United States Nuclear Regulatory Commission - Protecting People and the Environment

LICENSEE: SIEMENS POWER CORPORATION          
SITE: SIEMENS POWER CORPORATION             EN NUMBER:31366
DOCKET: 07001257                         EVENT DATE: 11-21-96
RX TYPE:                                 EVENT TIME: 00:00
VENDORS:                                NOTIFY DATE: 11-21-96
EMERGENCY CLASS: N/A  REGION: 4 STATE: WA      TIME: 15:40
OPS OFFICER: STEVE SANDIN             
10 CFR SECTION: CCCC  21.21               UNSPECIFIED PARAGRAPH

10 CFR PART 21 NOTIFICATION OF DEFECT IN 1986 EXEM PWR LBLOCA    
MODEL                                                            
                                                                 
"THIS FACSIMILE IS TO INFORM THE NRC OF A REPORTABLE DEFECT PER  
10 CFR PART 21."                                                 
                                                                 
"IN A TELEPHONE CONVERSATION ON OCTOBER 10, 1996, SIEMENS POWER  
CORPORATION (SPC) AND ITS CURRENT PWR UTILITY CUSTOMERS WERE     
INFORMED THAT THE NRC HAD REJECTED SPC's PROPOSED 1991 CHANGES   
MADE TO THE FCTF REFLOOD HEAT TRANSFER CORRELATIONS IN THE       
TOODEE2 CODE IN THE APPROVED 1986 EXEM PWR LARGE BREAK LOSS OF   
COOLANT ACCIDENT (LBLOCA) EVALUATION MODEL.  THESE CHANGES WERE  
SUBMITTED TO ELIMINATE A NON-PHYSICAL TREND IN HEAT TRANSFER     
COEFFICIENTS AS A FUNCTION OF REFLOOD RATE IN THE 1986 EXEM PWR  
LBLOCA EVALUATION MODEL. THE NRC ALSO CONCLUDED, BASED ON THE    
INFORMATION AVAILABLE TO THE STAFF, THE NON-PHYSICAL TREND IN THE
1986 EXEM PWR LBLOCA EVALUATION MODEL WAS CONSIDERED TO BE AN    
UNACCEPTABLE ERROR.  THESE NRC DETERMINATIONS WERE DOCUMENTED IN 
A LETTER FROM R.C. JONES (USNRC) TO H.D. CURET (SPC) DATED       
OCTOBER 11, 1996.  AS A RESULT OF THESE DETERMINATIONS, SPC      
PERFORMED A 10 CFR 21 EVALUATION IN ACCORDANCE WITH THE SPC      
PROCEDURES.  THIS LETTER DOCUMENTS THE RESULTS OF THIS PART 21   
EVALUATION."                                                     
                                                                 
"THE SPC PART 21 EVALUATION CONCLUDED THE ERROR IN THE FCTF HEAT 
TRANSFER CORRELATIONS IN THE 1986 EXEM PWR EVALUATION MODEL TO BE
A SUBSTANTIAL SAFETY DEFECT.  THE BASIS FOR THIS CONCLUSION RESTS
ON THE FACT THAT CERTAIN PLANTS ANALYZED WITH THE INTERIM        
CORRECTIONS TO THE FCTF HEAT TRANSFER CORRELATIONS EXCEEDED 10   
CFR 50.46 LIMITS."                                               
                                                                 
"THE AFFECTED PWR UTILITIES WERE INFORMED OF THE TELEPHONE       
CONVERSATION, A MEETING CONDUCTED BY THE NRC HELD ON WEDNESDAY,  
OCTOBER 16, 1996 IN ROCKVILLE, MD REGARDING THE IMPACT OF THE    
DEFECT ON CALCULATED 10 CFR 50.46 CRITERIA, AND DIRECT           
COMMUNICATIONS BETWEEN THE UTILITIES AND SPC.  ACTIONS TAKEN AND 
TO BE TAKEN TO ADDRESS THE ISSUE ARE TO BE PROVIDED IN A WRITTEN 
REPORT TO THE NRC IN COMPLIANCE TO 10 CFR 21.21 (d)(3)(ii)."     

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