Any of the following:* Pregnant women* Nursing women* Men or women of childbearing potential who are unwilling to employ adequate contraception Women of childbearing potential and male participants who are sexually active must agree to use a medically effective means of birth control The following categories are ineligible:* Pregnant women* Nursing women* Men or women of childbearing potential who are unwilling to employ adequate contraception or contraceptive method during this study and 6 months following the completion of chemotherapy treatments Women of childbearing potential and male participants must practice adequate contraception Any of the following:* Pregnant women* Nursing women* Men or women of childbearing potential who are unwilling to employ adequate contraception for the duration of study participation; men and women should continue to use adequate birth control after the last administration of sorafenib and TH-302 under the guidance of their treating physician Any of the following* Pregnant women* Nursing women* Men or women of childbearing potential who are unwilling to employ adequate contraception Any of the following:* Pregnant women* Nursing women* Women of childbearing potential who are unwilling to employ adequate contraception (as determined by the treating physician) Sexually active women of childbearing potential and sexually active men must practice adequate contraception during therapy and for 12 months after protocol treatment completion Any of the following:* Pregnant women* Nursing women* Men or women of childbearing potential who are unwilling to employ adequate contraception Women of childbearing potential and male participants must agree to practice adequate contraception while on study and for at least 6 months following the last dose of radiation therapy (RT) and for at least 28 days following the last dose of sorafenib (whichever is later) Any of the following:* Nursing women* Pregnant women* Women of childbearing potential who are unwilling to employ adequate contraception (non-barrier method) Women of childbearing potential and male participants who are sexually active must practice adequate contraception during treatment and for 6 weeks following treatment Women of childbearing potential and male participants who are sexually active must agree to use a medically effective means of birth control Inability or refusal to practice effective contraception during therapy or the presence of pregnancy or active breastfeeding (men and women of childbearing potential must use an effective method of birth control or abstinence during treatment and for 4 months after completion of treatment) Women of childbearing potential and male participants must practice adequate contraception Women of childbearing potential and male participants who are sexually active must agree to use a medically effective means of birth control throughout protocol treatment Not pregnant and not nursing; for women of childbearing potential only, a negative serum pregnancy test must be obtained within 14 days prior to registration* Women of childbearing potential must use adequate contraception from study start to one month after the last dose of protocol therapy; adequate contraception is defined as hormonal birth control, intrauterine device, double barrier method or total abstinence; men must practice complete abstinence or agree to use an adequate contraception method from study start to one month after the last dose of protocol therapy Men or women of childbearing potential who are unwilling to employ adequate contraception (e.g., hormonal or barrier method of birth control; abstinence) for the duration of study treatment and for 4 months after the last dose of study therapy Female patients of childbearing potential and men receiving MK-3475 (pembrolizumab) who are sexually active with women of childbearing potential must be willing to use an adequate method of contraception for the course of the study through 120 days after the last dose of MK-3475 (pembrolizumab); note: abstinence is acceptable if this is the usual lifestyle and preferred contraception for the patient Women of childbearing potential must not be known to be pregnant or lactating