The Magic of Spent Fuel

David LochbaumDirector, Nuclear Safety Project

June 30, 2012

Amateurs!Magician wanna be’s!

Pretenders of illusion!

Spent Fuel in BWR SFPs

is

REAL MAGIC!

When in the reactor core, irradiated fuel is so hazardous as to require highly reliable cooling and containment systems with highly reliable backups.

When in a repository, irradiated fuel is so hazardous as to require isolation for the next 10,000 years.

In-between, irradiated fuel is so benign it can be crowded in a pool cooled by a single non-safety system without backups.

The non-safety-related, non-Class 1E spent fuel pool cooling system is a non-essential load on the closed cooling water system.

Its backup?

Nine Mile Point Unit 2 Technical Specifications

Spent Fuel in BWR SFPs: Doesn’t need water

(except when being moved about)

Cooper Technical Specifications

Spent Fuel in BWR SFPs: Doesn’t need water Doesn’t need containment

(except when being moved about)

NUREG-1433, Vol. 1, Rev. 3 BWR/4 Improved Technical Specifications

Spent Fuel in BWR SFPs: Doesn’t need water Doesn’t need containment Doesn’t need AC power

(except when being moved about)

Browns Ferry Unit 1 Technical Specifications (ML052780019)

Spent Fuel in BWR SFPs: Doesn’t need water Doesn’t need containment Doesn’t need AC power Doesn’t need DC power

(except when being moved about)

Browns Ferry Unit 1 Technical Specifications (ML052780019)

Spent Fuel in BWR SFPs: Doesn’t need water Doesn’t need containment Doesn’t need AC power Doesn’t need DC power Doesn’t need control room AC

(except when being moved about)

Criterion 44—Cooling water. A system to transfer heat from structures, systems, and components important to safety, to an ultimate heat sink shall be provided. The system safety function shall be to transfer the combined heat load of these structures, systems, and components under normal operating and accident conditions.

Suitable redundancy in components and features, and suitable interconnections, leak detection, and isolation capabilities shall be provided to assure that for onsite electric power system operation (assuming offsite power is not available) and for offsite electric power system operation (assuming onsite power is not available) the system safety function can be accomplished, assuming a single failure.

General Design Criterion 44 (GDC 44) in Appendix A to 10 CFR Part 50

10 CFR Part 50.49, Environmental Qualification of Electrical Equipment

(i) This equipment is that relied upon to remain functional during and following design basis events to ensure--

(A) The integrity of the reactor coolant pressure boundary;(B) The capability to shut down the reactor and maintain it in a safe shutdown condition; or(C) The capability to prevent or mitigate the consequences of accidents that could result in potential offsite exposures comparable to the guidelines in § 50.34(a)(1), § 50.67(b)(2), or § 100.11 of this chapter, as applicable.

(ii) Design basis events are defined as conditions of normal operation, including anticipated operational occurrences, design basis accidents, external events, and natural phenomena for which the plant must be designed to ensure functions (b)(1)(i) (A) through (C) of this section.(2) Nonsafety-related electric equipment whose failure under postulated environmental conditions could prevent satisfactory accomplishment of safety functions specified in subparagraphs (b)(1) (i) (A) through (C) of paragraph (b)(1) of this section by the safety-related equipment.

During a reactor accident, irradiated fuel in BWR spent fuel pools becomes invisible – one can still see the pool, but it magically empties of irradiated fuel as far as safety studies of reactor building cooling loads for GDC 44 and environmental qualifications for 10 CFR 50.49 go. Amazing!

Spent Fuel in BWR SFPs: Doesn’t need water Doesn’t need containment Doesn’t need AC power Doesn’t need DC power Doesn’t need control room AC Doesn’t need to affect GDC 44

or 10 CFR 50.49(except when being moved about)

BWR Spent Fuel Science Fiction

Irradiated fuel in spent fuel pools, even when not being moved, needs: to be covered by water

to be within reliable containment

to have ac power for its cooling system

to have dc power for its I&C systems

to enable control room habitability

to enable GDC 44 to be met

to enable 10 CFR 50.49 to be met

Far, Far Better Place to Store Spent Fuel

Slide 26

Five years after discharge from reactor cores, spent fuel can and should be transferred into dry storage.

Lessons from Fukushima Dai-Ichi

Hydrogen explosions removed walls and roofs, allowing water cannons and helicopters to provide feed & bleed cooling of these BWR spent fuel pools.

Nearly 400 BWR spent fuel assemblies were in this building, inundated by the tsunami, but not requiring explosions and Rube Goldberg water cooling.

Could the irradiated fuel in the Unit 4 SFP have been cooled w/o the explosions?

Spent Fuel Hazard: The Sites

Slide 29

ConclusionsIrradiated fuel in BWR spent fuel pools poses undue hazards.

Safety studies and tech specs must consider spent fuel pool events other than dropping an assembly or banging it into something.

The decay heat from BWR spent fuel pools must be considered in GDC 44 and 10 CFR 50.49 calculations.

As soon as possible after 5 years’ decay, irradiated fuel must be moved to dry storage.

Slide 30