There are few subjects involving greater sensitivity — and for that matter, time, money and effort — for the Army in Hawai'i than Makua Military Reservation, Stryker vehicles and depleted uranium.

All three have come up in recent weeks, and all represent the challenge of keeping up a strategically important military presence in a relatively small island chain.

Hawai'i's stock and trade is natural beauty and tourism, but its second greatest economic driver — which is not acknowledged nearly enough — is the military.

The challenge is to reconcile the two.

Lt. Gen. John M. Brown III, the commander of U.S. Army Pacific, with headquarters at Fort Shafter, recently said at a Chamber of Commerce of Hawai'i meeting that both an environmental impact statement for the Stryker brigade and a long-stalled study of military training in Makua Valley have been completed.

Both studies are under review at the Pentagon.

The Stryker brigade is a $1.5 billion effort, and millions have been spent in court to try to regain use of Makua Valley for live-fire training.

Army officials, meanwhile, recently briefed the state Legislature on efforts to assess the effects of an old training remnant — depleted uranium.

The heavy metal was used in aiming, or "spotting," rounds for a 1960s weapon system called the Davy Crockett.

In January 2006, the Army confirmed it had found 15 projectile tailfin assemblies that contained depleted uranium at a Schofield Barracks munitions impact range.

The depleted uranium was used in XM-101 aiming rounds that simulated the trajectory of the Davy Crockett, a formerly classified recoilless rifle that could fire a 76-pound nuclear bomb.

The Cold War weapon was intended to be used as a last-ditch effort against hordes of Soviet soldiers in the event of war.

Last summer, the Army said it had found more depleted uranium fragments at Schofield, and that the aiming rounds also may have been fired at Makua Valley. Depleted uranium, or DU, also was confirmed at Pohakuloa Training Area on the Big Island.

Some Big Island residents were concerned that dust containing depleted uranium might be kicked up, spread on the wind and possibly inhaled.

Russell Takata, program manager for the state Health Department's Noise, Radiation and Indoor Air Quality Branch, previously said he saw no immediate danger to the public.

According to the World Health Organization, a radiation dose from DU would be about 60 percent of that from purified natural uranium with the same mass.

Because of its high density — about twice that of lead — the weakly radioactive material is used for counterweights in aircraft and radiation shields. DU is used in armor-penetrating military ordnance because of its density, and also because DU can ignite on impact if the temperature exceeds 600 degrees Celsius.

A United Nations report on impact sites in Kosovo indicated that environmental contamination by DU was limited to a few dozen yards around the impact sites.

The Army continues to study the impact of the depleted uranium found in Hawai'i. According to records, soldiers fired 714 spotting rounds containing depleted uranium in the 1960s.

Stryker vehicles in Hawai'i do not train with or fire depleted uranium.

"This is a very sensitive issue, and we understand that," Col. Howard Killian, deputy director of the U.S. Army Installation Command for the Pacific, said in a release. "Our intent is to gather the facts in a transparent and collaborative manner and let those facts speak for themselves."

In August, the Army's Joint Munitions Command completed a survey of ranges at Schofield, Makua and Pohakuloa. More than 16,000 air, vegetation and soil samples have been sent to the Mainland for testing and analysis, the Army said.

The Army said collected data will lead to a risk assessment that will be finalized and made public in February.

IN BRIEF

DISCRIMINATION LAWSUIT SETTLED

The Navy and a 20-year Pearl Harbor Naval Shipyard worker have settled a reverse discrimination lawsuit, the employee's attorney said.

Michael Plowman, 54, a foreman in the piping and temporary services shop since 1991, alleged in a federal lawsuit that he was denied a promotion to waterfront general foreman, and didn't receive bonuses for 2004 and 2005, because of race, age and reprisal discrimination.

Plowman's attorney, Clayton C. Ikei, said his client will receive the promotion and $50,000 as part of the settlement reached with the Navy in U.S. District Court.

Ikei said Plowman, who is Caucasian, was unjustly passed over for promotion in favor of an Asian-American, and while other employees received "nuclear bonuses," Plowman did not because of actions taken by supervisors, all of whom were of Asian or part-Asian descent.

The Navy said it had "legitimate non-discriminatory reasons" for taking the personnel actions, and denied fault and liability in the settlement.

According to court records, the racial composition in 2005 of temporary service shop supervisors at selected pay grades who received the nuclear bonus in Shop 99 was: 9 Japanese, 1 Hawaiian, 1 Filipino and 2 Caucasian.

The racial composition that year of supervisors who did not receive the bonus was: 3 Japanese, 1 Chinese, 1 Hawaiian and 5 Caucasian.

HICKAM C-17S JOINING THAI TRAINING

Two C-17 cargo aircraft from Hickam Air Force Base are scheduled to participate in the exercise Cope Tiger 2008, the only multilateral field training exercise held in Thailand.

More than 1,400 people will participate in the exercise from Saturday to Feb. 5, including approximately 700 U.S. service members and 700 service members from Thailand and Singapore.

About 30 active-duty airmen from the 535th Airlift Squadron will take part in the training, along with about 20 airmen from the 204th Airlift Squadron of the Hawai'i Air National Guard.

Reach William Cole at wcole@honoluluadvertiser.com.