EVACUATICN TIMES '

For the critical time period (Su=mer Sunday) , a 15-minute notification 7 would make almost no noticeable improvement in evacuation times over those estimated with the existing notification system in use. The evacuation time for the Summer Sunday situation is determined almost totally by the rate at which the beaches can be evacuated; speeding up the notification process, under these circumstances, simply accelerates the rate at which motorists enter the axisting traffic congestion.

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t a

? IMPACT OF SEVERE WEATHER ON EVACUATION TIMES Severe weather, in the form of a major winter storm, would lengthen the normal weather evacuation times to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and.30 minutes after start of notification (i.e., 40 minutes more than evacuation ti=es under normal .

, weather conditions on a Winter Weekday). -

This severe weather evacuation time assumes a slowdown in traffic but no

icss in street capacity (i.e. , no lanes or streets blocked) . The impact of contingencies which cause loss of traffic capacity (i.e., blocked lanes ..

or entire roads) cannot be estimated without specifying the exact nature of the problem. In general, any loss of capacity on any major evacuation

)

route will cause major traffic problems throughout tha evacuation period.

i i

SUMMARY

CF EVACUATICN TIMES Table a su=marises total evacuation times for:

l

o. Summer Sunday and Winter Weekday cases.

o Nor=al weather conditions. -

o Severe weather conditions.

o Evacuation in which a 15-minute notification is achieved.

4 o Selective evacuation of the two-mile radius, five-mile

• radius, and 10-mile radius. -

PROBLEM, ISSUES AND RECOMMENDATICNS Beach Traffic Concestion ,

A l

i In a Summer Sunday evacuation' at the beach area, traffic delay ranges up to a maximum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> 15 minutes; that is, a vehicle may be stopped for-i

72 4

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' TABLE 8 ^

i l EVACUATION TIMES FOR SEABROOK STATICN f

i Case A Case B i- Summer Sunday Winter Weekday i -

Normal Weather 6. hours 10 minutes 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 40 minutes Severe Winter Weather (not applicable) 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> 30 minutes *

,1 With 15-Minute

~

l 4

hetification 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 10 minutes (not estimated) -

l 2-Mile Radius j Selective Evacuation 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> 10 minutes (not estimated)

5-M11e Radius l Selective Evacration 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> 40 minutes (not estimated) i 10-Mile Radius, Selective Evacuation l to Northwest 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> 10 minutes (not estimated) '

! 10-Mile Radius,.

l Selective Evacuation to Southwest 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 10 minutes (not estimated) ]

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over four hours in traffic congestion. Most of the traffic caught in congestion is within five miles of the Seabrook Stacion, with a substantial .,

portion within direct sight of the plant. The behavior of drivers under these conditions of delay and proximity to the Seabrook Station can only be guessed. However, any breakdown in orderly traffic flow will result in evacuation times greater than those estimated. For an evacuation in which --

traffic control is generally ineffective, total times will range from 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> 30 minutes to 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> 40 minutes. .

Two possible actions can be taken to reduce the rate at which vehicles _

enter the street system, thereby reducing the length of traffic queues and the amount of time spent in them by motorists:

1. Sequential evacuation of the beach area. Under this strategy,.

evacuation of the beach area would be staged, with one section cleared before evacuation of the next section begins.

Sequential evacuation can be managed through selective noti-fication of the population, detailed broadcast information ,

and traffic control. .

Soquential evacuation does not in itself reduce the total evacuation time. However, it reduces the amount of time spent in vehic1es by the evacuating population, and it also reduces the chance of a chaotic breakdown in traffic control.

2. Sheltering on the beach. Some of the population may be

• sheltered in their residences on the besch, thereby reducing -

the number of vehicles attempting to enter the road system.

Sheltering could be done as part of a sequential evaluation, in which sheltered population evacuates as congestion diminishes.

The radiological exposure trade-off of sheltering vs. waiting in a vehicle stopped in traffic congestion is outside the scope of this analysis. However, available information suggests that exposure risk is high for persons in vehicles.

74

r More Use of I-95 The capacity of I-95, as it presently operates, cannot be fully used in an evacuation. Entry ramps are limited in number and not located ideally for evacuation.

Additional emergency-only ra=ps could be added to I-95, southbound as well as northbound. These ramps, similar to maintenance-vehicle ramps already in use, would involve minimal construction and would not be used under normal conditions. ,

Buses for the Transit-Dependent Population The dominating factor in the evacuation time for the transit-dependent population (i.e., the non-auto owning population and th'e population in institutions) is the availability of transit buses and ambulances. The estimated evacuation time in this report assumes an availability of vehicles such that half of the ambulatory transit-dependent populatien can be carried at one tine. This assumpcion of bus availability, however, is 7

far in advance of the actual number of buses secured by the local plans. ,,-

The consequences of a smaller fleet are substantial. As the fleet drops below the size necessary to acccmmodate one-half the anbulatory transit-dependent population at once, a third round-trip by some buses becomes necessary, sharply raising the time needed for evacuation of that population. - - - - -

In view of the large bus requirements for evacuating the transit-dependent .

popula' tion, it is recommended that:

1. Sources of buses be clearly identified as the local pre-paredness plan develeps, and that a fleet adequate to carry the transit-dependent pcpulation in two round-trips be secured (80-90 buses) .

2. Receptien areas for the transit-dependent population be located as close to the EPZ as possible to mininise the travel time.

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c VIII. VEHICLES AND MANPCWER REQUIRED FOR -

EVACUATING THE SEABROOK STATICN EPZ INTRODUCTICN

, Two resources needed for the evacuation of the Seabrock Nuclear Station --

EPZ are (1) Vehicles .

A. school buses, transit buses and ambulances for trans- _

porting persons not having access to a private vehicle for evacuation.

B. traffic control and towing vehicles (2) Manpower A. drivers.for school buses, transit buses and ambulances B. tow truck operators C. traffic centrol personnel D. supervisory and coordination personnel 9

e VEHICLE REQUIPIMENTS _

School Buses A total of 250 school buses are required for the evacuation of the school population in the EPZ. This bus requirement is based on the transportation, in a single trip, of all school "opulation frca the EPZ.

• Schoo'l buses will be obtained frem all districts within or partly within the EPZ, and from other school districts within about a 20-mile distance from the EPZ (that is, within a 40-mile radius of the Seabrook Station).

Privately-owned fleets as well as publicly owned fleets will be mobilized.

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Transit Buses ,

Between 80 and 90 transit buses are required for the evacuation of the non-auto owning households and persons in institutions. The range in this requirement is due to'the variation that might occur in the number of persons from non-auto owning households that will be evacuated in private automobiles of friends, neighbors, or relatives. The bus require- ,

ment of 80 to 90 vehicles is based en transporting the non-auto owning ,

population and the population in institutions in two trips per vehicles -

that is, after carrying the first lead of passengers to a reception center, -

each bus returns to the EPZ for a second load.

Transit buses will be mobilized from private common carrier fleets located in the vicinity of the EPZ, and from public transit fleets in the Ports-mouth and Boston urban areas.

Ambulances .

Between 80 and 130 ambulances are required for the evacuation of the ,

non-ambulatory population in institutions. The range in this require- -

ment is due to (1) fluctuations in the size of the non-anbulatory -.:

population in the EPZ (2) uncertainties as to the fraction of non-ambu-latory population that.might be evacuated in regular buses and (3) range in the fraction tlutt might.be sheltered within the EPZ rather than evacuated from it.

~

The. requirement for 80 to 130 ambulances is based on each ambulance making .tliree trips out of the EPZ. _-

Ambulances will be mobilised frem all sources within the EPZ, including hospitals, nursing homes, rescue units, and private carriers. Ambu-lances will also be mobilized from all available sources within a 20-25 mile area surrounding the EPZ.

77

)

s ..

Traffic Control and Towing vehicles ,_

s A total of 77 critical traffic control. points have been identified for the routes assumed in this evacuation time estimate. Each of these loca-tions requires a traffic control officer on duty .for most of the duration d ~~

of the evacuation process. Since radio communication with these traffic control points is critical, a need for 77 radio dispatched vehicles is .

identified for traffic control use at critical locations. ,

Between 30 and 50 towing vehicles will be needed during most of the -

i evacuation time period. Tow trucks will remove disabled or abandoned vehicles which are blocking evacuation routes.

Tow trucks will be mobilized from the fleet now based within the EPZ, as well as from immediately surrounding areas.

4

, MANPCWER REQUIREMENTS ,

School Bus, Transit Bus and Ambulance Drivers

-f i s pperation of the vehicle fleets as discussed above will require 220 --

school bus drivers,.80 to 90 transit bus drivers and 80 to 130 ambulance

drivers.

Traffic Control Providing traffic control at the 77 critical intersections in the EPZ will require 77 to 120 traffic control personnel. The range is due to _-

the possibility that more than a single traffic control person will be needed at'some locations.

Tew Truck operators l

' Cperation of the tow truck fleet as described above will require 30 to 50 tow truck operators.

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Supervisory and Coordinating Personnel ,

c

, A total of 360 to 430 persons are needed to conduct the evacuation at the local (town) level. Activities include operation of the notification system, supervision of traffic control,. operation of collection points for non-auto owning population, manning of local evacuation headquarters and confirmation of evacuation. This personnel will consist of the local ,

preparedness officers and designated staff. ,

J

SUMMARY

OF VEHICLE AND MANPCWER REQUIREMENTS -

Table 9 summarizes the vehicle and manpower requirements for the evacua-tion of the Seabrook Station EPZ.

It is stressed that these requirements are for only those activities i related directly to transportation, and do not include requirements for many other evacuation activities. For example, vehicle _and manpower requirements for such non-transportation activities as notification, public safety, sheltering activity or operation of the reception centers ,

are not included in the requirements summarized in Table 8. ~

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TABLE 9 -*

VEHICLE AND MANPCWER REQUIREMENTS FOR EVACUATING SEABROCK STATION EPZ RANGE OF RESCURCES FOR EVACUATION CF ENTIRE SEABROCK .

RESCURCE STATICN EPZ .

VEMICI2S SCHOOL BUSES 220 buses TRANSIT BUSES 80-90 buses AMBULANCES80-139 ambulances TPAFFIC CCNTROL 77 police cruisers TCWING 30-50 towing vehicles MANPCWER SCHOOL BUS DRIVERS 220 drivers q

~

TRANSIT BUS DRIVERS 80-90 drivers AMBULANCE DRIVERS80-130 drivers -

TRAFFIC CONTROL 77-120 traffic officers TCWING CPERATORS 30-50 towing operaters SUPERVISORY AND , . 360-430 persons COCRDINATICN IERSCNNEL o

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'80 1

e v- .,9 IX. CCNFIPMATICN OF EVACUATICN .- .-

CONFIRMATICN PROCESS Tha confirmation process measures how effectively the evacuation is

.being accomplished. Confirmation is conducted by the local civil defense ' ~~

agancies, beginning at about the time at which evacuation was estimated . _

to be complete. . .

Confirmation of evacuation is essential for security reasons, to assure - -

that all population has left the area, and to assist those persons having difficulties in evacuating.

PCSSIBLE APPROACIIES TO CONFIPRING THE EVACUATICN CF *1C EPZ Confimation of evacuation may be approached in various ways: ,

o Active or passive: Proof of evacuation may require some action by the evacuee, or, en the other h,nd, may be accomplished . - - , .

through other means, without any action on the part of the - -

~~

evacuee. -

-~

o Extent of coverage of the population: The confirmction process - '

may _ include 10Q percent of the population (that is, every household) or it may be on a sampling basis, with scene fraction

' ' ~

of the total population surveyed. ~

,o Cetailed method of confirmation: A variety of detailed methods -

of confirmation is possible. Cne such method is for the evacu-ating household to leave some indication (sign, flag, symbol, etc.) at their residence upon evacuating. Security personnel would patrol through the EPZ, monitoring the progress of the evacuation and the rate at which the residents are leaving. -

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