ML18057A684

Proposed Tech Spec 3.1.7 Re Overpressure Analysis for Primary & Secondary Safety Valves

ML18057A684
Person / Time
Site:	Palisades
Issue date:	12/28/1990
From:	CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Shared Package
ML18057A683	List: ML18057A682 ML18057A684
References
NUDOCS 9101020366
Download: ML18057A684 (2)

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ATTACHMENT Consumers Power Company Palisades Plant Docket 50-255 TECHNICAL SPECIFICATIONS CHANGE REQUEST PRESSURIZER SAFETY VALVE SETPOINT Page Marked up with Proposed Changes 1 Page I f\.*.* ' \ ,* b 90122::: .. 910102036-05000255 {\ F'DR . ADOCK PDR Ll ! . P, ---------------------------

3. l PRIMARY COOL T SYSTEM (Contd) 3. 1. 7 . _. Primary and condary Safety Valves Specifications . a. The reactor shall not be made critical unless all three ' . '\ ____ . _________

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-settings maintained between 2500. psia and 2580 psia (:!: -;;;.) * '\ h b. A of one operable safety valve shall be installed the pressurizer whenever the reactor head is on the vessel. c. Whenever the reactor' is in power operation, a minimum of ""b 23 secondary system safety valves shall be operable with their a lift settings between 985 psig (+/- 30 psig) and 1025 (+/- 3%) psig. q 0 () '-.{ . ..\)

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.t() :s "" I' l \) '-1 & VJ The primary and secondary safety valves pass sufficient steam to limit the primary system pressure to 110 percent of design (2750 psia) following a complete loss of turbine generator . (l) load without simultaneous reactor trip while operating at 2650 MWt. The reactor is assumed to trip on a "High Primary Coolant System Pressure" signal. To determine the.maximum steam flow, the only other pressure relieving system assumed operational is_ the secondary system safety valves. Conservative.values for all system parameters, delay times and core moderator coefficient are assumed. Overpressure protection is provided to. the portions of the primary coolant _system which are at the highest. pressure considering pump head, flow pressure drops and elevation heads. If no residual heat were removed by any of the means available, the amount of steam which could be generated at safety valve lift pressure would be less than of one valve'scapacity.

One valve, there.fore, provides adequate defense against overpressurization when the reactor is subcritical.

The total relief cagacity of the 24 secondary system safety is 11. 7 x 10 lb/h. This .is based on a steam flow equivalent to an NSSS power level of 2650 MW at the nominal 1000 psia valve lift

• t At the power: rating of 2530 MWt' a relief capacity of less than 11.2 x 10 6 lb/h is required. prevent overpressurization of _ secondary systetD: of loss *of load .c.onditions, and-23 valves . . 6 (1'2) provide relieving capability of 11.2 x 10 lb/h. '

• overpressurization analysis for the of load event <2>.p.01 .e'1e/c. g*l1:.) I suppo the specified secondary safety* valve lift pressure *

• tolerance*

• . ASME B&PV Code, 1986 edition,Section XI, I subsection IWV-3500, specifies ANSI/ASME OM-1-1981 requirements.

which allow the specified tolerances in the lift pressures of the safety valves. References.

(1) Updated FSAR, Section 4.3./i and 4.3.9.4 (2) ANF-87-150(NP), Volume 2,.Section.15.2.1 3-25 Amendment No. Jr, Uf, {:3\ Ad. d M / /. n *

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