05000336/LER-2004-001, Manual Reactor Trip on Low Steam Generator Level Resulting from a Feedwater Pump Spurious Relay Operation
| ML041250381 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 04/26/2004 |
| From: | Price J Dominion Nuclear Connecticut |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 04-223 LER 04-001-00 | |
| Download: ML041250381 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
| 3362004001R00 - NRC Website | |
text
, -,,!! M.MR4 a Dominion-Dominion Nuclear Connecticut, Inc.
Millstone Power Starion Rope Ferry Road Waterford, CT 06385 AMR 2 6 MO4 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Serial No.
MPS Lic/RWM Docket No.
License No.04-223 RO 50-336 DPR-65 DOMINION NUCLEAR CONNECTICUT. INC.
MILLSTONE POWER STATION, UNIT 2 LICENSEE EVENT REPORT 2004-001-00 MANUAL REACTOR TRIP ON LOW STEAM GENERATOR LEVEL RESULTING FROM A FEEDWATER PUMP SPURIOUS RELAY OPERATION This letter forwards Licensee Event Report (LER) 2004-001-00, documenting an event that occurred at Millstone Power Station, Unit 2, on March 6, 2004. This LER is being submitted pursuant to 10 CFR 50.73(a)(2)(iv)(A), as an event or condition that resulted in a manual actuation of a reactor protection system.
If you have any questions or require additional information, please contact Mr. David W. Dodson at (860) 447-1791, extension 2346.
Very truly yours, J.
ce Si ce President - Millstone
.-2,2-
e
Serial No.04-223 LER 2004-001-00 Page 2 of 2 Attachments:
(1)
Commitments made in this letter: None.
cc:
U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-1415 Mr. V. Nerses Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 8C2 Rockville, MD 20852-2738 Mr. S. M. Schneider NRC Senior Resident Inspector Millstone Power Station
Serial No.04-223 LER 2004-001-00 Millstone Power Station, Unit No. 2 LER 2004-001-00 Dominion Nuclear Connecticut, Inc.
NRC FORM 366 U.S. NUCLEAR REGULATORY APPROVED BY OMB NO. 3150-01104 EXPIRES 7-31-2004 (7201)
CMMISION
, the NRC may not conduct or sponsor, (See reverse for required number of diqitstcharacters for each block) and a person Is not required to respond to, the Information collection.
FACILITY NAME (1)
DOCKET NUMBER (2)
PAGE (3)
Millstone Power Station - Unit 2 05000336 1 OF3 TITLE (4)
Manual Reactor Trip on Low Steam Generator Level Resulting From a Feedwater Pump Spurious Relay Operation EVENT DATE (5)
LER NUMBER (6)
REPORT DATE (7)
OTHER FACILITIES INVOLVED (8)
FACILITY NAME DOCKET NUMBER MO DAY YEAR YEAR SEQUENTIAL REV MO DAY YEAR 05000 NUMBER INO.
MO DY YA I0 FACILITY NAME DOCKET NUMBER 03 06 2004 2004 - 001-00 04 26 2004 05000 OPERATING I
THIS REPORT IS SUBMITTEDPURSUANT TO THE REQUIREMENTS OF 10 CF R: (Check all that apply) (11)
M ODE (9) 20.2201(b) 20.2203(aX3Xii) 50.73(a)(20ii)(B)
_ 50.73(a)(2Xix)(A)
POWER 100 20.2201 (d) 1 20.2203(aX4) 50.73(a)(200iii) 50.73(a)(2yx)
LEVEL (10)
_ 20.2203(aX))
50.36(cXl))(i)(A) x 50.73(a)(2Xiv)(A) 73.71 (a)(4)
- - _ 20.2203(aN2)(i) 50.36(cN1)(iiNA) 50.73(a)(2XvyA) 73.71(a)(5) 20.2203(aX2)(ii) 50.36(cX2) 50.73(a)(2XvXB)
OTHER 20.2203(aX2)(iii)
_ 50.46(aX3)(ii) 50.73(a)(2XvXC)
Specify In Abstract below or 20.2203(aX2)(iv) 50.73(aX2)(i)(A) 50.73(a)(2Xv)(D) in (If more space is required, use additional copies of NRC Form 366.A) (17)
3. Assessment of Safety Consequences
The purpose of the steam generator feedwater (SGFW) system is to provide water to the SGs for the transfer of thermal energy from the primary side of the SGs to the secondary side. After the trip, the Main Feedwater (MFW) function of the SGFW system became unavailable for decay heat removal. This function is credited in the PRA, but is not risk significant. As a result, the risk associated with this reactor trip was calculated to be slightly higher than the risk associated with the general plant transient, in which the MFW remains available. During and after the plant trip there was no challenge to the mitigating systems, and the required safety equipment was operable. The MFW function is not safety related. There was no loss of any credited safety function from structures, systems and components. Consequently, this event is considered to be of low safety significance.
4. Corrective Action
As a result of the Event Investigation Team (EIT) findings in response to the immediate issue of relay contact sensitivity, a relay's operation in the speed control circuit for the SGFW pumps was changed from an energized closed to an energized open configuration with the associated software changes. This reduces the HGA relay sensitivity to agitation and will avert additional SGFW pump trips. "Trip sensitive equipment" signs and barriers were added for the terminal box for this control relay.
Corrective actions that are related to this event, including lessons learned surrounding the considerations for use of digital interfacing, are being addressed in accordance with the Millstone Corrective Action Program.
5. Previous Occurrences
No previous similar events/conditions were identified.
Energy Industry Identification System (EIIS) codes are identified in the text as [XX].