根据January 28, 2021新建的ALPS Treated Water Q&A页面问题4：

Why are two options suggested by the expert committee feasible?

A: “1) Vapor release” and “2) discharge into the sea” are suggested by the committee.
Both option 1) and 2) are recommended to be realistic, because of the precedents and track records for them. “2) Discharge into the sea” can be implemented more reliably, considering the ease of discharge facilities operation and proper monitoring methods.
 The International Atomic Energy Agency (IAEA) acknowledged that the options suggested by expert committee is “based on a sound scientific and technical basis of analysis”.

＜Reference＞

Statements made by IAEA Director General Rafael Grossi in February 2020 

IAEA Reviews Management of Water Stored at Fukushima Daiichi Nuclear Power Station (2 April 2020) 

TEPCO’s Draft Study Responding to the Subcommittee Report on handling ALPS-Treated Water (24 March 2020)

日方提出了两种废水释放方案：稀释入海/蒸发，都是有先例且可行的，与6楼说法类似。国际原子能机构在上述参考链接2中写道：

In a review published today, the team said the two options for controlled disposal outlined by a Japanese advisory subcommittee in February – vapor release and discharges to the sea – were both technically feasible. They are also routinely used by operating nuclear power plants worldwide under specific regulatory authorisations based on safety and environmental impact assessments. The IAEA experts said the subcommittee’s recommendations to the Government of Japan were based on a comprehensive and scientifically sound analysis addressing the necessary technical, non-technical and safety aspects.

也印证了这一说法。