IR 05000498/1979015
| ML19210E160 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 10/19/1979 |
| From: | Crossman W, Phillips H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML19210E156 | List: |
| References | |
| 50-498-79-15, 50-499-79-15, NUDOCS 7911300619 | |
| Download: ML19210E160 (5) | |
Text
U. S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND mlFORCEMENT
REGION IV
Report No. 50-498/79-15; 50-499/79-15 Docket No. 50-498; 50-499 Category A2 Licensee: Houston Lighting and Power Company Post Office Box 1700 Houston, Texas 77001 Facility Name: South Texas Project, Units 1 and 2 Inspection at.:
South Tex.o Project, Matagorda, Texas Inspection conducted: September 17-30, 1979 Inspector:
h
_
/C 9/79 H. S. Phillips, Resident Reactor Inspector Date Approved:
/C!/9 79 W. A. Crossman, Chief, Projects Section Date Inspection Summary:
Inspection of September 1979 (Report 50-498/79-15; 50-499/79-15)
Areas Inspected: Routine inspection by the Resident Reactor Inspector (RRI)
of safety related construction activities including the placement of containment structural concrete, Unit 2.
Construction progress was assessed during two plant tours of the Reactor Containment Buildings, Units 1 and 2.
The inspec-tion involved sixteen inspector-hours by one NRC inspector.
Results: One item of nonccmpliance (infraction - failure to follow concrete placement procedures paragraph 3) was identified in one of two areas inspected.
)hY 7911300 (/'/
DETAILS SECTION 1.
Persons Contacted Principal Licensee Personnel L. D. Wilson, Site QA Supervisor D. G. Long, QA Lead Engineer T. J. Jordan, QA Lead Engineer C. L. Grosso, Associate Engineer B. R. Shulte, QA Junior Engineer Other Personnel M. Craig, Civil Engineer, Brown & Root (B&R)
S. Maitra, Civil Engineer, B&R J. Swanner, Lead QC Inspector, B&R R. Peabody, Civil Engineer, B&R C. Ballentine, Concrete Superintendent, B&R 2.
Site Tour The RRI walked through various areas to observe the status of con-struction, work activities in progress and general housekeeping.
The RRI observed thre,
_:tical tendon sheaths in Reactor Containment Building (RCB-1) at the. 'vation 155' (Az 210 ) which had been taped to exclude foreign matetral. Holes had been made in the tape which would allow foreign material to enter. Since all other vertical sheaths were capped, the RRI considered this an isolated instance. The sheaths were promptly corrected, therefore, the RRI has no further concern at this time.
At the same elevation Az 238 and 270, the RRI observed catwalk bracing piled around the vertical sheathing. Although the sheathing was not damaged, the potential existed. The condition was promptly corrected, therefore, the RRI has no further concern at this time.
Thimble guides were wrapped for protection and were stored in the incore instrumentation room. Holes had been inadvertently punched in the material used for protecting the stainless steel guides. Brown and Root (B&R)
inspection had previously identifico this condition on Nonconformance Report No. SG2637, therefore, the RRI had no further questions at this time.
No items of noncompliance or deviations were idettified.
1437 354
___
.
3.
Containment Structural Concrete On June 22, 1979, the licensee invoked a stop-work order on the placement of safety-related concrete at the South Texas Project, Units 1 and 2.
This action was the result of the licensee's identifying voids (8th and 15th lift) in the Reactor Containment Building, Unit 1 outer shell. The deficiency was reported in accordance with 10 CFR 50.55(e).
The stop-work order was lifted after the problem was investigated and corrective action was taken to preclude repetition. Region IV management /
inspectors met with licensee management and it was agreed that concrete placement could be resumed after reviewing planned actions to correct the condition and preclude recurrence.
Placement of safety-related concrete was resumed on September 17, 1979.
A preplacement meeting was held at 7:30 a.m. to review and discuss the placement plan. The inspection plan for Pour CS2-W7, to be placed in Reactor Containment Building, Unit 2 elevation 47'-0" to 53'-0",
covered the equipment for use and backup, placement personnel and the concrete placements (covered in steps a - s).
The RRI reviewed the concrete pour card final signoff which was required to be signed before 9:00 a.m. on the day of the pour.
Final signoff by B&R craft supervision, engineering, and quality control indicated that eleven areas were acceptable.
Concrete was subsequently ordered.
The RRI observed that the required equipment and personnel were available. Access for inspection personnel was at Az 30.
Lighting and tremies were at the proper locations.
The RRI observed that part of the weather protection had not been installed.
The RRI questioned the lack of weather protection, and the craft super-intendent replied that he had it on ground level to avoid damage and if rain threatened he would install it.
Then he changed his mind and directed that it be installed even though there were no signs of rain.
The RRI walked the placement line above the placement to observe clean-liness.
The placement was clean; however, it was noted that water had accumulated on small areas of the existing concrete joint.
Closer examination of Az 240 - 311 area revealed a significant amount of water (k - \\ inches deep over an area 4' x 8-10') which covered 95% of an area on the existing joint. The crews started blowing the water out just before the RRI observed the large area of water. A small puddle of water (apgroximately 1-3" deep by 12" diameter) was also observed at Az 245 between the main steam penetrations, a highly congested area.
Several other areas were observed to have standing water but were not considered significant because they were less than k" deep and did not cover a significant area.
Brown and Root Specification 2A010CS028-C,Section 3.2.8 dated April 26, 1979, states in part, "No excessive amounts of free standing water or materia! which would reduce the quality of the concrete shall be present in the placement or on the surface on which the concrete is to be poured."
3A37 355
.
Field Request for Engineering Action (FREA) dated September 4,1979, block 7 recommends a change in the specification to read:
"DCN, Specification, to delete saturated surface dry requirement and propose that specification state that the construction joint be wetted as defined by the area engineer prior to the placement of the next lift of concrete. Excessive free standing water shall be removed to the satisfaction of the area engineer.
Some free standing water resulting from construction joint cleanup immediately preceding the concrete pour is permissible as approved by the area engineer." The reviewer did not approve the recommended FREA disposition, instead he interpreted the existing paragraph 3.2.8 requirement in light of its context as written.
Brown and Root QA Procedure CCP-3, Revision 11, Section 3.3 "Prepour Inspection", paragraph 3.3.3(2) states, " Assure that all surfaces are wetted and no significant amount of free standing water remains."
The area engineer stated that he did not consider the amount of water present to be excessive and had therefore signed the prepour card.
The RRI considered the amount of free standing water to be excessive or significant. The crafts were still attempting to blow the free standing water out of the entrapped area almost an hour after the RRI first observed the water. Apparently, it delayed the pour for approximately an hour. The water was finally removed by soaking the water up with rags and squeezing them out.
The specification and procedures use words like "significant" and "ex-cessive". The acceptance criteria in this case is subjective and should be clarified by stating more quantitive acceptance criteria. This matter is considered unresolved (0 pen Item No. 499/79-15-1).
At approximately 1:00 p.m.,
a very hard driving rain occurred. A rain out was declared for all workers except the concrete crew at 1:15 p.m.
The RRI observed the pour areas again at 1:55 p.m. and found that rainwater had blown very hard against the west / southwest side of the Reactor Containment wall. The construction crews were pumping the water accumulated on top of the freshly placed concrete. The pour was stopped bemose of the accumulation.
It was noted that the space between the main wo!1 steel (inside face) and the liner had no covering to keep the rain ut.
In some places, large areas of the placements (several feet long) were covered with approximately three or more inches of rainwater.
Review of this matter after the pour revealed that the Concrete Place-ment Plan, Item S required, " Weather protection will be available in the area of the pour."
However, the RR1 was unable to find a description in the Specification or Procedure CCP-4, Revision 10, Section 3.4 as to her placements would be protected from rain or how the water / cement ratio should be tested / assured if excessive rainwater was not precluded.
'
1437 356
-
.
_.
.
This matter is considered unresolved pending the determination of what constitutes adequate protection (0 pen Item No. 499/79-15-2) and what actions will be taken to assure proper water to cement ratio if rainwater enters the placement.
The RRI observed at least seven workmen using vibrators at the Az 160 - 165 placement area.
One worker was improperly vibrating the concrete in that the internal vibrator did not penetrate through the upper layer and at least six inches into the next lower plastic layer to ensure thorough bonding as required by Brown and Root Procedure CCP-4, Revision 10, Section 3.5, paragraph 3.5.4 which describes steps to be taken to assure proper consolidation of concrete. The RRI pointed out the improper vibrating to the Brown and Root QC inspector who agreed and had the area revibrated. The RRI then proceeded to the other side of the containment.
In a few minutes, the foreman sent word that the man was leveling not vibrating. The RRI replied that the area was improperly vibrated.
This finding represents a noncompliance with Criterion V of 10 CFR 50, Appendix B.
See Appendix A of this report.
4.
Unresolved Items Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable items, items of non-compliance, or deviations. Two unresolved items disclosed during the inspection are discussed in paragraph 3.
5.
Management Meetings The RRI met with licensee representatives on September 17 and 20 to discuss inspection findings.
Concerning the unresolved matters, the licensee representative agreed that conditions existed as described.
The RRI stated that these matters must be resolved before the next lift CS-2-W8.
The RRI stated that the improper vibration was an apparent noncompliance with B&R Placement Procedure CCP-4, Revision 10 and 10 CFR 50, Appendix B, Criterion V.
)437 357
5