ML18101A515

Record of Telcon W/Nrc on 941123 Re LCR 94-06 RCS Flow Measurements,Feedwater Line Breaks & Comparison of Feedwater Malfunction Event to Rod Withdrawal from Subcritical

ML18101A515
Person / Time
Site:	Salem
Issue date:	11/23/1994
From:	Mctigue W Public Service Enterprise Group
To:
References
NUDOCS 9501310259
Download: ML18101A515 (3)

Text

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• UG'OLATORY AGENCY CONTACT JmMORAND'tJK Continuation Sheet RCS Plow Measurement The September 19, 1994 letter (reference 2) atatA~ that the latest RCS flow measurement [366,054 gpm] is approximately 2.5%

above the Teoh Spec limit [357.200 gpmJ. NRC requested confirmation that the 2.st margin was determined based on the difference between the measured valnA and the Tech Spec limit; i.e., (366,054 - 357,200) + 357,200, without any additional uncertainties applied. PSE&G ~onfirm.ed thie to be the ~aee.

Because the Teoh Spec limit already accounts for meas~rement uncertainty (as :i.ndicated in Table 3.2-1), direct oompa:risou Qf the measured value to the Tech Spec limit ia appropriate.

compari*on of Feedwater Malfunction BVent (l'WJI) to Roel Wi~hdra,.,a1 ~rom S'UboricioQl (RWl-S)

The ~ebrua:ry J, 1994 amendment reques~ (reference 1) states that the FWM event at zero power is acceptable because it remains bounded by the n.WFO. NRC asketl why the ewe transients are compared to each other, since FWM ia a primary system cooldown and RWFS ia a heatup tr.:m~l~nt. PSE.XG replied* that the events are compared because they are both positive reactivity insertione, cam...,e1.rison o! these transients is made in the current UFSAR (Section 15.2.10). The FWM remains bounded by the RWFS wiLb the proposed reduction in RCS flow.

~eedwater Line Break NRC requested clarification of two statements made in reference l, pg. 6 relative to the feedwater line brP.ak evaluation: i.e, that the proposed reduction in flow would result in a small decrease in steam generator mass, and that the current licensing basis analyses contain sufficient margin to accommodate the decay heat removal pP-n,..l.ty associated with the proposed reduction in RCS flow.

PSE&G replied that these statements were based on sensitivity calculations performed by We.atinghouse. These cQlculations ahow that the proposed reduction in RCS flow would result in a slight decrease in the steam generator inventory ~o an initial cond1Llon for the postulated transient. Additional calculations show that this slight decrP-~Be in inventory would result in a sli9hL reduction in margin to the hot leg saturation temperature, but that thE'! RCS would remain aubooolcd [R.cs subcoollnH is used to conservatively demonstrate that core cooling is maintained throughout the transient] .

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'Locked Rotoz- lvent and Rupture of a Control Rod t>rive Mech&niliDll (CIU)M) Housing NRC asked why the effect of the flow reduction on Peak Clad Temperature (PCT) is discussed for these events, as oppoAAn to evaluating these transients for Departure From Nucleate Boiling (DNB} . NRC also noted that no UFSAR section referP.n~e. was provided for the Locked Rotor Event. -

PSE&G replied that the Locked Rotor Event (described in UFSAR section 15.4.5) and the Rupture of R P.RDM Housing fall under i\N~

Condition IV, Limiting Faults, which is the same category as Large Break LOCA. ThereforP., t.hese events a.:re evalutltcd to ensure that core cooling capability is maintained. DNB is assumed to occur fn~ these transients, PCT is an appropriate criterion for Condition IV events.

NRC asked why the three criteria on pg. 7 of reference l are used for t'.h.,:\ rod Rupture of the Cl:IDM Ilouaing

• i.e., ll1ulL::i on average fuel pellet enthalpy, percentage of fuel melt at the hot spot, and pQak RCS pressure less than Faulted Cumlition limits.

PSE&G replied that these criterld. g,.r;e used by Westinghouse to conservatively demonstrate that Condition IV criteria are met for thia event.

Nn.C ~tated they wuuld conslder toe information presented during this call, and would get back to PSE&G if additional information is required Lo process the amendment request.

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