#Fukushima I Nuke Plant Reactor 4: Leak Continues from Reactor Well/SFP/DS

TEPCO hasn't identified the leak, but the leak is evidenced by the rapidly dropping water level of the Skimmer Surge Tank.

From Jiji Tsushin (2/3/2012):

東京電力は３日、福島第１原発の４号機原子炉建屋の原子炉と使用済み燃料プール、機器用プールに共通して張っている水が建屋内に依然として漏れ続けている とみられると発表した。水位はほぼ満水状態に維持しているが、あふれた水を受けるタンクの水位が通常の２倍のペースで低下しているため、漏出の可能性が高 いと分かった。

TEPCO announced on February 3 that the water in the Reactor Pressure Vessel, Spent Fuel Pool and DS Pool in Reactor 4 continues to leak into the reactor building. The RPV, SFP, and DS Pool are filled with water to the near-full level, but the water level of the Skimmer Surge Tank is dropping twice as fast as normal, which likely indicates a leak.

　この水は放射能汚染水で、もともと汚染水がたまっている建屋地下へ流れているとみられる。配管接続部などの凍結、損傷が考えられ、作業員が場所の特定を急いでいる。

The water is contaminated with radioactive materials, and is considered to be flowing to the basement of the reactor building where the contaminated water has already been sitting. The possible causes include the frozen or damaged pipe joints, and the workers are trying to identify the location(s).

From TEPCO's Plant Parameter data, the water levels of Reactor 4 Skimmer Surge Tank:

2/3 11AM: 3179 millimeters
2/3: 5AM: 2085 mm
2/2 11AM: 2498 mm
2/2 5AM: 2784 mm
2/1 11AM: 3223 mm
2/1 5AM: 3225 mm
1/31 11AM: 3977 mm
1/31 5AM: 4357 mm
1/30 11AM: 5416 mm
1/30 5AM: 5208 mm

The relationship of the Reactor Well (RPV), SFP, and DS Pool:

SFP and Skimmer Surge Tank:

(Graphics created by @pluredro based on TEPCO's information)

Tweet