Secondary beam production facility layout discussions SBLNF meeting 5 th Dec. 2012

1. Secondary beam production facility layout discussionsSBLNF meeting 5th Dec. 2012 M. Calviani, A. Ferrari, R. Losito (EN/STI) H. Vincke (DGS/RP)

2. 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 MC - Updates on SBLNF secondary beam facility layout

3. 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.)! MC - Updates on SBLNF secondary beam facility layout

4. 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) • 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 concrete H*(10) (mSv/h) Z averaged middle DP Vertical direction 5 mSv/h level MC - Updates on SBLNF secondary beam facility layout

5. Neutrino production area proposition MC - Updates on SBLNF secondary beam facility layout

6. Neutrino production area proposition • Present configuration assume: • Machine rooms & morgue excavated lateral to chase < 15 mSv/h • 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 < 1 mSv/h < 10 mSv/h MC - Updates on SBLNF secondary beam facility layout

7. 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? MC - Updates on SBLNF secondary beam facility layout

8. Neutrino production area MC - Updates on SBLNF secondary beam facility layout

9. 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 • 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 Front side MC - Updates on SBLNF secondary beam facility layout

10. 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 MC - Updates on SBLNF secondary beam facility layout

11. 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 shutterseparating 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 system MC - Updates on SBLNF secondary beam facility layout

12. 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? (*) with an open air atmosphere these would be probably exchanged for a forced air cooling loop MC - Updates on SBLNF secondary beam facility layout

13. Decay pipe • 3 or 3.5 m Ø~90 meters long volume (~110 m from target) • Shape cylindricalor 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) Courtesy: J. Osborne MC - Updates on SBLNF secondary beam facility layout

14. DP - geomembrane • DP: high level of prompt dose rate over a large distance  risks of soiland water activation • Geosynthetic barrier system: protect the surrounding groundwater from any possible tritiated water escaping the decay region • Separate barriers (LBNE approach): • Geomembrane • Geosynthetic clay liner barrier • Geonet leak detection layer http://lbne2-docdb.fnal.gov:8080/0046/004623/006/CDR_Vol_5_MI-10CF_20120313.pdf MC - Updates on SBLNF secondary beam facility layout

15. Hadron absorber area MC - Updates on SBLNF secondary beam facility layout

16. Hadron absorber area • 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 Pit1/HS Pit2 • Pit2: • Could potentially be even a barrack – no RP issues foreseen (H. Vincke, link) • No fixed crane required MC - Updates on SBLNF secondary beam facility layout

17. 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 Target hall = 53 m length, ~8 m wide MC - Updates on SBLNF secondary beam facility layout

18. FNAL NuMI configuration MC - Updates on SBLNF secondary beam facility layout

19. 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 MC - Updates on SBLNF secondary beam facility layout

20. JPARC/T2K configuration MC - Updates on SBLNF secondary beam facility layout

21. Conclusions • Updated secondary beam line functional specifications • Location of the morgueto be confirmed in collaboration with DGS/RP • Cooling station/hot service roomslocation 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? MC - Updates on SBLNF secondary beam facility layout