ML20168A740

Final ASP Analysis - Turkey Point 3 (LER 250-74-LTR)

ML20168A740
Person / Time
Site:	Turkey Point
Issue date:	06/16/2020
From:	Christopher Hunter NRC/RES/DRA/PRB
To:
Littlejohn J (301) 415-0428
References
LER 1974-LTR
Download: ML20168A740 (4)

Text

PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:

91676 Date:

May 17, 1974

Title:

Malfunction of Auxciliary Feedwater Pumps at Turkey Point 3 The failure sequence was:

1. With the reactor at power, an attempt was made to start all three auxiliary feedwater pumps.

2. Two of the pumps failed to start due to overtightened packings.

3. The third pump failed to start due to a turbine regulating valve pneumatic controller malfunction.

Corrective action;

1. The packing on the "A" AFW pump was loosened and later replaced.

After replacement, a sticking governor linkage was also discovered.

2. The "B" A91 pump was repacl-ed.

3. The."C" AFW pump governor was exercised and its pneumatic controller output signal was increased in value.

Design purpose of failed system or component:

1. The auxiliary feedwater system provides feedwater to the steam generators for reactor cooling when main feedwdter is unavailable.

Unavailability of system per WASH 140G:*

Auxiliary feedwater system:

2.5 x 1lO4 (start + 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />)

Unavailability of component per WASH 1400:*

pump, failure to start: 1

• 10-3/D

• Unavailabilitieq are in units of per demand D-1. Failure rates are in units of per hour HR-'.

of Reactor Auxiliary PORV PORV or High Long Term Potential Sequence Tri Fedater and DeanV PORV ola-Pressure Core Severe No.

'ater Secondary tion Valve Injection Cooling Core Heat Removal Closure Damage No 1

No 2

Yes 3

Yes 4

No 5

No 6

Yes 7

rYes 8

No 9

No 10 LA Yes11 Yes 12 Yes 13 NSIC 91676 -

Sequence of Interest for Malfunction of Auxiliary Feedwater Pumps at Turkey Point 3

• Use of HPI following AFW failure not included in mitigation procedures.

CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NU~MBER:

91676 DATE OF LER:

May 17, 1974 DATE OF EVENT:

May 8, 1974 SYSTEM INVOLVED:

Auxiliary feedwater COMPONENT INVOLVED:

Auxiliary feedwater pumps CAUSE:

Overtightened packings, turbine regulating valve pneumatic controller malfunction human maintenance error SEQUENCE OF INTEREST:

Loss of feedwater ACTUAL OCCURRENCE:

Failure of three auxiliary feedwater pumps to start, and run during testing.

REACTOR NAME:

Turkey Point 3 DOCKET NUMBER:

50-250 REACTOR TYPE:

PWR DESIGN ELECTRICAL RATING:

693 MWe REACTOR AGE:

1.9 yr VENDOR:

Westinghouse ARCHITECT-ENGINEERS:

Bechtel OPERATORS:

Florida Power & Light Co.

LOCATION:

• Z5. miUesa.outh_: of Miami, Fla.

DURATION:

360(a) hours PLANT OPERATING CONDITION:

At 98% power SAFETY FEATURE TYPE OF FAILURE:

(a) inadequate performance; nbfailed to start; (c) made inoperable; (d) __________

DISCOVERY METHOD:

During testing COMMENT:

The three ANW pumps which failed to start also provide auxiliary feedwater to Unit 4.