05000255/LER-2006-004, Re Reactor Protection System Actuation
| ML061790584 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 06/28/2006 |
| From: | Harden P Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 06-004-00 | |
| Download: ML061790584 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(ix) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2) |
| 2552006004R00 - NRC Website | |
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June 28,2006 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 06-004, Reactor Protection Svstem Actuation Licensee Event Report (LER)06-004 is enclosed. The LER describes an actuation of the reactor protection system and is reportable in accordance with 10 CFR 50.73(a)(2)(iv)(A).
Summary 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 06-004, Reactor Protection System Actuation 2 Pages Follow
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES 6-30-2007 (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.
LICENSEE EVENT REPORT (LER)
Send comments regarding burden estimate to the Records and FOINPrivacy service Branch (T-5 F52), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, orby internet e-(See reverse for required number of mail to infocollectsQnrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0066), Office of Management and Budget, Washington, DC 20503.
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FACILIW NAME (7)
DOCKET NUMBER (2)
PAGE (3)
Palisades Nuclear Plant 1 of 2
TITLE (4)
Reactor Protection System Actuation EVENT DATE 15)
LER NUMBER (6)
REPORT DATE (7)
OTHER FACILITIES INVOLVED (8) p p
FACILITY NAME DOCKET NUMBER MO DAY YEAR 05 04 2006 2006 -- 004 -- 00 06 28 2006 FACILITY NAME DOCKET NUMBER OPERATING THISREPORT IS SUBMIWED PURSUANT TO M E REQUIREMENTS OF 10 CFR 0 : (Check all that apply) (11) 20.2203(a) (3)(ii) 50.73(a) (2) (ii)(B) 50.73(a)(2) (ix){A) 20.2203(a)(4) 50.73(a)(2)(iii) 50.73(a)(2) (x)
+
50.36(c)(l)(i)(A)
X 50.73(a) (2) (iv) (A) 73.71 (a)(4) 50,36(c)(l)(ii)(A) 50.73(a)(Z)(v)(A) 73.71 (a)(5) 20.2203(a)(2)(ii) 50.36(~)(2) 50.73(a)(2)(v)(B)
OTHER 20.2203(a)(2)(iii) 50.46(a)(3)(ii) 50.73(a)(2)(v)(C)
Specify in Abstract below or in 20.2203(a)(2)(iv) 50.73(a)(2)(i)(A) 50.73(4(2)(v)(D) 20.2203(a) (2)(v) 50,73(a)(2)(i)(Bj 50.73(a)(2) (vii) 20.2203(a)(Z)(vi) 50.73(aj(2)(i)(C) 50.73(a)(2) (viil)(A) 50.73(aj/2)(ii)(A) 50,73(a)(2)(viii)(8)
LICENSEE CONTACT FOR THIS LER (12)
NAME TELEPHONE NUMBER (Include Area Code)
Daniel G. Malone (269) 764-2463 MANU-REPORTABLE MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT FACTURER TO EPlX
CAUSE
SYSTEM COMPONENT FA CTURER TO EPlX SUPPLEMENTAL REPORT EXPECTED (1 4)
EXPECTED MONTH DAY YEAR YES (If yes, complete EXPECTED SUBMISSION DATE).
SUBMISSION DATE (1 5)
ABSTRACT On May 4, 2006, with the plant in Mode 5, an actuation of the reactor protection system (RPS) occurred during performance of startup testing activities. The RPS actuation signal was generated from activation of the 'A' steam generator low level trip circuitry.
At the time of occurrence, a slight nitrogen overpressure of approximately 1.3 psi was being maintained on the secondary side of 'A' steam generator for chemistry control, as is typical for idle steam generators when in Mode 5.
Subsequently, when the main steam isolation valves were opened to support a planned test activity, a sudden release of the nitrogen overpressure in 'A' steam generator occurred. This resulted in a momentary level oscillation within 'A' steam generator between the tube bundle region and the downcomer region where steam generator level is measured.
While there was no loss of water inventory from 'A' steam generator, level in the downcomer region oscillated approximately 1 5% above and below the initial indicated level of approximately 40%. Since the RPS trip setpoint for low steam generator level is approximately 28%, the magnitude of the level oscillation was sufficient to exceed the RPS trip setpoint. U.S. NUCLEAR REGULATORY COMMISSION (1 -2001)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
Palisades Nuclear Plant DOCKET NUMBER 2 -
05000-255 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)
EVENT DESCRIPTION
On May 4, 2006, with the plant in Mode 5, an actuation of the reactor protection system (RPS) [JC]
occurred during performance of startup testing activities. The RPS actuation signal was generated from activation of the 'A' steam generator [SG;AB] low level trip circuitry.
At the time of occurrence, the RPS was reset and a single control rod was fully withdrawn for testing.
As a result of the RPS actuation, the withdrawn control rod inserted into the core as expected.
This actuation is reportable in accordance with 10 CFR 50.73(a)(2)(iv)(A).
CAUSE OF THE EVENT
At the time of occurrence, a slight nitrogen overpressure of approximately 1.3 psi was being maintained on the secondary side of 'A' steam generator for chemistry control, as is typical for idle steam generators when in Mode 5.
Subsequently, when the main steam isolation valves (MSIVs) [ISV;SB] were opened to support a planned test activity, a sudden release of the nitrogen overpressure in 'A' steam generator occurred.
This resulted in a momentary level oscillation within 'A' steam generator between the tube bundle region and the downcomer region where steam generator level is measured.
While there was no loss of water inventory from 'A' steam generator, level in the downcomer region oscillated approximately 15% above and below the initial indicated level of approximately 40%.
Since the RPS trip setpoint for low steam generator level is approximately 28%, the magnitude of the level oscillation was sufficient to exceed the RPS trip setpoint.
CORRECTIVE ACTIONS
Procedures will be revised to appropriately address the potential consequences of opening MSlVs when the reactor is reset as observed in this occurrence.
SAFETY SIGNIFICANCE
The safety significance of this occurrence is considered minimal since the reactor was already in a shutdown condition. There was no adverse safety impact on any equipment or the plant.
PREVIOUS SIMILAR EVENTS
None