IR 05000454/1988014
| ML20153D373 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 08/29/1988 |
| From: | Danielson D, James Gavula NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20153D369 | List: |
| References | |
| 50-454-88-14, NUDOCS 8809020180 | |
| Download: ML20153D373 (5) | |
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U. S. NUCLEAR REGULATORY COMMISSION
REGION III
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Report No.:
50-454/8f>014(DRS)
Docket No.:
50-454 License No.:
NPF-37 Licensee:
Commonwealth Edison Company
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Post Office Box 767 Chicago, IL 60690 Facility Name: Byron Station, Unit 1 Inspection At:
Sargent and Lundy Engineers 0ffices, Chica;o, IL
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Inspection Conducted August 10-12, 1988 Inspector:.
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cb7G/ w W Approved By:
D. H. Daniel on, Chief Phk#
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Materials and Processes Section Date Inspection %ummary Inspection on August 10-12, 1988 (Report No. 50-454/88014(DRS))
Areas Inspected: Special safety inspection of facility modifications associated with snubber reduction (37701), traih.ag (41400), and licensee action on previous inspection findings (92702).
Results:
No violations or deviations were identified.
Previous deficiencies from the first snubber reduction effort
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were adequately rddressed.
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Third party technical audits of the work were performed.
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PDR ADOCK 0U000454 l
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DETAILS 1.
Persons Contacted Commonwealth Edison Company (Ceco)
P. Donavin, PWR Engineer
- C. Moerke, PWR Project Engineer
- S. Bakhtiari, PWR Engineer Sargent and Lundy Engineers (S&L)
- W.
C. Cleff, Project Director
- C. S. Lim, Mechanical Project Engineer
- R. D. Gerke,.EMD Project Engineer
- G. H. DeBoo, EMD Supervisor
- J. R. Meister, Project Manager
- Denotes those attending the exit interview on August 12, 1988.
2.
Licensee Action on Previous Inspection Findings a.
(Closed) Violation (454/87007-01):
Procedures prescribing snubber reduction efforts did not 1) adequately address all seismic interactions due to increased displacements; 2) include seismic anchor movements for interaction considerations; and 3) give adequate guidance for inclusion of zero period acceleration in seismic analyses.
CECO's response to the above violation is dated August 21, 1987, and January 26, 1988.
The corrective actions as stated in these letters determined the full extent of the subject violation, performed the necessary followup actions to correct the present conditions and developed the appropriate procedures to preclude recurrence of similar circumstances.
Implementation of these procedures were verified as discusseo in Paragraph 3 in this report. This item is considered closed, b.
(Closed) Violation (454/87007-02): Design activities for snubber reduction efforts did not 1) consider zero period acceleration (ZPA)
effects; 2) provide justification for the seismic interaction clearance criteria; 3) establish the technical bases for rattle point resolution criteria; and 4) perform adequate design verification.
CECO's response to the above violation is dated August 21, 1987, and January 26, 1988.
The corrective actions as stated in these letters detennined the full extent of the subject violation, performed the necessary followup actions to correct the present conditions and
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developed appropriate measures to preclude recurrence of similar circumstances.
Implementation of these corrective actions were verified as discussed in Paragraph 3 below. This item is considered closed.
3.
Snubber Reduction Program - Phase II
a.
Introduction As a continuation of the program initiated in late 1986 (refer to NRC Inspection Report No. 50-454/87007 for details) the second phase of the snubber reduction effort was started in late 1987.
Implemen-tation of the modifications is scheduled to be completed by the end of the second refueling outage in late 1988. The previous effort consisted almost entirely of subsystems inside containment. The latest effort includss subsystems located mostly in the Auxiliary
Building. Of the 488 snubbers originally installed on the Phase II subsystems, 83 will still remain with 92 being replaced by struts and 313 being completely eliminated.
b.
Document and Procedure Review The NRC inspector reviewed relevant portions of the following documents and procedures to verify compliance with NRC requirements and licensee conunitments.
- Project Plan, "Priority 3 and 4 Snubber Reduction Program",
February 10, 1988.
- S&L, PI BB-112, "Processing of Station Nuclear Engineering Department Modifications", Revision 2, August 8,1988, t
S&L, PI BB-113. "Limited Clearance Walkdowns for Byron Unit 1 Snubber Reduction Subsystems", Revision 0, April 15, 1988.
"Interface Agreement Byron 1 Snubber Reduction Program",
Revision 0, January 5, 1987.
- S&L, EMD-064447, "Piping and Support Modification Limited Clearance Walkdown Requirements and Evaluation Criteria",
Revision 00, April 11, 1988.
No adverse coments were made during the reviews; however, several
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points of discussion were made by the NRC inspector, j
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First, the guidelines given in CECO's Architect Engineer (AE)
Guidebook for preparation of project plans needs to be clarified.
The AE Guidebook's Paragraph 3.4.3.4 states:
... a reference to
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the AE's QA program elements that will be applied to the project i
should be made in this section". However, the title of the paragraph
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calls for "special" QA requirements and as such, no QA requirements were specified since it was an "ordinary" type of project.
Based on
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discussions with the licensee representatives, the AE Guidebook is i
being revised in the near future and consideration will be given to
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this clarification.
Secondly, although an interface agreement was established for the project, revisions to the scope of work required that Westinghouse perform an analysis of one subsystem instead of S&L.
This change reverted the design process back to an interface arrangement similar to initial construction for that one subsystem. Although no interface problems were noted and the previous interface agreement could be applied, this change was not documented in the project plan.
The changes in scope of work and the subsequent effects on interface requirements need to be considered more diligently.
Previous deficiencies identified in the initial snubber reduction effort (see Paragraph 2 above) were corrected relative to seismic interaction walkdown criteria, ZPA considerations and rattle point resolution criteria.
No violations or deviations were identified, c.
Piping Analysis Review The NRC inspector reviewed portions of the following calculations to verify compliance with NRC requirements and licensee commitments.
- FW-08, EMD-64160, "Snubber Reduction Analysis-Feedwater".
Revision 01.
Structural calculation for the above subsystem No.13.1.25.
- RH-07, EMD-64553, "Snubber Reduction Analysis-Residual Heat Removal", Revision 03.
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l Structu,al calculation for the above subsystem No. 13.1.25.
- SI-17, EMD-64200, "Snubber Reduction Analysis-Safety Injection",
Revision 3.
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For the portions of the analyses reviewed, model dimensional
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accuracy corresponded to isometric as-built dimensions.
Reasonable correlation with original design dimensions was also spot checked to identify any gross as-built discrepancies. None were noted.
Restraint capability was checked and it was noted that supports with revised loads containing uplift were redesigned and properly analyzed.
Supports with increased loads were checked for sufficient
margin and if necessary, modified and reanalyzed to accommodate
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revised loads.
One minor technical issue was discussed during the inspection.
During the requalification of an end bracket assembly, proper consideration was not given to the angular installation tolerance for
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a load application.
Based on discussions with the AE representatives, adequate margin existed in the analyses since extremely conservative assumptions were used.
Engineering judgement was used to dismiss the critical nature of the angular tolerance but this judgement had not been documented. Tha NRC inspecter concurred w'th this assessment and based on the 'imit'd number of evaluations conducted for similar instances, no fu"ther investigations were required.
No violations rr deviations were identified.
d.
Conclusions The Byron Snubber RrJuction Phase II effort appeared to be well organized and fully addressed all the previously identified deficiencies in the Phase I work.
The nature of the Phase II work differed from t'ie Phase I work in that an adequate lead time was given for the development of the necessary procedures and for the performance of the actual analyses.
The initial project had approximately a 3 month lead time whereas the latest effort had i
approximately one year.
Both phases are similar in that CECO did not 3rovide technical guidance co the AE's during the project. Altlough technical audits with third party reviewers were performed during the course of both projects, CECO continues to rely exclusively on external expertise and does not have the capability to review and monitor technical aspects of the work.
4.
Exit Interview The Region III inspector mot with the licensee representatives (denoted in Paragraph 1) at the conclusion of the inspection on August 12, 1988.
The inspector summarized the purpose and findings of the inspection.
The licensee representatives acknowledged this information.
The inspector slso discussed the likely informational content of the inspection eport with regard to documents or processes reviewed during the inspection.
The licensee representatives did no identify any such documents / processes as proprietary.
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