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NASA Ball NASA
Procedural
Requirements 		NPR 8715.26
Effective Date: February 03, 2022
Expiration Date: February 03, 2027
COMPLIANCE IS MANDATORY FOR NASA EMPLOYEES
Printable Format (PDF)

Subject: Nuclear Flight Safety

Responsible Office: Office of Safety and Mission Assurance


| TOC | Preface | Chapter1 | Chapter2 | Chapter3 | Chapter4 | AppendixA | AppendixB | AppendixC | AppendixD | AppendixE | AppendixF | AppendixG | ALL |

Appendix D. Calculation of the A2 Mission Multiple

D.1 Determination of A2 Mission Multiple

D.1.1 The instructions below relate to the use of IAEA guidance as it pertains to nuclear flight safety, consistent with the use of this same guidance in NSPM-20 and preceding Presidential direction. This guidance is used as a matter of convenience, understanding that the guidance was not developed specifically for use in launch or reentry. Its invocation here may differ from other NASA uses of this guidance, as they pertain to transportation of radioactive material by land, sea, or air under the authorization or licensing by other Federal agencies.

D.1.2 The latest available version of IAEA SSR-6 should be used. Note: IAEA SSR-6 provides values in terabecquerels (TBq), while NASA sources are often catalogued in curies (Ci), so care should be taken when calculating the mission multiple (1 TBq = approx. 27 Ci).

D.1.3 While the table provided in IAEA SSR-6 (Table 2 in the case of the 2018 Update) is typically sufficient for obtaining the necessary A2 multiples, the user should be aware of the caveats and explanation that appears before and after that table (e.g., Sections 402-407 in the case of the 2018 Update), which are applicable to special circumstances.

D.1.4 The A2 mission multiple will be determined using the equation below, where n represents each source of radioactive material on the launch vehicle and spacecraft. A simple example is provided in Table 3.

Equation for using the A2 mission multiple.

Table 3: Sample Multi-source A2 Mission Multiple Illustration

Radioisotope Activity (Ci) A2 value1 (Ci) A2 mission multiple
Ni-63 0.005 800 6∙10-6
Co-60 0.005 10 5∙10-4
Cm-244 0.0005 0.05 0.01
Total A2 mission multiple = ~0.01 (1.05∙10-2)


| TOC | Preface | Chapter1 | Chapter2 | Chapter3 | Chapter4 | AppendixA | AppendixB | AppendixC | AppendixD | AppendixE | AppendixF | AppendixG | ALL |
 
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