ML20129H505
| ML20129H505 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 06/24/1985 |
| From: | Jens W DETROIT EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| GL-85-06, GL-85-6, NE-85-0901, NE-85-901, NUDOCS 8507190207 | |
| Download: ML20129H505 (3) | |
Text
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C yne H. Jsne '
Vice Pr.sident Nwdeat Operations Edison =orthDagHghweg
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June 24, 1985 NE-85-0901 Mr. Jamon G. Roppler Regional Administrator Region III U. S. Nuclear Regulatory Commionion 799 Roooovelt Road Glen Ellyn, Illinoin 60137 References (1)
Formi 2 NRC Docket No. 50-341 i
NRC Liconoo llo. NPP-33 (2)
Dottoit Edinon to NRC Rogion III Letter, "Dotroit Edison Rooponac Inspection Report l
50-341/85009", VP-85-0132, June 5, 1985
Subject:
Additional Information on Electrical Scoaration i
The Referenco (2) letter provided additional information concerning 13 reprocontativo canon where IE and non-IE circuito electrically interfaced.
Your ataff recently identified two additional related concerno.
Thio letter providen additional clarifying information which should resolve this matter.
ATUS Recirculation Pumn Trip This circuit tripo the Rocirculation Pump field breaker on high reactor pronouro or low level to anoint in mitigation of a potential ATHS ovent.
The Recirculation Pump, ito breaker, and control ayatema are non-IC.
Tho donign whereby a non-IE devico in tripped by IE cignalo han boon i
thoroughly reviewed by NRR and accepted.
This modification in known an the "!!onticollo" ATHS Rocirculation Pump Trip l
(RPT) docign and la reforrod to on pago 7-22 of the Formi 2 Safety Evaluation Report.
In the "Dania for the Final Rulo ao Promulgated by the Commionion" published with the ATUS rulo (PR26036, June 26, 1904), the nococcity for IE and 2
non-IU devicon to interfaco in recognized and discuocod.
In fact, it in specially noted in a footnote to a Tablo published with the rult referenced above that " Existing recirculation pump trip equipment inotalled in DWna in accordanco with previous otaff requiremonto for the mitigation of anticipated tranciento without UCRA!! nood not be modifiod" becauco of the rule.
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!!r. Jamen G. Keppler June 24. 1985 11E-85-0901 Page 2 After discuccions with your staff, however, Detroit Edicon agreen to install ficxibic conduit as practicabic on one of the divisional control cabico for initiation of RPT in each of the Recirculation Pump field breaker cabinets.
Since this conduit in intended to provide incroaced accurance that the RPT will function as designed, it in appropriate the modification be installed consistent with the impicmentation cchedule for modifications necessitated by the ATUS rule.
The rule calla for utilitica to submit their implementation schedulco 180 days after the staff's incuance of OA guidance accociated with the rule.
This guidance was innued on April 16, 1985 in Gencric Lotter 85-06.
Accordingly, Edison will cubmit itc ochedule to !!RC in October and include in that cchedule the innta11ation of the floxibic conduit oc dcocribed above.
niin sample Valven IE cabico uced in the control circuita for the primary containment isolation valvon in Riln campic lincu woro downgradod to non-IE aince the design basic for the cyctcm in dcenergi:c-to-operate and sinco both divisionally routed circuito for theco volyco were brought to the como local panol.
The cabloc woro IE qualified cab 1cc and routed divinionally until they interface at the panel.
Each of the two DilR loopa han a canplo lino connected to the downctream nido of each heat exchanger.
Each campic lino, cinco it in connected to the reactor coolant pecucure boundary, han a cafety-grado isolation ochemo conointent with the I:ucicar Steam Supply Shut-off System (!!S4) decign banin.
The dcoign, provided by General Electric, concioto of two normally cloned, primary containment isolation valven connected in nerica for each naraplo line.
Each valvo in air-oporated, pilot-colonoid controlled, f ail-closed on loan of air or electric power, AUltE Clano II.
The nolonoid valven and control relaya for cach valvo arc clancified by G.E. an activo-conential.
The cloctric power for the colonoida in cupplied by the Itcactor Protection Syutem !!G-Sota; !!G Set A poworing the inboard valve's colonoldu and itG Set il the outboard.
The !!S4 initiaten automatic clocuro of the valvoc in rooponno to signala from the Itonctor Protection Syntom.
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11E-85-0901 Page 3 This automatic clocure of the valves follows the RPS/t!S4 basis of trip on loan of energy.
The activo-cacential classification upccified by G.E.
is made becauno the valvoc must go closed on actuation of the !JS4 trip.
Local-manual control and indication for the valves is provided by switchen and indicators on local instrument racks, II21-P018 and Il21-P021.
Since cach of thoce rackc la the control interface for one sample line valvo pair, each rack has cabling of both diviaions terminated thereon.
Providing the controla and cabling for both divisionu (one inboard and one outboard valvo pair) on one instrument rock was donc to allow operation of the valvec from one location.
This f acilitatco taking of a car..ple which otherwise would have been more difficult if the divisional controln had boon located in separate rooms.
The divisional valve icolation circuits on cach inotrument rack are contained in metal enclosurca which are grounded and are ocparated by at least 1 foot.
The control cabico for each of the two valves in the campic line are routed to each of the instrument racko in ocparate divicion cubic trayu.
Providing coparate onclouutos and cabic tray ayatema acceptably minimizco the pocaibility of a singic failure causing inadvertant opening of a campic line.
Daced on thin, the inctallation ao doccribed was conaidered acceptabic.
If you nhould have any additionni questionc, picace contact
!!r. Lewin Dregni at (313) 586-5003.
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!!r. P. fl. Dyron
!!r. !!. J. Chrianotitaoa
!!r. J. Strecter lit. C. C. Uillionn UUllRC Document Control Donk Machington, D.C. 20555
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