ML20062J148

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Provides Info Re Action Item 3 in Response to IE Bulletin 82-02, Degradation of Threaded Fasteners in RCPB of PWR Plants. Control Rod Drive Flanges & Pressurizer Heater Connections Seal Welded
ML20062J148
Person / Time
Site: Robinson Duke Energy icon.png
Issue date: 07/30/1982
From: Furr B
CAROLINA POWER & LIGHT CO.
To: James O'Reilly
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-SSINS-6820 IEB-82-02, IEB-82-2, NUDOCS 8208160278
Download: ML20062J148 (2)


Text

, A RO f Carolina Power & Light Codhknf ^

JUL 301982 p '3 '

7.D ytp1G4 Mr. James P. O'Reilly, Regional Administrator United States Nuclear Regulatory Commission Region II 101 Marietta Street, N.W. , Suite 3100 Atlanta, CA 30303 H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-261 LICENSE NO. DPR-23 RESPONSE TO IE BULLETIN 82-02

Dear Mr. O'Reilly:

Carolina Power & Light Company (CP&L) has reviewed your letter, dated June 2,1982, IE Bulletin 82-02, " Degradation of Threaded Fasteners in the Reactor Coolant Pressure Boundary of PWR Plants." In response, as required by the bulletin, CP&L is providing the following information relative to H. B. Robinson Unit No. 2 (HBR2) for Action Item 3.

a. A review of the maintenance history (Work Requests) for the most recent- ~

operating cycle (October,1980 - July, .1982) revealed only one case of a Reactor Coolant Pressure Boundary (RCPB). leak that was within the scope of this bulletin. This leak occurred on a Pressurizer Manway and was attributed to improper Installation of the flexitallic gasket. Iuspection of the manway studs did not reveal any erosion / corrosion damage._ The repair efforts, performed under direct Ouality Assurance observation, consisted of cleaning the gasket seating surfaces, inspection and lubrication of the studs, and installation of a new gasket. These efforts successfully stopped the' leakage.

The Reactor Vessel also experienced slight leakage during the last' operating cycle at the vessel-to-head 0-ring surface. - This leakage is attributed to.0-ring failure. Although MBR2 is not committed to-Regulatory Guide 1.65, the Reactor Vessel Head studs are inspected in accordance with ASME Section XI(UT, VT-1, MT). There have been no cases of Reactor Vessel Head stud degradation.

The control rod drive flanges and pressurizer heater connections are seal welded and thus are excluded from action as provided for in the scope of -

the bulletin.

b. There has not been any use of injection sealants on bolted closures of the

-RCPB at HBR2.

C208160278 820f30 DR ADOCK 05000261 PDR _

411 Fayetteville Street

  • P. O. Box 1$51
  • Raleigh. N. C. 27602 m . , _ .

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A-In accordance with the NSSS vendor recommendations, the lubricant used for all primary system closure studs at HBR2 is Fel-Pro-N-5000 which is composed of Nickel-Graphite. The lubricants used prior to the most recent operating cycle were Fel-Pro CSA (for general use) and Molykote-Z (for reactor vessel closure studs). Neither of these lubricants are currently recommended nor used due to the possible formation and/or decomposition of certain lubricant constituents into compounds which are known promoters of stress corrosion cracking.

In summary, HBR2 has not had any corrosion problems associated with bolts or studs in RCPB closures within the scope of this Bulletin nor have there been any instances of stress corrosion cracking of threaded fasteners associated with lubricants or injection sealants. Although outside the scope of this bulletin, it should be noted that chloride stress cracking of the dif fuser adapter bolts internal to "A" and "B" Reactor Coolant Pumps was detected and corrected as previously reported in LER 82-03.

As requested, the staff time spent in the research and. preparation of this response is approximately 80 man-hours.

If you have any questions regarding this information, please contact a member of my staff.

Yours ve ruly,

./

B. . Furr Vice President Nuclear Operations DCW/ce (927 CIT 4)

B. J. Furr, having been first duly sworn, did depose and say that the information contained herein is true and correct to his own personal knowledge or based upon information and belief.

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My consnission expires: W Camien ham 6 3 8$

cc: Mr. S. Weise (Resident Inspector)

Mr. G. Requa (NRR)

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