ML19320D016
| ML19320D016 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 07/01/1980 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Peoples D COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8007180438 | |
| Download: ML19320D016 (5) | |
Text
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/N UNITED STATES 3
' g NUCLEAR REGULATORY COMMISSION y3 E
WASHINGTON, D. C. 20555 E
July 1, 1980
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Docket No. 50-10 Mr. D. Louis Peoples Director of Nuclear Licensing Commonwealth Edison Cogany Post Office Box 767 Chicago, Illinois 60690 l
Dear Mr. Peoples:
RE: SEP TOPIC U I.10. A THERMAL OVERLOAD PROTECTION FOR MOTORS OF MOTOR OPERATED VALVES Enclosed is a copy of our evaluation of Systematic Evaluation Program Topic III-10.A, Thermal Overload Protection for Motors of Motor Operated Valves. This assessment compares your facility, as described in Docket No. 50-10 with the criteria currently used by the regulatory staff for licensing new facilities.
Please inform us if your as-built facility differs from the licensing basis assumed in our assessment.
We have discussed this assessment with your staff and believe the facts concerning your plant are correct.
Therefore, our review of this topic is complete and this evaluation will be a basic input to the integrated safety assessment for your facility unless you identify changes needed to reflect the as-built conditions at your facility. This topic assess-ment may be revised in the future if your facility design is changed or if NRC criteria relating to this topic are modified before the integrated assessment is completed.
Sin erely, Dennis M. Crutchfield, Chef Operating Reactors Branch #5 Division of Licensing
Enclosure:
Cogleted SEP Topic III-10.A cc w/ enclosure:
See next page l
! 8007180$9
[
Mr. D. Louis Peoples July 1, 1980 cc w/ enclosure:
Isham, Lincoln & Beale Director, Technical Assessment Counselors at Law Division One First National Plaza, 42nd Floor Office of Radiation Programs Chicago, Illinois 60603 (AW-459)
U. S. Environmental Protection Mr. B. B. Stephenson Agency Plant Superintendent Crystal Mall #2 Dresden Nuclear Power Station Arlington, Virginia 20460 Rural Route #1 Morris, Illinois 60450 U. S. Environmental Protection Agency U. S. Nuclear Regulatory Commission Federal Activities Branch Resident Inspectors Office Region V Office Dresden Station ATTN: EIS COORDINATOR RR #1 230 Sout i Dearborn Street Morris, Illinois 60450 Chicago, Illinois 60604 Susan N. Sekuler Mr. Richard E. Schaffstall Assistant Attorney General KMC Incorporated 3
Environmental Control Division 1747 Pennsylvania Avenue, NW 188 W. Randolph Street Washington, DC 20006 Suite 2315 Chicago, Illinois 60601 Norris Public Library 604 Liberty Street Morris, Illinois 60451 Chairman Board of Supervisors of Grundy County Grundy County Courthouse Morris Illinois 60450 Department of Public Health ATTN: Chief, Division of Nuclear Safety 535 West Jefferson Springfield, Illinois 62761
SEP TECHNICAL EVALUATION TOPIC III-10.A THERMAL-0VERLOAD PROTECTION FOR MOTORS OF MOTOR-OPERATED VALVES DRESDEN 1 TOPIC III-10.A Thermal-Overload Protection for Motors of Motor-Operated valves' The objective of this review is to provide assurance that th'e appli-cation of thermal-overload protection devices to motors assoc'iated with safety-related motor-operated valves do not result in needless hindrance e.J the valves to perform their safety functions.
In accordance with this objective, the application of either one of the two tecommendations contained in Regulatory Guide 1.106, " Thermal-Overland Protection -for Electric Motors on Motor-Oper.ated valves," is ade-quate. These recommendations are as follows:
(1) Provided that the completion of the safety function is
. not jeopardi5ed or that other safety systems are not degraded, (a) the thermal-overload protection devices should be continuously bypassed and temporarily placed in force only when the valve motors are undergoing periodic or maintenance testing, or (b) those thermal-overload protection devices that cre normally in force during plant operation should be bypassed under acci-dent conditions.
(2) The trip setpoint of the ther sal-overload protection devices should be established with all uncertainties resolved in favor of ec.mpleting the safety-related action. With i..gt to those uncertainties, consider-ation should be given to (a) variations in the ambient
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temperature at the installed location of the overload 1
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protection devices and the valve motors, (b) inaccura-cies in motor heating data and the overload protection device trip characteristics and the matching of these two items, and (c) setpoint drift. In order to ensure continued functional reliability and the accuracy of the trip point, the thermal-overload protection device should be periodically tested.
In addition, the current licensing criteria require that:
(3) In Mov designs that use a torque switch to limit the opening or closing of the valve, the automatic opening or closing signal should be used in conjunction with a corresponding limit switch.
DISCUSSION On May 31, 1977, Commonwealth Edison stated that overload trips of esseitial equipment for HPCI and ESAP systems vcald be bypassed under LOCA conditions.4 Review of a sample of Dresden 1 drawings indicates that these bypasses have been incorporated.5-8 However, for the valves exam-ined, valve travel is terminated by a torque switch rather than a limit switch.
EVALUATION Thermal-overload protection for motor-operated valves at Dresden 1 does not comply with current licensing criteria. While thermal-overload devices for ESF valves are bypassed under LOCA conditions, torque switches rather than limit switches are used to terminate valve travel.
REFERENCES 1.
IEEE Standard 179-1971, " Criteria for Protection Systems for Nuclear Power Generating Stations."
2
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3 ranch Technical Position EICSB-27, " Design Criteria for Thermal Over-load Protection for Motors of Motor-Operated Valves."
3.
Regulatory Guide 1.106, " Thermal Overload Protectics for Electric Motors on Motor-Operated Valves."
4.
Letter, Coenonwealth Edison (Turbak), to DOR (Davis), dated May 31, 1977.
5.
Dresden 1 Drawing 12E-1420A, Revision 3, dated 12-4-78.
6.
Dresden 1 Drawing 12E-14203, Revision B, dated 12-4-78.
i 7.
Dresden i Urawing 12E-1421A, Revision 3, dated 12-4-78.
8.
Dresden 1 Drawing 12E-14213, Revision 3, dated 12-4-78.
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