ML20076H526

Answers to First Set of Interrogatories on Pressurized Thermal Shock Contention.Certificate of Svc Encl

ML20076H526
Person / Time
Site:	Limerick
Issue date:	06/09/1983
From:	Boyer V PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Lewis M LEWIS, M.
Shared Package
ML20076H518	List: ML20076H515 ML20076H526
References
REF-GTECI-A-49, REF-GTECI-RV, TASK-A-49, TASK-OR NUDOCS 8306160609
Download: ML20076H526 (16)

Text

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V'1I TE 0 STATES 3F AMERICA

'UCLEAR

2EGULAraaY C OMM I 5 3 I Col ,

In the M atter of )

1 Ph il-idelph ia El ectr ic Company ) Cocket *cs. 50-352

) 50-353 (Liverick Generatinc) Station )

'Jn i t s L and 2) )

APPLICAP.T'S ANSWE?.S TO INTERVE'4C4 LEnI 5' S FIRST SET GF IN TERROG A TOR IE S CM PTS CO.NTENTIO*1 CISC0VERY 3 JUNE L3, L983 l

m s5 C306160609 830613 PDR ADOCK 05000352 l 0 PM ,

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. Tn*4rro.ator! *10._1 Is pressurized thermal shoc4 s pecclem in faRs; speci f ic 311 f Limerick.1 0 2? ,

ans er

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3articieints in o recaration cf Answer _

rink :. Ccoke o rincipal initneer, Vessel Oesign General El ec tr ic Coc. cony 175 C urtner avenue San Jose, CA 95125 Vincent S. Sayer Senior Vice oresident - Nucl ea r power 3hil adel ch i a Electri c Ccmpany 2301 . Market Street 3hilaaelania, PA 19101 1

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Interro 23torv so. 2

- . anat is the basis fo r th e c a.cc l u s i on that 075 (pressurizec ther9al snock) will not caase a failure at Limerick of safety r'e I d t e d or iTport3nt to safety s tr uc ture s? or Converselye to snat ex tent do you concl uoe tn a t safety reloted and i ? o c r t.i n t to safety will De affected JnO to ahat ex ten t dffected? (.:Or instance, describe f ailu re.) j l

inswar Pressurized Thermal Shock ( P TS ) is a condition that results from the t ntroduction cf cold water into a not pressure vessel anile tne pressure is maintained. The temocrature drop resulting from cold water injection causes enermal stresses in the vessel.

These s tresses could hypothe t i ca ll y cause crack ing if the vessel pressure were maintained at a hich level and if material were emerittled significantly due to radiation effects. PTS is not a problem for boiling water reactors (9WR) since the two necessary crerequisites -- high pr essure dur ing cold water injection and high vessel radiation levels -- do not occur in a SaR. Specific reasons for this are as follows:

a. Since a BWR ope ra tes at saturaticn conditions, the pressure in a SWR follows the steam saturation curve.

When cold water inj ec tion occu rs , resulting in temperature reduction, the pressure in the BWR drops

! immediately along the saturation curve. Therefore, high l pressure and a rapi d change in s tress pattern resulting from the introduc tion of cold wa ter into tne vessel cannot occur .it the same time.

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, b. The neutr on fluenco e t tne vessel aall in a 'i a ; as comoeratively very l o 'a because of tne presence of a 13rqe aater-filled anrulus betaeen tne vessel-an: tne core shroud. R ad i a t i cn embr i ttl ement effects are n eg i t q t b l, e in a J aR .

Thererore, cracking due to P TS is not of concern to boiling

.<ater reactor pressure vessels.

The aoil ity of the Limerick reactor vessel s to r espond in a non-or i ttl e manner to thermall y induced s tresses has ceen evaluated and found to be witnin the acceptance limits of Code of Cederal Requlations 10CFR50, Appendix G, as described in craft Section 5.3 of the L imer ick FSAR ( hereaf ter "FSAR Section 5.3",

and destanated as Discovery 8, Item 1), which is to be suomatted formally tn July, 1983. G oe r a t i ng l imi ts wnich assu re adecuate fracture tcughness o f tn e reac tor pressure vessel materials are defined in Figure 5.3-4 of FSAR Sec t i on 5.3 and will ce in the operating Technical Sp ec i f i c at i ons . A separate fracture mechanics evaluation of accident condi tions also confi rms Sn 2.

design adequacy For ther ma l shock. (See response to Interrogatory 3).

While not normally Consigered as part of the PTS Concerne for completeness of tnis response, p ip i ng att ac hed to the R PV in the d r yw el l i s al so addres sed. OTS is not a problem for this piptng because the design considers the tracture toughness of the 4

materials involvcd at the lowest temperatures which such piping sight experience. This piping can be divided into two categories; austenitic steel and ferritic steel. The austenitic steel, due to its crystalline structnre, saintains its fracture toughness to extremely low temperatures and is thus not subject to brittle fracture as a result of PTS. ?erritic steels, as a group, can potentially experience reduction in fracture toughness  :

at temperatures which could occur during a PTS event. To account for this. possibility the ferritic steels used for the Limerick piping attached to the RPY were required to be accompanied by saterial test results, i.e. Charpy Y-Notch impact test results, which assure that fracture toughness is saintained in and well below this temperature range.

The ferritic steel piping systes which could experience cold water during a postulated PTS is the feedvater piping. This piping was specified and purchased with impact testing which seats the requirements of 1532 Section III, 1971 Edition, including the Winter 1971 Addenda. The test temperature specified was - 300F.

Since all of the piping attached to the RP7 is shielded from the core by the full thickness of the reactor vessel wall, the concrete sacrificial shield; and considerable distance, the shift in nil ductility transition temperature would not be of importance.

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. Pareicisacts _ 0 Drgar at ic e -cf *rsser cranw E. Cooke orincicol incineer, Vessel esign 14:n e r a l El ec tr ic Concany 17 5 C urtner . Avenue - '

Gen Jose, C A 95125 vincent 5. Scyer -

Santor vice or es iden t -

'lu c l e a r Power j- 9hiladelonia Electric Company 2301 Market Street onil.3delonia. 3A 191J 1 Daul A. Tutton Senior-Engineer

?nilacelonia diectri c Company '

2301 Market Street

? n i l .3 d e l on i a . PA 19101 e

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3rovice tne 3ctual numer ic a l d ita tnat nas ,es? rate; t^e answer to Interrogatory 2, 30cve. Provide . a r. i . c31ca12t:ons, l :eometries trom 71ue0rints. c;ecuter run resuits, .i n d crofessional coinicns. a k e < cur answer as conglete as 00sstole:

a. tamoerature ;radients scross tne :AV .all far a sariei' of cool down rates ,

b. temoerature gradients across any other structure adversely a f f ec ted (pipes. etc.)

c. sens i t t vi ty analysts for tne rat tonale for cnoosing soeCific Cool down rites

d. stress levels and l oads a ssociated wi th t9e above cool cown rates

9. total integrated neutron flux calcul ations and measurements spec if ic to actual parts in cuestion onc to reactors of s i.n i t ar J es ig n to Limerick

f. calcul at ton of resultant loss of Qindt due to above neu tron flux.

Ans-er ine f rac ture toucnne ss propert ies o f tne Limerick reactor vessel m a ter ia l s were es tabl is hed using the methods described in FSAR Section 5.3, Suosec tion 5.3.1 5. The thermal conditions ano stress intensity factor for the core beltline region of tne reac tor vessel a re c asec on a spec i f ic anal y s i s of hycrotest anc normal he a tu p and cooldown conditions and the shift in material properties cue to i r radi at ion. Additionall f, the results of fracture tcuqnness evalu at ions f or a comparable-sized 9. a A / 5 reactor pressure vessel were used in the Limerick evaluation oy ad jus ti ng tne matertal tracture toughness proper ties to those of the Ltmericx reactor pressur e vessel s. These evaluations considered tne core bettinne plus the reactor vessel 7

d t sc on?. i nu i t y relians of higher stress 5UC7 Js One r 7dC tor WasseI nozz l es , cotto- heed .enetrations, .s n c <essel closure flantes.

The tnar el in 3rassare e f f ec ts ncluced i variaty of o a e r a t t 9 ',

conoitions ant; t r ins ient events as snown en General Eiectric 4

Company 7raain: 'io . 7 6 2 E c 5 'l en ti tl ed " eactor C ycles" (cesi; ate:

Discovery 3, Item 2).

Temperatur? gradients, s tres se s , and to2ds Ossociated with the JDove coolJcon rates, and tne vessel aeli tnickness dimensions are included in the report entitled "~rscture "echanics Evaluet t on of a *! oiling Water 3eactor vessel Foltoaing a Do s tu l a t ec Lo s s-O f -C oo l a n t acc td an t" ( des t gn ated C iscovery d, Item 3; crevioust / p ro vi ded as Discavery 2, Enclosure 3. Item 1).

Additional r el atec dccuments are NE00-21773A " Transient 3ressure Rises Af f ec tin a Fr ictu re T cu gn ne ss Requirements for 'oilinq Water Reac to r s" (des tgnated Discovery 3. Item 4; previousiy craviaed as Oiscovery 2, Enclosure 3. Item 1), and NE00-10029 "An Anal y tic al Stuov on 3ritt le F r actur e o f G E-9d 7 vessel subject to tne Jesign 3ase Ac c i den t" ( de s i gn at ed Discovery d. Itan sa; prevtously orov iceo as 7 tscover y 2. Enclosure 3. Item L).

The i n te lr ateo neu tr on flux calculations anc neasurements apolic3cle to Limerick L C 2 reactor vessels are con tained in the document entitled "?lo te s to ORF (Oes ign R ecord File) A00-7CC" (ces ignated 7tscovery  ?, Item 5; grevtously provided as Oiscovery 2, enclosure 3, - I tem 5). Calculation of resultant snift to oTndt due to the JDove neutr on flux is tncluded in FSA4 Section 5.3, I

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s u t s ac *. i o n 5 3.'.o.3.

. .eu t r :n t h, < calculitions inc asure rnts e

for reacter vessels st -il 3r in : ss i ;n *c Limeric< ara crosicec in t.o r ec ar t s en t i t l ad "3r o n's :a rr f ,Jn i t 3 In */essel '.autron jp +c t r ! 1 Analysis" (casi;nited  ?. : ic:very .i . Item s; .creviously orovicac as Oiscover y 2, Enclosure 3, Item i) and ":.eu tr on F l ox Calcilations Aeport Findinjs" (ces i gnated Otscovery d, Item 7; oreviousi f provided as J iscovery 2, ~ Enc i o su r e 3, : tem 3).

• sutron flux ~c31culations for reactor vessel similar to L i .n e r i c < are al so pr ov iced in tn e form of enree plots and tnrea computer printouts ( des i gnated C is cover y 3. Item 5; creviously proviceo as Discovery 2, Enclosure 3, item 3).

Darticioints in Preoaration of Answer Items a, o, c, c: Frank E. Cooke 3rincioal Enaineer, vessel Cesign General El ec tric Company 175 Curtner Avenue San Jose, CA 75125 Item e: Lloyd S. 9 urns o r i nc i pal Engineer, R ad i cl o g ic a l Analyses General Elec tr ic Company 179 Curtner Avenue San Jose, CA 95125 Item f: Steven E. Carter Engineer, Plant Mate r ial s General El ec tr ic Company 175 Curtner Avenue San Jose, CA C5129 Vincent S. doyer Senior Vice Pr es iden t - Nuclear ?ower 3ni l adel on ia El ect ri c Company 2301 M a r '< e t Street Phi l a cel an i a, PA 19101 9

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I n t e r r o g3 t ra r y No g_3 ,

. 3rovice a definitton of 3ressurtzed Thermal Snock and reference tne document wherein that definition lies. Strilarly a and " safety orovide definitions for "impcrtant to safety l related."

ans-er

'ressurized Thermal Shock is ce finec in the response to In te f r oga tor y No. 2 inis definition is d er ived from tne "3roblem Gescription" of 3ressurized Thermal Shock, UnresolveJ Safety Issue A *9, contained in NUR EG-0 606, entitled " Unresolved Safety Issues Summary", Vol. 5, No. 1, February 18, 1983, U.S. Nuclear 3egul ator y C ommi ss ion, which reads as follows:

"'!e u t r o n ir radi at ion of reactor pressure vessel weld and plate mater ials decreases the f rac ture toughness of the materidls. The fracture toughness sensi t iv i ty to raciation incuced change is increased by oresence of certain materi31s such as copper. Decreased fracture t cughness makes it more likely that, if a severe overcooling event occurs followed by or concurrent with n i .j h vessel pre ssur e, and if a small crack is present on the vessels inner surface, that crack could grow to a size that might thr,ea ten ve ssel in tegr i t y."

Cefinitions of " [.n po r t an t to S a f ety" and " Safety .R e l a t e d " are

-not relevant to PTS.

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2,s i g n 0. . 51acmstrand senior Engineer, P ro jects L icans ing 1eneral Electric Comoony

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L79 Cartner Avenue 1an Josa, CA '5125 Vincent S. Soyer

' Sen tor V ice 3res icent - Nuclear Dower Dniladelchia Electric Company 2301 Market Street Dni l .ide t on i a , PA 1710L t

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• Give tnicanesses eno sterials t"3t neutron flu < would r 3ve ao penetr a te oetween 3rigin anc affected structures. (For instance c i s a n c .3 7 a t ee n fuel anJ 5el tl i ne weld.)

Ansoar i

Tne materials and thetr tn ic'<nes se s b etween the care' and the vessel are shown in FSAA F i .;u r e 4. 3- 2 9 (d es ignated D i scover y d, Ite.n v).

3 3rticipants in Prec3 ration of A ns ser Lloyd S. Eurns Orinciaal Engineer, R ad i o l og ic a l Anal yses r eneral El ec tric Company 175 Curtner Avenue San Jose, CA 95125 Vincent S. Sayer 5entor 'sice Dresicent .Nu c l ea r Power 3ni t edel onia Electri c Company 230L tiarket Street 2niladelchia, PA 17101 12

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. i n ~. : r r m : s t a r v ':.

~3ve an/ "t e s couco ns" Of a f f ac tec m sta r t il s 7een t er ac: : ,-

i a 14 1s :f :esign s ira i l a r to LtrertcK? d roit a in 1 .estec *ru results and co cu 'en t at io n.

_s n s n a r Test ceu1cns tive teen i rr ac i a t e.: and testec.

The results of r ac i at ion e f f ec t s on p re s sure vessel steel 3re documented in Nd20-21705, "Radiati on E f f ects in 3oilinc . ster Je ac tor 3ressure vessel Steel" (designated 3iscovery J, [ tem 10; crev iousl y crovidea as ;iscovery 2, Encl o sur e 3. Item 3).

carticiaants in Dr ea ar at i on of a ns we r Steven 2. C arter Encineer, Plant w a r.e r i a l s General El ec tr ic Co:noany 175 Curtner- avenue

$3n Jcse, CA C5125 Vincent 5. Soyer ,

Senior V ice P r e s id en t 'f u c l ea r Dower

'Jhi l adel ph i a E l ect ri c Comp any 230L "arket Street 3n i l icel or. i a, 24 19101 I

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e COMMONWEALTH OF PENNSYLVANIA  :

ss.

COUNTY OF PHIIADELPHL4  :

V. S. Boyer, being first sworn, deposes and states:

That he is Senior Vice President of Philadelphia Electric Company, the Applicant herein; that he has read the foregoing Applicant's Answers to Intervenor Lewis 's First Set of Interrogatories on PTS Contention and knows the contents thereof; and that the statements and matters set forth therein are true and correct to the best of his knowledge, information and belief.

Senior Vice President i

Subscribed and sworn to l

before me this day o f June , 1983.

t PATRICIA D. SCHOLU Netsry Public. Philadelphia. FN!:dat;$!a Co.

My Commisstove Experts February 0. I!25

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of )

)

Philadelphia Electric Company ) Docket Nos. 50-352

) 50-353 (Limerick Generating Station, )

Units 1 and 2) )

CERTIFICATE OF SERVICE I hereby certify that copies of " Applicant's Answer to Intervenor Lewis's First Set of Interrogatories on PTS Contention" dated June 13, 1983, in the captioned matter have been served upon the following by deposit in the United States mail this 13th day of June, 1983:

, Judge Lawrence Brenner (2)* Docketing and Service Section l Atomic Safety and Licensing Office of the Secretary 1

Board U.S. Nuclear Regulatory U.S. Nuclear-Regulatory Commission Commission Washington, D.C. 20555 Washington, D.C. '20555 Ann P. Hodgdon, Esq.

Judge Richard F. Cole

• Elaine I. Chan, Esq.

Atomic Safety and Licensing . Counsel for NRC Staff Board Office of the Executive U.S. Nuclear Regulatory Legal Director Commission U.S. Nuclear Regulatory Washington, D.C. 20555 Commission Washington, D.C. 20555 Judge Peter A. Morris

• Atomic Safety and Licensing Atomic Safety and Licensing Board Board Panel U.S. Nuclear Regulatory U.S. Nuclear Regulatory Commission Commission Washington, D.C. 20555 Washington, D.C. 20555 Atomic Safety and Licensing Philadelphia Electric Company Appeal Panel ATTN: Edward G. Bauer, Jr.

U.S. Nuclear Regulatory Vice President &

Commission General Counsel Washington, D.C. 20555 2301 Market Street Philadelphia, PA 19101

• Hand Delivered 4

w ,-, , , , - ..-_y-- e , , , , . - - . ,- _ - - - . - .

4 Mr. Frank R. Rcmano David Wersan, Esq. Consumer 61 Forest Avenue Assistant Advocate Ambler, Pennsylvania 19002 Office of Consumer Advocate 1425 Strawberry Square Mr. Robert L. Anthony Harrisburg, PA 17120 Friends of the Earth of the Delaware Valley Steven P. Hershey, Esq.

P. O. Bcx 186 Community Legal -

103 Vernon Lane Services, Inc. i Moylan, Pennsylvania 19065 Law Center North Central Beury Bldg.

Mr. Marvin I. Lewis 3701 North Broad Street 6504 Bradford Terrace Philadelphia, PA 19140 Philadelphia, PA 19149 Donald S. Bronstein, Esq. I Judith A. Dorsey, Esq. 1425 Walnut Street 1315 Walnut Street Philadelphia, PA 19102 Suite 1632 Philadelphia, PA 19107 Mr. Joseph H. White, III 8 North Warner Avenue Charles W. Elliott, Esq. Bryn Mawr, PA 19010 Brose and Postwistilo 1101 Building Robert J. Sugarman, Esq.

lith & Northampton Streets Sugarman & Denworth Suite Easton, PA 18042 510 North American Building 121 South Broad Street Jacqueline I. Ruttenberg Philadelphia, PA 19107 Keysteon Alliance 3700 Chestnut Street Director, Pennsylvania Philadelphia, PA 19104 Emergency Management Agency Basement, Transportation Thomas Y. Au, Esq. and. Safety Building Assistant Counsel Harrisburg, PA 17120 Commonwealth of Pennsylvania DER Martha W. Bush, Esq.

505 Executive House P.O. Box Kathryn S. Lewis, Esq.

2357 Harrisburg, PA 17120 City of Philadelphia Municipal Services Bldg.

Thomas Gerusky, Director 15th and JFK Blvd.

Bureau of Radiation Philadelphia, PA 19107 Protection Department of Environmental Resources 5th Floor, Fulton Bank Bldg.

Third and Locust Streets Harrisburg, PA 17120 f%

Y) N Marh/J.'Wetterhahn