ML20092P458

Responds to NRC Re Violations Noted in IE Insp Repts 50-438/84-03 & 50-439/84-03.Corrective Actions: Procedures to Be Revised to Provide Design Clarification That Bolt Torques Not Required to Be Reproducible

ML20092P458
Person / Time
Site:	Bellefonte
Issue date:	03/30/1984
From:	Kammer D TENNESSEE VALLEY AUTHORITY
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20092P457	List: ML20092P458
References
NUDOCS 8407060319
Download: ML20092P458 (4)

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- TENNESSEE' VALLEY ' AUTHORITY CHATTANOOGA. TENNESSEE 37401 400 Chestnut Street Tower II i $4 b b hia 30, 1984 U.S. Nuclear Regulatory Commission Region II Attn: Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - RESPONSE TO VIOLATION 50-438/84-03-01, 50-439/84-03 FAILURE TO FOLLOW PROCEDURES FOR CONCRETE EXPANSION ANCHOR BOLTS AND PIPE SUPPORT INSPECTIONS This is in response to R. C. Lewis' letter dated February 29, 1983, report numbers 50-438/84-03, 50-439/84-03 concerning activities at the Bellefonte Nuclear Plant which appeared to have been in violation of NRC regulations.

We shall be submitting additional information on this violation by August 1, 1984. Enclosed is our response to the citations.

If you have any questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2688.

To the best of my knowledge, I declare the statements contained herein are complete and true.

Very truly yours, TENNESSEE VALLEY AUTHORITY o s%

D. S. Kammer Nuclear Engineer Enclosure cc: Mr. Richard C. DeYoung, Director (Enclosure)

Office of Inspection and Enforcement U.S. Nuclear Regulatory Conmission i .

Washington, D.C. 20555

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Records Center (Enclosure) ,

Institute of Nuclear Power Operations ,

1100 Circle 75 Parkway, Suite 1500 .

Atlanta,-Georgia 30339 8407060319 840618 1983-TVA SOTH ANNIVERSARY PDR ADOCK 05000438  ?

l '() PDR An Equal Opportunity Employer

, , ENCLO3URE I

BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 l

, RESPONSE TO SEVERITY LEVEL IV VIOLATION l 50-438/84-03-01, 50-439/84-03-01 FAILURE TO FOLLOW PROCEDURES FOR CONCRETE EXPANSION ANCHOR BOLTS AND PIPE SUPPORT INSPECTIONS Description of Deficiency 10 CFR 50, Appendix B, Criterion V, as implemented by TVA Bellefonte FSAR Section 17, paragraph 17.1.B.5, requires in part that activities affecting quality be accomplished in accordance with instructions, procedures, and -

drawings.

Bellefonte QCP-2.8, paragraph 6.3 3.4 requires that a washer shall be placed over the bolt. ... The bolt shall then be driven down until the nut, washer, and attachment are in solid contact; Attachment Q, provides specified torque values for installed wedge anchors; Attachment D requires that installed wedge anchors shall be able to withstand the specified torques. QCP-6.17 provides requirements for hanger nonconfbrmances. Construction specification G-43, Appendix A, specifies maximum gap tolerance for hanger installation.

Contrary to the above, between February 7-10, 1984, activities affecting quality were not being accomplished in accordanca with documented procedures and drawings in that a reinspection of 32 installed wedge anchors, 14 installed self-drilling shell anchors and 2 pipe supports, revealed the following discrepancies from the documented requirements:

(1) Washers were missing on 4 inetalled wedge anchors for hanger No. ONM-MPHG-0901.

(2) One installed wedge anchor fbr hanger No. 2KC-MPHG-1023-R4 could not withstand a required torque value of 192 ft.-lb.

(3) Eight of the 32 installed wedge anchors were undertorqued (i.e. the nat on the anchor turned during torque testing).

(4) Rear bracket of the sway strut for hanger No. 2KC-MPHG-1322-sh 1-RO had been disconnected.

(5) Measured pipe gap exceeded the maximum gap tolerance for hanger No. OKC-MPHG-1378-R2.

TIA Respcnse t

.1 Adnission or Denial of the Alleged Violation 9

TVA will address each item of this violation separately.

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1. TVA admits the violation occurred as stated. ,

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2. TVA denico the alleged viointion. - -

At tho time of installntion, tha subject wedge bolt on support 2KC-MPHG-1023 had been torqued to the required value. The turning of the single wedge bolt that was found at the time of inspection can be attributed to the loss of preload in the wedge bolt. The purpose for torquing of .

wedge bolts is to preapply the maximum design load to the anchor. This assures that the inelastic slip of the anchor, when loaded to its maximum design load, will be minimized. The anchor preload resulting from the torque is not permanent. Creep of the concrete in the vicinity of the wedging devices will result in almost complete loss of preload with time. However, after preload is lost, the anchor deflection required to develop the maximum design load will only be that required to overcome the concrete creep that has occurred. TVA never intended for wedge bolt torques to be permanently reproducible. TVA's Division of Engineering Design (EN DES) nonconformance report (NCR) 2854 was written to document the NRC violation and request EN. DES concurrence that the wedge bolt installation is acceptable to "use-as-is." TVA will revise G-32 by September 20, 1984, and BNP-QCP-2.8 by October 31, 1984, to provide design clarification that bolt torques are sat ecquired to be reproducible after relaxation. This will eliminate the past conservative practice by Division of Constru2 tion (CONST) to replace bolts in which the torque car.not be reproduced.

3 TVA denies the allegod violation.

The inability of TVA to reproduce the torque values on wedge bolts again can be attributed to relaxation of the bolt and adjacent concre te. The position of TVA with respect to the NRC concern is identical to Item 2 above. NCR 2943 was written to allow EN DES review and to provide concurrence that the anchors may be "use-as-is."

4. TVA admits the violation occurred as stated.

5. TVA denies the alleged violation.

At the time of installation of hanger OKC-MPHG-1378R2 the gaps did meet the allowable tolerances. The d1anging of these gaps is a result of construction testing and operation. This concern previously was identified by unresolved item 438-439/81-21-03, " Gaps in Seismic Pipe Supports," and was addressed by a memo from EN DES to CONST dated May 16,1983 In part, the letter states, "It is not the intent of EN DES to require additional gap inspections once the total gaps are l verified and documented in accordance with G-43 requirements. . . . In I many cases, the gap will completely disappear during operation. . . .

Revision 6 to G-43 indicates that pipe will shift in the support and the gap may open on one side and close on the other due to fbeces or expansion daring construction."

These gap changes are a function of the load-deformation and thermal expansion properties of the material and support configuration and i

cannot be avoided. Further, the tolerances were established with full realization of these variations.

NCR 2855 was initiated to document the pipe gap condition and to obtain EN DES concurrence that the current configuration can be "use-as-is."

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2. Rresons for~ tha Violetion

1. The absence of washers on the wedge bolts for hanger No. ONM-MPHG-0901 can be attributed to craft and quality control personnel not following procedure. This failure to follow procedure resulted from possibly inadequate instructions contained in BNP-QCP-2.8, " Bolt Anchors Set in Hardened Conomte." The acceptance criteria did not specifically address the requirement for inclusion of washers on wedge bolts.

4. The reason for the disconnection of the sway strut on support 2KC-MPHG-1322 sh.1 was to facilitate construction activity in the adjacent area. The responsible steamfitter craftsmen failed to ,

l follow procedum in that engineering authorization was not obtained prior to disconnection of the sway strut.

3 Corrective Steps Taken And Results Achieved 5

1. NCR 2842 was written to correct tha wedge bolts by mquiring installation of washers and subsequent reinspection.

4. NCR 2843 was written to document this ccndition and require reinstallation- of the sway strut and albsequent reinspection.

4. Corrective Steps Taken to Avoid Further Violations l

1. TVA CONST will conduct a random survey to determine the extent of missing washers on wedge bolts. Any missing washers will be documented and corrected. TVA will provide the results of the survey and appropriate corrective action, as necessary, in our final response on this violation.

Additionally, BNP-QCP-2.8 will be revised to include the requirement l for wedge bolt washers as acceptance criteria.

i 4. Steamfitter craft personnel have received a memorandum emphasizing that unauthorized work on QC accepted hangers could result in j-disciplinary action.

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5. Date When Full Compliance Will Be Achieved

1. The results of the random survey will be provided by August 1,1984.

The revision to BNP-QCP-2.8 will be issued by May 4,1984.

Installation of washers on the wedge bolts in question (per NCR 2842) will be completed by May_ 31.-1984.

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4. Full compliance on this item will be achieved by May 31, 1984.

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