ML24215A398
| ML24215A398 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 07/12/2024 |
| From: | Public Commenter Public Commenter |
| To: | NRC/NMSS/DREFS |
| NRC/NMSS/DREFS | |
| References | |
| 89FR53659 | |
| Download: ML24215A398 (5) | |
Text
From:
Bruce Bibee <bruce626@gmail.com>
Sent:
Friday, July 12, 2024 5:26 AM
Subject:
[External_Sender] Fwd: zero CO2 power for Naval bases The US defense establishment has been tasked to move to a zero CO2 energy consumption policy. The USN has two major advantages in doing this. First, the only reliable zero CO replacement for base load is nuclear power with which the USN has decades of experience with small (almost modular) nuclear power plants used on many of its ships -
especially submarines; and, second, most of its large bases are located in coastal areas. To get a quick start on such a project, the USN could consider the refueling and reuse of many mothballed reactors currently on hand. These were designed to be used in a floating submersible platform and could likely quickly be rehoused in a large pre-stressed concrete pressure vessel - a large diameter pipe with two hemispherical end caps - designed to float vertically in the water column - possibly moored underwater deep enough to avoid surface shipping and wave action and tsunamis. Placed three miles offshore, the USN will only have to deal with Federal environmental and safety regulations which have already been demonstrated by decades of accident-free operation of its reactors. A USN owned undersea power cable can deliver stable base power directly to Naval installations -
and perhaps sell excess power to civilian power operators. The USN could also consider using new nuclear power plants that were recently designed for the Virginia and Columbia class submarines which are now coming online - if production can be ramped up without causing problems in delivering new submarines as contracted, Once the USN has demonstrated that this is a safe and viable concept to provide shore power, it could lead to more widespread adoption of commercial siting using the numerous modular designs now available.
Perhaps this will be a reason to look at floating modular thorium molten salt nuclear fission reactors that are inherently safe and produce little waste to provide reliable base load power for the country (and possibly for export as these reactors do not use bomb materials). Floating reactors can be positioned in the Pacific Ocean, Arctic waters, the Gulf of Mexico, and the Atlantic Ocean as most of the population is near coasts and they are out of sight under water and likely over the horizon as well - yet relatively near where the power is needed. Many land based nuclear power plants are reaching the end of their life and are being shut down with few, if any, replacements.
The International Energy Agency published a report (JUN 2919) declaring that without more nuclear energy, global carbon dioxide emissions will surge and efforts to transition to a cleaner energy system will become drastically harder and more costly. How costly?
The IEA estimates that $1.6 trillion in additional investment would be required in the electricity sector in advanced economies from 2018 to 2040 if the use of nuclear energy continued to decline. That, in turn,
would mean higher prices, as electricity supply costs would be close to $80 billion higher per year on average for advanced economies as a whole. New land based nuclear generating plants will be expensive and tied up for years (forever?) in litigation, while floating nuclear plants
- more than three miles offshore - will only need Federal regulatory approval and have no land acquisition costs (or neighbors). The only leverage any state has is to regulate these commercial nuclear plants are the undersea transmission lines - but they will likely have to issue such regulations to accommodate offshore wind farms (with new model turbines able to produce twelve+ megawatts each) and it will be difficult (if not impossible) to discriminate transmission regulations based on the power source - indeed, it will likely be cost effective to place the floating modular nuclear plants further out to sea (where they are largely immune to tsunami issues) and then just run undersea cables to use the wind farm grid, transmission lines and shore stations.
Note that the wind farms themselves may be more than three miles offshore for aesthetic reasons. Nuclear startup NuScale has received (SEP 2020) a landmark final safety evaluation report (FSER) for its 50 MW (moving toward 60 MW) modular reactor design. NuScales design uses classic nuclear fission water reactor technology but is a natural circulation light water reactor with the reactor core and helical coil steam generators located in a common reactor vessel in a cylindrical steel containment, The reactor vessel containment module is submerged in water in the reactor building safety related pool, which is also the ultimate heat sink for the reactor. The pool portion of the reactor building is located below grade. In the event of any runaway reactor event, the reactor quenches itself in its pool, making it passively safe". The small size and tall cylindrical form factor is a good fit with a vertical floating reinforced concrete capsule design where the reactor will be below sea level - a potential second layer of passive coolant. This design could come online quickly while a thorium molten salt design is perfected.
The biggest issues that anti-nuclear power people and organizations cite are safety issues related to siting near population centers which is where the power is most needed (largely eliminated by the new passive safe designs); and the disposal of radioactive waste The Federal government is bringing on line processing plants that can reliably take care low and medium level waste. High level waste is actually very valuable and it consists largely of 'spent' fuel rods which can be reprocessed into new fuel if there is the political will to do so - especially if the market for fuel expands with a large number of new and/or repurposed reactors. This highly radioactive end product produces a lot of heat, which is why they sit in cooling ponds for years on end wasting this resource. The thermal atomic battery is any device that converts the heat emitted by radioactive isotopes to electricity. Like nuclear reactor, the power generated by thermal atomic battery is ultimately derived from atomic energy. However, atomic battery relies solely on the spontaneous radioactive decay of
atomic nucleus, rather than artificially-triggered nuclear fusion or fission in a nuclear reactor. Although currently costly, an atomic battery has an extremely long-life span and high energy density compared to a chemical battery. Therefore, they are usually used in situations requiring long operation without battery replacement or recharging, such as unmanned scientific deep seabed facilities, unmanned underwater vehicles, (all of potential use to the USN) and etc. The atomic battery can be categorized by the form of energy converter and radioisotopes that it uses. The thermal atomic battery converts the atomic energy into heat first and then electricity. While thermal-to-electric conversion techniques have been studied extensively, there are many of them that are available to be generalized to heat source powered by radioisotopes. To date, thermal converters include the following forms: thermionic converter, radioisotope thermoelectric generator, thermos-photovoltaic cell, alkali-metal thermal to electric converter, and Sterling radioisotope generator.
The conversion of atomic energy to heat is quite simple. In thermal conversion atomic battery, the radioisotope, called fuel, is placed in a container. Alpha particles generated by alpha decay or beta particles generated by beta decay can easily interact with atoms of shielding materials and lose energy. This part of energy is dissipated in the form of heat. Therefore, the container and the radioisotope itself are used as heat source in thermal conversion atomic battery.
In thermionic converter, the heat generated from radioactive decay is used to heat a hot electrode to emit electrons through thermionic emission at temperature 1500-2000 °K. The emitted electron is collected by a cold electrode. Plasma, usually consisting of Cs vapor, is maintained between the two electrodes to reduce the work needed for electron emission, magnify the current to increase efficiency and modify the electron conducting property between electrodes. The efficiency can also be increased by lowering the potential difference between the top of the potential barrier in the interelectrode space and the Fermi level of the anode. However, in practice, the efficiency of thermionic converter can be close to 20%.
Radioisotope thermoelectric generator makes use of Seebeck effect to directly transfer the temperature difference between heat source and heat sink to electricity. Its structure is quite simple. The hot end of a thermopile is attached to the heat source, and its cold end is attached to the heat sink, usually the ambient temperature. Thermopile for power generation is usually made of pairs of connected P-type and N-type semiconductors. In presence of temperature difference, the velocity of charge carrier in both semiconductors is different, which forms current. Due to its simplicity, radioisotope thermoelectric generator is very reliable and can be made very small, and thus widely
used in spacecraft. However, the efficiency of this converter is very low, about 7% in practical use. One possible way to improve efficiency is to hybridize the system with another converter. The working temperature of a typical radioisotope thermoelectric generator is much lower than that of thermionic converter. The hot end temperature is 811 °K while the cold end temperature is 394 °K.
There are at least three possible uses for high level waste, two of which can significantly overlap with USN operations. First, both the USN and the scientific community would like to place sensors on the deep seabed that would sit passively and collect / transmit data for long periods of time. Both the USN and oceanographic research would be interested in environmental data while the USN would be most interested in acoustical tracking of enemy surface and sub-surface military activity; and the research establishment in seismic, salinity, current flow, temperature, and other such data. A large number of such instruments placed on the deep seabed would use as much high level waste that can be funded - removing it from human contact for very long periods of time - especially those placed in subduction zones. The USN has a mature capability for placing sea mines on the seabed and can likely easily adapt this capability for the placement of sensors - they can be simply dropped through the water column and be guided to their desired location using built in fins; and perhaps be stabilized by a simple low-cost biodegradable drogue that detaches somewhat before impact. A simple system of pipes can direct water at the sensors to keep them clean and functioning using a small pressure pump. Another dual use is a deep running long duration undersea drone which can collect both seabed ISR and scientific data. A commercial adaption of this vehicle would be scaled up to a deep-sea cargo vessel that uses and recharges smaller collection drones which would cruise just above the seabed and collect valuable metallic nodules with minimal environmental impact. The collected cargo would periodically collected by simply using electrolysis to create sufficient gas to lift the cargo to a waiting surface transport. The operative principle here is to reuse the 'waste' and not just try to bury it on land where contact with humans is more likely. Feel free to share. Have a good day.
Federal Register Notice:
89FR53659 Comment Number:
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[External_Sender] Fwd: zero CO2 power for Naval bases Sent Date:
7/12/2024 5:26:15 AM Received Date:
7/12/2024 7:08:08 AM From:
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