05000263/LER-2010-006, Mode Change Made with PCIVs Inoperable
| ML103570031 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 12/22/2010 |
| From: | O'Connor T Xcel Energy, Northern States Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-MT-083 LER 10-006-00 | |
| Download: ML103570031 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 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)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 2632010006R00 - NRC Website | |
text
@ Xcel EnergyB December 22,201 0 Monticello Nuclear Generating Plant 2807 W County Road 75 Monticello, MN 55362 L-MT-10-083 10 CFR 50.73 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Monticello Nuclear Generating Plant Docket No. 50-263 Renewed License No. DPR-22 LER 201 0-006, Mode Chanqe Made With PClVs Inoperable The Licensee Event Report (LER) for this occurrence is attached.
Summaw of Commitments This letter contains no new commitments and no revisions to existing commitments.
sitevice President, Monticello Nuclear Generating Plant Northern States Power - Minnesota Enclosure cc:
Administrator, Region Ill, USNRC Project Manager, Monticello, USNRC Resident Inspector, Monticello, USNRC
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (1 0-201 0)
LICENSEE EVENT REPORT (LER)
(See reverse for required number of digitslcharacters for each block)
APPRoVEDB'f OMB NO 3150-0104 EXPIRES 10/31/2013 Est~mated, the NRC may not conduct or sponsor, and a person is not requlred to respond to, h e
~nformatton collectlon
- 3. PAGE 1 OF3
- 1. FACILITY NAME Monticello Nuclear Generating Plant
- 2. DOCKET NUMBER 05000 263
- 4. TITLE Mode Change Made with PClVs Inoperable
- 5. EVENT DATE
- 9. OPERATING MODE 2
- 10. POWER LEVEL 0%
- 6. LER NUMBER
- 7. REPORT DATE MONTH 11
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 5: (Check all that apply)
C]
20.2201(b)
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20.2203(a)(3)(i)
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50,73(a)(2)(i)(C)
[7 50,73(a)(2)(vli)
[7 20.2201(d)
C]
20.2203(a)(3)(ii)
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50,73(a)(2)(ii)(A)
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50 73(a)(2)(viii)(A)
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20.2203(a)(I) 20.2203(a)(4)
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50.73(a)(2)(ii)(B)
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50 73(a)(2)(viii)(B)
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20.2203(a)(2)(i)
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50.36(c)(l)(i)(A)
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50.73(a)(2)(iii)
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50.73(a)(2)(ix)(A)
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20.2203(a)(2)(ii)
[7 50,36(c)(l)(ii)(A)
C]
50,73(a)(2)(iv)(A)
[7 50.73(a)(2)(x)
[7 20.2203(a)(2)(ili)
[7 50.36(~)(2)
[7 50 73(a)(2)(v)(A) 73.71 (a)(4)
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20.2203(a)(2)(iv)
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50.46(a)(3)(ii)
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50 73(a)(2)(v)(B)
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73.71 (a)(5)
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20.2203(a)(2)(v)
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50.73(a)(2)(i)(A) 50 73(a)(2)(v)(C)
[7 OTHER C]
20.2203(a)(2)(vi)
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50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)
Speclfy In Abstract below or In 8. OTHER FACILITIES INVOLVED SEQUENTIAL MONTH I 2 FACILITY NAME FACILITY NAME REV DAY 22 DOCKET NUMBER 05000 DOCKET NUMBER 05000 YEAR I NUMBER I NO 2010-006
- - 00 DAY 22 YEAR 2010
- 12. LICENSEE CONTACT FOR THlS LER YEAR 2010 NAME Steven K. Speight TELEPHONE NUMBER (Include Area Code) 763.271.7636 REPORTABLE TO EPlX YEAR ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On November 22, 2010 the plant was in Mode 4 with preparations for startup in progress. The duty crew transferred the reactor vent path to the path through Main Steam Line Drain valves MO-2373 (Main Steam Line Drain - Inboard), MO-2374 (Main Steam Line Drain - Outboard), and MO-2565 (Steam Line Drain Orifice Bypass). The valves were opened and their associated breakers were tagged open. At 1647, the change from Mode 4 to Mode 2 was completed. At 1700, a page announcement was made that Reactor Startup was commencing. The oncoming Operations Work Control Manager recalled helping tag open MO-2373 and MO-2374, which are Primary Containment Isolation Valves (PCIV), on the previous night shift. He called the control room to verify the valves had been restored prior to the mode change. He immediately notified the duty crew and Operations Management of the Technical Specification violation when he was informed they had not been restored. Startup activities were halted pending investigation and resolution of the issue. PCIV operability was restored. Startup activities were recommenced later in the shift after prerequisites had been verified and a stand down conducted.
NRC FORM 366 (10-2010)
CAUSE
CAUSE
- 14. SUPPLEMENTAL REPORT EXPECTED 0 YES (If yes, complete 15. EXPECTED SUBMISSION DATE).
O NO SYSTEM SYSTEM COMPONENT
- 15. EXPECTED SUBMISSION DATE COMPONENT MANU-FA CTURER MANU-FACTURER MONTH REPORTABLE TO EPlX DAY
I LICENSEE EVENT REPORT (LER) I U.S. NUCLEAR REGULATORY COMMlSSlON I
CONTINUATION SHEET I
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- 6. LER NUMBER
- 3. PAGE 05000 263 YEAR SEQUENTIAL REV Monticello Nuclear Generating Plant NUMBER NO.
2 0 F 3 I
1 2010 -
006
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EVENT DESCRIPTION
On November 22, the site transferred the Reactor Plant Vessel (RPV) vent path to the Main Steam Line Drains in preparation for drywell closeout. As part of this, the breakers for MO-2373 and MO-2374 were tagged open to de-energize the valves.
Later that day, startup preparations were commenced. Although discussions concerning the status of the PClVs were held, no action was taken as operators assumed the Startup Checklist would ensure the proper condition of the PClVs prior to Mode change. The Duty Shift Manager improperly signed off the prerequisites that Primary Containment Operability was verified on the Startup Checklist, including specific signatures for Tech Spec 3.6.1.I (Primary Containment) and 3.6.1.3 (PCIVs). The inappropriate sign off was caused by a belief that Operability only mattered in the Mode of Applicability.
At 1647, the Mode Change from Mode 4 to Mode 2 was completed by positioning the Mode Switch from REFUEL to START & HOT STBY.
Shortly after hearing a page announcement that Reactor Startup was commencing, the Operations Work Control Manager, who was arriving for night shift support, recalled that he had helped tag open MO-2373 and MO-2374 on the previous night shift. He called the control room to verify that the valves had been restored prior to the mode change. He was informed that the valves remained tagged open with control power removed. Recognizing the TS violation, he immediately informed the duty crew and Operations Management.
Startup activities were halted pending investigation and resolution of the issue. Startup activities were recommenced after prerequisites had been verified and a standdown conducted to discuss the event.
EVENT ANALYSIS
The event is reportable to the NRC under 10 CFR 50.73(a)(2)(v)(C and D) - Event or Condition that could have Prevented Fulfillment of a Safety unction. The station reported the event to the NRC under 10 CFR 50.72 (b)(3)(v)(C and D) on November 22, 201 0.
This event is considered a Safety System Functional Failure because the primary containment system would have been prevented from fulfilling its safety function with the two main steam drain PCIVs tagged open.
onticello Nuclear Generating Plant here were no nuclear, radiological or industrial safety significant consequences related to this event.
assessment, even though the plant was shut down for the event. The ICDP calculation resulted in 1.21 E-11 and the ILERP calculation resulted in 1.23E-11. Both are below the threshold for risk significance. The safety significance in terms of reactor safety and radiological release to the environment during this event is considered to be very low.
Main steam line drain valves (MO-2373 and MO-2374) (which are PCIVs) were de-energized in the OPEN position to establish a reactor vent path during a short outage. Documentation barriers for PClV status were not properly utilized, and the duty Operations crew failed to ensure that the valves were restored prior to transitioning to Mode 2. This was a cognitive error and actions contrary to procedures were taken.
CORRECTIVE ACTION
The following actions were taken or are planned and will be tracked in the Monticello Corrective Action Suspended the startup until all prerequisites were verified and a standdown conducted Removed responsible personnel from watchstanding pending remediation A Root Cause Evaluation Revise prestart checklists andlor procedures as applicable Review, and revise as necessary, guidance for acceptance of exceptions to prestart checklists and methods of tracking inoperable equipment while not in the mode of applicability
PREVIOUS SIMILAR EVENTS
There were no similar previous events in the last three years.