ML20249C649
| ML20249C649 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 06/24/1998 |
| From: | Gordon Peterson DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-96-06, GL-96-6, TAC-M96794, TAC-M96795, NUDOCS 9806300504 | |
| Download: ML20249C649 (4) | |
Text
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f Duk] Power V] g Casau:ba Nudear Station j
l 4800 Concord Road York, SC 29745 Gary R. Peterson (803) 8314251 ornct Mce 14rsident (803) 831-3426 fax
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June 24, 1998 U.
S. Nuclear Regulatory Commission ATTENTION:. Document Control Desk Washington, DC 20555-0001
SUBJECT:
Duke Energy Corporation Catawba Nuclear Station, Unit l'& 2 Docket Nos. 50-413/414 Request for Additional Information Related to Generic Letter 96-06 Response (TAC Nos. M96794 and M969795)
Attached please find Duke's response to the NRC Staff's i
Request for Additional Information dated March 19, 1998 related to Duke's response to Generic Letter 96-06 dated January 28, 1997.
There are no regulatory commitments contained in this response.
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l Questions regarding this response should be directed to Skip
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Copp at (803) 831-3622.
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eterson 1
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L. A..Reyes
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i U.
S. Nuclear Regulatory Commission Regional Administrator, Region II
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Atlanta Federal Center I
61 Forsyth St.,
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l Atlanta, GA 30303-P. S. Tam l
l NRC Senior. Project Manager (CNS)
U. S. Nuclear Regulatory Commission Mail Stop O-14H25 Washington, DC 20555-0001 i
D. J. Roberts
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Senior Resident Inspector (CNS)
U.
S. Nuclear Regulatory Commission Catawba Nuclear Site l
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Attachment Response to Request for Additional Information Related to Catawba Nuclear Station Generic Letter 96-06 Response j
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Request 1:
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4 The licensee's response indicated that for certain t
scenarios, the containment penetrations for cooling water to l
the upger and lower containment headers isolate and the Emergency Operating Procedures (EOPs) do not direct the 1
operators to restore cooling water to these headers for
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accident mitigation.
However, during accident conditions, l
plant operators may elect to take actions to restore the containment cooling water headers to service if the situation calls for it.
Describe any measures that exist or that have been taken to assure that these headers will not be restored as an option to mitigate accident conditions during these event scenarios.
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Response
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For accident situations where the upper and lower I
containment headers are isolated, there is no provision in the Emergency Operating Procedures (EOPs) for the Operators to restore these non safety-related containment cooling headers for accident mitigation.
Plant operators would not deviate from their Emergency Procedures, therefore plant operators would not " elect to take actions to restore the containment cooling water headers to service if the situation calls for it" as part of accident mitigation.
1 If a decision to deviate from the EOPs were made to restore flow from either the Containment Chilled Water (YV) System or the Nuclear Service Water (RN) System to the containment headers, the Technical Support Center (TSC) would evaluate the effects on plant operation of this action.
The TSC evaluation would include engineering and safety analysis personnel and would balance the operational need for placing the YV or RN system in service with potential consequences such as water-hammer.
Overall, it is not likely that these systems would be placed in service until containment l
conditions returned to normal since this containment cooling system is not safety-related and is not needed for accident mitigation.
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As part of the recovery from an accident, it is expected that normal containment cooling would eventually be restored j
to service.
This type of action would be accomplished after
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containment temperature and pressure had returned to l
" normal" and there would be no concerns with water hammer or two phase flow conditions.
This evolution would be l
carefully evaluated and controlled by the TSC staff which would oversee all plant operations during an accident and plant recovery.
Requests 2 through'6:
These requests are applicable to accident scenarios where the containment penetrations for cooling water are not j
isolated and the potential exists for water-hammer and/or two-phase flow to occur.
Response
There are no water hammer or two phase flow concerns for postulated accidents where the containment cooling water penetrations are not isolated.
Consequently, no rigorous analyses for water hammer or two phase flow conditions have l
been performed for containment cooling water piping systems under accident conditions.
Therefore, no detailed response is provided for Requests 2 through 6.
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