05000321/LER-2007-001, Unit 1, Re High Pressure Coolant Injection Inoperable Due to Component Failures
| ML071030157 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 04/09/2007 |
| From: | Madison D Southern Nuclear Operating Co |
| To: | Document Control Desk, NRC/NRR/ADRO |
| References | |
| NL-07-0647 LER 07-001-00 | |
| Download: ML071030157 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat |
| 3212007001R00 - NRC Website | |
text
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Vice President* Hatch April 9, 2007 Docket No.: 50-321 SolIIIIHI NICI..,
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Plant Edwin I.Hatch 11028 Hatch Parkway. North Baxley. Georgia 31513 Tel 912.537.5859 fax912.356.2077 NL..()7..()647 U. S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant - Unit 1 Licensee Event Report High Pressure Coolant Injection System lnOj)erableDye to Component Failures Ladies and Gentlemen:
In accordance with the requirements of 10CPR 50.73(a)(2)(v)(B), Southern Nuclear Operating Company is submitting the enclosed Licensee Event Report (LER) concerning two separate component failure events that caused the High Pressure Coolant Injection System to become inoperable.
This letter contains no NRC commitments. If you have any questions, please advise.
Sincerely,
~7J£ D. R. Madison Vice President - Hatch Edwin I. Hatch Nuclear Plant 11028 Hatch Parkway North Baxley, GA 31513 DRM/OCVIphr
Enclosure:
LER 1-2007-001 cc:
Southern Nuclear Operating Company Mr. 1. T. Gasser, Executive Vice President Mr. D. H. Jones, Vice President - Engineering RTYPE: CHA02.004 U. S. Nuclear Rewlatorv Commission Dr. W. D. Travers, Regional Administrator Mr. R. E. Martin, NRR Project Manager - Hatch Mr. D. S. Simpkins, Senior Resident Inspector - Hatch
Abstract
On 2/7/07 at 1640 EST, Unit I was in the Run mode at approximately 100 percent ofrated thermal power. At that time, a control room operator was performing a control board walk-down when he noticed the position indicating light for the High Pressure Coolant Injection (HPCI, EllS Code BJ) system's minimum flow control valve was extinguished. Further investigations discovered a degraded resistor on the position indicating light and a blown control power fuse in the valve's motor control center (MCC). As a result, the minimum flow valve was incapable ofoperating, rendering HPCI inoperable.
On 2/8/07 at 0431 EST, with Unit I in the Run Mode at approximately 100 percent ofrated thermal power, operations personnel were performing a HPCI pump operability test when the turbine steam supply valve failed to open. As a result, turbine speed did not increase and the HPCI system did not initiate as required.
In each case, the HPCI system was declared inoperable and the appropriate Technical Specifications Required Action Statement was entered.
The cause of the failed minimum flow valve was a degraded resistor which resulted in a blown control power fuse in the valve's MCC. The turbine steam supply valve did not open due to a failed motor which investigations determined likely resulted from past bonnet pressurization events and thermal aging. Pressurization could occur ifwater enters the valve bonnet and is subsequently heated.
Corrective actions for the failed minimum flow valve included replacing the fuse and resistor. Also, resistors with indicating lamps for DC motor operated valves of the HPCI and RCIC systems will be checked and replaced as necessary. The failed steam supply valve motor was replaced and the HPCI procedure was revised to ensure any water is drained from the valve bonnet following events
",hi"h r..<:l1ltin the. HPrT <:t.. ~m lin.. h..ina fiIJ..tl Ulith water.
NRC FORM 3&6 (6-2004)
NRCFORM368A (1-2001)
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (lER)
YEAR I SEQUENTIAL !REVISION NUMBER INUMBER
- 1. FACILITYNAME Edwin 1. Hatch Nuclear Plant - Unit 1
- 2. DOCKET 05000-321
- 8. LER NUMBER 2007 001 00
- 3. PAGE 20F 5
- 17. NARRATIVE (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additionalcopiesof NRC Form 366A)
The failed motor for the 1E41-FOOI valve was replaced.
The Unit 1 and Unit 2 procedures 3480-E41-001, "High Pressure Coolant Injection (HPCI) System," have been revised to require stroking the E41-FOOI valve after water has been drained from the steam line. This will allow any water that may have gotten into the valve to drain out.
ADDITIONAL INFORMATION
Other Systems Affected:
No systems other than those previously described in this report were affected by this event.
Failed Components Information
Master Parts List Number: 1E41-FOO1 Manufacturer: Anchor Darling Model Number: E-6550-1-1 Type: 20 Manufacturer Code: A391 Master Parts List Number: lE41-F202 Manufacturer: General Electric Model Number: 165A7844P3 Type: Modifier, Current Manufacturer Code: G080 EllS System Code: BJ Reportable to EPIX: Yes Root Cause Code: X EllS Component Code: 20 EllS System Code: BJ Reportable to EPIX: Yes Root Cause Code: X EllS Component Code: 1M Commitment Information: There are no commitments provided in this Licensee Event Report.
Previous Similar Events
There were no previous events in the past two years, where a HPCI system resistor failed resulting in a blown control power fuse or where bonnet pressurization resulted in a pressure lock situation resulting in an inability to cycle the steam supply valve.