ML19209B234

LER 79-026/01T-0:on 790919,during Power Reduction Below 90% Power,Axial Flux Difference Left Target Band While Power Was Still Above 90% Power.Caused by Operator Error.Power Reduced to Below 90% & Event Discussed W/Personnel

ML19209B234
Person / Time
Site:	Prairie Island
Issue date:	10/03/1979
From:	Hunstad A NORTHERN STATES POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19209B232	List: ML19209B231 ML19209B234
References
LER-79-026-01T, LER-79-26-1T, NUDOCS 7910090362
Download: ML19209B234 (1)

Text

NRC FORM 366 U. L NUCLEAR REGULATORY COMMISSION (7 77)

LICENSEE EVENT REPORT CONTROL BLCCK: l l l l l l l (PLEASE PRINT OR TYPE ALL REQUtRED INFORMATION) l o l t l l M l N l P l 1 l N l 2 l@l 0 l 0l- l 0 l0 l 0 j 0 ] O ] - l 0 l 0 l@ 4 l 1 1l 1 l 1 l@l$7 l l@

7 8 9 LICENSEE CODE le 1$ LICENSE NuveEH JS 26 LICENSE T 4PE Jo LAI $8 CON'T LoJ Ll 7 8 5 UR% 60 i L l@l 61 01 sDOCKET i 010101310 NUMBER l 668GLO 69 I 9EV5NT I 119DATE 7 19 74l@ 751 0 10 3 REPORT DATE 7I9 @ 80 EVENT DESCRIPTION AND PROB ABLE CONSEQUENCES h 10 I 21 l During a power reduction to below 90% for axial of fset calibration, axial flux l I O l a l l dif ference was allowed to leave the target band while reactor power was still above l o 4 190%. Power was reduced to below 90% in half an hour. Subsequent flux maps showed l I

E lthat the same flux distribution at 100% power would not have produced unacceptable l l0 l6 l lnonking fnernre. Nn offner nn nnhlic hon 1th nr e,forv. l 0 7 l

0ta l I 7 8 9 80 C DE CO E SU8CO E COYPONENT CODE SU8 CODE SU E Lohl8 7

I R l C lh (A,_jh (,,A,j IJh l ZlZ,l 2 l Z l Z l 2 lh Wh b h 9 to 11 12 18 20 19

_ SE QUE NTI A L OCCURRENCE REPORT REVISION LE R Av EVENT YE AR REPORT NO. CODE TYPE NO-

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. l21 719 22 l 2J 24 26 27 28 .7 30 31 32 AKEN A T ON ON PLANT MET D HOURS S8 iT D FOR UB SUPPL MANUFACTURER lz_J@la JJ 34 J@ LLJ@ Lz.J@ 10 10 10 10i Lu.J@ lN_1@ l?_J@ lzI9I9I9l@

Jo 36 37 40 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h 1 0 Perennnol orrnr_ Power una rodncod e n h ol mu 90'r . The cront uns di sciis c;ed with 1 i i linvolved personnel. All licensed operators and license candidates will review the I i 2 l event report.

Wl l 1 4 1 1 7 8 9 80 STA S  % POWER OTHE R STATUS Di$ 0 RY DISCOVERY OESCRIPTION

[1 J,5_j W@ l0 l 9 l 5 l@l N/A l l A l@l Review of operating logs ACTIVITY CONTENT RELEASE OF RELE ASE AMOUNT OF ACTIVITY LOCATION OF RE LE ASE liIcl[Zj @D IZl@lNo l 1 NA l 7 8 9 10 11_ 44 45 R0 PERSONNE L EXPOSURES NUP/8 E 9 TYPE DESCRIPTION LLU] I O I 0 I o l@Lzj@l NA

' PERSONNd'IN,U4ES Nuvs E R DEScRiPTiONh LLLaj I n i n i n l@l u I 7 8 9 11 12 50 t OSS OF OR DAMAGE TO FACILITY TYPE DESCRIPTION LLLJ Lij@l m I 7 M 9 10 80 ISSUE DESCRIPTION

• 12 l a l [3,J@l u_ l l l!lllllllly 7 8 9 10 59 69 80 &

NAME OF PREPARER A A Hunstad PHONE NN 791009036A lll4 034