ML20147E236

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Summarizes Discussions Between Nrr,Region III & Util Re saftey-related Classification of 24/48 Ventilation Duct Chase Power Supply Sys & Recommends Sys Classification
ML20147E236
Person / Time
Site: Quad Cities  Constellation icon.png
Issue date: 01/14/1988
From: Ross T
Office of Nuclear Reactor Regulation
To: Butterfield L
COMMONWEALTH EDISON CO.
References
TAC-57784, TAC-57785, NUDOCS 8801210049
Download: ML20147E236 (3)


Text

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o Docket Nos.: 50-254 DISTRIBUTION and 50-265 M et File OGC-Beth.

NRC & Local File EJordan PDIII-2 Rdg. File JPartlow Mr. L. D. Butterfield, Jr. GHolahan ACRS(10)

Nuclear Licensing Manager LLuther Plant File Commonwe ith Edison Company TRoss Post Offi a Box 767 Chicago, Illinois 60690

Dear Mr. Butterfield:

SUBJECT:

24/48 VDC POWER SUPPLY CLASSIFICATION AND TS STATUS (TAC NOS. 57784 AND 57785)

The purpose of this letter is to sumarize discussions between NRR, Region III, and Comonwealth Edison Company (Ceco) concerning saf tey-related classification of 24/48 VDC power supply components ar.d/or system, and to recommend the manner in which this system should be classified.

The 24/48 Volt DC system supplies electrical power to source range and intermediate range neutron flux instrumentation which are counted upon to provide the post accident neutron monitoring capability prescribed by Regulatory Guide (RG) 1.97, "Instrumentation for Light Water Cooled Nuclear Power Plants to Assess Plant Conditions During and Following an Accident". RG 1.97, Revision 2, designates neutron flux as a key Type B variable which must be measured by instrumentation that meets Category 1 design and qualification criteria. ,

Category 1 instumentation is required to be energized from station Class 1E standby power sources in accordance with RG 1.32, "Criteria for Saf tey-Related Electric Power Systems for Nuclear Power Plants".

On June 12, 1984 the Commission issued Quad Cities Nuclear Power Station (QCNPS) an Order confirming CECO commitments regarding emergency response capability.

In accordance with the timetable established by this order, Ceco issued a letter dated August 1,1985 which documented their review of existing instrumentation against the requirements of RG 1.97 and described proposed actions for compliance. This letter stated that the 24/48 VDC electrical bus, which supplies power to neutron flux monitoring instrumentation, complies with RG 1.97.

To date, only the batteries of the 24/48 VDC system at QCNPS have been upgraded to Class 1E standards. Other 24/48 VDC power supply components (e.g. battery chargers) are not Class 1E. Furthermore, neither the 24/48 VDC system or any of its components are currently classified as saftey-related.

6801210049 080114 4 DR ADOCK OSO

a To be consistent with RG 1.97 Category 1 design and qualification criteria, the staff recomends a saftey-related classification for the 24/48_ VDC power system. Accordingly, CECO should reclassify 24/48 VDC batteries, and other 24/48 VDC power supply components as appropriate, to comply with RG 1.97.

Comunications with Station and Corporate engineering personnel indicate the safety-related classification status of 24/48 VDC power supply components and/or system at QCNPS is presently under evaluation.

Thierry Ross, Project Manager Project Directorate III-2

Division of Reactor Projects - III, IV, V and Special Projects .

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Hr. L. D. Butterfield, Jr. Quad Cities Nuclear Power Station Comonwealth Edison Company Units I and 2  ;

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Mr. Stephen C. Shelton '

Vice President Iowa-Illinois Gas and Electric Company P.O. Box 4350 Davenport. Iowa 5??C3 Mr. Michael Miller  !

Isham, Lincoln & Beale Three First National Plaza Suite 5200 Chicago, Illinois 60602 Mr. Richard Bax Station Manager Quad Cities Nuclear Power Station -

22710 206th Avenue North Cordova, Illinois 61242 Resident Inspector U.S. Nuclear Regulatory Comission 22712 206th Avenue North Cordova, Illinois 61242 Chairman Rock. Island County Board of Supervisors ,

1504 3rd Avenue Rock Island County Office Bldg.

Rock Island, Illinois 61201 Mr. Michael C. Parker, Chief '

Division of Engineering  ;

Illinois Department of Nuclear Safety 1035 Outer Park Drive Springfield, Illinois 62704 5 Regional Administrator, Region III '

1 U.S. Nuclear Regulatory Comission 799 Roosevelt Road l Glen Ellyn, Illinois 60137 i

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