Loss of Primary Containment

Incidents which didn t meet the definition of PS incident metric (e.g., all other Loss of Primary Containment or fire). 

Tiers 1 and 2 are suitable for nationwide public reporting and thus have a tightly defined scope. Any Tier 1 or Tier 2 Process Safety Event begins with an unplanned or uncontrolled release of any material, including nontoxic and nonflammable materials resulting in one or more consequences described in the RP. These events are referred to as a Loss of Primary Containment (LOPC), which is defined as follows ... 

Other Loss of Primary Containment (LOPC) events that are less than what is required for Tier 2. 

Protecting against loss of primary containment using high integrity systems... 

Engineering against escalation of loss of primary containment... 

Operators of Buncefield-type sites should employ measures to deteot hazardous conditions arising from loss of primary containment, including the presence of high levels of flammable vapours in secondary containment. Operators should without delay undertake an evaluation to identify suitable and appropriate measures. This evaluation should include, but not be limited to, consideration of the following ... 

The sector should begin to develop guidance without delay to incorporate the latest knowledge on preventing loss of primary containment and on inhibiting escalation if loss occurs. This is likely to require the sector to collaborate with the professional institutions and trade associations... 

Failure of an overfill protecfion sysfem places reliance on fhe tank to avoid the uncontrolled loss of primary containment of hazardous substances. The adoption of appropriate design standards should ensure tank integrity and suitable overflow and venting mechanisms. Throughout the life of the tank, integrity of primary containment should be maintained through a process of periodic inspection, maintenance and repair. 

EEMUA 159 and API 653 represent relevant good practice and should form the basis of minimum industry standards for tank integrity management and repair to prevent loss of primary containment. 

While priority should be given to preventing a loss of primary containment, adequate secondary and tertiary containment remains necessary for environmental protection and safety of people in the event of a loss of primary containment of hazardous substances. Tfie failure of secondary and tertiary containment at Buncefield contributed significantly to the failure to prevent a major accident to the environment (MATTE). 

A bund should be capable of withstanding the full hydrostatic head of liquid that may arise from the loss of primary containment. 

A Tier 1 Process Safety Event (T-1PSE) is a loss of primary containment (LOPC) with the greatest consequence. It is an unplanned or uncontrolled release of any material,... 

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