IR 05000315/1987005
| ML20212A965 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 02/20/1987 |
| From: | Danielson D, Yin I NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20212A916 | List: |
| References | |
| 50-315-87-05, 50-315-87-5, 50-316-87-05, 50-316-87-5, IEIN-86-102, NUDOCS 8703030448 | |
| Download: ML20212A965 (5) | |
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U.S. NUCLEAR REGULATORY CCFNISSION
REGION III
Reports No. 50-315/87005(DRS);50-316/87005(DRS)
Docket Nos. 50-315; 50-316 Licenses No. DPR-58; DPR-74 Licensee: American Electric Power Service Corporation Indiana and Michigan Power Company 1 Riverside Plaza Columbus, OH 43216 Facility Name:
D. C. Cook Nuclear Power Plant. Units 1 and 2 (
Inspection At:
D. C. Cook Site, Bridgman, Michigan Inspection Conducted:
February 11-12, 1987 Inspector:
I. T. Yin
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2[M/f7 Approved By:
D. H. Danielson, Chief Materials and Processes Section Date Inspection Summary No. 50-316/87 February 11-12,1987 (Reports No. 50-315/8700_5(DRS);
Inspection on 005(DRS))
Areas Inspected: Routine announced inspe.ction of the licensee's inspection, testing, ar.d seal replacement program for the large bore steam generator snubbers (SGSs) (30703B, 703708).
Results: No violations or deviations were identified.
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DETAILS 1.
Persons Contacted Indiana and Michigan Power Company
- W. G. Smith, Jr., Plant Manager
- D. L. Gallagher, Maintenance /ACC
~ *L. H. Van Ginhoven, Technical Engineer, Maintenance
-*A. A. Blind, Assistant Plant Manager
- J. Rutkowski, Assistant Plant Manager
- T. K. Postlewait. Technical Engineer Superintendent
- R.T.Rickman, Technical,InserviceInspection,(ISI)
~*C. A. Freer, Technical, ISI
- N. L. Daavettila, Technical Engineer, Maintenance V. Allard, Maintenance Superintendent M. P. Alexich, Vice President, Nuclear Operations L. S. Gibson, Assistant Plant Manager M. M. Tenny, Technical Engineer American Electrica_1 Power Service Corpo_ra_ti_on (AE_P1
- K. J. Santos, FPED
- J. C. Feinstein, Manager, NS&L
- M. t'arrccco, Manager, MEEP
- T. Sutyan Sharma, Senior Engineer, HS&L
- R. T. Huerter, Site Quality Assurance
- R. S. Papps, Engineer U.S. Nuclear Regulatory Comission Region III (RIlll
- B. L. Jorgensen, Senior Resident Inspector
- Denotes those attended the managsment exit interview on February 12, 1987.
2.
Review of Plant Technical Sp_ecification ESl
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The NRC inspector reviewed the D. C. Cook TS Section 3/4.7.8, " Snubbers,"
and determined that it was in compliance with the NRC generic letters listed below. Functional test exemptions for the large bore snubbers with load capacity of 50 kips and above had been removed, hRC-hRR Director, Division of Licensing letter to all power reactor Licensees (except SEP Licensees), " Technical Specification Revisions for Snubbers Surveillance," November 20, 1980.
NRC-NRR Director, Division of Licensing letter to all SEP licensees,
same subject, March 23, 1981.
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3.
Review of SGS Testing Program The NRC inspection was prompted by the issuance of NRC IE Information Notice (IE IN) No.86-102,'" Repeated Multiple Failure of Steam Generator Hydraulic Snubbers Due to Control Value Sensitivity," December 15, 1986, and the fact that the D. C. Cook SGSs are similar Anker-Holth (AH) snubbers described in IE IN No.86-102.
a.
SGS Seal Life Expectancy There are four steam generators (SG) in each of the two reactor units. There are two pairs of SGSs (each snubber-is rated 800 kips)
installed on each SG. The present functional testing schedule is two (one pair) SGSs during each plant refueling outage. After testing, all'Viton A seals are to be replaced with new Ethylene Propylene seals.
The present 12 year seal life cycle is considered acceptable; however, some SGS seals in Unit 1 may be in service for up to 20 years. The NRC inspector considered the 20 year service life marginally acceptable based on:
The replaced seal material (Viton A) appeared to'be in good
physical condition.
An AEP engineering study in seal material life expectancy under radiation service condition.
Provisions have been made to replace all seals with spare parts
that are in stock should adverse conditions be identified during
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testing or disassembly, b.
Review Test Results There were 11 SGSs tested at Wyle Laboratory since July 29, 1983.
The NRC inspector reviewed the follcwing as-fcund test records (the first seven are Unit 1 SGSs, and the last four are Unit 2 SGSs):
Tension Corpression SGS No.
LV (ipm)*
BR (ipm)*
LV (ipm)
BR (ipm)
3.0
.068 2.65
.038
8.54
.054 4.0
.051
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4.35
.052 4.75
.047
6.9
.049 8.7
.049
2.5
.049 2.15
.046
1.33
.047 1.05
.048
.75
.047 1.73
.047
2.5
.048 1.1
.05
1.7
.045 0.2
.047
1.12
.041 1.7
.04
1.6
.043 1.5
.045
- LV = Lockup Velocity BR = Bleed Rate
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SGS No. 7 failed the second functional test. Disassembly of the unit disclosed-that a small portion of the seal was sliced cut away from the piston T seal ring.
c.
Review of AH Production Test Record The NRC' inspector reviewed the McDowell Wellman Engineering Company (the AH SGS manufacturer) certificate letters to AEP, September 25, 1972; September 30, 1972; and October 9, 1972, as had no adverse consents.
d.
Review of SGS Test Acceptance Criteria The SGS acceptance criteria are:
LV: 0.1 ipm to 20 ipm BR:
less than'0.07 ipm The NRC inspector requested that AEP verify that the design and transient thermal movements are less than 0.1 ipm, and provide technical justification for the low BR. This is an unresolved item (315/87005-01; 316/87005-01).
4.
SGS Ball Bushing Acceptability NRC IE IN No. 84-73, "Dcwnrating of Self-Aligning Ball Bushings Used in Snubbers," September 14, 1984, notes that some AH SGS ball bushings failed under test. The problem was discussed with the AEP staff during the NRC inspection. AEP presented a letter from Paul-Munroe, Inc. (the company who purchased the AH design and service rights) to AEP, "Torrington Bearing Ratings, Bearing No. 37SF60, oc 950," December 17, 1984, which stated, "The bearings are rated at a maximum load of 1,000,000 pounds; this exceeds the design load rating...." The hRC irispector considers the matter closed. This closure is based on the ball bushing design rating and the fact that full load tests of 10 SGS did not reveal bushing cracks.
5.
Personnel Interviews Throughout the NRC inspection the AEP staff demonstrated technical competence ar.d a clear understanding of SGS design and testing.
In addition, the NRC inspector was impressed by the close working relationship and understanding between the AEP management and technical staff.
6.
Unresolved Item An unresolved item is a matter about which n. ore infomation is required in order to ascertain whether it is an acceptable item, an open item, a deviation, or a violation. Cne unresolved item disclosed during this inspection is discussed in Paragraph 4.d.
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7.
Exit Interview TheNRCinspectormetwithlicenseerepresentative(denotedin Paragraph 1) at the conclusion of the inspection. The inspector sunanarized the scope and findings of the inspection. The inspector also discussed the likely informational content of the inspection report with regard to documents reviewed by the inspector during the inspection. The licensee representatives did not identify any such documents as prcprietary.
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