LER-2013-003, Regarding Manual Reactor Scram Due to Main Electro-Hydraulic Control System Failure |
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| Report date: |
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| Reporting criterion: |
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)(iv)(A), System Actuation
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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| 4612013003R00 - NRC Website |
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A Exelon Generation, Clinton Power Station 8401 Power Road Clinton, IL 61727 U-604126 10 CFR 50.73 June 24, 2013 SRRS 5A.108 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461
Subject:
Licensee Event Report 2013-003-00 Enclosed is Licensee Event Report (LER) No. 2013-003-00: Manual Reactor SCRAM Due To Main Electro-Hydraulic Control System Failure. This report is being submitted in accordance with the requirements of 10 CFR 50.73.
There are no regulatory commitments contained in this report.
Should you have any questions concerning this report, please contact Ms. Kathy Ann Baker, Regulatory Assurance Manager, at (217)-937-2800.
Respectf ully, William G. Noll Site Vice President Clinton Power Station RSF/blf
Enclosures:
Licensee Event Report 2013-003-00 cc:
Regional Administrator - NRC Region III NRC Senior Resident Inspector - Clinton Power Station Office of Nuclear Facility Safety - IEMA Division of Nuclear Safety
K -
NFRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the digits/characters for each block) information collection.
- 3. PAGE Clinton Power Station, Unit 1 05000461 1 OF 4
- 4. TITLE Manual Reactor SCRAM Due To Main Electro-Hydraulic Control System Failure
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO.
MONTH DAY YEAR 05000 FACILITY NAME DOCKET NUMBER 04 26 2013 2013 003 00 06 24 2013 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
E0 20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
[I 50.73(a)(2)(vii)
El 20.2201(d)
El 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)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B) 0_ 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
[I 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii) 0l 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
[0 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71(a)(4) 097
[
20.2203(a)(2)(iv) 0l 50.46(a)(3)(ii) 0 50.73(a)(2)(v)(B)
El 73.71(a)(5)
[] 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
[I 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi)
El 50.73(a)(2)(i)(B)
[I 50.73(a)(2)(v)(D)
Specify in Abstract below or in
C. CAUSE OF EVENT
The cause analysis identified that the most probable cause for this event was inadequate work instructions in the 2008 work order that led to a failure to install appropriate lock washers on the shutoff valve connection to Main Steam Turbine Control Valve Number 4, resulting in the socket head cap screws becoming loose due to the dynamic service loading on the shutoff valve connection over the five years since installation, ultimately failing due to fatigue.
A contributing cause for this event is the mounting bolt installation kits for the shutoff valves came with the cap screws but did not have any lock washers for the shutoff valve connection. This may have led the installer to assume the kit was complete with all parts needed to install (i.e., human error trap).
D. SAFETY CONSEQUENCES
The actuation of the Reactor Protection System placed the plant in a safe and stable condition. There were no plant safety limits exceeded, and no other Engineered Safety Feature actuations, and risk significance was low. Safety-related systems functioned correctly in response to this event with critical plant parameters remaining within the bounds of plant design, Technical Specifications, Updated Safety Analysis Report, Offsite Dose Calculation Manual, and Core Operating Limits Report. The affected system (i.e., TG system) is not-safety related.
No loss of safety function occurred during this event.
E. CORRECTIVE ACTIONS
The hydraulic shutoff valve on Control Valve 1TGCV4 and its associated cap screws were replaced and torqued to the required 25 foot-pounds, and the EHC system was pressurized to verify it was free of leaks.
As an extent of condition review, the bolting torque for all hydraulic shutoff valves for turbine control valves, stop valves, and intermediate valves was verified to be at the proper torque value of 25 foot-pounds.
Work Orders are being created to install lock washers during the next refueling outage on the shutoff valve for 1TGCV4 and, as part of the extent of condition review, on the shutoff valve for turbine control valve number 2 (1TGCV2) which was also found without lock washers. The other turbine control valves (1TGCV1 and 1TGCV3) were found to have the required lock washers installed.
The model work order for replacing shutoff valves on control valves will be revised to add shutoff valve Original Equipment Manufacturer (OEM) installation requirements including job steps to validate that the proper lock washers have been installed.
A review of the model work orders used to install the hydraulic shutoff valves on the turbine control valves and combined intermediate valves was performed and found that the work orders included specific steps to install the lock washers. However, work orders will be created to validate lock washers are installed on all hydraulic shutoff valves on main steam valves.
The station will ensure the bill of materials in model work orders for installing shutoff valves on control valves specifies the appropriate lock washers for the application.
F.
PREVIOUS OCCURRENCES
A review for previous occurrences did not identify similar events at Clinton Power Station.
G. COMPONENT FAILURE DATA
Component Description: Stainless steel shut-off valve for EHC System on main turbine steam valves Manufacturer: General Electric Company Manufacturer Part Number: 0843E704G0003
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| | | Reporting criterion |
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| 05000461/LER-2013-001, Inadequate Risk Identification Results in Loss of Safety Function | Inadequate Risk Identification Results in Loss of Safety Function | 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) | | 05000461/LER-2013-002, Deficient Fuse Causes Main Generator Trip, Turbine Trip and Reactor Scram | Deficient Fuse Causes Main Generator Trip, Turbine Trip and Reactor Scram | 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) | | 05000461/LER-2013-003, Regarding Manual Reactor Scram Due to Main Electro-Hydraulic Control System Failure | Regarding Manual Reactor Scram Due to Main Electro-Hydraulic Control System Failure | 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) | | 05000461/LER-2013-004, Regarding Loss of Emergency Diesel Room Ventilation Due to Damper Hydramotor Failure | Regarding Loss of Emergency Diesel Room Ventilation Due to Damper Hydramotor Failure | 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)(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) | | 05000461/LER-2013-005, Regarding Safe Shutdown Analysis Noncompliance for Diesel Generator Room Ventilation | Regarding Safe Shutdown Analysis Noncompliance for Diesel Generator Room Ventilation | 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) | | 05000461/LER-2013-006, Implementation of Enforcement Guidance Memorandum (EGM) 11-003, Revision 1 | Implementation of Enforcement Guidance Memorandum (EGM) 11-003, Revision 1 | 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) | | 05000461/LER-2013-007, Regarding Failed to Enter Tech Spec Action for Exceeding Reactor Coolant Heatup Rate | Regarding Failed to Enter Tech Spec Action for Exceeding Reactor Coolant Heatup Rate | 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) | | 05000461/LER-2013-008, Regarding Failure of Division I Transformer Leads to Isolation of Instrument Air Supply to Containment, Lowering Scram Pilot Air Header Pressure, and Manual Reactor Scram | Regarding Failure of Division I Transformer Leads to Isolation of Instrument Air Supply to Containment, Lowering Scram Pilot Air Header Pressure, and Manual Reactor Scram | 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) | | 05000461/LER-2013-009, Regarding Software Errors in New Digital Feedwater Control System Result in Manual Reactor Scram Due to Approaching High Reactor Pressure Vessel Water Level Setpoint | Regarding Software Errors in New Digital Feedwater Control System Result in Manual Reactor Scram Due to Approaching High Reactor Pressure Vessel Water Level Setpoint | 10 CFR 50.73(a)(2)(iv)(A), System Actuation
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)(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)
10 CFR 50.73(a)(2)(viii)(A)
10 CFR 50.73(a)(2)(viii)(B) |
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