Operator reports valve leak: reserve operation of nuclear power plant Isar 2 is questionable

Isar 2 in Bavaria is planned as one of two nuclear power plants for reserve operation until April 2023. Now there is a valve leak that puts those plans in question. The federal government must examine its plans.

The federal government is putting the plans for the planned reserve operation of the Isar 2 nuclear power plant to the test after the operator reported a valve leak. “The Federal Environment Ministry, like the Ministry of Economics, is examining the new situation and its effects on the design and implementation of the standby reserve,” said the environment department.

The ministry reported that the operator Preussen Elektra “informed about an internal valve leak in the Isar 2 nuclear power plant last week”. This does not affect the safety of the facility. The power plant can also continue to run until the end of operations, which is actually planned, on December 31, it said. For reserve operation beyond this date, however, a repair would be necessary as early as October, which would result in the reactor being idle for a week, Preussen Elektra reported.

The problem is the reserve mode

The leak becomes a problem because Isar 2 is considered one of two nuclear power plants for possible reserve operation – and should continue to be operational after December 31, 2022. At the beginning of September, Federal Economics Minister Robert Habeck (Greens) announced that the Isar 2 power plants in Bavaria and Neckarwestheim in Baden-Württemberg should remain available as emergency reserves until mid-April 2023 in the event of bottlenecks.

In order for this to work in Bavaria, the Isar 2 nuclear power plant would have to be shut down for a week in October, according to Preussen Elektra. Because the fuel elements of the reactor core have only a low reactivity, the operator tells the Federal Ministry for the Environment. So low that the system could no longer be shut down and restarted in November.

Ministry: “New Facts”

According to the ministry, your level of information has been different so far: So far, the operator has always stated that the system will run at almost full capacity until the end of the year.

According to the ministry, the new information from Preussen Elektra contains “some important new facts” compared to those that the operator made in a letter dated August 25 to the Ministry of Economic Affairs.

According to Preussen Elektra, the ministry found out about the internal valve leak last week – during technical talks about preparing a standby reserve.

Ministry of the Environment is examining plans for the standby reserve

According to the Ministry of the Environment, these new facts must now be taken into account when planning the availability of the nuclear power plant for electricity production after December 31st.

Both ministries are therefore examining “the new situation and its impact on the design and implementation of the standby reserve”. For the Federal Environment Ministry, the priority is that the current high safety standards of German nuclear power plants continue to be guaranteed.

Warning already in September

“Particular attention is paid to examining the assessment of the nuclear supervisory authority of the state of Bavaria and the operator with regard to the leakage of the valve,” said the ministry responsible for nuclear safety. In the aforementioned letter from Preussen-Elektra dated September 6, the operator warned against transferring the system to a reserve from the turn of the year.

Habeck’s proposal in this regard was “technically not feasible,” it said. The Economics Minister had expressed “surprised” about the letter from the company.