ML20037B886

Forwards Update to 800104 Response to IE Bulletin 79-26 Re Boron Loss from BWR Control Blades.Manpower Required for Review & Preparation Approx 20-h

ML20037B886
Person / Time
Site:	Browns Ferry
Issue date:	11/25/1980
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
IEB-79-26, NUDOCS 8101080184
Download: ML20037B886 (3)

Text

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s TENNESSEE V ALLEY AUTHORITY 2'

o C H All A NW >G A.

1 F N r. [ 1, ', F F 3 /.101 400 rhestnut Street Tower II CJ

' y f," 4 7 November 5, 1080 L:

Ed Ti

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u ft1 f3 Mr. Jamen P. O'Reilly, Director office of Inspectien and Enforcement U.S.

Nuclear Regulatory Commission Fagion II - Suite 3100 iol Marietta Street Atlanta, Georgia 30303

'>ar !1r. O'Reilly:

OFFICE OF INSEECT'ON A!1QFORCEMENT BULLETIN 70-?6, REVISIPJ 1 -

HII:JU d 259, -?60, ~20L ' BROW'1S PERRY NUCLEAR PLANT

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In response to your letter dated Aucust Po. 1000, to H. G.

Parris, which transmitted TE Eulletin 79-?e,, Revinion 1,

we have upciated our Janu.iry 4, 1930, renpense (enclocect).

Tha manpower extended to review thin tulletin and prepare a response is approximatelv

] man haurn.

If you have any questions, pleace call Jin Domar at FTS 357-?914 Very truly vaurn, TENNISEE VALLEY AUTilGRITY

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" ina ge r Nuclear Recul'ition ani Safety dabaerited A ^d, sworn to,before n' this-2')A day of jl. u.

1930.

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Notary Fublic

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"y Cc-,ission Expiren /- O_

E: :lcmure 0"fico of Insnection an.1 Enforcennnt (Enc 1ccure)

U.S.

Nuclear Re2ulatory Commisnica Division of Reactor Operations In:<pection

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i ENCLOSURE i.

I;FSPONSE TO IE BULLETIN 70-26, REV. 1 l

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BFO'.NS FERRY NUCLt'AR PLANT j

(Sc-259, -?60, -2a6) l 4

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r e..; t o r is to 1e teviewed to establish a

e :Lin; :iator oJ'l' t i-e i

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tant depletien averac d over the upper one-fourth l

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b ade r e ce:

contral bl.de, the t.

< rd i;. to be u i..t a i ned o:.

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iintain ani update a

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thin T., a p 3e to :

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avira e'

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-r ene-f au r th o f the il be u? lated at least once every l

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P idt.atified control bladt

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pext refuelin., au:

Itt 2a nd 2b there

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I ith tite shit t de wn argi t e.. u i r e::.en t in a

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in, I u lie a pl r e:ne n t in the

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ENCLOSURE

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BESPONSE TO IE BULLETIN 79-26, REV. 1 BF0'dNS FERRY NUCLEAR PLANT (50-259, -260, -296) 1 4

! ten 1 i

to be reviewed to establish a Theoperatinghistoryoythereactoris recerd of the current B depletion averap,ed over the upper one-fourth of the blade for every control blade: the record is to be maintained on i

a cont inning, buis.

This action is required on all reactorr, whether i

j shutdown for refueling or operating.

1 I'. ect'ause to Ite, 1

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At present, the y exists within TVA a program to aalut.iin and update a i

record vi the L depletion averaged over the upper one-fourth of the l

blade for every blade. This record will be updated at least once every i

refueling outa,e.

I Iten 2 t

Igntif'.anycenrolblader predicted to have greater than 3I. percent 3

depletion averaged over the upper one-fourth of the blade by the i

nc reiuelin,eutage.

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a.

Det ribe yeur plans for replacenent of identified control bladen.

a b

Describe me mure: which you plan to tso justifying continued ope ra t.' am. '. -ii the next re uoi inc ;pe-iticall' a d d rew; i ng

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m.

b i.'.i e ith re. ter Lnm

' 2 pe' u*

deplet ion averto;ed over 1

h.

upper e

.c - f s utib uf the b:ade;

.o.d (.' ) the.onditton ubere you find gre ner than 26 perce:

af the control blader, ca'culated m

to nave steater than 34 percent depletiou averaned over the upper one-fourth of the blade.

i pet.+ u :e ta Ite, 2

. contral red b!ide: are predicted to have reater than 34 percen-a".

1 J yletien averagej over tr< upper one-fourth of the bla.e before the l

n. :t refueling outage.

I t enni 2a 'nd 2b theretore do not apply.

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.I 1:en 'l t t he u c.: t c ;J nitdo.in or refuel.n out i, conduct :hutdown r;:are.n t

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f u l l wi t b ' rau.i t o f.nr. cont:a! blade from the cold xenon-free core w::t r.'t re:.it in crit icalit c; and b,

eo.:pliance wtth the shutdown nargin r eilu i r emen t in a manner that accc moda*.en the boron loss pht m=enon (i.e.,

by includin. a plant tp c.* c l a e r e:ne n t in the.hutdown u r,', f n that taken the potentia!

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F-f ra:a cor t al blade:, identified from evaluation of 4

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...tc can:tderatien).

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-,sponse to Ter 3a A

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B-fore startup fellowing a refueling outare, each control rod is fully withdrawn an.i i:t.: erred to functionall. test the control rod drive.

No i

unusual count ratcs L.ee been observed from the scarce range monitors-j during these tests.

.e shal.1 continue to perforn this test after each j

refueling cuta;e and munitomise source range monitors for criticality.

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This testing is in addition to the nornal shGidown nargin test perfarned the beginning of each cy_le using #eneral diee tric Company provided at control red worth information.

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_l_e_s n a n s e to ltem 3h According to C<neral Electrie, no cracking of the B,C tubes has been observed wher.,the averane exposure of the control bTade is less than 25-percent B depleted.

Becaus gthere are no control blades in any unit predicted to exceeJ 25-percent B depletion before the end of the next cycle, no additioac.1 increment is required for the shutdown margin. We will ma intn ic contac t with Ceneral Elec tric to determine if and when the i

shutde-m mrgin requirements need to be adjuated to account for the 1

baren less pcv meaan.

When at: ad j u s t raen t is necessary, the additional i

h increment will be inclu ied in the shutdova argin test.

Irw 4 4

1 Perform a destructive examination of the most hip,hly exposed control l

blade at tb end of the ne.<t cycle and provide results of the exanination withir one calendar year after remaval of the blade.

The results to be reparted shculd.aclude:

a 1

a.

Tube m ber er ident dication.

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i The els u ou n: each crack in the tubiny.

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The calculated 3'0 depletion versus eleva tion for each tube.

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'lhe at:asured

' 1o33 Verf:us eleva t ion for each tube.

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loc..I depletion for t uiz e:. ba v i n,; na cras

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1 The na>.

um local de;)letion tor tubes havire no los, of boron.

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j Alternatel, th results of a destructivo examination of a blade of

inflar tal~i r.ien and operational histor

g/ be provided na later l

..m bri: _.

1"nl.

L: the hi;:he:." 1 cal 3 depletion is less than 50 percent,..i; examination can be deferred until the next re ueline, J

nJ rhe e:.ar :

.:on results provided '. i t h i n one calendar year.I the rt v 11 of

• niad

...mne to :.

5 13 par t i _.p ning in General Elec t r ic 's Proposal for Control Rod i

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.s in Pesponse to Iten 4 of NRC Inspection and Enforcement

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ti' ::c. ' 9 _' 6.

The results of the destructive ana l ys h of a blade l

imil-

- c uation and operatienal iistory as those in browns Ferry

. 2c lea r Plan anit.. 1, 1, a rid 3 will be provided as soon as IVA receives tne ren.L : re.: i,ene ral 1:lec t rit 4

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