IR 05000295/1979026
| ML19309A551 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 02/07/1980 |
| From: | Danielson D, Yin I NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML19309A543 | List: |
| References | |
| 50-295-79-26, 50-304-79-25, NUDOCS 8003310422 | |
| Download: ML19309A551 (6) | |
Text
U.S. NUCLEAR REGULATORY COMMISSION
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OFFICE OF INSPECTION AND ENFORCEMENT
REGION III
Report No. 50-295/79-26; 50-304/79-25 Docket No. 50-295; 50-304 License No. DPR-39; DPR-48 Licensee: Commonwealth Edison Company P. O. Box 767 Chicago, IL 60690 Facility Name:
Zion Station, Units 1 and 2 Inspection At:
Zion site, Zion, IL, November 29, 1979 Sargent and Lundy Engineers, Chicago, IL, December 20, 1979 NRC, Region III, January 3, 1980 Bergen-Paterson Pipesupport Corporation, Laconia, NH, January 4, 1980 NRC IE:HQ, January 10, 1980 Inspection Dates: November 29, December 20, 1979 and January 3-4, and 10, 1980.
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Inspector sl. T. Yin 7/ ft
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zw Approved By:
D. H. Danielson, Chief o /*7/ s'c:
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Engineering Support Section 2
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Inspection Summary Inspection on November 29, December 20, 1979 and January 3, 4, and 10, 1980 (Report Nos. 50-295/79-26 and 50-304/79-25)
Areas Inspected:
Special inspection of damaged Bergen-Paterson large bore hydraulic snubbers installed on Unit I steam generators. The inspection involved 28 inspector-hours by one NRC inspector.
-Results: No items of noncompliance or deviations were identified.
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b DETAILS Persons Contacted Inspection at Zion site on November 29, 1979
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Licensee Employees J. J. Gilmore, Assistant Technical Staff Supervisor J. Wennerholm, Zion Technical Staff Inspection at Sargent and Lundy Engineers (S&L) on December 20, 1979 Licensee Employee C. Richardson, SNED Engineer S&L Employee R. A. Hameetman, Mechanical Engineer Meeting at NRC Region III Office on January 3, 1980 Licensee Employees E. F. Murach, Maintenance Assistant Superintendent, Zion J. J. Gilmore, Assistant Technical Staff Supervisor W. F. Naughton, Nuclear Licensing Administrator J. Wennerholm, Zion Technical Staff NRC RIII D. H. Danielson, Chief, Engineering Support Section 1 D. C. Boyd, Reactor Inspector I. T. Yin, Reactor Inspector Inspection at Bergen-Paterson Pioesupport Corporation (B-P) on January 4, 1980 B-P Personnel H. Erikson, Vice President, Chief Engineer K. Asmundsson, Product Manager W. F. Becksted, QA Manager M. Myshrall, Designer Meeting at NRC Headquarters on January 10, 1980 Commonwealth Edison Company (CECO) Representatives E. Murach J. Gilmore-2-
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W. F. Naughton C. Richardson S&L Representatives R. B. Johnson Wyle Latoratory Representatives J. Bowman P. T. Johnson B-P Representative H. Erikson NRC Representatives H. A. Wilber, IE:HQ P. Kellogg, IE:RII H. L. Whitener, IE:RII D. H. Danielson, IE:RIII 1. T. Yin, IE:RIII H. K. Shaw, DOR-EB J. J. Zudans, DOR-EB K. R. Wichman, DOR-EB D. Neighbors, D0R-ORB 1 Functional or Program Areas Inspected During a routine licensee surveillance on the 16 large bore B-P snubbers installed on the four steam generators inside the Unit 1 containment, excessive leakage was identified on Snubbers No. 8, 11, and 13.
These snubbers were disassembled at the site and significant gouging of the piston rod and gland seal surfaces were located at various areas above and below the installed horizontal position. The inspector visited the site on November 29,-1979, to observe the scored conditions and to dis-cuss licensee evaluation and resolution. During a discussion with B-P representatives on the phone, it was noted that Surry Nuclear Power Plant large bore snubbers also had experienced similar scoring problems, and the cause of the damage could be due to:
(1) During or subsequent to the installation of the snubbers, a weld arc was set between the ram and the gland surfaces due to an improper ground, and/or (2) fluid. contamination before, during, or after installation. Subsequently, the cause of the damage was attributed to the close prox'mity of the ram and gland metal surface hardness.
Numerous discussions between the NRC Regional offico NRC Headquarters,
-and the licensee were conducted between November 29, 1979, and January 2, 1980.
In the meantime, the licensee randomly selected two Unit I steam
generator snubbers, No. 12 and 14, for testing at the Wyle Laboratories l
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in Huntsville, Alabama. The inspector also visited the the A-E (S&L) of-fice on December 20, 1979, to review the snubber design specification, including the snubber test performance acceptance criteria.
On January 3, 1980, a presentation was made by the licensee at the NRC Region III office of the results of the snubber testing performed at Wyle. Laboratories from December 19 to 30, 1979.
Certain deficiencies were identified during testing for which the reasons and/or the causes could not explained. The licensee was asked to provide additional evalu-ation.
On January 4, 1980, RIII inspection was conducted at the B-P office in Laconia, New Hampshire to review the snubber qualification test reports including the procedures used and data obtained, and to discuss some of the deficiencies identified during the testing done at the Wyle Labora-tories. The inspector reviewed the qualification test procedures and had no adverse comments. The test reports, including:
(1) cylinder static pressure test, (2) valve block test, and (3) snubber assembly test, were not available for review. Some of the data on the valve block flow rate test reports appeared to be inconclusive and test conditions were not documented.
In discussions between the insp3ctor, Wyle Laboratories, and B-P regarding the anomalies identified during the tests conducted at Wyle Laboratories there appeared to be some disagreement regarding the test set up and interpretation of the results.
A meeting was convened at the NRC office in bethesda, Md., to allow all involved organizations to present their test programs and results.
During the meeting, NRC concurred with the licensee's planned schedule for re-turning Zion Units 1 and 2 to service, contingent upon the following ad-ditional corrective actions:
1.
The 12 inch Bergen-Paterson snubber reservoir levels will be checked weekly when the unit is in service until the snubbers are inspected, repaired, and modified.
Continuation of this weekly check on Unit 1 beyond the end of the Unit 2 outage is contingent upon the evaluation of snubber test results.
2.
Immediately following an earthquake, the 12 inch Bergen-Paterson snubber reservoir levels will be checked and fluid added as neces-sary.
3.
For every reactor temperature change in excess of 100 F, the 12 inch Bergen-Paterson snubber reservoir levels will be checked and fluid added as necessary.
4.
A procedure will be developed to functionally test the 12 inch Bergen-Paterson snubbers. The valve control block will be included as part of the snubber tests. Test acceptance criteria will be included in this procedure. This procedure will be reviewed by the NRC staff prior to its use.
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Two randomly selected Unit 2, 12 inch Bergen-Paterson snubbers shall be tested prior to their repair and modification using the above
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procedure.
6.
.Two of the modified Unit 2, 12 inch Bergen-Paterson snubbers shall be tested using the above procedure.
7.
All 16 of the Unit 2, 12 inch Bergen-Paterson snubbers will be in-spected, repaired, and modified during the May 1980, refueling out-
age.
8.
A report of all laboratory test results, snubber nonconformance evaluations and corrective actions, and any significant increase in snubber seal leakage will be submitted to the NRC promptly.
9.
The continued operation of Unit 1 is contingent upon NRC staff acceptance of the Unit 2 snubber test results.
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Exit Interview The inspector met with licensee representatives at the conclusion of the inspection on November 29, 1979.
The inspector stated that due to the
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nature and severity of t'ne problems, further review and evaluation was required. Subsequently, discussions were held between licensee manage-ment / technical representatives and the NRC staff as reported herein.
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