ML20155K396
| ML20155K396 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 05/21/1986 |
| From: | Danielson D, James Gavula NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20155K383 | List: |
| References | |
| 50-266-86-07, 50-266-86-7, 50-301-86-07, 50-301-86-7, NUDOCS 8605280131 | |
| Download: ML20155K396 (4) | |
See also: IR 05000266/1986007
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U.S. NUCLEAR REGULATORY COMMISSION
REGION III
Reports No. 50-266/86007(DRS); 50-301/86007(DRS)
Docket-Nos. 50-266; 50-301
Licensee: Wisconsin Electric Power Company
231 West Michigan
Milwaukee, WI 52303
Facility Name: Point Beach Nuclear Plant, Units 1 and 2
Inspection At:
Point Beach site, Two Creeks, WI
Inspection Conducte : May 8 and 9, 1986
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Inspector:
J. A. Gavula
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Approved By:
D. H. Danielson, Chief
Materials and Processes
Date
Section
Inspection Summary
I_nspection on May 8 and 9, 1986 (Reports No. 50-266/86007(DRS);
50-301/86007(DRS))
Areas Inspected: Unannounced special safety inspection of the licensee's
actions taken in response to a 10 CFR Part 21 report issued for their steam
generator hydraulic snubbers.
Results: No violations or deviations were identified.
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DETAILS
1.
Persons Contacted
Wisconsin Electric Power Company WEPCo)
- J. J. Zach, Manager, Point Beach Nuclear Plant
- J. E. Knorr, Regulatory Engineer
- J. G. Schweitzer, Lead Mechanical Engineer
- F. A. Flentje, Administrative Specialist, EQRS
J. C. Reisenbuechler, Superintendent, EQRS
Nuclear Regulatory Commission
- R. L. Hague, Senior Resident Inspector, Point Beach
- J. A. Gavula, Reactor Inspector, Mechanical
- R. J. Leemon, Resident Inspector, Point Beach
- Denotes those attending the exit interview.
2.
Licensee Action on 10 CFR 21 Items
a.
(Closed) 10 CFR 21 (266/86007-01; 301/86007-01): The original
notification of a design deficiency in WEPCo's Point Beach Anker-Holth
hydraulic snubbers was made on June 5, 1984. This documentation as
well~as subsequent correspondence on June 21 and August 10,' 1984,
detailed defective spherical bearings in the 500 KIP and 800 KIP
hydraulic snubbers attached to the steam generators and main steam
lines for both units. The subsequent information identified the blind
end cover and piston rod for the 500 KIP snubber as also having
design deficiencies. The manufacturer's recommendation was to replace
the spherical bearings in the 500 KIP and 800 KIP snubbers and to
replace the blind end covers and piston rod eyes on the 500 KIP
An operability assessment was made for the 500 KIP and 800 KIP snubbers
using the information provided by the snubber manufacturer as well as
new snubber loads from the revised piping analyses. Although some
theoretical localized yielding was predicted, the snubbers were
determined to be operable and would have been able to perform their
safety-related function. At the same time, a commitment was made to
replace the defective parts during the first outage following the
receipt of the replacement parts. This work was performed during
the 1985 Spring outage for Unit 1 and during the 1984 and 1985 Fall
outages for Unit 2.
The documentation reviewed by the NRC inspector showed that the
revised maximum load and capacities of the snubber components were
as follows:
Snubber Rating
500 KIP
800 KIP
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Maximum Design Load
386 KIP (compression)
360 KIP
228 KIP (tension)
(tension or
compression)
Blind End Cover-
248 KIP
497 KIP
(maximum capacity)
Rod End Eye
449 KIP
(not available
(maximum capacity)
greater than
497 KIP)
Using this information, it was decided that in addition to replacing
-the spherical bearings for the two sets of snubbers, the blind end
covers would be replaced on the 500 KIP snubbers and both sets of
snubbers would be derated to match their weakest component capacity.
On this basis the 500 KIP snubber was derated to 449 KIPS and the
800 KIP snubber was derated to 497 KIPS.
In both instances the
derated capacity exceeded the maximum design load for each snubber.
Documentation for the replacement of the required components is
covered in the Point Beach Nuclear Plant Modification Requests
No.84-179 and No.84-180 for Units 1 and 2 respectively.
The
spherical bearings in four 800 KIP snubbers and six 500 KIP snubbers
were replaced with part numbers PA 89492 and PA 89467.
The blind
end covers for the 500 KIP snubbers were replaced with part number
PD 89555 made from ASTM-A-668-79. The installation and maintenance
procedure used to perform the modification was Special Maintenance
Procedure SMP No. 565 "500 KIP Anker-Holth Blind End Cover
Replacement" Revision 0, dated February 18, 1985.
During the course of the modification work, it was found that the
blind end cover on snubber 1HS-10 had been elongated 0.068 inches in
the direction of the load.
This condition was determined to be the
result of the full rated load test conducted by the manufacturer
prior to shipment. Only one 500 KIP snubber was tested in this
manner.
Inspection of the rod end eye showed that no deformation or
elongation had occurred and continuation of service was justified.
Additional documentation reviewed by the NRC inspector included the
following:
Point Beach Construction Instruction Manual PBCI-85-1511
Manual No. 21.12620.007 "449K Hydraulic Shock Suppressor"
Revision 4, dated December 3, 1985.
PBCI-85-679 Manual No. 21.16620.013 "497K Hydraulic Shock
Suppressor" Revision 1, dated May 31, 1985.
Based on a review of the above information, the NRC inspector agrees
with tFe actions taken and considers this item closed.
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3.
Exit Interview
The inspector met with site representatives (denoted in Paragraph 1) at
the conclusion of the inspection.
The inspector summarized the scope
and findings of the inspection noted in this report.
The inspector also
discussed the likely ir.formational content of the inspection report with
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regard to documents or processes reviewed by the inspector during the
inspection.
The licensee did not identify any such documents / processes
as proprietary.
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