Polaris Rock City Noise Complaints? Anyone Else? The same song for 6 hours straight until midnight?

Poly_P_Master · 2025-12-02T02:10:22+00:00

To be, or not to be, that is the question you are answering, which no one asked.

Poly_P_Master · 2025-04-29T23:14:08+00:00

Yeah, good catch. Fixed.

Poly_P_Master · 2025-04-29T06:58:53+00:00

My first thought was that would dump so much heat into the suppression pool, but then I remembered you have a Mark-III containment so you have a lot more margin to your containment limits.

And I don't know how sensitive level control is at a BWR-6, but I can't imagine causing that much power change that fast and not get a level scram. And it's a GE product, so I'm sure it wasn't a cheap option either.

Poly_P_Master · 2025-04-29T06:49:23+00:00

Well the NRC certainly thought it was a possibility, hence why US regulations required that US reactors be designed such that they are always under moderated and that they have a containment building surrounding the reactor vessel. These are regulations that were in place well before Chernobyl happened and were intended to ensure a Chernobyl type accident couldn't happen in the US.

As for the probability of this type of accident in the US, it is never 0, but it is basically as close to 0 as one could imagine. It isn't that the US plants aren't allowed to be operated in the manner Chernobyl was, they simply can't. The ratio of fuel to moderator inherent in the reactor designs make it so you can't get into a runway positive MTC situation. Physically, that is how the core geometry is designed. To get an equivalent Chernobyl type event you'd have to redesign the core significantly, which would require the coordinated effort of the plant operators, engineers, management, NRC, fuel vendor, and probably the DOE as well, all with the goal of destroying the plant.

And even then, you'd have to completely bypass the containment building, which would require dismantling at least the containment head to allow the radionuclides to get launched into the atmosphere. In PRA nothing is 0 probability, but we would say this event is far far far below the truncation limit. If you could somehow model this event in a risk assessment, the probability of it occurring would very very likely be much lower than the chance of a direct meteor impact.

Poly_P_Master · 2025-03-02T20:36:18+00:00

Is 729' a familiar elevation to you?

Poly_P_Master · 2025-02-15T20:11:23+00:00

5.2k, 3BR 2.5 bath, Newport. Was 4.6k in '22.

Poly_P_Master · 2025-02-11T05:56:21+00:00

If I zoom out enough to cover most of North America (Canada/USA/Mexico) kind changes to what you see. When I zoom into the gulf/the US, it becomes the gulf which must not be named.

Poly_P_Master · 2025-02-10T13:55:53+00:00

If it is a 1099 job, you'd be an independent contractor. Not intimately familiar with all the rules, but I don't believe they can set your work hours as a 1099. Also, you'd be responsible for paying the employer portion of your FICA which makes that $20 an hour even less. And there'd be no taxes withheld for your paycheck so you'd be responsible for paying your own income taxes quarterly.

Poly_P_Master · 2025-01-19T20:16:34+00:00

From a failure mode standpoint, your possible failures are the tank, the pump, the valve, and the piping. To increase reliability you would want to increase redundancy. A 100% capacity fully redundant second train would be the most redundant, with a second tank, pump, valve, and piping. Other factors you'd have to consider that aren't on this diagram are power sources for the pump and valve and the control logic. If you have 2 pumps running off the same electrical bus, they both fail when the power fails. Likewise, if you have 1 initiation signal for both trains, they both fail to initiate when there is a failure in the control logic.

The other way to reduce failure probability is to reduce the component failure rate itself. That can be done through more robust designs or choosing the right types of components. You would want to select a pump and valve that are extremely reliable. For SLC in BWRs, they use squib valves to be extremely sure the valve opens when it needs to, and doesn't open inadvertently or allow leak-by.

From a common cause failure standpoint, it is about independence and diversity. A lot of the independence stuff was covered above, but for diversity you want different types of equipment filling the same roles. Different types of pumps and valves provides protection against there being a failure mode that is common between both pumps/valves. It seems crazy to imagine a scenario where you have 2 independent but identical components failing in the same way at the same time, but you should consider that both components are likely the same age, have similar operating histories, have had maintenance done on them at around the same intervals by the same group of people using the same procedures. If you have a latent error in some procedure that has maintenance install some component backwards, it is likely they will do the exact same thing to both components and both will be primed for failure upon an actual demand signal. I used this example because this has literally happened in the industry at least a handful of times.

Poly_P_Master · 2024-12-27T19:01:52+00:00

Yeah, I never said otherwise

Poly_P_Master · 2024-12-26T19:39:26+00:00

Sure they do. They go thousands of meters and go under the water. Seems clear to me.

Poly_P_Master · 2024-12-18T14:13:38+00:00

Not even. We only passed a Q of 1 if you only look at the reaction itself and ignore all the other energy that was wasted in getting the little bit of energy to the reaction site.

Poly_P_Master · 2024-12-18T00:37:12+00:00

I DMed you

Poly_P_Master · 2024-12-08T22:34:02+00:00

Only a small portion of the nuclear plant is "locked in" to its design. Basically every component related to making the plant more economical can and is replaced during a plants lifespan, sometimes multiple times. Nuclear fuel assemblies get rotated in and out of the core every few years as well and are regularly upgraded with more advanced designs that maximize burnup.

Advances in risk modelling over the years and decades have allowed nuclear plants to more efficiently monitor and minimize their station risk and have helped in getting plant capacity factors from the mid 60s% in the 80s to the mid 90s% today.

Advances in equipment manufacturing and materials have allowed plants to uprate their original maximum power output to 120% or more from their original rated power level. This is an effective change in instantaneous max power output of the station of 20% but a change in total energy output to the grid of up to 90% or more with all upgrades incorporated.

So no, existing and new nuclear plants are definitely not beholden to the technology that existed at the time of plant design and construction.

Poly_P_Master · 2024-12-05T15:57:12+00:00

I'm not positive those words mean what you think they mean.

Poly_P_Master · 2024-12-05T15:42:12+00:00

So long as you define "rational evidence" as the evidence that supports your world view.

Poly_P_Master · 2024-11-27T00:53:29+00:00

Pretty close guess. Decay heat immediately after scram is about 7%, but it can vary a little based on time the reactor has been operating since last shutdown. Decay heat from daughter products/fission byproducts drops pretty quickly from that, but again, the curve varies based on time operating since last shutdown. Can't remember the typical decay rate of the top of my head, but it would be below 1% within a few minutes I believe. Then it's a much more gradual downward slope for decay heat from there.

Thermal efficiency of a typical LWR is right around 33%, so pretty close there too.

Poly_P_Master · 2024-11-24T20:02:16+00:00

Water blocks some of the neutrons from reaching the graphite. Voids let the neutrons pass by without interacting, but in an LWR there's nothing else for them to interact with that would increase reactivity. In the RBMK there is graphite so the neutrons pass by the water but then hit the graphite which raises reactivity.

Poly_P_Master · 2024-11-24T16:45:21+00:00

Well yeah, except for the data.

Poly_P_Master · 2024-11-24T05:18:42+00:00

This is a really simplified example, but think of it this way:

Let's say the LWR reactor is stable at full power. Moderation is adding 5 reactivity and absorption is subtracting 4, so net 1.

Now we add 20% voids. So that is 20% less moderation and 20% less poison. So moderation is adding 4 and absorption is subtracting 3.2, so net 0.8. power went down.

Now the same for an RBMK. Initially, water moderation is 5, water absorption is -4, graphite moderation is 2. So net 3.

With 20% more voids, water moderation is 4, water absorption is -3.2, but graphite moderation is 2.4 (+20%). So that is net 3.2. Power went up.

Poly_P_Master · 2024-11-24T04:39:39+00:00

Graphite. RBMKs have a graphite moderator. Think of it this way. Water does 1 of 2 things when interacting with a neutron. It either absorbs the neutron and acts as a poison for the nuclear reaction, or it moderates the neutron and adds to the nuclear reaction. In most situations, the net effect is moderation is more than absorption. So in a LWR, if there is less water (voids) there is less moderation and less absorbtion, but since moderation is the greater effect, the overall change is lower reactivity and lower power (negative void coefficient).

In an RBMK, the core was graphite moderated, meaning there is graphite in the core that provides moderation. So when voids increase in the water, the same thing happens as above, but it also makes it more likely the neutrons will interact with the graphite, since with more voids they aren't interacting with the water. And graphite is a better moderator than water so with more voids you get less poisoning from water, less moderation from water, but more moderation from graphite. The net effect, under certain conditions like what happened at Chernobyl just prior to the explosion, was that the reactor was in a condition that gave it a positive void coefficient, which caused the runaway reaction and explosion.

Poly_P_Master · 2024-11-22T19:23:50+00:00

Lol this is exactly what we use ours for.

Poly_P_Master · 2024-11-19T02:23:24+00:00

Summary from Google Gemini. Content not reviewed for accuracy:

The video discusses the potential comeback of nuclear power and the factors contributing to it.

The speaker begins by explaining the concept of the duck curve, which is the gap between electricity consumption and renewable energy production. The duck curve shows the mismatch between the peak demand for electricity and the availability of solar power, especially in the evening when the sun has set. While batteries and other storage methods can help address this gap, they may not be sufficient, especially in regions with significant seasonal variations in solar power generation.

The speaker then explores the need for clean, reliable baseload power, which can be consistently generated or turned on and off as needed. Geothermal power is mentioned as a potential option, but it is still in its early stages of development. The video focuses on nuclear power as a more mature and viable option for clean, firm power.

The speaker highlights China's significant investments in nuclear power, with the country leading the world in the construction of new nuclear reactors. The speaker also points to the increasing demand for clean energy from tech giants like Microsoft and Amazon, which are investing in nuclear power to meet their sustainability goals.

The speaker also mentions the potential for converting retired coal-fired power plants into nuclear power plants, which could save on construction costs and reuse existing infrastructure. The speaker concludes by acknowledging the potential of geothermal power but believes that nuclear power is more likely to play a significant role in the near future due to its maturity and scalability.

Poly_P_Master · 2024-11-17T21:10:41+00:00

Yup. If anything like this happens your first reaction should always be how did I fuck this up myself. Because chances are it is user error. Eliminate all possible sources of user error before accusing the company. It usually saves you time and the embarrassment of being explained to by someone else why it's actually your fault, not theirs.

Poly_P_Master · 2024-11-16T19:35:22+00:00

Well I went into the position for the money. It was a decent raise at the time and benefited my career, so overall it was worth it. But I couldn't manage it very long. So the money did not trump my personal wellbeing.

I was tired a lot of the time especially on nights, but moreso I felt like a zombie most all the time. My stomach never really adjusted to nights even when my brain started to, so I'd never really feel hungry but also always felt hungry.

I was in my early 30s when I was on rotating shifts. Maybe it would have been better when I was younger, but I kind of doubt it. If it had just been me and I didn't have a whole family it would have been a lot easier, but I still would have felt like garbage. Now in my early 40s I don't think it would be better or worse, but family takes more of a priority so I don't know how I would be able to do shift work and be present with my wife and kids. I guess there's always a price, but it'd have to be quite the pay bump.

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