ML20086K911

AO 74-7:on 740305,MSIV Closing Time Exceeded Max Permissible Operating Time & Drywell Floor Drain Sump Pump Outboard Isolation Valve Failed to Close on Group II Isolation Signal

ML20086K911
Person / Time
Site:	Peach Bottom
Issue date:	03/15/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20086K912	List: ML20086K911 ML20086K918
References
AO-74-7, NUDOCS 8402070070
Download: ML20086K911 (2)

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PHILADELPHIA. PA.191G1 N.g k- IO py 4. P['4 .de% *' q 1215) 8414ooo h, /f March 15, 1974 N. , qd L._N Mr. A. Giambusso 50-277 Deputy Director of Reactor Projects United States Atomic Energy Commission Directorate of Licensing  !

Washington, D.C. 20545

Subject:

Abnormal Occurrence The following occurrence was reperted to Mr. R. A. Feil, Region I Regulatory Operations Office on March 6, 1974. Written notification was made to Mr. James P. O'Reilly, A.E.C. Region I Regulatory Operations Office on March 6. 1974. In accordance with Section 6 7 2.A of the Technical Specifications, Appendix A of DPR-44 for Unit 2 Peach Bottom Atomic Power Station, the following report is being submitted to the Directorate of Licensing as an Abnormal Occurrence.

Reference:

License Number DPR-44, Ammendment Number 1 ~

Technical Specification Table 3 7.1 Report No.: 50-277-74-7 Report Date: 3/15/74 l Occurrence Date: 3/5/74 Facility: Peach Bottom Atomic Power Station - Unit 2 R.D. 1, Delta, Pennsylvania 17314 Identification of Occurrence:

A. A main steam isolation valve closing time slightly exceeded the maximum permissable operating time.

B. The drywell floor drain sump pump outboard isolation valve failed to close on a Group II isolation signal.

Conditions Prior to Occurrence:

Reactor at approximately 23% power and stable. Main steam isolation test initiated.

Description of Occurrence:

A. During the mlin steam line isolation test initiated from 23%

power, all main steam isolation valve closure. times were re- f corded. The closing time for A0-2-2-80A was 5.1 seconds.

This exceeds the maximum allowable operating ' time of 5 8402070070 740315 p 'h' I

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seconds provided in the Technical Specifications.

B. During the Group II isolation caused by low reactor vessel

. level following the isolation of the main steam lines, 4

A0-2-83, the outboard isolation valve for the drywell floor

drain sump pump failed to close.

Designation of Apparent Cause of Occurrence:

A. The cause for the slight change in valve closing speed has j not been identified.

B. Preliminary investigation indicates that the solenoid valve i associated with A0-2-83 failed to port properly when the solenoid was de-energized. .

Analysis of Occurrence: t A. Main steam line isolation was properly accomplished wi thin the allowable time frame during the test. The small increase in operating time of the valve has no safety implications.

B. The floor drain sump pump discharge line has both an inboard and outboard isolation valve. Proper operation of the in-i board valve as a result of the Group II isolation signal

! properly isolated this line. No safety significance is attached to this occurrence.

Corrective Action:

A. MSIV A0-2-2-80A was re-adjusted, stroke tested and timed prior to reactor start-up. The valve was subsequently tested and timed with steam flow. All hydraulic adjustment needle valves

have been marked such that any future change in position with time or vibration can be identified.

B. The solenoid valve associated with A0-2-83 was dis-assembled, j internally cleaned and re-assembled. Proper operation of A0-2-83 was verified following repair.

j Very truly yours, t.-j te c M. J. Cooney Ass't' Gen'l Superintendent Generation Division

, cc: Mr. J. P. O'Reilly Director, Region i United States Atomic Energy Conmission 631 Park Avenue i King of Prussia, PA' 19f4 06 1

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