ML20041E160
| ML20041E160 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 03/08/1982 |
| From: | Shoemaker C Atomic Safety and Licensing Board Panel |
| To: | NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| References | |
| ISSUANCES-SP, NUDOCS 8203100204 | |
| Download: ML20041E160 (5) | |
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UNITED STATES OF AMERICA 74 NUCLEAR REGULATORY COMMISSION f
7s p.a..L j'p' ATOMIC SAFETY AND LICENSING APPEAL BOARDcs
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Q Administrative Judges:
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Alan S.
Rosenthal, Chairman Dr. John H. Buck
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s Christine N. Kohl s
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In the Matter of
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SACRAMENTO MUNICIPAL UTILITY DISTRICT
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Docket No. 50-312 SP
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(Rancho Seco Nuclear Generating
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Station)
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MEMORANDUM AND ORDER March 8, 1982 In our October 7, 1981 memorandum and order (ALAB-655, 14 NRC 799), we expressed concern about the number of high pres-sure injections that have been initiated at the Rancho Seco facility.
We noted that both staff and licensee witnesses acknowledged that all three of the HPI nozzles had undergone "in the 'ballpark~ of 30 thermal cycles."
We also not'ed that, according to the staff, the Commission's May 1979 order in this case was "'likely'" to increase the number of reactor trips and thus high pressure injections as well.
We therefore concluded g$
that "there is a substantial chance that the permitted lifetime g
number of HPI cycles for each nozzle [40] will soon be reached" j j 8203100204 820308 PDR ADOCK 05000312 l
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. (id. at 810).
Because, inter alia, we believed that ".SMUD's testimony reflects no tangible basis for the original lifetime limit of 40 HPI cycles plus 40 test cycles for each nozzle" (pl. at 811), we retained jurisdiction pending further analyses by SMUD and the staff and requested a schedule from both parties for supplying this information (pl. at 811, 817).
The licensee replied with an affidavit (dated December 11, 1981) purporting to respond directly to our expressed concerns, rather than providing a schedule for the requested analyses.
This submission states (at p.
6-6) that operating procedures have been changed at Rancho Seco such that HPI nozzles are no longer thermally cycled following a normal reactor trip.
The presently existing analyses provide an adequate number ~of available cycles for the remainder of the plant life.
In an accompanying memorandum of law, licensee also seeks recon-sideration of our request for analyses of the maximum allowable number of thermal cycles on the HPI nozzle, insofar as its response fails to comply with our order.
The staff initially responded that it had done no analyses but would review and comment on SMUD's submittal at a later time.
The staff concluded from its interim review, however, that "there is sufficient existing margin to the design thermal cycle limits on the HPI nozzles to permit continued plant operation over the near term."
Affidavit of Mark L. Padovan (January 5, 1982) at
e
. p.
2.
The staff now informs us that it "has identified question-able assumptions in SMUD's analysis" of the maximum number of thermal cycles on the HPI nozzles and cannot proceed further with its review until it obtains additional information frcm licensee.
Affidavit of John F. Stolz (February 25, 1982) at 2.1/
The staff also requires additional information from p.
SMUD on the other HPI questions raised in ALAB-655, 14 NRC at 811, 817.
Id. at 3-4.2/
The receipt and staff review of all of this forthcoming licensee data are not expected to be com-pleted for several months.
At the conclusion of this most recent affidavit, the staff informs us tnat an incident related to thermal cycling of HPI nozzles occurred at the Crystal River facility on February 5, 1982
-1/
Numerous documents, letters, etc., were attached to this affidavit.
Because the copies submitted to the members of this Board have quite a few pages Lissing, we request the staff to resubmit the complete materials along with an explanatory index.
-2/
The additional information concerns:
the effectiveness of licensee's inservice inspection program in detecting thermal cycling effects on the HPI' nozzles; the analysis that shows there is no temperature change and thus no additional thermal cycling on the normal make-up nozzle during manually actuated HPI; and SMUD's procedures for manually initiating HPI after a reactor trip.
c.
.. (the actual incident apparently was on January 29, 1982).
Following the discovery of leakage in the area, a crack was located in the normal make-up nozzle and " thermal cycling is thought to be a contributor to the cracking."
Stolz Affidavit at p.
4.
See also Preliminary Notification of Event or Un-usual Occurrence PNO-II-82-13 (January 29, 1982) and PNO-II-82-13A (February 1, 1982).
The staff has thus asked SMUD to evaluate the HPI make-up nozzle at Rancho Seco in view of the Crystal River incident.
Moreover, it has come to our attention that discovery of similar cracking has recently occurred at the Oconee facility.
See PNO-II-82-24 (March 1, 1982), PNO-II-82-24A (March 3, 1982),
and PNO-II-82-24B (March 4, 1982).
This reactor, like those at Rancho Seco and Crystal River, is a Babcock and Wilcox PWR.
We are troubled by the information received thus far and by the lengthy delays anticipated before the staff receives and evaluates the additional data from licensee.
We therefore re-quest the staff to answer the following questions by March 31, 1982:
1.
What are the differences, if any, in the method of manual initiation of HPI to the make-up nozzle at Rancho Seco, Crystal River and Oconee?
(As noted above at fn.
2, the Rancho Seco pro-cedure assertedly produces no temperature change, while thermal
.. stress has apparently caused the make-up nozzle cracks at Crystal River and Oconee.)
2.
Are the inservice inspection procedures relative to the nozzle tests at Crystal River, Oconee and Rancho Seco the same?
How often are the nozzles at each location surveyed?
When was the last test performed at each facility and with what results?
3.
As of March 1, 1982, how many thermal cycles have been applied to the nozzles at Crystal River?
At Oconee?
At Rancho Seco?
In each case how many of these cycles have occurred after the initiation of the procedures required by the Commission's May 1979 order?
4.
In view of the alleged errors in the SMUD analyses and the recent events at Oconee and Crystal River, does the staff still believe that the Rancho Seco facility can be safely operated "over the near term" up to the design basis limit of 40 HPI cycles?
Why?
It is so ORDERED.
FOR THE APPEAL BOARD O. b b kb C. J Qn Shoemaker Secretary to the Appeal Board
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