05000251/LER-2010-001, Regarding Two Shutdown Bank Rods Were Dropped from Fully Withdrawn Position

Regarding Two Shutdown Bank Rods Were Dropped from Fully Withdrawn Position

ML100350391
Person / Time
Site:	Turkey Point
Issue date:	01/25/2010
From:	Kiley M Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2010-005 LER 10-001-00
Download: ML100350391 (5)

LER-2010-001, Regarding Two Shutdown Bank Rods Were Dropped from Fully Withdrawn Position

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv), System Actuation 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
2512010001R00 - NRC Website

text

0 FPL.

POWERING TODAY.

EMPOWERING TOMORROW.0 10 CFR § 50.73 L-2010-005 January 25, 2010 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555-0001 Re:

Turkey Point Unit 4 Docket No. 50-251 Reportable Event: 2010-001-00 Date of Event: November 26, 2009 Two Shutdown Bank Rods Were Dropped from Fully Withdrawn Position The attached Licensee Event Report 05000251/2010-001-00 is being submitted pursuant to 10 CFR 50.73(a)(2)(iv) to provide notification of the subject event.

If there are any questions, please call Mr. Robert Tomonto at 305-246-7327.

Very truly yours, Michael Kiley Vice President Turkey Point Nuclear Plant Attachment cc:

Regional Administrator, USNRC, Region II Senior Resident Inspector, USNRC, Turkey Point Nuclear Plant an FPL Group company

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/201(

(9-2007)

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 LICENSEE EVENT REPORT (LER)

F52), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to infocollects@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (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 information collection.

3. PAGE Turkey Point Unit 4 05000251 I

1 of 4

4. TITLE Two Shutdown Bank Rods Were Dropped from Fully Withdrawn Position

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR NUMBER NO.

_____FACILITY NAMNE DOCKET NUMBER 11 26 2009 2010 -001

- 00 1

25 2010

9. OPERATING MODE

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

El 20.2201(b)

[1 20.2203(a)(3)(i)

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

El 50.73(a)(2)(vii).

3 El 20.2201(d)

El 20.2203(a)(3)(ii)

El 50.73(a)(2)(ii)(A)

El 50.73(a)(2)(viii)(A)

El 20.2203(a)(1)

El 20:2203(a)(4)

El 50.73(a)(2)(ii)(B)

[ El 50.73(a)(2)(viii)(B)

El 20.2203(a)(2)(i)

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

El 50.73(a)(2)(iii)

El 50.73(a)(2)(ix)(A)

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

El 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(iv)(A)

[E 50.73(a)(2)(x)

El 20.2203(a)(2)(iii) 0l 50.36(c)(2)

El 50.73(a)(2)(v)(A)

El 73.71(a)(4)

El 20.2203(a)(2)(iv)

El 50.46(a)(3)(ii)

El 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)

El 50.73(a)(2)(v)(C)

El OTHER El 20.2203(a)(2)(vi)

El 50.73(a)(2)(i)(B)

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

Specify in Abstract below or in

ANALYSIS OF THE EVENT

Background

The Rod Control System [EIIS, JD] performs the following functions:

1. Controls the motion of the control rods within the core, in response to signals from the In-Hold-Out switch or the reactor control unit.

2. Maintains programmed reactor coolant system temperature, by regulating reactivity within the core, to within a programmed temperature range.

The regulation circuit for this operation is controlled from the sampling registers within the. Rod Control System cabinets. The Rod Cluster Control Assembly (RCCA) drop event is an analyzed event in Section 14.1.4 of the Updated Final Safety Analysis Report.

Reportability

The event was reported to the NRC in accordance with 10 CFR 50.72(b)(3) on November 26, 2009. A review of the reporting requirements of 10 CFR 50.72 and 10 CFR 50.73 and NRC guidance provided in NUREG-1022, Revision 2, Event Reporting Guidelines 10 CFR 50.72 and 10 CFR 50.73, was performed for the subject condition. As a result of this review, the condition was deemed reportable in accordance with 10 CFR 50.73(a)(2)(iv)(A), due to manual actuation of the Reactor Protection System to trip the reactor, inserting all rods November 26, 2009.

Analysis of Safety Significance At the time of the rod drop event, the reactor was in Mode 3 (Hot Standby) and the plant was performing post-modification testing of the NARPI system. The Technical Specifications for Rod Misalignment are applicable in Modes 1 and 2 and did not apply. Plant procedures directed the reactor-to be manually tripped due to the unexpected rod drop condition. At the time of the test, the boron concentration was high enough to maintain the shutdown margin with, all rods out. As the reactor was sub-critical with adequate shutdown margin, and since the reactor trip function was available, the safety significance of this event is considered to be minimal. Upon manually opening the reactor trip breakers, the rods that were withdrawn from the core were fully inserted.

CORRECTIVE ACTIONS

Corrective actions include the following:

1. Corrective actions included cleaning and tightening of the Unit 4 affected connections followed by an inspection of all the connections of the neutral buses. Unit 3 uses the same model rod control cabinets and is subject to similar loose connections. Any additional troubleshooting on Unit 3 will be performed at the first available opportunity when the unit is offline.

2. The preventive maintenance procedure (applicable to both units) is to be revised prior to the next Unit 3 refueling outage to include a more thorough inspection and cleaning of the feedback sensor resistor bank connections.

ADDITIONAL INFORMATION

EIIS Codes are shown in the format [IEEE system identifier, component function identifier, second component function identifier (if appropriate)]. Condition Report 2009-33606 was initiated due to this event.

FAILED COMPONENTS IDENTIFIED: None

PREVIOUS SIMILAR EVENTS

None - However, rod H6 dropped again November 27, 2009 due to the conditions described in this event report, prior to the corrective actions being completed. Condition Report 2009-33607 was initiated due to this event.