ML19269D531

LER 78-001/03L-0 on 771210:azimuthal Power Tilt Exceeded Tech Specs Limits.Caused by Positive Bias Being Estimated Slightly Below Value of 0.020.Proposed Tech Spec Change Submitted to Permit Use of Addl Incore Detector Segments

ML19269D531
Person / Time
Site:	Calvert Cliffs
Issue date:	01/09/1978
From:	Russell L BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19269D528	List: ML19269D527 ML19269D531
References
LER-78-001-03L, LER-78-1-3L, NUDOCS 7906040202
Download: ML19269D531 (2)

Text

-l i O__iCENSEE EVENT REPORT ] .

I CONTROL BLOCK:ll l l l l l (pt2Ast PRINT ALL REQUIRED INFORMATION) 1 6 LCENSEE LEENSE IVENT NAME LCENSE NUMBER TYPE TYPE O1 lM l D l Cl Cl Nl 1l l 0 l 0 l_ l 0 l 0l 0l 0l 0l _,l 0 l 0 l lk l1 l1 l1 l1 l l0l3l 7 89 14 15 25 26 30 31 32 .

CATEGCRY Ty p CCCKET NUMSEA EVENT CATE AEPCAT CATE 7 8 O 1 CON'T l' l l Wy 0 l 5l 0l-l 0l 3l117 l l i l 2 l ll 01 71 7l 0 l 11 O l 91 Tl 8l 57 58 59 60 61 68 69 74 75 80 EVENT OESCAIPTION DE l On several occasions during the east 30-day period while at rover eteration, azimuthall 7 89 80 M l power tilt (Tc) exceeded the limits of Technical Srecification 1.2.h(0.090) . Tn ewhI 7 89 80 T and Fr T EE l occurrence Fxy vere verified to be within their specification limits. These l 7 89 80 0 l events occurred on the followine occasions: I 7 89 80

@l 7 89 .,

(LER 78-1/3L cont'd on attached sheet) 80 CE $CCE COMPCNENT CCOE ACTUFER VCLATON O Iz lz l l Fl I zl zl zl zi 4 zl l zI Iz 19 19 l9 I IN l 7 89 10 11 12 17 43 44 47 48 CAL 1E DESCRIPTION O l One of the four tilt esti=ates made in the upper half of the core has historically l 7 89 80 h l exhibited a positive bias slightly balov the value of 0.020. Thus during tower l 7 89 80 10 l changes and/or CEA insertions into t . acter half of the core, (cont'd on attached Fac:UTv METH00 CF STATLS  % ACWER OTHER STATUS CSCOVEAY CGCCVERY CESCASTCN 1

7 8 9 lE l l0l7l7l12 13l N/A l lAl N/A l 10 44 45 48 80 AEL $0 CF E SE AMOUNT OF AcinnTV LCCATON OF AELEASE i l N/A l N/A (z_] Lz_J l l 7 8 9 10 11 44 45 80 PERSONNEL EXPOSUAES NUMBEA TYPE CESCAWTON 1

l0l0l0l lzl l N/A l 7 89 11 12 13 80 PERSONNEL INJUA:ES NUMBEA DESCAtPTON N l0 0 0l l N/A 7 89 11 12 80 CFFSITE CONSEQUENCES 1

l N/A l 7 89 80 LOSS CA DAMAGE TO FACILITY TY PE CESCAipTtCN E@ y l N/A l 7 89 10 80 PUBL CITY 1

N/A l 7 89 80 ADDITIONAL FACTCAS 7 89 80 1

l N/A 7006040Ao1 l 7 89 80 NAME: L. B. Russell 301 23h-792L PHCNE:

"P0 091 647

o

-l .

o LICENSEE EVENT REPORT 78-1/3L Event Date 12/10/77 Report Date 01/09/78 Sheet 2 of 2 EVENT DESCRIPTION (cont'd)

POWER TIME Tq RETURNED DATE TINE LEVEL MAGNITUDE OF To TO 0.020 12/10/77 0830 77% 0.0203 1530 12/23/77 1610 98% 0.0201 1710 12/27/77 0015 565 0.022h 0320 1/1/78 0015 53% 0.0239 0730 1/3/78 1/3/78 1616 85% 0.0205 0012 1/h/78 1/5/78 0500 83% 0.0203 0011 1/6/78 1/6/78 1630 8h5 0.0206 0010 1/7/78 1/8/78 08io 80% 0.0205 1655 CAUSE DESCRIPTION (cont'd) the measured Tq is likely to be increased slightly above the li=it of 0.020. In all occasions listed above, this is what occurred.

A proposed Technical Specification change has been submitted to allow the use of additional incere detector seg=ents (three of a four fold symmetric set) to more precisely determine Tq. It is believed that with this additional information the adverse effect of a biased detector vill be minimized and thus Tq vill rarely exceed 0.020.

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