Pages

August 05, 2009

Faster and Cheaper Nuclear Plant Construction



An 83 page presentation on the Westinghouse AP1000 and the recent Korean experience with nuclear plant construction.

Schedule Validation With 4D Tools
Allows the details of construction, erection and test activities as well as their interactions to be worked out well in advance of actual construction.
Primavera linked to Intergraph Smart Plan was used for the AP1000.

Intergraph has articles discussing their Smart Plan software successes.

Korea's Successes with Faster and Cheaper Construction

Korea's nuclear plants are being built faster and cheaper.










The AP1000 uses 5 times less concrete and steel as older nuclear plants to generate the same power.


Uprating Existing Nuclear Reactors

The design of every U.S. commercial reactor has the excess capacity needed to potentially allow for an uprate, which can fall into one of three categories: 1) measurement uncertainty recapture power uprates, 2) stretch power uprates, and 3) extended power uprates.
1) Measurement uncertainty recapture power uprates are power increases less than 2 percent of the licensed power level, and are achieved by implementing enhanced techniques for calculating reactor power. This involves the use of state of the art devices to more precisely measure feedwater flow which is used to calculate reactor power. More precise measurements reduce the degree of uncertainty in the power level which is used by analysts to predict the ability of the reactor to be safely shut down under possible accident conditions.
2) Stretch power uprates are typically between 2 % and 7 %, with the actual increase in power depending on a plant design's specific operating margin. Stretch power uprates usually involve changes to instrumentation settings but do not involve major plant modifications.
3) Extended power uprates are greater than stretch power uprates and have been approved for increases as high as 20 %. Extended power uprates usually require significant modifications to major pieces of non-nuclear equipment such as high-pressure turbines, condensate pumps and motors, main generators, and/or transformers.
Exelon’s uprate projects use proven technologies and are overseen by the US? Nuclear Regulatory Commission(NRC.) They fall into four general categories:

* "Measurement uncertainty recapture" (MUR) uprates, in which more accurate metering allows more precise reactor operations and more electrical output. MUR uprates increase reactor thermal power and require NRC approval.
* Extended power uprates, in which reactor power can be safely increased by up to 20 % after careful, rigorous analysis, equipment upgrades and NRC approval.
* Generator rewinds, in which replacing certain generator components with new copper makes it possible for the generator to produce more electricity. Power plants will continue to meet all NRC license basis requirements.
* Turbine retrofits, in which advanced technology has allowed production of new and better shapes and sizes of turbine parts, such as blades, rotors and casings. These new parts make the turbines more efficient, akin to improving the gas mileage on an automobile by using computer-controlled fuel injection rather than a carburetor. Power plants will continue to meet all NRC license basis requirements.

An approximate 38-megawatt increase in output at an Exelon Nuclear plant last week launched a series of planned power uprates across the company’s nuclear fleet that will generate between 1,300 and 1,500 MW of additional generation capacity within eight years.

Annular Fuel (Dual Cooled Fuel) Progressing to Implementation in Korea

There is advanced nuclear fuel technology under development which could enable a significant increase in nuclear power generation. The technology is referred to as annular fuel or dual cooled fuel. The new fuels could enable ultra power uprates for existing pressure water reactors of from 20-50% by safely enabling a higher power density and uprates for existing boiler water reactors by 20-30%.

Annular fuel is especially well suited for pressurized water reactors, which make up 60% of the world's 443 reactors. The designer, MIT Professor Pavell Hejzlar says that utilities in the U.S., Japan, and South Korea have expressed interest in his design. The annular fuel would boost power by up to 50%. Nanoparticles in fluid would boost power by 20% for existing reactors and 40% for new reactors. Cross-shaped spiral design would boost boiler water reactors by 30%. The MIT fuel is thin walled donuts with pellets inside and using nanoparticles in the fluid.

Korea is studying MIT’s annular fuel and they think can achieve 20% uprates with minimal changes to the existing plants.

Research abstract on the work to resolve the details of implementing annular fuel for Korean reactors

Technical paper on Korean annular fuel research

Annular fuel allows PWR (what is PWR) power density to be raised by 50% within current safety limits. The sintered fuel pellets appear viable with appropriate manufacturing need lead tests. Annular fuel uprating is economic, depending on plant remaining lifetime, with IRR (pls spell out IRR) from 20% to 27%

A Potential of Dual Cooled Annular Fuel for OPR-1000 Power Uprate
T-H Chun, C-W Shin, W-K In, K-H Lee, K-H Bae, K-W Song (KAERI-Korea)

A highly promising concept of externally and internally cooled annular fuel for PWRs was studied earlier by MIT to increase the power density substantially. The reference plant of the study was the standard Westinghouse PWR. The purpose of this study is to evaluate a potential of the annular fuels for the OPR-1000 in Korea in terms of power uprate along with different constraints. The constraints are those considerations like more adaptive to the existing power plants by means with fewer changes on the plant system components and less impact on the current fuel design practice. Specifically, first of all, the fuel array configuration has to be structurally compatible with the current solid fuel in the operation of current control rod driving mechanism. Others are no reactor coolant pump changes, same core outlet temperature in standpoint of the plant system and operation, and 3 batch reload, fuel enrichment less than 5 w/o, maximum fuel burn-up less than 60 Mwd/kgU for the fuel management scheme. In this paper a proposed annular fuel for OPR will show the satisfaction of power uprate up to 20% through the reactor physics analysis, thermal-hydraulic analysis and safety analysis.

Structural integrity of the components of a dual-cooled fuel rod is studied in this paper. The investigated topics are: i) the thickness determination of a cladding tube (especially outer tube of a large diameter), ii) vibration issue of an inner cladding tube, iii) design concern of plenum spring and spacer.

A Study on the Structural Integrity Issues of a Dual-Cooled Fuel Rod
Hyung-Kyu Kim*, Kang-Hee Lee, Young-Ho Lee, Kyung-Ho Yoon, Jae-Yong Kim, Kun-Woo Song
Korea Atomic Energy Research Institute,

Irradiation Test of Dual-cooled Annular Fuel Pellets
Yong Sik Yang1, Dae Ho Kim1, Je Geon Bang1, Hyung Kyu Kim1, Tae Hyun Chun1, Keon
Sik Kim1, Chul Gyo Seo2, Hee Taek Chae2, Kun Woo Song1 Innovative Nuclear Fuel Division,

Thermo-mechanical analysis of a dual cooled annular fuel behavior
Ju-Seong Kima, Yong-Soo Kima+, Yong-Sik Yangb, Je-Geon Bangb, KunWoo Songb
a Hanyang University, bKorea Atomic Energy Research Institute,

The maximum temperature of the annular pellet turn out to be below 700_, even in 200% power up-rated conditions, pellet temperature remains below 950_. Furthermore in accident conditions, sub-channel local boiling occurs, pellet temperature is still below 1000_ that is very small value compare to existing solid fuel.





blog comments powered by Disqus