We study a pair consisting of a smooth 3-fold defined over an algebraically closed field and a "general" real ideal. We show that the minimal log discrepancy ("mld" for short) of every such a pair is computed by a prime divisor obtained by at most two weighted blow-ups. This bound is regarded as a weighted blow-up version of Mustaţǎ-Nakamura's conjecture. We also show that if the mld of such a pair is not less than 1, then it is computed by at most one weighted blow-up. As a consequence, ACC of mld holds for such pairs. Corollary 1.10 (Corollary 5.9). Assume N = 3. Let E be a prime divisor over A computing mld(0; A, a) for a pair (A, a). Assume that the center C ⊂ A 1 of E on the first blow-up A 1 −→ A is a curve of degree ≥ 2 in the exceptional divisor E 1 ≃ P 2 . Then a "standard blow-up" at C gives a divisor computing mld(0; A, a).Note that in this case the first blow-up is also a standard blow-up. Example 3.2 is just in this case. In Section 5, we show a more general corollary. On the other hand, if we restrict to the case mld ≥ 1, then we have the following:Theorem 1.11. Assume N = 3. Then, for every general pair (A, a) with a and mld(0; A, a) ≥ 1 , the minimal log discrepancy is computed by a prime divisor obtained by one weighted blow-up.Corollary 1.12. Assume N = 3. In {(A, a) | mld(0; A, a) ≥ 1 with general a} Mustaţǎ-Nakamura Conjecture holds and also ACC Conjecture holds for char k ≥ 0.