LER-2013-002, Regarding Automatic Reactor Trip Due to Low Condenser Vacuum |
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| Report date: |
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| 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 |
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| 2502013002R00 - NRC Website |
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L-2013-127 10 CFR § 50.73 APR 11 2013 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555-0001 Re:
Turkey Point Unit 3 Docket No. 50-250 Reportable Event: 2013-002-00 Automatic Reactor Trip due to Low Condenser Vacuum The attached Licensee Event Report 05000250/2013-002-00 is submitted in accordance with 10 CFR 50.73(a)(2)(iv)(A) due to valid actuations of the Reactor Protection and Auxiliary Feedwater Systems.
If there are any questions, please call Mr. Robert J. Tomonto at 305-246-7327.
Very truly yours, Michael Kiley Vice President Turkey Point Nuclear Plant Attachment cc:
Regional Administrator, USNRC, Region II Senior Resident Inspector, USNRC, Turkey Point Nuclear Plant Florida Power & Light Company 9760 SW 344t' St., Florida City, FL 33035 TjziýO
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10-20 10)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Turkey Point Unit 3 05000250 1 of 4
- 4. TITLE Automatic Reactor Trip due to Low Condenser Vacuum
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE I
- 8. OTHER FACILITIES INVOLVED IFACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEARI NUMBER NO.
FACILITY NAMIE DOCKET NUMBER 2
11 2013 2013 002 00 4
11 2013
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply) 0] 20.2201(b)
El 20.2203(a)(3)(i)
Dl 50.73(a)(2)(i)(C) 0 50.73(a)(2)(vii)
Mode 1 El 20.2201(d)
[I 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
E] 50.73(a)(2)(ii)(B)
[I 50.73(a)(2)(viii)(B) 0_ 20.2203(a)(2)(i)
Dl 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii) 0l 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL E] 20.2203(a)(2)(ii) 0l 50.36(c)(1)(ii)(A)
Z 50.73(a)(2)(iv)(A) 0l 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
[I 50.36(c)(2)
El 50.73(a)(2)(v)(A) 0l 73.71(a)(4)
El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)0 El 50.73(a)(2)(v)(B)
El 73.71(a)(5) 99 El 20.2203(a)(2)(v)
[E 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
[E OTHER [E
20.2203(a)(2)(vi)
El 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in
BACKGROUND INFORMATION
The turbine gland sealing system prevents steam leakage out of the turbine and air leakage into the turbine at the rotor glands. If steam seal header pressure builds up to 5.5 psig, the gland steam spillover valve, CV 3725, opens to spill excess steam to the condenser. At lower loads and during startup, sealing steam is supplied by the main steam header to the gland seal regulator, CV-3-3724. The regulator maintains the seal steam pressure at 3 to 5 psig as sensed by the gland seal steam pressure controller (PC-3708) [TC, PCO]. The turbine gland seal low pressure alarm E 5/5 will annunciate in the Control Room [NA] if the supply pressure decreases to 2 psig. Manual bypass valves are provided in parallel with CV-3-3724 and CV-3-3725. Gland steam pressure is indicated locally by a pressure indicator and in the Control Room (PI-3-161 1).
Overpressure protection is provided by a relief valve [TC, RV] set for 25 psig and a rupture disk [TC, RPD]
set for 100 psig.
ANALYSIS OF EVENT
Gland seal steam was incorrectly considered to have little potential impact to plant availability. Operators accepted informal guidance to bypass the spillover valve with a clearance. The risk of a unit trip due to loss of condenser vacuum when bypassing the spillover valve was not considered as a worst possible consequence. It was the wrong standard to perform the evolution via a clearance without adequate guidance for bypassing the spillover valve. Procedure guidance for the evolution did not exist. As a result, the pressure band selected for local control of gland seal header pressure was incorrect, leading to throttling open the spillover bypass valve to the extent that condenser vacuum decreased to the turbine trip setpoint.
Control Room indicator PI-3-1611 [NA, PIC], gland steam header pressure, and Control Room alarm E 5/5 [NA, PA] (turbine gland seal low pressure set at 2 psig) were not available during the clearance evolution.
The pressure indicator and alarm receive input from PT-3-3417. If the E 5/5 alarm had come in, operators would have identified the source of air inleakage before indication of loss of vacuum.
ANALYSIS OF SAFETY SIGNIFICANCE Decreasing condenser vacuum caused a turbine trip which resulted in the automatic reactor trip. Plant response to the decrease in condenser vacuum and reactor trip was as expected. As a result, the safety significance of the event is considered low.
CORRECTIVE ACTIONS
Corrective actions are documented in AR 1847369 and include the following:
- 1. Revise plant procedure 3/4-NOP-089.01, Turbine Gland Seals and High Pressure Cylinder Heating, to include guidance for bypassing spillover valves.
- 2. Implement an improvement plan to reinforce operational standards.
- 3. Perform a review of bypass valves of control valves in the gland seal and cylinder heating systems that do not have existing procedural guidance for being placed in-service, and develop procedural guidance to control this action.
- 4. Brief appropriate Operations personnel on proper identification of Control Room deficiencies during screening of work orders.
FAILED COMPONENTS IDENTIFIED: None
PREVIOUS SIMILAR EVENTS
None
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| 05000251/LER-2013-001, Regarding Power Operated Relief Valve Inoperable for Greater than Allowed Outage Time Due to Lifted Leads | Regarding Power Operated Relief Valve Inoperable for Greater than Allowed Outage Time Due to Lifted Leads | 10 CFR 50.73(a)(2)(iv)(A), System Actuation
10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
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)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)(x)
10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
10 CFR 50.73(a)(2)(viii)(A)
10 CFR 50.73(a)(2)(viii)(B) | | 05000250/LER-2013-001, Regarding Procedure Noncompliance Causes Incorrect Instrument Setting and Condition Prohibited by Technical Specifications | Regarding Procedure Noncompliance Causes Incorrect Instrument Setting and Condition Prohibited by Technical Specifications | 10 CFR 50.73(a)(2)(iv)(A), System Actuation
10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
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)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
10 CFR 50.73(a)(2)(viii)(A)
10 CFR 50.73(a)(2)(viii)(B) | | 05000251/LER-2013-002, Reactor Trip Due to Loss of Offsite Power Resulting from Generator Testing | Reactor Trip Due to Loss of Offsite Power Resulting from Generator Testing | 10 CFR 50.73(a)(2)(iv)(A), System Actuation
10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
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)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)(x)
10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
10 CFR 50.73(a)(2)(viii)(A)
10 CFR 50.73(a)(2)(viii)(B) | | 05000250/LER-2013-002, Regarding Automatic Reactor Trip Due to Low Condenser Vacuum | Regarding Automatic Reactor Trip Due to Low Condenser Vacuum | 10 CFR 50.73(a)(2)(iv)(A), System Actuation
10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
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)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)(x)
10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
10 CFR 50.73(a)(2)(viii)(A)
10 CFR 50.73(a)(2)(viii)(B) | | 05000250/LER-2013-003, Regarding Manual Reactor Trip Due to Increasing Reactor Coolant Pump Seal Leakage | Regarding Manual Reactor Trip Due to Increasing Reactor Coolant Pump Seal Leakage | 10 CFR 50.73(a)(2)(iv)(A), System Actuation
10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
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)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)(x)
10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
10 CFR 50.73(a)(2)(viii)(A)
10 CFR 50.73(a)(2)(viii)(B) | | 05000250/LER-2013-004, Safety Injection Flow Path Not Isolated Due to Manual Valve Out of Position | Safety Injection Flow Path Not Isolated Due to Manual Valve Out of Position | 10 CFR 50.73(a)(2)(iv)(A), System Actuation
10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
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)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)(x)
10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
10 CFR 50.73(a)(2)(viii)(A)
10 CFR 50.73(a)(2)(viii)(B) | | 05000250/LER-2013-005, Reactor Trip Due to Turbine Header Pressure Spike While Testing Turbine Control Valves | Reactor Trip Due to Turbine Header Pressure Spike While Testing Turbine Control Valves | 10 CFR 50.73(a)(2)(iv)(A), System Actuation
10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
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)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)(x)
10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
10 CFR 50.73(a)(2)(viii)(A)
10 CFR 50.73(a)(2)(viii)(B) | | 05000250/LER-2013-006, Regarding Reactor Protection and Auxiliary Feed Water System Actuations Due to Trip of Operating Feed Water Pumps | Regarding Reactor Protection and Auxiliary Feed Water System Actuations Due to Trip of Operating Feed Water Pumps | 10 CFR 50.73(a)(2)(iv)(A), System Actuation
10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
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)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)(x)
10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
10 CFR 50.73(a)(2)(viii)(A)
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10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
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)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)(x)
10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
10 CFR 50.73(a)(2)(viii)(A)
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10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
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)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)(x)
10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
10 CFR 50.73(a)(2)(viii)(A)
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10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
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)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)(x)
10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
10 CFR 50.73(a)(2)(viii)(A)
10 CFR 50.73(a)(2)(viii)(B) |
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