ML20215F884

Amends Util 870331 Response to Violation Item 86-13-18 Noted in Insp Rept 50-508/86-13.Spec Combined W/Design Drawings Meet Rebar Spacing Requirements of ACI Code

ML20215F884
Person / Time
Site:	Satsop
Issue date:	06/15/1987
From:	Olson P WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
GO3-87-169, NUDOCS 8706230041
Download: ML20215F884 (3)

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I Washington Public Power Supply System Box 1223 Elma, Washington 98541 (206)482-4428 June l15,1987-G03-87-169 Docket No. 50-508 U. S. Nuclear . Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Subjecti NUCLEAR PROJECT 3 NRC INSPECTION AT WNP-3 IE REPORT NO. 50-508/86-13 VIOLATION ITEM 86-13-18 1

Reference:

Letter (G03-87-82), P. D. Olson to NRC, .same subject, ' dated -3 i

March 31; 1987, The referenced letter- included the Supply -System . response to . the'. subject ,

violation. In response, the Supply System did not -agree .that af violation-existed. As a result of a. subsequent discussion with the NRC, the: Supply System-has agreed to amend. the response to: more. clearly define the specific condition-described in the violation.

Attached ~is the Supply. System amended response to Violation: Item 86-13-18.-

8706230041 870615

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'U.: S. Nuclear Regulatory Commission June 15, 1987 Page Two. G03-87-169-Should you have .any questions or desire further. information, please contact'me a

'directly.

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Program' Director, WNP-3 AGC/cae Attach' men't -

cc: Mr.'J. A. Adams,.NESCO

Mr.lM. F. Barnoski, Combustion Engineering-Mr. R. M. Boucher, Pacific Power.&' Light Co.

.Mr. W._L. Bryan,~ Washington-Water Power Co.

Mr..R. E. Dyer, Portland General Electric Co.

Mr. W. J. Finnegan, Puget Sound Power &_ Light Co.

M . J. R. Lewis, BPA . . . . -

Mr. J. 'B. Martin, U. S. NRC Region V Office, Regional Administrator Mr. R. J. Pate, U. S. NRC Region V Office ..

Mr. N. S. Reynolds, Bishop, Cook,- Purcell & Reynolds Mr. D. Smithpeter, BPA Ms. R. M. Taylor, Ebasco - Elma Ebasco - New York i

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NOTICE OF VIOLATION NO. 1 l 10 CFR Appendix B Criterion V requires, in part, that " Instructions, procedures or drawings shall include appropriate quantitative or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished".

The WP-3 Final Safety Analysis Report identifies ACI-318-71 as the applicable '

industry standard for construction of WNP-3 concrete and reinforcing steel j structures.

Contrary to the above, at the time of the inspection the WNP-3 construction specification for concrete installed for the reactor building, WPPS-3240-412, did not incorporate the appropriate reinforcing steel clearance acceptance criteria of ACI-318-71 Part 7.4.1 and 7.4.5, which require a minimum of one nominal bar diameter clear distance between parallel bars (i.e., 1.4 inches for size #11 bar) . The WPPSS specifications allowed as little as 1.0 inch clearance, based upon 3/4 inch and less aggregate size allowed by the specifications.

This is a Severity Level IV Violation (Supplement II).

RESPONSE

The Ebasco rebar design for WNP-3 includes not only the basic rebar size and layout, but also the detailed location and configuration ' required for rebar fabrication and placing. The minimum rebar spacing for this Project is genern11y governed by the maximum size of the coarse aggregate rather than by rebar diameter. Size No. 11 rebar is nominally 1.410 inch in diameter and the maximum aggregate size allowed by Specification 3240-411 is 1-1/2 inches. Using the largest allowable aggregate size, the minimum spacing allowed by ACI Code paragraph 3.3.2 is 1-1/3 times the maximum aggregate size or 2 inches. The rebar minimum spacing design for~ this project exceeds 2 inches, which is shown on the Engineer approved placing drawings. Specification 3240-412, paragraph 5.02 requires that the clear distance between bars shall not be less than 1 inch nor less than 1-1/3 times the maximum size of the coarse aggregate. This specification recognizes that in ' isolated areas it may be necessary to shift bars to avoid interfence with other embedded items in accordance with the ACI Code tolerances. In these special cases, the absolute minimum ~ spacing allowed is based on the actual aggregate size used, but never less than 1 inch.

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The ACI-318-71  :

commentary to states that. the minimum limits (spacing i requirements) were established to permit concrete to flow 'readily into spaces  !

between bars and forms without honeycomb and to assure against concentration of a bars on a line that might result in shear or shrinkage cracking. '

The specification combined with the design drawings meet the rebar spacing requirements of the ACI Code.

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