05000325/LER-2010-001, Regarding Reactor Core Isolation Cooling (RCIC) Manually Started to Maintain RPV Level Following Pre-planned Scram
| ML101250303 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 04/27/2010 |
| From: | Wills E Carolina Power & Light Co, Progress Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BSEP 10-0047 LER 10-001-00 | |
| Download: ML101250303 (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)(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 |
| 3252010001R00 - NRC Website | |
text
Progress Energy "APR 2 7 2010 SERIAL: BSEP 10-0047 10 CFR 50.73 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Brunswick Steam Electric Plant, Unit No* 1 Renewed Facility Operating License No. DPR-71 Docket No. 50-325 Licensee Event Report 1-2010-001 Ladies and Gentlemen:
In accordance with the Code of Federal Regulations, Title 10, Part 50.73,-Carolina Power
& Light Company, now doing business as Progress EnergyCarolinas, Inc:, submits.the enclosed Licensee Event Report (LER). This report fulfillsthe requirementfor a written report within sixty (60) days of a reportable occurrence.
Please refer any questions regarding this submittal to Ms. Annette Pope,-Supervisor -
Licensing/Regulatory Programs, at (910) 457-2184.
Sincerely, Edward L. Wills, Jr.
Plant General Manager Brunswick Steam Electric Plant LJG/ljg
Enclosure:
Licensee Event Report Progress Energy Carolinas, Inc.
Brunswick Nuclear Plant PO Box 10429 Southport, NC 28461
Document Control Desk BSEP 10-0047 / Page 2 cc (with enclosure):
U. S. Nuclear Regulatory Commission, Region I1 ATTN: Mr. Luis A. Reyes, Regional Administrator Marquis One Tower 245 Peachtree Center Ave. N.E., Suite 1200 Atlanta, GA 30303-1257 U. S. Nuclear Regulatory Commission ATTN: Mr. Philip B. O'Bryan, NRC Senior Resident Inspector 8470 River Road Southport, NC 28461-8869 U. S. Nuclear Regulatory Commission (Electronic Copy Only)
ATTN: Mrs. Farideh E. Saba (Mail Stop OWFN 8G9A) 11555 Rockville Pike Rockville, MD 20852-2738 Chair - North Carolina Utilities Commission P.O. Box 29510 Raleigh, NC 27626-0510
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010 (9-2007)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 1. FACILITY NAME
- 2..DOCKETNUMBER T
PAGE Brunswick Steam Electric Plant (BSEP), Unit 1 05000325 1 of 4
- 4. TITLE Reactor Core Isolation Cooling (RCIC) Manually Started to Maintain RPV Level Following Pre-planned Scram.
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED I
FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR NUMBER I NO.
D 05000 FACILITY NAME DOCKET NUMBER 02 27 2010 2010 - 001 - 00 04 27 2010 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
EU 20.2201(b)
EU 20.2203(a)(3)(i)
EU 50.73(a)(2)(i)(C)
E] 50.73(a)(2)(vii) 3 E 20.2201(d)
EU 20.2203(a)(3)(ii)
EU 50.73(a)(2)(ii)(A)
EU 50.73(a)(2)(viii)(A)
[U 20.2203(a)(1)
[U 20.2203(a)(4)
EU 50.73(a)(2)(ii)(B)
E] 50.73(a)(2)(viii)(B)
EU 20.2203(a)(2)(i)
[U 50.36(c)(1)(i)(A)
EU 50.73(a)(2)(iii)
[I 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL [U 20.2203(a)(2)(ii)
Ul 50.36(c)(1)(ii)(A)
E 50.73(a)(2)(iv)(A)
[U 50.73(a)(2)(x)
[U 20.2203(a)(2)(iii)
EU 50.36(c)(2)
EU 50.73(a)(2)(v)(A)
EU 73.71(a)(4) 000 [1 20.2203(a)(2)(iv)
EU 50.46(a)(3)(ii)
[U 50.73(a)(2)(v)(B)
U 73.71(a)(5)
Ul 20.2203(a)(2)(v)
EU 50.73(a)(2)(i)(A)
[U 50.73(a)(2)(v)(C)
U OTHER U 20.2203(a)(2)(vi)
[U 50.73(a)(2)(i)(B)
E] 50.73(a)(2)(v)(D)
Specify in Abstract below or I in signal closed all of the PCIVs that were open at the time of the expected actuation. All other affected plant equipment and systems responded as designed.
After the expected coolant level shrink, reactor coolant level increased, as expected, above the RFP high level trip setpoint, and the IA RFP tripped at 0118 hours0.00137 days <br />0.0328 hours <br />1.951058e-4 weeks <br />4.4899e-5 months <br /> on high reactor water level of 208 inches. At approximately 0143 hours0.00166 days <br />0.0397 hours <br />2.364418e-4 weeks <br />5.44115e-5 months <br />, with RPV level restored to normal, the lA RFP was restarted and began injecting into the RPV. The combined flows from the RFP, Condensate Booster Pumps (CBP) [SD], and Reactor Water Cleanup (RWCU) [CE] reject resulted in the Hotwell level increasing above normal. This resulted in the RFP high turbine casing drain level alarm (i.e., 1-UA-04 1-5, RFP A Turb Drains Level Hi).
With the 1A RFP turbine casing drain level reaching 8 inches and rising, the 1A RFP was manually tripped due to high turbine casing drain level.
At this point, with the 1B RFP not immediately available due to being out of service for maintenance, the RPV level continued to lower. Operators raised Control Rod Drive [AA] flow to try to maintain normal RPV level, and established a RPV level of 180 inches for injecting with RCIC. At 0159 hours0.00184 days <br />0.0442 hours <br />2.628968e-4 weeks <br />6.04995e-5 months <br />, with RPV level at 180 inches and lowering, Operators manually started the RCIC system to maintain RPV coolant level. The RCIC system maintained RPV coolant level until the lB RFP could be returned to service. At 0220 hours0.00255 days <br />0.0611 hours <br />3.637566e-4 weeks <br />8.371e-5 months <br />, the lB RFP was started, and the RCIC system was subsequently shutdown at 0306 hours0.00354 days <br />0.085 hours <br />5.059524e-4 weeks <br />1.16433e-4 months <br />.
Event Cause
When the reactor pressure is above 350 psig, a RFP should be available for RPV level control. The root cause of this event is that the Operators made the redundant RFP unavailable while the RPV pressure was still above 350 psig. When the IA RFP had to be secured due to the high turbine casing drain level, Operators had to start the RCIC system to control vessel level since the redundant lB RFP was unavailable due to maintenance. A contributing cause to this event was that licensed operator training did not provide sufficient detail for the interrelations between the condenser hotwells and the components that input to them on a shutdown unit.
Safety Assessment
The safety significance of this event is considered minimal. In addition to RCIC, the Emergency Core Cooling Systems and the Automatic Depressurization System were operable and available to provide adequate core cooling if needed. Operators maintained RPV level within the normal band while RCIC was used for level control. All systems functioned as designed.
Corrective Actions
The following corrective action to prevent recurrence will be taken.
o Revise 1(2)OP-32, "Condensate and Feedwater System Operating Procedure," to add a Caution that, during a reactor shutdown, a RFP should not be made unavailable before Reactor Pressure is less than 350 psig, except in case of an emergency, or if removing a RFP from service to conduct required maintenance while at power. This action is scheduled to be completed by May 27, 2010.
Additional corrective actions include the following.
o Revise 1 (2)OP-29, "Circulating Water System," to include a note with information about the inputs to the hotwells, including RWCU reject, Condensate Pump minimum flow, CBP minimum flow, and RFP minimum flow. This action is scheduled to be completed by May 27, 2010.
- Identify the performance gaps in Licensed Operator training in relation to this event, and include a case study of this event, to improve Operator training. This action is scheduled to be completed by May 27, 2010.
Previous Similar Events
A review of LERs and corrective action program condition reports for the past three years identified the following similar previous occurrences.
LER 1-2009-005, dated November 19, 2009, documents a condition where Unit 1 received valid actuations of the Reactor Protection System (RPS) and the Primary Containment Isolation System (PCIS) while Operators were placing the High Pressure Coolant Injection (HPCI) system in service for reactor pressure control. The root cause was determined to be an inadequate procedure, and the corrective action was to revise the procedure to include plant conditions with low decay heat and low RPV pressure when using HPCI in pressure control mode. Thus, the corrective actions associated with LER 1-2009-005 could not have reasonably been expected to prevent the condition reported in this LER.
Commitments
No regulatory commitments are contained in this report.
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