March 25th, 2011 – Controlled failure of a nuclear reactor – Scrubbing Fission Product Releases

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From:Lee, Richard
Sent:- Friday, March 25, 2011 3:48 PM
To:’[email protected]'”
Subject:FW: Garwin comments of Science Group call of 03/24. To Binkley list of 03/24.

Another one,

From: Sheron, Brian
Sent: Friday, March 25, 2011 12:44 PM
To: Lee, Richard
Subject: FW: Garwin comments of Science Group call of 03/24. To Binkley list of 03/24.

From: Richard L Garwin [mailto:[email protected]]
Sent: Friday, March 25, 2011 11:32 AM
To: Binkley, Steve
Cc: Brinkman, Bill; Hurlbut, Brandon; Sheron, Brian; Poneman, Daniel; ‘[email protected]’; Adams, Ian; ‘[email protected]’; Kelly, John E (NE); ‘[email protected]’; Owens, Missy; ‘[email protected]’; Lyons, Peter; ‘[email protected]’;  [email protected]’; ‘R][email protected]’; ‘[email protected]’; SCHU; Aoki, Steven; Koonin, Steven; ‘[email protected]’; DAgostino, Thomas
Subject: Garwin comments of Science Group call of 03/24. To Binkley list of 03/24.

Some observations by Dick Garwin:

1. GET DATA ON VENTING AS IT HAPPENS. I believe it was John Kelly who said that if one watched Japanese TV one could hear a statement from TEPCO that they were about to vent, and there would be a TV image of the accompanying “white smoke” (steam).

It would be very valuable to us all to have this information in the next report rather than “3 days later.” There must be millions of Japanese people at home, glued to their TV, a few of whom could be asked/paid to send an email or IM or twitter recounting the venting statement.

That way we would have redundant, timely reporting that could be provided in a section of the 12-hr SITREP or elsewhere.

2. DETAILS OF HARDENED VENT PIPE. We have heard of the “hardened vent pipe” to the plant stack. Could we have details of that, please, sa well a of any filters in the stack? Bob Budnitz and I were two of the authors of the 1975 Report to the Amerian Physical Society of the study group on light-water-reactor safety,” as was Frank von Hippel, who just published an OpEd in the New York Times.

Similarly in PWR accidents where the containmnet might fail due to a melt-through by the core, rather than by overpressure, the total fission product release is assumed to be reduced greatly as a result of the filtering action of the soil. (Draft WASH-1400, Appendix V)

These possible effects suggest that emphasis be placed on containment designs which ensure that, in the case of containment failure, fission products would be scrubbed and/or filtered before their release.

Thus for example, a BWR containment might be designed to fail in a controlled way via pressure release valves which vented from the pressure suppression pool or through large stabilized bed filters.  The remaining gases could then be filtered through the standby gas treatment system.

The von Hippel OpEd states, “Even before Three Mile Island, a group of nuclear engineers had proposed that filtered vents be attached to buildings around reactors, which are intended to contain the gases released from overheated fuel.

If the pressure inside these containment buildings increased dangerously – as has happened repeatedly at Fukushima – the vents would release these gases after the filters greatly reduced their radioactivity.

France and Germany installed such filters in their plants, but the Nuclear Regulatory Commission declined to require them.

Given the influence of America’s example, had the commission demanded the addition of filtered vents, they would likely have been required worldwide, including in Japan.”

Perhaps TEPCO has installed such filters.

Does any of the Science Group know?

Can we provide some expedient filters that will handle the temperature and heat load?

3. MOVING FLUIDS BY PUMPING OR VALVING AIR. We mentioned moving fluids by periodically pressurizing containments or other vessels. This requires pipe access to the fluid to be moved.

A generic pump of this kind would be a tank with an inlet valve and an outlet valve, with air space above the fluid.

Closing the outlet valve, opening the inlet valve and venting the air (through a filter) would allow the pump volume to be largely filled with fluid.

Closing the inlet, opening the outlet and pumping air into the head space would expel the fluid. If the fluid evolves hydrogen, then nitrogen should be used for pressurizing.

4. PREPARING FOR MASSIVE REPLUMBING. In the control of the Macondo well at 5000-ft water depth, remotely operatec vehicles (ROV) were essential.

But so were the ingenious and powerful hydraulically powered wrenches, not much bigger than the massive bolts and nuts they were to unscrew or reinsert.

Our labs, industry, and counterparts on the Japanese side should amass and test this capability, together with waterjet cutters and other tools suitable for remote operation.

It might even be desirable to bore holes through concrete containment under modest internal pressure, without leaking much of the contents.

I believe that that sort of operation is routine in the oil industry– with structures under much higher pressure.

Perhaps a US-Japanese technical working group could be created for this task.

5. MITIGATING CORROSION FROM SALT. In addition to the super-important impact of massive salt accumulation on the ability to cool the reactor, there was early recognition of the corrosive effects of salt.

A note from a retired Canadian engineer experienced in both nuclear power and desalination is attached.

Most of this we know and are acting on, but I was ignorant of the zirconium corrosion hazard. I pass this to those in contact with our experts, for whatever new it may add.

Garwin Comments of Science Group Call of 03-24 – Pages From C142449-02E-3

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