Another approach to consider is that this isn't your problem to solve. I know it's hard to think that way, because doing your job well is such a source of pride to you and in fact the vacation you're going on is the result of an award for doing your job so well. But making sure all the jobs get done is, in fact, your boss's job, and I'm kind of surprised (well, not really, based on bosses I've known) that they haven't discussed this with you already.
So you could go into the boss's office and say, "I'm preparing for my trip, and I was wondering who was going to take over my job while I'm gone, and when I should start training them." If your boss gets this big-eyed look of shock like they haven't thought of that, well, that's not a good sign. Leaving aside the part about doing things well enough to contribute towards your possible award next year, this isn't a frivolous job--people expect to get paid on time and there are financial and legal repercussions for not keeping the books accurately.
You could say, "Bob usually takes over the coding when I'm gone. I'd be happy to give him a refresher course on how to do that so things go more smoothly."
And then you could say, "I'm also concerned about the submission process. Currently no one else on staff knows how to do that. If no one does it, I'll need to work overtime when I get back, and based on past experience, that would take X hours, for $Y total. I'd prefer to train someone so that they can be doing it while I'm gone."
Of course the boss might say, "Oh, that amount of overtime is fine." And then you have to decide whether you will just accept that, or whether you will push further. Because although getting the submissions done well enough to earn this award is hugely satisfying to you, you are right that you're asking for something that's mainly only in your interest, and not the company's. I mean, I could see how, after the fact, you might say, "I was really frustrated that you didn't create the opportunity for me to win this award a second time, because it's a major part of my job satisfaction, and I'm thinking seriously of moving to another job where the executive support is better." But that seems like kind of an ugly conversation to have right before you go on vacation, you know? Maybe better for an annual job review or something.
And, if I understand correctly, the work that gets done while you're gone will contribute to your own possible future award, with no benefit to the person who actually does the work for that week and a half. So even if the boss agrees that you can train Alice to do it, it's possible Alice won't have much motivation to make sure it all gets done, or is done well. So if this scenario arises you might want to think about how Alice could be rewarded for learning this new task and doing it well, whether that's something official through work or you being very appreciative and bringing her back a gift from vacation, being willing to cover her job for her sometimes, etc..