The Swedish Radiation Safety Authority has asked nuclear waste contractors at the Oskarshamn nuclear plant to review their security requirements after cracks were found in the pools where nuclear waste is stored on site.
The nuclear plant at Oskarshamn is one of three active nuclear power stations in Sweden, and is also the home of CLAB (Centralt mellanlager för använt kärnbränsle – Swedish for Central Interim Storage Facility for Spent Nuclear Fuel’), the temporary storage facility for spent nuclear fuel from all Swedish reactors.
In the storage facility, spent nuclear fuel is stored in deep water pools, 30 kilometers beneath the ground under 8 feet of water. CLAB was originally designed to store 5,000 tons of spent nuclear fuel, but the plant was expanded in the 2000s and today has a capacity totaling 8,000 tons, and currently holds over 5,000 tons of spent nuclear fuel. Each Swedish nuclear reactor produces between 15 and 25 tons per year, and the CLAB facility receives approximately 300 tons per year.
The calls for review of security measures were placed after cement walls were found to be cracked in two of ten waste pools at the CLAB storage facility, which is run by the Swedish Nuclear Fuel and Waste Management Company.
The utility submitted an action plan in September 2012. But the Safety Authority requires that the safety report is updated. Cracks were discovered in the concrete in CLAB’s oldest storage pool several years ago.
The Safety Authority does not share the utilities opinion that the current status of the storage pools meets the requirements of the safety report, but so far has not made any assessment themselves of how the cracks may affect the security of the storage facility.
“We see no immediate risk of leakage. But we want to know how the system is affected in the long term. Today we have too little knowledge of the area. Therefore, we require that SKB makes further analysis,” said Elizabeth High, one of the inspectors handling the case. She added that the cracks may have been there since the facility was constructed.
The utility must now look into whether the pools still live up to safety requirements and report back to the Radiation Safety Authority. The main aim of the review is to make sure no water nor gas can leak out, the statement noted.
It is the second time in less than a week that the Radiation Safety Authority has enforced actions against the Oskarshamn nuclear plant.
On December 6th, 2012, it ordered the temporary closure of one of the three reactors onsite. “We decided that Oskarshamn nuclear power plant (OKG) should take nuclear reactor O2 offline immediately,” the Radiation Safety Authority said in a statement.
“One of the diesel generators was not serviced as planned in 2011. That now has to be done,” Leif Karlsson, head of section at the authority said. “The other generator needs to go through at least a 48-hour durability test.”
“The power supply to the reactors is extremely important. This was one of the main problems at Fukushima,” safety inspection chief Leif Karlsson told the TT new agency.
“If you don’t have this system running, you cannot add water to the reactor.”
Source: The Local
Source: Sveriges Radio
Source: SvD Nyheter