ML19325D911
| ML19325D911 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 10/17/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19325D906 | List: |
| References | |
| NUDOCS 8910270151 | |
| Download: ML19325D911 (2) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION
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W ASHINGTON, 0. C. 20655
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.101 TO FACILITY OPERATING LICENSE NO. NPF-6 ARKANSAS POWER AND LIGHT COMPANY ARKANSAS NUCLEAR ONE, UNIT NO. 2 t
DOCKET NO. 50-368 INTRODUCTION' By letter dated June 13, 1989, Arkansas Power and Light Company (AP&L or the licensee) requested an arr.endment to the Technical Specifications (TS) appended to Facility Operating License No. NPF-6 for Arkansas Nuclear One, Unit 2 (ANO-2).
The proposed amendment would delete TS Section 4.3.1.1.4.
This. TS only contains the surveillance requirements for the existing Core Protection Calculator (CPC) isolatien equipnient.
EVALUATION ArkansasPowerandLight(AP&L)ispresentlyintheprocessofreplacingpa-t of the hardware in the ANO-2 Core Protection Calculator System.
This e fort is scheduled for completion during the current 2R7 refueling outage, whSch began on September 25, 1989. A portion of the hardware upgrade includes nen fiber-optics devices to provide interchannel isolation for the CPC/ Core Elemt:
Assembly Calculator (CEAC) data links and the control element assembly (CEtl I
position isolation airp11fiers. The use of fiber-optics equipment for date transmission offers superior isolation capabilities compared to the existint system, which uses condu:tive wiring and optical isolators to achieve the required channel isolation.
j This fiber-optic cable which will be installed at tNO-2 transmits digital I
information using light % stead of electric current and is a unique isolator which possesses inherent characteristics that eliminate ground loops and consw
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ground-shifts in electronic circuits and provides complete electrical ground isolation between transmittu and receiver.
Fiber-optic cables present no fin l
hazards when their fibers are damaged.
In addition no local secondary damages 1
L can occur because fiber optics neither produce sparks nor dissipate heat.
The construction of the fiber-optic cable is such that the cable contains no electrically conductive material. The relative permittivity (dielectri; constant) of a material is a measure of the material's isolation capability.
The dielectric constant of a material is referenced relative to free space (a vacuum)andisadimensionlessnumbar.
Dry air possesses a dielectric constant of 1.00059. Glass possesses a dielectric constant ir the range of 4.0 to ~.0 l-depending upon the specific type. The higher the dielectric constant, the 8910270131 891017 ADOCK0500((jg8 DR u
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creater the isolatiLn that is provided. Thus, fiber-optic cables have an Isolation capability that is 4 to 7 times greater than dry air. The voltage breakdown rating of a typical fiber-optic cable is on the ordcr of 250 KV per l
meter.
A fault at either end of the data link might destroy the modem but will not propagate over the fiber-optic cable.
For example, one of the tests that must be perforned to qualify)an isolator is the application of the r..aximum credible fault (voltage, current to the output of the device to verify that the fault does not propagate or degrade the input (Class 1E) side. This postulated failure does not affect fiber-optic cable, and as stated above, the optical fibers are totally dielectric (i.e., the electrical energy resulting from the fault will not. propagate through the optical fiber). Another characteristic of the optical fiber cable is its nonsusceptibility to the coupling of cross-talk tndelectromagneticinterference(EMI).
Tcchnical Specificaticn 4.3.1.1.4 only contains the surveillance requirements for the specific isciation equipment in the existing CPCS hardware. Testing of the new devices in eccordance with thc cxisting TS is neither necessary nor practical, as the new equipn.ent uses non-conducting fiber-optics cable as describtd abcVe.
The existing TS will nc longer be apprcpriate upon completion of the CPCS upgrade and, therefore, the staff approves the request to remove thett requirements.
ENVIRONMENTAL CONSIM. RATION The amen 66r.t 'nvolves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Pert 20, and changes to surveillance requirements. The steff has determined that the amendment hivolves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cunulative occupational radiation exposures. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section 51.22(c)(9).Pursuantto10CFR51.P2(b),noenvironmentalimpactstetementor environrental assessment need be prepared in connection with the issuance of the amendment.
CONCLUSION The staff has concluded, based on the considerations discussed above, that:
will ret be endangered by operation in the proposed manner, and (2) public (1) there is reasonable assurance that the health and safety of the such ectivities will be conducted in compliance with the Commission's regulations, and the issuance of the amendment vill not be inimical to the comor defense and security or to the health and safety of the public.
Date:
October 17, 1989 Principal Contributor:
C. Poslusny
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