Dose Investigation/ Dose Estimate (DI/DE)

Question 1

When is a dose investigation conducted?

Answer 1

Used anytime a dosimeter measurement is in question.

Question 2

When is a dose estimate conducted?

Answer 2

When you need to assign a dose when a dosimeter measurement is unable to.

Question 3

True or false, all dose investigations require an dose estimate.

Answer 3

False, all dose estimates require dose investigation.

Question 4

What are some conditions in which investigation and estimate is initiated?

Answer 4

1. When Primary TLD is lost, damaged, or destroyed.
2. Entering a radiation area without an TLD
3. A member wears someone else TLD.
4. Suspected TLD reading i.e. unexpectedly high or low exposure.
5. A technical, electronic, software, or mechanical problem is noted during TLD processing.
6. TLD is not worn correctly.
7. Operational conditions prevent evaluation of TLD in a timely manner.
8. Significant difference between primary and secondary dosimeter (30/30 Rule).

Question 5

What is the 30/30 Rule?

Answer 5

Primary and secondary dosimeter measurements differ by 30% or more and the primary dosimeter is measurement is greater than or equal to 100 mrem.

Primary and secondary dosimeter measurements differ by 30 mrem or more and the primary dosimeter is less than 100 mrem.

Question 6

What are the required documents for an DI/DE?

Answer 6

• Reason it is being performed.
• Signed and dated worker statement.
• Glow Curves
• All supporting documentation
• The dose estimate with the applicable type and the period cover.

Question 7

What is DI/DE?

Answer 7

Dose Investigation and Dose Estimation

Question 8

How are long are DI/DE retained?

Answer 8

Indefinitely.

Question 9

Where is the estimated dose recorded?

Answer 9

NAVMED 6470/10 Block 7-13.
NAVMED 6470/1

Question 10

What are the methods used to determine a dose IAW NAVMED P-5055?

Answer 10

• Secondary dosimeter measurements.
• Doses from similar work performed.
• Exposure times and dose rate study

Question 11

How would a “Doses from similar work performed” be conducted?

Answer 11

• Gather 3 TLDs from co-workers who perform similar duties to the member who needs an estimate.
• Issue new TLDs to the said co-workers and stow the old ones in a low background area.
• Submit the old ones with your batch to the processing facility at the end of the issue period or return of underway period.
• Document the reason for collection on NAVMED 6470/3