Swiss Solution

Swiss nuclear waste storage systems exceed US safety standards

Chart SONGS Chernobyl Other Alvarez Figure 4

San Onofre contains 89 times the curies of Cesium-137 released from Chernobyl  R.Alvarez June 2013

The Swiss Zwilag interim nuclear waste dry storage facility meets much higher safety standards than US nuclear waste dry storage systems. The US NRC ignores its own safety regulations, US ASME N3 safety codes and other US safety requirements in order to approve inferior thin-wall canisters that cannot be monitored or maintained to prevent major radiological releases.  Switzerland and most countries use thick-wall casks that meet US and other safety requirements. Until all US thin-wall canisters are replaced with thick-wall casks that can be maintained and monitored to prevent major radiological releases, none of us are safe. A nuclear pandemic will make the coronavirus pandemic look like a walk in the park.

Each canister holds roughly the amount of Cesium-137 released from the 1986 Chernobyl disaster. The San Onofre (SONGS) facility has 89 times the Cesium-137 released from the Chernobyl nuclear disaster. R.Alvarez June 2013. How would the US economy survive with a nuclear disaster in California? or New York? or elsewhere in the country?

Thick-wall casks are the only option

Switzerland uses thick-wall casks that meet or exceed U.S. ASME N3 Nuclear Pressure Vessel standards as well as other safety standards.  The Swiss currently use Areva thick-wall casks and CASTOR® thick-wall casks, but only models that meet their high safety standards

The Swiss evaluated various Areva systems, the Holtec HI-STAR 180L system and two CASTOR® systems. They procured the CASTOR® V/19 and V/52 transport and storage cask systems that met their high standards. The Swiss do not want to standardize on one company in order to avoid being dependent on one company. The models they currently use from Areva (such as the TN24GB and TN24BHL/BH), meet much higher safety standards than the thin-wall and thick-wall Areva systems used in the U.S.  The Holtec HI-STAR 180L thick-wall cask design was apparently rejected by the Swiss.  

In the US, the Nuclear Regulatory Commission (NRC) gives numerous exemptions to dry storage and transport standards and weakens existing standards in order to approve unsafe thin-wall nuclear waste storage and transport containers for the US nuclear utility industry.

The Sandia National Lab Department of Energy (DOE) December 2019 Technology Gap Analysis Report moved to Priority #1 the problem of the risks of short-term through wall cracks in thin-wall canisters. However, there appears to be no effort by the DOE, NRC or US nuclear industry to consider the only real solution — thick-wall casks that meet ASME N3 and other safety standards. Gap Analysis to Guide DOE R&D in Supporting Extended Storage and Transportation of Spent Nuclear Fuel: An FY2019 Assessment SAND2019-15479R, December 23, 2019

The NRC needs to stop giving exemptions to safety standards and stop ignoring the safety requirements in the Nuclear Waste Policy Act (NWPA) for monitored retrievable fuel storage and transport. Instead, US elected officials in California and elsewhere are co-sponsoring bills that lower dry storage and transport safety standards. Their focus is finding “someplace else” to dump these unsafe thin-wall canisters.  This will no more solve the US nuclear waste storage problem than rearranging the deck chairs on the Titanic would have stopped it from sinking.  These thin-wall canisters are lemons and must be replaced. They are not safe for storage or transport.

Hot cell facilities needed

Zwilag has an on-site hot cell facility (dry transfer system) for inspection, maintenance and for repackaging fuel assemblies to new casks, as needed.
Watch hot cell video.

The US has no hot cells large enough or designed to inspect, maintain or repackage fuel assemblies to new casks. The US has no system in place to prevent or stop major radioactive releases from US thin-wall canisters, in spite of knowing these thin-wall canisters are subject to short-term failure from cracking. The last US hot cell facility large enough to repackage large nuclear waste storage containers, the Idaho National Lab Test Area North Hot Cell Facility (TAN), was destroyed in 2007.

Inside Zwilag hot cell: Fuel assembly being lowered into thick-wall cask.

Interior view of cask with fuel assembly being lowered into fuel basket cell.

View from outside the hot cell.

Another view from outside the hot cell.

Storage buildings needed for environmental and security protection

Zwilag stores nuclear fuel waste casks in hardened buildings for additional environmental and security protection. With 24 hour remote continuous monitoring systems of various types, they can identify and fix problems BEFORE radioactive releases. Watch cask storage hall video.

The US stores cask and canister systems are stored outdoors at existing nuclear waste generating stations in what are called Independent Spent Fuel Storage Installations (ISFSIs). Many of these outdoor sites are located in areas vulnerable to numerous environmental and security risks. Thin-wall canisters are pressure vessels yet have no continuous radiation monitoring, no pressure monitoring, no helium monitoring and no ability to inspect for or repair cracks or other problems.  We will only know after canisters fail and release highly radioactive particles and only then if the utilities and NRC choose to tell us about the radioactive releases. More on that later.

Zwilag cask storage hall

Zwilag Facility Guided Tour – additional videos available at this link

Swiss dry storage safety standards

This Swiss presentation to the US Nuclear Waste Technical Review Board (NWTRB) highlights Swiss minimum storage and transport requirements.  Management and Transportation of Spent Nuclear Fuel in Switzerland slide presentation, US Nuclear Waste Technical Review Board, Summer 2015 Meeting, Williams, June 24, 2015

The below slide from Page 9 list some key Swiss regulatory requirements for storage. Storage approval is provided by the country in which the Package will be stored on the basis of the T(opical) SAR (Safety Analysis Report). In Switzerland, this is governed by [ENSI] guidelines (G05, G04), which impose their own criteria on the package

  1. Resistance to static and dynamic loads: including aircraft impact
  2. Requirements for the lid system: double lid
  3. Requirements for the leak tightness: continual surveillance
  4. Criticality requirements: by flooding
  5. Material ageing: over the assumed storage period
  6. Requirements on pressure barriers: all welds can be tested
  7. Resistance to Aircraft impact: scale test or transfer of similar test results
  8. Resistance to effects of earthquake: casks should not topple
  9. Dose rates: surface < 0.5mSv/h average [millisieverts/hour]
  10. Temperature of the contents: temperature limits to preclude degradation
  11. Temperature of the cask surface: 120°C [248°F]
  12. Removability of fuel: during the storage period

Solution or Radiation Cover-up?

Until thin-wall canisters are replaced with thick-wall casks, none of us are safe. With some US thin-wall canisters only 1/2″ thick and already 27 years old, we’re on borrowed time.  See US Canister Inventory (2 pages) for age and type of canisters and casks in each state.

Instead of solving this problem, the NRC has approved license amendments that allow Calvert Cliffs, San Onofre and other facilities to stop measuring radiation levels from outlet (rooftop) air vents where canisters are stored. The NRC and Southern California Edison continue to refuse to provide the radiation levels from the outlet (rooftop) air vents of the aging Areva NUHOMS thin-wall canister systems at San Onofre. The San Onofre canisters are only 5/8″ thick and some are already 17 years old. What are they hiding?

Our elected officials must demand the NRC enforce safety regulations for storage and transport.  Instead, the legislative focus is on where can we dump these unsafe thin-wall canisters. The President appoints the five NRC Commissioners that control our nuclear safety, but the Senate must confirm them. Over the last several decades normally only one of the five NRC Commissioners prioritizes safety over nuclear industry profits. All Commissioners have an equal vote.  NRC engineers who make recommendations to protect our safety continue to be overruled by NRC management.

More facts and recommendations regarding major problems with US spent fuel storage and transportation, and related issues, at

Additional References