ML20244C592
| ML20244C592 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 06/07/1989 |
| From: | Withers B WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| WM-89-0167, WM-89-167, NUDOCS 8906150036 | |
| Download: ML20244C592 (3) | |
Text
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j W$LF CREEK
~
NUCLEAR OPERATING CORPORATION Bert D. Withers President and Chief Executwo Omoor June 7,1989 WM 89-0167 U. S. Nuclear Regulatory Commission ATTN: Document Controi Desk Mail Station P1-137 Washington, D..C.
20555 Reference Letter dated May 10, 1989 from L. J. Callan, NRC to B. D. Withers, WCNOC
Subject:
Docket No. 50-482: Response to Request for Additional Information on Violation 482/8907-01 Gentlemen:
This letter provides Wolf Creek Nuclear Operating Corporation's (WCNOC) respense to the request for additional information documented in the Reference. The request for additional information was in conjunction with Violation 482/8907-01 involving the failure to provide a written safety evaluation for a temporary modification.
If you have any questions concerning this matter, please contact me or Mr. O. L. Maynard of my staff.
Very truly yours, Bart D. Withers President and Chief Executive Officer co u l M A-'
[8 BDW/aem i Ob CDO Attachment
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cc:
B. L. Bartlett (NRC), w/a p,@
E. J. Holler (NRC), w/a R. D. Martin (NRC), w/a
$ct D. V. Pickett (NRC), w/a G
I P.O. Box 411/ Burhngton, KS 66839 / Phone: (316) 364-8831 An Equal opportunny Employer MT4CVET l
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Attcchmint to WM 89-0167' 5'.P:g2 1;of 2' Response to Request for Additional Information on Violation.482/8907-01:
Reauests' Provide additional information concerning instructions,
- guidance, and/or-training that will be provided to individuals that. prepare and review safety.
evaluations and report responses to assure that they understand the revised
!c procedure (ADM 01-022) and other measures you have taken to prevent recurrence of this type of issue.
Response
As identified.in' letter dated April' 13, 1989 from B. D. Withers,. WCNOC, to I
the NRC,. procedure ADM 01-022,
' Authorization of. Changes,
-Tests and Experiments'.(10 CFR-50.59)" was revised to provide additional guidance on when a. written safety evaluation should be initiated.
Specifically, the revision provides the guidance that when the Updated Safety Analysis Report (USAR) description is-general in nature and the change cannot. be easily determined to.: affect the 10 CFR 50.59 Section (a)(i) criteria. :then a written ~ safety evaluation should be initiated.
A letter has been sent' to other WCNOC organizations identifying 1 the need to review and revise, as appropriate, their procedures governing the 10 CFR 50.59 safety evaluation process to incorporate this guidance.
Additionally, Violation 482/8907-01 and the revised procedure ADM 01-022 have been explained in detail to those individuals: who assist in the review and preparation of safety evaluations associated'with temporary modifications.
Recuest:
Provide additional information concerning the results of the reevaluation of the Nuclear Safety Evaluation (S. E. No.
89-SE-021) considering the effects of the decreased voltage of the battery bank with a cell.jumpered as it is being. discharged under design accident conditions.
Response
Nuclear Safety Evaluation, S. E. No. 89-SE-021, was revised and reviewed by i:
the Plant Safety Review Committee on May 30, 1989.
This revisien to~ the l
Nuclear Safety Evaluation provides additional supporting information to the l
original ~ evaluation, and was determined to not constitute an unreviewed safety question. The following provides the results of the re-evaluation:
The removal (electrically) of a cell from the subject bank has been i
calculated to remove 2.7% of the rated capacity of the bank (reference EER 89-NK-02).
Therefore, the loss of a cell, which represents a 2.7%
g capacity loss, is insignificant to the system's function because the system's function only requires 37% of 100% total system capacity.
I.
ii.
p. 4
- v ' ' ~ ' Attachment to W 89-0167 i-Page 2 of 2 Response (cont.):
The. calculation has also shown that it would require the removal of at least five cells before voltage would drop below-105 volts (minimum' required) during the worst case load, i.e., station blackout.
.During a station blackout. AC and charger power are losts. thus, the fully charged' battery terminal voltage.with one jumpered out' cell would.be P
expected to drop to an initial nominal terminal voltage ou.the -order of 120.95-volts verses-123 volts for 60 cells.
This lower voltage will not affect the functional requirements of the battery bank. At no time during the station blackout will battery-terminal voltage drop below the overall minimum battery voltage of 105 volts.
In addition, the removal of one cell or 2.25 volts (if it were a good cell) from the bank which floats between 132-135 volts will not-have any noticeable effect upon the. system since this loss is within the described ficat voltage range.
To provide the same minimum battery ^
voltage of 105 volts with one cell jumpered out, it should be noted that the individual cell voltage has changed from 1.75 to 1.78 volts.
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