ML20137V148

Special Rept 1-SR-86-006:on 860203,safety Injection Actuation,Containment Isolation Actuation & Main Steam Isolation Signals Occurred Due to Reactor Trip.Caused by Low Level in Steam Generator 2.Plant Parameters Stabilized

ML20137V148
Person / Time
Site:	Palo Verde
Issue date:	02/10/1986
From:	Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION (ADM)
References
1-SR-86-006, ANPP-34968-EEVB, NUDOCS 8602190444
Download: ML20137V148 (2)

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Arizona Nuclear Power Project P o. BOX $2034 e PHOENIX, ARIZONA 85072-2034 February 10, 1986 ANPP-34968-EEVB/RAB/98.05 U. S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 1 Docket No. STN 50-528, License No. NPF-41 Report of Notification of Unusual Event - Reactor Trip File: 86-056-026; 86-020-404; G.1.01.10

Dear Sirs:

Attached please find a report describing a Notification of Unusual Event . at the Palo Verde Nuclear Generating Station on February 3, .1986. This report addresses a reactor trip resulting from a low level in Steam Generator Number 2.

This report is prepared and submitted pursuant to Table 5.3.-l of the PVNGS Fnergency Plan Rev. 6. By copy of this letter, we are also forwarding a copy of the report to the Regional Administrator of the Region V Office and other offsite authorities.

If you have any questions or concerns, please contact Mr. W. F. Quinn of my staff.

Very truly yours, r" r

-E. a..Lt au{

E. E. Van Brunt , Jr.

Executive Vice President Project Director EEVB/RAB/ dim Attachment cc: J. B. Martin (all w/a)

R. P. Zimmerman R. F. Fish, Jr.

E. A. Licitra R. A. Colson, ADES C. E. Tedford, ARRA R. E. Bluhm, MCDCD&ES R. G. Godbehere, MCSO R. T. Milstead, DPS INPO Records Center 8602190444 860210 DR ADOCK O 28; g&&

• Ir

Attachmerit .

to ANPP-34968 PALO VERDE NUCLEAR GENERATING STATION UNIT 1 NOTIFICATION OF UNUSUAL EVENT OF FEBRUARY 3,1986 Docket No. 50-528 License No. NPF-41 Special Report No.1-SR-86-006 At 1207 MST on February 3,1986, the NRC Operations Center was notified via- the Emergency Notification System, of the declaration of a NOTIFICATION OF UNUSUAL' EVENT . for Unit 1 of the Palo Verde Nuclear Generating Station. The NOTIFICATION OF UNUSUAL EVENT was declared pursuant to the Palo Verde Emergency Plan, which requires the reporting of a reactor trip which is. complicated by concurrent or subsequent events or conditions.

At approximately 1145, the plant was in Mode 1 at 60% reactor power, with pressure at 2225 psia and Reactor Coolant System cold leg temperature of 564 degrees F, when a reacts: trip occurred due to low level in Steam Generator (SG) Number 2.

Main Feedwater Pump (MFP) "A" was operd ing, and.MFP."B" was shutdown for maintenance. S.G. #1 had an abnormal blowdown to the condenser, and S.G.

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1. 2 had a high rate blowdown to the condenser when the primary side reactor operator noticed an increase in cold leg temperature as well as a Control Element Assembly (CEA) insertion demand. When informed of these changes, the secondary side reactor operator noted steady main ' generator H ad but decreasing S.G. level.-

Feedwater to Main Steam differential pressure was noted to be app m imately 30 psi low with both economizer feed regulating valves wide open. An attempt was made to increase the differential pressure by-increasing MFP "A" speed through utilization of the speed bias on the MFP  !

speed controller. Bias adjustment had no effect on pump speed, and the I pump remained steady at approximately 4500 RPM. An unsuccessful attempt was made to match deviation in order to transfer MFP control', to manual, and the reactor tripped on low S.G. #2 level.

Due to a double quick open of the Steam Bypass valves and the high flow - l rates . of - S.G. blowdown, a Safety Injection - Actuation Signal L(SIAS),

Containment Isolation Actuation Signal (CIAS) and a Main Steam Isolation Signal (MSIS) occurred. Due to the actuation of safety systeas and the classification per Emergency Classification EPIP-02, a Notification of Unusual Event was declared at 1207 and appropriate notifications were made.

All safety equipment functioned as designed ~ and . no safety limits _ were Following the MSIS, plant parameters stabilized normally and

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violated.

, the Notification of Unusual Event was terminated at 1311.

A Licensee Event Report will be submitted within 30 days to further-describe this event.

G

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