ML17206A642

RO 335-B-78-09 on 781227:condenser Temp Rise in Excess of 24 F.Cause Described in Previous RO-335-78-03,04,07 & 08. Awaiting Licensing Action on Request to Allow Condenser Temp Limit to Be Increased to 265 F

ML17206A642
Person / Time
Site:	Saint Lucie
Issue date:	01/18/1979
From:	FLORIDA POWER & LIGHT CO.
To:
Shared Package
ML17206A641	List: ML17206A640 ML17206A642
References
NUDOCS 7902010168
Download: ML17206A642 (4)

Text

FLORIDA POWER &, LIGHT COMPANY ST. LUCIE UNIT NO. 1 REPORTABLE OCCURRENCE NO. 335 TITLE: Maximum Condenser Temperature Rise A. Descri tion, Anal sis and Evaluation Reportable Occurrence Nos. 335-B-78-03, -04, -07 and -08 described occasions on which the condenser temperature rise at. St. Lucie Unit: No. 1 was observed to be in excess of 24 F. Another instance of this type occurred in December. as follows:

TIME dT POWER FLOW 12-27-78 0300 24.75 F 100 495,000 gpm As was described in the'arlier R.O.'s cited above, the circulating water system at. the. St. Lucie Plant has been experiencing conditions of'ystem fouling which have caused the condenser temperature rise to slightly exceed 24'F. These conditions of fouling make the temperature rises which have been- experienced. acceptable as per ETS 2.1 2 This. event is being reported., however, as a continuing item. of potential public interest concerning environmental. impact from plant. operation in accordance with.. ETS 5.6 2 a No instance. of. discharge canal temperature exceeding the limit of 111'F (ETS 2.1.1) was observed at. a time corre-sponding to the reported. condenser temperature rise.

Therefore, it; is believed. that. no adverse environmental impact has zesulted from this. event Also, the discharge area thermograph recorders'hich are located in the vicinity of the hot spot have shown no times at which the maximum allowable instantaneous temperature in the hot, spot was exceeded.

B. Cause The conditions of the circulating water system which caused these. events have been described in the previous R.O. reports which were cited in Section A, above.

~ C'. Corrective Action Operation of the condensers at greater-than-design flow has been undertaken occasionally to help prevent exceeding the condenser hT limit. and can continue up to some point.

However, this mode of operation is considered undesirable for long term operation since it of the Aluminum-Brass condenser tubes.

will affect the integrity V9080x 0 /C g

fH 8 )f Y

By letter dated August 29, 1978 (L-78-281) we requested that the allowable condenser LT be increased to 26'F for an interim period. Ne are awaiting licensing action on this request.

At this time, it is planned to replace the existing Aluminum-Brass condenser tubes with titanium tubes during the cycle 3 refueling outage for St. Lucie 1, expected to begin in April, 1979. Although this is expected to re-store some of the operating margin to the system, such that the condenser hT can be maintained at or below 24'F for some period of time it does not address any anti-cipated. future degradation. in system performance. FPL therefore plans to request a permanent modification of the ETS to allow operation at. a higher condenser hT upon completion of the necessary environmental. assessments.