# Presentation: 266190

## Gained Life Expectancy as a Risk Performance Measure for the Hanford Cleanup Mission

- Daniel J. Strom and Jeffery D. Vick
- Pacific Northwest National Laboratory
- Presented at the Joint Meeting of the Society for Risk Analysis and International Society for Exposure Analysis
- New Orleans, December 11, 1996
- PNNL-SA-28581

## Hanford Cleanup

- 1500 km2 site in Washington state
- Scrub-steppe terrain with Columbia River
- 70-year effort to deal with legacy from defense nuclear materials production
- 177 underground tanks containing highly radioactive material and toxic chemical wastes
- irradiated nuclear fuel and radioactive sources
- contaminated buildings, land and ground water

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## Complex Problem WithMultiple Drivers

- What, when, and how work is done
- Multiple decision dimensions
- Public and worker safety and health
- Environment
- Compliance
- Mission impact (outcomes)
- Cost efficiency
- Social, political, economic, and cultural
- Technology development
- Values and concerns of stakeholders, Tribes, and regulators
- Potential for reduced support from the larger public and Congress

- (not all inclusive)

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## Hanford Strategic Success Indicators

- Reduced risks to the worker, the public, and the environment
- Increased amount of land and other resources recovered for other (private and governmental uses)
- Reduced/eliminated total amount of inventory and materials remaining to be cleaned up

- Backup slide

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## Bottom Line:  Are We Making Hanford Safer?

- One of four Hanford strategic success indicators: “Reduced risk to the public, worker, ...”
- Are the “what, when, and how” in Hanford strategies and work plans reducing risk?
- Naïve question: “How much safer is Hanford this year than it was last year?”
- No common quantitative basis for comparing risks over time exists at Hanford.

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## Proposed RiskPerformance Measures

- Measures of human health risk
- Requires comparison of scenarios, e.g., benchmark scenario and alternative cleanup scenarios
- Based on short- and long-term risk due to Hanford’s legacy from now until ...

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## Uses of Proposed Risk Performance Measures

- Prospective use: strategic planning and evaluating mission success
- Retrospective use: gauging contractor performance
- similar to ‘earned value’ technique in project performance measurement
- some risks too “lumpy” over time for retrospective use, e.g., worker fatalities

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## 5 Human Health Risks

- prompt fatalities
- days lost to injury
- days lost to illness
- cancer fatalities
- heritable (genetic) ill-health
- Each risk is weighted to convert to years of Lost Life Expectancy *(LLE)*

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## Collective Committed Risk

- Collective: Summed over all persons over a specified time
- Committed: Actions taken now are projected to lead to
- exposures
- intakes
- biological change
- expectation of harm

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## Cleanup Action

- Time

- Level
- of Effort

- Time

- Release
- Rate

- Projected Off-Site
- Release of Toxic Material

- Time

- Intake
- Rate

- Possible Exposure
- of an Individual
- Due to Off-Site Release

*A genetic mutation occurs in exposed individual*

*Exposed individual’s child inherits the mutation*

- Time

- Occur
- -rences

- Possible Occurrences
- of Genetic Ill-Health
- in Exposed Individual’s Descendants

- Centuries
- Later

- Present

- Still Later

- After That

- Time

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## Risk Performance Measures

- Committed collective risk *(CCR)* due to benchmark maintenance and monitoring scenario
*CCR* due to particular cleanup and remediation scenario

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## Benchmark Maintenance and Monitoring Scenario

- Level
- of Effort

- Time

- Conc.
- in River

- Time

- Projected
- CCR Rate

- Time

- Cleanup and Remediation Scenario

- Level
- of Effort

- Time

- Conc.
- in River

- Time

- Projected
- CCR Rate

- Time

- cleanup
- complete

- Cleanup
- CCR (area
- under curve)

- Benchmark
- CCR (area
- under curve)

- Time

- Risk Performance Measure
-  = Benchmark CCR - Cleanup CCR
- (difference between areas under curves)

- Difference in
- Projected
- CCR Rates

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## Trading Risk: Workers & Public

- Cleanup puts workers at risk
- voluntary, clear benefit (paycheck)
- informed
- more or less controlled
- Cleanup averts risk to public
- involuntary, no perceived benefit
- uninformed
- uncontrolled

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## Balancing Risks

- Human
- Health
- Risk from
- Release of
- Toxic Material

- Worker
- Exposure,
- Illness, Injury,
- Fatality

- During DD&ER

- During and After
- DD&ER

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**Notes:**
Factors increasing human health risk from accidental or long-term release of toxic material:
do nothing, do the wrong thing, do the right thing poorly

Factors decreasing human health risk from accidental or long-term release of toxic material:
do D & D, waste management, environmental restoration, accident prevention, maintenance, emergency response

Factors increasing worker risk during decontamination, decommissioning, and environmental restoration:
neglect worker protection, do work that’s more hazardous, do more work

Factors decreasing worker risk during decontamination, decommissioning, and environmental restoration:  
use robotics, do less work, have hazards management program, train workers, have worker protection programs, do work that’s less hazardous

## Human Health Risk from Accidental or

- Long-Term Release of Toxic Material

- Worker Risk: Exposure, Illness,
- Injury, Fatality During DD&ER

- Do
- Nothing

- Do the
- Wrong
- Thing

- Do the
- Right
- Thing Poorly

- Do Work
- That’s More
- Hazardous

- Neglect
- Worker
-  Protection

- Do
-  More
-   Work

- Main-
- tenance

- Waste
- Management

- D & D

- Environmental
- Restoration

- Emergency
- Response

- Worker
- Protection
- Programs

- Do
- Less
- Work

- Do Work
- That’s Less
- Hazardous

- Hazards
- Management
- Programs

- Accident
- Prevention

- Training

- Robotics

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**Notes:**

[This slide will probably not be used.]

## Worker:Public Risk Tradeoff

- Radiation limits:
- 10:1 (5 rems: 0.5 rem)
- 50:1 (5 rems: 0.1 rem)
- 333:1 (5 rems: 0.015 rem)
- Chemical limits:
- you name it, you can find it
- Accidents

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- Pacific Northwest National Laboratory

## Combining 5 Health Risks

*CCR *(in years *LLE*) = *i** k**i**R**i**,*                where*                                                                     **	**k**i* is the weighting factor for risk type *i          **	**	*that converts it to LLE*                                    **	**R**i* is the value of risk type *i*
*CCR * is computed separately for
- acute risk to workers from normal work hazards
- risks from accidental releases to both workers and public

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## Gained Life Expectancy

- Worker* LLE *is weighted and added to* LLE *due to releases:                              		            *LLE* = *LLE**releases* + *w**worker** LLE**worker, routine*
- A* negative *difference in years of lost life expectancy is a *gained life expectancy (GLE)*
*RPM* (years *GLE*) = *LLE**cleanup** - LLE**benchmark*

*RPM* - risk performance measure

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## Disadvantages of GLE

- Need consensus on weighting factors for 5 health endpoints
- Need consensus on worker:public tradeoff factor
- May be impractical to calculate without sufficient information
- Risk surrogates may be required

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**Notes:**
2001-09-04 “Risk Surrogates” changed to “Substitute Quantities for Risk” 

## Advantages of GLE

- A single, common measure that permits comparison of alternative scenarios
- A quantitative answer to the question, “Is Hanford any safer?”
- Forces a formal look at the tough tradeoffs

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## Conclusion

- Gained Life Expectancy is a single, unified concept for comparing unrelated hazards and technical cleanup alternatives
*GLE* includes health effects to workers and public from routine operations and releases of material
- Incentives are needed for rewarding work

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