ANCHOR BOLTS FOR NUCLEAR POWER PLANT APPLICATIONS

Transcription

1 ANCHOR BOLTS FOR NUCLEAR POWER PLANT APPLICATIONS EXPERIENCE FROM DESIGN AND CONSTRUCTION OF OLKILUOTO UNITS Kukkola Timo

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3 OL1 AND OL2 CROSS-SECTION 3

4 OL1 AND OL2 OL1 and OL2 continuous improvement through modernization projects and plant modifications renewal of operating licence. 4

5 OL1 AND OL2 ANCHOR PLATES DESIGN Codes: -Concrete code of Finland Steelcode of Finland1958 and St BK-NI 1970 Method: -Källersjö&Trepp -steelplate thickness (Fe37B, allowable stress 137MPa) is designed according to normal steelcode allowable stress methods assuming symmetric and unsymmetric load -anchor bolts are either smooth or reinforcement bars, anchoring lenghts are taken from concrete code -load excentric assumed -load combination (shear, tension) has been taken account, see next page 5

6 OL1 AND OL2 COMBINATION RULES As an example: -P2 is tensile force, max 2Mp -Rx and Ry are shearforce components, also max 2Mp 6

7 OL1 AND OL2 MATERIAL Anchor plates -thickness typically 15-50mm and depends on chosen anchors c/c -ultrasonic testing Anchor bolts: -either smooth or weldable reinforcement bars -allowable stress 220MPa Concrete material minimum K25 Every anchorplate has its own number and coated also from side surfaces. 7

8 OL1 AND OL2 FOUR STANDARD TYPE ANCHOR PLATES Type A: -size 300mm, height n*150mm -anchors c/c 150 length 300mm, welded Type B: -size 300mm, height n*250mm -anchors c/c 250 length 300mm, welded Type C: -size 300mm, height n*300mm -anchors c/c 300 length 300mm, welded Type D: -size 300*300-4 anchors, length 300mm, welded 8

9 OL1 AND OL2 9

10 OL1 AND OL2 OTHER ANCHOR PLATES Typically materials and calculation methods are not changing: -Plate size is changing -Anchor length is changing Special anchor plates differs a lot: -examble LOCA giljotine break anti whip strain anchor plates 10

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12 OL1 AND OL2 ANCHORPLATES 12

13 OL1 AND OL2 DETALJER Reinforcement anchorbars ribs have been grinded in welding area 13

14 OL1 AND OL2 POSTINSTALLED ANCHOR PLATES Later on post installed anchor plates has been used. Some problems has been found if postinstalled anchors has been used for pipe fixing (dynamic forces) or crane fixing. In that kind of locations in-service inspection is needed. It is allowed to use post-installed anchors according to TVO rules. 14

15 OL3 15

16 OL3 OL3 construction works completed and installation works on the final stages, I&C engineering proceeding 16

17 OL3 ANCHOR PLATES Embedded anchor plates (AP) with headed stud anchors, total number of approximately over in Nuclear Island (AREVA) and in Turbine Island (Siemens). Several manufactures of APs: Peikko, Anstar, Barlage Types of embedded anchor bolts: Nelson, KÖCO Basic line has been to limit the use of post installed anchors Post-Installed Anchor Plates (PIAP) -Post-installed anchors: Hilti, Liebig, Fischer 17

18 OL3 ANCHOR PLATES Traceability: -identification number, manufacturing number, type Surface treatment: -sandblasting, coating, sides and also partly backside according to specification 18

19 OL3 ANCHOR BOLT, DESIGN CODES NI Design according to European Technical Approvals (Nelson, KÖCO) and ETAG 001, Annex C, 3 rd Amendment August CEN TS has been applied in certain individual cases. However, ETAG has been valid from the beginning of the project and fulfillment of ETAG, as OL3 valid code, has been generally checked. 19

20 OL3, ANCHOR DESIGN FLOW Mostly, the design has been performed by using catalogues prepared by civil experts of AREVA and approved by TVO and STUK. The catalogues have been made by using conservative parameters and assumptions. The designers from different disciplines (piping, HVAC, electricity ) have chosen suitable AP (size, load capacity) by using catalogue. Also the utilization ratio have been checked. However, the catalogues are not always applicable and in many cases they are too conservative. Therefore in special cases, a more detailed calculation has been performed by civil engineers (Single Validation). At the end of construction phase, the utilizations are checked by civil engineers, considering the final loads as well as the vicinity influence of afterwards installed PIAPs and openings (this final verification of anchorages work is now ongoing). 20

21 ANCHOR PLATES 21

22 ANCHOR PLATES 22

23 ANCHOR PLATES 23

24 OL3 ANCHOR BOLTS SPECIAL CASE: SITE TEST Small steel angles L 100 x 75 x have been used in OL3 for fastening of door frames. It has been noticed that ETAG is not directly applicable for calculation of capacity of these angles. Following has been made: the capacity was calculated using approach based on engineering judgement, applying ETAG. The method is not fully covered by current valid codes, standards or technical approvals for validation of the calculated capacity, a site test was performed six angles in real structure were tensioned until maximum force of 25 kn (determined by calculation), taking deformation measurements in each 2.5 kn steps deformation measurement results were within the limits and no cracks were observed above-described calculated capacity (< < 25 kn) has been accepted for these certain door frames in OL3, based on the test 24

25 OLKILUOTO 3 ANCHOR BOLTS SPECIAL CASE: SITE TEST 25

26 OL3 ANCHOR BOLTS In OL3, a conservative approach has been chosen in the design of embedded anchor plates with headed studs and post-installed anchors plates. The as-built verification considering the final loads as well as the vicinity influence of afterwards installed PIAPs and core drilling openings is ongoing. The capacity exceeding is not foreseen but the work is challenging due to high amount of the plates. It has been also noted that the codes are very conservative in some cases when considering the real structures in OL3. For example, it is difficult to see pry-out as governing failure mechanism in OL3 structures where the slabs and walls are strongly reinforced and the anchor plates are deeply embedded into the concrete and l/d ratio of the headed studs is quite high. One simplified site test has been done by tensioning small angle fastenings located in wall edge next to door opening. No cracks were occurred although the test force was high considering the theoretical capacity and the fact that the main reinforcement of wall edge is located behind the studs. 26

27 PEIKKO, ANCHOR PLATES SPECIAL PROJECT: special requirements high quality demands factory production control (FPC) specified quality system OL3: - post-installed fasteners were not allowed cast in place headed fastners / studs required - Peikko delivered/supplied >> anchor plates + other frames and embedded parts 27

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30 THANK YOU