ML20054B740
| ML20054B740 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 04/15/1982 |
| From: | Shoemaker C NRC ATOMIC SAFETY & LICENSING APPEAL PANEL (ASLAP) |
| To: | NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD), SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| ISSUANCES-SP, NUDOCS 8204190155 | |
| Download: ML20054B740 (3) | |
Text
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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION
'82 AR 16 A7 50 ATOMIC SAFETY AND LICENSING APPEAL BOARD i
Administrative Judges:
Alan S.
Rosenthal, Chairman Dr. John H.
Buck Christine N.
Kohl g ED n m 161301
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In the Matter of
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SACRAMENTO MUNICIPAL UTILITY
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MEMORANDUM AND ORDER April 15, 1982 We recently received a board notification (BN-82-37) informing us that ultrasonic and radiographic inspections during a special shutdown at Rancho Seco revealed cracking in at least one high pressure injection nozzle (nozzle A, the normal makeup nozzle).
It also states that the thermal sleeve for this nozzle " appear [s] to be missing," and that the sleeve "could enter the reactor coolant system inlet nozzle and be carried downward to the bottom of the reactor vessel where it would be trapped by the flow distributor."
We are told that "no flow distribution effects have been 3DSA 5
noticed," but that the licensee and Babcock and Wilcox are I
evaluating the effects this might have on reactor operation.
Lastly, the board notification indicates unspecified l
" repairs" are scheduled and are expected to take about 30 8204190155 820415 PDR ADOCK 05000312 PDR G
2 days, during which the plant will remain shut down.
We are greatly concerned about the quality of the information conveyed by the board notification.1/
- Indeed, it is notable more for what it does not say than what it says.
We therefore pose the following questions to both the licensee and the NRC staff.
1.
If the thermal sleeve has traveled to the bottom of the reactor vessel, what offect might this have on the instrumentation guide tubes?
2.
Do the intended repairs include location and perhaps removal of the missing thermal sleeve?
3.
In replacing the sleeve, will the original design of the sleeve retention buttons be J
changed?
If so, how?
If not, how will this problem be avoided in the future?
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We are also troubled that this board notification, which deals with a safety matter under our active review, was submitted to us eight days after the inspections revealed cracking and the absence of the thermal sleeve in nozzle A.
We cannot emphasize too strongly the importance of promptly notifying the licensing and appeal boards of such matters.
The eight-day delay in this notification is unwarranted, and we expect a better effort from the staff in the future.
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What is being done to prevent the loss of the thermal sleeves in the other nozzles?
If nothing is contemplated, why?
5.
How can we be assured of safe operation if the plant returns ;tx) full power after the completion of these repairs?
The answers to these questions are to be received by us no later than close of business Wednesday, April 21, 1982.
Further, licensee is to notify us at least three business days prior to the scheduled return of the Rancho Seco facility to operation.2/
It is so ORDERED.
FOR THE APPEAL BOARD 4
C. Jean Shoemaker Secretary to the Appeal Board 2/
We understand that Rancho Seco is now expected to remain shut down for about 30 more days to replace the l
" thermal sleeve and safe-end nozzle" on nozzle B as well.
Licensee is also working on a newly discovered and unrelated problem concerning excessive hydrogen concentration in the primary coolant system.
See Preliminary Notification of Event or Unusual Occurrence PNO-V-82-14c (April 14, 1982).
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