2019 - 02 - 22 San Luis Obispo Mothers for Peace calls for testing of Diablo Canyon Unit One

Mothers for Peace strongly urges Pacific Gas and Electric Company (PG&E) to drop its request that the Nuclear Regulatory Commission (NRC) grant Diablo Canyon an exemption from inspection of a highly radioactive component of the plant. The reliability and safety of the nuclear plant depends on knowledge of the effects of aging on the reactor vessels that have been bombarded by radiation for 35 years. The following letter was sent to Jon Franke, Chief Nuclear Officer, Pacific Gas and Electric Company.

San Luis Obispo Mothers for Peace (MFP) strongly urges Pacific Gas and Electric Company (PG&E) to take the opportunity to conduct crucial tests related to both reliability and safety during the current outage of Diablo Canyon Unit One.

Since 2003 Unit One has a documented history of having a dangerously embrittled reactor vessel.  Because the internal components of all nuclear reactors are subjected to intense heat, pressure, and radiation, critical metals and welds can lose their resiliency.  Should a loss-of-coolant-accident necessitate emergency flooding of cooling water, embrittled components could shatter, leading to catastrophe.  The degree of embrittlement at Unit One can be easily and cheaply tested while the reactor is shut down for refueling.  

All reactor pressure vessels and other key components can crack over time.  Unit One’s age makes it imperative that remotely controlled ultrasound devices be deployed to inspect the reactor internally, which can be done relatively easily and inexpensively. In 2013, PG&E applied for and received permission to delay testing for cracking, and so the ultrasound test has not been conducted since 2005.

MFP is aware that PG&E has requested the Nuclear Regulatory Commission for an exemption to the requirement for a” Reactor Vessel Internal Visual Examination” in the near future. MFP suggests that such an inspection would be in the best interests of PG&E as well as the public. This reactor vessel has been exposed to high levels of radiation for decades. In order to assure the reliability as well as the safety of the plant, it needs to be inspected.