05000341/LER-2009-001, Regarding Manual Reactor Scram in Response to High Turbine Vibration
| ML091480254 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 05/22/2009 |
| From: | Plona J DTE Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NRC-09-0036 LER 09-001-00 | |
| Download: ML091480254 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3412009001R00 - NRC Website | |
text
Joseph H. Plona Site Vice President 6400 N. Dixie Highway, Newport, MI 48166 Tel: 734.586.5910 Fax: 734.586.4172 DTE Energy-10CFR50.73 May 22, 2009 NRC-09-0036 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington D C 20555-0001 Reference: Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43
Subject:
Licensee Event Report No. 2009-001, "Manual Reactor Scram in Response to High Turbine Vibration" Pursuant to 10 CFR 50.73(a)(2)(iv)(A), Detroit Edison is hereby submitting the enclosed Licensee Event Report (LER) No. 2009-001. This LER documents a manual scram that occurred on March 28, 2009 when plant operators placed the reactor mode switch to shutdown as required by plant procedures in response to high main turbine vibration.
No commitments are made in this LER.
Should you have any questions or require additional information, please contact Mr.
Rodney W. Johnson of my staff at (734) 586-5076.
Sincerely, 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
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: No. 3150-0104 Expires 8/31/2010 (9-2007)
, the NRC may (See reverse for required number of not conduct or sponsor, and a person is not required to respond to, the digits/characters for each block) information collection.
- 3. PAGE Fermi 2 05000341 1 OF 3
- 4. TITLE Manual Reactor Scram in Response to High Turbine Vibration
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR I SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCKET NUMBER NUMBER NO 05000 03 28 2009 2009 001 00 05 22 2009 FACILITY NAME DOCKET NUMBER 05000
- 9. OPERATING MODE
- 11. THIS REPORT SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)
El 20.2201 (b) 0 20.2203(a)(3)(i) 0 50.73(a)(2)(i)(C) 0 50.73(a)(2)(vii) 1l 20.2201 (d) 020.2203(a)(3)(ii) 050.73(a)(2)(ii)(A) 0 50.73(a)(2)(viii)(A)
El 20.2203(a)(1) 0 20.2203(a)(4) 050.73(a)(2)(ii)(B) 0 50.73(a)(2)(viii)(B)
E] 20.2203(a)(2)(i) 050.36(c)(1 )(i)(A) 050.73(a)(2)(iii) 0 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 0] 20.2203(a)(2)(ii) 0 50.36(c)(1 )(ii)(A) 9 50.73(a)(2)(iv)(A) 0 50.73(a)(2)(x)
El 20.2203(a)(2)(iii) 50.36(c)(2) 050.73(a)(2)(v)(A) 073.71 (a)(4) 24%
0 20.2203(a)(2)(iv) 050.46(a)(3)(ii)
Q 50.73(a)(2)(v)(B) 073.71 (a)(5) 0 20.2203(a)(2)(v) 050.73(a)(2)(i)(A) 050.73(a)(2)(v)(C) 0 OTHER 0
20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)
Specify in abstract below or in (If more space is required, use additional copies of NRC Form 366A)
Initial Plant Conditions
Mode 1 Reactor Power 24 Percent Description of the Event At 0146 hours0.00169 days <br />0.0406 hours <br />2.414021e-4 weeks <br />5.5553e-5 months <br /> EDT March 28, 2009, the reactor mode switch [HS] was taken to shutdown in response to high vibration levels on the Main Turbine [TA] number 1 bearing. Reactor power had been reduced in preparation for a manual scram from below 25 percent power to enter into a unit Refueling Outage (RF13). The reactor protection system (RPS) [JD] performed as expected, and all rods were fully inserted into the core. Reactor water level reached a low of approximately 162 inches above top of active fuel and recovered to normal level automatically without operator intervention.
Reactor water level was maintained in the normal band of 173 to 214 inches with the Control Rod Drive System after the scram. Reactor pressure control was maintained by the turbine bypass valves. The peak Reactor Pressure was 965.3 psig, within normal pressure control limits. Reactor water Level 3 isolations occurred as expected.
There was no maintenance or testing in progress that would affect turbine vibration levels. Safety related plant equipment responded as expected to the manual reactor scram. At the time of the scram all Emergency Core Cooling Systems (ECCS) and Emergency Diesel Generators (EDGs) [DG] were operable.
Reactor water level was maintained above Level 2, and as expected, none of the primary containment isolations or safety injection systems initiations associated with Level 2 occurred. Safety related plant equipment responded as expected to the manual reactor scram.
The high turbine vibration was attributed to a High Pressure (HP) Turbine rub transversing bearing number 1. Cooling of the Moisture Separator Reheaters (MSRs) [SB] occurred early in the shutdown process, and it was determined that the rub was due to the MSR cool down process.
Significant Safety Consequences and Implications
This event posed no significant safety implications because the reactor protection and safety related systems functioned as designed following the manual reactor trip. The transient was compared to the UFSAR transient analysis for the Manual Scram, and the actual response was enveloped by the UFSAR analysis.
IU.S. NUCLEAR REGULATORY COMMISSION (9-2007)
LICENSEE EVENT REPORT (LER)
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE YEAR SEQUENTIAL REVISION Fermi 2 05000341 NUMBER NUMBER 3 OF 3 2009 001 00 Therefore, the health and safety of the public were not affected by this event.
This event is being reported under 10 CFR 50.73(a)(2)(iv)(A), as an event or condition that resulted in manual actuation of the reactor protection system and a reactor scram. A 4-hour non-emergency notification was made to the NRC Operations Center at 0345 EDT on March 28, 2009 (EN 44942) in accordance with 10 CFR 50.72(b)(2)(iv)(B) for an actuation of the reactor protection system.
Cause of the Event
The manual scram was inserted when turbine vibration levels on bearing #1 reached 15 mils during the shutdown for RF13. The high turbine vibration was due to a HP Turbine rub transversing bearing number 1.
By comparing the shutdown for RF13 with previous shutdowns and with other industry events where cooling of the MSRs occurred early in the shutdown process, it was determined that the rub was due to the MSR cool down process.
Operations personnel followed the system operating procedures (SOP) for the shutdown process.
Corrective Actions
The shutdown procedures will be reviewed in conjunction with vendor information and industry operating experience to determine potential procedure enhancement. Improvements will be made where applicable.
This event is documented and evaluated in the Fermi 2 corrective action program. Other actions are being considered to address this event. These actions will be tracked and implemented by the corrective action program
Additional Information
A. Failed Components: None B. Previous LERs on Similar Problems: None I