Health and Safety
Executive / Commission
Nuclear
LLC reports
This report is issued as part of the Health and Safety Executive's commitment to make information about inspection and regulatory activities relating to the above site available to the public. It is for distribution to members of the Dounreay Site Stakeholder Group (DSSG) and covers activities associated with the regulation of safety at Dounreay. These reports are distributed quarterly and are available also from the Internet at http://www.hse.gov.uk/nuclear/index.htm. Site Inspectors of HM Nuclear Installations Inspectorate (part of the Health and Safety Executive’s Nuclear Directorate) normally attend the Dounreay SSG meetings and will be happy to respond to questions raised there or subsequently by members of the Dounreay SSG. Any other person wishing to inquire about matters covered by this report should contact the HSE’s, Nuclear Directorate on 0151-951-3484/3290.
Nuclear Directorate
Health and Safety Executive
Redgrave Court
Merton Road
Bootle
Merseyside
20 7HS
NII Site Inspectors and Specialist Inspectors visited Dounreay on the following dates:
Compliance inspections were undertaken against a number of the Licence Conditions. No major issues were raised.
Close dialogue and assessment of the decommissioning activities at PFR and DFR has continued. After a lengthy assessment and inspection process, NII issued a Licence Instrument to UKAEA at the end of June 2006, agreeing to the start of inactive commissioning of the NaK disposal plant at DFR. The commissioning process is being monitored in preparation for moving to the active commissioning phase. Other decommissioning activities at both reactors will be subject to regulatory hold points, notably the development of the process for removing the hazardous alkali metal residues from the vessels and circuits of the reactors, which will take place following removal of the bulk coolants.
There has been some progress with the audit recommendations during this reporting period with eight recommendations having been closed out .
NII continues to monitor the effects of the recent reorganisation of the Dounreay Division and has scrutinised the current and future staffing levels. UKAEA has agreed to provide NII with information on staffing levels at Dounreay on a regular basis so that any trends can be monitored. NII expects that UKAEA will suspend projects if staff levels are deemed to be insufficient.
NII continues to engage with UKAEA on its company wide restructuring .
NII has registered a response of no objection to the Highland Council regarding the planning application for the proposed Low Level Waste facility. NII supports the development of such a facility and considers it to be a critical enabler to the decommissioning and restoration activities on the Dounreay site. NII has also registered a response of no objection to the Highland Council regarding the planning application for the proposed D3900 facility. The facility will be used principally to encapsulate liquid waste from the PFR and DFR fuel reprocessing programme .
UKAEA informed NII of a suspected Plutonium intake by an employee working in the Fuel Cycle Area at Dounreay. NII has investigated the matter and are currently considering an appropriate level of regulatory response.
NII Inspectors have continued to monitor the decontamination activities at DCP and the preparations for personnel entry to the shielded cell. The radiation exposure to the workforce from this undertaking is expected to be low . Access to the encapsulation cell will require the removal of shielding and a number of important items of equipment. Systems involving equipment that has to be reinstalled will need to be carefully recommissioned before the plant can be restarted .
NII has acknowledged UKAEA’s safety case for strengthening of the concrete plug in the tunnel from the Shaft to the Pentland Firth. Reinforcement is required so that the water level in the Shaft can be safely lowered during waste retrieval. NII has specified that construction of the grout curtain around the Shaft should not proceed without further permission .
During July, NII was informed of an interruption to the power supply to the Fuel Cycle Area(FCA) arising from an electrical storm. The loss of power tripped the main ventilation system and as a result, controlled entries were required to a number of buildings in the FCA. No contamination was found during these controlled entries. NII specialist inspectors will be examining this failure and other electrical power supply issues in the near future .
A small but highly radioactive tube, of dimensions 45 cm long by 4.5 cm in diameter, was found at the bottom of the DMTR pond. The tube is believed to be part of an irradiated Dido/Pluto type fuel element. The pond is undergoing clean-out in preparation for decommissioning : all fuel was considered to have been removed .
The Inspectorate has powers under the licence to issue Consents, Approvals and Directions. In addition, the Inspectorate uses Licence Instruments to issue Specifications, Acknowledgements, and Agreements under either the conditions attached to the Licence, or arrangements made by UKAEA for complying with those conditions. NII has issued the following Licence Instruments during the 3 rd quarter of 2006:
| LI No. 525 | Acknowledgement of the Combined Pre-construction, Pre-Commissioning & Pre-operational Safety Report for Shaft Isolation Project. |
| LI No. 526 | Specification of a hold point before construction of grout curtain around the Dounreay shaft, D1225. |
| LI No. 527 | Agreement to change the categorisation of the AT089 facilities from Category 2 to Category 3. |