ML18144A723

LER 1977-004-00 for St. Lucie Unit 1, Digital Data Processing System Calorimetric

ML18144A723
Person / Time
Site:	Saint Lucie
Issue date:	02/18/1977
From:	Schmidt A Florida Power & Light Co
To:	Moseley N NRC/IE, NRC/RGN-II
References
PRN-LI-77-37 LER 1977-004-00
Download: ML18144A723 (3)

Text

Cl i. BOX 013100, MIAMI, FL 3310'I

~ ~

~'

-GEEST FLORIDA POWER 5 LIGHT COMPANY February 18, 1977 PRN-LI-77-37 Mr. Norman C. Moseley, Director, Region Office of Inspection and Enforcement II U. S. Nuclear Regulatory Commission 230 Pcachtxcc Street, N. W., Suite 1217 Atlanta, Georgia 30303

Dear Mr. Moseley:

REPORTABLE OCCURRENCE 335-77-4 ST. LUCIE UNIT 1 DATE OF OCCURRENCE: JANUARY 20, 1977 DDPS CALORIMETRIC The attached Lj.censee Event, Report. is being submitted in accordance with Technical Specification 6.9 to provide 30-day notification of the subject occurrence.

Very truly yours, A. D. Schmidt Vice President Power Resources MAS/cpc Attachment cc: Robert Lowenstein, Esquire Director, Office of Inspection and Enforcement (30)

Director, Of fice of Management Information and Program Control (3)

PEOPLE .. ~ SERVING PEOPLE

IN:ENBEE EVENT REPORT CONTROL BLOCK: (PLEASE PRIBT ALL REQUIRED II4IFORIVIATION)

I L!CEN SEE ~ LIENEE EVENT toog F L S N4ME L S 1 0 0-oloooo NUMBER 'CENSE 0 0

'6 4 1 TYPE 1 1 ~o~

TYPE

~'6 7 89 14 15 25 30. 31 32 I

REPORT AEPOAT CATEGORY TYPE SOURCE COClilET NUMBER EVENT'4TE AEPQAT 04TE

~01 00N"r ~L ~L 0 5 0 0 3 3 5 0 1 2 0 7l 7 0 2 1 8 7 7 7 8 57 5S 60 61 66 69 74 75 80 EVENT OESCRIPTION Qa2 While reviewincr ower ascension test data from before and after the 7 8 9 60 QOg 5-month fuel reconstitution shutdown See LER 335-76-35 dated 7 23 76 a 7 89 80 ital

~

~04 possible error in indicated ower from the Di Da'ta Processin S stem 7 89 80

~05 DDPS calorimetric rimar heat balance) ro ram was noted. An inten-89:'ive investi ation confirmed that the calorimetric ro ram was in error 80 MGLS 7 89 PRME 80 C'SI ICE COMPCNcNT C MPQNENT CQQE COOS COMPCiNFNT COOE SUPPUER MANUF4CTUPER VCL4TCN

~07 7 8 S

~IF 10

~B 11 12 I N S T R U N 44 F 112 0 47 N

48 CAUSE OESCRIPTION ol~ There are two methods in the calorimetric ro ram for convertin analo 7 8 9 60 g f dwater flow si nals to di ital en ineerin units. One method involves l 7 8 9 60 .

~1 0 a direct 4 to 20 ma linearization while the other method allows for a 7 89 METHOC OF 80 FAC:Lfii'T4TUS

.C POWER ~ OTHErl STATUS CLSCQVEAY ClSCCVEAY CESCAlPTZN l4141 7 8

~B 9

~og 10 o

12 13 NA 44 45 46 NA FORM OF ACTMTY CQAl cNT AELBLSEO OF AEL~MSE AMCUNT QF 4C44VITY LOCATlQN CF A'cC4SE

@~2 Z ~Z NA NA 7 9 9 10 11 PERSONNEL EXPOSURES NUMBER TYPE CESCAIPTlQN Pg~oo 7 9 9 o

11 z

12 13 NA 80 PERSONNP IiVJURIES NUMBER CESCAl~QN

~4 89

~oo o NA 60 7 11 12 PROBjQLF- CONSEQUENCES t11l NA 99 LOSS OR OAMAGE TO FACILITY TYPE OESCAIPTICN z NA 7 89 10 PUSLICITY I 7 89 60 ACOITIONAL .=ACTORS

~1IS P o for continuation of Event Descri tion and Cause Descri tion.

7 89 60

~19 7 89 60 M. A. Scho man cpo 04t4 og'p

~ "P~e EVENT REPORT 'g'ICENSEE REPORTABLE OCCURRENCE 335-77-4 PAGE TWO .

r EVENT DESCRIPTION (Continued) and indicated 2.57% below actual power (at nominal 80%). The program was corrected and now functions properly. This is the first occurrence involving software problems with the DDPS.

(335-77-4).

'AUSE DESCRIPTION (Continued) special linearization curve for each flow transmitter. The second method will allow for non-linear behavior of different transmitters. During initial power ascension, the direct 4 to 20 ma linearization method was used.

Following fuel reconstitution, the program and data base were reloaded into the DDPS and the second method of converting analog signals to engineering units was used. However, the program contained an erroneous scaling factor for the.'range of the flow transmitted. This error caused the'indicated feedwater flow'and reactor power to be lower than actual. The program has been corrected and all calorimetric inputs reviewed to verify that no further errors. are present in the special linearization method.