Sensitivity Tests of Aluminum Precipitate Preparation Methods on Head Loss through Debris Beds on a Sump Screen

Journal Article · Fri Jul 01 04:00:00 EDT 2016 · Transactions of the American Nuclear Society

OSTI ID:23042891

Lee, Saya; Kyriakopoulos, Vasileios; Abdulsattar, Suhaeb; Vaghetto, Rodolfo; Hassan, Yassin A. ^[1]; Leavitt, Janet ^[2]

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1. Department of Nuclear Engineering, Texas A and M University, 3133 TAMU, College Station, Texas 77843 (United States)
2. Alion Science and Technology, 6200 Uptown Boulevard NE Suite 200, Albuquerque, New Mexico 87110 (United States)

During a Loss-of-Coolant Accident (LOCA) in Pressurized Water Reactors (PWRs), buffered borated water as a coolant from the Refueling Water Storage Tank (RWST) will be injected into the primary loop to cool down the core depending on the break size. For long-term cooling, the coolant will be collected in the containment sump. Then, the Emergency Core Cooling System (ECCS) will pump the coolant through the sump strainers into the reactor. During this phase, buffered borated water produces chemical precipitate by reacting with the structural materials in the containment. Chemical effects evaluated as part of Generic Safety Issue 191 (GSI-191) resolution studies are broadly defined as any chemically induced phenomenon that affects ECCS performance. Initial chemical effects studies jointly sponsored by the Nuclear Regulatory Commission (NRC) and Industry collaborators led to a Westinghouse Owners Group (WOG) study that provided bases for deterministic quantification of chemical effects. The WCAP-16530-NP developed protocols to produce Aluminum Oxyhydroxide (AlOOH), Calcium Phosphate, and Sodium Aluminum Silicate (SAS). The surrogate generation protocol used the metal salt (aluminum nitrate and calcium acetate) unlike post-LOCA accident scenarios where metals leach into a buffered borated solution. Bahn et al. demonstrated that the WCAP-16530-NP SAS precipitate did not produce as much head loss as the WCAP-16530-NP AlOOH precipitate, thus, the present study focused on the effect of AlOOH precipitate on head loss through a fibrous debris bed. In the past, most of the tests were conducted in high approach velocity conditions, approximately 0.03 m/s. After modifications of sump strainer size in PWRs, the approach velocity to the sump strainer was reduced by an order of magnitude, approximately 0.001 ∼ 0.003 m/s. Howe et al. and Kim et al. conducted several head loss tests at the approach velocity of 0.003 m/s. In the present study, an approach velocity of 0.0006 m/s was selected for an extremely slow power plant condition. A PCI strainer design was used as previous head loss tests and debris bypass tests conducted by Lee et al. Three different chemical precipitate preparation methods were used in this study. The additional head loss of the debris bed caused by those chemical precipitates was investigated. The debris bed was produced with NUKON{sup R} fiberglass thermal insulator and additional particulates including dirt, Tin powder, acrylic powder, and Calcium silicate (CalSil). (authors)

• OSTI ID: 23042891
• Journal Information: Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 115; ISSN 0003-018X
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
42 ENGINEERING
ALUMINIUM NITRATES
ALUMINIUM SILICATES
BORATES
BUFFERS
BYPASSES
CALCIUM PHOSPHATES
CALCIUM SILICATES
CONTAINMENT
COOLANTS
COOLING
ECCS
FIBERGLASS
LOSS OF COOLANT
NUCLEAR INDUSTRY
PARTICULATES
PRECIPITATION
PRIMARY COOLANT CIRCUITS
PWR TYPE REACTORS
SENSITIVITY
WATER