ML20002C988

Advises That Licensee in Fifth Wk of 6-wk Refueling Outage. Nuclear Fuel Inspected,Reactor Core Loaded & Various Analyses Completed

ML20002C988
Person / Time
Site:	Big Rock Point File:Consumers Energy icon.png
Issue date:	03/26/1970
From:	Walke G CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	Morris P US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 8101150672
Download: ML20002C988 (7)

Text

{{#Wiki_filter:- ^ f F~ CONSUMERS POWER COMPANY r [ PARNALL ROAD OFFICE IWX IINCOMirN = JACKSON MICHIGAN g { TVI - 517-787-1987 1970 MAR 26 ;;; 8 2/ 1 3-26-70, 8-00 AM U.S. ATOM C ENERGY COMM. Twx U M DR P A MORRIS. DIRECTOR 4 DIVISION OF REACTOR LICENSING UNITED STATES ATOMIC ENERGY COMNISSION WASHINGTON, DC 20545 E . i.L'rT17?>?' U DEAR DR MORRIS - ATTENTION - MR D J SKOVHOLT ~ WE ARE CURRENTLY IN THE FIFTH WEEK OF A SIX-WEEK REFUELING OUTAGE FOR WE BIG ROCK POINT NUCLEAR PLANT. THE NUCLEAR FUEL HAS BEEN INSPECTED, THE REACTOR CO.RE HAS BEEN LOADED AND VARIOUS ANALYSES RELATED.THERETO HAVE BEEN COMPLETED. IT IS THE PURPOSE OF THIS LETTER TO APPRISE YOU OF THE RESULTS OF THESE ANALYSES. s APPROACH TO CRITICALITY .....1.I50072 010 gni

P ( VESSEL UPON COMPLETING THE REACTOR CORE LOADING, WITH THE REACTOR / HEAD OFF, A CHICK WAS MADE OF THE NEUTRON COUNT RATE. WITH THE INITIAL ELEC-TRONIC INSTRUMENTATION CONFIGURATION, THE COUNT RATE WAS INDICATED AS SLIGHTLY LESS THAN 3 COUNTS PER SECOND WITH A SIGNAL-TO-NOISE RATIO OF LESS THAN 3 TO 1. TO IMPROVE THE SIGNAL, A LENGTH OF NOISY CABLE FOR THE B-10 STARTOP COUNTERS / CHANNELS 6 AND 7/ WAS REPLACED. THIS CHANG 5 REDUCED THE CABLE NOISE AND IMPROVED THE SIGNAL TO THE POINT WHERE THE COUNT RATE AND THE SI'GNAL-TO-NOISE RATIO WERE WITHIN THE TECHNICAL SPT.CIFICATIONS LIMITS, IE, MINIMUM COUNT RATE WAS 2.6 TO 2.9 CPS AND BACKGROUND COUNT RATE WAS ABOUT 0.9 CPS, BOTH T;i, TINGS TAKEN ON AN ACCURATE SCALAR RATFER THAN THE LOG COUNT RATE METE? SINCE THIS CORE LOADING APPEARED TO BE LESS REACTIVE THAN SOME PREVIOUS LOADINGS, IT WAS DECIDED TO INSERT TWO SPECI AL IN-CORE FISSION CHAMBERS-TO MONITOR MORE CLOSELY THE APPROACH TO CRITICALITY. THIS LOWER INITI AL REACTIVITY IS ATTRIBUTED TO TEE FACT THAT THE CURRENT LOADING CONTAINS MORE THAN THE NORMAL COMPLEMENT OF FRESH AND ONE-CYCLE E-G FUEL BUNDLES WHICH CONTAIN A BURNABLE POISON, GADOLINIUM. THE FOLLOWING TABLE LISTS THE DATA COLLECTED ON THE APPROACH TO CRITICALITY-9^1 / 9 l

STARTUP SPEC'*L CONTROL ROD CHANNELS, CPS IN-CORES, CPS ESTIMATED CONFIGURATION 6 7 8 9 KEFF ALL RODS IN 2.6 2.9-8' 6 0.928 GP A AT 7 3.0 3.5 22 20 0.975 GP A AT 10 ' 4.5 4.0 36 31 GP B AT 5 6.2 5.9 72 65 0.992 GP B AT 10 125 106 '1000 900 0.999 ~ NOTE-ALL STARTUP CHANNEL' COUNT RATES WERE TAKEN FROM AN ACCURATE SCALAR, NOT THE LOG COUNT RATE METER. THE_SPECIAL-FISSION CHAMBER IN-CORES WERE LOCATED ON TOP OF THE CORE AT POSITIONS 04-56, 57, 58 AND 07-53, 54, 55, RESPECTIVELY. BACKGROUND COUNT RATE WAS ABOUT 0.9 CPS FOR THE STARTUP CHANNELS 6 AND 7. ANALYSIS'0F THIS DATA FURTPER CONFIRMS OUR CONCLUSION THAT WE WERE WITHIN THE VISIBILITY REQUIREMENTS AS EXPRESSED IN OUR TECHNICAL SPECI-FICATIONS. E-G FUEL WITH 70 GM PER FOOT COBALT LOADING 9"1 3

BECApSE OF PAST TUEL ILURE5, IT WAS NECESSARY h THE CURRENT CORE LOADING TO INSERT MORE THAN A NORMAL NUMBER OT'TRESH AND ONE-CYCLE ~ E-G TUEL BUNDLES.. To MELP SHAPE CORE POWER, IT WAS NEC',SSARY TO I,NCLUDE IN THE CURRENT LOADING 14 E-G TUEL BUNDLES WITH A COBALT LOADING OT 70 RATHER THAN 35 GM PER TOOT. LISTED BELOV IS THE VARIATION'IN LOCAL RCD POWER FOR THE E-G TUEL WITH A 70 GM PER TOOT COSALT LOADING AS COM-PARED TO A 35 GM PER TOOT LOADING, TOR 1/8 SYMMETRY-4 LOCAL PEAKING TA; TOR - 70 GM/TT LOCAL PEAKING TACTOR - 35 GM/TT CENTER LINE RATIO EQUALS 1 2 3 4 5 1 C0 0.944 0.988 1.010 1.016 2 0.9 63 0.9944 '1.612 i.029 3 1.012 1.023 1.027 i.029 '1.031 4 5.033 CL. 5 AS CAN BE NOTED ABOVE, THE BUNDLE LOCAL POWER IS PUSHED AWAY TROM THE CORNER WATER CAP INTO THE CENTER. WE BELIEVE THIS IS AN IMPROVEMENT IN THE OPTIMAL USE OF THE URANIUM IN THE BUNDLE.-T. I LIMITING LOCAL PEAKING TACTOR IS IhCREASED BY ABOUT ONE PERCENT TO 1.27. THE OTHER PHYSICS AND THERMAL-HYDRAULIC CHARACTERISTICS REMAIN ESSE TIALLY THE SAME. WE CON-SIDER THIS TUEL TO BE COMPLETELY INTERCHANGEABLE WITH THE E-FUEL WITN A 70 GM PER TOOT COBALT LOADING. / E-G TUEL BUNDLE REPAIR rw ~ w> 9n1 4 -....................p_.

• ~ - -

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• Di[ RING THE TUEL IIAM

.TIONS OF THE PRESENT CUTAg, A SINGLE TUEL ROD WAS TOUND TO HAVE TAILED IN TUEL BUNDLE E-59. SINCE THE TAILED R0D APPEARED TO HAVE RESULTED TROM. A SINGLE MANUTACTURING DETECT AND THE REST OF THE TUEL_ RODS VERE IN GOOD, CONDITION, IT WAS DECIDED TO RECON-STITUTE THE BUNDLE WI'TH ONE TUEL RCD MISSING. A SET OF ANALYSES WERE DONE TO DETERMINE THE ETTECT OT OPERATING E-59 VITH ONE TUEL R0D MISSING. LISTED BELOW IS THE VARIATION TROM NORMAL 0F THE LOCAL PEAKING TACTOR BECAUSE OF THE TRANSTER OT ROD 2C TO LOCATION 5B AND DISCHARGING 55 VITH A VACANCY LETT IN 2C. THESE VALUE3 ARE NCRMALIZED TO 77 RODS. LOCAL PEAKING TACTOR - ROD MISSING RATIO EQUALS LOCAL PEAKING TACTOR - R0D NORMAL 1 2 3 4 5 6 7 8 9 A 1.021 1.0 18 1.015 1.013 1.001 .992.988 B 1.048 5.087 1.059 1.045 i.340 i.025 .998 .978 .985 C i.08 6 ~ 0 i.105 i.044 i.041 i.016 .993.989 .98 2 D ).050 1.099 i.6 60 i.0 19 i.003 ~.952 .984 .9't 1 .978 E 1.010 5.014 i.011 .998 .988 .983 .978 .976 .975 T,'.952 '.952 .989 .93% .980 .976 .974 .974 .973 C .984 .988 .984 .978 .976 .973 .972.972 .972 F .98 2 .971 .583 .977 .973 .973 .971.971 .971 .975 .978 .974 .972 .971 .975.975 I l THIS PERTURBATION ALSO INCLUDES THE ETTECT OF REPLACING THE TWO PU RODS IN LOCATIONS 88 AND 2H WITH 2.5 PERCENT ENRICHED TRESH. U RODS. IFE LIMITING LOCATION 1D HAS A LOCAL PEAKING TACTOR INCREASE OF I 5 PERCENT AT 4,000 MWD 2T AND WILL BE ACCOUNTED TOR IN THE CORE LOADING PATTERN. Y1 b .-.d ~ nev :6.e ~ .n s l

,n. NJNDLE E-59 NAS BEEN (* ACED IN CORE LOCATION 03-{, WHICH IS ONE OF THE LOVEST POWER LOCATIONS IN THE CORE. THE CHANGE IN KEFT SECAUSE OF THE VA, CANT ROD LOCATION IS ABOUT ONE PERCENT POSITIVE. THE OTHER PHYSICS AND THERMAL-HYDRAULICS CHARACTERISTICS REMAIN ESSENTIALLY THE SAME. WE BELIEVE THAT WHEN THE INCREASED LOCAL PEAKING IS TAKEN INTO CONSIDER-ATION, BUNDLE E-59 IS INTERCHANGEABLE WITH A'NY OTHER E-G FUEL. BUNDLE. IT IS OUR INTENTION TO RETURN THE PLANT TO SERVICE EARLY THE WEEK OF MARCH 29.-IF YOU HAVE ANY QUESTIONS, PLEASE DO NOT HESITATF TO CALL. GERALD J WALKE NUCLEAR FUEL MANAGEMENT ADMINISTRATOR i CC-R L HAUETER C J HARTMEN CORRECTION - SECo"D NUMBER UNDER 3 IN SECO?{D TABLE SHOULD READ 0.'994 INSTEAD OF 0.9944. END - DW

3 6 -...-,.~......ym,.p7 - p... .-...,a. ,..~... NO.s ~ l DATE nECfIVED g"1 DATE OF DOCUMENT FM"OCs 3.j,3 Consumers Power A 3,g" g i.T n. uLuos nEronTa OT H Eni Jackson, Mich. wg Gersid J. 'Jalhe ORIG.s CCs OTH ERs 70: 1 1 Morris ACTION MECEs.ARY O IconcunaEuCE O DATE AnsvvEneD MO ACTION Mrcas.ARY l COMMENT O avi Post OFFICE FILE CODE CLA!4t Fa S_155 REFERRED TO D AT E RECEIVED BY DATE MEO.NO: (Must D.g lassified) unc 3 2620 D EICRIPTION: 111 WI advising Big b ek is la the 7,g,,,,,, Sch week of a six wee' refueling outsas.. w/ 6 m fw ad % Fuel has been inspeccad....reacter core loaded....& varises smalyes have DISTRIBUTIOlh EnCooeunts: been completed.....plsas. ,,, g ggg, g chauld bem in operation by 3 29-70 AEC PDR Compliance (2) OGC-R-;-s Skovholt co_NoLRcitime

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