ML20076C684
| ML20076C684 | |
| Person / Time | |
|---|---|
| Site: | Mcguire, Catawba, McGuire  |
| Issue date: | 07/17/1991 |
| From: | Tuckman M DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9107230377 | |
| Download: ML20076C684 (5) | |
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OUKE POWER July 17, 1991 U. S. 11uclear Regulatory Commission ATTH: Document Control Desk Washington, D.
C.
20555
Subject:
McGuire liuclear Station Docket !! umbers 50-369 and ~370 Catawba Nuclear Station Docket Numbers 50-413 and -414 ECCS Model Changost Report Required by 10CFit 50.46
..ttached are sun.ma'. ios of changes to Emergency Core Cooling System models which are used for McGuire (Attachment 1) and Catawba (Attachment 2) Nuclear Stations.
Reports of changes to those models are required by 10CPR 50.46(a)
(3)
(ii).
Duke roccived notification of thoso changes by letters from Westinghouso Electric Corporation dated June 20, 1991.
In kooping with the significance of the changos, this report is provided within 30 days of that notification.
If there are any questions, please call Scott Gewehr at (704) 373-7581.
Very truly youra, I
b Nr. f'\\ m W M.
S.
Tuckman occachg/ sag 9107230377 910'717 3 V POR ADOCK 05000369 F
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4 Nuclear Regulatory Commission July 17, 1991 Page 2 cc:
Mr. T.
A.- Road, Project Manager Offico of Nucionr Roactor Regulation U.
S.
Huuloar Regulatory Commission Mail Stop 9113, OWFH i
Wanhington, D.
C.
20555 Mr.
R.E. Martin, Project Managor Offico of Nuclear Reactor Regulation U.
S.
Nuclear Hogulatory Commionion Mail Stop 9113, OWFN Washington, D.
C.
20555 Mr.
S.
D.
Ebnoter, Regional Administrator U.S.
Nuclonr Regulatory Commission - Region II 101 Mariotta Strout, NW - Suito 2900 Atlanta, Goorgia 30323 Mr. P. K. Van Doorn Senior Resident Inspector McGuire Nuclear Station Mr. W. T. Orders i
NRC Rosident Inspector Catawba Nuc1 car Station t
r, Y
At t aciunent !
1990/1991 11cGui s e ECCS Evaluut ion 11odel Chango Dunenary
' 1.
LANGE HkEA}; LOC A IWAl.UAT10!J t10Dlib A.
Changes wer e saade t o inahe t he LOCA t uel ud raodolo consist ont wit h the donign f uel t od inodeln.
Tlu-incicane in p(ak clad 1
t empoi n t u r e titT) i t, leas t han 10 F f or the DAUlf evaluation inodal.
I h,
ThO ' COfid) Allal 101) of LOCA 4 ca!e shutdown 4atthquake- (SSR) loadinan Inight cauce N t eata Generat or tube collopne to an extent yt eates than had previously been evaluated, r esu l t in;,
ir. a t eduction'in the available area t brough which t o vent the nteam generated duting core reilood and an accompanying-increase in peak c lad temperatuto.
Thin effect in bounded by an 8F PCT inct eane Ic1 nplit f low pt eheat. at eum generator n.
There numbet a nhould be used to adjust the 2138.6oF reault which was subnd tted ta t he 11RC on August 1, 1990 and in t het elot e more recent t han the 1841*f value given in the cur rent fleUul t e FSAk.
11.
S!4ALL DREAlt h(TA INALtIATIO!J liODEL A.
Changou wet e made t o inake t he LOCA f uel rod Inodel n conni nt ent-with the design fuel rod models.
The incicane in peak clad i
t empera t u t e ( PCT ) ia lean than 370F f or the !JOTRUMP evaluation inodel.
D.
An input to the evaluat ion inodel. is the time required to pur ge high ent halpy taain f eedwater itom the oteam generator inlet piping octore the lowet ent halpy auxiliaty Ieedwater.i n delivered The standat d input. f or t his t itne was f ound to be nonconcet vat j ve Wit h t enpect to the plant opeci f i c ' va l ue. Tho impact on PCT is 2 3"F f or t hi n ef f ect.
Those numbers ut e' in addition to the 42*F penalty which was document.ed in the 1989 vez sion of this let ter but is not reflected in the cutient McGuire FCAk.
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LAlm ImEAM LR A IX1d,UATlO!1 !!c DLL A.
Ch: urn, urt e mmb t o la 4ke t ht-LOC / luel 2 od an;de l t eenui ut i'nt vit h t he de.iun fuvi od on > !< 1:
The itactease in l><ak clad t t ape t at u t e (H!T) i: le t h an 10"F i or the bhUll evaluat iun uudel.
D.
The conbilut ion of I DJ_' A 4
<aie ahutdown ear t hqua ke' U CE) l o ;ad i nu n Inight caune steam (p nol at ut t ul e collapne to un ext ont at eat et than hwl pieviously 1% n evaluate 1, t t "..u l t i ng in a t oduct ion in t he available ar ea t hr ouah which t o vent the St eain Genel at iMI dUl ilig ruz e Ief1 odd and all a cC ott lially i nQ inci at.e ia l>eak clad t eml et at u r e.
'I h i el f eet i; bounded by an HoF ICT i r nr t ea. < f or aplat f l w pt eheat st eam generat ot :
(Unit 1) atul a J0oF l'CT inclease f or count i t f low pr e heat ; team genri at 01 : (Unit 2).
C.
The pt edict ion of fuel i od clad ling butnt was liane 1 on the avetnoe power in t he het o m sbly.
Cince a >ur iuel Iods at e at a highet powel t han thin avetage, t he t ine of c l ailili na butst, atul of t he aci umpanying channel i J ow I orkage an1 down-at i < am clad ling heat up, cou ld be un le t pt edi ct ed.
B+cause tlu-etIect of t hi:, underpie lict ion on itT depernir un i o f lood i n-..:
t at e and on the time of l 'C T, the lena lt y, if any, is plant apecific.
For Cat awba t he PCT l enalt y i:
110"F.
lt har been confirmed by Mt inghuuc.e L t.a t t in t < > in no callespondina 11cGuire iCT pe'nalty.
t).
TM axial powi r dint ribut ion nennit ivit y cLudy lot f oimed t ut t he ol&r evaluat ion modelt did not iemain completely valid for the PART/PAUli evaluat ion modeln.
It is possible that certain skewed axial powet diat ribut ion: might. t e s.u l t in highet calculat ed ICTL than doeu the analyred dist ribut ion.
Thin etteet may be account ed f el in t wo wayo.
A ICT penalty of 100 F will Inund t he inc r ea t.e il these dint ributions ar e encountered.
Alt er nat ively, t he Cot e Opet at.ing Limit n Repor t E ( **. ) limit thay le r educed t'll3ul t-t h at. t heGe diut t ibut jonc do not atine.
Catawba takes the f or me t appioach, receanit at ing a 100oF penalt y.
!!cGuite takes the lat t er apploach and t hel etot e haD no Coll e 3pon: ling lit-nal t y.
These penalt ie, die in addition to the 10DF penalty cu t 1 ent. ly docun ent ed in Table 15 % of the October 1,
1990 Ca t av;ba FDAk updaro.. SMALL IPEAK I.OCA E'v'ALUATIUi1 !ODEL A. Chang wet e mJide to make t he LOC A f uel I od modelI conuiateut wit h t he donian fuel t ud itKdel '. Tlug inctease in peak clad t 4 %pt t o ' ul U ( 11 'T ) i: le t h.111 313F fei t lue IJOTPJil1P evaluat 1011 Ikk.b ! }. l
i 9 9 4 14 Att input t o t he evaluat ion Inodi>l i n ' he t ilne z equit ed t o pul go high ent halpy ruin lev &Mter t r oin ? m st earn gera>t ot ot inlet piping betore the lowet ent halpy aux i 1 ia ry ivedwatel in deliveted. The at andar d it.put 101 t hin t irne was tourut to be nonconset vat ive wit h t espect t o t he plant opeci f j e value. The isnpac t. on PCT i n - 2 7F f or t his ellect. i C. A c m i-Pction to the clothlino nt ain foodel caused a plant speci f w PCT penalt y, due to a bina ll er tuel clad gep, for cituat 1o. n in which t he kr5 precaute was above the fuel lod ] intelna1 piercuie at t 1"? t i tne of I'CT. Tho va1ue of tho Catawba penalty in 3 0 F. It han been conf i t tned by Weut ing-house that thete in no co21 e0ponding licGui1e penalty. l'enalt ies A ond C ar e in addit ion ' o the 690F penalt y curlently dot:uinent ed ir Table l '; - 3 4 of the a t ebot 1, 1990 Catawba FDAk update. Pene;<y.1) i n already included in t hr e 69"F value, I 1 I l F s Y + 3 e i 1 t t. 1 l-i pre-hun.'r%-y,...,m,,.,~...,,,,,,%.,%.,,,_,,,,m,,,.m. ...,%._w._,._ __._,,,,,,m., . _ _,,,,. ~,,., _.. _, _.,. ww.,-Y}}