ML20155K396

Insp Repts 50-266/86-07 & 50-301/86-07 on 860508-09.No Violations or Deviations Noted.Major Areas Inspected: Licensee Actions Taken in Response to 10CFR21 Rept Issued for Steam Generator Hydraulic Snubbers

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: ML20155K378 ML20155K396
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 Licenses No. DPR-24; DPR-27

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 6!218b

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Approved By:

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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

snubbers.

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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