Friday, 6 June 2014

TAP WAMSR - a few points

Looking at this project, I can't see any major hindrances to its success. It looks the be the most astute nuclear plant design out there.

Introduction: Solve for X video | White paper | Patent (WO 2013077941 A2)

Of all the MSR designs available this one has been specifically created to overcome nearly all hurdles. The designers seem to be fully aware of all the technical, economic, political and social factors in play.

It's not a breeder and fissile concentration if very low (at 2%). So proliferation is no issue.
WAMSR :- 'waste annihilating molten salt reactor'. It's designed to dispose of LWR spent nuclear fuel.
Very low overnight build and short construction time will make it the most competitive w.r.t. capital. Zero fuel costs and less finicky carrier requirements (it needs only high purity Li-7, not ultra-pure) gives it low running costs too. The overnight cost of a WAMSR is predicted to be $1.5bn per 520 MWe plant at a time-scale of only 3 years (when modularized). This much shorter build time makes it far more competitive than any existing nuclear plant. ROI is sooner, interest and capital costs lower. Price of electricity generated is estimated to be ~ 6¢/kWh (4p/unit)

There's funding available in the USA to dispose of SNF. PWR nuclear operators could find themselves subsiding their WAMSR competitors to dispose of spent nuclear fuel.

Decay heat and 'storage tanks'

Some anti-nuclear activists have tried to argue that the drain tanks will be a huge risk if the reactor core is drained. I don't see how there's a risk. If an issue occurs while the reactor is working, the fuel is designed to drain away (under gravity) into drain tanks. Fuel is removed from the moderator so fission ends. The heat decay of fission products will still be a risk for another week or so, and a serious risk for one or two days. Once the fuel has drained:

  • Nothing can meltdown it's already molten.
  • The molten salt in the core is at 650°C and must be heated to b.p.: 1400°C, before it's dangerous.
  • fission material in the fuel is dilute ~ 2%. Fission products will be quite dilute too.
  • To a small extent, the fuel is continually reprocessed to remove fission products.
  • There can be several drain tanks, making it easier for decay heat to disperse.


Is a total red herring. The most likely customers are USA, Europe, Japan, China, Russia. They are all NPT signatories and either already nuclear powers or have shown no desire to become so. The dilute nature of WAMSR fuel makes this reactor less of a proliferation concern than any other design.

Can there be a thorium version of the WAMSR?

Yes. We can have a thorium version of the MIT WAMSR, and, in theory, it will be even better. Such a reactor is ideally blanket and core. Thorium is only present in the blanket and must still be reprocessed to remove protactinium-233 as it builds up. It will be:

  • much smaller (due to ZrH replacing graphite moderator),
  • cheaper (because Li-7 no longer needs to be at 99.9975% purity),
  • safer (it's no longer using FLiBe, but only FLi :- that toxic beryllium has gone).

The WAMSR is burner not a breeder, but is has a high conversion ratio close to 1. Apart from politics and the need for regulatory approval, there's not practical reason why there couldn't also be a breeder version too. A thorium reactor will have to be a breeder.


No comments:

Post a Comment