ML20140C660

Forwards Revised Response to Question 1-2,incorporating Addl Info Requested by NRC & Corrected Response to Question 1-3 Re Proposed Analog Transmitter Trip Sys Tech Spec Changes, Per 840613 Telcon

ML20140C660
Person / Time
Site:	Hatch
Issue date:	06/14/1984
From:	Gucwa L GEORGIA POWER CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
NED-84-321, TAC-54169, TAC-54433, TAC-54607, NUDOCS 8406190402
Download: ML20140C660 (3)

Text

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Georgia Power Cortpany

,, 333 Piedmont Avenue

• A:tanta, Georgia 30308 Telephone 404 5266526 Marting Address:

Post Office Box t'E Atlanta. Georgia 30302 h Georgia Power L T. Gucwa the southern electro system Manager Nuclear Engineeong and Chref Nuclear Egneer NED-84-321 1

June 14, 1984 Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 Division of Licensing U. S. Nuclear Regulatory Cmmission Washington, D. C. 20555 NRC DOCKEIS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 EDNIN I. HAICH NUCLEAR PLANT UNITS 1, 2 REVISED RESPONSES TO NRC STAFF QUESTIONS ON PROPOSED ATTS TECHNICAL SPECIFICATION CHANGES Gentlenen:

By letter dated June 7,1984 (NED-84-281), Georgia Power Campany (GIC) provided information to the NRC concerning the Analog Transmitta Trip Systen (ATTS) which is currently being installed on Plant Hatch Unit 2.

This subnittal included answers to fourteen specific NRC staff questions (Attachment 2 to that letter) . As a result of additional discussions held with the NRC staff on June 13, 1984, GPC is providing, by this letter, a revised response to question 1-2, which incorporates additional information requested by the staff; and a corrected response to question 1-3, as discussed in the June 13, 1984, telephone conference.

Sincerely yours, 2 )I'i..

v L. T. Gucwa CBS Enclosures xc: J. T. Beckhan, Jr.

H. C. Nix, Jr.

J. P. O'Reilly (NRC- Region II)

Senior Resident Inspector Q

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j$#'AD8eA"O!!ggg, PDR

F QUESTION 1-2 Does the MG set on the RPS systs also supply sme non-class lE loads, and if so, what type of isolation devices separate the class 1E and non-class lE systes? Also, what type of surveillance is performed on those isolation devices?

RESPONSE l-2 The RPS MG sets supply a 120 volt AC power to the below listed loads. The design of these systes, including the additional hardware for the RPS portion of the ATTS system is consistent with the design criteria established in the FSAR. It is also noted that all safety actuations associated with the listed systems, as well as the RPS portion of the A77S system goes to their safety position on a loss of RPS power. The additional hardware associated with the RPS portion of the ATTS systs is no more susceptible to failures than the non-ATTS associated with the RPS. The systes powered frm the RPS are as follows:

o RPS MG SET A Neutron Monitoring Syste Reactor Protection Systen Nuclear Steam Supply Shut Off Systs Primary Contaiment Isolation System Process Radiation Monitoring Systs o RPS MG SET B Neutron Monitoring Systen Reactor Protection Syste Nuclear Steam Supply Shut Off Systen Primary Contaiment Isolation Systen Process Radiation Monitoring Systen Offgas Radiation Monitoring Systen l 1he ECCS DC distribution panels which supply essential DC power to the ECCS l ATTS cabinets also supply sane non-class lE loads. These distribu ion panels are supplied frm the plant class lE batteries which are backed up by l chargers fed by the energency buses. Breakers are used to separate the non-class 1E and the class lE systens. This is also consistent with the l original design basis of the plant The addition of ATTS into the plant design does not modify the original licensing basis of the plant with respect to the application of breakers in the RPS systen. The breakers used for undervoltage protection are Class lE. Surveillance testing is required for these breakers per Unit 2 Technical Specifications Section 4.8.2.7. There is no camtitment to perform surveillance testing on other breakers within the systen. This is consistent with the original design basis of the plant in that Plant Hatch, Unit 2 is not required to meet Regulatory Guide 1.75.

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QUESTION 1-3 Please provide the setpoints for the gross failure alarm.

RESPONSE l-3 The high/ low gross failure setpoints are to be set at values of 35 + 0.5 and 0.5 + 0.5 ma., respectively. These values are different than what was provIded earlier to the NBC via telecon. The alarms are provided to indicate a short-cirmit and open-cirmit. 'Iherefore,. the setpoint values can be varied significantly cutside the saturation rarne of the transmitter and still provide adeg2 ate protection.

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