ML19260D442
| ML19260D442 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System |
| Issue date: | 01/03/1980 |
| From: | Renberger D WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | Spencer G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| Shared Package | |
| ML19260D439 | List: |
| References | |
| GO1-8008, NUDOCS 8002110056 | |
| Download: ML19260D442 (5) | |
Text
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y Washington Public Power Supply System A JOINT OPERATING AGENCY 5
P O Bos 965 3000 Geo. Wa eMING foM Wav It sc M L A N D WasMtNGfoM 99J52 PMoans1909) 3755000 January 3,1980 w
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[6 Nuclear Regulatory Commission 8 1980 Region V Suite 202, Walnut Creek Plaza d
1990 N. California Boulevard
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Walnut Creek, California 94596 4
L 8
Attention:
Mr. G. S. Spencer, Chief Reactor Construction and Engineering Support Branch
Dear Mr. Spencer:
Subject:
WPPSS NUCLEAR PROJECTS NOS. 1/4 NRC INSPECTION - WNP 1/4 DATES OF INSPECTION - OCTOBER l-31,1979 DOCKET NOS. 50-460 AND 50-513 CONSTRUCTION PERMIT NOS. CPPR-134 AND 174
Reference:
Letter from G. S. Spencer to N. O. Strand, NRC Inspection at WNP l/4 Site, dated December 4, 1979 The referenced correspondence delineated the results of the October 1-31, 1979 inspection of activities authorized by NRC Construction Permits Nos. CPPR-134 and 174.
Further, the referenced correspondence identified a certain activity which was not conducted in full compliance with PSAR requirements set forth in the Notice of Violation enclosed as Appendix A.
This item of noncompliance has been categorized into a level as described in your correspondence to all NRC licensees dated December 31, 1974.
In addition, Appendix B identifies an item categorized as a deviation.
This letter is submitted in response to the referenced correspondence. The specific NRC finding, as identified, and the Supply System response is provided herewith as Appendicies A & B.
Very truly yours, M
D. L. Renberger Assistant Director, Technology pb Attachment 89 H 088 cc:
CR Bryant - BPA SB Barnes - UE&C, Phil.
BD Redd - UE&C, Phil.
J. Freeman - UE&C, Phil.
AD Toth - NRC, Site 1/4 0
8002110 80-01
~
APPENDIX A Nuclear Regulatory Commission Region V Suite 202, Walnut Creek Plaza 1990 N. California Boulevard Walnut Creek, California 94596 Docket Nos. 50-460 and 50-513 Construction Permit Nos. CPPR-134 and 174 Notice of Violation Based upon the results of the HRC inspection of activities conducted on October 1-31, 1979, it appears that one of your activities was not conducted in full compliance with conditions of your NRC Construction Permit No. CPPR-134 as indicated below.
Criterion V of Appendix B of 10 CFR 50 requires that activities affecting quality shall be prescribed by documented instructions and procedures ---
and shall be accomplished in accordance with these instructions, procedures, or drawings.
Section 17 of the PSAR commits you to comply with Appendix B.
Further, PSAR Section 3.8.1.2 identifies the codes and standards applicable for quality control provisions for the reactor containment structure, includ-ing ASME Section III Division 2 and ACI-318-71 codes. The job specification 9779-253 part 10.1.1 specifically requires that concrete construction work shall be performed in accordance with the ASME Code Section III Division 2 Article CC4200 and other referenced ACI standards, unless stricter or additional require-ments are stated in the specification.
The ASME Code Section III Division 2 Article CC4200 requires the following:
a.
Paragraph CC-4252 requires that the construction specification shall specify the method of construction joint preparation to ensure that before concrete is placed against a fresh joint, all debris water and ice are removed from the space to be occupied by the concrete. ACI-318-71 part 6.4.1 similarly requires removal of standing water prior to subsequent placement of concrete.
b.
Subparagraph CC-4226.1 requires that concrete shell be thoroughly worked around the reinforcement and embedded fixtures and into
.ners of the fonns.
ACI-309 shall be used as a guide to develop suitable consolidation techniques. The job specification 9779-253 paragraph 10.4.1 reiterates these requirements and requires that vibrators shall be " lowered vertically into the concrete" as prescribed by ACI-309 part 7.1.
Contrary to the above, during reactor containment shell concrete placement number C-2102 on October 5-6, 1979, construction personnel failed to comply with the above requirements in the following respects:
[939089 ervenske
Appendix A Page 2 a.
Standing water was not removed from depressions, pockets and slots between the hardened concrete and the containment liner plate, prior to placement of subsequent concrete intended to occupy these spaces.
U U
b.
Several laborers inserted vibrators at angles of 30 - 45, sometimes pulling the vibrators through the concrete horizontally after the con-crete had achieved a level surface, and concrete near steel liner stif-fener tee-sections was not thoroughly consolidated to work the concrete into the corners.
This is an infraction.
SUPPLY SYSTEM RESPONSE Corrective Actions Taken and Results Achieved a.
The Contractor was apprised of the unacceptability of free standing water in the formwork immediately prior to subsequent concrete placement. A letter was transmitted to the Contractor, by WNP-1/4 Construction Management, indi-cating that " thoroughly saturated" was a visibly wet condition without free standing water.
b.
Our engineers have reviewed the subject concrete placement. The maximum lif t height was 14".
Vibrators were inserted into the previously placed concrete layer to ensure that the two lifts are monolithic.
Vibrators were generally inserted to as near to the vertical position as practicable, how-ever, on occasion when vibrators were not inserted vertically, the amount of vibration was adequate for ensuring the escape of entrapped air, and bonding between successive lifts.
Also, subsequent form removal did not reveal any honey-combed surface, rock pockets or other evidence of improper consolidation.
Direction was given to the contractor on 10/10/79, to require pencil vibrators to be inserted between the liner and inside curtain of rebar in order to further ensure consolidation between and around tee-stiffeners.
Corrective Actions Taken to Preclude Recurrence 1.
The Contractor gave training sessions on 10/8/79, 10/10/79 and 10/11/79 to the placing crews on the use of vibrators and consolidation techniques.
2.
Surveillance of subsequent code concrete placements af ter C-2102 has noted that the identified concerns have not been repeated.
Date of Full Compliance Full compliance was achieved by 10/11/79.
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APPENDIX B Nuclear Regulatory Coamission Region V Suite 202, Walnut Creek Plaza 1990 N. California Boulevard Walnut Creek, California 94596 Docket Nos. 50-460 and 50-513 Construction Permit Nos. CPPR-134 and 174 Notice of Deviation Based on the results of an NRC inspection conducted during the period of October 1-31, 1979, it appears that one of your activities was not conducted in conformance with your commitments to the Commission as indicated below:
a.
Contrary to ACI-318-71, part 6.4.1 (apnlicable code referenced in PSAR Section 3.8.4), standing water was not removed from the horizontal con-struction joint nor was neat cement grout applied to the vertical con-struc' ion joint during the placement of concrete in the Unit 4 spray pond southwest corner wall during placement number S-164, concrete order number 217A on October 31, 1979.
This is a deviation.
SUPPLY SYSTEM RESPONSE a.
With respect to the standing water:
The contractor initiated Nonconformance Report 4-CNCR-252-17 identifying the standing water on the horizontal contruction joint and submitted it to the Engineer for evaluation and disposition.
Training sessions were held on 10/31/79 to indoctrinate the craft against leaving standing water at the construction joint surfaces.
Subsequent con-crete placement on 11/1/79 revealed all instructions imparted in this train-ing session have been implemented.
Continued monitoring of this Contractor's performance has revealed no further violations of this nature.
With respect to the vertical construction joint surfaces not coated with neat cement grout innediately before placing of new concrete:
The Construction Specifications for the Spray Pond and Pump House, Contract 252, Article 10.2.3, Section 3A, requires all construction joint surfaces to be free of laitance and roughened intentionally to result in a roughness of 1/4" minimum depth. This ensures positive shear transfer at the inter-face when concrete is placed against previously hardened concrete surface
( ACI-318-71, Article 11.15.7).
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Appendix B Page 2 Horizontal reinforcing steel was designed and placed continuous through the construction joint. This provides continuity to the wall for resist-ing inplane forces and also ensures adequate lateral resistance against separation at the construction joint surfaces.
All vertical and horizontal construction joint surfaces are provided with rubber water-stops, and the concrete m'x used was designed to be water-tight, with a water / cement ration not exceeding 0.48.
This ensures a watertight structure.
The design of the Spray Pond structure was based on the " Shear Friction" theory, which requires aggregate interlock at the interfacing surfaces, which is achieved by the specified surface preparation at the construction joint surfaces. The rubber water-stops and the watertight mix used, along with adequately designed reinforcing placed continuous through the joint, provides a pror^rly designed construction joint surface which ensures a watertight st/u ture.
The above design features preclude the need to coat vertical construction joint surfaces with neat cement grout.
Applicable portions of ACI 318-71 as referenced in the PSAR have been and will continue to be utilized for the design and construction of the Spray Ponds.
1939 092
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