By Romeo St-Martin
Canadian Nuclear Association
Since 2001, much of the Western world has been living with what’s been called the “New Normal,” which came in the shadow of the 9/11 attacks.
Increased security at airports, borders and major public events is part of this new way of life.
Being part of critical infrastructure, the nuclear power industry is often cited in media stories as a potential terrorist target.
Shortly after 9/11, there was much media speculation, especially in the U.S., about the possibility of terrorists hijacking a commercial airliner and flying it into a nuclear reactor causing a meltdown.
In 2002, the U.S. Nuclear Energy Institute released a study that concluded, “The structures that house reactor fuel are robust and protect the fuel from impacts of large commercial aircraft.”
In Canada, the Canadian Nuclear Safety Commission has also examined the issue of an airliner attack on a nuclear plant and concluded that the public would not be at risk to radiation exposure as a result of such an event.
“Robustness design covers the physical design of nuclear facilities for sufficient robustness against anticipated threats, such as protection against a malevolent aircraft crash,” the CNSC said in a 2013 report.
“The assessment and ratings for this specific area are based on licensee performance in meeting the commitments provided to CNSC staff through an exchange of correspondence, including the submission of detailed aircraft impact assessments. Licensees have demonstrated, through analysis using conservative initial assumptions and significant safety margins, that vital areas and critical SSCs (structures systems and components) are protected to the extent that no offsite consequences are expected for general aviation aircraft impact.”
Even before 9/11, nuclear reactors in the U.S. were designed and built with thick concrete walls to withstand strong earthquakes and hurricane force winds.
In 1989, Sandia National Labs in New Mexico conducted a test that sent a rocket-propelled F-4 fighter jet into a containment wall at 480 miles per hour. The jet exploded but there were less than three inches of penetration of the wall. And there’s video to prove it.
Okay, so a plane cannot penetrate a reactor from the side. But what if it made a precise nose dive into the top of the reactor?
The NEI study examined that scenario. Here’s its conclusion.
“The wing span of the Boeing 767-400 (170 feet) – the aircraft used in the analyses – is slightly longer than the diameter of a typical containment building (140 feet). The aircraft engines are physically separated by approximately 50 feet. This makes it impossible for both an engine and the fuselage to strike the centerline of the containment building,” the NEI study concluded.
“As a result, two analyses were performed. One analysis evaluated the ‘local’ impact of an engine on the structure. The second analysis evaluated the ‘global’ impact from the entire mass of the aircraft on the structure. In both cases, the analysis conservatively assumed that the engine and the fuselage strike perpendicular to the centerline of the structure. This results in the maximum force upon impact to the structure for each case.
“The analyses indicated that no parts of the engine, the fuselage or the wings – nor the jet fuel – entered the containment buildings. The robust containment structure was not breached, although there was some crushing and spalling (chipping of material at the impact point) of the concrete.”