05000412/LER-2008-001, Regarding Unplanned Actuation of the Auxiliary Feedwater System During Plant Startup
| ML082070078 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 07/23/2008 |
| From: | Sena P FirstEnergy Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-08-222 LER 08-01-00 | |
| Download: ML082070078 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| 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) 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 10 CFR 50.73(a)(2)(iv)(B)(6) |
| 4122008001R00 - NRC Website | |
text
FENOC FirstEnergy Nuclear Operating Company Peter P. Sena IIl 724-682-5234 Site Vice President Fax: 724-643-8069 July 23, 2008 L-08-222 10 CFR 50.73 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 LER 2008-001-00 Enclosed is Licensee Event Report (LER) 2008-001-00, "Unplanned Actuation of the Auxiliary Feedwater System During Plant Startup."
There are no regulatory commitments contained in this submittal. Any actions discussed in this document that represent intended or planned actions are described for the NRC's information, and are not regulatory commitments.
If you have questions or require additional information, please contact Mr. Colin P.
Keller, Manager, Regulatory Compliance at 724-682-4284.
Sincerely, Peter P. Sena III Attachment c:
Mr. S. J. Collins, NRC Region I Administrator Mr. D. L. Werkheiser, NRC Senior Resident Inspector Ms. N. S. Morgan, NRR Project Manager INPO Records Center (via electronic image)
Mr. L. E. Ryan (BRP/DEP)
A4 ?7
NRC FORM 366 (9-2007)
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
(See reverse for required number of digits/characters for each block)
APPROVED BY OMB NO. 3150-0104 EXPIRES 08/31/2010
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 1. FACILITY NAME DOCKET NUMBER
- 3. PAGE Beaver Valley Power Station Unit Number 2 0500 4121jo
- 4. TITLE Unplanned Actuation of the Auxiliary Feedwater System During Plant Startup
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER I
NO.
MONTH DAY YEAR None 05 24 2008 2008 001 00 07 FACILITY NAME
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 0 20.2201(b)
F] 20.2203(a)(3)(i)
[
50.73(a)(2)(i)(C)
LI 50.73(a)(2)(vii) 1
[] 20.2201(d)
Ej 20.2203(a)(3)(ii)
E] 50.73(a)(2)(ii)(a)
E] 50.73(a)(2)(viii)(A)
E] 20.2203(a)(1)
[] 20.2203(a)(4)
E] 50.73(a)(2)(ii)(B)
E] 50.73(a)(2)(viii)(B)
E] 20.2203(a)(2)(i)
E] 50.36(c)(1)(i)(A)
LI 50.73(a)(2)(iii)
[: 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL E] 20.2203(a)(2)(ii)
E] 50.36(c)(1)(ii)(A)
E 50.73(a)(2)(iv)(A)
E] 50.73(a)(2)(x)
[] 20.2203(a)(2)(iii)
LI 50.36(c)(2)
F1 50.73(a)(2)(v)(A)
I] 73.71(a)(4) 16 E] 20.2203(a)(2)(iv)
E] 50.46(a)(3)(ii)
LI 50.73(a)(2)(v)(B)
LI 73.71(a)(5)
E] 20.2203(a)(2)(v)
E] 50.73(a)(2)(i)(A)
LI 50.73(a)(2)(v)(C)
LI OTHER Specify in Abstract below E] 20.2203(a)(2)(vi)
LI 50.73(a)(2)(i)(B)
LI 50.73(a)(2)(v)(D) or in At approximately 09:40, the control room crew reset the Feedwater Isolation signal and restarted the 'B' main feedwater pump. At approximately 09:41, the motor-driven Auxiliary Feedwater System pumps were stopped and placed back into automatic control. At approximately 09:43, normal feedwater flow was re-established to the steam generators.
The reactor remained stable at approximately 16% reactor power.
REPORTABILITY
The unplanned automatic initiation of a Feedwater Isolation signal and the resultant automatic initiation of the Auxiliary Feedwater System due to tripping of the Main Feedwater pump was an event reportable pursuant to 10 CFR 50.72(b)(3)(iv)(A) as a valid actuation of the PWR emergency feedwater system listed in 10 CFR 50.72(b)(3)(iv)(B)(6). The NRC was notified of this event at 15:06 on May 24, 2008 (NRC Event Notification 44239).
Similarly, this event is reportable pursuant to 10 CFR 50.73(a)(2)(iv)(A) as a valid actuation of the emergency feedwater system listed in 10 CFR 50.73(a)(2)(iv)(B)(6).
CAUSE OF EVENT
The Operations crew on duty during this event was unfamiliar with steam generator level control using bypass feed regulating valves at low power with the main turbine not latched and in response made excessive manual changes in feedwater flowrate. There were numerous broken barriers and causal factors that allowed this worker knowledge deficiency to exist. Since any one of these barriers and causal factors could have potentially prevented the inadvertent Auxiliary Feedwater System automatic initiation, the root cause is considered to be the common factor in all of these issues. Thus, the root cause of this event is that the Operations Management Team, including the Shift Manager, failed to ensure the startup crew was staged for success in operating the plant in a low power configuration.
SAFETY IMPLICATIONS The safety significance of the feedwater isolation on May 24, 2008 was very low. Steam generator inventory remained above the low water level trip throughout this event and its restoration.
As designed, feedwater isolation occurred when the "A" steam generator indicated narrow range level reached the high level setpoint of greater than or equal to 92.2 percent.
Following initiation of the automatic feedwater isolation signal, all ESF equipment responded as expected. The running steam generator main feedwater pump tripped, the remaining steam generator bypass feedwater regulating valves closed, the Feedwater Containment Isolation Valves closed, and the two motor-driven Auxiliary Feedwater System pumps started, as designed. The feedwater isolation signal also closes the main feedwater regulating valves (which were already closed) and trips the Main Turbine (which was offline).
Following the unplanned actuation, the feedwater isolation signal was reset, normal feedwater flow was re-established via the "B" main feedwater pump, and auxiliary feedwater pumps were manually secured and placed back into automatic control. There were no adverse effects identified to the main steam system from the indicated high water level in the steam generators. The reactor remained stable at approximately 16% reactor power.
At the time of the BVPS Unit 2 feedwater isolation, the only out-of-service components modeled in the Unit 2 Probabilistic Risk Analysis were the "A" & "B" containment instrument air compressors, with containment instrument air being supplied from station instrument air through the open cross-tie valve 21AC-MOV131. Additionally, with the main turbine and generator offline, the breakers associated with the fast bus transfer function were still transferred to the off-site power supplies. Also, since the reactor power level was less than 40 percent, Anticipated Transients Without Scram (ATWS) concerns are not postulated. Using these assumptions and assuming a postulated Total Loss of Main Feedwater Initiating Event (i.e., setting the Probability to 1.0), the Conditional Core Damage Probability is very small.
Based upon the above, the safety significance of the event condition was very low.
CORRECTIVE ACTIONS
- 1.
The BVPS Licensed Operator Retraining program will be modified to include simulator and classroom sessions that address manual operations of the bypass feedwater regulating valves at low power level, with a periodic re-training frequency.
- 2.
Plant criteria on Just-In-Time (JIT) Training will be revised to require all control room crews and operators involved in plant startup/shutdown to attend the JIT Training.
- 3.
Supplemental actions will be performed based upon additional performance gap analysis and safety culture assessment results.
Completion of the above and other corrective actions are being tracked through the BVPS corrective action program.
PREVIOUS SIMILAR EVENTS
A review found no prior BVPS Unit 1 and one prior BVPS Unit 2 Licensee Event Report within the last ten years for an event involving an actuation of the Auxiliary Feedwater System due to high steam generator water level.
BVPS Unit 2 LER 2000-001, "ESF Actuation of Feedwater Isolation While Shutting the Plant Down for Refueling." This LER event resulted from lack of procedural clarity combined with simulation training not being consistent with actual plant response. The previous corrective actions were ineffective because 1) previous training to correct personnel knowledge errors was only performed one time, and 2) previous reinforcement of expectations/standards resulted in unclear expectations relative to the hierarchy of procedures.