RSSOs at CERN

Prepared by Ans Pardons for the CERN RSSO training day

With input from J. Pedersen

Evolution

RSSO?Past

Evolution

RSSO?Past

EDMS 1114705, July 2011:

The RSSO is a Safety Linkman that has received specialised training on radiation safety matters. The RSSO assists the group leader in executing his safety duties and works in close collaboration with the departmental Safety Officers and the experts of the HSE/RP Unit.

Evolution

RSSO?Past

! ?Present

December 2014:

34 RSSOs at CERN in 3 departments:BE (8), EN (14) and TE (12).

Several candidates for the next years.

EvolutionRSSOs of the world unite!

Future?

RSSO?Past

! ?Present

New RSSOs join “the force” every year.

Radiation safety rules and tools for RSSOs are regularly updated.

We are a network! Let’s get connected and exchange experiences.

Therefore, today is about: RSSOs of the world unite!

Future?

RSSO?Past

! ?Present

© xkcd

ExpectationsThe RSSO role was created to have, in each group, at least one person with in-depth knowledge of:

What – know the group’s equipment

Where – know the group’s intervention areas

How – know general and CERN radiation safety rules

ExpectationsThe RSSO role was created to have, in each group, at least one person with in-depth knowledge of:

What – know the group’s equipment

Where – know the group’s intervention areas

How – know general and CERN radiation safety rules

The RSSO shall apply this knowledge to guide the technical teams through justification, optimization and preparation of the interventions of the group.

Congratulations: Your Group Leader Chose You as RSSO

The Group Leader must provide the RSSO with:

• The training opportunities needed (RPE course but also networking and training meetings)

• A clear mandate of general & group-specific tasks, summarized in an official departmental memo.

• The work time needed to execute the tasks in your mandate as well as the time needed to stay up-to-date as RSSO. This must be clearly visible in the MARS document.

Congratulations: Your Group Leader Chose You as RSSO

The Group Leader must provide the RSSO with:

• The training opportunities needed (RPE course but also networking and training meetings)

• A clear mandate of general & group-specific tasks, summarized in an official departmental memo.

• The work time needed to execute the tasks in your mandate as well as the time needed to stay up-to-date as RSSO. This must be clearly visible in the MARS document.

Message to RSSO: Ask for what you need !Message to Group Leader: An RSSO does not come for free !

Added Value of RSSO• The interventions run smoother, with less dose taken and in

safer conditions thanks to consistent and thorough preparation and monitoring.

• There is a better a posteriori understanding of the interventions, thanks to monitoring, analysis and closing.– Did it turn out as planned? If not, why not?– What have we learned? What can be improved?

• The RSSOs form a network to exchange experience.

Message to Group Leader: An RSSO does not come for free !

LS1 Worked Well, Thanks to You!This comparison of total doses of LS1 L3-interventions shows ALARA at work, both during preparation and in-situ follow-up.

ISOLD

E-Exch

ange

of robots

LHC-Ex

tra ca

ble tray

s IR 3/7

PS-Ven

tilation co

nsolidati

on

PSB-Bea

m dump remova

l

SPS-L

SS1 ca

ble ex

change

phase 1

SPS-L

SS1 ca

ble exc

hange

phase 2

PS-Magn

et ren

ovation

SPS-T

DC2 consolid

ation

SPS-T

S2- ca

bling

SPS-L

SS1 ca

ble ex

change

phase 3 &

repair

s

ISOLD

E-Front e

nd modificati

on

ISOLD

E-Med

icis M

ontrac in

stalla

tion

SPS-T

DC2 CF Cab

ling

SPS-T

DC2 LV Cab

ling

0

20

40

60

80

100

120

140

160

180

200

66

4

49

5

33

168

32

170

13

59

115

58

178

104

28

3

21

92

24

85

8

53

3 4

5359

134

121

11

52

15

49

4

39

3 3

2213

Est. dose before optimisation [mSv] Est. dose approved by ALARA committee [mSv] Dose effectively taken [mSv]

Understanding the Gap

Operational dosimetry and IMPACT allow comparing estimated dose with real dose. But what does this comparison teach us?

The aim is NOT to have a perfect estimate or always be below 100%.The aim is to understand the difference, learn from the experience and apply it in future interventions.

ISOLDE LHC PS PSB SPS PS SPS SPS ISOLDE ISOLDE0%

20%

40%

60%

80%

100%

120%

140%

160%

Ratio of real vs optimised dose for each LS1 L3 intervention

Summary (RSSOs at CERN)• LS1 was the first large scale test for most RSSOs.• The results show your added value, being a “catalytic” and pro-

active RSSO. • Not only was the work very “ALARA”, but your efforts also

contributed to better work organization, follow-up and understanding.

RSSO

Summary (RSSOs at CERN)• LS1 was the first large scale test for most RSSOs• The results show your added value, being a “catalytic” and pro-

active RSSO. • Not only was the work very “ALARA”, but your efforts also

contributed to better work organization, follow-up and understanding.

• You have the tools & experience to deal with what comes next.

LS2

ALARA News(*)

Prepared by Ans Pardons for the CERN RSSO training day

(*)since early 2013

ALARA CriteriaWe all agree that an intervention in a radiation area needs:

some preparation some optimisationsome kind of approval

ALARA CriteriaWe all agree that an intervention in a radiation area needs:

some preparation, some optimisation,some kind of approval.

But what is an appropriate level? What is reasonable?“Every intervention is different”.

Yes, but some guideline values would be useful.

ALARA CriteriaWe all agree that an intervention in a radiation area needs:

some preparation some optimisationsome kind of approval

But what is an appropriate level? What is reasonable?“Every intervention is different”.

Yes, but some guideline values would be useful.

The five ALARA criteria (dose rate, collective dose, maximum individual dose, airborne activity and surface contamination) are good indicators of the complexity of the intervention and the extent of its consequences.

The New RulesThe first CERN ALARA procedures and practices date from 2006.The ALARA Review Working Group published in 2013 their final report, updating the rules and guidelines regarding:

• ALARA Criteria• DIMR Procedure• Modalities of the ALARA Committee

EDMS 1244380

ALARA Criteria and Levels• Group 1 or “hard” criteria define the ALARA level.

ALARA Criteria and Levels• Group 1 or “hard” criteria define the ALARA level.

• Group 2 criteria define the need for a radiological risk assessment. It concerns criteria where standard responses usually can be applied to mitigate risks and doses.

ALARA Criteria and LevelsIn case a level 3 limit is attained for one or more group 2 criteria, the ALARA classification will be based on the radiological risk assessment and will be defined by the RSO and the RP physicist.

ALARA Criteria and Levels

Example: Repair of SPS TIDVG: Dose rate at intervention location above 2mSv/h (level 3), but collective & individual doses lower than 5mSv, resp. 1mSv (level 2).

In case a level 3 limit is attained for one or more group 2 criteria, the ALARA classification will be based on the radiological risk assessment and will be defined by the RSO and the RP physicist.

ALARA Criteria and Levels

Example: Repair of SPS TIDVG: Dose rate at intervention location above 2mSv/h (level 3), but collective & individual doses lower than 5mSv, resp. 1mSv (level 2). Eventually considered a level 2 intervention.Risk assessment extract:

Task Task Related Hazards Hazard Risk Reduction Action In Case Hazard Materializes

Expected Extra Dose (µSv)

Disassemble 6 screws on the TIDVG.

Larger torque than can be provided needed to unscrew (Rust and paint particles)

Use manual key to unlock bolts and electric screw-driver to remove the screws.

Leave area and come back with different tool 25

Assembly lifting rings (TIDVG's old core).

Task can't be performed by the robot. Human intervention, shielded

by screens and blocks 83

Close yoke new core Mecanical interferenceDimension measurements on new core, visual inspection of old yoke

Repeat action n times (1 time is ~100µSv extra) 200

In case a Level 3 limit is attained for one or more group 2 criteria, the ALARA classification will be based on the radiological risk assessment and will be defined by the RSO and the RP physicist.

Work flow

EDMS 1244380

DIMR Workflow: SoonThe DIMR is initiated by the work coordinator, but each DIMR will have an RSSO attributed to the intervention.The RSSO is actively involved in the preparation, optimisation and approval process (integration in IMPACT in 2015).Closing (understanding) becomes an integral part of the workflow.

More will be shown in Gerald’s presentation today.https://indico.cern.ch/event/352121/contribution/2/material/slides/0.pptx

Also in the ARWG Report• Procedure applicable when exceeding the estimate significantly,

meaning reaching more than 150% of collective dose estimate or more than 130% of max. individual dose estimate.

• Procedure applicable when reaching the Group 1 level 3 threshold for an intervention previously approved as level 2.

• ALARA committee procedure and members for– Unanticipated urgent intervention (reduced committee)– Emergency intervention (no committee but emergency crisis plan)

• Requirements and procedure to obtain waiving of a Group 1 level 3 intervention.This mostly occurs for optimised recurrent routine operations, where a similar intervention was already approved by the committee.

EDMS 1244380

Remembering LS1 (in EN)• Project leaders & RSSOs recorded feedback discussions and

interviews with the intervening groups. Conclusions and recommendations will be made official to the management.

• The main feedback is presented to the ALARA committee today.• An EN Safety procedure describing ALARA intervention procedure

based on LS1 experience will be released later this month. It is a concise guide for RSSOs, project leaders and work coordinators.

Remembering LS1 (in EN)• Project leaders & RSSOs recorded feedback discussions and

interviews with the intervening groups. Lessons learnt and recommendations will be made official to the management.

• The main feedback is presented to the ALARA committee today.• An EN Safety procedure describing a new ALARA intervention

procedure based on LS1 experience will be released later this month. It is a concise guide for RSSOs and work coordinators.

• Initiate• Plan• Approve• Execute, monitor, control• Close

Summary (ALARA news)• Hard and soft ALARA criteria were introduced early 2013, stressing

the importance of a radiological risk analysis.• A new DIMR workflow is defined and should be applied for each

ALARA level. It will be implemented in IMPACT in 2015.• LS1 experience is analyzed and presented to the management.

Summary notes with recommendations will be released.• A new EN ALARA intervention procedure, based on common EN

practices and on lessons learnt from LS1, will be released soon.

For all the rest: read the ARWG summary report on EDMS.