05000255/LER-2006-005, Regarding Uncoupled Control Rod
| ML061920082 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 07/07/2006 |
| From: | Harden P Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 06-005-00 | |
| Download: ML061920082 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(1) |
| 2552006005R00 - NRC Website | |
text
July 7, 2006 10 CFR 50.73(a)(2)(i)(B) 10 CFR 50.73(a)(2)(iv)(A)
U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Palisades Nuclear Plant Docket 50-255 License No. DPR-20 Licensee Event Report 06-005, Uncoupled Control Rod Licensee Event Report (LER)06-005 is enclosed. The LER describes the discovery that a control rod had remained uncoupled following a scheduled refueling outage, which is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as operation which was prohibited by Technical Specifications. The LER also describes an associated manual actuation of the reactor protection system that occurred during the subsequent plant shutdown that had been initiated to correct the condition. The actuation is reportable in accordance with 10 CFR 50.73(a)(2)(iv)(A).
Summarv of Commitments This letter contains no new commitments and no revisions to existing commitments.
Paul A. Harden Site Vice President, Palisades Nuclear Plant Nuclear Management Company, LLC Enclosure (1 )
CC Administrator, Region Ill, USNRC Project Manager, Palisades, USNRC Resident Inspector, Palisades, USNRC 27780 Blue Star Memorial Highway Covert, Michigan 49043-9530 Telephone: 269.764.2000
ENCLOSURE 1 LER 06-005, Uncoupled Control Rod 3 Pages Follow
EXPIRES 6-30-2007 Estimated burden per response to comply wlth this mandatory collectlon 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 lrcenslng process and fed back to Industry LICENSEE EVENT REPORT (LER)
Send comments regarding burden estlmate to the Records and FOIAIPrrvacy Sewlce Branch (T-5 F52), U S Nuclear Regulatory Comm~ss~on, Washlngton, DC 20555-0001, or by Internet e-(See reverse for required number of mall to ~nfocollectsQnrc gov, and to the Desk Offlcer, Office of lnformatlon and Regulatory Affairs, NEOB-10202, (3150-0066), Off~ce of Management and Budget, Washlngton, DC 20503 digitslcharacters for each block)
If a means used to lmpose an lnformatlon collection does not display a currently valld OMB Uncoupled Control Rod OTHER FACILITIES INVOLVED (8)
FACILITY NAME DOCKET NUMBER GEOUENTIAL REV YEAR YEAR NUMBER NO MO DAY YEAR FACILITY NAME DOCKET NUMBER 10 2006 2006 -- 005 -- 00 07 07 2006 OPERATING 1
THIS REPORT IS SUBMIllED PURSUAFiTTO THE MODE (9) 20 2201 (b) 20.2203(a)(3)(i1)
POWER 20.2201 (d) 20.2203(a)(4)
LEVEL (I 0)
OZ2 -202203(a)op50.36ic)il)0/A)-
, : (Check all that apply) (11) 50.73(a)(2)(lx)(A) 50.73(a)(2)(x) 73.71 (a)(4) 73.71 (a)(5)
OTHER Speclfy ~n Abstract below or ~n I REQUAMENTS OF 10 CFA LICENSEE CONTACT FOR THlS LER (12)
X-20.2203(a){2) (1) 20.2203(a)(2)(il) 20 2203(a)(2)(ili) 20 2203(a)(2)(1v) 20.2203(aj(2)(v) 20.2203(a) (2)(v1) 20.2203(a) (3)(i)
NAME Daniel G. Malone 50.73(a)(2) (1 I)(B) 50.73(a)(2)(11i) 50.73(~)(2)(1v)(A) 50 73(a)(2)(v)(A) 50 73(a)(2)(v)(~)
5O0.73(a)(2)(v)(C) 50.73(a)(2)(v)(D) 50.73(a)
(2)(vii) 50,73(a)(Z)(viii)(A) 50,73(a)(Z)(viii)(B)
TELEPHONE NUMBER (Include Area Code)
(269) 764-2463 50.36(c)(l )(li)(A) 1 50.36(c)(2) 50.46(a)(3)(11) 750.730(2)(I)(A)
X COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THlS REPORT (13) 50.73(a)(2)(1)(B) 50.73(a)(2)(l)(C) 50.73(a)(2) (rl)(A)
On May 10, 2006, an unexpected quadrant power tilt was identified during reactor core startup physics testing. At the time of discovery, plant power was being maintained at approximately 22%
following initial power ascension from a recently completed refueling outage. Subsequent analysis determined the most probable cause of the quadrant power tilt to be Control Rod 33 fully inserted into the core as opposed to being fully withdrawn as indicated. A shutdown was initiated to facilitate further troubleshooting. The reactor was manually tripped from approximately 11 % power.
On May 13, 2006, investigation determined that Control Rod 33 was uncoupled from its drive assembly, having not been successfully coupled during the refueling outage. Consequently, Control Rod 33 had remained fully inserted into the core throughout plant startup from the refueling outage.
Prior to discovery, the upward mode changes into Mode 2 and Mode 1 that occurred on May 9 and May 10, 2006, respectively, were performed in violation of Technical Specification (TS) 3.0.4, since the intent of TS 3.1.4.D.1 is to prevent a reactor startup with an immovable control rod.
Consequently, this event is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as operation which was prohibited by Technical Specifications. In addition, the manual reactor protection system actuation is reportable in accordance with 10 CFR 50.73(a)(2)(iv)(A).
CAUSE
NO REPORTABLE TO EPlX SYSTEM REPORTABLE TO EPlX MANU-FACTURER SYSTEM COMPONENT COMPONENT SUPPLEMENTAL REPORT EXPECTED (1 4)
MANU-FA CTURER YES (If yes, complete EXPECTED SUBMISSION DATE).
DAY EXPECTED SUBMISSION DATE (I 5)
X MONTH U.S. NUCLEAR REGULATORY COMMISSION (1 -2001)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
DOCKET NUMBER (2)
Palisades Nuclear Plant 05000-255 TEXT (If more space a requ~red, use additional coples of NRC Form 366A) (17)
EVENT DESCRIPTION
On May 10, 2006, an unexpected quadrant power tilt was identified during reactor [RCT;AB] core startup physics testing. At the time of discovery, plant power was being maintained at approximately 22% following initial power ascension from a recently completed refueling outage.
On May 11, 2006, subsequent analysis of core power distribution data determined the most probable cause of the quadrant power tilt to be Control Rod 33 [ROD;AA] fully inserted into the core as opposed to being fully withdrawn as indicated.
Based on this conclusion, Off Normal Procedure ONP-5.1, "Control Rod Drop" was conservatively entered and a shutdown to Mode 5 was initiated to facilitate further troubleshooting. The reactor was manually tripped from approximately 11 % power in accordance with procedural guidance.
On May 13, 2006, investigation determined that Control Rod 33 was uncoupled from its drive assembly, having not been successfully coupled during the refueling outage. Consequently, Control Rod 33 had remained fully inserted into the core throughout plant startup from the refueling outage.
Prior to discovery, the upward mode changes into Mode 2 and Mode 1 that occurred on May 9 and May 10, 2006, respectively, were performed in violation of Technical Specification (TS) 3.0.4, since the intent of TS 3.1.4.D.1 is to prevent a reactor startup with an immovable control rod.
Consequently, this event is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as operation which was prohibited by Technical Specifications. In addition, the manual reactor protection system [JC] actuation is reportable in accordance with 10 CFR 50.73(a)(2)(iv)(A).
CAUSE OF THE EVENT
The failure to couple Control Rod 33 involved deficiencies in performance of the coupling procedure, as well as deficiencies in verification and oversight of the activity.
CORRECTIVE ACTIONS
Control Rod 33 was coupled to its drive assembly.
The activity of coupling control rods will be strengthened through a combination of procedural enhancements, personnel qualification improvements, and additional administrative controls. U.S. NUCLEAR REGULATORY COMMISSION
- 1-2001)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
Palisades Nuclear Plant 05000-255 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)
SAFETY SIGNIFICANCE
The safety significance of this occurrence is considered minimal. Since the inserted control rod was identified prior to exceeding 25% power, TS required actions for one misaligned and immovable control rod were already satisfied without further action.
For the manual reactor trip, the reactor protection system functioned as expected.
This event does not involve a safety system functional failure.
PREVIOUS SIMILAR EVENTS
None VRC FORM 366A (1 -2001)