Yes, the pressure safety relief system on LH2 tanks is sized for the loss of vacuum condition. The spring-loaded safety valves are sized for lower demand cases such as runaway pressure build or loss of vacuum. Higher demand requirements, such as loss of vacuum combined with fire, are handled by the rupture discs and are sized for such an event.

It is common to have combustible materials and fuels in a building during construction activities. Commissioning is typically considered part of construction. It is good to see that fire suppression is available. However, given the lack of alarm capabilities, it would seem prudent to have a fire watch posted when hazardous materials are present or being used. Regarding requirements, the International Building Code (Chapter 33) and the International Fire Code are the primary applicable codes. NFPA 241 also provides guidance but may not be required by the local jurisdiction. It may also be beneficial to contact the contractor’s or owner’s insurance company to see if they have any specific requirements as a result of the increased risk. 

In particular and with regard to hydrogen, it is unusual that H2 would be needed for construction activity in the same way that other gases such as propane, natural gas, or acetylene might be used for welding, brazing, or cutting.  When bringing H2 into a building for commissioning activity, the building and fire codes should be followed with respect to maximum allowable quantities (MAQ), control areas, and ventilation. Consult with the local authority having jurisdiction for specific requirements from the model fire code and associated codes for the hazardous materials and processes planned for the premises. Occupancy certificates are typically issued by the AHJ upon final inspection and approval by several code Officers such as building, electrical plumbing, Fire etc. Typically all life safety systems required by codes must be functional regardless if the premises is occupied or not.

In addition to ANSI/CSA FC1-2014, search for fuel cells in the Hydrogen Fuel Cell Codes & Standards
or H2Tools Bibliography sections.

The British Standards Institute (BSI) has published BS ISO 22734:2019, a British nationalized version of the packaged water electrolyzer safety certification standard. This standard can be used by a Notified Body (BSI is one of many operating in the UK and in Europe) to certify electrolyzer safety to established norms for this equipment. This standard addresses safety of containerized hydrogen generators using low temperature water electrolysis technologies PEM and KOH. It includes requirements to assess hazardous area classification using IEC 60079-10 and to employ methods to mitigate hazardous areas using air dilution and/or equipment designed for hazardous areas per the ISO 60079 series in accordance with the ATEX directive. The standard provides requirements for on-board GH2 storage.

This can be a complex problem and response to insulation failure should be considered in the emergency response guidelines and procedures. 
First, a tank with an insulation failure may boil off at an elevated rate which applicable codes build into the relief device and vent system design.
Second, ice and oxygen enriched liquefied air can form where inadequately insulated surfaces are exposed to air. Ice is the most likely symptom of insulation failure, and this can lead to various issues such as higher probability of seal leaks, additional weight loads on piping, and frost heaving of the foundation. Loss of vacuum insulation rarely leads to creation of liquified air, but as a precaution, any material that could be exposed to liquid air must be compatible for both oxygen and cryogenic hazards. For example, flammable materials such as asphalt are not permitted below LH2 systems. 

Example safety guidelines are listed below but may not be all-inclusive (e.g., they do not cover general practices such as lockout/tagout, management of change, job safety analysis), and most are the same as for gaseous hydrogen. Also reference NFPA 2 and CGA documents such as H-3, H-5, and H-7. Additional safety training material can also be found on the following link to courses and information offered by the AIChE Center for Hydrogen Safety.

Fundamental Hydrogen Safety Credential

1. Wear proper personal protective clothing (fire-resistant clothing, safety shoes, hard hat, safety glasses). Due to potential cold injury, insulated gloves and a full-face shield are also recommended when handling liquid hydrogen.
2. Carry an operating personal flammable gas monitor. 
3. Purge piping of hydrogen when opening to the atmosphere and purge the air from the piping after completing maintenance. Purge gases, warm or cold, should always be an inert, non-flammable gas.
4. Purge with helium gas for cold liquid piping or vessels at or below the freezing temperature of nitrogen (~-320 F). It is recommended that helium be used for any temperatures below -250 F. All purge gases except helium will solidify at LH2 temperatures. Vacuum-jacketed pipe can remain cold for days since they are insulated to minimize heat transfer. LH2 tanks can remain cold for a week or more and may contain residual LH2 that is difficult to drain.
5. Pressure test/leak test before introducing hydrogen back into the piping or vessel.
6. Check the operation of all safety instrumentation at startup and at least annually thereafter.
7.  Check vent stacks for condensate by opening the drain valves (preferably spring-return automatic closing valve).
8. Check the vent stack supports with emphasis on damage, corrosion, or loosening of supports (e.g., guy wire).
9. If the LH2 tank supports are greater than 18  ”, they must be fireproofed (per NFPA 2). Improperly sealed fireproofing can lead to corrosion that is difficult to find. Check the sealing of the fireproofing and check for corrosion on the steel underneath.
10. Liquid hydrogen may create liquefied air on the exterior of uninsulated process and vent piping. Personnel must take care to avoid contact with cold piping and liquefied air due to potential for cryogenic burns. The liquefied air should also not be allowed to contact flammable materials since it will be oxygen-enriched.
11. Keep hot work at least 50 ft from the hydrogen system. Use a job safety analysis and hot work permit system if the work must be closer to assure safety is addressed by developing safe procedures and processes.
     

The primary safety standards for applicable to this piping in the U.S. are ASME B31.3, B31.12, and NFPA 2. The editions used should be those adopted by the local jurisdiction. Design of an LH2 piping system should always be conducted and reviewed by engineers experienced in cryogenic piping design. The equipment should also be installed per NFPA 2 and NFPA 55. IT is recommended that the piping be inspected at least once per quarter. The inspection should look for corrosion, exterior damage, frayed flexible sections, proper support, and for evidence of water condensation or ice on the outer piping Ice and water condensation is indicative of vacuum degradation. The outer jacket relief device should also be inspected to ensure it is in good condition and available to operate when needed.