L-MT-05-106, Report of Changes and Errors in ECCS Evaluation Models
| ML060040152 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 12/29/2005 |
| From: | Conway J Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-MT-05-106 | |
| Download: ML060040152 (4) | |
Text
Committed to Nuchear Excejj 2 Monticello Nuclear Generating Plant Operated by Nuclear Management Company, LLC December 29, 2005 L-MT-05-106 10 CFR 50.46(a)(3)
U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Monticello Nuclear Generating Plant Docket 50-263 License No. DPR-22 2005 Report of Changes and Errors in ECCS Evaluation Models
References:
- 1) GE Report: NEDC-32514P, Revision 1, "Monticello SAFER/GESTR LOCA Loss of Coolant Accident Analysis," dated October 1997.
(Exhibit G to LAR, Revision 1, Dated July 26, 1996, Supporting Monticello Nuclear Generating Plant Power Rerate Request Program.)
- 2) GE Report: GE-NE-J1 103878-09-02P, "Monticello ECCS-LOCA Evaluation for GE14," GE Proprietary Information, dated August 2001.
- 3) NMC to NRC letter, "2004 Report of Changes and Errors in ECCS Evaluation Models," (L-MT-04-074), dated December 22, 2004.
Pursuant to 10 CFR 50.46(a)(3), Nuclear Management Company, LLC (NMC) is providing the annual report of changes or errors identified in the Emergency Core Cooling System (ECCS) evaluation models or application for the Monticello Nuclear Generating Plant (MNGP). This report is for the period between July 2004 and July 2005.
The MNGP Loss of Coolant Accident (LOCA) analyses of record (AOR) are contained in General Electric (GE) reports submitted for the MNGP rerate (Reference 1) and the LOCA analysis for the GE14 fuel type (Reference 2). Two GE fuel types are currently in use, the GE1 I and GE1 4 fuel types. No notifications of changes or errors resulting in a change in Peak Cladding Temperature (PCT) were received from GE for either fuel type during this period. Because of this, the licensing basis PCT and summary of applicable changes and errors in the LOCA analyses (from when the last AOR was performed) provided in the 2004 annual report (Reference 3) remain unchanged.
2807 West County Road 75
- Monticello, Minnesota 55362-9637 Telephone: 763.295.5151
- Fax: 763.295.1454 7al
Document Control Desk Page 2 The current adjusted licensing basis PCT for the fuel types in use at MNGP are:
Fuel Type Licensing Basis PCT (0F)
GE1 1 2137 GE14 1945 provides a summary table of the applicable changes and errors in the LOCA analyses from when the last analyses of record (AOR) were performed.
This letter makes no new commitments or changes to any existing commitments.
John T.
n ay Site Vice r sident, Monticello Nuclear Generating Plant Nuclear M agement Company, LLC Enclosure cc:
Administrator, Region l1l, USNRC Project Manager, Monticello, USNRC Resident Inspector, Monticello, USNRC Minnesota Department of Commerce
ENCLOSURE I TABLE 1 -
SUMMARY
OF MONTICELLO LOCA CHANGES AND ERRORS INVOLVING CHANGES IN PEAK CLADDING TEMPERATURE (PCT)
Applicable Analysis or Ref.
Basis PCT (OF Error Description o l_
GE11 I GE14 Monticello Loss of Coolant Accident (LOCA) Analyses of Record (AOR):
NEDC-32514P, Rev. 1, Monticello SAFER/GESTR-LOCA Loss-of-Coolant Accident Analysis 1
2087 GE-NE-J1103878-09-02P, Monticello ECCS-LOCA Evaluation for GE14 2
<1960 Impact of SAFER Time Step Size on the PCT for Jet Pump Plant Analyses (Notification Letter 2000-04)
The time step size used in the SAFER-LOCA code was 3
- 5 N/A determined inappropriate to achieve good numerical convergence for an accurate PCT.
Impact of SAFER Pressure Rate Inconsistency Error on PCT (Notification Letter 2001-02)
An inconsistent core exit steam flow was used in the SAFER 4
+ 10 N/A pressure equation, resulting in premature termination of ECCS condensation, and an increase in the second peak PCT.
SAFER Core Spray Injection Elevation Error (Notification Letter 2002-01)
An error in the automation code that prepared input for SAFER 5
+ 60 N/A resulted in the core spray sparger elevation being specified lower than actual.
Impact of SAFER LevelNolume Table Error on PCT (Notification Letter 2003-01)
Level and volume tables used by SAFER were not updated 6
- 15
- 15 when a revised initial water level was implemented.
Sum of absolute value of changes during the current reporting period.
0 0
Sum of absolute value of changes since last AOR.
90 15 Algebraic sum of changes during the current reporting period.
0 0
Algebraic sum of changes since last AOR.
50
-15 Current Adjusted Peak Cladding Temperature 2137
<1945 Page 1 of 2
I ENCLOSURE 1 References
- 1.
GE Report: NEDC-32514P, Revision 1, "Monticello SAFER/GESTR-LOCA Loss-of-Coolant Accident Analysis," dated October 1997. (This report is Exhibit G of Revision 1 to License Amendment Request Dated July 26, 1996, Supporting Monticello Nuclear Generating Plant Power Rerate Request Program.)
- 2.
GE Report: GE-NE-J 1 03878-09-02P, "Monticello ECCS-LOCA Evaluation for GE14," GE Proprietary Information, dated August 2001.
- 3.
10 CFR 50.46 Notification Letter 2000-04, "Impact of SAFER Time Step Size on the Peak Clad Temperature (PCT) for Jet Pump Plant Analyses," dated November 8, 2000.
- 4.
10 CFR 50.46 Notification Letter 2001-02, "Impact of SAFER Pressure Rate Inconsistency Error on the Peak Clad Temperature (PCT).
- 5.
10 CFR 50.46 Notification Letter 2002-01, "SAFER Core Spray Injection Elevation Error," GE Proprietary Information, dated June 13, 2002.
- 6.
10 CFR 50.46 Notification Letter 2003-01, "Impact of SAFER Level/olume Table Error on the Peak Cladding Temperature (PCT)," GE Proprietary Information, dated May 6, 2003.
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