Preparation for conducting Decommissioning Actions.

Transcription

1 Preparation for conducting Decommissioning Actions. Site Preparation for Dismantling A Review of the Moata site Gary Simms ANSTO Major Projects Delivery Office

2 The Challenges Allow normal operation of adjacent accelerator operations. Provide a Emergency Static containment enclosure. Provide an adaptable extract system. Provide filtration of exhaust air. Activity monitoring Manage airborne particulate within the Containment. Provide egress of 280+ ton of concrete without compromising containment ventilation. Keep budget to <10% of the overall cost of removing the reactor. Zero tolerance to containment breech Carbon 14. Space management for the contractor. Managing Various Ansto departments with respect to containment use and design. Emergency Planning Safe personnel entry and egress.

3 Why Static Containment? In the event of ventilation failure the tent shall simply be closed and taped up. The emergency Plan allowed for a auxiliary Stand-by Exhaust Fan and filter be hooked up to the discharge duct of the dust separator, which could be run off a generator indefinitely providing approx. -3pa to atmosphere. Prevent Gold plating. the need for a stand-by exhaust fan, and complex control systems not required.

4 Some Dos and Don ts with containment. DO Check that the tent is functioning and in good condition Daily (John to go in to detail with daily site checks). Have daily tool box talks and a formal hand over of a containment system that is Fit for Purpose Monitor air quality Monitor area for Radiation. Practice the emergency plan. Monitor for fire with thermal sensors and hook in to local fire alarm panel. install site PA system. Have emergency eyewash and shower Have fire extinguishers. Have good lighting. Have Good housing keeping policy

5 Some Dos and Don ts with containment. Don t Have both the outer door and the door between the secondary and tertiary door open at the same time. Use combustion engine driven plant unless unavoidable. overcrowd the site.. keep non essential personnel out. Work more than 2 hours without a break (dehydration issues in suits and P3 masks)

6 Containment how?

7 Rubb Containment Solution Often referred to as giant tents or tent buildings, these are actually engineered fabric structures developed to ISO 9001 standards. These are engineered "temporary structures" that have been in use for over 25 years.

8 Potential solutions for larger Projects?

9 Why Rubb Inc? Previous experience with containment systems. Easy to assemble with Local builder (with Rubb on site advise) Quick to build (15 days) PVC skin does not propagate flame, self venting Skin can be welded, zero leak assures static containment Structure can easily expanded or contracted (Length wise) Easily relocated with out loss of building Material Building can be easily dismantle and sold after use shipped easily in to a standard container. (which is what Happened) Skin is easily repaired. No foundation required

10 The Moata Containment tent

11 General Structure Note cavity wall which was used as supply air path

12 Ventilation Design

13 Ventilation Schematic Air curtain Using recirculated Air Exhaust Path Dust separator Supply Air Path Modulated volume control dampers Hepa Filter EX Fan

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17 Keep exhaust system Flexible You can use the same exhaust system for. Direct extraction from point of dust generation extraction General secondary dust extract Direct vehicle exhaust extract Vacuuming dust from the floor, Machines, personnel.

18 Pictures of the Moata Tent

19 Containment design process Design input sources Radiation Protection advisors Health Physics Surveyors Waste Management Demolition Consultant. Health & Safety Advisors Site Operations Safety Supervisor Project team PM, Technical Advisors, Procurement, Safety Assessment committee Building Manager Building users

20 Co-ordination of the Containment tent design process Concerns Project Manager Alec Kimber had concerns over how long meetings take with regard to recapping decisions that have already been agreed to. How busy all the design input team are (not able to commit to regular meetings) Stakeholders involved with other projects not just Moata. Minutes of meetings far to big and cumbersome. Drawing office not able to provide quick turn around on design improvements. Time taken to write and distribute design revisions. Not being able to visualise the look of the proposed containment solutions. Humans tend to read only those things that concern them.big picture thinking lost

21 Site Function Planning Site Function Planning can be described as an Extremely simple way of capturing design ideas on one page as and when they evolve, in a pictorial form

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23 Advantages of Site Function Planning Convenient The SFP was projected on the screen during the meeting and edited in real time. Allows ideas to be captured immediately. Reduced the size of the design minutes. No training needed (ssshhh its just a word document) SFP were generally ed out within the hour and sometimes before the design team got back to their offices. Allowed an organic step by step progress.very few backward steps taken.

24 SFP rules. Golden Rules for using the SFP process. Must be a one page document. Only one editor. Circulate PDFs only. Contradicting ideas can not appear on the same Revision. General agreement on design before adding in to the SFP Anyone can have an input, (best ideas came from the Moata building users i.e. use of standby power for the exhaust fan)

25 Advantages of Site Function Planning Other uses SAC submission Arpansa submission Contractor scope of work document Fire and safety equipment layout Entry room construction Electrical layout (lighting, GPO, monitoring, power requirment) Ventilation layout Process design for Waste Operations Process flow for the Tender Ventilation concept design Tender Specification documentation. Emergency planning

26 SFP The SFP is a one page document that directly connected ideas as they happened though the following stages (golden thread thinking) Concept stage (17 revisions) SAC submission Regulator Arpansa review Tent construction Demolition Historical Review

27 Owning the Environment Ansto provided the environmental control and ensured the that systems were checked each day before worked started, and handed over to the demo contractor as Fit for Purpose, with a toolbox talk. Key parameters were alarmed. Internal pressure. Area Radiation monitoring. Air quality monitoring

28 Daily Site Check lists and records Note.John Macleod shall provide detail as to the content in a later presentation.

29 Questions?