Schools in Mito City in Ibaraki Prefecture, just south of Fukushima Prefecture, have started PE classes using swimming pools.
From Tokyo Shinbun (6/29/2011):
水戸市教育委員会は二十七日、プールがある三十二の小学校、十三の中学校で水質検査を実施した。プールの水は水道水で、放射性物質は検出されなかった。安全性が裏づけられたのを受け、同市教委は水泳授業を始めてもよいとの通達を同日中に出した。
The Board of Education in Mito City [in Ibaraki Prefecture] measured the radiation in swimming pool water at 32 elementary schools and 13 junior high schools in the city on June 27. The water was from tap water, and there was no radioactive materials detected. Safety of the water thus assured, the city's Board of Education issued the notice the same day that the schools may start the swimming classes.
二十八日は、二十二の小学校、三の中学校で水泳授業がスタートした。笠原小では新たに購入した高圧洗浄機で念入りにプール内やプールサイドを洗い 流すなどして、今月上旬から準備を進めていた。気温三〇度近い晴天の下、プールに飛び込んだ同小六年の竹内康君（１２）は「すごく気持ちいい。水泳をした かったのでよかった」と笑顔だった。
On June 28, 22 elementary schools and 3 junior high schools started the swimming classes. In one of the elementary schools, they've been preparing for the pool opening by washing the pool and the poolsides with a high pressure washer since the beginning of this month. A 6-grader boy was all smiles, after diving in the water on a hot, sunny day, "It feels great. I've been wanting to swim, so this is great."
同市教委によると、安全性が確認されても保護者から「プールに入れたくない」との声が出ているという。授業を辞退する申し出があったら認めるとしており、既に数校から報告が入っている。
According to the city's Board of Education, there are some parents who don't want their children to use the swimming pools even after the safety has been confirmed. If parents don't want swimming classes for their children they can submit the requests to the schools, and the Board will accept such requests. There are already several schools with parents requesting that their children do not participate.
県教委によると、県内四十四の自治体のうち、四十二の市町村が水泳授業を既に行っているか、近日中に始める。日立市は国から安全基準が示されるのを待っている状況で、北茨城市は中止を決めている。
According to the Ibaraki prefectural Board of Education, 42 municipalities out of 44 in Ibaraki have already started the swimming classes or are about to start. Hitachi City is waiting for the national standard to be set for swimming pools, and Kita Ibaraki City has decided not to hold swimming classes.
Good for Kita Ibaraki City.
The key is this: by default, swimming classes are on, for everyone. The parents have to submit a request to not have their children participate in the swimming classes.
"Yes, you can refuse to participate in the swimming classes. Now, DO YOU REFUSE?"
Or "Yes, you can refuse to participate. Your child's grade in PE will be 1, lowest grade, because without participation we have no way of grading him/her."
Or both. Sadly. That's Japan, and very a regimented educational system under the Ministry of Education and Science, with prefectural and municipal Board of Education as the Ministry's extension, even in this unprecedented nuclear accident that has spread a large amount of radioactive materials all over the northern hemisphere and even some in the southern hemisphere.
School schedules and events must be maintained at all costs.