ML20118B583

Provides CP&L Response to Requested Actions of NRC GL 92-04, Resolution of Issues Related to Reactor Vessel Water Level Instrumentation in BWRs Pursuant to 10CFR50.54(f)

ML20118B583
Person / Time
Site:	Brunswick
Issue date:	09/28/1992
From:	Starkey R CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-92-04, GL-92-4, NLS-92-267, NUDOCS 9210050170
Download: ML20118B583 (5)

Text

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CD&L

, Camlina Power & Ught Company P O tbu t55 Rate.gh, N C 27602 16 28 1992 R B STAAkiY,JR '

vu e,eseeni Nm Sme Deawnt 10 CFR 50.54(f)

United States Nuclear Regulatory Comtras.uen

> ATTENTION: Document Control Desk Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50 325 & 50-324/ LICENSE NOS. DPR 71 & DPR 62 CP&L RtSPONSC 10 NRC G'IERIC LETlER 92-04, " RESOLUTION OF THE ISSUES RELATED TO REAC. aR VESSEL WATER LEVEL INSTRUMENTATION IN BWRs PURSUANT TO 10 CFR 50.54(F)"

Gentlemen:

The purpose of this letter is to provide Carolina Power & Light Company's (CP&_) response to the requested actions of NRC Genenc Letter No. 92 04, " Resolution of the issues Related to Reactor Vessel Water Level Instrumentation in BWRs Pursuant to 10 CFR 50.54(t)" for the Brunswick Steam Electric Plant (BSEP), Unit Nos.1 and 2. Generic Letter No. 92 04 was issued by the NRC w on August 19,1992, requesting licensee responses to specific actions regarding the adequacy of i and corrective actions for BWR water level instrumentation with respect to the i:.ects of non-condensable gases on system operrition. Carolina Power & Light Company responses for BSEP for each reqtasted action of the generic letter are provided in Enclosure 1 to this letter.

Please refer any questic.is regarding this submittal to Mr, M. R. Oates at (919) 546 6063.

Yours very truly,

< 'N j

R. B. Starkey, Jr. /

JCP/]cp (9204 wpf)

Enclosure R. B. Starkey, Jr., having been first duly sworn, did depose and say that the information contained '

herein is true and correct to the best of his information, knowledge and belief; and the sources of his information are officers, employees, contractors, and ar,ents of Carolina Power & Light Company, o""'""e ,

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• 1 ENCLOSURE 1 BRUNSWlCK STEAM ELECTRIC PLANT, UNITS 1 AND 2 l

NRC COCKET NOS. 50 325 & 50-324 l OPERATING LICENSE NOS. DPR-71 & DPR-62

! CP&L RESPONSE TO NRC GENERIC LETTER NO. 92-04 Egguested Action 1.

i l 1. In light of potential errors resulting from the effects of non-condensable gas, each licensee should determine:

! a. The impact of potentiallevelindication errors en automatic safety system responses

! during alllicensing basis transients and accidents.

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b. The impact of potential level indication errors on opurators' short and long term ections during and after all licensing basis accidents and transients

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c. The impact of potential level indication errors on operator i tions prescribed in emergency operating procedures or other iffected p.c,cedurec not covered in (b).

Cf&L Response to Peauested Action la.

4 The BWR Owner:.' Group (BWROG) provided to the NRC and each BWROG mernber utility BWROG

! Report-92074, "BWR Heactor Vessel Water Level Instmmentation, Revision 1," August 28,1992 l (Reference 1). This generic report addresses the safety impact of potential water levelindication errors on automatic safety system response during alllicensing basis transients and accidents. This 3

analysis basis is contained in Section 6.0, Safety Analysis. of the report and is summarized in i Section 2.2, Plant Resoonse to Postulated Accident Scenarios. Carolina Power & Light Company roognizes that there are differences between the designs of BWR plants and systems; howaver, comparison of the BSEP Final Safety Analysis Report (FSAR), BSEP SAFER /GESTR Arialysis

(Reference 5), and the BSEP Engineering Anabsis Description (Reference 6) to the BWROG l Report-92074 reinforces CP&L's general understanding that the basic plant response tc the design basis transients and accidents is sufficiently similar to obviate additional plant unique re-analysis.

The diverse initiating signal for low pressure Emergency Core Cooling Syst6m 4r BSEP requiros

! both a high drywell pressure and a low reactor vessel pressure, rather than onei a high drywell

. pressure as in the report. Since the two required signals are not dependent on reference leg inventory, the conclusions of the report are still valid.

CP&L Resoonse to Reauested Action 1b.

4 The BWROG report addresses, in Section 6.9, Ooerator Resoonse. the anticipated operator actions to potential water level indication errors. In the short term, the report discusses in Section 6.0 that -

the automatic safety actions will be performed as necessary. Consistent with the recommendations addressed within the Emergency Procedures Committee (EPC) letter to plant operations superintendents dated August 19,1992 (Referenec 2i, additional guidance will be provided to appropriate plant operations personnel as part of either licensed operator retraining or sSift training prior to scheduled startup. This interim guidance information will sensitize the opsrators to the possible concerns with accurate water level readings following a rapid

, depressurization, while not necessitating a change to the existing lonc term guidance provided in the Emergency Operating Procedures (EOP).

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' As stated in Section 6.9 of the report and the 1.b response above, the nrvators have adequate guidance in the present EOrs when augmented by the recent sensitiza o.1 ar 'ormation provided d within Reference 2. In addition, CP&L has reviewed and concurs with thc rat.pc c 1 providi,d within i the BWROG !etter

• Response To Tiiird Requested Action of Generic L.;ur 92-04," dated l September 24,1992 (Reference 3). The EPC is continuing to review the potential need for any

additional guidance in the Emergency Procedure Guidelines (EPG) to further address the potential water level indication errors. Such review wih take into account the information from the BWROG program of analysis and testing regarding this issue.

. Ecouested Acti 9 n1 l 2. Based upon the results of (1) above, each license 6 should notify the NRC of short term

' actions taken, such as:

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a. Periodic rnonitoring o' level instrumentation system ;eakage; and,

b. Implementation of procedures and operator training to assure that potential

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level errors will not result in improper ope ator actions.

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OPet Resoonso to R t2Wlt_stion d L l

( Based upon the results of 1 above, CP&L has established the folk wing interim operator training-

• i actions:

• Review of the EPC letter to plant operations superintendents dated August 19,1992 i

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• Dovelopment of ogorator training regarding the phenomenon of non-condensable gases coming out of solution. This training willinclude 9 description of l depressurization (both slow and rapid) and probable lene indication response.

• Review of expected operator actions for loss of level indication, including Technical

[ Specification action statements, EOPs, etc.

l j' These items will be implemented prior to scheduhd startup.

CP&L is considering the following additional actions to monitor this pheriomenon:

• Analysis of reactor water level data during future shutdowns.

• Performance of periedb instrument rack walkdowns.

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Eeauested Action 3.

i' 3. Each licensee should provide its plans and schedule for corrective actions, including any proposed hardware modifications nJCessary to ensure the level instrumentation system l design is of high functional reliability for long term operation Since this instrumentation plays an important role in p! ant safety and is required for both normal and accident conditions, the staff recommends that sach utility implement its longer term ar.tions to assure a level instrumertation system of high functional rcliability at the first opportunity but prior to starting up after the next refueling outage commencing 3 months after the date

of this lettor.

CP.&1 Resoonse to Reattisted Action 3.

Carolina Power & Light Company endorses the BWROG plans originally provided in the BWROG l letter of August 12,1992 (Reference 4). Carolina Power & Light Company also reaffirms support of the BWROG plan by endorsing the BWROG letter of September 24,1992 (Reference 3). The i BWROG testing and analytical development program should provide a mc,re accurate estimate of l the effects of non-condensables t.oming out of solution on reference legs under depressurization.

Carolina Power & Light Compar'y expects that the results of this investigation will show that BSEP '

has a levelinstrumentation system of high functional reliability, if the BWROG Program indicates l

that mod;fications are necessary to assure that the level instrumentation is of high functional J reliability, such modification schedules will be prosided to the NRC at that time. The next refueling

outage (Reload 8, Cycle 9) for BSEP Unit No.1 is currently scheduled to begin on March 4,1393.

The next refueling outage for BSEP Unit No. 2 (Reload 9, Cycle 10)is scheduled to begin on September 9,1993. .

hi engn:

i 1) BWROG-32074 Report, "BWR Reactor Vest.el Water Level Instrumentation, Revision 1,"

August 28,1992

! 2) Letter, B. T. Wil!iamson 11 (EPC) to BWR Owner's Group Members Plant Operations Superintendents, " Effects Of Non-Condensable Gases On BWR Cold Leg RPV Water Level Instrumentation," August 19,1992.

j_ 3) BWROG-92082, G. J. Beck (BWROG) to NRC, Response 4 Third Requested Action Of

Car,aric Letter 92 04," September 24,1992 l

l 4) BWROG-92072, G. J. Beck (BWROG) to W. T. Russell (NRC), " Reactor Vessel Water Level i instrumentation," August 12,1992 i - 51 GE NEDC-31624P, " Brunswick Steam Electric Plant Units 1 and 2 SAFER /GESTR-LOCA, l Loss-Of-Coolant Accident Analysis," Revision 2, July 1990 i

6) GE Document No. EAS-62-1088, "Brur.: wick Steam Electric Plant Loss-Of-Coolant Accident l tngineermg Analysis Description." February 1990 i i

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