ML20127K758
| ML20127K758 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 06/24/1985 |
| From: | Jens W DETROIT EDISON CO. |
| To: | Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| NE-85-0900, NE-85-900, NUDOCS 8506270571 | |
| Download: ML20127K758 (5) | |
Text
____ _ _ -___ _____
Wayne H. Jens Vice President g
Nuclear Opera %ns
!,I E$ Noon Dme Hghway June 24,1985 g n newpon. uiensan 48tse NE-85-0900
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%F (313) 586-4150 Mr. B. J. Youngblood, Chief Director of Nuclear Reactor Regulation Licensing Branch No. 1 Division of L'icensing U. S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear !!r. Youngblood:
Reference:
(1)
Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-33 (2)
Detroit Edison to NRC Region III Letter,
" Detroit Edison Response - Inspection
~,.
i43 Report 50-341/85009", VP-85-0132, June 5, 1985
Subject:
Additional Information Concerning Electrical Seoaration The Reference (2) letter provided information to Region III relevent to Unresolved Item 85-009-01 in Inspection Report No. 50-341/85009.
The letter was subsequently referred to the Instrumentation and controls Branch (ICSB) and the Power Systems Branch (PSB) of NRR for review.
Based on phone conversations with 11r. M. D.
Lynch of your staff and reviewers from ICSB and PSB on June 20, 1985, additional information and clarification was requested.
Accordingly, attached to this letter is the requested information which should resolve remaining concerns on this matter.
It is our understanding that items from Reference (2) not mentioned in the attached are satisfactory.
If you should have any further questions concerning this matter please contact !!r. O. K. Earle (313) 586-4211.
Sincerely, V
s~a cc:
Mr. P. M. Byron Mr. N. J. Chrissotimos Mr.
Z. Falevits
!!r. J. Streeter Mr. C. C. Williams USNRC Document Control Desk
, T Nd I
Washington, D. C. 20555
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Attachment Attachment A to the Reference (2) letter identified 13
" representative samples" of cases where IE and non-IE circuits interfaced.
Additional information and clarification is provided below for the " representative samples" where questions arose.
Representative Sample No. 2 The valve mimic referred to in Attachment A to Reference (2) for this sample is out-of-service and is being modified.
Accordingly, the IE/non-IE " interfaces" in the panel are currently deenergized.
When the nodified panel is installed, the twelve " Case A" wiring schemes will no longer exist.
Separation criteria will be met for these cases as described in " Case D" or "C" which we understand is acceptable.
It should be noted that the valve mimic is strictly an operator aid and provides redundant information to that provided elsewhere in the Control Room.
It is not depended on to provide status information to support any normal, abnormal, or emergency operating procedures.
Representative Sample No. 3 The six amp fuses in the 24Vdc flasher circuits will be added to the Fermi 2 fuse control program prior to exceeding 5%
power.
The fuse control program is described in Detroit Edison's response to Inspection Report 50-341/84-17, EF2-69709, September 27, 1984.
That response details the control and verification requirements for fuses in the fuse control program.
It should be noted that all such fuses are required to be independently verified prior to returning any electrical equipment to service.
The listing of the fuses in the program is maintained in a single specification and applicable drawings reference the specification (Specification No. 3071-128 Std EJ) for details of fusing information and requirements.
Representative Samole No. 6 The circuit in question is a condensate tank level alarm switch for the RCIC system.
The RCIC system is not relied on in the safety analysis in the FSAR to meet design basis
~
limits.
However, recognizing the importance of the RCIC for operational control, portions of the system necessary for proper system operation have been designed in conformance with IE standards.
The circuit in question provides an alarm only and is not required for acceptable RCIC operation.
In order to provide additional assurance that failure of the condensate level circuit will not impact RCIC operation, Detroit Edison vill be installing an additional 5 amp fuse in series with the one mentioned.
Both fuses will be maintained in the fuse control program mentioned in Sample No. 3 above.
This fuse will be installed in the fall outage tentatively scheduled for September / October 1985.
Operation until this time is justified since as Etated above the RCIC is not necessary to meet design basis limits.
A fault in the RCIC condensate level circuit will not affect any other system than the RCIC itself.
Reoresentative Sanole No._7 As stated in Reference (2), the computer in question is the process computer which is used for data acquisition and calculation.
It is not used for controlling any process for any safety related purpose.
Until qualified isolation devices are installed for the five instrument loops in question, the subject loops will be electrically isolated from the process computer.
This isolation vill be accomplished prior to exceeding 5% power.
Representative Sample No. 8 Due to a typographical error, the 1 amp fuse referred to Attachment A to Reference (2) for this cample should be a 6 amp fuse.
The fuse vill be added to the fuse control progran mentioned in Sample No. 3 above prior to exceeding 5% power.
Representative Sanole No. 11 The diagran submitted with this cample in Attachment A to Reference (2) had coac typographical errors in it and a revised diagram is attached.
The fuses shown in the diagram are maintained in the fuse control progran discussed in Sample No. 3 above.
As discussed with representatives from ICSD and PSD on June 24, 1985, Detroit Edison agrees to provide a second fuse in series with the ones shown on the diagram for the branch circuits from the potential transformers supplying the non-IE indicating instruments for the switchgear.
This will be accomplished as availability permits and will be completed prior to Startup after the first refueling outage.
These second fuses will also be maintained in the fuse control program.
Representative Sample No. 12 The Division II Shutdown Panel discussed in this sample, will be disabled when the independent alternate shutdown system
('3L' panel) is installed and enabled.
The 3L panel totally obviates the need for the old " Division II" panel.
The schedule for the installation of the 3L panel is the subject of License Condition 2.C. (9) (d) of the Fermi 2 low power OL (License No. NPP-33).
Briefly, the 3L panel is to be ready to be enabled during the first known outage of 3 weeks or longer after September 30, 1985 - assuming NRR approval of the requisite Technical Specification changes.
The analysis provided in Sample 12 gives sufficient interim justification that the IE/non-IE interface described for this sample is acceptable until the changeover to the 3L panel is complete.
Briefly, the circuits discussed in this sample are electrically isolated until the Division II shutdown panel is required for use.
The panel's use is only necessary given a specific fire in the Control Room involving panels P601 and P602.
Two typographical errors were made for this case in Reference (2).
Relay C35-K73 should be C35-K93.
Relay C35-K35 should be C35-K95.
Representative Sample No. 13 The Recirculation Pump MG set trip function provided on Fermi 2 was an early ATUS mitigation trip provided with NRC acceptance in the early 1970's.
As stated in the discussion for this sample in Attachment A to Reference (2), the safety analysis no longer takes credit for this trip since now a trip of the Recirculation Pump field breakers is provided (i.e., the "Monticello" ATWS Recirculation Pump Trip - see the Fermi 2 SER-page 7-22).
Accordingly, based on NRC request, the MG set trip will be electrically isolated by removing the applicable fuses prior to exceeding 5% power.
Completion of appropriate work for removal of the circuit will be accomplished at a convenient outage prior to startup after the first refueling outage.
' M(.ov Bus Representative Sample No. 11 7
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