# Presentation: 012951

##  Over-Pressure Events at the Idaho National Engineering and Environmental Laboratory

***James Wolski***
***Department of Energy - Idaho Operations Office***

*May 13, 2003*

## Idaho National Engineering and  Environmental Laboratory Site

-       	Glass flask rupture due to failed pressure regulator gauge
-       	Airline rupture during dosimetry badge check
-       	Rupture of laboratory gas drying units
-       	Personnel injury resulting from failed high-pressure fitting

## GLASS FLASK RUPTURES DUE TO FAILED PRESSURE REGULATOR GAUGE

## GLASS FLASK RUPTURES DUE TO FAILED PRESSURE REGULATOR GAUGE

***Background***
- Event occurred at the Idaho Nuclear Technology and Engineering Center (INTEC)
- The activity in progress was to conduct a bubble leak test on a portable sample station
- The function of the sample station was to sample and purge underground spent nuclear fuel storage vaults
- The glass flask shattered sending shards over roughly a ten foot radius

## GLASS FLASK RUPTURES DUE TO FAILED PRESSURE REGULATOR GAUGE

- The sample station structural capability pressure had never been determined
- Bubble leak test was to be performed at 12 psi
- Rubber stopper on top of the glass flask came out during the test.  Zip ties were used to hold the rubber stopper, but did not hold.  A hose clamp was used to hold the rubber stopper
- An unusual whistling sound was noted coming out of the HEPA filter, but the test continued
- The glass flask shattered very shortly after passing the bubble leak test

## GLASS FLASK RUPTURES DUE TO FAILED PRESSURE REGULATOR GAUGE

- After the flask shattered, the system was modified to install a calibrated pressure indicator.
- The regulator was used to pressurize the system.  The regulator pressure gauge read 12 psi; the calibrated gauge read 28 psi.
- The pressure regulator pressure gauge was tested.  The gauge read 10 psi with the test system pressure reading up to 100 psi.
- Use of the glass flask in a pressurized system was not recommended by the flask manufacture.

## GLASS FLASK RUPTURES DUE TO FAILED PRESSURE REGULATOR GAUGE

***      *No pressure relief protection was provided.
-       No calibrated pressure indicator gauge was installed during the bubble leak testing.
-       No maintenance inspection criteria or pre-operational check was provided for compressed gas regulators
-       Company polices and procedures did not adequately implement appropriate compressed gas standards
* *

## GLASS FLASK RUPTURES DUE TO FAILED PRESSURE REGULATOR GAUGE

- Problems that contributed to the glass flask rupture
-       Personnel directing and performing work did not follow   approved work control process
-       Workers failed to stop work when activities went beyond scope of work request
-       Workers continued to troubleshoot the cause and did not preserve the scene
-       The nitrogen regulator was tested and found to be defective causing over pressurization of the sample station
-       Calibrated gauge was not used to ensure correct system pressure was achieved

- AIR LINE RUPTURE DURING** **
- DOSIMETRY BADGE CHECK

## AIR LINE RUPTURE DURING DOSIMETRY BADGE CHECK 

**Background**
* *
***      *Radiological and Environmental Laboratory at Central Facilities Area
-       Air Operated Thermoluminescent Dosimeter Badge opening device
-       System is operated with nitrogen pressure at 85 psig
-       The pressurized tubing expanded and broke at normal operating pressure.  One employee was treated for noise exposure

## AIR LINE RUPTURE DURING DOSIMETRY BADGE CHECK

-       Badge opening station was relocated
-        Modifications were needed to the existing airline system
-        An under rated piece of 1⁄4-inch tygon tubing was used, the 	tygon tubing was rated for 60 pounds per square inch
-        The piece of tubing was selected based on the available 	length, rather than evaluating the pressure specifications of 	the tubing
-        A formal stop work was put in place pending a review of the incident

## AIR LINE RUPTURE DURING DOSIMETRY BADGE CHECK

- Problems that contributed to the air line rupture
-        There was no configuration management system      in place for this system
-       The employee did not use known pressure specifications to select the tubing used for the badge opening station
-       The piece of tubing was selected based on available length, rather than evaluating the pressure specifications of the tubing

- RUPTURE OF LABORATORY GAS

## RUPTURE OF LABORATORY GAS DRYING UNITS

-        The INEEL Research Center (IRC) is an R & D Laboratory Facility for the Idaho National Engineering and Environmental Laboratory
-        A researcher was switching an experiment in the laboratory from nitrogen to compressed air
-        A system was established that used a new gas cylinder, a new pressure regulator and existing laboratory gas drying units
-        After pressure was applied to the system, the drying units ruptured
-         Fragments, contents and parts from the drying units scattered throughout the laboratory. Three workers were injured

## RUPTURE OF LABORATORY GAS DRYING UNITS

-       The system manual required a two-stage medium duty regulator, with a designed delivery range of 4-80 psig
-       The laboratory gas dryer units had a maximum working pressure of 90 psig
-       The researcher selected a regulator that he believed was appropriate for the application from a regulator storage drawer
-       He thought he had a two-stage regulator with a 0-300 psig delivery pressure gauge

## RUPTURE OF LABORATORY GAS DRYING UNITS

- He actually had a 0-300 bar or 0-4000 psi single stage regulator with a designed delivery range of 50-2500 psig, at high flow rates
- The cylinder valve was opened and there was no supply pressure gauge indication
- The regulator T-handle was loosened and removed, later reinserted until some resistance was felt
-      The cylinder valve was opened, the system pressurized and the drying units ruptured* *

## RUPTURE OF LABORATORY GAS DRYING UNITS

*	*Problems that resulted in the rupture of the drying units
-       Improper regulator with defective supply pressure gauge was selected for the work to be performed
-       Inappropriate adjustment of the regulator left at an unknown preset delivery pressure
-       Compressed gas training courses did not contain sufficient information on hazards, lessons learned, relief valves, selection of regulators, maximum operating pressure and burst pressure
-       The researcher was not familiar with the vendor manual or the appropriate procedure

## PERSONNEL INJURY RESULTING  FROM FAILED  HIGH PRESSURE FITTING 

## Personnel Injury Resulting From Failed High Pressure Fitting

- An In Situ Grouting Treatability study was in progress at the Cold Test Pit South of the Radioactive Waste Management Complex (RWMC).  The work was in a pit with buried simulated waste material.
- Activities taking place involved drilling and grouting of a series of holes in the Cold Test Pit.
- A Worker was struck in the right temple area by metal from a ruptured high-pressure fitting.  There was a Type B accident investigation

## Personnel Injury Resulting From Failed High Pressure Fitting

- The high pressure pumping station consists of a positive displacement pump that was powered by a diesel engine through a gearbox and clutch.
- The pumping station experienced problems with plugging.
- A manual pressure relief on the pump was used to relieve pressure after the pump was secured.
- The pump included an automatic pressure safety shutdown.  The recommended setpoint was 290-435 psi above operating pressure.  The safety shutdown was set at 8700 psi.
- No overpressure prevention device was provided downstream of the pump.* *

## Personnel Injury Resulting From Failed High Pressure Fitting

-     The 45o swivel elbow that was replaced in the high-pressure grout line was designed in accordance with the SAE-J514 standard with a working pressure rating of 2500 psi
-      Normal system pressure was about 6000 psi
-      While using the grouting system, pressure was raised to establish flow.  A fitting connecting the high pressure pump to a pressure/flow sensor failed, striking a subcontractor worker
-     The subcontractor did not communicate similar high-pressure failure of this system to M&O contractor.

## Personnel Injury Resulting From Failed High Pressure Fitting

-     Subcontractor process for the high-pressure grout system was inadequate.  Parts were purchased and installed that did not meet system design.
-      M&O contractor oversight of operations, maintenance and configuration management was inadequate.
-      Subcontractor did not follow and M&O contractor did not adequately enforce the subcontract requirements.
-      DOE oversight of the project was inadequate

- Path forward
- INEEL Pressure Systems Task Team was established
- Developed a checklist for compressed gas assemblies to identify safety vulnerabilities
- Evaluated applicable systems, identified deficiencies, corrected deficiencies or took systems out of service
- Reviewed regulatory requirements, performed gap analysis
- Reviewed human performance contributing causes and error precursors
- Team proposed corrective actions, plan for site-wide implementation of immediate corrective actions until corrective actions are implemented