Nuclear Waste Management

Introduction

The nuclear industry has invested substantial amounts of money in new plants to treat and package waste from reprocessing operations.
The wastes are classified into High, Intermediate and Low level streams. Discharges from all nuclear sites must follow strict Government authorisations in accordance with international rules; this creates engineering jobs in Cumbria and once the solution has been decided it is then the audit and strategic planning jobs that are created.

Waste Classification

• High-level waste (HLW) is radioactive enough to generate heat.  This waste is what remains when uranium and plutonium have been reprocessed.
• Intermediate-level waste (ILW) is far less radioactive than high-level waste.  It is made up of such things as fuel element cladding, contaminated equipment and sludge that come from the treatment processes.
• Low-level waste (LLW) includes paper towels, clothing and laboratory equipment, which have been used in areas where radioactive materials are used.

Waste Management Processes

High-level waste

Only 1% of nuclear waste is High-level waste.  High level nuclear waste is the most radioactive type of nuclear waste but is not created in nuclear power stations. High-level nuclear waste is generated after the used nuclear fuel has been removed from nuclear power stations and reprocessed at Sellafield. This high level waste is converted into granules and mixed with molten glass and then stored.

Intermediate-level waste

Nineteen percent of nuclear waste is intermediate-level waste which is far less radioactive than high-level waste.
At Sellafield, there are two encapsulation plants where this sort of waste is put into stainless steel drums, which are then filled with cement.  These drums are then lidded, washed and monitored before being placed into a special above-ground storage facility at Sellafield.
The decision as to where this waste will be stored in the longer term will be made by the government although it is possible it will be in the same place and therefore securing engineering jobs in Cumbria, the Lake District for many years.

Low-level waste

Low-level waste, which forms 80% of all nuclear waste, is only slightly radioactive and includes things like protective clothing, laboratory equipment, paper towels and gloves etc, items that have been used in controlled areas of a nuclear site, or in hospitals and nuclear research centres. It is these items that create jobs at Sellafield indirectly through the supply chain. This waste is treated at Sellafield in the Waste Monitoring and Compaction Plant (WAMAC).

At WAMAC the waste is placed inside drums which are monitored and then compacted down to a quarter of their original size using a high force compactor. These drums, or ‘Pucks’ as they are called, are then transported, normally by rail, to the low-level waste repository at Drigg.
At the Drigg repository, the containers are infilled with cement before being placed into a purpose-built concrete lined vault.
When each vault is full it is capped with a waterproof membrane and then landscaped. The impact of this is for construction engineers to be on site and working with the mechanical and electrical engineers to ensure a smooth process.

The future of the Drigg Repository

The Nuclear Decommissioning Authority (NDA) has come to an agreement with Copeland, the borough where Drigg is located, to ensure continuing use of the Drigg facility; this will ensure engineering jobs in Cumbria, the Lake District for a significant time; this in turn protects house prices.
Following the award of a contract to UK Nuclear Waste Management Ltd for the future Management and Operations of the Drigg site the NDA now expects ongoing operations at Drigg to continue until 2070.
This in turn will ensure ongoing long-term future employment for the wide variety of job skills that are required at the repository.

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