[Official] New Reactors design thread.

  • High efficiency fluid MOX:

    2300120C0A120D0C0A06230C0D0C0D0C0D14230C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C140C0D0C0D0C0D0C140D140C0A120D0C140Drh1770rid01

    1344 HU/t at 51+ heat.

    33.6 (50.4 on steam) MEU per fuel, more effective than regular MOX reactors.

  • I was messing around with the fluid reactor designs and I got two high HU/t and stable reactors by slightly changing the fuel rod/reflector arrangement.


    1367.8 HU/t, 3 reflectors, efficiency 19

    2303230C09110D0C0A03230C0D0C0D0C0D12010C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D110D120D120D120D11


    1359.83 HU/t, 1 reflector, efficiency 13.08

    0323000C0A120D0C0A01030C0D0C0D0C0D12030C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D110D120D120D120D11

    IC2 reactors has 196,627,050,475,552,913,618,075,908,526,912,116,283,103,450,944,214,766,927,315,415,537,966,391,196,809 (2754) combinations. HAYO!

    :Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log:

    My avatar is from a video of Operation Upshot-Knothole.


    The post was edited 2 times, last by KrisBigK: Found a cheaper version for the 1367 reactor & messed up the unit of heat ().

  • I got another one. I just added a core heat exchanger on albijoe's design and it runs a full cycle. I also changed a few components to make it cheaper.

    1375.83 HU/t, no reflectors, efficiency 12.28

    0302130C09110D0C0A03000C0D0C0D0C0D12030C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D110D120D120D120D11

    IC2 reactors has 196,627,050,475,552,913,618,075,908,526,912,116,283,103,450,944,214,766,927,315,415,537,966,391,196,809 (2754) combinations. HAYO!

    :Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log:

    My avatar is from a video of Operation Upshot-Knothole.


  • I got another one. I just added a core heat exchanger on albijoe's design and it runs a full cycle. I also changed a few components to make it cheaper.

    1375.83 HU/t, no reflectors, efficiency 12.28

    0302130C09110D0C0A03000C0D0C0D0C0D12030C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D110D120D120D120D11

    Hey, I can't get the reactor planner working, your design seems like something I'd need, could you post a screenshot of it instead? Thanks!

  • Hey, I can't get the reactor planner working, your design seems like something I'd need, could you post a screenshot of it instead? Thanks!

    The 2.2.1 version of the reactor planner is a little buggy. Sometimes pasting the code doesn't make the components show up. Restarting the planner might solve the issue. Here is the screenshot, anyway.

    Images

    IC2 reactors has 196,627,050,475,552,913,618,075,908,526,912,116,283,103,450,944,214,766,927,315,415,537,966,391,196,809 (2754) combinations. HAYO!

    :Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log:

    My avatar is from a video of Operation Upshot-Knothole.


  • The 2.2.1 version of the reactor planner is a little buggy. Sometimes pasting the code doesn't make the components show up. Restarting the planner might solve the issue. Here is the screenshot, anyway.

    Wait wait wait, you might've mixed up Hu/t with Hu/s

  • Wait wait wait, you might've mixed up Hu/t with Hu/s

    I tested it in-game and the output number floats around 27500HU/s. Divide it by 20 and you get 1375 HU/t. I used steam generators to test it's power and it got 1032 EU/t.

    IC2 reactors has 196,627,050,475,552,913,618,075,908,526,912,116,283,103,450,944,214,766,927,315,415,537,966,391,196,809 (2754) combinations. HAYO!

    :Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log:

    My avatar is from a video of Operation Upshot-Knothole.


  • New!

    1383.78 HU/t, no reflectors, efficiency 14.41

    0302130C09110D0C0A03010C0D0C0D0C0D12010C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D110D120D120D120D11

    IC2 reactors has 196,627,050,475,552,913,618,075,908,526,912,116,283,103,450,944,214,766,927,315,415,537,966,391,196,809 (2754) combinations. HAYO!

    :Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log:

    My avatar is from a video of Operation Upshot-Knothole.


  • I just designed a high output but unstable fluid reactor. I haven't tested it in-game because I'm running out of time today but I'm quite sure it will work.

    1451.79 HU/t, 1 reflector, efficiency 12.96, runs 8 sec on and 1 sec off

    2302130C0D0C0D0C1303030C0D0C0D0C0D0C030C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C

    When running without redstone control and cooled off completely before doing so, the first vents will overheat at 242 seconds, and the reactor WILL explode at 289 seconds, so use it at your own risk.


    I also have some questions about it.

    1.Why does replacing the top-right core heat exchanger with a reactor heat vent causes the average heat output to drop to 1450.01 HU/t while the reactor is still stable?

    2.Why does removing the top-left core heat exchanger causes the reactor to explode within a cycle but doing so on the right one doesn't?

    3.Why does 0223130C0D0C0D0C1303030C0D0C0D0C0D0C030C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C not work despite it generating the same heat and having the same rods/reflector, the same heat vents?

    4.Is a fluid reactor with a higher average output than this one possible? I'll be glad to hear about it.


    Note: I tested whether a reactor is "stable" by using Pulsed Automation with no component automation selected and suspending & resuming temperatures in Pulse Configuration is set to 10001.

    IC2 reactors has 196,627,050,475,552,913,618,075,908,526,912,116,283,103,450,944,214,766,927,315,415,537,966,391,196,809 (2754) combinations. HAYO!

    :Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log:

    My avatar is from a video of Operation Upshot-Knothole.


  • I think I can answer a couple of your questions:

    2.Why does removing the top-left core heat exchanger causes the reactor to explode within a cycle but doing so on the right one doesn't?

    3.Why does 0223130C0D0C0D0C1303030C0D0C0D0C0D0C030C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C0D0C not work despite it generating the same heat and having the same rods/reflector, the same heat vents?

    It isn't obvious from the IC2 Wiki, but unless this has changed in newer versions of IC2, the reactor heat exchanger accepts heat from adjacent sources (such as that dual fuel rod near the upper left corner). Thus, if you remove the exchanger or swap the rod's position with the reflector, the dual rod will be pumping all its heat directly into the reactor instead of the exchanger.

  • I think I can answer a couple of your questions:

    It isn't obvious from the IC2 Wiki, but unless this has changed in newer versions of IC2, the reactor heat exchanger accepts heat from adjacent sources (such as that dual fuel rod near the upper left corner). Thus, if you remove the exchanger or swap the rod's position with the reflector, the dual rod will be pumping all its heat directly into the reactor instead of the exchanger.

    I know that components can accept heat from adjacent sources, but all the components that I used can pull heat from the reactor, so the total venting should be the same regardless of how the fuel rods are placed. Then what's the difference between pulling 80 heat from the rod then give 72 to the reactor and pull 72 heat from the reactor and vent 8 heat? I can't see any difference in that.

    IC2 reactors has 196,627,050,475,552,913,618,075,908,526,912,116,283,103,450,944,214,766,927,315,415,537,966,391,196,809 (2754) combinations. HAYO!

    :Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log:

    My avatar is from a video of Operation Upshot-Knothole.


  • I know that components can accept heat from adjacent sources, but all the components that I used can pull heat from the reactor, so the total venting should be the same regardless of how the fuel rods are placed. Then what's the difference between pulling 80 heat from the rod then give 72 to the reactor and pull 72 heat from the reactor and vent 8 heat? I can't see any difference in that.

    Okay, let me try to clarify: the exchanger is not "pulling" 80 heat from the rod, the rod is "pushing" 80 heat into the exchanger before the exchanger does its thing. This means the exchanger in question can theoretically be gaining as much as 152 heat per reactor tick when a rod is adjacent to it.

  • Okay, let me try to clarify: the exchanger is not "pulling" 80 heat from the rod, the rod is "pushing" 80 heat into the exchanger before the exchanger does its thing. This means the exchanger in question can theoretically be gaining as much as 152 heat per reactor tick when a rod is adjacent to it.

    First, I think pulling heat from the rod and pushing heat to the core heat exchanger makes no difference. To my understanding, the core heat exchanger is like a “heat capacitor” that vents/pulls heat from the reactor. If it gains 152 heat, it cools the reactor down and basically doesn’t do anything because a few ticks later (or less) the reactor will be cooled enough for it to vent back the 72 heat pulled from the reactor in the beginning. If it is touching the rod, it takes damage at a rate of 80/s and heals at a rate of 8/s. Once its damage percentage is greater than heat percentage of the reactor, it will start to vent 72 heat into the reactor, thus not destroying itself.


    Let's put that to a side, but the core heat exchanger can vent heat at 8/s wherever it was put, right? Then why does one place work while the other one doesn't?

    IC2 reactors has 196,627,050,475,552,913,618,075,908,526,912,116,283,103,450,944,214,766,927,315,415,537,966,391,196,809 (2754) combinations. HAYO!

    :Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log:

    My avatar is from a video of Operation Upshot-Knothole.


    The post was edited 1 time, last by KrisBigK: Accidentally clicked "Submit" ().

  • First, I think pulling heat from the rod and pushing heat to the core heat exchanger makes no difference. To my understanding, the core heat exchanger is like a “heat capacitor” that vents/pulls heat from the reactor. If it gains 152 heat, it cools the reactor down and basically doesn’t do anything because a few ticks later (or less) the reactor will be cooled enough for it to vent back the 72 heat pulled from the reactor in the beginning. If it is touching the rod, it takes damage at a rate of 80/s and heals at a rate of 8/s. Once its damage percentage is greater than heat percentage of the reactor, it will start to vent 72 heat into the reactor, thus not destroying itself.


    Let's put that to a side, but the core heat exchanger can vent heat at 8/s wherever it was put, right? Then why does one place work while the other one doesn't?

    TBH, I've never fully understood the heat exchangers even after looking at decompiled code for them. Among other things, they have some weird quirks when their heat level is close to zero. However, based on your statement in the second paragraph, you seem to be misunderstanding something - the heat exchanger is not venting the heat by itself - the adjacent component heat vents are each removing up to 4/s from it (and not "accepting" heat themselves, which is significant for the quad rods which are simply pushing their heat to the reactor, since there's nowhere else for the heat to go).


    Now I have some questions for you:

    1. You claimed that "removing the top-left core heat exchanger causes the reactor to explode within a cycle but doing so on the right one doesn't". Was this something you found in-game or with the simulator? Using the "Simple Cycle" simulation, it looks like removing the top-left core heat exchanger will only cause it to explode 22 seconds sooner than having both in place, and a "Pulsed Cycle" simulation with 8 seconds on, 1 second off and the top left core heat exchanger removed shows a reactor max temperature of 3000. If it explodes in-game even with an 8-1 pulsed cycle, then that's a severe inaccuracy in my simulator that I will have to investigate.

    2. Same question regarding your findings when switching the dual fuel rod with the reflector - it looks to me like it still works, just less heat output - your first design shows 1451.79 Hu/s average, and a reactor maximum temperature of 723. Swapping the reflector with the dual rod produces 944.35 Hu/s average (because several of the overclocked heat vents broke, the first at just 249 seconds), and the reactor got up to a temperature of 2568.

  • However, based on your statement in the second paragraph, you seem to be misunderstanding something - the heat exchanger is not venting the heat by itself - the adjacent component heat vents are each removing up to 4/s from it (and not "accepting" heat themselves, which is significant for the quad rods which are simply pushing their heat to the reactor, since there's nowhere else for the heat to go).

    Isn't it like 1+2 and 2+1? I think both are the same.


    1.You claimed that "removing the top-left core heat exchanger causes the reactor to explode within a cycle but doing so on the right one doesn't". Was this something you found in-game or with the simulator?

    1. First in the simulator and then in-game. When designing it, I mainly use Simple Cycle to see how much heat is generated and how long a reactor can sustain without redstone control. I use pulsed automation to see its long-term stability.

    Using the "Simple Cycle" simulation, it looks like removing the top-left core heat exchanger will only cause it to explode 22 seconds sooner than having both in place

    That is because the 5000 heat that could be stored in the core heat exchanger can't after its removal.


    and a "Pulsed Cycle" simulation with 8 seconds on, 1 second off and the top left core heat exchanger removed shows a reactor max temperature of 3000. If it explodes in-game even with an 8-1 pulsed cycle, then that's a severe inaccuracy in my simulator that I will have to investigate.

    There is no severe inaccuarcy in your planner. The "severe inaccuarcy" that you see is just because you forgot to set the suspending temperature to 10001.

    So far, your planner seem to be right. Removing the top-left heat exchanger do cause the reactor to explode in-game with a pulsed redstone control. I just tested that. The reactor exploded after burning the top two vents and some bottom vents. The explosion was not very powerful, though.

    2. Same question regarding your findings when switching the dual fuel rod with the reflector - it looks to me like it still works, just less heat output - your first design shows 1451.79 Hu/s average, and a reactor maximum temperature of 723. Swapping the reflector with the dual rod produces 944.35 Hu/s average (because several of the overclocked heat vents broke, the first at just 249 seconds), and the reactor got up to a temperature of 2568.


    2. I haven't tested that yet because my setup got blown up. Based on my answers of 1, I think it will explode too because after burning some vents, the heat will stack up in the reactor.

    IC2 reactors has 196,627,050,475,552,913,618,075,908,526,912,116,283,103,450,944,214,766,927,315,415,537,966,391,196,809 (2754) combinations. HAYO!

    :Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log:

    My avatar is from a video of Operation Upshot-Knothole.


    The post was edited 2 times, last by KrisBigK ().

  • I was thinking about the design the whole day and become more confused - Why do the overclocked vents that are surrounded by 3 component vents break in the first place? During the 8 seconds of heating, the vents take damage at 4/s (36-20-3*4), with a total damage of 4*8=32 at the end of heating, and during the 1 second of cooldown, it vents 20+3*4=32 heat, right? It should be balanced, but why it isn't? Did I done the math wrong or is it a IC2 bug?

    IC2 reactors has 196,627,050,475,552,913,618,075,908,526,912,116,283,103,450,944,214,766,927,315,415,537,966,391,196,809 (2754) combinations. HAYO!

    :Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log:

    My avatar is from a video of Operation Upshot-Knothole.


  • I run the reactor on a 8 sec on and 1 sec off cycle.

    Please read the posts before that one, thank you.

    IC2 reactors has 196,627,050,475,552,913,618,075,908,526,912,116,283,103,450,944,214,766,927,315,415,537,966,391,196,809 (2754) combinations. HAYO!

    :Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log::Rubber Log:

    My avatar is from a video of Operation Upshot-Knothole.


    The post was edited 1 time, last by KrisBigK ().

  • On OC vents breaking: during cool down they are still taking in 36 heat from the reactor. They don't stop taking in heat just because the reactor is off, or it would defeat the purpose of the shutdown.