OSHA Inspection: CALPINE CORPORATION

Issued

Oct 29, 2025

Abate by

Dec 17, 2025

Penalty

Initial $16,550 · Current $16,550

General-duty citation text

OSH ACT of 1970 Section (5)(a)(1): The employer did not furnish employment and a place of employment which were free from recognized hazards that were causing or likely to cause death or serious physical harm to employees in that employees were exposed to vacuum-induced differential pressure forces during manway opening:  a) Heat Recovery Steam Generator (HRSG) Structure, Level 8 Drum Deck - On or about April 29, 2025, and at times prior thereto, at the Calpine Hay Road Energy Center combined cycle facility, the employer failed to protect employees performing maintenance from a sudden vacuum-induced differential pressure forces during manway removal, in that employees were directed to remove the securing bolts and lugs on an inward-swinging manway door to the LP drum of HRSG Unit 6 without confirming that internal and external pressures were equalized. The DCS (Distributed Control System) pressure display at the control panel indicated practically 0 psig, which operators incorrectly interpreted as atmospheric pressure. However, this reading did not account for internal vacuum conditions within the drum. The actual pressure remained below atmospheric, and no local mechanical gauge or vent verification step was used to confirm pressure equalization. The drum vent valve was found closed. In addition, no vacuum-relief device or pressure-equalizing valve, as described in ASME Section VIII (UG-28 and UG-35), API 510 Section 6.5.2, and NBIC Part 2, Section 4.4.3, which require vessels subject to internal or external pressure to be protected against vacuum collapse and to be safely vented to atmosphere prior to opening was provided. As the drum cooled, a residual vacuum developed inside the vessel. When the final bolts were removed, the resulting pressure differential caused a violent inrush of air that pulled the heavy manway door inward, drawing the operator toward the vessel opening. The operator sustained catastrophic blunt-force trauma to the head and torso as a direct result of the suction-force impact.

Issued

Oct 29, 2025

Abate by

Nov 25, 2025

Penalty

Initial $16,550 · Current $16,550

General-duty citation text

29 CFR  1910.269(a)(2)(i)(A): Each employee was not trained in, and familiar with, the safety-related work practices, safety procedures, and other safety requirements in this section that pertain to his or her job assignments:  (a) Heat Recovery Steam Generator (HRSG) - On or about April 29, 2025, and at times prior thereto, at the Calpine Hay Road combined cycle facility, the employer did not ensure that employees assigned to perform maintenance on the low-pressure (LP) drum of HRSG Unit 6 were adequately trained and familiar with safety-related work practices required for the safe opening of inward-swinging manway doors on pressure vessels that may retain vacuum or residual pressure after shutdown. Operators had not been trained to recognize that a drained HRSG drum can develop a vacuum during cool-down, nor in the specific methods to verify and equalize pressure using vent valves before removing bolts and strongbacks. They were not instructed on staged bolt removal, stand-clear procedures, or the requirement to verify zero energy by both instrument and physical venting prior to breaking the seal. As a result, employees worked on a vessel that was not verified at atmospheric pressure, and an operator was fatally struck when the manway door was violently drawn inward by vacuum suction.

Issued

Oct 29, 2025

Abate by

Nov 25, 2025

Penalty

Initial $16,550 · Current $16,550

General-duty citation text

29 CFR  1910.269(c)(2): The job briefing did not cover at least the following subjects:  hazards associated with the job, work procedures involved, special precautions, energy-source controls, and personal protective equipment requirements:   (a) Heat Recovery Steam Generator (HRSG) - On or about April 29, 2025, and at times prior thereto, at the Hay Road combined cycle facility, the job briefing preceding work on the HRSG Unit 6 LP drum failed to address critical hazards and procedures associated with opening a drum manway under vacuum. The briefing did not identify the potential for vacuum formation during draining and cool-down, did not review steps to verify zero energy through vent valves, did not specify stand-clear precautions during lug or bolt removal, and did not discuss atmospheric equalization or temperature hazards. The job briefing also omitted discussion of required PPE for potential impact hazards, nor did it specify the method for communicating isolation or confirming vent status with the control room. These omissions left employees unaware of stored mechanical energy hazards and contributed to the fatal incident when the inward-swinging hatch was pulled open by suction.

Issued

Oct 29, 2025

Abate by

Dec 17, 2025

Penalty

Initial $16,550 · Current $16,550

General-duty citation text

29 CFR  1910.269(d)(2)(iv)(D): The procedure did not clearly and specifically outline specific requirements for testing a machine or equipment to determine and verify the effectiveness of lockout devices, tagout devices, and other energy control measures:  (a) Heat Recovery Steam Generator (HRSG) - On or about April 29, 2025, and at times prior thereto, at the Hay Road combined cycle facility, the employer's HRSG lockout/tagout and hydrostatic-test procedure did not clearly and specifically outline how employees must test and verify the effectiveness of energy-control measures before opening HRSG drums. The written procedure failed to include explicit steps to identify and open designated vent valves, confirm atmospheric equalization using independent gauges, record and communicate verification results to the control room, and require a stand-clear position during final fastener removal. In the absence of clear procedural direction, operators relied on a DCS screen reading '0 psig' and opened the manway without confirming zero pressure, resulting in a fatal vacuum-suction event.

Issued

Oct 29, 2025

Abate by

Dec 17, 2025

Penalty

Initial $16,550 · Current $16,550

General-duty citation text

29 CFR  1910.269(d)(2)(v): The employer did not conduct a periodic inspection of the energy control procedure at least annually to ensure that the procedure and the provisions of paragraph (d) of this section were being followed:   (a) Heat Recovery Steam Generator (HRSG) - On or about April 29, 2025, and at times prior thereto, the employer failed to perform and document the required annual inspection of HRSG-specific lockout/tagout procedures. The energy-control inspections conducted did not include HRSG drum isolation steps. As a result, long-standing deficiencies, such as missing vent identification, lack of step-by-step pressure verification, and absence of vacuum-relief instructions, were never identified or corrected. The failure to inspect and update these procedures annually allowed employees to perform drum-opening operations without confirmed zero-energy verification, exposing them to lethal vacuum and impact hazards.

Issued

Oct 29, 2025

Abate by

Dec 17, 2025

Penalty

Initial $16,550 · Current $16,550

General-duty citation text

29 CFR  1910.269(d)(6)(i): Before an authorized or affected employee turns off a machine or equipment, the authorized employee shall have knowledge of the type and magnitude of the energy, the hazards of the energy to be controlled, and the method or means to control the energy:  (a) Heat Recovery Steam Generator (HRSG) - On or about April 29, 2025, and at times prior thereto, at the Hay Road combined cycle facility, the employer did not ensure that authorized and affected employees understood the type and magnitude of hazardous energy present in the HRSG low-pressure drum, nor the method to control it before opening the manway. Operators were unaware that the energy source included both positive and negative pressure differentials, specifically, vacuum suction that can form during cool-down. They did not know that the potential energy from a pressure differential could cause an inrush of air strong enough to violently pull the door inward and strike a worker. The method to control this energy, opening vent valves and verifying equalized pressure, was not taught or reinforced. As a result, an employee was fatally struck when the inward-swinging manway door was drawn inward by vacuum.

Issued

Oct 29, 2025

Abate by

Dec 17, 2025

Penalty

Initial $16,550 · Current $16,550

General-duty citation text

29 CFR  1910.269(d)(6)(vi): The employer did not ensure that verification of isolation was continued where there was a possibility of re-accumulation of stored energy to a hazardous level:  (a) Heat Recovery Steam Generator (HRSG) - On or about April 29, 2025, and at times prior thereto, at the Hay Road combined cycle facility, the employer failed to ensure continued verification where stored energy could reaccumulate during HRSG cool-down. Although the corporate LOTO Standard required 'Operational Verifiers' to confirm energy dissipation, this process was not applied to HRSG drum work. The LP drum was drained but left closed, allowing vacuum to rebuild as steam condensed. An employee was fatally injured as the residual vacuum instantly drew air inward, pulling the hatch open and this employee toward the drum opening.

Issued

Oct 29, 2025

Abate by

Dec 17, 2025

Penalty

Initial $16,550 · Current $16,550

General-duty citation text

29 CFR 1910.269(e)(4): Before removing the entrance cover to the enclosed space, the employer did not determine whether it was safe to do by checking for the presence of atmospheric pressure or temperature differences, and did not evaluate whether a hazardous atmosphere might exist in the space. Conditions that made it unsafe to remove the cover were not identified or eliminated before the cover was removed:  (a) Heat Recovery Steam Generator (HRSG) - On or about April 29, 2025, and at times prior thereto, at the Hay Road combined cycle facility, before removing the manway cover of HRSG Unit 6's low-pressure drum, the employer did not determine whether it was safe to do so. Employees did not check for the presence of vacuum (below-atmospheric pressure) or temperature differentials within the vessel, nor did they evaluate whether a hazardous atmosphere or negative pressure existed. Conditions that made it unsafe-specifically, residual vacuum and elevated temperature inside the drum-were not identified or eliminated before the manway bolts were removed. When the final dogs were released, the pressure differential caused the manway door to swing violently inward, fatally striking the operator standing at the opening.