full2010.pdf - page 312

274
3. œ°„‹µ„œ¸Ê ¥´ŠÅ—oœÎ µ o°¤¼¨‡nµÁŒ¨¸É¥ °Š‡n µ„´¤¤´œ˜£µ¡‹ÎµÁ¡µ³ °Šœ· ªÅ‡¨—r 40K 226 Ra ¨³ 232Th š¸É
˜¦ª‹ª´ —Å—o¤µÄoĜ„µ¦‡Îµœª–°´˜¦µž¦·¤µ–¦´ Š¸—¼—„¨ºœÄœ°µ„µ« (absorbed dose rates in air ; D) „´¤¤´œ˜£µ¡
¤¤¼¨Á¦Á—¸¥¤ (radium equivalent activity ; Raeq) ¨³—´œ¸‡ªµ¤Á¸É¥Š °Š¦´Š¸£µ¥œ°„ (external hazard index ; Hex)
°Š˜´ª°¥nµŠ—·œ ץčo ¤„µ¦—´Š˜n°Åžœ¸Ê
1
K Ra Th D(nGyh ) 0.0414C 0.461C 0.623C ....................................... (1)
eq K Ra Th Ra 0.077C C 1.43C .................................................. (2)
d K Ra Th
ex
C C C
H 1
4810 370 259
.............................................. (3)
Á¤ºÉ° C K CRa ¨³ CTh ‡º° ‡nµ„´¤¤´œ˜£µ¡‹Î µÁ¡µ³ °Š 40K 226 Ra ¨³ 232Th ˜µ¤¨Îµ—´ (S.Singh et al., 2005)
œ°„‹µ„œ¸Ê ¥´ŠÅ—o‡Îµœª–°´˜¦µž¦·¤µ–¦´Š¸¥´ŠŸ¨š¸Éŗo¦´˜n°že (annual effective dose rate ; AEDout) Ž¹ÉŠ
Áž}œ‡nµž¦·¤µ–¦´Š¸š¸É ŗo¦´˜n°že‹µ„£µ¥œ°„°µ‡µ¦oµœÁ¦º°œ ץčo‡nµ°Š‡r ž¦³„°Îµ®¦´„µ¦Âž¨Š‡nµ (conversion
factor) Ášnµ„´ 0.7 Sv/Gy 宦´ÄoĜ„µ¦Âž¨Š‡nµž¦·¤µ–—¼—„¨ºœ¦´ Š¸Â„¤¤µÄœ°µ„µ«Áž}œ‡n µž¦·¤µ–¦´Š¸Â„¤
¤µ¥´ŠŸ¨š¸Éŗo¦´Ã—¥»‡‡¨š´ÉªÅžš¸É čoÁª¨µ°¥¼n£µ¥œ°„oµœÁ¦º°œž¦³¤µ– 20% °ŠÁª¨µš´ÊŠ®¤—Äœ 1 že (S.Singh et
al., 2005) ץčo ¤„µ¦—´Š˜n°Åžœ¸Ê
Annual Effective Dose Rate (mSv) = Absorbed Dose Rate (nGy/h) x 8,760 h
x 0.2 x 0.7 Sv/Gy x 10-6 ..................................... (4)
5. Áž¦¸¥Áš¸¥ o°¤¼¨š¸Éŗo ‹µ„„µ¦ª·Á‡¦µ³®r Ĝ˜´ª°¥nµŠ—· œš´ÊŠ 103 ˜´ª°¥nµŠ „´‡nµš¸É ˜¦ª‹ª´—Å—o°Š
εœ´ „Šµœž¦¤µ–¼Á¡ºÉ°´œ˜· o°¤¼¨ °Š„¨»n¤œ´ „ª·‹´¥Äœ˜n µŠž¦³Áš«š´ÉªÃ¨„ ¨³„µ¦Áž¦¸¥Áš¸¥Ÿ¨„µ¦š—¨°Šš¸Éŗo¤µ
oµŠ˜oœ„´‡n µš¸É„ε®œ—Ūo×¥°Š‡r „¦‡ªµ¤¦nª¤¤º°šµŠÁ«¦¬“«µ˜¦r ¨³„µ¦¡´•œµ (Organization for Economic
Cooperation and Development : OECD,1979) ¨³‡–³„¦¦¤„µ¦ª· š¥µ«µ˜¦r°Š°Š‡r „¦®ž¦³µµ˜·Á„¸É¥ª„´ 
Ÿ¨ °Š¦´Š¸ž¦¤µ–¼ (United Nations Scientific Committee on the Effects of Atomic Radiation : UNSCEAR, 1988,
1993, 2000)
Ÿ¨„µ¦ª·‹´¥Â¨³°£·ž¦µ¥Ÿ¨
‹µ„Ÿ¨„µ¦˜¦ª‹ª´—¨³ª·Á‡¦µ³®r‡nµ„´¤¤´œ˜£µ¡‹ÎµÁ¡µ³ °Šœ·ªÅ‡¨—r„´¤¤´œ˜¦´Š¸Äœ›¦¦¤µ˜· 40K 226Ra
232Th ¨³ 137Cs š¸É˜¦ª‹ª´—Å—oĜ˜´ª°¥nµŠ—·œš¸ÉÁ„ȝ‹µ„°ÎµÁ£°Á¤º°Š °ÎµÁ£°„³š¼o ¨³°ÎµÁ£°™¨µŠ ‹´Š®ª´—£¼Á„Ș Á¤ºÉ°
œÎ µÅžÁž¦¸¥Áš¸ ¥„´ o°¤¼¨„µ¦˜¦ª‹ª´ —¨³ª·Á‡¦µ³®rĜ˜´ª°¥nµŠ—· œš¸ÉÁ„ȝ‹µ„µŠ¦·Áª–Äœ‹´ Š®ª´—Š ¨µ˜´ÊŠÂ˜nže
¡.«. 2537-2545 °ŠÎµœ´ „Šµœž¦¤µ–¼Á¡ºÉ°´œ˜· ¨³ o°¤¼¨‹µ„„µ¦ª·‹´¥š´ÉªÃ¨„ ץ—ŠŸ¨„µ¦Áž¦¸¥Áš¸¥š¸ÉŗoŪo
Ĝ˜µ¦µŠš¸É 1