NRC-08-0035, Submittal of 2007 Safety Relief Valve Challenge Report, Main Steam Bypass Line Report, and ECCS Cooling Performance Evaluation Model Changes or Errors Report

Submittal of 2007 Safety Relief Valve Challenge Report, Main Steam Bypass Line Report, and ECCS Cooling Performance Evaluation Model Changes or Errors Report

ML081280486
Person / Time
Site:	Fermi
Issue date:	04/28/2008
From:	Detroit Edison
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC-08-0035, VP-86-0154
Download: ML081280486 (8)

Text

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Fermi 2 6400 North Dixie Hwy., Newport, MI 48166 Detroit Edison TS 5.6.6 VP-86-0154 10CFR50.46 April 28, 2008 NRC-08-0035 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington D C 20555

Reference:

Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

Subject:

Submittal of 2007 Safety Relief Valve Challenge Report, Main Steam Bypass Line Report, and ECCS Cooling Performance Evaluation Model Changes or Errors Report The Fermi 2 Technical Specifications (TS) contains a requirement for submitting an annual report for safety relief valve challenges (TS 5.6.6). Enclosure 1 provides the Safety Relief Valve .Challenge Report for 2007.

Enclosure 2 provides the annual Service Life of the Main Steam Bypass Lines Report for 2007. This satisfies the commitment stated in Detroit Edison's letter to the NRC dated November 7, 1986 (VP-86-0154).

Enclosure 3 provides the annual Emergency Core Cooling System (ECCS) Cooling Performance Evaluation Model Changes or Errors Report for 2007. This report is provided in accordance with 10 CFR 50.46(a)(3)(ii).

Should you have any questions or require additional information, please contact me at (734) 586-5197.

Sincerely,

,Lc24)42L-

"42-,w A-DTE Energy Company

USNRC NRC-08-0035 Page 2

Enclosures:

1. Safety Relief Valve Challenge Report

2. Service Life of Main Steam Bypass Lines Report

3. ECCS Cooling Performance Evaluation Model Changes or Errors Report cc: NRC Project Manager NRC Resident Office Reactor Projects Chief, Branch 4, Region III Regional Administrator, Region III Supervisor, Electric Operators, Michigan Public Service Commission

ENCLOSURE 1 TO NRC-08-0035 FERMI 2 SAFETY RELIEF VALVE CHALLENGE REPORT JANUARY 1 - DECEMBER 31, 2007 DETROIT EDISON COMPANY NRC DOCKET NO. 50-341 FACILITY OPERATING LICENSE NO. NPF-43 to NRC-08-0035 Page 1 Safety Relief Valve Challenges There were no instances in 2007 where reactor pressure was high enough to require Safety Relief Valve (SRV) actuation. There were no instances in 2007 where an SRV actuation was demanded by an automatic logic system. On November 15, 2007, following completion of the Twelfth Refueling Outage (RFl 2), Surveillance Procedure 24.137.11, "Safety Relief Valve Operability Test," was satisfactorily performed, which cycled all 15 SRVs.

ENCLOSURE 2 TO NRC-08-0035 FERMI 2 SERVICE LIFE OF MAIN STEAM BYPASS LINES REPORT JANUARY 1 - DECEMBER 31, 2007 DETROIT EDISON COMPANY NRC DOCKET NO. 50-341 FACILITY OPERATING LICENSE NO. NPF-43 to NRC-08-0035 Page 1 Service Life of Main Steam Bypass Lines In accordance with Detroit Edison letter to the NRC dated November 7, 1986 (VP-86-0154), the cumulative time the main steam bypass lines are operated with the bypass valves between 30 and 45 percent open will be reported annually. A cumulative value of 100 days is not to be exceeded without prior NRC notification.

Evaluations performed by Stone and Webster and by Hopper and Associates concluded that the bypass lines are acceptable for safe operation when operated within the 100 day constraint.

Based on these evaluations, the main steam bypass piping that was installed in 1985 has a service life that will allow it to function for the life of the plant under anticipated operating conditions.

As of December 31, 2007, the main steam bypass lines cumulative usage was 41.32 days.

ENCLOSURE 3 TO NRC-08-0035 FERMI 2 ECCS COOLING PERFORMANCE EVALUATION MODEL CHANGES OR ERRORS REPORT JANUARY 1 - DECEMBER 31, 2007 DETROIT EDISON COMPANY NRC DOCKET NO. 50-341 FACILITY OPERATING LICENSE NO. NPF-43 to NRC-08-0035 Page 1 ECCS Cooling Performance Evaluation Model Changes or Errors There have been two -errors identified since last year's report:

General Electric 10CFR50.46 Notification Letter 2006-01, dated July 28, 2006, identified a 55 degree Fahrenheit (55°F) increase in the licensing basis Peak Cladding Temperature (PCT) for the GEl 1 and GEl4 fuel types small break LOCA analyses. The Fermi 2 limiting transient for the licensing basis PCT for the GEl 1 fuel was the large break LOCA.' The identified error was not large enough to make the small break LOCA more limiting for GEl 1 fuel. The limiting transient for the GE14 fuel was the small break LOCA; therefore, the error resulted in a 55°F increase in the licensing basis PCT for GE14 fuel. Detroit Edison letter NRC-07-0038, dated July 3, 2007, reported this error.

General Electric 10CFR50.46 Notification Letter 2007-0 1, dated December 18, 2007, identified a 105lF increase in the licensing basis PCT for the GEl 1 fuel type and a 255°F increase for the GE14 fuel type. The error affected the small break LOCA PCTonly. The Fermi 2 limiting transient for the licensing basis PCT for the GEl 1 fuel was the large break LOCA; however, this error caused the small break LOCA PCT to become more limiting. The limiting transient for the GEl4 fuel was the small break LOCA; therefore, the error resulted in a 255°F increase in the licensing basis PCT., Detroit Edison letter NRC-08-0003, dated January 16, 2008, reported this error.

Based on the two notifications above, the current licensing basis PCT is 1696°F for GEl 1 fuel and 1930'F for GEl4 fuel. This results in a minimum of 270'F margin to the 2200'F PCT limit in 10CFR50.46. The small break LOCA is currently the licensing basis PCT most limiting transient for both fuel types. As discussed in Detroit Edison letter NRC-08-0003, the LOCA analyses for both fuel types are being re-performed to incorporate the applicable error reports and results will be reported to the NRC by June 30, 2008.