ML20148G771

Forwards Rept of Helium Circulator S/N C-2101 & Inlet Piping S/N 2001 Repair & Mod Activities, Per Commitment in . Insp Findings & Proposed Tech Spec Amend to Be Submitted 8 Months Following Removal of Circulator for Insp

ML20148G771
Person / Time
Site:	Fort Saint Vrain
Issue date:	01/22/1988
From:	Robert Williams PUBLIC SERVICE CO. OF COLORADO
To:	Calvo J NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM), Office of Nuclear Reactor Regulation
Shared Package
ML20148G775	List: ML20148G771 ML20148G794 ML20148G830 ML20148G851
References
P-88019, TAC-65992, NUDOCS 8801270029
Download: ML20148G771 (4)

Text

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January 22, 1988 $ n'v!r7cEso201.os4o Fort St. Vrain R.O. WILLIAMS, JR.

Unit No. I P-88019 g E9OEN9o U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Attention: Mr. Jose A. Calvo Director, Project Directorate IV Docket No. 50-267

SUBJECT:

Engineering Report on Circulator C-2101 Damage

REFERENCES:

1) PSC Letter, R.0. Williams, Jr. to J.A. Calvo, dated 9/21/87 (P-87327)

2) NRC Letter, K.L. Heitner to R.0. Williams, Jr.

dated 12/8/87 (G-87434)

Dear Mr. Calvo:

This letter transmits, as Attachment 1, Public Service Company of i Colorado's (PSC) engineering report, "Report of Helium Circulator S/N l

C-2101 Damage and Inlet Piping S/N 2001 Repair and Modification Activities", dated January 22, 1988, in accordance with PSC's commitment contained in Reference 1.

This report identifies all corrective actions that PSC considers appropriate for the interim and long term operation of the helium circulators at Fort St. Vrain and provides the plan and schedule for their implementation. The nine (9) questions transmitted to PSC by Reference 2 have also been addressed in this report. Attachment 2 identifies the Attachment i location of PSC's response to each NRC question.

The schedule for the Spring 1988 outage for the refurbishment of the helium circulators, which is presently expected to extend over a twelve week period, has not been firmly established. Delivery dates for certain replacement parts for the installed circulators have not been finalized, and the time required for performing weld repairs to

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8801270029 880122 ~

PDR ADOCK 05000267 G PDR \g

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P-88019 January 22, 1988 the ste'am ducting struts of the C-2101 helium- circulator is being-determined. It is expected that the schedule for the Spring 1988 helium circulator outage will_ be established by mid-February.

Prior to the end of the next refueling outage, about mid 1989, one of the presently installed helium circulators will be removed for performance of the 10 calendar year surveillance inspection of one entire helium circulator that is required by Technical Specification SR 5.2.18. It is anticipated that the refurbished C-2101 circulator assembly will be installed in place of.the helium circulator removed for the SR 5.2.18 inspection. Based upon the results of the SR 5.2.18 inspection on the removed helium circulator, PSC will propose

-modifications to the SR 5.2.18 interval and_ inspection requirements to factor in the inspection findings and the turbine end fastener replacement program. The inspection findings and proposed Technical Specification amendment will be submitted eight months following removal of the helium circulator for the SR 5.2.18 inspection.

If you have any questions concerning this summary, please contact Mr.

M.H. Holmes at (303) 480-6960.

Very truly yours, f

R. O. Williams, Jr.

Vice President Nuclear Operations R0W/AHW:jw Enclosure cc: Regional Administrator, Region IV Attention: Mr. T.F. Westerman, Chief Project Section B Mr. R.E. Farrell Senior Resident Inspector Fort St. Vrain

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Attachment 2-P-88019 PSC'S RESPONSES TO NRC'S NINE QUESTIONS NRC' Question 1 What are the preload stresses that you_ intend to use on the A-286 and X-750 materials, compared to the specified yield and ultimate tensile strengths?

PSC Response See Section 5.3 and Table 3 of Attachment 1.

NRC Question 2 What method will be used in the repair of C2101 helium circulator?

PSC Respons_e_

See Section 5.3 and Table 3 of Attachment 1.

NRC Question 3 What heat-treatments are to be specified for each of the fastener materials; what is the specified hardness after heat-treatment?

PSC Response See Section 5.2.1 and Table 2 of Attachment 1.

NRC Question 4 Is this considered to be an issue in the manufacture of the fastener materials for the Fort St. Vrain circulator repair?

i PSC Response l

! See Item 14 in Section 6.0 of Attachment 1.

NRC Question 5 What experimental data are available to indicate that silicone-molykote (the lubricant specified for use in the Fort St. Vrain circulator repair) will be stable and compatible with the environment under circulator operation?

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Attachment 2 P-88019.

PSC Response See Section 5.6-of Attachment 1.

'NRC'Ouestion 6 What quality assurance procedures will be used to inspect the fasteners during manufacture in order to ensure. a high quality fastener-and avoid manufacturing defects?

PSC Response See Section 6.0 of. Attachment 1.

NRC Question 7 Provide a description of the inservice inspection program and/or procedures to be implemented to assure continuous integrity of the fastener materials.

PSC Response See Section 7.0 of Attachment 1.

NRC Question 8 Describe the process that will be used during refurbishing the circulators to clean the bolt holes in which the new fasteners will be placed.

i PSC Response See Section 5.6 of Attachment 1.

NRC Ouestion 9 Provide the specification that will.be implemented for each of the drive materials.

PSC Response.

See Sections 9.3 and 9.4 of Attachment 1. It is noted that reheat steam and fire water are not specifically addressed in these sections of the report because reheat steam is controlled by the condensate /feedwater specifications and fire water is considered a one-time emergency condition for which there is no specification.

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