05000285/LER-2006-004, Re Loss of Shutdown Cooling Redundant Train Due to Valve Mispositioning

Re Loss of Shutdown Cooling Redundant Train Due to Valve Mispositioning

ML063250339
Person / Time
Site:	Fort Calhoun
Issue date:	11/10/2006
From:	Bannister D Omaha Public Power District
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LIC-06-0119 LER-06-004-00
Download: ML063250339 (6)

LER-2006-004, Re Loss of Shutdown Cooling Redundant Train Due to Valve Mispositioning

Event date:
Report date:
Reporting criterion:	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)(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
2852006004R00 - NRC Website

text

mmi n rm Omaha Public Power District 444 South 16th Street Mall Omaha NE 68102-2247 November 10, 2006 LIC-06-0119 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station P1-137 Washington, DC 20555

Reference:

Subject:

Docket No. 50-285 Licensee Event Report 2006-004 Revision 0 for the Fort Calhoun Station Please find attached Licensee Event Report 2006-004, Revision 0, dated November 10, 2006.

This report is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(B). If you should have any questions, please contact me.

Sincerely, D. J. Bannister Plant Manager - Fort Calhoun Station DJB/DKG/dkg Attachment c:INPO Records Center Employment with Equal Opportunity

NRC FORM 366 U.S. NUCLEAR REGULATORY COMI APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/30/2007 (6-2004.)

Estimated burden per response to comply with this mandatory collection request: 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br />.

Reported lessons learned are incorporated into the licensing process and fed back to industry.

Send comments regarding burden estimate to the Records and FOIA/Privacy Service Branch (T-5 F52), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail LICENSEE EVENT REPORT (LER) to infocollects@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-1 0202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the (See reverse for required number of information collection.

digits/characters for each block)

3. PAGE Fort Calhoun Station 05000285 1 OF 5

4. TITLE Loss of Shutdown Cooling Redundant Train Due to Valve Mispositioning

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED

FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL REV 05000 NUMBER NO.

MONTH DAY YEAR05000 FACILITY NAME DOCKET NUMBER 09 12 2006 2006 004 00 11 10 2006 05000

9. OPERATING

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)

MODE

[-] 20.2201(b)

El 20.2203(a)(3)(i)

El 50.73(a)(2)(i)(C)

El 50.73(a)(2)(vii)

[1 20.2201(d)

El 20.2203(a)(3)(ii)

El 50.73(a)(2)(ii)(A) 0l 50.73(a)(2)(viii)(A) 5 El 20.2203(a)(1)

El 20.2203(a)(4)

El 50.73(a)(2)(ii)(B) 0l 50.73(a)(2)(viii)(B)

[] 20.2203(a)(2)(i)

El 50.36(c)(1)(i)(A)

El 50.73(a)(2)(iii)

[] 50.73(a)(2)(ix)(A)

10. POWER LEVEL F1 20.2203(a)(2)(ii)

El 50.36(c)(1)(ii)(A)

El 50.73(a)(2)(iv)(A)

El 50.73(a)(2)(x)

El 20.2203(a)(2)(iii)

El 50.36(c)(2)

El 50.73(a)(2)(v)(A) 0l 73.71(a)(4)

[] 20.2203(a)(2)(iv)

[] 50.46(a)(3)(ii)

[] 50.73(a)(2)(v)(B)

El 73.71(a)(5) 0 El 20.2203(a)(2)(v)

El 50.73(a)(2)(i)(A) 0l 50.73(a)(2)(v)(C)

El OTHER El 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B)

El 50.73(a)(2)(v)(D)

Specify in Abstract below or in (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)

A qualitative assessment was performed by evaluating different failure scenarios that could lead to core damage. Failure of the shutdown cooling heat exchanger, AC-4A, would have caused a loss of shutdown cooling. Failures identified for AC-4A were loss of CCW to the operating heat exchanger or a failure of the manual SI inlet or outlet valves for AC-4A. In either failure mode it would be extremely unlikely as a transfer closed event would have to occur for there to be a failure to provide cooling. A loss of CCW would require either of the CCW supply valves to transfer closed. Both valves fail open on loss of air or power. A spurious signal would be required to close the valves. For the manual isolation valves, this would require a disc to stem separation. In either failure event, this would be extremely remote.

PREVIOUS SIMILAR EVENTS

There have not been any other LERs for valve mispositioning events. However, there have been valve mispositioning events noted in the corrective action program. Condition reports included an event when the safety injection refueling water tank (SIRWT) level was rising when no fill evolution was in progress (CR 200501832), containment sump level was observed to be rising when fill was in progress (CR 200501561), and the spent regenerate tank was relieved when the shutdown cooling purification was being placed back in service (CR 200500906). It was determined that associated valves were found in open positions instead of expected closed positions. These events were of minimal safety significance.

Mispositioning events are routinely tracked and trended to identify adverse trends. These and other events have been reviewed to determine if there is an adverse trend with regards to Operations valve mispositions. The tracking and trending calculated the number of mispositions per 10,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> worked and the mispositions per 1000 tags issued. This review determined that there is not an adverse trend in Operations valve mispositionings.

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