RNPP Unit-1 safety valve problem resolved

The safety valve problem at Rooppur Nuclear Power Plant’s Unit-1 was resolved, with the valve successfully tested at 16 MPa, officials said.

Dr Zayedul Hasan, managing director of the Nuclear Power Plant Company Bangladesh Limited (NPCBL), confirmed late Wednesday night that the Pressure Operated Relief Valve (PORV/POSV) problem had been resolved and the test was successfully completed.

He said the test, which began the previous night, was conducted from both the Main Control Room (MCR) and the Emergency Control Room (ECR). During the test, the performance of the control valves was checked. After their operation was found satisfactory, the functioning and response of the relevant Main Safety Valve (MSV) were also tested.

The valve’s response, opening and closing operations, alarms and various related process parameters were closely monitored during the test.

Dr Zayedul Hasan said the test was conducted in strict compliance with approved procedures and all necessary safety requirements.

Before and during the test, communication systems, fire safety, radiation protection and other relevant safety measures were verified, he said.

He said the successful completion of the PORV test was an important milestone in the commissioning process of the nuclear power plant, as the system is directly associated with maintaining safe pressure in the reactor’s primary system.

Emphasising that safety is being given the highest priority during commissioning, he said every test is being conducted only after ensuring the necessary preparations, approvals, briefings and safety conditions. “There will be no compromise on safety in order to maintain the scheduled timeline,” he said. In the next phase, another test is expected to be conducted at a pressure of around 18 MPa.

The commissioning team is proceeding step by step, carefully verifying each stage before moving on to the next.
Earlier, the start of electricity supply from Rooppur Unit-1 to the national grid had become uncertain due to a fault in the safety valve.
Repeated problems with the PORV installed in the reactor’s pressuriser had caused the complication. The valve is an important safety component that helps control excessive pressure in the primary cooling system.
Officials had earlier said that JSC ASE, the Russian nuclear engineering contractor responsible for the project, had proposed transferring a pilot-operated relief valve (PORV) from Unit-2 to Unit-1 to facilitate the startup of Unit-1.
At a press conference held at the ICT Tower in Agargaon, Dhaka, on September 3, Science and Technology Minister Faqir Mahbub Anam said the schedule for supplying electricity from Unit-1 to the national grid was being delayed due to the safety valve problem.
At that time, no specific timeline had been announced for resolving the fault or starting power generation.
Later, following discussions with Russia to resolve the problem, a five-member Russian expert team arrived at Rooppur on September 22.
According to the NPCBL managing director, the PORV problem was resolved and subsequent testing was completed through joint efforts by Bangladeshi and Russian experts.
The original estimated cost of the Rooppur Nuclear Power Plant project was around Tk 113,100 crore. Under the revised estimate, the cost has increased to approximately Tk 138,700 crore.
Being constructed under a government-to-government (G2G) arrangement with Russia, the Rooppur Nuclear Power Plant is regarded as a major source of low-carbon electricity for Bangladesh’s power system.
The resolution of the PORV problem and successful completion of the test mark progress in the commissioning of the plant.