TNAG-1658-FCO40-2306-Daya-Bay-nuclear-power-station-project-safety-concerns-in-Ho-1987 — Page 85

NOV

12

or 11·00 TIBVVVLL/

HK GUX IPJUG SHENZHEN

APPENDIX 1

VERIFICATION OF TOTAL REINFORCEMENT IN FIRST LAYER

P.Oct.10

The

reactor building raft is built in five layers (see attached diagram). The first layer which contains the non-conformance is

is further sub-divided into a central area with four outer segments.

The various types of reinforcement in the first layer are i

(1) In the centrai 1744 there is a rectangular mesh of horizontal bare.

There are 4 layers of bar at the base and 2 at the top.

(2) In the outer segments there is a radial horizontal bara. There are 7 layers at

(3) There aze vertical bars throughout

protrude from the top.

and

and circumferential mesh of the base and 4 at the top.

the first layer, all of which

(4) There is the single ring of inclined startar bars which MT: tha

subject of the non-conformance.

Tha

total number of bare installed with the first layer is 14,388 (8,076 vertical + inclined and 6,312 horizontal) and the total weight 1# approximately 523 Ta. The non-coaformance is the omission of 316 inclined starter bars of a total weight of 9.6 Te.

Having found the non-conformance in the inclined starter

bars, and having

concluded it WEB due to ETTOTE in construction management and quality control, it was necessary to re-check all types of ber in the first layer to determine whether any others were affected. This re-check WHA performed separately by HCCM and

HCCM and JVC and

then subject to an independent audit by JVC QA Department.

JVC QA Department. A further review of the re-check was also made by Eir and a statement obtained from their senior management.

STA

.

There were several methods used in the re-check. For the vertical bara which protrude from the concrete the check was made directly by comparing the bars actually in place with

with those required

the drawings.

Verification that the lower ends of these bars were correctly placed was obtained from photographs taken during construction.

For the horizontal bars, which are completely embedded, the check Wan mede using installation records and photographs taken during construction.

The installation records cover :

氰

Details of the preparation of the bars, ie, the cutting and bending.

Checks by HCCM during installation of the bars.

Checks by JVC during installation of the bara.

The photographa We re takan at Various etzgas

progressive installation of the different types of areas of the raft.

of the work and show the bar in the different