ML19323F139

First Interim Deficiency Rept Re Const QA Audits for Sampling Gradation & Tests of Cylindrical Concrete Specimens.Items Under Evaluation.Next Rept Will Be Forwarded by 800709

ML19323F139
Person / Time
Site:	Yellow Creek
Issue date:	05/21/1980
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML19323F137	List: ML19323F136 ML19323F139
References
NCR-YC-C-80-03, NCR-YC-C-80-3, NUDOCS 8005280583
Download: ML19323F139 (1)

Text

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o ENCLOSURE YELLOW CREEK NUCLEAR PLANT UNITS 1 AND 2 CONSTRUCTION QA AUDIT - SIGNIFICANT DEFICIENCIES YC-C-80-03 10 CFR 50.55(e)

FIRST INTERD1 REPORT

__ Description of Deficiency The following are Construction Quality Assurance audit deficiencies which are considered significcnt conditions adverse to quality.

1. Sampling and Reduction of Sample - The centrci mixing plant was found not to have provisions for procuring representative samples of the material being batched as required by General Construction Specifica-tion G-2 directly from the scale discharge. Therefore, the sample was being obtained by opening the discharge gates and catching some of the discharged material in a shovel. This sampling method is contrary to ASTM D-75. Also ASTM C-702 establishes approximate minimum mass of field samples and requires that the field sample be mixed and reduced by quartering. Noncompliance to these requirements was also obse rved.

2. Cradation - Observations indicate that gradation, including weighing, is being performed in accordance with the requirements of QCI C-204.

Review of form TVA 10141 - Sieve Analysis of Concrete Aggregates, form TVA 10249 - Screen Analysis of Aggregate Combination, and Sieve Analy-sis of aggregates revealed that during the period February 19, 1099, through March 26, 1980, the 3/8" aggregate in the mixing plant s'. stage bins was out of specified limits numerous times. This review ar.d subsequent investigation revealed six areas of noncompliance with the QA program requirements.

3. Tests of Cylindrical Concrete Specimens - The auditors observed concrete test cylinder molding, curing, unit weight determination, verification of diameter and perpendicularity, cappine, and compressive strength determination. With the exception of compressive strength determina-tion performed on March 24, 1980, using equipment number TVA 4.~.970, -

all observed activities appeared to be in accordance with the appli-cable portions of the QA program. On March 24, 1980, the load was applied to the cylinders in excess of the 20-50 psi /s limits, and no special note of the type of failure and the appearance of the concrete l was taken.

Interim Progress

1. QC-M&C employees have been instructed to obtain the material correctly.

At present, a pan is being used to collect the full cross sec11on of the flow until a permanent method is installed. Sample size has been increased to the correct amount.

7. This item is still being evaluated.

3. QC-M&C employees have been instructed of the requirements. A sign reminding employees of the requirements has been attached to the test equipment.

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