05000311/LER-2004-007, Manual Reactor Trip Due to a Malfunction of a Main Feedwater Regulating Valve (23BF19)
| ML042660124 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 09/13/2004 |
| From: | Fricker C Public Service Enterprise Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LR-N04-0402 LER 04-007-00 | |
| Download: ML042660124 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
| 3112004007R00 - NRC Website | |
text
PSEG Nuclear LLC P.O. Box 236, Hancocks Bridge, New Jersey 08038-0236 0 PSEG SEP 13 2004 NuclearLLC LR-N04-0402 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 LER 311104-007-00 SALEM - UNIT 2 FACILITY OPERATING LICENSE NO. DPR-75 DOCKET NO. 50-311 This Licensee Event Report, uSalem Unit 2 Manual Reactor Trip Due to a Malfunction of a Main Feedwater Regulating Valve (23BF19)," is being submitted pursuant to the requirements of the Code of Federal Regulations 1 OCFR50.73(a)(2)(i)(A).
The attached LER contains no commitments.
SincerelW r ricker S em Plant Manager Attachment
/EHV C
Distribution LER File 3.7 95-2168 REV. 7199
NRC FORME 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150.0104 EXPIRES: 06/30/2007 6-2004)
, the NRC may digits/cha s for each block) not conduct or sponsor, and a person Is not required to respond to, the
- 3. PAGE Salem Generating Station Unit 2 050003 1 OF 5
- 4. TITLE Salem Unit 2 Manual Reactor Trip Due to a Malfunction of a Main Feedwater Regulating Valve (23BF1 9)
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE B. OTHER FACILmES INVOLVED SEUNILRVFACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NSEUEN L REVO. MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 07 15 2004 2004 - 007 -
00 09 13 2004
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply) o 20.2201(b) 0 20.2203(aX3Xi) 0 50.73(aX2)(i)(C) 0 50.73(aX2)(vii) 1 0 20.2201(d) 0 20.2203(a)(3Xii) 0 50.73(aX2)(iiXA) 0 50.73(aX2)(vfiiXA) o 20.2203(aXl) 0 20.2203(a)(4) 0 50.73(aX2)(iiXB) 0 50.73(aX2XviiiXB) 0 20.2203(a)(2Xi) 0 50.36(c)(1XiXA) 0 50.73(aX2)(iii) 0 50.73(aX2yix)(A)
- 10. POWER LEVEL 0 20.2203(a)(2Xii) 0 50.36(c)(1Xii)(A) 0 50.73(aX2)(ivXA) 0 50.73(a)(2Xx) 0 20.2203(a)(2Xiii) 0 50.36(c)(2) 0 50.73(aX2)(v)(A) 0 73.71 (a)(4) o 20.2203(a)(2Xiv) 0 50.46(aX3Xii) 0 50.73(aX2XvXB) 0 73.71 (a)(5) 8%
0 20.2203(a)(2Xv) 0 50.73(a)(2Xi)(A) 0 50.73(a)(2XvXC) 0 OTHER 0 20.2203(a)(2Xvl) 0 50.73(a)(2XiXB) 0 50.73(a)(2XvXD)
Specify In Abstract below nr In NRC'. Fnrm RRRA
- 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME TELEPHONE NUMBER (incude Area Code)
E. H. Villar, Licensing Engineer 856-339-5456CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX FACTURER TO EPIX B
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR SUBMISSION o YES (If yes, complete 15. EXPECTED SUBMISSION DATE) 0 NO DATE ABSTRACT (Limit to 1400 spaces, I.e., approximately 15 single-spaced typewritten lines)
On Thursday July 15, 2004, Salem Unit 2 was manually tripped while returning to power following the July 13, 2004 automatic reactor trip (LER 311/2004-006, dated September 13, 2004).
During start-up, at approximately 8% power, feedwater flow was automatically transitioning from the feedwater bypass valve (BF40) to the main feedwater regulating valves (BF1 9). As the demand for the main feedwater regulating valves increased the demand for the BF40s decreased, as designed. However, the actual position of the number 23 loop main feedwater regulating valve (23BF19) did not move in response to the increasing demand.
As the level in 23 Steam Generator continued to decrease due to the lack of response from 23BF19, the control.
room operator manually initiated a reactor trip with 23 Steam Generator level at approximately 16%. The apparent cause of the failure has been determined to be a positioner failure due to overshoot and sticking positioner pilot stem. Some of the corrective actions taken were: (1) The 23 BF19 positioner, as well as all Unit 2 feedwater regulating valves (21, 22, and 24BF1 9s), were replaced and calibrated under direction of the manufacturer, (2) The overshoot condition for the Unit 2 BF19s positioners was corrected prior to Unit restart, (3) A rollout was performed with appropriate PSEG personnel with specific recommendations to test each positioner pilot spool. Some longer term corrective actions being considered include: (1) Replacing the positioners with a different design and (2)
Installing in line air filters (in parallel) at the redundant air panels for the BF19s.
This report is being made in accordance with 1 OCFR50.73(a)(2)(iv)(A), 'any event or condition that resulted in manual or automatic actuation of any of the systems listed in paragraph (a)(2)(iv)(B)."
NRC FORM 366(6-2004)
PRINTED ON RECYCLED PAPER NRC FORM 366 (6-2004)
PRINTED ON RECYCLED PAPER
(If more space Is required, use additional copies of (If more space Is required, use additional copies of (if more space Is required, use additional copies of NRC Forn 366A)
PREVIOUS OCCURRENCES
A review of reportable events for Salem and Hope Creek in the last two years identified the following reportable events involving the steam generator feedwater control system.
LER 311/2004-006 issued on September 13, 2004, described a Salem Unit 2 automatic reactor trip as a result of 21 BF19 failing to control steam generator water level. The root cause of this event was determined to be the failure of the positioner due to the failure of the I/P.
LER 272/2003-003 issued on December 5, 2003, described a Salem Unit 1 Shutdown as a result of 14BF19 failing to control level because of being immovable. The root cause of this event was determined to be foreign material lodged between the valve plug and the inside diameter of the cage.
LER 272/2002-004 issued on January 13, 2003, described a Salem Unit 1 manual reactor trip as a result a Steam Generator Feedwater Pump (SGFP) runback resulting from voltage decrease in the control power to its governor.
With the exception of LER 311/2004-006, the root causes for these events were different than the root cause for the event being reported in this LER, thus the corrective actions taken for these previous events would not have prevented this occurrence. The corrective actions associated with LER 311/2004-006 were appropriate and adequate; however, the investigation was not comprehensive and did not fully understand the failure of the positioner and take appropriate corrective actions to prevent recurrence.
SAFETY CONSEQUENCES AND IMPLICATIONS
There were no safety consequences associated with this event.
At Salem there are two valves in each main feed line that serve to isolate main feedwater flow following a steamline break; (1) the main feedwater regulator valve (BF19), which receives dual, separate train trip signals from the Plant Protection System on any safety injection signal and closes within 10 seconds (including instrument delays), and (2) the feedwater isolation valve (BF1 3) that also receives dual, separate train trip signals from the reactor protection system following a safety injection signal.
The BF13 valves are motor operated and close within 32 seconds (including instrument delays).
Additionally, the main feed water pumps receive dual, separate train trips from the protection system following a steam line break.
A review of this event determined that a Safety System Functional Failure (SSFF) as defined in NEI 99-02 did not occur.
(If more space Is required, use additional copies of NRC Form 366A)
CORRECTIVE ACTIONS
- 1. The 23 BF19 positioner, as well as all other Unit 2 feedwater regulating valves (21, 22, and 24BF1 9s), were replaced and calibrated under direction of the manufacturer.
- 2. The overshoot condition for the Unit 2 BFI 9s positioners was corrected prior to Unit restart. The overshoot was corrected by the installation of a volume booster on the discharge of the positioner to reduce the backpressure from the actuator. A similar modification to the Unit 1 positioners will be performed during the next outage of sufficient duration.
- 3. An air operated valve diagnostic test was satisfactorily performed.
- 4. A rollout of Operating Experience 14854 to appropriate PSEG personnel was performed with specific recommendations to test each positioner pilot spool.
- 5. The current Operating Experience Program will be reviewed for enhancements.
- 6. Longer term corrective actions being considered include:
(a) Replacing the positioners with a different design and (b) Installing in line air filters (in parallel) at the redundant air panels for the BF1 9s.
COMMITMENTS
This LER contains no Commitments.