Critics of geological disposal always ask the “what if” question: what if something goes wrong underground? The concern is genuine and needs addressing. But those same critics never ask the question: what if something goes wrong, period?
Because IF something is to go wrong, it will either happen underground, or overground on the surface. There are no other options to keeping radioactive waste: it is either underground or overground. So, if something goes wrong, and there is an undesired radioactive release, it will either happen underground or overground. Which would you prefer?
The relative risks between a radiological leak happening overground or underground is currently a ‘live’ issue in the United States. Following the rupture of a waste package at the US’ geological disposal repository, WIPP, a US government nuclear watchdog has been warning that similar packages to the one which ruptured are still being stored on the surface, presenting a much greater environmental and public health risk.
Even worse, the watchdog says that because of poor record-keeping, it is hard to identify which of these packages are most at risk of rupturing. Which begs an important secondary question about human fallibility: what will be more stable and reliable over the next 100,000 years — deep underground rock that’s been constant for the past billion-plus years, or the human beings living overground on the surface?
Underground or overground? Emplace the waste deep underground in unmoving rock far away from an ever-changing surface environment, or entrust the safe-keeping of that waste for the next 100,000 years to humans overground on the basis that homo sapiens is capable of, and guaranteed to, never ever make a mistake?
These issues underpin the concerns of an official US nuclear watchdog, the Defense Nuclear Facilities Safety Board (DNFSB), expressed in a terse and technical letter to the US Government, following an inspection at the Los Alamos National Laboratories (LANL) in 2020.
The rupture incident at the Waste Isolation Pilot Plant (WIPP) in 2014 “did not pose a public health concern”, according to the US’ Environmental Protection Agency. This is because the event happened in a contained environment deep underground. However, the DNFSB is worried that if a similar package were to rupture on the surface it could release lethal doses of radiation, and be more hazardous to the public and to the environment.
Making matters worse, is the fact that because of poor record-keeping it is hard to identify the hundreds, and possibly thousands, of ‘at risk’ packages — compounding the original human error of failure to follow safety protocols, which caused the package rupture at WIPP in the first place.
At the time of the WIPP incident, critics were quick to point to the dangers of geological disposal. Whereas, in fact, the good fortune that the rupture happened underground, rather than overground, saved and protected the public and surface environment from far worse consequences. As is now being highlighted by the DFNSB.
It should be noted at this point, that the US government is taking remedial steps in response to the DFNSB’s concerns. And that from a UK perspective, technical standards and regulatory oversight are much more stringent here than in the US. So, while we may not face the same immediate risk, the principles remain the same: over the long-term, which is the least-riskiest way to manage radioactive waste — overground or underground?
Communities considering whether to host a geological repository (a GDF) will inevitably, and rightly, be concerned about the long-term safety of an underground facility. However, to over-focus on the risks, real or perceived, of underground emplacement means that we can delude ourselves to ignoring the greater risks of keeping radioactive waste overground for the duration.
During the 100,000 years we need to concern ourselves with, civilizations will rise and fall, ices ages will come and go. The issues of climate change and a changing surface environment, allied with human fallibility to manage radioactive waste, are currently being played out on a remote Pacific island, Runik Atoll.
In the 1960s, the US placed radwaste from its nuclear test programme in a purpose-built facility on the uninhabited atoll. They did so before climate change was a consideration. But with rising sea-levels, there is early evidence that radioactivity is or is about to start escaping the facility. The US response has been slow, because even after just 60 years, the facility had basically been ‘forgotten’ by the US Defense Department.
So, within our lifetime, the consequences of human inability to predict changing planetary surface conditions, and our ability to perform administratively less well than we’d like, are revealing the stark risk differentials between keeping radwaste underground or overground over the long-term.
Fears about contaminated water or radiation leaking back to the surface from deep beneath us are to be expected. There is an absolute need to carefully evaluate every proposed repository site, and involve the local community in that process, to address concerns and build reassurance. But that should not blind those communities or anyone else to the greater risks to our air, water and soil that keeping such radwaste overground presents over time, when compared to placing it permanently underground.
Critics of geological disposal seem to assume that we are taking radwaste from relative ‘safety’ and creating additional risks, when in fact, as the DFNSB concerns and Runik Atoll situation highlight, the opposite is true: placing radwaste underground reduces long-term risks compared to keeping overground.
There are literally thousands of sites across the planet in which radioactive waste is currently stored overground. Every single country with such facilities has plans to move that waste to underground facilities. And while those communities impacted by a potential repository site can perceive this as a ‘local’ issue, in fact this is a planet-wide programme. It is a massive global undertaking, akin to the scale of the climate change challenge, and as important to protecting our planet and ourselves long into the future.
Nobody alive today chose to have this waste. It is a legacy bequeathed by previous generations. We may yet decide to halt further production of such radioactive wastes, but pending that decision should not delay us in taking steps to end the cycle of inaction on managing the radioactive wastes that already exist. It is an uncomfortable and difficult conversation, but we have a choice whether to start addressing the issue on behalf of future generations.
That choice starts with answering the simple “underground or overground” question. You probably don’t need an advanced degree in mathematics to make that fundamental risk assessment. But we do need to be clever in how we go about ensuring the risks are reduced when placing radioactive waste deep underground, and nurturing public understanding and support.
So, underground or overground? Trust to the stability of the Earth’s deep geology for the next 100,000 years, or over the same timescales, trust to the stability of human behaviour and the planet’s surface environment?