DRAFT
TECHNICAL NOTEOptions for Inspection Cell Layout
Prepared by: / Name / ILH, DT, TPChecked by: / Name / SR
Approved by: / Name
DOCUMENT INFORMATION
Document Number:
Revision:
Date: / 11/03/07
Contract Number:
Contractor:
Reference Number:
DRAFT
TECHNICAL NOTE
CONTENTS
Summary………………………………………………………………………………….1
Aim…………………………………………………………………………………………2
Introduction………………………………………………………………………………3
4. Location………………………………………………………………………………..
4.1 Option 1……………………………………………………………………………….
4.1.1 Option 1 – Exit/entry of Package………………………………………………
4.1.2 Single Crane………………………………………………………………………
4.1.3 Single Crane plus Horizontal Shift……………………………………………
4.1.4 Single Crane to Transfer Tunnel……………………………………………..
4.2 Option 2………………………………………………………………………………
4.2.1 Emplacement Crane to Transfer Bogie (dual-way)…………………………
4.2.2 Emplacement Crane to Transfer Bogie (one-way)…………………………
5. Component Parts of Inspection Cell…………………………………………….
5.1 Primary Features………………………………………………………………….
5.1.1 Docking/Inlet Area……………………………………………………………….
5.1.2 Buffer Store………………………………………………………………………..
5.1.3 Windows/Viewing Areas…………………………………………………………
5.1.4 Inspection Area…………………………………………………………………….
5.1.5 Reworking Area……………………………………………………………………..
5.1.6 Lifting Gear…………………………………………………………………………
5.1.7 Package Transfer Equipment…………………………………………………….
5.1.8 Outlet Area………………………………………………………………………….
5.2 Secondary Features…………………………………………………………………
5.2.1 Overpack Store……………………………………………………………………
5.2.2 Stillage Store……………………………………………………………………….
6. Development of a Conceptual Design………………………………………………
6.1 Design Process…………………………………………………………………………
6.1.1 Description of Initial Designs………………………………………………………
Drawing 1…………………………………………………………………………………….
Drawing 1 Flow – chart……………………………………………………………………
Drawing 2 …………………………………………………………………………………..
357976 / iDRAFT
TECHNICAL NOTE
INSPECTION CELL - LAYOUT
1 SUMMARY
The purpose of this document is to present the design options for all important issues associated with the inspection cell at a conceptual level. The work to date looks at three main areas, namely the location of the cell within the PGRC, the primary and secondary component requirements of the inspection cell and the overall operational layout of the cell. Each section details the main options considered in these areas so as to demonstrate the development of a current design of the overall inspection cell and the advantages and disadvantages of each element are considered.
The report is separated into two main sections, although they are written to allow continuous reading. The first section looks at all the considerations required before the design process can begin properly. The second section demonstrates the design techniques used to date and how the process has developed to reach the current design stage. Initially, a conceptual design was developed from scratch that included all primary and secondary operational requirements identified prior to this and forms the basis on which further designs would be developed.
2 AIM
The purpose of this document is to explain the main features of a range of design options for the layout of the inspection cell. This includes a justification of each design feature that has proven advantageous and identification of any disadvantages. The overall functional aim of the inspection cell is to facilitate the inspection and necessary reworking of all types of ILW packages stored within the vaults. The capacity of the inspection cell must be such that the demand for the inspection of packages at both cyclic and random rates can be met without compromising capacity.
3 INTRODUCTION
The design of the inspection cell involves consideration of both its internal functional features as well as its integration into the PGRC. It may be worthwhile to first clarify some of the terms used in this document to avoid confusion. The inspection cell refers to the whole working area, including all the functional elements required of the inspection process. The hot cell refers to the area within the inspection cell where packages are to be inspected by the methods defined in the waste inspection document.
As was described in the aim, the purpose of the inspection cell has been identified as a facility for accepting UILW packages for inspection, primarily by means of direct viewing, and to assess the condition of the packages. This assessment of the condition of packages is the main purpose of the inspection process itself and involves determining whether packages are suitable for continued vault storage or whether they require repair or reworking. This document will only consider the methods to be used to do this as opposed to what design parameters are to be measured (this is found in the waste inspection document).
4 LOCATION
It is proposed that each storage vault will contain an inspection cell to ensure a reasonable allowable rate of inspection and minimise congestion throughout the PGRC. It is necessary to consider the location of the inspection cell in terms of optimising performance of operations in both the vault and the entire PGRC. There are two main possible locations for the inspection cell that have been considered so far, and both are integrated into the existing facilities of the PGRC vault design at the operational end of the vault. The reason for this is twofold; firstly, the inspection cell must operate harmoniously with the existing functional elements of the PGRC; secondly, integrating the design into the existing layout will reduce or potentially completely remove the requirement for excavating further rock to house the cell. However, the main issue associated with this is that the inspection cell is dimensionally constrained by the existing features, meaning that the final design must use the volume available as efficiently as possible. These two options are described below.
4.1 Option 1
Option 1 is demonstrated below in figure 1 by the green label (location 1). In this case, the inspection cell is integrated into the upper level facilities, which are mainly used for crane maintenance activities in the existing PGRC design. The main advantages of this location are related to the ease of access to the inspection cell for both the existing vault overhead crane and for remote inspection personnel. It can be seen from figure 1 that the emplacement crane can traverse across as far as location one so it would be practical to transfer packages directly from the vault to the inlet area of the inspection cell. Additionally, this area is already accessible by maintenance personnel, so should not pose significant shielding issues.
However, the main constraint on using this location is the volume of space available to integrate the inspection cell DIMENSIONS.
Figure 1: Possible locations of inspection cell.[1]
4.1.1 Option 1 - Entry/exit of Package
In addition to the location of the inspection cell, it has been necessary to consider the movement of packages between to and from the vault, which presents a number of further options. The priority here is to minimise package movement and to minimise the amount of mechanical lifting and transfer equipment for obvious reasons. Three different options are presented below for option 1.
4.1.2 Single Crane
The crane in the storage vault will pass over the transfer tunnel and place the package into the docking area (3). The package will be transferred to the outlet (4) during the inspection process. The emplacement Crane will then carry the inspected package back to the storage vault (6) or onto a transfer bogie (5) in the transfer tunnel, should the package need to be taken to the overpacking cell.
Figure 2: Entry/exit of packages using option 1 - single crane.
4.1.3 Single Crane plus Horizontal Shift
This method would be the same as for Option 1 – Single Crane except that the emplacement crane could only take a package at the outlet (4) back to the storage vault. A secondary crane or conveyor belt would transport the package to the transfer bogie (5) should this be necessary.
Figure 3: Entry/exit of package using option 1 - single and horizontal shift.
4.1.4 Single Crane to Transfer Tunnel
The Storage Vault Crane only takes the package to and from the transfer bogie, either (1) to (2) OR (5) to (6). Like ‘Option 1 – Single Crane + horizontal shift’, a secondary crane or conveyor belt would transfer the package between (4) and (5) but also between (2) and (3).
Figure 4: Entry/exit of packages using option 1 - single crane to transfer tunnel.
4.2 Option 2
Option 2 considers the location of the inspection cell identified as location 2 in figure 1. This is within the same region of the vault but utilises the space available beneath the maintenance area. At present, the primary function of this area is ventilation but there is more volume available for integrating the inspection cell into this region DIMENSIONS compared to the upper region described in option 1. Using this region does not necessitate significant changes to the internal layout of the inspection cell but it does, however, require additional consideration as to the processes required for the transfer of packages between the cell and the vault. As a result of the inspection cell being located beneath the upper region of the maintenance and viewing area, it is not possible to directly emplace packages into the cell using the emplacement crane. Consequently, an intermediate transfer stage is required between the vault and the cell. This option is considered below.
4.2.1 Emplacement Crane to Transfer Bogie (dual – way)
In this case, the emplacement crane is used to transfer a package from its stack to a transfer bogie located at an inlet area outside the inspection cell.
Figure 5: Intermediate transfer of packages between vault and cell.
This process consists of five main stages, the first of which is direct emplacement of a package from its stack to a transfer bogie waiting at the inlet stage outside the inspection cell. The package is then transferred at ground level by the transfer bogie into the cell. After inspection has been completed, the package exits the inspection on a separate transfer bogie, where it stops to await collection by the emplacement crane. At this point, the package is lifted by the emplacement crane and either transferred back to the vault stack or to the transfer tunnel, depending on its condition determined during the inspection process.
4.2.2 Emplacement Crane to Transfer Bogie (one – way)
Figure 6: Intermediate transfer of packages from vault to cell using only one transfer bogie.
Figure 6 shows an alternative method of package transfer, which involves an identical cycle of processes to that of figure 5 but only uses one transfer bogie for both inlet and outlet functions. This reduces the amount of space required for the inspection cell significantly but at the same time will reduce its operational capacity, which could cause problems if the maximum rate of inspection is required.
5 COMPONENT PARTS OF INSPECTION CELL
There are a number of features of the inspection cell concept layout that are common to all designs and have been identified as necessary to the overall ability of the system to function successfully. These can be considered as either primary or secondary features, where primary features are those necessary to the operation and secondary features are those providing functional benefits but not necessarily a prerequisite for basic operations.
5.1 Primary Features
5.1.1 Docking/Inlet Area
The purpose of this feature is to allow the successful transfer of packages from their vault to its respective inspection cell. Each of the conceptual designs proposed so far has a different method of docking the packages but all use the vault overhead crane. Design 1 is located above the ventilation area, adjacent to the maintenance area, which means the access to the cell is best provided through the top of the cell roof by a sliding door in the horizontal plane. This enables the vault crane to be used to directly emplace a package into the cell without the need for any intermediate package transfer.
Design 2 is located in the region beneath crane maintenance area, meaning that it is not possible to directly emplace a package using the overhead crane because the cell cannot be accessed vertically. In this case, the transfer bogie used within the cell is able to move out of the cell into the vault, enabling packages to be emplaced directly onto it by the overhead crane.
Both the options described above are advantageous in their own right but it is the other features of their designs that constrain whether the whole design is superior to another.
5.1.2 Buffer Store
The purpose of the buffer store is to provide additional temporary storage capacity if the inspection cell is at operational capacity when further packages arrive. This would occur when a package arrives for inspection and its relevant inspection hot cell is in use or possibly when a package has been deemed unsafe and the inspection cell must await receipt of overpacking material for containment of the package during its transfer to the overpacking cell.
5.1.3 Windows/Viewing Areas
Inspection of packages will take place using predominantly direct and indirect viewing methods and the hot cell working area will be isolated from human access by industry standard shielded windows and concrete walls.
5.1.4 Inspection Area
An area in which packages can be located to perform the necessary inspection methods effectively is necessary in all designs. As a result of the significant difference in design of the 500l drums and 3m3 drums and boxes, it will be necessary to provide separate inspection areas for both types of package. This will also aid in maximising operational capacity of the facility.
5.1.5 Reworking Area
Minor reworking of packages will be conducted within the inspection cell to reduce the demand placed on the overpacking cell and transfer tunnel to it. Although it is unlikely this will be necessary on a regular basis (assuming packages perform to their predicted standards), mechanical reworking of the outer packaging is a relatively straightforward process when using master slave manipulators and so can be performed by an experienced operator. Only mechanical reworking will be conducted here, as opposed to processes involving chemicals or welding, because it involves minimal production of process waste and is not relatively difficult or time-consuming to conduct.
The reworking hot cell will be located adjacent to the inspection hot cell for all types of drum to allow simple transfer between the two, should that be necessary. It is not necessary to provide radiation shielding between the two areas but isolation of any waste or solid matter produced as a result of reworking processes from the rest of the cell.
5.1.6 Lifting Gear
The design process has been so far been conducted with minimising the amount of lifting gear in mind. This is to reduce the amount of maintenance required throughout the life of the PGRC and also minimises the risk of mechanical failure. Movement of packages can potentially be conducted purely at ground level, which would help to minimise the amount of lifting gear, but additionally there will be certain points throughout the inspection process that require packages to be lifted (e.g. removal of drums from stillages).