Party's WSOP NL MTT Qualifier 6th hand... KK

[Equal]

No read on the Villian, 6th hand of the MTT.

Party Poker No-Limit Hold'em Tourney, Big Blind is t15 (10 handed) converter

Hero (t850)
MP2 (t1190)
MP3 (t925)
CO (t820)
Button (t975)
SB (t985)
BB (t1085)
UTG (t1185)
UTG+1 (t985)
UTG+2 (t1000)

Preflop: Hero is MP1 with K[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/spade.gif[/img].
<font color="#666666">1 fold</font>, UTG+1 calls t15, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to t55</font>, <font color="#666666">5 folds</font>, BB calls t40, UTG+1 calls t40.

Flop: (t172.50) 5[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/club.gif[/img], 2[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, UTG+1 checks, <font color="#CC3333">Hero bets t90</font>, BB calls t90, UTG+1 calls t90.

Turn: (t442.50) 7[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, UTG+1 checks, <font color="#CC3333">Hero bets t250</font>, BB folds, UTG+1 calls t250.

River: (t942.50) K[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>

I have about 450 left, Villian has me covered. What's my play? Do I check behind the scare card, or am I losing value being paranoid about the runner runner flush? Am I committed to the pot if I make any bet?