ML19332D926
| ML19332D926 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 02/14/1989 |
| From: | Morris K OMAHA PUBLIC POWER DISTRICT |
| To: | Milano P Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.E.1.1, TASK-TM LIC-89-149, TAC-59096, NUDOCS 8912060047 | |
| Download: ML19332D926 (4) | |
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n cFebruary 14, 1989-
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-LIC-89-149 j
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K Mr.:P.:D. Milano, NRC' Project Mgr.
1 Project Directorate:IV ~
- Division of Reactor-Projects III,-IV, V
= and. Special Projects-U. S.-Nuclear Regulatory Commission
.Ma11LStation OWFN 13-D ;
~L, Washington,sDC 20555 I
References:
1.
- Dock'et No. 50~285 2.
Letter from NRC'(P..D.-Milano) to OPPD (K.~J. Morris) dated l_
beember 7, 1988
Dear Mr. Milano:
SUBJECT:
'Com)11ance with Requirements of ATWS Rule,.10 CFR 50'62, for~ Fort'
- Cal 1oun Station (TAC 59096) i
! Reference 2 requested the'0maha Public' Power District (OPPD) provide additional information concerning-the adequacy of. isolation _ devices used as electrical' interfaces between safety related and non-safety related circuits.
j Specifically, OPPD was requested to:
L 1.
Identify the newly created safety /non-safety related interfacei; which are the result of the~ implementation of the ATWS rule.
3 1
2.
Identify the isolation device (s) proposed for_ use in crotecting' the' p
safety circuit interfaces 11dentified in No. I above. '
3.
Provide data showing that a) the isolation devicer identified in.No.' 2 above have been tested by application of the WT voltage /cu-rent !c the transverse mede to its non-safety side and b) the isolatun devices in this application are bounded by the MCF tests.
LTh'e following information is responsive to the first two itets requested. As you and Mr. P. R. Bemis of my staff have discussed, tests are currant 1.y in progress to develop documentation of the Maximwn Credible fault (ift.C aata needed to respond to item 3.of your request. As agreed, the test chsults will be provided by April 19, 1989.,
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- LIC-89-149-i
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.OPPD RESPONSE TO ITEMS 1 AND_J Newly created safety /non-safety related interfaces which are the result of I
k implementation of the ATWS rule are limited to the Diverse Scram System at Fort EP '
'Calhoun Station and ue as follows:
r
- 1.-
Tag No.:. A/PA-120-2 B/PA-120-2 C/PA-120-2 D/PA-120-2 Iso'lation Device Name:
entact Output Irolators Model No.:
Foxboro Model #N-2AO-L2C-R
==
Description:==
Accepts four (4) contact inputs and has custom DPDT relay
. output for each input. Output contacts are rated SA at 120VAC or 28VDC and-are also rated at 0.5A at 125VDC. The isolators provido an interface between low level DC system logic signals and high level load switching circuits.
Drsign Application:
Safety related contact functicns (trips) are separated j
from non-safety related contact functions (annunciation and testing) by the use of different relay modules. This provides coil to ca.. tact isolation of
. safety-related and non-safety related functions.
Maximum Credible Fault (MCF) Voltage / current:. 140 VDC or 120 # C with t
l
. current limited by a protective fuse in the non-safety related circuit.
Qual _ification Test Data:
Foxboro Model #N-2A0-L2C-R is qualified for.
L nuclear Class IE (safety related) service per IEEE-323-1974 and i
IEEE-344-1975 as documented in the Fort Calhoun Station Mild Environment Qualification File, EEQ-M-07.
Per Foxboro document PAD #P4400-006, L
isolation converters (analog and contact) have the tested capability to L
isolate shorts, grounds, and open faults to allow up to 600 Volts A.C to be applied to the isolation converter without degracation of Class IE circuits connected to the input.
. OPPD is currently in the-process of obtaining the MCF test data from Foxboro and will provide the data to the NRC by April 19, 1989.
The subject isolation devices used in Panels AI-196, AI-197, AI-198, and AI-199 3re bounded by the MCF-test voltage / current.
' Also, the analog signals from A/PT-120 and B/PT-120 are transmitted to A and B channels of QSPD5 which provide; safety related to non-safety related isolation to the ERF computer. A fiber optic link to the ERF computer has J
, been used to provide nolation, i1
.2.,
Tag No.:
86 A/ DSS, 26 B/ DSS Isoltion device name:
Lockout Relay Model No.:
GE 12HEA61A223 m
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Mr!. P. D. Milano m1 SLIC-89-149-f Page 3-h.:
N De:crintiont The design of the Diverse Scram System (DSS) uses each of the lockout relays to energiza two trip relays. The trip relays then activate t
the reactor trip breaker in each vifety train. Both break m must trip to 7
achieve: a full reactor trip.
W Design Application:- The safey ralated relay coil is powered f: 'm the 125V DC Class IE p wer source. One contact of the relay is used_ia the safety related tripping circuit and the other contact is used ia the non-safety i
.related annunciation t ircuit to alarm DSS relay actuation. The lockout relay provides coil to ccntact ar.d contact to contact. isolation.
i Maximum Credible Fault Voltage / Current:
140VDCorI20VACwithcurrent t
limited by protective fuse in non sefety related circuit.
Qualification Test Data. Th'e subject GE relays _are qualified per-IEEE-323-1974,.IEEE-344 1975, and IEEE-037-93 as documented in OPPD Miiu Environment Qualification File, EEQ-M 09.
However, testing was not l
perforced to demonstrate isolation capability of this relay to the requirements of IEEE-384-1981, Paragraph 7.2.2.1.
l 1
OPPD is in the process of testing the relavs to deconstrate that the
. isolation devices meet the requirements of IEEE-384-1981. The results of the test will be provided o the IGC by April 19, 1989, 3.
Tag No.: 86A/DSSS,'86E/DSSS Isolation Device Name: Supervisory Relay i
.Model No.: GE12HGA111J2 i
==
Description:==
The supervisory relays monitor operation of the lockout l
L relays described.in Item 2.
E Design Application: - The safety related co;l is powered from a Class IE source. One of the contacts is used in the non-safety related annunciation nircuit. to alarm lockout relay malfunction. The relay provides coil to contact isolation.
Maximum Credible Fault Voltage / Current:
140 VDC or 120 VAC with current limited by a protective fuse in the non-safety related circuit.
Qualification Tcst Data: The subject GE relays are qualified per IEEE-323-1974, IEEE-344-1975, and IEEE-C37-98 as documented in OPPD Mild Environment Qualification File, EEQ-M-09.
However, testing was not perfo'rmad'to demonstrate isolation capability of this relay to the requirements of IEEE-384-1981, Paragran 7.2.2.1.
OPPD is in the process of testing the relays to demonstrate that the isolation devices meet the requirements of IEEE-384-1981.
The results of the test will be provided to the NRC by April 19, 1989.
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- Lle,.89-149 Page'4
!4. Tag No.: Al/TS-DSS,Bl/TS-DSS Isolation-Device Name: DSS-Test Switch Model No.: Microswitch Part No. P1XEB'332C
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==
Description:==
Three position key operated selector switch
. Design Application: This switch is used to test the DSS actuation o
circuit.
Two contacts of the selector switch are powered from the 125VDC Class IE power source and the o her two contacts are used in a non-safety related annunciation circuit to alarm the OFF NORMAL position of switch.
This provide!, contact to contact isolation between safety and non-safety related functions.
Maximum Credible Fault Voltage / Current:
140 VDC or 120 VAC wits current limited by a protective fuse in the non-safety related circuit.
Qualification Test Data: The subject switch is Class ~1E qualified in
,accordance with IEEE-323-1974 and IEEE-344-1975 as documented in the Fort r
Calhoun Station Mi'.( Environment Qualification File, EEQ-M-04. However, additional testing was not performed to demonstrate isolation capability of the selector switches per the requirements of IEEE-384-1981, Paragraph'
- 7. 2. 2. l ~.
OPPD is in the process of testing the DSS Test Switch to demonstrate that the isolation device meets the requirements of IEEE-384-1981.
The results of the test will be provided to the NRC by April 19, 1989.
The Auxiliary Feedwater (AFW) System design at Fort Calhoun Station was upgraded following the TMI accident in accordance with TMI Action Plan Item II.E.1.1.
This design was found acceptable during post-THI reviews.
Design of-Diverse. Turbine Trip (DTT) utilizes equipment of the original plant design.
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Since there are no new electrical interfaces, adequacy of the electrical isolators used in the AFW and DTT systems does not require additional verifica. tion.
If you have questions please contact us.
-Sincerely, C
K. & Morr s Division Manager Nuclear Operations KJM/sa c:
LeBoeuf, Lamb, Leiby & MacRae R. D. Martin, NRC Regional Administrator P. H. Harrell, NRC Senior Resident Inspector Document Control Dt.sk e.:
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