ML20042F737
| ML20042F737 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 05/03/1990 |
| From: | Trevors G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20042F738 | List: |
| References | |
| NLS9000157, NUDOCS 9005090326 | |
| Download: ML20042F737 (3) | |
Text
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GENERAL OFFICE Nebraska Public Power District
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NLS9000157 May 3, 1990 U.S. Nuclear Regulatory Conuniosion Attention: Document Control Desk Washington, DC 20555.
Gontlemen:
Subject:
- Revision to Technical Specification Bases Section Cooper Nuclear Station Docket 50-298, DPR-46
References:
- 1) Letter from D.
M. Crutchfield (NRC) to G. A. Trevors (NPPD) dated September 22,
- 1987,
" Safety System Functional Inspection. Report Number 50-982/87-10"
- 2) Letter from L. J. Callan (NRC) to G. A. Trevors (NPPD) April 10, 1989, NRC Inspection Report N), 50-298/89-03 INTRODUCTION The Nebraska public Power District (District) transmits the attached Cooper Nuclear St.ation (CNS) Technical Specifications Bases page change for your information.
The District's safety review committees have reviewed this change and have concluded that it does not constitute an unreviewed safety question.
The attached change to the CNS Technical Specifications Bases, Section 3.12.C,
" Service Water System" (Attachment 1), is a result of the CNS Safety System Functional Inspection (SSFI), documented by NRC Inspection Reports Nos. 87-10 and-89-03 (References 1 and 2) and the subsequent implementation of CNS Design Change No.90-009, " Automatic Isolation of SW-MOV-37MV on Low Service Water pressure."
BACKGROUND
' Attachment 2 (previous Lervice Water System Configuration) illustrates the
. configuration of the Service Water System (SWS) nonessential water header isolation scheme at the time of the SSFI. Upon a Loss of Offsite Power (LOOP) event, SWS pumps 1A and 1C are powered by Emergency Diesel Generator (EDG) No.
1 (Division I) and SWS Pumps 1B and 1D are powered by EDG No. 2 (Division II).
Upon' a loss of Division II power, MOV-117 (Division I) would automatically isolate the nonessential SWS header upon a low pressure signal from either PS-364A or PS-364B, thereby ensuring Service Water flow to essential cooling 9005090326 900503 PDR ADOCK 05000298 g/' f p
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loads. However, upon a loss of Division I power, MOV-117 would fail in its P
normally open position, requiring the control room operators to isolate the nonessential SWS header, if required, by closing MOV-37 IDivision II).from_the Control Room.
The NRC SSFI team concluded that control room operators did not possess
~ sufficient procedural guidance to respond to such an event and had not received formal training in this area. Consequently, the NRC identified'this.
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- concern as Unresolved Item 50-298/87-10-03 in NRC Inspection Report - No.
50-298/87-10. -In response to this concern, the District revised CNS Procedure 2.4.0.3.1,
" Loss of Service' Water pumps," to specify operator actions associated with the Service Water System during a Loss of Coolant Accident (LOCA) concurrent with a LOOP, and included this procedure in the licensed operator requalification training.
Following this change, the District performed a more comprehensive review of CNS Procedure 2.4.8.3.1.
This review resulted in an extensive re' vision tc CNS Procedure 2.4.8.3.1 and renamed it " Service Water System Casualties."
This revision was then incorporated into the licensed operator requalification training.
l The NRC, in Inspection Report No. 50-298/89-03 (Reference 2), closed out this I
item.
DISCUSSION
. Subsequent to NRC closure of ' this concern, the District initiated 'a design L
change to remove PS-364B - from the control circuit of MOV-117, and add it to tho ' control - circuit of MOV-37, This design change results in automatic
- isolation of MOV-37 upon a low pressure signal from PS-364B.
As 'a result of this design change, the nonessential Service Water System header will be j
g isolated automatically 'upon a loss of either Division I or Division II power and-a low ' pressure signal from either SWS pump discharge - header.
The new
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configuration-_is depicted in Attachment 3 (Current Service Water System Configuration).
l This design change necessitates a change to the CNS Technical Specifications Bases section.
The " Bases" section of 3.12.C, " Service Water System" states 1
currently that upon a loss of all AC power, a drop in the SWS header pressure will isolate the turbine building cooling water isolation valve (MOV-117).
Therefore,.the affected Bases section change is revised to reflect Design Change 90-009, which causes the nonessential (turbine building cooling) header to be isolated automatically through closure of either MOV-117 or MOV-37, regardless of:which division of power is lost.
l Design Change 90-009 has been evaluated in accordance with 10 CFR 50.59, and has been found to be acceptable.
The attached Technical Specifications Bases change has been reviewed by the onsite and offsite review committees and found to be acceptable.
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_ May 3,;1990 Page 3 t
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The District will issue this Technical' Specification page change to all copy R
holders in accordance with its normal procedure.
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Please'. contact me if you have any questions.
Sincerely,
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G..A.
Trevors Division Manager Nuclear Support
/jw Attachments cci U.S. Nuclear Regulatory Commission Region IV r
Arlington, TX NRC Resident Inspector Cooper Nuclear Station S
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