secondary beam production facility layout discussions sblnf meeting 5 th dec. 2012

Secondary beam production facility layout discussionsSBLNF meeting 5th Dec. 2012

M. Calviani, A. Ferrari, R. Losito (EN/STI)H. Vincke (DGS/RP)

2 MC - Updates on SBLNF secondary beam facility layout

Outline

Update on the conceptual functional layout Neutrino production area Annex services (“morgue”, hot handling area, etc.) Building sizes and requirements

Comparison with similar installations in USA/Japan

5th December 2012


Updates on the neutrino production area

Present solution adopts the “trench/chase” approach: ~20/25 meters long, for an internal size of ~3 meters

New proposition: Machine (cooling systems) rooms on the lateral/size to the

target area Depends on the size of the trench that can be excavated Impact on costs but reduced pipings

Morgue and local shielding storage lateral to the target area Hot handling cell located downstream the target vault Personnel access to the target building from upstream Shielding thickness adapted to radiation levels at 240 kW (MC,

link) Disclaimer: this proposition reflects requirements – it’s

not integrated with services groups (CV, EL, etc.)!

5th December 2012

http://indico.cern.ch/getFile.py/access?contribId=4&resId=1&materialId=slides&confId=212864


Access conditions and H*(10) levels

No routine access to the target hall during operation Shielding should be designed to respect an H*(10) of < 15 mSv/h

on the target vault during operation at 240 kW Levels outside the building will have to be <0.5 mSv/h (non

designated)

5th December 2012

Decay pipe: 250 cm thick concrete

shielding 5 mSv/h at 10 m from beam axis –

DP possibly fenced on the surface Concrete/soil interface at ~30

mSv/h 5 mSv/h would require ~400

cm thick concrete5 mSv/h level

H*(10) (mSv/h)Z averaged middle DPVertical direction


Neutrino production area proposition

5th December 2012


Neutrino production area

proposition

5th December 2012

Shielding: There are

margins to reduce the H*(10) on the vault floor by adding concrete blocks

Chase size matched with a 3 m diameter DP

< 15 mSv/h

< 1 mSv/h < 10 mSv/h

Present configuration assume: Machine rooms & morgue excavated lateral to chase


Possible configuration of the “morgue”

Two possibilities could be envisaged for the radioactive material disposal area Ground level lateral from the main target vault

Less underground works Need significant shielding + complex transport?

Located in a separate trench lateral to the target chase Easier shielding in case of very hot objects (objects could reach

~Sv/h) Can be used also to temporary store shielding blocks More complex CE works to excavate the trench Could be used to prepare the shielded transport cask

Size will depend on assumptions on hot objects exchange rates & transport requirements – temporary storage?

5th December 2012


Neutrino production area

5th December 2012


Hot handling work cell possible configuration

Potential use of a “radioactive working cell”: Horn mechanical connection to the shielding module,

remote strip line clamp, waterline connection to horn, electrical connection to horn, target inspection

5th December 2012

Location? On the target vault floor,

downstream the chase shielding Easier manipulation and access

Concrete enclosure, w/ internal cameras for local inspection No lead glass window

Fron

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He-vessel conceptual

He-vessel enclosure, 1 atm He-gas: Pros:

Reduce pion absorption Suppress 3H by ~25% wrt air Suppress NOx production and corrosion (factor of ~100x) Suppress 7Be, 41Ar, 32P, etc. sure benefits for global releases

See H. Vincke, link Cons:

Quite complicated to build – huge He volume to handle – need to guarantee leak tightness for feedthroughs

Expensive solution Target station & decay volume – unique volume No beam window required between TS and DP

5th December 2012



He-vessel conceptual

Configuration: Thick steel layer – ~20 m (L), 3 m (W), 8 m (H) Evacuation of the He-vessel required to remove air and

avoid condensation (i.e. corrosion) during operation Cooling channels might be needed to cool down the

vessel (~20/30 kW deposited) Air/water cooled?

Is a shutter separating the TS from the DP during access required?

In order to recuperate He during evacuation, need of external compartments

Total volume ~1100 m3 (480 TS + 620 DP) It’s urgent to study the viability of this option

vs. an open air circulation system5th December 2012


What needs to be cooled in the

chase? Target – possibly an He cooling system Horn/reflector – water cooling He-vessel circulation (*) – He cooling

system He-vessel plates (*) – water (or air?) cooling DP collimator (?) – water cooling Hadron Absorber – water cooling Upstream collimator/baffle – cooling not

needed?

5th December 2012

(*) with an open air atmosphere these would be probably exchanged for a forced air cooling loop


Decay pipe 3 or 3.5 m Ø ~90 meters

long volume (~110 m from target)

Shape cylindrical or parallelepiped (a-la-T2K)

What’s the level of the moraine/molasse interface? 1974 bore: close to TCC2,

waterbed in moraine at 20 m below ground level (431 m)

Molasse ~429 m (22 m from surface)

5th December 2012

Courtesy: J. Osborne


DP - geomembrane DP: high level of prompt dose rate over a large

distance risks of soil and water activation Geosynthetic barrier system: protect the

surrounding groundwater from any possible tritiated water escaping the decay region

5th December 2012

Separate barriers (LBNE approach): Geomembrane Geosynthetic clay

liner barrier Geonet leak

detection layerhttp://lbne2-docdb.fnal.gov:8080/0046/004623/006/CDR_Vol_5_MI-10CF_20120313.pdf

http://lbne2-docdb.fnal.gov:8080/0046/004623/006/CDR_Vol_5_MI-10CF_20120313.pdf





Hadron absorber area

5th December 2012


Hadron absorber area

5th December 2012

Pit1/HS Absorber cooling

mandatory – cooling station will be certainly quite hot (~50 kW power to dissipate)

Access limited for maintenance

Pit1 access requires local bunker due to material activation

Crane required

Pit2: Could potentially be even a barrack –

no RP issues foreseen (H. Vincke, link) No fixed crane required

Pit1/HS Pit2



FNAL NuMI configuration

NuMI target station deep underground (beam level ~50 meters below ground); target hall is ~40 meters deep

Facility adapted to handle 400 kW beam power Surface target service building to access the deeper vault

5th December 2012

Target hall = 53 m length, ~8 m wide


FNAL NuMI configuration

5th December 2012


JPARC/T2K configuration

JPARC has a surface target vault, with a beam axis located ~20 meters below ground level

Facility adapted to handle 750 kW (1.6 MW) beam power Several annex buildings are located on the surface

5th December 2012


JPARC/T2K configuration

5th December 2012


Conclusions

Updated secondary beam line functional specifications

Location of the morgue to be confirmed in collaboration with DGS/RP

Cooling station/hot service rooms location to be confirmed/discussed with DGS/RP and GS/SE, as the target vault/chase size depends on this as well

He-vessel certainly an advantage, but costs and technical complexity worth?

5th December 2012

secondary beam production facility layout discussions sblnf meeting 5 th dec. 2012

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