IR 05000282/1988009
| ML20196H897 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 06/30/1988 |
| From: | Danielson D, James Gavula NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20196H884 | List: |
| References | |
| 50-282-88-09, 50-282-88-9, 50-306-88-09, 50-306-88-9, NUDOCS 8807060278 | |
| Download: ML20196H897 (4) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION III
Reports No. 50-282/88009(DRS); 50-306/88009(ORS)-
Docket Nos. 50-282; 50-306 Licenses No. OPR-42; OPR-60 Licensee: Northern States Power Company 414 Nicollet Mall Minneapolis,.MN 5540i Facility Name:
Prairie Island Nuclear Gene:ating Plants Units 1 and 2 Inspection At:
Fluor Daniel Inc. 0ffice, Chicago, Illinois-Inspection Conducted: May 26 and June 17, 1988 Inspector:
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Date
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Approved By:
D. H. Danielson, Chief
'/36 ff Materials and Processes Section Date Inspection Summary Inspection on May 26 and June 17,1988 (Reports No. 50-282/88009(ORS);
50-306/88009(ORS))
Areas Inspected:
Special safety inspection of licensee action on previously identified concerns related to piping operability analyses (92701).
Results: No violations or deviations were identified.
8807060278 880630 PDR ADOCK 05000282 O
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DETAILS
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1.
Persons Contacted Northern States Power Company (NSP)
- J.'Donatell, Engineer Fluor Daniel Inc. (FDI)
- B. Dickerson, Project Piping Engineer
- H Bartholomees, QA Manager
"C. Agan, Project Manager
-*W. Brennan, Project Engineering Manager
- Denotes those-attending the exit meeting on June 17, 1988.
2.
(0 pen) Open Item (282/87018-01: 306/87017-01):
Supplemental reviews of original IE Bulletin 79-14 work are being performed to identify and correct inconsistencies in applying and documenting reconciliation criteria.
As part of this ongoing program, valve data used in the seismic analyses is routinely reconfirmed using vendor drawings.
For valves identified as 3/4"-1A58-RE, the original drawing could not be located and as a result, FDI contacted Copes Vulcan in order to verify the weight and center of gravity (c.g.) location.
Subsequently, the original drawing vas found in the NSP file and it was confirmed that the original data used in the seismic analysis corresponded to the information given on that original drawing.
However, new information subsequently sent by Copes Vulcan to FDI showed a radical change in both the c.g. and weight of the valve.
The old information showed the c.g. at somewhere above 5 inches and a weight of 170 pounds.
The new information showed the c.g. at 19.25 inches and the weight at-240 pounds, This change invalidated the existing seismic analyses which was based on the original information.
As a result of this discrepancy, all locations where this model valve was used were identified and the potential effects on the seismic analyses were evaluated.
The review identified approximately 21 locations where the discrepancy could cause a significant effect on the seismic stresses.
The most adversely affected analyses were also identified at this time.
An operability analysis was then performed on the worst case situation to verify that continued operation could be justified for that as well as all other cases.
The intent was to show that although the FSAR stress criteria was exceeded, the plant could be safely operated until the next outage when repairs could be made.
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FDI ' Report No. OVST-1, "Operability Study from Increased Weights and l
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Changes in the Center of Gravity Location for Small Bore Copes Vulcan
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Valves," April 26, 1988, was issued for the Safety Injection Part -108, Unit 1 Accumulator Test System.
Otsed on an analytical methodology utilizing ASME Section III fatigue evaluation,. it was concluded that the system was operable.
Upon review,-the NRC inspector questioned the operability of the above
. sy stem..Primarily, the use of Class I fatigue-evaluations as a basis for continued operation of a ANSI B31.1 system had never been seen before.. The fact that the evaluation was performed using operability
- criteria which had not been previously reviewed by NRR technical staff caused additional concern.
A detailed review of the piping stress analysis indicated that at least one support was significantly overstressed and potentially exceeded the operability limits for anchor bolts previously established under IE Bulletin 79-02. On this basis, the overall validity of the FDI report was questioned by the NRC inspector.
Because of these concerns, the status of the modifications to this specific system was requested.
Based on information from the site, the modifications to'resupport the valve operators had been completed.
As a result of this information, the operability of the worst case situation was no longer an issue, but due to the concerns expressed above,.the operability of the remaining cases was brought into question.
On this basis, the licensee was requested to evaluate the next worst-case situation and to submit the evaluation along with an operability
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procedure to the Region. This information was received in NSP's letter
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from J. Goldsmith to A Burgess (NRC-RIII) dated June 8, 1988.
Pending the review and appaval of the methodology and criteria contained in the procedure, this will be considered an Open Item. (282/88009-01;
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306/88009-01)
The second operability analysis, FDI Report No. OVST-2, "Operability Study Resulting from Increased Weights and Changes in the Center of Gravity Location for Small Bore Copes Vulcan Valves," was reviewed by
the NRC inspector.
Calculation No, Mech 0259-02, Revision 0, dated June 6,1988, documented the piping stress analyses u:ed as a basis for the above report.
The initial analysis of the Safety Injection Line No. 103, indicated that Support RSIH-19, would exceed the operability acceptance limit for the support's baseplate. Another analysis was subsequently performed
assuming the support had failed completely.
The results of this analysis
showed that the piping system would be within the recently transmitted
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operability criteria and on this basis, the system was declared operable.
A next worst case analysis was also performed during this titce period.
For Safety Injection Line No.104, the analysis with the revised valve
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c.g. and weights indicated that the piping stresses were all within FSAR
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stress criteria.
However, revised loads for Support RSIH-31 resulted in
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the baseplate exceeding the FSAR stress allowable.
These stresses were within the operability criteria and therefore the system was able to be declared operable.
The NRC inspector also reviewed FDI Calculation No. Mech 0259.1,
"Determination of the Affects of Valve Weight and Center of Gravity Changes on the Pipe Stress Anaiyses for Small Bore Lines Containing Copes Vulcan Control Valves," Revision 1, June 7, 1988. This calculation _ quantified the affects of the valve weight and c.g.
changes on the piping stresses. _ Using conservative, simplified assumptions, a total of 21 subsystems were determined to rogvire reevaluation due to the valve data changes.
To.date, the three worst cases have been evaluated in detail. Analysis
=of the remaining subsystems is currently ongoing with the intent of
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completing all_ work prior to the next Unit 1 outage when any required modifications can be made.- The overall extent of the valve data problem is also being pursued through Westinghouse to determine if other Copes Vulcan valves at Prairie Island have similar discrepancies and if other utilities potentially have the same problem.
3.
Open Items Open items are matters which have been discussed with the licensee, which will be reviewed further by the inspector, and which involves some action on the part of the NRC or licensee or both. The open item disclosed in this inspection is discussed in Paragraph 2.
Exit Interview
Tre Region III inspector met with the licensee representatives (denoted l
'n Paragraph 1) at the conclusion of the inspection on June 17, 1988.
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The inspector summarized the purpose and findings of the inspection.
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The licensee representatives acknowledged this information.
The inspector also discussed the likely informational content of the inspection report with regard to documents or processes reviewed during the inspection.
The licensee representatives did not identify any such documents / processes as proprietary.
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