– Record radiation level in underground water well near ocean at Fukushima — Tepco: “Rise in radiation readings is an obvious concern” — 1.4 billion Bq/m³ of strontium/beta emitters (ENENews, Dec 8, 2013):
TEPCO: Immediate release: GRADUAL RISE IN RADIATION READINGS AT WELL MAY BE LINKED TO IMPROVEMENTS IN GROUNDWATER CONTROL, Dec. 5, 2013 (emphasis added): […] gradual rise in radiation readings at a test well on the site of Fukushima Daiichi NPS appears to be the result of successful efforts to pump groundwater and divert it from flowing into the ocean […] Readings at the well site had generally been within the range of 400,000 to 800,000 bequerels per liter of gross beta (total amount of beta nuclides), but had begun rising in the end of October this year. Various efforts to control the flow of contaminated water toward the ocean had been begun on July 8 […] On November 28th, the reading at well 1-16, located in this area near Units 1 and 2, rose to 1.1 million bq/l, and on December 2 the reading was 1.3 million bq/l. […] no change has been observed in seawater radiation density readings, which TEPCO measures and announces every day [though levels have not decreased, as would be expected if flow was blocked]. […] there is no increased risk to human health or the environment. However, engineers are […] continuing to analyze the results to more precisely determine the cause of the increase. Lake H. Barrett […] an advisor to TEPCO, said: “While the rise in radiation readings is an obvious concern that needs to be carefully monitored, in some respects it is an indication of the success of TEPCO’s concerted efforts to isolate contaminated water and prevent its flow into the sea. The situation warrants continuous monitoring and careful analysis, but there appears no increased level of risk to workers, the public, or the environment.”
The most recent results from December 5, 2013 showed gross beta at well 1-16 rising to 1.4 million Bq/L or 1.4 billion Bq/m³.
On December 6, 2013, new results showed that strontium-90 is a very high percentage of the overall gross beta measurement.
- 1T-4: 7,500 of 9,500 Bq/L — 79%
- 1T-5: 2,900 of 3,200 Bq/L — 91%
- 2T-2: 740 of 830 Bq/L — 89%
Yet, testing for strontium-90 levels has been reduced from 2 per month to just 1 at locations near the sea. (Source: Tepco, pg. 6)