05000255/LER-2005-005, Regarding Reactor Protection System and Auxiliary Feedwater System Actuation
| ML053050420 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 10/24/2005 |
| From: | Harden P Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 05-005-00 | |
| Download: ML053050420 (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)(A) 10 CFR 50.73(a)(2)(iii) 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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(B) |
| 2552005005R00 - NRC Website | |
text
Palisades Nuclear Plant Committed to Nuclear Operated by Nuclear Management Company, LLC October 24, 2005 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 05-005. Reactor Protection System and Auxiliary Feedwater System Actuation Licensee Event Report (LER)05-005 is attached. The LER describes a manual actuation of the reactor protection system and subsequent actuation of the auxiliary feedwater system. This event 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 2
A,
ENCLOSURE 1 LER 05-005, REACTOR PROTECTION SYSTEM AND AUXILIARY FEEDWATER 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 FOlAfPrivacy Service Branch (T.5 F52), U.S. Nuclear Regulatory Commission, Washington, DC 20555-001
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FACILITY NAME (1)
DOCKET NUMBER (2)
PAGE (3)
Palisades Nuclear Plant 05000-255 I
of 2 TITLE (4)
Reactor Protection System and Auxiliary Feedwater System Actuation EVENT DATE (5)
LER NUMBER (6)
REPORT DATE (T)
OTHER FACILITIES INVOLVED (8)
FACILITY NAME DOCKET NUMBER MO DAY YEAR YEAR NUMBER NO MO DAY YEAR 09 01 2005 2005
-- 005 00 10 24 2005 FACIUTYNAME DOCKETNUMBER OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR.: (Check all that apply) (11)
MODE (9) 1 20.2201(b) 20.2203(a)(3)(ii) l 50.73(a)(2)(ii)(B) l 50.73(a)(2)(ix)(A)
POWER 100 20.2201(d) 20.2203(a)(4) 50.73(a)(2)(iii) 50.73(a)(2)(x)
LEVEL (IO) 20.2203(a)(1) 50.36(c)(1)(i)(A)
X 50.73(a)(2)(iv)(A) 73.71 (a)(4) 20.2203(a)(2)(i) 50.36(c)(1)(ii)(A) 50.73(a)(2)(v)(A) 73.71 (a)(5) 20.2203(a)(2)(ii) 50.36(c)(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(a)(2)(v)(D) 20.2203(a)(2)(v) 50.73(a)(2)(i)(B) 50.73(a)(2)(vii) 20.2203(a)(2)(vi) 50.73(a)(2)(i)(C) 50.73(a)(2)(viii)(A) 20.2203(a)(3)(i) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(B)
LICENSEE CONTACT FOR THIS LER (12)
NAME TELEPHONE NUMBER (include Area Code)
Daniel G. Malone 1
(269) 764-2463 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) i MANU-REPORTABLE MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT FACTURER TO EPIX
CAUSE
SYSTEM COMPONENT FA CTURER TO EPIX X
TB PSF W120 Y _ l SUPPLEMENTAL REPORT EXPECTED (14)
EXPECTED MONTH DAY YEAR SUBMISSION YES (Ifyes.completeEXPECTEDSUBMISSIONDATE).
X INO DATE(15) lll ABSTRACT On September 1, 2005, at 1025 hours0.0119 days <br />0.285 hours <br />0.00169 weeks <br />3.900125e-4 months <br />, with the plant operating at 100% power, the reactor was manually tripped due to a hydrogen leak associated with the main generator. The manual reactor trip was a precautionary measure to facilitate expeditious removal from service of the main generator to allow hydrogen to be isolated and purged from the main generator, and preclude the potential for formation of an explosive hydrogen/air mixture. Following the reactor trip, the auxiliary feedwater system started automatically to maintain steam generator water level. The plant was stabilized in Mode 3 to investigate and repair the cause of the hydrogen leak. The hydrogen leak was at a socket weld at a piping tee connection on the main generator's leak detection line. The socket weld was repaired by grinding out the weld area and re-welding the connection. The most probable causes are cyclic fatigue of the weld due to vibration of the line and a weld flaw.
The safety significance of this event was minimal. All safety systems functioned as expected during the plant trip. This event does not involve a safety system functional failure.
This event is reportable in accordance with 10 CFR 50.73(a)(2)(iv)(A) as an event that resulted in a manual actuation of the reactor protection system and automatic actuation of the auxiliary feedwater system.U.S. NUCLEAR REGULATORY COMMISSION (1-2001)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
DOCKET NUMBER (2)
LER NUMBER (6)
PAG YEAR SEQUENTIAL IREVISION l
NUMBER NUMBER 2of2 Palisades 05000-255 2005 005 00
[
TEXT (fmore space is required, use additional copies of NRC Form 366A) (17)
EVENT DESCRIPTION
On September 1, 2005, at 1025 hours0.0119 days <br />0.285 hours <br />0.00169 weeks <br />3.900125e-4 months <br />, with the plant operating at 100% power, the reactor [RCT;AB] was manually tripped due to a hydrogen leak associated with the main generator [GEN;TB]. The manual reactor trip was a precautionary measure to facilitate expeditious removal from service of the main generator to allow hydrogen to be isolated and purged from the main generator, and preclude the potential for formation of an explosive hydrogen/air mixture. Following the reactor trip, the auxiliary feedwater system [BA] started automatically to maintain steam generator [SG;AB] water level. The plant was stabilized in Mode 3 to investigate and repair the cause of the hydrogen leak.
This event is reportable in accordance with 10 CFR 50.73(a)(2)(iv)(A) as an event that resulted in a manual actuation of the reactor protection system [JC] and automatic actuation of the auxiliary feedwater system.
CAUSE OF THE EVENT
The hydrogen leak was at a socket weld at a piping tee connection on the main generator's leak detection line. The primary purpose of the leak detection line is to allow detection of either a service water [KG] leak from the hydrogen coolers [CLR;TK] or a seal oil [TB] leak into the main generator.
The socket weld was repaired by grinding out the weld area and re-welding the connection. The grinding associated with the repair effectively precluded the ability to examine the socket weld and to positively determine a root cause. The most probable causes are cyclic fatigue of the weld due to vibration of the line and a weld flaw.
SAFETY SIGNIFICANCE
The safety significance of this event was minimal. All safety systems functioned as expected during the plant trip. This event does not involve a safety system functional failure.
CORRECTIVE ACTIONS
As noted above, the socket weld was repaired by re-welding the connection.
PREVIOUS SIMILAR EVENTS
None