Short version of proposed Severe Accident Prevention

(Shortcut)

It is a must to give the operators of nuclear power plant a final rope of hope in case everything went wrong!

Recognizing that a severe accident with fuel damage in PWR and BWR NPP goes through a relatively lengthy phase of stagnant steam bubble formation and heat-up, there is an opportunity to intervene and halt the progression of accident toward the severe accident by venting the collecting steam and rapidly depressurizing the reactor. It allows the inflow of staged water reserves into the reactor.

Therefore the solution is a vent line added to the top of reactor, which is opened by the operator in case the connection to the ultimate heat sink is lost, or the forced circulation through the reactor is failed or there is no information about the state of reactor.

Response to NRC preliminary evaluation

[PDF] 2010/11/24-Comment (3) of Aladar Stolmar, on New England ...

... Van, Attached for docketing is a comment on PRM-50-93/50-95 from Aladar Stolmar that I received via the regulations.gov website on 11/24/10. ... pbadupws.nrc.gov/docs/ML1033/ML103340250.pdf - 2010-12-09 It is a much overdue duty of NRC and IAEA to evaluate the evidence provided by the TMI-2 accident, Chernobyl-4 accident, Paks-2 incident, and related experiments. Evaluating this evidence, one can see that the ignition of the zirconium fire in the steam occurs at a local temperature of the fuel cladding of around 1000-1200'C, [[and that a self-feeding with steam due to the precipitation of eroded fuel pellets and zirconia reaction product from the hydrogen stream into the water pool, causes intense evaporation.]] There are insignificant differences in the progression of the firestorms that occurred in the TMI-2 reactor severe accident, Paks washing vessel incident, and Chernobyl-4 reactor accident; the later defined only by the amount of zirconium available for the reaction. At the mean time, there are significant similarities in the processes leading to the ignition of the firestorm. In all three of the compared cases, it took several hours of ill-fated actions or in-actions of the operators to cause the ignition condition. Also, there are similarities in the end result of the firestorm; namely, that the extent of the fuel damage is much less than it was predicted from any other severe fuel damage causing scenarios, introduced for explanations. Therefore the fraction of released fission products is significantly less than was anticipated from the fuel melting or a so called "steamexplosion" scenario. Also, the fiery steam-zirconium reaction results in a much higher than anticipated (from any other scenarios) rate of Hydrogen production, which in turn requires a review of containment designs.

[PDF] 2010/03/24-Comment (3) of Aladar Stolmar, on PRM-50-93 ...

... From: Aladar Stolmar [astolmar@gmail.com] Sent: Wednesday, March 24, 2010 2:59 AM To: Rulemaking Comments Subject: Docket ID NRC-2009 ... pbadupws.nrc.gov/docs/ML1008/ML100830501.pdf - 2010-11-26

Similar destruction and relocation of nuclear reactor fuel was observed in the TMI-2 and Chernobyl-4 severe reactor accidents and in the Paks-2 refueling pond reactor fuel washing accident.

The similarities in these tests and accidents are the formation of gaseous (steam) bubbles in the upper regions of fuel bundles, the ignition of Zirconium in the steam and generation of Hydrogen and zirconia (ZrO2) reaction products in a very intense fire, essentially in a firestorm. Therefore, the conservative regulation shall mandate that the owners and operators of Nuclear Reactors and Reactor Fuel Handling Facilities shall demonstrate that there will be no dry-out of the fuel bundles in any circumstances. Also, in order to prevent the exposure of the public to the harmful consequences of an accident in a reactor, the housing of the reactor (containment) shall withstand the detonation of the air-Hydrogen mixture with the amount of Hydrogen calculated from the consumption of the entire inventory of Zircaloy in the reactor core or in the entire enclosed in a vessel volume, where such bubble formation is possible.

There are several reports presenting the same issue as Mark Leyse. The cladding of nuclear fuel made of Zirconium alloy ignites and burns in the steam. The same process can be recognized (and should be recognized) as the common cause of the TMI-2 and Chernobyl-4 reactor severe accidents and the Paks-2 refueling pond accident. And the regulations in 10 CFR 50 series shall mandate to deal with the real issues and real processes.

[PDF] 2011/06/28 - - NRC Public Blog April 2011 through May 2011

... comment #652 posted on 2011-04-06 07:31:03 by Aladár Stolmár comment #644 posted on 2011-04-04 20:11:31 by duxx ... pbadupws.nrc.gov/docs/ML1117/ML11179A192.pdf - 2011-06-29

As I wrote in the comment to US NRC http://pbadupws.nrc.gov/docs/ML1033/ML103340250.pdf

: „It is a much overdue duty of NRC and IAEA to evaluate the evidence provided by the TMI-2 accident, Chernobyl-4 accident, Paks-2 incident, and related experiments. Evaluating this evidence, one can see that the ignition of the zirconium fire in the steam occurs at a local temperature of the fuel cladding of around 1000-1200'C, [[and that a self-feeding with steam due to the precipitation of eroded fuel pellets and zirconia reaction product from the hydrogen stream into the water pool, causes intense evaporation.]] There are insignificant differences in the progression of the firestorms that occurred in the TMI-2 reactor severe accident, Paks washing vessel incident, and Chernobyl-4 reactor accident; the later defined only by the amount of zirconium available for the reaction. At the mean time, there are significant similarities in the processes leading to the ignition of the firestorm. In all three of the compared cases, it took several hours of ill-fated actions or in-actions of the operators to cause the ignition condition. Also, there are similarities in the end result of the firestorm; namely, that the extent of the fuel damage is much less than it was predicted from any other severe fuel damage causing scenarios, introduced for explanations. Therefore the fraction of released fission products is significantly less than was anticipated from the fuel melting or a so called "steam explosion" scenario. Also, the fiery steam-zirconium reaction results in a much higher than anticipated (from any other scenarios) rate of Hydrogen production, which in turn requires a review of containment designs.” I hope the gentlemen will recognize the same process in the Fukushima Daiichi 1-3 reactors as the leading, key process. I hope we will have a thorough investigation of the fiery steam-zirconium reaction and there will be issued a call for shutting down the 11 still operating Chernobyl type (RBMK) reactors in Russia

[PDF] 2011/04/08 - - NRC Public Blog February 2011 through March ...

... comment #441 posted on 2011-03-18 13:44:34 by Diesel comment #412 posted on 2011-03-17 07:06:13 by Aladár Stolmár ... pbadupws.nrc.gov/docs/ML1109/ML110980787.pdf - 2011-04-13

A few of us, nuclear engineers were, are fighting for lifetime for the consideration of real processes in the reactor severe accidents. As I formulated in a comment to US NRC: Consideration of the zirconium-steam reaction and the ignition and intense firestorm in

nuclear reactor fuel rods is well overdue. Reevaluating the evidence provided by the TMI-2 reactor accident, Chernobyl-4 reactor accident, and Paks Unit 2 fuel washing incident, with consideration of this intense fiery process, will bring us closer to an ultimately safe nuclear power plant design. http://pbadupws.nrc.gov/docs/ML1033/ML103340250.pdf

Also, I called two years ago for a review: If the hydrogen which is generated in the reactor core from the reaction of the steam (coolant) with the zirconium alloy (or other low neutron absorbing metal cladding and other fuel bundle elements) explodes inside the building surrounding the reactor, this detonation still will not cause a break of the pressure boundary of the containment. Thirty years after the TMI-2 accident and 23 years after the Chernobyl disaster, I feel obligated to formulate this guideline in order to protect the public from further irradiation from the use of nuclear power. The Chernobyl type reactors (RBMK), which are still operating, have to be shut down immediately because they do not satisfy this guideline. Other nuclear reactors operating and future designs shall be reviewed for compliance to this key requirement and the result of such review shall be defining for their future. http://aladar-mychernobyl.blogspot.com/

Returning to the comment to US NRC http://pbadupws.nrc.gov/docs/ML1033/ML103340250.pdf

: „It is a much overdue duty of NRC and IAEA to evaluate the evidence provided by the TMI-2 accident, Chernobyl-4 accident, Paks-2 incident, and related experiments. Evaluating this evidence, one can see that the ignition of the zirconium fire in the steam occurs at a local temperature of the fuel cladding of around 1000-1200'C, [[and that a self-feeding with steam due to the precipitation of eroded fuel pellets and zirconia reaction product from the hydrogen stream into the water pool, causes intense evaporation.]] There are insignificant differences in the progression of the firestorms that occurred in the TMI-2 reactor severe accident, Paks washing vessel incident, and Chernobyl-4 reactor accident; the later defined only by the amount of zirconium available for the reaction. At the mean time, there are significant similarities in the

processes leading to the ignition of the firestorm. In all three of the compared cases, it took several hours of ill-fated actions or inactions of the operators to cause the ignition condition. Also, there are similarities in the end result of the firestorm; namely, that the

extent of the fuel damage is much less than it was predicted from any other severe fuel damage causing scenarios, introduced for explanations. Therefore the fraction of released fission products is significantly less than was anticipated from the fuel melting or a so called "steam explosion" scenario. Also, the fiery steam-zirconium reaction results in a much higher than anticipated (from any other scenarios) rate of Hydrogen production, which in turn requires a review of containment designs.” I hope You will find useful this information for the background of the Fukushima Daiichi plant recent events.

Response to Fukushima Daiichi accident

1. Perform experiments to verify that a well timed rapid depressurization in the light water (BWR, PWR) reactors can avoid the ignition (ballooning and burst) of cladding of nuclear fuel in the reactor

2. Design means of well timed rapid depressurization and subsequent passive prolonged flooding of the nuclear reactor’s core and deployment of these means

3. Organization of international rapid response team and their national civil defense counterparts for nuclear emergency response coordination

4. Review of channel type reactors to verify the impossibility of development of zirconium fire in the steam (in CANDU), immediate shut down of RBMKs still operating on three sites in Russia

5. Development of evacuation procedures for the time of completion of no2 and perform mock evacuations and public trainings

6. New nuclear power plants should be developed with underground sealed containment systems as per Edward Teller’s suggestion

7. Mandatory release of data collected about the state of reactor during the accident to the public

8. Rejecting the proposals put forward by Russian President Dmitry Medvedev as offending, because at the Fukushima Daiichi NPP in Japan

a. The state provided timely and adequate response to the accident following the March 11 2011 earthquake and tsunami and minimized its impact

b. There is a well defined coordination and cooperation between the state, the operating organization and the supervisory agency in accident management to reduce its impact

c. The level of nuclear safety was not below the level corresponding to the IAEA standards, and action plans were in effect for emergencies related to the operation of nuclear power stations

d. Additional requirements were included in the regulations on nuclear power plant construction in seismic zones and in areas with a high risk of natural disasters, taking into account their possible compound effect, but a never before observed magnitude of these disasters occur

e. The proposals on the infrastructure and the level of the information to be provided about the accident, depending on its severity on the IAEA scale simply does not relate to the Japan case and may represent limitation from the current requirement of full disclosure.

9. The international world community of nuclear power users express their desire to reprehend the Russian Rosatom for their effort to divert the attention from the continued operation of unsafe RBMK units and for expressing criticism of the actions of Japan operating, government and oversight organizations, uncalled for and undeserved.

Russian President Dmitry Medvedev put forward proposals to further improve international legislation on the safety of nuclear power stations.

The proposals are the result of analysis of events at the Fukushima-1 NPP in Japan and are a response to the rapid growth of civil nuclear power facilities around the world.

The initiatives propose supplementing the existing conventions and the IAEA statute with a number of provisions stipulating:

- responsibility of the state for providing a timely and adequate response to an accident in order to minimise its impact;

- the adoption of regulations for coordination and cooperation between the state, the operating organisation and the supervisory agency in accident management to reduce its impact;

- the responsibility of the states using nuclear energy to ensure the level of nuclear safety is not below the level corresponding to the IAEA standards, and the existence of action plans in each country for emergencies related to the operation of nuclear power stations;

- the requirement for the countries intending to build nuclear power facilities to establish infrastructure in accordance with IAEA recommendations and with the participation of the supplier of the nuclear plant’s equipment.

- additional requirements to be included in the regulations on nuclear power plant construction in seismic zones and in areas with a high risk of natural disasters, taking into account their possible compound effect.

- adopting regulations regarding the information to be provided about the accident, depending on its severity on the IAEA scale.

http://eng.kremlin.ru/news/2135

The above proposals of the Russian Federation on the development and safety of nuclear energy have been submitted to the IAEA and the leaders of the G8, BRICS and CIS countries.

Commentary of Presidential Aide Arkady Dvorkovich on Dmitry Medvedev’s initiatives on developing the international system for safe and secure operation of nuclear power facilities

April 26, 2011

“Per Russian President’s directive, following a thorough analysis of the events in Japan, Rosatom has prepared proposals to improve the international regulations related to the safety of nuclear power stations.

Today, the Russian Foreign Ministry submitted these proposals to the G8 countries. Considering that nuclear safety is a responsibility shared by a large number of states, the proposals have also been forwarded to Russia’s partners in BRICS, the CIS and the IAEA as an authorised international organisation. Russia expects for a discussion of its initiatives to be launched in all of these formats.

France, which currently holds the rotating presidency in the G8, has already included the issue of nuclear safety in the agenda of the upcoming G8 summit in Deauville, and Russia hopes that its proposals will form the basis for the measures adopted at the summit.”

http://eng.news.kremlin.ru/ref_notes/47

Key to safe nuclear power

My Chernobyl details the problems and are available on BookSurge.com and Amazon.com
If the hydrogen which is generated in the reactor core from the reaction of the steam (coolant) with the zirconium alloy (or other low neutron absorbing metal cladding and other fuel bundle elements) explodes inside the building surrounding the reactor, this detonation still will not cause a break of the pressure boundary of the containment.
Thirty years after the TMI-2 accident and 23 years after the Chernobyl disaster, I feel obligated to formulate this guideline in order to protect the public from further irradiation from the use of nuclear power. The Chernobyl type reactors (RBMK), which are still operating, have to be shut down immediately because they do not satisfy this guideline. Other nuclear reactors operating and future designs shall be reviewed for compliance to this key requirement and the result of such review shall be defining for their future.
Aladar Stolmar

Russia must cease operation of RBMKs

http://www.rosenergoatom.ru/rus/press/askgeneraldirector/faq1/
“I asked the general director Sergej A. Obozov of OAO Concern Energoatom: When they plan to end the operation of the RBMK type reactors?
I got the answer:
Currently the use of units 1 Kursk NPP, units 1 and 2 Leningrad NPP are already extended and there are work in progress aimed to extend the operation of other units in the Nuclear Power Plants Kursk and Leningrad and in addition the unit 1 of Smolensk NPP. The extension of operation of power plant units with the mandatory fulfillment of all the safety regulations gives an opportunity to obtain an electrical power installed for a fraction of the cost of a new unit from zero - $3000 for a kW (new power unit) compared to $300 (or about that) for the extension of operation.
The youngest RBMK unit is the Smolensk unit 3 started in 1990 with a design lifespan of operation 30 years. After the operating life depending on the condition of the non-exchangeable equipment and other consideration of preferences an extension of operation for 15-20 years is possible. Therefore, in case there will be an extension of operation decided for this power plant unit, the last RBMK reactor will be in operation until the year 2035-2040.”

This answer does not satisfy me and many other concerned individuals with knowledge of the real unsafe construction of RBMKs.
The financial crisis unfolding also gives a real opportunity to replace the unsafe RBMK units with safe VVERs, where the reactor is enclosed in a containment, sized for the maximum amount of zircalloy cladding reacted with steam and will withstand the explosion of generated Hydrogen-air mixture. The still operating RBMKs are as unsafe now as they were in the time of Chernobyl Disaster! The Russian Federation has to shut them down now!

My Chernobyl details the problems and available on BookSurge.com and Amazon.com.

Kirkus Discoveries review

Nuclear engineer Stolmar offers a concise version of the events that precipitated the Chernobyl nuclear disaster and the prospects of the nuclear industry today.
Stolmar examines the design flaws that resulted in the explosion at Chernobyl, with a populist twist. Still, a degree of familiarity with nuclear physics goes a long way toward understanding his contention “that the zirconium-steam reaction was the governing process in all nuclear power plant severe accidents.” He explains the process: impeded water flow initiated a local power increase and a crisis in boiling, which led to a hugely volatile zirconium-steam reaction on the fuel cladding. Beyond that, the author notes, the reactor vessel was too weak to contain a failure and the reactor was uncontained. Yet incredibly, considering these basic design issues, twelve RBMK reactors of the type at Chernobyl are still active today. It is unclear what vested interests in Russia are keeping these plants in operation, and it would have been fascinating for Stolmar—who was born in Hungary and trained in Moscow—to expand on comments like, “[b]ehind our backs, or way above our heads, the intrigues and clan interests were played, so characteristic for the Communist totalitarian system,” regarding nuclear decision-making in the Soviet Union. Though the author’s prose has an appealing Eastern-European inflection, more polish would help lay readers understand the more arcane chemical reactions. Stolmar remains largely in support of nuclear power, which he sees as the only immediate, viable alternative to fuels that are peeding global warming and a way of turning swords to plowshares in decommissioning nuclear weapons. His call for international cooperation in the building and inspection of nuclear facilities is heartening, though spent fuel will be left “to our children as part of their inheritance,” a gift that keeps on decaying.
A thoughtful peek into the guts of a failed reactor and a cautionary tale.
Available on BookSurge.com and Amazon.com

Contents of My Chernobyl

In Memoriam Larry Hochreiter. 2
Contents. 3
Introduction. 4
Acts of God—My Preparation for Chernobyl 5
Session of the Politbureau of the CPSU Central Committee on July 3, 1986 29
What Caused the Explosion of the Chernobyl Unit 4 Reactor and What Processes Led to the Disaster? 33
The Causes of the Chernobyl Disaster. 40
The Processes Leading to the Accident 42
Cover-ups and Corrections for Show.. 48
KGB Agents in the USA.. 62
Headfirst into the Wall 64
New Nuclear Power Plants for a Brighter Future. 71
Questions and Answers. 76
What Do I Expect?. 78