ML18052B042

Responds to Three of Four NRC Concerns Re Util Endorsement of C-E Owners Group Methodology on Reactor Coolant Pump Trip Per Request in Generic Ltr 86-06

ML18052B042
Person / Time
Site:	Palisades
Issue date:	05/29/1987
From:	Kuemin J CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
TASK-2.K.3.05, TASK-TM GL-86-06, GL-86-6, NUDOCS 8706040025
Download: ML18052B042 (4)

Text

consumers

• Power l'OWERINli MICHlliAN"S l'ROliRESS General Offices: 1945 West Parnell Road, Jackson, Ml 49201 * (517) 788-0550 May 29, 1987 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -

IMPLEMENTATION OF TMI ACTION ITEM II.K.3.5 - AUTOMATIC TRIP OF REACTOR COOLANT PUMPS - GENERIC LETTER NO. 86-06 NRC Generic Letter No. 86-06 requested licensees who endorse the Combustion Engineering Owners Group (CEOG) methodology on reactor coolant pump trip to submit information to the NRC needed for plant specific reviews. Consumers Power Company letter of November 13, 1986 delayed submittal of the information due to the then existing plant shutdown and an uncompleted parallel effort by the CEOG to develop generic instrument uncertainties for a harsh environment.

The CEOG work is not yet complete however we are providing responses to three of the four NRC concerns as requested in GL 86-06 in the attachment. The second item of concern (instrument uncertainties) is provided as preliminary information pending final inhouse technical review and completion of the CEOG work which is now scheduled for completion in September, 1987. Upon completion of the CEOG work we will review the methodology and conclusions, compare them with our evaluation of instrument uncertainties and inform the NRC of any necessary changes.

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Staff Licensing Engineer CC Administrator, Region. III, NRC NRC Resident Inspector - Palisades Attachment 8706Q40025c87QS29 PDR ADOCK.05000255

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OC0587-0080-NL04

ATTACHMENT Consumers Power Company Palisades Plant Docket 50-255 IMPLEMENTATION OF TM! ACTION ITEM II.K.3.5 AUTOMATIC TRIP OF REACTOR COOLANT PUMPS GENERIC LETTER NO. 86-06 May 29' 1987 2 Pages OC0587-0080-NL04

Attachment IMPLEMENTATION OF TMI ACTION ITEM II.K.3.5 AUTOMATIC TRIP OF REACTOR COOLANT PUMPS GENERIC LETTER NO. 86-06

1. Identify the instrumentation to be used to determine the RCP trip setpoints, including the degree of redundancy of each parameter signal needed for the criteria chosen.

Response

The instruments used to determine the RCP trip setpoints are three wide range pressurizer pressure instruments and 16 PCS temperature instruments. The degree of redundancy is not appropriate for manual actuation. Low pressurizer pressure is the parameter used for manual tripping of the first two RCPs. Pressure and temperature are used to determine if the RCPs have adequate NPSH.

The following instrumentation is used to assist the operator in differentiating between events. Four low Steam Generator Pressure instruments per Steam Generator are used to differentiate between a Steam Line Break and a LOCA. Six containment radiation and four secondary side radiation monitors may be used for a differentiation between a Steam Generator Tube Rupture and an LOCA.

Consumers Power Company endorses CEN-268, however, consistent with the Emergency Procedure Guidelines (CEN-152), we have retained the use of Steam Generator pressure as a variable for determining whether a LOCA or SLB exists. We also note that the EPGs as implemented in the plant EOPs require tripping. all the RCPs on inadequate NPSH, and also in a Loss of all Feedwater event.

2. Identify the instrumentation uncertainties for both normal and adverse containment conditions. Describe the basis for the selection of the adverse containment parameters. Address, as appropriate, local conditions such as fluid jets or pipe whip which might influence the instrumentatiqn reliability.

Response

The preliminary results for the instruments uncertainties are:

PCS Pressure Steam Generator Pressure Normal 60 psi 22 psi Accident 83 psi 71 psi The effects of fluid jets and pipe whip were not determined due to the redundancy, independence and separation of the instrumentation.

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3. In addressing the selection of the criterion, consideration of uncertainties associated with the CEOG supplied analyses values must be provided. These uncertainties include both uncertainties in the computer program results and uncertainties resulting from plant specific features not representative of the CEOG generic data group.

Response

Implementation by Consumers Power Company of the Trip Two/Leave Two strategy described in the document CEN-152 which uses CEN-268 will utilize plant specific features which are representative of the CEOG generic data group.

The uncertainties associated with the computer code results are adequately addressed in the documents CEN-268 and CEN-268 Supplement 1-NP.

4. Identify all plant procedures (except for those concerning normal operations such as normal cooldown) which require RCP trip guidelines.

Reference to the CEOG EPGs is acceptable if endorsed by the licensee.

Include training and procedures which provide direction for use of individual steam generators with and without operating RCPs.

Response

The recently revised Emergency Operating Procedures, which used the CEN-152 as their basis, provide the appropriate RCP trip guidelines.

The Emergency Operating Procedures for Steam Generator Tube Rupture, Excess Steam Demand Event, and Functional Recovery provide guidance for use of an individual steam generator with or without operating RCPs.

Formal training including simulator training was conducted on the above Emergency Operating Procedures, prior to their implementation and training continues as specified in our Licensed Operator Training Programs.

OC0587-0080-NL04