ML20199H208

Revised TS Bases Page B 3/4 4-15

ML20199H208
Person / Time
Site:	South Texas
Issue date:	11/20/1997
From:	HOUSTON LIGHTING & POWER CO.
To:
Shared Package
ML20199H207	List: ML20199H208 NOC-AE-000023, Forwards Revised TS Bases Page,Per 10CFR50.59 as Described in Util
References
NUDOCS 9711260048
Download: ML20199H208 (1)

Text

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REACTOR COOLANT SYSTEM ,

BASES. ,

LOW TEMPERATURE OVERPRESSURE PROTECTION (Continued) overshoot beyond the PORV Setpoint which can occur as a result of time delays in signals processing and valve opening, instrument uncertainties, and single failure. To ensure that a. ass and heat input transients more severe than those assumed cannot occur. Technical Specifications require lockout of all high head safety injection Jum)s while in M0F 5 and MODE 6 with the reactor vessel head on. All but one 1191 head safety injection pump are required to be locked out in MODE 4. Technical Specifications also require lockout of the positive dis)lacement pump and all but one charging pump while in MODES 4. 5.

and 6 with 11e reactor vessel head installed and disallow start of an RCP if secondary temperature is more than 50*F 6bove primary temperature.

Administrative controls and two RHR relief valves will be used to provide cold overpressure protection (COMS) during the ASME stroke testing of two administratively declared inoperable PORVs. During the performance of the PORV function test, two RHR trains wiil be OPERABLE and in operation with the auto closure interlock bypasses (or deleted) to provide COMS.

With one PORV inoperable. COMS will be provided during the ASME test by the OPERABLE PORV and one RhR relief valve associated with an OPERABLE and operating RHR train which has the auto closure interlock bypassed (or deleted). Each RHR relief valve 3rovides sufficient capacity to relieve the flow resulting from the maximum clarging flow with concurrent loss of letdown.

Analysis conservatively demonstrates that the RHR relief valves limit RCS pressure to approximately 590 psig.

Therefore two OPERABLE and operating RHR trains .g.t one OPERABLE PORV and one OPERABLE and operating RHR train will provide adequate and redundant overpressure protection. Use of the RHR relief valves will maintain the RCS pressure below the low temperature limits of ASME Section Ill. Appendix G. l With regard to the MODE 6 a)plicability of this Technical Specification, the statement "with the head on tie reactor vessel" means any time the head is installed with or without tensioning the RPV studs.

The Maximum Allowed PORV Setpoint for the COMS will be updated based on the results of examinations of reactor vessel material irradiation surveillance specimens performed as required by 10 CFR Part 50. Appendix H.

3/4.4.10 STRUCTURAL INTEGRITY - BASES The inservice inspection and testing programs for ASME Code Class 1. 2.

and 3 components ensure that the structural integrity and operational readiness of these components will be maintained at an acceptable level SOUTH TEXAS - UNITS 1 & 2 B 3/4 4-15 Unit 1 - Amendment No. 4. as. 65 1119-97 Unit 2 - Amendment No. N . 44 1 9711260040 971120 '

PDR ADOcK 05000490 P PDR

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