The purpose of this intervention was to conduct a system based inspection (SBI) of EDF Energy Nuclear Generation Ltd’s (NGL) Heysham 2 Power Station in relation to the solid and gaseous radwaste systems. This was undertaken as part of a series of planned interventions that are listed in the Heysham 2 Integrated Intervention Strategy 2017/2018.
The inspection was undertaken by the ONR nominated site inspector and two ONR nuclear liabilities specialist inspectors. This was a joint inspection with the Environment Agency.
We performed a safety case informed SBI of the solid and gaseous radioactive waste systems. Through examination of these systems, compliance inspections were performed against the following Licence Conditions (LC):
The inspections were based on sampling the implementation of the licensee’s arrangements at Heysham 2 against the LCs. The objective of the inspection was to determine whether the licensee’s arrangements were adequately implemented and in accordance with the systems’ safety case requirements.
In addition to the SBI, compliance inspections against LC32 (Accumulation of Radioactive Waste), LC33 (Disposal of Radioactive waste), and LC34 (Leakage and Escape) were undertaken.
The above interventions were performed in line with ONR’s guidance.
From this inspection, we judged that overall the safety provisions applicable to the solid and gaseous radioactive waste systems met the requirements of the safety case.
An SBI of the solid and gaseous radwaste systems was carried out to judge the adequacy of the implementation of Heysham 2 arrangements to ensure that relevant equipment can perform its requisite safety function. In deciding whether this safety case has been adequately implemented, we inspected compliance against the licence conditions detailed above.
During the course of this SBI, it was found that Heysham 2 Power Station has arrangements to ensure that the solid and gaseous radwaste systems inspected are maintained and, as necessary, operated in accordance with the safety case. The arrangements examined complied with NGL’s legal duties based on the areas sampled during the inspection. The inspection identified potential areas for improvement, none of which gave rise to significant concern. Due to the low significance of these observations, we were content that NGL will address these through its own arrangements and do not require further follow up by ONR.
On the plant walkdown, we noted that the housekeeping arrangements met the standards and expectations the licensee aspires to. However, we did note several areas which did not meet those expectations. We found several examples of light bulbs not being replaced, and one example where gas bottles were not stored and maintained adequately. NGL has raised two internal actions: one to specifically address the latter issue, and another one to address the remaining minor issues identified during the plant walkdown.
In summary, the SBI of the solid and gaseous radwaste systems inspected, for Licence Conditions 10, 23, 24, 27, 28, and 34 is rated as Green on the basis that relevant good practice was met and identified deficiencies in compliance arrangements were of minor significance.
For the LC32, LC33, and LC34 compliance inspection, we examined the station’s compliance against its primary implementation arrangements. We considered the station’s arrangements for the labelling and recording of solid waste storage, and the arrangements for the monitoring and sampling of gaseous discharges.
For the LC32 compliance inspection, we noted some deficiencies in the approval and recording process for storage of non-standard items to the High Activity Debris Vault. To ensure that stored items meet the limits of the safety case, NGL has agreed to update its arrangements. We also noted minor deficiencies in the labelling of HEPA filters and other routine LLW items. The addition of these deficiencies was considered a minor non-compliance; an ONR regulatory issue has been raised to follow its progress.
For the LC34 compliance inspection, ONR acknowledged the ongoing work by Heysham 2 in replacing and upgrading the gaseous discharge sampling and monitoring equipment. We were satisfied that suitable and sufficient arrangements were in place to ensure adequate control and containment of radioactive material and radioactive waste.
As a result of the evidence sampled and discussions with the station staff, and in line with ONR’s Inspection Rating Guide, a rating of Green has been assigned to the compliance inspection for LC32, 33, and 34.
After considering the evidence examined during the sample inspection undertaken against Licence Conditions 10, 23, 24, 27, 28 and 34, we concluded that the licensee complied with its legal duties regarding the solid and gaseous radwaste systems inspected and met the requirements of the safety case.
After considering the evidence examined during the sample inspection undertaken against Licence Conditions 32, 33, and 34, we concluded that the licensee complied with its legal duties. A minor non-compliance within the LC32 arrangements was identified and a single ONR regulatory issue has been raised to monitor progress in its resolution.
There are no findings from this intervention that could significantly undermine nuclear safety.