Inside the Decommissioning of San Onofre Nuclear Power Station

today i'm down in san diego county at the san onofre nuclear power generating station this place is in the process of being decommissioned and so i'm curious to see what goes into decommissioning a site such as this and how radioactive areas of it are i mean if you're not familiar with that with the operating principles here the heat source is the reactor with the fuel in it inside the containment building um that serves as a as the heat source to supply heat hot water to the steam generators big boilers and inside the boilers you create steam right this is the secondary loop that steam is processed through a turbine spin the turbine make electricity connect it to the grid for our customers well the steam exits the turbine and exhausts to a condenser and it becomes water again okay condensate as we call it and that condensate is treated through these full flow demineralizers that take out any iron or copper or anything like that might be inside the water and then that water is returned to the steam generators through a feed water system and that's basically a closed loop it continues while we operate the plant and make electricity okay the plant would operate on a cycle of about 18 months of running continuously at 100 power then we would shut down the shut down the plant dismantle the reactor enough to remove the fuel replace the replace some of the fuel assemblies and then you know restore the reactor heat it back up again and start over and run for another 18 months or so so now how long would the refueling process take on this plant took about two months to go through the whole process and while we were refueling a reactor we'd be on this side of the plant doing maintenance on a turbine and other systems as well today i think there's probably involved on for all our operations probably about 400 people 150 something like that wow it varies day to day yeah but um so this was a pressurized water reactor this is the san onofre plant was a pressurized water reactor okay this is units two and three over there used to be unit one okay the site was we started developing this site in 1964. built unit one operated it until 1992 shut it down and then we dismantled it mostly in the early 2000s okay and it's in its place we built a dry storage facility for the storage of spent nuclear fuel so that's what exists on that location over here starting in the mid 1970s we started developing this site to construct units two and three and uh these sites were built together and came out of the ground together here and they went operational in uh 8283 8384 time frame i forget the exact dates okay and they operated until 2012. 2012 we had some issues with the new steam generators we installed here and after some consideration for about a year and a half we decided the most economical thing we could do would be to shut the plant down and move into decommissioning okay so that brought us to where we are today we started this active dismantlement work in uh 2020 after we went through a very rigorous environmental review with the state of california so that was with the state california at the nrc no the nrc we already had the approvals we needed from the nrc to start but we needed approvals from the state california coastal commission california state lands commission we needed their uh their reviews and approvals and we finally got through all of that and finished with it in 2019 and then we started the you know the real work in 2020. plants built on marine corps base camp pendleton uh edison releases this property from the navy uh for the for the purpose to operate you know nuclear plants here so you know we're in the process of dismantling the plant then restoring this site to a condition that's going to be acceptable to the navy to take the site again when we're finished here the united states government's responsibility to come take the fuel find a repository for it and then take the fuel from all nuclear plants okay and so far they've failed on their responsibility so until they they uh figure that out the fuel is kind of stranded here like it is at all commercial nuclear plants the non-rheological parts are all easy compared to everything else right uh every everything has its difficulties uh i wouldn't say the radiological side's any more difficult some different methods are employed to control contamination and so on yeah okay now what are like usually like the contaminants you have to deal with like in that environment um actually this is a very clean plant compared to some some nuclear plants but mainly cobalt 60 some cesium those would be the things from a radiological point of view that would be most concerned with controlling the contamination and that's all just from neutron activation of the metals well activation of materials you know contaminated basically metals that are that are uh you know in the plant okay so corrosion products for example this is where most of where the cobalt 60 comes from so you have wear of pumps and valves and that that wear uh has cobalt in it the cobalt gets in the in the um in the nuclear steam supply system it becomes activated that's where the cobalt's coming from so now what's this why would why would this be radiological like how they have tags on them it's really just potentially contaminated just out of abundance like this okay this is just part of the uh this is where we're standing is part of the intake structure okay so we drew when we were operating the plant we drew water in from the ocean through some long conduits that are installed offshore that water flowed in here and then went to unit 3 or unit 2 to cool the condensers and then it was discharged back to the ocean so that was basically an open loop to the ocean okay okay so that was its whole purpose was to cool the condenser now so you know the plant generated about 1150 megawatts when we were for electrical power but to create 1150 megawatts you need about 4 000 megawatts of thermal energy so it turns out that unlike all these plants most of the most of the energy ends up going to the ocean the heatsink because they're only about 30 to 33 percent efficient wow okay that was that's just that's if you had an oil-fired plant to be the same or a coal-fired plant be about the same efficiency so we no longer bring water into the plant to cool it we don't reject any heat now to the ocean all this system is isolated basically how much heat actually was it like that would come like from the plant back into the ocean like so there was a small there was a small temperature rise in the water that we deposited back in the ocean just a couple of degrees oh wow okay that's not bad at all because it was distributed through a bunch of diffusers on these conduits okay okay processing about one million gallons per minute per unit when we were operating wow a lot of water there were huge pumps that were installed here or just beyond those walls there's big circulating pumps that were used to move the water from the ocean to the condenser and then back to the ocean and this area has been removed now but in this area is where the traveling screens were to take out any debris that was in the ocean water like seaweed for example we were also entrained some fish right those fish would collect there unharmed and this elevator would lift them and sluice them back to the ocean to another conduit wow so that was continuously happening right so any fish turn to the ocean basically unharmed now also sometimes marine mammals would come in like sea lions wow they would enter the conduits way offshore take a ride down here and end up right over there oh man and it was like a smorgasbord right right so they would be consuming things like one one learned about that and they're like hey they would come back we would we would capture them yeah okay so we would get we would collect the marine mammals when they did arrive here in these cages and then take them on a truck and put them back in the ocean someplace right and sometimes they would return you know they didn't find their way back so now everything below ground is going to be back filled with concrete right not with concrete in this area we're going to fill this area with concrete because we need a good solid surface to work off of but the rest of the voids that are remaining after we complete this phase of decommissioning will be back filled with native soils from here on site so drew this is the unit 3 turbine building you can see this part of it's largely intact that's what unit 2 looked like just a few weeks ago so now these cranes what were these primarily used for to service uh the turbine generator for maintenance okay the turbine rotors and the generator itself so we would shut down for the refueling outages we would dismantle you know parts of the turbine the generator inspect and then restore it because you know we wanted it to operate reliably for like 18 months continuously these are remnants here of the unit three turbine rotors the contractor's been cutting these up into manageable pieces you see how big those components are they're huge right at one time you see all the scrap over here they were uh basically turbines right with different stages and they were like huge wheels that would spin uh when steam was admitted to them and you can just see what's remaining here of all of this steel so again all this stuff it gets gets chopped up into smaller pieces and then it's going to be sent off site to be recycled so it's just primarily steel just steel yeah carbon steel so this is what's left of uh the turbine it's been uh cut up pretty good and it is massive there's a lot of material here uh kind of a loss for words that uh how incredibly huge all this is and it's not until you like really close up to something like this you can actually understand the scope and size of a power plant like this and how much energy it produced it's very impressive the steam generator had to be reliable in its operation for it to be reliable it can't vibrate to make sure it doesn't vibrate you need a substantial foundation for that machine the bottom of the turbine building the foundation is 15 feet thick of reinforced concrete and on top of that foundation were built pedestals basically columns that rose up from that foundation to support the turbine the turbine was not supported off this steel you see here it was supported independently off of these columns or pedestals as we call them so that created the foundation so the turbine was reliable in its operation okay and it was a very well balanced machine again so it doesn't vibrate and uh operates reliably for like an 18-month run it was rotating at 1800 rpm um and it was uh generating voltage at 24 000 volts so the output of this of the turbine generator was connected here to a huge transformer and that transformer would boost that voltage up to 220 000 volts at one time there were power lines that connect connected from the switch yard here to that transformer the voltage boosted here to the grid voltage 220 000 volts is connected to the grid and then that's what was supplied to our customers of course through a distribution network that reduce the voltage down to like what you use in your house 120 volts or 220 volts like that so this switch yard today is really just an interconnect between southern california edison's transmission system and san diego gas and electrics transmission system they connect right here so that's going to remain too everything else that you see here is removed to at least three feet below where we're standing then what remains is cleaned up decontaminated to meet nrc uh license termination requirements then we're gonna backfill everything all the voids that that we created will be backfilled with native soil and then we'll stabilize this area basically back at this elevation and we'll wait for the government to do its job with the spent nuclear fuel okay to remove it from this site yeah so this is a radiation area radioactive material storage you need a radiation exposure permit to go inside you have to notify health physics before entry and you need health physics approval to remove any of this material okay so this is a typical sign that you might find for a radiation area here on site this is a barrier beyond which unless you meet these requirements you're not supposed to go beyond that that limit so you guys have different color rope that signifies different things here on site yeah this is yellow and magenta it looks like the magenta's kind of faded out on this particular rope looks a bit more purple but that's what this is yeah okay so this is supposed to be a glass wall as it cuts like where you can look at it you just can't crush it don't reach over it yeah there's definitely a increase here [Music] not a lot but yeah if you go right up to the i mean it's barely anything yeah it's like maybe [Music] almost probably eight times above background [Music] you know you're measuring count rate we usually measure miller in this one that's we're using so you know later today you can jeff will show you our meters and so on yeah it was kind of cool with this one's i could actually switch it over to mellowram and to counts and sieverts and grays and disintegrations huh what was the miller round something 50.50 yeah [Music] yeah 60 to 60 micro rim yeah so i don't have a filter on here pretty low yeah yeah but still that's like yeah really really low containment dome that is a really substantial structure it's an engineering marvel actually so it's about four feet thick it's reinforced with steel and then after it was constructed it was tensioned okay we call this a post-tensioned reactor containment building see this buttress right here with the nipple sticking off the side of it that's a termination point for for tendons that's stretched around the building there's three buttresses like this 120 degrees apart so once that building was tensioned it had the equivalent strength of about 12 feet of steel reinforced concrete substantial building so why was it so substantial because inside the building was the nuclear steam supply system that was operating at very high uh temperatures and pressures so it was a lot of energy in the reactor coolant system in a unlikely scenario where there was like a loss of cooling accident where we had a sudden break in the reactor coolant system and the water escapes would immediately turn to steam you have a huge pressure event inside the building going from around ambient up to about 60 psi so this building was designed to withstand those types of events you know you've heard of what happened at chernobyl chernobyl didn't have a building like this it was basically a tin structure okay um because they just had like a cover over the top of the reactor it was like an industrial building okay unfortunately and when when things went wrong at chernobyl um it didn't have a structure like this to protect the environment from the consequences of what's happening inside so here we have a substantial building lots of concrete able to withstand the event and it provides a lot of shielding too okay so you're asking why do we have that that place where we obviously made an opening back in 2009 and 10 we replaced the steam generators in units 2 and units 3. okay the steam generators are big components they weigh about 550 tons it was too big to fit through the equipment hatch which was just below this area so to to support the process of replacing the old steam generators with new ones we had to make this opening so to make the opening we had to detention the building remove the tendons make the opening replace the steam generators then form this up replace the rebar place the concrete let it cure and then we could retention the building so that's why you see that scar if you will up there so how long did that whole process that took about 100 days per unit wow okay with a very large force of people working here and a very super detailed schedule of many thousands of activities that had to be very carefully coordinated it was quite a big project that's why when we had the problem with these new steam generators they're they're custom made components they've got about a five-year lead time and then you have to go through a replacement proce process like this it became uneconomical for us to consider to you know keep the plant here and wait for new ones to show up to replace them so that's why we decided to shut the plan i'm curious though because like that that was like right around the same time as like because what fukushima was in 2011 yeah and so i was always kind of curious i'm like was there like just a ton of pressure from the community from the local government from all this other stuff also so like southern california edison was just like you know what fine we'll listen to you guys as you guys are crying over this so much we're just gonna give you what you want uh no not really okay um what what what really transpired here was yes but when we had the problems with the steam generators that occurred in 2012 and as we investigated and understood better what had happened uh yes there was members of the public here that didn't want the plant to continue to operate but they never wanted it here in the first place some people didn't but there were other people that were either ambivalent about it or were supportive so you had a whole range of opinions but there were people here that didn't want it that's absolutely true um but you know from a technical perspective we felt that we could have restarted the plant and operated at a lower power level and continued to operate but that that uh convincing the regulator that we were able to do that became very hard and uncertain so we finally just said it's better just to move on and that's that's what we did yeah i was just always was curious about that because it was like such an interesting time period right there for nuclear energy because everyone was like germany was shutting down so many other plants and all this stuff and then this happened and i was just like well how much of this has to do with that so yeah it has to do with fast forward to the day and it's a different different thought process exactly earlier today yeah especially in western europe right now where there's a huge energy crunch right imagine if those nuclear plants were still available and operating today what would be the you know what would be the political uh issues around what's going on in europe today you know when you make these decisions you don't know what the future holds either so so now how are they going to uh take down these vessels because as i was understanding they were going to do it from the bottom up correct so how does that work yeah that's because that sounds engineeringly challenging well imagine what it would take if you try to do it from the top down the true okay it'd be pretty hard to do and we had to manage all that material if you do it from the bottom you basically just hammer at the building from the outside with those big excavators and from the inside too until you weaken this structure to a point where it just basically collapses okay so uh just weaken a structure and lifts of like six to eight feet or so give or take the building building settles muck out all the concrete and rebar dispose of it and do it again you do it over and over and over again and eventually the building is gone it's pretty cool actually now how long would that take how long is that process slated to take i don't remember precisely but it's in the neighborhood of about nine nine months to a year to remove the building wow [Music] [Music] this level of around 800 counts per minute is about 20 times above background radiation and the type of radiation that i'm more than likely detecting is from gamma radiation based off the type of contamination that's here on the site but now to put things into perspective let's go to another location this is the adamson house in malibu california not too far away from san onofre i'm actually getting a higher level of radiation here at this fountain than what i was at san onofre and that's because these tiles actually contain uranium in the glazes which make them radioactive granted the type of radiation that is coming off of these tiles is mainly beta radiation whereas the type of radiation i was detecting in san onofre was gamma radiation this building here this is the uh fuel handling building for unit three so this is a truck bay this area when new fuel arrived on site it would come on a flatbed and specialized containers okay and then they would be uh the containers would be lifted here through this small hatch that hatched there into the fuel handling building fuel assemblies would be inspected and then placed in the fuel pool okay and then those new fuel assemblies would be used in the reactor and they would be used maybe three times for three cycles so you know assume three 18-month cycles wow typically two to three and then they just kind of rotate them where they are they would move them around they would change the core configuration every refueling outage replenish it with some new fuel and discharge the old fuel that was used up okay so then there's a refueling pool here on that side right i just mentioned it um the uh the pool the top of that deck for the pool is about the 63 foot elevation again 33 feet above us it's full of water demineralized water that kept the fuel cool while it was there so that water was circulated through heat exchangers when we were operating through heat exchangers and the heat was eventually discharged to the ocean the heat not the water yeah okay after we shut down the plant we they're not here anymore but we installed some uh basically air conditioning units big refrigeration units that were here and we used those to cool the pool water until we could get all the fuel out okay and in the dry storage okay so that's that's what this building was used for housing new fuel and uh used fuel and then what we call spent fuel and then eventually today they're empty of the fuel we all slept in there now is water that hatch is where the canisters of spent nuclear fuel the dry storage canisters they would be filled under water in this building they'll be taken out of the pool the water will be discharged from the canister the canister will be dried a lid like this about nine inches thick would be welded on the top of it then the canister would be handled through this hatch onto a waiting transporter here and then hauled over to the dry storage facility where it will be placed inside of a vault we call this a restricted area okay but it doesn't have any nuclear security attributes to it today that's because all the spent nuclear fuel has been removed okay and after it was removed we reduced this area to what we call a restricted area before then when we had fuel here it was called a protected area and the ability to get in here was very very restricted and controlled and the perimeter of this entire site from the sea wall around here to the north side there was guarded by this fence and this fence was an active fence if you approach the fence it would alarm and there's camera systems no longer in use but you'll see cameras all over the place here that were monitored uh looking for you know any potential intruders that would be trying to get into the plant so the plant was very well guarded from a nuclear safety point of view when we were operating and why we had spent nuclear fuel here today the only protected area that remains for the plant is around the espacie so when or dry storage facilities you know if you want to take a radiation measurement oh yeah i'd love to hear i hear something else it sounds like a ludlum in here oh there it is right there i noticed that chirp at all yeah that's that's background yeah yeah now if you were able to get past this you can see inside we've actually removed some of the internal bioshield walls already and even even though those really thick structures are removed you're not seeing any appreciable change in radiation out here [Music] since this video is getting a little long i'm going to split this trip into two parts the second half is going to be dealing with the radiological controlled area or the rca where we get scanned a couple times along with our camera gear before entering and exiting it's like the beginning of the running man and in this area we get to see the spent fuel cool and then we get to take a trip out to sea where the spent fuel now resides so if you enjoyed this video like it subscribe and i'll see you in the next one

Channel: Radioactive Drew

Views: 253,804

Keywords: uranium, radiation, radioactive, Radioactive Drew, radioactivedrew, nuclear, nuclear power, decommissioning, SONGS, San Onofre, San Onofre Nuclear, spent nuclear fuel, nuclear fuel storage, dry storage, Southern California, Edison, Southern California Edison, radiation zone, contamination, Chernobyl, Fukushima

Id: fQgJkzs63oo

Length: 27min 42sec (1662 seconds)

Published: Sat Jun 25 2022

Reddit Comments

[u/WithDisGuy]

Everywhere I look, something reminds me of her

[u/Tmbaladdin]

If only SCE had properly maintained it… we desperately need more nuclear power to offset the nightly drop from solar/wind

[u/SSADNGM]

Inside the $5 billion demolition of the shuttered San Onofre nuclear plant