A new computer program for shielding calculation. has been prepared.The program is available for estimating effective doses of photons from radioisotapes, i. e., γ rays and bremsstrahlung X rays emitted by the interaction ofβrays with targets.Main features of the program are as follows:
1) The dose estimation method in the program is the same as the method using effective dose build-up coefficients, Which is given in the manual of shielding calculation for radiation facility.
2) The estimation for any γ-ray and β-ray emitting nuclides can be performed by inputting nuclear data, i. e., γray.energies, γ-ray intensity ratios, β-ray maximum energy and β-decay branching ratio.
3) The estimation for multi-shielding layers of different materials is available.
4) The estimation with different densities of shielding materials and different chemical form of target materials for β rays is available.
The computer program has been carefully tested by comparing with the data in the manual of shielding calculation: for radiation facilities, i. e., dose rate, constants and penetration factors of γ-ray and β-ray emitting nuclides. Some equations re-formulated for the dose calculation and the. constitution of the computer program are explained in this paper. The result of the comparison is also discussed, indicating some. differences between the present estimation and the values in the manual.