Japan revises Fukushima cleanup plan, delays key steps

Japan on Friday revised a romap for tsunami-wrecked Fukushima nuclear plant cleanup, furr delaying removal of thousands of spent fuel units that remain in cooling pools since 2011 disaster. It's a key step in deceslong process, underscoring high riation and or risks. government and plant operator, Tokyo Electric Power Co., still keep a 30- to 40-year completion target.

A look at some of challenges:

MORE THAN 4,700 UNITS OF FUEL IN POOLS

More than 4,700 units of fuel rods remain inside three melted reactors and two ors that survived 2011 earthquake and tsunami. y pose a high risk because ir stor pools are uncovered and a loss of water in case of ar major disaster could cause fuel rods to melt, releasing massive riation. ir removal at Units 1 and 2, after repeated delays, is w delayed by up to 10 years from initial target of 2018, with more preparation needed to reduce riation and clear debris and or risks.

Fuel rods removal at . 1 reactor pool will begin sometime in 2027-2028 after debris is cleaned up and a huge rooftop cover installed to contain rioactive dust. Fuel removal at Unit 2 pool is to begin in 2024-2026. Work at . 3 reactor pool began in April 2019 and all 566 units will be removed by March 2021. TEPCO has emptied pool at Unit 4, which was offline and only suffered building dam, and aims to have all remaining rods in reactor pools removed by 2031 for safer stor in dry casks.

1.2 MILLION TONS OF RIOACTIVE WATER

TEPCO has been unable to release 1.2 million tons of treated but rioactive water kept in nearly 1,000 tanks at plant, fearing public repercussions and impact on area's struggling fishing and farming. water keeps growing by 170 tons daily because it is used to cool melted fuel.

Ministry of Ecomy, Tre and Industry recently drafted a proposal to release water to sea or air, or a combination of both. TEPCO says it can only store up to 1.37 million tons until summer of 2022. Time is limited because preparation is needed before any water release. TEPCO and government say tanks pose risks if y were to spill out contents in ar major earthquake, tsunami or flood. y also need to free up to build stor for melted fuel removed from reactors beginning 2021.

water is still somewhat contaminated, but TEPCO says furr treatment can remove all but rioactive tritium to levels allowed for release. Experts say tritium is t harmful to humans in small amounts and has been routinely released from nuclear plants around world. 

880 TONS OF MELTED FUEL

Removing an estimated 880 tons of molten fuel from Fukushima's three melted reactors is toughest and unprecedented challenge. It's six times amount dealt with in aftermath of 1979 Three Mile Island partial core melt.

Removal is to begin in 2021 at Unit 2, where robotic probes have me bigger progress than at Units 1 and 3. A robotic arm was developed to enter reactor from side to reach melted fuel that has largely fallen to bottom of primary containment vessel. A side-entry would allow a simultaneous removal of fuel rods in pool from reactor's top. A melted fuel removal will begin with just a spoonful, which will be carefully measured and analyzed per International Atomic Energy ncy instructions. government hopes to grually expand scale of removal, though furr expertise and robotic development are needed. first dece through 2031 is a crucial phase that would affect future progress. Units 1 and 3 fell behind due to high riation and water levels respectively, requiring more investigation.

770,000 TONS OF RIOACTIVE WASTE

Japan has yet to develop a plan to dispose of highly rioactive melted fuel and or debris that come out of reactors. TEPCO will compile a plan for those after first dece of melted fuel removal. Managing waste will require new techlogies to reduce ir volume and toxicity. TEPCO and government say y plan to build a site to store waste and debris removed from reactors, but finding one and getting public consent would be difficult.

ditionally, re will be an estimated 770,000 tons of solid rioactive waste by 2030, including contaminated debris and soil, sludge from water treatment, scrapped tanks and or waste. y will be sorted out, treated, compacted for safe stor under a plan to be compiled by 2028.

8 TRILLION YEN

government says Fukushima's decommissioning cost is estimated at 8 trillion yen ($73 billion), though ding compensation, decontamination of surrounding areas and medium-term stor facilities would bring total to an estimated 22 trillion yen ($200 billion). Japan Center for Ecomic Research, a think tank, estimates that decommissioning alone would cost 51 trillion yen ($470 billion) if water is t released and a tritium removal techlogy is pursued.

10,000 WORKERS

More than 10,000 workers will be needed annually in coming years, about one third assigned to work related to rioactive water. Securing an experienced workforce for deces-long cleanup is a challenge in a country with a rapidly ing and declining population. Nuclear Regulation Authority Chairman Toyoshi Fuketa raised concerns about a possible labour short following recent mir mishaps at plant. TEPCO has expressed intention of hiring workers for decommissioning under Japan’s new policy allowing more unskilled foreign labour, but plan is on hold following government instructions to dress langu and safety concerns.