ML20053B255

Forwards Final Evaluation of SEP Topic III-4.A, Tornado Missiles. Info Indicating Ability of Reactor to Shut Down & Maintain Safe Shutdown Until Final Resolution Reached During Integrated Assessment Requested within 30 Days

ML20053B255
Person / Time
Site:	Millstone
Issue date:	05/25/1982
From:	James Shea Office of Nuclear Reactor Regulation
To:	Counsil W NORTHEAST NUCLEAR ENERGY CO.
References
TASK-03-04.A, TASK-3-4.A, TASK-RR LSO5-82-05-059, LSO5-82-5-59, NUDOCS 8205280225
Download: ML20053B255 (28)

Text

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May 25,1982 Docket No. 50-245 L S05-82 059 Mr. W. G. Counsil, Vice President Nuclear Engineering and Operations Northeast Nuclear Energy Company Post Office Box 270 thrtford, Connecticut 06101

SUBJECT:

SEP TOPIC III-4.A. TORNADO MISS LES MILLSTONE Enclosed is a copy of our final evaluation of SEP Topic III-4.A. The evaluation compares infomation you supplied in your Safety Analysis Report dated August 31, 1981 and other infomation on Docket No. 50-245 with criteria currently used to license new plants.

The evaluation concludes tha' there are a number of systems which have not been shown to be adequately protected from tornado missiles. Because of the large number of vulnerable systems, you are requested to provide infonnation within 30 days showing the ability of the reactor to safely shutdown and maintain safe shutdown until final resolution is reached during the integrated assessment.

This evaluation may be revised in the future if your facility design is changed of if HRC criteria is modified before completion of the integrated assessment.

Sincerely, JrisIEc.1 cIcn:id Er.T James J. Shea, Project Manager Operating Reactors Branch No. 5 Division of Licensing SEM M -

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Mr. W. G. Counsil cc William H. Cuddy, Esquire State of Connecticut Day, Berry & Howard Office of Policy & Management Counselors at Law ATTN:

Under Secretary Energy One Constitution Plaza Division Hartford, Connecticut 06103 80 Washington Street Hartford, Connecticut 06115 Ronald'C. Haynes, Regional Administrator Nuclear Regulatory Commission Region I Office 631 Park Avenue King',of Prussia, Pennsylvania.19406 Northeast Nuclear Energy dompany

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ATTN:

Superintendent Millstone Plant P. O. Box 128

~ Waterford, Connecticut 06385 Mr. Richard T. Laudenat Manager, Generation Facilities. Licensing Noa theast U_tilities Service Company P. O. Box 270 Hartford, Connecticut 06101 Resident Inspector

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c/o U. S. NRC HP. O. Box Drawer KK Niantic, Connecticut 06357 First-Selectman of the Town of Waterford Hall.of Records 200 Boston Post Road 7 Waterford, Connecticut, 06385 John F. Opeka Systems Superintendent Northecst Utilities Service Company P. O. Box 270 Hartford, Connecticut 06105 U. S. Environmental Protection Agency Region I Office ATTN:. Regional Radiation Representative JFK Federal Building Boston, Massachusetts 02203 e

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a MILLSTONE NUCLEAR POWER STATION, UNIT NO. 1 TOPIC III-4.A - TORNADO MISSILES 1

I.

Introduction

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Tornado generated missiles could cause s u f f i c i e n't damage to a plant so that the actual safety of the plant is reduced.

Topic III-4.A is intended to review the plant design ~to' assure that those structures, systems and components impor-tant to safety can withstand the impact of an appropriately

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p'ostulated spectrum of tornado generated missiles.

I These inetyde those required to assure:

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1.

The integrity of the reactor coolant pressure bounda,'ry, 2.

The capability to shutdown the reactor and maintain if in'a safe. shutdown condition, end 3.

The capability.to prevent a c c i d e n t s.. w.h i c h could result in unacceptable offsite exposures.

Scope of RevieN The scope of the review is as outlined in the Standard Review 7

Plan (SRP) Section 3.5.1.4, " Missiles Generated by Natural 1

I Phenomena."

j An assessmdnt of the adequacy of a plant to withstand the'~

impact of tornado missiles includes:

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1.

Determination of the capability of th'e'ex' posed systems,

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components and struc.tures to withstand key missilei s

• (including.small missiles wi t h pene t r a t i n'gi c hb ra ct e ri s-

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tics and larger missiles which resultiin an overall str'uctural impact); and 2.

Determination of whether any areas of the plant require additional p r o t e 'e t i o n.

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II.

Review Criteria:

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The plant design was reviewed with regard't6-Gener&L Design'

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C r i t e r. i o n 2, " Design Bases for Protection'Against NatOfat'-:

Phenomena" which requires that struct6rei, systems and c'omponents essential to safety be designed to withstand the effects of natural ph.enomena such as tornadoes and General Design. Criterion 4,

" Environmental and Missile Design Bases" which requires that these same plant f.s_,s,t6res b6' protect &d'-

against missiles.

The plant,was als.c-revi,wed agsinst:th6 guidance contained in Regulatory G ui d e s :1 ;13, S pent t F u6 t * '

Storage Facility Design Bases," 1.27, "Ultimat6 Heat Sink" for Nuclear' Power Plants," 1.117, " Tornado Design Classifi -

y I

cation and 1.76, " Design Basis Tornado;fdr N06 lea'f.'PoQdf-l Plants" with regard to plant protection"against' tornado

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I missiles.

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III.

Related S a f e.t y Topics To pi c.II-2. A, "S ev e r e We a t h e r Phenomena" describes the tor-nado characteristics for the plant.

Topic III-2, " Wind and Tornado Loadings" reviews the capability of the plant structures, systems and components to withstand wind loadings.

Topic VII-3," " Systems' Required for S a f e S h u t d o w n'.' reviews those systems needed to a c h i 'e v e and maintain the plant in a safe shutdown condition.

IV.

R e.v i e w Guidelines The review was performed in accordance with Standard. Review Plan (SRP) 3.5.1,4, " Missiles Generated by Natural' Phenomena,"

Revision 1.

This SRP states that the assessment of possible

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hazards due to missiles generated by the natural phenomena is based on the applicant having met the requirements of General Design Criteria 2 and 4 by:

(1) meeting Regulatory Guide 1.76, Positions C-1 and C-2 and (2) meeting Regulatory Guide 1.117, P6si,tions C-1 and C-3.

SRP 3.5.1.4 further

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states that plants'which were not required at the construc-I tion permit stage.to design to the missile spectrum in Revision 0 to the SRP should show the capability to with-stand the two pos'tulated missiles discussed below.

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-ese.

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The following missiles are described i n"SRP 3.5.1.4 as being appropriate for evaluati.ng OL app li ca t i ons for plants s

which cere not required to be protected against the full tornado missile spectrum during the CP stage:

1.

Steel Rod, 1" dia., 3' long, 8 lbs, hor,izontal velocity,

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0.6 x total tornado velocity.

'2.

Ut,ility Pole, 13 1/2" dia., 35' l'o n g, 1490 lbs, hori-zontal velocity - 0.4 x total tornado velocity.

The systems, structures, and components required to be pro-tected because of their i m p o r t a 'n c e to safety are identified in the Appendix to Regulatory Guide 1.117.

V.

Evaluation A.-

Tornado. Event Description In accordance with Regulatory Guide 1.76, the Millstone Plant is in Tornado Region I.

Accord ngly, the design basis tornado is characterized by a maximum wind speed of 360 miles per hour with an occurrence frequency of no greater than 10 per year.

The tornado characteris-

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tics described in SEP Topic II.2.A for'the Mit'Lstone site are of similar severity.

Therefore, Regulatory I

Guide 1.76 will provide'an adequate design basis tor-nado for the Millstone Plant..

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Therefore, in accordance with SRP 3. 5.1. 4.,

Revision 0, the total horizontal velocitifs for the two postulated missiles are:

1.

Steel Rod, 317 ft./sec.

2.

Utility Pole, 211 ft./sec.

These missiles are considered to be capable of striking in all-di r ections wi th ve rti ca l speeds equal to 80% of

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the horizontal speeds listed above.

B.

Structural Considerations In our evaluation, we have considered the adequacy of the following structures for tornado missile protection:

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1.

Reactor Building; 2.

Turbine Bui t'di ng;

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3.

Controt Bui ldi ng; 4.

Radwaste Building; 5.

Gas Turbine Generator Euilding; and 6.

Intake Structure In order to assess t.h e adequacy of tornado missile pro-we have compared their l

tection of these s,tructures, wall and roof thicknesses *to the current NRC redbire-ments for the.tw6 postulated missiles for the Region I

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design basis tornado.

For a concrete strength of f'c :

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4000 psi, the required concreto thicknesses are os stated below:

s REQUIRED WALL REQUIRED ROOF MISSILE THICKNESS (INCHES)

THICKNESS (INCHES)

Telephone pole 12 12

' -1" s t ee l rod 8

8 The reactor building is construc,ted of 4000 psi con-crete.

The other buildings of interest were con-structed on 3000 psi concrete, but it is assumed that the strength of this concrete after aging is at.Least 4000 psi.

C._.S y s t e m Considerations

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The following structures, systems and components as listed in the Appendix to Regulatdry Guide 1.117 were

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' evaluated to determine their susceptibility to the postulated tornado generated missiles.

1.

Reactor Coolant Pressure Boundary i

The reactor coolant pressure boundary, up to the outboard main steam isolation valves and contain-ment isolation valves, is located in the reactor building.

The portion of the reactor coolant 9

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system.inside the drywell is completely enclosed by a five foot thickness of reinforced concrete.

Th.e reactor building walls enclosing the remainder of the reactor coolant system up to the outboard containment isolation valves are reinforced concrete 18 inches thick.

TFe dryweLL encl'osure and reactor building provide adequate tornado missile protection for the..

reactor coolant pressure boundary.

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2.

Reactor Core and Individual Fuel Assemblies The. reactor vessel which houses the core constitute.s a portion of the reactor core pressure boundary.which is discussed in Item 1,above.

The feel assemblies in the reactor vessel are adequately protected from tar-nado mi,ssile damage by the drywell enclosure and reactor building structure surrounding the drywell.

Protection provided stored spent fuel assemblies is discussed in Item 4 below.

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3.

S_y_s t e m s or Portions of Systems Required for Att'aining Safe Shutdown We have reviewed t,he tornado missile protection provided for the following components and systems listed in SEP Topic VII-3, " Systems Required for Safe Shutd.own" as discus' sed in the letter from D.

M.

Crutchfield to C o u n s. i t.d.a t e d M a y 11, 1981.

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s a.

Automatic Pressure Relief System The automatic pressure relief system valves are, locat,ed within the drywell.

Tornado missite' pro-s tection is provided by the drywell enclosure and reactor building structure surrounding the drywell as discussed in Item 1 above.

These structures provide adequate protection to the automatic pres-sure r eli 4 f "va lves against damage from tornado missiles.

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b.

Fe'edwater Coolint In~j e c t i o n System

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The major components in this system are.the con-densate pumps, condensate booster pumps, and reactor feed pumps.,

One feedwater train is used for safe

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shutdown and includes one condensate pump, one condensate booster pump and one feedwater pump.-

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Thes'e pumps take suction from the condenser hot ".

Well and deliver water to the_ reactor vessel for shutdown.

Makeup to the condense,r is from the, condensate storage tank (see Item 3k)._ ALL of the pumps in the.feedwater coolant injection system are located on the 14 feet 6 inches elevation of the turbine building.

The condensate and con-densate booster pumps are located in the north end of the turbine building and are vulnerable to tornado missiles approaching from the west'.-

They t

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are protected from horizontal missiles from other directions.by other plant-buildings and the turbine generator enclosure.

The walls on the west side of the pumps are concrete block which do not provioe adequate protection against either of the. postulated

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tornacs, missiles.

The ceiling above_these pumps is a six inch reinforced concrete slab at elevation 34 feet 6 inches with metal hatch c, overs above.the

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pumps.

The pumps.are theref* ore vulner'able to ' tele-phone poles approaching from a vertical direction.

Since the highest grade elevation within a one-half mite radius $f the plant is 50 feet above sea' Level, telephone poles are. postulated as tornado missiles up to elevation 80 feet above sea" level in accor-d a n.c e Qith Standard Revj ew Plan 3.5.1.4.

The reactor feed pumps are located on the east side of the turbine building at elevation 14 feet 6 inches..

The pumps are protected on the' north by the turbine generater enclospre.

The ceactor building. shields all but one feed pump (M2-10CJ i

on the east side.

The east concrete b' lock turbine building wall does not provide adequate protection to feed pu'mp M2-10C.

The walls to the south of the feed pumps are concrete block and.do not by them-selves,proyide adequate protection.

However, the eeS 5

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.., intervening equipment (i.e, diesel g.eherator) on

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the south side ~of the pumps wouLd prevent missile damage from this direction.

The six inch thick s

reinforced concrete ceiling and four inch thick reinforced concrete roof in combination provide adequate protection against vertical missiles.

As-discussed:above, there is not adequate tornado missile protection for th'e c'ondensate. pumps,

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con-densate booster pump's and reactor feed pump M2-10C.

The ot,her two feed pumps are adequately, protected.

c.

Service Water and Emergency Service Water Systems

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The service water pumps and emergency service water pumps a r'e used for safe shutdown of the giant.

ALL. of these pumps are located in the intake struc-

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ture.

,The walls of the intake are 12 inchirein-forced concrete.

The roof of the intake struct're u

is a concfete stab that varies in thickness between five and eight inches.

Steel hatch covers (3/16 and 1/4 inch thick) are located in the roof above the service water and emergency service water pumps.

We conclude that the thin hatch covers and con-crete roof slab do not offer adequate protection against vertical tornado missiles for the service water and emergency service water pumps.

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d.

L6w -P r es s ur e Coolant Injection / Containment Spray s

System The LPCI/ Containment Spray system pumps are located on the base elevation of the reactor building.

Piping'and. valves for this system are located in

• the r e a c t o r bui ldi r.g and inside the drywell.

Pro-tection for this system is the same as described

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in Item 1.

We conclude that the tornado missile

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protection for the LPCI/ Containment Spray System

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is adequate.

e.

Emergency Power System - Switchgear

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Emergency switchgear is located at elevation 36 feet 6 inches o f.t h'e turbine b u i l d i n g~.

Although som~e of this equipment is shielded on the east by the reactor-building, there is, i n.,g e n..e r h l, inadequate protection for the emergency swit,chgear against horizontal tornado missiles.

The exterior walls of the turbine-building are constructed of 12-inch thick.

reinforced concrete block which'does not provide i

I acceptable missile protection.

Various internal 1

walls shield s'ome of the switchgear.

These interior l-walls are constructed of 8-inch thick solid concrete block.

Th'ere is not adequate j usti fi cation to ' con-

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clude that this concrete block construction would protect against the postulated tornado missiles.

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The r.c o f is a four i n c h t h i c'k reinforced concrete slab at elevation 54 feet 6 inches., We conclude that there~is.not adequate protection for.the emergency switchgear a g a i n s t ' e i t h'e r horizontal or ve'rtical tornado missiles'.

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f.

Emergency Power System - Batteri'es and Battery

Chargers.

The un,it batteries are located in two a dj oi ni ng rooms on elevation 36 feet 6 inches of the turbine

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building.

The battery chargers are located in an open areas of the turbine building o u t si d e the bat-tery rooms.

The batteries are enclosed by t h e 12-inc.h thick r ei n f or c ed con c r e t e block walls of the turttine

' I building and 8-inch thick concrete block interior walls.

Similar walls surround'the battery chargers except that the south turbine building wall in the vicinity of the battery chargers is a metal-sided wall..

The roof over the batteries and battery chargers is a four-inch thick reinforced concrete slab at el'evation 54 feet 6 inches.

We conclude that there is not adequate protection for the batteries hnd battery chargers against either horizonta'l or vertical tornado missiles.

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Emergency Power System Diesel Generotd'r The ' emergency diesel generator is located in a com-

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partment on the east side of the t.u r b i n'e b u i l d i n g at elevation 14 feet 6 inches.

The compartment is shielded on the n rth side by the remainder of the plant..

The west, so'uth and east watts of the com-partment are constructed of 12-inch reinforced con-

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crete block.

Protection from vertical tornado missiles is provided by a six-inch thi,ck reinforc'ed concrete stab' ceiling at elevation 34 feet 6 inches and the four-inch thick reinforced concrete' stab roof at e,tevation 54 feet 6 inches.

We conclude that there is not adequate protection for the dieset generator against h6rizontal tornado missiles approaching from the east, west or south.

In addi-tion, the Licensee has not demonstrated that the diesel generator air intake a d exhaust vents at elevation 54 feet 6 inches on the turbine building roof ar,e adequately protected against tornado nissiles.'

h.

Emergency Power System - Gas Turbine The emergency gas turbine is housed in a separate building on the south. side of the plant.

Although

,the walls of the building are constructed of 10-inch thick reinforced concrete, there are a number O

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'o f large unprotected penetration's in the wells.

The roof of the b u i l d i.n g, at elevation 41 feet, is a six-inch reinforced concrete stab.

There are also large, unprotected openings in the roof.

Ce conc lude t hat the emergency gas turbine is not adequately protected from horizontal or vertical tornado m'i s s i l e s.

In additio', the Licensee has n

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not demonstrated that the gas' turbine intake and exhaust vents on (he roof of 'the building are adequately protected against tornado missiles.

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Emergency Power System - Fuel oil System The fuel oil storage tanks for the emergency diesel and gas turbine are located south of the plant.

They are buried tanks an'd are adequately protecte'd by a covering of at leas,t three feet of compacted

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backfi L L or crushed stone.

However, the fuel oil transfer pumps and some associated piping are exposed at grade elevation.

Therefore, tornado missiles could interrupt the fuel supply to the gas turbine and. diesel generator.

The diesel generator day tank is in a compartmen't on the east side of the turbine building at elevation 36 feet 6 inches.

The compartment is shielded on e.

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3 the north side by other plant structures.

However, the concrete block walls on the east, west and south do not provide adequate protection against horizontal tornado missiles for the day tank.

Like-wise, the 6-inch thick reinforced concrete slab roof at elevation 54 feet 6 inches is not adequate pro-

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tection against vertical missiles.

Therefore, we conclude that the diesel, generator' day tank and'the f uel' oil t ransf er pumps and piping are not.' adequately protected against the effects of tornado missiles.

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Instrumentation and Control for Safe Shutdown Ecuipment Instrumentation and c o n t'r o l for safe shut.down equip-ment is located in the co nt r ol-r o om.

The majority of the cables are routed ^from t h e.. c o n t r o l room through the cable vault and into the reactor building dir'

[y idjacent to the south of the control room

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and cable vault.

Other cables are routed through the turbine building at elevation 34 feet 6 inches to the switchgear at the, south end of the turbine building.

Cables routed to the intake structure and gas turbine building are buried.

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'Tho exterior walls and roof of the control roon are 24. inch thick reinforced c o ri c r e t e.

The reactor bui t'di ng walls are 18-inch thick reinforced concrete.

We conclude that the reactor building and the controt room enclosure provide adequate tornsdo missile pro-t e'c t i o n for the cables located in these two struc-tures.'e The cable vault is located directly below the control room and is protected from vertical missiles by the contro[ room enclosure.. Part of the cab'Le vault south wall is the 18-inch thick reactor bu'itding wall.

The remainder'.of the cable vault south wall is an 18-inch thick solid concrete block wall shared with the turbine building.

Parts of the west wall (shared with' the turbine. building) and north wall (shared -

with the Unit 2 cable vault) 'are atso 18-inch thick solid concrete blo-k wall. 'The other s e c t i ons "of t he west and north walls ar'e 27 inch thick r-e i n f o r c e d i

I concrete.

Although th.e adequacy of solid concrete block'to withst.and tornado missiles,has not been demonstrated by the licensee, the cable vault i s-adequately shielded on the north by other Unit 2 structures and on the west by equipment in the turbine building.,

The east wall of the cable vault is 18-l e

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i n e'h. r e i n f o r c e d concrete.

We conclud'e that the

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cable, vault enclosure and surrounding buildings s

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provide adequate tornado missile protection to cables routed through the cable vault..

As discussed above, equipment located in the in-

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building and parts of take s truct ure, lsa s t urbine the turbine building is not adequately protect'ed against tornado missiles.

Therefore, cables located in these areas would also be vulnerable to tornado missiles.

This is especially true for the' conc'en '

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tration of' cables in the suitchgear and battery areas in-the south end of the turbine building.

In addition, t h.e "L i c en s e e has not demonstrated that the

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buried cables routed to-the gas turbine building and intake str0cture are a d e q u a t e,l,y, protected against tornado missiles.

There' fore,~we, conclude that cables in the turbine building (unless shielded by other

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s t 'r u c t u r e s ), gas turbine. building and intake struc-ture as well as buried cables routed to the gas i

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turbine building and intake structure are not pro-tected against' tornado missiles.

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Condensate Storage Tank The condensate sto. rag e tank provides ma keup" to the condenser which is in turn the sour.ce of water for the feedwater coolant injection s y s t e m f o i-s a f e..

s'h u t do w n.

The tank is located in the yard' and is enclosed within a six-inch thick reinforced. concrete watt extending from grade elevation up to elevation 19 feet.

The wa t t t hi*ckness will not ' adequately protect against the postulated missiles.

No protection, other than the tank thickness, is provided for vertical

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missiles or horizontal missiles above elevation 19 fe We conclude that the condensate storage tank is not ad protected against tornado missiles.

L.

Space Coote s and HVAC Systems

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The controi r.c o m HVAC system is the ont'y cooling or HVAC system identified "to date by the Licensee as essential.

The neid for other space cooters wi.tt be addressed under Topic IX-5.

The tornado

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7 missite protection for space cooters serving safe shutdown. equipment and located within. compartments housing the safe shutdown equipment would be the the protection a f forded the saf e shutdown same as equipmen,t discussed above.

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Th,e control room HVAC systen is located in ths ven+ilation equipment area at elevation 5.4 feet

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6 inc,hes of the turbine building.

The north

.and south walls of this area"are metal sides exter-nal walls. 'The east wall is a reactor building wall.

The west wall'is an 8-inch thick' concrete block wall.

The roof is a steel-decking built up roof.

The intake f or the control r om HVAC system is located on the. turbine btsilding roof and is not fully prot'ected against t0rbine missiles.

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We*conclud.e'that the control room HVAC system is not adequ'ately' protected against tornado missiles except where protected,by the reactor b6ilding.

Likewise, those space coolers in, inadequately protected com-

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partments housing other safe shutdown eq'uipment Sie [ [\\

also vulnerable'to tornado missiles.

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Turbine Building Secondary closed Cooling Water Systems

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The turbine building secondary closed cooling wa ter -

(TBCCW) system was not identi-fied is an essential safe shutdown sys' tem in the letter from D.

M.

Crutchfield to W.

G. Counsit dated May 1,1, 19,81 on E.

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e Topic VII-3.

However, the TBCCW systen cools severaL space cooters serving safe shutdown eq0ipmen),

inctbding the condensate pump space coolers and diesel generator space cooler.

The need for these space coolers wilL be discussed und'er SEP Topic I'X-5.

The TBCCW also cools the control room air

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conditioning units.

The need for,the.s.e uni,ts.wilL be addressed,in TMI Action Blan., Item III.D.3.4,

" Control Room H a b i t a b i l i t y.,"

The TbCCW pumps and heat exchangers'are located on elevation 14 feet 6 inches on the turbine building.

Except on the north side where this equipment is sh.ielded by other plant structures, the TBCCW equip-ment is 6nt'y protected by c6ncrete block walts'.

We conclude that the T5CCW pumps and heat exchan -

gers are not adequately protVct ed f rom the effects of tornado m i s s i t e's.

4'.

Spent Fuel' Pool' and spent F6e l'. P o o l C o bl.i n a S v's t e m.

The spent ~ fuel boEL is located within,the reactor

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building ~with.the top of the pool open to the 108 ft.

6 inc'h elevation. -The Qalts of the reactor building

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are approximateLy 18-inch thick reinforced concrete up to elevation.108 ft. 6 inch.

Above the top of the

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d spent fuel pool, tha reactor building consists of 12 inch thick

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reinforced concrete walls and the roof consists of metal siding.

Below 108 ft. 6 inch, the spent fuel pool is adequately protected by the reinforced concrete reactor building walls.

The top of the pool, however, is vulnerable to missile damage due to the inadequacy of the roof.

Of the two postulated missiles, only the ons inch steel rod could be expected to im, pact the top of the spent fuel pool.

Otility poles are assumed to reach heights no' greater than 30 feel above the maximum

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grade elevation within one-half mile of the plant.

l Since the maximum g r a'd e elevation withih one-half mile is 50 feet above sea Level, a utility pole is

.. _ assumed,to impact no higher than 80 feet during a tor-

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nado.

The 18-inch thick reactor building walls pro-vide protection against utility pole impact up to an elevation of 108 feet 6 inches.

N,e-It is p6ssibLe for the one inch steel rod to penetrate the spent fuel pool area above elevation 108 feet 6 inches through the metal-sided roof.

How-ever, the effects of the.one inch steel rod have been evaluated in previous analyses (e.g., within staff testimony and responses to interrogati6ns on spent

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fuel pool protection against tornado missiles for florth Anna and Phlis'ades).

The results indicate that the potential offsite radiological consequences,are_well within 10 CFR Part 100 guidelines.

In view of the above considecations, we c o. n c. l u d e

,. hat..

t the Millstone Unit 1 spent fuel po.ol.is a c c e.p t.a b l e regarding tornado mi s si L e p ro t.e cti on..

The spent 16el pool cooling' system consists of two

. u' p mps, two heat exchangers, filters, piping, valves and instrumentation.

Most of this equipment is, Located

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below' elevation 82 feet 9 inches in the reactor, building and is protected by the 18-inch thick reinforced con-crete s.t r u c t u r e.

.The spent fuel pool filters are located in the radwaste building which is a below grade

~ ~ 'h' e s" pent' fuel pool reinforced concrete structure.

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. cooling system is cooled by the reactor building closed cooling water (RBCCW) system.

All RBCCW system com-

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ponents are located in'the reactor building.

We there-fore' conclude that adequate tornado missile protection' l

is afforded the spent. fuel pool cooling system and -

RBCCW.

However, the RBCCW heat exchangers. rej ect spent '

fuel heat to the service water system which is not adequately protected (see Item 3.c).

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5.

Reattivity Control System

.,The reactivi"ty control system' consists of a control rod drive system and the standby liquid ' control system.

Essential components for these systems are located in the reactor building and drywell.

These components are thick reactor building a d e q u a t.e l y p r o t e c t,e d. by. t h e.18-i.n c h.

z.,

w a 'l l s and the'drywe.lt enclosure.

All cables for the reactivity control systems.are routed from the control t h r o u g h t h e 'c a b'L e s p r e a di n g room directly below and-room throug.h the reactor building directly adj a cent to the cable room to the south.

See Item 3.j for the protectidn afforded cables in these' areas.

Based on the above considerations, " --

we conclude.that the, reactivity control systeds are ade-

" q ua t e l y protected against the effects of tornado missiles.

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.y 6.

Control Room e

The control room is adequately protected against the effects of tearnado missiles.as discussed in Item 3.j above.

However, the control room HVAC system is vulnerab'le to damage from tornado missiles,(see Item 3.l).

7.

Radwaste Treatment Systems All liquid and gaseous radwaste systems are lo c a t e d.i n t h e radwaste buil' ding and/or underground from t fie building to e

t

o the plant stack.

The liquid radwaste bu.ilding is a below-grade reinforced concrete structure.

Portions of the

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s off gas system in the turbine building are protected by the three-foot thick condenser enclosure.

The licensee has analyzed the r a di o'l o g i c a l consequences of failure of

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the off gas treatment system.

The results'of' this analysis

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wel'l belod id'CFR' Td0' Limits.

Weiconclude yiel-d doses that the liquid and solid radwaste " systems are adequately protected against the effec'.ts of tdrnado missiles.

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8.

Isolation Condenser The isolation condenser is located in the reactor building below the operating floor and is,therefore, adequately protected from tornado missiles for the reasons stated in Item 1.

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VI.

CONCLUSIONS Based upon our evaluation of the infori'ation provided by the Licensee, we conclude that the foll6 wing p'ortions of the Millstone Nuclear Power Station, Unit 1 are adequately pro-tected from the effects of t e rnado missiles:

l 1.

Reactor c o o.l a n t pressure boundary; l

2.

Reactor core and individual fuel assemblies located f

within the core; l

l 3.

Automatic pressure relief-system; 4.

Reactor f.eedwater pumps.(except pump M2-10C);

5.

Low pressure coolant i n j e c t i o n / c o n t a i nh e n't spray system; l

6.

Diesel and gas turbine' fuel oil storage t a n k s,;

1

! i

p T

7.

Safe shutdown cables (control room, cable vault, reactor buildings; s

i 8..

Spent fuel pool; 9.

Spent fuel pool cooling system; 5

10.

Reactor building closed cooling water system; 11.. Reactivity control system; 12.

Control room; 13.

Radwaste treatment systems; and 14.

Isolation condenser.

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Therefore, the above features meet the requirements of General D'esign Criteria 2 and 4 with respect to missites,and e n y,i r o n m e n t a l e f f e c t s.

3 Howe'ver, we have conc.luded that the Millstone Nuclear Power Station, Unit 1 does not meet the current criteria for e

j, jr tornado missile protection in the f o l l o w.i n g. a r e a s :

1..

Condensate and condensate booster pumps; F

y I 21.. R e a c t o r feedwater pump M2-10C; l 3., Service water ahd emergency service water pumps;

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4.

Emergency switchgear; r

i 5.

Emergency batteries and battery chargers;

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7. _g [ ; 6.

Emergency diesel generr e and fuel oil day tank; 7.

Gas turbine;

- 8.

Safe shutdown cables (t u bine building, yard cable trenches, intake structure, gas turbine b u i'l d i ng );

f l-9.

Condensate storage tank; e

9'. : i 10.

C'o n t r o l room HVAC;

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e e 9

11.

Space coolers (condensate and condensate boost'er pump, diesel generat'or); and 12.

Turbine building secondary closed cooling water. system.

The need for providing additional tornado missile protection to-these systems will be evaluated d'uring the i ntegrated assess-men't of the Millsto[ie Nuclear Power Stati~on, Unit ~ 1.

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