# Gen IV Nuclear Plants

1. Sep 17, 2003

### LURCH

The new Generation-IV nuclear power plants under consideration by the DOE will encase their fuel in graphite, rather than zerconium, for safety, and that seems a great advantage. But the DOE has also demanded that this generation of power plant must produce Hydrogen for fuel cells as a byproduct. The current front-runner in the competition is predicted to produce about 10 tons per hour. This could be very usefull on a number of fronts.

Does anyone think these new designs will be safe enough and usefull enough to warrant their construction? Would you live near one?

2. Sep 17, 2003

### kerimek

Iam very sceptical in question of new type NP construction. Advanced reactors are known 40 years and only rest in designers offices. They are too expensive, dangerous, unproved , say goverments. Safety at first! Safety of no-problem in next elections, of course. Only new miles of safety walls and parallel data lines will be builded in current NPs. Only developing countries as Russia or China have some advance in realization of the problematic projects. In Europe, USA or Japan no chance! Its crazy that iranian Busehr nuclear plant will be most modern in whole world, if completed How many thousands people must die in growing greenhouse catastrophes?!

3. Sep 17, 2003

### Staff: Mentor

Well I think existing reactors, none of which are less than 20 years old, are plenty safe and useful. Newer designs are even better. Unfortunately the US will never build another nuclear power plant without a major change in public opinion or a strong-willed president.

And yes, I'd even move in next to Three Mile Island.

4. Sep 20, 2003

### Clausius2

I live in Spain. Here the "nuclear energy philosophy" is completely different, the people are rejected about this type of energy. But we don't take into account that rennewable energy is not enough developed. So the goverment is pushed to disable the nuclear powerplants without another way of energy, because of people that tends to communism ideas (SURE it doesn't exist in US).
Then, our resources of energy has been redirected to gas turbines (combined cycle), because it is evident that solar or wind energy are not able to bear the spanish demand.
I am in favour of nuclear powerplants IF there is nothing better. They possibilities the steady state in the energy flow, and it's correspond with the demand now.
Hopely, we are waiting the ITER to be installed in our country (You must support us because of the support (excesive) of our president Aznar to Bush!!).
See you soon.

5. Oct 10, 2009

### CFDFEAGURU

I thought I would post in this old thread so we can see what has changed in the years since this thread was originally posted.

From Russ Waters

Here is a press release from Westinghouse dated 1/5/2009.

It is for two AP1000 units to be installed in the USA.

http://westinghousenuclear.mediaroom.com/index.php?s=43&item=39

The AP1000 is listed a generation 3+ on the Westinghouse site. I am not sure if that makes a generation 4 or just and advanced generation 3.

Thanks
Matt

Last edited by a moderator: Apr 24, 2017
6. Oct 10, 2009

### Astronuc

Staff Emeritus
AP1000 (Westinghouse), EPR (AREVA), and APWR (Mitsubishi) use pretty much the same technology as Gen 3 plants, and in fact the reference fuel designs are those in current operation (17x17 with 9.5mm cladding OD). Fuel cladding, spacer grid and guide tubes are still Zr alloys, nozzles are still SS304 or derivative, and springs are still Inconel (usually 718). The core operating conditions are much the same as current PWRs, but AP1000 is rated with the highest duty PWRs, currently Braidwood, Byron and Vogtle. The EPR and APWR have lower core average LGHRs.

All three PWRs use 14-ft fuel, althought EPR and APWR are designed with a 13.8 ft (4.2 m) active fuel length. The AP1000 is designed 157 assemblies while EPR has 241 (like Palo Verde) and APWR has 257 assemblies. Larger (wider) cores may be more susceptible to flow-induced vibration, which may increase the potential for grid-to-rod fretting.

AP1000 has a thermal rating of approximately 3400 MWt and that is the nominal output of a standard W 4-loop NSSS with 193 assemblies and 12 ft (3.66 m) active fuel length.

The ABWR (GEH and Toshiba) is an extension of current BWR/6 technology, and the major innovation is the location of the recirculation pumps inside the pressure vessel as opposed to the jet pumps. ABB and Siemens introduced internal recirc pumps in their most modern designs which are currently operating.

The ESBWR is an innovative design that extends the height of the PV and exploits the difference in density of the coolant water in the annulus and the core to produce natural convection, although the feedwater system does still use forced (pumped) flow.

The Gen IV systems, which use water coolant, are considerably different. For example, the SWR (Superheated Water Reactor) necessarily uses higher pressure because of the superheat.

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Here's an abstract of an upcoming paper that would be worth getting.

Contributions from Service Experience with Failure Investigations and Age Related Degradation Mechanisms in the Materials and Manufacturing Selection for the New AP1000 Nuclear Power Plant Design
Gutti Rao, Cynthia M. Pezze, Westinghouse Electric Co.

The evolution of the Westinghouse AP1000 Nuclear Power Plant design is based on careful evaluation of failure investigations and assessment of mitigating approaches to potential material degradation issues based on nearly 40 years of operating plant experience. The purpose of the current paper is to review key component material degradation issues based on metallurgical investigations, and discuss the remedial actions and improvements implemented to mitigate the issues. Westinghouse has reviewed specific aging degradation mechanisms and operating experiences to assure lessons learned are effectively factored into the AP1000 design. On this basis, it was determined that most agingrelated degradation has been accounted for in the AP1000 design and selection of materials and processes. Ongoing successful usage of these materials in existing plants supports confidence in their similar application in the AP1000 design.

This paper provides a summary of key considerations and AP1000 attributes. Mechanisms of degradation considered will include environmentally induced, fabrication process induced, mechanically induced, and radiation induced conditions. The features of the AP1000 design, material selections, manufacturing process, and fabrication that mitigate degradation will be summarized.

Design enhancements discussed will include elimination of susceptible materials by replacing with proven and superior materials; innovative approaches in fabrication technology to prevent sources of degradation; and improvements in diagnostic techniques.

To be presented at the Charles R. Morin Memorial Symposium on Failure Analysis & Prevention
ASM International, MS&T '09, Pittsburgh, Oct 25-29, 2009

Last edited: Oct 10, 2009
7. Oct 10, 2009

### CFDFEAGURU

I will have to attend that one. I have a friend on the ASM. He is Dr. Howard Kuhn. Very nice person.

Thanks
Matt

8. Oct 12, 2009

### QuantumPion

Eh? You are behind on the times. Multiple utilities are in the early stages of building new reactors that should be on line before the end of the next decade.

What they will do with their spent fuel is anybody's guess though :)

9. Oct 12, 2009

### CFDFEAGURU

10. Oct 12, 2009

### Astronuc

Staff Emeritus
Please note that the quoted post by RW was made Sep18-03 - six years ago. Times have indeed changed - but licensing a new plant design, or obtaining an ESP or COL are still a long way off from actually building and commissioning a plant.

11. Oct 12, 2009

### QuantumPion

Hmm it seems I am prone to doing that frequently around here