The trouble-plagued Millstone Unit 2 – which went online in 1975, nearly 40 years ago – has asked the NRC to waive a mandatory inspection of its reactor vessel, due to take place once every ten years through the life of the reactor, by extending the upcoming inspection interval from 10 years to 20 years.
By letter dated October 18, 2016, the NRC rubber-stamped Dominion’s risky application.
Millstone Unit 2 has suffered record numbers of unplanned shutdowns and was so badly operated that the state wanted to declare it “no longer used and useful.”
The reactor vessel contains the critical nuclear components of the plant: the nuclear reactor and fuel assemblies. It provides a critical role in nuclear safety because the pressure vessel must contain the reactor core at high temperatures and pressures and serve as a barrier to prevent escape of radiation.
Over time, the reactor vessel is constantly bombarded by neutron irradiation which leads to embrittlement, formation of voids and bubbles, and material and structural degradation. The phenomenon of “creep” also occurs when high levels of stress lead to plastic deformation. Embrittlement of the reactor vessel from constant irradiation can also cause cracks to form in the reactor vessel.
In its letter authorizing deferral of Unit 2’s reactor vessel inspection from March 31, 2020 to March 31, 2030, the NRC stated the designated 10-year inspections are necessary “to detect anomaly and degradation indications so that structural integrity” of the reactor vessel can be maintained.
The Department of Homeland Security has recognized that the reactor vessel “provide[s] substantial barriers and defense-in-depth protection against the release of radioactive fission products to the environment.”
WHY IS THE NRC ALLOWING DOMINION TO TEMPT FATE AND RISK THE HEALTH AND SAFETY OF THE COMMUNITY?
For more information go to: Subject: Millstone Power Station, Unit No. 2 – Alternative Request RR-04-22 to Implement Extended Reactor Vessel Inservice Inspection Interval (CAC No. MF7369). ADAMS Accession No.: ML16277A678