05000366/LER-1980-010-03, /03L-0:on 800131,during Reactor Startup,At 58% Power,Max Total Peaking Factor Was Calculated at 3.0 Compared to Design Value of 2.38.Caused by Lower than Normal Xenon Distribution During Startup

/03L-0:on 800131,during Reactor Startup,At 58% Power,Max Total Peaking Factor Was Calculated at 3.0 Compared to Design Value of 2.38.Caused by Lower than Normal Xenon Distribution During Startup

ML19294A972
Person / Time
Site:	Hatch
Issue date:	02/15/1980
From:	Coggin C GEORGIA POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19294A968	List: 05000366/LER-1980-010, Forwards LER 80-010/03L-0 05000366/LER-1980-010-03, /03L-0:on 800131,during Reactor Startup,At 58% Power,Max Total Peaking Factor Was Calculated at 3.0 Compared to Design Value of 2.38.Caused by Lower than Normal Xenon Distribution During Startup
References
LER-80-010-03L-01, LER-80-10-3L-1, NUDOCS 8002260527
Download: ML19294A972 (2)

LER-1980-010, /03L-0:on 800131,during Reactor Startup,At 58% Power,Max Total Peaking Factor Was Calculated at 3.0 Compared to Design Value of 2.38.Caused by Lower than Normal Xenon Distribution During Startup

Event date:
Report date:
3661980010R03 - NRC Website

text

F,HLJ FurtM.100 U. S. NUbbt Art M ttaVLA t urt T L,UMMibbeUN (7 77)

LICENSEE EVENT REPORT CON THOL 8 LOCK: l l

l l

l l lh (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) i e

R IGlAlElIIHI2l@l0 l0l-l0l0 0 0l0l-l0l0l@l4l1l1l1l1l@l l,_j @

7 8 9 LICENSEE CODE 14 lb UCENSE NUMdEH 25 26 UCENSE T4PE J0 5 7 CA T bd CO' ITlil

$'E lLl@l015101010131616l@l01Il3111810l@l012l11518l0l@

I 8

60 61 DOCKET NUMBER t=3 M

EVENT DATE 14 76 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSECUENCES h 10uring reactor startuo at 58% cower. the MTPF was calculated to be 3.0 comoared to a I

o 2

lo 131 Idesign value of 2.38.

Corrective action was taken but did not lower the MTPF to allow I ladiustment of APPMs oer Tech Soecs section 3.2.2.

Preoarations were made to reduce j

o 4

lo Isl treactor oower to less than or ecual to 25% within the next 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, but the problem I

Iwas corrected before any sicnificant__teduction occurred and startuo continued.

There I o

s lo l 7 I Iware no effects on oublic health and safety.

This is a repetitive occurrence - see I

o a ILER 50-366/1979-100.

I 80 7

8 9 C DE CODE SLB O E COMPON ENT CODE SU8C DE S

ODE IT R Iz Iz l@ Lx_J@ l x l@ I z I z I z I z I z I z l@ Iz l@ LZ_J @

7 8

9 10 11 12 1J Id 19 20 SEOUE N TI AL OCCURRENCE REFORT REVISION LER 93 EVENTVEAR REPORT NO.

CODE TYPE NO.

@ sgog 18101 1-1 1011101 el 1013 l l Ll l-l l0 l a

t,,21 22 23 24

6 27 23 29 30 31 32 K f ACTO ON PLANT MET MOURS S B IT D FO B.

SUP8 LIE MANUF CTLRER lx l@l H l@

l z l@

lzl@

l 010 l 0 l pj l Y l@

Nl@

l z l@

l z 1919 loj@

i J3 34 JS 06 37 40 41 42 4J 44 47 CAUSE DEOCRIPTION AND CORRECTIVE ACTIONS lich MTPF wu due to lower than nor al vanon distribution durino startue. The I

1 0

lThe i

i i failurn of tbn initial action

+6 rerrar+ +hn cr-blom roc ul tori fra an i n a c e"ra n rM I

ITT-l Ipattern ard LPRM readinas beino used by the comcuter. The rod cattern adjustments 1

couoled with rectifying the comouter inouts corrected the oroblem.

Personnel will be l 1

3 f familiarized with the event to orevent recurrence.

I i

4 8o 7

8 9 ST S

% POWER OTHER STATUS DISCO RY DISCOVERY DESCRIPTION [F_j @ l 0l Sl Sl @ l NA l

lBl@l En9ineer Observation l

i 5

ACTIVITY CC TENT RELE ASED OF RELE ASE AYOUNT OF ACTIVITY LOCATION OF RELEASE l

NA l

l NA l

fM l z I @ Lz.J@OES Iy

()

• [] I FD ]

a PeRSONsEt :xPCs s

zl NA H L:l l Ll eJ V "

l TYPE @l DE SCRIPTIO.,

n NUMBER 10l0l0l@l i

7 2

i3 so

' PERSOnNE t iN;u'R,,,

oESCRiPTiCN@

NuveER 10 010l@l NA l

i a

7 8 9 11 12 83 LOSS OF OR D avage TO FACILITY nm4 51g, go<:cR'"'o~

ng 7

8 9 10 80 IIT l l N f@ DESCRIPTION fSSUE l

NA i

llllllll1IIIli 7

8 9 10 68 69 80 5 r. I enggin. Suot. P'l t. Ena. Serv. psong 912-367-7781 2,

NAME OF PREPARER

1 1

,.4 Licensee Name: Georgia Power Company Facility Name:

Plant E. I. Hatch Docket No.:

50-366 LER No.:

50-366/1980-010

Narrative

Report for LER # 2-80-010 At approximately 0030 CST on January 31, 1980, the reactor engineer complet-ed an LPRM-Process Computer calibration (00-1) and requested a "P-1" calcul-ation. The P1 indicated that the core maximum peaking factor was 3.078 I

relative to the design valvue of 2.38.

The engineer began taking action with-in the prescribed 15 minutes to alleviate the peaking problem by control rod pattern adjustments, but at ';he end of the two-hour limit the CMPF was st'ill too high to allow aajustment of the APRMs as required by Tech Specs 3.2.2.

Deviation Report 2-80-36 was subsequently filed and preparations were made to have the reactor below 25% of rated power within the next four hours.

The CMPF was lowered and APRMs adjusted during the 4-hour period and normal reactor startup was continued.

Several days later, on another startup, after an 00-1 and P1, again a CMPF of 3.0 was indicated and again action was taken within the prescribed time limit to lower the CMPF. After approximately an hour and a half the CMPF was still excessive, so the engineer took the conservative move of shoving two high worth groups of shallow rods to kill the power in the lower portion i

of the core. At the two hour limit, however, the P1 still indicated a CMPF too high to allow for APRM adjustment and a deviation was filed.

Subsequently the engineer noticed that the problem areas were those around three bypassed "A" level LPRMs and TIP scans were run next to these detectors to input the power readings to the computer. The following P1 showed a CMPF of less than j

2.38, indicating that the peaking problem had indeed been corrected by the l

rod insertions but not correctly accounted for by the process computer.

The APRMs were adjusted as required, and normal startup was continued.

Looking back at the computer edits from the oeviation on the 31st it is evident that the three bypassed detectors were a contributing factor. The calibrat-ed LPRM readiny. remained high even'after the shallow rods were shoved.

Also it was discovered that at 0141 CST the computer " misplaced" a full-out

{

rod at position 8 resulting in an incorrect asymmetric calculation, further compounding the problems. Taking this into account and studying the rod pat-tern that existed at 0219 CST, it is probable that the CMPF had been signific-antly reduced to have allowed timely adjustment of the APRMs had the comput-er calculation been correct.

To avoid these type occurrences in the future, all station nuclear engineers will be informed of the details of the event, particularly the root causes.

Also effort is being made to return the three A level detectors to service and investigate possibiitty of similar problem on Unit 1.

This type event des occurred before and was reported under LER 50-366/1979-100.

s