Reprocessing And Recycli

Safet

y And Risk Informati

U.S. Nuclear Regulatory Commissio

Reprocessing Workshop

October 19-20, 2010

Albuquerque, NM
Two Main Aspects

• Total safety and risk

– Aggregation of impact (safety/risk) from a

accident sequences

– A safety/risk goal

–

A minimization 

p ( g , pp rocess 

(e.

g., application o

ALARA)

• Safety and risk assessment approach 

methodology

• NRC website on risk: 

http://www.nrc.gov/about-nrc/regulatorinformed.html

October 2010
U.S. NRC Approach To R

Five fundamental documents:• Policy Statement: Safety Goals for the Op

of Nuclear Power Plants (1986)

• Policy Statement: Use of Probabilistic Ris

Assessment (PRA) Methods in Nuclear Re

g y () ulator

y Activities 

(1995

)

• White Paper on Risk-Informed and Perfo

Based (RIPB) Regulation (1998)

• Revised Part 70: Domestic Licensing of S

Nuclear Material (2000)

• Risk Informed Decision Making (RIDM) fo

Nuclear Material and Waste Applications, Revision 1 (2008)

October 2010
NRC Safety Goals (1986

• Qualitative

– Public individual: no significant additional risk 

health from nuclear power plant operations

– Society: nuclear power risks comparable or le

other viable, electrical generation risks and shbe a si

gnificant contributor to societal risks

• Quantitative (individual)

– Prompt public fatality/accidents: < 0.1% sum o

other U.S. accident risks

– Cancer risk: <0.1% sum of all typical cancer f

• On average, these generally translate to a 

than one in a million per year (<1E-6/year

October 2010
Commission PRA

Policy Statement (1995)

• Increase use in all policy matters to 

extent supported by the state-of-the-

• Reduce unnecessary conservatism 

support proposals for additional regu

requirements

• PRA evaluations to be as realistic as 

practicable

• Safety goals and subsidiary objectiv

be used with appropriate consideratuncertainties

October 2010
PRA Usage

• Current PRA standards and guidance dev

operating LWRs:

– Different amounts of detail– Different intended results (e.g., probabilities o

types and quantities of releases, consequenc

• Current PRA standards do not fully addre

Current PRA standards do not fully addre

facility aspects, for example the scope for

– Plant design and construction– Passive systems

• Additional standards will be needed to sup

designs and a fully risk-informed regulatostructure

• PRA significantly more quantitative than IS

October 2010
RIPB – Risk-Informed, 

Performance Based (1998)

RIPB uses risk insights, engineering anal

and judgements, and performance history 

• Focus attention on the most important ac• Establish objective criteria based upon ris

Establish objective criteria based upon ris

insights for evaluating performance

• Develop measurable or calculable param

for monitoring performance

• Focus on the results as the primary basis 

regulation

October 2010
Part 70 Risk Informed

Fuel Cycle Regulation (2000)

• Subpart H added for SNM processing facilities• Incorporates risk via binning process, similar to 

industry approaches

– Three consequence levels – high, medium, low (defau– Three likelihood levels – highly unlikely, unlikely, not u

(d f lt) (d

e

fault)

– Qualitative/semi-quantitative methodologies– Also includes chemical risks and baseline design crite

• Requires ISA and safety controls (IROFS)• Sequence, not aggregate risk• Generally corresponds to facility risk less than o

million per year to an individual 

October 2010
Risk-Informed DecisionMaking (ML080720238, 2008)

• RIDM describes general concepts of risk and tot

quantitative health guidelines (QHGs) 

• Provides three regions of risk (unacceptable, tol

ne

gg ) li

gible

)

• Suggests QHGs 

– For acute and latent fatality – generally one in a million – Negligible dose risk/limit– Limit for serious injury several times higher than fatalit

• These are total risk values (summed over all sce

2006 U.S. worker fatality risk around 3.9E-5/yr

October 2010
Potential Questions

For Discussion

• Should NRC have safety/risk goal for repr

or is the current approach for fuel cycle facsufficient to demonstrate adequate public and safety? 

• What type of safety/risk assessment meth

What type of safety/risk assessment meth

should NRC require for reprocessing facili

– Type of methodology – PRA, ISA, LOPA

a combination of these?

• Can semi-quantitative or qualitative risk 

assessment methodologies, such as those Part 70 facilities, be used?

October 2010
Potential Questions

For Discussion

• How can NRC apply its PRA Policy Statement 

reprocessing facilities?

• Based on current practice with PRA, are there 

obstacles on use of PRA for evaluating reproc

facility risks? facility risks?

• What should be the balance between risk-info

performance based requirements, such as ISA PRA, and specific or prescriptive regulatory requirements, such as GDCs, technical specifetc.?

• Are there any specific hazards and accident c

that should be quantitatively assessed in reprofacility safety analysis?

October 2010
Background Slide
Matrix - Part 70 and Limits

Receptor

Event

Worker Individual Ou

Controlled A(aka General 

High Consequence:

- Prevent to highly

lik l

- > 100 rem (TEDE) > 100 rem (TEDE)- Endanger life of worker Endanger life of worker 

(chemical)

- > 25 rem > 25 rem- > 30 mg solub

> 30 mg solub

- Irreversible or 

Irreversible or 

October 2010

unlik

ely

- Prevent or mitigate to

intermediate or low 

long-lasting he

lasting he

(chemical)

Intermediate Consequence:- Prevent to unlikely- Mitigate to “low”

- > 25 rem- Irreversible or serious

long-lasting effect(chemical)

- > 5 rem- Mild transient 

effects (chemic

- > 5000x Part 

(Low Consequence)

Mild transient health effects or less

Lesser effects