ML17252A852

Letter Regarding an Occurrence Where the Reactor Was Brought Critical Preparatory to Placing the Plant Back in Service Following Completion of Repairs Associated with the 11/13/1973 Feedwater Line Break Incident - Indian Point Unit No. 2

ML17252A852
Person / Time
Site:	Indian Point
Issue date:	01/31/1974
From:	Cobean W Con Edison, Consolidated Edison Co of New York
To:	O'Reilly J US Atomic Energy Commission (AEC)
References
Download: ML17252A852 (1)

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. Rt::: lndi~n F*o.int Unit No. 2 Af.C- Dc.n::kt'! l l~t). 50- 24 7 Fae i l i ty Op~i*f.iting LiC~Tl~t!

DI*'l\-26 A.0.-4-2-6 Mr

• J arne s 'P

• Q 1* He i 11 y , Dire ctr) r R~gulatory Oper~tionE, Megion I

u. S. l\tomic EntJ.rgy Cc)ff!l'i1) ;:;::;ion

(\~ 1 Park A\F(~riue King of Prussia, P~nnsylvania 19406 On January 25, 1974 th0 reactor was hrou9ht Griti6al prep~ratory*

t.c1 pl ac in9 tt~r:: plant ba.ck in sc;.rvice fol 1-owing cc)mpl ~ti on* of re*

p~_ire aesocdat.ed wi.t.h ~~he NO"JL-miber 13, 1973 fe1:.dwa.ter linl': brea:k incident., critit~ality w.:-t~ *"c:hieve.d with the C::" banl-'. of ct'>ntrr,1 11 rods 45 step:.; withdrm*m from th(~ <::ore.* Tl1e criti.c_':'~l- pc1eitions

~f the control rod~ w~re approxirn~telY 27 steps below the in&cr-t.ion Ii.mite ehown on P.ig,_1_t'.c':_ 3.10-1 of the Tcc::hriicill 8pecificj~

tions. At th~ time of the ocG~~rence tho reactor coolant. system

~.t.**~asure and lempc:t**i1ture wer.~ 2235 p:;.~g. and ~,4QOJ:~ resper.tively with ~l l. fc.1u-T r(':actor G~lli ant pump~ in se;:ivj ('!~ and the borc,n con-ccntra tion wis~ 112[i ppm boron. Th~ 27 ~.tcp di~t;~rr-:ntial repre-scnt.e a dcr:i.:-rea~e in the rt-quired shutc.~_1)wr1 mi'\rg-; n of ~bi.>\)t 0. 2-6't, re:activi ty. Minimum boron c.-:oric.e:ntrat.1on req1.1.ire:d to maint~ln the

~*~quired $hutdown margin (Pi9ure 3, t0-3 of t.h0. 'l'echnit;al Speci..-

f ic~tion.e) is i;-alcul.-,tc:-:d to be 77 Ci ppm. Therefc,rc~ 1 the * ~hutdown l\\lU'gin <<t the timt! of the 0Gc.:1~:i:-Yence. waF. conc.ic.~c~L"ably more th~-~)

that required by Figure J.l0a3, We tlre inv~.etig~t.l.ng thG c.:::sut:t:s of this OGGux*rt!nce. "nd corrl!lc':'t.ive action nece:;:H~ry to prevent rGc.~urr~nco. Mr.

• Ant.hcny Fui::..~ no of your off ic-e w;is nutif ie-d r:.f this Qc~c,1..i:t."Tt?n~C? by telephone by Mr.

John M~Y.epeac~ on ~J~m~i:::.t.**y 30, 1974.

Very truly youts,

.(l~Jiai,, \~ (i{J£pi,,_ j, W~rren R. Cobe~n, Jr., Manager Nucleilr Po~c~ Genoration J