Cryonics, July 2014

How to Cryopreserve Everyone

A Big Hairy Audacious Goal for Cryonics

By Ralph Merkle

The opinions expressed herein are those of the author and do not necessarily reflect those of Alcor or its Board.


To succeed, an organization needs a vision which is at once challenging, achievable, and above all, compelling [1]. Alcor’s vision is a future in which everyone alive today can enjoy good health and a long life in a world of material abundance for all. While it has been clear for some time that advances in technology will eventually make this future a reality, the problem has always been how people alive today could bridge the decades until that future world becomes reality, and even more, how to bridge that gap economically so that more than just a handful of people might benefit.

Cryonics does the job, but the obvious problems are (1) how to reduce the long term patient care costs and (2) how to reduce the cost of the upfront procedure.


The simplest way to reduce long term patient care costs is to increase the scale of operations and to rely on the fact that surface area (and therefore thermal losses) increase as the square of the linear size, while volume increases as the cube. Larger refrigerators have lower cooling costs per unit volume. The economies of scale can be quite remarkable.

We look at an example where costs are well known: the natural gas industry, which builds 100,000+ kiloliter -162° Centigrade LNG storage tanks. Alcor could adapt this technology to provide long term patient care facilities for everyone in the world who needed our services. At this scale costs would be so low everyone could afford it. Capital costs could be tens of dollars per person, and annual operating costs could be $1 per person or less.

Large LNG storage facility Shimizu’s 250,000 kiloliter LNG
storage facility in Yokohama. The tank was completed in 2013


The second major problem is providing cryopreservation services at a cost that most people can afford. Alcor’s introduction of a simple Field Cryoprotective Perfusion (Alcor’s FCP) protocol for overseas cases suggests a way to achieve this goal.

Field Cryoprotective Perfusion (FCP) means replacing blood with cryoprotectant (by perfusion) and cooling to at least dry ice temperature in the same locality that legal death occurs rather than transporting to a dedicated cryonics facility to begin these procedures. State-of-the-art cryoprotectant perfusion and cooling to cryogenic temperatures is complex. Someday it may be possible to do procedures as complex as are currently done at Alcor in the field. However, in the meantime Alcor has developed a relatively simple FCP and dry ice cooling procedure for use at distant locations that otherwise would require freezing to dry ice temperature without cryoprotectant. This procedure, Alcor’s FCP, is a low cost method for introducing cryoprotectant into the brain which can be carried out by (1) a trained Alcor coordinator [2], (2) a health care professional (or other culturally acceptable official) trained to carry out specific surgical tasks (cannulate the carotids, separate the cephalon from the body and, if needed, cannulate the vertebrals after this separation), and (3) a third person to provide general assistance (though this person is not absolutely required). They require (4) a surgical kit including disposable supplies, (5) 10 2-liter bags of pre-mixed perfusate [3], (6) a place to work, (7) enough dry ice (a few hundred pounds) [4] to cool the cephalon and keep it cool during shipment to Alcor, (8) a neuro dry ice shipper and (9) shipping costs.

The 9 categories are shown in the table below with a rough guess at possible future costs.

Cost Category
Potential cost per use
at scale (neuro)
Potential cost per use
at scale (whole body)
Alcor Coordinator
Healthcare Professional
Surgical kit
Perfusate (10 bags)
Dry ice
Dry ice shipper

Alcor’s FCP is amenable to systematic cost reductions and quality improvements, as examination of items 1-9 above should show. Development of a field deployable temperature/pressure/flow regulator would further improve the quality of Alcor’s FCP. Economies of scale would be enormous if large numbers of cryopreservations were being performed.

Alcor’s FCP as currently implemented works best for neuro patients, for whom access to both carotid and vertebral arteries is possible. However Alcor’s FCP can also achieve cryoprotection of the brain of whole body patients if either (a) cannulation of the vertebrals is unnecessary (because the Circle of Willis is intact), or (b) cannulation of the vertebrals is necessary and cephalic isolation and separate storage of the trunk is acceptable. Cephalic isolation exposes the vertebrals, after which their cannulation is relatively easy. Cannulation of the vertebrals in a whole body patient without cephalic isolation requires a highly skilled vascular surgeon. Such surgeons are both rare and costly. An intact Circle of Willis makes cannulation of the vertebrals unnecessary, but not all patients have an intact Circle of Willis [5].

Labor costs today are higher than need be because cryopreservations are not scheduled events. Even though the patient might be terminal, heavily sedated to control pain (not always with complete success), wanting to be cryopreserved as soon as practicable, and having no other hope for survival except cryopreservation, only a few jurisdictions give the patient autonomy to take the obvious action.

Today, we are forced to carry out expensive “standbys” which, as the name implies, consist largely of highly trained people standing by, waiting for legal pronouncement of death to occur before they can apply their skills.

A world with mass use of cryopreservation is likely to be a world which accepts cryopreservation as a medical procedure, a world which would no longer force us to carry out expensive and unnecessary standbys. The combined impact of high volume and legalized advance scheduling should have an enormous impact on the labor (and other) costs involved [6].

The cost of the surgical kit on a perpatient basis would primarily be the cost of cleaning the kit for the next use and the cost of replacing the disposable supplies.

While the cost of perfusate for Alcor’s FCP is currently ~$1,500, that cost should drop substantially in large volume, both because licensing costs on a per-patient basis could be reduced, and because lower cost production methods could be developed when justified by sufficiently high volume. Note that this cost is for both neuro and whole body, as Alcor’s FCP anticipates straight freeze of the trunk. The focus is on cryopreservation of the brain.

The facility cost is little more than the cost for a room with a high ceiling [7] for a few hours. Particularly if the facility is in constant use, the actual cost per patient for the square footage actually used would be modest.

The dry ice and the dry ice shipper might not be needed if the long-term patient care facility is close enough to the surgical facility. Shipping costs will obviously vary dramatically depending on the distance to the long term patient care facility. If this is nearby, shipping costs could be quite small. In a world with mass use of cryonics, the distance is unlikely to be too great.

In the remainder of this article, we focus on how to provide low cost long term care. FCP is further reviewed elsewhere.


The annual mortality for the planet is ~55M people per year. A spherical dewar 30 meters in radius would comfortably accommodate 5.5M neuros. Building ten such dewars a year would be enough to accommodate everyone in need.

The radius is 30 meters

Assuming we use neuro (just the brain, retaining the cephalon for physical protection) and assuming that we use a spherical-close-packed arrangement with 0.3 meters (one foot) center-to-center spacing of the cephalons, then the total volume of a Really Big Dewar (RBD) will be the volume of each cephalon-containing sphere (= 4/3 π (0.15)3 ≈ 0.0141) x the number of cephalons (= 5.5M) x the packing inefficiency for the spherical-closepacked arrangement (= sqrt(18)/π ≈ 1.35) with the grand total coming to 0.0141 m3 x 5.5M x 1.35 = 1.05 x 105 m3 = a sphere of radius 29.3 meters, which we’ll round up to 30 meters [8].

While the RBD can hold 5.5M neuros, it could also be used to hold 0.55M whole body patients, or any mix of neuro and whole body patients where the number of neuros plus ten times the number of whole body patients sums to 5.5M. As the cost for long term care using this approach is quite low, many people might be willing to pay the additional cost required to maintain a whole body. The major concern would then become the cost of the cryoprotective perfusion.

It costs $11M to fill with LN2

An RBD of 30 meters radius has a volume of 113,097 m3, or ~113K cubic meters, or 113M liters. This is similar in size to many LNG facilities that have been built today. Liquid nitrogen in bulk costs ~$0.10/liter, so the total cost of filling an RBD the first time would be $11M (neglecting the cost of cooling the RBD’s insulating surface, which is designed to be insulating and therefore should not cause a substantial error in this approximate estimate).

Large LNG storage facility Shimizu’s 250,000 kiloliter LNG
storage facility in Yokohama. The tank was completed in 2013. This photo taken in Summer 2010 shows a view of the sky from about 60 meters underground; the tank has an inner diameter of 72.0 meters, and a depth of 61.7 meters

LNG tank costs Construction costs for larger tanks are smaller per unit volume. The proposed RBD is 60 meters in diameter, about the same size as many existing LNG storage tanks.

Boil off is less than a penny per patient per year

Thereafter, the cost of keeping it cool would depend on thermal losses. Thermal losses will depend on the thickness of the walls and their insulative properties.

If we use perlite, which has a conductivity of 0.00137 W/(m K) when a modest vacuum is maintained (see Wikipedia’s List of thermal conductivities), then our energy loss, assuming one meter thickness of perlite, becomes ~ (300-77)K * 4 π 302 m2 / 1 m * 0.00137 W/(m K) = 3.5 x 103 W. It takes ~3.48 x 105 Joules to boil a liter of liquid nitrogen and bring the resulting gaseous N2 to 300K [9], meaning the boil off rate of an RBD is ~ 1 liter every 100 seconds. As 1 liter costs ~$0.10 to replace, our cost for maintaining our patients is ~24*60*60*0.01*$0.10 = $86/ day, or ~$32K/year. There will be 5.5M patients, so this comes to $32K/5.5M/year per patient, or $0.006/year per patient, or less than one cent per person per year for liquid nitrogen.

If we assume a higher Boil Off Rate (BOR) of 0.05 vol%/day (achievable by modern tank designs [10]), annual costs of liquid nitrogen on a per-patient basis would be about $0.35/year. At a conservative 2% per year interest, this would require $17.50 in the Patient Care Fund to provide liquid nitrogen for the indefinite future. Additional costs (maintenance of the RBD) might reasonably triple this to ~$1/ year, requiring $50 in the Patient Care Fund to provide long term care for the patient for the indefinite future. The equivalent cost for a whole body patient would be ten times this, or $500.

We have here assumed the use of boiling liquid nitrogen, which provides a simple method of providing a very stable temperature of 77K. The great thermal mass of an RBD would allow selection of essentially any operating temperature. A temperature closer to 148K might be advantageous [11]. The use of such higher temperatures should reduce thermal losses. A closed-circuit cooling system, which cools and reliquefies evaporated gases when their temperature is only slightly above the temperature of the liquid refrigerant, might further improve efficiency. These kinds of efficiency improvements become feasible in very large scale systems.

There will be other operating costs

If we want improved insulation and reduced BOR as compared with existing tank designs, there will be some additional cost for maintaining the soft vacuum for the perlite. Presumably, the insulating perlite is divided into relatively small sections (perhaps 10 m x 10 m in size), so that if vacuum is lost in one section it does not cause problems in other sections. Perlite has the advantage that its conductivity only increases by about a factor of ten even when vacuum is lost, which will merely increase energy loss in a damaged section until it is repaired. As the total surface area is 4 π 302 m2 = 1.13 x 104 m2, one or two sections losing vacuum should not have a significant impact.

The simplest operating procedure would be to lower individual patients into a small opening in the top. Each neuro would be separately packaged to provide protection, and to achieve neutral buoyancy. The spherical close-packed arrangement is one that would be achieved spontaneously by approximately spherical objects, such as neuro patients appropriately protected, when allowed to settle, although a more systematic packing system might be desirable. Whole body patients would likely require a more systematic packing method. Maximum cost reduction would suggest the use of minimal packing mechanism in a facility sited in a highly geologically stable area and built with sufficient redundancy to ensure a high probability of survival during a conservative design lifetime. If some additional cost is acceptable, then additional mechanism can be provided to facilitate selective retrieval.

Capital costs are only tens of dollars per patient

Costs of $150M to $160M for a 138,000 m3 tanker, or $150M for a 95,000 m3 land-based facility to be finished in 2015, are typical [12,13]. A modern tank design can have a boil off rate of 0.05 vol%/day. Better insulation for this application should be feasible. The cost of perlite is not a limiting factor [14].

If tanks cost this much, the amortized capital cost per patient will be $24 to $32. Again, multiply these costs by 10 for whole body patients, giving $240 to $320 for each whole body patient. At these costs, cryopreservation would be affordable even by the very poor and could proceed on a mass scale [15].

The RBD should ideally be sited in a geologically stable location. Underground siting might be advantageous. It need not be exactly spherical, cylindrical shapes are more common in practice. The site at Yucca Mountain has been extensively studied [16]. Purchase would have to be negotiated.


Cryonics can easily scale, and could in fact scale to a size able to handle everyone on the planet. To do this, we could build Really Big Dewars (RBDs) for long-term patient care by adapting methods used to build existing LNG storage tanks. RBD’s able to hold ~5M patients each are well within the state-of-the-art. To literally handle all 55M people who die each year, we would have to build a new RBD about once a month. An RBD might cost $150M to $200M. Ongoing care costs should be small, possibly $1/year per patient.

The cost of Alcor’s Field Cryoprotective Perfusion (Alcor’s FCP) for neuro patients can drastically reduce the up-front surgical costs of cryonics. The surgical skills required can be greatly simplified as we require only (a) cannulation of the carotids, (b) cephalic isolation, and sometimes (c) cannulation of the vertebrals following cephalic isolation. The cost for supplies is limited to the cost for the surgical kit, which can be minimal, and the cost for 10 2-liter bags [17] of perfusate, which can be reduced by using bulk preparation methods. Dry ice is also not intrinsically expensive. Custom development of a low-cost field-deployable temperature-pressure-flow regulator would significantly further improve the quality of Alcor’s FCP. This custom development would likely have a high capital cost. When operated at scale, Alcor’s FCP could be substantially cost reduced.

Total one-time cost for Alcor’s FCP plus long term patient care for neuro patients can likely be driven below $1,500 if volume is high enough (many millions of patients annually). For whole body patients, total one-time cost for Alcor’s FCP plus long term patient care can likely be driven below $3,500. By comparison, Alcor currently charges $80,000 for neuro and $200,000 for whole body.

Extensive exit interview data at Alcor, gathered over decades, strongly supports the view that cost is the single biggest factor that causes existing members to end their membership. It is very likely the single biggest factor in limiting the growth rate of cryonics. Adopting procedures and protocols that can deliver good quality cryopreservation and long term care in a manner that can be substantially cost-reduced is crucial to our long-term growth and success.

These cost reductions require either high volume or substantial subsidies to reduce the per-patient costs of cryonics. Achieving them using evolutionary methods appropriate for existing or anticipated near-term patient caseloads does not appear likely.

High volume is unlikely unless some large organization decides to adopt cryonics en masse. Such an organization would likely be predisposed to technological solutions, understand the concept of exponentially growing technological capabilities, have a centralized decision making structure, and place a high value on the lives of its members.

Alternatively, a capital-intensive approach that pursued a balanced reduction in both the cost of the up-front procedure (possibly by investing in some variant of Alcor’s FCP) and the cost of long-term patient care by building a larger dewar (possibly not as large as the RBD discussed here, but large enough to provide significant economies of scale) might bring down the cost of cryonics enough to reach a larger community of potential members.


For a general discussion see “In-Gound LNG Storage Tanks” on the website of Tokyo Gas. For examples, see “The world’s largest-capacity underground storage tank for Liquefied Natural Gas is under construction” on the Shimizu Corporation website.

LNG tanks
Overview of Tokyo Gas’s in-ground LNG tanks. The 250,000 kiloliter tank can be seen as the rightmost small blue dot (the only Third Generation storage tank).

The Tokyo Gas Ohgishima LNG Terminal in the waterfront area of Yokohama supplies city gas to the Tokyo region, and consists of three underground LNG storage tanks, each with a capacity of 200,000 kiloliters. Driven by growing demand for clean and safe natural gas, plans called for a fourth tank, which has been under construction since April 2009, with Shimizu handling all design and construction activities. On completion, this will be the world’s largest-capacity underground LNG storage tank, with a storage capacity of 250,000 kiloliters. The construction project adopts a soil-covered roof in which part of the tank’s domed top will rise above the surface of the ground and be covered in soil. This method achieves considerable cost savings by keeping costly underground excavation to roughly the same depth as that required for a 200,000-kiloliter tank and by using excavated earth as banking.

In February 2011, work proceeded over four consecutive days and nights on the most challenging part of this project: concrete placement for the eight-meterthick base of the tank. Requiring a total of 39,050 cubic meters of concrete, this became the largest continuous concrete placement project ever attempted in Japan.


1. Big Hairy Audacious Goals are sometimes abbreviated BHAGs. A BHAG “is a strategic business statement similar to a vision statement which is created to focus an organization on a single medium-long term organization-wide goal which is audacious, likely to be externally questionable, but not internally regarded as impossible. The term ‘Big Hairy Audacious Goal’ was proposed by James Collins and Jerry Porras in their 1994 book entitled Built to Last: Successful Habits of Visionary Companies. A BHAG encourages companies to define visionary goals that are more strategic and emotionally compelling.”

2. The Alcor Coordinator could also take on the role of the trained health care professional and carry out the surgical procedures, depending on the circumstances.

3. The perfusate has a shelf life of several years when stored in an ordinary refrigerator. Alcor’s purchase price for the ingredients in all 10 2-liter bags of perfusate, including M22, is ~$1,500. The concentration of M22 increases by a factor of 1.67 between bags, except that the last 3 bags have the same terminal concentration. While 10 bags is sufficient to achieve the desired terminal jugular cryoprotectant concentration, 16 bags were prepared for the initial trial (the final 9 bags having the same terminal concentration) to ensure that enough bags were available to achieve terminal jugular cryoprotectant concentration.

4. Dry ice can be purchased retail for $2/kg or less. A reasonable cost per metric tonne of compressed liquid CO2 in bulk is $25 or less ( Commercial products to convert liquid CO2 to dry ice, without the need for other power or electricity, are available. When liquid CO2 is released from a pressure vessel and becomes a gas, it undergoes substantial cooling. This principle assists CO2 fire extinguishers, which both smother and cool the fire. “The DILVAC Portable Dry-Ice compact and lightweight, requires no electrical power and is safe and simple to use.... The DILVAC Portable Dry-Ice Maker produces a block (not slush!) of approximately 2.2Lbs (1KG) in weight in about 1 minute. Yield from a 75 lbs liquid cylinder - 5 to 6 blocks at room temperature.” If 75 pounds of CO2 produces 5 blocks (11 pounds) of dry ice, then CO2 at $25/tonne produces dry ice at $170/tonne. A neuro case would use <$30 worth at this price.

5. Our knowledge of the actual statistics requires further investigation. Experience in Alcor’s OR with neuro patients suggests cannulation of the vertebrals is seldom required, but the sample size is small. It is well known that a significant fraction of patients do not have an intact Circle of Willis, but we are asking a more specific question: we are perfusing both carotids, and want to know if this results in adequate flow through the Circle of Willis to the regions of the brain served by the vertebrals.

6. Even heart surgery can be dramatically reduced in cost. “In the US a heart surgery costs perhaps 20 or 30 times what it costs here [in the Narayana Hrudayalaya in Bangalore, the largest heart surgery hospital in the world]. We are able to do a complex heart surgery for $1,800 (£1,140), and we want to bring it down to $800.” “Despite the huge volume of operations, mortality rates are comparable with or better than those in Britain and the US, and costs are much lower.” “Production line heart surgery.” BBC News, Health, 2 August 2010, See also “India’s Secret to Low-Cost Health Care,” Harvard Business Review, Oct. 15, 2013, FCP is relatively simple in comparison, so it should be more amenable to cost reductions when practiced on a mass scale.

7. The high ceiling is required because gravity feed is used to provide pressure for perfusion. This method is simple, reliable, low cost, and provides very stable perfusate pressure to the cannulae from the bags of perfusate.

8. 1 liter is 0.001 m3. 1 kiloliter is 1 m3. 1 kiloliter is 1 kl. 1 liter is 1 l. 1 meter is 1 m. 1,000,000 is 1M. 1 Kelvin is 1K. 1 Watt is 1 W. 1 Joule is 1 J. 1,000 Joules is 1 kJ. 1,000,000,000 is 1B. 1 kilogram is 1 kg.

9. 199.1 kJ/kg + (300-273)K * 1.04 kJ/(kg K)) * 0.808 kg/liter = 348 kJ per liter.

10. Development of the World’s Largest Above-Ground Full Containment LNG Storage Tank, 23rd World Gas Conference, Amsterdam 2006,

11. Systems for Intermediate Temperature Storage for Fracture Reduction and Avoidance, by Brian Wowk, Cryonics, 3rd Quarter 2011,

12. “Construction costs have dropped from $280 million in 1995 (for a 138,000-cubic-meter-capacity ship) to $150 to $160 million today—still more than double the cost of a crude oil tanker. Most added costs relate to the construction of insulated tanks. LNG shipping costs vary based on the ship’s operating and amortization costs, the size of the cargo, and the distance transported.”

13. “Desfa SA, a Greek natural gas grid operator, invited international investors to bid for the design and construction of a third liquefied natural gas storage tank at its Revithoussa LNG terminal facility near Athens. The tank, expected to cost as much as 115 million euros ($150 million), will have capacity of 95,000 cubic meters and will increase the facility’s total LNG storage to 225,000 cubic meters, Athens-based Desfa said in a statement today.”

14. Total cost for 1.13 x 104 m3 of perlite (the total surface area of the RBD times its one meter thickness), at $0.20/L (a typical commercial price), would be ~$2.3M.

15. If we assume a 113,000 m3 RBD has a cost similar to the cost of the 138,000-cubic-meter-capacity ship, that is, $160M, then the capital cost per patient for an RBD will be ~$160M/138,000 * 113,000 / 5.5M = $24/patient. If we assume it has a cost similar to a 95,000 m3 $150M land facility, then the capital cost will be ~$150M/95,000 * 113,000 / 5.5M = $32/neuro patient.

16. Yucca Mountain nuclear waste repository.

17. The existing data supports the idea that 10 bags of perfusate is sufficient for a satisfactory cryoprotective perfusion. Further discussion and evaluation of the benefits of a larger volume of perfusate is likely. The exact number of bags and the volume thereof can be adjusted as further data becomes available.

18. Toward more safe and secure products: In-Ground LNG Tank.