What is a PPE?

Currently there are more than 18 new nuclear reactors proposed in Ontario and Alberta, plus one new nuclear project planned in New Brunswick. The proponents are applying for environmental review, without identifying the type of reactor they are planning. How is this possible? The answer is the “PPE.”

What is the “Plant Parameter Envelope” Procedure?

Nuclear reactor proponents in Canada are using a “Plant Parameter Envelope” (PPE) approach instead of identifying one reactor design in Impact Assessment and CNSC reviews.

The PPE is a Pretty Poor Excuse for environmental review of a new nuclear reactor.

The PPE originates from a US lobby group, the Nuclear Energy Institute. The NEI published a document with a toolkit to develop a PPE. The PPE is intended to reduce the time needed for a nuclear proponent to obtain an Early Siting Permit for a proposed new reactor from the US NRC (equivalent to a CNSC site preparation licence). Both the NRC and the CNSC have accepted the PPE as a tool designed by the industry to streamline the approvals process.

The PPE is essentially a large spreadsheet. Various parameters (quantifiable characteristics) are listed in the many rows, with one column for each of several candidate reactor designs. Reactor vendors provide the numbers in the spreadsheet. The regulator can examine the range of values for each parameter to ensure they are within certain bounds, regardless of the reactor type. If the regulator accepts these bounds, indicating that all relevant regulatory guidelines could be met by any one of the candidate designs, an Early Siting Permit may be granted and site preparation can commence.

Therefore, in the absence of a specific design, the proponent can use the PPE approach as a surrogate in safety and environmental reviews.

This is worrisome in particular because the vendors supply all the information in the PPE. This includes the “normal and accident source term” – that represents the maximum amount of radioactivity available to be released to the environment under both normal and accidental circumstances. In Canada the source term for a severe nuclear accident in a CANDU reactor was pegged at 100 terabecquerels of cesium-137, which is in fact a small fraction of what might realistically be released in the event of a major nuclear accident involving severe fuel damage (core melting).

The danger is not only that the numbers may be skewed but also that the entire exercise of conducting an environmental evaluation and granting a site preparation licence is reduced to a numerical box-checking exercise in lieu of a detailed examination of one specific reactor design. The PPE approach is off-putting for intervenors who cannot evaluate and critique a specific reactor design.

This information was prepared by the Canadian Coalition for Nuclear Responsibility (CCNR). See one of the CCNR interventions on PPE concerns related to the “Darlington New Nuclear Project” (the BWRX-300):
Mischief in the Making