05000285/LER-2011-001, Regarding Inadequate Flooding Protection Due to Ineffective Oversight

Regarding Inadequate Flooding Protection Due to Ineffective Oversight

ML110871994
Person / Time
Site:	Fort Calhoun
Issue date:	03/28/2011
From:	Reinhart J Omaha Public Power District
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LlC-11-0021 LER 11-001-00
Download: ML110871994 (5)

LER-2011-001, Regarding Inadequate Flooding Protection Due to Ineffective Oversight

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(v), Loss of Safety Function 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)(8) 10 CFR 50.73(a)(2)(viii)(8) 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)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)
2852011001R00 - NRC Website

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DjjjjD Omaha Public PowerOlslttct 444 South JrJh Street Mall Omaha, NE 68102-2247 LlC-11-0021 March 28, 2011 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Reference: Docket No. 50-285

Subject:

Licensee Event Report 2011-001, Revision 0, for the Fort Calhoun Station Please find attached Licensee Event Report 2011-001, Revision 0, dated, March 28, 2011. This report is being submitted pursuant to 10CFR50.73(a)(2)(v)(D). If you should have any questions, please contact me.

ff ey Reinhart Si e Vice President JAR/epm Attachment c:

E. E. Collins, Jr., NRC Regional Administrator, Region IV L. E. Wilkins, NRC Project Manager J. C. Kirkland, NRC Senior Resident Inspector INPO Records Center Employment with Equal Opportunity

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (10-2010)

LICENSEE EVENT REPORT (LER)

(See reverse for required number of digits/characters for each block)

APPROVED BY OMB: NO. 3150-0104 1::}\\,t"IHI::~: '0/;$1I~0';j

, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

1. FACILITY NAME Fort Calhoun Station

2. DOCKET NUMBER

13. PAGE 05000285 1 OF 4

4. TITLE Inadequate Flooding Protection Due To Ineffective Oversight

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR I SEQUENTIAL I REV NUMBER NO.

MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 05000 1

27 2011 2011 - 001 -

0 3

28 2011 FACILITY NAME DOCKET NUMBER 05000

9. OPERATING MODE 1

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) o 20.2201 (b) o 20.2203(a)(3)(i) o 50.73(a)(2)(i)(C) o 50.73(a)(2)(vii) o 20.2201 (d) o 20.2203(a)(3)(ii) o 50.73(a)(2)(ii)(A) o 50.73(a)(2)(viii)(A) o 20.2203(a)(1) o 20.2203(a)(4) o 50.73(a)(2)(ii)(8) o 50.73(a)(2)(viii)(8) o 20.2203(a)(2)(I) o 50.36(c)( 1 )(i)(A) o 50.73(a)(2)(iii) o 50.73(a)(2)(ix)(A) o 20.2203(a)(2)(10 o 50.36(c)(1)(il)(A) o 50.73(a)(2)(iv)(A) o 50.73(a)(2)(x) o 20.2203(a)(2)(iii) o 50.36(c)(2) o 5O.73(a)(2)(v)(A) o 73.71(a)(4) o 20.2203(a)(2)(lv) o 50.46(a)(3)(li) o 5O.73(a)(2)(v)(8) o 73.71(a)(5) o 20.2203(a)(2)(v) o 50.73(a)(2)(i)(A) o 50.73(a)(2)(v)(C) o OTHER o 20.2203(a)(2)(vi) o 50.73(a)(2)(I)(8) 181 50.73(a)(2)(v)(O)

Specify in Abstract below or in

EVENT DESCRIPTION

During identification and evaluation of flood barriers (condition report (CR) 2010-2387), in response to NRC findings previously noted, unsealed through wall penetrations in the intake structure were identified that are below the licensing basis flood elevation. These penetrations were installed during the installation of the original plant security system and were abandoned when the security system was replaced (approximately 1985). The penetrations for the "new" security system were appropriately sealed. The old penetrations were abandoned and not sealed. As a result of the penetrations not being sealed, the intake structure was vulnerable to water inflow during an extreme flooding event.

This inflow had the potential to affect the operability of both trains of safety related raw water pumps (ultimate heat sink). On February 27,2011, an eight (8) hour report was made under 10 CFR 50.72 (b)(3)(v)(D) to the NRC Headquarters Operation Office (HOO) at 1623 CST. The report should have been made on January 27,2011. This report is being made per 10 CFR 50.73(a)(2)(v)(D).

CONCLUSION A root cause determination was prepared in connection with CR 2010-2387 which documents the causes of the problem.

The following four (4) root causes explain why written procedures were inadequate to mitigate the external flood conditions prescribed by the Updated Safety Analysis Report (USAR). These root causes address the NRC issued yellow finding as well as the specific penetration being addressed in this LER.

Historically, when procedures for flooding protection were restructured or substantially augmented, a weak procedure revision process did not assure FCS met its USAR requirements.

Supervisory and management oversight of work activities associated with external flood matters was not sufficient to prevent this issue from occurring.

The FCS organization has not been effective in ensuring that performance deficiencies related to external flooding are adequately identified, evaluated, and resolved.

Mindsets existed that FCS was safe "as-is" relative to external flooding events. These mindsets collectively led to the incorrect conclusion that regulatory requirements were being met.

CORRECTIVE ACTIONS

The penetrations were temporarily sealed. A configuration change was developed and permanent seals were installed in the subject conduits. Comprehensive corrective actions to address the root and contributing causes are being developed and will be addressed through the corrective action program.

Additional corrective actions will be identified in a revision to this LEA.

SAFETY SIGNIFICANCE

The Fort Calhoun Station is required to be protected from flooding within the station's licensing basis.

The station raw water pumps, which are part of the ultimate heat sink, are located in the intake structure. The openings could have jeopardized the ability of the raw water pumps to perform their design basis function during an accident. Another method of removing decay heat is available.

However, FCS recognizes that external flooding has substantial importance to safety.

SAFETY SYSTEM FUNCTIONAL FAILURE This event does result in a safety system functional failure in accordance with NEI-99-02.

PREVIOUS EVENTS This issue was identified in NRC inspection report 05000285/2010008 dated October 6, 2010. During the extent of cause analysis for the issue these penetrations were identified.