ML20053C587
| ML20053C587 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 05/25/1982 |
| From: | William Jones OMAHA PUBLIC POWER DISTRICT |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| LIC-82-206, NUDOCS 8206020349 | |
| Download: ML20053C587 (4) | |
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Omaha Public Power District 1623 HARNEY e OMAHA, NEBRASKA 68102 s TELEPHON E 536-4000 AREA CODE 402 May 25, 1982 LIC-82-206 Mr. Robert A. Clark, Chief U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Licensing Operating Reactors Branch No. 3 Washington, D.C.
20555
Reference:
Docket No. 50-285
Dear Mr. Clark:
10 CFR 50, Appendix R Requirements The Comnission's letter to Omaha Public Power District, dated April 8, 1982, forwarded the Safety Evaluation Report (SER) on the Fort Calhoun Station alternate safe shutdown capability. The SER provided the results of the Commission's evaluation of the Fort Calhoun Station's alternate safe shutdown capability against the criteria of 10 CFR 50, Appendix R, Section III.G.3.
The SER identified three open items.
The District's response and/or plans for resolving the three open items is a ttached.
The April 8,1982 letter indicated the Commission has a special concern about the effects of associated circuits on alternate shutdown capa-bility (open item three).
This special concern was denoted by your statement:
"if your response to open item three is not complete...,
you will be found in violation of 10 CFR 50.48."
The District had previously addressed this concern in our letter dated March 27, 1981 and had considered our response to be complete. Therefore, to ensure there is a common understanding on what is considered a " complete response" on this issue, the District initiated a telephone conference (telecon) with the Commission's technical reviewers.
The telecon held on April 20, 1982 included Messrs. Patterson and GamF r of the District; Messrs.
Tourigny, Ridgely, Lobel, Wambach, a ravante of the Commission; and Messrs. MacDougall and Smith of Brool
.1 National Labs.
The Dis-trict's initial response to this is-
"ided in our letter of March 27, 1981 (i.e., our response to recomme.ioation' i.7)) was collectively reviewed during this telecon. A consensus was reached that, had the 1
8206020349 820525 hI\\
PDR ADOCK 05000285 P
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e Mr. Robert A. Clark LIC-82-206 Page Two I
District included the control room circuits in our March 27, 1981 I
response, it would have been considered a " complete response." The control room circuits were considered associated circuits in our initial review, although they were not specifically identified as such in our March 27, 1981 letter.
Our attached response to open item three has been revised to include the control room and this should resolve the Commission's concerns.
4 Sincerely,
'W'LV i
W.C./dones Divisi'on Manager Production Operations I
Attachment cc:
LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N.W.
Washington, D.C.
20036 6
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Attachment OMAHA PUBLIC POWER DISTRICT'S RESPONSE TO THREE OPEN ITEMS IDENTIFIED IN THE COMMISSION'S L'.TTER DATED APRIL 8,1982 Open Item 1 Modification must be made to the plant such that no wiring changes or pulling of fuses is necessary to achieve and maintain hot standby.
Response
This comment relates to the pressurizer heaters. A control switch will be installed at the motor control center or at the alternate shutdown (ASD) panel to allow local control of one bank of pressurizer heaters.
Also, necessary wiring changes will be made to provide means for iso-lation of heater control circuits from the fire area (cable spreading room and control room), and to ensure proper operation following fire in the cable spreading room and/or control room. These modifications will be completed during the next Fort Calhoun Station refueling outage tentatively scheduled to start in December 1982.
Open Item 2 A source range flux monitor independent of the cable spreading room and control room should be installed on the new instrument rack (ASD panel).
Response
The existing source range flux monitors for the Fort Calhoun Station are scheduled to be replaced during the 1984 refueling outage. At that time, a remote source range flux monitor, independent of the reactor pressure system drawers in the control room and cable spreading room, will be installed at the ASD panel.
Please note that because of the long equipment delivery times on this equipment an earlier replacement is not feasible.
Open Item 3 The licensee should address the concern that there could be non-safety related circuits that are associated with the alternate safe shutdown circuits that could fail due to a fire and affect safe shutdown by short circuits or grounds, i
Response
As explained in our response dated March 27, 1981 and clarified in our telephone conversation of April 20, 1982, the alternate shutdown capa-bility has been provided for achieving hot shutdown in case of fire in the cable spreading room and/or control room.
Effects of fire induced failures in the associated circuits (including non-safety related cir-cuits that are associated with alternate safe shutdown circuits) were evaluated and it was decided to consider all cables in the cable spread-ing room and/or control room as associated circuits. Also, it was
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decided to identify and isolate cables required for achieving hot shutdown from these associated circuits.
Tables B, C, and D included in our March 27, 1981 letter provide a listing of cables required for hot shutdown and discuss various isolaticn schemes. These isolation schemes have been reviewed and accepted by the NRC. Also, necessary modifi-cations as detailed in our previous subnittals have been installed to ensure that fire induced failures in any circuits located in the cable spreading room and control room (including non-safety related circuits) will not prevent proper operation of equipment required for achieving safe shutdown.
As per the telephone conversation of April 20, 1982 between NRC and District' representatives, the District's submittal of March 27, 1981, as supplemented by this response, is considered a complete response and no additional action is required on this item.
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