ML20138D795

Responds to IE Bulletin 82-02 Re Development & Implementation of Maint Procedures for Threaded Fastener Practices,Including Maint Crew Training & Controls for Disassembly & Reassembly of Component Closure Connections

ML20138D795
Person / Time
Site:	Three Mile Island
Issue date:	12/05/1985
From:	Hukill H GENERAL PUBLIC UTILITIES CORP.
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
5211-85-2198, IEB-82-02, IEB-82-2, NUDOCS 8512130301
Download: ML20138D795 (5)

Text

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Middletown, Pennsylvania 17057-0191 717 944-7621 TELEX 84 2386 Writer's Direct Dial Number December 5, 1985 5211 219t.

Dr. Thoms E. flurley Region I, Regional Administrator U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pa. 19406

Dear Dr. Murley:

Three Mile Island Nuclear Station Unit 1 (TMI-l)

Operating License No. DPR-50 Docket No. 50-289 IE Bulletin 82-02 Final Response By letter dated August 3, 1982 (5211-82-182), TMI-l responded to IEB 82-02, items 3 and 5. The enclosure to this letter responds to the remining items of the Bulletin.

Sincerely, H. D. Huki 1 Director, TMI-l HDH/CWS/spb:0426A cc: J. Thoma R. Conte Enclosure Sworn and Subscribed h$k G

$Dobk f to before ne this y A day of /),n,n,;/ui ,1985.

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~/1/NoMta ry. 60blMNW ic St! ARON P, BR0'.'IN. fiOTARY TUSLIC MfDOLETOWN E0R0. DAUPHIN COUNTY MY COMul!;10N EXPlRES JUNE 12,1989 Member. Pennsyfvania Ass:tistion of Nota GPU Nuclear Corporation is a subsidiary of the General kublic Utilities Corporation -

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5 ENCLOSURE RESPONSE TO IEB 82-02 Item 1:

Where procedures do not exist, develop and implement maintenance procedures for threaded fastener practices. These procedures should include, but not be If mited to the following: (1) maintenance crew training of proper bolting / stud practices, tools application, specifications and requirements,

-(2) detensioning and retensioning practices (torque iteration), specified tolerances, and other controls for disassenbly and reassenbly of component closure / seal connections, (3) gasket installation and controls, and (4) retensioning methods and other neasures to eliminate reactor coolant leakage during operations.

Quality assurance neasures should also be established for proper selection, procurenent, and application of fastener lubricants and injection sealant compounds to minimize fastener susceptibility to SCC environments.

Response to Item 1:

TMI-l has naintenance procedures in-place for Reactor Coolant Pressure Boundary (RCPB) Components within the scope of IEB 82-02 as follows:

1. MP 1401-4.4 Renoval and Replacement of Manway and Inspection Covers of the OTSG.

2. MP 1401-2.4 Pressurizer Manway Cover, Renoval and/or Replacement.

3. MP 1401-5.2 CRDM Renoval and Replacement.

4. MP 1401-1.2 Reactor Coolant Pump Internals Removal and Installation.

5. MP 1410-V-18 Disassemble, Inspect, Clean, Repair and Assenble of Check Valves. The RCPB valves of interest are CF-V4A/B and SA/B. For CF-V4A/B and SA/B the hinge pin retaining cover studs are pressure retaining.

The above list of procedures includes all of the applicable IEB 82-02 studs and bolts and these procedures are written to assure that: the known applicable and appropriate specifications, detensioning and retensioning practices, torque sequences, tolerances, gasket installation requirements and controls are included to minimize RC leakage. TMI-l does not ordinarily l retension RCPB pressure-retaining bolting at system operating pressure to 1 eliminate reactor coolant leakage; in the event such neasures were deened necessary, special procedures would be provided. Ordinarily, TMI-l would consider-injection of leak sealing compounds as the preferred method of minindzing RC leakage during operations.

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o Maintenance crew training is not specified in these procedures. Maintena nce crew training is conducted separately. The Bolting Procedures Training was provided by the Training Department in mid 1983 and again to Mechanical Maintenance personnel in May through June of 1985. The Bolting Procedure Training is now part of the Mechanical Maintenance On the Job Training (0JT)

Program.

TMI-l does have measures that assure the proper selection, procurement and application of fastener lubricants and injection sealant conpounds to minimize fastener susceptibility to strass corrosion cracking (SCC). Lubricants and injection sealants for important-to-safety applications are subjected to Engineering and Quality Assurance reviews prior to selection, procurement, and application. These conpounds are purchased with documentation indicating low leachable halogen content, where applicable.

To date, THI-l has used Furanite injection sealant compound for only one RCPB component, Decay Heat Removal Valve (DH-V1). Maintenance Procedure MP 1410-Y-44, "Use of Furanite," requires use of " Nuclear Grade" Furanite on all RCPB applications. The Nuclear Grade Furmanite is low in leachable halogens and sulfur content. DH-V1 was initially injected with Furanite in Novenber, 1976. In November,1983 the Furnanite compound was removed when the valve was disassembled and permnent repairs were made. This use was to seal a bonnet seal ring leak on a pressure seal valve and did not expose any RCPB bolting to SCC susceptibility.

Item 2:

Threaded fasteners of closure connections, identified in the scope of this bulletin, when opened for component inspection or maintenance shall be removed, cleaned, and inspected per IWA-2210 and IWA-2220 of ASME Code Section XI (1974 edition or later) before being reused.

Response to Item 2:

Item 4b and c of IEB 82-02 requires a report of the specific connections examined in Item 2. Attachnent A provides this report and Attachment A shows that TMI-l has not detected any RCPB stud or bolt failures in the period since IEB 82-02 was issued. All the fasteners were examined while removed from the respective component except where noted in Attachment A.

Item 4:

A written report signed under oath or affirmtion under provisions of Section 182a, Atomic. Energy Act of 1954 as amended, shall be submitted to the Regional Administrator of the appropriate NRC Regional Office within 60 days following the completion of the outage during which Action Item 2 was performed. The report is to include:

a. A statement that Action Item 1 has been completed,

b. Identification of the specific connections examined as required by Action Item 2.

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c. The results of the exandnations perforned on the threaded fasteners as required by Action Item 2. If no degradation was observed for a particular connection, a statement to that effect, identification of the connection and, whether the fasteners were examined in place or removed is all that is required. If degradation was observed, the report should provide detailed information.

Response to Item 4:

This letter provides the requested information for Items 4a, b, and c.

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ATTACMENT A IEB 82-02 FASTENERS EXAMINED SINCE THE DATE OF IEB 82-02 JUNE 2, 1982.

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C(MPONENT METHOD /DATE RESULTS '

OTSG A Upper Primry Manway Studs VT/3-30-84 MT/3-20-84 No degradation '

OTSG B Upper Prisery Manny Studs VT/3-30-84 MT/3-20-84 No degradation OTSG A Lower Primary Manway Studs VT/3-30-84 MT/3-20-84 No degradation {

i OTSG B Lower Primry Manway Studs VT/3-30-84 MT/3-20-84 No degradation OTSG'A Upper Primry Manway Studs VT/6-29-84 MT/8-8-84 No degradation l OTSG B Upper Primry Manny Studs VT/6-29-84 MT/8-8-84 No degradation OTSG A Lower Primry Manway Studs VT/7-21 -84 MT/7-21 -84 No degradation '

OTSG B Lower Priary Manway Studs VT/6-29-84 MT/8-8-84 No degradation Pressurizer Manway Studs VT/ MT/4-6-83 8 4-8-83 Studs 1, 3, 4, 7, 8, 9 showed no degradation.

Studs 2, 6,10,11,12 had minor thread dange (several nicks N .010" deep and several small areas of galling), were repaired and re-examined satisfactorily. Stud 5 was a partial exam, since it could not be removed from the pressurizer. The partial exam of Stud 5 showed no degradation.

RC-PlB Main Flange Bolts VT/3-24-84 MT/3-23-84 See Footnote 1 (all except Nos.12 & 13)

RC-P1B Lower Seal Housing Bolts VT, MT/3-24-84 No degradation FOOTNOTE 1 RC-PlB flange bolts exhibited boric acid wastage or boric acid corrosion. Wastage thread damage occurred on only the first four or five threads. Most of these threads I

were not engaged in the pump casing. Also, in most cases, the wastage extended to an area 1" to 1-1/2" above the threads on the bolt shank. All bolt diameters except Nos. 12 and 13 es compared towere measured.-

the nominal The smallest diameter of 4.317".diameter in the corroded area was 4.302" The reduction in bolt area has been svaluated as having no significant effect on bolt stress. There are a total of 24 bolts and the'UT and MT Examinations performed on 22 bolts (bolts No. 12 and 13 were not examined) did not reveal any reportable conditions. The VT of the bolts to be reused was evaluated as satisfactory for reinstallation. The following bolts were replaced:

No. 1, 2, 4, 12, 13, 16, 17, and 18. These bolts exhibited more wastage I than the bolts to be reused. Also, some of these bolts were damaged by impact hammer s impressions that were made during the bolt removal operation. Bolt No. 4 was replaced because it was evaluated to be excessively hard. This was a precautionary measure. )

The eight replacement bolts were VT, MI, and UT examined satisfactorily. The source cf the boric acid solution that caused the wastage was attributed to seal injection

flange joint leakage. The leaking flange jointa have been repaired.

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